WorldWideScience

Sample records for gashydrate und permafrost

  1. Gas hydrates and permafrost in continental northern West Siberia; Gashydrate und Permafrost im kontinentalen noerdlichen Westsibirien

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, B. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Braun, A.; Poelchau, H.S. [Forschungszentrum Juelich (Germany). Inst. fuer Erdoel und Organische Geochemie; Littke, R. [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle

    1997-12-31

    The largest natural gas pool in the world is located in northern part of the West Siberian Basin. During the Quaternary this reservoir became overlaid with several hundreds of metres of permafrost. The pressure and temperature conditions prevailing under this permafrost zone have led to the development of gas hydrates. As far as is known today there is no genetic relationship between the formation of the gas pool and the development of gas hydrates. The present contribution deals with these questions in detail. (MSK) [Deutsch] Im Nordteil des westsibirischen Beckens liegt die groesste Erdgaslagerstaette der Erde. Darueber hat sich im Quartaer ein mehrere hundert Meter maechtiger Permafrost gebildet. Die unter der Premafrostzone herrschenden Druck-und Temperaturbedingungen ermoeglichten die Bildung von Gashydraten. Nach heutigen Erkenntnisse besteht kein genetischer Zusammenhang zwischen Lagerstaettenbildung und Gashydraten. Im Folgenden werden Einzelheiten geschildert.

  2. Lectures held at the congress on ``Gas hydrates: problem substance / resource``, organised by the GDMK Division for ``Exploration and Extraction`` and the Institute for Mineral Oil and Natural Gas Research, in Clausthal-Zellerfeld (Harz) on 6/7 November 1997. Author`s manuscripts; Vortraege der Veranstaltung ``Gashydrate: Problemstoff/Resource`` des GDMK-Fachbereichs `Aufsuchung und Gewinnung` und dem Institut fuer Erdoel- und Erdgasforschung am 06. und 07. November 1997 in Clausthal-Zellerfeld (Harz). Autorenmanuskripte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The following topics are dealt with in detail: the chemical and physical properties of gas hydrates as derivable from their phase behaviour; the significance and occurrence of gas hydrates in offshore areas; gas hydrates and permafrost in continental northern West Siberia; information on HYACE, a research project of the European Union on test drilling for gas hydrates in offshore areas; sediment-mechanical criteria of gas hydrate formation in deep-sea sediments; gas hydrate formation in gas cavern storages; the use of hydrate inhibitors in operating natural gas storages; and the inhibition of gas hydrates with kinetic inhibitors. Eight abstracts were abstracted individually for the Energy Database. (MSK) [Deutsch] Folgende Themen werden detailliert behandelt: die chemischen und physikalischen Eigenschaften von Gashydraten,welche aus dem Phasenverhalten der Gashydrate herzuleiten sind; zur Bedeutung und Vorkommen von Gashydraten im Offshore-Bereich; Gashydrate und Permafrost im kontinentalen noerdlichen Westsibirien; Informationen zu HYACE, einem Forschungsprojekt der Europaeischen Union zu Probebohrungen nach Gashydraten im Offshore-Bereich; sedimentmechanische Kriterien bei der Gashydratbildung in Tiefseesedimenten; die Gashydratbildung in Gaskavernenspeichern; der Einsatz von Hydratinhibitoren beim Betrieb von Erdgasspeichern sowie die Inhibierung von Gashydraten mit kinetischen Inhibitoren. Fuer die Datenbank Energy wurden acht Beitraege einzeln aufgenommen.

  3. Well log characterization of natural gas-hydrates

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.

    2012-01-01

    In the last 25 years there have been significant advancements in the use of well-logging tools to acquire detailed information on the occurrence of gas hydrates in nature: whereas wireline electrical resistivity and acoustic logs were formerly used to identify gas-hydrate occurrences in wells drilled in Arctic permafrost environments, more advanced wireline and logging-while-drilling (LWD) tools are now routinely used to examine the petrophysical nature of gas-hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Resistivity- and acoustic-logging tools are the most widely used for estimating the gas-hydrate content (i.e., reservoir saturations) in various sediment types and geologic settings. Recent integrated sediment coring and well-log studies have confirmed that electrical-resistivity and acoustic-velocity data can yield accurate gas-hydrate saturations in sediment grain-supported (isotropic) systems such as sand reservoirs, but more advanced log-analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. New well-logging tools designed to make directionally oriented acoustic and propagation-resistivity log measurements provide the data needed to analyze the acoustic and electrical anisotropic properties of both highly interbedded and fracture-dominated gas-hydrate reservoirs. Advancements in nuclear magnetic resonance (NMR) logging and wireline formation testing (WFT) also allow for the characterization of gas hydrate at the pore scale. Integrated NMR and formation testing studies from northern Canada and Alaska have yielded valuable insight into how gas hydrates are physically distributed in sediments and the occurrence and nature of pore fluids(i.e., free water along with clay- and capillary-bound water) in gas-hydrate-bearing reservoirs. Information on the distribution of gas hydrate at the pore scale has provided invaluable insight on the mechanisms

  4. Significance and occurrence of gas hydrates in offshore areas; Bedeutung und Vorkommen von Gashydraten im Offshore-Bereich

    Energy Technology Data Exchange (ETDEWEB)

    Wehner, H.; Faber, E. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany)

    1997-12-31

    The present contribution describes the boundary and stability conditions under which gas hydrates are able to exist. It also discusses the occurrence and genesis of gas hydrates and their role as an energy raw material of the future. Furthermore, it deals with the possibility of gas hydrates being the cause of submarine slumps and with their influence on the climate. (MSK) [Deutsch] Die Rand-und Stabilitaetsbedingungen unter denen die Gashydrate existent sein koennen werden beschrieben. Ebenso wird das Vorkommen von Gashydraten, ihre Genese und ihre Rolle als Energierohstoff der Zukunft diskutiert. Darueberhinaus werden die Gashydrate als moegliche Ursache fuer untermeerische Rutschungen und ihr Einfluss auf Klimaaenderungen erlaeutert.

  5. Exergy analysis of a gas-hydrate cool storage system

    International Nuclear Information System (INIS)

    Bi, Yuehong; Liu, Xiao; Jiang, Minghe

    2014-01-01

    Based on exergy analysis of charging and discharging processes in a gas-hydrate cool storage system, the formulas for exergy efficiency at the sensible heat transfer stage and the phase change stage corresponding to gas-hydrate charging and discharging processes are obtained. Furthermore, the overall exergy efficiency expressions of charging, discharging processes and the thermodynamic cycle of the gas-hydrate cool storage system are obtained. By using the above expressions, the effects of number of transfer units, the inlet temperatures of the cooling medium and the heating medium on exergy efficiencies of the gas-hydrate cool storage system are emphatically analyzed. The research results can be directly used to evaluate the performance of gas-hydrate cool storage systems and design more efficient energy systems by reducing the sources of inefficiency in gas-hydrate cool storage systems. - Highlights: • Formulas for exergy efficiency at four stages are obtained. • Exergy efficiency expressions of two processes and one cycle are obtained. • Three mainly influencing factors on exergy efficiencies are analyzed. • With increasing the inlet temperature of cooling medium, exergy efficiency increases. • With decreasing the inlet temperature of heating medium, exergy efficiency increases

  6. Delineation, Characterization and Assessment of Gas-hydrates: Examples from Indian Offshore

    Science.gov (United States)

    Sain, K.

    2017-12-01

    Successful test productions in McKenzie delta, Alaska, Nankai Trough and more recently in South China Sea have provided great hopes for production of gas-hydrates in near future, and boosted national programs of many countries including India. It has been imperative to map the prospective zones of gas-hydrates and evaluate their resource potential. Hence, we have adopted a systematic strategy for the delineation, characterization and quantification of gas-hydrates based on seismic traveltime tomography, full-waveform inversion, impedance inversion, attributes computation and rock-physical modeling. The bathymetry, seafloor temperature, total organic carbon content, sediment-thickness, rate of sedimentation, geothermal gradient imply that shallow sediments of Indian deep water are good hosts for occurrences of gas-hydrates. From the analysis of multi-channel seismic (MCS) data, we have identified the Krishna-Godavari (KG), Mahanadi and Andaman basins as prospective for gas-hydrates, and their presence has been validated by drilling and coring of Indian Expeditions-01 and -02. The MCS data also shows BSR-like features in the Cauvery, Kerala-Konkan and Saurashtra basins indicating that gas-hydrates cannot be ruled out from these basins also. We shall present several approaches that have been applied to field seismic and well-log data for the detection, characterization and quantification of gas-hydrates along the Indian margin.

  7. Chemical and physical properties of gas hydrates; Chemische und physikalische Eigenschaften von Gashydraten

    Energy Technology Data Exchange (ETDEWEB)

    Meyn, V. [Inst. fuer Erdoel- und Erdgasforschung, Clausthal-Zellerfeld (Germany)

    1997-12-31

    Numerous properties of gas hydrates can be inferred directly from their phase behaviour. The present contribution gives a short overview of the properties of gas hydrates using pressure-temperature curves to depict their phase behaviour. It also describes the growth kinetics and inhibition of gas hydrates. (MSK) [Deutsch] Eine Vielzahl der Eigenschaften von Gashydraten lassen sich direkt aus ihrem Phasenverhalten herleiten. In kurzer Form wird ein Ueberblick ueber die Eigenschaften der Gashydrate gegeben. Druck-Temperatur-Diagramme erlaeutern des Phasenverhalten. Ebenso wird die Wachstumskinetik und die Inhibierung der Gashydrate beschrieben.

  8. NEW PERMAFROST FEATURE – DEP CRATER IN CENTRAL YAMAL (WEST SIBERIA, RUSIA AS A RESPONSE TO LOCAL CLIMATE FLUCTUATIONS

    Directory of Open Access Journals (Sweden)

    Marina O. Leibman

    2014-01-01

    Full Text Available This paper is based on field data obtained during short visits to a newly formed permafrost feature in a form of relatively narrow, deep crater. Excluding impossible and improbable versions of the crater’s development, the authors conclude that it originated from warmerground temperatures and an increase in unfrozen water content, leading to an increase in pressure from gas emissions from permafrost and ground ice. This conclusion is also supported by known processes in the palaeo-geography of Yamal lakes and recent studies of gas-hydrate behavior and subsea processes in gas-bearing provinces.

  9. Is the extent of glaciation limited by marine gas-hydrates?

    Science.gov (United States)

    Paull, Charles K.; Ussler, William; Dillon, William P.

    1991-01-01

    Methane may have been released to the atmosphere during the Quaternary from Arctic shelf gas-hydrates as a result of thermal decomposition caused by climatic warming and rising sea-level; this release of methane (a greenhouse gas) may represent a positive feedback on global warming [Revelle, 1983; Kvenvolden, 1988a; Nisbet, 1990]. We consider the response to sea-level changes by the immense amount of gas-hydrate that exists in continental rise sediments, and suggest that the reverse situation may apply—that release of methane trapped in the deep-sea sediments as gas-hydrates may provide a negative feedback to advancing glaciation. Methane is likely to be released from deep-sea gas-hydrates as sea-level falls because methane gas-hydrates decompose with pressure decrease. Methane would be released to sediment pore space at shallow sub-bottom depths (100's of meters beneath the seafloor, commonly at water depths of 500 to 4,000 m) producing zones of markedly decreased sediment strength, leading to slumping [Carpenter, 1981; Kayen, 1988] and abrupt release of the gas. Methane is likely to be released to the atmosphere in spikes that become larger and more frequent as glaciation progresses. Because addition of methane to the atmosphere warms the planet, this process provides a negative feedback to glaciation, and could trigger deglaciation.

  10. Influence of surfactants on gas-hydrate formation' kinetics in water-oil emulsion

    Science.gov (United States)

    Zemenkov, Yu D.; Shirshova, A. V.; Arinstein, E. A.; Shuvaev, A. N.

    2018-05-01

    The kinetics of gas hydrate formation of propane in a water-oil emulsion is experimentally studied when three types of surfactants (SAA (surface acting agent)) - anionic type emulsifiers - are added to the aqueous phase. It is shown that all three types of surfactants decelerate the growth of the gas-hydrate in the emulsion and can be considered as anti-agglutinating and kinetic low-dose inhibitors. The most effective inhibitor of hydrate formation in water-oil emulsion of SV-102 surfactant was revealed. For comparison, experimental studies of gas-hydrate formation under the same conditions for bulk water have been carried out. It is shown that in bulk water, all the surfactants investigated act as promoters (accelerators) of hydrate formation. A qualitative explanation of the action mechanisms of emulsifiers in the process of gas-hydrate formation in water-oil emulsion is given.

  11. Geo-scientific investigations of gas-hydrates in India

    Digital Repository Service at National Institute of Oceanography (India)

    Sain, K.; Gupta, H.; Mazumdar, A.; Bhaumik, A.K.; Bhowmick, P.K.

    The best solution to meet India's overwhelming energy requirement is to tap the nuclear and solar power to the maximum extent possible. Another feasible major energy resource is gas-hydrates (crystalline substances of methane and water) that have...

  12. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the

  13. Gas-hydrates in Krishna-Godavari and Mahanadi basins: New data

    Digital Repository Service at National Institute of Oceanography (India)

    Sain, K.; Ojha, M.; Satyavani, N.; Ramadass, G.A.; Ramprasad, T.; Das, S.K.; Gupta, H.

    the present energy crisis of India. Future Work By employing a suite of approaches for the qualification and quantification of gas-hydrates (Sain and Gupta, 2012 and references therein) to the new data, we will be able to provide information with regard to (i...

  14. Permafrost Monitoring Sonnblick

    Science.gov (United States)

    Reisenhofer, Stefan; Riedl, Claudia

    2014-05-01

    Within the project 'Permafrost Monitoring Sonnblick' (PERSON) the spatial distribution of permafrost is investigated by the 'Zentralanstalt für Meteorologie und Geodynamik' (ZAMG) in the Sonnblick area, in the Hohe Tauern in Austria. The aim of PERSON is to identify parameters affecting permafrost (geological, geomorphological, orographical and climatic factors), to determine its spatio-temporal behaviour under present day climate conditions and to estimate its possible future extension under a climate change scenario. PERSON makes use of a permafrost monitoring network that was installed 2005 in the Sonnblick area and is made up by four study sites: On the one hand the spatial extension of permafrost was focused at the ice-dammed lake Pilatus and the rock glacier Zirmsee. On the other hand, at two sites, namely Goldbergspitze and Wintergasse measurements of 'Ground-Surface Temperature' (GST) and 'Bottom Temperatures of the Snow cover' (BTS) are measured. In order to record temperatures in the uppermost layer of the ground and avoid heating by direct solar radiation loggers were buried a few centimetres into the ground or installed in boreholes at depths between 2 and 140 cm. Each of the 'Near Surface Temperature' (NST) borehole mouths is closed up with insulating foam to protect the measurements from atmospheric influence. In addition to these measurements, continuous temperature records from three 20 m deep boreholes located at the southern slope of Hoher Sonnblick are available since 2007, which represent the longest series of its kind in Austria. Furthermore, data from seismic and geoelectric measurements, temperature sensors readings at the surface and extensive meteorological observations from the Sonnblick Observatory are available. Already collected and evaluated data indicate that the thickness of the debris layer around the boreholes reaches a depth of 2 m but no more. The active layer thickness measured in the borehole next to the glacier ranges between

  15. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and

  16. A study of the process of joint formation of methane gas-hydrate and authigenic carbonates in bottom sediments in the Sea of Okhotsk

    Energy Technology Data Exchange (ETDEWEB)

    Esikov, A D [AN SSSR, Moscow (USSR). Water Problems Inst.; Pashkina, V I [AN SSSR, Moscow (USSR). Inst. Okeanologii

    1990-01-01

    The discovery of gas-hydrates in bottom sediments in the Sea of Okhotsk has allowed isotope fractionation of oxygen and hydrogen to be determined in the formation of the crystal lattice. It was established that the structure of gas-hydrate selectively included the heavier isotopes of oxygen and hydrogen, so that the gas-hydrate water had values of {delta}{sup 18}O = +1.9 per mille and {delta}D = +23 per mille, whereas the interstitial water was ''lighter'' in isotopes, with the values of {delta}{sup 18}O = -0.5 per mille and {delta}D = -5 per mille (relative to SMOW (standard mean ocean water)). The formation of gas-hydrates under the conditions of underwater discharge of methane alters the chemical composition of interstitial water, so that the carbonate equilibrium is shifted, and carbonates of authigenic origin are formed. The isotope composition of the carbonates is characterized by a low content of {sup 13}C({delta}{sup 13}C from -39.3 to -51.8 per mille PDB) and a high content of {sup 18}O({delta}{sup 18}O from + 2.7 to +6.3 per mille PDB) in comparison with carbonates of sea origin. These characteristics of the isotope composition suggest the participation of methane in the formation of authigenic carbonates, due to its anaerobic oxidation and the involvement of sulfate in the silt water. (author).

  17. Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

    Science.gov (United States)

    Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

    2015-12-01

    Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

  18. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    Science.gov (United States)

    Kristofer D. Johnson; Jennifer W. Harden; A. David McGuire; Mark Clark; Fengming Yuan; Andrew O. Finley

    2013-01-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF),...

  19. The microbial ecology of permafrost

    DEFF Research Database (Denmark)

    Jansson, Janet; Tas, Neslihan

    2014-01-01

    Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost......-gas emissions. This Review describes new data on the microbial ecology of permafrost and provides a platform for understanding microbial life strategies in frozen soil as well as the impact of climate change on permafrost microorganisms and their functional roles....

  20. FY 1998 annual report on the preliminary research and development of techniques for developing resources from gas-hydrate. Studies on gas-hydrate exploration, excavation techniques, methods for assessing environmental impacts, and gas hydrate handling systems; 1998 nendo gas hydrate shigenka gijutsu sendoken kaihatsu seika hokokusho. Tansanado ni kansuru kenkyu kaihatsu, kussaku gijutsu nado ni kansuru kenkyu kaihatsu, kankyo eikyo hyokaho no kenkyu kaihatsu, riyo system ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This R and D project is for the preliminary studies on development of the following 4 types of techniques for developing resources from gas-hydrates (GH): (1) gas-hydrate exploration, (2) excavation techniques, (3) methods for assessing environmental impacts, and (4) gas hydrate handling systems. The FY 1988 R and D results are described. For gas-hydrate exploration, the methods for analyzing inorganic ions and trace quantities of elements, which are necessary for accurately estimating the offshore GH around Japan, are established; and case studies are conducted for methods of predicting GH deposit forming mechanisms, and stability fields of GH, based on terrestrial heat flow and seismic data. For excavation techniques, GH decomposition rate is analyzed using a laboratory system which reproduces conditions of excavation of GH layers. For methods for assessing environmental impacts, a geo-hazard predicting model is established, to study ground displacement and gas leakage sensing systems and data transmission systems to cope with the hazards. For gas hydrate handling systems, an overall system is studied, and storage and transportation systems are outlined. (NEDO)

  1. Examining Environmental Gradients with satellite data in permafrost regions - the current state of the ESA GlobPermafrost initative

    Science.gov (United States)

    Grosse, G.; Bartsch, A.; Kääb, A.; Westermann, S.; Strozzi, T.; Wiesmann, A.; Duguay, C. R.; Seifert, F. M.; Obu, J.; Nitze, I.; Heim, B.; Haas, A.; Widhalm, B.

    2017-12-01

    Permafrost cannot be directly detected from space, but many surface features of permafrost terrains and typical periglacial landforms are observable with a variety of EO sensors ranging from very high to medium resolution at various wavelengths. In addition, landscape dynamics associated with permafrost changes and geophysical variables relevant for characterizing the state of permafrost, such as land surface temperature or freeze-thaw state can be observed with spaceborne Earth Observation. Suitable regions to examine environmental gradients across the Arctic have been defined in a community white paper (Bartsch et al. 2014, hdl:10013/epic.45648.d001). These transects have been revised and adjusted within the DUE GlobPermafrost initiative of the European Space Agency. The ESA DUE GlobPermafrost project develops, validates and implements Earth Observation (EO) products to support research communities and international organisations in their work on better understanding permafrost characteristics and dynamics. Prototype product cases will cover different aspects of permafrost by integrating in situ measurements of subsurface and surface properties, Earth Observation, and modelling to provide a better understanding of permafrost today. The project will extend local process and permafrost monitoring to broader spatial domains, support permafrost distribution modelling, and help to implement permafrost landscape and feature mapping in a GIS framework. It will also complement active layer and thermal observing networks. Both lowland (latitudinal) and mountain (altitudinal) permafrost issues are addressed. The status of the Permafrost Information System and first results will be presented. Prototypes of GlobPermafrost datasets include: Modelled mean annual ground temperature by use of land surface temperature and snow water equivalent from satellites Land surface characterization including shrub height, land cover and parameters related to surface roughness Trends from

  2. The effect of permafrost thaw on short- and long-term carbon accumulation in permafrost mires

    Science.gov (United States)

    Olid, Carolina; Klaminder, Jonatan; Monteux, Sylvain; Johansson, Margareta; Dorrepaal, Ellen

    2017-04-01

    Permafrost stores twice as much carbon (C) as is currently present in the atmosphere. During recent years, warmer temperatures in the Arctic has caused rapid thawing of permafrost, which have dramatically altered permafrost C storage by increasing both microbial decomposition and plant productivity. Although current research focuses on the effects of climate change on these two processes, there are still no scientific consensus about the magnitude or even the direction of future C feedbacks from permafrost ecosystems. Field manipulation experiments have been widely used during the last decade to improve our knowledge about the net effects of permafrost thaw in the permafrost C storage. However, due to the slow response (decades) of permafrost ecosystems to environmental changes and the short-time nature of these experiments (usually shorter than 5-9 years), there are still concerns when attempting to extrapolate the results to predict long term effects. In addition, measurements are mostly taken exclusively during the summer season, without taking into account inter-annual variability in C fluxes and underestimating microbial activity throughout the cold season. The need to develop a comprehensive understanding of C fluxes over the entire year and at long temporal scales sets the basis of this study. This study aims to quantify the effects of permafrost thawing in permafrost C fluxes using a 12 years permafrost thaw experiment in northern Sweden. Our aims were to quantify the effect of permafrost thaw in both decomposition and primary production in active layer and newly thawed permafrost, and its implications for the C balance. Based on previous observations, we hypothesized that 1) soil decomposition rates were higher in manipulated thaw plots. However, 2) the observed increase in nutrients availability and the higher presence of vascular plants after thawing stimulate primary production, which compensates to some extent the increased C losses by respiration. To

  3. Permafrost Hazards and Linear Infrastructure

    Science.gov (United States)

    Stanilovskaya, Julia; Sergeev, Dmitry

    2014-05-01

    The international experience of linear infrastructure planning, construction and exploitation in permafrost zone is being directly tied to the permafrost hazard assessment. That procedure should also consider the factors of climate impact and infrastructure protection. The current global climate change hotspots are currently polar and mountain areas. Temperature rise, precipitation and land ice conditions change, early springs occur more often. The big linear infrastructure objects cross the territories with different permafrost conditions which are sensitive to the changes in air temperature, hydrology, and snow accumulation which are connected to climatic dynamics. One of the most extensive linear structures built on permafrost worldwide are Trans Alaskan Pipeline (USA), Alaska Highway (Canada), Qinghai-Xizang Railway (China) and Eastern Siberia - Pacific Ocean Oil Pipeline (Russia). Those are currently being influenced by the regional climate change and permafrost impact which may act differently from place to place. Thermokarst is deemed to be the most dangerous process for linear engineering structures. Its formation and development depend on the linear structure type: road or pipeline, elevated or buried one. Zonal climate and geocryological conditions are also of the determining importance here. All the projects are of the different age and some of them were implemented under different climatic conditions. The effects of permafrost thawing have been recorded every year since then. The exploration and transportation companies from different countries maintain the linear infrastructure from permafrost degradation in different ways. The highways in Alaska are in a good condition due to governmental expenses on annual reconstructions. The Chara-China Railroad in Russia is under non-standard condition due to intensive permafrost response. Standards for engineering and construction should be reviewed and updated to account for permafrost hazards caused by the

  4. PYRN-Bib: The Permafrost Young Researchers Network Bibliography of Permafrost-Related Degree-Earning Theses

    Science.gov (United States)

    Grosse, Guido; Lantuit, Hugues; Gärtner-Roer, Isabelle

    2010-05-01

    PYRN-Bib is an international bibliographical database aiming at collecting and distributing information on all theses submitted for earning a scientific degree in permafrost-related research. PYRN-Bib is hosted by the Permafrost Young Researchers Network (PYRN, http://pyrn.ways.org), an international network of early career students and young scientists in permafrost related research with currently more than 750 members. The fully educational, non-profit project PYRN-Bib is published under the patronage of the International Permafrost Association (IPA). The bibliography covers all theses as long as they clearly treat aspects of permafrost research from such diverse fields as: Geophysics, Geology, Cryolithology, Biology, Biogeochemistry, Microbiology, Astrobiology, Chemistry, Engineering, Geomorphology, Remote Sensing, Modeling, Mineral and Hydrocarbon Exploration, and Science History and Education. The specific goals of PYRN-Bib are (1) to generate a comprehensive database that includes all degree-earning theses (e.g. Diploma, Ph.D., Master, etc.), coming from any country and any scientific field, under the single condition that the thesis is strongly related to research on permafrost and/or periglacial processes; (2) to reference unique but buried sources of information including theses published in languages other than English; (3) to make the database widely available to the scientific community and the general public; (4) to solicit PYRN membership; and (5) to provide a mean to map the evolution of permafrost research over the last decades, including regional trends, shifts in research direction, and/or the place of permafrost research in society. PYRN-Bib is available online and maintained by PYRN. The complete bibliography can be downloaded at no cost and is offered in different file formats: tagged Endnote library, XML, BibTex, and PDF. New entries are continuously provided by PYRN members and the scientific community. PYRN-Bib currently contains more than

  5. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated

  6. Permafrost slowly exhales methane

    Science.gov (United States)

    Herndon, Elizabeth M.

    2018-04-01

    Permafrost soils store vast quantities of organic matter that are vulnerable to decomposition under a warming climate. Recent research finds that methane release from thawing permafrost may outpace carbon dioxide as a major contributor to global warming over the next century.

  7. Web-GIS visualisation of permafrost-related Remote Sensing products for ESA GlobPermafrost

    Science.gov (United States)

    Haas, A.; Heim, B.; Schaefer-Neth, C.; Laboor, S.; Nitze, I.; Grosse, G.; Bartsch, A.; Kaab, A.; Strozzi, T.; Wiesmann, A.; Seifert, F. M.

    2016-12-01

    The ESA GlobPermafrost (www.globpermafrost.info) provides a remote sensing service for permafrost research and applications. The service comprises of data product generation for various sites and regions as well as specific infrastructure allowing overview and access to datasets. Based on an online user survey conducted within the project, the user community extensively applies GIS software to handle remote sensing-derived datasets and requires preview functionalities before accessing them. In response, we develop the Permafrost Information System PerSys which is conceptualized as an open access geospatial data dissemination and visualization portal. PerSys will allow visualisation of GlobPermafrost raster and vector products such as land cover classifications, Landsat multispectral index trend datasets, lake and wetland extents, InSAR-based land surface deformation maps, rock glacier velocity fields, spatially distributed permafrost model outputs, and land surface temperature datasets. The datasets will be published as WebGIS services relying on OGC-standardized Web Mapping Service (WMS) and Web Feature Service (WFS) technologies for data display and visualization. The WebGIS environment will be hosted at the AWI computing centre where a geodata infrastructure has been implemented comprising of ArcGIS for Server 10.4, PostgreSQL 9.2 and a browser-driven data viewer based on Leaflet (http://leafletjs.com). Independently, we will provide an `Access - Restricted Data Dissemination Service', which will be available to registered users for testing frequently updated versions of project datasets. PerSys will become a core project of the Arctic Permafrost Geospatial Centre (APGC) within the ERC-funded PETA-CARB project (www.awi.de/petacarb). The APGC Data Catalogue will contain all final products of GlobPermafrost, allow in-depth dataset search via keywords, spatial and temporal coverage, data type, etc., and will provide DOI-based links to the datasets archived in the

  8. Challenges, uncertainties, and issues facing gas production from gas-hydrate deposits

    Science.gov (United States)

    Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswel, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.B.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.A.

    2011-01-01

    The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas-hydrate (GH) petroleum system; to discuss advances, requirements, and suggested practices in GH prospecting and GH deposit characterization; and to review the associated technical, economic, and environmental challenges and uncertainties, which include the following: accurate assessment of producible fractions of the GH resource; development of methods for identifying suitable production targets; sampling of hydrate-bearing sediments (HBS) and sample analysis; analysis and interpretation of geophysical surveys of GH reservoirs; well-testing methods; interpretation of well-testing results; geomechanical and reservoir/well stability concerns; well design, operation, and installation; field operations and extending production beyond sand-dominated GH reservoirs; monitoring production and geomechanical stability; laboratory investigations; fundamental knowledge of hydrate behavior; the economics of commercial gas production from hydrates; and associated environmental concerns. ?? 2011 Society of Petroleum Engineers.

  9. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    International Nuclear Information System (INIS)

    Johnson, Kristofer D; Harden, Jennifer W; David McGuire, A; Clark, Mark; Yuan, Fengming; Finley, Andrew O

    2013-01-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow (<28 cm) versus deep organic (≥28 cm) layers. The probability of observing permafrost sharply increased by 0.32 for every 10-cm OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. Across the MAT gradient, PF in sandy soils varied little, but PF in loamy and silty soils decreased substantially from cooler to warmer temperatures. The change in OLT was more heterogeneous across soil texture types—in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened at warmer locations. Furthermore, when soil organic carbon was estimated using a relationship with thickness, the average increase in carbon in OLTd soils was almost four times greater compared to the average decrease in carbon in OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance. (letter)

  10. Field Biogeochemical Measurements in Support of Remote Sensing Signatures and Characterization of Permafrost Terrain: Integrated Technologies for Delineating Permafrost and Ground-State Conditions

    Science.gov (United States)

    2015-03-01

    Characterization of Permafrost Terrain Integrated Technologies for Delineating Permafrost and Ground-State Conditions En gi ne er R es ea rc h an d...Signatures and Characterization of Permafrost Terrain Integrated Technologies for Delineating Permafrost and Ground-State Conditions Robyn A. Barbato...Center-Directed Research Project, “Integrated Technologies for Delineating Permafrost and Ground-State Conditions” ERDC TR-15-1 ii Abstract This

  11. Simulations of permafrost evolution at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Hartikainen, J. [Aalto Univ., Espoo (Finland)

    2013-07-15

    This report provides numerical estimations of the evolution of permafrost and perennially frozen ground at Olkiluoto on time-scales of 60,000 and 125,000 years using Olkiluoto's site-specific information on time histories of ground level temperatures, ice sheet thickness, basal conditions, shoreline migration, soil and vegetation cover as well as heat generation from the spent fuel at a depth of 420 metres. When considering environmental conditions akin to the last glacial cycle for a 125,000 years long period, the maximum permafrost depth over the repository area can exceed the depth of 300 m and the maximum depth of perennially frozen ground the depth of 270 m. If Olkiluoto, after a 50,000 years long temperate phase of boreal climate, was subjected to a 10,000 years long periglacial period with air temperature decreased between -5 deg C and -10 deg C, the maximum permafrost depth would range between 60 and 240 m and the maximum depth of perennially frozen ground between 50 and 220 m. Furthermore, permafrost would reach the repository depth in 10,000 years, if the air temperature was lowered down to -15 deg C and the ground surface had a very thin vegetation and snow cover. Alternatively, if Olkiluoto experienced a 125,000 years long glacial cycle with a very long periglacial periods of low air temperatures and thin vegetation and snow cover and without any ice sheet development, permafrost would reach the depth of 400 m in 98,000 years and perennially frozen ground in 101,000 years. The areal distribution of permafrost and perennially frozen ground are broadly affected by the snow cover, lakes and the peat areas, especially when an extensive peat growth occurs. The lack of snow cover can enhance the evolution of the maximum depth of permafrost and perennially frozen ground by over 50 %. In addition, ground thermal conditions and the heat generation from the spent fuel modify the spatial and temporal development of permafrost and perennially frozen ground. A

  12. Simulations of permafrost evolution at Olkiluoto

    International Nuclear Information System (INIS)

    Hartikainen, J.

    2013-07-01

    This report provides numerical estimations of the evolution of permafrost and perennially frozen ground at Olkiluoto on time-scales of 60,000 and 125,000 years using Olkiluoto's site-specific information on time histories of ground level temperatures, ice sheet thickness, basal conditions, shoreline migration, soil and vegetation cover as well as heat generation from the spent fuel at a depth of 420 metres. When considering environmental conditions akin to the last glacial cycle for a 125,000 years long period, the maximum permafrost depth over the repository area can exceed the depth of 300 m and the maximum depth of perennially frozen ground the depth of 270 m. If Olkiluoto, after a 50,000 years long temperate phase of boreal climate, was subjected to a 10,000 years long periglacial period with air temperature decreased between -5 deg C and -10 deg C, the maximum permafrost depth would range between 60 and 240 m and the maximum depth of perennially frozen ground between 50 and 220 m. Furthermore, permafrost would reach the repository depth in 10,000 years, if the air temperature was lowered down to -15 deg C and the ground surface had a very thin vegetation and snow cover. Alternatively, if Olkiluoto experienced a 125,000 years long glacial cycle with a very long periglacial periods of low air temperatures and thin vegetation and snow cover and without any ice sheet development, permafrost would reach the depth of 400 m in 98,000 years and perennially frozen ground in 101,000 years. The areal distribution of permafrost and perennially frozen ground are broadly affected by the snow cover, lakes and the peat areas, especially when an extensive peat growth occurs. The lack of snow cover can enhance the evolution of the maximum depth of permafrost and perennially frozen ground by over 50 %. In addition, ground thermal conditions and the heat generation from the spent fuel modify the spatial and temporal development of permafrost and perennially frozen ground. A

  13. Permafrost: An International Approach to 21th Century Challenges

    Science.gov (United States)

    Brown, J.

    2003-12-01

    Whereas glaciers are easily discernible to the human eye and satellites, permafrost terrains and their physical components are not easily detected from the surface without supplemental knowledge and measurements. In the Northern Hemisphere, approximately 17 million km2 of exposed land contains some extent of permafrost or ground that remains frozen for more than two years. The vast majority, or 11 million km2, of permafrost terrain has temperatures of 5° C or below, with perennially frozen ground underlying essentially all ground surfaces to considerable depths. Permafrost in the remaining regions, including mid-latitude mountains, is both warmer and is spatially variable (discontinuous). As climate warms the uppermost permafrost is subjected to increase thaw with resulting ground subsidence, accelerated erosion, and related biogeochemical modifications. The challenging questions to geocryologists, modelers and the public relate to the rate of change and the spatial variability of the projected thaw, particularly in the warmer zones where actual areal and subareal distribution of permafrost is poorly known. An international network of active layer measurements and borehole sites now exists under the Global Climate Observing System (GCOS), but requires additional sites for representative coverage. This Global Terrestrial Network for Permafrost (GTN-P) is coordinated by the 24-member, International Permafrost Association. At the Eighth International Conference on Permafrost (ICOP) in Zurich in July 2003, the IPA Council agreed on the scope of new activities for the next five years, many of which will be undertaken in cooperation with other international organizations (e.g. WCRP/CliC; ICSI, IASC, SCAR, IGU, IUGS). Examples of the activities of the IPA Working Groups are: 1. Antarctic Permafrost and Periglacial Environments (active layer processes, maps, database). 2. Coastal and Offshore Permafrost (sediment and organic transfers, subsea permafrost dynamics). 3

  14. Geophysical Investigations of Saline Permafrost at Ilulissat, Greenland

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Foged, Niels Nielsen; Butzbach, Rune

    2008-01-01

    The technical properties and general state of permafrost in Greenland is not well documented. A new coordinated investigation has been initiated, for ground temperature measurements and permafrost mapping in Greenlandic towns in sporadic, discontinuous and continuous permafrost zones. We present...... investigation results from one of the sites, located at Ilulissat, in an area of discontinuous saline permafrost. We have established ground temperature measurement stations and conducted a shallow geoelectrical study. Our results show that the sediments in the studied area mainly consist of very frost...... susceptible silty clays. The area has permafrost with a maximum active layer thickness between 0.9 and 1 m. In spite of low permafrost temperatures a considerable part of the pore water is unfrozen, due to high residual salt concentrations. Consequently, the unfrozen water content dominates the technical...

  15. Circumpolar Active-Layer Permafrost System (CAPS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Circumpolar Active-Layer Permafrost System (CAPS) contains over 100 data sets pertaining to permafrost and frozen ground topics. It also contains detailed...

  16. Permafrost Degradation Risk Zone Assessment using Simulation Models

    DEFF Research Database (Denmark)

    Daanen, R.P.; Ingeman-Nielsen, Thomas; Marchenko, S.

    2011-01-01

    In this proof-of-concept study we focus on linking large scale climate and permafrost simulations to small scale engineering projects by bridging the gap between climate and permafrost sciences on the one hand and on the other technical recommendation for adaptation of planned infrastructures...... to climate change in a region generally underlain by permafrost. We present the current and future state of permafrost in Greenland as modelled numerically with the GIPL model driven by HIRHAM climate projections up to 2080. We develop a concept called Permafrost Thaw Potential (PTP), defined...... as the potential active layer increase due to climate warming and surface alterations. PTP is then used in a simple risk assessment procedure useful for engineering applications. The modelling shows that climate warming will result in continuing wide-spread permafrost warming and degradation in Greenland...

  17. A New Wave of Permafrost Warming in the Alaskan Interior?

    Science.gov (United States)

    Romanovsky, V. E.; Nicolsky, D.; Cable, W.; Kholodov, A. L.; Panda, S. K.

    2017-12-01

    The impact of climate warming on permafrost and the potential of climate feedbacks resulting from permafrost thawing have recently received a great deal of attention. Ground temperatures are a primary indicator of permafrost stability. Many of the research sites in our permafrost network are located along the North American Arctic Permafrost-Ecological Transect that spans all permafrost zones in Alaska. Most of the sites in Alaska show substantial warming of permafrost since the 1980s. The magnitude of warming has varied with location, but was typically from 0.5 to 3°C. However, this warming was not linear in time and not spatially uniform. In some regions this warming even may be reversed and a slight recent cooling of permafrost has been observed recently at some locations. The Interior of Alaska is one of such regions where a slight permafrost cooling was observed starting in the late 1990s that has continued through the 2000s and in the beginning of the 2010s. The cooling has followed the substantial increase in permafrost temperatures documented for the Interior during the 1980s and 1990s. Permafrost temperatures at 15 m depth increased here by 0.3 to 0.6°C between 1983 and 1996. In most locations they reached their maximum in the second half of the 1990s. Since then, the permafrost temperatures started to decrease slowly and by 2013 this decrease at some locations was as much as 0.3°C at 15 m depth. There are some indications that the warming trend in the Alaskan Interior permafrost resumed during the last four years. By 2016, new record highs for the entire period of measurements of permafrost temperatures at 15 m depth were recorded at several locations. The latest observed permafrost warming in the Interior was combined with higher than normal summer precipitations. This combination has triggered near-surface permafrost degradation in many locations with adverse consequences for the ground surface stability affecting ecosystems and infrastructure. In

  18. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    Science.gov (United States)

    Johnson, Kristofer D.; Harden, Jennifer W.; McGuire, A. David; Clark, Mark; Yuan, Fengming; Finley, Andrew O.

    2013-09-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow (OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. Across the MAT gradient, PF in sandy soils varied little, but PF in loamy and silty soils decreased substantially from cooler to warmer temperatures. The change in OLT was more heterogeneous across soil texture types—in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened at warmer locations. Furthermore, when soil organic carbon was estimated using a relationship with thickness, the average increase in carbon in OLTd soils was almost four times greater compared to the average decrease in carbon in OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance.

  19. Permafrost Meta-Omics and Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Mackelprang, Rachel; Saleska, Scott R.; Jacobsen, Carsten Suhr; Jansson, Janet K.; Taş, Neslihan

    2016-06-29

    Permafrost (i.e., soil that has been frozen for at least 2 consecutive years) represents a habitat for microbial life at subzero temperatures (Gilichinsky et al. 2008). Approximately one quarter of the Earth’s surface is underlain by permafrost, which contains 25-50% of the total global soil carbon pool (Schuur et al. 2008, Tarnocai et al. 2009). This carbon is largely protected from microbial decomposition by reduced microbial activity in frozen conditions, but climate change is threatening to induce large-scale permafrost thaw thus exposing it to degradation. The resulting emissions of greenhouse gasses (GHGs) can produce a positive feedback loop and significantly amplify the effects of global warming. Increasing temperatures at high latitudes, changes in precipitation patterns, and frequent fire events have already initiated a widespread degradation of permafrost (Schuur et al. 2015).

  20. High biolability of ancient permafrost carbon upon thaw

    NARCIS (Netherlands)

    Vonk, J.E.; Mann, P.J.; Davydov, S.; Davydova, A.; Spencer, R.G.M.; Schade, J.; Sobczak, W.V.; Zimov, S.; Bulygina, E.; Eglinton, T.I.; Holmes, R.M.

    2013-01-01

    Ongoing climate warming in the Arctic will thaw permafrost and remobilize substantial terrestrial organic carbon (OC) pools. Around a quarter of northern permafrost OC resides in Siberian Yedoma deposits, the oldest form of permafrost carbon. However, our understanding of the degradation and

  1. Data-driven mapping of the potential mountain permafrost distribution.

    Science.gov (United States)

    Deluigi, Nicola; Lambiel, Christophe; Kanevski, Mikhail

    2017-07-15

    Existing mountain permafrost distribution models generally offer a good overview of the potential extent of this phenomenon at a regional scale. They are however not always able to reproduce the high spatial discontinuity of permafrost at the micro-scale (scale of a specific landform; ten to several hundreds of meters). To overcome this lack, we tested an alternative modelling approach using three classification algorithms belonging to statistics and machine learning: Logistic regression, Support Vector Machines and Random forests. These supervised learning techniques infer a classification function from labelled training data (pixels of permafrost absence and presence) with the aim of predicting the permafrost occurrence where it is unknown. The research was carried out in a 588km 2 area of the Western Swiss Alps. Permafrost evidences were mapped from ortho-image interpretation (rock glacier inventorying) and field data (mainly geoelectrical and thermal data). The relationship between selected permafrost evidences and permafrost controlling factors was computed with the mentioned techniques. Classification performances, assessed with AUROC, range between 0.81 for Logistic regression, 0.85 with Support Vector Machines and 0.88 with Random forests. The adopted machine learning algorithms have demonstrated to be efficient for permafrost distribution modelling thanks to consistent results compared to the field reality. The high resolution of the input dataset (10m) allows elaborating maps at the micro-scale with a modelled permafrost spatial distribution less optimistic than classic spatial models. Moreover, the probability output of adopted algorithms offers a more precise overview of the potential distribution of mountain permafrost than proposing simple indexes of the permafrost favorability. These encouraging results also open the way to new possibilities of permafrost data analysis and mapping. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. High biolability of ancient permafrost carbon upon thaw

    NARCIS (Netherlands)

    Vonk, Jorien E.; Mann, Paul J.; Davydov, Sergey; Davydova, Anna; Spencer, Robert G. M.; Schade, John; Sobczak, William V.; Zimov, Nikita; Zimov, Sergei; Bulygina, Ekaterina; Eglinton, Timothy I.; Holmes, Robert M.

    2013-01-01

    Ongoing climate warming in the Arctic will thaw permafrost and remobilize substantial terrestrial organic carbon (OC) pools. Around a quarter of northern permafrost OC resides in Siberian Yedoma deposits, the oldest form of permafrost carbon. However, our understanding of the degradation and fate of

  3. Risiko Video- und Computerspiele? Eine Studie über Video- und Computerspielnutzung und Aggression bei 12- und 16- jährigen Jugendlichen

    OpenAIRE

    Schiller, Eva-Maria; Strohmeier, Dagmar; Spiel, Christiane

    2009-01-01

    Video -und Computerspielen ist heutzutage eine beliebte Freizeitaktivität von Kindern und Jugendlichen, besonders von Jungen. Trotz der großen Vielfalt der angebotenen Video- und Computerspiele für Kinder und Jugendliche, konzentriert sich die Forschung vorwiegend auf negative Einflüsse von gewalthaltigen Video- und Computerspielen. Da nicht alle Kinder und Jugendliche ausschließlich gewalthaltige Video- und Computerspiele spielen, betrachten wir diesen Fokus in der Wissenschaft als zu eng ge...

  4. Permafrost Stores a Globally Significant Amount of Mercury

    Science.gov (United States)

    Schuster, Paul F.; Schaefer, Kevin M.; Aiken, George R.; Antweiler, Ronald C.; Dewild, John F.; Gryziec, Joshua D.; Gusmeroli, Alessio; Hugelius, Gustaf; Jafarov, Elchin; Krabbenhoft, David P.; Liu, Lin; Herman-Mercer, Nicole; Mu, Cuicui; Roth, David A.; Schaefer, Tim; Striegl, Robert G.; Wickland, Kimberly P.; Zhang, Tingjun

    2018-02-01

    Changing climate in northern regions is causing permafrost to thaw with major implications for the global mercury (Hg) cycle. We estimated Hg in permafrost regions based on in situ measurements of sediment total mercury (STHg), soil organic carbon (SOC), and the Hg to carbon ratio (RHgC) combined with maps of soil carbon. We measured a median STHg of 43 ± 30 ng Hg g soil-1 and a median RHgC of 1.6 ± 0.9 μg Hg g C-1, consistent with published results of STHg for tundra soils and 11,000 measurements from 4,926 temperate, nonpermafrost sites in North America and Eurasia. We estimate that the Northern Hemisphere permafrost regions contain 1,656 ± 962 Gg Hg, of which 793 ± 461 Gg Hg is frozen in permafrost. Permafrost soils store nearly twice as much Hg as all other soils, the ocean, and the atmosphere combined, and this Hg is vulnerable to release as permafrost thaws over the next century. Existing estimates greatly underestimate Hg in permafrost soils, indicating a need to reevaluate the role of the Arctic regions in the global Hg cycle.

  5. Permafrost and urban Development in Norilsk Russia.

    Science.gov (United States)

    Shiklomanov, N. I.; Streletskiy, D. A.; Grebenets, V. I.

    2017-12-01

    The city of Norilsk was established in 1935 as a GULAG mining and metallurgy work camp to explore the rich deposits of non-ferrous metals. By the 1989, the population of Norilsk reached 179,757 people. Two additional cities were developed in proximity to Norilsk in the 1960s-1980s: Talnakh (1989 population 65,710); and Kaerkan (1989 population 29,824) making the Norilsk region a major Arctic metropolis. While such rapid growth is not unusual for developing industrial cities, the geographic location makes Norilsk rather unique among world urban centers. It was built in Central Siberia at 69°51' N latitude (above the Arctic Circle), in region characterized by harsh subarctic climate (mean annual temperature around -10 oC), over forest tundra/tundra transitional landscapes underlined by perennially frozen ground (permafrost). Throughout its existence, the Norilsk region was highly isolated: it is not connected to Russian road and railroad systems. The harsh environmental conditions provided significant and rather unique challenges to Norilsk development. Specifically, the presence of ice-rich permafrost imposed restrictions on application of standard urban planning and engineering practices. This presentation analyzes the history of permafrost construction in Norilsk. It shows how though initial trial and errors, a set of guiding principles and engineering methods of construction on permafrost were developed allowing a rapid urbanization of the area during the 1960-1980s. However, despite significant advances in permafrost engineering, the pronounced permafrost degradation has become evident in Norilsk by the mid 1980s and has accelerated rapidly since the mid 1990s resulting in widespread deformation of buildings. Climatic changes are frequently identified as a major cause of accelerated deterioration of infrastructure build on permafrost. However, we argue that other factors, including the complexity of interactions between deferent components of urban

  6. Surface and subsurface conditions in permafrost areas - a literature review

    International Nuclear Information System (INIS)

    Vidstrand, Patrik

    2003-02-01

    This report contains a summary of some of the information within existing technical and scientific literature on permafrost. Permafrost is viewed as one of the future climate driven process domains that may exist in Scandinavia, and that may give rise to significantly different surface and subsurface conditions than the present. Except for changes in the biosphere, permafrost may impact hydraulic, mechanical, and chemical subsurface processes and conditions. Permafrost and its influences on the subsurface conditions are thus of interest for the performance and safety assessments of deep geological waste repositories. The definition of permafrost is 'ground that stays at or below 0 deg C for at least two consecutive years'. Permafrost will effect the geological subsurface to some depth. How deep the permafrost may grow is a function of the heat balance, thermal conditions at the surface and within the ground, and the geothermal heat flux from the Earth's inner parts. The main chapters of the report summaries the knowledge on permafrost evolution, occurrence and distribution, and extracts information concerning hydrology and mechanical and chemical impacts due to permafrost related conditions. The results of a literature review are always dependent on the available literature. Concerning permafrost there is some literature available from investigations in the field of long-term repositories and some from mining industries. However, reports of these investigations are few and the bulk of permafrost literature comes from the science departments concerned with surficial processes (e.g. geomorphology, hydrology, agriculture, etc) and from engineering concerns, such as foundation of constructions and pipeline design. This focus within the permafrost research inevitably yields a biased but also an abundant amount of information on localised surficial processes and a limited amount on regional and deep permafrost characteristics. Possible conclusions are that there is

  7. Surface and subsurface conditions in permafrost areas - a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik [Bergab, Goeteborg (Sweden)

    2003-02-01

    This report contains a summary of some of the information within existing technical and scientific literature on permafrost. Permafrost is viewed as one of the future climate driven process domains that may exist in Scandinavia, and that may give rise to significantly different surface and subsurface conditions than the present. Except for changes in the biosphere, permafrost may impact hydraulic, mechanical, and chemical subsurface processes and conditions. Permafrost and its influences on the subsurface conditions are thus of interest for the performance and safety assessments of deep geological waste repositories. The definition of permafrost is 'ground that stays at or below 0 deg C for at least two consecutive years'. Permafrost will effect the geological subsurface to some depth. How deep the permafrost may grow is a function of the heat balance, thermal conditions at the surface and within the ground, and the geothermal heat flux from the Earth's inner parts. The main chapters of the report summaries the knowledge on permafrost evolution, occurrence and distribution, and extracts information concerning hydrology and mechanical and chemical impacts due to permafrost related conditions. The results of a literature review are always dependent on the available literature. Concerning permafrost there is some literature available from investigations in the field of long-term repositories and some from mining industries. However, reports of these investigations are few and the bulk of permafrost literature comes from the science departments concerned with surficial processes (e.g. geomorphology, hydrology, agriculture, etc) and from engineering concerns, such as foundation of constructions and pipeline design. This focus within the permafrost research inevitably yields a biased but also an abundant amount of information on localised surficial processes and a limited amount on regional and deep permafrost characteristics. Possible conclusions are that

  8. Climate hazards caused by thawing permafrost? Background information of the Federal Environmental Agency; Klimagefahr durch tauenden Permafrost? UBA-Hintergrundpapier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-08-15

    The thawing of permafrost regions is supposed to increase climatic change processes due to the released methane. During the last decades the temperature of permafrost soils has increased by several tenths of degree up to 2 deg C. It is supposed that 10 to 20% of the permafrost regions will thaw during the next 100 years. The southern boundary of the permafrost region will move several hundred kilometers toward the north. Besides the increased risk for the climate system there will also be disadvantageous consequences for the ecosystems. Negative economic consequences are already observed and will be enhanced in the futures with significant cost for the public.

  9. Permafrost Meta-Omics and Climate Change

    DEFF Research Database (Denmark)

    Mackelprang, Rachel; Saleska, Scott R.; Jacobsen, Carsten Suhr

    2016-01-01

    Permanently frozen soil, or permafrost, covers a large portion of the Earth's terrestrial surface and represents a unique environment for cold-adapted microorganisms. As permafrost thaws, previously protected organic matter becomes available for microbial degradation. Microbes that decompose soil...

  10. Permafrost hydrology in changing climatic conditions: seasonal variability of stable isotope composition in rivers in discontinuous permafrost

    International Nuclear Information System (INIS)

    Streletskiy, Dmitry A; Shiklomanov, Nikolay I; Nyland, Kelsey E; Tananaev, Nikita I; Opel, Thomas; Streletskaya, Irina D; Tokarev, Igor’; Shiklomanov, Alexandr I

    2015-01-01

    Role of changing climatic conditions on permafrost degradation and hydrology was investigated in the transition zone between the tundra and forest ecotones at the boundary of continuous and discontinuous permafrost of the lower Yenisei River. Three watersheds of various sizes were chosen to represent the characteristics of the regional landscape conditions. Samples of river flow, precipitation, snow cover, and permafrost ground ice were collected over the watersheds to determine isotopic composition of potential sources of water in a river flow over a two year period. Increases in air temperature over the last forty years have resulted in permafrost degradation and a decrease in the seasonal frost which is evident from soil temperature measurements, permafrost and active-layer monitoring, and analysis of satellite imagery. The lowering of the permafrost table has led to an increased storage capacity of permafrost affected soils and a higher contribution of ground water to river discharge during winter months. A progressive decrease in the thickness of the layer of seasonal freezing allows more water storage and pathways for water during the winter low period making winter discharge dependent on the timing and amount of late summer precipitation. There is a substantial seasonal variability of stable isotopic composition of river flow. Spring flooding corresponds to the isotopic composition of snow cover prior to the snowmelt. Isotopic composition of river flow during the summer period follows the variability of precipitation in smaller creeks, while the water flow of larger watersheds is influenced by the secondary evaporation of water temporarily stored in thermokarst lakes and bogs. Late summer precipitation determines the isotopic composition of texture ice within the active layer in tundra landscapes and the seasonal freezing layer in forested landscapes as well as the composition of the water flow during winter months. (letter)

  11. Presence of rapidly degrading permafrost plateaus in south-central Alaska

    Science.gov (United States)

    Jones, Benjamin M.; Baughman, Carson; Romanovsky, Vladimir E.; Parsekian, Andrew D.; Babcock, Esther; Stephani, Eva; Jones, Miriam C.; Grosse, Guido; Berg, Edward E

    2016-01-01

    Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0 °C. In this study, we document the presence of residual permafrost plateaus in the western Kenai Peninsula lowlands of south-central Alaska, a region with a MAAT of 1.5 ± 1 °C (1981–2010). Continuous ground temperature measurements between 16 September 2012 and 15 September 2015, using calibrated thermistor strings, documented the presence of warm permafrost (−0.04 to −0.08 °C). Field measurements (probing) on several plateau features during the fall of 2015 showed that the depth to the permafrost table averaged 1.48 m but at some locations was as shallow as 0.53 m. Late winter surveys (augering, coring, and GPR) in 2016 showed that the average seasonally frozen ground thickness was 0.45 m, overlying a talik above the permafrost table. Measured permafrost thickness ranged from 0.33 to  >  6.90 m. Manual interpretation of historic aerial photography acquired in 1950 indicates that residual permafrost plateaus covered 920 ha as mapped across portions of four wetland complexes encompassing 4810 ha. However, between 1950 and ca. 2010, permafrost plateau extent decreased by 60.0 %, with lateral feature degradation accounting for 85.0 % of the reduction in area. Permafrost loss on the Kenai Peninsula is likely associated with a warming climate, wildfires that remove the protective forest and organic layer cover, groundwater flow at depth, and lateral heat transfer from wetland surface waters in the summer. Better understanding the resilience and vulnerability of ecosystem-protected permafrost is critical for mapping and predicting future permafrost extent and degradation across all permafrost regions that are currently warming

  12. Microbial diversity in European alpine permafrost and active layers.

    Science.gov (United States)

    Frey, Beat; Rime, Thomas; Phillips, Marcia; Stierli, Beat; Hajdas, Irka; Widmer, Franco; Hartmann, Martin

    2016-03-01

    Permafrost represents a largely understudied genetic resource. Thawing of permafrost with global warming will not only promote microbial carbon turnover with direct feedback on greenhouse gases, but also unlock an unknown microbial diversity. Pioneering metagenomic efforts have shed light on the permafrost microbiome in polar regions, but temperate mountain permafrost is largely understudied. We applied a unique experimental design coupled to high-throughput sequencing of ribosomal markers to characterize the microbiota at the long-term alpine permafrost study site 'Muot-da-Barba-Peider' in eastern Switzerland with an approximate radiocarbon age of 12 000 years. Compared to the active layers, the permafrost community was more diverse and enriched with members of the superphylum Patescibacteria (OD1, TM7, GN02 and OP11). These understudied phyla with no cultured representatives proposedly feature small streamlined genomes with reduced metabolic capabilities, adaptations to anaerobic fermentative metabolisms and potential ectosymbiotic lifestyles. The permafrost microbiota was also enriched with yeasts and lichenized fungi known to harbour various structural and functional adaptation mechanisms to survive under extreme sub-zero conditions. These data yield an unprecedented view on microbial life in temperate mountain permafrost, which is increasingly important for understanding the biological dynamics of permafrost in order to anticipate potential ecological trajectories in a warming world. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Gas hydrates in gas storage caverns; Gashydrate bei der Gaskavernenspeicherung

    Energy Technology Data Exchange (ETDEWEB)

    Groenefeld, P. [Kavernen Bau- und Betriebs-GmbH, Hannover (Germany)

    1997-12-31

    Given appropriate pressure and temperature conditions the storage of natural gas in salt caverns can lead to the formation of gas hydrates in the producing well or aboveground operating facilities. This is attributable to the stored gas becoming more or less saturated with water vapour. The present contribution describes the humidity, pressure, and temperature conditions conducive to gas hydrate formation. It also deals with the reduction of the gas removal capacity resulting from gas hydrate formation, and possible measures for preventing hydrate formation such as injection of glycol, the reduction of water vapour absorption from the cavern sump, and dewatering of the cavern sump. (MSK) [Deutsch] Bei der Speicherung von Erdgas in Salzkavernen kann es unter entsprechenden Druck- und Temperaturverhaeltnissen zur Gashydratbildung in den Foerdersonden oder obertaegigen Betriebseinrichtungen kommen, weil sich das eingelagerte Gas mehr oder weniger mit Wasserdampf aufsaettigt. Im Folgenden werden die Feuchtigkeits-, Druck- und Temperaturbedingungen, die zur Hydratbildung fuehren erlaeutert. Ebenso werden die Verringerung der Auslagerungskapazitaet durch die Hydratbildung, Massnahmen zur Verhinderung der Hydratbildung wie die Injektion von Glykol, die Verringerung der Wasserdampfaufnahme aus dem Kavernensumpf und die Entwaesserung der Kavernensumpfs selbst beschrieben.

  14. Anaerobic methanotrophic communities thrive in deep submarine permafrost.

    Science.gov (United States)

    Winkel, Matthias; Mitzscherling, Julia; Overduin, Pier P; Horn, Fabian; Winterfeld, Maria; Rijkers, Ruud; Grigoriev, Mikhail N; Knoblauch, Christian; Mangelsdorf, Kai; Wagner, Dirk; Liebner, Susanne

    2018-01-22

    Thawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in submarine permafrost sediments has been proposed, but the responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic assemblages of marine and terrestrial origin (ANME-2a/b, ANME-2d) both in frozen and completely thawed submarine permafrost sediments. Besides archaea potentially involved in anaerobic oxidation of methane (AOM) we found a large diversity of archaea mainly belonging to Bathyarchaeota, Thaumarchaeota, and Euryarchaeota. Methane concentrations and δ 13 C-methane signatures distinguish horizons of potential AOM coupled either to sulfate reduction in a sulfate-methane transition zone (SMTZ) or to the reduction of other electron acceptors, such as iron, manganese or nitrate. Analysis of functional marker genes (mcrA) and fluorescence in situ hybridization (FISH) corroborate potential activity of AOM communities in submarine permafrost sediments at low temperatures. Modeled potential AOM consumes 72-100% of submarine permafrost methane and up to 1.2 Tg of carbon per year for the total expected area of submarine permafrost. This is comparable with AOM habitats such as cold seeps. We thus propose that AOM is active where submarine permafrost thaws, which should be included in global methane budgets.

  15. Permafrost stores a globally significant amount of mercury

    Science.gov (United States)

    Schaefer, K. M.; Schuster, P. F.; Antweiler, R.; Aiken, G.; DeWild, J.; Gryziec, J. D.; Gusmeroli, A.; Hugelius, G.; Jafarov, E.; Krabbenhoft, D. P.; Liu, L.; Herman-Mercer, N. M.; Mu, C.; Roth, D. A.; Schaefer, T.; Striegl, R. G.; Wickland, K.; Zhang, T.

    2017-12-01

    Changing climate in northern regions is causing permafrost to thaw with major implications for the cycling of mercury in arctic and subarctic ecosystems. Permafrost occurs in nearly one quarter of the Earth's Northern Hemisphere. We measured total soil mercury concentration in 588 samples from 13 soil permafrost cores from the interior and the North Slope of Alaska. The median concentration was 47.7±23.4 ng Hg g soil-1 and the median ratio of Hg to carbon was 1.56±0.86 µg Hg g C-1. We estimate Alaskan permafrost stores 56±32 kilotons of mercury and the entire northern hemisphere permafrost land mass stores 773±441 kilotons of mercury. This increases estimates of mercury stored in soils by 60%, making permafrost the second largest reservoir of mercury on the planet. Climate projections indicate extensive permafrost thawing, releasing mercury into the environment through a variety of mechanisms, for example, terrestrial transport via dissolved organic carbon (DOC), gaseous elemental mercury (GEM) evasion, forest fires, atmospheric mixing processes with ozone, and Springtime atmospheric Hg depletion after the polar sunrise. These findings have major implications for terrestrial and aquatic life, the world's fisheries, and ultimately human health.

  16. Permafrost stores a globally significant amount of mercury

    Science.gov (United States)

    Schuster, Paul F.; Schaefer, Kevin; Aiken, George R.; Antweiler, Ronald C.; DeWild, John F.; Gryziec, Joshua D.; Gusmeroli, Alessio; Hugelius, Gustaf; Jafarov, Elchin E.; Krabbenhoft, David P.; Liu, Lin; Herman-Mercer, Nicole M.; Mu, Cuicui; Roth, David A.; Schaefer, Tim; Striegl, Robert G.; Wickland, Kimberly P.; Zhang, Tingjun

    2018-01-01

    Changing climate in northern regions is causing permafrost to thaw with major implications for the global mercury (Hg) cycle. We estimated Hg in permafrost regions based on in situ measurements of sediment total mercury (STHg), soil organic carbon (SOC), and the Hg to carbon ratio (RHgC) combined with maps of soil carbon. We measured a median STHg of 43 ± 30 ng Hg g soil−1 and a median RHgC of 1.6 ± 0.9 μg Hg g C−1, consistent with published results of STHg for tundra soils and 11,000 measurements from 4,926 temperate, nonpermafrost sites in North America and Eurasia. We estimate that the Northern Hemisphere permafrost regions contain 1,656 ± 962 Gg Hg, of which 793 ± 461 Gg Hg is frozen in permafrost. Permafrost soils store nearly twice as much Hg as all other soils, the ocean, and the atmosphere combined, and this Hg is vulnerable to release as permafrost thaws over the next century. Existing estimates greatly underestimate Hg in permafrost soils, indicating a need to reevaluate the role of the Arctic regions in the global Hg cycle.

  17. Historical and Possible Future Changes in Permafrost and Active Layer Thickness in Alaska: Implications to Landscape Changes and Permafrost Carbon Pool.

    Science.gov (United States)

    Marchenko, S. S.; Helene, G.; Euskirchen, E. S.; Breen, A. L.; McGuire, D.; Rupp, S. T.; Romanovsky, V. E.; Walsh, J. E.

    2017-12-01

    The Soil Temperature and Active Layer Thickness (ALT) Gridded Data was developed to quantify the nature and rate of permafrost degradation and its impact on ecosystems, infrastructure, CO2 and CH4 fluxes and net C storage following permafrost thaw across Alaska. To develop this database, we used the process-based permafrost dynamics model GIPL2 developed in the Geophysical Institute Permafrost Lab, UAF and which is the permafrost module of the Integrated Ecosystem Model (IEM) for Alaska and Northwest Canada. The climate forcing data for simulations were developed by the Scenarios Network for Alaska and Arctic Planning (SNAP, http://www.snap.uaf.edu/). These data are based on the historical CRU3.1 data set for the retrospective analysis period (1901-2009) and the five model averaged data were derived from the five CMIP5/AR5 IPCC Global Circulation Models that performed the best in Alaska and other northern regions: NCAR-CCSM4, GFDL-CM3, GISS-E2-R, IPSL-CM5A-LR, MRI-CGCM3. A composite of all five-model outputs for the RCP4.5 and RCP8.5 were used in these particular permafrost dynamics simulations. Data sets were downscaled to a 771 m resolution, using the Parameter-elevation Regressions on Independent Slopes Model (PRISM) climatology. Additional input data (snow characteristics, soil thermal properties, soil water content, organic matter accumulation or its loss due to fire, etc.) came from the Terrestrial Ecosystem Model (TEM) and the ALFRESCO (ALaska FRame-based EcoSystem COde) model simulations. We estimated the dynamics of permafrost temperature, active layer thickness, area occupied by permafrost, and volume of seasonally thawed soils within the 4.75 upper meters (original TEM soil column) across the Alaska domain. Simulations of future changes in permafrost indicate that, by the end of the 21st century, late-Holocene permafrost in Alaska will be actively thawing at all locations and that some Late Pleistocene carbon-rich peatlands underlain by permafrost will

  18. Microorganisms Trapped Within Permafrost Ice In The Fox Permafrost Tunnel, Alaska

    Science.gov (United States)

    Katayama, T.; Tanaka, M.; Douglas, T. A.; Cai, Y.; Tomita, F.; Asano, K.; Fukuda, M.

    2008-12-01

    Several different types of massive ice are common in permafrost. Ice wedges are easily recognized by their shape and foliated structure. They grow syngenetically or epigenetically as a result of repeated cycles of frost cracking followed by the infiltration of snow, melt water, soil or other material into the open frost cracks. Material incorporated into ice wedges becomes frozen and preserved. Pool ice, another massive ice type, is formed by the freezing of water resting on top of frozen thermokarst sediment or melting wedges and is not foliated. The Fox Permafrost Tunnel in Fairbanks was excavated within the discontinuous permafrost zone of central Alaska and it contains permafrost, ice wedges, and pool ice preserved at roughly -3°C. We collected samples from five ice wedges and three pool ice structures in the Fox Permafrost Tunnel. If the microorganisms were incorporated into the ice during its formation, a community analysis of the microorganisms could elucidate the environment in which the ice was formed. Organic material from sediments in the tunnel was radiocarbon-dated between 14,000 and 30,000 years BP. However, it is still not clear when the ice wedges were formed or subsequently deformed because they are only partially exposed and their upper surfaces are above the tunnel walls. The objectives of our study were to determine the biogeochemical conditions during massive ice formation and to analyze the microbial community within the ices by incubation-based and DNA-based analyses. The geochemical profile and the PCR-DGGE band patterns of bacteria among five ice wedge and 3 portions of pool ice samples were markedly different. The DGGE band patterns of fungi were simple with a few bands of fungi or yeast. The dominant bands of ice wedge and pool ice samples were affiliated with the genus Geomyces and Doratomyces, respectively. Phylogenetic analysis using rRNA gene ITS regions indicated isolates of Geomyces spp. from different ice wedges were affiliated

  19. Semiautomatic mapping of permafrost in the Yukon Flats, Alaska

    Science.gov (United States)

    Gulbrandsen, Mats Lundh; Minsley, Burke J.; Ball, Lyndsay B.; Hansen, Thomas Mejer

    2016-01-01

    Thawing of permafrost due to global warming can have major impacts on hydrogeological processes, climate feedback, arctic ecology, and local environments. To understand these effects and processes, it is crucial to know the distribution of permafrost. In this study we exploit the fact that airborne electromagnetic (AEM) data are sensitive to the distribution of permafrost and demonstrate how the distribution of permafrost in the Yukon Flats, Alaska, is mapped in an efficient (semiautomatic) way, using a combination of supervised and unsupervised (machine) learning algorithms, i.e., Smart Interpretation and K-means clustering. Clustering is used to sort unfrozen and frozen regions, and Smart Interpretation is used to predict the depth of permafrost based on expert interpretations. This workflow allows, for the first time, a quantitative and objective approach to efficiently map permafrost based on large amounts of AEM data.

  20. The International Permafrost Association: current initiatives for cryospheric research

    Science.gov (United States)

    Schollaen, Karina; Lewkowicz, Antoni G.; Christiansen, Hanne H.; Romanovsky, Vladimir E.; Lantuit, Hugues; Schrott, Lothar; Sergeev, Dimitry; Wei, Ma

    2015-04-01

    The International Permafrost Association (IPA), founded in 1983, has as its objectives to foster the dissemination of knowledge concerning permafrost and to promote cooperation among persons and national or international organizations engaged in scientific investigation and engineering work on permafrost. The IPA's primary responsibilities are convening International Permafrost Conferences, undertaking special projects such as preparing databases, maps, bibliographies, and glossaries, and coordinating international field programs and networks. Membership is through adhering national or multinational organizations or as individuals in countries where no Adhering Body exists. The IPA is governed by its Executive Committee and a Council consisting of representatives from 26 Adhering Bodies having interests in some aspect of theoretical, basic and applied frozen ground research, including permafrost, seasonal frost, artificial freezing and periglacial phenomena. This presentation details the IPA core products, achievements and activities as well as current projects in cryospheric research. One of the most important core products is the circumpolar permafrost map. The IPA also fosters and supports the activities of the Global Terrestrial Network on Permafrost (GTN-P) sponsored by the Global Terrestrial Observing System, GTOS, and the Global Climate Observing System, GCOS, whose long-term goal is to obtain a comprehensive view of the spatial structure, trends, and variability of changes in the active layer thickness and permafrost temperature. A further important initiative of the IPA are the biannually competitively-funded Action Groups which work towards the production of well-defined products over a period of two years. Current IPA Action Groups are working on highly topical and interdisciplinary issues, such as the development of a regional Palaeo-map of Permafrost in Eurasia, the integration of multidisciplinary knowledge about the use of thermokarst and permafrost

  1. Permafrost degradation in West Greenland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2012-01-01

    Important aspects of civil engineering in West Greenland relate to the presence of permafrost and mapping of the annual and future changes in the active layer due to the ongoing climatically changes in the Arctic. The Arctic Technology Centre (ARTEK) has worked more than 10 years on this topic...... and the first author has been involved since 1970 in engineering geology, geotechnical engineering and permafrost related studies for foundation construction and infrastructures in towns and communities mainly in West Greenland. We have since 2006 together with the Danish Meteorological Institute, Greenland...... Survey (ASIAQ) and the University of Alaska Fairbanks carried out the US NSF funded project ARC-0612533: Recent and future permafrost variability, retreat and degradation in Greenland and Alaska: An integrated approach. This contribution will present data and observations from the towns Ilulissat...

  2. Permafrost at its limits: The most easterly evidence of existing permafrost in the European Alps as indicated by ground temperature and geoelectrical measurements

    Science.gov (United States)

    Kellerer-Pirklbauer, A.; Kühnast, B.

    2009-04-01

    Mountain permafrost is a widespread phenomenon in alpine regions in the European Alps. For instance, some 2000 km² or 4% of the Austrian Alps are underlain by permafrost. Up to recent times most research on permafrost issues in Austria focused on the central and highest section of the Austrian Alps. By contrast, knowledge concerning marginal permafrost zones is fairly limited. To increase knowledge about the easternmost limit of permafrost in the European Alps, a research project focusing on the Seckauer Tauern Mountains (14°30'E to 15°00'E) and particularly on the Hochreichart area was initiated in 2004 by the first author. Since then, different methods have been applied such as e.g. geomorphic mapping, numerical permafrost modelling, multi-annual BTS measurements (since 2004) or continuous ground surface and near ground surface temperature measurements by miniature temperature data loggers/MTDs (since 2004). In order to verify the temperature data and to extend the spatial knowledge about permafrost distribution beyond point information, a geoelectrical survey was carried out at the end of August 2008 by applying the electrical resistivity tomography (ERT) method along a 120 m long profile covering the upper part of the rooting zone of a (more-or-less) relict rock glacier and the talus slope above. For this survey the two-dimensional (2D) electrical surveys was performed using the Wenner-Alfa configuration with 2.5 m spacing and an LGM-Lippmann 4-Punkt light hp resistivity-meter. The ERT results indicate an active layer of 2 to 4 m underlain by a permafrost body along 3/4 of the entire profile with resistivity values between 50 to 100 kOhm.m and extending to a depth of 10 to 15 m. The permafrost body is substantially thicker at the lower part of the profile (rock glacier; first 50 m of profile) compared to most of the upper part (talus slope). Focusing on the talus slope, the permafrost body is thickest on the central section of the profile (~5-6 m thickness

  3. Quantifying uncertainties of permafrost carbon–climate feedbacks

    Directory of Open Access Journals (Sweden)

    E. J. Burke

    2017-06-01

    Full Text Available The land surface models JULES (Joint UK Land Environment Simulator, two versions and ORCHIDEE-MICT (Organizing Carbon and Hydrology in Dynamic Ecosystems, each with a revised representation of permafrost carbon, were coupled to the Integrated Model Of Global Effects of climatic aNomalies (IMOGEN intermediate-complexity climate and ocean carbon uptake model. IMOGEN calculates atmospheric carbon dioxide (CO2 and local monthly surface climate for a given emission scenario with the land–atmosphere CO2 flux exchange from either JULES or ORCHIDEE-MICT. These simulations include feedbacks associated with permafrost carbon changes in a warming world. Both IMOGEN–JULES and IMOGEN–ORCHIDEE-MICT were forced by historical and three alternative future-CO2-emission scenarios. Those simulations were performed for different climate sensitivities and regional climate change patterns based on 22 different Earth system models (ESMs used for CMIP3 (phase 3 of the Coupled Model Intercomparison Project, allowing us to explore climate uncertainties in the context of permafrost carbon–climate feedbacks. Three future emission scenarios consistent with three representative concentration pathways were used: RCP2.6, RCP4.5 and RCP8.5. Paired simulations with and without frozen carbon processes were required to quantify the impact of the permafrost carbon feedback on climate change. The additional warming from the permafrost carbon feedback is between 0.2 and 12 % of the change in the global mean temperature (ΔT by the year 2100 and 0.5 and 17 % of ΔT by 2300, with these ranges reflecting differences in land surface models, climate models and emissions pathway. As a percentage of ΔT, the permafrost carbon feedback has a greater impact on the low-emissions scenario (RCP2.6 than on the higher-emissions scenarios, suggesting that permafrost carbon should be taken into account when evaluating scenarios of heavy mitigation and stabilization

  4. Transient thermal modeling of permafrost conditions in Southern Norway

    Directory of Open Access Journals (Sweden)

    S. Westermann

    2013-04-01

    Full Text Available Thermal modeling is a powerful tool to infer the temperature regime of the ground in permafrost areas. We present a transient permafrost model, CryoGrid 2, that calculates ground temperatures according to conductive heat transfer in the soil and in the snowpack. CryoGrid 2 is forced by operational air temperature and snow-depth products for potential permafrost areas in Southern Norway for the period 1958 to 2009 at 1 km2 spatial resolution. In total, an area of about 80 000 km2 is covered. The model results are validated against borehole temperatures, permafrost probability maps from "bottom temperature of snow" measurements and inventories of landforms indicative of permafrost occurrence. The validation demonstrates that CryoGrid 2 can reproduce the observed lower permafrost limit to within 100 m at all validation sites, while the agreement between simulated and measured borehole temperatures is within 1 K for most sites. The number of grid cells with simulated permafrost does not change significantly between the 1960s and 1990s. In the 2000s, a significant reduction of about 40% of the area with average 2 m ground temperatures below 0 °C is found, which mostly corresponds to degrading permafrost with still negative temperatures in deeper ground layers. The thermal conductivity of the snow is the largest source of uncertainty in CryoGrid 2, strongly affecting the simulated permafrost area. Finally, the prospects of employing CryoGrid 2 as an operational soil-temperature product for Norway are discussed.

  5. Coupled Northern Hemisphere permafrost-ice-sheet evolution over the last glacial cycle

    Science.gov (United States)

    Willeit, M.; Ganopolski, A.

    2015-09-01

    Permafrost influences a number of processes which are relevant for local and global climate. For example, it is well known that permafrost plays an important role in global carbon and methane cycles. Less is known about the interaction between permafrost and ice sheets. In this study a permafrost module is included in the Earth system model CLIMBER-2, and the coupled Northern Hemisphere (NH) permafrost-ice-sheet evolution over the last glacial cycle is explored. The model performs generally well at reproducing present-day permafrost extent and thickness. Modeled permafrost thickness is sensitive to the values of ground porosity, thermal conductivity and geothermal heat flux. Permafrost extent at the Last Glacial Maximum (LGM) agrees well with reconstructions and previous modeling estimates. Present-day permafrost thickness is far from equilibrium over deep permafrost regions. Over central Siberia and the Arctic Archipelago permafrost is presently up to 200-500 m thicker than it would be at equilibrium. In these areas, present-day permafrost depth strongly depends on the past climate history and simulations indicate that deep permafrost has a memory of surface temperature variations going back to at least 800 ka. Over the last glacial cycle permafrost has a relatively modest impact on simulated NH ice sheet volume except at LGM, when including permafrost increases ice volume by about 15 m sea level equivalent in our model. This is explained by a delayed melting of the ice base from below by the geothermal heat flux when the ice sheet sits on a porous sediment layer and permafrost has to be melted first. Permafrost affects ice sheet dynamics only when ice extends over areas covered by thick sediments, which is the case at LGM.

  6. Übergewicht und Adipositas in Kindheit und Jugend

    OpenAIRE

    Nitzko, Sina

    2010-01-01

    Einführend wird auf wesentliche Entwicklungsaspekte der interessierenden Lebensphasen Kindheit und Jugend eingegangen. Im Anschluss daran werden verschiedene Aspekte von Übergewicht und Adipositas in Kindheit und Jugend thematisiert. Neben der Definition und Diagnostik, wird auf Möglichkeiten der Klassifikation sowie die Epidemiologie eingegangen. Dargestellt werden darüber hinaus körperliche und psychische Folgestörungen, welche mit Adipositas assoziiert sein können. Basierend auf der...

  7. Monitoring Seasonal Changes in Permafrost Using Seismic Interferometry

    Science.gov (United States)

    James, S. R.; Knox, H. A.; Abbott, R. E.

    2015-12-01

    The effects of climate change in polar regions and their incorporation in global climate models has recently become an area of great interest. Permafrost holds entrapped greenhouse gases, e.g. CO2 and CH4, which are released to the atmosphere upon thawing, creating a positive feedback mechanism. Knowledge of seasonal changes in active layer thickness as well as long term degradation of permafrost is critical to the management of high latitude infrastructures, hazard mitigation, and increasing the accuracy of climate predictions. Methods for effectively imaging the spatial extent, depth, thickness, and discontinuous nature of permafrost over large areas are needed. Furthermore, continuous monitoring of permafrost over annual time scales would provide valuable insight into permafrost degradation. Seismic interferometry using ambient seismic noise has proven effective for recording velocity changes within the subsurface for a variety of applications, but has yet to be applied to permafrost studies. To this end, we deployed 7 Nanometrics Trillium posthole broadband seismometers within Poker Flat Research Range, located 30 miles north of Fairbanks, Alaska in a zone of discontinuous permafrost. Approximately 2 years worth of nearly continuous ambient noise data was collected. Using the python package MSNoise, relative changes in velocity were calculated. Results show high amounts of variability throughout the study period. General trends of negative relative velocity shifts can be seen between August and October followed by a positive relative velocity shift between November and February. Differences in relative velocity changes with both frequency and spatial location are also observed, suggesting this technique is sensitive to permafrost variation with depth and extent. Overall, short and long term changes in shallow subsurface velocity can be recovered using this method proposing seismic interferometry is a promising new technique for permafrost monitoring. Sandia

  8. Permafrost: occurrence and physiochemical processes

    International Nuclear Information System (INIS)

    Ahonen, L.

    2001-10-01

    Bedrock of the Northern Hemisphere areas to the north of about the 60th latitude are nowadays dominated by permafrost conditions. Fennoscandia is a major exception being characterised by temperate climate. In studying deep geological disposal of long-living nuclear waste, long-term climatic changes have to be taken into account. One of the scenarios to be studied is the extension of the deep permafrost conditions to the disposal site. Quaternary climatic fluctuations and their possible reasons are discussed shortly. The author's conclusion is that future climatic changes cannot be undoubtedly derived from the past variations, mainly because of the current anthropogenic involvement and of the poorly known dynamics of the major climate-affecting factors like ocean currents, which cannot be treated in a deterministic way. In low-porosity crystalline rocks permafrost may propagate to the depth of about 500 metres in some thousands to ten thousands of years. On the other hand, the major effects of permafrost are related to the freezing of water in the pores. Water expands about 9 percent in freezing, and the increasing stress may lead to pressure melting of ice. Dissolved salts in water do not accommodate into the solid ice, but they form saline water or brine segregations having freezing point of even less than minus ten degrees. A front of saline water may develop beneath the frozen bedrock. Pockets of saline water may also occur in ice, and unfrozen adsorption water may occur on the grain boundaries. With respect to the radionuclide transport processes, permafrost as such is a barrier, while the unfrozen domains (taliks) beneath major lake and river systems are potential flow paths. (orig.)

  9. Permafrost: occurrence and physiochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Ahonen, L. [Geological Survey of Finland, Espoo (Finland)

    2001-10-01

    Bedrock of the Northern Hemisphere areas to the north of about the 60th latitude are nowadays dominated by permafrost conditions. Fennoscandia is a major exception being characterised by temperate climate. In studying deep geological disposal of long-living nuclear waste, long-term climatic changes have to be taken into account. One of the scenarios to be studied is the extension of the deep permafrost conditions to the disposal site. Quaternary climatic fluctuations and their possible reasons are discussed shortly. The author's conclusion is that future climatic changes cannot be undoubtedly derived from the past variations, mainly because of the current anthropogenic involvement and of the poorly known dynamics of the major climate-affecting factors like ocean currents, which cannot be treated in a deterministic way. In low-porosity crystalline rocks permafrost may propagate to the depth of about 500 metres in some thousands to ten thousands of years. On the other hand, the major effects of permafrost are related to the freezing of water in the pores. Water expands about 9 percent in freezing, and the increasing stress may lead to pressure melting of ice. Dissolved salts in water do not accommodate into the solid ice, but they form saline water or brine segregations having freezing point of even less than minus ten degrees. A front of saline water may develop beneath the frozen bedrock. Pockets of saline water may also occur in ice, and unfrozen adsorption water may occur on the grain boundaries. With respect to the radionuclide transport processes, permafrost as such is a barrier, while the unfrozen domains (taliks) beneath major lake and river systems are potential flow paths. (orig.)

  10. Improving permafrost distribution modelling using feature selection algorithms

    Science.gov (United States)

    Deluigi, Nicola; Lambiel, Christophe; Kanevski, Mikhail

    2016-04-01

    The availability of an increasing number of spatial data on the occurrence of mountain permafrost allows the employment of machine learning (ML) classification algorithms for modelling the distribution of the phenomenon. One of the major problems when dealing with high-dimensional dataset is the number of input features (variables) involved. Application of ML classification algorithms to this large number of variables leads to the risk of overfitting, with the consequence of a poor generalization/prediction. For this reason, applying feature selection (FS) techniques helps simplifying the amount of factors required and improves the knowledge on adopted features and their relation with the studied phenomenon. Moreover, taking away irrelevant or redundant variables from the dataset effectively improves the quality of the ML prediction. This research deals with a comparative analysis of permafrost distribution models supported by FS variable importance assessment. The input dataset (dimension = 20-25, 10 m spatial resolution) was constructed using landcover maps, climate data and DEM derived variables (altitude, aspect, slope, terrain curvature, solar radiation, etc.). It was completed with permafrost evidences (geophysical and thermal data and rock glacier inventories) that serve as training permafrost data. Used FS algorithms informed about variables that appeared less statistically important for permafrost presence/absence. Three different algorithms were compared: Information Gain (IG), Correlation-based Feature Selection (CFS) and Random Forest (RF). IG is a filter technique that evaluates the worth of a predictor by measuring the information gain with respect to the permafrost presence/absence. Conversely, CFS is a wrapper technique that evaluates the worth of a subset of predictors by considering the individual predictive ability of each variable along with the degree of redundancy between them. Finally, RF is a ML algorithm that performs FS as part of its

  11. Diagnostic and model dependent uncertainty of simulated Tibetan permafrost area

    Science.gov (United States)

    Wang, W.; Rinke, A.; Moore, J. C.; Cui, X.; Ji, D.; Li, Q.; Zhang, N.; Wang, C.; Zhang, S.; Lawrence, D. M.; McGuire, A. D.; Zhang, W.; Delire, C.; Koven, C.; Saito, K.; MacDougall, A.; Burke, E.; Decharme, B.

    2016-02-01

    We perform a land-surface model intercomparison to investigate how the simulation of permafrost area on the Tibetan Plateau (TP) varies among six modern stand-alone land-surface models (CLM4.5, CoLM, ISBA, JULES, LPJ-GUESS, UVic). We also examine the variability in simulated permafrost area and distribution introduced by five different methods of diagnosing permafrost (from modeled monthly ground temperature, mean annual ground and air temperatures, air and surface frost indexes). There is good agreement (99 to 135 × 104 km2) between the two diagnostic methods based on air temperature which are also consistent with the observation-based estimate of actual permafrost area (101 × 104 km2). However the uncertainty (1 to 128 × 104 km2) using the three methods that require simulation of ground temperature is much greater. Moreover simulated permafrost distribution on the TP is generally only fair to poor for these three methods (diagnosis of permafrost from monthly, and mean annual ground temperature, and surface frost index), while permafrost distribution using air-temperature-based methods is generally good. Model evaluation at field sites highlights specific problems in process simulations likely related to soil texture specification, vegetation types and snow cover. Models are particularly poor at simulating permafrost distribution using the definition that soil temperature remains at or below 0 °C for 24 consecutive months, which requires reliable simulation of both mean annual ground temperatures and seasonal cycle, and hence is relatively demanding. Although models can produce better permafrost maps using mean annual ground temperature and surface frost index, analysis of simulated soil temperature profiles reveals substantial biases. The current generation of land-surface models need to reduce biases in simulated soil temperature profiles before reliable contemporary permafrost maps and predictions of changes in future permafrost distribution can be made for

  12. Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009

    Science.gov (United States)

    McGuire, A. David; Koven, Charles; Lawrence, David M.; Clein, Joy S.; Xia, Jiangyang; Beer, Christian; Burke, Eleanor J.; Chen, Guangsheng; Chen, Xiaodong; Delire, Christine; Jafarov, Elchin; MacDougall, Andrew H.; Marchenko, Sergey S.; Nicolsky, Dmitry J.; Peng, Shushi; Rinke, Annette; Saito, Kazuyuki; Zhang, Wenxin; Alkama, Ramdane; Bohn, Theodore J.; Ciais, Philippe; Decharme, Bertrand; Ekici, Altug; Gouttevin, Isabelle; Hajima, Tomohiro; Hayes, Daniel J.; Ji, Duoying; Krinner, Gerhard; Lettenmaier, Dennis P.; Luo, Yiqi; Miller, Paul A.; Moore, John C.; Romanovsky, Vladimir; Schädel, Christina; Schaefer, Kevin; Schuur, Edward A.G.; Smith, Benjamin; Sueyoshi, Tetsuo; Zhuang, Qianlai

    2016-01-01

    A significant portion of the large amount of carbon (C) currently stored in soils of the permafrost region in the Northern Hemisphere has the potential to be emitted as the greenhouse gases CO2and CH4 under a warmer climate. In this study we evaluated the variability in the sensitivity of permafrost and C in recent decades among land surface model simulations over the permafrost region between 1960 and 2009. The 15 model simulations all predict a loss of near-surface permafrost (within 3 m) area over the region, but there are large differences in the magnitude of the simulated rates of loss among the models (0.2 to 58.8 × 103 km2 yr−1). Sensitivity simulations indicated that changes in air temperature largely explained changes in permafrost area, although interactions among changes in other environmental variables also played a role. All of the models indicate that both vegetation and soil C storage together have increased by 156 to 954 Tg C yr−1between 1960 and 2009 over the permafrost region even though model analyses indicate that warming alone would decrease soil C storage. Increases in gross primary production (GPP) largely explain the simulated increases in vegetation and soil C. The sensitivity of GPP to increases in atmospheric CO2 was the dominant cause of increases in GPP across the models, but comparison of simulated GPP trends across the 1982–2009 period with that of a global GPP data set indicates that all of the models overestimate the trend in GPP. Disturbance also appears to be an important factor affecting C storage, as models that consider disturbance had lower increases in C storage than models that did not consider disturbance. To improve the modeling of C in the permafrost region, there is the need for the modeling community to standardize structural representation of permafrost and carbon dynamics among models that are used to evaluate the permafrost C feedback and for the modeling and observational communities to

  13. Terrestrial Permafrost Models of Martian Habitats and Inhabitants

    Science.gov (United States)

    Gilichinsky, D.

    2011-12-01

    The terrestrial permafrost is the only rich depository of viable ancient microorganisms on Earth, and can be used as a bridge to possible Martian life forms and shallow subsurface habitats where the probability of finding life is highest. Since there is a place for water, the requisite condition for life, the analogous models are more or less realistic. If life ever existed on Mars, traces might have been preserved and could be found at depth within permafrost. The age of the terrestrial isolates corresponds to the longevity of the frozen state of the embedding strata, with the oldest known dating back to the late Pliocene in Arctic and late Miocene in Antarctica. Permafrost on Earth and Mars vary in age, from a few million years on Earth to a few billion years on Mars. Such a difference in time scale would have a significant impact on the possibility of preserving life on Mars, which is why the longevity of life forms preserved within terrestrial permafrost can only be an approximate model for Mars. 1. A number of studies indicate that the Antarctic cryosphere began to develop on the Eocene-Oligocene boundary, after the isolation of the continent. Permafrost degradation is only possible if mean annual ground temperature, -28°C now, rise above freezing, i.e., a significant warming to above 25°C is required. There is no evidence of such sharp temperature increase, which indicates that the climate and geological history was favorable to persistence of pre-Pliocene permafrost. These oldest relics (~30Myr) are possibly to be found at high hypsometric levels of ice-free areas (Dry Valleys and nearby mountains). It is desirable to test the layers for the presence of viable cells. The limiting age, if one exists, within this ancient permafrost, where the viable organisms were no longer present, could be established as the limit for life preservation below 0oC. Positive results will extend the known temporal limits of life in permafrost. 2. Even in this case, the age of

  14. Evidence for nonuniform permafrost degradation after fire in boreal landscapes

    Science.gov (United States)

    Minsley, Burke J.; Pastick, Neal J.; Wylie, Bruce K.; Brown, Dana R.N.; Kass, M. Andy

    2016-01-01

    Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. We present a combination of multiscale remote sensing, geophysical, and field observations that reveal details of both near-surface (1 m) impacts of fire on permafrost. Along 11 transects that span burned-unburned boundaries in different landscape settings within interior Alaska, subsurface electrical resistivity and nuclear magnetic resonance data indicate locations where permafrost appears to be resilient to disturbance from fire, areas where warm permafrost conditions exist that may be most vulnerable to future change, and also areas where permafrost has thawed. High-resolution geophysical data corroborate remote sensing interpretations of near-surface permafrost and also add new high-fidelity details of spatial heterogeneity that extend from the shallow subsurface to depths of about 10 m. Results show that postfire impacts on permafrost can be variable and depend on multiple factors such as fire severity, soil texture, soil moisture, and time since fire.

  15. The Global Terrestrial Network for Permafrost Database: metadata statistics and prospective analysis on future permafrost temperature and active layer depth monitoring site distribution

    Science.gov (United States)

    Biskaborn, B. K.; Lanckman, J.-P.; Lantuit, H.; Elger, K.; Streletskiy, D. A.; Cable, W. L.; Romanovsky, V. E.

    2015-03-01

    The Global Terrestrial Network for Permafrost (GTN-P) provides the first dynamic database associated with the Thermal State of Permafrost (TSP) and the Circumpolar Active Layer Monitoring (CALM) programs, which extensively collect permafrost temperature and active layer thickness data from Arctic, Antarctic and Mountain permafrost regions. The purpose of the database is to establish an "early warning system" for the consequences of climate change in permafrost regions and to provide standardized thermal permafrost data to global models. In this paper we perform statistical analysis of the GTN-P metadata aiming to identify the spatial gaps in the GTN-P site distribution in relation to climate-effective environmental parameters. We describe the concept and structure of the Data Management System in regard to user operability, data transfer and data policy. We outline data sources and data processing including quality control strategies. Assessment of the metadata and data quality reveals 63% metadata completeness at active layer sites and 50% metadata completeness for boreholes. Voronoi Tessellation Analysis on the spatial sample distribution of boreholes and active layer measurement sites quantifies the distribution inhomogeneity and provides potential locations of additional permafrost research sites to improve the representativeness of thermal monitoring across areas underlain by permafrost. The depth distribution of the boreholes reveals that 73% are shallower than 25 m and 27% are deeper, reaching a maximum of 1 km depth. Comparison of the GTN-P site distribution with permafrost zones, soil organic carbon contents and vegetation types exhibits different local to regional monitoring situations on maps. Preferential slope orientation at the sites most likely causes a bias in the temperature monitoring and should be taken into account when using the data for global models. The distribution of GTN-P sites within zones of projected temperature change show a high

  16. Ellbogen- und Handgelenksendoprothetik beim Rheumatiker - Richtlinien und Rehabilitation

    Directory of Open Access Journals (Sweden)

    Chochole M

    2008-01-01

    Full Text Available Die Endoprothetik an Ellbogen und Handgelenk ist seit etwa drei Jahrzehnten etabliert. An beiden Gelenken haben sich einzelne Implantate oder Designs durchgesetzt. Operationstechniken und Nachuntersuchungsergebnisse sind publiziert. Wenig ist jedoch zum Thema Nachbehandlung und Nachsorge veröffentlicht. Diese Arbeit beschäftigt sich detailliert mit der ärztlichen und therapeutischen Betreuung nach Implantation einer Ellbogen- oder Handgelenksendoprothese beim Patienten mit rheumatischer Arthritis unter Aufgliederung in Krankenhausaufenthalt, ambulanter Nachsorge sowie stationärer Rehabilitation. Dabei werden Zeitrahmen, Therapieziele und Behandlungen gesondert angeführt.

  17. International Field School on Permafrost, Polar Urals, 2012

    Science.gov (United States)

    Streletskiy, D. A.; Grebenets, V.; Ivanov, M.; Sheinkman, V.; Shiklomanov, N. I.; Shmelev, D.

    2012-12-01

    The international field school on permafrost was held in the Polar Urals region from June, 30 to July 9, 2012 right after the Tenth International Conference on Permafrost which was held in Salekhard, Russia. The travel and accommodation support generously provided by government of Yamal-Nenets Autonomous Region allowed participation of 150 permafrost young research scientists, out of which 35 students from seven countries participated in the field school. The field school was organized under umbrella of International Permafrost Association and Permafrost Young Research Network. The students represented diverse educational backgrounds including hydrologists, engineers, geologists, soil scientists, geocryologists, glaciologists and geomorphologists. The base school camp was located near the Harp settlement in the vicinity of Polar Urals foothills. This unique location presented an opportunity to study a diversity of cryogenic processes and permafrost conditions characteristic for mountain and plain regions as well as transition between glacial and periglacial environments. A series of excursions was organized according to the following topics: structural geology of the Polar Urals and West Siberian Plain (Chromite mine "Centralnaya" and Core Storage in Labitnangy city); quaternary geomorphology (investigation of moraine complexes and glacial conditions of Ronamantikov and Topographov glaciers); principles of construction and maintains of structures built on permafrost (Labitnangy city and Obskaya-Bovanenkovo Railroad); methods of temperature and active-layer monitoring in tundra and forest-tundra; cryosols and soil formation in diverse landscape condition; periglacial geomorphology; types of ground ice, etc. Every evening students and professors gave a series of presentations on climate, vegetation, hydrology, soil conditions, permafrost and cryogenic processes of the region as well as on history, economic development, endogenous population of the Siberia and the

  18. Diagnostic and model dependent uncertainty of simulated Tibetan permafrost area

    Science.gov (United States)

    Wang, A.; Moore, J.C.; Cui, Xingquan; Ji, D.; Li, Q.; Zhang, N.; Wang, C.; Zhang, S.; Lawrence, D.M.; McGuire, A.D.; Zhang, W.; Delire, C.; Koven, C.; Saito, K.; MacDougall, A.; Burke, E.; Decharme, B.

    2016-01-01

     We perform a land-surface model intercomparison to investigate how the simulation of permafrost area on the Tibetan Plateau (TP) varies among six modern stand-alone land-surface models (CLM4.5, CoLM, ISBA, JULES, LPJ-GUESS, UVic). We also examine the variability in simulated permafrost area and distribution introduced by five different methods of diagnosing permafrost (from modeled monthly ground temperature, mean annual ground and air temperatures, air and surface frost indexes). There is good agreement (99 to 135  ×  104 km2) between the two diagnostic methods based on air temperature which are also consistent with the observation-based estimate of actual permafrost area (101  × 104 km2). However the uncertainty (1 to 128  ×  104 km2) using the three methods that require simulation of ground temperature is much greater. Moreover simulated permafrost distribution on the TP is generally only fair to poor for these three methods (diagnosis of permafrost from monthly, and mean annual ground temperature, and surface frost index), while permafrost distribution using air-temperature-based methods is generally good. Model evaluation at field sites highlights specific problems in process simulations likely related to soil texture specification, vegetation types and snow cover. Models are particularly poor at simulating permafrost distribution using the definition that soil temperature remains at or below 0 °C for 24 consecutive months, which requires reliable simulation of both mean annual ground temperatures and seasonal cycle, and hence is relatively demanding. Although models can produce better permafrost maps using mean annual ground temperature and surface frost index, analysis of simulated soil temperature profiles reveals substantial biases. The current generation of land-surface models need to reduce biases in simulated soil temperature profiles before reliable contemporary permafrost maps and predictions of changes in future

  19. Editorial: Computerspiele und Videogames in formellen und informellen Bildungskontexten

    Directory of Open Access Journals (Sweden)

    Johannes Fromme

    2008-01-01

    Full Text Available Computer- und Videospiele sind heute ein selbstverständlicher Bestandteil der Lebenswelt vieler Kinder und Jugendlicher, aber auch von (jüngeren Erwachsenen, die mit diesen neuen Medien aufgewachsen sind. Lange Zeit haben elektronische Bildschirmspiele allenfalls sporadische Beachtung gefunden. Weder in der Medienforschung oder Medienpädagogik noch in der breiteren Öffentlichkeit waren sie ein Gegenstand von breiterem Interesse.* In den letzten knapp zehn Jahren sind Video- und Computerspiele allerdings zunehmend in den Fokus der Aufmerksamkeit gerückt. Dabei sind in der massenmedial vermittelten Öffentlichkeit vor allem Amokläufe in Schulen in einen direkten Zusammenhang mit den Vorlieben (der Täter für bestimmte Computerspiele gebracht worden. Die auch von prominenten Politikern aufgegriffene These lautete, dass gewalthaltige Spiele wie der First Person Shooter «Counterstrike» ein virtuelles Trainingsprogramm für das Töten und daher als wesentliche Ursache solcher Schulmassaker anzusehen seien. Auf der Basis dieser kausalen Wirkungsannahmen bzw. der unterstellten negativen Lern- und Trainingseffekte werden seither immer wieder Forderungen nach einem Verbot solcher «Killerspiele» oder gar nach der Verbannung aller Bildschirmmedien aus den Kinderzimmern abgeleitet. Neben solcher skandalisierter Thematisierung ist aber zunehmend auch eine nüchterne wissenschaftliche Auseinandersetzung zu konstatieren. So haben sich seit Beginn des neuen Jahrtausends die «digital game studies» als interdisziplinäres Forschungsfeld etabliert. Im Jahr 2000 wurde innerhalb der Gesellschaft für Medienwissenschaft z.B. die AG Games gebildet, die sich zu einem wichtigen deutschsprachigen Forum für die wissenschaftliche Beschäftigung mit Computerspielen entwickelt hat, und im Jahr 2002 entstand die internationale Digital Games Research Association (DiGRA, die im September 2009 ihre vierte grosse Konferenz nach 2003, 2005 und 2007 durchgeführt hat

  20. Tundra permafrost thaw causes significant shifts in energy partitioning

    Directory of Open Access Journals (Sweden)

    Christian Stiegler

    2016-04-01

    Full Text Available Permafrost, a key component of the arctic and global climate system, is highly sensitive to climate change. Observed and ongoing permafrost degradation influences arctic hydrology, ecology and biogeochemistry, and models predict that rapid warming is expected to significantly reduce near-surface permafrost and seasonally frozen ground during the 21st century. These changes raise concern of how permafrost thaw affects the exchange of water and energy with the atmosphere. However, associated impacts of permafrost thaw on the surface energy balance and possible feedbacks on the climate system are largely unknown. In this study, we show that in northern subarctic Sweden, permafrost thaw and related degradation of peat plateaus significantly change the surface energy balance of three peatland complexes by enhancing latent heat flux and, to less degree, also ground heat flux at the cost of sensible heat flux. This effect is valid at all radiation levels but more pronounced at higher radiation levels. The observed differences in flux partitioning mainly result from the strong coupling between soil moisture availability, vegetation composition, albedo and surface structure. Our results suggest that ongoing and predicted permafrost degradation in northern subarctic Sweden ultimately result in changes in land–atmosphere coupling due to changes in the partitioning between latent and sensible heat fluxes. This in turn has crucial implications for how predictive climate models for the Arctic are further developed.

  1. Computing a ground appropriateness index for route selection in permafrost regions

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2017-10-01

    Full Text Available The reasonable calculation of ground appropriateness index in permafrost region is the precondition of highway route design in permafrost region. The theory of knowledge base and fuzzy mathematics are applied, and the damage effect of permafrost is considered in the paper. Based on the idea of protecting permafrost the calculation method of ground appropriateness index is put forward. Firstly, based on the actual environment conditions, the paper determines the factors affecting the road layout in permafrost areas by qualitative and quantitative analysis, including the annual slope, the average annual ground temperature of permafrost, the amount of ice in frozen soil, and the interference engineering. Secondly, based on the knowledge base theory and the use of Delphi method, the paper establishes the knowledge base, the rule base of the permafrost region and inference mechanism. The method of selecting the road in permafrost region is completed and realized by using the software platform. Thirdly, taking the Tuotuo River to Kaixin Mountain section of permafrost region as an example, the application of the method is studied by using an ArcGIS platform. Results show that the route plan determined by the method of selecting the road in permafrost region can avoid the high temperature and high ice content area, conform the terrain changes and evade the heat disturbance among the existing projects. A reasonable route plan can be achieved, and it can provide the basis for the next engineering construction.

  2. Nationale und transnationale Vernetzung polnischer Städte und Regionen: Auf dem Weg zu einer nachhaltigen Stadt- und Regionalentwicklung

    OpenAIRE

    Dorsch, Pamela

    2003-01-01

    "Die Studie 'Nationale und transnationale Vernetzung polnischer Städte und Regionen - Bedeutung für eine nachhaltige Stadt- und Regionalentwicklung' liefert einen Überblick über die Einbindung polnischer Kommunen und Wojewodschaften in allgemeine und politikfeldspezifische Netzwerke auf nationaler und transnationaler Ebene. Besondere Berücksichtigung findet hierbei die Vernetzung in Fragen von Nachhaltigkeit und des Umweltschutzes. Einführend zeigt die Studie den Prozess zunehmender Dezentral...

  3. Impact of physical permafrost processes on hydrological change

    Science.gov (United States)

    Hagemann, Stefan; Blome, Tanja; Beer, Christian; Ekici, Altug

    2015-04-01

    Permafrost or perennially frozen ground is an important part of the terrestrial cryosphere; roughly one quarter of Earth's land surface is underlain by permafrost. As it is a thermal phenomenon, its characteristics are highly dependent on climatic factors. The impact of the currently observed warming, which is projected to persist during the coming decades due to anthropogenic CO2 input, certainly has effects for the vast permafrost areas of the high northern latitudes. The quantification of these effects, however, is scientifically still an open question. This is partly due to the complexity of the system, where several feedbacks are interacting between land and atmosphere, sometimes counterbalancing each other. Moreover, until recently, many global circulation models (GCMs) and Earth system models (ESMs) lacked the sufficient representation of permafrost physics in their land surface schemes. Within the European Union FP7 project PAGE21, the land surface scheme JSBACH of the Max-Planck-Institute for Meteorology ESM (MPI-ESM) has been equipped with the representation of relevant physical processes for permafrost studies. These processes include the effects of freezing and thawing of soil water for both energy and water cycles, thermal properties depending on soil water and ice contents, and soil moisture movement being influenced by the presence of soil ice. In the present study, it will be analysed how these permafrost relevant processes impact projected hydrological changes over northern hemisphere high latitude land areas. For this analysis, the atmosphere-land part of MPI-ESM, ECHAM6-JSBACH, is driven by prescribed SST and sea ice in an AMIP2-type setup with and without the newly implemented permafrost processes. Observed SST and sea ice for 1979-1999 are used to consider induced changes in the simulated hydrological cycle. In addition, simulated SST and sea ice are taken from a MPI-ESM simulation conducted for CMIP5 following the RCP8.5 scenario. The

  4. E-Government und E-Banking: Aktueller Stand, Evaluation und Erfolgsfaktoren

    OpenAIRE

    Bayer, Tobias

    2002-01-01

    Zu Max Webers Zeiten entsprach die Bürokratie noch ganz dem Vorbild des preussischen Militärs " klare Hierarchien und klare Aufgabenbereiche schlugen sich nieder in Effizienz und Effektivität. Heute ist das Bild getrübt und Worte wie "Erstarrung", "Überreglementierung" und "Verwaltungskultur" machen die Runde. Neben den gestiegenen Erwartungen der Bürger, die sich in Zeiten des E-Banking und E-Commerce nicht mehr in lange Warteschlangen einreihen wollen und auf die rigiden Öffnungszeiten der ...

  5. The long-term fate of permafrost peatlands under rapid climate warming

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal

    2015-01-01

    Permafrost peatlands contain globally important amounts of soil organic carbon, owing to cold conditions which suppress anaerobic decomposition. However, climate warming and permafrost thaw threaten the stability of this carbon store. The ultimate fate of permafrost peatlands and their carbon...... stores is unclear because of complex feedbacks between peat accumulation, hydrology and vegetation. Field monitoring campaigns only span the last few decades and therefore provide an incomplete picture of permafrost peatland response to recent rapid warming. Here we use a high-resolution palaeoecological...... approach to understand the longer-term response of peatlands in contrasting states of permafrost degradation to recent rapid warming. At all sites we identify a drying trend until the late-twentieth century; however, two sites subsequently experienced a rapid shift to wetter conditions as permafrost thawed...

  6. Continuous recording of seismic signals in Alpine permafrost

    Science.gov (United States)

    Hausmann, H.; Krainer, K.; Staudinger, M.; Brückl, E.

    2009-04-01

    Over the past years various geophysical methods were applied to study the internal structure and the temporal variation of permafrost whereof seismic is of importance. For most seismic investigations in Alpine permafrost 24-channel equipment in combination with long data and trigger cables is used. Due to the harsh environment source and geophone layouts are often limited to 2D profiles. With prospect for future 3D-layouts we introduce an alternative of seismic equipment that can be used for several applications in Alpine permafrost. This study is focussed on controlled and natural source seismic experiments in Alpine permafrost using continuous data recording. With recent data from an ongoing project ("Permafrost in Austria") we will highlight the potential of the used seismic equipment for three applications: (a) seismic permafrost mapping of unconsolidated sediments, (b) seismic tomography in rock mass, and (c) passive seismic monitoring of rock falls. Single recording units (REFTEK 130, 6 channels) are used to continuously record the waveforms of both the seismic signals and a trigger signal. The combination of a small number of recording units with different types of geophones or a trigger allow numerous applications in Alpine permafrost with regard to a high efficiency and flexible seismic layouts (2D, 3D, 4D). The efficiency of the light and robust seismic equipment is achieved by the simple acquisition and the flexible and fast deployment of the (omni-directional) geophones. Further advantages are short (data and trigger) cables and the prevention of trigger errors. The processing of the data is aided by 'Seismon' which is an open source software project based on Matlab® and MySQL (see SM1.0). For active-source experiments automatic stacking of the seismic signals is implemented. For passive data a program for automatic detection of events (e.g. rock falls) is available which allows event localization. In summer 2008 the seismic equipment was used for the

  7. Dynamic response of wind turbine towers in warm permafrost

    Institute of Scientific and Technical Information of China (English)

    Benjamin Still; ZhaoHui Joey Yang; Simon Evans; FuJun Niu

    2014-01-01

    Wind is a great source of renewable energy in western Alaska. Consistent winds blow across the barren tundra underlain by warm permafrost in the winter season, when the energy demand is the highest. Foundation engineering in warm permafrost has always been a challenge in wind energy development. Degrading warm permafrost poses engineering issues to design, construction, and operation of wind turbines. This paper describes the foundation design of a wind turbine built in western Alaska. It presents a sys-tem for response monitoring and load assessment, and data collected from September 2013 to March 2014. The dynamic proper-ties are assessed based on the monitoring data, and seasonal changes in the dynamic properties of the turbine tower-foundation system and likely resonance between the spinning blades and the tower structure are discussed. These analyses of a wind turbine in warm permafrost are valuable for designing or retrofitting of foundations in warm permafrost.

  8. Assessment of three mitigation techniques for permafrost protection

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr

    The presence of permafrost is an important aspect in civil engineering in arctic regions. The construction of engineering structures, such as road and airfield embankments, will change the thermal regime of the ground, and may lead to permafrost degradation under or adjacent to such structures....... This problem, has in the last decades, been amplified by the climate warming, which has been most evident in the arctic regions. The construction of a road embankment usually results in an increased mean annual surface temperature, which will increase the thawing of permafrost and expose the road embankment...... objective has been to study the three above-mentioned techniques and evaluate their potential for minimizing the problems with thaw settlements in permafrost areas. The air convection embankment and heat drain techniques have been tested for the implementation in the shoulders of road and airfield...

  9. Sorption und Verbreitung per- und polyfluorierter Chemikalien (PFAS) in Wasser und Boden

    OpenAIRE

    Gellrich, Vanessa

    2014-01-01

    PFAS (= Perfluoroalkyl and Polyfluoroalkyl Substances) sind persistente organische Spurenstoffe, die weltweit in verschiedenen Umweltkompartimenten nachgewiesen werden konnten. Im Rahmen dieser Dissertation sollte die Frage geklärt werden, wie die physikalisch-chemischen Eigenschaften der PFAS - besonders ihre Sorption am Boden - ihr Verhalten und ihre Verbreitung in der Umwelt beeinflussen. Dazu wurde zunächst eine Messmethode entwickelt, optimiert und validiert, mit der 17 per- und polyf...

  10. Neue Laser und Strahlquellen - alte und neue Risiken?

    DEFF Research Database (Denmark)

    Paasch, Uwe; Schwandt, Antje; Seeber, Nikolaus

    2017-01-01

    Die Entwicklungen im Bereich dermatologischer Laser, hochenergetischer Blitzlampen, LED und neuer Energie- und Strahlquellen der letzten Jahre haben gezeigt, dass mit neuen Wellenlängen, Konzepten und Kombinationen zusätzliche, zum Teil über den ästhetischen Bereich hinaus gehende therapeutische ...

  11. Neue Shandite und Parkerite. Darstellung und röntgenographische Charakterisierung

    OpenAIRE

    Anusca, Irina

    2009-01-01

    Das Ziel dieser Arbeit war es, neue Verbindungen mit Shandit- und Parkeritstruktur zu darstellen und mittels röntgenographischen Methoden (Pulverdiffraktometrie und Einkristallanalyse), das thermische Verhalten durch DTA / DSC - Messungen und Elektronenmikroskopische Untersuchungen (REM, EDX) zu charakterisieren. Die vorliegende Arbeit ist wie folgt im zwei Themen gegliedert: Shandite und Parkerite. Der ersten Teil dieser Arbeit befaßt sich mit metallreichen ternären Chalkogeniden M3A2X2, ...

  12. Zoophilie in Zoologie und Roman: Sex und Liebe zwischen Mensch und Tier bei Plutarch, Plinius dem Älteren, Aelian und Apuleius

    Directory of Open Access Journals (Sweden)

    Judith Hindermann

    2011-09-01

    Full Text Available Die Bedeutung von Zoophilie in der antiken Literatur wurde bislang – mit Ausnahme des Mythos – kaum untersucht. Überblickt man die überlieferten literarischen Texte, fällt auf, dass Zoophilie ausserhalb des Mythos vor allem in zwei literarischen Gattungen auftritt : Einerseits in den zoologischen Schriften von Plutarch, Plinius dem Älteren und Aelian, andererseits im antiken Roman, d.h. in den Metamorphosen des Apuleius und im pseudo-lukianischen Onos. In diesem Beitrag soll untersucht werden, welche Funktion Zoophilie in den beiden literarischen Gattungen hat und wie die Autoren die sexuelle Praktik bewerten, die weder nach griechischem noch römischen Recht strafbar war. Da Vorstellungen über Tiere eng mit Gender und Geschlechterhierarchien verbunden sind, soll insbesondere die Frage berücksichtigt werden, inwiefern männliche und weibliche Verhaltens- und Rollenzuschreibungen bei der Darstellung zoophiler Akte wirksam werden.

  13. Die biene und ihre produkte in der kunst und im alltagsleben (Fruhchristliche und byzantinische Zeit

    Directory of Open Access Journals (Sweden)

    Liveri Angeliki

    2010-01-01

    Full Text Available Die vorliegende Arbeit ist in zwei Teile geteilt: den kunst- und kulturhistorischen Teil. Im ersten Teil werden Darstellungen uber Bienen Bienenzucht, Honig und Wachs seit der fruhchristlichen bis zur spatbyzantinischen Zeit vorgefuhrt. Daher ist es als Beitrag in der "Ikonographie" der Biene wahrend dieser Zeit zu verstehen. Im kulturhistorischen Teil werden Informationen uber die Bienenzucht, den Handel mit Honig und Wachs sowie ihre vielfaltige Anwendung von der byzantinischen Gesellschaft an Hand der primaren Quellen, des Standes der Forschung und der archaologischen Funden erwahnt. Damit ist erwunscht ein moglichst gutes Bild der byzantinischen Bienenzucht wieder zu geben und die Nutzung der Bienenprodukte in Byzanz anschaulich zu machen.

  14. Vom Stabilitäts- und Wachstumsgesetz zum Wohlstands- und Nachhaltigkeitsgesetz

    OpenAIRE

    Koll, Willi

    2016-01-01

    Das Stabilitäts- und Wachstumsgesetz wird bald 50 Jahre alt. Neue Herausforderungen erfordern eine Wirtschaftspolitik, die weit über die Ziele des Gesetzes hinausweist. Sie muss wirtschaftliches Wachstum und Stabilität mit den Zielen fiskalischer, sozialer und ökologischer Nachhaltigkeit auf nationaler und europäischer Ebene verbinden. Der Autor gibt einen Über blick über solche umfassenden Zielsysteme und leitet daraus ab, wie eine derart erweiterte wirtschaftspolitische Agenda in ein Wohlst...

  15. Review: Impacts of permafrost degradation on inorganic chemistry of surface fresh water

    Science.gov (United States)

    Colombo, Nicola; Salerno, Franco; Gruber, Stephan; Freppaz, Michele; Williams, Mark; Fratianni, Simona; Giardino, Marco

    2018-03-01

    Recent studies have shown that climate change is impacting the inorganic chemical characteristics of surface fresh water in permafrost areas and affecting aquatic ecosystems. Concentrations of major ions (e.g., Ca2 +, Mg2 +, SO42 -, NO3-) can increase following permafrost degradation with associated deepening of flow pathways and increased contributions of deep groundwater. In addition, thickening of the active layer and melting of near-surface ground ice can influence inorganic chemical fluxes from permafrost into surface water. Permafrost degradation has also the capability to modify trace element (e.g., Ni, Mn, Al, Hg, Pb) contents in surface water. Although several local and regional modifications of inorganic chemistry of surface fresh water have been attributed to permafrost degradation, a comprehensive review of the observed changes is lacking. The goal of this paper is to distil insight gained across differing permafrost settings through the identification of common patterns in previous studies, at global scale. In this review we focus on three typical permafrost configurations (pervasive permafrost degradation, thermokarst, and thawing rock glaciers) as examples and distinguish impacts on (i) major ions and (ii) trace elements. Consequences of warming climate have caused spatially-distributed progressive increases of major ion and trace element delivery to surface fresh water in both polar and mountain areas following pervasive permafrost degradation. Moreover, localised releases of major ions and trace elements to surface water due to the liberation of soluble materials sequestered in permafrost and ground ice have been found in ice-rich terrains both at high latitude (thermokarst features) and high elevation (rock glaciers). Further release of solutes and related transport to surface fresh water can be expected under warming climatic conditions. However, complex interactions among several factors able to influence the timing and magnitude of the impacts

  16. Potential remobilization of belowground permafrost carbon under future global warming

    Science.gov (United States)

    P. Kuhry; E. Dorrepaal; G. Hugelius; E.A.G. Schuur; C. Tarnocai

    2010-01-01

    Research on permafrost carbon has dramatically increased in the past few years. A new estimate of 1672 Pg C of belowground organic carbon in the northern circumpolar permafrost region more than doubles the previous value and highlights the potential role of permafrost carbon in the Earth System. Uncertainties in this new estimate remain due to relatively few available...

  17. Altautoverwertung zwischen Staat und Markt: Bedingungen und Potentiale zur Modernisierung von Lagerhaltung und Marketing gebrauchter Autoteile

    OpenAIRE

    Lucas, Rainer

    2000-01-01

    Das Arbeitspapier diskutiert vor dem Hintergrund veränderter gesetzlicher Rahmen-und Wettbewerbsbedingungen in der Autoverwertung Ziele und Maßnahmen zurStärkung kleiner und mittelständischer Verwertungsbetriebe. Der Bereich GebrauchteAutoteile wird im Rahmen eines regionalen Fallbeispiels einer tiefergehenden Analyseunterzogen. Hieraus werden Vorschläge zur regionalen Netzwerkbildung innerhalb derBranche und neue Dienstleistungsperspektiven abgeleitet. Ein wesentliches Koope-rationsfeld ist ...

  18. The transcriptional response of microbial communities in thawing Alaskan permafrost soils

    Science.gov (United States)

    Coolen, Marco J. L.; Orsi, William D.

    2015-01-01

    Thawing of permafrost soils is expected to stimulate microbial decomposition and respiration of sequestered carbon. This could, in turn, increase atmospheric concentrations of greenhouse gasses, such as carbon dioxide and methane, and create a positive feedback to climate warming. Recent metagenomic studies suggest that permafrost has a large metabolic potential for carbon processing, including pathways for fermentation and methanogenesis. Here, we performed a pilot study using ultrahigh throughput Illumina HiSeq sequencing of reverse transcribed messenger RNA to obtain a detailed overview of active metabolic pathways and responsible organisms in up to 70 cm deep permafrost soils at a moist acidic tundra location in Arctic Alaska. The transcriptional response of the permafrost microbial community was compared before and after 11 days of thaw. In general, the transcriptional profile under frozen conditions suggests a dominance of stress responses, survival strategies, and maintenance processes, whereas upon thaw a rapid enzymatic response to decomposing soil organic matter (SOM) was observed. Bacteroidetes, Firmicutes, ascomycete fungi, and methanogens were responsible for largest transcriptional response upon thaw. Transcripts indicative of heterotrophic methanogenic pathways utilizing acetate, methanol, and methylamine were found predominantly in the permafrost table after thaw. Furthermore, transcripts involved in acetogenesis were expressed exclusively after thaw suggesting that acetogenic bacteria are a potential source of acetate for acetoclastic methanogenesis in freshly thawed permafrost. Metatranscriptomics is shown here to be a useful approach for inferring the activity of permafrost microbes that has potential to improve our understanding of permafrost SOM bioavailability and biogeochemical mechanisms contributing to greenhouse gas emissions as a result of permafrost thaw. PMID:25852660

  19. The transcriptional response of microbial communities in thawing Alaskan permafrost soils

    Directory of Open Access Journals (Sweden)

    M J L Coolen

    2015-03-01

    Full Text Available Thawing of permafrost soils is expected to stimulate microbial decomposition and respiration of sequestered carbon. This could, in turn, increase atmospheric concentrations of greenhouse gases, such as carbon dioxide and methane, and create a positive feedback to climate warming. Recent metagenomic studies suggest that permafrost has a large metabolic potential for carbon processing, including pathways for fermentation and methanogenesis. Here, we performed a pilot study using ultrahigh throughput Illumina HiSeq sequencing of reverse transcribed messenger RNA to obtain a detailed overview of active metabolic pathways and responsible organisms in up to 70 cm deep permafrost soils at a moist acidic tundra location in Arctic Alaska. The transcriptional response of the permafrost microbial community was compared before and after eleven days of thaw. In general, the transcriptional profile under frozen conditions suggests a dominance of stress responses, survival strategies, and maintenance processes, whereas upon thaw a rapid enzymatic response to decomposing soil organic matter (SOM was observed. Bacteroidetes, Firmicutes, ascomycete fungi, and methanogens were responsible for largest transcriptional response upon thaw. Transcripts indicative of heterotrophic methanogenic pathways utilizing acetate, methanol, and methylamine were found predominantly in the permafrost table after thaw. Furthermore, transcripts involved in acetogenesis were expressed exclusively after thaw suggesting that acetogenic bacteria are a potential source of acetate for acetoclastic methanogenesis in freshly thawed permafrost. Metatranscriptomics is shown here to be a useful approach for inferring the activity of permafrost microbes that has potential to improve our understanding of permafrost SOM bioavailability and biogeochemical mechanisms contributing to greenhouse gas emissions as a result of permafrost thaw.

  20. Permafrost Thaw increases Emissions of Nitrous Oxide from Subarctic Peatlands

    Science.gov (United States)

    Voigt, C.; Marushchak, M. E.; Lamprecht, R. E.; Jackowicz-Korczynski, M.; Lindgren, A.; Mastepanov, M.; Christensen, T. R.; Granlund, L.; Tahvanainen, T.; Martikainen, P. J.; Biasi, C.

    2017-12-01

    Permafrost soils in the Arctic are thawing, exposing not only carbon but also large nitrogen stocks. The decomposition of this vast pool of long-term immobile C and N stocks results in the release of greenhouse gases to the atmosphere. Among these, carbon dioxide (CO2) and methane (CH4) are being studied extensively, and gaseous C release from thawing permafrost is known to be substantial. Most recent studies, however, show that Arctic soils may further be a relevant source of the strong greenhouse gas nitrous oxide (N2O). As N2O is almost 300 times more powerful in warming the climate than CO2 based on a 100-yr time horizon, the release of N2O from thawing permafrost could create a significant non-carbon permafrost-climate feedback. To study the effect of permafrost thaw on N2O fluxes, we collected peat mesocosms from a Subarctic permafrost peatland, and subjected these intact soil-plant systems to sequential thawing from the top of the active layer down to the upper permafrost layer. Measurements of N2O fluxes were coupled with detailed soil analyses and process studies. Since N2O fluxes are highly dependent on moisture conditions and vegetation cover, we applied two distinct moisture treatments (dry vs. wet) and simulated permafrost thaw in vegetated as well as in naturally bare mesocosms. Under dry conditions, permafrost thaw clearly increased N2O emissions. We observed the largest post-thaw emissions from bare peat surfaces, a typical landform in subarctic peatlands previously identified as hot spots for Arctic N2O emissions. There, permafrost thaw caused a five-fold increase in emissions (0.56 vs. 2.81 mg N2O m-2 d-1). While water-logged conditions suppressed N2O emissions, the presence of vegetation lowered, but did not prevent post-thaw N2O release. Based on these findings, we show that one fourth of the Arctic land area could be vulnerable for N2O emissions when permafrost thaws. Our results demonstrate that Arctic N2O emissions may be larger than

  1. Collaboration in Education: International Field Class on Permafrost

    Science.gov (United States)

    Streletskiy, D. A.; Shiklomanov, N. I.; Grebenets, V. I.

    2011-12-01

    Field work is a dominant research component in the earth sciences. Understanding and proper use of field methods can enhance the quality of research, while lack of understanding in acquiring data can lead to misleading interpretation of results. Early involvement in field work helps students to bridge the gap between theoretical knowledge and practical applications and to be better prepared for future jobs. However, many University curriculums lack adequate, required field methods courses. Presented are results of collaboration between the George Washington and Moscow State Universities in organization of field courses on Arctic physical and social environments. The latest field course took place in summer 2011 in the Central Siberian region and is a part of the International Permafrost Association education and outreach effort initiated during International Polar Year. The 25 day course involved fifteen Russian and US students who traveled from Moscow to Krasnoyarsk, and then along Yenisey river to Norilsk. This route was chosen as having diversity of natural conditions and variety of economic, engineering, and demographic problems associated with development. The main goal of the class was to investigate permafrost conditions of Central Siberia; dynamics of upper permafrost due to changing climate and under anthropogenic influence; and to understand factors responsible for the diversity of permafrost conditions in the region. The students and instructors were required to make presentations on a variety of topics focusing on the region or research methods, such as climate, vegetation, hydrology, history of development, economics, remote sensing, etc. The emphasis in the field was made on understanding permafrost in relation to other components of the natural system. For example, landscape conditions (including microclimatic, biogeographic and pedologic conditions) were described at every site located in natural settings. Sites located in settlements were evaluated

  2. The behaviour of petroleum spills in permafrost soils

    International Nuclear Information System (INIS)

    Biggar, K. W.; Nahir, M.

    1999-01-01

    Recent laboratory and field investigations of the migration of non-aqueous phase liquids into frozen soil dispelled the general assumption that permafrost provides an impermeable barrier, thus preventing the migration of spilled hydrocarbons into the frozen soil. In actual fact, these investigations confirm gravity-driven downward migration in the presence of air voids within the frozen soil matrix. This paper reviews the results of research on the migration of hydrocarbons into permafrost and frozen soils, and explains the mechanisms believed to be responsible for the phenomenon. To date, unfrozen portion of the pore water in permafrost, air voids in unsaturated fill installed for construction pads, and the network of fissures that develop as a result of frozen soil undergoing thermal contraction as temperature decreases, have been identified as conduits facilitating the migration of free phase petroleum hydrocarbons into permafrost or frozen soils. Each of these mechanisms and their potential impact are discussed. 4 refs., 5 figs

  3. Marktkonstitution und Regulierung der unabhängigen Film- und Fernsehproduktion : Staat, Verbände und Gewerkschaften im deutsch-britischen Vergleich

    OpenAIRE

    Elbing, Sabine; Voelzkow, Helmut

    2006-01-01

    "In einem internationalen Vergleich von Deutschland und Großbritannien wird untersucht, welche Beiträge die staatliche Politik und die Wirtschafts- und Sozialpartner (Wirtschafts- und Arbeitgeberverbände sowie Gewerkschaften) zur Förderung der unabhängigen Film- und Fernsehproduktion leisten. Es wird gezeigt, dass die britische Medienpolitik die Position der unabhängigen Film- und Fernsehproduktion gegenüber den Fernsehsendern gestärkt hat. In Deutschland hat die Medienpolitik darauf verzicht...

  4. Threshold loss of discontinuous permafrost and landscape evolution.

    Science.gov (United States)

    Chasmer, Laura; Hopkinson, Chris

    2017-07-01

    This study demonstrates linkages between the 1997/1998 El Niño/Southern Oscillation index and a threshold shift to increased permafrost loss within a southern Taiga Plains watershed, Northwest Territories, Canada. Three-dimensional contraction of permafrost plateaus and changes in vegetation structural characteristics are determined from multitemporal airborne Light Detection And Ranging (LiDAR) surveys in 2008, 2011 and 2015. Morphological changes in permafrost cover are compared with optical image analogues from 1970, 1977, 2000 and 2008 and time-series hydro-climate data. Results demonstrate that significant changes in air temperature, precipitation, runoff and a shortening of the snow-covered season by 35 days (1998-2014) and 50 days (1998 only) occurred after 1997. The albedo reduction associated with 35 and 50 days less snow cover leads to increases in shortwave energy receipt during the active thaw period of ~12% (3% annually) and ~16% (5% annually), respectively. From 2000 to 2015, sporadic permafrost loss accelerated from 0.19% (of total basin area) per year between 1970 and 2000 to 0.58% per year from 2000 to 2015, with a projected total loss of permafrost by ~2044. From ~1997 to 2011, we observe a corresponding shift to increased runoff ratio. However, observed increases in the proportion of snow precipitation and the volumetric contribution of permafrost loss to runoff post-1997 (0.6-6.4% per year) cannot fully explain this shift. This suggests increases in drainage efficiency and possible losses from long-term groundwater storage as a result of subtle terrain morphological and soil zone hydraulic conductivity changes. These hydrological changes appear coincident with high vegetation mortality at plateau margins combined with succession-related canopy growth in some bog and fen areas, which are presumed to be drying. Similar changes in runoff response were observed at adjacent Birch, Trout and Jean Marie River watersheds indicating that observations

  5. Derivation and analysis of a high-resolution estimate of global permafrost zonation

    Directory of Open Access Journals (Sweden)

    S. Gruber

    2012-02-01

    Full Text Available Permafrost underlies much of Earth's surface and interacts with climate, eco-systems and human systems. It is a complex phenomenon controlled by climate and (sub- surface properties and reacts to change with variable delay. Heterogeneity and sparse data challenge the modeling of its spatial distribution. Currently, there is no data set to adequately inform global studies of permafrost. The available data set for the Northern Hemisphere is frequently used for model evaluation, but its quality and consistency are difficult to assess. Here, a global model of permafrost extent and dataset of permafrost zonation are presented and discussed, extending earlier studies by including the Southern Hemisphere, by consistent data and methods, by attention to uncertainty and scaling. Established relationships between air temperature and the occurrence of permafrost are re-formulated into a model that is parametrized using published estimates. It is run with a high-resolution (<1 km global elevation data and air temperatures based on the NCAR-NCEP reanalysis and CRU TS 2.0. The resulting data provide more spatial detail and a consistent extrapolation to remote regions, while aggregated values resemble previous studies. The estimated uncertainties affect regional patterns and aggregate number, and provide interesting insight. The permafrost area, i.e. the actual surface area underlain by permafrost, north of 60° S is estimated to be 13–18 × 106 km2 or 9–14 % of the exposed land surface. The global permafrost area including Antarctic and sub-sea permafrost is estimated to be 16–21 × 106 km2. The global permafrost region, i.e. the exposed land surface below which some permafrost can be expected, is estimated to be 22 ± 3 × 106 km2. A large proportion of this exhibits considerable topography and spatially-discontinuous permafrost, underscoring the importance of attention to scaling issues

  6. ADAPT: building conceptual models of the physical and biological processes across permafrost landscapes

    Science.gov (United States)

    Allard, M.; Vincent, W. F.; Lemay, M.

    2012-12-01

    Fundamental and applied permafrost research is called upon in Canada in support of environmental protection, economic development and for contributing to the international efforts in understanding climatic and ecological feedbacks of permafrost thawing under a warming climate. The five year "Arctic Development and Adaptation to Permafrost in Transition" program (ADAPT) funded by NSERC brings together 14 scientists from 10 Canadian universities and involves numerous collaborators from academia, territorial and provincial governments, Inuit communities and industry. The geographical coverage of the program encompasses all of the permafrost regions of Canada. Field research at a series of sites across the country is being coordinated. A common protocol for measuring ground thermal and moisture regime, characterizing terrain conditions (vegetation, topography, surface water regime and soil organic matter contents) is being applied in order to provide inputs for designing a general model to provide an understanding of transfers of energy and matter in permafrost terrain, and the implications for biological and human systems. The ADAPT mission is to produce an 'Integrated Permafrost Systems Science' framework that will be used to help generate sustainable development and adaptation strategies for the North in the context of rapid socio-economic and climate change. ADAPT has three major objectives: to examine how changing precipitation and warming temperatures affect permafrost geosystems and ecosystems, specifically by testing hypotheses concerning the influence of the snowpack, the effects of water as a conveyor of heat, sediments, and carbon in warming permafrost terrain and the processes of permafrost decay; to interact directly with Inuit communities, the public sector and the private sector for development and adaptation to changes in permafrost environments; and to train the new generation of experts and scientists in this critical domain of research in Canada

  7. Sport und soziale Integration

    OpenAIRE

    Turan, Günes

    2012-01-01

    Sport und soziale Integration : Chancen, Probleme und Perspektiven für Städte und Kommunen ; Tagungsband der gleichnamigen Tagung am 28. und 29. Juni 2011 in Augsburg / Helmut Altenberger ... (Hrsg.). - Hamburg : Feldhaus, Ed. Czwalina, 2012. - 104 S. - (Sportwissenschaft und Sportpraxis ; 161)

  8. The long-term fate of permafrost peatlands under rapid climate warming

    Science.gov (United States)

    Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal; Watson, Elizabeth J.; Turner, T. Edward; Roland, Thomas P.; Amesbury, Matthew J.; Kokfelt, Ulla; Schoning, Kristian; Pratte, Steve; Gallego-Sala, Angela; Charman, Dan J.; Sanderson, Nicole; Garneau, Michelle; Carrivick, Jonathan L.; Woulds, Clare; Holden, Joseph; Parry, Lauren; Galloway, Jennifer M.

    2015-01-01

    Permafrost peatlands contain globally important amounts of soil organic carbon, owing to cold conditions which suppress anaerobic decomposition. However, climate warming and permafrost thaw threaten the stability of this carbon store. The ultimate fate of permafrost peatlands and their carbon stores is unclear because of complex feedbacks between peat accumulation, hydrology and vegetation. Field monitoring campaigns only span the last few decades and therefore provide an incomplete picture of permafrost peatland response to recent rapid warming. Here we use a high-resolution palaeoecological approach to understand the longer-term response of peatlands in contrasting states of permafrost degradation to recent rapid warming. At all sites we identify a drying trend until the late-twentieth century; however, two sites subsequently experienced a rapid shift to wetter conditions as permafrost thawed in response to climatic warming, culminating in collapse of the peat domes. Commonalities between study sites lead us to propose a five-phase model for permafrost peatland response to climatic warming. This model suggests a shared ecohydrological trajectory towards a common end point: inundated Arctic fen. Although carbon accumulation is rapid in such sites, saturated soil conditions are likely to cause elevated methane emissions that have implications for climate-feedback mechanisms. PMID:26647837

  9. NORPERM, the Norwegian Permafrost Database - a TSP NORWAY IPY legacy

    Science.gov (United States)

    Juliussen, H.; Christiansen, H. H.; Strand, G. S.; Iversen, S.; Midttømme, K.; Rønning, J. S.

    2010-10-01

    NORPERM, the Norwegian Permafrost Database, was developed at the Geological Survey of Norway during the International Polar Year (IPY) 2007-2009 as the main data legacy of the IPY research project Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard (TSP NORWAY). Its structural and technical design is described in this paper along with the ground temperature data infrastructure in Norway and Svalbard, focussing on the TSP NORWAY permafrost observatory installations in the North Scandinavian Permafrost Observatory and Nordenskiöld Land Permafrost Observatory, being the primary data providers of NORPERM. Further developments of the database, possibly towards a regional database for the Nordic area, are also discussed. The purpose of NORPERM is to store ground temperature data safely and in a standard format for use in future research. The IPY data policy of open, free, full and timely release of IPY data is followed, and the borehole metadata description follows the Global Terrestrial Network for Permafrost (GTN-P) standard. NORPERM is purely a temperature database, and the data is stored in a relation database management system and made publically available online through a map-based graphical user interface. The datasets include temperature time series from various depths in boreholes and from the air, snow cover, ground-surface or upper ground layer recorded by miniature temperature data-loggers, and temperature profiles with depth in boreholes obtained by occasional manual logging. All the temperature data from the TSP NORWAY research project is included in the database, totalling 32 temperature time series from boreholes, 98 time series of micrometeorological temperature conditions, and 6 temperature depth profiles obtained by manual logging in boreholes. The database content will gradually increase as data from previous and future projects are added. Links to near real-time permafrost temperatures, obtained

  10. Using Modeling Tools to Better Understand Permafrost Hydrology

    Directory of Open Access Journals (Sweden)

    Clément Fabre

    2017-06-01

    Full Text Available Modification of the hydrological cycle and, subsequently, of other global cycles is expected in Arctic watersheds owing to global change. Future climate scenarios imply widespread permafrost degradation caused by an increase in air temperature, and the expected effect on permafrost hydrology is immense. This study aims at analyzing, and quantifying the daily water transfer in the largest Arctic river system, the Yenisei River in central Siberia, Russia, partially underlain by permafrost. The semi-distributed SWAT (Soil and Water Assessment Tool hydrological model has been calibrated and validated at a daily time step in historical discharge simulations for the 2003–2014 period. The model parameters have been adjusted to embrace the hydrological features of permafrost. SWAT is shown capable to estimate water fluxes at a daily time step, especially during unfrozen periods, once are considered specific climatic and soils conditions adapted to a permafrost watershed. The model simulates average annual contribution to runoff of 263 millimeters per year (mm yr−1 distributed as 152 mm yr−1 (58% of surface runoff, 103 mm yr−1 (39% of lateral flow and 8 mm yr−1 (3% of return flow from the aquifer. These results are integrated on a reduced basin area downstream from large dams and are closer to observations than previous modeling exercises.

  11. Kommunikation und Lernen in partizipativen kulturellen und medialen Räumen

    Directory of Open Access Journals (Sweden)

    Elke Zobl

    2012-12-01

    Full Text Available Eine der interessantesten Transformationen in der Jugendkultur seit den 1990er-Jahren ist die steigende Zahl vor allem an Mädchen und jungen Frauen, die zu aktiven kulturellen Produzentinnen wurden. In diesem Artikel wird argumentiert, dass sie mit ihren eigenen kulturellen Produktionen und Netzwerken neue soziale und mediale Räume öffnen, die durch eine partizipative Kultur, selbst-organisiertes Lernen in informellen Kontexten und lokale, transnationale und virtuelle Vernetzung und Kommunikation geprägt sind. Ziel dieses Artikels ist es, das Kommunizieren und Lernen in partizipativen kulturellen (bzw. sozialen und medialen Räumen am Beispiel queer-feministischer Festivals – sogenannter „Ladyfeste“ – darzustellen und ihre Bedeutung in (medien-pädagogischen Kontexten zu diskutieren.One of the most interesting transformations in youth culture since the 1990s is the growing number of girls and young women as active cultural producers. By creating their own cultural productions and networks, this article argues, that they open up new cultural (i. e. social and media spaces which are characterized by a participatory culture, self-organised learning and local, transnational and virtual networks and communication. Taking the example of queer-feminist festivals (so called “Ladyfests”, the aim of this article is to discuss communication and learning in participatory cultural and media spaces and their meaning in the context of (media-pedagogy.

  12. Subsea Permafrost Mapped Across the U.S. Beaufort Sea Using Multichannel Seismic Data

    Science.gov (United States)

    Brothers, L.; Hart, P. E.; Ruppel, C. D.

    2011-12-01

    Circum-Arctic continental shelves at water depths less than ~100 m were subaerial permafrost prior to the onset of sea-level rise starting in the late Pleistocene. Rapid transgression and the resulting temperature increase at the sediment surface have led to thawing of the inundated permafrost, landward retreat of the leading edge of the permafrost, and dissociation of permafrost-associated gas hydrates. Past numerical modeling has shown that gas hydrate dissociation is particularly pronounced at the permafrost-to-no permafrost transition offshore. On the U.S. Beaufort margin, subsea permafrost has never been systematically mapped, and the best insights about permafrost and associated gas hydrate have been based on a limited number of offshore boreholes and numerical studies, with sometimes contrasting predictions of the permafrost's seaward extent. We bring together 5370 km of multichannel seismic (MCS) data acquired during various proprietary exploration industry and public domain government surveys between 1977 and 1992 to map a velocity anomaly diagnostic of submerged permafrost along 500 km of the US Beaufort coastline. These high-velocity (>~2.8 km/s) refractions (HVR), which are evident in prestack MCS shot records, reveal laterally continuous layers of shallow, ice-bonded, coarse-grained sediments beneath the inner continental shelf. The HVR occur in less than 5% of the tracklines, and calculated HVR depths range from 60 to 350 m below seafloor. The velocity anomaly is not observed seaward of the 20 m isobath, and is only found within 30 km of the current shoreline. These results can be used to: 1) create a map of the minimum distribution of remaining US Beaufort shelf subsea permafrost; 2) reconcile discrepancies between model-predicted and borehole-verified offshore permafrost distribution; and 3) constrain where to expect hydrate dissociation.

  13. Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by Integration of Ground-Based Geophysical Permafrost Characterization and Numerical Modeling

    Science.gov (United States)

    2015-05-01

    freeze/thaw dynamics, geophysics, ground ice, groundwater modeling, hydrologic impacts , interior Alaska, lakes, permafrost, sub-arctic, taliks, Yukon...21  Figure 4.1.1 Location map of Beaver Meadow and Twelvemile study areas...modeling, hydrologic impacts , interior Alaska, lakes, permafrost, sub-arctic, taliks, Yukon Flats Acknowledgements We would like to

  14. Soil CO2 production in upland tundra where permafrost is thawing

    Science.gov (United States)

    Hanna Lee; Edward A.G. Schuur; Jason G. Vogel

    2010-01-01

    Permafrost soils store nearly half of global soil carbon (C), and therefore permafrost thawing could lead to large amounts of greenhouse gas emissions via decomposition of soil organic matter. When ice-rich permafrost thaws, it creates a localized surface subsidence called thermokarst terrain, which changes the soil microenvironment. We used soil profile CO2...

  15. Improving Permafrost Hydrology Prediction Through Data-Model Integration

    Science.gov (United States)

    Wilson, C. J.; Andresen, C. G.; Atchley, A. L.; Bolton, W. R.; Busey, R.; Coon, E.; Charsley-Groffman, L.

    2017-12-01

    The CMIP5 Earth System Models were unable to adequately predict the fate of the 16GT of permafrost carbon in a warming climate due to poor representation of Arctic ecosystem processes. The DOE Office of Science Next Generation Ecosystem Experiment, NGEE-Arctic project aims to reduce uncertainty in the Arctic carbon cycle and its impact on the Earth's climate system by improved representation of the coupled physical, chemical and biological processes that drive how much buried carbon will be converted to CO2 and CH4, how fast this will happen, which form will dominate, and the degree to which increased plant productivity will offset increased soil carbon emissions. These processes fundamentally depend on permafrost thaw rate and its influence on surface and subsurface hydrology through thermal erosion, land subsidence and changes to groundwater flow pathways as soil, bedrock and alluvial pore ice and massive ground ice melts. LANL and its NGEE colleagues are co-developing data and models to better understand controls on permafrost degradation and improve prediction of the evolution of permafrost and its impact on Arctic hydrology. The LANL Advanced Terrestrial Simulator was built using a state of the art HPC software framework to enable the first fully coupled 3-dimensional surface-subsurface thermal-hydrology and land surface deformation simulations to simulate the evolution of the physical Arctic environment. Here we show how field data including hydrology, snow, vegetation, geochemistry and soil properties, are informing the development and application of the ATS to improve understanding of controls on permafrost stability and permafrost hydrology. The ATS is being used to inform parameterizations of complex coupled physical, ecological and biogeochemical processes for implementation in the DOE ACME land model, to better predict the role of changing Arctic hydrology on the global climate system. LA-UR-17-26566.

  16. Ausbildung und Erwartungshaltung

    Science.gov (United States)

    Knoke, Holger

    1997-09-01

    werden Geologiestudenten zeitgemäß ausgebildet? Wird in der Angewandten Geologie das gelehrt, was in Wirtschaftsunternehmen an Wissen von einem Geologen erwartet wird? Erfolgt die spezielle Ausbildung zum Hydrogeologen fundiert und umfassend? Eine Antwort auf diese Fragen kann sicherlich nicht allumfassend gegeben werden, da sie von der jeweiligen Sichtweise abhängig ist. Ein Geologieprofessor wird die Ausbildung seiner Studenten im Großen und Ganzen als zeitgemäß einstufen, eventuell hier und da Verbesserungen für möglich halten. Auffällig ist die hohe Anzahl der in den letzten Jahren bereits geänderten oder zur Änderung anstehenden Studienordnungen. Es zeigt, daß die Straffung des Studiums sowie eine zumindest teilweise neue Wichtung der Schwerpunkte notwendig war bzw. ist, wobei im allgemeinen eine höhere Stundenzahl in den Grundlagenfächern Mathematik, Physik und Chemie angesetzt wird. Betrachtet man die Gesamtstundenzahlen der alten und der reformierten Studienordnungen, kann jedoch von einer Kürzung der Pflichtstunden in den meisten Fällen nicht die Rede sein. Eine grundlegende Reform des Geologiestudiums ist zur Zeit nicht zu erkennen, eher eine Verschulung des Studienganges. Die Entwicklung scheint zur Zeit weg von der freien Kurswahl und hin zu Modulangeboten mit vorgegebenen Kursen und Reihenfolgen zu gehen. Für die Hydrogeologie-Professoren ist es sicherlich nicht einfach zu entscheiden und in ihrem Kollegenkreis durchzusetzen, was aus dem generellen geowissenschaftlichen Kursangebot für einen Hydrogeologen notwendig oder aber entbehrlich ist. Genügen die Grundlagen der Paläontologie und der Mineralogie? Kann man ganz darauf verzichten? Was erwarten Behörden und Wirtschaftsunternehmen an allgemeinen und Spezialkenntnissen? Geologische Landesämter z. B. wollen, pauschal betrachtet, Geologen alten Stils. Ist ausdrücklich ein Angewandter Geologe oder speziell ein Hydrogeologe erwünscht, soll dieser die Spezialkenntnisse zus

  17. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Letgallen. Stadt, Land und Konfession 1500-1721. 2. und 3. Teil] / Anti Selart

    Index Scriptorium Estoniae

    Selart, Anti, 1973-

    2012-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Letgallen. Stadt, Land und Konfession 1500-1721. Hrsg. von Matthias Asche, Werner Buchholz, Anton Schindling. 2. und 3. Teil.

  18. Data analysis and mapping of the mountain permafrost distribution

    Science.gov (United States)

    Deluigi, Nicola; Lambiel, Christophe; Kanevski, Mikhail

    2017-04-01

    In Alpine environments mountain permafrost is defined as a thermal state of the ground and corresponds to any lithosphere material that is at or below 0°C for, at least, two years. Its degradation is potentially leading to an increasing rock fall activity, rock glacier accelerations and an increase in the sediment transfer rates. During the last 15 years, knowledge on this phenomenon has significantly increased thanks to many studies and monitoring projects. They revealed a spatial distribution extremely heterogeneous and complex. As a consequence, modelling the potential extent of the mountain permafrost recently became a very important task. Although existing statistical models generally offer a good overview at a regional scale, they are not always able to reproduce its strong spatial discontinuity at the micro scale. To overcome this lack, the objective of this study is to propose an alternative modelling approach using three classification algorithms belonging to statistics and machine learning: Logistic regression (LR), Support Vector Machines (SVM) and Random forests (RF). The former is a linear parametric classifier that commonly used as a benchmark classification algorithm to be employed before using more complex classifiers. Non-linear SVM is a non-parametric learning algorithm and it is a member of the so-called kernel methods. RF are an ensemble learning method based on bootstrap aggregating and offer an embedded measure of the variable importance. Permafrost evidences were selected in a 588 km2 area of the Western Swiss Alps and serve as training examples. They were mapped from field data (thermal and geoelectrical data) and ortho-image interpretation (rock glacier inventorying). The dataset was completed with environmental predictors such as altitude, mean annual air temperature, aspect, slope, potential incoming solar radiation, normalized difference vegetation index and planar, profile and combined terrain curvature indices. Aiming at predicting

  19. Mapping ice-bonded permafrost with electrical methods in Sisimiut, West Greenland

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas

    2006-01-01

    Permafrost delineation and thickness determination is of great importance in engineering related projects in arctic areas. In this paper, 2D geoelectrical measurements are applied and evaluated for permafrost mapping in an area in West Greenland. Multi-electrode resistivity profiles (MEP) have been...... collected and are compared with borehole information. It is shown that the permafrost thickness in this case is grossly overestimated by a factor of two to three. The difference between the inverted 2D resistivity sections and the borehole information is explained by macro-anisotropy due to the presence...... of horizontal ice-lenses in the frozen clay deposits. It is concluded that where the resistivity method perform well for lateral permafrost mapping, great care should be taken in evaluating permafrost thickness based on 2D resistivity profiles alone. Additional information from boreholes or other geophysical...

  20. Future permafrost conditions along environmental gradients in Zackenberg, Greenland

    DEFF Research Database (Denmark)

    Westermann, Sebastian; Elberling, Bo; Pedersen, Stine Højlund

    2015-01-01

    The future development of ground temperatures in permafrost areas is determined by a number of factors varying on different spatial and temporal scales. For sound projections of impacts of permafrost thaw, scaling procedures are of paramount importance. We present numerical simulations of present...

  1. The Role of Arctic Soils in the Permafrost – Climate Feedback

    International Nuclear Information System (INIS)

    Richter, A.

    2016-01-01

    The total organic carbon pool in arctic and boreal permafrost soils has been estimated to be about 1,760 Petagram (10"1"5 g) C, more than twice today’s atmospheric C pool and about half of the global soil carbon. A significant proportion of this C pool may be vulnerable to climate warming through permafrost thawing and subsequent decomposition by microorganisms. Thus, it has been suggested that permafrost soils may become a future source of CO_2 and CH_4 to the atmosphere and lead to a strong positive feedback to global warming (up to + 0.5 °C until 2200). I will present results from several projects that aimed at understanding the mechanisms behind the permafrost-climate feedback, by identifying the major soil organic matter (SOM) stabilization mechanisms of permafrost SOM. I will address a range of different mechanisms by which SOM can be protected from decomposition, such as unfavourable temperature and moisture regimes, physical protection by formation of organo-mineral associations and chemical recalcitrance of SOM. I will focus, however, on energy and nutrient constraints of heterotrophic microbial communities and their role in SOM decomposition. I will then show that the physiology of the tiniest organisms on Earth will ultimately determine the vulnerability of the global permafrost carbon pool and thus the global permafrost-climate feedback. (author)

  2. Human-Modified Permafrost Complexes in Urbanized Areas of the Russian North

    Science.gov (United States)

    Grebenets, V. I.; Streletskiy, D. A.

    2013-12-01

    Economic development in permafrost regions is accompanied by modification of natural geocryological conditions. Drastic landscape transformations in urbanized areas on permafrost are characterized by changes of heat and moisture exchange in permafrost - atmosphere system, and by engineering and technogenic influence upon the frozen ground, leading to alteration of its physical, thermal and mechanical properties. In northern cities this leads to overall increase of ground temperature relative to undisturbed areas and intensification of hazardous cryogenic processes in areas under engineering development, which together leads to reduction in stability of geotechnical environment. For example, deformations of structures in Norilsk district, Northern Siberia, in the last 15 years, became much more abundant than those revealed throughout the previous 50 years. About 250 large buildings in the local towns were deformed considerably due to deterioration of geocryological conditions, about 100 structures were functioning in emergency state, and almost 50 nine- and five-storey houses, built in the 1960-80s, have been recently disassembled. Increase in accident risk for various facilities (water and oil pipelines, industrial enterprises, etc.) enhances the technogenic pressure on permafrost, leading to the new milestone of changes in permafrost characteristics, i.e. to creation of 'another reality' of geocryological conditions. Social and natural factors dictate clustered spatial pattern of industrial development in permafrost regions. Cryogenic processes within the urban areas on permafrost are seldom similar with those under the natural conditions as intensity, duration and extent of the processes changes under technogenic impacts. Moreover, new cryogenic processes and phenomena may occur, which have not been typical for a given region. This makes mapping and characterization of these processes difficult task. Peculiar natural-technogenic geocryological complexes (NTGC

  3. Mediendidaktik und Wissensmanagement

    Directory of Open Access Journals (Sweden)

    Gabi Reinmann-Rothmeier

    2002-10-01

    Full Text Available Mediendidaktik und Wissensmanagement – das ist auf den ersten Blick ein ungleiches Paar: Die Mediendidaktik ist eine Teildisziplin der (Medien- Pädagogik, während Wissensmanagement ein genuin wirtschaftliches Thema mit betriebswirtschaftlichen Akzenten ist. Annäherungen zwischen der Mediendidaktik und Wissensmanagement gibt es zum einen durch den sog. E-Learning-Trend seitens der Wirtschaft, der mediendidaktisches Wissen und Können auf den Plan ruft, zum anderen durch wachsendes Interesse am Thema Wissensmanagement seitens der Pädagogik. Der Beitrag beschreibt sowohl für das E-Learning als auch für das Wissensmanagement aus pädagogisch-psychologischer Sicht jeweils ein Orientierungsmodell; beide Modelle machen die Berührungspunkte zwischen Mediendidaktik und Wissensmanagement deutlich. Neben einem Überblick über wirtschaftliche Argumente für eine Verschmelzung von E-Learning und Wissensmanagement werden aufbauend auf den beiden Orientierungsmodellen theoretische und praktische Verbindungslinien zwischen E-Learning und Wissensmanagement sowie die Rolle der Mediendidaktik in dem daraus entstehenden Wechselverhältnis herausgearbeitet.

  4. Variations in Growing-Season NDVI and Its Response to Permafrost Degradation in Northeast China

    Directory of Open Access Journals (Sweden)

    Jinting Guo

    2017-04-01

    Full Text Available Permafrost is extremely sensitive to climate change. The degradation of permafrost has strong and profound effects on vegetation. The permafrost zone of northeastern China is the second largest region of permafrost in China and lies on the south edge of the Eurasian cryolithozone. This study analyzed the spatiotemporal variations of the growing-season Normalization Difference Vegetation Index (NDVI in the permafrost zone of northeastern China and analyzed the correlation between NDVI and ground surface temperatures (GST during the years 1981–2014. Mean growing-season NDVI (MGS-NDVI experienced a marked increase of 0.003 year−1 across the entire permafrost zone. The spatial dynamics of vegetation cover had a high degree of heterogeneity on a per pixel scale. The MGS-NDVI value increased significantly (5% significance level in 80.57%, and this increase was mostly distributed in permafrost zone except for the western steppe region. Only 7.72% experienced a significant decrease in NDVI, mainly in the cultivated and steppe portions. In addition, MGS-NDVI increased significantly with increasing growing-season mean ground surface temperature (GS-MGST. Our results suggest that a warming of GS-MGST (permafrost degradation in the permafrost region of northeastern China played a positive role in increasing plant growth and activities. Although increasing ground surface temperature resulted in increased vegetation cover and growth in the short time of permafrost degradation, from the long term point of view, permafrost degradation or disappearance may weaken or even hinder vegetation activities.

  5. International Permafrost Field Courses in Siberia: the Synthesis of Research and Education

    Science.gov (United States)

    Ablyazina, D.; Boitsov, A.; Grebenets, V.; Kaverin, D.; Klene, A.; Kurchatova, A.; Pfeiffer, E. M.; Zschocke, A.; Shiklomanov, N.; Streletskiy, D.

    2009-04-01

    During summers of 2007 and 2008 a series of International University Courses on Permafrost (IUCP) were conducted in West Siberia, Russia. Courses were organized as part of the International Permafrost Association (IPA) International Polar Year activities. The North of West Siberia region was selected to represent diverse permafrost, climatic and landscape conditions. The courses were jointly organized by the Moscow State University (MSU) and the Tumen' Oil and Gas University (TOGU) with the help from German and U.S. institutions. The program attracted undergraduate and graduate students with diverse interests and backgrounds from Germany, Russia and the U.S. and involved instructors specializing in different aspects of permafrost research. Courses were designed to address three major topics of permafrost-related research: a) permafrost environments characteristic of the discontinuous and continuous zones; b) field instrumentation and techniques; c) permafrost engineering and problems of development in permafrost regions. Methodologically, courses consisted of systematic permafrost investigations at long-term monitoring sites and survey-type expeditions. Systematic, process-based investigations were conducted at a network of sites which constitute the TEPO established by TOGU in collaboration with the gas company NadymGasProm. The observation complex includes an array of 30-m deep boreholes equipped with automatic data collection systems and representing characteristic permafrost landscapes of West Siberia. Boreholes are complemented by sites for snow cover, vegetation, soil, ground ice, and geomorphologic investigations. As part of student research activities, four new Circumpolar Active Layer Monitoring (CALM) sites were established in proximity to boreholes for monitoring spatial distribution and long-term dynamic of the active layer. New sites represent diverse landscapes characteristic of the West Siberian previously underrepresented in the CALM network

  6. Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils

    Science.gov (United States)

    Treat, C.C.; Jones, Miriam C.; Camill, P.; Gallego-Sala, A.; Garneau, M.; Harden, Jennifer W.; Hugelius, G.; Klein, E.S.; Kokfelt, U.; Kuhry, P.; Loisel, Julie; Mathijssen, J.H.; O'Donnell, J.A.; Oksanen, P.O.; Ronkainen, T.M.; Sannel, A.B.K.; Talbot, J. J.; Tarnocal, C.M.; Valiranta, M.

    2016-01-01

    Permafrost dynamics play an important role in high-latitude peatland carbon balance and are key to understanding the future response of soil carbon stocks. Permafrost aggradation can control the magnitude of the carbon feedback in peatlands through effects on peat properties. We compiled peatland plant macrofossil records for the northern permafrost zone (515 cores from 280 sites) and classified samples by vegetation type and environmental class (fen, bog, tundra and boreal permafrost, and thawed permafrost). We examined differences in peat properties (bulk density, carbon (C), nitrogen (N) and organic matter content, and C/N ratio) and C accumulation rates among vegetation types and environmental classes. Consequences of permafrost aggradation differed between boreal and tundra biomes, including differences in vegetation composition, C/N ratios, and N content. The vegetation composition of tundra permafrost peatlands was similar to permafrost-free fens, while boreal permafrost peatlands more closely resembled permafrost-free bogs. Nitrogen content in boreal permafrost and thawed permafrost peatlands was significantly lower than in permafrost-free bogs despite similar vegetation types (0.9% versus 1.5% N). Median long-term C accumulation rates were higher in fens (23 g C m−2 yr−1) than in permafrost-free bogs (18 g C m−2 yr−1) and were lowest in boreal permafrost peatlands (14 g C m−2 yr−1). The plant macrofossil record demonstrated transitions from fens to bogs to permafrost peatlands, bogs to fens, permafrost aggradation within fens, and permafrost thaw and reaggradation. Using data synthesis, we have identified predominant peatland successional pathways, changes in vegetation type, peat properties, and C accumulation rates associated with permafrost aggradation.

  7. Multi-omics of permafrost, active layer and thermokarst bog soil microbiomes.

    Science.gov (United States)

    Hultman, Jenni; Waldrop, Mark P; Mackelprang, Rachel; David, Maude M; McFarland, Jack; Blazewicz, Steven J; Harden, Jennifer; Turetsky, Merritt R; McGuire, A David; Shah, Manesh B; VerBerkmoes, Nathan C; Lee, Lang Ho; Mavrommatis, Kostas; Jansson, Janet K

    2015-05-14

    Over 20% of Earth's terrestrial surface is underlain by permafrost with vast stores of carbon that, once thawed, may represent the largest future transfer of carbon from the biosphere to the atmosphere. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing, permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils and a rapid shift in functional gene composition during short-term thaw experiments. However, the fate of permafrost carbon depends on climatic, hydrological and microbial responses to thaw at decadal scales. Here we use the combination of several molecular 'omics' approaches to determine the phylogenetic composition of the microbial communities, including several draft genomes of novel species, their functional potential and activity in soils representing different states of thaw: intact permafrost, seasonally thawed active layer and thermokarst bog. The multi-omics strategy reveals a good correlation of process rates to omics data for dominant processes, such as methanogenesis in the bog, as well as novel survival strategies for potentially active microbes in permafrost.

  8. Modeling sub-sea permafrost in the East Siberian Arctic Shelf: the Dmitry Laptev Strait

    International Nuclear Information System (INIS)

    Nicolsky, D; Shakhova, N

    2010-01-01

    The present state of sub-sea permafrost modeling does not agree with certain observational data on the permafrost state within the East Siberian Arctic Shelf. This suggests a need to consider other mechanisms of permafrost destabilization after the recent ocean transgression. We propose development of open taliks wherever thaw lakes and river paleo-valleys were submerged shelf-wide as a possible mechanism for the degradation of sub-sea permafrost. To test the hypothesis we performed numerical modeling of permafrost dynamics in the Dmitry Laptev Strait area. We achieved sufficient agreement with the observed distribution of thawed and frozen layers to suggest that the proposed mechanism of permafrost destabilization is plausible.

  9. Quantifying shallow and deep permafrost changes using radar remote sensing

    Science.gov (United States)

    Teshebaeva, K.; van Huissteden, K. J.

    2017-12-01

    Widespread thawing of permafrost in the northern Eurasian continent cause severe problems for infrastructure and global climate. Permafrost thaw by climate warming creates land surface instability, resulting in severe problems for infrastructure, and release of organic matter to the atmosphere as CO2 and CH4. Recent discoveries of CH4 seeps in lakes, in the Arctic Ocean, and CH4 emitting craters in the permafrost. These features indicate that permafrost destabilization might no longer be a surface feature only, but that also deeper layers of the permafrost, up to tens of meters, may be affected by warming. We study two potential areas in Siberian arctic; one of the test site is the Kytalyk research station near Chokurdagh town affected with a recent inundation of the Indigirka river in July 2017, which resulted in standing surface water for the period over a month. The wet soil and standing water may cause changes in active layer thickness and influence the thermal regime of the permafrost for the next decades in the region. The second test site is Yamal peninsula with recently CH4 emitting craters, which may start to contribute to emission hotspots. We hypothesize that these deeper subsurface processes also can be detected by mapping surface elevation changes using advanced SAR techniques. We test the potential of SAR imagery to enhance detection of these features, including surface movement related to permafrost active layer changes using InSAR time-series analysis. We also apply radar backscatter signal to detect seasonal changes related to the freeze-thaw cycles. The PRISM elevation data are used to estimate elevation changes in the region along with ground-based geophysical and geodetical fieldwork.

  10. Estimating Rates of Permafrost Degradation and their Impact on Ecosystems across Alaska and Northwest Canada using the Process-based Permafrost Dynamics Model GIPL as a Component of the Integrated Ecosystem Model (IEM)

    Science.gov (United States)

    Marchenko, S. S.; Genet, H.; Euskirchen, E. S.; Breen, A. L.; McGuire, A. D.; Rupp, S. T.; Romanovsky, V. E.; Bolton, W. R.; Walsh, J. E.

    2016-12-01

    The impact of climate warming on permafrost and the potential of climate feedbacks resulting from permafrost thawing have recently received a great deal of attention. Permafrost temperature has increased in most locations in the Arctic and Sub-Arctic during the past 30-40 years. The typical increase in permafrost temperature is 1-3°C. The process-based permafrost dynamics model GIPL developed in the Geophysical Institute Permafrost Lab, and which is the permafrost module of the Integrated Ecosystem Model (IEM) has been using to quantify the nature and rate of permafrost degradation and its impact on ecosystems, infrastructure, CO2 and CH4fluxes and net C storage following permafrost thaw across Alaska and Northwest Canada. The IEM project is a multi-institutional and multi-disciplinary effort aimed at understanding potential landscape, habitat and ecosystem change across the IEM domain. The IEM project also aims to tie three scientific models together Terrestrial Ecosystem Model (TEM), the ALFRESCO (ALaska FRame-based EcoSystem Code) and GIPL so that they exchange data at run-time. The models produce forecasts of future fire, vegetation, organic matter, permafrost and hydrology regimes. The climate forcing data are based on the historical CRU3.1 data set for the retrospective analysis period (1901-2009) and the CMIP3 CCCMA-CGCM3.1 and MPI-ECHAM5/MPI-OM climate models for the future period (2009-2100). All data sets were downscaled to a 1 km resolution, using a differencing methodology (i.e., a delta method) and the Parameter-elevation Regressions on Independent Slopes Model (PRISM) climatology. We estimated the dynamics of permafrost temperature, active layer thickness, area occupied by permafrost, and volume of thawed soils across the IEM domain. The modeling results indicate how different types of ecosystems affect the thermal state of permafrost and its stability. Although the rate of soil warming and permafrost degradation in peatland areas are slower than

  11. The microbial diversity, distribution, and ecology of permafrost in China: a review.

    Science.gov (United States)

    Hu, Weigang; Zhang, Qi; Tian, Tian; Cheng, Guodong; An, Lizhe; Feng, Huyuan

    2015-07-01

    Permafrost in China mainly located in high-altitude areas. It represents a unique and suitable ecological niche that can be colonized by abundant microbes. Permafrost microbial community varies across geographically separated locations in China, and some lineages are novel and possible endemic. Besides, Chinese permafrost is a reservoir of functional microbial groups involved in key biogeochemical cycling processes. In future, more work is necessary to determine if these phylogenetic groups detected by DNA-based methods are part of the viable microbial community, and their functional roles and how they potentially respond to climate change. This review summaries recent studies describing microbial biodiversity found in permafrost and associated environments in China, and provides a framework for better understanding the microbial ecology of permafrost.

  12. Resilience and vulnerability of permafrost to climate change

    Science.gov (United States)

    M.Torre Jorgenson; Vladimir Romanovsky; Jennifer Harden; Yuri Shur; Jonathan O' Donnell; Edward A.G. Schuur; Mikhail Kanevskiy; Sergei. Marchenko

    2010-01-01

    The resilience and vulnerability of permafrost to climate change depends on complex interactions among topography, water, soil, vegetation, and snow, which allow permafrost to persist at mean annual air temperatures (MAATs) as high as +2 °C and degrade at MAATs as low as -20°C. To assess these interactions, we compiled existing data and tested effects of varying...

  13. Discovery of a novel methanogen prevalent in thawing permafrost.

    Science.gov (United States)

    Mondav, Rhiannon; Woodcroft, Ben J; Kim, Eun-Hae; McCalley, Carmody K; Hodgkins, Suzanne B; Crill, Patrick M; Chanton, Jeffrey; Hurst, Gregory B; VerBerkmoes, Nathan C; Saleska, Scott R; Hugenholtz, Philip; Rich, Virginia I; Tyson, Gene W

    2014-01-01

    Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Here we determine microbial community composition along a permafrost thaw gradient in northern Sweden. Partially thawed sites were frequently dominated by a single archaeal phylotype, Candidatus 'Methanoflorens stordalenmirensis' gen. nov. sp. nov., belonging to the uncultivated lineage 'Rice Cluster II' (Candidatus 'Methanoflorentaceae' fam. nov.). Metagenomic sequencing led to the recovery of its near-complete genome, revealing the genes necessary for hydrogenotrophic methanogenesis. These genes are highly expressed and methane carbon isotope data are consistent with hydrogenotrophic production of methane in the partially thawed site. In addition to permafrost wetlands, 'Methanoflorentaceae' are widespread in high methane-flux habitats suggesting that this lineage is both prevalent and a major contributor to global methane production. In thawing permafrost, Candidatus 'M. stordalenmirensis' appears to be a key mediator of methane-based positive feedback to climate warming.

  14. Adaptation to permafrost in the Canadian north: Present and future

    International Nuclear Information System (INIS)

    Woo Mingko; Rouse, W.R.; Young, K.L.; Lewkowicz, A.G.

    1993-01-01

    Human-induced climate warming is believed to be imminent, although its exact magnitude is uncertain. Such a warming will have a dramatic effect on permafrost, which underlies about half of Canada's land mass. Adaptation of the land to climatic warming will include diminution of permafrost both in lateral and vertical extent, with concomitant responses in the landscape such as development of thermokarst, slides and slumping in hilly terrain, and altering of hydrologic regimes. Since northern development has relied on special techniques that preserve permafrost to ensure foundation stability, climatic warming will demand adjustment in engineering designs for new facilities and alteration of maintenance procedures for existing facilities. Recommendations are presented for future research, both on permafrost and its linkages to climatic and other environmental factors, and on risk analyses of engineering projects

  15. Subsidence from an artificial permafrost warming experiment.

    Science.gov (United States)

    Gelvin, A.; Wagner, A. M.; Lindsey, N.; Dou, S.; Martin, E. R.; Ekblaw, I.; Ulrich, C.; James, S. R.; Freifeld, B. M.; Daley, T. M.; Saari, S.; Ajo Franklin, J. B.

    2017-12-01

    Using fiber optic sensing technologies (seismic, strain, and temperature) we installed a geophysical detection system to predict thaw subsidence in Fairbanks, Alaska, United States. Approximately 5 km of fiber optic was buried in shallow trenches (20 cm depth), in an area with discontinuous permafrost, where the top of the permafrost is approximately 4 - 4.5m below the surface. The thaw subsidence was enforced by 122 60-Watt vertical heaters installed over a 140 m2 area where seismic, strain, and temperature were continuously monitored throughout the length of the fiber. Several vertical thermistor strings were also recording ground temperatures to a depth of 10 m in parallel to the fiber optic to verify the measurements collected from the fiber optic cable. GPS, Electronic Distance Measurement (EDM) Traditional and LiDAR (Light and Detection and Ranging) scanning were used to investigate the surface subsidence. The heaters were operating for approximately a three month period starting in August, 2016. During the heating process the soil temperatures at the heater element increased from 3.5 to 45 °C at a depth of 3 - 4 m. It took approximately 7 months for the temperature at the heater elements to recover to their initial temperature. The depth to the permafrost table was deepened by about 1 m during the heating process. By the end of the active heating, the surface had subsided approximately 8 cm in the heating section where permafrost was closest to the surface. This was conclusively confirmed with GPS, EDM, and LiDAR. An additional LiDAR survey was performed about seven months after the heaters were turned off (in May 2017). A total subsidence of approximately 20 cm was measured by the end of the passive heating process. This project successfully demonstrates that this is a viable approach for simulating both deep permafrost thaw and the resulting surface subsidence.

  16. Methane production as key to the greenhouse gas budget of thawing permafrost

    Science.gov (United States)

    Knoblauch, Christian; Beer, Christian; Liebner, Susanne; Grigoriev, Mikhail N.; Pfeiffer, Eva-Maria

    2018-04-01

    Permafrost thaw liberates frozen organic carbon, which is decomposed into carbon dioxide (CO2) and methane (CH4). The release of these greenhouse gases (GHGs) forms a positive feedback to atmospheric CO2 and CH4 concentrations and accelerates climate change1,2. Current studies report a minor importance of CH4 production in water-saturated (anoxic) permafrost soils3-6 and a stronger permafrost carbon-climate feedback from drained (oxic) soils1,7. Here we show through seven-year laboratory incubations that equal amounts of CO2 and CH4 are formed in thawing permafrost under anoxic conditions after stable CH4-producing microbial communities have established. Less permafrost carbon was mineralized under anoxic conditions but more CO2-carbon equivalents (CO2-Ce) were formed than under oxic conditions when the higher global warming potential (GWP) of CH4 is taken into account8. A model of organic carbon decomposition, calibrated with the observed decomposition data, predicts a higher loss of permafrost carbon under oxic conditions (113 ± 58 g CO2-C kgC-1 (kgC, kilograms of carbon)) by 2100, but a twice as high production of CO2-Ce (241 ± 138 g CO2-Ce kgC-1) under anoxic conditions. These findings challenge the view of a stronger permafrost carbon-climate feedback from drained soils1,7 and emphasize the importance of CH4 production in thawing permafrost on climate-relevant timescales.

  17. Romanistik und gender studies

    Directory of Open Access Journals (Sweden)

    Susanne Schlünder

    2000-11-01

    Full Text Available Die beiden Bände bieten ein breites Spektrum von Beiträgen zur französischen, italienischen und spanischen Literaturwissenschaft. Gedankliche Grundlage der im einzelnen unterschiedlichen Ansätze und Zielsetzungen ist ein im Anschluß an Judith Butler gender-reflektierendes, diskursives Konzept von Geschlecht, dessen wissenschaftsgeschichtliche Herleitung und Perspektiven Renate Kroll einleitend darlegt. Die einzelnen Artikel beschäftigen sich zum einen mit literarischen Strategien, die Schriftstellerinnen vom Mittelalter bis zur Gegenwart erprobt haben, und hinterfragen dabei die Rolle weiblicher Autoren in Literaturgeschichte und Literaturgeschichtsschreibung. Zum anderen widmen sie sich den literarischen Inszenierungs- und Repräsentationsformen von Weiblichkeit und stellen darüber einen Bezug zur Lebenswelt der behandelten Autorinnen her.

  18. Grey relation projection model for evaluating permafrost environment in the Muli coal mining area, China

    Energy Technology Data Exchange (ETDEWEB)

    Wei Cao; Yu Sheng; Yinghong Qin; Jing Li; Jichun Wu [Chinese Academy of Sciences, Lanzhou (China). State Key Laboratory of Frozen Soil Engineering

    2010-12-15

    This study attempts to estimate the current stage of the permafrost environment in the Muli coal mining area, an opencast mining site in the Qinghai-Tibet plateau, China. The estimation is done by regarding this site's permafrost environment as a system which was divided into three subsystems consisting of permafrost freeze-thaw erosion sensibility, permafrost thermal stability, and permafrost ecological fragility. The subsystems were characterized with their influencing indicators, each of which was assigned with a weight according to analytic hierarchy process. The relationship between these indictors is established using an environmental evaluation model based on grey system theory. The evaluated results show that currently the normalised grey relation projection values (GRPV) of permafrost freezing-thawing erosion sensibility, permafrost thermal stability, permafrost ecological fragility and permafrost environment are 0.58 (general situation), 0.47 (bad situation), 0.63 (general situation) and 0.56 (general situation), respectively. These values imply that the permafrost environment has been deteriorated to a certain degree by human activities and potentially could be further degraded. However, at this degree, a new equilibrium could be achieved if the current environmental degradation ratio is held and if effective treatments are constructed against further damages.

  19. Influences of Moisture Regimes and Functional Plant Types on Nutrient Cycling in Permafrost Regions

    Science.gov (United States)

    McCaully, R. E.; Arendt, C. A.; Newman, B. D.; Heikoop, J. M.; Wilson, C. J.; Sevanto, S.; Wales, N. A.; Wullschleger, S.

    2017-12-01

    In the permafrost-dominated Arctic, climatic feedbacks exist between permafrost, soil moisture, functional plant type and presence of nutrients. Functional plant types present within the Arctic regulate and respond to changes in hydrologic regimes and nutrient cycling. Specifically, alders are a member of the birch family that use root nodules to fix nitrogen, which is a limiting nutrient strongly linked to fertilizing Arctic ecosystems. Previous investigations in the Seward Peninsula, AK show elevated presence of nitrate within and downslope of alder patches in degraded permafrost systems, with concentrations an order of magnitude greater than that of nitrate measured above these patches. Further observations within these degraded permafrost systems are crucial to assess whether alders are drivers of, or merely respond to, nitrate fluxes. In addition to vegetative feedbacks with nitrate supply, previous studies have also linked low moisture content to high nitrate production. Within discontinuous permafrost regions, the absence of permafrost creates well-drained regions with unsaturated soils whereas the presence of permafrost limits vertical drainage of soil-pore water creating elevated soil moisture content, which likely corresponds to lower nitrate concentrations. We investigate these feedbacks further in the Seward Peninsula, AK, through research supported by the United States Department of Energy Next Generation Ecosystem Experiment (NGEE) - Arctic. Using soil moisture and thaw depth as proxies to determine the extent of permafrost degradation, we identify areas of discontinuous permafrost over a heterogeneous landscape and collect co-located soilwater chemistry samples to highlight the complex relationships that exist between alder patches, soil moisture regimes, the presence of permafrost and available nitrate supply. Understanding the role of nitrogen in degrading permafrost systems, in the context of both vegetation present and soil moisture, is crucial

  20. Amount and timing of permafrost carbon release in response to climate warming

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Kevin; Zhang, Tingjun; Barrett, Andrew P. (National Snow and Ice Data Center, Cooperative Inst. for Research in Environmental Sciences, Univ. of Colorado at Boulder, Boulder (United States)), e-mail: kevin.schaefer@nsidc.org; Bruhwiler, Lori (National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Boulder (United States))

    2011-04-15

    The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO{sub 2} concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate.We use surface weather from three global climate models based on the moderate warming, A1B Intergovernmental Panel on Climate Change emissions scenario and the SiBCASA land surface model to estimate the strength and timing of the PCF and associated uncertainty. By 2200, we predict a 29-59% decrease in permafrost area and a 53-97 cm increase in active layer thickness. By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 +- 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO{sub 2} concentration

  1. Fossil organic matter characteristics in permafrost deposits of the northeast Siberian Arctic

    Science.gov (United States)

    Lutz Schirrmeister; Guido Grosse; Sebastian Wetterich; Pier Paul Overduin; Jens Straub; Edward A.G. Schuur; Hans-Wolfgang. Hubberton

    2011-01-01

    Permafrost deposits constitute a large organic carbon pool highly vulnerable to degradation and potential carbon release due to global warming. Permafrost sections along coastal and river bank exposures in NE Siberia were studied for organic matter (OM) characteristics and ice content. OM stored in Quaternary permafrost grew, accumulated, froze, partly decomposed, and...

  2. Interactions between Shrubs and Permafrost in the Torngat Mountains, Northern Labrador, Canada

    Science.gov (United States)

    Lewkowicz, A.; Way, R. G.; Hermanutz, L.; Trant, A.; Siegwart Collier, L.; Whitaker, D.

    2017-12-01

    Discontinuous permafrost is acutely sensitive to climate warming and vegetation dynamics. Shrub height is positively correlated with accumulation of snow in the tundra resulting in warming of the ground in winter, and greater shading and lower surface temperatures in summer. Rapid greening due to climate warming has been observed throughout northeastern Canada and particularly in the coastal mountainous terrain of the Torngat Mountains National Park. Our research examines how this shrubification in the Torngat Mountains is modifying permafrost characteristics using observations which extend over a 100 km south-north transect from the sporadic zone (Saglek, Torr Bay) to where permafrost is widespread (Nakvak Brook, Kangalaksiorvik Lake) and potentially continuous (Komaktorvik River). We use air and ground temperature monitoring, vegetation surveys, dendrochronology, frost probing and electrical resistivity tomography (ERT) to describe the complex interactions between shrub growth, geomorphology, climate and permafrost in a region where climate warming is rapidly altering the landscape. Preliminary analysis of field data shows low resistivity anomalies in the ERT profiles at some sites with thin permafrost, interpreted as unfrozen zones correlated with areas of tall shrubs (Alnus spp., Salix spp. and Betula glandulosa; ranging from prostrate to 2 m). Elsewhere, high resistivities extend to the base of the ERT profiles, indicating thicker permafrost, and no obvious impact of medium to low-prostrate shrubs (Salix spp., Betula glandulosa, Rhododendron spp., and Vaccinium spp.; up to 50 cm). Permafrost is interpreted to be present at most sites with low or prostrate shrubs, except where hydrological conditions favour warmer ground temperatures. We infer that the net impact of increasing shrub heights on the active layer and permafrost depends on antecedent ground temperatures and surficial geology. Increasing shrub heights may cause permafrost degradation at sites where

  3. Medienpädagogik und die Digitale Gesellschaft im Spannungsfeld von Regulierung und Teilhabe

    Directory of Open Access Journals (Sweden)

    Stefan Iske

    2014-12-01

    Full Text Available Vor 25 Jahren stellte Tim Berners-Lee sein Konzept eines World Wide Web (WWW vor und legte damit einen der bedeutendsten Grundsteine der digitalen Vernetzung. Was ursprünglich zum Austausch von Informationen und Daten unter Forschenden entworfen wurde, hat sich zu einem umfassenden Kultur- und Bildungsraum entwickelt und ist ein universaler und zentraler Dienst des Internet geworden. Dieser gegenwärtige Status des Internet und des World Wide Web ist der vorläufige Zwischenstand einer historischen Entwicklung, der sowohl Transformationen und Veränderungen als auch Konstanten zugrunde liegen. Nicht erst zum diesjährigen Geburtstag des World Wide Web wird deutlich, dass durch digitale und vernetzte Technologien zentrale Kategorien wie Bildung, Erziehung und Sozialisation berührt werden. Beispielhaft kann auf die aktuellen Debatten über Regulierungsmechanismen im Internet wie auch auf die Enthüllungen Edward Snowdens hingewiesen werden. Aus dem Vorangehenden lassen sich medienpädagogische Fragestellungen ableiten, die zum Beispiel die Handlungsautonomie von Subjekten sowie Möglichkeitsräume der Mitgestaltung von und Teilhabe an Gesellschaft (Winter 2012, Swertz 2014 thematisieren. Zudem sind es Fragen der Mediensozialisation und der Konstruktion von Identität in digital vernetzten Räumen (Jörissen/Marotzki 2008, die sowohl bei der Theoriebildung als auch im Rahmen medienpädagogischer Praxis eine hohe Relevanz besitzen.

  4. Thermodynamik grundlagen und technische anwendungen

    CERN Document Server

    Baehr, Hans Dieter

    2009-01-01

    Für die aktualisierte 14. Auflage des bewährten Lehrbuchs der Technischen Thermodynamik wurde das Kapitel über Wärmekraftanlagen gründlich bearbeitet und durch einen Abschnitt zur Energiewandlung ergänzt: Die Energiebedarfsstruktur von Deutschland wird erläutert, und die möglichen Energiewandlungspfade werden diskutiert. Schwerpunkt des Buches ist die ausführliche und auch dem Anfänger verständliche Darstellung der Grundlagen der Thermodynamik mit der sorgfältigen Einführung der thermodynamischen Begriffe und den fundamentalen Bilanzgleichungen für Energie, Entropie und Exergie. Die thermodynamischen Eigenschaften reiner Fluide und fluider Gemische werden eingehend erläutert. Darauf aufbauend wird die Thermodynamik der Gemische und der chemischen Reaktionen entwickelt. Auch die thermodynamischen Aspekte wichtiger energie- und verfahrenstechnischer Anwendungen werden praxisnah behandelt: - Strömungs- und Arbeitsprozesse, - thermische Stofftrennverfahren, - Verbrennungsprozesse und Verbrennungsk...

  5. Neuausrichtung und Konsolidierung

    Science.gov (United States)

    Grohmann, Heinz

    Mit der Wahl von Wolfgang Wetzel zum Vorsitzenden der Deutschen Statistischen Gesellschaft im Jahre 1972 begann eine 32jährige Ära, in der die praktische und die theoretische Statistik in einem ausgewogenen Verhältnis gepflegt wurden. Ein regelmäßiger vierjähriger Wechsel im Vorsitz stärkte die Gemeinschaft und die praktische wie die wissenschaftliche Arbeit gleichermaßen. Die jährlichen Hauptversammlungen behandelten gesellschaftlich aktuelle wie zukunftsorientierte Themen, und die Ausschüsse sowie weitere Veranstaltungen gaben Gelegenheit zur Förderung und Pflege einer Vielzahl von Arbeitsgebieten der Statistik. Darüber wird nicht nur in diesem Kapitel, sondern auch in den Teilen II und III des Bandes berichtet.

  6. Borehole permafrost data, Kumtor and Taragai Valleys, Tienshan, Kazakhstan, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset includes observations of the permafrost temperatures in the Inner Tien Shan were started in 1986 by Kazakhstan Alpine Permafrost Laboratory....

  7. Zur historischen Aufarbeitung und medialen Vermittlung der Shoah in Italien und Deutschland

    Directory of Open Access Journals (Sweden)

    Peter Kuon

    2016-03-01

    Full Text Available Claudia Müller, Patrick Ostermann und Karl-Siegbert Rehberg, Hrsg., Die Shoah in Geschichte und Erinnerung: Perspektiven medialer Vermittlung in Italien und Deutschland (Bielefeld: transcript, 2015.

  8. Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints

    Science.gov (United States)

    Ruppel, Carolyn D.; Herman, Bruce M.; Brothers, Laura L.; Hart, Patrick E.

    2016-01-01

    Borehole logging data from legacy wells directly constrain the contemporary distribution of subsea permafrost in the sedimentary section at discrete locations on the U.S. Beaufort Margin and complement recent regional analyses of exploration seismic data to delineate the permafrost's offshore extent. Most usable borehole data were acquired on a ∼500 km stretch of the margin and within 30 km of the contemporary coastline from north of Lake Teshekpuk to nearly the U.S.-Canada border. Relying primarily on deep resistivity logs that should be largely unaffected by drilling fluids and hole conditions, the analysis reveals the persistence of several hundred vertical meters of ice-bonded permafrost in nearshore wells near Prudhoe Bay and Foggy Island Bay, with less permafrost detected to the east and west. Permafrost is inferred beneath many barrier islands and in some nearshore and lagoonal (back-barrier) wells. The analysis of borehole logs confirms the offshore pattern of ice-bearing subsea permafrost distribution determined based on regional seismic analyses and reveals that ice content generally diminishes with distance from the coastline. Lacking better well distribution, it is not possible to determine the absolute seaward extent of ice-bearing permafrost, nor the distribution of permafrost beneath the present-day continental shelf at the end of the Pleistocene. However, the recovery of gas hydrate from an outer shelf well (Belcher) and previous delineation of a log signature possibly indicating gas hydrate in an inner shelf well (Hammerhead 2) imply that permafrost may once have extended across much of the shelf offshore Camden Bay.

  9. Synthese und Charakterisierung wasserfreier Seltenerdmetall-Nitrate, -Acetate und -Oxyacetate

    OpenAIRE

    Heinrichs, Christina

    2013-01-01

    Durch thermische Entwässerung der Seltenerdmetall(SE)-Nitrat-Hydrate und der SE-Acetat-Hydrate im Argon-Strom/Vakuum konnten wasserfreie SE-Nitrate und SE-Nitrat-Monohydrate bzw. wasserfreie SE-Acetate erhalten werden. Es gelang zudem, SE-Oxyacetate durch thermische Zersetzung der SE-Acetate darzustellen. Des Weiteren wurde beim Erhitzen von Praseodym-Carbonat-Hydrat ein Pr-Carbonat-Hydroxid erhalten. Die Verbindungen wurden mittels Röntgenpulverdiffraktometrie und an ausgewählten Beispielen ...

  10. Recht und Rechtssystem als globale Struktur und Medium der Verhaltensorientierung / Raul Narits

    Index Scriptorium Estoniae

    Narits, Raul, 1952-

    2008-01-01

    Äratr.: Multiple Modernität, Globalisierung der Rechtsordnung und Kommunikationsstruktur der Rechtssysteme : Internationales Symposium zur Theorie der Rechtskommunikation an der Universität Tartu im April 2006 ; II. Sonderheft Estland. Berlin, 2008, lk. 219-238. - (Rechtstheorie : Zeitschrift für Logik und Juristische Methodenlehre, Rechtsinformatik, Kommunikationsforschung, Normen- und Handlungstheorie, Soziologie und Philosophie des Rechts ; Bd. 38, 2007, H. 2/3)

  11. Microbial populations in Antarctic permafrost: biodiversity, state, age, and implication for astrobiology.

    Science.gov (United States)

    Gilichinsky, D A; Wilson, G S; Friedmann, E I; McKay, C P; Sletten, R S; Rivkina, E M; Vishnivetskaya, T A; Erokhina, L G; Ivanushkina, N E; Kochkina, G A; Shcherbakova, V A; Soina, V S; Spirina, E V; Vorobyova, E A; Fyodorov-Davydov, D G; Hallet, B; Ozerskaya, S M; Sorokovikov, V A; Laurinavichyus, K S; Shatilovich, A V; Chanton, J P; Ostroumov, V E; Tiedje, J M

    2007-04-01

    Antarctic permafrost soils have not received as much geocryological and biological study as has been devoted to the ice sheet, though the permafrost is more stable and older and inhabited by more microbes. This makes these soils potentially more informative and a more significant microbial repository than ice sheets. Due to the stability of the subsurface physicochemical regime, Antarctic permafrost is not an extreme environment but a balanced natural one. Up to 10(4) viable cells/g, whose age presumably corresponds to the longevity of the permanently frozen state of the sediments, have been isolated from Antarctic permafrost. Along with the microbes, metabolic by-products are preserved. This presumed natural cryopreservation makes it possible to observe what may be the oldest microbial communities on Earth. Here, we describe the Antarctic permafrost habitat and biodiversity and provide a model for martian ecosystems.

  12. Lexikon Schulpraxis Theorie- und Handlungswissen für Ausbildung und Unterricht

    CERN Document Server

    Homberger, Dietrich

    2003-01-01

    Das Lexikon Schulpraxis wendet sich an Lehrerinnen und Lehrer, die gezielt Fragen zu einem pädagogischen oder schulischen Sachthema klären oder ohne großen Aufwand eine knappe, präzise Information zu einem entsprechenden Stichworterhalten wollen. Die zahlreichen Querverweise ermöglichen darüber hinaus die Erschließung größerer thematischer Zusammenhänge. Insbesondere kann das Lexikon Schulpraxis von Lehrerinnen und Lehrern in der Ausbildung sowie von Berufsanfängern genutzt werden; es erschließt die Berufsfunktionen, gibt Hinweise zur Organisation und Verwaltung im Schulalltag, zu den Dienstpflichten und Vorschriften, es sichert die allgemeinen didaktischen und methodischen Grundlagen des Fachunterrichts, bietet rasche Orientierung sowie Hilfen bei der Vorbereitung und Reflexion des eigenen Unterrichts. Das Lexikon Schulpraxis hat stets das praktische Informationsinteresse eines Kollegen oder einer Kollegin im Blick. Besonders geachtet wurde auf eine verständliche Sprachgestaltung, auf erläuter...

  13. Data Integration Tool: Permafrost Data Debugging

    Science.gov (United States)

    Wilcox, H.; Schaefer, K. M.; Jafarov, E. E.; Pulsifer, P. L.; Strawhacker, C.; Yarmey, L.; Basak, R.

    2017-12-01

    We developed a Data Integration Tool (DIT) to significantly speed up the time of manual processing needed to translate inconsistent, scattered historical permafrost data into files ready to ingest directly into the Global Terrestrial Network-Permafrost (GTN-P). The United States National Science Foundation funded this project through the National Snow and Ice Data Center (NSIDC) with the GTN-P to improve permafrost data access and discovery. We leverage this data to support science research and policy decisions. DIT is a workflow manager that divides data preparation and analysis into a series of steps or operations called widgets (https://github.com/PermaData/DIT). Each widget does a specific operation, such as read, multiply by a constant, sort, plot, and write data. DIT allows the user to select and order the widgets as desired to meet their specific needs, incrementally interact with and evolve the widget workflows, and save those workflows for reproducibility. Taking ideas from visual programming found in the art and design domain, debugging and iterative design principles from software engineering, and the scientific data processing and analysis power of Fortran and Python it was written for interactive, iterative data manipulation, quality control, processing, and analysis of inconsistent data in an easily installable application. DIT was used to completely translate one dataset (133 sites) that was successfully added to GTN-P, nearly translate three datasets (270 sites), and is scheduled to translate 10 more datasets ( 1000 sites) from the legacy inactive site data holdings of the Frozen Ground Data Center (FGDC). Iterative development has provided the permafrost and wider scientific community with an extendable tool designed specifically for the iterative process of translating unruly data.

  14. Multi-decadal degradation and persistence of permafrost in the Alaska Highway corridor, northwest Canada

    International Nuclear Information System (INIS)

    James, Megan; Lewkowicz, Antoni G; Smith, Sharon L; Miceli, Christina M

    2013-01-01

    Changes in permafrost distribution in the southern discontinuous zone were evaluated by repeating a 1964 survey through part of the Alaska Highway corridor (56° N–61° N) in northwest Canada. A total of 55 sites from the original survey in northern British Columbia and southern Yukon were located using archival maps and photographs. Probing for frozen ground, manual excavations, air and ground temperature monitoring, borehole drilling and geophysical techniques were used to gather information on present-day permafrost and climatic conditions. Mean annual air temperatures have increased by 1.5–2.0 ° C since the mid-1970s and significant degradation of permafrost has occurred. Almost half of the permafrost sites along the entire transect which exhibited permafrost in 1964 do so no longer. This change is especially evident in the south where two-thirds of the formerly permafrost sites have thawed and the limit of permafrost appears to have shifted northward. The permafrost that persists is patchy, generally less than 15 m thick, has mean annual surface temperatures >0 ° C, mean ground temperatures between −0.5 and 0 ° C, is in peat or beneath a thick organic mat, and appears to have a thicker active layer than in 1964. Its persistence may relate to the latent heat requirements of thawing permafrost or to the large thermal offset of organic soils. The study demonstrates that degradation of permafrost has occurred in the margins of its distribution in the last few decades, a trend that is expected to continue as the climate warms. (letter)

  15. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen : Stadt, Land und Konfession 1500-1721. Teil 4. Hrsg. von Matthias Asche, Werner Buchholtz und Anton Schindlin

    Index Scriptorium Estoniae

    Maasing, Madis, 1984-

    2013-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen : Stadt, Land und Konfession 1500-1721. Teil 4. (Katholisches Leben und Kirchenreform im Zeitalter der Glaubensspaltung, 72). Hrsg. von Matthias Asche, Werner Buchholtz und Anton Schindling. Verlag Aschendorff. Münster 2012

  16. Changes to the Carbon and Energy fluxes in a Northern Peatland with Thawing Permafrost

    Science.gov (United States)

    Harder, S. R.; Roulet, N. T.; Crill, P. M.; Strachan, I. B.

    2017-12-01

    The maintenance of thaw of high carbon density landscapes in the permafrost region ultimately depends of how the energy balance is partitioned as temperatures and precipitation change, yet there are comparatively few energy balance studies, especially in peatlands that contain permafrost. While permafrost peatlands are currently net sinks of carbon, as Arctic temperatures rise and permafrost thaws, the future of these ecosystems and their capacity for carbon uptake is in question. Since 2012 we have been measuring the spatially integrated CO2, energy and water vapour fluxes from the Stordalen peatland (68°22'N, 19°03'E) using eddy covariance (EC). The Stordalen peatland is a heterogeneous peatland in the discontinuous permafrost zone where permafrost thaw is actively occurring, resulting in large changes to the landscape from year to year. Areas where permafrost is present are elevated by up to 1.5 m compared to the areas where permafrost has thawed causing differences in water table depth, peat temperatures, snow distribution, vegetation community and therefore in the carbon and energy fluxes. Our EC tower is located on the edge of a permafrost peat plateau (or palsa) where one fetch measures fluxes from an area underlain by permafrost and the other fetch sees the portion of the peatland where the permafrost has thawed. Within each sector, we have an array of soil temperature and water content sensors to determine the physical characteristics of each fetch. Extensive vegetation surveys (based on plant functional types or PFTs) have also been conducted to run a footprint analysis on the flux data to complete a comparative analysis of the magnitude and variability of the carbon and energy exchanges from PFT. The footprint analysis allows us to explain the difference in energy and carbon fluxes by examining the ecological, biogeochemical and physical characteristics within each footprint. We see distinctly different energy partitioning between the fetches

  17. Molekulargenetische Studie zur Verbreitung und Interaktion von PCV-2 bei Haus- und Wildschweinen

    OpenAIRE

    Bronnert, Bastian Balthasar Marcel

    2014-01-01

    Im Rahmen der vorliegenden Arbeit wurden Wild- und Hausschweingewebeproben aus den Jahren 2005 bis 2008 mittels nested PCR auf das Vorkommen von PCV-2 untersucht und die positiv getesteten Proben mittels Realtime PCR quantifiziert. Zusätzlich wurden die Proben im Institut für Pathologie der Justus-Liebig-Universität histologisch und immunhistologisch untersucht (Dissertation Hohloch). Ziel war es das Vorkommen von PCV-2 und die Häufigkeit von PCV-2 assoziierter Erkankungen bei Haus- und Wilds...

  18. Petroleum contamination movement into permafrost in the high Arctic

    International Nuclear Information System (INIS)

    Biggar, K.W.

    1997-01-01

    The extent of petroleum hydrocarbon contamination that has penetrated the active layer into the permafrost at sites where spills have occurred in Canada's Arctic was discussed. There was evidence to suggest that hydrocarbon contamination may enter the permafrost layer through gravity drainage and cap suction through fissures in the frozen soil, and perhaps by diffusion through the unfrozen water of fine-grained soils. Core samples were taken in frozen silty clay to be sectioned and analyzed for total petroleum hydrocarbons, using ultrasonic solvent extraction and gas chromatography and mass spectrometry analysis. It was concluded that it is possible for petroleum contamination in permafrost to migrate by gravity drainage down soil fissures and then diffuse into surrounding soil. 2 figs

  19. Osteoporose und Laktoseintoleranz

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2008-01-01

    Full Text Available Laktosemalabsorption oder Laktoseintoleranz ist eine symptomatische Unverträglichkeit von Milchzucker (Laktose, zumeist aufgrund einer autosomal rezessiv erblichen, irreversiblen Abnahme des Enzyms Laktase im Jugendalter, die bei etwa der Hälfte der Weltbevölkerung auftritt. Die Betroffenen meiden oft instinktiv Milch und Milchprodukte wegen der damit verbundenen Malabsorptions-Symptome. Damit scheiden diese Nahrungsmittel aber auch als Kalziumlieferanten aus und es kann zu einer Mangelversorgung des Knochens mit Kalzium und damit zu Osteoporose kommen. Da in Österreich etwa 20–25 % der Bevölkerung betroffen sind, ist diese Stoffwechselveränderung nicht zu vernachlässigen. Diagnostische und begleitende ernährungsmedizinische Maßnahmen und gegebenenfalls eine osteotrope Therapie sollten zum Erhalt der Knochenmasse eingesetzt werden.

  20. PHP und MySQL der Web-Baukasten fur Einsteiger und Individualisten

    CERN Document Server

    Damaschke, Giesbert

    2015-01-01

    Sie haben schon eigene Webseiten gebaut und mochten diese nun mit Funktionen ausstatten, fur die Sie PHP und MySQL benotigen? Giesbert Damaschke zeigt Ihnen in diesem Buch, wie Sie das schaffen. Schritt fur Schritt erlernen Sie die benotigten Programmier- und Datenbankgrundlagen - immer im Rahmen von typischen dynamischen Anwendungen. So erheben und speichern Sie zum Beispiel mit Formularen Kontaktdaten, prufen Benutzereingaben, erstellen Menus, richten einen Besucherzahler ein, verschicken E-Mails mit PHP oder entwickeln sogar einen eigenen Blog. Alle Codebeispiele werden ausfuhrlich erklart,

  1. Steuern und Governance

    Directory of Open Access Journals (Sweden)

    Eduard Müller

    2014-05-01

    Full Text Available ENGLISH: Taxation, in the modern state, has long been a mass phenomenon with an interdisciplinary outlook. On the macro level of the state, a new generation of administrative reforms has crystallized under the label “good public governance”. These reforms seek to resolve regulatory interdependence of state and non - state actors by way of cooperation and interaction. In parallel, on the micro level of businesses, “corporate governance” – voluntary compliance with legal and ethical standards – has become an increasingly important issue. With a view to tax law and tax collection, these developments open up new possibilities to raise tax compliance by means of consensual and cooperative instruments and, accordingly, address taxation as a mass phenomenon. DEUTSCH: Besteuerung ist im modernen Staat ein Massenphänomen und längst interdisziplinär ausgerichtet. Auf der Makro-Ebene des Staates hat sich unter dem Begriff Good Public Governance eine neue Generation von Staats- und Verwaltungsreformen herausgebildet, die Regelungsbeziehungen von staatlichen und nichtstaatlichen Akteuren durch Kooperationen und Interaktionen zu lösen versucht. Parallel dazu hat auf der Mikro-Ebene der Unternehmen mit dem Thema Corporate Governance die freiwillige Einhaltung von rechtlichen und ethischen Regeln an Bedeutung gewonnen. Für das Steuerrecht und den Steuervollzug resultieren aus diesen Entwicklungen neue Möglichkeiten, durch Nutzung konsens- und kooperationsorientierter Instrumente die Tax Compliance zu erhöhen und so dem Massenphänomen Besteuerung gerecht zu werden.

  2. Computerspielgewalt und Aggression: Längsschnittliche Untersuchung von Selektions- und Wirkungseffekten

    OpenAIRE

    Staude-Müller, Frithjof

    2011-01-01

    Auf Grundlage sozialkognitiver Aggressionsmodelle wurde die Beziehung zwischen Computerspielgewohnheiten und der Aggressionsneigung sowie Verzerrungen in der sozialen Informationsverarbeitung untersucht. Dazu wurden 499 Schüler/innen weiterführender Schulen (6.-8. Kl. Gymnasium, Haupt- und Realschule) in zwei Erhebungen mit einem Intervall von einem Jahr befragt. Mit hierarchischen Regressionsanalysen wurden Wirkungs- und Selektionseffekte geprüft, wobei relevante Drittvariablen (Monitoring u...

  3. [Sascha Möbius. Das Gedähtnis der Reichsstadt. Unruhen und Kriege in der lübeckischen Chronistik und Kriege und Erinnerungskultur des späten mittelalters und der frühen Neuzeit

    Index Scriptorium Estoniae

    Hormuth, Dennis

    2012-01-01

    Arvustus: Sascha Möbius. Das Gedähtnis der Reichsstadt. Unruhen und Kriege in der lübeckischen Chronistik und Kriege und Erinnerungskultur des späten mittelalters und der frühen Neuzeit. (Göttingen, 2011)

  4. CRYOLINK: Monitoring of permafrost and seasonal frost in southern Norway

    Science.gov (United States)

    Farbrot, Herman; Hipp, Tobias; Etzelmüller, Bernd; Humlum, Ole; Isaksen, Ketil; Strand Ødegârd, Rune

    2010-05-01

    The modern southern boundary for Scandinavian permafrost is located in the mountains of Southern Norway. Permafrost and seasonal frost are considered key components of the cryosphere, and the climate-permafrost relation has acquired added importance with the increasing awareness and concern of rising air temperatures. The three-year research project CRYOLINK ("Permafrost and seasonal frost in southern Norway") aims at improving knowledge on past and present ground temperatures, seasonal frost, and distribution of mountain permafrost in Southern Norway by addressing the fundamental problem of heat transfer between the atmosphere and the ground surface. Hence, several shallow boreholes have been drilled in August 2008 in three areas (Juvvass, Jetta and Tron) situated along a west-east transect. On most borehole sites air and ground temperatures are measured. Further, vertical arrays of Miniature Temperature Dataloggers (MTDs; Thermochron iBottons®) at fixed heights above the ground surface have been installed to roughly determine the snow depths at the sites, which is also indicated by digital cameras providing daily pictures of snow and weather conditions. In addition individual MTDs have been placed out to measure ground surface temperature at different aspects and snow settings. This presentation will focus on the field set up and give examples of data obtained from the sites.

  5. Distinct microbial communities in the active and permafrost layers on the Tibetan Plateau.

    Science.gov (United States)

    Chen, Yong-Liang; Deng, Ye; Ding, Jin-Zhi; Hu, Hang-Wei; Xu, Tian-Le; Li, Fei; Yang, Gui-Biao; Yang, Yuan-He

    2017-12-01

    Permafrost represents an important understudied genetic resource. Soil microorganisms play important roles in regulating biogeochemical cycles and maintaining ecosystem function. However, our knowledge of patterns and drivers of permafrost microbial communities is limited over broad geographic scales. Using high-throughput Illumina sequencing, this study compared soil bacterial, archaeal and fungal communities between the active and permafrost layers on the Tibetan Plateau. Our results indicated that microbial alpha diversity was significantly higher in the active layer than in the permafrost layer with the exception of fungal Shannon-Wiener index and Simpson's diversity index, and microbial community structures were significantly different between the two layers. Our results also revealed that environmental factors such as soil fertility (soil organic carbon, dissolved organic carbon and total nitrogen contents) were the primary drivers of the beta diversity of bacterial, archaeal and fungal communities in the active layer. In contrast, environmental variables such as the mean annual precipitation and total phosphorus played dominant roles in driving the microbial beta diversity in the permafrost layer. Spatial distance was important for predicting the bacterial and archaeal beta diversity in both the active and permafrost layers, but not for fungal communities. Collectively, these results demonstrated different driving factors of microbial beta diversity between the active layer and permafrost layer, implying that the drivers of the microbial beta diversity observed in the active layer cannot be used to predict the biogeographic patterns of the microbial beta diversity in the permafrost layer. © 2017 John Wiley & Sons Ltd.

  6. Impact of Black Dust Pollution on Permafrost Temperature Regime in Pechora Basin

    Science.gov (United States)

    Khilimonyuk, V.; Pustovoit, G.; Filatova, M.

    2011-12-01

    Pechora Coal basin locates in North- Easter part of Europe within permafrost zone. The coal mining and post processing lead to emission of black dust (BD) and pollution of Earth surface. The scale of snow pollution surrounding Vorkuta city reaches to 260 g/sq.m of dust that is about 1000 ppmm BD concentration in snow before melting period. Such a large concentration of dust reduces snow reflectivity (Warren and Wiscombe, 1980; Chýlek et al., 1983,Gorbacheva, 1984, Zender et al, 2010) and can thereby trigger albedo feedbacks. The goal of this study is to evaluate the role of dirty surface albedo in the observed changing of permafrost regime in this basin. Two key sites: Workuta (North permafrost zone) and Inta (South permafrost zone) areas were selected for this study. For each site the zoning of territory by typical conditions of permafrost formation was performed. For the selected typical landscapes 1-D vertical heat transfer model coupled with the surface radiation-thermal balance equation at topsoil was simulated. The simulation was performed for the soil profile of 20 m depth during 20 years period with periodical input data at dirty surface averaged on monthly base. The initial measured not disturbed soil temperature profile was used for assessment the soil thermal property for the given landscape and natural surface radiation-thermal balance. The annual cycle of albedo change for dirty surface was taken from experimental measurement (Gorbacheva, 1984) for both sites as the function of the distance from the dust source. The simulation results next were used for mapping the vulnerability of permafrost thermal regime due to black dust pollution. Generally the simulation results show that South permafrost zone with mean temperature of permafrost (-0.5 -0.1C) is more vulnerable to albedo change than North permafrost zone with mean temperature (-2.5 -2C) for the same order of dust impact on albedo.

  7. Von Nischen und Infrastrukturen - Herausforderungen und neue Ansätze politischer Technologien

    Directory of Open Access Journals (Sweden)

    Felix Stalder

    2011-06-01

    Full Text Available Neue Technologien aus dem aktivistischen Umfeld bieten radikale Alternativen zu kultureller Nischenbildung und zentralisierten Web 2.0-Infrastrukturen. Die sozialen und politischen Realitäten der Digitalisierung und Vernetzung sind heute von zwei konstitutiven, aber grundsätzlich unterschiedlichen, ja teilweise sogar entgegengesetzten Dynamiken geprägt. Beide stellen den Medienaktivismus vor neue Herausforderungen. Zum einen können wir ein Aufblühen neuer kultureller Nischen und horizontaler Organisationsformen beobachten. Zum anderen erleben wir gleichzeitig eine enorme Zentralisierung und Konzentration auf der Ebene der Plattformen, welche einen grossen Teil der infrastrukturellen Grundlage des Wachstum der Nischen und neuen Kooperationsmuster darstellen. Nachdem der Aufbau alternativer Infrastrukturen – Zeitschriften, TV Kanäle und Internetplattformen – in den ersten 30 Jahren medienaktivistischer Projekte eine grosse Rolle gespielt hat (Stalder 2008 sind diese Fragen in den letzten 10 Jahren etwas in den Hintergrund getreten. Denn die Komplexität der Infrastrukturen nahm stetig zu, was es immer aufwendiger machte, sie zu betreiben und die neuen, offene Plattformen, wie sie für Web 2.0 typisch sind, stellten allen - scheinbar ohne Einschränkungen - mächtige Werkzeuge zu Verfügung. Warum eine eigene Plattform betreiben, wenn grosse professionelle Anbieter das besser, sicherer und kostenfrei anbieten? Heute sind die Probleme dieser Entwicklungen aber deutlich zu erkennen. Im Folgenden werden die Herausforderungen dieser Nischenbildung, die dunkle Seite der zentralisierten Infrastrukturen sowie die darauf reagierenden, neue Entwürfe für de-zentrale Infrastrukturen skizziert.

  8. Rudolf Streinz. Meinungs- und Informationsfreiheit zwischen Ost und West / Henn-Jüri Uibopuu

    Index Scriptorium Estoniae

    Uibopuu, Henn-Jüri, 1929-2012

    1983-01-01

    Tutvustus: Streinz, Rudolf. Meinungs- und Informationsfreiheit zwischen Ost und West : Möglichkeiten und Grenzen intersystemarer völkerrechtlicher Garantien in einem systemkonstituierenden Bereich. Ebelsbach : Rolf Gremer, 1981

  9. Cyberbullying und Empathie : affektive, kognitive und medienbasierte Empathie im Kontext von Cyberbullying im Kindes- und Jugendalter

    OpenAIRE

    Pfetsch, Jan; Müller, Christin R.; Ittel, Angela

    2014-01-01

    "Bei medial vermittelter Kommunikation sinkt sowohl die Hemmschwelle für aggressive Verhaltensweisen wie Cyberbullying als auch die Wahrscheinlichkeit empathischer Reaktionen. Im Fokus der vorliegenden Studie mit 979 Schülerinnen und Schülern der 4.-8. Klassen (M=12.01, SD=1.68 Jahre, 55% weiblich) stand die Frage, ob Cyberbullies geringere Ausprägungen für affektive, kognitive und medienbasierte Empathie aufweisen als Unbeteiligte. Empathie wurde im Selbst- und Peerbericht erhoben. Hypothese...

  10. Methane emissions from permafrost thaw lakes limited by lake drainage.

    NARCIS (Netherlands)

    van Huissteden, J.; Berrittella, C.; Parmentier, F.J.W.; Mi, Y.; Maximov, T.C.; Dolman, A.J.

    2011-01-01

    Thaw lakes in permafrost areas are sources of the strong greenhouse gas methane. They develop mostly in sedimentary lowlands with permafrost and a high excess ground ice volume, resulting in large areas covered with lakes and drained thaw-lake basins (DTLBs; refs,). Their expansion is enhanced by

  11. A 20-year record (1998-2017) of permafrost, active layer and meteorological conditions at a high Arctic permafrost research site (Bayelva, Spitsbergen)

    Science.gov (United States)

    Boike, Julia; Juszak, Inge; Lange, Stephan; Chadburn, Sarah; Burke, Eleanor; Overduin, Pier Paul; Roth, Kurt; Ippisch, Olaf; Bornemann, Niko; Stern, Lielle; Gouttevin, Isabelle; Hauber, Ernst; Westermann, Sebastian

    2018-03-01

    Most permafrost is located in the Arctic, where frozen organic carbon makes it an important component of the global climate system. Despite the fact that the Arctic climate changes more rapidly than the rest of the globe, observational data density in the region is low. Permafrost thaw and carbon release to the atmosphere are a positive feedback mechanism that can exacerbate global warming. This positive feedback functions via changing land-atmosphere energy and mass exchanges. There is thus a great need to understand links between the energy balance, which can vary rapidly over hourly to annual timescales, and permafrost, which changes slowly over long time periods. This understanding thus mandates long-term observational data sets. Such a data set is available from the Bayelva site at Ny-Ålesund, Svalbard, where meteorology, energy balance components and subsurface observations have been made for the last 20 years. Additional data include a high-resolution digital elevation model (DEM) that can be used together with the snow physical information for snowpack modeling and a panchromatic image. This paper presents the data set produced so far, explains instrumentation, calibration, processing and data quality control, as well as the sources for various resulting data sets. The resulting data set is unique in the Arctic and serves as a baseline for future studies. The mean permafrost temperature is -2.8 °C, with a zero-amplitude depth at 5.5 m (2009-2017). Since the data provide observations of temporally variable parameters that mitigate energy fluxes between permafrost and atmosphere, such as snow depth and soil moisture content, they are suitable for use in integrating, calibrating and testing permafrost as a component in earth system models.The presented data are available in the Supplement for this paper (time series) and through the PANGAEA and Zenodo data portals: time series (https://doi.org/10.1594/PANGAEA.880120, https://zenodo.org/record/1139714) and

  12. The effect of petroleum spills on permafrost at CFS Alert

    International Nuclear Information System (INIS)

    Haidar, S.; Jarrett, P.

    1997-01-01

    Site investigations have been carried out at two decommissioned tank farm sites at Canadian Forces Station Alert on the northern tip of Ellesmere Island. The purpose was to study the mechanism of spilt fuel movement in frozen ground and its effects on frozen soils. The investigations consisted of sampling to depths below the permafrost table to assess vertical fuel migration, hydrocarbon pollutant concentration and water content. Results showed vertical migration of spilled fuel into permafrost. The migration was attributed to gravity drainage through interconnected air voids in fill material or movement through fissures in the soil induced by thermal contraction. Unweathered contaminants were found below the liners on top of the permafrost, believed to have been caused by holes in the liner. The entrapment of the spilled fuel may have been responsible for the enhanced vertical migration of contaminants observed at these sites. It was concluded that permafrost should not be considered as an impermeable barrier to contaminants with freezing points below 0 degree C. 4 figs

  13. Brief Communication : Future avenues for permafrost science from the perspective of early career researchers

    NARCIS (Netherlands)

    Fritz, M.; Deshpande, B. N.; Bouchard, F.; Högström, E.; Malenfant-Lepage, J.; Morgenstern, A.; Nieuwendam, A.; Oliva, M.; Paquette, M.; Rudy, A. C A; Siewert, M. B.; Sjöberg, Y.; Weege, S.

    2015-01-01

    Accelerating climate change and increased economic and environmental interests in permafrost-affected regions have resulted in an acute need for more directed permafrost research. In June 2014, 88 early career researchers convened to identify future priorities for permafrost research. This

  14. Teilchendetektoren Grundlagen und Anwendungen

    CERN Document Server

    Kolanoski, Hermann

    2016-01-01

    In diesem Buch werden die experimentellen Grundlagen von Teilchendetektoren und ihre Anwendung in Experimenten beschrieben. Die Entwicklung von Detektoren ist ein wichtiger Bestandteil der Teilchen-, Astroteilchen- und Kernphysik und gehört daher zum Handwerk des Experimentalphysikers in diesen Gebieten. Dieses umfassende Werk beinhaltet den kompletten Stoff für entsprechende Master-Module in der experimentellen Teilchenphysik, geht aber im Inhalt auch darüber hinaus. Zielgruppe sind Studierende, die sich in die Materie vertiefen möchten, aber auch Lehrende und Wissenschaftler, die das Buch zum Einstieg in das wissenschaftliche Arbeiten an Detektorentwicklungen verwenden können. Zielrichtung des Buches ist, die physikalischen Grundlagen für die Detektoren und ihrer verschiedenen Ausführungen so klar wie möglich und so tiefgehend wie nötig darzustellen. Die Breite des für die Detektorentwicklung nötigen Wissens umfasst viele Bereiche der Physik und Technik, von den Wechselwirkun...

  15. Exploring Viral Mediated Carbon Cycling in Thawing Permafrost Microbial Communities

    Science.gov (United States)

    Trubl, G. G.; Solonenko, N.; Moreno, M.; Sullivan, M. B.; Rich, V. I.

    2014-12-01

    Viruses are the most abundant biological entities on Earth and their impact on carbon cycling in permafrost habitats is poorly understood. Arctic C cycling is particularly important to interpret due to the rapid climate change occurring and the large amount of C stockpiled there (~1/3 of global soil C is stored in permafrost). Viruses of microbes (i.e. phages) play central roles in C cycling in the oceans, through cellular lysis (phage drive the largest ocean C flux about 150 Gt yr-1, dwarfing all others by >5-fold), production of associated DOC, as well as transport and expression during infection (1029 transduction events day-1). C cycling in thawing permafrost systems is critical in understanding the climate trajectory and phages may be as important for C cycling here as they are in the ocean. The thawed C may become a food source for microbes, producing CO2 and potentially CH4, both potent greenhouse gases. To address the potential role of phage in C cycling in these dynamic systems, we are examining phage from an arctic permafrost thaw gradient in northern Sweden. We have developed a protocol for successfully extracting phage from peat soils and are quantifying phage in 15 peat and 2 lake sediment cores, with the goal of sequencing viromes. Preliminary data suggest that phage are present at 109 g-1 across the permafrost thaw gradient (compared to the typical marine count ~105 ml-1), implying a potentially robust phage-host interaction web in these changing environments. We are examining phage from 11 depth intervals (covering the active and permafrost layer) in the cores to assess phage-host community dynamics. Phage morphology and abundance for each layer and environment are being determined using qTEM and EFM. Understanding the phage that infect bacteria and archaea in these rapidly changing habitats will provide insight into the controls on current and future CH4 and CO2 emissions in permafrost habitats.

  16. Aussteigen aus dem Rechtsextremismus: Foto-Praxis, bildwissenschaftliche Analyse und Ausstellungsarbeit als Methoden individueller Reflexion und des wissenschaftlichen und (sozialpädagogischen Kompetenzerwerbs

    Directory of Open Access Journals (Sweden)

    Ulrike Pilarczyk

    2013-06-01

    Full Text Available Der Beitrag zeigt die medienpädagogischen und bildwissenschaftlichen Dimensionen eines zeitlich und thematisch gestaffelten Projektes auf. Ausgangspunkt war das in den Jahren 2009/10 von der Organisation EXIT-Deutschland in Berlin mit Aussteigern/-innen aus der rechtsextremen Szene initiierte Fotoprojekt «Lebensbilder». Die im Rahmen biografisch orientierter, medien- und sozialpädagogischer Fallarbeit entstandenen Fotos wurden als Prozess individueller Bilderzeugung und als Mittel zur Reflexion der jeweiligen Lebenssituation der Aussteiger(innen verstanden und eingesetzt. Eine Ausstellung schloss diese erste Phase des hier beschriebenen Projektes ab. Dem Wunsch folgend, die praktischen Erfahrungen aus der Arbeit mit Fotos wissenschaftlich überprüfen zu lassen, wurden in den Jahren 2011 und 2012 mit Studierenden am erziehungswissenschaftlichen Institut der TU Braunschweig die «Lebensbilder» zunächst einer wissenschaftlichen Bildanalyse unterzogen und anschliessend in einem gestalterisch-interpretativen Projekt durch die Studierenden zu einer Ausstellung weiterentwickelt.

  17. Distribution of near-surface permafrost in Alaska: estimates of present and future conditions

    Science.gov (United States)

    Pastick, Neal J.; Jorgenson, M. Torre; Wylie, Bruce K.; Nield, Shawn J.; Johnson, Kristofer D.; Finley, Andrew O.

    2015-01-01

    High-latitude regions are experiencing rapid and extensive changes in ecosystem composition and function as the result of increases in average air temperature. Increasing air temperatures have led to widespread thawing and degradation of permafrost, which in turn has affected ecosystems, socioeconomics, and the carbon cycle of high latitudes. Here we overcome complex interactions among surface and subsurface conditions to map nearsurface permafrost through decision and regression tree approaches that statistically and spatially extend field observations using remotely sensed imagery, climatic data, and thematic maps of a wide range of surface and subsurface biophysical characteristics. The data fusion approach generated medium-resolution (30-m pixels) maps of near-surface (within 1 m) permafrost, active-layer thickness, and associated uncertainty estimates throughout mainland Alaska. Our calibrated models (overall test accuracy of ~85%) were used to quantify changes in permafrost distribution under varying future climate scenarios assuming no other changes in biophysical factors. Models indicate that near-surface permafrost underlies 38% of mainland Alaska and that near-surface permafrost will disappear on 16 to 24% of the landscape by the end of the 21st Century. Simulations suggest that near-surface permafrost degradation is more probable in central regions of Alaska than more northerly regions. Taken together, these results have obvious implications for potential remobilization of frozen soil carbon pools under warmer temperatures. Additionally, warmer and drier conditions may increase fire activity and severity, which may exacerbate rates of permafrost thaw and carbon remobilization relative to climate alone. The mapping of permafrost distribution across Alaska is important for land-use planning, environmental assessments, and a wide-array of geophysical studies.

  18. Groundwater controls on post-fire permafrost thaw: Water and energy balance effects

    OpenAIRE

    Rocha, Adrian; Mckenzie, Jeffrey; Lamontagne-Halle, Pierrick; Zipper, Samuel

    2018-01-01

    Fire frequency and severity is increasing in high latitude regions, with large impacts on the water and energy balances. However, the degree to which groundwater flow impacts the permafrost response to fire remains poorly understood and understudied. Here, we use the Anaktuvuk River Fire (Alaska, USA) as an archetypal example to investigate groundwater-permafrost interactions following fire. We identify key thermal and hydrologic parameters controlling permafrost and active layer response to ...

  19. Edaphic and microclimatic controls over permafrost response to fire in interior Alaska

    International Nuclear Information System (INIS)

    Nossov, Dana R; Kielland, Knut; Torre Jorgenson, M; Kanevskiy, Mikhail Z

    2013-01-01

    Discontinuous permafrost in the North American boreal forest is strongly influenced by the effects of ecological succession on the accumulation of surface organic matter, making permafrost vulnerable to degradation resulting from fire disturbance. To assess factors affecting permafrost degradation after wildfire, we compared vegetation composition and soil properties between recently burned and unburned sites across three soil landscapes (rocky uplands, silty uplands, and sandy lowlands) situated within the Yukon Flats and Yukon-Tanana Uplands in interior Alaska. Mean annual air temperatures at our study sites from 2011 to 2012 were relatively cold (−5.5 ° C) and favorable to permafrost formation. Burning of mature evergreen forests with thick moss covers caused replacement by colonizing species in severely burned areas and recovery of pre-fire understory vegetation in moderately burned areas. Surface organic layer thickness strongly affected thermal regimes and thaw depths. On average, fire caused a five-fold decrease in mean surface organic layer thickness, a doubling of water storage in the active layer, a doubling of thaw depth, an increase in soil temperature at the surface (−0.6 to +2.1 ° C) and at 1 m depth (−1.7 to +0.4 ° C), and a two-fold increase in net soil heat input. Degradation of the upper permafrost occurred at all burned sites, but differences in soil texture and moisture among soil landscapes allowed permafrost to persist beneath the active layer in the silty uplands, whereas a talik of unknown depth developed in the rocky uplands and a thin talik developed in the sandy lowlands. A changing climate and fire regime would undoubtedly influence permafrost in the boreal forest, but the patterns of degradation or stabilization would vary considerably across the discontinuous permafrost zone due to differences in microclimate, successional patterns, and soil characteristics. (letter)

  20. Informationskompetenz und Information Literacy

    OpenAIRE

    Ingold, Marianne

    2012-01-01

    Informationskompetenz ist heute als Begriff , Konzept und praktisches Tätigkeitsfeld von Bibliotheken weltweit etabliert. Entstehung, Verbreitung und Entwicklung von „Informationskompetenz“ im deutschsprachigen Raum stehen in engem Zusammenhang mit dem in den USA und international seit den 1980er Jahren diskutierten und praktisch umgesetzten Konzept der „Information Literacy“. Auch wenn die beiden Begriffe in der Regel gleichbedeutend verwendet werden, zeigt ein Vergleich der vorwiegend aus e...

  1. Quantifying Permafrost Extent, Condition, and Degradation at Department of Defense Installations in the Arctic

    Science.gov (United States)

    Edlund, C. A.

    2017-12-01

    The Department of Defense (DoD) is planning over $500M in military construction on Eielson Air Force Base (AFB) within the next three fiscal years. This construction program will expand the footprint of facilities and change the storm water management scheme, which will have second order effects on the underlying permafrost layer. These changes in permafrost will drive engineering decision making at local and regional levels, and help shape the overall strategy for military readiness in the Arctic. Although many studies have attempted to predict climate change induced permafrost degradation, very little site-specific knowledge exists on the anthropogenic effects to permafrost at this location. In 2016, the permafrost degradation rates at Eielson AFB were modeled using the Geophysics Institute Permafrost Laboratory (GIPL) 2.1 model and limited available geotechnical and climate data. Model results indicated a degradation of the discontinuous permafrost layer at Eielson AFB of up to 7 meters in depth over the next century. To further refine an understanding of the geophysics at Eielson AFB and help engineers and commanders make more informed decisions on engineering and operations in the arctic, this project established two permafrost monitoring stations near the future construction sites. Installation of the stations occurred in July 2017. Permafrost was located and characterized using two Electrical Resistivity Tomography surveys, as well as direct frost probe measurements. Using this data, the research team optimized the placement location and depth of two long term ground temperature monitoring stations, and then installed the stations for data collection. The data set generated by these stations are the first of their kind at Eielson AFB, and represent the first systematic effort in the DoD to quantify permafrost condition before, during, and after construction and other anthropogenic activities in order to fully understand the effects of that activity in the

  2. Review and synthesis: Changing permafrost in a warming world and feedbacks to the Earth System

    Science.gov (United States)

    Grosse, Guido; Goetz, Scott; McGuire, A. David; Romanovsky, Vladimir E.; Schuur, Edward A.G.

    2016-01-01

    The permafrost component of the cryosphere is changing dramatically, but the permafrost region is not well monitored and the consequences of change are not well understood. Changing permafrost interacts with ecosystems and climate on various spatial and temporal scales. The feedbacks resulting from these interactions range from local impacts on topography, hydrology, and biology to complex influences on global scale biogeochemical cycling. This review contributes to this focus issue by synthesizing its 28 multidisciplinary studies which provide field evidence, remote sensing observations, and modeling results on various scales. We synthesize study results from a diverse range of permafrost landscapes and ecosystems by reporting key observations and modeling outcomes for permafrost thaw dynamics, identifying feedbacks between permafrost and ecosystem processes, and highlighting biogeochemical feedbacks from permafrost thaw. We complete our synthesis by discussing the progress made, stressing remaining challenges and knowledge gaps, and providing an outlook on future needs and research opportunities in the study of permafrost–ecosystem–climate interactions.

  3. Dynamics of the larch taiga-permafrost coupled system in Siberia under climate change

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ningning [Graduate School of Environmental Studies, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Yasunari, Tetsuzo [Hydrospheric Atmospheric Research Center, Nagoya University, Nagoya 464-8601 (Japan); Ohta, Takeshi, E-mail: zhangningning@lasg.iap.ac.cn [Study Consortium for Earth-Life Interactive Systems (SELIS) of Nagoya University, Nagoya (Japan)

    2011-04-15

    Larch taiga, also known as Siberian boreal forest, plays an important role in global and regional water-energy-carbon (WEC) cycles and in the climate system. Recent in situ observations have suggested that larch-dominated taiga and permafrost behave as a coupled eco-climate system across a broad boreal zone of Siberia. However, neither field-based observations nor modeling experiments have clarified the synthesized dynamics of this system. Here, using a new dynamic vegetation model coupled with a permafrost model, we reveal the processes of interaction between the taiga and permafrost. The model demonstrates that under the present climate conditions in eastern Siberia, larch trees maintain permafrost by controlling the seasonal thawing of permafrost, which in turn maintains the taiga by providing sufficient water to the larch trees. The experiment without permafrost processes showed that larch would decrease in biomass and be replaced by a dominance of pine and other species that suffer drier hydroclimatic conditions. In the coupled system, fire not only plays a destructive role in the forest, but also, in some cases, preserves larch domination in forests. Climate warming sensitivity experiments show that this coupled system cannot be maintained under warming of about 2 deg. C or more. Under such conditions, a forest with typical boreal tree species (dark conifer and deciduous species) would become dominant, decoupled from the permafrost processes. This study thus suggests that future global warming could drastically alter the larch-dominated taiga-permafrost coupled system in Siberia, with associated changes of WEC processes and feedback to climate.

  4. Dynamics of the larch taiga-permafrost coupled system in Siberia under climate change

    International Nuclear Information System (INIS)

    Zhang Ningning; Yasunari, Tetsuzo; Ohta, Takeshi

    2011-01-01

    Larch taiga, also known as Siberian boreal forest, plays an important role in global and regional water-energy-carbon (WEC) cycles and in the climate system. Recent in situ observations have suggested that larch-dominated taiga and permafrost behave as a coupled eco-climate system across a broad boreal zone of Siberia. However, neither field-based observations nor modeling experiments have clarified the synthesized dynamics of this system. Here, using a new dynamic vegetation model coupled with a permafrost model, we reveal the processes of interaction between the taiga and permafrost. The model demonstrates that under the present climate conditions in eastern Siberia, larch trees maintain permafrost by controlling the seasonal thawing of permafrost, which in turn maintains the taiga by providing sufficient water to the larch trees. The experiment without permafrost processes showed that larch would decrease in biomass and be replaced by a dominance of pine and other species that suffer drier hydroclimatic conditions. In the coupled system, fire not only plays a destructive role in the forest, but also, in some cases, preserves larch domination in forests. Climate warming sensitivity experiments show that this coupled system cannot be maintained under warming of about 2 deg. C or more. Under such conditions, a forest with typical boreal tree species (dark conifer and deciduous species) would become dominant, decoupled from the permafrost processes. This study thus suggests that future global warming could drastically alter the larch-dominated taiga-permafrost coupled system in Siberia, with associated changes of WEC processes and feedback to climate.

  5. Der Nahostkonflikt und die Medien

    Directory of Open Access Journals (Sweden)

    Carola Richter

    2014-06-01

    Full Text Available Diese Einführung in eine Themenausgabe zu den vielfältigen Rollen der Medien im Nahostkonflikt skizziert die Probleme, die sich für Medien und Journalisten als Akteure im Konflikt, Adressaten der Konfliktparteien und Anlass für Konflikt durch ihre Berichterstattung ergeben. Das Konfliktgebiet Israel und Palästina ist sowohl für Forschung über Auslandsbericht-erstattung, über transnationale Agenda Building- und Public Diplomacy-Prozesse als auch über mediensystemische Entwicklungen in Besatzer- und Besatzungsgebieten interessant. Der Artikel gibt einen Überblick über das Feld und führt dabei in die in der Themenausgabe präsentierten empirischen Studien zum Nahostkonflikt und den Medien ein.

  6. Bacterial communities in ancient permafrost profiles of Svalbard, Arctic.

    Science.gov (United States)

    Singh, Purnima; Singh, Shiv M; Singh, Ram N; Naik, Simantini; Roy, Utpal; Srivastava, Alok; Bölter, Manfred

    2017-12-01

    Permafrost soils are unique habitats in polar environment and are of great ecological relevance. The present study focuses on the characterization of bacterial communities from permafrost profiles of Svalbard, Arctic. Counts of culturable bacteria range from 1.50 × 10 3 to 2.22 × 10 5 CFU g -1 , total bacterial numbers range from 1.14 × 10 5 to 5.52 × 10 5 cells g -1 soil. Bacterial isolates are identified through 16S rRNA gene sequencing. Arthrobacter and Pseudomonas are the most dominant genera, and A. sulfonivorans, A. bergeri, P. mandelii, and P. jessenii as the dominant species. Other species belong to genera Acinetobacter, Bacillus, Enterobacter, Nesterenkonia, Psychrobacter, Rhizobium, Rhodococcus, Sphingobacterium, Sphingopyxis, Stenotrophomonas, and Virgibacillus. To the best of our knowledge, genera Acinetobacter, Enterobacter, Nesterenkonia, Psychrobacter, Rhizobium, Sphingobacterium, Sphingopyxis, Stenotrophomonas, and Virgibacillus are the first northernmost records from Arctic permafrost. The present study fills the knowledge gap of culturable bacterial communities and their chronological characterization from permafrost soils of Ny-Ålesund (79°N), Arctic. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Complete and Partial Photo-oxidation of Dissolved Organic Matter Draining Permafrost Soils.

    Science.gov (United States)

    Ward, Collin P; Cory, Rose M

    2016-04-05

    Photochemical degradation of dissolved organic matter (DOM) to carbon dioxide (CO2) and partially oxidized compounds is an important component of the carbon cycle in the Arctic. Thawing permafrost soils will change the chemical composition of DOM exported to arctic surface waters, but the molecular controls on DOM photodegradation remain poorly understood, making it difficult to predict how inputs of thawing permafrost DOM may alter its photodegradation. To address this knowledge gap, we quantified the susceptibility of DOM draining the shallow organic mat and the deeper permafrost layer of arctic soils to complete and partial photo-oxidation and investigated changes in the chemical composition of each DOM source following sunlight exposure. Permafrost and organic mat DOM had similar lability to photomineralization despite substantial differences in initial chemical composition. Concurrent losses of carboxyl moieties and shifts in chemical composition during photodegradation indicated that photodecarboxylation could account for 40-90% of DOM photomineralized to CO2. Permafrost DOM had a higher susceptibility to partial photo-oxidation compared to organic mat DOM, potentially due to a lower abundance of phenolic moieties with antioxidant properties. These results suggest that photodegradation will likely continue to be an important control on DOM fate in arctic freshwaters as the climate warms and permafrost soils thaw.

  8. Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils

    Science.gov (United States)

    Schädel, Christina; Bader, Martin K.-F.; Schuur, Edward A.G.; Biasi, Christina; Bracho, Rosvel; Čapek, Petr; De Baets, Sarah; Diáková, Kateřina; Ernakovich, Jessica; Estop-Aragones, Cristian; Graham, David E.; Hartley, Iain P.; Iversen, Colleen M.; Kane, Evan S.; Knoblauch, Christian; Lupascu, Massimo; Martikainen, Pertti J.; Natali, Susan M.; Norby, Richard J.; O'Donnell, Jonathan A.; Roy Chowdhury, Taniya; Šantrůčková, Hana; Shaver, Gaius; Sloan, Victoria L.; Treat, Claire C.; Turetsky, Merritt R.; Waldrop, Mark P.; Wickland, Kimberly P.

    2016-01-01

    Increasing temperatures in northern high latitudes are causing permafrost to thaw, making large amounts of previously frozen organic matter vulnerable to microbial decomposition. Permafrost thaw also creates a fragmented landscape of drier and wetter soil conditions that determine the amount and form (carbon dioxide (CO2), or methane (CH4)) of carbon (C) released to the atmosphere. The rate and form of C release control the magnitude of the permafrost C feedback, so their relative contribution with a warming climate remains unclear. We quantified the effect of increasing temperature and changes from aerobic to anaerobic soil conditions using 25 soil incubation studies from the permafrost zone. Here we show, using two separate meta-analyses, that a 10 °C increase in incubation temperature increased C release by a factor of 2.0 (95% confidence interval (CI), 1.8 to 2.2). Under aerobic incubation conditions, soils released 3.4 (95% CI, 2.2 to 5.2) times more C than under anaerobic conditions. Even when accounting for the higher heat trapping capacity of CH4, soils released 2.3 (95% CI, 1.5 to 3.4) times more C under aerobic conditions. These results imply that permafrost ecosystems thawing under aerobic conditions and releasing CO2 will strengthen the permafrost C feedback more than waterlogged systems releasing CO2 and CH4 for a given amount of C.

  9. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    Science.gov (United States)

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A. Britta K.; Sjöberg, Ylva; Günther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, Juri; Siewert, Matthias B.; Riley, William J.; Koven, Charles D.; Boike, Julia

    2017-06-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002-2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( pangaea.de/10.1594/PANGAEA.868349" target="_blank">https://doi.pangaea.de/10.1594/PANGAEA.868349.

  10. Geschmackspapillendichte und Geschmackswahrnehmung bei Jugendlichen mit Essstörungen und einer gesunden Kontrollgruppe

    OpenAIRE

    Kaltenhofer, Alice

    2009-01-01

    Fragestellung Die Schmeckwahrnehmung wird u.a. über Lernprozesse, kognitive Vorgänge, genetische und biochemische Faktoren reguliert. Ess- und Diätverhalten werden durch sie beeinflusst. Den anatomisch und physiologisch ersten Abschnitt der Schmeckwahrnehmung bilden die fungiformen Geschmackspapillen. In den Geschmackspapillen liegen die Geschmacksknopsen, mit deren Hilfe die Schmeckstoffe aufgenommen und in Form von Aktionspotentialen zum Thalamus, dem limbischen System,dem Gyrus postzentral...

  11. Kontrolle des Verwaltungsrates : eine Untersuchung der internen und externen Kontrollinstitutionen, -instrumente und -mechanismen

    OpenAIRE

    Reust, Dominik

    2014-01-01

    Eine wichtige Erkenntnis dieser Arbeit ist, dass eine effiziente und effektive Kontrolle des Verwaltungsrates nur über das Zusammenspiel der internen körperschaftlichen Kontrollinstitutionen und -instrumente mit den externen Kontrollinstitutionen und Kontrollmechanismen des Marktes erreicht wird. Die Vorschriften der VegüV betreffend transparente Entschädigungspolitik und unabhängige Stimmrechtsvertreter sowie die in der Aktienrechtsrevision angestrebte Stärkung der Informations-, Mitwirk...

  12. Steueroasen und Regulierungsoasen – Auswirkungen auf die Stabilität des Finanzmarkts und politische Implikationen

    Directory of Open Access Journals (Sweden)

    Michaela Schmidt

    2012-12-01

    Full Text Available In diesem Beitrag wird dargelegt, dass Steuer- und Regulierungsoasen nicht nur Steuerausfälle und Kapitalflucht ermöglichen, sondern auch eine Hauptursache für die Finanzkrise 2007/2008 waren und weiterhin die Stabilität des Finanzmarkts gefährden. Sie haben den Boden bereitet für das Aufkommen nicht regulierter Finanzinstitutionen, sogenannter Schattenbanken. Regulierungsoasen ermöglichen Finanzmarktakteuren eine Umgehung von Regulierungs- und Aufsichtsvorschriften und heizen den Wettbewerb um niedrige Regulierungsvorschriften maßgeblich an. Jeder Schritt zu einer finanzpolitischen Re-Regulierung von Steuer- und Regulierungsoasen sowie Schattenbanken ist ein aktiver Schritt zur Krisenvorbeugung und damit zum Schutz der ArbeitnehmerInnen vor den gewaltigen volkswirtschaftlichen Kosten von Finanzkrisen.

  13. Milch, Milchprodukte, Analoge und Speiseeis

    Science.gov (United States)

    Coors, Ursula

    Die Produktpalette Milch und Erzeugnisse aus Milch beinhaltet Konsummilch, die aus Milch oder Bestandteilen der Milch hergestellten Milcherzeugnisse wie Sauermilch-, Joghurt-, Kefir-, Buttermilch-, Sahne-, Kondensmilch-, Trockenmilch- und Molkenerzeugnisse, Milchmisch- und Molkenmischprodukte (Produkte mit beigegebenen Lebensmitteln), Milchzucker, Milcheiweißerzeugnisse, Milchfette und Käse.

  14. Permafrost-associated gas hydrate: is it really approximately 1% of the global system?

    Science.gov (United States)

    Ruppel, Carolyn

    2015-01-01

    Permafrost-associated gas hydrates are often assumed to contain ∼1 % of the global gas-in-place in gas hydrates based on a study26 published over three decades ago. As knowledge of permafrost-associated gas hydrates has grown, it has become clear that many permafrost-associated gas hydrates are inextricably linked to an associated conventional petroleum system, and that their formation history (trapping of migrated gas in situ during Pleistocene cooling) is consistent with having been sourced at least partially in nearby thermogenic gas deposits. Using modern data sets that constrain the distribution of continuous permafrost onshore5 and subsea permafrost on circum-Arctic Ocean continental shelves offshore and that estimate undiscovered conventional gas within arctic assessment units,16 the done here reveals where permafrost-associated gas hydrates are most likely to occur, concluding that Arctic Alaska and the West Siberian Basin are the best prospects. A conservative estimate is that 20 Gt C (2.7·1013 kg CH4) may be sequestered in permafrost-associated gas hydrates if methane were the only hydrate-former. This value is slightly more than 1 % of modern estimates (corresponding to 1600 Gt C to 1800 Gt C2,22) for global gas-in-place in methane hydrates and about double the absolute estimate (11.2 Gt C) made in 1981.26

  15. Methane Ebullition During Simulated Lake Expansion and Permafrost Degradation

    Science.gov (United States)

    Mazéas, O.; von Fischer, J. C.; Whelan, M.; Rhew, R.

    2007-12-01

    Methane, a potent greenhouse gas, is emitted by Arctic tundra and lakes. Ebullition, or bubbling, of methane from Arctic lakes has been shown to be a major transport mechanism from the sediment to the atmosphere, and ebullition rates are greatest near the edges of the lakes where active erosion is occurring. In regions of continuous permafrost, Arctic lakes have been expanding in recent decades, attributed to permafrost melting and development of thermokarst. Lake expansion occurs when the margins erode into water, supplying large amounts of organic rich material to the sediment-water interface. This allows carbon that was previously stored in the soil (active layer and permafrost) to become bioavailable and subject to decomposition. An increase in Arctic methane emissions as a result of permafrost thawing and lake expansion would constitute a positive feedback to Arctic warming. In order to better understand these processes, an experiment was initiated in July 2007 at the Barrow Environmental Observatory, Barrow, AK. Different layers of locally collected tundra soil were placed into incubation chambers at the bottom of a shallow (about 1 m deep) lake. Each experimental chamber consists of a bucket fixed underneath an inverted funnel, with a sampling port on top to capture and collect the emitted gases. Gas samples are analyzed for methane and carbon dioxide concentrations, as well as relevant isotopic compositions. Gas sampling has occurred at frequent intervals during the late summer and will continue through the early winter. Three replicates of each layer (active layer, seasonally frozen active layer and permafrost) were incubated, as well as an empty control chamber. An additional chamber containing thawed permafrost and cellulose-rich sawdust was placed for comparison, as cellulose is a major component of plant tissue and the fermentation of the cellulose should yield substrates for methanogenesis. Total production of methane versus organic carbon content of

  16. Investigation of Soil and Vegetation Characteristics in Discontinuous Permafrost Landscapes Near Fairbanks, Alaska

    Science.gov (United States)

    2015-08-01

    ER D C TR -1 5- 7 ERDC Center-Directed Research Investigation of Soil and Vegetation Characteristics in Discontinuous Permafrost ...Characteristics in Discontinuous Permafrost Landscapes Near Fairbanks, Alaska Jacob F. Berkowitz U.S. Army Engineer Research and Development Center (ERDC...Washington, DC 20314-1000 Under ERDC Center-Directed Research project “Integrated Technologies for Delineat- ing Permafrost and Ground-State

  17. A 20-year record (1998–2017 of permafrost, active layer and meteorological conditions at a high Arctic permafrost research site (Bayelva, Spitsbergen

    Directory of Open Access Journals (Sweden)

    J. Boike

    2018-03-01

    Full Text Available Most permafrost is located in the Arctic, where frozen organic carbon makes it an important component of the global climate system. Despite the fact that the Arctic climate changes more rapidly than the rest of the globe, observational data density in the region is low. Permafrost thaw and carbon release to the atmosphere are a positive feedback mechanism that can exacerbate global warming. This positive feedback functions via changing land–atmosphere energy and mass exchanges. There is thus a great need to understand links between the energy balance, which can vary rapidly over hourly to annual timescales, and permafrost, which changes slowly over long time periods. This understanding thus mandates long-term observational data sets. Such a data set is available from the Bayelva site at Ny-Ålesund, Svalbard, where meteorology, energy balance components and subsurface observations have been made for the last 20 years. Additional data include a high-resolution digital elevation model (DEM that can be used together with the snow physical information for snowpack modeling and a panchromatic image. This paper presents the data set produced so far, explains instrumentation, calibration, processing and data quality control, as well as the sources for various resulting data sets. The resulting data set is unique in the Arctic and serves as a baseline for future studies. The mean permafrost temperature is −2.8 °C, with a zero-amplitude depth at 5.5 m (2009–2017. Since the data provide observations of temporally variable parameters that mitigate energy fluxes between permafrost and atmosphere, such as snow depth and soil moisture content, they are suitable for use in integrating, calibrating and testing permafrost as a component in earth system models.The presented data are available in the Supplement for this paper (time series and through the PANGAEA and Zenodo data portals: time series (https://doi.org/10.1594/PANGAEA.880120, https

  18. Arbeitszeitflexibilisierung in der westdeutschen Metall- und Elektroindustrie und die Verbandsstrategien - Eine vergleichende Analyse der arbeitszeitpolitischen Strategien des Arbeitgeberverbandes Gesamtmetall und der Industriegewerkschaft Metall

    OpenAIRE

    Altun, Ufuk

    2005-01-01

    Arbeitszeitpolitik und Arbeitszeitgestaltung haben seit dem Tarifkompromiss im Jahre 1984 in der Metall-, und Elektroindustrie in der politischen und wissenschaftlichen Diskussion einen immensen Bedeutungszuwachs erfahren. Die Forderungen nach einer flexibleren Arbeitszeitgestaltung haben zeitgleich sowohl aus der Globalisierungsdiskussion und der Debatte um die Wettbewerbsfähigkeit des "Wirtschaftsstandorts Deutschland" heraus wie auch aus beschäftigungspolitischen Gründen neuen Auftrieb bek...

  19. Microbial Community Dynamics from Permafrost Across the Pleistocene-Holocene Boundary and Response to Abrupt Climate Change

    Science.gov (United States)

    Hammad, A.; Mahony, M.; Froese, D. G.; Lanoil, B. D.

    2014-12-01

    Earth is currently undergoing rapid warming similar to that observed about 10,000 years ago at the end of the Pleistocene. We know a considerable amount about the adaptations and extinctions of mammals and plants at the Pleistocene/Holocene (P/H) boundary, but relatively little about changes at the microbial level. Due to permafrost soils' freezing anoxic conditions, they act as microbial diversity archives allowing us to determine how microbial communities adapted to the abrupt warming at the end of P. Since microbial community composition only helps differentiate viable and extant microorganisms in frozen permafrost, microbial activity in thawing permafrost must be investigated to provide a clear understanding of microbial response to climate change. Current increased temperatures will result in warming and potential thaw of permafrost and release of stored organic carbon, freeing it for microbial utilization; turning permafrost into a carbon source. Studying permafrost viable microbial communities' diversity and activity will provide a better understanding of how these microorganisms respond to soil edaphic variability due to climate change across the P/H boundary, providing insight into the changes that the soil community is currently undergoing in this modern era of rapid climate change. Modern soil, H and P permafrost cores were collected from Lucky Lady II site outside Dawson City, Yukon. 16S rRNA high throughput sequencing of permafrost DNA showed the same trends for total and viable community richness and diversity with both decreasing with permafrost depth and only the richness increasing in mid and early P. The modern, H and P soils had 50.9, 33.9, and 27.3% unique viable species and only 14% of the total number of viable species were shared by all soils. Gas flux measurements of thawed permafrost showed metabolic activity in modern and permafrost soils, aerobic CH­­4 consumption in modern, some H and P soils, and anaerobic CH­­4 production in one H

  20. Permafrost thaw and wildfire: Equally important drivers of boreal tree cover changes in the Taiga Plains, Canada

    Science.gov (United States)

    Helbig, M.; Pappas, C.; Sonnentag, O.

    2016-02-01

    Boreal forests cover vast areas of the permafrost zones of North America, and changes in their composition and structure can lead to pronounced impacts on the regional and global climate. We partition the variation in regional boreal tree cover changes between 2000 and 2014 across the Taiga Plains, Canada, into its main causes: permafrost thaw, wildfire disturbance, and postfire regrowth. Moderate Resolution Imaging Spectroradiometer Percent Tree Cover (PTC) data are used in combination with maps of historic fires, and permafrost and drainage characteristics. We find that permafrost thaw is equally important as fire history to explain PTC changes. At the southern margin of the permafrost zone, PTC loss due to permafrost thaw outweighs PTC gain from postfire regrowth. These findings emphasize the importance of permafrost thaw in controlling regional boreal forest changes over the last decade, which may become more pronounced with rising air temperatures and accelerated permafrost thaw.

  1. Impacts of the active layer on runoff in an upland permafrost basin, northern Tibetan Plateau.

    Science.gov (United States)

    Gao, Tanguang; Zhang, Tingjun; Guo, Hong; Hu, Yuantao; Shang, Jianguo; Zhang, Yulan

    2018-01-01

    The paucity of studies on permafrost runoff generation processes, especially in mountain permafrost, constrains the understanding of permafrost hydrology and prediction of hydrological responses to permafrost degradation. This study investigated runoff generation processes, in addition to the contribution of summer thaw depth, soil temperature, soil moisture, and precipitation to streamflow in a small upland permafrost basin in the northern Tibetan Plateau. Results indicated that the thawing period and the duration of the zero-curtain were longer in permafrost of the northern Tibetan Plateau than in the Arctic. Limited snowmelt delayed the initiation of surface runoff in the peat permafrost in the study area. The runoff displayed intermittent generation, with the duration of most runoff events lasting less than 24 h. Precipitation without runoff generation was generally correlated with lower soil moisture conditions. Combined analysis suggested runoff generation in this region was controlled by soil temperature, thaw depth, precipitation frequency and amount, and antecedent soil moisture. This study serves as an important baseline to evaluate future environmental changes on the Tibetan Plateau.

  2. Intermediale Synchronisation zwischen Volltext und Film und ihre Realisierung in Hybrideditionen

    OpenAIRE

    Bülow, Gilles

    2017-01-01

    Diese Arbeit behandelt die theoretische Erfassung und prototypische Erzeugung komplexer Musterdokumente mit synchronisiertem »Volltext« und »Bewegtbild«. Dabei werden wesentliche Randbedingungen für die Dokumentengliederung ermittelt. Diese Randbedingungen erlauben es dann, unterhalb der Plattformebene (des »reinen« Buchs und des »reinen« Films) neue multimediale Hybrideditionen auf Basis elektronischer Publikationsformate als Ausgabeplattform »sinnvoll« zu generieren. Empirisch wird der F...

  3. Scaling-up permafrost thermal measurements in western Alaska using an ecotype approach

    Directory of Open Access Journals (Sweden)

    W. L. Cable

    2016-10-01

    Full Text Available Permafrost temperatures are increasing in Alaska due to climate change and in some cases permafrost is thawing and degrading. In areas where degradation has already occurred the effects can be dramatic, resulting in changing ecosystems, carbon release, and damage to infrastructure. However, in many areas we lack baseline data, such as subsurface temperatures, needed to assess future changes and potential risk areas. Besides climate, the physical properties of the vegetation cover and subsurface material have a major influence on the thermal state of permafrost. These properties are often directly related to the type of ecosystem overlaying permafrost. In this paper we demonstrate that classifying the landscape into general ecotypes is an effective way to scale up permafrost thermal data collected from field monitoring sites. Additionally, we find that within some ecotypes the absence of a moss layer is indicative of the absence of near-surface permafrost. As a proof of concept, we used the ground temperature data collected from the field sites to recode an ecotype land cover map into a map of mean annual ground temperature ranges at 1 m depth based on analysis and clustering of observed thermal regimes. The map should be useful for decision making with respect to land use and understanding how the landscape might change under future climate scenarios.

  4. "Tabula Sinvs Venetici" von W. Barents und ihre Geschichtilische und Geographische Bedeutung

    Directory of Open Access Journals (Sweden)

    Mithad Kozličić

    1999-06-01

    Full Text Available In der wissenschaftlichen Literatur sind zwei Varianten der Seekarte der Adria vom niederländischen Seefahrer und Polarforscher Willem Barents (1550-1597 bekannt. Die erste, in diesem Aufsatz als K-1 bezeichnete Karte, wurde in Amsterdam 1595 hergestellt und gedruckt. Sie hatte anfänglich eine praktisch-navigatorische Funktion. Die zweite, K-2, ins Jahr 1595 datierte (1637-1662 Karte, wurde als geostrategische Karte der Adria und der südlichen Teile Europas ausgenützt. An den adriatischen Nordküsten, besonders in ihrem Hinterland, geschahen mit dem Durchbruch der Türken seit der Hälfte des 16. Jahrhunderts wichtige militärische und politische Änderungen. In den “Atlanten” des Niederländers Jan (Johann; Joannes Janssonius (1588-1664 fehlte gerade solch eine Karte, die auch mehrmals in Amsterdam gedruckt wurde, aber zwischen 1637 und 1662. Die K-1 von Barents, deren Druckplatte Janssonius zur Verfügung hatte, konnte diese Funktion befriedigen. Deswegen machte Janssonius nur die nötigen dem darstellenden Standard der ersten Hälfte des 17. Jahrhunderts entsprechenden Änderungen, und als solche wurde sie gedruckt. Die K-2 verlor ihre ursprüngliche praktisch-navigatorische Funktion und wurde eine Karte von geostrategischer Bedeutung. Mit diesen Grundfragen befaßt sich dieser Aufsatz.

  5. Referenzmodelle im Mobile Business: Analyse und Entwicklung neuer Rollen, Szenarien und Geschäftsmodelle

    OpenAIRE

    Hufenbach, Yvonne

    2016-01-01

    Das digitale Zeitalter ist charakterisiert durch sich stetig wandelnde Märkte, Techniken und wirtschaftliche Voraussetzungen. Klassische Wertschöpfungsketten brechen auf und wandeln sich zu Wertschöpfungsnetzen. Dabei findet eine Neuzuordnung zwischen Wertschöpfungstätigkeiten und Marktteilnehmern statt. Diese digitale Welt ist zudem durch hohe Interdependenzen wirtschaftlicher, informationstechnischer und rechtlicher Fragestellungen gekennzeichnet. Vor diesem Hintergrund verfolgt die Arb...

  6. Klima- und umweltbezogene Lernprozesse in partizipativen Produktentwicklungsverfahren: Möglichkeiten und Grenzen

    Directory of Open Access Journals (Sweden)

    Marlen Arnold

    2009-08-01

    Full Text Available Für erfolgreiche und nachhaltige Produktentwicklung reichen heute Marktbeobachtung und Kund/innenbefragungen alleine nicht mehr aus. Mit Verfahren zur partizipativen Produktentwicklung (PPE können sowohl das kreative Potenzial von Nutzer/innen für die Produktentwicklung erschlossen als auch marktfähige nachhaltige Produkte entwickelt werden. Sie ermöglichen so aktives Nachhaltigkeitsmanagement. Am Beispiel des INNOCOPE-Pilotverfahrens wird diskutiert, wie nachhaltigkeitsbezogene Lernprozesse in PPE-Prozessen initiiert werden können und welche Faktoren dabei wesentlich sind. Insgesamt zeigt sich, dass vor allem die sich wiederholende, direkte und möglichst gleichberechtigte Interaktion von Unternehmensvertreter/innen und von Konsument/innen einen themenbezogenen Wissensaustausch und wechselseitige Lernprozesse ermöglicht. Dabei sind der inhaltliche Aufbau der Treffen und der zeitlich gestaffelte Einsatz von Lernmethoden wesentlich.Today, market observation and customer surveys alone do not suffice to develop successful and sustainable products. Methods of participatory product development (PPD allow to open up the creative potential of users for product development, and to develop marketable sustainable products. Thereby, they support active sustainability management. Taking the INNOCOPE pilot process as an example, we discuss the possibilities and the relevant factors to initiate sustainability- and climate-related learning processes within PPD processes. Our findings indicate that repeated, direct and equitable interaction between company representatives and customers are fundamental for relevant knowledge exchange and mutual learning processes. Other key issues are the thematic structure of the meetings and the timing of learning methods.

  7. Thermokarst transformation of permafrost preserved glaciated landscapes.

    Science.gov (United States)

    Kokelj, S.; Tunnicliffe, J. F.; Fraser, R.; Kokoszka, J.; Lacelle, D.; Lantz, T. C.; Lamoureux, S. F.; Rudy, A.; Shakil, S.; Tank, S. E.; van der Sluijs, J.; Wolfe, S.; Zolkos, S.

    2017-12-01

    Thermokarst is the fundamental mechanism of landscape change and a primary driver of downstream effects in a warming circumpolar world. Permafrost degradation is inherently non-linear because latent heat effects can inhibit thawing. However, once this thermal transition is crossed thermokarst can accelerate due to the interaction of thermal, physical and ecological feedbacks. In this paper we highlight recent climate and precipitation-driven intensification of thaw slumping that is transforming permafrost preserved glaciated landscapes in northwestern Canada. The continental distribution of slump affected terrain reflects glacial extents and recessional positions of the Laurentide Ice sheet. On this basis and in conjunction with intense thermokarst in cold polar environments, we highlight the critical roles of geological legacy and climate history in dictating the sensitivity of permafrost terrain. These glaciated landscapes, maintained in a quasi-stable state throughout much of the late Holocene are now being transformed into remarkably dynamic environments by climate-driven thermokarst. Individual disturbances displace millions of cubic metres of previously frozen material downslope, converting upland sedimentary stores into major source areas. Precipitation-driven evacuation of sediment by fluidized mass flows perpetuates non-linear enlargement of disturbances. The infilling of valleys with debris deposits tens of metres thick increases stream base-levels and promotes rapid valley-side erosion. These processes destabilize adjacent slopes and proliferate disturbance effects. Physically-based modeling of thaw slump development provides insight into the trajectories of landscape change, and the mapping of fluvial linkages portrays the cascade of effects across watershed scales. Post-glacial or "paraglacial" models of landscape evolution provide a useful framework for understanding the nature and magnitude of climate-driven changes in permafrost preserved glaciated

  8. Klimaanpassung in Land- und Forstwirtschaft: Ergebnisse eines Workshops der Ressortforschungsinstitute FLI, JKI und Thünen-Institut

    OpenAIRE

    Schimmelpfennig, Sonja; Heidecke, Claudia; Beer, Holger; Bittner, Florian; Klages, Susanne; Krengel, Sandra; Lange, Stefan

    2018-01-01

    Das Working Paper stellt die Ergebnisse einer Umfrage und eines Workshops zusammen, die von Wissenschaftlern und Wissenschaftlerinnen der Ressortforschungsinstitute Thünen-Institut, Julius Kühn-Institut (JKI) und Friedrich-Loeffler-Institut (FLI) im Herbst 2016 zusammengetragen und diskutiert worden sind. Ziel des Workshops und der Umfrage war, den Stand des Wissens zu Klimaanpassungsthemen in der Ressortforschung des BMEL und die zukünftigen Herausforderungen einer Anpassung an den Klimawand...

  9. Climate change and the permafrost carbon feedback.

    Science.gov (United States)

    Schuur, E A G; McGuire, A D; Schädel, C; Grosse, G; Harden, J W; Hayes, D J; Hugelius, G; Koven, C D; Kuhry, P; Lawrence, D M; Natali, S M; Olefeldt, D; Romanovsky, V E; Schaefer, K; Turetsky, M R; Treat, C C; Vonk, J E

    2015-04-09

    Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.

  10. Permafrost and infrastructure in the Usa Basin (Northeast European Russia) : Possible impacts of global warming

    NARCIS (Netherlands)

    Mazhitova, G.; Karstkarel, N.; Oberman, N.; Romanovsky, V.; Kuhry, P.

    The relationship between permafrost conditions and the distribution of infrastructure in the Usa Basin, Northeast European Russia, is analyzed. About 75% of the Basin is underlain by permafrost terrain with various degrees of continuity (isolated patches to continuous permafrost). The region has a

  11. Applying GIPL2.0 Model to assess the permafrost dynamics on the Qinghai-Tibet Plateau

    Science.gov (United States)

    Wu, T.

    2017-12-01

    The modeling of active layer and permafrost distribution is of great importance to understand the permafrost dynamics of cold regions, especially in those regions where are difficult to approach such as the Qinghai-Tibet Plateau (QTP). In this study we have applied the Geophysical Institute Permafrost Lab model (GIPL2.0) to estimate the active layer thickness and assess the permafrost thermal regime on the QTP. The GIPL 2.0 have been widely applied in the Arctic regions of Alaska, however less on the QTP. The model has been calibrated according to the four active layer in-situ measurement sites which have different underlying surface and soil characteristics. We extended the original GIPL2 model depth to the depth of 18 m. After the calibration of the GIPL2.0 at those four sites, the first-hand single point model is expanded to a regional model. The key permafrost parameters were simulated, including active layer thickness (ALT), mean annual ground temperature (MAGT) at multiple soil layers, and the permafrost classification was also carried out in order to study the permafrost the thermal stability across the QTP. To validate the performance of expanded regional-GIPL2 model, we compare simulated ALT and MAGT at the depth of zero annual amplitude (DZAA) with observed data. It is demonstrated that the modifications regional-GIPL2 model are able to improve the accuracy of permafrost thermal regime simulations greatly on the QTP. The simulated ALT are generally underestimate the observed ones with the MBE value of -0.14 m and the RMSE value of 0.22 m. For the MAGT at the DZAA of all 51 sites, the simulation errors range from - 0.9 ° to 0.9 ° with the RMSE value of 0.41 °. For the whole permafrost area of the QTP, the simulated ALT ranges from 0 to 8 m, with an average of 2.30 m. The simulated results indicate that most of regions were underlain by the sub-stable permafrost and less regions were underlain by the extremely stable permafrost.

  12. The thin brown line: The crucial role of peat in protecting permafrost in Arctic Alaska

    Science.gov (United States)

    Gaglioti, B.; Mann, D. H.; Farquharson, L. M.; Baughman, C. A.; Jones, B. M.; Romanovsky, V. E.; Williams, A. P.; Andreu-Hayles, L.

    2017-12-01

    Ongoing warming threatens to thaw Arctic permafrost and release its stored carbon, which could trigger a permafrost-carbon feedback capable of augmenting global warming. The effects of warming air temperatures on permafrost are complicated by the fact that across much of the Arctic and Subarctic a mat of living plants and decaying litter cover the ground and buffer underlying permafrost from air temperatures. For simplicity here, we refer to this organic mat as "peat". Because this peat modifies heat flow between ground and air, the rate and magnitude of permafrost responses to changing climate - and hence the permafrost-carbon feedback - are partly slaved to the peat layer's slower dynamics. To explore this relationship, we used 14C-age offsets within lake sediments in Alaskan watersheds underlain by yedoma deposits to track the changing responses of permafrost thaw to fluctuating climate as peat accumulated over the last 14,000 years. As the peat layer built up, warming events became less effective at thawing permafrost and releasing ancient carbon. Consistent with this age-offset record, the geological record shows that early in post-glacial times when the peat cover was still thin and limited in extent, warm intervals triggered extensive thermokarst that resulted in rapid aggradation of floodplains. Today in contrast, hillslopes and floodplains remain stable despite rapid warming, probably because of the buffering effects of the extensive peat cover. Another natural experiment is provided by tundra fires like the 2007 Anaktuvuk River fire that removed the peat cover from tundra underlain by continuous permafrost and resulted in widespread thermkarsting. Further support for peat's critical role in protecting permafrost comes from the results of modeling how permafrost temperatures under different peat thicknesses respond to warming air temperature. Although post-industrial warming has not yet surpassed the buffering capacity of 14,000 years of peat buildup in

  13. Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

    Directory of Open Access Journals (Sweden)

    S. W. Lyon

    2009-05-01

    Full Text Available Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. While permafrost thawing due to climate change has been observed in the arctic and sub-arctic, direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

  14. Reviews and syntheses : Effects of permafrost thaw on Arctic aquatic ecosystems

    NARCIS (Netherlands)

    Vonk, J. E.; Tank, S. E.; Bowden, W.B.; Laurion, I.; Vincent, W. F.; Alekseychik, P.; Amyot, M.; Billet, M. F.; Canário, J.; Cory, R. M.; Deshpande, B. N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; Macmillan, G.; Rautio, M.; Walter Anthony, K. M.; Wickland, K.P.

    2015-01-01

    The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current

  15. Diagnostik und Therapie der kutanen Androgenisierung im klimakterischen Übergang sowie in der Peri- und Postmenopause: Hirsutismus und Alopezie

    Directory of Open Access Journals (Sweden)

    Geisthövel F

    2012-01-01

    Full Text Available Die weibliche Androgenisierung umfasst ein weites Spektrum an heterogenen Dysfunktionen und Erkrankungen. Um die Therapieprinzipien des Hirsutismus sowie der Alopecia androgenetica während des klimakterischen Übergangs („menopausal transition“ [MT] und der Peri-/Postmenopause zu erfassen, ist es sinnvoll, sich auf eine Gruppe von androgenisierten Patientinnen zu beschränken, bei der die Haut pathogenetisch im Fokus liegt. Solch eine klar definierte Patientengruppe, die „funktionell kutane Androgenisierung“ (FCA, kann meist schon über die Diagnostikebene 1 (Screening-Ebene unseres Klassifikations-Algorithmus diagnostiziert werden. Der Ferriman-Gallwey-Index bzw. eine modifizierte Sinclair-Scale dienen zur Gradeinteilung von Hirsutismus bzw. Alopezie. Die ausgeprägte endokrine Dynamik während der MT ist hormondiagnostisch zu beachten. Wachsepilation und Lasertherapie sind vielfältig eingesetzte topischmechanische bzw. -physikalische Therapieverfahren. Eine topische Behandlung des Hirsutismus kann auch mit Eflornithin-Creme durchgeführt werden, die den Effekt einer Lasertherapie unterstützt. Minoxidil-Lösung gilt als Mittel der ersten Wahl bei der topischen Therapie der Alopecia androgenetica. Steroidale Präparate, welche aus der kontrazeptiven Kombination von Ethinylestradiol und antiandrogenen Gestagenen (AA bestehen, sind therapeutische Prinzipien bei androgenisierten Patientinnen in der MT, sie sind hingegen in der Postmenopause kontraindiziert. Die orale Einnahme von Spironolacton und/oder Finasterid, beides nicht-steroidale Antiandrogene, ist während der MT unter sicherer Kontrazeption und jene von Spironolacton für die Alopezie in der Postmenopause gut geeignet. Die Einnahme von Kombinationsprapäraten, welche die nicht-kontrazeptiven natürlichen Östrogene und AA enthalten, sind für die Behandlung der FCA bei Patientinnen indiziert, die zusätzlich unter klimakterischen und peri-/postmenopausalen Störungen leiden

  16. Logos und etos der Heiligkeit im Licht der liturgischen Texte vom hl. Stanislaus, Bischof und Märtyrer

    Directory of Open Access Journals (Sweden)

    Jan Józef Janicki

    2003-12-01

    Full Text Available Im Jahr 2003 feiert die Kirche in Polen das 750-jährige Jubiläum der Heiligsprechung des Bischofs Stanislaus (1030-1079, der im Jahre 1253 in Assisi, als erste Pole, kanonisiert wurde und zum Patron von ganz Polen ernannt. Der Verfasser analisiert das Messformular und Stundengebetsformular von der liturgischen Feier des hl. Stanislaus, Bischof und Märtyrer am 8 Mai und sucht dadurch die Lehre (logos über das christliche Leben und die konkrete Lebens-Konsequenzen (etos aufzuzeigen. Die erneuerten liturgischen Texte der Gebete des neuen römischen Messbuches und des Stundengebetes zeigen den Glauben der betenden Kirche nach dem alten Prinzip: legem credendi lex statuat supplicandi (oder kurz ausgedrückt: lex orandi lex credendi. Der Zweck also des hier vorgestellten Artikels ist es, den Glauben der Kirche über das heilige Leben der Christen zu demonstrieren, welches uns eine Analyse der euchologischen Texte und der Texte der Wortliturgie ermöglicht. Der Verfasser benutzte dann die Möglichkeit, diese ganze Problematik im breiten theologisch-liturgischen und pastoralen Kontext darzustellen. Dabei benutzte er die Dokumente der Kirche der letzten Jahre, insbesondere die Lehre des II. Vatikanischen Konzils wenn es um den pastoralen Dienst der Bischöfe geht, dann die pastoral-theologischen Briefe des Papstes Pius XII und des Papstes Johannes Paul II, zum 700-jährigen und zum 750-jährigen Jubiläum der Kanonisation des hl. Bischofs Stanislaus. Es geht aber auch um alles das, was Johannes Paul II und früher als Kardinal Karol Wojtyła zum Jahrestag des Märtyrertodes geschrieben hat. Die liturgischen Gebetstexte lex orandi und die Wortliturgie unterstreichen in ihrer lex credendi, dass der hl. Stanislaus in seinem Leben, in seiner Zeit und seiner Kirche, den Auftrag und die Vollmacht - die Christus den Aposteln und ihren Nachfolgern gegeben hat - alle Völker zu lehren, die Menschen in der Wahrheit zu heiligen und sie zu weiden, verwirklicht

  17. Editorial zum Tagungsband: Spannungsfelder und blinde Flecken. Medienpädagogik zwischen Emanzipationsanspruch und Diskursvermeidung

    Directory of Open Access Journals (Sweden)

    Sven Kommer

    2017-10-01

    Full Text Available Die erziehungswissenschaftliche Auseinandersetzung mit Medien hat in Deutschland eine lange und vielfältige Tradition. In den letzten Jahrzehnten hat sich die Medienpädagogik zu einer eigenständigen akademischen (Teil-Disziplin entwickelt, die in der (Fach-Öffentlichkeit wahrgenommen wird und sich aktiv in aktuelle gesellschaftliche Diskurse einbringt. Sichtbar wird die Etablierung als Fach u. a. daran, dass an einer Reihe von Hochschulen Professuren geschaffen wurden, die für medienpädagogische Studienelemente oder -gänge und/oder Zusatzausbildungen verantwortlich sind. Der gestiegene Stellenwert der Disziplin zeigt sich auch an ihrer Rolle in der Deutschen Gesellschaft für Erziehungswissenschaft, innerhalb derer sie sich von einer «Arbeitsgemeinschaft auf Zeit» (Mitte der 1990er-Jahre zu einer eigenständigen Sektion (seit 2010 entwickelt hat. Angesichts der gegenwärtig zu beobachtenden Entwicklungen im Medienbereich (u. a. Digitalisierung, Globalisierung, Algorithmisierung, deren Folgen für gesellschaftliche und pädagogische Prozesse und Bereiche kaum zu unterschätzen sind, erstaunt es, dass die Medienpädagogik bis heute dazu neigt, Rechtfertigungsstrategien für die eigenen Existenz zu generieren. Bei einer kritischen Betrachtung (z. B. der universitären Stellenpolitik ist aber zu konstatieren, dass sich die Medienpädagogik auch 40 Jahre nach dem Erscheinen von Dieter Baackes wegweisender Schrift Kommunikation und Kompetenz ihrer Anerkennung und festen Verankerung im akademischen Feld tatsächlich noch immer nicht sicher sein kann. Eine Ursache hierfür liegt möglicherweise in der noch immer grossen (und oftmals geradezu zelebrierten Heterogenität des Faches. So sind die unterschiedlichen Traditionslinien des pädagogischen Umgangs mit Medien, die mitunter nur bedingt miteinander vereinbar sind, bis heute zu beobachten und wirkmächtig. Zu unterscheiden ist hierbei bspw. eine auf Emanzipation, kommunikative Kompetenz

  18. Assessing and Projecting Greenhouse Gas Release due to Abrupt Permafrost Degradation

    Science.gov (United States)

    Saito, K.; Ohno, H.; Yokohata, T.; Iwahana, G.; Machiya, H.

    2017-12-01

    Permafrost is a large reservoir of frozen soil organic carbon (SOC; about half of all the terrestrial storage). Therefore, its degradation (i.e., thawing) under global warming may lead to a substantial amount of additional greenhouse gas (GHG) release. However, understanding of the processes, geographical distribution of such hazards, and implementation of the relevant processes in the advanced climate models are insufficient yet so that variations in permafrost remains one of the large source of uncertainty in climatic and biogeochemical assessment and projections. Thermokarst, induced by melting of ground ice in ice-rich permafrost, leads to dynamic surface subsidence up to 60 m, which further affects local and regional societies and eco-systems in the Arctic. It can also accelerate a large-scale warming process through a positive feedback between released GHGs (especially methane), atmospheric warming and permafrost degradation. This three-year research project (2-1605, Environment Research and Technology Development Fund of the Ministry of the Environment, Japan) aims to assess and project the impacts of GHG release through dynamic permafrost degradation through in-situ and remote (e.g., satellite and airborn) observations, lab analysis of sampled ice and soil cores, and numerical modeling, by demonstrating the vulnerability distribution and relative impacts between large-scale degradation and such dynamic degradation. Our preliminary laboratory analysis of ice and soil cores sampled in 2016 at the Alaskan and Siberian sites largely underlain by ice-rich permafrost, shows that, although gas volumes trapped in unit mass are more or less homogenous among sites both for ice and soil cores, large variations are found in the methane concentration in the trapped gases, ranging from a few ppm (similar to that of the atmosphere) to hundreds of thousands ppm We will also present our numerical approach to evaluate relative impacts of GHGs released through dynamic

  19. Nutrient Controls on Methane Emissions in a Permafrost Thaw Subarctic Peatland

    Science.gov (United States)

    Kashi, N. N.; Perryman, C. R.; Malhotra, A.; Marek, E. A.; Giesler, R.; Varner, R. K.

    2015-12-01

    Permafrost peatlands in northern latitudes are large reservoirs of sequestered carbon that are vulnerable to climate change. While peatlands account for a small fraction of total global land surfaces, their potential to release sequestered carbon in response to higher temperatures is of concern. Of particular relevance is the conversion of these carbon stores into methane (CH4), a strong greenhouse gas with a global warming potential 20 times greater than that of CO2 over a 100-year time frame. Here, we explore how key nutrients impact the consumption of CH4 at the Stordalen Mire in Abisko, Sweden, a discontinuous permafrost peatland with expanding thaw over the last century. Peatland CH4 emissions are highly spatially variable due to multiple emission pathways and strong dependence on several environmental factors. Among controls on CH4 emissions, such as temperature and water table depth, primary production of wetland vegetation is also a strong factor in the variability of CH4 emissions. Plant community shifts among permafrost thaw stages subsequently change nutrient cycling and availability, which in turn impacts primary production. Early stages of permafrost thaw are mosaicked with a variety of vascular plants and mosses. We analyzed potential enzymatic activities of chitinase, glucosidase, and phosphatase as proxies for organic nitrogen, carbon, and phosphorus cycling, respectively, in tandem with potential CH4 oxidation rates. In addition, stoichiometric ratios of carbon, nitrogen, and phosphorus concentrations are used to illustrate nutrient limitation controls on CH4 oxidation rates. While CH4 emissions are low throughout initial thaw stages, highest rates of potential CH4 oxidation. These permafrost thaw-induced CH4 oxidation rates are 5 and 11 times higher, in the surface and depth of the peat profile respectively, than subsequent aerobic permafrost thaw stages. As CH4 emissions are low in intact permafrost peatlands, these high rates of potential CH4

  20. Digitalisierung und Selbstbestimmung

    Directory of Open Access Journals (Sweden)

    Bezemek, Christoph

    2017-12-01

    Full Text Available Der vorliegende Beitrag skizziert das Zusammenspiel von Digitalisierung und individueller Selbstbestimmung, stellt die Frage, welche Herausforderungen dieses Zusammenspiel birgt und diskutiert, wie ihnen begegnet werden kann.

  1. Editorial 01/2013 Normen und Normierungen

    Directory of Open Access Journals (Sweden)

    Christian Swertz

    2013-03-01

    Full Text Available Auf unterschiedlichsten Ebenen werden die Diskussionen und Forschungen der Medienpädagogik von normativ aufgeladenen Begriffen durchzogen: so, wenn es um Standards in der Medienbildung geht, wenn beispielsweise diskutiert wird, welche Inhalte in welcher Form vermittelt werden sollen; so auch wenn zur Debatte steht, wie Medienpädagogik institutionalisiert werden sollte und welche Voraussetzungen gegeben sein müssen, um einen geplanten Bildungsprozess zu lenken oder anzuleiten.Derartige Norm(ierungen wurden bereits mit der Konzeptualisierung des Begriffs Medienkompetenz und im Blick auf die Emanzipation des Menschen kritisch beleuchtet, womit auch Kritik an gesellschaftlichen Herrschafts- und Machtstrukturen verbunden war. Die Orientierung an der sozialwissenschaftlich verstandenen Emanzipation des Menschen ist allerdings in anderen pädagogischen Disziplinen durchaus umstritten. Gleichzeitig ist zu beobachten, dass die gesellschaftskritische Perspektive im medienpädagogischen Diskurs über die Orientierung von Medienkompetenz und Medienbildung eine immer geringere Rolle spielt. Deshalb hat sich die Redaktion der MEDIENIMPULSE entschlossen, dem Thema Normen und Normierungen eine eigene Ausgabe zu widmen.Dabei sollten folgende Fragen behandelt werden:Wie sieht es mit Norm(ierungen im Bereich der Mediendidaktik aus? Wie sind die mit aktuellen Medienkompetenz- und Medienbildungsbegriffen verbundenen Normen epistemologisch und (medientheoretisch abgestützt? Wie lassen sich – nur scheinbar paradox formuliert – wissenschaftlich begründbare medienpädagogische Normen finden, die sich den genannten Normierungen widersetzen und entziehen? Inwiefern führt die Einführung von Laptopklassen oder Smartboards im schulischen Bereich oder die Gestaltung von Videospielprojekten in der außerschulischen Medienbildung zu einer unreflektierten Sozialdisziplinierung, die als illegitime Form(atierung des Menschen verstanden werden kann? Der Schwerpunktteil

  2. Fluchen und Flamen, um ein Mann zu sein? Die Verknüpfung von Geschlecht und Sprache durch Vorurteile

    Directory of Open Access Journals (Sweden)

    Nicola Döring

    2001-11-01

    Full Text Available Die hier besprochene Monographie der Linguistin Anja Gottburgsen beschäftigt sich theoretisch und empirisch mit sprachbezogenen Geschlechterstereotypen, also mit unseren Vorstellungen darüber, ob und wie Männer und Frauen jeweils in spezifischer und distinkter Weise sprachlich kommunizieren. Im Theorieteil der Arbeit wird der aktuelle Stand der soziolinguistischen und sozialpsychologischen Diskussion zu Geschlecht, Sprachverhalten und Stereotypisierung kritisch referiert und die Bedeutung von sprachbezogenen Geschlechterstereotypen erläutert. Im empirischen Teil berichtet die Autorin die Ergebnisse von drei Fragebogen-Studien mit deutschsprachigen Studierenden. Es zeigt sich, dass bei Studierenden unabhängig von Geschlecht und Geschlechtsrollenorientierung stereotype Vorstellungen über das sprachliche Verhalten von Männern und Frauen verbreitet sind.

  3. Influence of vertical and lateral heat transfer on permafrost thaw, peatland landscape transition, and groundwater flow

    Science.gov (United States)

    Kurylyk, Barret L.; Masaki, Masaki; Quinton, William L.; McKenzie, Jeffrey M.; Voss, Clifford I.

    2016-01-01

    Recent climate change has reduced the spatial extent and thickness of permafrost in many discontinuous permafrost regions. Rapid permafrost thaw is producing distinct landscape changes in the Taiga Plains of the Northwest Territories, Canada. As permafrost bodies underlying forested peat plateaus shrink, the landscape slowly transitions into unforested wetlands. The expansion of wetlands has enhanced the hydrologic connectivity of many watersheds via new surface and near-surface flow paths, and increased streamflow has been observed. Furthermore, the decrease in forested peat plateaus results in a net loss of boreal forest and associated ecosystems. This study investigates fundamental processes that contribute to permafrost thaw by comparing observed and simulated thaw development and landscape transition of a peat plateau-wetland complex in the Northwest Territories, Canada from 1970 to 2012. Measured climate data are first used to drive surface energy balance simulations for the wetland and peat plateau. Near-surface soil temperatures simulated in the surface energy balance model are then applied as the upper boundary condition to a three-dimensional model of subsurface water flow and coupled energy transport with freeze-thaw. Simulation results demonstrate that lateral heat transfer, which is not considered in many permafrost models, can influence permafrost thaw rates. Furthermore, the simulations indicate that landscape evolution arising from permafrost thaw acts as a positive feedback mechanism that increases the energy absorbed at the land surface and produces additional permafrost thaw. The modeling results also demonstrate that flow rates in local groundwater flow systems may be enhanced by the degradation of isolated permafrost bodies.

  4. Quantifying Permafrost Characteristics with DCR-ERT

    Science.gov (United States)

    Schnabel, W.; Trochim, E.; Munk, J.; Kanevskiy, M. Z.; Shur, Y.; Fortier, R.

    2012-12-01

    Geophysical methods are an efficient method for quantifying permafrost characteristics for Arctic road design and engineering. In the Alaskan Arctic construction and maintenance of roads requires integration of permafrost; ground that is below 0 degrees C for two or more years. Features such as ice content and temperature are critical for understanding current and future ground conditions for planning, design and evaluation of engineering applications. This study focused on the proposed Foothills West Transportation Access project corridor where the purpose is to construct a new all-season road connecting the Dalton Highway to Umiat. Four major areas were chosen that represented a range of conditions including gravel bars, alluvial plains, tussock tundra (both unburned and burned conditions), high and low centered ice-wedge polygons and an active thermokarst feature. Direct-current resistivity using galvanic contact (DCR-ERT) was applied over transects. In conjunction complimentary site data including boreholes, active layer depths, vegetation descriptions and site photographs was obtained. The boreholes provided information on soil morphology, ice texture and gravimetric moisture content. Horizontal and vertical resolutions in the DCR-ERT were varied to determine the presence or absence of ground ice; subsurface heterogeneity; and the depth to groundwater (if present). The four main DCR-ERT methods used were: 84 electrodes with 2 m spacing; 42 electrodes with 0.5 m spacing; 42 electrodes with 2 m spacing; and 84 electrodes with 1 m spacing. In terms of identifying the ground ice characteristics the higher horizontal resolution DCR-ERT transects with either 42 or 84 electrodes and 0.5 or 1 m spacing were best able to differentiate wedge-ice. This evaluation is based on a combination of both borehole stratigraphy and surface characteristics. Simulated apparent resistivity values for permafrost areas varied from a low of 4582 Ω m to a high of 10034 Ω m. Previous

  5. Editorial: Informationstechnische Bildung und Medienerziehung

    Directory of Open Access Journals (Sweden)

    Annemarie Hauf-Tulodziecki

    2001-10-01

    Full Text Available Die schulische Medienerziehung bzw. die Medienbildung hat ihre derzeit hohe öffentliche Aufmerksamkeit nicht zuletzt der Tatsache zu verdanken, dass gerade die so genannten «Neuen Medien» - heute oft mit den Schlagworten «Multimedia» oder «Internet» abgekürzt - wichtige Erziehungs- und Bildungsmassnahmen erforderlich machen. In der öffentlichen Diskussion gehören inhaltliche Kurzschlüsse zur Tagesordnung: Wenn von «Medienkompetenz» die Rede ist, verbirgt sich dahinter häufig nur ein «Internetführerschein». Diese Beobachtung ärgert nicht nur Medienpädagogen, sondern auch Vertreter einer Informationstechnischen Bildung (1, da berechtigte pädagogische Ansprüche beider Gruppen wenig Beachtung finden. Mittlerweile gibt es eine Reihe von Empfehlungen von BLK und KMK zu diesem Thema, in denen zudem deutlich auf die wechselseitigen Bezüge hingewiesen werden. Die wachsende Bedeutung des Mediums Computer und die weiter zunehmende Digitalisierung traditioneller Medien erfordert sowohl für die Medienerziehung als auch für die Informatische Bildung eine Weiterentwicklung ihrer Ziele und Inhalte. Die Gesellschaft für Informatik e.V. hat 1999 in ihrer Empfehlung «Informatische Bildung und Medienerziehung» aus ihrer Perspektive dargestellt, welche Aufgaben auf die Medienerziehung zukommen, wenn auch die Informations- und Kommunikationstechnologien bzw. die computerbasierten Medien in einer angemessenen Form thematisiert werden sollen. Erste praktische Ansätze, Inhalte aus beiden Bereichen bewusst zusammenzuführen, auch unter einer gemeinsamen Fach- oder Kursbezeichnung, sind häufig additiv und orientieren sich – trotz vorhandener Überschneidungen – an den etablierten medienpädagogischen oder an den informatischen Unterrichtsprinzipien. In dem vorliegenden Themenheft wird aus einer übergeordneten, medienpädagogischen Perspektive die Frage gestellt, wie eine konsistente Weiterentwicklung der Medienerziehung unter angemessener

  6. Characterization and Modeling Of Microbial Carbon Metabolism In Thawing Permafrost

    Science.gov (United States)

    Graham, D. E.; Phelps, T. J.; Xu, X.; Carroll, S.; Jagadamma, S.; Shakya, M.; Thornton, P. E.; Elias, D. A.

    2012-12-01

    Increased annual temperatures in the Arctic are warming the surface and subsurface, resulting in thawing permafrost. Thawing exposes large pools of buried organic carbon to microbial degradation, increasing greenhouse gas generation and emission. Most global-scale land-surface models lack depth-dependent representations of carbon conversion and GHG transport; therefore they do not adequately describe permafrost thawing or microbial mineralization processes. The current work was performed to determine how permafrost thawing at moderately elevated temperatures and anoxic conditions would affect CO2 and CH4 generation, while parameterizing depth-dependent GHG production processes with respect to temperature and pH in biogeochemical models. These enhancements will improve the accuracy of GHG emission predictions and identify key biochemical and geochemical processes for further refinement. Three core samples were obtained from discontinuous permafrost terrain in Fairbanks, AK with a mean annual temperature of -3.3 °C. Each core was sectioned into surface/near surface (0-0.8 m), active layer (0.8-1.6 m), and permafrost (1.6-2.2 m) horizons, which were homogenized for physico-chemical characterization and microcosm construction. Surface samples had low pH values (6.0), low water content (18% by weight), low organic carbon (0.8%), and high C:N ratio (43). Active layer samples had higher pH values (6.4), higher water content (34%), more organic carbon (1.4%) and a lower C:N ratio (24). Permafrost samples had the highest pH (6.5), highest water content (46%), high organic carbon (2.5%) and the lowest C:N ratio (19). Most organic carbon was quantified as labile or intermediate pool versus stable pool in each sample, and all samples had low amounts of carbonate. Surface layer microcosms, containing 20 g sediment in septum-sealed vials, were incubated under oxic conditions, while similar active and permafrost layer samples were anoxic. These microcosms were incubated at -2

  7. Mountain Permafrost in the Yukon Territory, Canada: Mapping and Modelling

    Science.gov (United States)

    Lewkowicz, A. G.; Bonnaventure, P.; Schultz, E.; Etzelmuller, B.

    2006-12-01

    The distribution and characteristics of mountain permafrost in North America are poorly known compared to lowland permafrost, and predictions of climatic change impacts are therefore subject to a higher degree of uncertainty. Recent DC resistivity soundings in association with borehole temperature information in the Yukon Territory, show the wide range of permafrost conditions that can exist at sites separated by short distances. To provide baseline information for future modelling, efforts are underway to produce a detailed map of permafrost probability in the mountains of the southern half of the Yukon Territory (60-65°N), an area greater than 200 x 103km2. The methodology is based on the Basal Temperature of Snow (BTS) technique, first developed in the European Alps. Ground surface temperatures measured at the base of snow > 80 cm thick in late winter are an indicator of permafrost presence or absence. We have used this method successfully in three study areas of about 200 km2: first, Wolf Creek basin near Whitehorse (Lewkowicz and Ednie, 2004) and now the western side of the Ruby Range adjacent to Kluane Lake, and the Haines Summit area in northwestern British Columbia. In each area, (1) we installed miniature temperature loggers at the ground surface and in the air to check on the timing of the BTS measurements; (2) we measured BTS values in the elevation zone across which permafrost was expected to become widespread; (3) we modelled the BTS spatial field using elevation (from a 30 m DEM) and potential incoming solar radiation (PISR) as the independent variables; and (4) we used logistic regression to compare the modelled BTS values with pit observations made in late-summer of the presence or absence of frozen ground. Both elevation and PISR were significant in the Wolf Creek and Ruby Range sites which have relatively continental climates and fall within the Upper Yukon-Stikine Basin climatic region (Wahl et al., 1987). For the Haines Summit area, however

  8. Global Governance und libertärer Paternalismus: Akteure, Normativität und Legitimität

    Directory of Open Access Journals (Sweden)

    Mende Janne

    2016-07-01

    Full Text Available Der libertäre Paternalismus weist ähnliche Bezugspunkte auf wie die Global Governance. Bei beiden handelt es sich um ein Bündel staatlicher und nichtstaatlicher Steuerungsversuche, die auf eine Lösung individueller und gesellschaftlicher Probleme abzielen. Eine Verschränkung der Perspektiven beider Konzepte verhilft zu einer genaueren Konturierung ihrer konzeptuellen und normativen Prämissen und zu einer Diskussion ihrer Engführungen und Stärken. Deutlich wird: Der normative Bezugsrahmen des ‚besseren Lebens‘ für die Einzelne (Nudging oder für die Gesellschaft (Global Governance benötigt jeweils genauere Bestimmungen des Verhältnisses von Freiheit und Struktur. Die Regulierungsfähigkeit staatlicher und nichtstaatlicher Akteure wird durch jeweils offenzulegende Legitimitätsannahmen bestimmt. Aus der Perspektivenverschränkung ergeben sich Fragen nach der Strukturierung von Entscheidungsräumen in Global Governance (Nudging Governance und nach den Kriterien für eine Regulierung des libertären Paternalismus (Governing Nudges. Eine Diskussion dieser Fragen ist unabdingbar für eine reflexive Fundierung der Kritik oder der Weiterentwicklung der Konzepte.

  9. Das Sabbatjahr für Lehrerinnen und Lehrer: Wer profitiert und in welcher Form?

    OpenAIRE

    Rothland, Martin

    2013-01-01

    Das Sabbatjahr für Lehrerinnen und Lehrer wird programmatisch als Maßnahme der Belastungsreduktion, der Regeneration sowie der Ressourcenstärkung diskutiert. Empirische Belege für die erwarteten Effekte finden sich jedoch kaum. Im Rahmen einer Längsschnittstudie mit drei Erhebungszeitpunkten vor, während und nach dem Sabbatjahr werden die Entwicklung der Belastungswahrnehmung, des Gesundheitszustands und allgemeiner sowie arbeitsbezogener Emotionen (Berufs- und Lebenszufriedenheit) auf der Ba...

  10. Forschende und ihre Daten: Ergebnisse einer österreichweiten Befragung. Report 2015 – Executive Summary und Empfehlungen

    Directory of Open Access Journals (Sweden)

    Bruno Bauer

    2015-01-01

    Full Text Available Der vorliegende Beitrag bringt Executive Summary und Empfehlungen aus „Forschende und ihre Daten: Ergebnisse einer österreichweiten Befragung. Report 2015“. Dieser Report gibt einen Überblick über die österreichweite Befragung zu Forschungsdaten, die im Rahmen des Projekts e-Infrastructures Austria 2015 durchgeführt wurde. Diese richtete sich an das wissenschaftliche und künstlerisch-wissenschaftliche Personal aller 21 öffentlichen Universitäten sowie an drei außeruniversitäre Forschungseinrichtungen in Österreich. Die Teilnehmenden wurden zu folgenden Themenbereichen befragt: Datentypen und Formate; Datenarchivierung, -sicherung und -verlust; ethische und rechtliche Aspekte; Zugänglichkeit und Nachnutzung; Infrastruktur und Services. Die in diesem Kontext erstmals auf nationaler Ebene durchgeführte Befragung diente der Erhebung des praktischen Umgangs mit Forschungsdaten in Österreich und ist somit die Basis für eine konsekutive Optimierung der zweckdienlichen Infrastruktur, für eine Anpassung der Serviceangebote sowie für eine Neuorientierung bei der Ermittlung von Ressourcen in diesem strategischen Bereich entsprechend der geäußerten Bedürfnisse der im Forschungsprozess Tätigen.

  11. Bewältigungsstrategien der Oberwalliser Primarlehrpersonen und Massnahmen der Gesundheitsförderung an Oberwalliser Primarschulen bei Stress und Burnout

    OpenAIRE

    Imhof, Barbara; Mattig, Astrid

    2009-01-01

    Die vorliegende Studie befasst sich mit der Gesundheitsförderung bei Stress und Burnout an den Oberwalliser Primarschulen und der Bewältigungsstrategien der Oberwalliser Primarlehrpersonen bei Stress und Burnout. Der theoretische Teil befasst sich mit Stress und Burnout und der Bewältigung von Stress und Burnout. Verschiedene Aspekte des Lehrerberufs werden näher angeschaut und es werden mögliche Massnahmen der Gesundheitsförderung bei Stress und Burnout aufgeführt. Die Untersuchung zeigt, da...

  12. Ice-Rich Yedoma Permafrost: A Synthesis of Circum-Arctic Distribution and Thickness

    Science.gov (United States)

    Strauss, J.; Fedorov, A. N.; Fortier, D.; Froese, D. G.; Fuchs, M.; Grosse, G.; Günther, F.; Harden, J. W.; Hugelius, G.; Kanevskiy, M. Z.; Kholodov, A. L.; Kunitsky, V.; Laboor, S.; Lapointe Elmrabti, L.; Rivkina, E.; Robinson, J. E.; Schirrmeister, L.; Shmelev, D.; Shur, Y.; Spektor, V.; Ulrich, M.; Veremeeva, A.; Walter Anthony, K. M.; Zimov, S. A.

    2015-12-01

    Vast portions of Arctic and sub-Arctic Siberia, Alaska and the Yukon Territory are covered by ice-rich silts that are penetrated by large ice wedges, resulting from syngenetic sedimentation and freezing. Accompanied by wedge-ice growth, the sedimentation process was driven by cold continental climatic and environmental conditions in unglaciated regions during the late Pleistocene, inducing the accumulation of the unique Yedoma permafrost deposits up to 50 meter thick. Because of fast incorporation of organic material into permafrost during formation, Yedoma deposits include low-decomposed organic matter. Moreover, ice-rich permafrost deposits like Yedoma are especially prone to degradation triggered by climate changes or human activity. When Yedoma deposits degrade, large amounts of sequestered organic carbon as well as other nutrients are released and become part of active biogeochemical cycling. This could be of global significance for the climate warming, as increased permafrost thaw is likely to cause a positive feedback loop. Therefore, a detailed assessment of the Yedoma deposit volume is of importance to estimate its potential future climate response. Moreover, as a step beyond the objectives of this synthesis study, our coverage (see figure for the Yedoma domain) and thickness estimation will provide critical data to refine the Yedoma permafrost organic carbon inventory, which is assumed to have freeze-locked between 83±12 and 129±30 gigatonnes (Gt) of organic carbon. Hence, we here synthesize data on the circum-Arctic and sub-Arctic distribution and thickness of Yedoma permafrost (see figure for the Yedoma domain) in the framework of an Action Group funded by the International Permafrost Association (IPA). The quantification of the Yedoma coverage is conducted by the digitization of geomorphological and Quaternary geological maps. Further data on Yedoma thickness is contributed from boreholes and exposures reported in the scientific literature.

  13. The impacts of recent permafrost thaw on land-atmosphere greenhouse gas exchange

    Science.gov (United States)

    Hayes, Daniel J.; Kicklighter, David W.; McGuire, A. David; Chen, Min; Zhuang, Qianlai; Yuan, Fengming; Melillo, Jerry M.; Wullschleger, Stan D.

    2014-01-01

    Permafrost thaw and the subsequent mobilization of carbon (C) stored in previously frozen soil organic matter (SOM) have the potential to be a strong positive feedback to climate. As the northern permafrost region experiences as much as a doubling of the rate of warming as the rest of the Earth, the vast amount of C in permafrost soils is vulnerable to thaw, decomposition and release as atmospheric greenhouse gases. Diagnostic and predictive estimates of high-latitude terrestrial C fluxes vary widely among different models depending on how dynamics in permafrost, and the seasonally thawed 'active layer' above it, are represented. Here, we employ a process-based model simulation experiment to assess the net effect of active layer dynamics on this 'permafrost carbon feedback' in recent decades, from 1970 to 2006, over the circumpolar domain of continuous and discontinuous permafrost. Over this time period, the model estimates a mean increase of 6.8 cm in active layer thickness across the domain, which exposes a total of 11.6 Pg C of thawed SOM to decomposition. According to our simulation experiment, mobilization of this previously frozen C results in an estimated cumulative net source of 3.7 Pg C to the atmosphere since 1970 directly tied to active layer dynamics. Enhanced decomposition from the newly exposed SOM accounts for the release of both CO2 (4.0 Pg C) and CH4 (0.03 Pg C), but is partially compensated by CO2 uptake (0.3 Pg C) associated with enhanced net primary production of vegetation. This estimated net C transfer to the atmosphere from permafrost thaw represents a significant factor in the overall ecosystem carbon budget of the Pan-Arctic, and a non-trivial additional contribution on top of the combined fossil fuel emissions from the eight Arctic nations over this time period.

  14. Trauma und Terror

    OpenAIRE

    Szyszkowitz, T. (Tessa)

    2007-01-01

    1. Einleitung Ausgehend von der Fragestellung, warum gerade bei Tschetschenen und Palästinensern der Selbstmordterrorismus in den letzten Jahren so populär geworden ist, analysiert die Autorin die Geschichte dieser beiden Völker. Einer der Gründe ist bisher wenig beachtet worden. Der Einfluss eines kollektiven Traumas, das als solches nicht anerkannt, behandelt und auch nicht einer politischen Lösung zugeführt wurde. 2. Geschichte der Palästinenser und Tschetschenen Im Zuge der Err...

  15. [St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879)] / Felix Köther

    Index Scriptorium Estoniae

    Köther, Felix

    2015-01-01

    Arvustus: St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879) / bearbeitet von Hartmut Walravens. Wiesbaden : Harrassowitz, 2013. (Orientalistik-Bibliographien und Dokumentationen ; Bd. 22)

  16. Work-Life-Balance und Frauenbiographien

    OpenAIRE

    Macha, Hildegard

    2006-01-01

    Work-Life-Balance und Frauenbiographien. - In: Bildungs- und Karrierewege von Frauen / Anne Schlüter (Hrsg.). - Opladen : Budrich, 2006. - S. 17-32. - (Reihe: Frauen- und Geschlechterforschung in der Erziehungswissenschaft ; 2)

  17. Determinants of carbon release from the active layer and permafrost deposits on the Tibetan Plateau

    Science.gov (United States)

    Chen, Leiyi; Liang, Junyi; Qin, Shuqi; Liu, Li; Fang, Kai; Xu, Yunping; Ding, Jinzhi; Li, Fei; Luo, Yiqi; Yang, Yuanhe

    2016-01-01

    The sign and magnitude of permafrost carbon (C)-climate feedback are highly uncertain due to the limited understanding of the decomposability of thawing permafrost and relevant mechanistic controls over C release. Here, by combining aerobic incubation with biomarker analysis and a three-pool model, we reveal that C quality (represented by a higher amount of fast cycling C but a lower amount of recalcitrant C compounds) and normalized CO2–C release in permafrost deposits were similar or even higher than those in the active layer, demonstrating a high vulnerability of C in Tibetan upland permafrost. We also illustrate that C quality exerts the most control over CO2–C release from the active layer, whereas soil microbial abundance is more directly associated with CO2–C release after permafrost thaw. Taken together, our findings highlight the importance of incorporating microbial properties into Earth System Models when predicting permafrost C dynamics under a changing environment. PMID:27703168

  18. Herausforderungen kleiner und mittlerer Unternehmen

    Science.gov (United States)

    Bergmann, Lars; Crespo, Isabel

    Vielfältige externe Herausforderungen, hervorgerufen durch die Dynamik, mit der sich die wirtschaftliche, technologische, soziokulturelle sowie politische Umwelt wandelt, muss jedes Unternehmen im Laufe der Zeit bestehen (Zäpfel 2000). Diese Herausforderungen werden heute insbesondere durch eine Globalisierung der Wettbewerbssowie Nachfragestrukturen verstärkt. Immer schnellere Prozessund Produktinnovationen, kürzere Produktlebenszyklen und Entwicklungszeiten, eine rasant steigende Variantenvielfalt, Nachfrageschwankungen sowie rasante Entwicklungen der Informations- und Kommunikationstechnologien sind einige der sich schnell verändernden Rahmenbedingungen. Zudem müssen sich Unternehmen an neue Gesetze und rechtliche Rahmenbedingungen anpassen. Im Bereich der Roh- und Einsatzstoffe sind Veränderungen insbesondere durch sich verknappende Rohstoffe und Primärenergieträger und in Folge dessen durch drastische Preissteigerungen für Materialien, Hilfsstoffe, Werkzeuge etc. geprägt.

  19. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil I] / Heinrich Wittram

    Index Scriptorium Estoniae

    Wittram, Heinrich, 1931-

    2011-01-01

    Arvustus : Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil I. Münster : Aschendorff, 2009. (Katholisches Leben und Kirchenreform im Zeitalter der Glaubensspaltung, 69)

  20. PeRL: A circum-Arctic Permafrost Region Pond and Lake database

    Science.gov (United States)

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A.B.K.; Sjoberg, Ylva; Gunther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, J.; Siewert, Matthias B.; Riley, William J.; Koven, Charles; Boike, Julia

    2017-01-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( s.l.) land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands. Waterbody maps, study area

  1. Shifts of methanogenic communities in response to permafrost thaw results in rising methane emissions and soil property changes.

    Science.gov (United States)

    Wei, Shiping; Cui, Hongpeng; Zhu, Youhai; Lu, Zhenquan; Pang, Shouji; Zhang, Shuai; Dong, Hailiang; Su, Xin

    2018-05-01

    Permafrost thaw can bring negative consequences in terms of ecosystems, resulting in permafrost collapse, waterlogging, thermokarst lake development, and species composition changes. Little is known about how permafrost thaw influences microbial community shifts and their activities. Here, we show that the dominant archaeal community shifts from Methanomicrobiales to Methanosarcinales in response to the permafrost thaw, and the increase in methane emission is found to be associated with the methanogenic archaea, which rapidly bloom with nearly tenfold increase in total number. The mcrA gene clone libraries analyses indicate that Methanocellales/Rice Cluster I was predominant both in the original permafrost and in the thawed permafrost. However, only species belonging to Methanosarcinales showed higher transcriptional activities in the thawed permafrost, indicating a shift of methanogens from hydrogenotrophic to partly acetoclastic methane-generating metabolic processes. In addition, data also show the soil texture and features change as a result of microbial reproduction and activity induced by this permafrost thaw. Those data indicate that microbial ecology under warming permafrost has potential impacts on ecosystem and methane emissions.

  2. Permafrost in vegetated scree slopes below the timberline - characterization of thermal properties and permafrost conditions by temperature measurements and geoelectrical monitoring

    Science.gov (United States)

    Schwindt, Daniel; Kneisel, Christof

    2010-05-01

    Discontinuous alpine permafrost is expected to exist at altitudes above 2400m a.s.l. at mean annual air temperatures (MAAT) of less than -1°C. Below timberline only a few sites are known, where sporadic permafrost exists in vegetated talus slopes with positive MAAT. Aim of the study is to characterize permafrost-humus interaction, the thermal regime and its influence on temporal and spatial permafrost variability. Results of geophysical and thermal measurements from three talus slopes, located in the Swiss Alps (Engadin, Appenzell) at elevations between 1200 and 1800m a.s.l. with MAAT between 2.8°C and 5.5°C are presented. Parent rock-material of the slopes are granite (Bever Valley, Engadin) and dolomite (Susauna Valley, Engadin; Brüeltobel, Appenzell). Joint application of electrical resistivity tomography (ERT) and refraction seismic tomography (RST) is used to detect and characterize permafrost. To observe temporal and spatial variability in ice content and characteristics year-around geoelectrical monitoring and quasi-3D ERT are used. A forward modeling approach has been applied to validate the results of geoelectrical monitoring. A number of temperature data loggers were installed in different depth of the humus layer and in different positions of the slope to monitor the ground thermal regime. Isolated permafrost has been detected by the combination of ERT and RST in the lower parts of the investigated talus slopes. Results from geophysical measurements and monitoring indicate a high spatial and temporal variability in ice content and ice characteristics (temperature, density, content of unfrozen water) for all sites. A distinct rise of resistivities between November and December indicates a decrease of unfrozen water content, caused by a pronounced cooling in the lower parts of the slope. Decreasing ice content and extent of the permafrost lenses can be observed in decreasing seismic velocities from 2600m/sec in spring to only 1500m/sec in October. Ice

  3. GIS und Fernerkundung für Landschaftsmonitoring und Landschaftsplanung

    Science.gov (United States)

    Blaschke, Thomas

    2002-09-01

    Der Beitrag beleuchtet die Rolle der Geographischen Informationsverarbeitung hinsichtlich der Aufgaben in der Umweltüberwachung. Dabei wird über etablierte "sektorale" Umweltbeobachtungssysteme (Boden, Wasser, Luft) hinaus zunehmend der Bedarf an einer integrativen Betrachtung der Landschaft deutlich, insbesondere in mittleren bis kleinen Maßstäben. Wie verändern sich ganze Landschaften in Deutschland, in Europa? Welches sind Bereiche kritischer Abnahme landschaftlicher Diversität? Wie können landschaftliche Vielfalt und Eigenart erhalten beziehungsweise deren Erhalt überwacht werden? Diese und weitere Fragen drängen sich vor allem bei der Erstellung langfristiger Szenarien der Veränderung ganzer Landschaften und in der Nachhaltigkeitsdiskussion auf.

  4. Suggested best practice for geotechnical characterisation of permafrost in the Nordic countries

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas; Foged, Niels Nielsen

    2012-01-01

    Even though permafrost is a specialty within Nordic geotechnical engineering, engineers and researcher will be faced with managing the consequences of projected climatic influences to construction design in permafrost areas. This requires the determination of the frozen soil engineering propertie...

  5. Effect of permafrost properties on gas hydrate petroleum system in the Qilian Mountains, Qinghai, Northwest China.

    Science.gov (United States)

    Wang, Pingkang; Zhang, Xuhui; Zhu, Youhai; Li, Bing; Huang, Xia; Pang, Shouji; Zhang, Shuai; Lu, Cheng; Xiao, Rui

    2014-12-01

    The gas hydrate petroleum system in the permafrost of the Qilian Mountains, which exists as an epigenetic hydrocarbon reservoir above a deep-seated hydrocarbon reservoir, has been dynamic since the end of the Late Pleistocene because of climate change. The permafrost limits the occurrence of gas hydrate reservoirs by changing the pressure-temperature (P-T) conditions, and it affects the migration of the underlying hydrocarbon gas because of its strong sealing ability. In this study, we reconstructed the permafrost structure of the Qilian Mountains using a combination of methods and measured methane permeability in ice-bearing sediment permafrost. A relationship between the ice saturation of permafrost and methane permeability was established, which permitted the quantitative evaluation of the sealing ability of permafrost with regard to methane migration. The test results showed that when ice saturation is >80%, methane gas can be completely sealed within the permafrost. Based on the permafrost properties and genesis of shallow gas, we suggest that a shallow "gas pool" occurred in the gas hydrate petroleum system in the Qilian Mountains. Its formation was related to a metastable gas hydrate reservoir controlled by the P-T conditions, sealing ability of the permafrost, fault system, and climatic warming. From an energy perspective, the increasing volume of the gas pool means that it will likely become a shallow gas resource available for exploitation; however, for the environment, the gas pool is an underground "time bomb" that is a potential source of greenhouse gas.

  6. Zu den Grundlagen der visuellen Soziologie: Wahrnehmen und Sehen, Beobachten und Betrachten

    OpenAIRE

    Bachleitner, Reinhard; Weichbold, Martin

    2015-01-01

    In diesem Beitrag werden die visuellen Modi des Wahrnehmens – das Sehen, Beobachten und Betrachten – in ihrem Wesen skizziert, und die doppelte Theorieabhängigkeit von Wahrnehmungsprozessen wird thematisiert. Dabei zeigt sich, dass mehrere offene methodologische und erkenntnistheoretische Fragen durch die Differenzierung des Wahrnehmungsvorgangs in drei Stufen (reines Sehen, kognitive Repräsentation, Transformation des Perzepts in Worte) sowie die Differenzierung der Wahrnehmungsmodi in jewei...

  7. Circumpolar assessment of permafrost C quality and its vulnerability over time using long-term incubation data

    DEFF Research Database (Denmark)

    Schädel, Christina; Schuur, Edward A.G.; Bracho, Rosvel

    2014-01-01

    High-latitude ecosystems store approximately 1700 Pg of soil carbon (C), which is twice as much C as is currently contained in the atmosphere. Permafrost thaw and subsequent microbial decomposition of permafrost organic matter could add large amounts of C to the atmosphere, thereby influencing...... the global C cycle. The rates at which C is being released from the permafrost zone at different soil depths and across different physiographic regions are poorly understood but crucial in understanding future changes in permafrost C storage with climate change. We assessed the inherent decomposability of C...... from the permafrost zone by assembling a database of long-term (>1 year) aerobic soil incubations from 121 individual samples from 23 high-latitude ecosystems located across the northern circumpolar permafrost zone. Using a three-pool (i.e., fast, slow and passive) decomposition model, we estimated...

  8. The Thermal State of Permafrost in the Nordic Area during the International Polar Year 2007-2009

    DEFF Research Database (Denmark)

    Christiansen, H. H.; Etzelmuller, B.; Isaksen, K.

    2010-01-01

    This paper provides a snapshot of the permafrost thermal state in the Nordic area obtained during the International Polar Year (IPY) 2007-2009. Several intensive research campaigns were undertaken within a variety of projects in the Nordic countries to obtain this snapshot. We demonstrate...... for Scandinavia that both lowland permafrost in palsas and peat plateaus, and large areas of permafrost in the mountains are at temperatures close to 0 degrees C, which makes them sensitive to climatic changes. In Svalbard and northeast Greenland, and also in the highest parts of the mountains in the rest...... affect the permafrost thermal state in the Nordic area. Time series of active-layer thickness and permafrost temperature conditions in the Nordic area, which are generally only 10 years in length, show generally increasing active-layer depths and risings permafrost temperatures....

  9. The potential significance of permafrost to the behaviour of a deep radioactive waste repository

    International Nuclear Information System (INIS)

    McEwen, T.; Marsily, G.de

    1991-02-01

    Permafrost is one of the scenarios that is being considered as part of the groundwater flow and transport modelling for the Project-90 assessment. It is included as one of the primary Features, Events and Processes (FEPs) which are being kept outside the Process System in the SKB/SKI scenario development project. There is a large amount of evidence that Sweden has suffered several cycles of permafrost development over the Quaternary, approximately the last 2My, and climatic predictions for the next hundred thousand years suggest that similar climatic cycling is likely to occur. The presence of permafrost could have important effects on the hydrogeological regime and could therefore be important in modifying the release and dispersion of radionuclides from a repository. The climatic conditions of permafrost would also influence radionuclide migration and accumulation in the biosphere and the associated radiation exposure of man. These biosphere aspects are not considered here but the implications for discharge into the biosphere are examined, including the abstraction of groundwater by man in permafrost regions. This report reviews the evidence relating to permafrost development and discusses the possible implications for the long-term safety of a deep repository. (78 refs.) (au)

  10. Vejbygning i områder med permafrost

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr

    2009-01-01

    Siden begyndelsen af 1990’erne er der registreret en markant stigning i den årlige middeltemperatur i Nunavik, Québec Canada. Dette har ført til en reduktion i udbredelsen af permafrost, hvilket truer stabiliteten af lufthavne og veje i området. I sommeren 2007 blev en teststrækning opført i...... Tasiujaq Lufthavn for at studere effekten af tre forskellige metoder, som skal være med til at reducere optøningen af permafrost under landingsbanen. De tre metoder, som er blevet undersøgt, er konvektionskøling (air convection embankment), varmeudtrækning (heat drain) samt et forsøg med ændring af...

  11. Permafrost at Lupin. Interpretation of SAMPO electromagnetic soundings at Lupin

    Energy Technology Data Exchange (ETDEWEB)

    Paananen, M.; Ruskeeniemi, T

    2003-07-01

    The Permafrost Project at the Lupin Mine in northern Canada is an international project, aiming to improve the understanding of behaviour and processes of crystalline bedrock under permafrost conditions. As a part of this project, the Geological Survey of Finland carried out electromagnetic SAMPO soundings in the vicinity of the mine between 11th and 23rd of June 2002 in order to give additional information on the permafrost depth, the location and electrical characteristics of fracture zones and possible talik structures. The total number of sounding points was 214, forming 17 separate survey lines. Used coil separation was 100 - 800 m. According to the temperature data from Lupin Mine, the base of the permafrost is at the depth of 540 m. However, there is no information about the depth distribution outside the mine. The starting point of this survey was the possible existence of a saline water horizon below the permafrost, resulting from repeated segregation and enrichment of salts in front of advancing freezing front. The main result of the survey was a deep conductor, observed at numerous sounding points irrespectively of the measurement configuration. These sounding anomalies form a subhorizontal layer at the depths between 400 and 700 m, in contrast to the vertical orientation of the geological units in the area. According to the results, the conductor gets weaker or deeper close to the Lake Contwoyto and seems to be absent below the lake. There also seems to be a lithological control, since the conducting layer is not observed in granodiorite. It is assumed that the conducting layer represents saline or brackish waters at the base of the permafrost; their calculated TDS-values are in a realistic range for such waters (5000-30 000 mg/l). The subvertical fracture zone VI, previously interpreted from the seismic survey, could be observed as a slight decrease in resistivity in 3 survey profiles using a coil separation of 100 m. (orig.)

  12. Permafrost at Lupin. Interpretation of SAMPO electromagnetic soundings at Lupin

    International Nuclear Information System (INIS)

    Paananen, M.; Ruskeeniemi, T.

    2003-01-01

    The Permafrost Project at the Lupin Mine in northern Canada is an international project, aiming to improve the understanding of behaviour and processes of crystalline bedrock under permafrost conditions. As a part of this project, the Geological Survey of Finland carried out electromagnetic SAMPO soundings in the vicinity of the mine between 11th and 23rd of June 2002 in order to give additional information on the permafrost depth, the location and electrical characteristics of fracture zones and possible talik structures. The total number of sounding points was 214, forming 17 separate survey lines. Used coil separation was 100 - 800 m. According to the temperature data from Lupin Mine, the base of the permafrost is at the depth of 540 m. However, there is no information about the depth distribution outside the mine. The starting point of this survey was the possible existence of a saline water horizon below the permafrost, resulting from repeated segregation and enrichment of salts in front of advancing freezing front. The main result of the survey was a deep conductor, observed at numerous sounding points irrespectively of the measurement configuration. These sounding anomalies form a subhorizontal layer at the depths between 400 and 700 m, in contrast to the vertical orientation of the geological units in the area. According to the results, the conductor gets weaker or deeper close to the Lake Contwoyto and seems to be absent below the lake. There also seems to be a lithological control, since the conducting layer is not observed in granodiorite. It is assumed that the conducting layer represents saline or brackish waters at the base of the permafrost; their calculated TDS-values are in a realistic range for such waters (5000-30 000 mg/l). The subvertical fracture zone VI, previously interpreted from the seismic survey, could be observed as a slight decrease in resistivity in 3 survey profiles using a coil separation of 100 m. (orig.)

  13. Soziologische Wissenskulturen zwischen individualisierter Inspiration und prozeduraler Legitimation. Zur Entwicklung qualitativer und interpretativer Sozialforschung in der deutschen und französischen Soziologie seit den 1960er Jahren

    Directory of Open Access Journals (Sweden)

    Reiner Keller

    2016-01-01

    Full Text Available Wie wissen Soziologinnen und Soziologen, was sie wissen? Trotz der Internationalisierung der Soziologie bestehen nach wie vor starke sprachräumliche Unterschiede in der soziologischen Wissensproduktion, in eingesetzten Theorien, Methoden und Fragestellungen. Der nachfolgende Beitrag erläutert die Entwicklung und Ausprägung der Unterschiedlichkeit soziologischer Wissenskulturen im Hinblick auf den Einsatz qualitativer bzw. interpretativer Ansätze seit den 1960er Jahren in Deutschland und Frankreich. Er stützt sich auf ein von uns 2012-2014 geleitetes Forschungsprojekt und dessen empirische Grundlagen: Dokumentenanalysen und Interviews. Wissenskulturen werden als die Arten und Weisen der Produktion und Legitimation von (hier: soziologischem Wissen verstanden. Diesbezüglich lässt sich von der Erkenntnisproduktion als dem zentralen Handlungsproblem soziologischen Forschens sprechen. Während für die französischsprachige Soziologie diagnostisch von einer Lösung dieses Erkenntnisproblems durch die den Forschenden zugeschriebenen Kompetenzen und Inspirationen ausgegangen werden kann, schiebt sich im deutschsprachigen Raume eine prozedurale Legitimation durch Verfahren in den Vordergrund. Der Beitrag rekonstruiert exemplarisch die Ausgangssituation dieser Entwicklungen um die Wende zu den 1960er Jahren und bettet sie in die weitere Entfaltung der jeweiligen Soziologien ein. Er will damit zur gegenwärtigen Entwicklung einer reflexiven Soziologie beitragen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1601145

  14. Mountain permafrost, glacier thinning, and slope stability - a perspective from British Columbia (and Alaska)

    Science.gov (United States)

    Geertsema, Marten

    2016-04-01

    The association of landslides with thinning glaciers and mapped, or measured, mountain permafrost is increasing. Glacier thinning debuttresses slopes and promotes joint expansion. It is relatively easy to map. Permafrost, a thermal condition, is generally not visually detectible, and is difficult to map. Much mountain permafrost may have been overlooked in hazard analysis. Identifying, and characterizing mountain permafrost, and its influence on slope instability is crucial for hazard and risk analysis in mountainous terrain. Rock falls in mountains can be the initial event in process chains. They can transform into rock avalanches, debris flows or dam burst floods, travelling many kilometres, placing infrastructure and settlements at risk.

  15. Groundwater storage changes in arctic permafrost watersheds from GRACE and in situ measurements

    International Nuclear Information System (INIS)

    Muskett, Reginald R; Romanovsky, Vladimir E

    2009-01-01

    The Arctic permafrost regions make up the largest area component of the cryosphere. Observations from the Gravity Recovery and Climate Experiment (GRACE) mission offer to provide a greater understanding of changes in water mass within permafrost regions. We investigate a GRACE monthly time series, snow water equivalent from the special scanning microwave imager (SSM/I), vegetation water content and soil moisture from the advanced microwave scanning radiometer for the Earth observation system (AMSR-E) and in situ discharge of the Lena, Yenisei, Ob', and Mackenzie watersheds. The GRACE water equivalent mass change responded to mass loading by snow accumulation in winter and mass unloading by runoff in spring-summer. Comparison of secular trends from GRACE to runoff suggests groundwater storage increased in the Lena and Yenisei watersheds, decreased in the Mackenzie watershed, and was unchanged in the Ob' watershed. We hypothesize that the groundwater storage changes are linked to the development of closed- and open-talik in the continuous permafrost zone and the decrease of permafrost lateral extent in the discontinuous permafrost zone of the watersheds.

  16. Neue Medien in der Lehrerausbildung. Zu angemessenen (und unangemessenen Zielen und Inhalten des Lehramtsstudiums

    Directory of Open Access Journals (Sweden)

    Sigrid Blömeke

    2003-01-01

    Full Text Available In vier Schritten wird dem Verhältnis von Lehrerausbildung und neuen Medien nachgegangen. Zunächst werden grundsätzliche medienpädagogische Aufgaben der Lehrerausbildung herausgearbeitet, bevor das Ausbildungsprofil ihrer ersten und zweiten Phase in den Blick genommen wird. Ausgangspunkt der Theoriebildung sind professions- und institutionentheoretische Ansätze, die auf die neuen Medien bezogen werden; Konkretisierungen erfolgen an Beispielen aus der Germanistik, der Anglistik, der Geschichte und der Mathematik. Anschliessend wird der Erwerb medienpädagogischer Kompetenz durch zukünftige Lehrerinnen und Lehrer von dem Erwerb basaler Medienkompetenz als eines Elements von Allgemeinbildung abgegrenzt. Zum Schluss werden Konsequenzen für die strukturelle Gestaltung der Lehrerausbildung gezogen.

  17. Landscape effects of wildfire on permafrost distribution in interior Alaska derived from remote sensing

    Science.gov (United States)

    Brown, Dana R. N.; Jorgenson, M. Torre; Kielland, Knut; Verbyla, David L.; Prakash, Anupma; Koch, Joshua C.

    2016-01-01

    Climate change coupled with an intensifying wildfire regime is becoming an important driver of permafrost loss and ecosystem change in the northern boreal forest. There is a growing need to understand the effects of fire on the spatial distribution of permafrost and its associated ecological consequences. We focus on the effects of fire a decade after disturbance in a rocky upland landscape in the interior Alaskan boreal forest. Our main objectives were to (1) map near-surface permafrost distribution and drainage classes and (2) analyze the controls over landscape-scale patterns of post-fire permafrost degradation. Relationships among remote sensing variables and field-based data on soil properties (temperature, moisture, organic layer thickness) and vegetation (plant community composition) were analyzed using correlation, regression, and ordination analyses. The remote sensing data we considered included spectral indices from optical datasets (Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI)), the principal components of a time series of radar backscatter (Advanced Land Observing Satellite—Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR)), and topographic variables from a Light Detection and Ranging (LiDAR)-derived digital elevation model (DEM). We found strong empirical relationships between the normalized difference infrared index (NDII) and post-fire vegetation, soil moisture, and soil temperature, enabling us to indirectly map permafrost status and drainage class using regression-based models. The thickness of the insulating surface organic layer after fire, a measure of burn severity, was an important control over the extent of permafrost degradation. According to our classifications, 90% of the area considered to have experienced high severity burn (using the difference normalized burn ratio (dNBR)) lacked permafrost after fire. Permafrost thaw, in turn, likely increased drainage and resulted in

  18. Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes

    International Nuclear Information System (INIS)

    Torre Jorgenson, M; Harden, Jennifer; Manies, Kristen; Kanevskiy, Mikhail; Shur, Yuri; O’Donnell, Jonathan; Wickland, Kim; Striegl, Robert; Ewing, Stephanie; Zhuang Qianlai; Koch, Josh

    2013-01-01

    The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil organic carbon (SOC) stocks along successional gradients within four landscapes: (1) rocky uplands on ice-poor hillside colluvium, (2) silty uplands on extremely ice-rich loess, (3) gravelly–sandy lowlands on ice-poor eolian sand and (4) peaty–silty lowlands on thick ice-rich peat deposits over reworked lowland loess. In rocky uplands, after fire permafrost thawed rapidly due to low ice contents, soils became well drained and SOC stocks decreased slightly. In silty uplands, after fire permafrost persisted, soils remained saturated and SOC decreased slightly. In gravelly–sandy lowlands where permafrost persisted in drier forest soils, loss of deeper permafrost around lakes has allowed recent widespread drainage of lakes that has exposed limnic material with high SOC to aerobic decomposition. In peaty–silty lowlands, 2–4 m of thaw settlement led to fragmented drainage patterns in isolated thermokarst bogs and flooding of soils, and surface soils accumulated new bog peat. We were not able to detect SOC changes in deeper soils, however, due to high variability. Complicated soil stratigraphy revealed that permafrost has repeatedly aggraded and degraded in all landscapes during the Holocene, although in silty uplands only the upper permafrost was affected. Overall, permafrost thaw has led to the reorganization of vegetation, water storage and flow paths, and patterns of SOC accumulation. However, changes have occurred over different timescales among landscapes: over decades in rocky uplands and gravelly–sandy lowlands in response to fire and lake drainage, over decades to

  19. Landscape Effects of Wildfire on Permafrost Distribution in Interior Alaska Derived from Remote Sensing

    Directory of Open Access Journals (Sweden)

    Dana R.N. Brown

    2016-08-01

    Full Text Available Climate change coupled with an intensifying wildfire regime is becoming an important driver of permafrost loss and ecosystem change in the northern boreal forest. There is a growing need to understand the effects of fire on the spatial distribution of permafrost and its associated ecological consequences. We focus on the effects of fire a decade after disturbance in a rocky upland landscape in the interior Alaskan boreal forest. Our main objectives were to (1 map near-surface permafrost distribution and drainage classes and (2 analyze the controls over landscape-scale patterns of post-fire permafrost degradation. Relationships among remote sensing variables and field-based data on soil properties (temperature, moisture, organic layer thickness and vegetation (plant community composition were analyzed using correlation, regression, and ordination analyses. The remote sensing data we considered included spectral indices from optical datasets (Landsat 7 Enhanced Thematic Mapper Plus (ETM+ and Landsat 8 Operational Land Imager (OLI, the principal components of a time series of radar backscatter (Advanced Land Observing Satellite—Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR, and topographic variables from a Light Detection and Ranging (LiDAR-derived digital elevation model (DEM. We found strong empirical relationships between the normalized difference infrared index (NDII and post-fire vegetation, soil moisture, and soil temperature, enabling us to indirectly map permafrost status and drainage class using regression-based models. The thickness of the insulating surface organic layer after fire, a measure of burn severity, was an important control over the extent of permafrost degradation. According to our classifications, 90% of the area considered to have experienced high severity burn (using the difference normalized burn ratio (dNBR lacked permafrost after fire. Permafrost thaw, in turn, likely increased drainage and resulted

  20. International student Arctic Field School on Permafrost and urban areas study

    Science.gov (United States)

    Suter, L.; Tolmanov, V. A.; Grebenets, V. I.; Streletskiy, D. A.; Shiklomanov, N. I.

    2017-12-01

    Arctic regions are experiencing drastic climatic and environmental changes. These changes are exacerbated in the Russian Arctic, where active resource development resulted in further land cover transformations, especially near large settlements. There is a growing need in multidisciplinary studies of climate and human- induced changes in the Arctic cities. In order to fill this gap, International Arctic Field Course on Permafrostand Northern Studies was organized in July 2017 to the Russian Arctic. The course was organized under the umbrella of the Arctic PIRE project in cooperation between the George Washington University, Moscow State University, and the Russian Center for Arctic Development. The course attracted twenty undergraduate and graduate students from Russia, USA, and EU countries and involved instructors specializing in Arctic system science, geocryology, permafrost engineering, and urban sustainability. The field course was focused on studying typical natural Arctic landscapes of tundra and forest tundra; transformations of natural landscapes in urban and industrial areas around Vorkuta and Salekhard; construction and planning on permafrost and field methods and techniques, including permafrost and soil temperature monitoring, active layer thickness (ALT) measurements, studying of cryogenic processes, stratigraphic and soil investigations, vegetation and microclimate studies. The students were also engaged in a discussion of climatic change and historical development of urban areas on permafrost,and were exposed to examples of both active and passive construction principles while conducting a field survey of permafrost related building deformations. During the course, students collected more than 800 ALT and soil temperature measurements in typical landscapes around Vorkuta and Salekhard to determine effects of soil and vegetation factors on ground thermal regime; surveyed several hundreds of buildings to determine locations with most deformation

  1. Selection of compressors and drives for natural gas storage and transport - technical and economic aspects; Auswahl von Verdichtern und Antriebsmaschinen fuer die Erdgasspeicherung und den Erdgastransport - technische und wirtschaftliche Aspekte

    Energy Technology Data Exchange (ETDEWEB)

    Heyer, F.; Wieke, S. [Heyer und Wieke Engineering, Muenchen (Germany)

    1998-12-31

    Selection of the proper compressor/drive combination is indispensable for optimizing natural gas storage. The contribution presents a comparison of the available systems. (orig.) [Deutsch] Fuer die Verdichtung von Erdgas fuer die Erdgasspeicherung und den Erdgastransport ist die Auswahl der fuer den jeweiligen Anwendungsfall geeigneten Verdichter-Antriebskombination eine wesentliche Voraussetzung fuer einen technisch und wirtschaftlich optimalen Betrieb. Unter Beruecksichtigung des Marktes werden die Varianten (Verdichter-Antriebskombinationen) definiert und in einem technischen Vergleich Vor- und Nachteile der einzelnen Alternativen gegenuebergestellt und bewertet. Die Einhaltung der Betriebsanforderungen und der Anforderungen der TA-Luft und TA-Laerm, der Wirkungsgrad, die Zuverlaessigkeit und Verfuegbarkeit muessen einer besonders intensiven Pruefung und Beurteilung unterzogen werden. Das Ergebnis der vergleichenden Bewertung der Varianten kann eine neue Definition der Varianten oder der Anforderungen notwendig machen. (orig.)

  2. Phase equilibria of carbon dioxide and methane gas-hydrates predicted with the modified analytical S-L-V equation of state

    Directory of Open Access Journals (Sweden)

    Span Roland

    2012-04-01

    Full Text Available Gas-hydrates (clathrates are non-stoichiometric crystallized solutions of gas molecules in the metastable water lattice. Two or more components are associated without ordinary chemical union but through complete enclosure of gas molecules in a framework of water molecules linked together by hydrogen bonds. The clathrates are important in the following applications: the pipeline blockage in natural gas industry, potential energy source in the form of natural hydrates present in ocean bottom, and the CO2 separation and storage. In this study, we have modified an analytical solid-liquid-vapor equation of state (EoS [A. Yokozeki, Fluid Phase Equil. 222–223 (2004] to improve its ability for modeling the phase equilibria of clathrates. The EoS can predict the formation conditions for CO2- and CH4-hydrates. It will be used as an initial estimate for a more complicated hydrate model based on the fundamental EoSs for fluid phases.

  3. In vitro-Permeationsstudien von hydrophilen und lipophilen Arzneistoffen an okularen Geweben und Zellkulturen

    OpenAIRE

    Scholz, Martina

    2003-01-01

    Da die Arzneistoffpermeation durch okulare Gewebe einen entscheidenden Einfluss auf die Heilung vieler Augenleiden hat, wurde die in vitro-Permeation hydrophiler und lipophiler Arzneistoffe durch okulare Gewebe und Zellkulturen in dieser Arbeit untersucht. Die Dissertation befasst sich vorrangig mit der Permeation des hydrophilen Modellarzneistoffs Pilocarpinhydrochlorid (P-HCl) durch isolierte Schweinecornea (SC), Schweinesklera, Kaninchenkonjunktiva und corneale bzw. konjunktivale Kan...

  4. A central database for the Global Terrestrial Network for Permafrost (GTN-P)

    Science.gov (United States)

    Elger, Kirsten; Lanckman, Jean-Pierre; Lantuit, Hugues; Karlsson, Ævar Karl; Johannsson, Halldór

    2013-04-01

    The Global Terrestrial Network for Permafrost (GTN-P) is the primary international observing network for permafrost sponsored by the Global Climate Observing System (GCOS) and the Global Terrestrial Observing System (GTOS), and managed by the International Permafrost Association (IPA). It monitors the Essential Climate Variable (ECV) permafrost that consists of permafrost temperature and active-layer thickness, with the long-term goal of obtaining a comprehensive view of the spatial structure, trends, and variability of changes in the active layer and permafrost. The network's two international monitoring components are (1) CALM (Circumpolar Active Layer Monitoring) and the (2) Thermal State of Permafrost (TSP), which is made of an extensive borehole-network covering all permafrost regions. Both programs have been thoroughly overhauled during the International Polar Year 2007-2008 and extended their coverage to provide a true circumpolar network stretching over both Hemispheres. GTN-P has gained considerable visibility in the science community in providing the baseline against which models are globally validated and incorporated in climate assessments. Yet it was until now operated on a voluntary basis, and is now being redesigned to meet the increasing expectations from the science community. To update the network's objectives and deliver the best possible products to the community, the IPA organized a workshop to define the user's needs and requirements for the production, archival, storage and dissemination of the permafrost data products it manages. From the beginning on, GNT-P data was "outfitted" with an open data policy with free data access via the World Wide Web. The existing data, however, is far from being homogeneous: is not yet optimized for databases, there is no framework for data reporting or archival and data documentation is incomplete. As a result, and despite the utmost relevance of permafrost in the Earth's climate system, the data has not been

  5. Limited contribution of permafrost carbon to methane release from thawing peatlands

    Science.gov (United States)

    Cooper, Mark D. A.; Estop-Aragonés, Cristian; Fisher, James P.; Thierry, Aaron; Garnett, Mark H.; Charman, Dan J.; Murton, Julian B.; Phoenix, Gareth K.; Treharne, Rachael; Kokelj, Steve V.; Wolfe, Stephen A.; Lewkowicz, Antoni G.; Williams, Mathew; Hartley, Iain P.

    2017-07-01

    Models predict that thaw of permafrost soils at northern high latitudes will release tens of billions of tonnes of carbon (C) to the atmosphere by 2100 (refs ,,). The effect on the Earth’s climate depends strongly on the proportion of this C that is released as the more powerful greenhouse gas methane (CH4), rather than carbon dioxide (CO2) (refs ,); even if CH4 emissions represent just 2% of the C release, they would contribute approximately one-quarter of the climate forcing. In northern peatlands, thaw of ice-rich permafrost causes surface subsidence (thermokarst) and water-logging, exposing substantial stores (tens of kilograms of C per square meter, ref. ) of previously frozen organic matter to anaerobic conditions, and generating ideal conditions for permafrost-derived CH4 release. Here we show that, contrary to expectations, although substantial CH4 fluxes (>20 g CH4 m-2 yr-1) were recorded from thawing peatlands in northern Canada, only a small amount was derived from previously frozen C (effect of permafrost thaw on CH4 emissions from northern peatlands.

  6. Thermal state of permafrost in North America: A contribution to the international polar year

    Science.gov (United States)

    Smith, S.L.; Romanovsky, V.E.; Lewkowicz, A.G.; Burn, C.R.; Allard, M.; Clow, G.D.; Yoshikawa, K.; Throop, J.

    2010-01-01

    A snapshot of the thermal state of permafrost in northern North America during the International Polar Year (IPY) was developed using ground temperature data collected from 350 boreholes. More than half these were established during IPY to enhance the network in sparsely monitored regions. The measurement sites span a diverse range of ecoclimatic and geological conditions across the continent and are at various elevations within the Cordillera. The ground temperatures within the discontinuous permafrost zone are generally above -3°C, and range down to -15°C in the continuous zone. Ground temperature envelopes vary according to substrate, with shallow depths of zero annual amplitude for peat and mineral soils, and much greater depths for bedrock. New monitoring sites in the mountains of southern and central Yukon suggest that permafrost may be limited in extent. In concert with regional air temperatures, permafrost has generally been warming across North America for the past several decades, as indicated by measurements from the western Arctic since the 1970s and from parts of eastern Canada since the early 1990s. The rates of ground warming have been variable, but are generally greater north of the treeline. Latent heat effects in the southern discontinuous zone dominate the permafrost thermal regime close to 0°C and allow permafrost to persist under a warming climate. Consequently, the spatial diversity of permafrost thermal conditions is decreasing over time.

  7. Evolving hydrologic connectivity in discontinuous permafrost lowlands: what it means for lake systems

    Science.gov (United States)

    Walvoord, M. A.; Jepsen, S. M.; Rover, J.; Voss, C. I.; Briggs, M. A.

    2015-12-01

    Permafrost influence on the hydrologic connectivity of surface water bodies in high-latitude lowlands is complicated by subsurface heterogeneity and the propensity of the system to change over time. In general, permafrost limits the subsurface exchange of water, solute, and nutrients between lakes and rivers. It follows that permafrost thaw could enhance subsurface hydrologic connectivity among surface water bodies, but the impact of this process on lake distribution is not well known. Changes in the extent of lakes in interior Alaska have important ecological and societal impacts since lakes provide (1) critical habitat for migratory arctic shorebirds and waterfowl, fish, and wildlife, and (2) provisional, recreational, and cultural resources for local communities. We utilize electromagnetic imaging of the shallow subsurface and remote sensing of lake level dynamics in the Yukon Flats of interior Alaska, USA, together with water balance modeling, to gain insight into the influence of discontinuous permafrost on lowland lake systems. In the study region with relatively low precipitation, observations suggest that lakes that are hydrologically isolated during normal conditions are sustained by periodic river flooding events, including ice-jam floods that occur during river ice break-up. Climatically-influenced alterations in flooding frequency and intensity, as well as depth to permafrost, are quantitatively assessed in the context of lake maintenance. Scenario modeling is used to evaluate lake level evolution under plausible changing conditions. Model results demonstrate how permafrost degradation can reduce the dependence of typical lowland lakes on flooding events. Study results also suggest that river flooding may recharge a more spatially widespread zone of lakes and wetlands under future scenarios of permafrost table deepening and enhanced subsurface hydrologic connectivity.

  8. In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems

    Directory of Open Access Journals (Sweden)

    M. A. Kass

    2017-12-01

    Full Text Available Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example geophysical investigations, ecological characterization, direct observations, remote sensing, and more. As part of a multiyear investigation into the impacts of wildfires on permafrost, we have collected in situ measurements of the nuclear magnetic resonance (NMR response of the active layer and permafrost in a variety of soil conditions, types, and saturations. In this paper, we summarize the NMR data and present quantitative relationships between active layer and permafrost liquid water content and pore sizes and show the efficacy of borehole NMR (bNMR to permafrost studies. Through statistical analyses and synthetic freezing simulations, we also demonstrate that borehole NMR is sensitive to the nucleation of ice within soil pore spaces.

  9. Finanzkrise, Sozialkrise und ungleiche Entwicklung in Südkorea und Thailand

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    2008-01-01

    Zehn Jahre ist es inzwischen her, dass die Finanzkrisen in Südostasien, Russland und Lateinamerika die Weltwirtschaft erschütterten. Angesichts dieses "Jubiläums" und der aktuellen US-Finanzkrise ist es Zeit für eine Bestandsaufnahme: Lektionen gelernt? Drei Fragestellungen stehen im Mittelpunkt...

  10. The permafrost carbon inventory on the Tibetan Plateau: a new evaluation using deep sediment cores.

    Science.gov (United States)

    Ding, Jinzhi; Li, Fei; Yang, Guibiao; Chen, Leiyi; Zhang, Beibei; Liu, Li; Fang, Kai; Qin, Shuqi; Chen, Yongliang; Peng, Yunfeng; Ji, Chengjun; He, Honglin; Smith, Pete; Yang, Yuanhe

    2016-08-01

    The permafrost organic carbon (OC) stock is of global significance because of its large pool size and the potential positive feedback to climate warming. However, due to the lack of systematic field observations and appropriate upscaling methodologies, substantial uncertainties exist in the permafrost OC budget, which limits our understanding of the fate of frozen carbon in a warming world. In particular, the lack of comprehensive estimates of OC stocks across alpine permafrost means that current knowledge on this issue remains incomplete. Here, we evaluated the pool size and spatial variations of permafrost OC stock to 3 m depth on the Tibetan Plateau by combining systematic measurements from a substantial number of pedons (i.e. 342 three-metre-deep cores and 177 50-cm-deep pits) with a machine learning technique (i.e. support vector machine, SVM). We also quantified uncertainties in permafrost carbon budget by conducting Monte Carlo simulations. Our results revealed that the combination of systematic measurements with the SVM model allowed spatially explicit estimates to be made. The OC density (OC amount per unit area, OCD) exhibited a decreasing trend from the south-eastern to the north-western plateau, with the exception that OCD in the swamp meadow was substantially higher than that in surrounding regions. Our results also demonstrated that Tibetan permafrost stored a large amount of OC in the top 3 m, with the median OC pool size being 15.31 Pg C (interquartile range: 13.03-17.77 Pg C). 44% of OC occurred in deep layers (i.e. 100-300 cm), close to the proportion observed across the northern circumpolar permafrost region. The large carbon pool size together with significant permafrost thawing suggests a risk of carbon emissions and positive climate feedback across the Tibetan alpine permafrost region. © 2016 John Wiley & Sons Ltd.

  11. The Ecological Situation in the Russian Arctic Permafrost Zone

    Directory of Open Access Journals (Sweden)

    Petrov Sergei

    2016-01-01

    Full Text Available The paper describes innovative approaches to ensure environmental safety in the production of hydrocarbon material in a permafrost zone. Studies the anthropogenic environmental factors, climatic and geographical and geological conditions of Purovskiy district of Yamalo-Nenets Autonomous Area (YaNAO. We consider the chemical characteristics of wastewater discharged into surface water objects, polluting emissions into the atmosphere. The conclusions of the environmental situation in Purovskiy and Ustpurovsk-Tazovskiy permafrost areas. Calculate the concentration of pollutants in the control section of the water object and the maximum ground-level concentrations of pollutants in the atmospheric air. The conclusions about the exceeding the maximum permissible concentration (MPC in the atmospheric air for solids, carbon monoxide, nitrogen dioxide. Was examined the climatic conditions of the Far North. Correlational analysis was performed between human factors and temperature conditions of the northern territories, as well as between the climate and natural features cryological and disturbed permafrost soils.

  12. Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw

    NARCIS (Netherlands)

    Vonk, J.E.; Mann, P.J.; Dowdy, K.L.; Davydova, A.; Davydov, S.P.; Zimov, N.; Spencer, R.G.M.; Bulygina, E.B.; Eglinton, T.I.; Holmes, R.M.

    2013-01-01

    Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic permafrost and is characterized by the presence of massive ice wedges. Due to its rapid formation by sediment accumulation and subsequent frozen storage, Yedoma OM is relatively well preserved

  13. Permafrost and lakes control river isotope composition across a boreal Arctic transect in the Western Siberian lowlands

    Science.gov (United States)

    Ala-aho, P.; Soulsby, C.; Pokrovsky, O. S.; Kirpotin, S. N.; Karlsson, J.; Serikova, S.; Manasypov, R.; Lim, A.; Krickov, I.; Kolesnichenko, L. G.; Laudon, H.; Tetzlaff, D.

    2018-03-01

    The Western Siberian Lowlands (WSL) store large quantities of organic carbon that will be exposed and mobilized by the thawing of permafrost. The fate of mobilized carbon, however, is not well understood, partly because of inadequate knowledge of hydrological controls in the region which has a vast low-relief surface area, extensive lake and wetland coverage and gradually increasing permafrost influence. We used stable water isotopes to improve our understanding of dominant landscape controls on the hydrology of the WSL. We sampled rivers along a 1700 km South-North transect from permafrost-free to continuous permafrost repeatedly over three years, and derived isotope proxies for catchment hydrological responsiveness and connectivity. We found correlations between the isotope proxies and catchment characteristics, suggesting that lakes and wetlands are intimately connected to rivers, and that permafrost increases the responsiveness of the catchment to rainfall and snowmelt events, reducing catchment mean transit times. Our work provides rare isotope-based field evidence that permafrost and lakes/wetlands influence hydrological pathways across a wide range of spatial scales (10-105 km2) and permafrost coverage (0%-70%). This has important implications, because both permafrost extent and lake/wetland coverage are affected by permafrost thaw in the changing climate. Changes in these hydrological landscape controls are likely to alter carbon export and emission via inland waters, which may be of global significance.

  14. Electron acceptor-based regulation of microbial greenhouse gas production from thawing permafrost

    DEFF Research Database (Denmark)

    Bak, Ebbe Norskov; Jones, Eleanor; Yde, Jacob Clement

    layer as well in the permafrost. These investigations are accompanied by characterization of the carbon, iron and sulfate content in the soil and will be followed by characterization of the microbial community structure. The aim of this study is to get a better understanding of how the availability...... of sulfate and iron and the microbial community structure regulate the production of CO2 and CH4 in thawing permafrost, and to elucidate how the rate of the organic carbon degradation changes with depth in permafrost-affected soils. This study improves our understanding of climate feedback mechanisms...

  15. New insights into the ground thermal regime of talus slopes with permafrost below the timberline

    Science.gov (United States)

    Schwindt, Daniel; Kneisel, Christof

    2013-04-01

    In the central Alps permafrost can be expected above 2400 m a.s.l., at altitudes where mean annual air temperatures are below -1° C. However, isolated permafrost occurrences are present in north-exposed talus slopes, far below the timberline, where mean annual air temperatures are positive. Driving factors are assumed to be a low income of solar radiation, a thick organic layer with high insulation capacities as well as the thermally induced chimney effect (Wakonigg, 1996). Investigated are three talus slopes with permafrost in the Swiss Alps that differ with regard to elevation level, talus material, humus characteristics and vegetation composition as well as the mean annual air temperatures. Aim is to achieve a deeper understanding of the factors determining the site-specific thermal regime, as well as the spatially limited and temporally highly variable permafrost occurrences in vegetated talus slopes. Focus is not solely on the question of why permafrost exists at these sites, but also why permafrost does not exist in the immediate surroundings. To detect the temporal variability and spatial heterogeneity of the permafrost occurrences, electrical resistivity tomography monitoring, seismic refraction tomography monitoring, and quasi-3D ERT were applied. To determine the ground thermal regime, air-, ground surface-, and humus temperatures, as well as temperatures within vents of the chimneys were recorded. Furthermore, humus characteristics (thickness, -temperature and -moisture) were mapped in permafrost-affected slope areas and in the immediate surroundings. To test the correlation between solar radiation, permafrost distribution, and humus/vegetation composition, digital elevation models were used to calculate the income of solar radiation. The areal extent of the permafrost bodies coincide precisely with slope sections where the organic layer is thickest, a consistent moss cover is present, and where temperatures at the transition between humus layer and

  16. Plazentaanatomie und -physiologie mit uteroplazentarem Kreislauf

    NARCIS (Netherlands)

    Engel, N.; Schreiber, J. U.; Kranke, Peter

    2017-01-01

    Die Plazenta besteht neben der Nabelschnur aus parenchymatösem Gewebe, der sog. Eihaut (Amnion) und der Zottenhaut (Chorion). Sie fungiert als Schnittstelle zwischen Mutter und Fetus und ermöglicht den physiologischen Transfer von Gasen, Nährstoffen und Metaboliten. Die Funktion der Plazenta ist als

  17. Monitoring of thermal regime of permafrost in the coastal zone of Western Yamal

    Science.gov (United States)

    Vasiliev, A.

    2009-04-01

    Data on thermal regime of permafrost are required for estimation of the climate change influence on permafrost dynamics. Monitoring of thermal regime of permafrost was arranged in the area of weather station "Marre-Sale", western Yamal. In terms of geomorphology, the area of our observations belongs to the second and third marine terraces; the surface of these terraces has been partly modified by recent cryogenic processes. The elevation varies from 10 to 30 m a.s.l. Marine clays lie at the base of the geological section of the coastal deposits. Their upper part was eroded and uneven surface of marine sediments is overlain by continental sandy sediments. Marine clays are saline. In the southern part of study area, low accumulative islands are forming. Their heights above sea level do not exceed 0.5 meters, and during high tides their surface is covered by sea water. The sediments accumulating at these islands are saline silty clays. Western Yamal region is located within continuous permafrost zone with thickness of 150 to 200 meters. Study of thermal regime in the on-shore zone has been performed since 1979 using the 10-12-m-deep boreholes. In 2007, five boreholes were included in the work program of the Thermal State of Permafrost (TSP) project developed as a part of IPY scientific activities. According to TSP program, temperature sensors were installed at depths 2, 3, 5, and 10 meters; measurements have been performed every six hours. In this presentation, results of our observations related to climate change are discussed. For different terrain units, increase of mean annual permafrost temperature during the last 30 years has reached 0.6 to 1.5 deg. C. In the transit zone, monitoring of thermal regime have been performed since 2006. Sensors were installed at depths 0, 0.25, 0.6, 0.75, 1.25, 1.75, and 2.25 meters. The active layer depth here reaches 1.9 meters, thus the 2.25-m-sensor is located within permafrost. Monitoring data show the sharp increase in mean

  18. Introduction to the special issue: permafrost and periglacial research from coasts to mountains

    Science.gov (United States)

    Schrott, Lothar; Humlum, Ole

    2017-09-01

    This special issue of Geomorphology includes eleven papers dealing with permafrost and periglacial research from coasts to mountains. The compilation represents a selection from 47 presentations (oral and posters) given at the 4th European Conference on Permafrost - IPA Regional Conference (EUCOP4, June 2014) in the session ;Periglacial Geomorphology;. Geomorphology as a leading journal for our discipline is particularly suitable to publish advances in permafrost and periglacial research with a focus on geomorphic processes. Since 1989 Geomorphology has published 121 special issues and two special issues are explicitly dedicated to permafrost and periglacial research, however, only with a focus on research in Antarctica. In this special issue we present papers from the Canadian Beaufort Sea, Alaska, Spitzbergen, central western Poland, the European Alps, the eastern Sudetes, the southern Carpathians, Nepal, and Antarctica.

  19. The GTN-P Data Management System: A central database for permafrost monitoring parameters of the Global Terrestrial Network for Permafrost (GTN-P) and beyond

    Science.gov (United States)

    Lanckman, Jean-Pierre; Elger, Kirsten; Karlsson, Ævar Karl; Johannsson, Halldór; Lantuit, Hugues

    2013-04-01

    Permafrost is a direct indicator of climate change and has been identified as Essential Climate Variable (ECV) by the global observing community. The monitoring of permafrost temperatures, active-layer thicknesses and other parameters has been performed for several decades already, but it was brought together within the Global Terrestrial Network for Permafrost (GTN-P) in the 1990's only, including the development of measurement protocols to provide standardized data. GTN-P is the primary international observing network for permafrost sponsored by the Global Climate Observing System (GCOS) and the Global Terrestrial Observing System (GTOS), and managed by the International Permafrost Association (IPA). All GTN-P data was outfitted with an "open data policy" with free data access via the World Wide Web. The existing data, however, is far from being homogeneous: it is not yet optimized for databases, there is no framework for data reporting or archival and data documentation is incomplete. As a result, and despite the utmost relevance of permafrost in the Earth's climate system, the data has not been used by as many researchers as intended by the initiators of the programs. While the monitoring of many other ECVs has been tackled by organized international networks (e.g. FLUXNET), there is still no central database for all permafrost-related parameters. The European Union project PAGE21 created opportunities to develop this central database for permafrost monitoring parameters of GTN-P during the duration of the project and beyond. The database aims to be the one location where the researcher can find data, metadata, and information of all relevant parameters for a specific site. Each component of the Data Management System (DMS), including parameters, data levels and metadata formats were developed in cooperation with the GTN-P and the IPA. The general framework of the GTN-P DMS is based on an object oriented model (OOM), open for as many parameters as possible, and

  20. InSAR-based detection of McKenzie River Delta Permafrost loss

    Science.gov (United States)

    Oliver-Cabrera, T.; Wdowinski, S.

    2017-12-01

    Permafrost underlies most of the McKenzie River, North America's largest delta. The in the delta is catalogued as discontinuous permafrost due to the influence of shifting river channels on near-surface ground temperatures. The area is affected by climate change, studies show that ground temperature has increased by 1.5°C since 1970, due to rising annual mean air temperature. Flooding regimes within the delta are also affected by the changing climate due to melting of near surface ground ice together with sea-level rise increasing the potential of land subsidence. Observed consequences of changes occurring in the region are vegetation growth and northward migration of the tree line. The growing vegetation can affect physical properties of the accumulated snow, including depth, density and thermal conductivity. Thogether these variations affect permafrost stability. Permafrost changes can be measured throughout the impacts on river runoffs, ground water, drainages, carbon release, land subsidence and even infrastructure damages. Degradation of permafrost can also be measured by observing ecological changes in the area. In this study, we use InSAR observations to detect permafrost changes and their transition to wetland or vegetated land cover. Our data consist of four ALOS-PALSAR frames covering the entire McKenzie River Delta with temporal coverage spanning from January 2007 to March of 2011. Each frame has 20 to 24 acquisitions, in which half of the data acquired with HH polarization and the other half with HH+HV. We process the data using ROI_PAC and PYSAR software packages. Preliminary results have detected the following spatial patterns: (1) An overall good coherence of summer interferograms with 46-92 day interferograms, (2) Low coherence of winter interferograms (November to February), probably to the increase in snow coverage, (3) Phase jumps along the border of the river reflecting morphological differences between the region near to the river and other

  1. Kunst und Revolution.John Berger und der sowjetische Bildhauer Ernst Neiswestni

    OpenAIRE

    Artinger, Kai

    2011-01-01

    John Berger war einer der einflussreichsten Kunstkritiker der Linken in den 1950er Jahren in Großbritannien. Er spielte eine zentrale Rolle in den Diskursen über die Situation der Kunst und ihre Zukunft. Bezeichnend für sein Kunstverständnis war es, ausgetretene Pfade zu verlassen und den herrschenden Kanon zu ignorieren. Daher erfasste sein Blick auch die osteuropäische Kunst. Seit 1953 besucht er mehrfach die UdSSR und die DDR. Als unabhängiger Marxist lehnte sich Berger an den Strategien...

  2. Wirkungen eines Bifidojoghurts mit Laktulose und eines konventionellen Joghurts auf Darmphysiologie und bakterielle Metaboliten als Risikomodulatoren der Kolonkarzinogenese sowie Darmflora und Blutlipide bei gesunden Erwachsenen

    OpenAIRE

    Gerlach, Stefanie

    2007-01-01

    Hintergrund: Probiotische und synbiotische Milchprodukte zählen zu den "funktionellen Lebensmitteln", denen im Vergleich zu herkömmlichen Produkten ein gesundheitsfördernder Zusatznutzen zugeschrieben wird. Dabei wird diskutiert, ob die Gesundheit bereits gesunder Personen noch optimierbar ist, ob und in welcher Weise die Darmflora gezielt "günstig" modifiziert werden kann und/oder ob diese Manipulation zu messbaren gesundheitsfördernden Veränderungen metabolischer und systemischer Biomarker ...

  3. Nitrogen availability increases in a tundra ecosystem during five years of experimental permafrost thaw.

    Science.gov (United States)

    Salmon, Verity G; Soucy, Patrick; Mauritz, Marguerite; Celis, Gerardo; Natali, Susan M; Mack, Michelle C; Schuur, Edward A G

    2016-05-01

    Perennially frozen soil in high latitude ecosystems (permafrost) currently stores 1330-1580 Pg of carbon (C). As these ecosystems warm, the thaw and decomposition of permafrost is expected to release large amounts of C to the atmosphere. Fortunately, losses from the permafrost C pool will be partially offset by increased plant productivity. The degree to which plants are able to sequester C, however, will be determined by changing nitrogen (N) availability in these thawing soil profiles. N availability currently limits plant productivity in tundra ecosystems but plant access to N is expected improve as decomposition increases in speed and extends to deeper soil horizons. To evaluate the relationship between permafrost thaw and N availability, we monitored N cycling during 5 years of experimentally induced permafrost thaw at the Carbon in Permafrost Experimental Heating Research (CiPEHR) project. Inorganic N availability increased significantly in response to deeper thaw and greater soil moisture induced by Soil warming. This treatment also prompted a 23% increase in aboveground biomass and a 49% increase in foliar N pools. The sedge Eriophorum vaginatum responded most strongly to warming: this species explained 91% of the change in aboveground biomass during the 5 year period. Air warming had little impact when applied alone, but when applied in combination with Soil warming, growing season soil inorganic N availability was significantly reduced. These results demonstrate that there is a strong positive relationship between the depth of permafrost thaw and N availability in tundra ecosystems but that this relationship can be diminished by interactions between increased thaw, warmer air temperatures, and higher levels of soil moisture. Within 5 years of permafrost thaw, plants actively incorporate newly available N into biomass but C storage in live vascular plant biomass is unlikely to be greater than losses from deep soil C pools. © 2015 John Wiley & Sons Ltd.

  4. Numerical simulation of permafrost depth during a future glaciation, Campine area, Northern Belgium

    International Nuclear Information System (INIS)

    Govaerts, Joan; Weetjens, Eef; Beerten, Koen

    2012-01-01

    Document available in extended abstract form only. Given the long time frames involved and their potential detrimental effects, climate changes are considered in the safety assessment of long-term geological disposal of radioactive waste. One such effect that climate changes may govern is the re-appearance of permafrost in north-western Europe. This condition already existed during previous glaciations (e.g., Weichselian glacial, 115-11 ka BP), and may have several consequences for the hydrosphere, geosphere, biosphere and repository. Here, we present calculations of permafrost depth based on the climatic scenario with the Weichselian (last glacial) as an analog to estimate the permafrost depth during a future glaciation. Whereas the lateral extent of permafrost can be deduced from surface features, not much is known about the maximum depth of permafrost during a cold stage in the Campine region. Realistic values of the latent heat of melting of pure water, and thermal conductivity of dry or frozen and unfrozen saturated sand and clay are used as input parameters. In addition, detailed and refined climatic scenarios for the last glacial are used to improve the quality of boundary conditions, together with a more advanced description of freezing/thawing processes. To describe heat transport in the subsoil of the Mol site, the one-dimensional enthalpy conservation equation is used with heat transport only occurring by conduction. In the first calculation case, the temperature at the top of the soil layer is set equal to the air temperatures of a realistic glacial cycle (Weichselian glaciation). In a second calculation case, the insulating effects of the surface cover are considered, and the air temperatures are converted into surface temperatures by making use of the 'n-factor concept', which yields an empirical relationship between the mean annual surface temperature, T s , and the mean annual air temperature, T a . In Figure 1 the permafrost pro-gradation front

  5. Zwischen Freakout und Normcore

    Directory of Open Access Journals (Sweden)

    Beate Großegger

    2017-06-01

    Full Text Available Bis Ende des 20. Jahrhunderts war Rebellion jugendkulturell ein großes Thema. Heute hat die Jugend das so genannte Establishment aus den Augen verloren; die breite Mehrheit gibt sich postheroisch, setzt auf individualitätsbezogene Werte und träumt, eingeschlossen in ihre bunten Lifestyleblasen, von einem perfekten Leben. Bezugnehmend auf aktuelle Befunde der Jugend- und Generationenforschung gibt Beate Großegger in ihrem Beitrag einen Überblick über die wichtigsten Werte- und Lifestyletrends im frühen 21. Jahrhundert und zeigt dabei, wie sehr die heutige Jugend Kind ihrer Zeit und Produkt gesellschaftlicher Rahmenbedingungen ist. Until the late 20th century rebellion was an important aspect of various youth subcultures. But today’s youth has a different mindset. The majority acts post-heroically, i.e. they rather focus on their individual, their private lifestyle than opposing against the establishment. Wrapped in their lifestyle filterbubbles, they dream of a perfect life. Based on recent youth und generation studies Beate Großegger gives an overview of the most important youth cultural trends in the fields of values and lifestyles and introduces today’s youth as a child of our times.

  6. Die Werte der Wertvermittler - Berufliches Rollenselbstverständnis und Weltanschauung von Journalistinnen und Journalisten

    Directory of Open Access Journals (Sweden)

    Andy Kaltenbrunner

    2010-09-01

    Full Text Available Der Beitrag analysiert professionelles Selbstverständnis, Weltanschauungen und ethische Überzeugungen von Journalistinnen und Journalisten in Österreich. Auf Basis aktueller Befragungen und Studien wird die Grundstruktur des journalistischen Wertesystems skizziert und der Zusammenhang mit täglicher Berichterstattung. Der Beitrag diskutiert mögliche Konsequenzen für Zukunft des Journalismus und Qualität der Öffentlichkeit. The article focuses on the professional values, political views and ethical beliefs of Austrian journalists. Based on recent surveys we outline the basic structure of the journalistic value system in Austria and the interdependence of these values and actual reporting and we discuss possible consequences for the future of journalism as a profession and for the quality of the public sphere.

  7. Supraleitung Grundlagen und Anwendungen

    CERN Document Server

    Buckel, Werner

    2013-01-01

    Grundlegende Konzepte und Eigenschaften von Supraleitern, die Herstellung und Entwicklung von neuen supraleitenden Materialien sowie moderne Anwendungsbereiche sind die Schwerpunktthemen des Buches. Das größte Potential zur Nutzung der Supraleitung liegt in der Energietechnik. Fast unbemerkt trägt die Einführung von Kabeln, Magneten, Transformatoren oder Lagern aus supraleitenden Materialien bei zur Effizienzsteigerung bei der Stromübertragung oder in Motoren. Durch seiner klare Sprache und zahlreiche erläuternde Abbildungen eignet sich der Band hervorragend als einführendes Lehrbuch. Der Schwierigkeitsgrad wird von Kapitel zu Kapitel gesteigert. So können auch Einsteiger ohne einschlägige Vorkenntnisse dem Stoff folgen. Dank der über 350 Literaturhinweise bekommt der Leser außerdem einen Überblick über die wichtigsten Publikationen zum Thema. Ein unverzichtbares Lehrbuch also für Physik-Studenten und Studierende der Ingenieurwissenschaften. Fachleuten in Forschung und Praxis leistet das Buch au...

  8. Editorial: Theoriebildung in Mediendidaktik und Wissensmanagement

    Directory of Open Access Journals (Sweden)

    Michael Kerres

    2002-10-01

    Full Text Available Das Internet trägt massgeblich zur Entstehung einer neuen Lern- und Wissenskultur bei und ist mittlerweile Gegenstand einer ganzen Reihe von Projekten in der Erziehungswissenschaft. So wird zum Beispiel der Frage nachgegangen, welche Möglichkeiten der Strukturierung und Gestaltung von Lernmaterialien am besten geeignet sind, um Lernprozesse anzuregen, wie die interpersonale Kommunikation im Internet durch didaktische Gestaltungsmassnahmen gefördert werden können oder wie die entfernte Betreuung von Lernenden über das Netz funktioniert. Zunehmend wird dabei auch der Übergang bedeutsam zwischen didaktisch aufbereiteten Lernangeboten, wie sie die Mediendidaktik traditionell beschäftigt, und dem Austausch von nicht didaktisch aufbereiteten Informationen in Organisationen, wie es im Bereich des Wissensmanagements diskutiert wird. In diesen Projekten werden vielfach Detailfragen behandelt, und isoliert, ohne Bezug zu grundlegenden Theoriefragen untersucht. Es mangelt an einer genuin mediendidaktischen Theoriediskussion, die einen übergreifenden Bezugsrahmen aus erziehungswissenschaftlicher Perspektive liefert. In der Vergangenheit ist die Mediendidaktik von Seiten einer «kritischen» Medienpädagogik zeitweise skeptisch beäugt und in ihrer Existenz grundlegend infrage gestellt worden. In der aktuellen Diskussion wird gerne auf lerntheoretische Ansätze zurückgegriffen, die Lernen als aktiven Vorgang der individuellen und kooperativen Wissenskonstruktion begreifen. Doch Wissens- und Lerntheorien ersetzen keine mediendidaktische Modell- und Theoriebildung, die Perspektiven für eine Gestaltung zukünftiger Lernwelten liefert und dabei zum Beispiel sowohl bildungstheoretische Überlegungen als auch Konzepte des instructional design einbezieht. In dem ersten Teil dieser Ausgabe geht es um theoretische Perspektiven der Mediendidaktik. So diskutiert der Artikel von Michael Kerres und Claudia de Witt den Beitrag der Positionen von Behaviorismus

  9. Das IHS und die Rolle der Forschungsinstitute

    OpenAIRE

    Keuschnigg, Christian

    2014-01-01

    Das Institut für Höhere Studien und wissenschaftliche Forschung (IHS) ist ein unabhängiges Forschungsinstitut und leistet Forschung und Ausbildung auf Spitzenniveau für Politik, Wirtschaft und Gesellschaft. Im Wettbewerb zwischen Universitäten und angewandten Forschungsinstituten ist das IHS einzigartig, weil es unter einem Dach Grundlagenforschung und forschungsnahe Lehre mit angewandter Forschung für die wissenschaftliche Politikberatung verbindet. Mit den drei Disziplinen Ökonomie, Soziolo...

  10. In situ nuclear magnetic response of permafrost and active layer soil in boreal and tundra ecosystems

    DEFF Research Database (Denmark)

    Kass, Mason Andrew; Irons, Trevor; Minsley, Burke J.

    2017-01-01

    Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience...... of the nuclear magnetic resonance (NMR) response of the active layer and permafrost in a variety of soil conditions, types, and saturations. In this paper, we summarize the NMR data and present quantitative relationships between active layer and permafrost liquid water content and pore sizes and show...

  11. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (similar to 200 km north of the Arctic Circle). Multivariate statistical ...

  12. Permafrost knowledge to serve as foundation for Inuit community planning

    Science.gov (United States)

    Gibéryen, T.; Allard, M.

    2011-12-01

    With the recent announcement of Québec's provincial government's Plan Nord, Nunavik will see a 500 new houses sweep onto it's territory over the next 5 years. The local Inuit communities are confronted with the pressuring need to find suitable land to safely accommodate the new infrastructures in the long term. Additional to human and environmental constraints are those related to warming permafrost. Intensive studies on four Nunavik communities (Inukjuak, Puvirnituq, Akulivik, Kangirsuk) have allowed us to extensively consult local and regional authorities on their planning and management considerations. Recent and archived drilling data have been used to corroborate air photo interpretation, surficial geology and permafrost mapping. All collected information are integrated into aggregated maps that will eventually serve as community master plans. General recommendations on how to best manage and plan for community expansions on warming permafrost are made. Appropriate engineering techniques assuring long-term stable foundations are outlined and additionally mapped, taking into consideration the variable terrain conditions and simulated changes in permafrost temperature and active layer thickness according to climate change scenarios. The final purpose of our results is for them to support local and regional governments in their community planning process towards the best possible climate change adaptation strategies.

  13. The impacts of recent permafrost thaw on land–atmosphere greenhouse gas exchange

    International Nuclear Information System (INIS)

    Hayes, Daniel J; Yuan, Fengming; Wullschleger, Stan D; Kicklighter, David W; Melillo, Jerry M; McGuire, A David; Chen, Min; Zhuang, Qianlai

    2014-01-01

    Permafrost thaw and the subsequent mobilization of carbon (C) stored in previously frozen soil organic matter (SOM) have the potential to be a strong positive feedback to climate. As the northern permafrost region experiences as much as a doubling of the rate of warming as the rest of the Earth, the vast amount of C in permafrost soils is vulnerable to thaw, decomposition and release as atmospheric greenhouse gases. Diagnostic and predictive estimates of high-latitude terrestrial C fluxes vary widely among different models depending on how dynamics in permafrost, and the seasonally thawed ‘active layer’ above it, are represented. Here, we employ a process-based model simulation experiment to assess the net effect of active layer dynamics on this ‘permafrost carbon feedback’ in recent decades, from 1970 to 2006, over the circumpolar domain of continuous and discontinuous permafrost. Over this time period, the model estimates a mean increase of 6.8 cm in active layer thickness across the domain, which exposes a total of 11.6 Pg C of thawed SOM to decomposition. According to our simulation experiment, mobilization of this previously frozen C results in an estimated cumulative net source of 3.7 Pg C to the atmosphere since 1970 directly tied to active layer dynamics. Enhanced decomposition from the newly exposed SOM accounts for the release of both CO 2 (4.0 Pg C) and CH 4 (0.03 Pg C), but is partially compensated by CO 2 uptake (0.3 Pg C) associated with enhanced net primary production of vegetation. This estimated net C transfer to the atmosphere from permafrost thaw represents a significant factor in the overall ecosystem carbon budget of the Pan-Arctic, and a non-trivial additional contribution on top of the combined fossil fuel emissions from the eight Arctic nations over this time period. (paper)

  14. Solidarität und Heterogenität in Gruppen: Theoretische und empirische Skizzen

    Directory of Open Access Journals (Sweden)

    Irma Rybnikova

    2015-03-01

    Full Text Available Für gewöhnlich wird Heterogenität der Gruppen als Hindernis für Solidarität ihrer Mitglieder angesehen: Je verschiedener die Mitglieder, umso schwieriger kommt Solidarität zustande. In der vorliegenden Studie hinterfrage ich diese Generalisierung, indem ich eine Reihe von theoretischen Ansätzen aus der Soziologie und der Gruppenpsychologie konsultiere. Während einige dieser Ansätze nahelegen, dass Heterogenität der Mitglieder die Solidarität der Gruppen untergräbt, bestreiten dies andere Ansätze und gehen davon aus, dass auch heterogene Gruppen solidarisch sein können, vor allem dann, wenn unter den Mitgliedern eine Interdependenz vorliegt. Diese widersprüchlichen theoretischen Annahmen animierten mich zu einer empirischen Untersuchung von Studierendengruppen in einer Lehrveranstaltung. Die Ergebnisse zeigen zwar, dass zwischen Heterogenität und Solidarität in den interdependenten Gruppen ein Zusammenhang anzunehmen ist, dass jedoch auch eine Ambivalenz besteht zwischen individueller und Kollegensolidarität. Vor dem Hintergrund der theoretischen und empirischen Erkenntnisse diskutiere ich Schlussfolgerungen für die Forschung und für die praktischen Bemühungen der Solidarisierung im Bereich der gewerkschaftlichen Organisierung.

  15. Gedenken, Geschichte und Versöhnung in Südafrika und Zimbabwe

    OpenAIRE

    Marx, Christoph

    2006-01-01

    'Die Gesellschaft Südafrikas hat sich nach der Überwindung der Apartheid mit der Einrichtung einer Wahrheits- und Versöhnungskommission auf eine wichtige öffentliche Debatte über ihre Vergangenheit eingelassen. Der Kontext dieser Debatte und die Vorgabe, dass die Beschäftigung mit der Vergangenheit in die Bildung einer neuen Nation münden solle, führten indes dazu, dass sich neue Formen von Inklusion und Exklusion entwickelten. Da Identität nur über die Betonung von Differenz möglich ist, läs...

  16. Relict Mountain Permafrost Area (Loess Plateau, China) Exhibits High Ecosystem Respiration Rates and Accelerating Rates in Response to Warming

    Science.gov (United States)

    Mu, Cuicui; Wu, Xiaodong; Zhao, Qian; Smoak, Joseph M.; Yang, Yulong; Hu, Lian; Zhong, Wen; Liu, Guimin; Xu, Haiyan; Zhang, Tingjun

    2017-10-01

    Relict permafrost regions are characterized by thin permafrost and relatively high temperatures. Understanding the ecosystem respiration rate (ERR) and its relationship with soil hydrothermal conditions in these areas can provide knowledge regarding the permafrost carbon cycle in a warming world. In this study, we examined a permafrost area, a boundary area, and a seasonally frozen ground area within a relict permafrost region on the east edge of the Qinghai-Tibetan Plateau, China. Measurements from July 2015 to September 2016 showed that the mean annual ecosystem CO2 emissions for the boundary area were greater than the permafrost area. The Q10 value of the ERRs in the seasonally frozen ground area was greater than the permafrost area, indicating that the carbon emissions in the nonpermafrost areas were more sensitive to warming. The 1 year open-top chamber (OTC) warming increased soil temperatures in both the permafrost and seasonally frozen ground areas throughout the year, and the warming increased the ERRs by 1.18 (0.99-1.38, with interquartile range) and 1.13 (0.75-1.54, with interquartile range) μmol CO2 m-2 s-1 in permafrost and seasonally frozen ground areas, respectively. The OTC warming increased annual ERRs by approximately 50% for both permafrost and seasonally frozen ground areas with half the increase occurring during the nongrowing seasons. These results suggest that the ERRs in relict permafrost are high in comparison with arctic regions, and the carbon balance in relict permafrost areas could be greatly changed by climate warming.

  17. Hinkelbeinchen und "little chicken's leg": deutsche und amerikanische Idiome als kommunikative Textsorten-Problematik

    Directory of Open Access Journals (Sweden)

    Martin Wierschin

    1998-12-01

    Full Text Available Als Marin Luther 1522 seine Übersetzung des Neuen Testaments nach der griechischen Edition des Erasmus von Rotterdam abschloß, hatte er dabei zwar mit größtem Sprachgefühl nicht nur dem deutschen, sondem auch dem idiomatischen 'logos' des Griechischen "auf das Maul" gesehen. Aber er mußte in seinem "Sendbrief vom Dolmetschen" 1530 dennoch zugeben, daß selbst er - zusammen mit seinen beiden Assistenten Melanchthon und Aurogallus - sehr oft zwei bis vier Wochen lang nach einem einzigen idiomatisch treffenden Wort zu suchen hatte. Damit wird von einem eminenten Kronzeugen, nämlich vom Schöpfer des protestantischen 'Hausbuches' Lutherbibel und vom eigentlichen Begründer einer einheitlichen deutschen Schrift­ sprache, samt ihrer sprach- und literargeschichtlich wirkungsmächtigen Idiomatik, die Schwierigkeit und Problematik idiomatischer Äquivalenzen und Transferenzen zwischen den Einzelsprachen verbürgt.

  18. Medienbildung und Schulkultur. Implikationen der Verbindung von Medienbildung und Schulkultur für die Medienpädagogik

    Directory of Open Access Journals (Sweden)

    Nina Grünberger

    2017-08-01

    Full Text Available Gegenwärtig werden häufig Fragen nach der Konstituierung der Medienpädagogik als Disziplin gestellt und Antwortversuche aus je unterschiedlicher Perspektive formuliert. Der vorliegende Beitrag unternimmt einen solchen Versuch durch die Diskussion von Implikationen weitreichender Medialisierungsprozesse für die «Disziplinierung» der Medienpädagogik und ihrer Forschungsfelder am Beispiel von Schule als genuin pädagogischem Ort. Die Zusammenführung einer poststrukturalistisch gedachten Medienbildung und einer damit einhergehenden Entdichotomisierung von Subjekt und Welt respektive Subjekt und Medien mit dem Konzept der Schulkultur und einem damit verbundenen holistischen Blick auf das Schulgefüge eröffnet eine neue, produktive und gleichsam kritische Perspektive, ohne dabei jeweils auf eine vereinfachte Gesellschaftskritik zurück zu fallen. Dies stellt bisherige medienpädagogische Theoreme und insbesondere das Medienkompetenzkonzept, das über den medienpädagogischen Wirkungskreis hinaus auch in anderen Kontexten etabliert ist, in Frage. So wird eine neue Perspektive auf Medienpädagogik und ihre Ziele eröffnet, die nicht vorschnell in Abgrenzungsmechanismen unterschiedlicher medienpädagogischer Schulen verfällt, sondern zu aller erst eine «offene» sein will.

  19. Impacts of Permafrost on Infrastructure and Ecosystem Services

    Science.gov (United States)

    Trochim, E.; Schuur, E.; Schaedel, C.; Kelly, B. P.

    2017-12-01

    The Study of Environmental Arctic Change (SEARCH) program developed knowledge pyramids as a tool for advancing scientific understanding and making this information accessible for decision makers. Knowledge pyramids are being used to synthesize, curate and disseminate knowledge of changing land ice, sea ice, and permafrost in the Arctic. Each pyramid consists of a one-two page summary brief in broadly accessible language and literature organized by levels of detail including synthesizes and scientific building blocks. Three knowledge pyramids have been produced related to permafrost on carbon, infrastructure, and ecosystem services. Each brief answers key questions with high societal relevance framed in policy-relevant terms. The knowledge pyramids concerning infrastructure and ecosystem services were developed in collaboration with researchers specializing in the specific topic areas in order to identify the most pertinent issues and accurately communicate information for integration into policy and planning. For infrastructure, the main issue was the need to build consensus in the engineering and science communities for developing improved methods for incorporating data applicable to building infrastructure on permafrost. In ecosystem services, permafrost provides critical landscape properties which affect basic human needs including fuel and drinking water availability, access to hunting and harvest, and fish and wildlife habitat. Translating these broad and complex topics necessitated a systematic and iterative approach to identifying key issues and relating them succinctly to the best state of the art research. The development of the knowledge pyramids provoked collaboration and synthesis across distinct research and engineering communities. The knowledge pyramids also provide a solid basis for policy development and the format allows the content to be regularly updated as the research community advances.

  20. Response of permafrost to projected climate change: Results from global offline model simulations with JSBACH

    Science.gov (United States)

    Blome, Tanja; Ekici, Altug; Beer, Christian; Hagemann, Stefan

    2014-05-01

    Permafrost or perennially frozen ground is an important part of the terrestrial cryosphere; roughly one quarter of Earth's land surface is underlain by permafrost. As it is a thermal phenomenon, its characteristics are highly dependent on climatic factors. The impact of the currently observed warming, which is projected to persist during the coming decades due to anthropogenic CO2 input, certainly has effects for the vast permafrost areas of the high northern latitudes. The quantification of these effects, however, is scientifically still an open question. This is partly due to the complexity of the system, where several feedbacks are interacting between land and atmosphere, sometimes counterbalancing each other. Moreover, until recently, many global circulation models (GCMs) lacked the sufficient representation of permafrost physics in their land surface schemes. In order to assess the response of permafrost to projected climate change for the 21st century, the land surface scheme of the Max-Planck-Institute for Meteorology, JSBACH, has recently been equipped with the important physical processes for permafrost studies, and was driven globally with bias corrected climate data, thereby spanning a period from 1850 until 2100. The applied land surface scheme JSBACH now considers the effects of freezing and thawing of soil water for both energy and water cycles, thermal properties depending on soil water and ice contents, and soil moisture movement being influenced by the presence of soil ice. To address the uncertainty range arising through different greenhouse gas concentrations as well as through different climate realisations when using various climate models, combinations of two Representative Concentration Pathways (RCPs) and two GCMs were used as driving data. In order to focus only on the climatic impact on permafrost, effects due to feedbacks between climate and permafrost (namely via carbon fluxes between land and atmosphere) are excluded in the experiments

  1. Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses

    Science.gov (United States)

    Harris, Charles; Arenson, Lukas U.; Christiansen, Hanne H.; Etzelmüller, Bernd; Frauenfelder, Regula; Gruber, Stephan; Haeberli, Wilfried; Hauck, Christian; Hölzle, Martin; Humlum, Ole; Isaksen, Ketil; Kääb, Andreas; Kern-Lütschg, Martina A.; Lehning, Michael; Matsuoka, Norikazu; Murton, Julian B.; Nötzli, Jeanette; Phillips, Marcia; Ross, Neil; Seppälä, Matti; Springman, Sarah M.; Vonder Mühll, Daniel

    2009-02-01

    We present a review of the changing state of European permafrost within a spatial zone that includes the continuous high latitude arctic permafrost of Svalbard and the discontinuous high altitude mountain permafrost of Iceland, Fennoscandia and the Alps. The paper focuses on methodological developments and data collection over the last decade or so, including research associated with the continent-scale network of instrumented permafrost boreholes established between 1998 and 2001 under the European Union PACE project. Data indicate recent warming trends, with greatest warming at higher latitudes. Equally important are the impacts of shorter-term extreme climatic events, most immediately reflected in changes in active layer thickness. A large number of complex variables, including altitude, topography, insolation and snow distribution, determine permafrost temperatures. The development of regionally calibrated empirical-statistical models, and physically based process-oriented models, is described, and it is shown that, though more complex and data dependent, process-oriented approaches are better suited to estimating transient effects of climate change in complex mountain topography. Mapping and characterisation of permafrost depth and distribution requires integrated multiple geophysical approaches and recent advances are discussed. We report on recent research into ground ice formation, including ice segregation within bedrock and vein ice formation within ice wedge systems. The potential impacts of climate change on rock weathering, permafrost creep, landslides, rock falls, debris flows and slow mass movements are also discussed. Recent engineering responses to the potentially damaging effects of climate warming are outlined, and risk assessment strategies to minimise geological hazards are described. We conclude that forecasting changes in hazard occurrence, magnitude and frequency is likely to depend on process-based modelling, demanding improved

  2. Permafrost degradation and associated ground settlement estimation under 2 °C global warming

    Science.gov (United States)

    Guo, Donglin; Wang, Huijun

    2017-10-01

    Global warming of 2 °C above preindustrial levels has been considered to be the threshold that should not be exceeded by the global mean temperature to avoid dangerous interference with the climate system. However, this global mean target has different implications for different regions owing to the globally nonuniform climate change characteristics. Permafrost is sensitive to climate change; moreover, it is widely distributed in high-latitude and high-altitude regions where the greatest warming is predicted. Permafrost is expected to be severely affected by even the 2 °C global warming, which, in turn, affects other systems such as water resources, ecosystems, and infrastructures. Using air and soil temperature data from ten coupled model intercomparison project phase five models combined with observations of frozen ground, we investigated the permafrost thaw and associated ground settlement under 2 °C global warming. Results show that the climate models produced an ensemble mean permafrost area of 14.01 × 106 km2, which compares reasonably with the area of 13.89 × 106 km2 (north of 45°N) in the observations. The models predict that the soil temperature at 6 m depth will increase by 2.34-2.67 °C on area average relative to 1990-2000, and the increase intensifies with increasing latitude. The active layer thickness will also increase by 0.42-0.45 m, but dissimilar to soil temperature, the increase weakens with increasing latitude due to the distinctly cooler permafrost at higher latitudes. The permafrost extent will obviously retreat north and decrease by 24-26% and the ground settlement owing to permafrost thaw is estimated at 3.8-15 cm on area average. Possible uncertainties in this study may be mostly attributed to the less accurate ground ice content data and coarse horizontal resolution of the models.

  3. Permafrost delineation for remediation planning : Fort Wainwright, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Astley, B. [Cold Regions Research and Engineering Laboratory, Anchorage, AK (United States); Snyder, C. [YEC Inc., Valley Cottage, NJ (United States); Delaney, A. [Cold Regions Research and Engineering Laboratory, Fairbanks, AK (United States); Arcone, S.; Lawson, D. [Cold Regions Research and Engineering Laboratory, Hanover, NH (United States)

    2003-07-01

    In the summer of 1999, geophysical and hydrogeological surveys were conducted at the Birch Hill Tank Farm and Truck Fill Stand in Fort Wainwright, Alaska to assess the distribution of benzene, 1,2-dichloroethane, and 1,2-dibromoethane. The Birch Hill site consists of a silt, sand and gravel fluvial deposit that overlies bedrock. Permafrost occurs discontinuously throughout the alluvium and underlying bedrock, resulting in a complex aquifer distribution. The bedrock beneath the Tank Farm is highly fractured and faulted with a weathered horizon that is 30 meters thick. The goal of this study was to map the discontinuous permafrost and aquifers in the alluvial deposits and weathered bedrock zone for the purpose of delineating bedrock depth and structural features that influence ground water flow. Several methods were used to define subsurface conditions, including borehole logs, DC resistivity, and ground-penetrating radar. A 3-D hydrogeologic model was used to develop a ground water flow model used to determine contaminant migration pathways and rates. The permafrost configuration was found to be the most important boundary condition in this model. 7 refs., 1 tab., 5 figs.

  4. Coupling of snow and permafrost processes using the Basic Modeling Interface (BMI)

    Science.gov (United States)

    Wang, K.; Overeem, I.; Jafarov, E. E.; Piper, M.; Stewart, S.; Clow, G. D.; Schaefer, K. M.

    2017-12-01

    We developed a permafrost modeling tool based by implementing the Kudryavtsev empirical permafrost active layer depth model (the so-called "Ku" component). The model is specifically set up to have a basic model interface (BMI), which enhances the potential coupling to other earth surface processes model components. This model is accessible through the Web Modeling Tool in Community Surface Dynamics Modeling System (CSDMS). The Kudryavtsev model has been applied for entire Alaska to model permafrost distribution at high spatial resolution and model predictions have been verified by Circumpolar Active Layer Monitoring (CALM) in-situ observations. The Ku component uses monthly meteorological forcing, including air temperature, snow depth, and snow density, and predicts active layer thickness (ALT) and temperature on the top of permafrost (TTOP), which are important factors in snow-hydrological processes. BMI provides an easy approach to couple the models with each other. Here, we provide a case of coupling the Ku component to snow process components, including the Snow-Degree-Day (SDD) method and Snow-Energy-Balance (SEB) method, which are existing components in the hydrological model TOPOFLOW. The work flow is (1) get variables from meteorology component, set the values to snow process component, and advance the snow process component, (2) get variables from meteorology and snow component, provide these to the Ku component and advance, (3) get variables from snow process component, set the values to meteorology component, and advance the meteorology component. The next phase is to couple the permafrost component with fully BMI-compliant TOPOFLOW hydrological model, which could provide a useful tool to investigate the permafrost hydrological effect.

  5. Controls on the methane released through ebullition affected by permafrost degradation

    Science.gov (United States)

    S.J. Klapstein; M.R. Turetsky; A.D. McGuire; J.W. Harden; C.I. Czimczik; X. Xu; J.P. Chanton; J.M. Waddington

    2014-01-01

    Permafrost thaw in peat plateaus leads to the flooding of surface soils and the formation of collapse scar bogs, which have the potential to be large emitters of methane (CH4) from surface peat as well as deeper, previously frozen, permafrost carbon (C). We used a network of bubble traps, permanently installed 20 cm and 60 cm beneath the moss surface, to examine...

  6. Evaluation of Electromagnetic Induction (EMI) Resistivity Technologies for Assessing Permafrost Geomorphologies

    Science.gov (United States)

    2016-08-01

    resistivity, have been used to interrogate the subsur- face in permafrost terrains at the meters to kilometers scales. Airborne measurement techniques have...burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense... interrogate the subsurface in permafrost terrains at the meters to kilometers scales. Airborne measurement techniques have broad applicability at the

  7. Poorly known microbial taxa dominate the microbiome of permafrost thaw ponds.

    Science.gov (United States)

    Wurzbacher, Christian; Nilsson, R Henrik; Rautio, Milla; Peura, Sari

    2017-08-01

    In the transition zone of the shifting permafrost border, thaw ponds emerge as hotspots of microbial activity, processing the ancient carbon freed from the permafrost. We analyzed the microbial succession across a gradient of recently emerged to older ponds using three molecular markers: one universal, one bacterial and one fungal. Age was a major modulator of the microbial community of the thaw ponds. Surprisingly, typical freshwater taxa comprised only a small fraction of the community. Instead, thaw ponds of all age classes were dominated by enigmatic bacterial and fungal phyla. Our results on permafrost thaw ponds lead to a revised perception of the thaw pond ecosystem and their microbes, with potential implications for carbon and nutrient cycling in this increasingly important class of freshwaters.

  8. Fotografie und atomare Katastrophe

    OpenAIRE

    Bürkner, Daniel

    2015-01-01

    Die Dissertation setzt sich mit den fotografischen Repräsentationen der Atombombenabwürfe auf Hiroshima und Nagasaki sowie der Havarie des Kernkraftwerks Tschernobyl auseinander. Dabei werden künstlerische, dokumentarische und touristische Bilder analysiert, die sich der jeweiligen Strahlenkatastrophe oftmals erst Jahre nach dem Ereignis annehmen und ikonografische oder medial-materielle Bezüge zu ihr aufweisen. Es zeigen sich zentrale Strategien, atomare Katastrophen, seien sie militäri...

  9. Climate warming over the past half century has led to thermal degradation of permafrost on the Qinghai-Tibet Plateau

    Science.gov (United States)

    Ran, Youhua; Li, Xin; Cheng, Guodong

    2018-02-01

    Air temperature increases thermally degrade permafrost, which has widespread impacts on engineering design, resource development, and environmental protection in cold regions. This study evaluates the potential thermal degradation of permafrost over the Qinghai-Tibet Plateau (QTP) from the 1960s to the 2000s using estimated decadal mean annual air temperatures (MAATs) by integrating remote-sensing-based estimates of mean annual land surface temperatures (MASTs), leaf area index (LAI) and fractional snow cover values, and decadal mean MAAT date from 152 weather stations with a geographically weighted regression (GWR). The results reflect a continuous rise of approximately 0.04 °C a-1 in the decadal mean MAAT values over the past half century. A thermal-condition classification matrix is used to convert modelled MAATs to permafrost thermal type. Results show that the climate warming has led to a thermal degradation of permafrost in the past half century. The total area of thermally degraded permafrost is approximately 153.76 × 104 km2, which corresponds to 88 % of the permafrost area in the 1960s. The thermal condition of 75.2 % of the very cold permafrost, 89.6 % of the cold permafrost, 90.3 % of the cool permafrost, 92.3 % of the warm permafrost, and 32.8 % of the very warm permafrost has been degraded to lower levels of thermal condition. Approximately 49.4 % of the very warm permafrost and 96 % of the likely thawing permafrost has degraded to seasonally frozen ground. The mean elevations of the very cold, cold, cool, warm, very warm, and likely thawing permafrost areas increased by 88, 97, 155, 185, 161, and 250 m, respectively. The degradation mainly occurred from the 1960s to the 1970s and from the 1990s to the 2000s. This degradation may lead to increased risks to infrastructure, reductions in ecosystem resilience, increased flood risks, and positive climate feedback effects. It therefore affects the well-being of millions of people

  10. Rosetta und Yella

    Directory of Open Access Journals (Sweden)

    Urs Urban

    2009-11-01

    Full Text Available L’apparition de l’homo oeconomicus marque la fin des grands récits et par là de l’ensemble social que ceux-ci avaient légitimé. En même temps cependant il entre dans les récits littéraires – et filmiques, par exemple dans Rosetta (1999 des frères Dardenne et Yella (2007 de Christian Petzold. L’article se propose de montrer comment ces derniers réussissent à mettre en scène les apories existentielles d’un sujet produit par le dispositif économique en appliquant des procédés narratifs permettant de problématiser la narration elle-même.Mit dem Auftauchen des homo oeconomicus scheint das Ende der großen Erzählungen und des von diesen legitimierten sozialen Zusammenhangs besiegelt. Genau in diesem Moment indes beginnen sich die kleinen, die literarischen und filmischen Erzählformen für den ökonomischen Menschen zu interessieren. In dem Artikel geht es darum zu zeigen, wie die Brüder Dardenne und Christian Petzold die Aporien eines vom ökonomischen Dispositiv produzierten Subjekts in ihren Filmen Rosetta (1999 und Yella (2007 erzählerisch umsetzen und dabei genau diese erzählerische Umsetzbarkeit in Frage stellen.

  11. Permafrost and indigenous land use in the northern Urals: Komi and Nenets reindeer husbandry

    Science.gov (United States)

    Istomin, Kirill V.; Habeck, Joachim Otto

    2016-09-01

    Permafrost is an integral part of the environmental conditions that frame indigenous peoples' livelihoods in many parts of the circumpolar region. On the basis of their long-term ethnographic field researches, the authors describe the various ways in which permafrost dynamics influence the lives and economic activities of two groups of reindeer-herding nomads in North-Eastern Europe and Western Siberia: Komi and Nenets. Permafrost affects the herders directly, for the herders have to take into account the probability of thermokarst while choosing the campsite and performing certain herding procedures. It also affects the herders indirectly, through its influence on landscape and vegetation and thus on reindeer behavior. More rapid permafrost degradation will have a range of adverse effects on reindeer herding.

  12. Ethik, Recht und Theologie. Reproduktionstechnologien in Polen

    Directory of Open Access Journals (Sweden)

    Susanne Lettow

    2006-03-01

    Full Text Available Die bisherigen Debatten um Stammzellforschung, Klonen und Reproduktionstechnologien wurden in Deutschland weitgehend im nationalstaatlichen Rahmen und mit Blick auf Entwicklungen im angelsächsischen Raum geführt. Dabei sind diese Forschungsrichtungen und Technologien kein genuin „westliches“ Phänomen – immerhin wurde das erste Retortenkind in Polen bereits 1987 geboren. Heidi Hofmann lässt in ihrem Band polnische Philosoph/-innen, Jurist/-innen und Politikerinnen zu Wort kommen und öffnet den Blick dafür, dass die Art und Weise, in der Reproduktionstechnologien gesellschaftlich problematisiert werden, in Polen durch ganz andere politische, kulturelle und historische Konstellationen geprägt ist als in Deutschland.

  13. Ein überfälliger Dialog. Wie Frauen- und Geschlechterforschung und Soziologie miteinander ins Gespräch kommen können

    Directory of Open Access Journals (Sweden)

    Heike Kahlert

    2007-03-01

    Full Text Available Die Monographie von Brigitte Aulenbacher zum Zusammenhang von Rationalisierung, Geschlecht und Gesellschaft ist in gegenstandsbezogener und methodologischer Hinsicht ambitioniert, überzeugend und lesenswert. Die Studie stellt eine solide, manchmal auch etwas zu weitschweifige und detailreiche Grundlage für weiterführende Diskussionen zwischen der (sozialwissenschaftlichen Frauen- und Geschlechterforschung und der Soziologie, genauer der Gesellschaftstheorie in zeitdiagnostischer Perspektive, Arbeits-, Industrie-, Organisations- und Techniksoziologie, dar.

  14. Classification of permafrost active layer depth from remotely sensed and topographic evidence

    International Nuclear Information System (INIS)

    Peddle, D.R.; Franklin, S.E.

    1993-01-01

    The remote detection of permafrost (perennially frozen ground) has important implications to environmental resource development, engineering studies, natural hazard prediction, and climate change research. In this study, the authors present results from two experiments into the classification of permafrost active layer depth within the zone of discontinuous permafrost in northern Canada. A new software system based on evidential reasoning was implemented to permit the integrated classification of multisource data consisting of landcover, terrain aspect, and equivalent latitude, each of which possessed different formats, data types, or statistical properties that could not be handled by conventional classification algorithms available to this study. In the first experiment, four active layer depth classes were classified using ground based measurements of the three variables with an accuracy of 83% compared to in situ soil probe determination of permafrost active layer depth at over 500 field sites. This confirmed the environmental significance of the variables selected, and provided a baseline result to which a remote sensing classification could be compared. In the second experiment, evidence for each input variable was obtained from image processing of digital SPOT imagery and a photogrammetric digital elevation model, and used to classify active layer depth with an accuracy of 79%. These results suggest the classification of evidence from remotely sensed measures of spectral response and topography may provide suitable indicators of permafrost active layer depth

  15. Seasonal and multi-year surface displacements measured by DInSAR in a High Arctic permafrost environment

    Science.gov (United States)

    Rudy, Ashley C. A.; Lamoureux, Scott F.; Treitz, Paul; Short, Naomi; Brisco, Brian

    2018-02-01

    Arctic landscapes undergo seasonal and long-term changes as the active layer thaws and freezes, which can result in localized or irregular subsidence leading to the formation of thermokarst terrain. Differential Interferometric Synthetic Aperture Radar (DInSAR) is a technique capable of measuring ground surface displacements resulting from thawing permafrost at centimetre precision and is quickly gaining acceptance as a means of measuring ground displacement in permafrost regions. Using RADARSAT-2 stacked DInSAR data from 2013 and 2015 we determined the magnitude and patterns of land surface change in a continuous permafrost environment. At our study site situated in the Canadian High Arctic, DInSAR seasonal ground displacement patterns were consistent with field observations of permafrost degradation. As expected, many DInSAR values are close to the detection threshold (i.e., 1 cm) and therefore do not indicate significant change; however, DInSAR seasonal ground displacement patterns aligned well with climatological and soil conditions and offer geomorphological insight into subsurface processes in permafrost environments. While our dataset is limited to two years of data representing a three-year time period, the displacements derived from DInSAR provide insight into permafrost change in a High Arctic environment and demonstrate that DInSAR is an applicable tool for understanding environmental change in remote permafrost regions.

  16. Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska

    Science.gov (United States)

    Wickland, Kimberly P.; Waldrop, Mark P.; Aiken, George R.; Koch, Joshua C.; Torre Jorgenson, M.; Striegl, Robert G.

    2018-06-01

    Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active-layer (seasonally frozen) and permafrost soil DOC, DON and DIN. We quantified DOC, total dissolved N (TDN), DON, and DIN leachate yields from deep active-layer and near-surface boreal Holocene permafrost soils in interior Alaska varying in soil C and N content and radiocarbon age to determine potential release upon thaw. Soil cores were collected at three sites distributed across the Alaska boreal region in late winter, cut in 15 cm thick sections, and deep active-layer and shallow permafrost sections were thawed and leached. Leachates were analyzed for DOC, TDN, nitrate (NO3 ‑), and ammonium (NH4 +) concentrations, dissolved organic matter optical properties, and DOC biodegradability. Soils were analyzed for C, N, and radiocarbon (14C) content. Soil DOC, TDN, DON, and DIN yields increased linearly with soil C and N content, and decreased with increasing radiocarbon age. These relationships were significantly different for active-layer and permafrost soils such that for a given soil C or N content, or radiocarbon age, permafrost soils released more DOC and TDN (mostly as DON) per gram soil than active-layer soils. Permafrost soil DOC biodegradability was significantly correlated with soil Δ14C and DOM optical properties. Our results demonstrate that near-surface Holocene permafrost soils preserve greater relative potential DOC and TDN yields than overlying seasonally frozen soils that are exposed to annual leaching and decomposition. While many factors control the fate of DOC and TDN, the greater relative yields from newly thawed Holocene permafrost soils will have the largest

  17. Use Of Amino Acid Racemization To Investigate The Metabolic Activity Of ?Dormant? Microorganisms In Siberian Permafrost

    Science.gov (United States)

    Tsapin, A.; McDonald, G.

    2002-12-01

    Permafrost occupies a significant part of North America and Eurasia, and accounts for around 20% of Earth?s land surface. Permafrost represents a temperature-stable environment that allows the prolonged survival of microbial lineages at subzero temperatures. Microorganisms from ancient permafrost have been revived and isolated in pure cultures. Permafrost is a unique environment serving as a "natural gene bank", with many species frozen in time (i.e. preserved in an unchanging evolutionary state). Permafrost presents a golden niche for future biotechnology, and is also a unique environment for studying longevity and survivability microorganisms (pro- and eukaryotes). Permafrost, alone among cold environments, offers a sedimentary column in which, in one borehole made in the thick permafrost, we can observe in the preserved genetic material the history of biological evolution during the last several hundred thousand or maybe even a few million years. A thorough study of the phylogenetic relationships of organisms at each depth, as well as comparisons between different depths of permafrost, using molecular evolution techniques, will give us a unique window into the process of evolution of microbial communities over geologic time. The longevity of (micro)organisms in cold environments is of great interest to astrobiology since cryospheres are common phenomena in the solar system, particularly on satellites, comets and asteroids, and on some of the planets. Recent data from the Mars Global Surveyor mission suggest the possibility of permafrost or perhaps even liquid water under the Martian surface. The probability of finding life on Mars, if it exists, is probably higher in such environments. In addition, the evaluation of the possibility of transfer of living organisms between planets via impact ejecta needs the information on the maximum time over which microorganisms in cold environments can remain dormant and subsequently revive and reproduce. Our strategy for the

  18. Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

  19. [Geisteswissenschaft und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts] / Manfred von Boetticher

    Index Scriptorium Estoniae

    Boetticher, Manfred von, 1947-

    2012-01-01

    Arvustus: Geisteswissenschaft und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts (Schriften der Baltischen Historischen Kommission, 17; Baltische Biographische Forschungen, 1). Hrsg. von Norbert Angermann, Wilhelm Lenz und Konrad Maier. (Berlin: LIT-Varlag, 2011)

  20. Dissolved organic carbon and nitrogen release from Holocene permafrost and seasonally frozen soils

    Science.gov (United States)

    Wickland, K.; Waldrop, M. P.; Koch, J. C.; Jorgenson, T.; Striegl, R. G.

    2017-12-01

    Permafrost (perennially frozen) soils store vast amounts of carbon (C) and nitrogen (N) that are vulnerable to mobilization to the atmosphere as greenhouse gases and to terrestrial and aquatic ecosystems as dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) upon thaw. Such releases will affect the biogeochemistry of arctic and boreal regions, yet little is known about active layer (seasonally frozen) and permafrost source variability that determines DOC and TDN mobilization. We quantified DOC and TDN leachate yields from a range of active layer and permafrost soils in Alaska varying in age and C and N content to determine potential release upon thaw. Soil cores from the upper 1 meter were collected in late winter, when soils were frozen, from three locations representing a range in geographic position, landscape setting, permafrost depth, and soil types across interior Alaska. Two 15 cm-thick segments were extracted from each core: a deep active-layer horizon and a shallow permafrost horizon. Soils were thawed and leached for DOC and TDN yields, dissolved organic matter optical properties, and DOC biodegradability; soils were analyzed for C and N content, and radiocarbon content. Soils had wide-ranging C and N content (<1-44% C, <0.1-2.3% N), and varied in radiocarbon age from 450-9200 years before present - thus capturing typical ranges of boreal and arctic soils. Soil DOC and TDN yields increased linearly with soil C and N content, and decreased with increasing radiocarbon age. However, across all sites DOC and TDN yields were significantly greater from permafrost soils (0.387 ± 0.324 mg DOC g-1 soil; 0.271 ± 0.0271 mg N g-1 soil) than from active layer soils (0.210 ± 0.192 mg DOC g-1 soil; 0.00716 ± 0.00569 mg N g-1 soil). DOC biodegradability increased with increasing radiocarbon age, and was statistically similar for active layer and permafrost soils. Our findings suggest that the continuously frozen state of permafrost soils has preserved

  1. Surface geophysical methods for characterising frozen ground in transitional permafrost landscapes

    Science.gov (United States)

    Briggs, Martin A.; Campbell, Seth; Nolan, Jay; Walvoord, Michelle Ann; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Lane, John W.

    2017-01-01

    The distribution of shallow frozen ground is paramount to research in cold regions, and is subject to temporal and spatial changes influenced by climate, landscape disturbance and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterise finer-scale processes and phenomena, which are better captured by integrated surface geophysical methods. Here, we demonstrate the use of electrical resistivity imaging (ERI), electromagnetic induction (EMI), ground penetrating radar (GPR) and infrared imaging over multiple summer field seasons around the highly dynamic Twelvemile Lake, Yukon Flats, central Alaska, USA. Twelvemile Lake has generally receded in the past 30 yr, allowing permafrost aggradation in the receded margins, resulting in a mosaic of transient frozen ground adjacent to thick, older permafrost outside the original lakebed. ERI and EMI best evaluated the thickness of shallow, thin permafrost aggradation, which was not clear from frost probing or GPR surveys. GPR most precisely estimated the depth of the active layer, which forward electrical resistivity modelling indicated to be a difficult target for electrical methods, but could be more tractable in time-lapse mode. Infrared imaging of freshly dug soil pit walls captured active-layer thermal gradients at unprecedented resolution, which may be useful in calibrating emerging numerical models. GPR and EMI were able to cover landscape scales (several kilometres) efficiently, and new analysis software showcased here yields calibrated EMI data that reveal the complicated distribution of shallow permafrost in a transitional landscape.

  2. Modelling the Effects of Temperature and Cloud Cover Change on Mountain Permafrost Distribution, Northwest Canada

    Science.gov (United States)

    Bonnaventure, P. P.; Lewkowicz, A. G.

    2008-12-01

    Spatial models of permafrost probability for three study areas in northwest Canada between 59°N and 61°N were perturbed to investigate climate change impacts. The models are empirical-statistical in nature, based on basal temperature of snow (BTS) measurements in winter, and summer ground-truthing of the presence or absence of frozen ground. Predictions of BTS values are made using independent variables of elevation and potential incoming solar radiation (PISR), both derived from a 30 m DEM. These are then transformed into the probability of the presence or absence of permafrost through logistic regression. Under present climate conditions, permafrost percentages in the study areas are 44% for Haines Summit, British Columbia, 38% for Wolf Creek, Yukon, and 69% for part of the Ruby Range, Yukon (Bonnaventure and Lewkowicz, 2008; Lewkowicz and Bonaventure, 2008). Scenarios of air temperature change from -2K (approximating Neoglacial conditions) to +5K (possible within the next century according to the IPCC) were examined for the three sites. Manipulations were carried out by lowering or raising the terrain within the DEM assuming a mean environmental lapse rate of 6.5K/km. Under a -2K scenario, permafrost extent increased by 22-43% in the three study areas. Under a +5K warming, permafrost essentially disappeared in Haines Summit and Wolf Creek, while in the Ruby Range less than 12% of the area remained perennially frozen. It should be emphasized that these model predictions are for equilibrium conditions which might not be attained for several decades or longer in areas of cold permafrost. Cloud cover changes of -10% to +10% were examined through adjusting the partitioning of direct beam and diffuse radiation in the PISR input field. Changes to permafrost extent were small, ranging from -2% to -4% for greater cloudiness with changes of the opposite magnitude for less cloud. The results show that air temperature change has a much greater potential to affect mountain

  3. Temperature response of permafrost soil carbon is attenuated by mineral protection.

    Science.gov (United States)

    Gentsch, Norman; Wild, Birgit; Mikutta, Robert; Čapek, Petr; Diáková, Katka; Schrumpf, Marion; Turner, Stephanie; Minnich, Cynthia; Schaarschmidt, Frank; Shibistova, Olga; Schnecker, Jörg; Urich, Tim; Gittel, Antje; Šantrůčková, Hana; Bárta, Jiři; Lashchinskiy, Nikolay; Fuß, Roland; Richter, Andreas; Guggenberger, Georg

    2018-05-18

    Climate change in Arctic ecosystems fosters permafrost thaw and makes massive amounts of ancient soil organic carbon (OC) available to microbial breakdown. However, fractions of the organic matter (OM) may be protected from rapid decomposition by their association with minerals. Little is known about the effects of mineral-organic associations (MOA) on the microbial accessibility of OM in permafrost soils and it is not clear which factors control its temperature sensitivity. In order to investigate if and how permafrost soil OC turnover is affected by mineral controls, the heavy fraction (HF) representing mostly MOA was obtained by density fractionation from 27 permafrost soil profiles of the Siberian Arctic. In parallel laboratory incubations, the unfractionated soils (bulk) and their HF were comparatively incubated for 175 days at 5 and 15°C. The HF was equivalent to 70 ± 9% of the bulk CO 2 respiration as compared to a share of 63 ± 1% of bulk OC that was stored in the HF. Significant reduction of OC mineralization was found in all treatments with increasing OC content of the HF (HF-OC), clay-size minerals and Fe or Al oxyhydroxides. Temperature sensitivity (Q10) decreased with increasing soil depth from 2.4 to 1.4 in the bulk soil and from 2.9 to 1.5 in the HF. A concurrent increase in the metal-to-HF-OC ratios with soil depth suggests a stronger bonding of OM to minerals in the subsoil. There, the younger 14 C signature in CO 2 than that of the OC indicates a preferential decomposition of the more recent OM and the existence of a MOA fraction with limited access of OM to decomposers. These results indicate strong mineral controls on the decomposability of OM after permafrost thaw and on its temperature sensitivity. Thus, we here provide evidence that OM temperature sensitivity can be attenuated by MOA in permafrost soils. © 2018 John Wiley & Sons Ltd.

  4. Metagenomic analysis of permafrost microbial community response to thaw

    Energy Technology Data Exchange (ETDEWEB)

    Mackelprang, R.; Waldrop, M.P.; DeAngelis, K.M.; David, M.M.; Chavarria, K.L.; Blazewicz, S.J.; Rubin, E.M.; Jansson, J.K.

    2011-07-01

    We employed deep metagenomic sequencing to determine the impact of thaw on microbial phylogenetic and functional genes and related this data to measurements of methane emissions. Metagenomics, the direct sequencing of DNA from the environment, allows for the examination of whole biochemical pathways and associated processes, as opposed to individual pieces of the metabolic puzzle. Our metagenome analyses revealed that during transition from a frozen to a thawed state there were rapid shifts in many microbial, phylogenetic and functional gene abundances and pathways. After one week of incubation at 5°C, permafrost metagenomes converged to be more similar to each other than while they were frozen. We found that multiple genes involved in cycling of C and nitrogen shifted rapidly during thaw. We also constructed the first draft genome from a complex soil metagenome, which corresponded to a novel methanogen. Methane previously accumulated in permafrost was released during thaw and subsequently consumed by methanotrophic bacteria. Together these data point towards the importance of rapid cycling of methane and nitrogen in thawing permafrost.

  5. Contribution of supra-permafrost discharge to thermokarst lake water balances on the northeastern Qinghai-Tibet Plateau

    Science.gov (United States)

    Pan, Xicai; Yu, Qihao; You, Yanhui; Chun, Kwok Pan; Shi, Xiaogang; Li, Yanping

    2017-12-01

    The seasonal hydrological mechanisms of two thermokarst lakes on the northeastern Qinghai-Tibet Plateau (QTP) were characterized by three-year intensive field observations and a water balance model. In three ice-free seasons, the supra-permafrost discharge contributed a mean ratio of over 170% of the precipitation. In the ice-cover seasons, the supra-permafrost discharge contribution varied between -20% and 22% of the water storage change. Results show that a large portion of the lake water storage change is because of the supra-permafrost discharge resulting from precipitation. Furthermore, a precipitation-subsurface runoff function is preliminarily identified in which the supra-permafrost discharge nonlinearly increased with more precipitation. Our results show that the recent lake expansion is linked with increasing supra-permafrost discharge dominated by precipitation. This study also suggests that we need to pay attention to the nonlinear increase of precipitation-controlled supra-permafrost discharge on the large lake expansion at the catchment scale in the QTP region, instead of only looking at the inputs (e.g., precipitation and river discharge) as shown in the previous studies.

  6. Frozen in Time? Microbial strategies for survival and carbon metabolism over geologic time in a Pleistocene permafrost chronosequence

    Science.gov (United States)

    Mackelprang, R.; Douglas, T. A.; Waldrop, M. P.

    2014-12-01

    Permafrost soils have received tremendous interest due to their importance as a global carbon store with the potential to be thawed over the coming centuries. Instead of being 'frozen in time,' permafrost contains active microbes. Most metagenomic studies have focused on Holocene aged permafrost. Here, we target Pleistocene aged ice and carbon rich permafrost (Yedoma), which can differ in carbon content and stage of decay. Our aim was to understand how microbes in the permafrost transform organic matter over geologic time and to identify physiological and biochemical adaptations that enable long-term survival. We used next-generation sequencing to characterize microbial communities along a permafrost age gradient. Samples were collected from the Cold Regions Research and Engineering Laboratory (CRREL) Permafrost Tunnel near Fox, AK, which penetrates a hillside providing access to permafrost ranging in age from 12 to 40 kyr. DNA was extracted directly from unthawed samples. 16S rRNA amplicon (16S) and shotgun metagenome sequencing revealed significant age-driven differences. First, microbial diversity declines with permafrost age, likely due to long-term exposure to environmental stresses and a reduction in metabolic resources. Second, we observed taxonomic differences among ages, with an increasing abundance of Firmicutes (endospore-formers) in older samples, suggesting that dormancy is a common survival strategy in older permafrost. Ordination of 16S and metagenome data revealed age-based clustering. Genes differing significantly between age categories included those involved in lipopolysaccharide assembly, cold-response, and carbon processing. These data point to the physiological adaptations to long-term frozen conditions and to the metabolic processes utilized in ancient permafrost. In fact, a gene common in older samples is involved in cadaverine production, which could potentially explain the putrefied smell of Pleistocene aged permafrost. Coupled with soil

  7. Soil organic carbon pools and stocks in permafrost-affected soils on the tibetan plateau.

    Directory of Open Access Journals (Sweden)

    Corina Dörfer

    Full Text Available The Tibetan Plateau reacts particularly sensitively to possible effects of climate change. Approximately two thirds of the total area is affected by permafrost. To get a better understanding of the role of permafrost on soil organic carbon pools and stocks, investigations were carried out including both discontinuous (site Huashixia, HUA and continuous permafrost (site Wudaoliang, WUD. Three organic carbon fractions were isolated using density separation combined with ultrasonic dispersion: the light fractions (1.6 g cm(-3 of mineral associated organic matter (MOM. The fractions were analyzed for C, N, and their portion of organic C. FPOM contained an average SOC content of 252 g kg(-1. Higher SOC contents (320 g kg(-1 were found in OPOM while MOM had the lowest SOC contents (29 g kg(-1. Due to their lower density the easily decomposable fractions FPOM and OPOM contribute 27% (HUA and 22% (WUD to the total SOC stocks. In HUA mean SOC stocks (0-30 cm depth account for 10.4 kg m(-2, compared to 3.4 kg m(-2 in WUD. 53% of the SOC is stored in the upper 10 cm in WUD, in HUA only 39%. Highest POM values of 36% occurred in profiles with high soil moisture content. SOC stocks, soil moisture and active layer thickness correlated strongly in discontinuous permafrost while no correlation between SOC stocks and active layer thickness and only a weak relation between soil moisture and SOC stocks could be found in continuous permafrost. Consequently, permafrost-affected soils in discontinuous permafrost environments are susceptible to soil moisture changes due to alterations in quantity and seasonal distribution of precipitation, increasing temperature and therefore evaporation.

  8. The Effects of Perchlorates on the Permafrost Methanogens: Implication for Autotrophic Life on Mars.

    Science.gov (United States)

    Shcherbakova, Viktoria; Oshurkova, Viktoria; Yoshimura, Yoshitaka

    2015-09-09

    The terrestrial permafrost represents a range of possible cryogenic extraterrestrial ecosystems on Earth-like planets without obvious surface ice, such as Mars. The autotrophic and chemolithotrophic psychrotolerant methanogens are more likely than aerobes to function as a model for life forms that may exist in frozen subsurface environments on Mars, which has no free oxygen, inaccessible organic matter, and extremely low amounts of unfrozen water. Our research on the genesis of methane, its content and distribution in permafrost horizons of different ages and origin demonstrated the presence of methane in permanently frozen fine-grained sediments. Earlier, we isolated and described four strains of methanogenic archaea of Methanobacterium and Methanosarcina genera from samples of Pliocene and Holocene permafrost from Eastern Siberia. In this paper we study the effect of sodium and magnesium perchlorates on growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. In this paper we study the effect of sodium and magnesium perchlorates on the growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. Furthermore, as shown in the studies strain M2(T) M. arcticum, probably can use perchlorate anion as an electron acceptor in anaerobic methane oxidation. Earth's subzero subsurface environments are the best approximation of environments on Mars, which is most likely to harbor methanogens; thus, a biochemical understanding of these pathways is expected to provide a basis for designing experiments to detect autotrophic methane-producing life forms on Mars.

  9. The Effects of Perchlorates on the Permafrost Methanogens: Implication for Autotrophic Life on Mars

    Directory of Open Access Journals (Sweden)

    Viktoria Shcherbakova

    2015-09-01

    Full Text Available The terrestrial permafrost represents a range of possible cryogenic extraterrestrial ecosystems on Earth-like planets without obvious surface ice, such as Mars. The autotrophic and chemolithotrophic psychrotolerant methanogens are more likely than aerobes to function as a model for life forms that may exist in frozen subsurface environments on Mars, which has no free oxygen, inaccessible organic matter, and extremely low amounts of unfrozen water. Our research on the genesis of methane, its content and distribution in permafrost horizons of different ages and origin demonstrated the presence of methane in permanently frozen fine-grained sediments. Earlier, we isolated and described four strains of methanogenic archaea of Methanobacterium and Methanosarcina genera from samples of Pliocene and Holocene permafrost from Eastern Siberia. In this paper we study the effect of sodium and magnesium perchlorates on growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. In this paper we study the effect of sodium and magnesium perchlorates on the growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. Furthermore, as shown in the studies strain M2T M. arcticum, probably can use perchlorate anion as an electron acceptor in anaerobic methane oxidation. Earth’s subzero subsurface environments are the best approximation of environments on Mars, which is most likely to harbor methanogens; thus, a biochemical understanding of these pathways is expected to provide a basis for designing experiments to detect autotrophic methane-producing life forms on Mars.

  10. InSAR observation of seasonal ground surface deformation in permafrost area near Batagay, Siberia

    Science.gov (United States)

    Yanagiya, K.; Furuya, M.

    2017-12-01

    Thawing of permafrost can lead to ground deformation. Ground deformation has been studied as a serious problem in the Arctic Ocean coastal area such as Russia for a long time, because the deformation causes damage to architectures at these areas. However, there have been no quantitative observation data, and the spatial and temporal distributions have hardly been investigated. On the other hand, by the recently global warming influence, the importance of organic carbon stored in permafrost is pointed out. Although the release of methane gas is confirmed in some thermokarst lakes, it is very difficult to observe the permafrost in a wide area by field study. Instead, it is technically possible to monitor the subsidence and uplift of the ground over the permafrost area, which could potentially make a significant contribution to the monitoring thawing process of permafrost. In this study, we attempted to detect ground deformation signal in permafrost area by remote sensing using interferometric synthetic aperture radar (InSAR). Using the data of two SAR satellites ALOS and ALOS2 launched by JAXA, we observed recent ground deformation from 2007 to 2016. Particularly recent observations of ALOS2 from 2014 to 2016 discovered distant displacements towards the LOS direction in the northeast region from the town of Batagay,Siberia. The diameter of the displacements area covers about 7.7 km. In this study, we considered that this signal is likely to be due to permafrost thawing, we also investigated the seasonal characteristics and looked back ALOS data of this area. In addition, since the high latitude area, observation results include noise due to the ionosphere, so we tried to remove the noise.

  11. [Geisteswissenschaften und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts] / Gert von Pistohlkors

    Index Scriptorium Estoniae

    Pistohlkors, Gert von, 1935-

    2013-01-01

    Arvustus: Geisteswissenschaften und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts. Hrsg. von Norbert Angermann, Wilhelm Lenz und Konrad Maier. (Schriften der Baltischen Historischen Kommission, Bd. 17; Baltische Biographische Forschungen, Bd. 1.) Lit. Münster 2011

  12. Climate Change and Thawing Permafrost in Two Iñupiaq Communities of Alaska's Arctic: Observations, Implications, and Resilience

    Science.gov (United States)

    Woodward, A.; Kofinas, G.

    2013-12-01

    For thousands of years the Iñupiat of northern Alaska have relied on ecosystems underlain by permafrost for material and cultural resources. As permafrost thaws across the Arctic, these social-ecological systems are changing rapidly. Community-based research and extensive local knowledge of Iñupiaq villagers offer unique and valuable contributions to understanding permafrost change and its implications for humans. We partnered with two Iñupiaq communities in Alaska's Arctic to investigate current and potential effects of thawing permafrost on social-ecological systems. Anaktuvuk Pass is situated on thaw-stable consolidated gravel in the Brooks Range, while Selawik rests on ice-rich permafrost in Beringia lowland tundra. Using the transdisciplinary approach of resilience theory and mixed geophysical and ethnographic methods, we measured active layer thaw depths and documented local knowledge about climate and permafrost change. Thaw depths were greater overall in Selawik. Residents of both communities reported a variety of changes in surface features, hydrology, weather, flora, and fauna that they attribute to thawing permafrost and / or climate change. Overall, Selawik residents described more numerous and extreme examples of such changes, expressed higher degrees of certainty that change is occurring, and anticipated more significant and negative implications for their way of life than did residents of Anaktuvuk Pass. Of the two villages, Selawik faces greater and more immediate challenges to the resilience of its social-ecological system as permafrost thaws.

  13. Rasterelektronenmikroskopische und immunhistochemische Untersuchungen am Eileiter vom Schwein während Zyklus und Trächtigkeit

    OpenAIRE

    Mayer, Judith

    2008-01-01

    In der vorliegenden Arbeit wurden zum einen mit Hilfe des Rasterelektronenmikroskops die morphologischen Veränderungen des Eileiterepithels und zum anderen die Expression hypophysärer wachstums- und proliferationsfördernder Hormone und ihrer Rezeptoren immunhistochemisch und mit der Reverse Transkriptase (RT)-PCR sowohl im Verlauf des Zyklus als auch der Trächtigkeit analysiert. Hierfür wurden, von 24 Schweinen der Deutschen Landrasse, die drei Abschnitte des Eileiters (Infundibulum, Ampulle,...

  14. Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems

    Science.gov (United States)

    Vonk, J.E.; Tank, S.E.; Bowden, W.B.; Laurion, I.; Vincent, W.F.; Alekseychik, P.; Amyot, Y.; Billet, M.F.; Canario, J.; Cory, R.M.; Deshpande, B.N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; MacMillan, G.; Rautio, Milla; Walter Anthony, K.M.; Wickland, Kimberly P.

    2015-01-01

    The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current state of knowledge regarding how permafrost thaw affects lentic (still) and lotic (moving) systems, exploring the effects of both thermokarst (thawing and collapse of ice-rich permafrost) and deepening of the active layer (the surface soil layer that thaws and refreezes each year). Within thermokarst, we further differentiate between the effects of thermokarst in lowland areas vs. that on hillslopes. For almost all of the processes that we explore, the effects of thaw vary regionally, and between lake and stream systems. Much of this regional variation is caused by differences in ground ice content, topography, soil type, and permafrost coverage. Together, these modifying factors determine (i) the degree to which permafrost thaw manifests as thermokarst, (ii) whether thermokarst leads to slumping or the formation of thermokarst lakes, and (iii) the manner in which constituent delivery to freshwater systems is altered by thaw. Differences in thaw-enabled constituent delivery can be considerable, with these modifying factors determining, for example, the balance between delivery of particulate vs. dissolved constituents, and inorganic vs. organic materials. Changes in the composition of thaw-impacted waters, coupled with changes in lake morphology, can strongly affect the physical and optical properties of thermokarst lakes. The ecology of thaw-impacted lakes and streams is also likely to change; these systems have unique microbiological communities, and show differences in respiration, primary production, and food web structure that are largely driven by differences in sediment, dissolved organic matter, and nutrient delivery. The degree to which thaw enables the delivery

  15. Unraveling of permafrost hydrological variabilities on Central Qinghai-Tibet Plateau using stable isotopic technique.

    Science.gov (United States)

    Yang, Yuzhong; Wu, Qingbai; Hou, Yandong; Zhang, Zhongqiong; Zhan, Jing; Gao, Siru; Jin, Huijun

    2017-12-15

    Permafrost degradation on the Qinghai-Tibet Plateau (QTP) will substantially alter the surface runoff discharge and generation, which changes the recharge processes and influences the hydrological cycle on the QTP. Hydrological connections between different water bodies and the influence of thawing permafrost (ground ice) are not well understood on the QTP. This study applied water stable isotopic method to investigate the permafrost hydrological variabilities in Beiluhe Basin (BLB) on Central QTP. Isotopic variations of precipitation, river flow, thermokarst lake, and near-surface ground ice were identified to figure out the moisture source of them, and to elaborate the hydrological connections in permafrost region. Results suggested that isotopic seasonalities in precipitation is evident, it is showing more positive values in summer seasons, and negative values in winter seasons. Stable isotopes of river flow are mainly distributed in the range of precipitation which is indicative of important replenishment from precipitation. δ 18 O, δD of thermokarst lakes are more positive than precipitation, indicating of basin-scale evaporation of lake water. Comparison of δ I values in different water bodies shows that hydrology of thermokarst lakes was related to thawing of permafrost (ground ice) and precipitation. Near-surface ground ice in BLB exhibits different isotopic characteristics, and generates a special δD-δ 18 O relationship (freezing line): δD=5.81δ 18 O-23.02, which reflects typical freezing of liquid water. From isotopic analysis, it is inferred that near-surface ground ice was mainly recharged by precipitation and active layer water. Stable isotopic and conceptual model is suggestive of striking hydrological connections between precipitation, river flow, thermokarst lake, and ground ice under degrading permafrost. This research provides fundamental comprehensions into the hydrological processes in permafrost regions on QTP, which should be considered

  16. The 50th Anniversary of the First International Conference on Permafrost

    Science.gov (United States)

    Brown, J.

    2013-12-01

    This year marks the 50th anniversary of the First International Conference on Permafrost (ICOP) that was held at Purdue University on 11-15 November 1963. The conference was a historic event in that it brought together for the first time the leading researchers and practitioners from North America and other countries that had diverse interests and activities in the study and applications of perennially frozen ground, cold regions engineering and related laboratory investigations. The 285 registered participants represented engineers, researchers, manufacturers and builders from the USA (231), Canada (42), the USSR (5), Sweden (3) and Argentina, Austria, Great Britain, Japan, Norway, Poland, Switzerland, and West Germany. The conference was organized by the Building Research Advisory Board of the U.S. National Academy of Sciences-National Research Council (NAS-NRC). The carefully edited volume, published in 1966 by the NAS, is considered to be the first multi-national, English-language collection of papers devoted entirely to permafrost topics. The 100 published papers followed closely the actual conference venue and panel discussions: soils and vegetation (9), massive ground ice (10), geomorphology (16), phase equilibrium and transition (8), thermal aspects (8), physico-mechanical properties (7), exploration and site selection (11), sanitary and hydraulic engineering (14), and earthwork and foundations (17). This 1963 Purdue conference essentially broke the 'ice' between East and West permafrost researchers and set the stage for the Second ICOP that was held in 1973 in Yakutsk, Siberia, and represented the first large international conference held in the restricted area of Siberia. All subsequent conferences maintained the interdisciplinary principles set forth at Purdue: two more in the United States (Fairbanks 1983, 2008), two in Canada (Edmonton 1978, Yellowknife 1998), and one in Trondheim, Norway (1988), Beijing, China (1993), and Zurich, Switzerland (2003

  17. Perception and processing of information relevant to critical incidents and emergencies; Wahrnehmung und Verarbeitung stoer- und unfallrelevanter Informationen

    Energy Technology Data Exchange (ETDEWEB)

    Dombrowsky, W.R. [Kiel Univ. (Germany). Katastrophenforschungsstelle

    1997-12-31

    Based on the results of empirical research, which implemented and evaluated information to the public requested by law (HIO-Paragraph-11a) and based on the general findings of crisis- and risk-communication research, some disturbing elements in the relationship between entrepreneurs, administration and the public will be described in terms of cognitive dissonance, prejudice, fears and false expectations. The empirical example of public information in emergencies will evidence the conflicting views on types, styles, size and profoundity of such information as well as the differences in perception, motivation and interest of all parties involved. Finally, the cultural context of risk perception and of coping capabilities will be interrelated with historical changes of risk-management to prepare for the understanding that risk- and crisis communication has to be more than talking about safety. (orig.) [Deutsch] Am Beispiel einer Implementations- und Evaluationsforschung zur Erstellung von Stoerfallinformationen nach Paragraph 11a BimSchG fuer zwei Unternehmen und auf Basis des Kenntnisstandes der internationalen Forschung zur Krisen- und Risikokommunikation wird verdeutlicht, welche kognitiven Dissonanzen zwischen Anlagenbetreibern, Behoerden und Bevoelkerung ueber Art, Umfang und Gestaltung von Gefahrinformationen bestehen, welche Vorurteile und Aengste eine sachliche Kommunikation behindern, welche gesellschaftlichen Faktoren bislang weitgehend uebersehen wurden, was von wem fuer `stoer- und unfallrelevant` gehalten wird und welche gesellschaftlichen, sozialen `settings`, d.h. welche menschlichen Bedingungen die Wahrnehmung und Verarbeitung welcher Informationen beeinflussen. Darin liegt die empirische Bestaetigung der Hypothese, dass sich die Wahrnehmung von Risiken und Bedrohungen historisch kurzfristig (bereits innerhalb einer Generation) veraendert und es keine `one-for-all`-Strategie der Risiko- und Krisenkommunikation geben kann, wohl aber allgemeine

  18. Bewegung bei Vorschulkindern: Empfehlungen und Wirklichkeit

    Directory of Open Access Journals (Sweden)

    Graf C

    2011-01-01

    Full Text Available Bewegung und körperliche Aktivität spielen insbesondere in der ganzheitlichen Entwicklung von Kindern eine wichtige Rolle. Heutzutage ist der kindliche Lebensstil allerdings von Bewegungsarmut und der Nutzung audiovisueller Medien geprägt. Bereits Kindergartenkinder sind überwiegend inaktiv bzw. verbringen viel Zeit mit Fernsehen. Eine mögliche Folge von mangelnder Bewegung können motorische Defizite darstellen. In eigenen Kollektiven schneiden mindestens 45 % der Kinder unterdurchschnittlich in den motorischen Hauptbeanspruchungsformen Koordination, Kraft und Schnelligkeit ab. Inwiefern sich dies langfristig auf die gesunde körperliche, aber auch geistige und emotionale Entwicklung der Kinder auswirkt, kann derzeit noch nicht beantwortet werden. Sicherlich unterstützen aber motorische Defizite ein Meidungsverhalten und den weiteren Rückzug aus der Bewegung sowie die Entwicklung von Übergewicht und Adipositas. Allgemein wird für Kinder in dieser Altersgruppe mindestens 2 Stunden tägliche Bewegungszeit sowie eine Reduktion der Fernsehzeit auf maximal 30 Min. empfohlen. Um diese Ziele zu erreichen bzw. zu unterstützen, sind effektive präventive Programme in den verschiedenen Lebensräumen der Kinder, Kindergärten, aber auch pädiatrischen Praxen etc. vonnöten. Bislang ist kein gesundheitsförderlicher/ präventiver „Königsweg“ bekannt, insbesondere nicht für Risikofamilien mit einem geringen sozioökonomischen Status und/oder Migrationshintergrund. Wichtig erscheinen aber die Förderung der intersektoralen Zusammenarbeit und ein Schwerpunkt in der Planung und Umsetzung auf Qualitätssicherung und Projektmanagement, um auch nachhaltig die Gesundheit der Kinder zu unterstützen.

  19. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil 1.] / Jürgen Beyer

    Index Scriptorium Estoniae

    Beyer, Jürgen, 1965-

    2010-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil 1. (Münster : Aschendorff, 2009)

  20. Draft Genome Sequence of Methylocella silvestris TVC, a Facultative Methanotroph Isolated from Permafrost

    OpenAIRE

    Wang, Jing; Geng, Kan; Farhan Ul Haque, Muhammad; Crombie, Andrew; Street, Lorna E.; Wookey, Philip A.; Ma, Ke; Murrell, J. Colin; Pratscher, Jennifer

    2018-01-01

    Permafrost environments play a crucial role in global carbon and methane cycling. We report here the draft genome sequence of Methylocella silvestris TVC, a new facultative methanotroph strain, isolated from the Siksik Creek catchment in the continuous permafrost zone of Inuvik (Northwest Territories, Canada).

  1. A review of published literature on the effects of permafrost on the hydrogeochemistry of bedrock

    International Nuclear Information System (INIS)

    Cascoyne, M.

    2000-06-01

    Salt-rejection into the aqueous phase from permafrost growth ('aggradation') during the onset of cold-climate conditions in the Pleistocene period is a mechanism that could account for the presence of saline groundwaters in the Fennoscandian Shield. This report describes the results of a review of scientific literature on the subject of permafrost, to search for and evaluate information which may indicate whether this mechanism is feasible for sites such as Olkiluoto and Aespoe on the Baltic Sea coast. The geomorphological characteristics of permafrost (such as development of patterned ground, ice wedging, pingo growth) have been studied in detail in the literature and provide an understanding of the effects of pore water expulsion and saline water formation. Evidence of salt-rejection during permafrost aggradation is found in results of analyses of the chemical and isotopic compositions of water in pingos and open taliks published in North American, Chinese and Russian literature over the last fifty years. While most studies have concentrated on shallow permafrost in soils and sediments, deep-drilling by the oil and gas industry has shown that permafrost may extend both laterally and to considerable depth. For instance, permafrost on the north slope of Alaska is laterally continuous over an area of at least 1000 km 2 and is associated with fluids of salinities up to 130 g/L. Also, in northern Siberia, permafrost has been observed to depths of over 900 m. Saline waters are ubiquitous in coastal areas that are currently underlain by permafrost. However, it is not clear how much of the salinity has been produced by the freezing process and how much is simply due to leaching of saline soils and sediments by groundwaters and the presence of residual seawater in the sediments. Possible indicators of concentration by freezing include the presence of brines (i.e. waters of greater salinity than seawater), mineral precipitates (e.g. mirabilite) that are formed on freezing

  2. A review of published literature on the effects of permafrost on the hydrogeochemistry of bedrock

    International Nuclear Information System (INIS)

    Gascoyne, M.

    2000-04-01

    Salt-rejection into the aqueous phase from permafrost growth during the onset of cold-climate conditions in the Pleistocene period is a mechanism that could account for the presence of saline groundwaters in the Fennoscandian Shield. This report describes the results of a review of scientific literature on the subject of permafrost, to search for and evaluate information which may indicate whether this mechanism is feasible for sites such as Olkiluoto and Aespoe on the Baltic Sea coast. The geomorphological characteristics of permafrost (such as development of patterned ground, ice wedging, pingo growth) have been studied in detail in the literature and provide an understanding of the effects of pore water expulsion and saline water formation. Evidence of salt-rejection during permafrost aggradation is found in results of analyses of the chemical and isotopic compositions of water in pingos and open taliks published in North American, Chinese and Russian literature over the last fifty years. While most studies have concentrated on shallow permafrost in soils and sediments, deep-drilling by the oil and gas industry has shown that permafrost may extend both laterally and to considerable depth. For instance, permafrost on the north slope of Alaska is laterally continuous over an area of at least 1000 km 2 and is associated with fluids of salinities up to 130 g/L. Also, in northern Siberia, permafrost has been observed to depths of over 900 m. Saline waters are ubiquitous in coastal areas that are currently underlain by permafrost. However, it is not clear how much of the salinity has been produced by the freezing process and how much is simply due to leaching of saline soils and sediments by ground- waters and the presence of residual seawater in the sediments. Possible indicators of concentration by freezing include the presence of brines (i.e.waters of greater salinity than seawater), mineral precipitates (e.g. mirabilite) that are formed on freezing of seawater

  3. A review of published literature on the effects of permafrost on the hydrogeochemistry of bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Gascoyne, M. [Gascoyne GeoProjects Inc., Pinawa (Canada)

    2000-04-01

    Salt-rejection into the aqueous phase from permafrost growth during the onset of cold-climate conditions in the Pleistocene period is a mechanism that could account for the presence of saline groundwaters in the Fennoscandian Shield. This report describes the results of a review of scientific literature on the subject of permafrost, to search for and evaluate information which may indicate whether this mechanism is feasible for sites such as Olkiluoto and Aespoe on the Baltic Sea coast. The geomorphological characteristics of permafrost (such as development of patterned ground, ice wedging, pingo growth) have been studied in detail in the literature and provide an understanding of the effects of pore water expulsion and saline water formation. Evidence of salt-rejection during permafrost aggradation is found in results of analyses of the chemical and isotopic compositions of water in pingos and open taliks published in North American, Chinese and Russian literature over the last fifty years. While most studies have concentrated on shallow permafrost in soils and sediments, deep-drilling by the oil and gas industry has shown that permafrost may extend both laterally and to considerable depth. For instance, permafrost on the north slope of Alaska is laterally continuous over an area of at least 1000 km{sup 2} and is associated with fluids of salinities up to 130 g/L. Also, in northern Siberia, permafrost has been observed to depths of over 900 m. Saline waters are ubiquitous in coastal areas that are currently underlain by permafrost. However, it is not clear how much of the salinity has been produced by the freezing process and how much is simply due to leaching of saline soils and sediments by ground- waters and the presence of residual seawater in the sediments. Possible indicators of concentration by freezing include the presence of brines (i.e.waters of greater salinity than seawater), mineral precipitates (e.g. mirabilite) that are formed on freezing of

  4. A review of published literature on the effects of permafrost on the hydrogeochemistry of bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Cascoyne, M. [Gascoyne GeoProjects Inc. (Canada)

    2000-06-01

    Salt-rejection into the aqueous phase from permafrost growth ('aggradation') during the onset of cold-climate conditions in the Pleistocene period is a mechanism that could account for the presence of saline groundwaters in the Fennoscandian Shield. This report describes the results of a review of scientific literature on the subject of permafrost, to search for and evaluate information which may indicate whether this mechanism is feasible for sites such as Olkiluoto and Aespoe on the Baltic Sea coast. The geomorphological characteristics of permafrost (such as development of patterned ground, ice wedging, pingo growth) have been studied in detail in the literature and provide an understanding of the effects of pore water expulsion and saline water formation. Evidence of salt-rejection during permafrost aggradation is found in results of analyses of the chemical and isotopic compositions of water in pingos and open taliks published in North American, Chinese and Russian literature over the last fifty years. While most studies have concentrated on shallow permafrost in soils and sediments, deep-drilling by the oil and gas industry has shown that permafrost may extend both laterally and to considerable depth. For instance, permafrost on the north slope of Alaska is laterally continuous over an area of at least 1000 km{sup 2} and is associated with fluids of salinities up to 130 g/L. Also, in northern Siberia, permafrost has been observed to depths of over 900 m. Saline waters are ubiquitous in coastal areas that are currently underlain by permafrost. However, it is not clear how much of the salinity has been produced by the freezing process and how much is simply due to leaching of saline soils and sediments by groundwaters and the presence of residual seawater in the sediments. Possible indicators of concentration by freezing include the presence of brines (i.e. waters of greater salinity than seawater), mineral precipitates (e.g. mirabilite) that are

  5. Permafrost collapse after shrub removal shifts tundra ecosystem to a methane source

    DEFF Research Database (Denmark)

    Nauta, Ake L.; Heijmans, Monique P.D.; Blok, Daan

    2015-01-01

    , including expansion of woody vegetation5,6, in response to changing climate conditions. How such vegetation changes contribute to stabilization or destabilization of the permafrost is unknown. Here we present six years of field observations in a shrub removal experiment at a Siberian tundra site. Removing...... the shrub part of the vegetation initiated thawing of ice-rich permafrost, resulting in collapse of the originally elevated shrub patches into waterlogged depressions within five years. This thaw pond development shifted the plots from a methane sink into a methane source. The results of our field......-emitting wet depressions could become more abundant in the lowland tundra landscape, at the cost of permafrost-stabilizing low shrub vegetation....

  6. Bakteriochlorophyllvorstufen und Pigment-Protein-Komplexe in Rhodospirillum rubrum ST3 und GN11

    OpenAIRE

    Hammel, Jörg U.

    2006-01-01

    In der vorliegenden Arbeit wurden zwei Mutanten des Alpha-Proteobakteriums Rhodospirillum rubrum untersucht, die im Bakteriochlorophyll-Biosyntheseweg unterbrochen sind, um einen Beitrag zum genaueren Verständnis der Biosynthese dieser Moleküle und der einzelnen daran beteiligten Schritte zu liefern. Von den beiden Stämmen ST3 und GN11 wurden die ins Kulturmedium ausgeschiedenen Pigmente aufgereinigt und spektroskopisch analysiert. Ebenfalls wurden sowohl von ST3, als auch von GN11 die in int...

  7. Ancient low-molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw.

    Science.gov (United States)

    Drake, Travis W; Wickland, Kimberly P; Spencer, Robert G M; McKnight, Diane M; Striegl, Robert G

    2015-11-10

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high-temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low-molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters.

  8. Ancient low–molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw

    Science.gov (United States)

    Drake, Travis W.; Wickland, Kimberly P.; Spencer, Robert G. M.; McKnight, Diane M.; Striegl, Robert G.

    2015-01-01

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high–temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low–molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters.

  9. Assessing the permafrost temperature and thickness conditions favorable for the occurrence of gas hydrate in the Qinghai-Tibet Plateau

    International Nuclear Information System (INIS)

    Wu Qingbai; Jiang Guanli; Zhang Peng

    2010-01-01

    Permafrost accounts for about 52% of the total area of the Qinghai-Tibet Plateau, and the permafrost area is about 140 x 10 4 km 2 . The mean annual ground temperature of permafrost ranges from -0.1 to -5 deg. C, and lower than -5 deg. C at extreme high-mountains. Permafrost thickness ranges from 10 to 139.4 m by borehole data, and more than 200 m by geothermal gradients. The permafrost geothermal gradient ranges from 1.1 deg. C/100 m to 8.0 deg. C/100 m with an average of 2.9 deg. C/100 m, and the geothermal gradient of the soil beneath permafrost is about 2.8-8.5 deg. C/100 m with an average of 6.0 deg. C/100 m in the Qinghai-Tibet Plateau. For a minimum of permafrost geothermal gradients of 1.1 deg. C/100 m, the areas of the potential occurrence of methane hydrate (sI) is approximately estimated to be about 27.5% of the total area of permafrost regions in the Qinghai-Tibet Plateau. For an average of permafrost geothermal gradients of 2.9 deg. C/100 m, the areas of the potential occurrence of methane hydrate (sI) is approximately estimated about 14% of the total area of permafrost regions in the Qinghai-Tibet Plateau. For the sII hydrate, the areas of the potential occurrence of sII hydrate are more than that of sI methane hydrate.

  10. Blogs und Journalismus – Konkurrenz oder Ergänzung? – Das Verhältnis von Blogs und Journalismus in Deutschland

    Directory of Open Access Journals (Sweden)

    Saskia Leidinger

    2015-12-01

    Full Text Available Mit der Frage, ob „Blogs und Journalismus - Konkurrenz oder Ergänzung“ sind, beschäftigt sich Saskia Leidinger in dem gleichnamigen Essay über „das Verhältnis von Blogs und Journalismus in Deutschland“. In vergleichender Perspektive richtet die Autorin ihr Hauptaugenmerk auf die Arbeitsweise sowie die Eigen- und Fremdwahrnehmung von Bloggern und Journalisten, um Gemeinsamkeiten und Unterschiede herauszustellen und ihre je spezifische Funktion innerhalb der der heutigen Informationsgesellschaft einzugrenzen.

  11. ›All for nothing?‹. Die symbolische Darstellungs- und Erkenntnisform als philosophische und literaturtheoretische Herausforderung

    Directory of Open Access Journals (Sweden)

    Falk Bornmüller

    2013-05-01

    Full Text Available Literaturwissenschaft und Philosophie sehen sich gleichermaßen mit der Frage konfrontiert, wie mit dem Erkenntnismedium Literatur umgegangen und wie es in das eigene Erkenntnisinteresse integriert werden kann. Dabei ist das epistemologische Verhältnis von Literatur und Philosophie nicht etwa als ein streng dichotomisches zu verstehen, das sich auf die Formel propositional vs. nicht-propositional reduzieren lässt. Vielmehr ist ein erkenntnistheoretischer Gehalt von Literatur anzunehmen, dem eine binäre Betrachtungsweise nicht gerecht wird. Anhand zentraler Stellen in Shakespeares »Hamlet« und Goethes »Wilhelm Meisters Lehrjahre« wird die »symbolische Darstellungs- und Erkenntnisform« der Literatur als ein Akt der Erkenntnis, als ein nachvollziehendes Verstehen herausgearbeitet.

  12. Lessing und der Islam

    OpenAIRE

    Muslim, Zahim Mohammed

    2010-01-01

    „Lessing und der Islam“ beschäftigt sich unparteiisch mit Lessings Auseinandersetzung mit dem Islam. Die Arbeit setzt sich das Ziel, den Leser und den Literaturkennern sowie der deutschen Bibliothek der Germanistik etwas von Lessings Auseinandersetzung mit dem Islam in die Hand zu geben, die bis heute als großes Modell für die interkulturelle und interreligiöse Menschheitstoleranzdebatte im Gedächtnis der deutschen Literatur vorhanden ist. Im ersten Teil widmet sich die vorliegende Arbeit de...

  13. [Christofer Herrmann. Kloster und Burg - die architektur des Deutschens Ordens im Pressen und Livland. In : Glaube, Macht und Pracht. GeistlicheGemeinschaften des Ostseeraums im Zeitalter der Backsteingotik] / Dennis Hortmuth

    Index Scriptorium Estoniae

    Hortmuth, Dennis

    2011-01-01

    Arvustus: Christofer Herrmann. Kloster und Burg - die Architektur des Deutschen Ordens in Preussen und Livland. In : Glaube, Macht und Pracht. GeistlicheGemeinschaften des Ostseeraums im Zeitalter der Backsteingotik (=Archäologie und Geschichte im Ostseeraum; Archaeology and History of the Baltic 6) Rahden : Verlag Marie Leidorf, 2009. S. 209-219. Saksa Ordu arhitektuurist Preisi- ja Liivimaal

  14. Erwachsenenbildung und Medienpädagogik: LinkedIn & Lynda, XING und Google als Bildungsanbieter

    Directory of Open Access Journals (Sweden)

    Anke Grotlüschen

    2018-03-01

    Full Text Available Eine der grossen Systematiken der Erwachsenenbildung ist die Unterscheidung in didaktische Handlungsebenen (Mikro-, Meso- und Makroebene, (Schmidt-Lauff 2012, mit Blick auf Internationalisierung und Globalisierung ergänzt um die Mega-Ebene (Egetenmeyer et al. 2017. Diese setzen auf Tietgens didaktischen Handlungsebenen auf. Digitale Möglichkeiten für die Erwachsenenbildung (von Augmented Reality bis Webinar, werden hier in systematisierender Absicht in den didaktischen Handlungsebenen verortet. Dadurch wird erkennbar, dass die Aufgabe der Erwachsenenbildung immer auch die Problematisierung und begründete Entscheidung didaktischer Arrangements enthält. Ein zentraler Aspekt lässt sich jedoch eher schlecht in das klassische Modell einfügen: Die Frage der personalisierten Werbung und der Nutzung bildungsrelevanter Kundendaten wie Lebensläufe und Stellenbörsen. Genau dies machen sich Unternehmen der Digitalwirtschaft (XING, Google, LinkedIn derzeit zunutze, um Zutritt zum Weiterbildungsmarkt zu erlangen. Entlang dreier Fallanalysen wird versucht – bei begrenztem Zugriff auf Betriebsgeheimnisse – eine vorsichtige Einschätzung zu geben, ob es sich hierbei um eine disruptive Entwicklung handelt.

  15. [Glanz und Elend - Mythos und Wirklichkeit der Herrenhäuser im Baltikum] / Karsten Brüggemann

    Index Scriptorium Estoniae

    Brüggemann, Karsten, 1965-

    2014-01-01

    Arvustus: Glanz und Elend - Mythos und Wirklichkeit der Herrenhäuser im Baltikum. Hrsg. von Ilse von zur Mühlen im Auftrag der Carl-Schirren-Gesellschaft e.V. und des Ostpreußischen Landesmuseums Lüneburg. Kunstverlag Josef Fink. Lindenberg im Allgäu 2012

  16. Baseline characteristics of climate, permafrost and land cover from a new permafrost observatory in the Lena River Delta, Siberia (1998–2011

    Directory of Open Access Journals (Sweden)

    J. Boike

    2013-03-01

    Full Text Available Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover, soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years. Data related to this article are archived under: http://doi. pangaea.de/10.1594/PANGAEA.806233 .

  17. Emotion, Motivation und Volition

    OpenAIRE

    Ulich, Dieter

    1996-01-01

    Emotion, Motivation und Volition / D. Ulich ; V. Brandstätter ; P. M. Gollwitzer. - In: Psychologie / hrsg. von Dietrich Dörner ... - 2., überarb. und erw. Aufl. - Stuttgart u.a. : Kohlhammer, 1996. - S. 115-135

  18. Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate

    Science.gov (United States)

    Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido; Bondurant, Allen C.; Romanovksy, Vladimir E.; Hinkel, Kenneth M.; Parsekian, Andrew D.

    2016-01-01

    Interactions and feedbacks between abundant surface waters and permafrost fundamentally shape lowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceeds lake depth and mean annual bed temperatures (MABTs) remain below freezing. However, declining MIT since the 1970s is likely causing talik development below shallow lakes. Here we show high-temperature sensitivity to winter ice growth at the water-sediment interface of shallow lakes based on year-round lake sensor data. Empirical model experiments suggest that shallow (1 m depth) lakes have warmed substantially over the last 30 years (2.4°C), with MABT above freezing 5 of the last 7 years. This is in comparison to slower rates of warming in deeper (3 m) lakes (0.9°C), with already well-developed taliks. Our findings indicate that permafrost below shallow lakes has already begun crossing a critical thawing threshold approximately 70 years prior to predicted terrestrial permafrost thaw in northern Alaska.

  19. Der Einfluss von sozialer Ungleichheit und kulturellen Unterschieden auf die Wahrnehmung von finanziellen und Arbeitsplatzrisiken: Überlegungen zur Risikogesellschaft

    OpenAIRE

    Abbott, David; Quilgars, Deborah; Jones, Anwen

    2006-01-01

    Der vorliegende Artikel beruht auf Daten einer Studie, die sich mit der Frage beschäftigt, wie verschiedene soziale und kulturelle Gruppen die Risiken von Einkommens- und Arbeitsplatzverlust wahrnehmen und darauf reagieren. Autoren wie LASH, DOUGLAS und LUPTON betonten die Bedeutung von Gruppenzugehörigkeit und sozialen Kategorien für die Strukturierung der Reaktionsweisen auf verschiedene Risikoarten. Sie sprechen daher lieber von Risikokulturen als von der Risikogesellschaft. Trotzdem erken...

  20. Design and Build of the Qinghai-Tibet Railway considering the Impacts of Warming Climate and Permafrost

    Science.gov (United States)

    Ma, W.; Jin, H.; Cheng, G.; Wu, Q.; Lai, Y.

    2005-12-01

    During the period from 1960 to 2000, an 1°C increase of air temperature has been observed along the Qinghai-Tibet Railway (QTR) traversing 632 km of warm and ice-rich permafrost through the interior of the Qinghai-Tibet Plateau. Correspondingly, mean annual ground temperatures (MAGTs) of warm (>-1 °C) permafrost on average increased about 0.3 to 0.5°C during 1970s-1990, while that of colder permafrost had increased by 0.1 to 0.3°C. During 1996-2004, ground temperatures at the permafrost table were increasing at the rates of 0.01-0.08°C a-1, and the permafrost table was lowering at the rates of 2.6 to 6.6 cm a-1; and the ground temperatures at depths of 6 to 8 m were warming at the rates of 0.02 to 0.05°C a-1. Consequently, the strengths of permafrost as the foundation of the QTR would be weakened if proper engineering measures were not taken. Based on the experiences and lessons learned from the road construction in permafrost regions from Alaska, Canada and Russia, and northeastern China, and taking into consideration of possible climatic warming along the QTR during the next 100 years, the design and construction of the QTR adopted the principle of``cooling the roadbed'' because most of the permafrost along the route is too deep to be thawed, too thermally sensitive to climatic warming and too critical to have appreciable thaw settlements. About 550 km of QTR is in continuous permafrost zone, 82 km is in discontinuous permafrost zone; 275 km is in warm permafrost areas, and 110 km of permafrost is ice-rich. The QTR is designed for safe operations during the next 100 years during which a warming of 2.2 to 2.6°C by 2050 is projected. Without engineering measures to keep ground frozen or maintain the settlement within the acceptable limits, thaw settlement in the foundation soils, and induced environmental instability would threaten the integrity and safety of QTR operation. However, only increasing therma resistance, such as increasing fill thickness or

  1. Superman = Persepolis = Naruto? Herausforderungen und Probleme der formalen und inhaltlichen Vielfalt von Comics und Comicforschung für die Regensburger Verbundklassifikation

    Directory of Open Access Journals (Sweden)

    Michael Franke-Maier

    2016-12-01

    Full Text Available Das populäre Medium Comic hat in den vergangenen Jahren zunehmend Interesse als wissenschaftliches Forschungsobjekt und damit auch als bibliothekarisches Sammlungsgut auf sich gezogen. Bibliotheken stehen vor der Aufgabe, die Primärquellen und vor allem die wissenschaftliche Forschungsliteratur zu Comics inhaltlich zu erschließen und nach wie vor auch systematisch zu präsentieren. Bis vor kurzem fand man in der in Deutschland am weitesten verbreiteten Klassifikation, der im Selbstverständnis wissenschaftsnahen Regensburger Verbundklassifikation, nur Einzelstellen in einzelnen Fachsystematiken und einen größeren Bereich in der Japanologie für das Phänomen Manga. Dieser Zustand war nicht ausreichend für eine differenzierte Aufstellung in Bibliotheken mit entsprechenden Beständen und Schwerpunkten. Der hier präsentierte RVK-Baum für Comics und Comicforschung wird diesem Desiderat gerecht und bietet eine Möglichkeit, Comicbestände adäquat klassifikatorisch abzubilden.   In recent years the popular medium of comics has attracted increasing research interest and, consequently, comics have been recognized as objects for collection in libraries. Libraries face the task of classifying the primary sources and especially the scientific research literature on comics in order to present them systematically. Until recently, the most widely used academic library classification in Germany, the Regensburg Classification (RVK, provided only individual notations in some subject classifications and, additionally, a larger area on manga in the Japanese studies section. This situation was not sufficient for a differentiated shelving, or, respectively, classifying in libraries with correspondent resources and priorities. The paper presents a tree of RVK-notations for comics and comic research, which satisfies the desiderata and provides a way to map comic collections adequately to a classificatory scheme

  2. Greenhouse gas balance over thaw-freeze cycles in discontinuous zone permafrost

    Science.gov (United States)

    Wilson, R. M.; Fitzhugh, L.; Whiting, G. J.; Frolking, S.; Harrison, M. D.; Dimova, N.; Burnett, W. C.; Chanton, J. P.

    2017-02-01

    Peat in the discontinuous permafrost zone contains a globally significant reservoir of carbon that has undergone multiple permafrost-thaw cycles since the end of the mid-Holocene ( 3700 years before present). Periods of thaw increase C decomposition rates which leads to the release of CO2 and CH4 to the atmosphere creating potential climate feedback. To determine the magnitude and direction of such feedback, we measured CO2 and CH4 emissions and modeled C accumulation rates and radiative fluxes from measurements of two radioactive tracers with differing lifetimes to describe the C balance of the peatland over multiple permafrost-thaw cycles since the initiation of permafrost at the site. At thaw features, the balance between increased primary production and higher CH4 emission stimulated by warmer temperatures and wetter conditions favors C sequestration and enhanced peat accumulation. Flux measurements suggest that frozen plateaus may intermittently (order of years to decades) act as CO2 sources depending on temperature and net ecosystem respiration rates, but modeling results suggest that—despite brief periods of net C loss to the atmosphere at the initiation of thaw—integrated over millennia, these sites have acted as net C sinks via peat accumulation. In greenhouse gas terms, the transition from frozen permafrost to thawed wetland is accompanied by increasing CO2 uptake that is partially offset by increasing CH4 emissions. In the short-term (decadal time scale) the net effect of this transition is likely enhanced warming via increased radiative C emissions, while in the long-term (centuries) net C deposition provides a negative feedback to climate warming.

  3. Permafrost Favorability Index: Spatial Modeling in the French Alps Using a Rock Glacier Inventory

    Directory of Open Access Journals (Sweden)

    Marco Marcer

    2017-12-01

    Full Text Available In the present study we used the first rock glacier inventory for the entire French Alps to model spatial permafrost distribution in the region. Climatic and topographic data evaluated at the rock glacier locations were used as predictor variables in a Generalized Linear Model. Model performances are strong, suggesting that, in agreement with several previous studies, this methodology is able to model accurately rock glacier distribution. A methodology to estimate model uncertainties is proposed, revealing that the subjectivity in the interpretation of rock glacier activity and contours may substantially bias the model. The model highlights a North-South trend in the regional pattern of permafrost distribution which is attributed to the climatic influences of the Atlantic and Mediterranean climates. Further analysis suggest that lower amounts of precipitation in the early winter and a thinner snow cover, as typically found in the Mediterranean area, could contribute to the existence of permafrost at higher temperatures compared to the Northern Alps. A comparison with the Alpine Permafrost Index Map (APIM shows no major differences with our model, highlighting the very good predictive power of the APIM despite its tendency to slightly overestimate permafrost extension with respect to our database. The use of rock glaciers as indicators of permafrost existence despite their time response to climate change is discussed and an interpretation key is proposed in order to ensure the proper use of the model for research as well as for operational purposes.

  4. Temporal Behavior of Lake Size-Distribution in a Thawing Permafrost Landscape in Northwestern Siberia

    Directory of Open Access Journals (Sweden)

    Johanna Mård Karlsson

    2014-01-01

    Full Text Available Arctic warming alters regional hydrological systems, as permafrost thaw increases active layer thickness and in turn alters the pathways of water flow through the landscape. Further, permafrost thaw may change the connectivity between deeper and shallower groundwater and surface water altering the terrestrial water balance and distribution. Thermokarst lakes and wetlands in the Arctic offer a window into such changes as these landscape elements depend on permafrost and are some of the most dynamic and widespread features in Arctic lowland regions. In this study we used Landsat remotely sensed imagery to investigate potential shifts in thermokarst lake size-distributions, which may be brought about by permafrost thaw, over three distinct time periods (1973, 1987–1988, and 2007–2009 in three hydrological basins in northwestern Siberia. Results revealed fluctuations in total area and number of lakes over time, with both appearing and disappearing lakes alongside stable lakes. On the whole basin scales, there is no indication of any sustained long-term change in thermokarst lake area or lake size abundance over time. This statistical temporal consistency indicates that spatially variable change effects on local permafrost conditions have driven the individual lake changes that have indeed occurred over time. The results highlight the importance of using multi-temporal remote sensing data that can reveal complex spatiotemporal variations distinguishing fluctuations from sustained change trends, for accurate interpretation of thermokarst lake changes and their possible drivers in periods of climate and permafrost change.

  5. Enterprise Portals und Enterprise Application Integration - Begriffsbestimmung und Integrationskonzeptionen

    OpenAIRE

    Schelp, Joachim; Winter, Robert

    2002-01-01

    Unter den Stichworten »Enterprise Portals« und »Enterprise Application Integration« werden neue Herausforderungen an die Applikationsarchitektur der Unternehmungen gestellt. Bei beiden spielt die Integration vorhandener und das Einfügen neuer Applikationen eine große Rolle. Beiden Themen ist gemein, dass sie die Diskussion bestimmter technischer Konzepte aus den vergangenen Jahren fortsetzen: Portale stellen das moderne Frontend dar, über das die verschiedenen E-Business-Konzepte umgesetzt we...

  6. Degradation and Local Survival of Permafrost Through the Last Interglaciation in Interior Alaska and Yukon Territory

    Science.gov (United States)

    Reyes, A. V.; Froese, D. G.; Jensen, B. J.

    2006-12-01

    Permafrost in northern North America is warming, and recent modeling efforts have predicted the widespread disappearance of permafrost through much of the northern hemisphere over the next century. However, little is known of the impacts of past sustained warm intervals on permafrost dynamics, antiquity, and distribution due to difficulties in establishing reliable chronologies. Permafrost thus remains the last element of the Arctic cryosphere for which there is poor understanding of its adaptability to past warmer-than-present climate. Here we present observations from three sites in the region of interior Alaska and Yukon Territory that remained ice-free during Plio-Pleistocene glaciations, which collectively demonstrate the variable nature of the response of permafrost to warming during the last interglaciation. Chronology for all sites is based on identification of Old Crow tephra (OCt; 140±10 ka) by glass major element composition. Throughout the study region, OCt is consistently associated with organic-rich sediments that represent the last interglaciation on the basis of pollen, insect, and macrofossil assemblages. At the Palisades site on the Yukon River, 250 km west of Fairbanks, OCt is 1.5-3.5 m below thick (>1m) organic-rich silts and peats that are locally rich in beaver-chewed wood and large wood stumps, some of which are in growth position. In contrast, placer mining at Thistle Creek in central Yukon Territory exposes a dramatic thaw unconformity that is presumably related to local, but incomplete, permafrost degradation during the last interglaciation. In upslope positions at Thistle Creek, OCt is incorporated into a steeply dipping, 30 cm thick, organic-rich silt horizon that truncates at least one intact, relict ice wedge. The steeply dipping organic- rich horizon grades downslope into organic-rich silt with dense accumulations of wood fragments, including tree stems up to 2 m long. Evidence for similar permafrost degradation during the last

  7. Restaurierung von Seen und Renaturierung von Seeufern

    Science.gov (United States)

    Grüneberg, Björn; Ostendorp, Wolfgang; Leßmann, Dieter; Wauer, Gerlinde; Nixdorf, Brigitte

    Süßwasserseen haben als ökosysteme und Lebensraum für Pflanzen und Tiere eine herausragende Bedeutung für die Artenvielfalt auf der Erde und prägen als Landschaftselemente unsere natürliche Umwelt. Seen fungieren als natürliche Stoffsenken, vor allem für Kohlenstoff und Nährstoffe, aber auch als Senken für in ihren Einzugsgebieten emittierte gelöste und feste Schadstoffe. Darüber hinaus ist Wasser eine wichtige Naturressource. Süßwasserseen stellen in den meisten Regionen der Erde lebenswichtige Quellen für die Versorgung mit Trinkwasser und tierischem Eiweiß (Fischfang) dar. Sie dienen als Wasserspeicher für die landwirtschaftliche und industrielle Nutzung. Auch für Erholungsaktivitäten des Menschen kommt ihnen eine große Bedeutung zu.

  8. Gosvig und das Problem der Geschichte

    DEFF Research Database (Denmark)

    Wentzer, Thomas Schwarz

    2016-01-01

    Der Essay geht der Frage nach, wieso so viele philosophische Bücher, insbesondere innerhalb der sogenannten 'kontinentalen' Philosophie des 20. Jhs, einen Titel tragen, der durch die Struktur 'x und y' gekennzeichnet ist. Hat Heideggers 'Sein und Zeit' auch hier Schule gemacht? Wenn ja, wie so? U...... These, dass die Iteration des 'und' tatsächlich und in Kontrast zur Genetivkonstruktion der Idealisten ('Phänomenologie des Geistes') die Geschichtlichkeit im Zeitalter postsubjektivistischen Denkens reflektiert....

  9. Minimum distribution of subsea ice-bearing permafrost on the US Beaufort Sea continental shelf

    Science.gov (United States)

    Brothers, Laura L.; Hart, Patrick E.; Ruppel, Carolyn D.

    2012-01-01

    Starting in Late Pleistocene time (~19 ka), sea level rise inundated coastal zones worldwide. On some parts of the present-day circum-Arctic continental shelf, this led to flooding and thawing of formerly subaerial permafrost and probable dissociation of associated gas hydrates. Relict permafrost has never been systematically mapped along the 700-km-long U.S. Beaufort Sea continental shelf and is often assumed to extend to ~120 m water depth, the approximate amount of sea level rise since the Late Pleistocene. Here, 5,000 km of multichannel seismic (MCS) data acquired between 1977 and 1992 were examined for high-velocity (>2.3 km s−1) refractions consistent with ice-bearing, coarse-grained sediments. Permafrost refractions were identified along sea ice-bearing permafrost, which does not extend seaward of 30 km offshore or beyond the 20 m isobath.

  10. Permafrost thawing in organic Arctic soils accelerated by ground heat production

    DEFF Research Database (Denmark)

    Hollesen, Jørgen; Matthiesen, Henning; Møller, Anders Bjørn

    2015-01-01

    Decomposition of organic carbon from thawing permafrost soils and the resulting release of carbon to the atmosphere are considered to represent a potentially critical global-scale feedback on climate change1, 2. The accompanying heat production from microbial metabolism of organic material has been...... recognized as a potential positive-feedback mechanism that would enhance permafrost thawing and the release of carbon3, 4. This internal heat production is poorly understood, however, and the strength of this effect remains unclear3. Here, we have quantified the variability of heat production in contrasting...... organic permafrost soils across Greenland and tested the hypothesis that these soils produce enough heat to reach a tipping point after which internal heat production can accelerate the decomposition processes. Results show that the impact of climate changes on natural organic soils can be accelerated...

  11. Temperature sensitivity of gaseous elemental mercury in the active layer of the Qinghai-Tibet Plateau permafrost.

    Science.gov (United States)

    Ci, Zhijia; Peng, Fei; Xue, Xian; Zhang, Xiaoshan

    2018-07-01

    Soils represent the single largest mercury (Hg) reservoir in the global environment, indicating that a tiny change of Hg behavior in soil ecosystem could greatly affect the global Hg cycle. Climate warming is strongly altering the structure and functions of permafrost and then would influence the Hg cycle in permafrost soils. However, Hg biogeochemistry in climate-sensitive permafrost is poorly investigated. Here we report a data set of soil Hg (0) concentrations in four different depths of the active layer in the Qinghai-Tibet Plateau permafrost. We find that soil Hg (0) concentrations exhibited a strongly positive and exponential relationship with temperature and showed different temperature sensitivity under the frozen and unfrozen condition. We conservatively estimate that temperature increases following latest temperature scenarios of the IPCC could result in up to a 54.9% increase in Hg (0) concentrations in surface permafrost soils by 2100. Combining the simultaneous measurement of air-soil Hg (0) exchange, we find that enhanced Hg (0) concentrations in upper soils could favor Hg (0) emissions from surface soil. Our findings indicate that Hg (0) emission could be stimulated by permafrost thawing in a warmer world. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Die Landschaft in der Geschichte, in der Kultur, in der Kunts und in der Stadtplanung: theoretische Annahmen und Erfahrungen

    Directory of Open Access Journals (Sweden)

    Mario Coletta

    2013-01-01

    Full Text Available Das vorgeschlagene Thema hat das Ziel, dem Konzept der Landschaft eine neue Definition zu geben. Sie soll nicht nur als Umhuellung des staedtischen und laendlichen Territoriums gesehen werden, das besiedelt und produktiv ist, zivilisiet und natuerlich belassen, sondern wie ein lebender Koerper, wenn auch nicht bei bester Gesundheit, der trotz seines Altes noch den vielen Veraenderungen standhaelt. Veraenderungen durch Naturkatatrophen herforgerufen, und besonders durch die vielen Wunden die das Werk der Menschen ihm zugefuegt hat. Als lebendes Wesen leidet die Landschaft und freut sich in guten Zeiten, kleidert sich lieber arm, aber schicklich, als reich und anmassend: Zeuge guter und schlechter Haushaltsfuehrung, jedoch Erbe einer Geschichte die sie erhebt, die Geschichte, Literatur, Ausdruecke der Kunts, kreative Planung beseelt hat. All das ist zusammengefasst in dem Wort "Kultur", die es verdient hat, erworben zu werden, vertieft und den naeschsten Generationen weitergegeben, moeglicherweise noch bereichert von dem, das die heutige Kultur ausarbeiten kann, auch auf dem Weg der Stadtplanung.

  13. Digitalisierung und Selbstbestimmung

    Directory of Open Access Journals (Sweden)

    Eisenberger, Iris

    2017-12-01

    Full Text Available Kurztext: Der Beitrag beleuchtet das Verhältnis von Digitalisierung und Recht. Am Beispiel der Blockchain-Technologie wird aufgezeigt, wie neue Formen und Räume der Selbstbestimmung geschaffen werden können. In distribuierten Systemen ist die Tendenz erkennbar, dass sich die rechtliche hin zu einer technologischen Steuerung verlagert. Wenn Funktionen, die für gewöhnlich der demokratisch legitimierte Gesetzgeber wahrnimmt, auf andere Systeme übergehen, führt dies zu Herausforderungen für rechtsstaatliche Demokratien. Fundamentale Fragen von Kontrolle und Machtbeschränkung iZm Digitalisierung stehen im Fokus. Der Beitrag plädiert schließlich für „legal foresight“-Forschung im Bereich neuer Technologien.

  14. Permafrost distribution in peatlands of west-central Canada during the Holocene warm period 6000 years BP

    Energy Technology Data Exchange (ETDEWEB)

    Zoltai, S.C. [Canadian Forest Service, Edmonton, AB (Canada)

    1995-12-31

    The extent and timing of permafrost development in peatlands of west-central Canada are examined. The floristic composition of the permafrost peatlands was determined from macrofossil samples of cores drilled at 161 locations. Radiocarbon dating of substantial changes in the peat sequences and of basal peat deposition was used to provide chronological control. The reconstructed paleoenvironments show the presence or absence of permafrost at the time of peat formation. Permafrost distribution in peatlands is estimated during the warm period 6000 years BP. It is estimated that the mean annual temperature was approximately 5{degree}C warmer than at present. 42 refs., 3 figs., 4 tabs.

  15. Confocal Raman microspectroscopy reveals a convergence of the chemical composition in methanogenic archaea from a Siberian permafrost-affected soil.

    Science.gov (United States)

    Serrano, Paloma; Hermelink, Antje; Lasch, Peter; de Vera, Jean-Pierre; König, Nicole; Burckhardt, Oliver; Wagner, Dirk

    2015-12-01

    Methanogenic archaea are widespread anaerobic microorganisms responsible for the production of biogenic methane. Several new species of psychrotolerant methanogenic archaea were recently isolated from a permafrost-affected soil in the Lena Delta (Siberia, Russia), showing an exceptional resistance against desiccation, osmotic stress, low temperatures, starvation, UV and ionizing radiation when compared to methanogens from non-permafrost environments. To gain a deeper insight into the differences observed in their resistance, we described the chemical composition of methanogenic strains from permafrost and non-permafrost environments using confocal Raman microspectroscopy (CRM). CRM is a powerful tool for microbial identification and provides fingerprint-like information about the chemical composition of the cells. Our results show that the chemical composition of methanogens from permafrost-affected soils presents a high homology and is remarkably different from strains inhabiting non-permafrost environments. In addition, we performed a phylogenetic reconstruction of the studied strains based on the functional gene mcrA to prove the different evolutionary relationship of the permafrost strains. We conclude that the permafrost methanogenic strains show a convergent chemical composition regardless of their genotype. This fact is likely to be the consequence of a complex adaptive process to the Siberian permafrost environment and might be the reason underlying their resistant nature. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Führung und Machiavellismus

    NARCIS (Netherlands)

    Belschak, F.D.; den Hartog, D.N.; Felfe, J.

    2015-01-01

    In diesem Beitrag wird der Zusammenhang zwischen Führung und Machiavellismus aus zwei verschiedenen Perspektiven betrachtet. Zum einen werden neuere Forschungsergebnisse referiert, wie machiavellistische Mitarbeiter auf verschiedene Führungsstile ihres Vorgestzten reagieren und so mit Hinblick auf

  17. Netzformen und VDE-Bestimmungen

    Science.gov (United States)

    Bernstein, Herbert

    Der Verband Deutscher Elektrotechniker (VDE) hat eine Reihe von Vorschriften ausgearbeitet, die dem Schutz von Leben und Sachen beim Umgang mit elektrischer Energie dienen. Besonders wichtig sind die in den VDE-Bestimmungen 0100 und 0411 festgelegten Vorschriften.

  18. Vergleichende Kraft-Dehnungs- und Dauerlastversuche mit kieferorthopädischen Gummizügen und pseudoelastischen Ni-Ti-Federn

    OpenAIRE

    Buch, Stefan

    2003-01-01

    Bei einer Behandlung mit festsitzenden Apparaturen stehen für Zahnverschiebungen in mesio-distaler Richtung und zur Okklusionseinstellung seit 1993 als Alternative zu Gummiringen aus Latex Zugfedern aus der Nickel-Titan-Legierung Sentalloy zur Verfügung. Die vorliegende Untersuchung zeigt die materialtechnischen Besonderheiten der beiden Werkstoffe auf und beschreibt die Vor- und Nachteile in der klinischen Anwendung der Gummizüge und der Federn. Es wurden Gummizüge aus Latex von Ormco Dental...

  19. Chemical indicators of cryoturbation and microbial processing throughout an alaskan permafrost soil depth profile

    Science.gov (United States)

    Although permafrost soils contain vast stores of carbon, we know relatively little about the chemical composition of their constituent organic matter. Soil organic matter chemistry is an important predictor of decomposition rates, especially in the initial stages of decomposition. Permafrost, organi...

  20. The circuitry of ecosystem metabolism: CO2 and CH4 flux from permafrost soils

    Science.gov (United States)

    Microbial decomposition of thawed permafrost organic matter could release greenhouse gases (GHG) to the atmosphere and accelerate the carbon (C)-climate feedback. Greenhouse gas emissions from thawed permafrost are difficult to predict because they result from complex interactions between abiotic dr...

  1. Draft Genome Sequence of Methylocella silvestris TVC, a Facultative Methanotroph Isolated from Permafrost.

    Science.gov (United States)

    Wang, Jing; Geng, Kan; Farhan Ul Haque, Muhammad; Crombie, Andrew; Street, Lorna E; Wookey, Philip A; Ma, Ke; Murrell, J Colin; Pratscher, Jennifer

    2018-02-22

    Permafrost environments play a crucial role in global carbon and methane cycling. We report here the draft genome sequence of Methylocella silvestris TVC, a new facultative methanotroph strain, isolated from the Siksik Creek catchment in the continuous permafrost zone of Inuvik (Northwest Territories, Canada). Copyright © 2018 Wang et al.

  2. Bildanalyse in Medizin und Biologie

    Science.gov (United States)

    Athelogou, Maria; Schönmeyer, Ralf; Schmidt, Günther; Schäpe, Arno; Baatz, Martin; Binnig, Gerd

    Heutzutage sind bildgebende Verfahren aus medizinischen Untersuchungen nicht mehr wegzudenken. Diverse Methoden - basierend auf dem Einsatz von Ultraschallwellen, Röntgenstrahlung, Magnetfeldern oder Lichtstrahlen - werden dabei spezifisch eingesetzt und liefern umfangreiches Datenmaterial über den Körper und sein Inneres. Anhand von Mikroskopieaufnahmen aus Biopsien können darüber hinaus Daten über die morphologische Eigenschaften von Körpergeweben gewonnen werden. Aus der Analyse all dieser unterschiedlichen Arten von Informationen und unter Konsultation weiterer klinischer Untersuchungen aus diversen medizinischen Disziplinen kann unter Berücksichtigung von Anamnesedaten ein "Gesamtbild“ des Gesundheitszustands eines Patienten erstellt werden. Durch die Flut der erzeugten Bilddaten kommt der Bildverarbeitung im Allgemeinen und der Bildanalyse im Besonderen eine immer wichtigere Rolle zu. Gerade im Bereich der Diagnoseunterstützung, der Therapieplanung und der bildgeführten Chirurgie bilden sie Schlüsseltechnologien, die den Forschritt nicht nur auf diesen Gebieten maßgeblich vorantreiben.

  3. Rechtspopulistische Einstellungen in Ost- und Westdeutschland

    Directory of Open Access Journals (Sweden)

    Beate Küpper

    2017-12-01

    Full Text Available Während sich die Mehrheit der Deutschen für Demokratie, Vielfalt und Gleichwertigkeit positioniert, sind zugleich rechtspopulistische Einstellungen lauter geworden. Der Beitrag berichtet über Befunde der Mitte-Studie der Friedrich-Ebert-Stiftung 2016 zu der Verbreitung rechtspopulistischer und rechtsextreme Einstellungen, wirft einen besonderen Blick auf potentielle Wähler_innen der AfD und diskutiert am Ende mögliche Erklärungen für die gefundenen Unterschiede zwischen Ost- und Westdeutschen.

  4. The role of climate change in regulating Arctic permafrost peatland hydrological and vegetation change over the last millennium

    Science.gov (United States)

    Zhang, Hui; Piilo, Sanna R.; Amesbury, Matthew J.; Charman, Dan J.; Gallego-Sala, Angela V.; Väliranta, Minna M.

    2018-02-01

    Climate warming has inevitable impacts on the vegetation and hydrological dynamics of high-latitude permafrost peatlands. These impacts in turn determine the role of these peatlands in the global biogeochemical cycle. Here, we used six active layer peat cores from four permafrost peatlands in Northeast European Russia and Finnish Lapland to investigate permafrost peatland dynamics over the last millennium. Testate amoeba and plant macrofossils were used as proxies for hydrological and vegetation changes. Our results show that during the Medieval Climate Anomaly (MCA), Russian sites experienced short-term permafrost thawing and this induced alternating dry-wet habitat changes eventually followed by desiccation. During the Little Ice Age (LIA) both sites generally supported dry-hummock habitats, at least partly driven by permafrost aggradation. However, proxy data suggest that occasionally, MCA habitat conditions were drier than during the LIA, implying that evapotranspiration may create important additional eco-hydrological feedback mechanisms under warm conditions. All sites showed a tendency towards dry conditions as inferred from both proxies starting either from ca. 100 years ago or in the past few decades after slight permafrost thawing, suggesting that recent warming has stimulated surface desiccation rather than deeper permafrost thawing. This study shows links between two important controls over hydrology and vegetation changes in high-latitude peatlands: direct temperature-induced surface layer response and deeper permafrost layer-related dynamics. These data provide important backgrounds for predictions of Arctic permafrost peatlands and related feedback mechanisms. Our results highlight the importance of increased evapotranspiration and thus provide an additional perspective to understanding of peatland-climate feedback mechanisms.

  5. Entwicklung und Anwendung neuer NMR-Methoden: Orientierungsmedien zur Strukturbestimmung mit anisotropen Parametern und Metabonomics

    OpenAIRE

    Büchler, Silke

    2014-01-01

    Das Ziel dieser Arbeit war die Entwicklung und Anwendung neuer Orientierungsmedien zur Strukturbestimmung mit anisotropen Parametern, sowie die Etablierung von Metabonomics-Studien an Flüssigzellkulturen und Reispflanzen.

  6. Assessment of permafrost distribution maps in the Hindu Kush Himalayan region using rock glaciers mapped in Google Earth

    NARCIS (Netherlands)

    Schmid, M.O.; Baral, P.; Gruber, S.; Shahi, S.; Shrestha, T.; Stumm, D.; Wester, P.

    2015-01-01

    The extent and distribution of permafrost in the mountainous parts of the Hindu Kush Himalayan (HKH) region are largely unknown. A long tradition of permafrost research, predominantly on rather gentle relief, exists only on the Tibetan Plateau. Two permafrost maps are available digitally that

  7. Von Zetteln und Apparaten. Subjektivierung in bundesdeutschen und britischen Arbeitsämtern der 1970er- und 1980er-Jahre

    Directory of Open Access Journals (Sweden)

    Wiebke Wiede

    2016-11-01

    Full Text Available The article examines the governance of unemployment by employment offices inthe Federal Republic of Germany and the United Kingdom in the 1970s and 1980s, which were times of persisting mass unemployment in both countries, focusing on social meanings encoded into the social space of employment offices. Applying concepts from actor-network theory, the article investigates the agency of things in the administration of unemployment, e.g. folders of files, queue numbers or vacancy notices. In particular, the article considers the mechanisation and increasing use of machines and IT systems in German and British employment offices. With regard to processes of subjectivisation, it investigates how the unemployed experienced things and objects in employment offices. While the newly designed British Jobcentre offered jobs as part of a self-service concept, the German employment offices remained in the bureaucratic tradition whereby the unemployed primarily waited for employment counselling and placement. Der Beitrag untersucht Arbeitsämter in der Bundesrepublik Deutschland und Großbritannien während der 1970er- und 1980er-Jahre, einer Zeit deutlich gestiegener Arbeitslosenzahlen. Im Fokus stehen die Verwaltungsvorgänge, begriffen als soziale Praktiken und Mensch-Ding-Verhältnisse. Mit der Akteur-Netzwerk-Theorie fragt der Aufsatz nach der Agency der Verwaltungsdinge im Arbeitsamt: den Bürogestaltungen, Aktenordnern, Wartenummern oder Stellenaushängen. Problematisiert wird besonders die in den 1970er- und 1980er-Jahren durchgesetzte Technisierung der administrativen Vorgänge, also der vermehrte Einsatz von Apparaten und EDV-Systemen in bundesdeutschen und britischen Arbeitsverwaltungen. In beiden Ländern wurde »Selbstbedienung« zu einem neuen Verhaltensdispositiv, das sich in den neu eingerichteten britischen Jobcentres jedoch schneller durchsetzte als im traditionellen deutschen Arbeitsamt, wo das passive Warten weiterhin eine vorherrschende

  8. Hydrogeology, chemical and microbial activity measurement through deep permafrost

    Energy Technology Data Exchange (ETDEWEB)

    Stotler, R.L.; Frape, S.K.; Freifeld, B.M.; Holden, B.; Onstott, T.C.; Ruskeeniemi, T.; Chan, E.

    2010-04-01

    Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples <40% drill fluid. The salinity of the non-drill fluid component was <20,000 mg/L, had a Ca/Na ratio above 1, with {delta}{sup 18}O values {approx}5{per_thousand} lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH{sub 4} was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH{sub 4} is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination.

  9. Strong geologic methane emissions from discontinuous terrestrial permafrost in the Mackenzie Delta, Canada.

    Science.gov (United States)

    Kohnert, Katrin; Serafimovich, Andrei; Metzger, Stefan; Hartmann, Jörg; Sachs, Torsten

    2017-07-19

    Arctic permafrost caps vast amounts of old, geologic methane (CH 4 ) in subsurface reservoirs. Thawing permafrost opens pathways for this CH 4 to migrate to the surface. However, the occurrence of geologic emissions and their contribution to the CH 4 budget in addition to recent, biogenic CH 4 is uncertain. Here we present a high-resolution (100 m × 100 m) regional (10,000 km²) CH 4 flux map of the Mackenzie Delta, Canada, based on airborne CH 4 flux data from July 2012 and 2013. We identify strong, likely geologic emissions solely where the permafrost is discontinuous. These peaks are 13 times larger than typical biogenic emissions. Whereas microbial CH 4 production largely depends on recent air and soil temperature, geologic CH 4 was produced over millions of years and can be released year-round provided open pathways exist. Therefore, even though they only occur on about 1% of the area, geologic hotspots contribute 17% to the annual CH 4 emission estimate of our study area. We suggest that this share may increase if ongoing permafrost thaw opens new pathways. We conclude that, due to permafrost thaw, hydrocarbon-rich areas, prevalent in the Arctic, may see increased emission of geologic CH 4 in the future, in addition to enhanced microbial CH 4 production.

  10. Microbial survival strategies in ancient permafrost: insights from metagenomics.

    Science.gov (United States)

    Mackelprang, Rachel; Burkert, Alexander; Haw, Monica; Mahendrarajah, Tara; Conaway, Christopher H; Douglas, Thomas A; Waldrop, Mark P

    2017-10-01

    In permafrost (perennially frozen ground) microbes survive oligotrophic conditions, sub-zero temperatures, low water availability and high salinity over millennia. Viable life exists in permafrost tens of thousands of years old but we know little about the metabolic and physiological adaptations to the challenges presented by life in frozen ground over geologic time. In this study we asked whether increasing age and the associated stressors drive adaptive changes in community composition and function. We conducted deep metagenomic and 16 S rRNA gene sequencing across a Pleistocene permafrost chronosequence from 19 000 to 33 000 years before present (kyr). We found that age markedly affected community composition and reduced diversity. Reconstruction of paleovegetation from metagenomic sequence suggests vegetation differences in the paleo record are not responsible for shifts in community composition and function. Rather, we observed shifts consistent with long-term survival strategies in extreme cryogenic environments. These include increased reliance on scavenging detrital biomass, horizontal gene transfer, chemotaxis, dormancy, environmental sensing and stress response. Our results identify traits that may enable survival in ancient cryoenvironments with no influx of energy or new materials.

  11. Data Science und Analytics in Bibliotheken

    Directory of Open Access Journals (Sweden)

    José Luis Preza

    2017-09-01

    Full Text Available Bibliotheken sind in einer priviligierten Situation: Sie verwalten riesige Mengen von Daten und Informationen. Data Science und Analytics-Methoden ermöglichen es Bibliotheken, den Inhalt, den sie verwalten, voll auszunutzen, um den Nutzern bessere Informationen, Suche und Empfehlungen zu bieten.

  12. Air temperature changes and their impact on permafrost ecosystems in eastern Siberia

    Directory of Open Access Journals (Sweden)

    Desyatkin Roman

    2015-01-01

    Full Text Available Significant increasing of mean annual air temperatures, freezing index and thawing index - have exerted a considerable impact on the state of permafrost landscapes and ecosystems in Eastern Siberia on the last few decades. Many animals and plants have shifted their ranges and this may be the precursor of northward shifts of the landscape zones. Landscapes that contain ground ice bodies in the underlying permafrost are especially sensitive to climate warming. Increase of mean annual air temperature for 2-3°C over the last three decades has resulted an increase in ground temperature by 0.4-1.3°C in the upper part of permafrost, which in turn has led intensification of negative cryogenic processes. Previous year’s measurements of greenhouses gases emission in the Middle Taiga forest of central Yakutia were found to show high values and spatial variability. The wet meadow soils and shallow lakes have highest methane fluxes, almost comparable with emissions from tropical peatlands. Permafrost ecosystems respond to global warming quite rapidly. This makes the study of their changes somewhat easier, but still requires meticulous attention to observations, research, and analysis of the processes under way.

  13. Batteries and accumulators: everything you always wanted to know. Batteries, accumulators and the environment - questions and answers; Batterien und Akkus - Das wollten Sie wissen.. Fragen und Antworten zu Batterien, Akkus und Umwelt

    Energy Technology Data Exchange (ETDEWEB)

    Leuthold, S.; Minkos, A. (comps.)

    2006-07-15

    Batteries and accumulators are part of our everyday life. This brochure answers problems related to their use and disposal, chargers and charging. Starter batteries for motor vehicles are left out of account, as are special batteries e.g. for electric fences or lights on building sites. The brochure also explains the legal fundamentals for disposal of batteries and provides information on environmental problems relating to production and disposal. Frequently asked questions are answered on the final pages. [German] Batterien und Akkus begleiten unseren Alltag. Solange sie die noetige mobile Versorgung ermoeglichen, sind sie gern gesehen. Versagen sie ihren Dienst, beginnen die Probleme: Wohin mit der leeren Batterie, dem nicht mehr funktionsfaehigen Akku (Keinesfalls in den Hausmuell.)? Welches ist das richtige Ladegeraet und das richtige Ladeverfahren fuer den Akku? Zu diesen und anderen Fragen rund um Geraetebatterien und -akkus gibt diese Broschuere Auskunft. Nicht betrachtet werden hier allerdings Starterbatterien (z.B. fuer Autos und Motorraeder) und bestimmte Spezialbatterien (z.B. fuer Weidezaeune oder Baustellenlampen), die einen Sonderfall darstellen. Die Broschuere erlaeutert auch die gesetzlichen Grundlagen fuer die Entsorgung unbrauchbarer Batterien und Akkus und gibt Informationen zur Umweltbelastung durch Herstellung und Entsorgung. Am Ende der Broschuere werden haeufig gestellte Fragen und deren Antworten zusammengestellt.

  14. Thin, Conductive Permafrost Surrounding Lake Fryxell Indicates Salts From Past Lakes, McMurdo Dry Valleys, Antarctica

    Science.gov (United States)

    Foley, N.; Tulaczyk, S. M.; Gooseff, M. N.; Myers, K. F.; Doran, P. T.; Auken, E.; Dugan, H. A.; Mikucki, J.; Virginia, R. A.

    2017-12-01

    In the McMurdo Dry Valleys (MDV), permafrost should be thick and liquid water rare. However, despite the well below zero mean annual temperature in this cryospheric desert, liquid water can be found in lakes, summer melt streams, subglacial outflow, and - recent work has shown - underneath anomalously thin permafrost. In part, this niche hydrosphere is maintained by the presence of salts, which depress the freezing point of water to perhaps as cold as -10° Celsius. We detected widespread salty water across the MDV in lakes and at depth using a helicopter-borne Time Domain Electromagnetic (TDEM) sensor. By using the presence of brines to mark the transition from frozen permafrost (near the surface) to unfrozen ground (at depth), we have created a map of permafrost thickness in Lower Taylor Valley (LTV), a large MDV with a complex history of glaciation and occupation by lakes. Our results show that permafrost is thinner ( 200m) than would be expected based on geothermal gradient measurements (up to 1000m), a result of the freezing point depression caused by salt and potentially enhanced by an unfinished transient freezing process. Near Lake Fryxell, a large, brackish lake in the center of LTV, permafrost is very thin (about 30-40m) and notably more electrically conductive than more distal permafrost. This thin ring of conductive permafrost surrounding the lake basin most likely reflects the high presence of salts in the subsurface, preventing complete freezing. These salts may be a remnant of the salty bottom waters of a historic larger lake (LGM glacially dammed Lake Washburn) or the remnant of salty basal water from a past advance of Taylor Glacier, which now sits many km up-valley but is known to contain brines which currently flow onto the surface and directly into the subsurface aquifer.

  15. Mensch und Maschine in Übersetzungsprozessen

    DEFF Research Database (Denmark)

    Hansen, Gyde

    2014-01-01

    gebrauchstauglich sein. In meinem empirischen Projekt zur Erforschung notwendiger Kompetenzen, zum Übersetzen, Revidieren und zum Pre- und Post-Editing, TraREdit, arbeite ich mit den Sprachen Deutsch, Dänisch und Englisch. Trotz offensichtlicher Mängel von Maschinenübersetzungen muss man erkennen, dass diese besser...

  16. [Das Bild und die Wahrnehmung der Stadt und der städtischen Gesellschaft im Hanseraum im Mittelalter und in der frühen Neuzeit] / Juhan Kreem

    Index Scriptorium Estoniae

    Kreem, Juhan

    2009-01-01

    Arvustus: Das Bild und die Wahrnehmung der Stadt und der städtischen Gesellschaft im Hanseraum im Mittelalter und in der frühen Neuzeit. hrsg. v. Roman Czaja. Torun, 2004. Torunis 2002. aastal toimunud konverentsi materjalid. Projekti "Pilt ja linn" raames ilmunud publikatsioonide loendit saab näha aadressil http://www.historiaurbium.org/english/attivita_images_en.html.

  17. Textbook with exercises on automation and process control. An introduction for engineers, industrial engineers and experts in business economics; Lehr- und Uebungsbuch Automatisierungs- und Prozessleittechnik. Eine Einfuehrung fuer Ingenieure, Wirtschaftsingenieure und Betriebswirtschaftler

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, J. [Hochschule fuer Technik, Wirtschaft und Sozialwesen Zittau/Goerlitz (FH), Zittau (Germany)

    1999-07-01

    This textbook addresses students at university level. It contains many examples and exercises and presents a detailed explanation of modelling in automation engineering, including equations and algorithms. Important problems of automation and their solutions are illustrated by an exemplary process control problem that recurs in the book and can be recalculated on the reader's PC. A CD-ROM is enclosed with a process automation system that can be analyzed and tested in several variants. [German] Dieses Lehr- und Uebungsbuch zur Automatisierungs- und Prozessleittechnik - eignet sich fuer die Ausbildung an Technischen Hochschulen, Fachhochschulen und Berufsakademien - ist fuer Studenten mit Automatisierungs- und Prozessleittechnik im Nebenfach konzipiert - enthaelt eine fuer das Grundverstaendnis notwendige, mit vielen Beispielen und Uebungen ergaenzte Lehrstoffauswahl - erlaeutert sehr verstaendlich die spezielle Modellwelt der Automatisierungstechnik mit ihren Beschreibungsformen und Loesungsalgorithmen - behandelt wesentliche Problemstellungen der Automatisierung und deren Loesungen anhand einer durchgaengigen, am Rechner nachvollziehbaren Prozessleitaufgabe. Das auf der beigefuegten CD-ROM visualisierte Prozessautomatisierungssystem kann in Variationen analysiert und getestet werden. (orig.)

  18. Landsat-based trend analysis of lake dynamics across northern permafrost regions

    Science.gov (United States)

    Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

    2017-01-01

    Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

  19. Neue Technologien und Erziehung/Bildung

    Directory of Open Access Journals (Sweden)

    Norbert Meder

    2015-03-01

    Full Text Available Es wird gezeigt, dass Computertechnologie zur pädagogischen Aufgabe wird, weil es sich um eine Kulturtechnik handelt. Ausgehend vom Begriff der Bildung als Ausbildung eines Verhältnisses zu mir selbst, zu anderen und zur Welt wird Computertechnologie als Problemlösungsautomat, Sprachentwicklungsmaschine, Simulationsmaschine, Kommunikationsmaschine, Bildschirmgestaltungsmaschine, Schlüsselloch und Superzeichenmaschine analysiert. Die Analyse zeigt, daß Computertechnologie ein neues Bildungsideal erforderlich macht: Den Sprachspieler. Der Sprachspieler kennt sein doppelt reflexives Verhältnis zu sich selbst, zu anderen und zur Welt und beherrscht so das Spiel mit der Sprache zur Ausübung von Macht und Gewalt in der Informationsgesellschaft. Der Text geht in folgenden Schritten vor: Zunächst werden mit den Begriffen "Kulturtechnik" und "Bildung" die Prinzipien der Analyse bestimmt. Anschließend wird eine Sachanalyse der Computertechnologie durchgeführt und die gefundenen Eigenschaften jeweils in Relation zum Kulturtechnik- und Bildungsbegriff gesetzt. Computer technology becomes a challenge for education if it is understood as a cultural technology. Starting with the term bildung as the formation of relations to my self, to others and the world, computer technology is analysed as problem solving machine, language development machine, simulation machine, communication machine, screen design machine, keyhole, and super sign machine. It is shown, that computertechnology reqiures a new ideal for bildung: the language player. The language player knows his double reflective relation to his self, to others and the world and thus rules the game with language that is used to excercise power and force in the information society. The text argues in the following steps: At first the principles of the analyses are defined with the terms cultural technology and bildung. Susequently, computer technology is analysed. The identified qualities are finally

  20. Exploring the ground ice recharge near permafrost table on the central Qinghai-Tibet Plateau using chemical and isotopic data

    Science.gov (United States)

    Wang, Weihua; Wu, Tonghua; Zhao, Lin; Li, Ren; Zhu, Xiaofan; Wang, Wanrui; Yang, Shuhua; Qin, Yanhui; Hao, Junmin

    2018-05-01

    Thawing permafrost on the Qinghai-Tibet Plateau (QTP) has great impacts on the local hydrological process by way of causing ground ice to thaw. Until now there is little knowledge on ground ice hydrology near permafrost table under a warming climate. This study applied stable tracers (isotopes and chloride) and hydrograph separation model to quantify the sources of ground ice near permafrost table in continuous permafrost regions of the central QTP. The results indicated that the ground ice near permafrost table was mainly supplied by active layer water and permafrost water, accounting for 58.9 to 87.0% and 13.0 to 41.1%, respectively, which implying that the active layer was the dominant source. The contribution rates from the active layer to the ground ice in alpine meadow (59 to 69%) was less than that in alpine steppe (70 to 87%). It showed well-developed hydrogeochemical depth gradients, presenting depleted isotopes and positive chemical gradients with depth within the soil layer. The effects of evaporation and freeze-out fractionation on the soil water and ground ice were evident. The results provide additional insights into ground ice sources and cycling near permafrost table in permafrost terrain, and would be helpful for improving process-based detailed hydrologic models under the occurring global warming.

  1. Effects of permafrost thaw on carbon emissions under aerobic and anaerobic environments in the Great Hing'an Mountains, China.

    Science.gov (United States)

    Song, Changchun; Wang, Xianwei; Miao, Yuqing; Wang, Jiaoyue; Mao, Rong; Song, Yanyu

    2014-07-15

    The carbon (C) pool of permafrost peatland is very important for the global C cycle. Little is known about how permafrost thaw could influence C emissions in the Great Hing'an Mountains of China. Through aerobic and anaerobic incubation experiments, we studied the effects of permafrost thaw on CH4 and CO2 emissions. The rates of CH4 and CO2 emissions were measured at -10, 0 and 10°C. Although there were still C emissions below 0°C, rates of CH4 and CO2 emissions significantly increased with permafrost thaw under aerobic and anaerobic conditions. The C release under aerobic conditions was greater than under anaerobic conditions, suggesting that permafrost thaw and resulting soil environment change should be important influences on C emissions. However, CH4 stored in permafrost soils could affect accurate estimation of CH4 emissions from microbial degradation. Calculated Q10 values in the permafrost soils were significantly higher than values in active-layer soils under aerobic conditions. Our results highlight that permafrost soils have greater potential decomposability than soils of the active layer, and such carbon decomposition would be more responsive to the aerobic environment. © 2013 Elsevier B.V. All rights reserved.

  2. Analysing the environmental harms caused by coal mining and its protection measures in permafrost regions of Qinghai–Tibet Plateau

    Directory of Open Access Journals (Sweden)

    Wei Cao

    2017-09-01

    Full Text Available The coal mining has brought a series of ecological problems and environmental problems in permafrost regions. Taking Muli coal-mining area as an example, this article attempts to analyse the environmental harms caused by coal mining and its protection measures in permafrost regions of Qinghai–Tibet Plateau. This article analyses the influence of open mining on the surrounding permafrost around the open pit by using the numerical simulation. The results show that (1 based on the interrelation between coal mining and permafrost environment, these main environmental harm include the permafrost change and the natural environment change in cold regions; (2 once the surface temperature rises due to open mining, the permafrost will disappear with the increase of exploitation life. If considering the solar radiation, the climate conditions and the geological condition around the pit edge, the maximum thaw depth will be more than 2 m; (3 the protection measures are proposed to avoid the disadvantage impact on the permafrost environment caused by coal mining. It will provide a scientific basis for the resource development and environment protection in cold regions.

  3. Vulnerability of Permafrost Soil Carbon to Climate Warming: Evaluating Controls on Microbial Community Composition

    Science.gov (United States)

    Abstract: Despite the fact that permafrost soils contain up to half of the carbon (C) in terrestrial pools, we have a poor understanding of the controls on decomposition in thawed permafrost. Global climate models assume that decomposition increases linearly with temperature, yet decomposition in th...

  4. Supraleitung Grundlagen und Anwendungen

    CERN Document Server

    Buckel, Werner

    2004-01-01

    Seit nunmehr drei Jahrzehnten ist der "Buckel" das Referenzwerk in deutscher Sprache zum Thema Supraleitung. Immer wieder aktualisiert, hat das Lehrbuch Generationen von Studenten begleitet. In der 6., vollständig überarbeiteten Auflage wird das bewährte didaktische Konzept beibehalten, inhaltlich wurde der Band dem aktuellen Stand von Forschung und Technik angepasst. Das Autorenteam um Prof. Kleiner verzichtet auf komplizierte mathematische Herleitungen. Es baut ganz auf das bewährte Step-by-Step-Prinzip: Der Schwierigkeitsgrad wird von Kapitel zu Kapitel gesteigert. So können auch Einsteiger ohne einschlägige Vorkenntnisse dem Stoff bequem folgen. Dank seiner klaren Sprache und zahlreicher Abbildungen eignet sich der Band hervorragend als einführendes Lehrbuch - und zwar nicht nur für Physik-Studenten, sondern auch für Studierende angrenzender Natur- und Ingenieurwissenschaften. Grundlegende Eigenschaften, supraleitende Elemente, Cooper-Paarung, Thermodynamik, kritische Ströme, Josephsonkontakte...

  5. Frauen in Philosophie und Wissenschaft

    Directory of Open Access Journals (Sweden)

    Regina Harzer

    2006-03-01

    Full Text Available Der von Brigitte Doetsch herausgegebene Band präsentiert die aktuelle Feministische Philosophie und sammelt Beiträge, die Einblick geben in den gegenwärtigen Forschungsstand, wie ihn „Philosophinnen im dritten Jahrtausend“ erreicht haben. Insgesamt neun, zum Teil interdisziplinär ausgerichtete Arbeiten werden vorgestellt. Das Themenspektrum ist weit: Geschichte der Philosophie; Politische Philosophie und Naturphilosophie; Epistemologie; Biopolitik und Bioethik als Bereiche praktischer Philosophie; Forschung über Geschlechterverhältnisse. Alle Beiträge gehen zurück auf eine Vortragsreihe des Braunschweiger Zentrums für Gender Studies (www.genderzentrum.de. Leser/-innen erhalten einen guten Überblick über die aktuelle Frauenforschung aus der Sicht theoretischer und praktischer Philosophie.

  6. Quantitative Analyse und Visualisierung der Herzfunktionen

    Science.gov (United States)

    Sauer, Anne; Schwarz, Tobias; Engel, Nicole; Seitel, Mathias; Kenngott, Hannes; Mohrhardt, Carsten; Loßnitzer, Dirk; Giannitsis, Evangelos; Katus, Hugo A.; Meinzer, Hans-Peter

    Die computergestützte bildbasierte Analyse der Herzfunktionen ist mittlerweile Standard in der Kardiologie. Die verfügbaren Produkte erfordern meist ein hohes Maß an Benutzerinteraktion und somit einen erhöhten Zeitaufwand. In dieser Arbeit wird ein Ansatz vorgestellt, der dem Kardiologen eine größtenteils automatische Analyse der Herzfunktionen mittels MRT-Bilddaten ermöglicht und damit Zeitersparnis schafft. Hierbei werden alle relevanten herzphysiologsichen Parameter berechnet und mithilfe von Diagrammen und Graphen visualisiert. Diese Berechnungen werden evaluiert, indem die ermittelten Werte mit manuell vermessenen verglichen werden. Der hierbei berechnete mittlere Fehler liegt mit 2,85 mm für die Wanddicke und 1,61 mm für die Wanddickenzunahme immer noch im Bereich einer Pixelgrösse der verwendeten Bilder.

  7. Microbial network, phylogenetic diversity and community membership in the active layer across a permafrost thaw gradient.

    Science.gov (United States)

    Mondav, Rhiannon; McCalley, Carmody K; Hodgkins, Suzanne B; Frolking, Steve; Saleska, Scott R; Rich, Virginia I; Chanton, Jeff P; Crill, Patrick M

    2017-08-01

    Biogenic production and release of methane (CH 4 ) from thawing permafrost has the potential to be a strong source of radiative forcing. We investigated changes in the active layer microbial community of three sites representative of distinct permafrost thaw stages at a palsa mire in northern Sweden. The palsa site (intact permafrost and low radiative forcing signature) had a phylogenetically clustered community dominated by Acidobacteria and Proteobacteria. The bog (thawing permafrost and low radiative forcing signature) had lower alpha diversity and midrange phylogenetic clustering, characteristic of ecosystem disturbance affecting habitat filtering. Hydrogenotrophic methanogens and Acidobacteria dominated the bog shifting from palsa-like to fen-like at the waterline. The fen (no underlying permafrost, high radiative forcing signature) had the highest alpha, beta and phylogenetic diversity, was dominated by Proteobacteria and Euryarchaeota and was significantly enriched in methanogens. The Mire microbial network was modular with module cores consisting of clusters of Acidobacteria, Euryarchaeota or Xanthomonodales. Loss of underlying permafrost with associated hydrological shifts correlated to changes in microbial composition, alpha, beta and phylogenetic diversity associated with a higher radiative forcing signature. These results support the complex role of microbial interactions in mediating carbon budget changes and climate feedback in response to climate forcing. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Nutzerorientiertes Management von materiellen und immateriellen Informationsobjekten

    OpenAIRE

    Hübsch, Chris

    2001-01-01

    Schaffung einer stabilen, erweiterbaren und skalierbaren Infrastruktur für die Bereitstellung von Diensten im Umfeld von Bibliotheken und ähnlichen wissensanbietenden Einrichtungen unter Verwendung von XML-RPC und Python.

  9. Gestaltung einer netzbasierten Lernumgebung für einen Fernstudiengang zu „Medien und Informationstechnologien in Erziehung, Unterricht und Bildung“

    Directory of Open Access Journals (Sweden)

    Gerhard Tulodziecki

    2017-07-01

    Full Text Available In diesem Beitrag stelle ich dar, wie wir in einem kooperativen Verbund eine netzbasierte Lernumgebung für einen Fernstudiengang zu „Medien und Informationstechnologien in Erziehung, Unterricht und Bildung“ gestalten. Das Projekt wird von zwei Arbeitsgruppen an der Universität Paderborn (Allgemeine Didaktik und Medienpädagogik, Didaktik der Informatik und einer Arbeitsgruppe an der Fernuniversität Hagen (Theorie der Schule und des Unterrichts getragen. Die Projektleitung teile ich mit Horst Dichanz, Bardo Herzig und Johannes Magenheim. Der Fernstudiengang basiert auf Entwicklungen zur Lehrerausbildung im Bereich neuer Medien, wie sie im Rahmen der Initiative „Bildungswege in der Informationsgesellschaft (BIG“ erarbeitet wurden (vgl. u.a. Tulodziecki/Moll/Gallasch 2001. Die – 1995 begonnene – BIG-Initiative geht auf die Bertelsmann Stiftung und Heinz Nixdorf Stiftung zurück. Die jetzige Projektarbeit wird von der ,,e-nitiative.nrw.Netzwerk für Bildung“ gefördert.

  10. Effects of permafrost thaw on nitrogen availability and plant nitrogen acquisition in Interior Alaska

    Science.gov (United States)

    Finger, R.; Euskirchen, E. S.; Turetsky, M.

    2013-12-01

    The degradation of ice-rich permafrost, which covers a large portion of Interior Alaska, typically leads to thermokarst and increases in soil saturation. As a result, conifer peat plateaus degrade and are often replaced by wet collapse scar bogs. This state change results in profound changes in regional hydrology, biogeochemical cycling, and plant community composition. Preliminary data suggest that permafrost thaw can increase surface soil inorganic nitrogen (IN) concentrations but it is still unknown whether these changes in nutrient availability are short-lived (pulse releases) and whether or not they impact collapse scar vegetation composition or productivity, particularly as collapse scars undergo succession with time-after-thaw. Therefore we are currently examining changes in plant community composition, N availability and plant N acquisition along three thermokarst gradients in Interior Alaska. Each gradient is comprised of a forested permafrost peat plateau, adjacent ecotones experiencing active permafrost degradation (including a collapsing forest canopy and a saturated moat), and a collapse scar bog where permafrost has completely degraded. We predicted that IN concentrations would be highest along the active thaw margin, and lowest in the peat plateau. We also predicted that IN concentrations would be positively related to shifts in vegetation community composition, nutrient use efficiency (NUE) and tissue 15N concentrations. Preliminary results have shown that IN concentrations increase in newer collapse scar features as well as with thaw depth. Our data also show a shift from feather moss and ericaceous shrub-dominate understories in the permafrost plateau to Sphagnum and sedge dominated thaw ecotone and bog communities. Further successional development of the collapse scar bog results in the reintroduction of small evergreen and deciduous shrubs as the peat mat develops. Over time, collapse scar succession and peat accumulation appears to lead to

  11. Permafrost thaw strongly reduces allowable CO2 emissions for 1.5°C and 2°C

    Science.gov (United States)

    Kechiar, M.; Gasser, T.; Kleinen, T.; Ciais, P.; Huang, Y.; Burke, E.; Obersteiner, M.

    2017-12-01

    We quantify how the inclusion of carbon emission from permafrost thaw impacts the budgets of allowable anthropogenic CO2 emissions. We use the compact Earth system model OSCAR v2.2 which we expand with a permafrost module calibrated to emulate the behavior of the complex models JSBACH, ORCHIDEE and JULES. When using the "exceedance" method and with permafrost thaw turned off, we find budgets very close to the CMIP5 models' estimates reported by IPCC. With permafrost thaw turned on, the total budgets are reduced by 3-4%. This corresponds to a 33-45% reduction of the remaining budget for 1.5°C, and a 9-13% reduction for 2°C. When using the "avoidance" method, however, permafrost thaw reduces the total budget by 3-7%, which corresponds to reductions by 33-56% and 56-79% of the remaining budget for 1.5°C and 2°C, respectively. The avoidance method relies on many scenarios that actually peak below the target whereas the exceedance method overlooks the carbon emitted by thawed permafrost after the temperature target is reached, which explains the difference. If we use only the subset of scenarios in which there is no net negative emissions, the permafrost-induced reduction in total budgets rises to 6-15%. Permafrost thaw therefore makes the emission budgets strongly path-dependent. We also estimate budgets of needed carbon capture in scenarios overshooting the temperature targets. Permafrost thaw strongly increases these capture budgets: in the case of a 1.5°C target overshot by 0.5°C, which is in line with the Paris agreement, about 30% more carbon must be captured. Our conclusions are threefold. First, inclusion of permafrost thaw systematically reduces the emission budgets, and very strongly so if the temperature target is overshot. Second, the exceedance method, that is the only one that complex models can follow, only partially accounts for the effect of slow non-linear processes such as permafrost thaw, leading to overestimated budgets. Third, the newfound

  12. CLILiG und Musikunterricht

    Directory of Open Access Journals (Sweden)

    Merle Jung

    2015-10-01

    Full Text Available Der Einsatz von Musik und Liedern im Sprachunterricht ist seit der Entwicklung der kommunikativen Methoden ein beliebtes Thema in der Fremdsprachendidaktik. Musik und Sprache haben Ähnlichkeiten bei den kognitiven Verarbeitungsprozessen und der gedächtnisstützende Einfluss der Musik und ihr Nutzen für das Sprachenlernen sind allgemein bekannt. Dieser Nutzen wird aber meistens nur aus der (fremdsprachlichen Perspektive gezogen, die musikalische Erziehung der Lernenden bleibt im Hintergrund. Dabei bietet der bilinguale Musikunterricht mit der klaren Ausrichtung auf die musikalischen Ziele eine gute Möglichkeit, diese zwei Bereiche – Musik und Sprache – gleichwertig miteinander zu verbinden. Das Ziel des vorliegenden Beitrags ist es, die Vorteile des bilingualen Musikunterrichts zu erörtern und an einem Beispielmodul zum Thema Wetter im Herbst zu verdeutlichen. The use of music and songs in language teaching has been a popular topic in foreign language didactics since the development of communicative methods. Music and language have similarities in cognitive processing and the memory supporting influence of music and its beneficial effect on language learning are generally known. However, this benefit will usually be drawn only from the (foreign language perspective, the musical education of the learners remains in the background. Yet bilingual music education with a clear focus on the musical goals provides a great opportunity to connect these two areas - music and language - equally to each other. The aim of this paper is to discuss the advantages of bilingual music education and to present an example based on the bilingual module Weather in Autumn.

  13. Diagrammatik und Wissensorganisation

    Directory of Open Access Journals (Sweden)

    Sascha Freyberg

    2012-11-01

    Full Text Available EinleitungDie Formen des „Sichtbarmachens“ in der Wissenschaft reichen von „Abbildungen“ über „Modelle“ bis hin zu „Simulationen“. Sie können u.a. gezeichnet, fotografiert, geometrisch konstruiert oder durch Sensorik vermittelt, digital prozessiert werden. Ihre Funktionen erstrecken sich von der Orientierung bis hin zur (hypothetischen Voraussage und somit auch vom Überblick bis zur Evidenzsuggestion. Generell handelt es sich um vereinfachte (und vereinfachende Darstellungen von (teilweise sehr komplexen Sachverhalten, zu deren Verständnis sie beitragen sollen; daher können sie bei Lernprozessen, d.h. in der Vermittlung und auch bei der Organisation von Wissen eine wichtige Rolle spielen. Diese kommt ihnen nun nicht nur zu, weil sie – wie in den mittelalterlichen Mnemotechniken – als Gedächtnisstützen für bekannte Sachverhalte dienen. Sondern resultiert auch aus ihrem Potenzial für die Entdeckung von neuen Zusammenhängen. Der folgende Artikel diskutiert die Darstellungsform des Diagramms. Es wird hier mit dem Gedanken gespielt, dass die in der universalen Zeichentheorie von C.S. Peirce entwickelte Diagrammatik wichtige Impulse für eine Untersuchung des Zusammenhangs von Wissen und Bildlichkeit geben kann.

  14. Changes in Hydrologic Conditions and Greenhouse Gas Emissions in Circumpolar Regions due to Climate Change Induced Permafrost Retreat

    Energy Technology Data Exchange (ETDEWEB)

    Whiticar, M. J. [School of Earth and Ocean Sciences, University of Victoria, Victoria (Canada); Bhatti, J.; Startsev, N. [Northern Forestry Centre, St Edmonton, AB (Canada)

    2013-07-15

    Thawing permafrost peatlands substantially influence Canadian northern ecosystems by changing the regional hydrology and mobilizing the vast carbon (C) reserves that results in increased greenhouse gas (GHGs) emissions to the atmosphere. With permafrost distribution controlled largely by topography and climate, our International polar y ear (IPY) study intensively monitored the local C cycling processes and GHG fluxes associated with different hydrologic and permafrost environments at 4 sites along a climatic gradient extending from the Isolated patches permafrost Zone (northern alberta), to the continuous permafrost Zone (Inuvik, NWT). Each site encompasses a local gradient from upland forest and peat plateau to collapse scar. Our multi-year measurements of peatland profiles and flux chambers for CH{sub 4} and CO{sub 2} concentrations and stable isotope ratios indicate processes, including methanogenesis, methanotrophy, transport and emission that control the distribution of these GHGs. These relationships are modulated by fluctuating local soil water and corresponding ecosystem conditions. The gas geochemistry shows that significant surface CH{sub 4} production occurs by both hydrogenotrophic and acetoclastic methanogenesis in submerged, anaerobic peats, e.g., collapse scars, whereas methane oxidation is restricted to aerobic, drier environments, e.g., upland sites and peat-atmosphere interface. The most active methanogenesis and emissions are in areas of actively thawing permafrost contrasting with sites under continuous permafrost. This degree of methanogenesis is being amplified by the increased rate of Arctic warming and the rapid retreat of permafrost in canada's arctic (approximately. 2.5 km/a). (author)

  15. Permafrost distribution in the European Alps: calculation and evaluation of an index map and summary statistics

    Directory of Open Access Journals (Sweden)

    L. Boeckli

    2012-07-01

    Full Text Available The objective of this study is the production of an Alpine Permafrost Index Map (APIM covering the entire European Alps. A unified statistical model that is based on Alpine-wide permafrost observations is used for debris and bedrock surfaces across the entire Alps. The explanatory variables of the model are mean annual air temperatures, potential incoming solar radiation and precipitation. Offset terms were applied to make model predictions for topographic and geomorphic conditions that differ from the terrain features used for model fitting. These offsets are based on literature review and involve some degree of subjective choice during model building. The assessment of the APIM is challenging because limited independent test data are available for comparison and these observations represent point information in a spatially highly variable topography. The APIM provides an index that describes the spatial distribution of permafrost and comes together with an interpretation key that helps to assess map uncertainties and to relate map contents to their actual expression in the terrain. The map can be used as a first resource to estimate permafrost conditions at any given location in the European Alps in a variety of contexts such as research and spatial planning.

    Results show that Switzerland likely is the country with the largest permafrost area in the Alps, followed by Italy, Austria, France and Germany. Slovenia and Liechtenstein may have marginal permafrost areas. In all countries the permafrost area is expected to be larger than the glacier-covered area.

  16. Vulnerability of permafrost carbon to climate change: implications for the global carbon cycle

    Science.gov (United States)

    Edward A.G. Schuur; James Bockheim; Josep G. Canadell; Eugenie Euskirchen; Christopher B. Field; Sergey V. Goryachkin; Stefan Hagemann; Peter Kuhry; Peter M. Lafleur; Hanna Lee; Galina Mazhitova; Frederick E. Nelson; Annette Rinke; Vladimir E. Romanovsky; Nikolay Shiklomanov; Charles Tarnocai; Sergey Venevsky; Jason G. Vogel; Sergei A. Zimov

    2008-01-01

    Thawing permafrost and the resulting microbial decomposition of previously frozen organic carbon (C) is one of the most significant potential feedbacks from terrestrial ecosystems to the atmosphere in a changing climate. In this article we present an overview of the global permafrost C pool and of the processes that might transfer this C into the atmosphere, as well as...

  17. Frozen-Ground Cartoons: An international collaboration between artists and permafrost scientists

    OpenAIRE

    Fritz, Michael; Bouchard, Fréderic; Deshpande, Bethany; Malenfant-Lepage, Julie; Nieuwendam, Alexandre; Paquette, Michel; Rudy, Ashley; Siewert, Matthias; Veillete, Audrey; Weege, Stefanie; Harbor, Jonathan M.; Habeck, J. O.; Sjöberg, Ylva

    2018-01-01

    Communicating science about a phenomenon found under ground and defined by its thermal properties in an easy, funny, and engaging way, can be a challenge. Two years ago, a group of young researchers from Canada and Europe united to tackle this problem by combining arts and science to produce a series of outreach comic strips about permafrost (frozen ground). Because this concerns us all. As the climate warms, permafrost thaws and becomes unstable for houses, roads and airports. The thawi...

  18. Social Bots und Fake News - Was EU- und UNESCO-Referenzrahmen zum Lernen im digitalen Zeitalter darüber (nicht sagen

    Directory of Open Access Journals (Sweden)

    Dietmar Janetzko

    2017-07-01

    Full Text Available In den letzten Jahren haben internationale Organisationen wie die EU und die UNESCO eine Reihe von Vorschlägen und Strategiepapieren zur Bildung und Ausbildung im Zusammenhang mit digitalen Medien entwickelt. Mit den dabei entstandenen Rahmenkonzepten der EU (Digital Competence, DigComp sowie der UNESCO (Media and Information Literacy, MIL werden im Kern zwei zusammenhängende Ziele verfolgt: (i digitale Bildung bzw. digitale Kompetenzen, Fähigkeiten und zugehörige Einstellungen umfassend zu kartographieren sowie (ii über die dabei konzipierten edukativ-politischen Rahmenkonzepte Projektförderungen, Bildungs- bzw. Ausbildungsinitiativen sowie Gesetzesvorlagen anzustossen. Tatsächlich sind DigComp und MIL bereits dabei, auf internationaler Ebene einen prägenden Einfluss zu nahezu allen Fragen der Bildung und Ausbildung im Bereich digitaler Medien auszuüben. Beide Initiativen haben innerhalb der genannten Organisationen Leuchtturmcharakter, werden bislang aber von der allgemeinen Öffentlichkeit und der medienpädagogischen Fachöffentlichkeit kaum wahrgenommen. Dessen ungeachtet verbindet sich mit DigComp und MIL jeweils ein impliziter Anspruch auf einen – im Bedarfsfall zu aktualisierenden – Gesamtentwurf zur Analyse und Gestaltung medienpädagogischer Bildung und Ausbildung. Dies gilt für Gesetzesvorlagen, Regulierungen, Forschungsaktivitäten. Sind diese Rahmenkonzepte anschlussfähig an medienpädagogische Debatten über disruptive Versuche, in via soziale Medien geführte öffentliche Debatten einzugreifen, die sich über social bots, fake news oder andere Formen der Einflussnahme manifestieren? Erschliessen sie dazu Reflexionsräume und Handlungsoptionen? Geleitet von diesen Fragen betrachtet der vorliegende Aufsatz, die Rahmenkonzepte der EU und UNESCO, DigComp and MIL. Dabei zeigt sich, dass beide Rahmenkonzepte von Schieflagen gekennzeichnet sind. DigComp und MIL überbetonen die instrumentelle, auf Verwertung am

  19. Hydrogeology, chemical and microbial activity measurement through deep permafrost.

    Science.gov (United States)

    Stotler, Randy L; Frape, Shaun K; Freifeld, Barry M; Holden, Brian; Onstott, Tullis C; Ruskeeniemi, Timo; Chan, Eric

    2011-01-01

    Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples <40% drill fluid. The salinity of the non-drill fluid component was <20,000 mg/L, had a Ca/Na ratio above 1, with δ(18) O values ∼5‰ lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH(4) was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH(4) is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  20. Delegation und Kooperation im Gesundheitswesen

    OpenAIRE

    Rosenau, Henning

    2010-01-01

    Delegation und Kooperation im Gesundheitswesen. - In: Tıpta işbirliği ve hukuksal sorunlar = Delegation und Kooperation im Gesundheitswesen / ed.: Hakan Hakeri ... - Samsun : Adalet, 2010. - S. 7-18

  1. Gas hydrate formation in deep-sea sediments - on the role of sediment-mechanical process determination; Gashydratbildung in Tiefseesedimenten - zur Rolle der sedimentmechanischen Prozesssteuerung

    Energy Technology Data Exchange (ETDEWEB)

    Feeser, V. [Kiel Univ. (Germany). Geologisch-Palaeontologisches Inst.

    1997-12-31

    Slope failures in gas hydrate regions are encountered throughout the oceans. The stability of seafloor slopes can be assessed and predicted by means of calculation methods based on mechanical laws and parameters which describe the deformation behaviour and/or mechanical strength of the slope-forming sediments. Thermodynamic conditions conducive to the formation of gas hydrates in marine sediments differ from conditions prevailing in exclusively water-filled systems. The present contribution describes the relevant energetic conditions on the basis of a simple spherical model giving due consideration to petrographic parameters. Depending on pore size distribution, lithological stress conditions, pore water pressure, and sediment strength gas hydrates will either develop as a cementing phase or as segregated lenses. (MSK) [Deutsch] In den Weltmeeren ereignen sich immer wieder Hangrutschungen in Gashydratgebieten. Die zur Beurteilung und Prognonse von Hangstabilitaeten zu verwendenden Berechnungsverfahren erfordern Stoffgesetze und Parameter, welche das Deformations-und/oder Festigkeitsverhalten der hangbildenden Sedimente beschreiben. Die thermodynamischen Bildungsbedingungen von Gashydraten in marinen Sedimenten unterscheiden sich von den Bedingungen in ausschliesslich wassergefuellten Systemen. Unter Einbeziehung petrographischer Eigenschaften werden die energetischen Bedingungen beschrieben. Dazu dient ein einfaches Kugelmodell. Je nach vorhandenem Porenraumspektrum, lithostatischen Spannungsverhaeltnissen, Porenwasserdruck und Sedimentfestigkeit wachsen Gashydrate als Porenraumzement oder als segregierte Linsen.

  2. Lew Kopelew - der Schriftsteller und Wissenschaftler, der Freund der Menschen und Verfechter ihrer Grundrechte

    OpenAIRE

    Keller, Werner

    2010-01-01

    Unsere Erwartung war anders als sonst – freudig, doch nicht frei von Erregung und leiser Furcht: Wird man im Kreml das gegebene Wort halten und nach einem Jahr die Rückkehr in die russische Heimat erlauben? Als Gast Heinrich Bölls kam Lew Kopelew im November 1980 nach Deutschland. In der Bonner Wohnung des Slawisten Wolfgang Kasack konnte ich mich ihm wenige Tage später vorstellen: Er war groß, von beeindruckender Physiognomie – nicht nur durch den Prophetenbart –, allerdings fast bleich und ...

  3. Stabile KHK und Hypertonie: Diagnostik, medikamentöse Therapie und Revaskularisierungsstrategien

    OpenAIRE

    Elsner D

    2008-01-01

    Nicht nur eine koronare Herzerkrankung (KHK) sondern auch Mikrozirkulationsstörungen führen bei Hypertonikern häufig zum Symptom der Angina pectoris. Grundpfeiler in der Diagnostik der KHK sind die entsprechenden Belastungstests. Allerdings ist die Aussagekraft bei Hypertonikern, insbesondere von Belastungs- EKG und Myokardszintigramm, eingeschränkt. Goldstandard bleibt daher die Koronarangiographie. Basis der Therapie der KHK ist die Modifikation des Lebensstils und Ausschaltung bz...

  4. Schaulust und Horror Soziokulturelle - Perspektiven auf PEEPING TOM

    Directory of Open Access Journals (Sweden)

    Thomas Ballhausen

    2010-09-01

    Full Text Available Die Geschichte des Kinos und des Films ist mindestens ebenso sehr eine Geschichte des Schreckens (und der damit verbundenen Schaulust wie sie eine Geschichte des Dokumentarischen zu sein scheint. Es sind die außergewöhnlichen Körper und deren Bewegungen, die das Publikum zu allen Zeiten faszinierten, schockierten und zum Schauen und Sehen lockten. Besonders das Genre des Horrorfilms ist mit diesem zentralen Aspekt des Kinos besonders deutlich verbunden.

  5. Konstruieren von Pkw-Karosserien: Grundlagen, Elemente und Baugruppen, Vorschriftenübersicht, Beispiele mit CATIA V4 und V5

    Science.gov (United States)

    Grabner, Jörg; Nothhaft, Richard

    Die Faszination, die vom Auto ausgeht, ist und bleibt ungebrochen. Entsprechend interessant ist es, sich vor dem Hintergrund konventioneller Konstruktionstechniken über die virtuelle Produktentwicklung von Pkw-Karosserien an modernen CAD-Arbeitsplätzen informieren zu können. Die Autoren führen in die Grundlagen ein und zeigen anhand von Beispielen und zahlreichen Abbildungen, wie mit dem System CATIA der Rohbau sowie die Ausstattung innen und au=C3=9Fen konstruiert werden. Darüber hinaus wird das so genannte "Package" an Beispielen beschrieben, also das Management und die Harmonisierung der Anforderungen an die Bauräume (z.

  6. Permafrost in the Himalayas: specific characteristics, evolution vs. climate change and impacts on potential natural hazards

    Science.gov (United States)

    Fort, Monique

    2015-04-01

    Mountain environments are very sensitive to climate change, yet assessing the potential impacts of these changes is not easy because of the complexity and diversity of mountain systems. The Himalayan permafrost belt presents three main specificities: (1) it develops in a geodynamically active mountain, which means that the controlling factors are not only temperature but also seismo-tectonic activity; (2) due to the steepness of the southern flank of the Greater Himalaya and potential large scale rock failures, permafrost evidence manifests itself best in the inner valleys and on the northern, arid side of the Himalayas (elevations >4000m); (3) the east-west strike of the mountain range creates large spatial discontinuity in the "cold" belt, mostly related to precipitation nature and availability. Only limited studies have been carried to date, and there is no permanent "field laboratory", nor continuous records but a few local studies. Based on preliminary observations in the Nepal Himalayas (mostly in Mustang and Dolpo districts), and Indian Ladakh, we present the main features indicating the existence of permafrost (either continuous or discontinuous). Rock-glaciers are quite well represented, though their presence may be interpreted as a combined result from both ground ice and large rock collapse. The precise altitudinal zonation of permafrost belt (specifying potential permafrost, probable permafrost, observed permafrost belts) still requires careful investigations in selected areas. Several questions arise when considering the evolution of permafrost in a context of climate change, with its impacts on the development of potential natural hazards that may affect the mountain population. Firstly, permafrost degradation (ground ice melting) is a cause of mountain slope destabilization. When the steep catchments are developed in frost/water sensitive bedrock (shales and marls) and extend to high elevations (as observed in Mustang or Dolpo), it would supply more

  7. Elevation-based upscaling of organic carbon stocks in High-Arctic permafrost terrain

    DEFF Research Database (Denmark)

    Weiss, Niels; Faucherre, Samuel; Lampiris, Nikos

    2017-01-01

    Accurate quantity and distribution estimates of permafrost soil organic carbon (SOC) stocks are needed to project potential feedbacks to climate, following warming. Still, upscaling from local field observations to regional estimates to circumarctic assessments remains a challenge. Here we explore...... elevation-based upscaling techniques for High-Arctic permafrost SOC stocks. We combine two detailed, high-resolution SOC inventories on Spitsbergen (Svalbard) with regional validation data. We find a clear relationship between elevation and SOC content, and use this observed exponential correlation, as well...... as discrete elevation classes, as upscaling models for Spitsbergen. We estimate the total amount of permafrost SOC currently present in soils on Spitsbergen to be 105.36 Tg (0.11 Pg), with a mean SOC content of 2.84 ± 0.74 kg C m−2 (mean ± 95% confidence interval). Excluding glaciers and permanent snowfields...

  8. Permafrost conditions at the Upper Kuskokwim river area and its influence on local communities.

    Science.gov (United States)

    Kholodov, A. L.; Panda, S. K.; Hanson, T.

    2017-12-01

    Research area located within the zone of discontinuous permafrost distribution. Recent mean annual air temperature here is close to the 0C. It means, that taking in consideration warming influence of the snow cower during winter, mean annual temperature at the ground surface is well above freezing point. It means that presence or absence of permafrost here completely controlled by the ecological conditions. Based on remote sensing data and the surveys conducted in 2016-17 we selected 6 main ecotypes typical for this area: black spruce boreal forest, wetlands, low and tall shrubs, deciduous and mixed forest. Most of them (low shrubs, deciduous and mixed forest) represent different stages of area recovering after forest fires that was confirmed by the presence of ashy layer close to ground surface in soil pits had been dug within these landscapes. Permafrost was observed only within 2 of them: low shrubs and black spruce boreal forest. Within these types of terrain temperature at the bottom of active layer varies from -0.2/-0.5C at the areas of low shrubs, recovered after relatively recent (approximately 30-50 years old) fires to -1/-1.5 within black spruce forest. Active (seasonally thawed) layer as thick as 0.6 to 0.8 m. Warmest ecotypes for the area are tall shrubs and deciduous forest, temperature at the depth close to 1 m is about +3C. At the mixed forest temperature at the same depth consists of +1/+2C. Active (seasonally frozen) layer thickness within permafrost free areas is 1-1.5 m at the drained sites and about 0.5 within wetlands. Ice-rich permafrost underlying the active layer was noticed only within the black spruce forest. Areas which are free of permafrost are much better drained, typical moisture of mineral soil is less than 30% versus 45-50% in seasonally thawed layer. The current state of permafrost and the fact that it presence completely depends on ecosystems limits land use abilities of local inhabitants. Any changes of forest coverage or organic

  9. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    Directory of Open Access Journals (Sweden)

    S. Muster

    2017-06-01

    Full Text Available Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013 high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( <  300 m a.s.l. land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands

  10. Changing Permafrost in the Arctic and its Global Effects in the 21st Century (PAGE21): A very large international and integrated project to measure the impact of permafrost degradation on the climate system

    Science.gov (United States)

    Lantuit, Hugues; Boike, Julia; Dahms, Melanie; Hubberten, Hans-Wolfgang

    2013-04-01

    The northern permafrost region contains approximately 50% of the estimated global below-ground organic carbon pool and more than twice as much as is contained in the current atmos-pheric carbon pool. The sheer size of this carbon pool, together with the large amplitude of predicted arctic climate change im-plies that there is a high potential for global-scale feedbacks from arctic climate change if these carbon reservoirs are desta-bilized. Nonetheless, significant gaps exist in our current state of knowledge that prevent us from producing accurate assess-ments of the vulnerability of the arctic permafrost to climate change, or of the implications of future climate change for global greenhouse gas (GHG) emissions. Specifically: • Our understanding of the physical and biogeochemical processes at play in permafrost areas is still insuffi-cient in some key aspects • Size estimates for the high latitude continental carbon and nitrogen stocks vary widely between regions and research groups. • The representation of permafrost-related processes in global climate models still tends to be rudimentary, and is one reason for the frequently poor perform-ances of climate models at high latitudes. The key objectives of PAGE21 are: • to improve our understanding of the processes affect-ing the size of the arctic permafrost carbon and nitro-gen pools through detailed field studies and monitor-ing, in order to quantify their size and their vulnerability to climate change, • to produce, assemble and assess high-quality datasets in order to develop and evaluate representations of permafrost and related processes in global models, • to improve these models accordingly, • to use these models to reduce the uncertainties in feed-backs from arctic permafrost to global change, thereby providing the means to assess the feasibility of stabili-zation scenarios, and • to ensure widespread dissemination of our results in order to provide direct input into the ongoing debate on

  11. Wie schneiden Sie ab?: Studie über Kontroll- und Prüfungsaktivitäten bei mittelgrossen Unternehmen, Spitälern und Hochschulen in der Schweiz

    OpenAIRE

    Ruud, T F; Isufi, S; Friebe, P; Stebler, W; Seheri, F; Emmenegger, M

    2008-01-01

    Kontroll- und Prüfungsaktivitäten unterstützen den Verwaltungsrat und die Geschäftsleitung bei der Steuerung und Kontrolle des Unternehmens. Bei mittelgrossen Unternehmen ist aufgrund der begrenzten personellen und finanziellen Ressourcen ein effektiver und effizienter Einsatz dieser Aktivitäten unerlässlich. Auch bei Spitälern und Hochschulen gewinnen Kontroll- und Prüfungsaktivitäten infolge erhöhter Wettbewerbsintensität und steigenden Kostendrucks sowie zunehmender Unabhängigkeit diese...

  12. Personen- und Güterverkehr

    Science.gov (United States)

    Flämig, Heike; Gertz, Carsten; Mühlhausen, Thorsten

    Im Jahr 2010 war in Deutschland der Verkehrssektor für fast 20 % der energiebedingten Treibhausgase verantwortlich. Das Klima hat sich bereits so weit verändert, dass zur Sicherung der Funktion der Verkehrssysteme auch Anpassungsmaßnahmen notwendig sind. Diese Maßnahmen müssen durch verkehrsreduzierende bzw. -beeinflussende Maßnahmen ergänzt werden. Ausgehend von den Emissionen im Verkehrssektor und möglichen Minderungen schlägt das Kapitel den Bogen zu Optionen der Anpassung an den Klimawandel, die ausführlich und konkret dargestellt werden. Besonders betrachtet werden die mannigfaltigen Gefahren der Rückkopplung sowie die vielfältigen Wechselwirungen mit anderen Themengebieten und Sektoren.

  13. Editorial: Virtualität und E-Learning

    Directory of Open Access Journals (Sweden)

    Horst Dichanz

    2001-04-01

    Full Text Available Wer Anfang April den Weltkongress des ICDE in Düsseldorf besuchte, der unter dem Titel veranstaltet wurde, war von der Fülle der Veranstaltungen überrascht, die sich auf die eine oder andere Weise aus unterschiedlichster Sicht mit Fragen von Virtuellen Lernwelten und den Möglichkeiten des E-Learning befassten. Mindestens ebenso schwer zu überblicken waren die zahlreichen Produkte, die von Firmen aus zahlreichen Ländern für Zwecke der Gestaltung von virtuellen Lernwelten und zur Durchführung von E-Learning-Veranstaltungen angeboten wurden. Diese E-Learning-Produkte reichten von simplen Datenbanken verschiedenster Fächer über Lern- und Kommunikationsplattformen bis hin zu komplexen Oberflächen oder Rahmenprogrammen zur Konstruktion eigener Lernsoftware. - Über solide, methodisch nachprüfbare Erfolgsuntersuchungen konnten allerdings nur wenige berichten. Die Szene im Internet, das man auf «Virtualiät» und «E-Learning» durchforstet, ist kaum anders: Dutzende von Firmen und Instituten bieten «E-Learning»-Produkte an. Ohne im Detail zu beschreiben, was an ihrem Produkt nun «E-Learning» ist. In den meisten Fällen stellt sich heraus, dass es sich dabei um elektronisch gespeicherten, bearbeitbaren und/oder gewinnbaren Lernstoff handelt, dessen Lernnutzen zweifelsfrei unterstellt wird. Ein zweiter Schwachpunkt: Was konkret unter «Lernen» mithilfe elektronischer Medien gemeint ist, was sich die Produzenten, Autoren u.ä. darunter vorstellen, wird noch seltener thematisiert. Gleichwohl ist der Markt in allen Bildungsbereichen riesig, er wird als expandierend eingeschätzt, in Verbindung mit den elektronischen Medien wird gelegentlich sogar der Bildungsmarkt als ein Wachstumsmarkt charakterisiert. Viel Grund zu Optimismus, noch mehr Grund zu detaillierten Rückfragen! Doch sind Arbeiten, genaue Untersuchungen zu den Komplexen «Virtualität» und «E-Learning» noch mit der Lupe zu suchen. Es gehört zweifellos zu den Aufgaben einer

  14. Circumpolar assessment of permafrost C quality and its vulnerability over time using long-term incubation data.

    Science.gov (United States)

    Schädel, Christina; Schuur, Edward A G; Bracho, Rosvel; Elberling, Bo; Knoblauch, Christian; Lee, Hanna; Luo, Yiqi; Shaver, Gaius R; Turetsky, Merritt R

    2014-02-01

    High-latitude ecosystems store approximately 1700 Pg of soil carbon (C), which is twice as much C as is currently contained in the atmosphere. Permafrost thaw and subsequent microbial decomposition of permafrost organic matter could add large amounts of C to the atmosphere, thereby influencing the global C cycle. The rates at which C is being released from the permafrost zone at different soil depths and across different physiographic regions are poorly understood but crucial in understanding future changes in permafrost C storage with climate change. We assessed the inherent decomposability of C from the permafrost zone by assembling a database of long-term (>1 year) aerobic soil incubations from 121 individual samples from 23 high-latitude ecosystems located across the northern circumpolar permafrost zone. Using a three-pool (i.e., fast, slow and passive) decomposition model, we estimated pool sizes for C fractions with different turnover times and their inherent decomposition rates using a reference temperature of 5 °C. Fast cycling C accounted for less than 5% of all C in both organic and mineral soils whereas the pool size of slow cycling C increased with C : N. Turnover time at 5 °C of fast cycling C typically was below 1 year, between 5 and 15 years for slow turning over C, and more than 500 years for passive C. We project that between 20 and 90% of the organic C could potentially be mineralized to CO2 within 50 incubation years at a constant temperature of 5 °C, with vulnerability to loss increasing in soils with higher C : N. These results demonstrate the variation in the vulnerability of C stored in permafrost soils based on inherent differences in organic matter decomposability, and point toward C : N as an index of decomposability that has the potential to be used to scale permafrost C loss across landscapes. © 2013 John Wiley & Sons Ltd.

  15. KRISENZUSTÄNDE UND ANWENDUNG VON ZWANGSMASSNAHMEN IN DER PSYCHIATRIE

    Directory of Open Access Journals (Sweden)

    Vesna Šendula Jengić

    2017-01-01

    Full Text Available In der Arbeit wird über die Phänomene der Aggressivität und Gewalt bei Menschen diskutiert, wobei man besonderen Wert auf die Personen mit seelischen Störungen legt. Krisenzustände und Gewaltverhalten gibt es nicht nur in der Psychiatrie. Es kann immer zu einem solchem Zustand und Verhalten kommen und jeder kann unter bestimmten Umständen sowohl Opfer als auch Täter sein. Multikausalität und Komplexität sowie auch individuelle Umstände und situationsbezogene Faktoren, welche zum Gewaltverhalten führen können, haben nur geringen Prognosekraft. Statistische Indikatoren andererseits können falsch positive und falsch negative Ergebnisse verbergen, wobei ein Fehler in der Einschätzung das Risiko zum Erscheinen eines Verhaltens drastisch erhöhen oder zum unrechtfertigten Entziehung der Freiheit führen kann. Zwangsmaβnahmen in der Psychiatrie sind nur ausnahmsweise anzuwenden, und zwar, wenn ein gefährliches Verhalten direkt das Leben und die Gesundheit einer Person oder einer Umgebung gefährdet. Darüber hinaus ist die Dauer von Zwangsmaβnahmen auch beschränkt. Die Gesetzesregulative, insbesondere das Gesetz über den Schutz von Personen mit seelischen Störungen (Amtsblatt der Republik Kroatien Nr. 76/2014 und die Ordnung über die Arten und die Weise der Anwendung von Zwangsmaβnahmen gegenüber den Personen mit schwierigen seelischen Störungen (Amtsblatt der Republik Kroatien Nr. 16/2015, dient als zusätzlicher Schutz der Rechte dieser Patientengruppe und schreibt die Arten und die Weise der Anwendung von Zwangsmaβnahmen sowie auch die Vorgehensweise. Zusätzliche Richtlinien und Vorgehensstrategien wurden auch von den Gesellschaften für Psychiatrie gegeben. In der Arbeit wird betont, dass bessere Bedingungen, Infrastruktur und Arbeitskräfte sowie auch ständige Entwicklung und Bewertung der Arbeitsqualität in der Psychiatrie erforderlich sind. Abschlieβend werden Standards und ethische Fragen in Betracht gezogen, wie

  16. Zustand und Perspektiven der Kapitalmarktfinanzierung in Deutschland

    DEFF Research Database (Denmark)

    Beck, Thorsten; Kaserer, Christoph; Rapp, Marc Steffen

    2016-01-01

    Die Autoren haben sich im Rahmen des durch das Bundesministerium für Wirtschaft und Energie (BMWi) in Auftrag gegebenen Forschungsprojekts „Beteiligungs- und Kapitalmarktfinanzierung im deutschen Finanzsystem: Zustand und Entwicklungsperspektiven“ (Dienstleistungsprojekt I C 4 -27/14) mit dem Zus...

  17. Simulation of permafrost changes due to technogenic influences of different ingeneering constructions used in nothern oil and gas fields

    Science.gov (United States)

    Filimonov, M. Yu; Vaganova, N. A.

    2016-10-01

    Significant amount of oil and gas is producted in Russian Federation on the territories with permafrost soils. Ice-saturated rocks thawing due to global warming or effects of various human activity will be accompanied by termocarst and others dangerous geological processes in permafrost. Design and construction of well pads in permafrost zones have some special features. The main objective is to minimize the influence of different heat sources (engineering objects) inserted into permafrost and accounting long-term forecast of development of permafrost degradation due to different factors in particular generated by human activity. In this work on the basis a mathematical model and numerical algorithms approved on 11 northern oil and gas fields some effects obtained by carrying out numerical simulations for various engineering systems are discussed.

  18. Alexander Kratochvil. Aufbruch und Rückkehr: Ukrainische und tschechische Prosa im Zeichen der Postmoderne.

    Directory of Open Access Journals (Sweden)

    Marko Pavlyshyn

    2015-01-01

    Full Text Available Alexander Kratochvil. Aufbruch und Rückkehr: Ukrainische und tschechische Prosa im Zeichen der Postmoderne. [Venturing Forth and Coming Back: Ukrainian and Czech Prose in the Context of Postmodernity.] Berlin: Kulturverlag Kadmos, 2013. 311 pp. Bibliography. Index. Paper.

  19. Planning, installation and use of ventilation systems for smoke and heat removal. Cooperation between architects, planners, and builder-owners; Planung, Einbau und Anwendung von Rauch- und Waermeabzugsanlagen. Zusammenwirken zwischen Architekt, Planer und Bauherr

    Energy Technology Data Exchange (ETDEWEB)

    Koschnitzki, K. [Duisburg Univ. (Germany). Inst. fuer Anlagenplanung und Systemtechnik; Berg, M. [e.t.s. Umwelt- und Sicherheitstechnik GmbH, Kleve (Germany)

    1998-05-01

    Cooperation between planners, builder-owners and technical experts is important for efficient fire prevention. This involves ventilation systems for smoke and heat removal as well as other safety components. Legal regulations must be implemented so as to obtain a fire protection concept with defined goals and to achieve maximum protection of furniture and inhabitants. (orig.) [Deutsch] Bei der Umsetzung von Brandschutzkonzepten in der Gebaeude- und Anlagenplanung ist das gemeinsame Vorgehen von Planer, Bauherr und Fachunternehmen von elementarer Wichtigkeit fuer ein ausgereiftes Sicherheitskonzept. Hierzu gehoeren Rauch- und Waermeabzugsanlagen und weitergehende sicherheitstechnische Komponenten. Auflagen und behoerdliche Bestimmungen sind so umzusetzen, dass ein Brandschutzkonzept mit definierten Schutzzielen entsteht. Fuer den Bauherrn soll ein maximaler Sachwert- und Personenschutz gewaehrleistet sein. (orig.)

  20. Einfluss von Hypothyreose und Mukoviszidose auf das Ruhe- und Belastungs-EKG

    OpenAIRE

    Gerlach, Julia

    2009-01-01

    Bei Menschen, die an cystischer Fibrose oder auch an einer Hypothyreose erkrankt sind, ist die Beteiligung des Herz-Kreislauf-Systems eine bekannte Komplikation. Ziel dieser Arbeit war, möglicherweise bislang unbekannte Auswirkungen dieser Erkrankungen auf das Belastungs-EKG von Kindern und Jugendlichen zu identifizieren und ggf. zu deuten. Dadurch sollte die Beurteilbarkeit des Belastungs-EKGs bei der Untersuchung der genannten Patientengruppen verbessert werden. Es wurden insgesamt 64 Patie...

  1. Verletzungen und Fehlbeanspruchungen im leistungsorientierten Rudersport

    OpenAIRE

    Bussian, Marc Robert

    2004-01-01

    Die Stellung der Breitensportart Rudern als gesundheitsfördernde Sportform ist in der Literatur gleichlautend positiv beschrieben. Im leistungsorientierten Rudersport müssen neben den Verletzungen und Fehlbeanspruchungen der eigentlichen Sportart die unabdingbaren Nebentrainingsformen berücksichtigt werden. In den neunziger Jahren vollzog sich ein trainingsmethodischer Wandel, die Einführung eines erschwinglichen Rudersimulators und eine technische Weiterentwicklung im Boots- und Ruderbau. Ei...

  2. Silage seepage and water protection. Production and recovery of silage seepage from animal feed and biomass for biogas plants. 7. ed.; Silagesickersaft und Gewaesserschutz. Anfall und Verwertung von Silagesickersaft aus Futtermitteln und Biomasse fuer Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Spiekers, Hubert [Bayerische Landesanstalt fuer Landwirtschaft (LfL), Freising-Weihenstephan (Germany); Attenberger, Erwin [Bayerisches Landesamt fuer Umwelt, Augsburg (Germany)

    2012-11-15

    The production of silage is now standard and an important basis for a successful milk and beef production. Silage is also needed in agricultural biogas plants as a substrate for energy production. This publication is intended to serve agriculture as a source of information and guidance document for the construction and operation of silos and the administration as an orientating work aid. The factors influencing the accumulation of silage seepage and the possibilities of prevention in silage and silage management are presented and evaluated from environmental and legal perspective. [German] Die Produktion von Silage ist heute Standard und eine wichtige Grundlage fuer eine erfolgreiche Milch- und Rindfleischerzeugung. Silage wird auch in landwirtschaftlichen Biogasanlagen als Substrat zur Energieerzeugung benoetigt. Die vorliegende Publikation soll der Landwirtschaft als Informationsquelle und Handlungsanleitung fuer den Bau und Betrieb von Siloanlagen und der Verwaltung als orientierende Arbeitshilfe dienen. Die Einflussgroessen auf den Anfall an Sickersaeften und die Moeglichkeiten der Vermeidung bei der Silierung und dem Silagemanagement werden dargestellt und aus umwelt- und rechtlicher Sicht bewertet.

  3. Zur medienpädagogischen Ausbildung von Lehrerinnen und Lehrern. Folgerungen aus der aktuellen lern- und professionstheoretischen Diskussion

    Directory of Open Access Journals (Sweden)

    Sigrid Blömeke

    2001-08-01

    Full Text Available Vor dem Hintergrund neuerer Ansätze in der Lerntheorie und in der Professionstheorie werden Folgerungen für die inhaltliche und die didaktisch- methodische Gestaltung der medienpädagogischen Lehrerausbildung gezogen. Dafür wird in einem ersten Schritt die Frage des Verhältnisses von Wissen und Handeln geklärt und der Wissenserwerb wird als aktiv-konstruierender Prozess beschrieben. Die in diesem Zusammenhang herausgearbeiteten grundsätzlichen Gestaltungsprinzipien werden dann in einem zweiten Schritt auf der Basis einer an den Aufgaben von Lehrerinnen und Lehrern orientierten näheren Bestimmung medienpädagogischer Kompetenz für den Erwerb dieser konkretisiert. In inhaltlich-systematischer Hinsicht steht die kognitive Strukturbildung im Vordergrund, in didaktisch-methodischer Hinsicht wird ein besonderer Akzent auf Fallarbeit gelegt, deren Möglichkeiten auch an-hand eines Beispiels verdeutlicht werden.

  4. Permafrost carbon−climate feedback is sensitive to deep soil carbon decomposability but not deep soil nitrogen dynamics

    Science.gov (United States)

    Koven, Charles D.; Lawrence, David M.; Riley, William J.

    2015-01-01

    Permafrost soils contain enormous amounts of organic carbon whose stability is contingent on remaining frozen. With future warming, these soils may release carbon to the atmosphere and act as a positive feedback to climate change. Significant uncertainty remains on the postthaw carbon dynamics of permafrost-affected ecosystems, in particular since most of the carbon resides at depth where decomposition dynamics may differ from surface soils, and since nitrogen mineralized by decomposition may enhance plant growth. Here we show, using a carbon−nitrogen model that includes permafrost processes forced in an unmitigated warming scenario, that the future carbon balance of the permafrost region is highly sensitive to the decomposability of deeper carbon, with the net balance ranging from 21 Pg C to 164 Pg C losses by 2300. Increased soil nitrogen mineralization reduces nutrient limitations, but the impact of deep nitrogen on the carbon budget is small due to enhanced nitrogen availability from warming surface soils and seasonal asynchrony between deeper nitrogen availability and plant nitrogen demands. Although nitrogen dynamics are highly uncertain, the future carbon balance of this region is projected to hinge more on the rate and extent of permafrost thaw and soil decomposition than on enhanced nitrogen availability for vegetation growth resulting from permafrost thaw. PMID:25775603

  5. Einleitung: Jahrbuch Medienpädagogik 5. Evaluation und Analyse

    Directory of Open Access Journals (Sweden)

    Ben Bachmair

    2017-09-01

    Full Text Available Evaluationsmethoden für E-Learning, Forschungsmethoden zur Mediennutzung und zur Analyse von Medienkulturen sind Gegenstand dieses Jahrbuchs Medienpädagogik. Dabei reicht das Spektrum der Medien von Fernsehen über Video bis zum Internet. Die Auswahl dieses Themenschwerpunkts kommt dabei nicht von ungefähr. Zum einen hat wissenschaftliche Medienforschung bereits eine lange Tradition und ist in vielen Disziplinen etabliert. Forschungsmethoden lieferten der medienpädagogischen Praxis empirisch fundierte Ergebnisse und Instrumente. Forschungsdesigns und Methodologien wurden entwickelt, um Mediennutzungsverhalten und Medienwirkungen zu erklären, Evaluationsmethoden eingesetzt, um Lernprozesse zu beurteilen. Zum anderen gewinnen Qualitätssicherung und Leistungsmessungen im Bildungssystem generell immer mehr an Bedeutung. In den Ergebnissen aktueller Evaluationen zeigen sich Bestrebungen nach Qualität von Bildungs- und Lernprozessen. Empirische Forschung kommt die Aufgabe zu medienpädagogische Wirkungsgrade und Zielerreichung zu überprüfen und zu kontrollieren. Quantitative Forschungsmethoden ermöglichen es Mediennutzungsverhalten bestimmter Zielgruppen in Wechselwirkung mit Programmstrukturen und -inhalten zu ermitteln. Nutzungsmuster von Medienangeboten – vor allem bei Kindern und Jugendlichen – sind auch bei der Entwicklung medienpädagogischer Ansätze wichtig. Qualitative Medienforschung dient als Planungsinstrument für medienpädagogische Konzeptionen sowie für medienpädagogische Praxis und hilft bei der Entwicklung neuer, mehr als bisher an inhaltlichen Kriterien orientierter Angebote eingesetzt werden. Eine der zentralen Fragestellungen war und ist dabei, mit welchen kognitiven und ästhetischen Vermittlungsformen die Inhalte einer Sendung am besten kommuniziert werden können. Dies ist zugleich eine der Grundfragen im Hinblick auf den Medieneinsatz in pädagogisch orientierten Lernprozessen (vgl. Dichanz 1998.

  6. Sprachvermittlung und Spracherwerb in Afrika. Deutsch nach ...

    African Journals Online (AJOL)

    erlernende Fremdsprache richtig und auf hohem Niveau sprechen zu lernen. Lehrende sollten alles daransetzen zu verhindern, dass die Lernenden in dieser Vereinfachungsphase stehen bleiben und ihre Sprache fossilieren. Die Bewusstmachung der Ähnlichkeiten von Zulu und. Deutsch kann dazu beitragen, indem man ...

  7. Herstellung und Charakterisierung von Li-Schwefel-Kathoden durch in-situ XRD, Impedanzspektroskopie und AFM-Messungen

    OpenAIRE

    Wagner, Norbert; Canas, Natalia; Hiesgen, Renate; Pascucci, Brigitta; Friedrich, K. Andreas

    2013-01-01

    Derzeit ist das wissenschaftliche und kommerzielle Interesse an der Entwicklung von Lithium-Schwefel Batterien sehr groß. Besondere Eigenschaften dieser Batte-rien sind, unter anderem, die hohe theoretische Energiedichte (2600 Wh/kg bzw. 2800 Wh/l) und Kapazität des Schwefels (1675 mAh/g), sowie das geringe Gewicht und die gute Verfügbarkeit von Schwefel als Ausgangsstoff für die Batterieherstel-lung. Um diese Werte auch in der Praxis zu erreichen, wird an der Optimierung der Nutzung des Akti...

  8. Leveraging Subsidence in Permafrost with Remotely Sensed Active Layer Thickness (ReSALT) Products

    Science.gov (United States)

    Schaefer, K. M.; Chen, A.; Chen, J.; Chen, R. H.; Liu, L.; Michaelides, R. J.; Moghaddam, M.; Parsekian, A.; Tabatabaeenejad, A.; Thompson, J. A.; Zebker, H. A.; Meyer, F. J.

    2017-12-01

    The Remotely Sensed Active Layer Thickness (ReSALT) product uses the Interferometric Synthetic Aperture Radar (InSAR) technique to measure ground subsidence in permafrost regions. Seasonal subsidence results from the expansion of soil water into ice as the surface soil or active layer freezes and thaws each year. Subsidence trends result from large-scale thaw of permafrost and from the melting and subsequent drainage of excess ground ice in permafrost-affected soils. The attached figure shows the 2006-2010 average seasonal subsidence from ReSALT around Barrow, Alaska. The average active layer thickness (the maximum surface thaw depth during summer) is 30-40 cm, resulting in an average seasonal subsidence of 1-3 cm. Analysis of the seasonal subsidence and subsidence trends provides valuable insights into important permafrost processes, such as the freeze/thaw of the active layer, large-scale thawing due to climate change, the impact of fire, and infrastructure vulnerability. ReSALT supports the Arctic-Boreal Vulnerability Experiment (ABoVE) field campaign in Alaska and northwest Canada and is a precursor for a potential NASA-ISRO Synthetic Aperture Radar (NISAR) product. ReSALT includes uncertainties for all parameters and is validated against in situ measurements from the Circumpolar Active Layer Monitoring (CALM) network, Ground Penetrating Radar and mechanical probe measurements. Here we present examples of ReSALT products in Alaska to highlight the untapped potential of the InSAR technique to understand permafrost dynamics, with a strong emphasis on the underlying processes that drive the subsidence.

  9. A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback.

    Science.gov (United States)

    Koven, C D; Schuur, E A G; Schädel, C; Bohn, T J; Burke, E J; Chen, G; Chen, X; Ciais, P; Grosse, G; Harden, J W; Hayes, D J; Hugelius, G; Jafarov, E E; Krinner, G; Kuhry, P; Lawrence, D M; MacDougall, A H; Marchenko, S S; McGuire, A D; Natali, S M; Nicolsky, D J; Olefeldt, D; Peng, S; Romanovsky, V E; Schaefer, K M; Strauss, J; Treat, C C; Turetsky, M

    2015-11-13

    We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a three-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100. Under a medium warming scenario (RCP4.5), the approach projects permafrost soil C losses of 12.2-33.4 Pg C; under a high warming scenario (RCP8.5), the approach projects C losses of 27.9-112.6 Pg C. Projected C losses are roughly linearly proportional to global temperature changes across the two scenarios. These results indicate a global sensitivity of frozen soil C to climate change (γ sensitivity) of -14 to -19 Pg C °C(-1) on a 100 year time scale. For CH4 emissions, our approach assumes a fixed saturated area and that increases in CH4 emissions are related to increased heterotrophic respiration in anoxic soil, yielding CH4 emission increases of 7% and 35% for the RCP4.5 and RCP8.5 scenarios, respectively, which add an additional greenhouse gas forcing of approximately 10-18%. The simplified approach

  10. Influence of permafrost on lake terraces of Lake Heihai (NE Tibetan Plateau)

    Science.gov (United States)

    Lockot, Gregori; Hartmann, Kai; Wünnemann, Bernd

    2013-04-01

    The Tibetan Plateau (TP) is one of the key regions for climatic global change. Besides the poles the TP is the third highest storage of frozen water in glaciers. Here global warming is three times higher than in the rest of the world. Additionally the TP provides water for billions of people and influences the moisture availability from the Indian and East Asian monsoon systems. During the Holocene extent and intensity of the monsoonal systems changed. Hence, in the last decades, a lot of work was done to reconstruct timing and frequency of monsoonal moisture, to understand the past and give a better forecast for the future. Comparative workings often show very heterogeneous patterns of timing and frequency of the Holocene precipitation and temperature maximum, emphasizing the local importance of catchment dynamics. In this study we present first results of lake Heihai (36°N, 93°15'E, 4500m a.s.l.), situated at the north-eastern border of the TP. The lake is surrounded by a broad band of near-shore lake sediments, attesting a larger lake extent in the past. These sediments were uplifted by permafrost, reaching nowadays heights ca. +8 meters above present lake level. Due to the uplift one of the main inflows was blocked and the whole hydrology of the catchment changed. To quantify the uplift of permafrost Hot Spot Analysis were accomplished at a DEM of the near-shore area. As a result regions of high permafrost uplift and those which mirror the original height of lake ground were revealed. The most obvious uplift took place in the northern and western part of the lake, where the four uplift centers are located. In contrast the southern and eastern areas show a rather degraded pattern (probably by fluvial erosion, thermokarst, etc.). The ancient lake bottom, without permafrost uplift was estimated to be 4-6 meters above the modern lake level. For a better understanding of permafrost interaction inside the terrace bodies a 5m sediment profile was sampled and

  11. Aggregation und Management von Metadaten im Kontext von Europeana

    Directory of Open Access Journals (Sweden)

    Gerda Koch

    2017-09-01

    Full Text Available Mit dem In-Beziehung-Setzen und Verlinken von Daten im Internet wird der Weg zur Umsetzung des semantischen Webs geebnet. Erst die semantische Verbindung von heterogenen Datenbeständen ermöglicht übergreifende Suchvorgänge und späteres „Machine Learning“. Im Artikel werden die Aktivitäten der Europäischen Digitalen Bibliothek im Bereich des Metadatenmanagements und der semantischen Verlinkung von Daten skizziert. Dabei wird einerseits ein kurzer Überblick zu aktuellen Forschungsschwerpunkten und Umsetzungsstrategien gegeben, und darüber hinaus werden einzelne Projekte und maßgeschneiderte Serviceangebote für naturhistorische Daten, regionale Kultureinrichtungen und Audiosammlungen beschrieben.

  12. Response characteristics of vegetation and soil environment to permafrost degradation in the upstream regions of the Shule River Basin

    International Nuclear Information System (INIS)

    Chen Shengyun; Liu Wenjie; Qin Xiang; Liu Yushuo; Ren Jiawen; Qin Dahe; Zhang Tongzuo; Hu Fengzu; Chen Kelong

    2012-01-01

    Permafrost degradation exhibits striking and profound influences on the alpine ecosystem, and response characteristics of vegetation and soil environment to such degradation inevitably differ during the entire degraded periods. However, up to now, the related research is lacking in the Qinghai–Tibetan Plateau (QTP). For this reason, twenty ecological plots in the different types of permafrost zones were selected in the upstream regions of the Shule River Basin on the northeastern margin of the QTP. Vegetation characteristics (species diversity, community coverage and biomass etc) and topsoil environment (temperature (ST), water content (SW), mechanical composition (SMC), culturable microorganism (SCM), organic carbon (SOC) and total nitrogen (TN) contents and so on), as well as active layer thickness (ALT) were investigated in late July 2009 and 2010. A spatial–temporal shifts method (the spatial pattern that is represented by different types of permafrost shifting to the temporal series that stands for different stages of permafrost degradation) has been used to discuss response characteristics of vegetation and topsoil environment throughout the entire permafrost degradation. The results showed that (1) ST of 0–40 cm depth and ALT gradually increased from highly stable and stable permafrost (H-SP) to unstable permafrost (UP). SW increased initially and then decreased, and SOC content and the quantities of SCM at a depth of 0–20 cm first decreased and then increased, whereas TN content and SMC showed obscure trends throughout the stages of permafrost degradation with a stability decline from H-SP to extremely unstable permafrost (EUP); (2) further, species diversity, community coverage and biomass first increased and then decreased in the stages from H-SP to EUP; (3) in the alpine meadow ecosystem, SOC and TN contents increased initially and then decreased, soil sandy fractions gradually increased with stages of permafrost degradation from substable (SSP

  13. Nitrogen availability drives priming effect by altering microbial carbon-use efficiency after permafrost thaw

    Science.gov (United States)

    Chen, L.; Liu, L.; Zhang, Q.; Mao, C.; Liu, F.; Yang, Y.

    2017-12-01

    Enhanced vegetation growth can potentially aggravate soil C loss by accelerating the decomposition of soil organic matter (SOM) ("priming effect"), thereby reinforcing the positive C-climate feedback in permafrost ecosystems. However, the degree to which priming effect alters permafrost C dynamics is expected to be modified by nitrogen (N) availability after permafrost thaw. Despite this recognition, experimental evidence for the linkage between priming effect and post-thaw N availability is still lacking. Particularly, the microbial mechanisms involved remain unknown. Here, using a thermokarst-induced natural N gradient combined with an isotope-labeled glucose and N addition experiment, we presented a strong linkage between soil N availability and priming effect in Tibetan permafrost. We observed that the magnitude of priming effect along the thaw gradient was negatively associated with soil total dissolved nitrogen (TDN) concentration. This negative effect of post-thaw N availability was further proved by a sharply reduced priming effect following mineral N supply. These two lines of evidence jointly illustrated that the priming effect along the thaw chronosequence was controlled by N availability, supporting the `N mining theory'. In contrast to the prevailing assumption, this N-regulated priming effect was independent from changes in C- or N-acquiring enzyme activities, but positively associated with the change in metabolic quotients (△SOM-qCO2), highlighting that decreased microbial metabolism efficiency rather than increased enzyme activities account for greater priming effect under reduced N availability. Taken together, these findings demonstrate that C dynamics in melting permafrost largely depends on post-thaw N availability due to its effect of retarding SOM mineralization. This C-N interaction and the relevant microbial metabolic efficiency should be considered in Earth System Models for a better understanding of soil C dynamics after permafrost thaw.

  14. Searching for eukaryotic life preserved in Antarctic permafrost

    DEFF Research Database (Denmark)

    Zucconi, L.; Selbmann, L.; Buzzini, P.

    2012-01-01

    Fungi and yeasts isolated in pure culture from Antarctic permafrost collected at different depths in the McMurdo Dry Valleys were identified with cultural, physiological and molecular methods. Fungi belonged to the genera Penicillium, Eurotium, Cladosporium, Alternaria, Engyodonthium, Aureobasidium...

  15. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    OpenAIRE

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward; Carrivick, Jonathan L.; Woulds, Clare; Raby, Cassandra; Mullan, Donal; Roland, Thomas P.; Galloway, Jennifer M.; Parry, Lauren; Kokfelt, Ulla; Garneau, Michelle; Charman, Dan J.; Holden, Joseph

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (~ 200 km north of the Arctic Circle). Multivariate statistical analysis confirms that water-table depth and moisture content are the dominant controls on the distribution of testate amoebae, corroborating the results from studies in mid-latitude peatlands. We present a ne...

  16. Effects of permafrost degradation on alpine grassland in a semi-arid basin on the Qinghai–Tibetan Plateau

    International Nuclear Information System (INIS)

    Yi Shuhua; Zhou Zhaoye; Ren Shilong; Xu Ming; Qin Yu; Chen Shengyun; Ye Baisheng

    2011-01-01

    Permafrost on the Qinghai–Tibetan Plateau (QTP) has degraded over the last few decades. Its ecological effects have attracted great concern. Previous studies focused mostly at plot scale, and hypothesized that degradation of permafrost would cause lowering of the water table and drying of shallow soil and then degradation of alpine grassland. However, none has been done to test the hypothesis at basin scale. In this study, for the first time, we investigated the relationships between land surface temperature (LST) and fractional vegetation cover (FVC) in different types of permafrost zone to infer the limiting condition (water or energy) of grassland growth on the source region of Shule River Basin, which is located in the north-eastern edge of the QTP. LST was obtained from MODIS Aqua products at 1 km resolution, while FVC was upscaled from quadrat (50 cm) to the same resolution as LST, using 30 m resolution NDVI data of the Chinese HJ satellite. FVC at quadrat scale was estimated by analyzing pictures taken with a multi-spectral camera. Results showed that (1) retrieval of FVC at quadrat scale using a multi-spectral camera was both more accurate and more efficient than conventional methods and (2) the limiting factor of vegetation growth transitioned from energy in the extreme stable permafrost zone to water in the seasonal frost zone. Our study suggested that alpine grassland would respond differently to permafrost degradation in different types of permafrost zone. Future studies should consider overall effects of permafrost degradation, and avoid the shortcomings of existing studies, which focus too much on the adverse effects.

  17. Erfahrungen an der Schnittstelle von Medienarbeit und Praxisforschung

    Directory of Open Access Journals (Sweden)

    Peter Holzwarth

    2007-11-01

    Full Text Available Der Beitrag reflektiert die Verbindung von praktischer Medienarbeit und Forschung am Beispiel eines internationalen EU-Forschungsprojekts zum Thema Medien und Migration. Neben didaktischen Prinzipien und Konzepten für die aktive Medienarbeit im Forschungskontext geht es um die Kooperation von medienpädagogischer Begleitung (MB und wissenschaftlicher Begleitung (WB sowie um deren spezifische Kompetenzen.

  18. Permafrost investigations at the Lake Hövsgöl, northern Mongolia, using DC resistivity tomography and DEM-analyses

    Science.gov (United States)

    Etzelmuller, B.; Heggem, E. S. F.; Frauenfelder, R.; Romanovsky, V.; Sharkhuu, N.; Jambaljav, Y.; Tumensetseg, S.; Kääb, A.; Goulden, C.

    2003-04-01

    The region of Lake Hövsgöl, northern Mongolia, lies at the southern edge of Siberia and forms the southern-most fringe of the Siberian continuous permafrost zone. Analysis of long-term temperature data from the area indicates that annual temperatures have warmed by about 1.5^oC over the last 40 years. Being at the southern fringe of permafrost existence, temperature changes are supposed to have a major impact on permafrost degradation and thus on the environment, in interaction with human activities like nomadic pasture use. The objective of this study is to define the distribution of permafrost and the depth of the active zones in detail, and to begin a monitoring program of soil and permafrost temperatures in the study area. During these studies (a) field measurements of ground temperature, (b) analyses of geophysical parameters (mainly ground resistivities), and (c) the generation and analyses of digital elevation models and satellite imagery were carried out. The field measurements provided the basis for the later development of statistical/empirical and physical models of the permafrost distribution in the Hövsgöl area. This presentation will focus on the DC-resistivity tomography mapping of permafrost and digital elevation model analyses. The study showed that DC resistivity tomography was useful to distinguish the active layer and permafrost thickness under different types of surface cover. The project is funded by a five-year grant from the Global Environment Facility to the Mongolian Academy of Sciences (MAS), implemented by the World Bank and a foundation of the Mongolian Long Term Ecological Research Program at Lake Hövsgöl.

  19. Northern Peatland Shifts Under Changing Climate and Their Impact on Permafrost

    Science.gov (United States)

    Shur, Y.; Jorgenson, T.; Kanevskiy, M. Z.

    2014-12-01

    Formation of peatlands depends primarily on climate and its interactions with hydrology, soil thermal regimes, plant composition, and nutrients. A water balance with precipitation exceeding evaporation is necessary for their formation. The rate of peat accumulation also greatly depends on thermal resources. The prominent impact of the water balance and temperature on peatland formation is evident in the West Siberia Lowland. The rate of peat accumulation steadily increases from arctic tundra to moss tundra, to forest tundra, to northern taiga, and to southern taiga. This increase is a result in increase in air temperature and length of the growing season because all of these zones have water balance favorable for peat formation. Further to south, evaporation prevails over precipitation and peat formation occurs only in isolated areas. Climate change will redefine geographical distribution of climatic and vegetation zones. It is predicted that in arctic and subarctic regions the difference between precipitation and evaporation will increase and as a result these regions will remain favorable to peat accumulation. With increase of thermal resources, the rate of peat accumulation will also increase. The Alaska Arctic Coastal Plain is of a special interest because it has thousands of shallow lakes, which due to warming climate would shift from open waterbodies to peatlands through shoreline paludification and infilling. The accumulation of organic matter will likely turn open water into shore fens and bogs, and eventually to peat plateaus, as is occurring in many boreal landscapes. Expected impact on permafrost in arctic and subarctic regions will include rise of the permafrost table, thickening of the ice-rich intermediate layer with ataxitic (suspended) cryostructure, and replacement of frost boils with earth hummocks. In the contemporary continuous permafrost zone, permafrost formed as climate-driven will be transformed into climate-driven ecosystem protected

  20. Biodegradability of dissolved organic carbon in permafrost soils and waterways: a meta-analysis

    Science.gov (United States)

    Vonk, J. E.; Tank, S. E.; Mann, P. J.; Spencer, R. G. M.; Treat, C. C.; Striegl, R. G.; Abbott, B. W.; Wickland, K. P.

    2015-06-01

    As Arctic regions warm, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to thaw and decomposition. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the reactivity and subsequent fate of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism and its biodegradability will determine the extent and rate of carbon release from aquatic ecosystems to the atmosphere. Knowledge of the mechanistic controls on DOC biodegradability is however currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences used as common practice in the literature. We further synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-Arctic trends in BDOC. An increasing extent of permafrost across the landscape resulted in higher BDOC losses in both soil and aquatic systems. We hypothesize that the unique composition of permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively shorter flow path lengths and transport times, resulted in higher overall terrestrial and freshwater BDOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January-December) decrease in BDOC losses in large streams and rivers, but no apparent change in smaller streams and soil leachates. We attribute this seasonal change to a combination of factors including

  1. Ulrich Richentals Chronik des Konstanzer Konzils und ihre Funktionalisierung im 15. und 16. Jahrhundert : Aspekte zur Rekonstruktion der Urschrift und zu den Wirkungsabsichten der überlieferten Handschriften und Drucke

    OpenAIRE

    Wacker, Gisela

    2001-01-01

    Dok. 1: Textteil Dok. 2: Bildteil (hohe Qualität) Dok. 3: Bildteil (geringe Qualität) ********************************* Die Untersuchung der Handschriften von Richentals Konzilschronik und von Nachrichten über ein verlorenes Manuskript beweisen, daß das verlorene Original eine Aktensammlung zum Konstanzer Konzil mit angehängtem Abbildungsteil war. Die Kontakte des Autors, seine Quellenkenntnis und die Vermarktung seiner Konzilsgeschichte in verschiedenen Versionen ...

  2. Einflüsse von Computer- und Mediennutzung auf die Persönlichkeitsentwicklung von Kindern und Jugendlichen

    OpenAIRE

    Süss, Daniel

    2007-01-01

    Kinder und Jugendliche entwickeln ihre Persönlichkeit in aktiver Auseinandersetzung mit Medien. Medienkompetenz ist zu einer Entwicklungsaufgabe geworden. Zugleich verändern die Medien die allgemeinen Sozialisationsprozesse wie die Integration in die Peergroup und die Ablösung von den Eltern. Medien können sowohl als Ressourcen wie auch als Risiken für die Entwicklung wirksam werden. Empirische Studien zeigen, dass Kinder einen immer reichhaltigeren Medienzugang haben und viel Zeit mit Bildsc...

  3. Drucken Images und mediale Diskurse über afrikanischen Fußball: Paternalismus, Rassismus und neoliberale Bewunderung

    Directory of Open Access Journals (Sweden)

    Kurt Wachter

    2010-03-01

    Full Text Available Die Wahrnehmung des afrikanischen Fußballs und seiner Spieler war und ist sowohl in den Stadien wie in den medialen Darstellungen von rassistischen Images aus der Zeit Kolonialismus geprägt. Der speziell in Europa konstatierbare Aufstieg des afrikanischen Fußballs im Zuge der Ökonomisierung und Globalisierung des Spiels brachte zwar neue Superstars hervor, alte Stereotype leben aber vor Ort wie im medialen Diskurs in transformierter Weise fort.

  4. Sustainability and social benefits of the planning of green areas and landscape planning versus their curteilment. Lifestyles as a challenge to, and an opportunity for, economy; Wirtschaft, Wissenschaft und Umwelt. Bd. 7. Nachhaltigkeit und gesellschaftlicher Nutzen von Gruenordnungsplanung und Landschaftsplanung kontra Reduktion. - Lebensstile als Herausforderung und Chance fuer die Wirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    The book contains the lecture series given within the framework of the 7th Economy Forum ``Economy, science and environment``, organized jointly by the Zentralstelle fuer Forschungs- und Entwicklungstransfer und Wissenschaftliche Weiterbildung (FET and WW) of Essen University and the chamber of industry and trade for Essen, Muelheim/Ruhr and Oberhausen in Essen. The lectures were delivered at the following events at the Essen University: `Sustainability and social benefits of the planning of green areas and landscapes versus their curtailment` (5 June 1997); and `Lifestyles as a challenge to and an opportunity for economy` (13 November 1997). (orig.) [Deutsch] Der Bericht gibt die Vortraege der Veranstaltungsreihe Wirtschaftsforum VII `Wirtschaft, Wissenschaft und Umwelt` wieder, veranstaltet von der FET and WW Zentralstelle fuer Forschungs- und Entwicklungstransfer und Wissenschaftliche Weiterbildung der Universitaet-GH Essen in Zusammenarbeit mit der Industrie- und Handelskammer fuer Essen, Muelheim an der Ruhr, Oberhausen zu Essen. Die Vortraege sind auf folgenden Veranstaltungen an der Universitaet-GH Essen gehalten worden:`Nachhaltigkeit und gesellschaftlicher Nutzen von Gruenordnungsplanung und Landschaftsplanung kontra Reduktion` am 5. Juni 1997 und `Lebensstile als Herausforderung und Chance fuer die Wirtschaft` am 13. November 1997. (orig.)

  5. Osteoporose und Genetik des Knochenstoffwechsels

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2002-01-01

    Full Text Available Osteoporose ist in hohem Maß genetisch determiniert. Neue Wege der molekularbiologischen Forschung haben sich in den letzten Jahren auf diesem Gebiet etabliert. "Gene mapping" mit polymorphen genetischen Markern auf der Suche nach Phänotyp-assoziierten Genen ist ein aufwendiges, aber vielversprechendes Verfahren und wird durch die Erkenntnisse des Human Genome Projects beschleunigt. So wurde jüngst u. a. das Low-density Lipoprotein 5-Gen als wichtig für den Knochenstoffwechsel identifiziert. Kandidaten-gene wie Hormonrezeptor-, Cytokin- oder Kollagen-Gene werden hinsichtlich ihrer Gen-Gen- und Gen-Umwelt- Interaktionen untersucht und erlauben neue funktionelle Einsichten in Erkrankungen des Knochenstoffwechsels. Mutationen der Kollagen-Gene sind bei einigen seltenen Erkrankungen, wie dem Osteoporose-Pseudogliom-Syndrom oder der Osteogenesis imperfecta gefunden worden, könnten aber auch für häufige Varianten von Bindegewebsstörungen wie der congenitalen Hüftdysplasie verantwortlich sein, die etwa 10 % der weiblichen kaukasischen Bevölkerung in unterschiedlichem Ausmaß betrifft. Osteoporose am Schenkelhals und erhöhte Gelenkslaxizität sowie andere generalisierte Veränderungen des Knochen- und Kollagenstoffwechsels können hier möglicherweise ebenfalls durch Störungen des Kollagen I alpha 1-Gens erklärt werden. In Summe können wir zahlreiche neue Einsichten in die Pathophysiologie des Skelettsystems erwarten, die uns auch neue Zugangswege für Diagnostik und Therapie unserer Patienten ermöglichen werden.

  6. Hegel und die Opferung der Philosophie: Dialektik der Ästhetik und Politik

    Directory of Open Access Journals (Sweden)

    Jovanov Rastko

    2013-01-01

    Full Text Available Dem Aufsatz liegen folgende Fragen zugrunde: Ist es gerechtfertigt, vom Erbe der tragischen Darstellung des Kampfes im Hegelschen Begriff der Philosophie und insbesondere in seiner Konzeption der Dialektik als Bewegung und Geschichtlichkeit des absoluten Geistes zu sprechen? Hat der Versöhnungsbegriff Hegels, der am konkretesten innerhalb des philosophischen Gedankens ausgeführt wird, bestimmte Folgen auch für den Begriff der Philosophie selber? Opfert sich die Philosophie einer endlichen Äußerlichkeit oder bedarf sie selbst eines Opfers, um das philosophische System als solches zu vervollständigen? Kann man auch heutzutage die geschichtlich-politischen Ereignisse und die Vergehen des Rechts als tragisch darstellen und betrachten? Vermag es die Politik noch immer (wie in der Moderne, die Rolle des Schicksals in der griechischen Tragödie zu übernehmen? Auf solche Fragen werden hier keine endgültigen Antworten gegeben, es wird vielmehr der Rahmen für weitere Betrachtungen bereitgestellt - innerhalb oder außerhalb der Philosophie Hegels. [Projekat Ministarstva nauke Republike Srbije, br. 179049: Politike društvenog pamćenja i nacionalnog identiteta: regionalni i evropski kontekst

  7. Wenn Edusphäre und Blogosphäre sich treffen. Weblogs an Hochschulen zwischen Zitationskartell und Diskursrevolte

    Directory of Open Access Journals (Sweden)

    Stefanie Panke

    2012-03-01

    Full Text Available Der vorliegende Beitrag widmet sich dem Thema «Edublogging», also der Nutzung von Weblogs im Bildungsbereich, und fokussiert dabei auf den Hochschulsektor. Weblogs werden vielerorts als Instrument für die Lehre, aber auch als ­Diskussionsplattform im E-Learning-Forschungsdiskurs sowie als Mittel zur Öffentlichkeitsarbeit in E-Learning-Zentren und anderen Zentraleinrichtungen eingesetzt. Hinzu kommen Blogfarmen bzw. Multiblogs, die jedem und jeder Hochschulangehörigen mit wenigen Klicks die Einrichtung einer Weblog-Präsenz eröffnen. Entsprechend facettenreich präsentiert sich die Landschaft der Edublogs. Der Artikel beleuchtet das Phänomen «Edublogosphäre» durch eine umfangreiche Literatursichtung, Web-Recherchen, Inhaltsanalysen und Befragungen. Angestrebt wird eine Kartografie der vielfältigen Landschaft an Edublogs. Im Ergebnis werden Besonderheiten der Weblog-Strategien von E-Learning-Einrichtungen, bloggenden E-Learning-Wissenschaftlern/-innen, Blogfarmen und weiteren Einsatzformen in Hochschulbereich beschrieben.

  8. Molecular investigations into a globally important carbon pool: permafrost-protected carbon in Alaskan soils

    Science.gov (United States)

    M.P. Waldrop; K.P. Wickland; R. White; A.A. Berhe; J.W. Harden; V.E. Romanovsky

    2010-01-01

    The fate of carbon (C) contained within permafrost in boreal forest environments is an important consideration for the current and future carbon cycle as soils warm in northern latitudes. Currently, little is known about the microbiology or chemistry of permafrost soils that may affect its decomposition once soils thaw. We tested the hypothesis that low microbial...

  9. RANK und RANKL - Vom Knochen zum Mammakarzinom

    Directory of Open Access Journals (Sweden)

    Sigl V

    2012-01-01

    Full Text Available RANK („Receptor Activator of NF-κB“ und sein Ligand RANKL sind Schlüsselmoleküle im Knochenmetabolismus und spielen eine essenzielle Rolle in der Entstehung von pathologischen Knochenveränderungen. Die Deregulation des RANK/RANKL-Systems ist zum Beispiel ein Hauptgrund für das Auftreten von postmenopausaler Osteoporose bei Frauen. Eine weitere wesentliche Funktion von RANK und RANKL liegt in der Entwicklung von milchsekretierenden Drüsen während der Schwangerschaft. Dabei regulieren Sexualhormone, wie zum Beispiel Progesteron, die Expression von RANKL und induzieren dadurch die Proliferation von epithelialen Zellen der Brust. Seit Längerem war schon bekannt, dass RANK und RANKL in der Metastasenbildung von Brustkrebszellen im Knochengewebe beteiligt sind. Wir konnten nun das RANK/RANKLSystem auch als essenziellen Mechanismus in der Entstehung von hormonellem Brustkrebs identifizieren. In diesem Beitrag werden wir daher den neuesten Erkenntnissen besondere Aufmerksamkeit schenken und diese kritisch in Bezug auf Brustkrebsentwicklung betrachten.

  10. A ground temperature map of the North Atlantic permafrost region based on remote sensing and reanalysis data

    DEFF Research Database (Denmark)

    Westermann, S.; Østby, T. I.; Gisnås, K.

    2015-01-01

    Permafrost is a key element of the terrestrial cryosphere which makes mapping and monitoring of its state variables an imperative task. We present a modeling scheme based on remotely sensed land surface temperatures and reanalysis products from which mean annual ground temperatures (MAGT) can be ...... with gradually decreasing permafrost probabilities. The study exemplifies the unexploited potential of remotely sensed data sets in permafrost mapping if they are employed in multi-sensor multi-source data fusion approaches.......Permafrost is a key element of the terrestrial cryosphere which makes mapping and monitoring of its state variables an imperative task. We present a modeling scheme based on remotely sensed land surface temperatures and reanalysis products from which mean annual ground temperatures (MAGT) can...

  11. Environment and urbanism in West Africa. Contributions to waste management and recycling; Umwelt und Urbanitaet in Westafrika. Beitraege zur Muellverwertung und Abfallproblematik

    Energy Technology Data Exchange (ETDEWEB)

    Chevron, M F; Reinprecht, C [Vienna Univ. (Austria); Traore, G [Direction Nationale de l' Action Sociale, Bamako (Mali)

    2002-07-01

    Scientists of different disciplines (ethnology, sociology, economy, ecotechnology) and practical experts from Mali and Austria discuss urban development, environmental aspects and waste problems in the cities of West Africa. Activities of different groups (e.g. women) at the point of contact between traditional networks and modern institutions are discussed. The problems of waste, environment and hygiene are discussed in consideration of the different social, cultural and ethnic groups and interpretation patterns involved. Technical solutions are presented. [German] Wissenschaftler unterschiedlicher Disziplinen (Ethnologie, Soziologie, Oekonomie und Oekotechnologie) und Praktiker aus Mali und Oesterreich bechaeftigen sich mit aktuellen Aspekten der urbanen Entwicklung, der Umwelt und der Abfallproblematik in den Staedten Westafrikas. Es geht um die Rolle verschiedener Akteure in der Gesellschaft, insbesondere auch von Basisinitiativen und Frauengruppen, an der Schnittstelle von traditionellen Netzwerken und modernen Institutionen. Die Bewertungen von Abfall, Umwelt und Hygiene werden unter Beruecksichtigung der jeweiligen solzialen, kulturellen bzw. ethnischen Handlungskreise und Deutungsmuster diskutiert. Auch technische Loesungsvorschlaege werden vorgestellt. (orig.)

  12. Diagnose und Therapie einer Depression im höheren Lebensalter – Einflüsse von Patienten- und Arztmerkmalen

    Science.gov (United States)

    von dem Knesebeck, Olaf; Bönte, Markus; Siegrist, Johannes; Marceau, Lisa; Link, Carol; McKinlay, John

    2013-01-01

    Zusammenfassung Studienergebnissee aus dem englischsprachigen Raum zeigen, dass diagnostische und therapeutische Entscheidungen von Hausärzten bei der Versorgung von depressiven Patienten systematischen Einflüssen unterliegen, und dass sowohl Merkmale des Arztes als auch des Patienten unabhängig vom Krankheitsbild Einfluss auf diese Entscheidungen haben. In der vorliegenden Arbeit werden Ergebnisse einer deutschen Studie präsentiert, in der die Einflüsse von Patienten- und Arztmerkmalen auf diagnostische und therapeutische ärztliche Entscheidungen bei einer Depression untersucht wurden. Unter Anwendung eines faktoriellen Experimentaldesigns spielten professionelle Schauspieler in Videofilmen die Rolle von Patienten, die Symptome für eine depressive Erkrankung äußern. In den Videofilmen, die alle auf einem identischen Skript basieren, wurden systematisch die Patientenmerkmale Alter (55 vs. 75 Jahre), Geschlecht und sozialer Status (Hausmeister vs. Lehrer) variiert. Die randomisierte Ärztestichprobe wurde nach dem Arztgeschlecht und professioneller Erfahrung ( 15 Jahre) geschichtet. Der Videofilm wurde insgesamt 128 niedergelassenen Ärzten für Allgemeinmedizin und hausärztlich tätigen Internisten in ihrer Praxis vorgespielt. Danach wurden die Ärzte zu unterschiedlichen Aspekten von Diagnose und Therapie befragt. Es wurde erhoben, ob der Arzt dem Patienten über das gezeigte Gespräch hinausgehende Fragen stellen würde, welche Diagnosen er für wahrscheinlich hält, wie sicher er sich mit seiner Diagnose ist, welche diagnostischen Tests er anordnen würde, ob er den Patienten überweisen würde oder ob er Medikamente verordnen oder ihm Empfehlungen zur Änderung seines Lebensstils geben würde. Die Ergebnisse weisen darauf hin, dass sowohl die Diagnose als auch die Therapie einer Depression durch niedergelassene Hausärzte in Deutschland nur geringfügig durch die untersuchten Merkmale der Patienten und der behandelnden Ärzte beeinflusst wird. PMID

  13. Umfrageforschung: Entscheidungsgrundlage für Politik und Wissenschaft

    OpenAIRE

    2011-01-01

    "Der vorliegende Tagungsband dokumentiert die Beiträge der wissenschaftlichen Tagung 'Umfrageforschung - Entscheidungsgrundlage für Politik und Wissenschaft', die am 30. Juni und 1. Juli 2011 gemeinsam vom Statistischen Bundesamt, dem ADM Arbeitskreis Deutscher Markt- und Sozialforschungsinstitute e.V. und der Arbeitsgemeinschaft Sozialwissenschaftlicher Institute e.V. (ASI) in Wiesbaden durchgeführt wurde." (Autorenreferat). Inhaltsverzeichnis: Christian König, Matthias Stahl, Erich Wiegand:...

  14. Studienbegleitender und studienvorbereitender Deutschunterricht international: Einführung

    Directory of Open Access Journals (Sweden)

    Sabine Ylönen

    2015-04-01

    Full Text Available Studienbegleitender und studienvorbereitender Deutschunterricht an Universitäten und Hochschulen steht weltweit vor Herausforderungen, sich den Anforderungen des globalen Wissenschaftsbetriebs zu stellen. Zum einen ist die Bedeutung des Deutschen in den letzten Jahren dramatisch gesunken, zum anderen sind innovative didaktische Ansätze für den Deutschunterricht gefragt. In welcher Weise sich studienbegleitender und studienvorbereitender Deutschunterricht diesen Anforderungen im In- und Ausland stellen, wird in diesem Themaheft beleuchtet. An zehn Beiträgen aus unterschiedlichen Ländern wird unter anderem deutlich, wie aktive Sprachenpolitik durch strategische Investitionen einerseits und Engagement von DeutschlektorInnen andererseits die Entwicklung neuer Konzepte für den studienbegleitenden und studienvorbereitenden Deutschunterricht fördern können. Dietmar Röslers Beitrag Studienbegleitender Deutschunterricht in naturwissenschaftlich-technischen Studiengängen an Universitäten außerhalb des deutschsprachigen Raums bietet eine Übersicht über die Vielfalt unterschiedlicher Zielgruppen und Lernziele des sowie Einflussfaktoren auf den studienbegleitenden Deutschunterricht und die sich daraus ergebenden didaktischen Konsequenzen. Daniela Marks berichtet in ihrem Beitrag Prüfen sprachlicher Kompetenzen internationaler Studienanfänger an deutschen Hochschulen – Was leistet der TestDaF? über eine Studie zu den sprachlichen Anforderungen des TestDaF und macht Vorschläge für inhaltliche Schwerpunkte studienbegleitenden und -vorbereitenden Deutschunterrichts. Michael de Jong stellt in seinem Beitrag Modularer studienbegleitender Deutschunterricht zur Vorbereitung auf Studium und Praktikum in Deutschland am Beispiel der German-Jordanian University in Amman, Jordanien das „Leuchtturmprojekt“ der deutschen Auslandshochschulen vor und diskutiert die Herausforderungen und Bedarfe dieses transnationalen Bildungsprojekts

  15. Permafrost degradation and methane: low risk of biogeochemical climate-warming feedback

    International Nuclear Information System (INIS)

    Gao Xiang; Adam Schlosser, C; Sokolov, Andrei; Anthony, Katey Walter; Zhuang Qianlai; Kicklighter, David

    2013-01-01

    Climate change and permafrost thaw have been suggested to increase high latitude methane emissions that could potentially represent a strong feedback to the climate system. Using an integrated earth-system model framework, we examine the degradation of near-surface permafrost, temporal dynamics of inundation (lakes and wetlands) induced by hydro-climatic change, subsequent methane emission, and potential climate feedback. We find that increases in atmospheric CH 4 and its radiative forcing, which result from the thawed, inundated emission sources, are small, particularly when weighed against human emissions. The additional warming, across the range of climate policy and uncertainties in the climate-system response, would be no greater than 0.1 ° C by 2100. Further, for this temperature feedback to be doubled (to approximately 0.2 ° C) by 2100, at least a 25-fold increase in the methane emission that results from the estimated permafrost degradation would be required. Overall, this biogeochemical global climate-warming feedback is relatively small whether or not humans choose to constrain global emissions. (letter)

  16. Paleo-Eskimo kitchen midden preservation in permafrost under future climate conditions at Qajaa, West Greenland

    DEFF Research Database (Denmark)

    Elberling, Bo; Matthiesen, Henning; Jørgensen, Christian Juncher

    2011-01-01

    characteristics measured in situ and from permafrost cores. Measurements of thermal properties, heat generation, oxygen consumption and CO2 production show that the kitchen midden can be characterized as peat but produces 4–7 times more heat than natural sediment. An analytical model from permafrost research has...

  17. Urämische Kardiomyopathie und der Einfluss der Hämodialyse

    OpenAIRE

    Valina, Ulrike Katrin

    2011-01-01

    ZIEL: Analyse von Risikofaktoren und Entstehungsmechanismen der urämischen Kardiomyopathie bei Hämodialysepatienten und Vergleich von Diagnostiken zur frühen Detektion kardialer Funktionstörungen zur Optimierung der Therapie bei terminaler Niereninsuffizienz und Senkung der hohen Mortalitätsrate. METHODEN: Einschluss von 32 Hämodialysepatienten. Messungen mittels Blutentnahme (Entzündungs-, Atherosklerose-, Anämieparameter, EPO, PTH und RAAS) und MRT (Herzfunktion, Herzmorphologie und Her...

  18. Recht und soziales Kapital im Wohlfahrtsstaat

    OpenAIRE

    Karstedt, Susanne

    1997-01-01

    'Das Konzept des sozialen Kapitals spielt eine zentrale Rolle in der Diskussion um den Um- und Abbau des Wohlfahrtsstaates. Zerstört der Wohlfahrtsstaat soziales Kapital? Können staatliche Sozialleistungen durch das soziale Kapital in Familien, Nachbarschaften und Gemeinden umstandslos ersetzt werden, und individuelle Rechtsansprüche als Forderungen an diese sozialen Netzwerke zurückverwiesen werden? Kann die angestrebte 'Verantwortungsgesellschaft' (Etzioni) die Leistungen übernehmen, mit de...

  19. Von Medien, Übertragungen und Automaten

    Directory of Open Access Journals (Sweden)

    Alessandro Barberi

    2013-12-01

    Full Text Available Im Zuge der Debatten zum Medialen Habitus wurde vielfach betont, dass die >Theorie der Praxispraxeologischen Medientheorie< des Medialen Habitus avant la lettre gesprochen werden kann. Dieser Artikel untersucht – ausgehend von den Debatten zur "Medienkompetenz" – wie Bourdieu Sprache, Sprechen und Diskurs, sowie Akteure, Felder und Habitus als Medien begreift und betont dabei die Nützlichkeit der Bourdieuschen Bildungssoziologie im Rahmen einer sozialwissenschaftlichen Grundlegung der Medienpädagogik.

  20. Polnische qualitative Soziologie: Entwicklung und Hauptthemen

    OpenAIRE

    Konecki, Krzysztof T.; Kacperczyk, Anna M.; Marciniak, Lukasz T.

    2005-01-01

    In dem vorliegenden Beitrag wird die Entwicklung der qualitativen Soziologie in Polen rekonstruiert, indem deren wesentliche intellektuelle Wurzeln und einige Hauptthemen der polnischen Soziologie vorgestellt werden. Romantizismus und die induktive Methode sind essenzielle Elemente für die Entwicklung der Disziplin in Polen gewesen und Charakteristika ihrer Besonderheit. Die Bedeutung von Florian ZNANIECKI für die Entstehung der polnischen qualitativen Soziologie wird gewürdigt. URN: urn:n...

  1. Transient thermal effects in Alpine permafrost

    Directory of Open Access Journals (Sweden)

    J. Noetzli

    2009-04-01

    Full Text Available In high mountain areas, permafrost is important because it influences the occurrence of natural hazards, because it has to be considered in construction practices, and because it is sensitive to climate change. The assessment of its distribution and evolution is challenging because of highly variable conditions at and below the surface, steep topography and varying climatic conditions. This paper presents a systematic investigation of effects of topography and climate variability that are important for subsurface temperatures in Alpine bedrock permafrost. We studied the effects of both, past and projected future ground surface temperature variations on the basis of numerical experimentation with simplified mountain topography in order to demonstrate the principal effects. The modeling approach applied combines a distributed surface energy balance model and a three-dimensional subsurface heat conduction scheme. Results show that the past climate variations that essentially influence present-day permafrost temperatures at depth of the idealized mountains are the last glacial period and the major fluctuations in the past millennium. Transient effects from projected future warming, however, are likely larger than those from past climate conditions because larger temperature changes at the surface occur in shorter time periods. We further demonstrate the accelerating influence of multi-lateral warming in steep and complex topography for a temperature signal entering the subsurface as compared to the situation in flat areas. The effects of varying and uncertain material properties (i.e., thermal properties, porosity, and freezing characteristics on the subsurface temperature field were examined in sensitivity studies. A considerable influence of latent heat due to water in low-porosity bedrock was only shown for simulations over time periods of decades to centuries. At the end, the model was applied to the topographic setting of the Matterhorn

  2. Matthias Asche, Werner Buchholz, Anton Schindling (Hrsg.): Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Tl. 2, Münste

    Index Scriptorium Estoniae

    Wittram, Heinrich, 1931-

    2011-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen : Stadt, Land und Konfession 1500-1721. Teil 2. Münster, 2010

  3. Methoden der Kommunikations- und Mediengeschichte: die Wechselwirkung unterschiedlicher Verfahren als Spezifikum der Kommunikations- und Mediengeschichte

    NARCIS (Netherlands)

    Hemels, J.; Averbeck-Lietz, S.; Klein, P.; Meyen, M.

    2009-01-01

    Dieser Beitrag verfolgt zwei Ziele: Einerseits wird beabsichtigt, nicht his-torisch geschulte Kommunikationswissenschaftler mit Grundlagen und Praxis kommunikationswissenschaftlicher Forschung vertraut zu ma-chen. Andererseits wird für ein Zusammenspiel zwischen führenden For-schungsansätzen und

  4. Stages of Gas-Hydrate Evolution on the Northern Cascadia Margin

    Directory of Open Access Journals (Sweden)

    the IODP Expedition 311 Scientists

    2006-09-01

    Full Text Available Natural gas hydrate occurs beneath many continental slopes and in arctic permafrost areas. Recent studies have indicated that the largest deposits of gas hydrate might lie in nearly horizontal layers several hundred meters beneath the seafloor of continental slopes, especially in the large, accretionary sedimentary prisms of subduction zones. Expedition 311 of the Integrated Ocean Drilling Program (IODP investigated the formation of gas hydrate in the accretionary prism of the Cascadia subduction zone (Fig. 1. The primary objectives of Expedition 311 were to test and constraingeological models of gas hydrate formation by upward fluidand methane transport in accretionary prisms. We specifi -cally sought to (a determine the mechanisms that controlthe nature, magnitude, and distribution of the gas hydrate,(b find the pathways of the fluid migration required to formlarge concentrations of gas hydrate, (c examine the effectsof gas hydrate on the physical properties of the host sediment,and (d investigate the microbiology and geochemistryassociated with the occurrence of gas hydrate. Furthermore,we concentrated on the contrast between methane transportby focused fl ow in fault zones and by dispersed pervasiveupward flow at various scales of permeability.

  5. Wetland development, permafrost history and nutrient cycling inferred from late Holocene peat and lake sediment records in subarctic Sweden

    DEFF Research Database (Denmark)

    Kokfelt, U.; Reuss, N.; Struyf, E.

    2010-01-01

    to re-deposition of peat into one of the lakes after ca. 2,100 cal BP, and stimulated primary productivity in the other lake at ca. 1,900-1,800 cal BP. Carbonate precipitation appears to have been suppressed when acidic poor fen and bog (palsa) communities dominated the catchment mire, and permafrost...... insight into nutrient and permafrost dynamics in a subarctic wetland and imply that continued permafrost decay and related vegetation changes towards minerotrophy may increase carbon and nutrient storage of mire deposits and reduce nutrient fluxes in runoff. Rapid permafrost degradation may on the other...

  6. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

    Science.gov (United States)

    Benjamin W. Abbott,; Jeremy B. Jones,; Edward A.G. Schuur,; F.S. Chapin, III; Bowden, William B.; M. Syndonia Bret-Harte,; Howard E. Epstein,; Michael D. Flannigan,; Tamara K. Harms,; Teresa N. Hollingsworth,; Mack, Michelle C.; McGuire, A. David; Susan M. Natali,; Adrian V. Rocha,; Tank, Suzanne E.; Merrit R. Turetsky,; Jorien E. Vonk,; Wickland, Kimberly P.; Aiken, George R.

    2016-01-01

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

  7. Responses of alpine grassland on Qinghai–Tibetan plateau to climate warming and permafrost degradation: a modeling perspective

    International Nuclear Information System (INIS)

    Yi, Shuhua; Wang, Xiaoyun; Qin, Yu; Ding, Yongjian; Xiang, Bo

    2014-01-01

    Permafrost plays a critical role in soil hydrology. Thus, the degradation of permafrost under warming climate conditions may affect the alpine grassland ecosystem on the Qinghai–Tibetan Plateau. Previous space-for-time studies using plot and basin scales have reached contradictory conclusions. In this study, we applied a process-based ecosystem model (DOS-TEM) with a state-of-the-art permafrost hydrology scheme to examine this issue. Our results showed that 1) the DOS-TEM model could properly simulate the responses of soil thermal and hydrological dynamics and of ecosystem dynamics to climate warming and spatial differences in precipitation; 2) the simulated results were consistent with plot-scale studies showing that warming caused an increase in maximum unfrozen thickness, a reduction in vegetation and soil carbon pools as a whole, and decreases in soil water content, net primary production, and heterotrophic respiration; and 3) the simulated results were also consistent with basin-scale studies showing that the ecosystem responses to warming were different in regions with different combinations of water and energy constraints. Permafrost prevents water from draining into water reservoirs. However, the degradation of permafrost in response to warming is a long-term process that also enhances evapotranspiration. Thus, the degradation of the alpine grassland ecosystem on the Qinghai–Tibetan Plateau (releasing carbon) cannot be mainly attributed to the disappearing waterproofing function of permafrost. (letter)

  8. Klare Regeln - effiziente und effektive FMEA-Anwendung

    OpenAIRE

    Schloske, Alexander

    2014-01-01

    Der Vortrag beschreibt klare Regeln zur effizienten und effektiven FMEA-Anwendung. - Denkmodelle für die verschiedenen FMEA-Arten (System-FMEA, Konstruktions-FMEA, Prozess-FMEA) - Anwendungsbereiche und FMEA-Planung - Strukturierung von FMEAs - Funktionen, Produktmerkmale und Prozessmerkmale - Risikoanalyse - Maßnahmendefinition - Risikobewertung - Präsentation von FMEAs - FMEA als "lebendes Dokument".

  9. Medien als Lernform und die Trimediale Redaktion

    Directory of Open Access Journals (Sweden)

    Wolf Hilzensauer

    2015-01-01

    Full Text Available Der vorliegende Artikel beschreibt ein Konzept für eine handlungsorientierte Medienpädagogik im Bildungsbereich. Im Mittelpunkt steht dabei die SO!-Campusredaktion, die als Methode für expansives Lernen die Möglichkeit bietet, unabhängig von Thema oder Medium die Verantwortung für den Lernprozess in die Hände der Lernenden zu legen. Der Dokumentation von Reflexion über den Lernprozess wird dabei eine besondere Bedeutung zugesprochen. Gleichzeitig werden unterschiedliche mediale Gestaltungsmöglichkeiten (Audio/Radio, Video/Fernsehen und Zeitung – sowohl als Print- als auch als Onlinemedium vorgestellt, die durch das Konzept BYOD – bring your own device – auch einfach und niederschwellig im Bildungskontext umsetzbar sind. Dadurch ergeben sich innovative Möglichkeiten, einen Lernprozess sichtbar zu machen und gleichzeitig eine Grundlage für eine alternative Leistungsbeurteilung anzubieten. Die SO!-Campusredaktion wird derzeit an der Pädagogischen Hochschule Salzburg in Kooperation mit dem Communitysender FS1 und der Radiofabrik entwickelt und erprobt. Community Medien nehmen als MedienpartnerInnen eine bedeutende Stellung ein: Durch ihren offenen Zugang zu Know How und Equipment sowie durch die Möglichkeit, Medienproduktionen über die verfügbaren Distibutionskanäle (Radiofrequenz oder Sendeplatz einer breiten Bevölkerung zugänglich zu machen, gewinnt die Medienpädagogik einen wichtigen Mehrwert in ihrer schulischen und außerschulischen Arbeit. (Dieser Artikel knüpft an den Artikel "BYOD, Smartphonefilme und webbasierte Videoschnittprogramme" der Medienimpulse, Ausgabe 2/2014, an.

  10. Das polyzystische Ovarialsyndrom: Im Spannungsfeld von Hormonen und Stoffwechsel

    Directory of Open Access Journals (Sweden)

    Wehr E

    2010-01-01

    Full Text Available Das polyzystische Ovarialsyndrom (PCOS ist eine komplexe Erkrankung und betrifft mindestens 5–10 % aller Frauen. Es ist charakterisiert durch Hyperandrogenismus (klinisch und/oder biochemisch, Oligo- oder Anovulation und polyzystische Ovarien. In der Pathogenese spielt neben der Hyperandrogenämie und der abnormen Gonadotropinsekretion die Insulinresistenz eine zentrale Rolle. Ein genetischer Hintergrund des PCOS wird vermutet, neben verschiedenen Kandidatengenen werden auch genomweite Assoziationsstudien neue Kenntnisse bringen, um in Zukunft sowohl Diagnose als auch Therapie des PCOS zu vereinfachen. Das PCOS bringt ein hohes metabolisches Risiko mit sich, ca. die Hälfte aller betroffenen Frauen ist adipös, viele leiden an Insulinresistenz, Glukosetoleranzstörungen und Diabetes mellitus Typ 2. Weiters sind viele Frauen mit PCOS von unerfülltem Kinderwunsch, Hirsutismus, Akne und androgenetischer Alopezie betroffen. Vor allem Adipositas und Hirsutismus führen zu einer starken psychischen Belastung betroffener Frauen, das Suizidrisiko ist deutlich erhöht. Zur exakten Diagnose des PCOS bedarf es einer genauen Anamnese und körperlichen Untersuchung mit anthropometrischen Messungen und Hirsutismus-Score. Ein Hormonstatus mit Bestimmung von Androgenen ist unerlässlich, ein LHRH-Test kann weitere diagnostische Hinweise liefern. Weiters sollten zur metabolischen Abklärung ein oraler Glukosetoleranztest, eine Messung der Körperfettverteilung und die Bestimmung eines Lipidstatus erfolgen. Therapeutisch ist vor allem bei adipösen Frauen eine Lebensstilintervention am wichtigsten, zusätzlich kommen Insulinsensitizer und orale Kontrazeptiva zum Einsatz. Zusammenfassend ist das PCOS eine extrem häufige Erkrankung mit komplexen Folgen und bedarf einer konsequenten, interdisziplinären individuellen Therapie bei betroffenen Frauen.

  11. Informationsdesign von Bildungsportalen : Struktur und Aufbau netzbasierter Bildungsressourcen

    OpenAIRE

    Panke, Stefanie

    2009-01-01

    Sowohl Unternehmen als auch Bildungseinrichtungen, Verlage, politische Organisationen, Verbände, Interessengruppen und Privatpersonen nutzen das Internet, um Informationen zu verbreiten. Die Varianz an Akteuren, Adressaten und Botschaften spiegelt sich wider in einem wachsenden Spektrum an Web-Genres: Suchmaschine, E-Commerce-Auftritt und Online-Zeitung teilen sich die Aufmerksamkeit der Leser unter anderem mit privaten Weblogs und kollaborativen Wissenssammlungen wie der Enzyklopädie Wikiped...

  12. Reputationsorientiertes Themen- und Issues-Management : Konzeption, Regelbetrieb, Weiterentwicklung

    OpenAIRE

    Fahrenbach, Christian

    2011-01-01

    Die Dissertation untersucht, wie Organisationen ein reputationsorientiertes Themen- und Issues-Management aufbauen, betreiben und weiterentwickeln können. Dazu wird das operative Modell des Issues Managements mit dem strategischen Zielkonstrukt Reputation verbunden. Zu Beginn der Arbeit beschreiben zwei Theorie-Kapitel ausführlich Relevanz und die Steuerung von Reputation und im Issues Management. Auf dieser Basis wird ein praxisorientiertes integriertes Modell entwickelt. Es beschreibt da...

  13. Comparing the sensitivity of permafrost and marine gas hydrate to climate warming

    International Nuclear Information System (INIS)

    Taylor, A.E.; Dallimore, S.R.; Hyndman, R.D.; Wright, F.

    2005-01-01

    The sensitivity of Arctic subpermafrost gas hydrate at the Mallik borehole was compared to temperate marine gas hydrate located offshore southwestern Canada. In particular, a finite element geothermal model was used to determine the sensitivity to the end of the ice age, and contemporary climate warming of a 30 m thick methane hydrate layer lying at the base of a gas hydrate stability zone prior to 13.5 kiloannum (ka) before present (BP). It was suggested that the 30 m gas-hydrate-bearing layer would have disappeared by now, according to the thermal signal alone. However, the same gas-hydrate-bearing layer underlying permafrost would persist until at least 4 ka after present, even with contemporary climate warming. The longer time for subpermafrost gas hydrate comes from the thawing pore ice at the base of permafrost, at the expense of dissociation of the deeper gas hydrate. The dissociation of underlying gas hydrate from climate surface warming is buffered by the overlying permafrost

  14. Permafrost Distribution along the Qinghai-Tibet Engineering Corridor, China Using High-Resolution Statistical Mapping and Modeling Integrated with Remote Sensing and GIS

    Directory of Open Access Journals (Sweden)

    Fujun Niu

    2018-02-01

    Full Text Available Permafrost distribution in the Qinghai-Tibet Engineering Corridor (QTEC is of growing interest due to the increase in infrastructure development in this remote area. Empirical models of mountain permafrost distribution have been established based on field sampled data, as a tool for regional-scale assessments of its distribution. This kind of model approach has never been applied for a large portion of this engineering corridor. In the present study, this methodology is applied to map permafrost distribution throughout the QTEC. After spatial modelling of the mean annual air temperature distribution from MODIS-LST and DEM, using high-resolution satellite image to interpret land surface type, a permafrost probability index was obtained. The evaluation results indicate that the model has an acceptable performance. Conditions highly favorable to permafrost presence (≥70% are predicted for 60.3% of the study area, declaring a discontinuous permafrost distribution in the QTEC. This map is useful for the infrastructure development along the QTEC. In the future, local ground-truth observations will be required to confirm permafrost presence in favorable areas and to monitor permafrost evolution under the influence of climate change.

  15. Erstellung eines multimedialen Lernprogramms über die Grundlagen der EKG-Aufzeichnung und Auswertung bei Hund und Katze

    OpenAIRE

    Weigel-Ossiander, Fiona Sarah

    2016-01-01

    Mit EKG Basics wurde ein detailliertes multimediales Lernprogramm über die Grundlagen der Elektrokardiographie bei Hund und Katze erstellt unter besonderer Berücksichtigung von didaktischen und ergonomischen Gesichtspunkten. Da vielen Veterinärmedizinerinnen/Veterinärmedizinern das Erlernen, Verstehen und Interpretieren der Elektrokardiographie schwer fällt, war das Ziel der vorliegenden Arbeit, sowohl Studierenden der Tiermedizin als auch interessierten Tierärztinnen/Tierärzten die Thema...

  16. Deutsch-slawischer Siedlungs- und Sprachkontakt im Gebiet zwischen Saale und Neiße – vorgestellt an ausgewählten Ortsnamen (Siedlungsnamen

    Directory of Open Access Journals (Sweden)

    Inge Bily

    2015-12-01

    Full Text Available Saale und Elbe bilden im Wesentlichen die westliche Begrenzung des ehemals kompakten altsorbischen Sprachgebietes. Im Norden schließt das Altsorbische an das Altpolabische, im Osten und Südosten an das Polnische und Tschechische an. Eigennamen bilden eine wichtige Quelle sowohl für die Aufhellung der Geschichte der Besiedlung wie auch ethnischer, sprachlicher und sozialer Verhältnisse, denn historische Siedlungsprozesse fanden ihren Niederschlag u.a. in historischen Belegen von Namen. Diese Belege wie auch die Ableitungsbasen und Benennungsmotive ebenso wie die phonologischen und morphologischen Merkmale der Namen des altsorbischen Kontaktgebietes enthalten eine Vielzahl von Zeugnissen deutsch-slawischer Kontinuität. Auf der Grundlage umfangreicher Studien zu Ortsnamen stellt der Beitrag ausgewählte Beispiele vor. Im ehemals altsorbischen Kontaktgebiet können Ortsnamen (Siedlungsnamen und ihre historische Überlieferung Hinweise auf Siedlungs- und Sprachkontakt geben. Dies belegen eine ganze Reihe von Merkmalen, so z.B.: 1. Unterscheidende Bestimmungswörter 2. Parallele Namengebung mit zeitweiliger Mehrnamigkeit 3. Umbenennung 4. Übersetzung 5. Benennungsparallelismus im deutsch-slawischen Kontaktgebiet 6. Scheinbare sekundäre semantische Verankerung (SSSV 7. Namenpaare 8. Unterscheidende Zusätze 9. Mischnamen (Hybride

  17. Subsurface gas hydrates in the northern Gulf of Mexico

    Science.gov (United States)

    Boswell, Ray; Collett, Timothy S.; Frye, Matthew; Shedd, William; McConnell, Daniel R.; Shelander, Dianna

    2012-01-01

    The northernGulf of Mexico (GoM) has long been a focus area for the study of gashydrates. Throughout the 1980s and 1990s, work focused on massive gashydrates deposits that were found to form at and near the seafloor in association with hydrocarbon seeps. However, as global scientific and industrial interest in assessment of the drilling hazards and resource implications of gashydrate accelerated, focus shifted to understanding the nature and abundance of "buried" gashydrates. Through 2005, despite the drilling of more than 1200 oil and gas industry wells through the gashydrate stability zone, published evidence of significant sub-seafloor gashydrate in the GoM was lacking. A 2005 drilling program by the GoM GasHydrate Joint Industry Project (the JIP) provided an initial confirmation of the occurrence of gashydrates below the GoM seafloor. In 2006, release of data from a 2003 industry well in Alaminos Canyon 818 provided initial documentation of gashydrate occurrence at high concentrations in sand reservoirs in the GoM. From 2006 to 2008, the JIP facilitated the integration of geophysical and geological data to identify sites prospective for gashydrate-bearing sands, culminating in the recommendation of numerous drilling targets within four sites spanning a range of typical deepwater settings. Concurrent with, but independent of, the JIP prospecting effort, the Bureau of Ocean Energy Management (BOEM) conducted a preliminary assessment of the GoM gashydratepetroleum system, resulting in an estimate of 607 trillion cubic meters (21,444 trillion cubic feet) gas-in-place of which roughly one-third occurs at expected high concentrations in sand reservoirs. In 2009, the JIP drilled seven wells at three sites, discovering gashydrate at high saturation in sand reservoirs in four wells and suspected gashydrate at low to moderate saturations in two other wells. These results provide an initial confirmation of the complex nature and occurrence of gashydrate-bearing sands in

  18. Philologie im Horizont der Geschichtlichkeit von Sprache und Text: zum Tagungsband von Wulf Oesterreicher und Maria Selig

    Directory of Open Access Journals (Sweden)

    Olaf Müller

    2016-03-01

    Full Text Available Wulf Oesterreicher und Maria Selig, Hrsg., Geschichtlichkeit von Sprache und Text: Philologien – Disziplingenese – Wissenschaftshistoriographie (Paderborn: Wilhelm Fink, 2014, 332 S.

  19. Stabilität und Frieden? Ehebeziehungen im Transformationsprozeß

    Directory of Open Access Journals (Sweden)

    Martina Ritter

    2001-03-01

    Full Text Available In der sehr guten Studie, die auf der Kooperation von amerikanischen und russischen Forscherinnen beruht, werden die ehelichen Beziehungen im gegenwärtigen Rußland diskutiert. Nach einer kontextuellen Einbettung in eine historische Reflexion über die Entwicklung von Ehe und Familie in Rußland und der Sowjetunion und nach transformationstheoretischen Überlegungen werden Themen wie Geschlechterbilder, Arbeitsteilung, Ehe-Qualität und Gewalt mit Hilfe quantitativer Methoden analysiert.

  20. Selective Leaching of Dissolved Organic Matter From Alpine Permafrost Soils on the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Wang, Yinghui; Xu, Yunping; Spencer, Robert G. M.; Zito, Phoebe; Kellerman, Anne; Podgorski, David; Xiao, Wenjie; Wei, Dandan; Rashid, Harunur; Yang, Yuanhe

    2018-03-01

    Ongoing global temperature rise has caused significant thaw and degradation of permafrost soils on the Qinghai-Tibetan Plateau (QTP). Leaching of organic matter from permafrost soils to aquatic systems is highly complex and difficult to reproduce in a laboratory setting. We collected samples from natural seeps of active and permafrost layers in an alpine swamp meadow on the QTP to shed light on the composition of mobilized dissolved organic matter (DOM) by combining optical measurements, ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry, radiocarbon (14C), and solid-state 13C nuclear magnetic resonance spectroscopy. Our results show that even though the active layer soils contain large amounts of proteins and carbohydrates, there is a selective release of aromatic components, whereas in the deep permafrost layer, carbohydrate and protein components are preferentially leached during the thawing process. Given these different chemical characteristics of mobilized DOM, we hypothesize that photomineralization contributes significantly to the loss of DOM that is leached from the seasonally thawed surface layer. However, with continued warming, biodegradation will become more important since biolabile materials such as protein and carbohydrate are preferentially released from deep-layer permafrost soils. This transition in DOM leachate source and associated chemical composition has ramifications for downstream fluvial networks on the QTP particularly in terms of processing of carbon and associated fluxes.