West Greenlandic Eskimo

DEFF Research Database (Denmark)

Trondhjem, Naja Blytmann; Fortescue, Michael David

West Greenlandic Eskimo. The current situation of the West Greenlandic language as principal means of communication among the majority Greenlandic population will be presented with special emphasis on the northwest hunting district of Upernavik, where traditional marine mammal hunting is still...... the principal economic activity. Research projects and language initiatives currently in progress within Greenland will be touched upon, as will the possibilities of communication with North American Inuit. West Greenlandic is unique among the native languages of the North American Arctic and Sub...

Amplified melt and flow of the Greenland ice sheet driven by late-summer cyclonic rainfall

DEFF Research Database (Denmark)

Doyle, Samuel H.; Hubbard, Alun; van de Wal, Roderik S.W.

2015-01-01

and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior....... We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern...

JET ENGINE INLET DISTORTION SCREEN AND DESCRIPTOR EVALUATION

Directory of Open Access Journals (Sweden)

Jiří Pečinka

2017-02-01

Full Text Available Total pressure distortion is one of the three basic flow distortions (total pressure, total temperature and swirl distortion that might appear at the inlet of a gas turbine engine (GTE during operation. Different numerical parameters are used for assessing the total pressure distortion intensity and extent. These summary descriptors are based on the distribution of total pressure in the aerodynamic interface plane. There are two descriptors largely spread around the world, however, three or four others are still in use and can be found in current references. The staff at the University of Defence decided to compare the most common descriptors using basic flow distortion patterns in order to select the most appropriate descriptor for future department research. The most common descriptors were identified based on their prevalence in widely accessible publications. The construction and use of these descriptors are reviewed in the paper. Subsequently, they are applied to radial, angular, and combined distortion patterns of different intensities and with varied mass flow rates. The tests were performed on a specially designed test bench using an electrically driven standalone industrial centrifugal compressor, sucking air through the inlet of a TJ100 small turbojet engine. Distortion screens were placed into the inlet channel to create the desired total pressure distortions. Of the three basic distortions, only the total pressure distortion descriptors were evaluated. However, both total and static pressures were collected using a multi probe rotational measurement system.

Spaceborne measurement of Greenland ice sheet changes: the ESA Greenland CCI project

DEFF Research Database (Denmark)

Forsberg, René; Sørensen, Louise Sandberg; Meister, Rakia

The ESA “Greenland_ice_sheet_cci” project is currently making past and present space measurements of Greenland ice sheet changes available for use by scientists, stakeholders and the general public. The data are part of a large set of ECV’s (Essential Climate Variables) made available by the ESA...... Climate Initiative, as a contribution to the global Climate Observing System. The ECV data produced for the Greenlandice sheet include detailed grids of elevation changes and ice flow velocities, as well as line data of grounding lines and calving front locations for major outlet glaciers. The “ice_sheets......_cci” goal is to generate a consistent, validated, long-term and timely set of ECV’s, a.o. to improve the impact of satellite data on climate research and coupled ice sheet/climate models. Special focus is on use of data from ESA missions such as ERS, Envisat and the new Sentinel missions, but in the 2nd...

Greenland

DEFF Research Database (Denmark)

Gad, Ulrik Pram

2014-01-01

in 1979 and made the 1985 withdrawal possible. On 25 November 2008, a majority of the people of Greenland voted in favour of enhanced home rule – ‘self-government’ – still within formal Danish sovereignty. Denmark and Greenland alike are preparing for a future envisioned as involving climate change...

The peopling of Greenland

DEFF Research Database (Denmark)

Pereira, Vania; Tomas Mas, Carmen; Sanchez, Juan J

2015-01-01

The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence...... of a sex-biased, admixed genetic background. This work further explores the genetics of the Greenlanders by analysing autosomal and X-chromosomal data to obtain deeper insights into the factors that shaped the genetic diversity in Greenlanders. Fourteen Greenlandic subsamples from multiple geographical...... settlements were compared to assess the level of genetic substructure in the Greenlandic population. The results showed low levels of genetic diversity in all sets of the genetic markers studied, together with an increased number of X-chromosomal loci in linkage disequilibrium in relation to the Danish...

Late Quaternary glaciation history of northernmost Greenland - Evidence of shelf-based ice

DEFF Research Database (Denmark)

Larsen, Nicolaj K.; Kjær, Kurt H.; Funder, Svend Visby

2010-01-01

We present the mapping of glacial landforms and sediments from northernmost Greenland bordering 100 km of the Arctic Ocean coast. One of the most important discoveries is that glacial landforms, sediments, including till fabric measurements, striae and stoss-lee boulders suggest eastward ice......-flow along the coastal plain. Volcanic erratic boulders document ice-transport from 80 to 100 km west of the study area. We argue that these findings are best explained by local outlet glaciers from the Greenland Ice Sheet and local ice caps that merged to form a shelf-based ice in the Arctic Ocean...... and possibly confirming an extensive ice shelf in the Lincoln Sea between Greenland and Ellesmere Island. It is speculated that the shelf-based ice was largely affected by the presence of thick multiyear sea ice in the Arctic Ocean that prevented it from breaking up and forced the outlet glaciers to flow...

TopoGreenland: Lithospheric structure and topography in Central-Eastern Greenland

Science.gov (United States)

Thybo, H.; Shulgin, A.; Kraft, H. A.; Vinnik, L. P.

2017-12-01

We present models of the seismic structure of the crust and upper mantle in the interior of Greenland based on new seismological data from the TopoGreenland experiment. Until this experiment, all seismic data in Greenland was acquired close to the coast, where the crustal structure is affected by oceanic break-up. The TopoGreenland data acquisition programme in central-eastern Greenland included the first controlled source seismic experiment in interior Greenland and deployment of 24 broadband (BB) onshore stations for 3 years, partly on the ice cap. The 320 km long seismic refraction/wide-angle reflection profile was acquired on the ice cap by a team of six people during two-months in summer of 2011. We present a 2D velocity model of the crust based on tomographic inversion and forward ray tracing modelling of the controlled source data. It shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western to 40 km in its eastern part of the profile. High lower crustal velocities (Vp 6.8 - 7.3 km/s) below central Greenland may result from past collision tectonics or be related to the passage of the Iceland mantle plume. Crustal receiver functions in the surrounding area demonstrate constant structure along the coast and pronounced, relatively sharp variation in crustal thickness around the mountains at the edge of the ice cap. Surprisingly the thickest crust is observed below the lowest topography under the ice cap, whereas the crust is thin below the high mountains at its edge, and thins further below elevated topography out to the coast. Receiver Function interpretation of the mantle and transition zone structure shows a complicated mosaic variation that cannot be correlated to the variation in topography. The origin of the pronounced mountain ranges around the North Atlantic Ocean with average elevation above 1500 m and peak elevations of more than 3.5 km near Scoresby Sund in Eastern Greenland, is unknown. Our new results demonstrate

Post-colonial identity in Greenland?

DEFF Research Database (Denmark)

Gad, Ulrik Pram

2009-01-01

could be furthered by bringing politics back in. Based on a discourse analysis of the Greenlandic debate on language, this paper makes three claims: First, the identity projects promoted in Greenland are based on an essentialist conception of identity. Secondly, Greenlandic identity discourse combines......In the gradual unravelling of Greenland’s colonial relationship to Denmark, an essentialist conceptualization of Greenlandic identity has played a significant role. However, both our scholarly understanding of post-colonial Greenlandic identity and the process towards independence for Greenland...... elements of traditional Inuit culture and elements of colonial modernity. Thirdly, monolingual Greenlanders are those with the most to gain from abandoning the dichotomy of essentialist identities. Strategically, the paper suggests a post-post-colonial Greenlandic identity as a means of avoiding...

Evidence of local and regional freshening of Northeast Greenland coastal waters

DEFF Research Database (Denmark)

Sejr, Mikael K.; Stedmon, Colin A; Bendtsen, Jørgen

2017-01-01

The supply of freshwater to fjord systems in Greenland is increasing as a result of climate change-induced acceleration in ice sheet melt. However, insight into the marine implications of the melt water is impaired by lack of observations demonstrating the fate of freshwater along the Greenland...... coast and providing evaluation basis for ocean models. Here we present 13 years of summer measurements along a 120 km transect in Young Sound, Northeast Greenland and show that sub-surface coastal waters are decreasing in salinity with an average rate of 0.12 ± 0.05 per year. This is the first...... observational evidence of a significant freshening on decadal scale of the waters surrounding the ice sheet and comes from a region where ice sheet melt has been less significant. It implies that ice sheet dynamics in Northeast Greenland could be of key importance as freshwater is retained in southward flowing...

Counterbalancing hydrodynamic sample distortion effects increases resolution of free-flow zone electrophoresis.

Science.gov (United States)

Weber, G; Bauer, J

1998-06-01

On fractionation of highly heterogeneous protein mixtures, optimal resolution was achieved by forcing proteins to migrate through a preestablished pH gradient, until they entered a medium with a pH similar but not equal to their pIs. For this purpose, up to seven different media were pumped through the electrophoresis chamber so that they were flowing adjacently to each other, forming a pH gradient declining stepwise from the cathode to the anode. This gradient had a sufficiently strong band-focusing effect to counterbalance sample distortion effects of the flowing medium as proteins approached their isoelectric medium closer than 0.5 pH units. Continuous free-flow zone electrophoresis (FFZE) with high throughput capability was applicable if proteins did not precipitate or aggregate in these media. If components of heterogeneous protein mixtures had already started to precipitate or aggregate, in a medium with a pH exceeding their pI by more than 0.5 pH units, the application of interval modus and media forming flat pH gradients appeared advantageous.

Greenland and Natural Resources

DEFF Research Database (Denmark)

Lyck, Lise

Greenland policy can delay and maybe change the future of the forecasted development of the use of natural resources. This book is relevant for anyone interested in Greenland in general and the development of Greenland both politically and economically and in relation natural resources....

Automated Ground-based Time-lapse Camera Monitoring of West Greenland ice sheet outlet Glaciers: Challenges and Solutions

Science.gov (United States)

Ahn, Y.; Box, J. E.; Balog, J.; Lewinter, A.

2008-12-01

Monitoring Greenland outlet glaciers using remotely sensed data has drawn a great attention in earth science communities for decades and time series analysis of sensory data has provided important variability information of glacier flow by detecting speed and thickness changes, tracking features and acquiring model input. Thanks to advancements of commercial digital camera technology and increased solid state storage, we activated automatic ground-based time-lapse camera stations with high spatial/temporal resolution in west Greenland outlet and collected one-hour interval data continuous for more than one year at some but not all sites. We believe that important information of ice dynamics are contained in these data and that terrestrial mono-/stereo-photogrammetry can provide theoretical/practical fundamentals in data processing along with digital image processing techniques. Time-lapse images over periods in west Greenland indicate various phenomenon. Problematic is rain, snow, fog, shadows, freezing of water on camera enclosure window, image over-exposure, camera motion, sensor platform drift, and fox chewing of instrument cables, and the pecking of plastic window by ravens. Other problems include: feature identification, camera orientation, image registration, feature matching in image pairs, and feature tracking. Another obstacle is that non-metric digital camera contains large distortion to be compensated for precise photogrammetric use. Further, a massive number of images need to be processed in a way that is sufficiently computationally efficient. We meet these challenges by 1) identifying problems in possible photogrammetric processes, 2) categorizing them based on feasibility, and 3) clarifying limitation and alternatives, while emphasizing displacement computation and analyzing regional/temporal variability. We experiment with mono and stereo photogrammetric techniques in the aide of automatic correlation matching for efficiently handling the enormous

Mountain building and the initiation of the Greenland Ice Sheet

DEFF Research Database (Denmark)

Solgaard, Anne Munck; Bonow, Johan; Langen, Peter Lang

2013-01-01

The effects of a new hypothesis about mountain building in Greenland on ice sheet initiation are investigated using an ice sheet model in combination with a climate model. According to this hypothesis, low-relief landscapes near sea level characterised Greenland in Miocene times until two phases...... superimposed by cold and warm excursions. The modelling results show that no ice initiates in the case of the low-lying and almost flat topography prior to the uplifts. However, the results demonstrate a significant ice sheet growth in response to the orographically induced increase in precipitation....... Under conditions that are colder than the present, the ice can overcome the Föhn effect, flow into the interior and form a coherent ice sheet. The results thus indicate that the Greenland Ice Sheet of today is a relict formed under colder conditions. The modelling results are consistent...

Telemedicine in Greenland: Citizens' Perspectives.

Science.gov (United States)

Nielsen, Lasse O; Krebs, Hans J; Albert, Nancy M; Anderson, Nick; Catz, Sheryl; Hale, Timothy M; Hansen, John; Hounsgaard, Lise; Kim, Tae Youn; Lindeman, David; Spindler, Helle; Marcin, James P; Nesbitt, Thomas; Young, Heather M; Dinesen, Birthe

2017-05-01

Telemedicine may have the possibility to provide better access to healthcare delivery for the citizens. Telemedicine in arctic remote areas must be tailored according to the needs of the local population. Therefore, we need more knowledge about their needs and their view of telemedicine. The aim of this study has been to explore how citizens living in the Greenlandic settlements experience the possibilities and challenges of telemedicine when receiving healthcare delivery in everyday life. Case study design was chosen as the overall research design. Qualitative interviews (n = 14) were performed and participant observations (n = 80 h) carried out in the local healthcare center in the settlements and towns. A logbook was kept and updated each day during the field research in Greenland. Observations were made of activities in the settlements. Data collected on citizens' views about the possibilities of using telemedicine in Greenland revealed the following findings: Greenlandic citizens are positive toward telemedicine, and telemedicine can help facilitate improved access to healthcare for residents in these Greenlandic settlements. Regarding challenges in using telemedicine in Greenland, the geographical and cultural context hinders accessibility to the Greenlandic healthcare system, and telemedicine equipment is not sufficiently mobile. Greenlandic citizens are positive toward telemedicine and regard telemedicine as a facilitator for improved access for healthcare in the Greenlandic settlements. We have identified challenges, such as geographical and cultural context, that hinder accessibility to the Greenlandic healthcare system.

Telemedicine in Greenland

DEFF Research Database (Denmark)

Nielsen, Lasse Overballe; Krebs, Hans Jørgen; Albert, Nancy M.

2017-01-01

BACKGROUND: Telemedicine may have the possibility to provide better access to healthcare delivery for the citizens. Telemedicine in arctic remote areas must be tailored according to the needs of the local population. Therefore, we need more knowledge about their needs and their view of telemedicine......: Data collected on citizens' views about the possibilities of using telemedicine in Greenland revealed the following findings: Greenlandic citizens are positive toward telemedicine, and telemedicine can help facilitate improved access to healthcare for residents in these Greenlandic settlements...

Brief communication: Getting Greenland's glaciers right - a new data set of all official Greenlandic glacier names

Science.gov (United States)

Bjørk, A. A.; Kruse, L. M.; Michaelsen, P. B.

2015-12-01

Place names in Greenland can be difficult to get right, as they are a mix of Greenlandic, Danish, and other foreign languages. In addition, orthographies have changed over time. With this new data set, we give the researcher working with Greenlandic glaciers the proper tool to find the correct name for glaciers and ice caps in Greenland and to locate glaciers described in the historic literature with the old Greenlandic orthography. The data set contains information on the names of 733 glaciers, 285 originating from the Greenland Ice Sheet (GrIS) and 448 from local glaciers and ice caps (LGICs).

Greenland climate change

DEFF Research Database (Denmark)

Masson-Delmotte, Valérie; Swingedouw, Didier; Landais, Amaëlle

2012-01-01

Climate archives available from deep-sea and marine shelf sediments, glaciers, lakes and ice cores in and around Greenland allow us to place the current trends in regional climate, ice sheet dynamics, and land surface changes in a broader perspective. We show that during the last decade (2000s......), atmospheric and sea-surface temperatures are reaching levels last encountered millennia ago when northern high latitude summer insolation was higher due to a different orbital configuration. Concurrently, records from lake sediments in southern Greenland document major environmental and climatic conditions...... regional climate and ice sheet dynamics. The magnitude and rate of future changes in Greenland temperature, in response to increasing greenhouse gas emissions, may be faster than any past abrupt events occurring under interglacial conditions. Projections indicate that within one century Greenland may...

Stable oxygen isotope variability in two contrasting glacier river catchments in Greenland

DEFF Research Database (Denmark)

Yde, Jacob C.; Knudsen, Niels T.; Steffensen, Jørgen P.

2016-01-01

the Greenland Ice Sheet (GrIS). At the Mittivakkat Gletscher river, a small river draining a local temperate glacier in southeast Greenland, diurnal oscillations in δ18O occurred with a 3 h time lag to the diurnal oscillations in run-off. The mean annual δ18O was -14.68±0.18‰ during the peak flow period...... event. Overall, a comparison of the δ18O compositions from glacial river water in Greenland shows distinct differences between water draining local glaciers and ice caps (between -23.0 and -13.7 ‰) and the GrIS (between -29.9 and -23.2 ‰). This study demonstrates that water isotope analyses can be used......Analysis of stable oxygen isotope (δ18O) characteristics is a useful tool to investigate water provenance in glacier river systems. In order to attain knowledge on the diversity of δ18O variations in Greenlandic rivers, we examined two contrasting glacierised catchments disconnected from...

A Synthesis of the Basal Thermal State of the Greenland Ice Sheet

Science.gov (United States)

Macgregor, J. A.; Fahnestock, M. A.; Catania, G. A.; Aschwanden, A.; Clow, G. D.; Colgan, W. T.; Gogineni, S. P.; Morlighem, M.; Nowicki, S. M. J.; Paden, J. D.;

An ice flow modeling perspective on bedrock adjustment patterns of the Greenland ice sheet

Directory of Open Access Journals (Sweden)

M. Olaizola

2012-11-01

Full Text Available Since the launch in 2002 of the Gravity Recovery and Climate Experiment (GRACE satellites, several estimates of the mass balance of the Greenland ice sheet (GrIS have been produced. To obtain ice mass changes, the GRACE data need to be corrected for the effect of deformation changes of the Earth's crust. Recently, a new method has been proposed where ice mass changes and bedrock changes are simultaneously solved. Results show bedrock subsidence over almost the entirety of Greenland in combination with ice mass loss which is only half of the currently standing estimates. This subsidence can be an elastic response, but it may however also be a delayed response to past changes. In this study we test whether these subsidence patterns are consistent with ice dynamical modeling results. We use a 3-D ice sheet–bedrock model with a surface mass balance forcing based on a mass balance gradient approach to study the pattern and magnitude of bedrock changes in Greenland. Different mass balance forcings are used. Simulations since the Last Glacial Maximum yield a bedrock delay with respect to the mass balance forcing of nearly 3000 yr and an average uplift at present of 0.3 mm yr⁻¹. The spatial pattern of bedrock changes shows a small central subsidence as well as more intense uplift in the south. These results are not compatible with the gravity based reconstructions showing a subsidence with a maximum in central Greenland, thereby questioning whether the claim of halving of the ice mass change is justified.

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

DEFF Research Database (Denmark)

Morlighem, M.; Williams, C. N.; Rignot, E.

2017-01-01

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine‐terminating glaciers. Here we...... present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface...

Oceans Melting Greenland: Early Results from NASA's Ocean-Ice Mission in Greenland

DEFF Research Database (Denmark)

Fenty, Ian; Willis, Josh K.; Khazendar, Ala

2016-01-01

the continental shelf, and about the extent to which the ocean interacts with glaciers. Early results from NASA's five-year Oceans Melting Greenland (OMG) mission, based on extensive hydrographic and bathymetric surveys, suggest that many glaciers terminate in deep water and are hence vulnerable to increased...... melting due to ocean-ice interaction. OMG will track ocean conditions and ice loss at glaciers around Greenland through the year 2020, providing critical information about ocean-driven Greenland ice mass loss in a warming climate....

Experimental Investigation of Inlet Distortion in a Multistage Axial Compressor

Science.gov (United States)

Rusu, Razvan

The primary objective of this research is to present results and methodologies used to study total pressure inlet distortion in a multi-stage axial compressor environment. The study was performed at the Purdue 3-Stage Axial Compressor Facility (P3S) which models the final three stages of a production turbofan engine's high-pressure compressor (HPC). The goal of this study was twofold; first, to design, implement, and validate a circumferentially traversable total pressure inlet distortion generation system, and second, to demonstrate data acquisition methods to characterize the inter-stage total pressure flow fields to study the propagation and attenuation of a one-per-rev total pressure distortion. The datasets acquired for this study are intended to support the development and validation of novel computational tools and flow physics models for turbomachinery flow analysis. Total pressure inlet distortion was generated using a series of low-porosity wire gauze screens placed upstream of the compressor in the inlet duct. The screens are mounted to a rotatable duct section that can be precisely controlled. The P3S compressor features fixed instrumentation stations located at the aerodynamic interface plane (AIP) and downstream and upstream of each vane row. Furthermore, the compressor features individually indexable stator vanes which can be traverse by up to two vane passages. Using a series of coordinated distortion and vane traverses, the total pressure flow field at the AIP and subsequent inter-stage stations was characterized with a high circumferential resolution. The uniformity of the honeycomb carrier was demonstrated by characterizing the flow field at the AIP while no distortion screens where installed. Next, the distortion screen used for this study was selected following three iterations of porosity reduction. The selected screen consisted of a series of layered screens with a 100% radial extent and a 120° circumferential extent. A detailed total

Towards an assessment of the balance state of the Greenland Ice Sheet

Energy Technology Data Exchange (ETDEWEB)

Boeggild, C.E.; Mayer, C.; Podlech, S.; Taurisano, A.; Nielsen, S.

2004-07-01

The climate of Europe is strongly influenced by heat transport by ocean currents flowing from equatorial regions towards the Arctic. During recent years, research has been increasingly focused on factors affecting this circulation, e.g. the freshwater budget of the Arctic that is influenced by glacial melt water from north and East Greenland outlet glaciers. Furthermore, the climate is affected by snow cover, which, apart from its contribution to the freshwater budget, provides feedback effects in that it reflects most of the solar radiation. Apart from Arctic sea-ice cover, the Greenland Ice Sheet is the largest permanent ice- and snow-covered area in the northern hemisphere, with an area of 1.67 x 10{sup 6} km{sup 2} and by far the largest storage of ice with a volume of 2.93 x 10{sup 6} km{sup 3}. Most of the mass loss from the Greenland Ice Sheet occurs in the marginal region of the ice sheet, which is also the area where the largest changes in albedo occur. The Geological Survey of Denmark and Greenland (GEUS) has for many years carried out research along the Greenland Ice Sheet margin to monitor changes of mass balance and melt conditions. (BA)

Airborne Geophysics and Remote Sensing Applied to Study Greenland Ice Dynamics

Science.gov (United States)

Csatho, Beata M.

2003-01-01

Overview of project: we combined and jointly analysed geophysical, remote sensing and glaciological data for investigating the temporal changes in ice flow and the role of geologic control on glacial drainage. The project included two different studies, the investigation of recent changes of the Kangerlussuaq glacier and the study of geologic control of ice flow in NW Greenland, around the Humboldt, Petermann and Ryder glaciers.

Experience with cochlear implants in Greenlanders with profound hearing loss living in Greenland

Directory of Open Access Journals (Sweden)

Preben Homøe

2013-08-01

Full Text Available Objective. Cochlear implant (CI treatment was introduced to the world in the 1980s and has become a routine treatment for congenital or acquired severe-to-profound hearing loss. CI treatment requires access to a highly skilled team of ear, nose and throat specialists, audiologists and speech-language pathologists for evaluation, surgery and rehabilitation. In particular, children treated with CI are in need of long-term post-operative auditory training and other follow-up support. Design. The study is retrospective with updated information on present performance. Results. Since 2001, a total of 11 Greenlandic patients living in Greenland have been treated with CI, 7 children and 4 adults. Of these children, 4 use oral communication only and are full-time CI-users, 2 with full-time use of CI are still in progress with use of oral communication, and 1 has not acquired oral language yet, but has started auditory and speech training. Six children attend mainstream public school while one child is in kindergarten. Of the adults, only 1 has achieved good speech perception with full-time use of CI while 3 do not use the CI. Discussion. From an epidemiological point of view, approximately 1–3 children below 6 years are in need of a CI every second year in Greenland often due to sequelae from meningitis, which may cause postinfectious deafness. Screening of new-borns for hearing has been started in Greenland establishing the basis for early diagnosis of congenital hearing impairment and subsequent intervention. The logistics and lack of availability of speech therapists in Greenland hampers possibilities for optimal language and speech therapy of CI patients in Greenland. This study aims at describing the results of CI treatment in Greenlanders and the outcome of the CI operations along with the auditory and speech/language outcomes. Finally, we present a suggestion for the future CI treatment and recommendations for an increased effort in the

TopoGreenland: crustal structure in central-eastern Greenland along a new refraction profile

Science.gov (United States)

Shulgin, Alexey; Thybo, Hans; Field Team TopoGreenland

2013-04-01

We present the seismic structure in the interior of Greenland based on the first measurements by the seismic refraction/wide angle reflection method. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where the crustal structure is affected by oceanic break-up and may not be representative of the interior of the island. Acquisition of geophysical data in onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The EW-trending profile extends 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the center of the ice cap. The planned extension of the profile by use of OBSs and air gun shooting in Scoresbysund Fjord to the east coast of Greenland was unfortunately canceled, because navigation was prevented by ice drift. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 125 kg at 35-85 m depth in individual boreholes. Two-dimensional velocity model based on tomographic inversion and forward ray tracing modeling shows a decrease of crustal thickness from 47 km below the center of Greenland in the western part to 40 km in the eastern part of the profile. Earlier studies show that crustal thickness further decreases eastward to ca. 30 km below the fjord system, but details of the changes are unknown. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the TopoGreenland profile may indicate past collision tectonics or may be related or to the passage of the Iceland mantle plume. The origin of the pronounced circum-Atlantic mountain ranges in Norway and eastern Greenland

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

DEFF Research Database (Denmark)

Morlighem, M.; Williams, C. N.; Rignot, E.

2017-01-01

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine‐terminating glaciers. Here we...... recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine‐based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing....

Morphology and sedimentology of glacigenic submarine fans on the west Greenland continental margin

Science.gov (United States)

O'Cofaigh, Colm; Hogan, Kelly A.; Dowdeswell, Julian A.; Jennings, Anne E.; Noormets, Riko; Evans, Jeffrey

2014-05-01

Along the West Greenland continental margin adjoining Baffin Bay, bathymetric data show a series of large submarine fans located at the mouths of cross-shelf troughs. Two of these fans, the Uummannaq Fan and the Disko Fan are trough-mouth fans built largely of debris delivered from ice sheet outlets of the Greenland Ice Sheet during past glacial maxima. On the Uummannaq Fan glacigenic debris flow deposits occur on the upper slope and extend to at least 1800 m water depth in front of the trough-mouth. The debris flow deposits are related to the remobilisation of subglacial debris that was delivered onto the upper slope at times when an ice stream was positioned at the shelf edge. In contrast, sedimentary facies from the northern sector of the fan are characterised by hemipelagic and ice-rafted sediments and turbidites; glacigenic debris flows are notably absent in cores from this region. Further south along the Greenland continental margin the surface of the Disko Fan is prominently channelised and associated sediments are acoustically stratified. Although glacigenic debris flow deposits do occur on the upper Disko Fan, sediments recovered in cores from elsewhere on the fan record the influence of turbidity current and meltwater sedimentation. The channelised form of the Disko fan contrasts markedly with that of the Uummannaq Fan and, more widely, with trough mouth fans from the Polar North Atlantic. Collectively these data highlight the variability of glacimarine depositional processes operating on trough-mouth fans on high-latitude continental slopes and show that glacigenic debris flows are but one of a number of mechanisms by which such large glacially-influenced depocentres form.

Isotopes in Greenland Precipitation

DEFF Research Database (Denmark)

Faber, Anne-Katrine

Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

Greenland Fracture Zone-East Greenland Ridge(s) revisited: Indications of a C22-change in plate motion?

DEFF Research Database (Denmark)

Døssing, Arne; Funck, T.

2012-01-01

a reinterpretation of the Greenland Fracture Zone -East Greenland Ridge based on new and existing geophysical data. Evidence is shown for two overstepping ridge segments (Segments A and B) of which Segment A corresponds to the already known East Greenland Ridge while Segment B was not detected previously......Changes in the lithospheric stress field, causing axial rift migration and reorientation of the transform, are generally proposed as an explanation for anomalously old crust and/or major aseismic valleys in oceanic ridge-transform-ridge settings. Similarly, transform migration of the Greenland...... Fracture Zone and separation of the 200-km-long, fracture-zone-parallel continental East Greenland Ridge from the Eurasia plate is thought to be related to a major change in relative plate motions between Greenland and Eurasia during the earliest Oligocene (Chron 13 time). This study presents...

Sustainable Mobile Tourist Hut for Greenland

DEFF Research Database (Denmark)

Qu, Jing; Villumsen, O.; Villumsen, Arne

Greenland is experiencing growing tourism in recent years, which increases demand for tourists’ accommodation. Small huts are a traditional way for overnight stays in Greenland due to scattered population and lack of infrastructure. However, the existing huts in Greenland cannot provide satisfact...

Inuit dietary patterns in modern Greenland

DEFF Research Database (Denmark)

Bjerregaard, Peter; Jeppesen, Charlotte

2010-01-01

The purpose of the study was to apply two different approaches of dietary pattern definition to data from Greenland and to analyse the contemporary dietary patterns of the Inuit in Greenland in relation to urbanization and socio-economic positions.......The purpose of the study was to apply two different approaches of dietary pattern definition to data from Greenland and to analyse the contemporary dietary patterns of the Inuit in Greenland in relation to urbanization and socio-economic positions....

Inuit health in Greenland

DEFF Research Database (Denmark)

Bjerregaard, P; Curtis, T; Borch-Johnsen, K

2003-01-01

During 1997-2001 a population survey was carried out amongst Greenland Inuit living in Denmark and West Greenland (Nuuk, Sisimiut, Qasigiannguit and four villages in Uummannaq municipality). Data collection comprised an interview, a questionnaire, clinical examinations and sampling of biological ...

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

DEFF Research Database (Denmark)

Morlighem, M.; Williams, C. N.; Rignot, E.

2017-01-01

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine‐terminating glaciers. Here we...... present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface......, yielding major improvements over previous data sets, particularly in the marine‐terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains...

A CFD Case Study of a Fan Stage with Split Flow Path Subject to Total Pressure Distortion Inflow

Science.gov (United States)

To, Wai-Ming

2017-01-01

This report is the documentation of the work performed under the Hypersonic Project of the NASA's Fundamental Aeronautics Program. It was funded through Task Number NNC10E444T under GESS-2 Contract NNC06BA07B. The objective of the task is to develop advanced computational tools for the simulation of multi-stage turbomachinery in support of aeropropulsion. This includes work elements in extending the TURBO code and validating the multi-stage URANS (Unsteady Reynolds Averaged Navier Stokes) simulation results with the experimental data. The unsteady CFD (Computation Fluid Dynamics) calculations were performed in full wheel mode with and without screen generated total pressure distortion at the computational inflow boundary, as well as in single passage phase lag mode for uniform inflow. The experimental data were provided by NASA from the single stage RTA (Revolutionary Turbine Accelerator) fan test program.Significant non-uniform flow condition at the fan-face of the aeropropulsion system is frequentlyencountered in many of the advanced aerospace vehicles. These propulsion systems can be eithera podded or an embedded design employed in HWB (Hybrid Wing Body) airframe concept. It isalso a topic of interest in military applications, in which advanced air vehicles have already deployedsome form of embedded propulsion systems in their design because of the requirementsof compact and low observable inlets. Even in the conventional airframe/engine design, the fancould operate under such condition when the air vehicle is undergoing rapid maneuvering action.It is believed that a better understanding of the fan’s aerodynamic and aeromechanical responseto this type of operating condition or off design operation would be beneficial to designing distortiontolerant blades for improved engine operability.The objective for this research is to assess the capability of turbomachinery code as an analysistool in understanding the effects and evaluating the impact of flow distortion

Acceleration of Humboldt glacier, north Greenland

Science.gov (United States)

Jeong, S.; Howat, I.; Noh, M. J.; King, M. D.

2017-12-01

Here we report on recent abrupt acceleration on the flow speed of Humboldt Glacier (HG) in northern Greenland. The mean annual discharge of this glacier in 2000 was estimated as 8.4Gt/a, placing it among the largest outlet glacier draining the northern coast (Enderlin et al., 2014). Using a combination of remote sensing datasets, we find that following a slight slowing before 2010, HG suddenly sped up by a factor of three between 2012 and 2013, maintaining that increased speed through 2016. Speedup was accompanied by up to 10 m of thinning near the terminus and followed slower, longer-term thinning and retreat. Here we assess possible causes for the speedup, potential for continued acceleration and implication to ice sheet mass balance. ReferenceEnderlin, E. M., I. M. Howat, S. Jeong, M.-J. Noh, J. H. van Angelen, and M. R. van den Broeke (2014), An improved mass budget for the Greenland ice sheet, Geophys. Res. Lett., 41, 866-872, doi:10.1002/2013GL059010.

Performance of a Low Speed Axial Compressor Rotor Blade Row under Different Inlet Distortions

Directory of Open Access Journals (Sweden)

R. Taghavi Zenouz

2017-05-01

Full Text Available Responses of an axial compressor isolated rotor blade row to various inlet distortions have been investigated utilizing computational fluid dynamic technique. Distortions have been imposed by five screens of different geometries, but with the same blockage ratio. These screens were embedded upstream of the rotor blade row. Flow fields are simulated in detail for compressor design point and near stall conditions. Performance curves for distorted cases are extracted and compared to the undisturbed case. Flow simulations and consequent performance characteristics show that the worst cases belong to non-symmetric blockages, i.e., those of partial circumferential configurations. These cases produce the largest wakes which can disturb the flow, considerably. Superior performances correspond to the inner and outer continuous circumferential distortion screens. Since, they produce no significant disturbances to the main flow in comparison to the non-symmetric screens.

Popular music from Greenland

DEFF Research Database (Denmark)

Otte, Andreas Roed

a sense of place in popular music. The second probes different strategies for co-branding popular music and Greenland. The third is concerned with music consumption patterns among Greenlandic youth. And the fourth article engages with an alternative form of nationalism found within the Nuuk underground...

The HIV epidemic in Greenland - a slow spreading infection among adult heterosexual Greenlanders

DEFF Research Database (Denmark)

Bjørn-Mortensen, Karen; Ladefoged, Karin; Obel, Niels

2013-01-01

We aimed to characterise the HIV epidemic in Greenland and to determine incidence, prevalence, mortality rates (MR) and specific causes of deaths.......We aimed to characterise the HIV epidemic in Greenland and to determine incidence, prevalence, mortality rates (MR) and specific causes of deaths....

Distortion

OpenAIRE

Schultz, Isabella Odorico; Zmylon, Nanna Nielsen; Britze, Juliane

2014-01-01

This paper investigates the audience’s perception of the music festival Distortion. By conducting a field-study focusing on the subject’s perception of Distortion, their perception of the Distortion-attendants, and their perception on the promotion of Distortion, the paper will relate the audience perception to the promotion of the event. Using the group’s own research on the promotion of Distortion, the paper points out both the consistencies and the inconsistencies between the promotion and...

Solitary Waves of Ice Loss Detected in Greenland Crustal Motion

Science.gov (United States)

Adhikari, S.; Ivins, E. R.; Larour, E. Y.

2017-12-01

The annual cycle and secular trend of Greenland mass loading are well recorded in measurements of solid Earth deformation. While bedrock vertical displacements are in phase with loading as inferred from space observations, horizontal motions have received almost no attention. The horizontal bedrock displacements can potentially track the spatiotemporal detail of mass changes with great fidelity. Our analysis of Greenland crustal motion data reveals that a significant excitation of horizontal amplitudes occurs during the intense Greenland melting. A suite of space geodetic observations and climate reanalysis data cannot explain these large horizontal displacements. We discover that solitary seasonal waves of substantial mass transport traveled through Rink Glacier in 2010 and 2012. We deduce that intense summer melting enhanced either basal lubrication or shear softening, or both, causing the glacier to thin dynamically. The newly routed upstream sublglacial water was likely to be both retarded and inefficient, thus providing a causal mechanism for the prolonged ice transport to continue well into the winter months. As the climate continues to produce increasingly warmer spring and summer, amplified seasonal waves of mass transport may become ever more present in years of future observations. Increased frequency of amplified seasonal mass transport may ultimately strengthen the Greenland's dynamic ice mass loss, a component of the balance that will have important ramifications for sea level rise. This animation shows a solitary wave passing through Rink Glacier, Greenland, in 2012, recorded by the motion of a GPS station (circle with arrow). Darker blue colors within the flow indicate mass loss, red colors show mass gain. The star marks the center of the wave. Credit: NASA/JPL-Caltech

Precipitation regimes over central Greenland inferred from 5 years of ICECAPS observations

Science.gov (United States)

Pettersen, Claire; Bennartz, Ralf; Merrelli, Aronne J.; Shupe, Matthew D.; Turner, David D.; Walden, Von P.

2018-04-01

A novel method for classifying Arctic precipitation using ground based remote sensors is presented. Using differences in the spectral variation of microwave absorption and scattering properties of cloud liquid water and ice, this method can distinguish between different types of snowfall events depending on the presence or absence of condensed liquid water in the clouds that generate the precipitation. The classification reveals two distinct, primary regimes of precipitation over the Greenland Ice Sheet (GIS): one originating from fully glaciated ice clouds and the other from mixed-phase clouds. Five years of co-located, multi-instrument data from the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) are used to examine cloud and meteorological properties and patterns associated with each precipitation regime. The occurrence and accumulation of the precipitation regimes are identified and quantified. Cloud and precipitation observations from additional ICECAPS instruments illustrate distinct characteristics for each regime. Additionally, reanalysis products and back-trajectory analysis show different synoptic-scale forcings associated with each regime. Precipitation over the central GIS exhibits unique microphysical characteristics due to the high surface elevations as well as connections to specific large-scale flow patterns. Snowfall originating from the ice clouds is coupled to deep, frontal cloud systems advecting up and over the southeast Greenland coast to the central GIS. These events appear to be associated with individual storm systems generated by low pressure over Baffin Bay and Greenland lee cyclogenesis. Snowfall originating from mixed-phase clouds is shallower and has characteristics typical of supercooled cloud liquid water layers, and slowly propagates from the south and southwest of Greenland along a quiescent flow above the GIS.

Avoidable deaths in Greenland 1968-1985

DEFF Research Database (Denmark)

Bjerregaard, Peter; Juel, K

1990-01-01

and several showed an increasing time trend. The regional patterns were particularly clear for infectious diseases and accidents, which showed low mortality rates in the capital and other towns and high mortality rates in settlements and in the remote East Greenland, while mortality rates from suicides...... and political will of the society. A list of avoidable deaths is proposed for Greenland which includes, inter alia, meningitis, lung cancer, acute respiratory infections, suicides, boat accidents and alcohol related diseases and accidents. All were considerably more common in Greenland than in Denmark...... and alcohol related diseases were high in the capital and East Greenland and low in West Greenlandic settlements. It is concluded that further studies on preventable diseases and causes of death, in particular certain infectious diseases, accidents and suicides, are needed....

Greenland Ice Sheet Mass Balance

Science.gov (United States)

Reeh, N.

1984-01-01

Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined.

Glacier dynamics over the last quarter of a century at Helheim, Kangerdlugssuaq and 14 other major Greenland outlet glaciers

Directory of Open Access Journals (Sweden)

S. L. Bevan

2012-09-01

Full Text Available The Greenland ice sheet is experiencing increasing rates of mass loss, the majority of which results from changes in discharge from tidewater glaciers. Both atmospheric and ocean drivers have been implicated in these dynamic changes, but understanding the nature of the response has been hampered by the lack of measurements of glacier flow rates predating the recent period of warming. Here, using Landsat-5 data from 1985 onwards, we extend back in time the record of surface velocities and ice-front position for 16 of Greenland's fastest-flowing tidewater glaciers, and compare these to more recent data from Landsat-7 and satellite-borne synthetic-aperture radar. Climate re-analysis data and sea surface temperatures from 1982 show that since 1995 most of Greenland and its surrounding oceans have experienced significant overall warming, and a switch to a warming trend. During the period from 1985 to 1995 when Greenland and the surrounding oceans were not warming, major tidewater outlet glaciers around Greenland, including Kangerdlugssuaq and Helheim, were dynamically stable. Since the mid-1990s, glacier discharge has consistently been both greater and more variable. Together, these observations support the hypothesis that recent dynamic change is a rapid response to climate forcing. Both air and ocean temperatures in this region are predicted to continue to warm, and will therefore likely drive further change in outlet glacier discharge.

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...

Population Structure of West Greenland Narwhals

DEFF Research Database (Denmark)

Riget, F.; Dietz, R.; Møller, P.

The hypothesis that different populations of narwhals in the West Greenland area exist has been tested by different biomarkers (metal and organochlorine concentrations, stable isotopes and DNA). Samples of muscle, liver, kidney, blubber and skin tissues of narwhals from West Greenland have been...... isotopes could not support the population structure with two West Greenland populations suggested by the genetic study....

Environmental radioactivity in Greenland in 1974

International Nuclear Information System (INIS)

Aarkrog, A.; Lippert, J.

1975-07-01

Measurements of fall-out radioactivity in Greenland in 1974 are reported. Strontium 90 (and Caesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1974. Three Greenlanders were measured by wholebody counting. (author)

Arctic Amplification and the Northward shift of a new Greenland melting record

Science.gov (United States)

Tedesco, Marco; Mote, Thomas; Fettweis, Xavier; Hanna, Edward; Booth, James; Jeyaratnam, Jeyavinoth; Datta, Rajashree; Briggs, Kate

2016-04-01

Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Using reanalysis data and the outputs of a regional climate model, here we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean was responsible for a northward shift of surface melting records over Greenland, and for increased accumulation in the south during the summer of 2015. Concurrently, new records of mean monthly zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5700±50 m isohypse over the Arctic were also set. An unprecedented (1948 - 2015) and sustained jet stream easterly flow promoted enhanced runoff, increased surface temperatures and decreased albedo in northern Greenland, while inhibiting melting in the south. The exceptional 2015 summer Arctic atmospheric conditions are consistent with the anticipated effects of Arctic Amplification, including slower zonal winds and increased jet stream wave amplitude. Properly addressing the impact of Arctic Amplification on surface runoff of the Greenland ice sheet is crucial for rigorously quantifying its contribution to current and future sea level rise, and the relative impact of freshwater discharge on the surrounding ocean.

Ocean impact on Nioghalvfjerdsfjorden Glacier, Northeast Greenland

Science.gov (United States)

Schaffer, Janin; Kanzow, Torsten; von Appen, Wilken-Jon; Mayer, Christoph

2017-04-01

The ocean plays an important role in modulating the mass balance of the Greenland Ice Sheet by delivering heat to the marine-terminating outlet glaciers around Greenland. The largest of three outlet glaciers draining the Northeast Greenland Ice Stream is Nioghalvfjerdsfjorden Glacier (also referred to as 79 North Glacier). Historic observations showed that warm waters of Atlantic origin are present in the subglacial cavity below the 80 km long floating ice tongue of the Nioghalvfjerdsfjorden Glacier and cause strong basal melt at the grounding line, but to date it has been unknown how those warm water enter the cavity. In order to understand how Atlantic origin waters carry heat into the subglacial cavity beneath Nioghalvfjerdsfjorden Glacier, we performed bathymetric, hydrographic, and velocity observations in the vicinity of the main glacier calving front aboard RV Polarstern in summer 2016. The bathymetric multibeam data shows a 500 m deep and 2 km narrow passage downstream of a 310 m deep sill. This turned out to be the only location deep enough for an exchange of Atlantic waters between the glacier cavity and the continental shelf. Hydrographic and velocity measurements revealed a density driven plume in the vicinity of the glacier calving front causing a rapid flow of waters of Atlantic origin warmer 1°C into the subglacial cavity through the 500 m deep passage. In addition, glacially modified waters flow out of the glacier cavity below the 80 m deep ice base. In the vicinity of the glacier, the glacially modified waters form a distinct mixed layer situated above the Atlantic waters and below the ambient Polar water. At greater distances from the glacier this layer is eroded by lateral mixing with ambient water. Based on our observations we will present an estimate of the ocean heat transport into the subglacial cavity. In comparison with historic observations we find an increase in Atlantic water temperatures throughout the last 20 years. The resulting

Alcohol in Greenland 1951-2010

DEFF Research Database (Denmark)

Aage, Hans

2012-01-01

Background. Fluctuations in alcohol consumption in Greenland have been extreme since alcohol became available to the Greenland Inuit in the 1950s, increasing from low levels in the 1950s to very high levels in the 1980s about twice as high as alcohol consumption in Denmark. Since then, consumption...... has declined, and current consumption is slightly below alcohol consumption in Denmark, while alcohol prices are far above Danish prices. Objective. Description of historical trends and possible causal connections of alcohol prices, alcohol consumption and alcohol-related mortality in Greenland 1951......-2010 as a background for the evaluation of the impact of various types of policy. Design. Time series for Greenland 1951-2010 for alcohol prices, consumption and mortality are compiled, and variation and correlations are discussed in relation to various policies aimed at limiting alcohol consumption. Corresponding...

Uranium geology and prospecting in Greenland

International Nuclear Information System (INIS)

Steenfelt, A.; Neilson, B.L.; Secher, K.

1977-01-01

The Geological Survey of Greenland is responsible for most of the uranium and thorium prospecting activity in Greenland, which involves airborne gamma spectrometry and scintillometry, geochemical sampling, geological investigations and ground scintillometry. Since 1971 large areas of east and west Greenland have been investigated by aerial surveys, geochemical sampling and most of the detailed scintillometric work having been restricted to small areas in east Greenland. Anomalous radioactivity in west Greenland is recorded from carbonatite intrusions, and from units in Proterozoic and Archaean gneisses. No mineralization has been found to date. In south Greenland investigations have been centred on the uranium and thorium deposit at Kvanefjeld, which is situated in a corner of the Ilimaussaq alkaline intrusion. The coincidence of favourable conditions during the differentiation and crystallization of the magma led to an extreme enrichment of uranium and thorium in the rocks that were last formed - the lujavrites. The deposit comprises parts of the lujavrites and a secondary enrichment zone in the contact between lujavrite and basaltic cover rocks. Reasonably assured reserves are 5800 t U with a grade of 310 ppm U. In the Caledonides of east Greenland some gneisses in basement cores, a dark siltstone in late Precambrian sediments and the Devonian acid magmatic rocks are characterized by a higher radiation level. A number of small mineral occurrences have been found, the majority of which are associated with the Devonian acid magmatic rocks. (author)

The Greenland shark

DEFF Research Database (Denmark)

Costantini, David; Smith, Shona; Killen, Shaun S.

2017-01-01

the oxidative status of the Greenland shark (Somniosus microcephalus), which has recently been found as the longest living vertebrate animal known to science with a lifespan of at least 272years. As compared to other species, the Greenland shark had body mass-corrected values of muscle glutathione peroxidase...... that the values of metrics of oxidative status we measured might be linked to ecological features (e.g., adaptation to cold waters and deep dives) of this shark species rather to its lifespan....

Short-term impacts of enhanced Greenland freshwater fluxes in an eddy-permitting ocean model

Directory of Open Access Journals (Sweden)

R. Marsh

2010-07-01

Full Text Available In a sensitivity experiment, an eddy-permitting ocean general circulation model is forced with realistic freshwater fluxes from the Greenland Ice Sheet, averaged for the period 1991–2000. The fluxes are obtained with a mass balance model for the ice sheet, forced with the ERA-40 reanalysis dataset. The freshwater flux is distributed around Greenland as an additional term in prescribed runoff, representing seasonal melting of the ice sheet and a fixed year-round iceberg calving flux, for 8.5 model years. By adding Greenland freshwater fluxes with realistic geographical distribution and seasonality, the experiment is designed to investigate the oceanic response to a sudden and spatially/temporally uniform amplification of ice sheet melting and discharge, rather than localized or gradual changes in freshwater flux. The impacts on regional hydrography and circulation are investigated by comparing the sensitivity experiment to a control experiment, without additional fluxes. By the end of the sensitivity experiment, the majority of additional fresh water has accumulated in Baffin Bay, and only a small fraction has reached the interior of the Labrador Sea, where winter mixed layer depth is sensitive to small changes in salinity. As a consequence, the impact on large-scale circulation is very slight. An indirect impact of strong freshening off the west coast of Greenland is a small anti-cyclonic component to the circulation around Greenland, which opposes the wind-driven cyclonic circulation and reduces net southward flow through the Canadian Archipelago by ~10%. Implications for the post-2000 acceleration of Greenland mass loss are discussed.

How Greenland melts

Directory of Open Access Journals (Sweden)

van den Broeke M.R.

2010-12-01

Full Text Available Satellite altimetry and gravimetry show that the Greenland ice sheet has been losing volume and mass since the beginning of this century. However, from these short time series of direct measurements we cannot infer what the causes of the mass loss are, i.e. ice dynamics or surface processes, or that maybe the ice sheet returns to normal after a period of volume increase and mass gain. By modelling and observing the individual components of the ice sheet mass balance, i.e. snowfall, meltwater runoff and iceberg production, we are able to identify the processes that led to the recent mass loss. We conclude that the Greenland ice sheet is significantly out of balance. Acceleration of outlet glaciers and increased runoff have contributed equally to recent Greenland mass loss. The potential for mass loss by surface processes, however, was three times greater than actually observed, due to refreezing and enhanced snowfall.

Seabird Colonies in Western Greenland

DEFF Research Database (Denmark)

Boertmann, D.; Mosbech, A.; Falk, K.

About 1 million seabirds (indvs) breed in 1032 colonies distributed along the coasts of western Greenland (Fig. 1). However, this figure does not include the little auk colonies in Avanersuaq. These colonies are roughly estimated to hold about 20 mill. pairs. All the basic information on seabird...... colonies in Greenland is compiled in a database maintained by NERI-AE. This report presents data on distribution, population numbers and population trends of 19 species of breeding colonial seabirds in western Greenland. Distributions are depicted on maps in Fig. 18-39. It is apparent that the major...... colonies are found in the northern part of the region, viz. Upernavik and Avanersuaq. The numbers of birds recorded in the database for each species are presented in Tab. 4, and on the basis of these figures estimates of the populations in western Greenland are given (Tab. 5). The most numerous species...

Vitamins and minerals in the traditional Greenland diet

DEFF Research Database (Denmark)

Andersen, S. M.

The relative importance of traditional Greenlandic food items has diminished during the last decades. Today these account for 25% of the Greenland diet with a dominance of fish, seabirds, and marine mammals. This report synthesises the available information on concentrations of vitamins and miner......The relative importance of traditional Greenlandic food items has diminished during the last decades. Today these account for 25% of the Greenland diet with a dominance of fish, seabirds, and marine mammals. This report synthesises the available information on concentrations of vitamins...... and minerals in the various food items that form the traditional Greenlandic diet. However, through this diet people in Greenland are also exposed to a high intake of heavy metals and organochlorines, due to a contamination of many of these food items. In combination with information on the concentration...... of contaminants, the information about vitamins and minerals will potentially make it possible to adjust the diet in Greenland, taking both nutrients and contaminants into account...

Seasonal migration, vertical activity and winter temperature experience of Greenland halibut Reinhardtius hippoglossoides (Walbaum) in West Greenland waters

DEFF Research Database (Denmark)

Boje, Jesper; Neuenfeldt, Stefan; Sparrevohn, Claus Reedtz

2014-01-01

resident in Disko Bay (mean range 2.6°C) than when resident in the ice fjord (mean range 1.4°C). Using the tagged halibut as a 'live tool,' we show that parts of the ice fjord are hundreds of meters deeper than previously thought. We also document the first seawater temperature measurements made beneath......The deep-water flatfish Greenland halibut Reinhardtius hippoglossoides (Walbaum) is common along the West Greenland coast. In the northwestern fjords, Greenland halibut is an important socio-economic resource for the Greenland community, but due to the deep and partly ice-covered environment, very...

Exploration history and place names of northern East Greenland: Colophon, abstract, introduction, official place names in Greenland

Directory of Open Access Journals (Sweden)

Higgins, Anthony K.

2010-12-01

Full Text Available The first recorded landing by Europeans on the coast of northern East Greenland (north of 69°N was that of William Scoresby Jr., a British whaler, in 1822. This volume includes a chronological summary of the pioneer 19th century exploration voyages made by British, Danish, Norwegian, Swedish, French and German expeditions – all of whom reported that the region had previously been occupied by the Inuit or Eskimo; also included are brief outlines of the increasing number of government and privately sponsored expeditions throughout the 20th century, whose objectives included cartography, geology, zoology, botany, trapping and the ascent of the highest mountain summits. In 1934 the Place Name Committee for Greenland was established, the tasks of which included a review of all place names hitherto recorded on published maps of Greenland, their formal adoption in danicised form, and the approval or rejection of new name proposals. In northern East Greenland, by far the largest numbers of new place names were those proposed by scientists associated with Lauge Koch’s geological expeditions that lasted from 1926 until 1958. This volume records the location and origin of more than 3000 officially approved place names as well as about 2650 unapproved names.The author’s interest in the exploration history and place names of northern East Greenland started in 1968, when the Geological Survey of Greenland initiated a major five-year geological mapping programme in the Scoresby Sund region. Systematic compilation of names began about 1970, initially with the names given by William Scoresby Jr., and subsequently broadened in scope to include the names proposed by all expeditions to northern East Greenland. The author has participated in 16 summer mapping expeditions with the Survey to northern East Greenland. Publication of this volume represents the culmination of a lifetime working in the Arctic.

Mapping Greenland's Firn Aquifer using L-band Microwave Radiometry

Science.gov (United States)

Miller, J.; Bringer, A.; Jezek, K. C.; Johnson, J. T.; Scambos, T. A.; Long, D. G.

2016-12-01

Greenland's recently discovered firn aquifer is one of the most interesting, yet still mysterious, components of the ice sheet system. Many open questions remain regarding timescales of refreezing and/or englacial drainage of liquid meltwater, and the connections of firn aquifers to the subglacial hydrological system. If liquid meltwater production at the surface of the Greenland ice sheet continues to increase, subsequent increases in the volume of mobile liquid meltwater retained within Greenland's firn aquifer may increase the possibility of crevasse-deepening via hydrofracture. Hydrofracture is an important component of supraglacial lake drainage leading to at least temporary accelerated flow velocities and ice sheet mass balance changes. Firn aquifers may also support hydrofracture-induced drainage and thus are potentially capable of significantly influencing ice sheet mass balance and sea level rise. Spaceborne L-band microwave radiometers provide an innovative tool for ice-sheet wide mapping of the spatiotemporal variability of Greenland's firn aquifer. Both refreezing and englacial drainage may be observable given the sensitivity of the microwave response to the upper surface of liquid meltwater retained within snow and firn pore space as well as the ability of L band instruments to probe the ice sheet from the surface to the firn-ice transition at pore close-off depth. Here we combine L-band (1.4 GHz) brightness temperature observations from multiple sources to demonstrate the potential of mapping firn aquifers on ice sheets using L-band microwave radiometry. Data sources include the interferometric MIRAS instrument aboard ESA's Soil Moisture and Ocean Salinity (SMOS) satellite mission and the radiometer aboard NASA's Soil Moisture Active Passive (SMAP) satellite mission. We will also present mulit-frequency L-band brightness temperature data (0.5-2 GHz) that will be collected over several firn aquifer areas on the Greenland ice sheet by the Ohio State

Towards Introducing a Geocoding Information System for Greenland

Science.gov (United States)

Siksnans, J.; Pirupshvarre, Hans R.; Lind, M.; Mioc, D.; Anton, F.

2011-08-01

Currently, addressing practices in Greenland do not support geocoding. Addressing points on a map by geographic coordinates is vital for emergency services such as police and ambulance for avoiding ambiguities in finding incident locations (Government of Greenland, 2010) Therefore, it is necessary to investigate the current addressing practices in Greenland. Asiaq (Asiaq, 2011) is a public enterprise of the Government of Greenland which holds three separate databases regards addressing and place references: - list of locality names (towns, villages, farms), - technical base maps (including road center lines not connected with names, and buildings), - the NIN registry (The Land Use Register of Greenland - holds information on the land allotments and buildings in Greenland). The main problem is that these data sets are not interconnected, thus making it impossible to address a point in a map with geographic coordinates in a standardized way. The possible solutions suffer from the fact that Greenland has a scattered habitation pattern and the generalization of the address assignment schema is a difficult task. A schema would be developed according to the characteristics of the settlement pattern, e.g. cities, remote locations and place names. The aim is to propose an ontology for a common postal address system for Greenland. The main part of the research is dedicated to the current system and user requirement engineering. This allowed us to design a conceptual database model which corresponds to the user requirements, and implement a small scale prototype. Furthermore, our research includes resemblance findings in Danish and Greenland's addressing practices, data dictionary for establishing Greenland addressing system's logical model and enhanced entity relationship diagram. This initial prototype of the Greenland addressing system could be used to evaluate and build the full architecture of the addressing information system for Greenland. Using software engineering

Building sustained partnerships in Greenland through shared science

Science.gov (United States)

Culler, L. E.; Albert, M. R.; Ayres, M. P.; Grenoble, L. A.; Virginia, R. A.

2013-12-01

Greenland is a hotspot for polar environmental change research due to rapidly changing physical and ecological conditions. Hundreds of international scientists visit the island each year to carry out research on diverse topics ranging from atmospheric chemistry to ice sheet dynamics to Arctic ecology. Despite the strong links between scientific, social, and political issues of rapid environmental change in Greenland, communication with residents of Greenland is often neglected by researchers. Reasons include language barriers, difficulties identifying pathways for communication, balancing research and outreach with limited resources, and limited social and cultural knowledge about Greenland by scientists. Dartmouth College has a legacy of work in the Polar Regions. In recent years, a National Science Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) in Polar Environmental Change funded training for 25 Ph.D. students in the Ecology, Earth Science, and Engineering graduate programs at Dartmouth. An overarching goal of this program is science communication between these disciplines and to diverse audiences, including communicating about rapid environmental change with students, residents, and the government of Greenland. Students and faculty in IGERT have been involved in the process of engaging with and sustaining partnerships in Greenland that support shared cultural and educational experiences. We have done this in three ways. First, a key component of our program has been hosting students from Ilisimatusarfik (the University of Greenland). Since 2009, five Greenlandic students have come to Dartmouth and formed personal connections with Dartmouth students while introducing their Greenlandic culture and language (Kalaallisut). Second, we have used our resources to extend our visits to Greenland, which has allowed time to engage with the community in several ways, including sharing our science via oral and poster presentations at Katuaq

Sexual and reproductive health in Greenland: evaluation of implementing sexual peer-to-peer education in Greenland (the SexInuk project).

Science.gov (United States)

Homøe, Anne-Sophie; Knudsen, Ane-Kersti Skaarup; Nielsen, Sigrid Brisson; Grynnerup, Anna Garcia-Alix

2015-01-01

For decades, the rates of sexually transmitted infections (STIs), such as gonorrhoea, chlamydia and syphilis, have increased in Greenland, especially within the young age groups (15-29 years). From 2006 to 2013, the number of abortions has been consistent with approximately 800-900 abortions per year in Greenland, which is nearly as high as the total number of births during the same period. Previous studies in Greenland have reported that knowledge about sexual health is important, both as prevention and as facilitator to stop the increasing rates of STIs. A peer-to-peer education programme about sexual health requires adaption to cultural values and acceptance among the population and government in order to be sustainable. Formative evaluation of a voluntary project (SexInuk), in relation to peer-to-peer education with focus on sexual health. Two workshops were conducted in Nuuk, Greenland, to recruit Greenlandic students. Qualitative design with focus group interviews (FGIs) to collect qualitative feedback on feasibility and implementation of the project. Supplemented with a brief questionnaire regarding personal information (gender, age, education) and questions about the educational elements in the SexInuk project. Eight Greenlandic students, who had completed one or two workshops, were enrolled. The FGIs showed an overall consensus regarding the need for improving sexual health education in Greenland. The participants requested more voluntary educators, to secure sustainability. The articulation of taboo topics in the Greenlandic society appeared very important. The participants suggested more awareness by promoting the project. Cultural values and language directions were important elements in the FGIs. To our knowledge, voluntary work regarding peer-to-peer education and sexual health has not been structurally evaluated in Greenland before. To achieve sustainability, the project needs educators and financial support. Further research is needed to investigate

Estimates of reproductive potential of Greenland halibut (Reinhardtius hippoglossoides) in East Greenland based on an update of maturity status

DEFF Research Database (Denmark)

Kennedy, James; Hedeholm, Rasmus B.; Gundersen, Agnes C.

2014-01-01

When estimating reproductive potential (RP), correct interpretation of the maturity status is essential. It has now become apparent the presence of vitellogenic oocytes within the ovary of Greenland halibut (Reinhardtius hippoglossoides) does not necessarily indicate they will spawn within the next...... twelve months. This has led to a revision of the interpretation of the maturity scale where fish which contain only a developing cohort (DC) of oocytes are considered immature. Comparisons were made of estimates of L50 of female Greenland halibut in East Greenland using the previous interpretation......), respectively. Combining the maturity data with abundance data of Greenland halibut in East Greenland, spawning stock biomass (SSB) and total egg production (TEP) was estimated in four quadrants between 1998 and 2012 using both the previous and current interpretation of the maturity scale. Using the new...

Success and failure of reindeer herding in Greenland

Directory of Open Access Journals (Sweden)

Christine Cuyler

1999-04-01

Full Text Available Animal husbandry is a recent innovation in Greenland, specifically reindeer husbandry is less than 50 years old. Reindeer husbandry was first established in mid-west Greenland and later in southern Greenland. The Greenland hunter tradition and culture is, however, still dominant in many communities. During the 1980s and 1990s, the incompatibility of these two traditions resulted in the failure of reindeer husbandry in mid-west Greenland. There were neither herding nor seasonal herd movements. Animals remained year round on the winter range, which was destroyed as lichens were trampled every summer. Without seasonal herd movements both sustainable range use and control of the herd were lost. Today, there are just two semi-domestic reindeer herds left, and both are in southern Greenland. One herd is commercially successful, and the other is under development. In mid-west Greenland, semi-domestic reindeer husbandry officially ended in 1998, and a hunt was initiated to remove the remaining population. Possibly, by the year 2000 any animals left in this region will be considered wild caribou.

Markers of futurity and aspect in West Greenlandic

DEFF Research Database (Denmark)

Trondhjem, Naja Blytmann

2014-01-01

if necessary. The Alaskan Iñupiaq has an opposition between past, present and future. In Inuktitut and West Greenlandic tense is marked by optional derivational affixes. In Inuktitut the tense affixes have developed a complicated remoteness system (future and past) (Swift, 2004). In West Greenlandic the future...... is unmarked and past time reference can be marked if necessary. The Alaskan Iñupiaq has an opposition between past, present and future. In Inuktitut and West Greenlandic tense is marked by optional derivational affixes. In Inuktitut the tense affixes have developed a complicated remoteness system (future......Markers of futurity and aspect in West Greenlandic Unlike European languages tense in the West Greenlandic (WG) language is not marked in the inflection, but it is marked by derivational affixes (henceforth affixes). The West Greenlandic language belongs to Inuit-languages, (Iñupiaq (Alaska...

East Greenland Caledonides: stratigraphy, structure and geochronology: Lower Palaeozoic stratigraphy of the East Greenland Caledonides

Directory of Open Access Journals (Sweden)

Smith, M. Paul

2004-12-01

Full Text Available The Lower Palaeozoic stratigraphy of the East Greenland Caledonides, from the fjord region of North-East Greenland northwards to Kronprins Christian Land, is reviewed and a number of new lithostratigraphical units are proposed. The Slottet Formation (new is a Lower Cambrian quartzite unit, containing Skolithos burrows, that is present in the Målebjerg and Eleonore Sø tectonic windows, in the nunatak region of North-East Greenland. The unit is the source of common and often-reported glacial erratic boulders containing Skolithos that are distributed throughout the fjord region. The Målebjerg Formation (new overlies the Slottet Formation in the tectonic windows, and comprises limestones and dolostones of assumed Cambrian–Ordovician age. The Lower Palaeozoic succession of the fjord region of East Greenland (dominantly limestones and dolostones is formally placed in the Kong Oscar Fjord Group (new. Amendments are proposed for several existing units in the Kronprins Christian Land and Lambert Land areas, where they occur in autochthonous, parautochthonous and allochthonous settings.

Occurrence of anisakid nematodes in Atlantic cod (Gadus morhua) and Greenland cod (Gadus ogac), West Greenland

DEFF Research Database (Denmark)

Mouritsen, Kim N.; Hedeholm, Rasmus; Schack, Henriette B.

2010-01-01

Anisakid nematodes commonly infect gadids, and are of economic and aesthetic importance to the commercial fishing industry in Greenland as some species are pathogenic to humans. However, very little is known about the occurrence of these parasites and their impact on the hosts in Greenland waters....... During a survey in 2005, stomach sample of 227 Atlantic cod (Gadus morhua) and 64 Greenland cod (Gadus ogac) was collected in Godthaab and Sisimiut fiord systems in West Greenland waters. All cod were dissected for stomach contents and anisakid nematodes were removed from the visceral cavity. Third stage...... nematode species regarding prevalence of infection and mean infection intensity was evident, and there was no relationship between fish condition and the intensity of nematode infections. Standardised for size, capelin-eating cod were in better condition and more heavily infected than fish subsisting...

Developing renewable energy in discontiguous Greenland

DEFF Research Database (Denmark)

Carruth, Susan

2016-01-01

Infrastructural Urbanism’s advocacy of creating synergies between technological, economical, and ecological processes holds great potential for guiding domestic energy planning in a transforming Greenland. However, the movement has largely been conceived in the context of regional paradigms very...... different from Greenland, and has yet to fully engage with the sociocultural dimensions of infrastructures. This article proposes that for Infrastructural Urbanism to offer real potential in Greenland it must engage with micro-scale, everyday material practices, thereby thickening the scale and the scope...

Homicide in Greenland 1985-2010

DEFF Research Database (Denmark)

Christensen, Martin R; Thomsen, Asser H; Høyer, Christian B

2016-01-01

PURPOSE: Homicide in Greenland has not often been investigated. The latest published study documented a dramatic rise in the homicide rate from around 1/100,000 inhabitants to more than 23/100,000 inhabitants from 1946 to 1984. The aim of our study was to characterize homicides in Greenland from ...

Quantifying the Jakobshavn Effect: Jakobshavn Isbrae, Greenland, compared to Byrd Glacier, Antarctica

Science.gov (United States)

Hughes, T.; Sargent, A.; Fastook, J.; Purdon, K.; Li, J.; Yan, J.-B.; Gogineni, S.

2014-04-01

The Jakobshavn Effect is a series of positive feedback mechanisms that was first observed on Jakobshavn Isbrae, which drains the west-central part of the Greenland Ice Sheet and enters Jakobshavn Isfjord at 69°10'. These mechanisms fall into two categories, reductions of ice-bed coupling beneath an ice stream due to surface meltwater reaching the bed, and reductions in ice-shelf buttressing beyond an ice stream due to disintegration of a laterally confined and locally pinned ice shelf. These uncoupling and unbuttressing mechanisms have recently taken place for Byrd Glacier in Antarctica and Jakobshavn Isbrae in Greenland, respectively. For Byrd Glacier, no surface meltwater reaches the bed. That water is supplied by drainage of two large subglacial lakes where East Antarctic ice converges strongly on Byrd Glacier. Results from modeling both mechanisms are presented here. We find that the Jakobshavn Effect is not active for Byrd Glacier, but is active for Jakobshavn Isbrae, at least for now. Our treatment is holistic in the sense it provides continuity from sheet flow to stream flow to shelf flow. It relies primarily on a force balance, so our results cannot be used to predict long-term behavior of these ice streams. The treatment uses geometrical representations of gravitational and resisting forces that provide a visual understanding of these forces, without involving partial differential equations and continuum mechanics. The Jakobshavn Effect was proposed to facilitate terminations of glaciation cycles during the Quaternary Ice Age by collapsing marine parts of ice sheets. This is unlikely for the Antarctic and Greenland ice sheets, based on our results for Byrd Glacier and Jakobshavn Isbrae, without drastic climate warming in high polar latitudes. Warming would affect other Antarctic ice streams already weakly buttressed or unbuttressed by an ice shelf. Ross Ice Shelf would still protect Byrd Glacier.

Environmental radioactivity in Greenland 1977

International Nuclear Information System (INIS)

Aarkrog, A.; Lippert, J.

1978-07-01

Measurements of fallout radioactivity in Greenland in 1977 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1977. (author)

Marginal thinning in Northwest Greenland during 2002-2011

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Kjær, K. H.; Wahr, J. M.

2012-01-01

Many glaciers along the southeast and northwest coast of Greenland have accelerated, increasing the Greenland ice sheet's (GrIS) contribution to global sea-level rise. Here, we map elevation changes in northwest Greenland during 2003-2009 using high-resolution Ice, Cloud and land Elevation Satell...

The role of meltwater in high-latitude trough-mouth fan development : the Disko Trough-Mouth Fan, West Greenland.

OpenAIRE

Cofaigh, Colm Ó.; Hogan, Kelly A.; Jennings, Anne E.; Callard, S. Louise; Dowdeswell, Julian A.; Noormets, Riko; Evans, Jeff

2018-01-01

The Disko Trough-Mouth Fan (TMF) is a major submarine sediment fan located along the central west Greenland continental margin offshore of Disko Trough. The location of the TMF at the mouth of a prominent cross-shelf trough indicates that it is a product of repeated glacigenic sediment delivery from former fast-flowing outlets of the Greenland Ice Sheet, including an ancestral Jakobshavn Isbrae, which expanded to the shelf edge during successive glacial cycles. This study focuses on the upper...

The Greenland Analogue Project (GAP). Literature review of hydrogeology/ hydrogeochemistry

Energy Technology Data Exchange (ETDEWEB)

Wallroth, Thomas; Lokrantz, Hanna; Rimsa, Andrius (Bergab Consulting Geologists, Goeteborg (Sweden))

2010-09-15

This report is produced as part of the Greenland Analogue Project (GAP), carried out as a collaboration project with the Canadian Nuclear Waste Management Organization (NWMO), Posiva Oy and the Swedish Nuclear Fuel and Waste Management Co (SKB). The overall aim of the project is to improve the current understanding of hydrogeological and hydrogeochemical processes associated with continental-scale glacial periods including with the presence of permafrost and the advance/retreat of ice sheets. The project will focus on studying how an ice sheet affects groundwater flow and water chemistry around a deep geological repository in crystalline bedrock. The Greenland Analogue Project consists of three active sub-projects (A-C) with individual objectives. Field studies are conducted in the Kangerlussuaq region, in central Western Greenland. Sub-projects A and B collectively aim at improving the understanding of ice sheet hydrology by combining investigations on surface water processes with ice sheet drilling and instrumentation. In sub-project C, the penetration of glacial melt water into the bedrock, groundwater flow and the chemical composition of water will be studied. Main planned activities in sub-project C include drilling of a deep borehole in front of the ice sheet, in which different downhole surveys, sampling and monitoring will be carried out. The primary aim of this report is to review available information about hydrogeology and hydrogeochemistry in central Western Greenland, with special emphasis on the area around Kangerlussuaq. The relevant information about this area is however very limited, and it was decided to extend the review to briefly include studies made in other regions with similar conditions in terms of geology, climate and glaciology. The number of published studies made in other areas with glaciers, ice sheets or permafrost is very large, and the review and list of references in this report is far from complete. It is also obvious that both

The Greenland Analogue Project (GAP). Literature review of hydrogeology/ hydrogeochemistry

International Nuclear Information System (INIS)

Wallroth, Thomas; Lokrantz, Hanna; Rimsa, Andrius

2010-09-01

This report is produced as part of the Greenland Analogue Project (GAP), carried out as a collaboration project with the Canadian Nuclear Waste Management Organization (NWMO), Posiva Oy and the Swedish Nuclear Fuel and Waste Management Co (SKB). The overall aim of the project is to improve the current understanding of hydrogeological and hydrogeochemical processes associated with continental-scale glacial periods including with the presence of permafrost and the advance/retreat of ice sheets. The project will focus on studying how an ice sheet affects groundwater flow and water chemistry around a deep geological repository in crystalline bedrock. The Greenland Analogue Project consists of three active sub-projects (A-C) with individual objectives. Field studies are conducted in the Kangerlussuaq region, in central Western Greenland. Sub-projects A and B collectively aim at improving the understanding of ice sheet hydrology by combining investigations on surface water processes with ice sheet drilling and instrumentation. In sub-project C, the penetration of glacial melt water into the bedrock, groundwater flow and the chemical composition of water will be studied. Main planned activities in sub-project C include drilling of a deep borehole in front of the ice sheet, in which different downhole surveys, sampling and monitoring will be carried out. The primary aim of this report is to review available information about hydrogeology and hydrogeochemistry in central Western Greenland, with special emphasis on the area around Kangerlussuaq. The relevant information about this area is however very limited, and it was decided to extend the review to briefly include studies made in other regions with similar conditions in terms of geology, climate and glaciology. The number of published studies made in other areas with glaciers, ice sheets or permafrost is very large, and the review and list of references in this report is far from complete. It is also obvious that both

Modelling the short-term response of the Greenland ice-sheet to global warming

NARCIS (Netherlands)

Wal, R.S.W. van de; Oerlemans, J.

1997-01-01

A two-dimensional vertically integrated ice flow model has been developed to test the importance of various processes and concepts used for the prediction of the contribution of the Greenland ice-sheet to sea-level rise over the next 350 y (short-term response). The mass balance is modelled by the

Pump-induced optical distortions in disk amplifier modules: holographic and interferometric measurements

International Nuclear Information System (INIS)

Linford, G.J.; Chau, H.H.; Glaze, J.A.; Layne, C.B.; Rainer, F.

1975-01-01

Interferometric measurements have been made of the optical distortions induced in laser disk amplifiers during the flashlamp pumping pulse. Both conventional interferometric methods and the techniques of double exposure holographic interferometry were used to identify four major sources of pump-induced optical distortions: subsonic intrusion of hot gas (traced to leakage of atmospheric oxygen into the amplifier), microexplosions of dust particles, thermally induced optical distortions in the glass disks, and gaseous optical distortion effects caused by turbulent flow of the purging nitrogen gas supply used within the laser amplifier head. Methods for reducing or eliminating the effects of each of these optical distortions are described

Bourdieu in Greenland

DEFF Research Database (Denmark)

Hussain, Naimah

2017-01-01

. There is almost no previous research on Greenlandic media in general and journalism practice in particular. Mapping this small but contested field allows us to highlight some of the key analytical strengths of Bourdieu’s field theory and its ability to capture the dynamic actor relationships in such a complex......, structured space. At the same time, however, the “post-colonial” realities of Greenlandic journalism can help us to pose some questions about the limits – or the need for further development – of Bourdieu’s initial sketch about the journalistic field. This chapter tests the analytical concepts of capital...

Weather Test Reference Year of Greenland

DEFF Research Database (Denmark)

Kragh, Jesper; Pedersen, Frank; Svendsen, Svend

2005-01-01

the construction of two test reference years of Greenland used in the work of establishing new energy frame for the coming building code of Greenland. The first test reference year is constructed using measurements of climatic parameters from the town Nuuk located in the southwestern part of Greenland. The second...... test reference year is constructed using measurements from the town Uummannaq located in the north part of Greenland on the west coast. The construction of the test reference years fulfills the procedures described in the standard EN ISO 15927-4 using the following main weather parameters: Dry bulb...... temperature, global radiation, relative humidity and mean wind speed. To construct the test reference years a program called REFYEAR was developed in MatLab. REFYEAR automatically constructs the test reference year using an input file containing the climatic measurements. The two constructed test reference...

Future markers of the West Greenlandic

DEFF Research Database (Denmark)

Trondhjem, Naja Blytmann

2010-01-01

Abstract West Greenlandic, a polysynthetic language, belongs to Inuit languages. In Inuktitut (Canada) and West Greenlandic (Inuit languages) tense is marked by optional tense suffixes and in both languages the temporal systems are based on a future/ non-future opposition. In Inuktitut the tense...... suffixes have developed a complicated remoteness system. In West Greenlandic the future tense suffixes have a distinction between vague and inevitable future, and the past time suffixes have developed different perfect meanings. In Iñupiaq (Alaska), the temporal system is based on an opposition between...... past, present and future, where tense is marked in the flectional morpheme, but only in the indicative mood. There are only a few tense suffixes. The meanings of these tense suffixes are the same as those of the West Greenlandic tense suffixes. My current work is a typological investigation about...

Environmental radioactivity in Greenland in 1981

International Nuclear Information System (INIS)

Aarkrog, A.; Dahlgaard, H.; Hansen, H.; Lippert, J.; Nilsson, K.; Holm, E.

1982-07-01

Measurements of fallout radioactivity in Greenland in 1981 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1981. Further results of the 239 , 240 Pu and 241 Am measurements on samples from the expedition to Thule in August 1979 are prsented. Brown algae collected in East Greenland in 1969 were analysed for Pu and Am. (author)

Greenland from Archaean to Quaternary, Descriptive text to the 1995 Geological Map of Greenland 1:2 500 000, 2nd edition

Directory of Open Access Journals (Sweden)

Kalsbeek, Feiko

2009-11-01

Full Text Available The geological development of Greenland spans a period of nearly 4 Ga, from Eoarchaean to the Quaternary. Greenland is the largest island on Earth with a total area of 2 166 000 km2, but only c. 410 000 km2 are exposed bedrock, the remaining part being covered by a major ice sheet (the Inland Ice reaching over 3 km in thickness. The adjacent offshore areas underlain by continental crust have an area of c. 825 000 km2. Greenland is dominated by crystalline rocks of the Precambrian shield, which formed during a succession of Archaean and Palaeoproterozoic orogenic events and stabilised as a part of the Laurentian shield about 1600 Ma ago. The shield area can be divided into three distinct types of basement provinces: (1 Archaean rocks (3200–2600 Ma old, with local older units up to >3800Ma that were almost unaffected by Proterozoic or later orogenic activity; (2 Archaean terrains reworked during the Palaeoproterozoic around 1900–1750 Ma ago; and (3 terrains mainly composed of juvenile Palaeoproterozoic rocks (2000–1750 Ma in age.Subsequent geological developments mainly took place along the margins of the shield. During the Proterozoic and throughout the Phanerozoic major sedimentary basins formed, notably in North and North-East Greenland, in which sedimentary successions locally reaching 18 km in thickness were deposited. Palaeozoic orogenic activity affected parts of these successions in the Ellesmerian fold belt of North Greenland and the East Greenland Caledonides; the latter also incorporates reworked Precambrian crystalline basement complexes. Late Palaeozoic and Mesozoic sedimentary basins developed along the continent–ocean margins in North, East and West Greenland and are now preserved both onshore and offshore. Their development was closely related to continental break-up with formation of rift basins. Initial rifting in East Greenland in latest Devonian to earliest Carboniferous time and succeeding phases culminated with the

East Greenland Ridge in the North Atlantic Ocean

DEFF Research Database (Denmark)

Andreasen, Arne Døssing; Dahl-Jensen, T.; Thybo, Hans

2008-01-01

The combined Greenland-Senja Fracture Zones (GSFZ) represent a first-order plate tectonic feature in the North Atlantic Ocean. The GSFZ defines an abrupt change in the character of magnetic anomalies with well-defined seafloor spreading anomalies in the Greenland and Norwegian basins to the south...... but ambiguous and weak magnetic anomalies in the Boreas Basin to the north. Substantial uncertainty exists concerning the plate tectonic evolution of the latter area, including the role of the East Greenland Ridge, which is situated along the Greenland Fracture Zone. In 2002, a combined ocean-bottom seismometer...

Crustal structure of the Central-Eastern Greenland: results from the TopoGreenland refraction profile

Science.gov (United States)

Shulgin, Alexey; Thybo, Hans

2014-05-01

Until present, seismic surveys have only been carried out offshore and near the coasts of Greenland, where the crustal structure is affected by oceanic break-up. We present the deep seismic structure of the crust of the interior of Greenland, based on the new and the only existing so far seismic refraction/wide-angle reflection profile. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass, made acquisition of geophysical data logistically complicated. The profile extends 310 km inland in E-W direction from the approximate edge of the stable ice cap near the Scoresby Sund across the center of the ice cap. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 125 kg at 35-85 m depth in individual boreholes. Given that the data acquisition was affected by the thick ice sheet, we questioned the quality of seismic records in such experiment setup. We have developed an automatic routine to check the amplitudes and spectra of the selected seismic phases and to check the differences/challenges in making seismic experiments on ice and the effects of ice on data interpretation. Using tomographic inversion and forward ray tracing modelling we have obtained the two-dimensional velocity model down to a 50 km depth. The model shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western part of the profile to 40 km in its eastern part. Relatively high lower crustal velocities (Vp 6.8 - 7.3 km/s) in the western part of the TopoGreenland profile may result from past collision tectonics or, alternatively, may be related to the speculated passage of the Iceland mantle plume. Comparison of our results

Trends of cervical cancer in Greenland

DEFF Research Database (Denmark)

Sander, Bente B; Rebolj, Matejka; Lynge, Elsebeth

2014-01-01

BACKGROUND: Due to its extraordinarily fast economic and social transition, virtually closed borders before 1940 and, moreover, that 85% of the population has the distinctive genetics of the Inuit, Greenland is a very interesting country to study cervical cancer from a historical perspective....... Nevertheless, little has been reported about long-term cancer trends in Greenland. Our aim was to describe and interpret the incidence of cervical cancer from 1950 to 2009. MATERIAL AND METHODS: We systematically searched PubMed for articles reporting the incidence of cervical cancer in Greenland. We...... supplemented this with data for 1980-2009 obtained from the Chief Medical Officer of Greenland. RESULTS: Incidence of cervical cancer was around 10 per 100 000 women (age-standardised, world population, ASW) in the 1950s, 30 per 100 000 in the 1960s, and in the 1980s around 60 per 100 000. From 1985 onwards...

Physical activity patterns in Greenland: A country in transition

DEFF Research Database (Denmark)

Dahl-Petersen, Inger; Jørgensen, Marit E; Bjerregaard, Peter

2011-01-01

To examine differences in physical activity patterns among Inuit in Greenland in relation to social transition. The Inuit in Greenland are an indigenous population in the circumpolar north who are experiencing rapid social transition.......To examine differences in physical activity patterns among Inuit in Greenland in relation to social transition. The Inuit in Greenland are an indigenous population in the circumpolar north who are experiencing rapid social transition....

Q fever in Greenland

DEFF Research Database (Denmark)

Koch, Anders; Svendsen, Claus Bo; Christensen, Jens Jorgen

2010-01-01

We report a patient with Q fever endocarditis in a settlement in eastern Greenland (Isortoq, Ammassalik area). Likely animal sources include sled dogs and seals. Q fever may be underdiagnosed in Arctic areas but may also represent an emerging infection.......We report a patient with Q fever endocarditis in a settlement in eastern Greenland (Isortoq, Ammassalik area). Likely animal sources include sled dogs and seals. Q fever may be underdiagnosed in Arctic areas but may also represent an emerging infection....

Modelling Greenland icebergs

Science.gov (United States)

Marson, Juliana M.; Myers, Paul G.; Hu, Xianmin

2017-04-01

The Atlantic Meridional Overturning Circulation (AMOC) is well known for carrying heat from low to high latitudes, moderating local temperatures. Numerical studies have examined the AMOC's variability under the influence of freshwater input to subduction and deep convections sites. However, an important source of freshwater has often been overlooked or misrepresented: icebergs. While liquid runoff decreases the ocean salinity near the coast, icebergs are a gradual and remote source of freshwater - a difference that affects sea ice cover, temperature, and salinity distribution in ocean models. Icebergs originated from the Greenland ice sheet, in particular, can affect the subduction process in Labrador Sea by decreasing surface water density. Our study aims to evaluate the distribution of icebergs originated from Greenland and their contribution to freshwater input in the North Atlantic. To do that, we use an interactive iceberg module coupled with the Nucleus for European Modelling of the Ocean (NEMO v3.4), which will calve icebergs from Greenland according to rates established by Bamber et al. (2012). Details on the distribution and trajectory of icebergs within the model may also be of use for understanding potential navigation threats, as shipping increases in northern waters.

Joint Science Education Project: Learning about polar science in Greenland

Science.gov (United States)

Foshee Reed, Lynn

2014-05-01

their states, regions, and countries with one another. A subset of the Field School students continue their polar science exploration by traveling to and experiencing science at the top of the Greenlandic ice sheet, as participants in Arctic Science Education Week. They launched weather balloons, took measurements of reflectivity to learn more about albedo, studied glaciers and ice sheets and created hands-on models to study their flow, shadowed the Summit science technicians on their rounds, practiced taking clean snow samples, examined a back-lit snow pit to observe the differences between seasonal snows and ice formation, and assisted researchers by taking samples from the snow pit for isotope analysis. Lastly, I will share one group multi- and interdisciplinary activity used at JSEP which illustrates how to combine mathematics and science with global studies. As noted in the Mathematics of Planet Earth 2013 initiative: "The challenges facing our planet and our civilization are multidisciplinary and multifaceted, and the mathematical sciences play a central role in the scientific effort to understand and to deal with these challenges." In particular, this group activity uses mathematical modeling and data representation to spark a discussion of civic engagement and to raise awareness that the polar regions are critically important to the global system.

Application of GRACE to the Evaluation of an Ice Flow Model of the Greenland Ice Sheet

Science.gov (United States)

Schlegel, N.; Wiese, D. N.; Watkins, M. M.; Larour, E. Y.; Box, J. E.; Fettweis, X.; van den Broeke, M. R.; Morlighem, M.; Boening, C.; Seroussi, H. L.

2014-12-01

Quantifying Greenland's future contribution to sea level rise is a challenging task and requires accurate estimates of ice flow sensitivity to climate change. Transient ice flow models are promising tools for estimating future ice sheet behavior. However, confidence in these types of future projections is low, especially because evaluation of model historical runs is so challenging due to the scarcity of continental-wide data for validation. For more than a decade, NASA's GRACE has continuously acquired time-variable measurements of the Earth's gravity field and has provided unprecedented surveillance of mass balance of the ice sheets, offering an opportunity for ice sheet model evaluation. Here, we take advantage of a new high-resolution (~300 km) monthly mascon solution for the purpose of mass balance comparison with an independent, historical ice flow model simulation using the Ice Sheet System Model (ISSM). The comparison highlights which regions of the ice sheet differ most from GRACE. Investigation of regional differences in trends and seasonal amplitudes between simulations forced with three different Regional Climate Model (RCM)-based estimates of surface mass balance (SMB) allows us to make conclusions about the relative contributions of various error sources in the model hindcast. This study constitutes the first regional comparison of GRACE data and an ice sheet model. Conclusions will aid in the improvement of RCM SMB estimates as well as ice sheet simulation estimates of present and future rates of sea level rise. This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Program and President's and Director's Fund Program.

Hydrologic Outlets of the Greenland Ice Sheet

Data.gov (United States)

National Aeronautics and Space Administration — The Hydrologic Outlets of the Greenland Ice Sheet data set contains GIS point shapefiles that include 891 observed and potential hydrologic outlets of the Greenland...

Improving the Greenlandic Greenhouse Gas Inventory

DEFF Research Database (Denmark)

Nielsen, Ole-Kenneth; Baunbæk, Lene; Gyldenkærne, Steen

The project to improve the Greenlandic greenhouse gas (GHG) inventory was undertaken due to the recommendations made by the UNFCCC review team in connection with the 2008 and 2009 submissions by the Kingdom of Denmark. The improvements made to the Greenlandic GHG emission inventory were substantial...

Reuse of harbour sediments in the Greenlandic construction industry

DEFF Research Database (Denmark)

Belmonte, Louise Josefine; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

2010-01-01

The purpose of this study is to investigate possibilities of using harbour sediments from the Greenlandic harbours as substitutes in the Greenlandic construction industry, mainly for concrete production and road construction. Materials for use in the Greenlandic construction industry are shipped...

Present conditions in Greenland and the Kangerlussuaq area

International Nuclear Information System (INIS)

Nielsen, A. B.

2010-01-01

Greenland is the world's largest island, with an area of 2.2 million square kilometres, 80 % of which is covered by the ice sheet. The climate is Arctic, but as Greenland stretches 2600 km from north to south, there is a huge variability in climate, with temperature decreasing from south to north. Due to the influence of oceanic currents, the west coast is slightly warmer than the east coast. Precipitation also decreases strongly from the south to the north, and also with distance from the coast. Kangerlussuaq is located in the dry, continental area of central west Greenland. The bedrock of Greenland is dominated by Precambrian gneisses, with sedimentary rocks occurring in some areas of East and North Greenland, and smaller areas of basalts. All of Greenland has been glaciated several times and has thus been eroded and shaped by the ice, as it still is at the ice margin. Soils are generally thin, and especially in the gneiss regions rather poor in plant nutrients. Permafrost occurs throughout the ice free areas of Greenland. It is continuous in the north, discontinuous along parts of the central east and west coast and occurs as isolated patches in the south. Kangerlussuaq is in the southernmost part of the continuous permafrost zone. The spatial variability in climate is also reflected in the vegetation zones, which range from Arctic dessert in the far north, through dwarf shrub zones with increasing plant height and density towards the south, to the arctic shrub zone in the continental parts of West Greenland and subarctic Birch forest in South Greenland. The terrestrial food chains in Greenland are generally short and with few species. Cyclic variation in population sizes has been observed in some mammal species, including lemming and caribou. Many species of mammals and birds are associated with the coastal environment, which is therefore also and important resource area for the human population. Fishery is the most economically important industry in Greenland

Assessing Fan Flutter Stability in Presence of Inlet Distortion Using One-Way and Two-Way Coupled Methods

Science.gov (United States)

Herrick, Gregory P.

2014-01-01

Concerns regarding noise, propulsive efficiency, and fuel burn are inspiring aircraft designs wherein the propulsive turbomachines are partially (or fully) embedded within the airframe; such designs present serious concerns with regard to aerodynamic and aeromechanic performance of the compression system in response to inlet distortion. Previously, a preliminary design of a forward-swept high-speed fan exhibited flutter concerns in clean-inlet flows, and the present author then studied this fan further in the presence of off-design distorted in-flows. Continuing this research, a three-dimensional, unsteady, Navier-Stokes computational fluid dynamics code is again applied to analyze and corroborate fan performance with clean inlet flow and now with a simplified, sinusoidal distortion of total pressure at the aerodynamic interface plane. This code, already validated in its application to assess aerodynamic damping of vibrating blades at various flow conditions using a one-way coupled energy-exchange approach, is modified to include a two-way coupled timemarching aeroelastic simulation capability. The two coupling methods are compared in their evaluation of flutter stability in the presence of distorted in-flows.

Resources of Greenland and the possibilities of a joint Danish/Greenland exploitation of specially the energy resources in a period of economic crisis

International Nuclear Information System (INIS)

Taagholt, J.

1983-01-01

As Greenland is very dependent on imported articles and fuels, mainly petroleum, economic crisis or just an energy crisis will affect Greenland very much. To evaluate Greenlands situation in a crisis an account is given of the climatic conditions, of the present economic situation, and of planned development projects, The Greenland Area has Denmarks largest potential energy reserves of known coal deposits, of partially surveyed uranium deposits, of partially surveyed potential hydroelectric power reserves, and of petroleum and natural gas deposits not yet pointed out. An analysis is made of the utilization of the Greenland energy resources today, and the plans of future extended utilization. (LN)

Impact of deep-sea fishery for Greenland halibut (Reinhardtius hippoglossoides) on non-commercial fish species off West Greenland

DEFF Research Database (Denmark)

Jørgensen, Ole A; Bastardie, Francois; Eigaard, Ole Ritzau

2014-01-01

Since the late 1980s, a deep-sea fishery for Greenland halibut (Reinhardtius hippoglossoides) has been developing gradually in West Greenland. Deep-sea fish species are generally long-lived and characterized by late age of maturity, low fecundity, and slow growth, features that probably cause low....... During the period 1988–2011, population abundance and size composition changed as catch and effort in the Greenland halibut fishery increased. Two species showed a significant decrease in abundance, and four populations showed a significant reduction in mean weight of individuals (p , 0.05). Correlation...... analyses show that most of the observed trends in abundance are probably not related to increasing fishing effort for Greenland halibut. The analysis did, however, show that most of the observed decreases in mean weight were significantly correlated with fishing effort during the 24-year period...

Norse Greenland

DEFF Research Database (Denmark)

Arneborg, Jette

2015-01-01

human agency, landscape changes, climate changes, resilience, sustainability and adaptation are key words and research has moved from local to more global perspectives. New results from research projects in recent years have diversified the discussion claiming that the Norse Greenlanders created...

Improving volume loss estimates of the northwestern Greenland Ice Sheet 2002-2010

DEFF Research Database (Denmark)

Korsgaard, Niels Jákup; Khan, Shfaqat Abbas; Kjeldsen, Kristian Kjellerup

Studies have been carried out using various methods to estimate the Greenland ice sheet mass balance. Remote sensing techniques used to determine the ice sheet volume includes airborne and satellite radar and laser methods and measurements of ice flow of outlet glaciers use InSAR satellite radar......) does not work on sloping surfaces and is affected by radar penetration into the snow. InSAR estimates require knowledge of outlet glacier thickness. GRACE has limited spatial resolution and is affected by mass variations not just from ice changes, but also from hydrologic and ocean mass variability...... and mass redistribution within the solid Earth. The accuracy of ice mass and ice volume estimates can be assessed by comparing results from different techniques. Here, we focus on volume loss estimates from ICESat, ATM and LVIS data. We estimate catchment-wide ice volume change in northwest Greenland...

Reduction of deepwater formation in the Greenland Sea during the 1980s: Evidence from tracer data

International Nuclear Information System (INIS)

Schlosser, P.; Boenisch, G.; Bayer, R.; Rhein, M.

1991-01-01

Hydrographic observations and measurements of the concentrations of chlorofluorocarbons (CFCs) have suggested that the formation of Greenland Sea Deep Water (GSDW) slowed down considerably during the 1980s. Such a decrease is related to weakened convection in the Greenland Sea and thus could have significant impact on the properties of the waters flowing over the Scotland-Iceland-Greenlad ridge system into the deep Atlantic. Study of the variability of GSDW formation is relevant for understanding the impact of the circulation in the European Polar seas on regional and global deep water characteristics. New long-term multitracer observations from the Greenland Sea show that GSDW formation indeed was greatly reduced during the 1980s. A box model of deepwater formation and exchange in the European Polar seas tuned by the tracer data indicates that the reduction rate of GSDW formation was about 80% and that the start date of the reduction was between 1978 and 1982. 24 refs., 4 figs

Modeling distortion of HIT by an Actuator Disk in a periodic domain

Science.gov (United States)

Ghate, Aditya; Ghaisas, Niranjan; Lele, Sanjiva

2017-11-01

We study the distortion of incompressible, homogeneous isotropic turbulence (HIT) by a dragging actuator disk with a fixed thrust coefficient (under the large Reynolds number limit), using Large Eddy Simulation (LES). The HIT inflow is tailored to ensure that the largest length scales in the flow are smaller than the actuator disk diameter in order to minimize the meandering of the turbulent wake and isolate the length scales that undergo distortion. The numerical scheme (Fourier collocation with dealiasing) and the SGS closure (anisotropic minimum dissipation model) are carefully selected to minimize numerical artifacts expected due to the inviscid assumption. The LES is used to characterize the following 3 properties of the flow a) distortion of HIT due to the expanding streamtube resulting in strong anisotropy, b) turbulent pressure modulation across the actuator disk, and the c) turbulent wake state. Finally, we attempt to model the initial distortion and the pressure modulation using a WKB variant of RDT solved numerically using a set of discrete Gabor modes. Funding provided by Precourt Institute for Energy at Stanford University.

Experience with cochlear implants in Greenlanders with profound hearing loss living in Greenland

DEFF Research Database (Denmark)

Homøe, Preben; Andersen, Ture; Grøntved, Aksel

2013-01-01

OBJECTIVE: Cochlear implant (CI) treatment was introduced to the world in the 1980s and has become a routine treatment for congenital or acquired severe-to-profound hearing loss. CI treatment requires access to a highly skilled team of ear, nose and throat specialists, audiologists and speech...... years are in need of a CI every second year in Greenland often due to sequelae from meningitis, which may cause postinfectious deafness. Screening of new-borns for hearing has been started in Greenland establishing the basis for early diagnosis of congenital hearing impairment and subsequent...

Environmental radioactivity in Greenland in 1976

International Nuclear Information System (INIS)

Aarkrog, A.; Lippert, J.

1977-07-01

Measurements of fall-out radioactivity in Greenland in 1976 are reported. Strontium-90 (and Caesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1976. (author)

Environmental radioactivity in Greenland in 1975

International Nuclear Information System (INIS)

Aarkrog, A.; Lippert, J.

1976-07-01

Measuremtns of fall-out radioactivity in Greenland in 1975 are reported. Strontium-90 (and Caesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1975. (author)

Cervical cancer screening in Greenland, 1997-2011

DEFF Research Database (Denmark)

Holst, Signe; Wohlfahrt, Jan; Kjær, Susanne Krüger

2016-01-01

of the screening program and to examine possible changes in cervical intraepithelial neoplasia (CIN3) incidence in Greenland during 1997-2011 according to calendar period and age. METHODS: Using nationwide registries, we calculated age-standardized incidence rates for all women born and living in Greenland......OBJECTIVE: In spite of the high incidence of cervical cancer in Greenland, no assessment has been made of the impact of organized cervical screening, introduced in 1998, in relation to occurrence of high-grade cervical lesions. The objectives of the present study were to estimate coverage...

Impact of public health research in Greenland

DEFF Research Database (Denmark)

Bjerregaard, Peter; Curtis, Tine

2004-01-01

research. Two health surveys have been carried out in Greenland by the National Institute of Public Health, and a follow-up is being planned together with the Directorate of Health. The results have been widely used by politicians, administrators, and health care professionals.......In 1992, the Greenland Home Rule Government took over the responsibility for health care. There has since been a growing cooperation between the Directorate of Health and researchers in Denmark and Greenland, for instance by the Directorate supporting workshops and funding a chair in health...

Hepatitis B prevalence and incidence in Greenland

DEFF Research Database (Denmark)

Børresen, Malene Landbo; Andersson, Mikael; Wohlfahrt, Jan

2015-01-01

Greenland remains a highly endemic area for hepatitis B virus (HBV) infection. This is in sharp contrast to other modern societies, such as Denmark. To address this discrepancy, we investigated the natural history of HBV infection in Greenland by estimating the age-specific incidence of HBV...... from all available HBV registries in Greenland to determine changes in HBV status over time. Incidence rates of HBV infection and hepatitis B surface antigen seroclearance were estimated after taking into account interval censoring. The incidence of HBV infection in 5-14-year-old subjects was less than...

A Case of Greenlandic Fisheries Co-Politics

DEFF Research Database (Denmark)

Jacobsen, Rikke Becker; Raakjær, Jesper

2012-01-01

Greenlandic governance institutions have been criticised for their colonial heritage of centralisation and lack of democratic participation. In the same manner, Greenlandic fisheries management is notorious in the academic literature for its centralised and locally illegitimate character. While r...

The observed katabatic flow at the edge of the Greenland ice sheet during GIMEX-91

NARCIS (Netherlands)

Broeke, M.R. van den; Duynkerke, P.G.; Oerlemans, J.

1994-01-01

Observations performed in the melting zone of the Greenland ice sheet and over the adjacent tundra in the summer of 1991 are described. The experimental area is the region near St ndre Stromfjord (67°N, 54°W), which is relatively dry and sunny, resulting in the highest mean temperature in

Seasonal changes in Fe along a glaciated Greenlandic fjord.

Directory of Open Access Journals (Sweden)

Mark James Hopwood

2016-03-01

Full Text Available Greenland’s ice sheet is the second largest on Earth, and is under threat from a warming Arctic climate. An increase in freshwater discharge from Greenland has the potential to strongly influence the composition of adjacent water masses with the largest impact on marine ecosystems likely to be found within the glaciated fjords. Here we demonstrate that physical and chemical estuarine processes within a large Greenlandic fjord are critical factors in determining the fate of meltwater derived nutrients and particles, especially for non-conservative elements such as Fe. Concentrations of Fe and macronutrients in surface waters along Godthåbsfjord, a southwest Greenlandic fjord with freshwater input from 6 glaciers, changed markedly between the onset and peak of the meltwater season due to the development of a thin (<10 m, outflowing, low-salinity surface layer. Dissolved (<0.2 µm Fe concentrations in meltwater entering Godthåbsfjord (200 nM, in freshly melted glacial ice (mean 38 nM and in surface waters close to a land terminating glacial system (80 nM all indicated high Fe inputs into the fjord in summer. Total dissolvable (unfiltered at pH <2.0 Fe was similarly high with concentrations always in excess of 100 nM throughout the fjord and reaching up to 5.0 µM close to glacial outflows in summer. Yet, despite the large seasonal freshwater influx into the fjord, Fe concentrations near the fjord mouth in the out-flowing surface layer were similar in summer to those measured before the meltwater season. Furthermore, turbidity profiles indicated that sub-glacial particulate Fe inputs may not actually mix into the outflowing surface layer of this fjord. Emphasis has previously been placed on the possibility of increased Fe export from Greenland as meltwater fluxes increase. Here we suggest that in-fjord processes may be effective at removing Fe from surface waters before it can be exported to coastal seas.

Crustal structure of the Central-Eastern Greenland: results from the Topo Greenland refraction profile

DEFF Research Database (Denmark)

Shulgin, Alexey; Thybo, Hans

2014-01-01

Until present, seismic surveys have only been carried out offshore and near the coasts of Greenland, where the crustal structure is affected by oceanic break-up. We present the deep seismic structure of the crust of the interior of Greenland, based on the new and the only existing so far seismic...... refraction/wide-angle reflection profile. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass, made...... acquisition of geophysical data logistically complicated. The profile extends 310 km inland in E-W direction from the approximate edge of the stable ice cap near the Scoresby Sund across the center of the ice cap. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along...

A synthesis of the basal thermal state of the Greenland Ice Sheet

Science.gov (United States)

MacGregor, Joseph A; Fahnestock, Mark A; Catania, Ginny A; Aschwanden, Andy; Clow, Gary D.; Colgan, William T.; Gogineni, Prasad S.; Morlighem, Mathieu; Nowicki, Sophie M .J.; Paden, John D; Price, Stephen F.; Seroussi, Helene

2016-01-01

The basal thermal state of an ice sheet (frozen or thawed) is an important control upon its evolution, dynamics and response to external forcings. However, this state can only be observed directly within sparse boreholes or inferred conclusively from the presence of subglacial lakes. Here we synthesize spatially extensive inferences of the basal thermal state of the Greenland Ice Sheet to better constrain this state. Existing inferences include outputs from the eight thermomechanical ice-flow models included in the SeaRISE effort. New remote-sensing inferences of the basal thermal state are derived from Holocene radiostratigraphy, modern surface velocity and MODIS imagery. Both thermomechanical modeling and remote inferences generally agree that the Northeast Greenland Ice Stream and large portions of the southwestern ice-drainage systems are thawed at the bed, whereas the bed beneath the central ice divides, particularly their west-facing slopes, is frozen. Elsewhere, there is poor agreement regarding the basal thermal state. Both models and remote inferences rarely represent the borehole-observed basal thermal state accurately near NorthGRIP and DYE-3. This synthesis identifies a large portion of the Greenland Ice Sheet (about one third by area) where additional observations would most improve knowledge of its overall basal thermal state.

A synthesis of the basal thermal state of the Greenland Ice Sheet.

Science.gov (United States)

MacGregor, Joseph A; Fahnestock, Mark A; Catania, Ginny A; Aschwanden, Andy; Clow, Gary D; Colgan, William T; Gogineni, S Prasad; Morlighem, Mathieu; Nowicki, Sophie M J; Paden, John D; Price, Stephen F; Seroussi, Hélène

2016-08-10

The basal thermal state of an ice sheet (frozen or thawed) is an important control upon its evolution, dynamics and response to external forcings. However, this state can only be observed directly within sparse boreholes or inferred conclusively from the presence of subglacial lakes. Here we synthesize spatially extensive inferences of the basal thermal state of the Greenland Ice Sheet to better constrain this state. Existing inferences include outputs from the eight thermomechanical ice-flow models included in the SeaRISE effort. New remote-sensing inferences of the basal thermal state are derived from Holocene radiostratigraphy, modern surface velocity and MODIS imagery. Both thermomechanical modeling and remote inferences generally agree that the Northeast Greenland Ice Stream and large portions of the southwestern ice-drainage systems are thawed at the bed, whereas the bed beneath the central ice divides, particularly their west-facing slopes, is frozen. Elsewhere, there is poor agreement regarding the basal thermal state. Both models and remote inferences rarely represent the borehole-observed basal thermal state accurately near NorthGRIP and DYE-3. This synthesis identifies a large portion of the Greenland Ice Sheet (about one third by area) where additional observations would most improve knowledge of its overall basal thermal state.

Identity and acculturation: The case of food consumption by Greenlanders in Denmark

DEFF Research Database (Denmark)

Askegaard, Søren; Kjeldgaard, Dannie; Arnould, Eric J.

relations are structured around the acquisition, consumption and disposal of food. 4. Food consumption in Greenlandic food culture was organised around experience of scarcity - scarcity of the provisions of the Greenlandic natural environment as well as the provisions available in the retail environment....... The experience of Danish food culture was dominated by a discourse of abundance - although the informants experienced scarcity of Greenlandic food products when in Denmark. 5. The symbolic values of Greenlandic food were tied to authenticity, and consumption of Greenlandic food was often associated...... with a more or less dual cultural background (due to the strong Danish cultural influence in Greenland). This duality of cultural identity means that Greenlandic immigrants' consumption reflects a well-known negotiation of Danish and Greenlandic consumer cultures under new conditions, rather than a classic...

Migration and breeding biology of arctic terns in Greenland

DEFF Research Database (Denmark)

Egevang, Carsten

(Sandøen) in high-Arctic Northeast Greenland. The level of knowledge of the Arctic tern in Greenland before 2002 was to a large extent poor, with aspects of its biology being completely unknown in the Greenland population. This thesis presents novel findings for the Arctic tern, both on an international...... scale and on a national scale. The study on Arctic tern migration (Manus I) – the longest annual migration ever recorded in any animal – is a study with an international appeal. The study documented how Greenland and Iceland breeding terns conduct the roundtrip migration to the Weddell Sea in Antarctica...

Environmental radioactivity in Greenland in 1978

International Nuclear Information System (INIS)

Aarkrog, A.; Hansen, H.; Lippert, J.

1979-07-01

Measurements of fallout radioactivity in Greenland in 1978 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Tritium was determined in samples of drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1978. (author)

Greenland unveils terms for offshore licenses

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that Greenland has spelled out terms for its first round of offshore licensing. The action off western Greenland could lead to the first oil and gas exploration there since an unsuccessful campaign in the 1970s. The Mineral Resources Administration (MRA) for Greenland pegged exploration license terms on 133 blocks, all south of the 66th parallel, at 10 years with options for 2 year extensions to a maximum of 6 more years. The license can cover as many as six blocks. In the first 3 year period companies will have only a seismic obligation of 1,588 km per six blocks. For the second 3 year period there will be a one well obligation and one well in each subsequent 2 year periods

Pathways of warm water to the Northeast Greenland outlet glaciers

Science.gov (United States)

Schaffer, Janin; Timmermann, Ralph; Kanzow, Torsten; Arndt, Jan Erik; Mayer, Christoph; Schauer, Ursula

2015-04-01

The ocean plays an important role in modulating the mass balance of the Greenland Ice Sheet by delivering heat to the marine-terminating outlet glaciers surrounding the Greenland coast. The warming and accumulation of Atlantic Water in the subpolar North Atlantic has been suggested to be a potential driver of the glaciers' retreat over the last decades. The shelf regions thus play a critical role for the transport of Atlantic Water towards the glaciers, but also for the transfer of freshwater towards the deep ocean. A key region for the mass balance of the Greenland Ice Sheet is the Northeast Greenland Ice Stream. This large ice stream drains the second-largest basin of the Greenland Ice Sheet and feeds three outlet glaciers. The largest one is Nioghalvfjerdsfjorden (79°N-Glacier) featuring an 80 km long floating ice tongue. Both the ocean circulation on the continental shelf off Northeast Greenland and the circulation in the cavity below the ice tongue are weakly constrained so far. In order to study the relevant processes of glacier-ocean interaction we combine observations and model work. Here we focus on historic and recent hydrographic observations and on the complex bathymetry in the Northeast Greenland shelf region, which is thought to steer the flux of warm Atlantic water onto the continental shelf and into the sub-ice cavity beneath the 79°N-Glacier. We present a new global topography data set, RTopo-2, which includes the most recent surveys on the Northeast Greenland continental shelf and provides a detailed bathymetry for all around Greenland. In addition, RTopo-2 contains ice and bedrock surface topographies for Greenland and Antarctica. Based on the updated ocean bathymetry and a variety of hydrographic observations we show the water mass distribution on the continental shelf off Northeast Greenland. These maps enable us to discuss possible supply pathways of warm modified Atlantic waters on the continental shelf and thus potential ways of heat

Public Consultation Processes in Greenland Regarding the Mining Industry

Directory of Open Access Journals (Sweden)

Maria Ackrén

2016-05-01

Full Text Available Since the Greenland Self-Government Act came into force in 2009, economic development and the right to utilize natural resources in Greenland lies in the hands of the Self-Government. Earlier efforts to establish this authority were made back in the 1970s, when discussions on Home Rule were first on the agenda. Mining industries are not a new activity in Greenland. During the Second World War, Greenlandic cryolite was used to produce aluminum for the North American aircraft industry. Other essential natural resources, such as gold and gemstones, have also received international interest over the years. Greenland's new development aim is to build up a large-scale mining industry. This article elucidates the form of public consultation processes followed in Greenland in connection with two large-scale mining projects and the different views various actors have regarding these events. How did the deliberative democratic process unfold in Greenland regarding these projects? Was the process followed an effective way to manage these kinds of projects? The article shows that two projects that received a lot of media attention: the 2005 iron ore mine project in Isukasia, and the 2001 TANBREEZ-project to extract rare earth elements, used highly different approaches when it comes to deliberative democracy. In the former case, a limited degree of deliberative democracy was used, while in the latter case, the opposite applies.

Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics

DEFF Research Database (Denmark)

Andersen, M. L.; Larsen, T. B.; Nettles, M.

2010-01-01

Understanding the behavior of large outlet glaciers draining the Greenland Ice Sheet is critical for assessing the impact of climate change on sea level rise. The flow of marine-terminating outlet glaciers is partly governed by calving-related processes taking place at the terminus but is also in...

Impact of public health research in Greenland

DEFF Research Database (Denmark)

Bjerregaard, Peter; Curtis, Tine

2004-01-01

In 1992, the Greenland Home Rule Government took over the responsibility for health care. There has since been a growing cooperation between the Directorate of Health and researchers in Denmark and Greenland, for instance by the Directorate supporting workshops and funding a chair in health resea...

The magnetic-distortion probe: velocimetry in conducting fluids.

Science.gov (United States)

Miralles, Sophie; Verhille, Gautier; Plihon, Nicolas; Pinton, Jean-François

2011-09-01

A new type of velocimeter, capable of local velocity measurements in conducting fluids, is introduced. The principle of the "magnetic-distortion probe" is based on the measurement of the induced magnetic field by the flow of a conducting fluid in the vicinity of a localized magnetic field. The new velocimeter has no moving parts, and can be enclosed in a sealed cap, easing the implementation in harsh environments, such as liquid metals. The proposed method allows one to probe both the continuous part and fluctuations of the velocity, the temporal and spatial resolution being linked to the actual geometric configuration of the probe. A prototype probe has been tested in a gallinstan pipe flow and in a fully turbulent flow of liquid gallium generated by the counter rotation of two coaxial impellers in a cylinder. The signals have been compared to a reference potential probe and show very good agreement both for time-averaged velocities and turbulent fluctuations. The prototype is shown to detect motion from a few cm s(-1) to a few m s(-1). Moreover, the use of the magnetic-distortion probe with large-scale applied magnetic field is discussed. © 2011 American Institute of Physics

The Greenland shark (Somniosus microcephalus)

DEFF Research Database (Denmark)

Nielsen, Julius

radiocarbon dating and a Bayesian calibration model to estimate longevity of the Greenland shark. The analyzed tissue stems from the eye lens nucleus – unique material which presumably reflects age 0 of the shark, as it has not undergone metabolic changes during the animal’s life. By studying 28 Greenland...... shark females between 81 cm and 502 cm, I estimate the oldest shark to be between 272 years and 512 years. With an estimated lifespan of at least 272 years, the Greenland shark is the longest living vertebrate animal in the world. In order to produce these age estimates, it has been necessary to study...... continental shelf waters in southern Greenland at depths between 200 and 550 m and fed primarily on cod, redfish and seals. From previous investigations of predatory sharks and whales in the north Atlantic, bomb radiocarbon has been widely applied, and I argue that a similar calibration approach is valid...

Spirometry in Greenland

DEFF Research Database (Denmark)

Nielsen, Lasse Overballe; Olsen, Sequssuna; Jarbøl, D. E.

2016-01-01

be common. International guidelines recommend the usage of spirometry as a golden standard for diagnosing COPD. The current number of spirometries performed among patients treated with medication targeting obstructive pulmonary disease in Greenland remains unexplored. Objective. To estimate the prevalence...... of patients aged 50 years or above treated with medication targeting obstructive pulmonary disease and the extent to which spirometry was performed among them within 2 years. Design. An observational, cross-sectional study based on the review of data obtained from electronic medical records in Greenland...... of the identified users of medication targeting obstructive pulmonary disease. Information on age, gender, town and spirometry was registered for each patient within the period from October 2013 to October 2015. Results. The prevalence of patients treated with medication targeting obstructive pulmonary disease aged...

Scientific activities in and about Greenland

DEFF Research Database (Denmark)

Graversen, Ebbe Krogh; Pedersen, Asger Dalsgaard

2018-01-01

This report presents the results of an investigation and analysis of opportunities, strengths and challenges of scientific activities involving Greenland as a research area or research object relative to other Arctic areas.......This report presents the results of an investigation and analysis of opportunities, strengths and challenges of scientific activities involving Greenland as a research area or research object relative to other Arctic areas....

Possible Greenland

DEFF Research Database (Denmark)

2012-01-01

at Greenland's structure, and ask some threshold questions. Which aspects of society are rooted in our human hardware? And, if we had the rare opportunity to build a new nation, what would we choose for ourselves? We hope this will inspire an open, imaginative and thoroughly human discussion about how...

Cyclic Symmetry Finite Element Forced Response Analysis of a Distortion-Tolerant Fan with Boundary Layer Ingestion

Science.gov (United States)

Min, J. B.; Reddy, T. S. R.; Bakhle, M. A.; Coroneos, R. M.; Stefko, G. L.; Provenza, A. J.; Duffy, K. P.

2018-01-01

Accurate prediction of the blade vibration stress is required to determine overall durability of fan blade design under Boundary Layer Ingestion (BLI) distorted flow environments. Traditional single blade modeling technique is incapable of representing accurate modeling for the entire rotor blade system subject to complex dynamic loading behaviors and vibrations in distorted flow conditions. A particular objective of our work was to develop a high-fidelity full-rotor aeromechanics analysis capability for a system subjected to a distorted inlet flow by applying cyclic symmetry finite element modeling methodology. This reduction modeling method allows computationally very efficient analysis using a small periodic section of the full rotor blade system. Experimental testing by the use of the 8-foot by 6-foot Supersonic Wind Tunnel Test facility at NASA Glenn Research Center was also carried out for the system designated as the Boundary Layer Ingesting Inlet/Distortion-Tolerant Fan (BLI2DTF) technology development. The results obtained from the present numerical modeling technique were evaluated with those of the wind tunnel experimental test, toward establishing a computationally efficient aeromechanics analysis modeling tool facilitating for analyses of the full rotor blade systems subjected to a distorted inlet flow conditions. Fairly good correlations were achieved hence our computational modeling techniques were fully demonstrated. The analysis result showed that the safety margin requirement set in the BLI2DTF fan blade design provided a sufficient margin with respect to the operating speed range.

Pneumatization and otitis media in Greenlandic Inuit before European colonization

DEFF Research Database (Denmark)

Homøe, P; Lynnerup, N; Skovgaard, L T

1995-01-01

A total of 127 Greenlandic Inuit crania from before the European colonization of Greenland and deriving from the West (W), Southeast (SE), and Northeast (NE) coast of Greenland were examined for sequelae of infectious middle ear disease (IMED) and for a relationship between the size of the pneuma...

Angalasut, an education and outreach project to create a bridge between scientists, local population in Greenland and the general public

Science.gov (United States)

Bourgain, Pascaline

2015-04-01

Bridging Science and Society has now become a necessity for scientists to develop new partnerships with local communities and to raise the public interest for scientific activities. The French-Greenlandic educational project called "Angalasut" reflects this desire to create a bridge between science, local people and the general public. This program was set up on the 2012-2013 school year, as part of an international scientific program dedicated to study the interactions between the ocean and glaciers on the western coast of Greenland, in the Uummannaq fjord. Greenlandic and French school children were involved in educational activities, in classrooms and out on the field, associated with the scientific observations conducted in Greenland (glacier flow, ocean chemical composition and circulation, instrumentation...). In Greenland, the children had the opportunity to come on board the scientific sailing boat, and in France, several meetings were organized between the children and the scientists of the expedition. In the small village of Ikerasak, the children interviewed Elders about sea ice evolution in the area. These activities, coupled to the organization of public conferences and to the creation of a trilingual website of the project (French, Greenlandic, English) aimed at explaining why scientists come to study Greenland environment. This was the opportunity for scientists to discuss with villagers who could testify on their changing environment over the past decades. A first step toward a future collaboration between scientists and villagers that would deserve further development... The project Angalasut was also the opportunity for Greenlandic and French school children to exchange about their culture and their environment through Skype communications, the exchange of mails (drawings, shells...), the creation of a society game about European fauna and flora... A meeting in France between the two groups of children is considered, possibly in summer 2015

Accumulation of cadmium in livers and kidneys in Greenlanders

International Nuclear Information System (INIS)

Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth; Hansen, Jens C.; Riget, Frank

2006-01-01

In the Arctic, the traditional diet exposes its people to a very high intake of cadmium because it is highly concentrated in the liver and kidneys of commonly eaten marine mammals. In one study in Greenland, the cadmium intake was estimated to 182 μg/day/person in the fall and 346 in the spring. To determine whether the cadmium is accumulated in humans, we analyzed autopsy samples of liver and kidneys from 95 ethnic Greenlanders (aged 19-89) who died from a wide range of causes. The cadmium concentration in liver (overall mean 1.97 μg/g wet wt) appeared to be unrelated to any particular age group, whereas the concentrations in the kidneys peaked in Greenlanders between 40 and 50 years of age (peak concentration 22.3 μg/g wet wt). Despite the high cadmium levels in the typical Greenlander diet, we found that the cadmium concentrations in livers and kidneys were comparable to those reported from Denmark, Sweden, Australia and Great Britain. Furthermore, even though the mean cadmium intake from the diet was estimated to be 13-25 times higher in Greenlanders than in Danes, we found similar cadmium levels in the kidneys of both. Seal livers and kidneys are the main source of cadmium in the diet of Greenlanders, but these tissues are not eaten in Denmark. Thus, our results suggest that the accumulation of cadmium from Greenlander's marine diet is very low

Accumulation of cadmium in livers and kidneys in Greenlanders

Energy Technology Data Exchange (ETDEWEB)

Johansen, Poul [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: poj@dmu.dk; Mulvad, Gert [Primary Health Care Center, DK-3900 Nuuk, Greenland (Denmark); Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Pedersen, Henning Sloth [Primary Health Care Center, DK-3900 Nuuk, Greenland (Denmark); Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Hansen, Jens C. [Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Riget, Frank [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2006-12-15

In the Arctic, the traditional diet exposes its people to a very high intake of cadmium because it is highly concentrated in the liver and kidneys of commonly eaten marine mammals. In one study in Greenland, the cadmium intake was estimated to 182 {mu}g/day/person in the fall and 346 in the spring. To determine whether the cadmium is accumulated in humans, we analyzed autopsy samples of liver and kidneys from 95 ethnic Greenlanders (aged 19-89) who died from a wide range of causes. The cadmium concentration in liver (overall mean 1.97 {mu}g/g wet wt) appeared to be unrelated to any particular age group, whereas the concentrations in the kidneys peaked in Greenlanders between 40 and 50 years of age (peak concentration 22.3 {mu}g/g wet wt). Despite the high cadmium levels in the typical Greenlander diet, we found that the cadmium concentrations in livers and kidneys were comparable to those reported from Denmark, Sweden, Australia and Great Britain. Furthermore, even though the mean cadmium intake from the diet was estimated to be 13-25 times higher in Greenlanders than in Danes, we found similar cadmium levels in the kidneys of both. Seal livers and kidneys are the main source of cadmium in the diet of Greenlanders, but these tissues are not eaten in Denmark. Thus, our results suggest that the accumulation of cadmium from Greenlander's marine diet is very low.

Uncovering the genetic history of the present-day greenlandic population

DEFF Research Database (Denmark)

Moltke, Ida; Fumagalli, Matteo; Korneliussen, Thorfinn Sand

2015-01-01

Because of past limitations in samples and genotyping technologies, important questions about the history of the present-day Greenlandic population remain unanswered. In an effort to answer these questions and in general investigate the genetic history of the Greenlandic population, we analyzed...... between the Norse Vikings who lived in Greenland for a limited period ∼600-1,000 years ago and the Inuit, we found no evidence supporting this hypothesis. Similarly, we found no evidence supporting a previously hypothesized admixture event between the Inuit in East Greenland and the Dorset people, who...

Phase Inversion: Inferring Solar Subphotospheric Flow and Other Asphericity from the Distortion of Acoustic Waves

Science.gov (United States)

Gough, Douglas; Merryfield, William J.; Toomre, Juri

1998-01-01

A method is proposed for analyzing an almost monochromatic train of waves propagating in a single direction in an inhomogeneous medium that is not otherwise changing in time. An effective phase is defined in terms of the Hilbert transform of the wave function, which is related, via the JWKB approximation, to the spatial variation of the background state against which the wave is propagating. The contaminating effect of interference between the truly monochromatic components of the train is eliminated using its propagation properties. Measurement errors, provided they are uncorrelated, are manifest as rapidly varying noise; although that noise can dominate the raw phase-processed signal, it can largely be removed by low-pass filtering. The intended purpose of the analysis is to determine the distortion of solar oscillations induced by horizontal structural variation and material flow. It should be possible to apply the method directly to sectoral modes. The horizontal phase distortion provides a measure of longitudinally averaged properties of the Sun in the vicinity of the equator, averaged also in radius down to the depth to which the modes penetrate. By combining such averages from different modes, the two-dimensional variation can be inferred by standard inversion techniques. After taking due account of horizontal refraction, it should be possible to apply the technique also to locally sectoral modes that propagate obliquely to the equator and thereby build a network of lateral averages at each radius, from which the full three-dimensional structure of the Sun can, in principle, be determined as an inverse Radon transform.

Lepton asymmetry, neutrino spectral distortions, and big bang nucleosynthesis

Science.gov (United States)

Grohs, E.; Fuller, George M.; Kishimoto, C. T.; Paris, Mark W.

2017-03-01

We calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton asymmetry enhances processes which give rise to nonthermal neutrino spectral distortions. Our results reveal how asymmetries in energy and entropy density uniquely evolve for different transport processes and neutrino flavors. The enhanced distortions in the neutrino spectra alter the expected big bang nucleosynthesis light element abundance yields relative to those in the standard Fermi-Dirac neutrino distribution cases. These yields, sensitive to the shapes of the neutrino energy spectra, are also sensitive to the phasing of the growth of distortions and entropy flow with time/scale factor. We analyze these issues and speculate on new sensitivity limits of deuterium and helium to lepton number.

Time distortion for expert and novice online game players.

Science.gov (United States)

Rau, Pei-Luen Patrick; Peng, Shu-Yun; Yang, Chin-Chow

2006-08-01

Online game addiction is a new mental disorder. This disorder is difficult to describe because of its comprehensive nature. Many online game players have problems controlling their playing time. They cannot stop playing a game that they enjoy. This research surveyed the past literature on "flow" and time disorder theory. A time distortion experiment was conducted. This research invited 64 children, teenagers, and young adults to investigate player skill and playing time effects on online game break-off. The playing experience and degree of time distortion were measured and analyzed. The results showed that both novice and expert online game players were subject to time distortion. The participants had difficulty breaking off from the game without intrusion by others in the real world. This research also suggests eight questions for self-evaluation for online game addiction.

Contaminants in the Greenland terrestrial and freshwater environment. National assessment

International Nuclear Information System (INIS)

Riget, F.; Aastrup, P.; Dietz, R.

1997-01-01

The present report reviews the available information on heavy metals, persistent organic pollutants and radioactivity in the Greenland freshwater and terrestrial environments. Levels in lake sediments, soil, humus and organisms are presented, spatial and temporal trends are discussed and where possible also biological effects. Many of the contaminants that occur in the Greenland environment originate from distant sources outside of the region, and are transported to the Arctic via three major pathways - atmospheric, terrestrial/freshwater and marine. The main sources of pollution in Greenland is considered to be the industrialization of Eurasia. Pollutants are mainly. The organochlorine levels in Greenland char are typically in the low range compared to values reported from Canada. The Greenland sediment samples showed all organochlorine values below the detection limits of 0.1 μg/kg dry weight, thus being among the lowest contaminated sediments within the Arctic. The total content of PAH in the Greenland sediment samples ranged between 78-635 μ3 g/kg dry wight, with a geometric mean of 178 μg/kg, comparable to or lower than reported values from other arctic countries. The lowest concentrations of anthropogenic radionuclides in the Greenland terrestrial and freshwater environment are found in the northern parts of Greenland and the highest in the south western parts. The main source of anthropogenic radioactivity is nuclear weapons testing in the atmosphere and the fallout from this activity is closely related to the amounts of precipitation. The predominant foodchain in the Arctic with regard to transport of radiocaesium to man is: Lichen-reindeer-man. Although the doses from the terrestrial foodchain are 20 times higher than those received from the marine foodchain, they are not considered to be of any relevance for the human health in Greenland. 4 appendices contain experimental results. (EG)

The Jurassic of North-East Greenland: Jurassic dinoflagellate cysts from Hochstetter Forland, North-East Greenland

Directory of Open Access Journals (Sweden)

Piasecki, Stefan

2004-11-01

Full Text Available Three sections in Hochstetter Forland, North-East Greenland, referred to the Jurassic Payer Dal and Bernbjerg Formations, have been analysed for dinoflagellate cysts. The dinoflagellate cysts,new finds of ammonites and previously recorded marine faunas form the basis for improved dating of the succession. The basal strata of the Payer Dal Formation at Kulhus is here dated as Late Callovian, Peltoceras athleta Chronozone, based on the presence of relatively abundant Limbicysta bjaerkei, Mendicodinium groenlandicum, Rhychoniopsis cladophora and Tubotuberella dangeardii in an otherwise poor Upper Callovian dinoflagellate assemblage. Ammoniteshave not been recorded from these strata. The upper Payer Dal Formation at Agnetesøelven is dated as Late Oxfordian, Amoeboceras glosense – Amoeboceras serratum Chronozones, based onthe presence of Sciniodinium crystallinum, together with Cribroperidinium granuligera and Stephanelytron sp. The age is in accordance with ammonites present in the uppermost part ofthe formation at Søndre Muslingebjerg. New ammonites in the Bernbjerg Formation at Agnetesøelven together with dinoflagellate cysts indicate an earliest Kimmeridgian age, Raseniacymodoce and Aulacostephanoides mutabilis Chronozones.The Upper Callovian dinoflagellate cysts from Hochstetter Forland belong to a local brackish to marginal marine assemblage, which only allows a fairly broad correlation to coeval assemblagesin central East Greenland. In contrast, the Oxfordian and Kimmeridgian assemblages are fully marine and can be correlated from Milne Land in central East Greenland via Hochstetter Forland to Peary Land in eastern North Greenland.

Nivation forms and processes in unconsolidated sediments, NE Greenland

DEFF Research Database (Denmark)

Christiansen, Hanne Hvidtfeldt

1998-01-01

Nivation, Nivation Hollow, Nival Backwall Faliure, Active layer Interflow, Pronival alluvial fans, NE Greenland......Nivation, Nivation Hollow, Nival Backwall Faliure, Active layer Interflow, Pronival alluvial fans, NE Greenland...

Cultural change and mental health in Greenland

DEFF Research Database (Denmark)

Bjerregaard, Peter; Curtis, Tine; Greenland, Population Study

2002-01-01

In Greenland, the rapid sociocultural change of the last 50 years has been paralleled by an epidemiological transition characterized by a reduction in infectious diseases, an increase in cancer and cardiovascular diseases, and an increased prevalence of mental health problems. During 1993......-94 and 1997-98, two health interview surveys were conducted among Inuit in Greenland and Inuit migrants in Denmark. The response rates were 71 and 55%. Information on mental health was obtained from 1388 and 1769 adults. As indicators of mental health, the prevalence of potential psychiatric cases according...... of poor mental health: as a result of successful integration into the modern Greenlandic society, some population groups have better mental health compared to other groups....

Iron status markers in 224 indigenous Greenlanders

DEFF Research Database (Denmark)

Milman, N; Byg, K E; Mulvad, G

2001-01-01

OBJECTIVE: To evaluate iron status in indigenous Greenlanders and its relationship to gender, age and intake of traditional Greenlandic foods. Methods: Serum ferritin, serum transferrin saturation and haemoglobin were evaluated in a population survey in 1993-1994 comprising 224 Greenlandic...... of living. Consumption of traditional foods was assessed by questionnaire. RESULTS: Intake of traditional foods was more prevalent among elderly than among young individuals and more frequent in Uummannaq than in Ilulissat and Nuuk. Ferritin levels were higher in men than in women (p....06; women, r(s)=0.73, ptraditional foods was correlated with ferritin in men (r(s)=0.29, p=0.01) and women (r(s)=0.40, p

Assessing Fan Flutter Stability in the Presence of Inlet Distortion Using One-way and Two-way Coupled Methods

Science.gov (United States)

Herrick, Gregory P.

2014-01-01

Concerns regarding noise, propulsive efficiency, and fuel burn are inspiring aircraft designs wherein the propulsive turbomachines are partially (or fully)embedded within the airframe; such designs present serious concerns with regard to aerodynamic and aeromechanic performance of the compression system in response to inlet distortion. Previously, a preliminary design of a forward-swept high-speed fan exhibited flutter concerns in clean-inlet flows, and the present author then studied this fan further in the presence of off-design distorted in-flows. A three-dimensional, unsteady, Navier-Stokes computational fluid dynamics code is applied to analyze and corroborate fan performance with clean inlet flow. This code, already validated in its application to assess aerodynamic damping of vibrating blades at various flow conditions using a loosely-coupled approach, is modified to include a tightly-coupled aeroelastic simulation capability, and then loosely-coupled and tightly-coupled methods arecompared in their evaluation of flutter stability in distorted in-flows.

Gestational diabetes mellitus in Greenland: a national study of prevalence and testing efficacy

Directory of Open Access Journals (Sweden)

Michael Lynge Pedersen

2016-08-01

Full Text Available Background: Within the last 20 years, the prevalence of gestational diabetes mellitus (GDM has been reported to be increasing worldwide in correlation with ethnic and geographic variations. The actual prevalence of GDM throughout all of Greenland remains unknown. Objective: The aim of this study was to estimate the prevalence of GDM among Greenlanders and non-Greenlanders living in Greenland and to estimate the efficacy of testing for GDM. Design: This study was performed as an observational, cross-sectional study including all women with permanent address in Greenland who had given birth to a singleton during 2014. The prevalence of GDM was calculated as the proportion of all pregnant women tested with a 75-g 2-h glucose tolerance test who had a 2-h capillary whole-blood glucose value of 8.5 mmol/l or above. Testing efficacy was calculated as the proportion of women who fulfilled the testing criteria who were actually tested in Greenland in 2014. Results: A total of 794 women (727 Greenlanders and 67 non-Greenlanders were included in the study. The prevalence of GDM among tested women was 3.3% (confidence interval, CI: 0.9–5.6 among Greenlanders and 12.5% (CI: 0–25.7 among non-Greenlanders, corresponding, respectively, to 1.0% (CI: 0.3–1.3 and 4.5% (CI: 0–9.4 of all singleton pregnancies in Greenland in 2014. The overall testing efficacy was 69.0% among all eligible residents of Greenland and 85.1% among eligible residents in the capital city, Nuuk. Conclusion: In conclusion, the prevalence of GDM seems quite low in Greenland. Although diagnostic testing activity has improved within the last 6 years, still around one-third of all pregnant women in all Greenland fulfilling the testing criteria were not tested. Universal testing for GDM may be needed to improve testing of GDM in Greenland.

Balance velocities of the Greenland ice sheet

DEFF Research Database (Denmark)

Joughin, I.; Fahnestock, M.; Ekholm, Simon

1997-01-01

We present a map of balance velocities for the Greenland ice sheet. The resolution of the underlying DEM, which was derived primarily from radar altimetery data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail......, the balance map is useful for ice-sheet modelling, mass balance studies, and field planning....

Greenland coastal air temperatures linked to Baffin Bay and Greenland Sea ice conditions during autumn through regional blocking patterns

Science.gov (United States)

Ballinger, Thomas J.; Hanna, Edward; Hall, Richard J.; Miller, Jeffrey; Ribergaard, Mads H.; Høyer, Jacob L.

2018-01-01

Variations in sea ice freeze onset and regional sea surface temperatures (SSTs) in Baffin Bay and Greenland Sea are linked to autumn surface air temperatures (SATs) around coastal Greenland through 500 hPa blocking patterns, 1979-2014. We find strong, statistically significant correlations between Baffin Bay freeze onset and SSTs and SATs across the western and southernmost coastal areas, while weaker and fewer significant correlations are found between eastern SATs, SSTs, and freeze periods observed in the neighboring Greenland Sea. Autumn Greenland Blocking Index values and the incidence of meridional circulation patterns have increased over the modern sea ice monitoring era. Increased anticyclonic blocking patterns promote poleward transport of warm air from lower latitudes and local warm air advection onshore from ocean-atmosphere sensible heat exchange through ice-free or thin ice-covered seas bordering the coastal stations. Temperature composites by years of extreme late freeze conditions, occurring since 2006 in Baffin Bay, reveal positive monthly SAT departures that often exceed 1 standard deviation from the 1981-2010 climate normal over coastal areas that exhibit a similar spatial pattern as the peak correlations.

Unsteady Reynolds-averaged Navier-Stokes simulations of inlet distortion in the fan system of a gas-turbine aero-engine

Science.gov (United States)

Spotts, Nathan

As modern trends in commercial aircraft design move toward high-bypass-ratio fan systems of increasing diameter with shorter, nonaxisymmetric nacelle geometries, inlet distortion is becoming common in all operating regimes. The distortion may induce aerodynamic instabilities within the fan system, leading to catastrophic damage to fan blades, should the surge margin be exceeded. Even in the absence of system instability, the heterogeneity of the flow affects aerodynamic performance significantly. Therefore, an understanding of fan-distortion interaction is critical to aircraft engine system design. This thesis research elucidates the complex fluid dynamics and fan-distortion interaction by means of computational fluid dynamics (CFD) modeling of a complete engine fan system; including rotor, stator, spinner, nacelle and nozzle; under conditions typical of those encountered by commercial aircraft. The CFD simulations, based on a Reynolds-averaged Navier-Stokes (RANS) approach, were unsteady, three-dimensional, and of a full-annulus geometry. A thorough, systematic validation has been performed for configurations from a single passage of a rotor to a full-annulus system by comparing the predicted flow characteristics and aerodynamic performance to those found in literature. The original contributions of this research include the integration of a complete engine fan system, based on the NASA rotor 67 transonic stage and representative of the propulsion systems in commercial aircraft, and a benchmark case for unsteady RANS simulations of distorted flow in such a geometry under realistic operating conditions. This study is unique in that the complex flow dynamics, resulting from fan-distortion interaction, were illustrated in a practical geometry under realistic operating conditions. For example, the compressive stage is shown to influence upstream static pressure distributions and thus suppress separation of flow on the nacelle. Knowledge of such flow physics is

Toxaphene in the aquatic environment of Greenland

International Nuclear Information System (INIS)

Vorkamp, Katrin; Rigét, Frank F.; Dietz, Rune

2015-01-01

The octa- and nonachlorinated bornanes (toxaphene) CHBs 26, 40, 41, 44, 50 and 62 were analysed in Arctic char (Salvelinus alpinus), shorthorn sculpin (Myoxocephalus scorpius), ringed seal (Pusa hispida) and black guillemot eggs (Cepphus grylle) from Greenland. Despite their high trophic level, ringed seals had the lowest concentrations of these species, with a Σ 6 Toxaphene median concentration of 13–20 ng/g lipid weight (lw), suggesting metabolisation. The congener composition also suggests transformation of nona- to octachlorinated congeners. Black guillemot eggs had the highest concentrations (Σ 6 Toxaphene median concentration of 971 ng/g lw). Although concentrations were higher in East than in West Greenland differences were smaller than for other persistent organic pollutants. In a circumpolar context, toxaphene had the highest concentrations in the Canadian Arctic. Time trend analyses showed significant decreases for black guillemot eggs and juvenile ringed seals, with annual rates of −5 to −7% for Σ 6 Toxaphene. The decreases were generally steepest for CHBs 40, 41 and 44. - Highlights: • Toxaphene was detected in freshwater and marine species of Greenland. • Relatively low concentrations in ringed seal suggest metabolisation. • The concentrations in Greenland appear lower than those in the Canadian Arctic. • Significant decreases were found in juvenile ringed seals and black guillemot eggs. - The banned insecticide toxaphene is widely present in the aquatic environment of Greenland, but concentrations are decreasing

Advancing land-terminating ice margin in North Greenland - characteristics, evolution, and first field measurements

Science.gov (United States)

Steiner, J. F.; Prinz, R.; Abermann, J.

2017-12-01

More than 40% of the ice sheet in North Greenland terminate on land, however the characteristics of this ice margin and response to a changing climate have so far received little attention. While land-terminating ice cliffs are a feature commonly found and studied in other regions, detailed investigations in Greenland were only carried out more than six decades ago in the Thule area (Red Rock, Northwest Greenland). These studies showed a continuous advance at one location over multiple years, while the local mass balance was reported negative. The purpose of our study is to revisit the location previously studied and extend the analysis to the complete Northern ice margin employing newly available high-resolution digital terrain models (Arctic DEM). First results show that the advance at Red Rock is indeed long-term, continuing unabated today at rates of up to several meter per year. Similar magnitudes were found for large other stretches along the ice margin. With our study we aim to show (a) the main characteristics of the land-terminating ice margin in Northern Greenland, namely its slope and aspect distribution and comparison to spatial datasets of flow velocity and mass balance and (b) to provide further explanations of physical processes driving the advance. We have therefore mapped the complete ice margin and present the first results of this analysis. First field work provides new data on energy fluxes and ice temperatures at the Red Rock site as well as high resolution DEMs obtained with the use of UAVs.

How much can Greenland melt? An upper bound on mass loss from the Greenland Ice Sheet through surface melting

Science.gov (United States)

Liu, X.; Bassis, J. N.

2015-12-01

With observations showing accelerated mass loss from the Greenland Ice Sheet due to surface melt, the Greenland Ice Sheet is becoming one of the most significant contributors to sea level rise. The contribution of the Greenland Ice Sheet o sea level rise is likely to accelerate in the coming decade and centuries as atmospheric temperatures continue to rise, potentially triggering ever larger surface melt rates. However, at present considerable uncertainty remains in projecting the contribution to sea level of the Greenland Ice Sheet both due to uncertainty in atmospheric forcing and the ice sheet response to climate forcing. Here we seek an upper bound on the contribution of surface melt from the Greenland to sea level rise in the coming century using a surface energy balance model coupled to an englacial model. We use IPCC Representative Concentration Pathways (RCP8.5, RCP6, RCP4.5, RCP2.6) climate scenarios from an ensemble of global climate models in our simulations to project the maximum rate of ice volume loss and related sea-level rise associated with surface melting. To estimate the upper bound, we assume the Greenland Ice Sheet is perpetually covered in thick clouds, which maximize longwave radiation to the ice sheet. We further assume that deposition of black carbon darkens the ice substantially turning it nearly black, substantially reducing its albedo. Although assuming that all melt water not stored in the snow/firn is instantaneously transported off the ice sheet increases mass loss in the short term, refreezing of retained water warms the ice and may lead to more melt in the long term. Hence we examine both assumptions and use the scenario that leads to the most surface melt by 2100. Preliminary models results suggest that under the most aggressive climate forcing, surface melt from the Greenland Ice Sheet contributes ~1 m to sea level by the year 2100. This is a significant contribution and ignores dynamic effects. We also examined a lower bound

Hydrologic Outlets of the Greenland Ice Sheet, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — The Hydrologic Outlets of the Greenland Ice Sheet data set contains GIS point shapefiles that include 891 observed and potential hydrologic outlets of the Greenland...

Environmental radioactivity in Greenland in 1979

International Nuclear Information System (INIS)

Aarkrog, A.; Dahlgaard, H.; Lippert, J.; Nilsson, K.; Holm, E.

1980-07-01

Measurements of fallout radioactivity in Greenland in 1979 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in the human diet in Greenland in 1979. Provisional results of the 239 , 240 Pu and 241 Am measurements on samples from the expedition to Thule in August 1979 are presented. (author)

Children in Greenland

DEFF Research Database (Denmark)

Kløvgaard, Marius; Nielsen, Nina Odgaard; Sørensen, Thomas Lund

2016-01-01

in Nuuk or Ilulissat (n=332). Data on diseases and health care system contacts were extracted. Diagnoses were validated retrospectively. Primary health care contacts were reviewed for a random sample of 1:6. RESULTS: In 311 children with valid social security number, the total number of health care system......, 39.5 versus 34.6 during the study period, p=0.02. The highest annual contact rates for diseases were: hospitalisations/acute respiratory diseases 13.9:1,000; outpatient contacts/otitis media 5.1:1,000; primary care/conjunctivitis or nasopharyngitis 410:1,000 children. Outpatient screening......BACKGROUND: Previous studies of Greenlandic children's disease pattern and contacts to the health care system are sparse and have focused on the primary health care sector. OBJECTIVE: We aimed to identify the disease pattern and use of health care facilities of children aged 0-10 in two Greenlandic...

Predicting the Geothermal Heat Flux in Greenland: A Machine Learning Approach

Science.gov (United States)

Rezvanbehbahani, Soroush; Stearns, Leigh A.; Kadivar, Amir; Walker, J. Doug; van der Veen, C. J.

2017-12-01

Geothermal heat flux (GHF) is a crucial boundary condition for making accurate predictions of ice sheet mass loss, yet it is poorly known in Greenland due to inaccessibility of the bedrock. Here we use a machine learning algorithm on a large collection of relevant geologic features and global GHF measurements and produce a GHF map of Greenland that we argue is within ˜15% accuracy. The main features of our predicted GHF map include a large region with high GHF in central-north Greenland surrounding the NorthGRIP ice core site, and hot spots in the Jakobshavn Isbræ catchment, upstream of Petermann Gletscher, and near the terminus of Nioghalvfjerdsfjorden glacier. Our model also captures the trajectory of Greenland movement over the Icelandic plume by predicting a stripe of elevated GHF in central-east Greenland. Finally, we show that our model can produce substantially more accurate predictions if additional measurements of GHF in Greenland are provided.

Measured and modelled absolute gravity changes in Greenland

DEFF Research Database (Denmark)

Nielsen, Jens Emil; Forsberg, René; Strykowski, Gabriel

2014-01-01

in Greenland. Theresult is compared with the initial measurements of absolute gravity (AG) change at selected GreenlandNetwork (GNET) sites.We find that observations are highly influenced by the direct attraction from the ice and ocean. Thisis especially evident in the measurements conducted at the GNET...

Conceptualizing and contextualizing food insecurity among Greenlandic children

DEFF Research Database (Denmark)

Niclasen, B.; Molcho, M.; Arnfjord, S.

2013-01-01

OBJECTIVE: To review the context of food insecurity in Greenlandic children, to review and compare the outcomes related to food insecurity in Greenlandic children, in other Arctic child populations and in other western societies, and to explore the measure used by the Health Behaviour in School-a...

Preliminary Results of the Determination of Inlet-Pressure Distortion Effects on Compressor Stall and Altitude Operating Limits of the J57-P-1 Turbojet Engine

Science.gov (United States)

Wallner, L. E.; Lubick, R. J.; Chelko, L. J.

1955-01-01

During an investigation of the J57-P-1 turbojet engine in the Lewis altitude wind tunnel, effects of inlet-flow distortion on engine stall characteristics and operating limits were determined. In addition to a uniform inlet-flow profile, the inlet-pressure distortions imposed included two radial, two circumferential, and one combined radial-circumferential profile. Data were obtained over a range of compressor speeds at an altitude of 50,000 and a flight Mach number of 0.8; in addition, the high- and low-speed engine operating limits were investigated up to the maximum operable altitude. The effect of changing the compressor bleed position on the stall and operating limits was determined for one of the inlet distortions. The circumferential distortions lowered the compressor stall pressure ratios; this resulted in less fuel-flow margin between steady-state operation and compressor stall. Consequently, the altitude operating Limits with circumferential distortions were reduced compared with the uniform inlet profile. Radial inlet-pressure distortions increased the pressure ratio required for compressor stall over that obtained with uniform inlet flow; this resulted in higher altitude operating limits. Likewise, the stall-limit fuel flows required with the radial inlet-pressure distortions were considerably higher than those obtained with the uniform inlet-pressure profile. A combined radial-circumferential inlet distortion had effects on the engine similar to the circumferential distortion. Bleeding air between the two compressors eliminated the low-speed stall limit and thus permitted higher altitude operation than was possible without compressor bleed.

Spectral Behavior of Weakly Compressible Aero-Optical Distortions

Science.gov (United States)

Mathews, Edwin; Wang, Kan; Wang, Meng; Jumper, Eric

2016-11-01

In classical theories of optical distortions by atmospheric turbulence, an appropriate and key assumption is that index-of-refraction variations are dominated by fluctuations in temperature and the effects of turbulent pressure fluctuations are negligible. This assumption is, however, not generally valid for aero-optical distortions caused by turbulent flow over an optical aperture, where both temperature and pressures fluctuations may contribute significantly to the index-of-refraction fluctuations. A general expression for weak fluctuations in refractive index is derived using the ideal gas law and Gladstone-Dale relation and applied to describe the spectral behavior of aero-optical distortions. Large-eddy simulations of weakly compressible, temporally evolving shear layers are then used to verify the theoretical results. Computational results support theoretical findings and confirm that if the log slope of the 1-D density spectrum in the inertial range is -mρ , the optical phase distortion spectral slope is given by - (mρ + 1) . The value of mρ is then shown to be dependent on the ratio of shear-layer free-stream densities and bounded by the spectral slopes of temperature and pressure fluctuations. Supported by HEL-JTO through AFOSR Grant FA9550-13-1-0001 and Blue Waters Graduate Fellowship Program.

Victimisation and PTSD in a Greenlandic youth sample

Directory of Open Access Journals (Sweden)

Sidsel H. Karsberg

2012-08-01

Full Text Available Background. Despite a growing number of studies and reports indicating a very high and increasing prevalence of trauma exposure in Greenlandic adolescents, the knowledge on this subject is still very limited. The purpose of the present study was twofold: To estimate the lifetime prevalence of potentially traumatic events (PTEs and post-traumatic stress disorder (PTSD and to examine the relationship between PTEs, estimated PTSD, and sociodemographic variables. Methods. In a Greenlandic sample from 4 different schools in 2 different minor towns in Northern Greenland, 269 students, aged 12–18 (M=15.4; SD=1.84 were assessed for their level of exposure to 20 PTEs along with the psychological impact of these events. Results. Of the Greenlandic students, 86% had been directly exposed to at least 1 PTE and 74.3% had been indirectly exposed to at least 1 PTE. The mean number of directly experienced PTEs was 2.8 and the mean number of indirectly experienced PTEs was 3.9. The most frequent direct events recorded were death of someone close, near drowning, threat of assault/beating, humiliation or persecution by others and attempted suicide. The estimated lifetime prevalence of PTSD was 17.1%, whereas another 14.2% reached a subclinical level of PTSD (missing the full diagnosis by 1 symptom. Education level of the father, and being exposed to multiple direct and indirect PTEs were significantly associated with an increase in PTSD symptoms. Conclusion. The findings indicate substantial mental health problems in Greenlandic adolescents and that these are associated with various types of PTEs. Furthermore, the findings indicate that Greenlandic adolescents are more exposed to certain specific PTEs than adolescents in similar studies from other nations. The present study revealed that Greenlandic girls are particularly vulnerable towards experiencing PTEs. Indeed, in general, girls reported more experiences of direct and indirect PTEs. Furthermore, girls

Microjet flow control in an ultra-compact serpentine inlet

Directory of Open Access Journals (Sweden)

Da Xingya

2015-10-01

Full Text Available Microjets are used to control the internal flow to improve the performance of an ultra-compact serpentine inlet. A highly offset serpentine inlet with length-to-diameter ratio of 2.5 is designed and static tests are conducted to analyze the internal flow characteristics in terms of pressure recovery, distortion and flow separation. Flow separation is encountered in the second S-turn, and two strong counter-rotating vortices are formed at the aerodynamic interface plane (AIP face which occupy a quarter of the outlet area and result in severe pressure loss and distortion. A flow control model employing a row of microjets in the second turn is designed based on the internal flow characteristics and simplified CFD simulations. Flow control tests are conducted to verify the control effectiveness and understand the characteristics as a function of inlet throat Mach number, injection mass flow ratio, jet Mach number and momentum coefficient. At all test Mach numbers, microjet flow control (MFC effectively improves the recovery and reduces the distortion intensity. Between inlet throat Mach number 0.2 and 0.5, the strong flow separation in the second S-turn is suppressed at an optimum jet flow ratio of less than 0.65%, resulting in a maximum improvement of 4% for pressure recovery coefficient and a maximum decrease of 75% for circumferential distortion intensity at cruise. However, in order to suppress the flow separation, the injection rate should retain in an effective range. When the injection rate is higher than this range, the flow is degraded and the distortion contour is changed from 90° circumferential distortion pattern to 180° circumferential distortion pattern. Detailed data analysis shows that this optimum flow ratio depends on inlet throat Mach number and the momentum coefficient affects the control effectiveness in a dual stepping manner.

Holocene environmental changes and climate development in Greenland

International Nuclear Information System (INIS)

Engels, Stefan; Helmens, Karin

2010-12-01

The primary aim of this report is to give an overview of the Holocene environmental and climatic changes in Greenland and to describe the development of the periglacial environment during the Holocene. Special emphasis is given to the influence of the ice sheet on its surroundings, both in terms of time (with respect to the response of the biosphere to deglaciation or ice sheet proximity) and in space (through the influence of the ice sheet on the regional climate, more specifically on temperature and aridity). Published records are reviewed, and regional trends are summarized. A range of different natural archives is available for such studies, including ice-core data, marine records, and continental sources of information, including peat profiles and lacustrine records. Because of the high number of lakes in all ice-free areas of Greenland, the lacustrine records offer the opportunity to get a spatial overview of past changes in environment and climate as well. This report focuses on (palaeo-) ecological studies, as it is intended to assemble basic information for future studies on adaptation of the biosphere to changes in climate. There is a bias towards pollen- and macro-remain-based reconstructions of past changes, as these dominate performed palaeoecological studies in Greenland; unfortunately, only a limited number of studies exist that include more modern proxies such as diatoms or chironomids (climate-indicators), but where available in the literature, these have been included. The report starts with an introduction where the current climatic and biological zonation of Greenland is discussed together with an overview of the geology of Greenland (on the full geological timescale) in order to put the following sections in perspective. Chapter 2 discusses the ice sheet history of Greenland from the Last Glacial Maximum (LGM) onward where special emphasis is given to the spatial variability of deglaciation at the onset of the Holocene. To enhance the

Holocene environmental changes and climate development in Greenland

Energy Technology Data Exchange (ETDEWEB)

Engels, Stefan; Helmens, Karin (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden))

2010-12-15

The primary aim of this report is to give an overview of the Holocene environmental and climatic changes in Greenland and to describe the development of the periglacial environment during the Holocene. Special emphasis is given to the influence of the ice sheet on its surroundings, both in terms of time (with respect to the response of the biosphere to deglaciation or ice sheet proximity) and in space (through the influence of the ice sheet on the regional climate, more specifically on temperature and aridity). Published records are reviewed, and regional trends are summarized. A range of different natural archives is available for such studies, including ice-core data, marine records, and continental sources of information, including peat profiles and lacustrine records. Because of the high number of lakes in all ice-free areas of Greenland, the lacustrine records offer the opportunity to get a spatial overview of past changes in environment and climate as well. This report focuses on (palaeo-) ecological studies, as it is intended to assemble basic information for future studies on adaptation of the biosphere to changes in climate. There is a bias towards pollen- and macro-remain-based reconstructions of past changes, as these dominate performed palaeoecological studies in Greenland; unfortunately, only a limited number of studies exist that include more modern proxies such as diatoms or chironomids (climate-indicators), but where available in the literature, these have been included. The report starts with an introduction where the current climatic and biological zonation of Greenland is discussed together with an overview of the geology of Greenland (on the full geological timescale) in order to put the following sections in perspective. Chapter 2 discusses the ice sheet history of Greenland from the Last Glacial Maximum (LGM) onward where special emphasis is given to the spatial variability of deglaciation at the onset of the Holocene. To enhance the

Studying health in Greenland

DEFF Research Database (Denmark)

Bjerregaard, Peter; Mulvad, Gert; Olsen, Jørn

2003-01-01

Health research in Greenland has contributed with several findings of interest for the global scientific community and has documented health problems and risk factors of importance for planning the local health care system. The study of how health develops in small, scattered communities during...... rapid epidemiological transition carries prospects of global significance. The Inuit are a genetically distinct people living under extreme physical conditions. Their traditional living conditions and diet are currently undergoing a transformation, which may approach their disease pattern...... to that of the industrialized world, while still including local outbreaks of tuberculosis. Health research in Greenland is logistically difficult and costly, but offers opportunities not found elsewhere in the world. A long tradition of registration enhances the possibilities for research. A number of research institutions...

Greenland and the international politics of a changing arctic

DEFF Research Database (Denmark)

Greenland and the International Politics of a Changing Arctic examines the international politics of semi-independent Greenland in a changing and increasingly globalised Arctic. Without sovereign statehood, but with increased geopolitical importance, independent foreign policy ambitions......, and a solidified self-image as a trailblazer for Arctic indigenous peoples’ rights, Greenland is making its mark on the Arctic and is in turn affected – and empowered – by Arctic developments. The chapters in this collection analyse how a distinct Greenlandic foreign policy identity shapes political ends and means...... for regional change in the Arctic. This is the first comprehensive and interdisciplinary examination of Greenland’s international relations and how they are connected to wider Arctic politics. It will be essential reading for students and scholars interested in Arctic governance and security, international...

China and Greenland

DEFF Research Database (Denmark)

Jakobsen, Uffe

2014-01-01

More thorough analysis and outreach on facts about Chinese activities in the Arctic are highly needed, not least in view of the almost alarmist response in Danish political debate to the prospects of growing Chinese interest in the Arctic in general and especially in Greenland...

Compressor Performance Scaling in the Presence of Non-Uniform Flow

Science.gov (United States)

Hill, David Jarrod

Fuselage-embedded engines in future aircraft will see increased flow distortions due to the ingestion of airframe boundary layers. This reduces the required propulsive power compared to podded engines. Inlet flow distortions mean that localized regions of flow within the fan and first stage compressor are operating at off-design conditions. It is important to weigh the benefit of increased vehicle propulsive efficiency against the resultant reduction in engine efficiency. High computational cost has limited most past research to single distortion studies. The objective of this thesis is to extract scaling laws for transonic compressor performance in the presence of various distortion patterns and intensities. The machine studied is the NASA R67 transonic compressor. Volumetric source terms are used to model rotor and stator blade rows. The modelling approach is an innovative combination of existing flow turning and loss models, combined with a compressible flow correction. This approach allows for a steady calculation to capture distortion transfer; as a result, the computational cost is reduced by two orders of magnitude. At peak efficiency, the rotor work coefficient and isentropic efficiency are matched within 1.4% of previously published experimental results. A key finding of this thesis is that, in non-uniform flow, the state-of-the-art loss model employed is unable to capture the impact of variations in local flow coefficient, limiting the analysis of local entropy generation. New insight explains the mechanism governing the interaction between a total temperature distortion and a compressor rotor. A parametric study comprising 16 inlet distortions reveals that for total temperature distortions, upstream flow redistribution and rotor diffusion factor changes are shown to scale linearly with distortion severity. Linear diffusion factor scaling does not hold true for total pressure distortions. For combined total temperature and total pressure distortions, the

Arctic Ocean UNCLOS Article 76 Work for Greenland Starts on Land

Science.gov (United States)

Dahl-Jensen, T.; Marcussen, C.; Jackson, R.; Voss, P.

2005-12-01

One of the most lonely and desolate stretches of coastline on the planet has become the target for UNCLOS article 76 related research. The Danish Continental Shelf Project has launched a work program to investigate the possibilities for Greenland to claim an area outside the 200 nm limit in the Arctic Ocean. The role of the Lomonosov Ridge as a Natural Prolongation of Greenland/Canada is an important issue, and in order to better evaluate the connection between Greenland and the Lomonosov Ridge the nature of not only the ridge but also of Northern Greenland is the target of deep crustal investigations. The North Greenland Fold belt covers the ice-free part of North Greenland and continues west in the Canadian Arctic. The foldbelt was formed during the Ellesmerian orogeny, where sediments from the Franklinian Basin where compressed and deformed. The deep structure of basin and its subsequent closure are broadly unknown. Three broad band earthquake seismological stations where installed in North Greenland to supplement the existing stations at Alert (Canada) and Station Nord to the east, and the first data was available summer 2005. Crustal thickness data from these first results are presented. Plans for the spring 2006 consist of wide-angle acquisition on the sea ice from the Greenland-Canadian mainland out onto the Lomonosov Ridge, a joint Danish - Canadian project with a 400 km long profile over difficult ice conditions, 18 tons of explosives, three helicopters, a Twin Otter and about 30 participants.

Radiation Climatology of the Greenland Ice Sheet Derived from Greenland Climate Network Data

Science.gov (United States)

Steffen, Konrad; Box, Jason

2003-01-01

The magnitude of shortwave and longwave dative fluxes are critical to surface energy balance variations over the Greenland ice sheet, affecting many aspects of its climate, including melt rates, the nature of low-level temperature inversions, the katabatic wind regime and buoyant stability of the atmosphere. Nevertheless, reliable measurements of the radiative fluxes over the ice sheet are few in number, and have been of limited duration and areal distribution (e.g. Ambach, 1960; 1963, Konzelmann et al., 1994, Harding et al., 1995, Van den Broeke, 1996). Hourly GC-Net radiation flux measurements spanning 1995-2001 period have been used to produce a monthly dataset of surface radiation balance components. The measurements are distributed widely across Greenland and incorporate multiple sensors

Evaluation of effect of inlet distortion on aerodynamic performance of helium gas compressor for gas turbine high temperature reactor (GTHTR300). Contract research

International Nuclear Information System (INIS)

Takada, Shoji; Takizuka, Takakazu; Yan, Xing; Kurokouchi, Naohiro; Kunitomi, Kazuhiko

2006-02-01

Because the main pipe is connected perpendicular to the flow direction inside the distributing header in the inlet casing of the helium gas compressor design of GTHTR300, the main flow flowing into the header tends to separate from the header wall and to cause reverse flow, which increases flow resistance in the header. This phenomenon increases the total pressure loss in the header and inlet distortion, which is considered to deteriorate the aerodynamic performance of the compressor. Tests were carried out to evaluate the effects of inlet distortion on aerodynamic performance of compressor by using a 1/3-scale helium gas compressor model by varying a level of inlet distortion. Flow was injected from the wall of header to make circumferential velocities uniform before and after the reverse flow region to dissipate the separation and reverse flow. At the design point, inlet distortion was reduced by 2-3% by injection, which resulted in increasing adiabatic efficiency of blade section by 0.5%. A modified flow rate at surge point was lowered from 10.0 kg/s to 9.6 kg/s. At the same time, pressure loss of the inlet casing was reduced by 3-5 kPa, which is equivalent to adiabatic efficiency improvement around 0.8%. By setting orifice at the inlet of the inlet casing, the level of inlet distortion became 3% higher and the adiabatic efficiency of blade section became 1% higher at the design point. The modified flow rate at surge point increased from 10.6 to 10.9 kg/s. A new correlation between inlet distortion and adiabatic efficiency of blade section at the rated flow rate was derived based on compressor-in-parallel model and fitted to the test results. An overall adiabatic efficiency of full-scale compressor was predicted 90.2% based on the test results of efficiency and Reynolds number correlation, which was close to 89.7% that was predicted by test calibrated design through-flow code. (author)

Exploring Greenland: science and technology in Cold War settings.

Science.gov (United States)

Heymann, Matthias; Knudsen, Henrik; Lolck, Maiken L; Nielsen, Henry; Nielsen, Kristian H; Ries, Christopher J

2010-01-01

This paper explores a vacant spot in the Cold War history of science: the development of research activities in the physical environmental sciences and in nuclear science and technology in Greenland. In the post-war period, scientific exploration of the polar areas became a strategically important element in American and Soviet defence policy. Particularly geophysical fields like meteorology, geology, seismology, oceanography, and others profited greatly from military interest. While Denmark maintained formal sovereignty over Greenland, research activities were strongly dominated by U.S. military interests. This paper sets out to summarize the limited current state of knowledge about activities in the environmental physical sciences in Greenland and their entanglement with military, geopolitical, and colonial interests of both the USA and Denmark. We describe geophysical research in the Cold War in Greenland as a multidimensional colonial endeavour. In a period of decolonization after World War II, Greenland, being a Danish colony, became additionally colonized by the American military. Concurrently, in a period of emerging scientific internationalism, the U.S. military "colonized" geophysical research in the Arctic, which increasingly became subject to military directions, culture, and rules.

Comparison of Engine/Inlet Distortion Measurements with MEMS and ESP Pressure Sensors

Science.gov (United States)

Soto, Hector L.; Hernandez, Corey D.

2004-01-01

A study of active-flow control in a small-scale boundary layer ingestion inlet was conducted at the NASA Langley Basic Aerodynamic Research Tunnel (BART). Forty MEMS pressure sensors, in a rake style configuration, were used to examine both the mean (DC) and high frequency (AC) components of the total pressure across the inlet/engine interface plane. The mean component was acquired and used to calculate pressure distortion. The AC component was acquired separately, at a high sampling rate, and is used to study the unsteady effects of the active-flow control. An identical total pressure rake, utilizing an Electronically Scanned Pressure (ESP) system, was also used to calculate distortion; a comparison of the results obtained using the two rakes is presented.

Characterization of household waste in Greenland

International Nuclear Information System (INIS)

Eisted, Rasmus; Christensen, Thomas H.

2011-01-01

The composition of household waste in Greenland was investigated for the first time. About 2 tonnes of household waste was sampled as every 7th bag collected during 1 week along the scheduled collection routes in Sisimiut, the second largest town in Greenland with about 5400 inhabitants. The collection bags were sorted manually into 10 material fractions. The household waste composition consisted primarily of biowaste (43%) and the combustible fraction (30%), including anything combustible that did not belong to other clean fractions as paper, cardboard and plastic. Paper (8%) (dominated by magazine type paper) and glass (7%) were other important material fractions of the household waste. The remaining approximately 10% constituted of steel (1.5%), aluminum (0.5%), plastic (2.4%), wood (1.0%), non-combustible waste (1.8%) and household hazardous waste (1.2%). The high content of biowaste and the low content of paper make Greenlandic waste much different from Danish household waste. The moisture content, calorific value and chemical composition (55 elements, of which 22 were below detection limits) were determined for each material fraction. These characteristics were similar to what has been found for material fractions in Danish household waste. The chemical composition and the calorific value of the plastic fraction revealed that this fraction was not clean but contained a lot of biowaste. The established waste composition is useful in assessing alternative waste management schemes for household waste in Greenland.

Seismic stratigraphic architecture of the Disko Bay trough-mouth fan system, West Greenland

Science.gov (United States)

Hofmann, Julia C.; Knutz, Paul C.

2015-04-01

Spatial and temporal changes of the Greenland Ice Sheet on the continental shelf bordering Baffin Bay remain poorly constrained. Then as now, fast-flowing ice streams and outlet glaciers have played a key role for the mass balance and stability of polar ice sheets. Despite their significance for Greenland Ice Sheet dynamics and evolution, our understanding of their long-term behaviour is limited. The central West Greenland margin is characterized by a broad continental shelf where a series of troughs extend from fjords to the shelf margin, acting as focal points for trough-mouth fan (TMF) accummulations. The sea-ward bulging morphology and abrupt shelf-break of these major depositional systems is generated by prograding depocentres that formed during glacial maxima when ice streams reached the shelf edge, delivering large amounts of subglacial sediment onto the continental slope (Ó Cofaigh et al., 2013). The aim of this study is to unravel the seismic stratigraphic architecture and depositional processes of the Disko Bay TMF, aerially the largest single sedimentary system in West Greenland, using 2D and 3D seismic reflection data, seabed bathymetry and stratigraphic information from exploration well Hellefisk-1. The south-west Disko Bay is intersected by a deep, narrow trough, Egedesminde Dyb, which extends towards the southwest and links to the shallower and broader cross-shelf Disko Trough (maximum water depths of > 1000 m and a trough length of c. 370 km). Another trough-like depression (trough length of c. 120 km) in the northern part of the TMF, indicating a previous position of the ice stream, can be distinguished on the seabed topographic map and the seismic images. The Disko Bay TMF itself extends from the shelf edge down to the abyssal plain (abyssal floor depths of 2000 m) of the southern Baffin Bay. Based on seismic stratigraphic configurations relating to reflection terminations, erosive patterns and seismic facies (Mitchum et al., 1977), the TMF

The right of indigenous peoples to education in their own language – Greenlanders in Denmark and in Greenland

DEFF Research Database (Denmark)

Næsborg-Andersen, Ayo; Khalaf, Bassah

2018-01-01

Both language and culture are interdependent pillars on which the identity of a people is maintained, including indigenous peoples. Without the appropriate linguistic terminology available to express indigenous philosophies and concepts, indigenous peoples lose some of their ability to accurately...... and in Denmark. As a part of this examination the paper also gives an overview of history of the Greenlandic school system. Finally the paper compares the current situation of Greenlanders in Denmark with the Sami peoples in Norway....

Small-scale fisheries in Greenlandic planning

DEFF Research Database (Denmark)

Jacobsen, Rikke Becker

2013-01-01

This article analyses an ongoing planning process in Greenlandic fisheries governance aiming to reform the coastal Greenland halibut fishery. It examines the way certain truths about this fishery and the need for reform are produced up to and in the final policy document ‘regulation concerning...... could also be understood as primarily a problem to a certain ‘governmentality’ mode of governance. Whereas some fishery studies document how governmentality modes of governance in fisheries succeeds in transforming subjectivities, this study offers a view into the process that might go before successful...

Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier

DEFF Research Database (Denmark)

de Juan, Julia; Elósegui, Pedro; Nettles, Meredith

2010-01-01

strongly with the step-like increases in glacier speed and longitudinal strain rate associated with glacial earthquakes. The enhanced response to the ocean tides may be explained by a temporary disruption of the subglacial drainage system and a concomitant reduction of the friction at the ice......Large calving events at Greenland's largest outlet glaciers are associated with glacial earthquakes and near-instantaneous increases in glacier flow speed. At some glaciers and ice streams, flow is also modulated in a regular way by ocean tidal forcing at the terminus. At Helheim Glacier, analysis...

Development of ice floe tracker algorithm to measure Lagrangian statistics in the eastern Greenland coast

Science.gov (United States)

Lopez, Rosalinda; Wilhelmus, Monica M.; Schodlok, Michael; Klein, Patrice

2017-11-01

Sea ice export through Fram Strait is a key component of the Arctic climate system. The East Greenland Current (EGC) carries most of the sea ice southwards until it melts. Lagrangian methods using sea ice buoys have been used to map ice features in polar regions. However, their spatial and temporal coverage is limited. Satellite data can provide a better tool to map sea ice flow and its variability. Here, an automated sea ice floe detection algorithm uses ice floes as tracers for surface ocean currents. We process Moderate Resolution Imaging Spectroradiometer satellite images to track ice floes (length scale 5-10 km) in the north-eastern Greenland Sea region. Our matlab-based routines effectively filter out clouds and adaptively modify the images to segment and identify ice floes. Ice floes were tracked based on persistent surface features common in successive images throughout 2016. Their daily centroid locations were extracted and its resulting trajectories are used to describe surface circulation and its variability using differential kinematic parameters. We will discuss the application of this method to a longer time series and larger spatial coverage. This enables us to derive the inter-annual variability of mesoscale features along the eastern coast of Greenland. Supported by UCR Mechanical Engineering Departmental Fellowship.

Continuity and discontinuity in the Inuit culture of Greenland

NARCIS (Netherlands)

Kylstra, Hans P.

1977-01-01

In november 1976 the Arctic Centre of the University of Gronlngen organized its third symposium. The third symposium was a Dutch-Danish one on the Greenlandic Inuit: 'Continuity and Discontinuity In Greenlandic Arctic Culture'. As on the two previous occasions, an exhibition was organized.

Climate Change and Baleen Whale Trophic Cascades in Greenland

Science.gov (United States)

2009-09-30

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Climate Change and Baleen Whale Trophic Cascades in Greenland...SUBTITLE Climate Change And Baleen Whale Trophic Cascades In Greenland 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

Electrical conductivity measurements from the GISP2 and GRIP Greenland ice cores

DEFF Research Database (Denmark)

Dahl-Jensen, Dorthe; Clausen, Henrik Brink; Taylor, K. C.

1993-01-01

. Here we present electrical conductivity records for the Greenland Ice Sheet Project 2 (GISP2) and Greenland Ice-core Project (GRIP) ice cores, drilled 28 km apart to enable direct comparison of the results. The upper parts of both records are consistent with previous evidence from other Greenland cores...

ROLE OF FCA WELDING PROCESS PARAMETERS ON BEAD PROFILE, ANGULAR AND BOWING DISTORTION OF FERRITIC STAINLESS STEEL SHEETS

Directory of Open Access Journals (Sweden)

VENKATESAN M. V.

2014-02-01

Full Text Available This paper discusses the influence of flux cored arc welding (FCAW process parameters such as welding current, travel speed, voltage and CO2 shielding gas flow rate on bead profile, bowing distortion and angular distortion of 409 M ferritic stainless steel sheets of 2 mm thickness. The bowing and angular distortions of the welded plates were measured using a simple device called profile tracer and Vernier bevel protractor respectively. The study revealed that the FCAW process parameters have significant effect on bead profile, and distortion. The relationship between bead profile and distortions were analyzed. Most favorable process parameters that give uniform bead profile and minimum distortion for the weld are recommended for fabrication.

Prevalence of age-related maculopathy and age-related macular degeneration among the inuit in Greenland. The Greenland Inuit Eye Study

DEFF Research Database (Denmark)

Andersen, Mads Varis Nis; Rosenberg, Thomas; la Cour, Morten

2008-01-01

To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland.......To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland....

Holographic measurement of distortion during laser melting: Additive distortion from overlapping pulses

Science.gov (United States)

Haglund, Peter; Frostevarg, Jan; Powell, John; Eriksson, Ingemar; Kaplan, Alexander F. H.

2018-03-01

Laser - material interactions such as welding, heat treatment and thermal bending generate thermal gradients which give rise to thermal stresses and strains which often result in a permanent distortion of the heated object. This paper investigates the thermal distortion response which results from pulsed laser surface melting of a stainless steel sheet. Pulsed holography has been used to accurately monitor, in real time, the out-of-plane distortion of stainless steel samples melted on one face by with both single and multiple laser pulses. It has been shown that surface melting by additional laser pulses increases the out of plane distortion of the sample without significantly increasing the melt depth. The distortion differences between the primary pulse and subsequent pulses has also been analysed for fully and partially overlapping laser pulses.

Towards Greenland Glaciation: cumulative or abrupt transition?

Science.gov (United States)

Ramstein, Gilles; Tan, Ning; Ladant, Jean-baptiste; Dumas, Christophe; Contoux, Camille

2017-04-01

During the mid-Pliocene warming period (3-3.3 Ma BP), the global annual mean temperatures inferred by data and model studies were 2-3° warmer than pre-industrial values. Accordingly, Greenland ice sheet volume is supposed to reach at the most, only half of that of present-day [Haywood et al. 2010]. Around 2.7-2.6 Ma BP, just ˜ 500 kyr after the warming peak of mid-Pliocene, the Greenland ice sheet has reached its full size [Lunt et al. 2008]. A crucial question concerns the evolution of the Greenland ice sheet from half to full size during the 3 - 2.5 Ma period. Data show a decreasing trend of atmospheric CO2 concentration from 3 Ma to 2.5 Ma [Seki et al.2010; Bartoli et al. 2011; Martinez et al. 2015]. However, a recent study [Contoux et al. 2015] suggests that a lowering of CO2 is not sufficient to initiate a perennial glaciation on Greenland and must be combined with low summer insolation to preserve the ice sheet during insolation maxima. This suggests rather a cumulative process than an abrupt event. In order to diagnose the evolution of the ice sheet build-up, we carry on, for the first time, a transient simulation of climate and ice sheet evolutions from 3 Ma to 2.5 Ma. This strategy enables us to investigate the waxing and waning of the ice sheet during several orbital cycles. We use a tri-dimensional interpolation method designed by Ladant et al. (2014), which allows the evolution of CO2 concentration and of orbital parameters, and the evolution of the Greenland ice sheet size to be taken into account. By interpolating climatic snapshot simulations ran with various possible combinations of CO2, orbits and ice sheet sizes, we can build a continuous climatic forcing that is then used to provide 500 kyrs-long ice sheet simulations. With such a tool, we may offer a physically based answer to different CO2 reconstructions scenarios and analyse which one is the most consistent with Greenland ice sheet buildup.

Lead sources in human diet in Greenland

DEFF Research Database (Denmark)

Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert

2004-01-01

Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider......, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993-1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations...... of approximately 75 microg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 microg/L, and those who reported daily intake had concentrations of 170 microg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food...

Greenlandic Sovereignty in Practice

DEFF Research Database (Denmark)

Kristensen, Kristian S.; Rahbek-Clemmensen, Jon

2018-01-01

how Greenlandic policymakers approach specific issues. It is the meeting point between independence, sovereignty, and concrete matters that shapes how the island orients itself towards the world. Understanding how threats to future independence is translated into tangible politics in public discourse...

One million years of glaciation and denudation history in west Greenland

DEFF Research Database (Denmark)

Strunk, Astrid; Knudsen, Mads Faurschou; Egholm, David Lundbek

2017-01-01

The influence of major Quaternary climatic changes on growth and decay of the Greenland Ice Sheet, and associated erosional impact on the landscapes, is virtually unknown beyond the last deglaciation. Here we quantify exposure and denudation histories in west Greenland by applying a novel Markov......-Chain Monte Carlo modelling approach to all available paired cosmogenic 10Be-26Al bedrock data from Greenland. We find that long-term denudation rates in west Greenland range from >50 m Myr−1 in low-lying areas to ∼2 m Myr−1 at high elevations, hereby quantifying systematic variations in denudation rate among...... different glacial landforms caused by variations in ice thickness across the landscape. We furthermore show that the present day ice-free areas only were ice covered ca. 45% of the past 1 million years, and even less at high-elevation sites, implying that the Greenland Ice Sheet for much of the time...

Proglacial river stage, discharge, and temperature datasets from the Akuliarusiarsuup Kuua River northern tributary, Southwest Greenland, 2008–2011

Directory of Open Access Journals (Sweden)

A. K. Rennermalm

2012-05-01

Full Text Available Pressing scientific questions concerning the Greenland ice sheet's climatic sensitivity, hydrology, and contributions to current and future sea level rise require hydrological datasets to resolve. While direct observations of ice sheet meltwater losses can be obtained in terrestrial rivers draining the ice sheet and from lake levels, few such datasets exist. We present a new hydrologic dataset from previously unmonitored sites in the vicinity of Kangerlussuaq, Southwest Greenland. This dataset contains measurements of river stage and discharge for three sites along the Akuliarusiarsuup Kuua (Watson River's northern tributary, with 30 min temporal resolution between June 2008 and July 2011. Additional data of water temperature, air pressure, and lake stage are also provided. Flow velocity and depth measurements were collected at sites with incised bedrock or structurally reinforced channels to maximize data quality. However, like most proglacial rivers, high turbulence and bedload transport introduce considerable uncertainty to the derived discharge estimates. Eleven propagating error sources were quantified, and reveal that largest uncertainties are associated with flow depth observations. Mean discharge uncertainties (approximately the 68% confidence interval are two to four times larger (±19% to ±43% than previously published estimates for Greenland rivers. Despite these uncertainties, this dataset offers a rare collection of direct measurements of ice sheet runoff to the global ocean and is freely available for scientific use at http://dx.doi.org/10.1594/PANGAEA.762818.

Societal costs and effects of implementing population-based mammography screening in Greenland

DEFF Research Database (Denmark)

Christensen, Maria Klitgaard; Niclasen, Birgit; Moesgaard Iburg, Kim

2017-01-01

With a low breast cancer incidence and low population density, Greenland is geographically and organisationally challenged in implementing a cost effective breast cancer screening programme where a large proportion of the Greenlandic women will have to travel far to attend. The aim of this paper ...... transportation and accommodation costs and loss of productivity, and none would be accepted as cost-effective per YLS/QALY gained within a conventional threshold level. The least expensive strategy was regional screening with hotel accommodation.......With a low breast cancer incidence and low population density, Greenland is geographically and organisationally challenged in implementing a cost effective breast cancer screening programme where a large proportion of the Greenlandic women will have to travel far to attend. The aim of this paper...... is to evaluate the cost effectiveness and cost utility of different strategies for implementing population-based breast cancer screening in Greenland. Two strategies were evaluated: Centralised screening in the capital Nuuk and decentralised screening in the five municipal regions of Greenland. A cost...

High-resolution Greenland Ice Core data show abrupt climate change happens in few years

DEFF Research Database (Denmark)

Steffensen, Jørgen Peder; Andersen, Katrine Krogh; Bigler, Matthias

2008-01-01

The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture...... source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition...

Hydrologic Sub-basins of Greenland

Data.gov (United States)

National Aeronautics and Space Administration — The Hydrologic Sub-basins of Greenland data set contains Geographic Information System (GIS) polygon shapefiles that include 293 hydrologic sub-basins of the...

Greenland Ice Sheet: High-Elevation Balance and Peripheral Thinning.

Science.gov (United States)

Krabill; Abdalati; Frederick; Manizade; Martin; Sonntag; Swift; Thomas; Wright; Yungel

2000-07-21

Aircraft laser-altimeter surveys over northern Greenland in 1994 and 1999 have been coupled with previously reported data from southern Greenland to analyze the recent mass-balance of the Greenland Ice Sheet. Above 2000 meters elevation, the ice sheet is in balance on average but has some regions of local thickening or thinning. Thinning predominates at lower elevations, with rates exceeding 1 meter per year close to the coast. Interpolation of our results between flight lines indicates a net loss of about 51 cubic kilometers of ice per year from the entire ice sheet, sufficient to raise sea level by 0.13 millimeter per year-approximately 7% of the observed rise.

Growth measures among preschool-age Inuit children living in Canada and Greenland.

Science.gov (United States)

Galloway, Tracey; Niclasen, Birgit V L; Muckle, Gina; Young, Kue; Egeland, Grace M

2012-12-01

The present study reports findings from a study of preschool-age Inuit children living in the Arctic regions of Canada and Greenland. We compare stature and obesity measures using cutoffs from the Centers for Disease Control and the International Obesity Task Force references. The sample is comprised of 1121 Inuit children (554 boys and 567 girls) aged 3-5 years living in Nunavut (n=376) and Nunavik (n=87), Canada, in the capital city of Nuuk, Greenland (n=86), and in Greenland's remaining towns and villages (n=572). Greenland Inuit children were significantly taller than their Canadian counterparts, with greatest height and weight observed among children from Nuuk. Overall prevalence of stunting was low with the three cutoffs yielding similar values for height-for-age z-scores. Obesity prevalence was higher among Canadian Inuit children than their Greenland counterparts. Inuit children have stature values consistent with those of the Centers for Disease Control reference and low prevalence of stunting, though geographic variability in mean stature values between Canadian and Greenlandic samples likely reflects differences in both socioeconomic status and genetic admixture. Obesity prevalence is high among both Canadian and Greenland Inuit preschoolers, with children living in the city of Nuuk exhibiting lower obesity prevalence than children living in either Nunavut or Nunavik, Canada or Greenland's towns and villages. Varying obesity prevalence may reflect varying degrees of food security in remote locations as well as the influence of stature and sitting height which have not been well studied in young Inuit children.

Norse agriculture in Greenland? Farming in a remote medieval landscape

DEFF Research Database (Denmark)

Henriksen, Peter Steen

The aim of the project Norse Farming in Greenland: Agriculture on the edge was to determine whether the Norse farmers actually cultivated crops in Greenland during colonisation in the Viking age and the medieval period. This was investigated by analysing macrofossils extracted from soil samples...... giving information about the local vegetation. Charred grains and threshing waste of barley was found in samples from four sites, strongly indicating that barley was cultivated in Greenland by the Norse farmers. The phosphate analyses showed no sign of any deliberate manuring of the infields as high...

Contrasting evidence of Holocene ice margin retreat, south-western Greenland

DEFF Research Database (Denmark)

Levy, L. B.; Larsen, N. K.; Davidson, T. A.

2017-01-01

Constraining the Greenland Ice Sheet's (GrIS) response to Holocene climate change provides calibrations for ice sheet models that hindcast past ice margin fluctuations. Ice sheet models predict enhanced ice retreat in south-western Greenland during the middle Holocene; however, few geological...... observations corroborating the extensive retreat are available. We present new data from lake sediment cores from the Isua region, south-western Greenland, which provide constraints on Holocene fluctuations of the GrIS margins. Our data indicate that the main GrIS margin was 30 km west of its present...

Mass balance and surface movement of the Greenland Ice Sheet at Summit, Central Greenland

DEFF Research Database (Denmark)

Hvidberg, C.S.; Keller, K.; Gundestrup, N.S.

1997-01-01

During the GRIP deep drilling in Central Greenland, the ice sheet topography and surface movement at Summit has been mapped with GPS. Measurements of the surface velocity are presented for a strain net consisting of 13 poles at distances of 25-60 km from the GRIP site. Some results are: The GRIP...... site is located approximately 2 km NW of the topographic summit; the surface velocity at the GISP 2 site is 1.7 m/yr in the W direction. The present mass balance at Summit is calculated to be -0.03+/-0.04 m/yr, i.e. close to steady state. This result is the best now available for Summit. A small...... thinning rate might be a transient response of the Greenland Ice Sheet due to the temperature increase at the Wisconsin-Holocene transition....

Burden of mortality in Greenland--today and tomorrow

DEFF Research Database (Denmark)

Nielsen, Lasse Christian; Hansen, Kristian Schultz; Nielsen, Ulla Ringgren

2004-01-01

: Concerted multi-sectoral approaches and broad holistic health strategies related to health promotion and prevention today will strategically improve the capability of the Greenlandic society to manage the future disease burden from ageing via its health care sector and the institutional sector for care......OBJECTIVES: Investigation of the relative impact of three factors expected to influence the future mortality burden in Greenland: demographic change, epidemiological transition and behavioural patterns. STUDY DESIGN: To identify general trends in public health status, evaluating the effect...... of public health campaigns and providing the basis for making predictions of future trends in the mortality burden data from the Greenlandic Death Causes Register to estimate Years of Life Lost (YLL) in the period 1976-1998 has been used. METHODS: YLL were estimated according to the Burden of Disease Method...

Physical Activity and Abdominal Fat Distribution in Greenland

DEFF Research Database (Denmark)

Dahl-Petersen, Inger Katrine; Brage, Søren; Bjerregaard, Peter

2017-01-01

with overall and abdominal fat distribution. CONCLUSION: Physical activity energy expenditure is associated with lower BMI, WC, and abdominal fat among Greenland Inuit. The importance of promoting an upward shift of the whole PA intensity distribution and to spur even short bouts of MVPA to limit excessive......PURPOSE: We examined how total volume of physical activity and reallocation of time spent at various objectively measured intensities of physical activity (PA) were associated with overall and abdominal fat distribution in adult Inuit in Greenland. METHODS: Data were collected as part...... of a countrywide cross-sectional health survey in Greenland. A combined accelerometer and HR monitor measured total physical activity energy expenditure (PAEE) and intensities of PA (N = 1536). Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by ultrasonography. Isotemporal...

Eemian interglacial reconstructed from a Greenland folded ice core

DEFF Research Database (Denmark)

Dahl-Jensen, Dorthe; Albert, M. R.; Aldahan, A.

2013-01-01

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new No...

Common mental disorders among patients in primary health care in Greenland

DEFF Research Database (Denmark)

Lynge, Inge; Munk-Jørgensen, Povl; Pedersen, Amalia Lynge

2004-01-01

There are many indications that mental health in Greenland is endangered and needs more attention.......There are many indications that mental health in Greenland is endangered and needs more attention....

Meltwater chemistry and solute export from a Greenland ice sheet catchment, Watson River, West Greenland

DEFF Research Database (Denmark)

Yde, Jacob C.; Knudsen, N. Tvis; Hasholt, Bent

2014-01-01

–2010 for the Watson River sector of the GrIS that drains into the fjord Kangerlussuaq. The hydrochemistry is dominated by Ca2+ and HCO3− with a relatively high molar K+/Na+ ratio of 0.6 ± 0.1, typical for meltwaters draining a gneissic lithology. Low molar Ca2+/Na+ and Mg2+/Na+ ratios indicate that weathering....... However, when normalized by discharge the denudation rates are comparable to other Arctic sites. When extrapolating the results from the Watson River catchment to the entire Greenland for 2007–2010, the solute export from Greenland meltwater varied between 7.1 × 106 and 7.8 × 106 tons, whilst the major...

Increasing mass loss from Greenland's Mittivakkat Gletscher

DEFF Research Database (Denmark)

Hasholt, Bent; Mernild, S.H.; Knudsen, N.T.

2011-01-01

Warming in the Arctic during the past several decades has caused glaciers to thin and retreat, and recent mass loss from the Greenland Ice Sheet is well documented. Local glaciers peripheral to the ice sheet are also retreating, but few mass-balance observations are available to quantify that ret...... a local phenomenon, but are indicative of glacier changes in the broader region. Mass-balance observations for the MG therefore provide unique documentation of the general retreat of Southeast Greenland's local glaciers under ongoing climate warming....

Geologic mapping in Greenland with polarimetric SAR

DEFF Research Database (Denmark)

Dall, Jørgen; Madsen, Søren Nørvang; Brooks, C. K.

1995-01-01

The application of synthetic aperture radar (SAR) for geologic mapping in Greenland is investigated by the Danish Center for Remote Sensing (DCRS) in co-operation with the Danish Lithosphere Centre (DLC). In 1994 a pilot project was conducted in East Greenland. The Danish airborne SAR, EMISAR...... mapping is complicated by an extreme topography leading to massive shadowing, foreshortening and layover. An artifact characterised by high cross-polarisation is observed behind many sharp mountain ridges. A multi-reflection hypothesis has been investigated without finding the ultimate proof...

Uncovering the Genetic History of the Present Day Greenlandic Population

DEFF Research Database (Denmark)

Moltke, Ida; Fumagalli, Matteo; Korneliussen, Thorfinn S

2015-01-01

Because of past limitations in samples and genotyping technologies, important questions about the history of the present-day Greenlandic population remain unanswered. In an effort to answer these questions and in general investigate the genetic history of the Greenlandic population, we analyzed...

MIS-11 duration key to disappearance of the Greenland ice sheet

Science.gov (United States)

Robinson, Alexander; Alvarez-Solas, Jorge; Calov, Reinhard; Ganopolski, Andrey; Montoya, Marisa

2017-07-01

Palaeo data suggest that Greenland must have been largely ice free during Marine Isotope Stage 11 (MIS-11). However, regional summer insolation anomalies were modest during this time compared to MIS-5e, when the Greenland ice sheet likely lost less volume. Thus it remains unclear how such conditions led to an almost complete disappearance of the ice sheet. Here we use transient climate-ice sheet simulations to simultaneously constrain estimates of regional temperature anomalies and Greenland's contribution to the MIS-11 sea-level highstand. We find that Greenland contributed 6.1 m (3.9-7.0 m, 95% credible interval) to sea level, ~7 kyr after the peak in regional summer temperature anomalies of 2.8 °C (2.1-3.4 °C). The moderate warming produced a mean rate of mass loss in sea-level equivalent of only around 0.4 m per kyr, which means the long duration of MIS-11 interglacial conditions around Greenland was a necessary condition for the ice sheet to disappear almost completely.

SU-G-IeP1-15: Towards Accurate Cerebral Blood Flow Quantification with Distortion- Corrected Pseudo-Continuous Arterial Spin Labeling

Energy Technology Data Exchange (ETDEWEB)

Hoff, M; Rane-Levandovsky, S; Andre, J [University of Washington, Seattle, WA (United States)

2016-06-15

Purpose: Traditional arterial spin labeling (ASL) acquisitions with echo planar imaging (EPI) readouts suffer from image distortion due to susceptibility effects, compromising ASL’s ability to accurately quantify cerebral blood flow (CBF) and assess disease-specific patterns associated with CBF abnormalities. Phase labeling for additional coordinate encoding (PLACE) can remove image distortion; our goal is to apply PLACE to improve the quantitative accuracy of ASL CBF in humans. Methods: Four subjects were imaged on a 3T Philips Ingenia scanner using a 16-channel receive coil with a 21/21/10cm (frequency/phase/slice direction) field-of-view. An ASL sequence with a pseudo-continuous ASL (pCASL) labeling scheme was employed to acquire thirty dynamics of single-shot EPI data, with control and label datasets for all dynamics, and PLACE gradients applied on odd dynamics. Parameters included a post-labeling delay = 2s, label duration = 1.8s, flip angle = 90°, TR/TE = 5000/23.5ms, and 2.9/2.9/5.0mm (frequency/phase/slice direction) voxel size. “M0” EPI-reference images and T1-weighted spin-echo images with 0.8/1.0/3.3mm (frequency/phase/slice directions) voxel size were also acquired. Complex conjugate image products of pCASL odd and even dynamics were formed, a linear phase ramp applied, and data expanded and smoothed. Data phase was extracted to map control, label, and M0 magnitude image pixels to their undistorted locations, and images were rebinned to original size. All images were corrected for motion artifacts in FSL 5.0. pCASL images were registered to M0 images, and control and label images were subtracted to compute quantitative CBF maps. Results: pCASL image and CBF map distortions were removed by PLACE in all subjects. Corrected images conformed well to the anatomical T1-weighted reference image, and deviations in corrected CBF maps were evident. Conclusion: Eliminating pCASL distortion with PLACE can improve CBF quantification accuracy using minimal

SU-G-IeP1-15: Towards Accurate Cerebral Blood Flow Quantification with Distortion- Corrected Pseudo-Continuous Arterial Spin Labeling

International Nuclear Information System (INIS)

Hoff, M; Rane-Levandovsky, S; Andre, J

2016-01-01

Purpose: Traditional arterial spin labeling (ASL) acquisitions with echo planar imaging (EPI) readouts suffer from image distortion due to susceptibility effects, compromising ASL’s ability to accurately quantify cerebral blood flow (CBF) and assess disease-specific patterns associated with CBF abnormalities. Phase labeling for additional coordinate encoding (PLACE) can remove image distortion; our goal is to apply PLACE to improve the quantitative accuracy of ASL CBF in humans. Methods: Four subjects were imaged on a 3T Philips Ingenia scanner using a 16-channel receive coil with a 21/21/10cm (frequency/phase/slice direction) field-of-view. An ASL sequence with a pseudo-continuous ASL (pCASL) labeling scheme was employed to acquire thirty dynamics of single-shot EPI data, with control and label datasets for all dynamics, and PLACE gradients applied on odd dynamics. Parameters included a post-labeling delay = 2s, label duration = 1.8s, flip angle = 90°, TR/TE = 5000/23.5ms, and 2.9/2.9/5.0mm (frequency/phase/slice direction) voxel size. “M0” EPI-reference images and T1-weighted spin-echo images with 0.8/1.0/3.3mm (frequency/phase/slice directions) voxel size were also acquired. Complex conjugate image products of pCASL odd and even dynamics were formed, a linear phase ramp applied, and data expanded and smoothed. Data phase was extracted to map control, label, and M0 magnitude image pixels to their undistorted locations, and images were rebinned to original size. All images were corrected for motion artifacts in FSL 5.0. pCASL images were registered to M0 images, and control and label images were subtracted to compute quantitative CBF maps. Results: pCASL image and CBF map distortions were removed by PLACE in all subjects. Corrected images conformed well to the anatomical T1-weighted reference image, and deviations in corrected CBF maps were evident. Conclusion: Eliminating pCASL distortion with PLACE can improve CBF quantification accuracy using minimal

Self-rated health among Greenlandic Inuit and Norwegian Sami adolescents

DEFF Research Database (Denmark)

Spein, Anna Rita; Pedersen, Cecilia Petrine; Silviken, Anne Cathrine

2013-01-01

Self-rated health (SRH) and associated risk and protective correlates were investigated among two indigenous adolescent populations, Greenlandic Inuit and Norwegian Sami.......Self-rated health (SRH) and associated risk and protective correlates were investigated among two indigenous adolescent populations, Greenlandic Inuit and Norwegian Sami....

Cool or hot Greenland?

DEFF Research Database (Denmark)

Ren, Carina Bregnholm

2016-01-01

shows how a Greenland of the future is portrayed and branded as a sustainable nation and destination through future scenarios. The performative approach to the exhibition and its scenarios displays how issues related to all three sides of sustainability e people, planet and profit e are enrolled...

Climate variability in West Greenland during the past 1500 years

DEFF Research Database (Denmark)

dos Santos Ribeiro, Sofia Isabel; Moros, Matthias; Ellegaard, Marianne

2012-01-01

-surface temperatures in Disko Bay are out-of-phase with Greenland ice-core reconstructed temperatures and marine proxy data from South and East Greenland. This is probably governed by an NAO-type pattern, which results in warmer sea-surface conditions with less extensive sea ice in the area for the later part....... Sea ice cover and primary productivity were identified as the two main factors driving dinoflagellate cyst community changes through time. Our data provide evidence for an opposite climate trend in West Greenland relative to the NE Atlantic region from c. AD 500 to 1050. For the same period, sea...

Winter Camp: A Blog from the Greenland Summit, Part II

Science.gov (United States)

Koenig, Lora

2009-01-01

An earlier issue presents the first half of the author's experience living and working at the National Science Foundation's (NSF) Greenland Summit Camp. The author is a remote-sensing glaciologist at NASA s Goddard Space Flight Center. She took measurements that will be used to validate data collected by NASA s Aqua, Terra, and Ice, Clouds, and land Elevation Satellite (ICESat) satellites with ground-truth measurements of the Greenland Ice Sheet she made at Summit Camp from November 2008-February 2009. This article presents excerpts from the second half of her stay and work at the Greenland Summit.

Seabird colonies in the Melville Bay, Northwest Greenland

DEFF Research Database (Denmark)

Boertmann, David; Huffeldt, Nicholas Per

This report describes the results of a survey for breeding and colonial seabirds in a hitherto un-surveyed area of Northwest Greenland - the Melville Bay. The results shall be included as background data for oil spill sensitivity mapping, preparation of environmental impact assessments of petroleum...... activities in Baffin Bay and for the regulation (by the Greenland government) of petroleum activities. The survey showed, that compared to other coasts of West Greenland, the Melville Bay holds only few breeding colonies and low numbers of breeding seabirds. The most widespread and numerous species...... is the black guillemot followed by the glaucous gull. However, one colony is of national significance – Sabine Øer, with high numbers of breeding Arctic terns and Sabine’s gulls. Other noteworthy observations were puffins on Thom Ø and many new Iceland gull colonies that extended the known northern breeding...

Volcanic influence on centennial to millennial Holocene Greenland temperature change.

Science.gov (United States)

Kobashi, Takuro; Menviel, Laurie; Jeltsch-Thömmes, Aurich; Vinther, Bo M; Box, Jason E; Muscheler, Raimund; Nakaegawa, Toshiyuki; Pfister, Patrik L; Döring, Michael; Leuenberger, Markus; Wanner, Heinz; Ohmura, Atsumu

2017-05-03

Solar variability has been hypothesized to be a major driver of North Atlantic millennial-scale climate variations through the Holocene along with orbitally induced insolation change. However, another important climate driver, volcanic forcing has generally been underestimated prior to the past 2,500 years partly owing to the lack of proper proxy temperature records. Here, we reconstruct seasonally unbiased and physically constrained Greenland Summit temperatures over the Holocene using argon and nitrogen isotopes within trapped air in a Greenland ice core (GISP2). We show that a series of volcanic eruptions through the Holocene played an important role in driving centennial to millennial-scale temperature changes in Greenland. The reconstructed Greenland temperature exhibits significant millennial correlations with K + and Na + ions in the GISP2 ice core (proxies for atmospheric circulation patterns), and δ 18 O of Oman and Chinese Dongge cave stalagmites (proxies for monsoon activity), indicating that the reconstructed temperature contains hemispheric signals. Climate model simulations forced with the volcanic forcing further suggest that a series of large volcanic eruptions induced hemispheric-wide centennial to millennial-scale variability through ocean/sea-ice feedbacks. Therefore, we conclude that volcanic activity played a critical role in driving centennial to millennial-scale Holocene temperature variability in Greenland and likely beyond.

Greenland, Arctic Orientalism and the search for definitions of a contemporary postcolonial geography

DEFF Research Database (Denmark)

Jensen, Lars

2015-01-01

This article begins by discussing the applicability of Orientalism in the Arctic where it was first applied by Ann Fienup-Riordan in her work in the 1990s in relation to Inuit representation in American cinema/documentary. The article moves on to consider more broadly approaches to the Arctic...... what postcolonial sensibilities can be articulated through an analysis of the three films with a particular emphasis on the negotiation of Greenlandic, Greenlandic-Danish and Danish identities. Reading Greenland through a postcolonial lens as manifested in the Greenlandic space the films grant returns...

A study of the peopling of Greenland using next generation sequencing of complete mitochondrial genomes

DEFF Research Database (Denmark)

Lopopolo, Maria; Børsting, Claus; Pereira, Vania

2016-01-01

the migration patterns in the Greenlandic population from a female inheritance demographic perspective. Methods We investigated the maternal genetic variation in the Greenlandic population by sequencing the whole mtDNA genome in 127 Greenlandic individuals using the Illumina MiSeq® platform. Results All......Objectives The Greenlandic population history is characterized by a number of migrations of people of various ethnicities. In this work, the analysis of the complete mtDNA genome aimed to contribute to the ongoing debate on the origin of current Greenlanders and, at the same time, to address...... Greenlandic individuals belonged to the Inuit mtDNA lineages A2a, A2b1, and D4b1a2a1. No European haplogroup was found. Discussion The mtDNA lineages seem to support the hypothesis that the Inuit in Greenland are descendants from the Thule migration. The results also reinforce the importance of isolation...

Governance and Tradition in Nineteenth-Century Greenland

DEFF Research Database (Denmark)

Rud, Søren

2014-01-01

as a restoration of a Greenlandic culture en route to its own destruction. The colonial authorities claimed that the establishments of new institutions were facilitating a return to the traditional practices of the past. Further the author argues that reforms effectuated in the latter part of the nineteenth...... century reflect a fundamental shift in the rationality behind the colonial project in Greenland. This analytical point is reached through the deployment of the theoretical concept colonial governmentality. Following the work of scholars such as Nicholas Thomas, David Scott and Gyan Prakash, it is argued...

Greenland Ice Shelves and Ice Tongues

DEFF Research Database (Denmark)

Reeh, Niels

2017-01-01

literature and physical properties are reviewed. There exists a difference between: (1) Floating glaciers in northern Greenland (>77°N) which experience bottom melting as their dominant ablation mechanism and calve relatively thin, but large (km-sized) tabular icebergs (‘ice islands’), and (2) Grounded...... glaciers further south (iceberg calving provides the dominant ablation mechanism. The relatively smaller iceberg discharge in northern Greenland is closely related to the occurrence of extended floating glacier sections, allowing bottom melting estimated at up to 10 m year−1 for locations...

Monitoring natural vegetation in Southern Greenland using NOAA AVHRR and field measurements

DEFF Research Database (Denmark)

Hansen, Birger Ulf

1991-01-01

vegetation, sheep farming, biomass production, Remote Sensing, NOAA AVHRR, Southern Greenland, NDVI......vegetation, sheep farming, biomass production, Remote Sensing, NOAA AVHRR, Southern Greenland, NDVI...

Bathymetry and retreat of Southeast Greenland glaciers from Operation IceBridge and Ocean Melting Greenland data

Science.gov (United States)

Millan, R.; Rignot, E. J.; Morlighem, M.; Bjork, A. A.; Mouginot, J.; Wood, M.

2017-12-01

Southeast Greenland has been one of the largest contributors to ice mass loss in Greenland in part because of significant changes in glacier dynamics. The leading hypothesis for the changes in glacier dynamics is that enhanced thermal forcing from the ocean has dislodged a number of glaciers from their anchoring positions and some of them retreated rapidly along a reverse bed. The glaciers response has been observed to vary significantly from one fjord to the next, but until now there was not enough data to understand or interpret these changes. In particular, there was no data on glacier bed topography and seafloor bathymetry in the fjords. Here we present the results of new fjord mapping by the NASA Ocean Melting Greenland mission combined with a recent high-resolution airborne gravity survey by NASA Operation IceBridge. We combine these data with a reconstruction of the bed using a mass conservation approach upstream extending into the glacial fjords for the first time. In the fjord and along the ice-ocean transition, we employ a 3D inversion of gravity data to infer the bed elevation along a set of 9 survey boxes spanning south of Helheim Glacier to the southern tip of Southeast Greenland. We combine the results with an analysis of the glacier front history since the 1930's and Conductivity Temperature Depth data obtained in the fjord by OMG in 2016. The data reveals bed elevations several 100-m deeper than previously thought, for almost all the glaciers, up to 500 m for some of them. For many glaciers, the bed profiles help to completely understand the history of retreat of the glaciers. For instance, glaciers stranded on sills have been stable; glaciers on a reverse slope have retreated rapidly; and glaciers with a normal slope have retreated slowly. The mapping also helps document the extent of the marine portion of the glacier basins. In many of the fjords, we document the presence of warm, salty Atlantic Water which fuels large melt rates. We employ

Movements of female polar bears (Usrus maritimus) in the East Greenland pack ice

DEFF Research Database (Denmark)

Wiig, Øystein; Born, Erik W.; Pedersen, Leif Toudal

2003-01-01

The movements of two adult female polar bears (Ursus maritimus) in East Greenland and the Greenland Sea area were studied by use of satellite telemetry between the fall of 1994 and the summer of 1998. One female was tracked for 621 days, the other for 1,415 days. During this time the females used...... for a closer monitoring of the effects of this change on the East Greenland polar bear population....... movement rates varied between 0.32 and 0.76km/h. Both bears had very large home ranges (242,000 and 468,000 km(2)) within the dynamic pack ice of the Greenland Sea. The facts that the bears made extensive use of the offshore sea ice and that there is a marked reduction of the Greenland Sea ice call...

Feeding habits of harp and hooded seals in Greenland waters

Directory of Open Access Journals (Sweden)

Finn O Kapel

2000-05-01

Full Text Available Results of stomach contents analyses of harp and hooded seals collected in West Greenland waters in the period 1986-1993 are reviewed, and compared with published data and circumstantial information from local hunters.  The diet of harp seals in this region is variable but consists mainly of pelagic crustaceans (Thysanoessa spp. and Parathemisto libellula and small fish species like capelin (Mallotus villosus, sandeel (Ammodytes spp., polar cod (Boreogadus saida and Arctic cod (Arctogadus glacialis. Species of importance for commercial fisheries in Greenland, such as Northern prawn (Pandalus borealis, Atlantic cod (Gadus morhua, and Greenland halibut (Reinhardtius hippoglossoides play a minor role in the diet of harp seals in this area. Variation in the diet of hooded seals is less well documented, but in addition to the species also taken by harp seals, larger demersal fishes like Greenland halibut, redfish (Sebastes spp., cod, and wolffish (Anarhichas minor are apparently important prey items.

Linkages between Icelandic Low position and SE Greenland winter precipitation

Science.gov (United States)

Berdahl, M.; Rennermalm, A. K.; Hammann, A. C.; Mioduszewski, J.; Hameed, S.; Tedesco, M.; Stroeve, J. C.; Mote, T. L.

2015-12-01

Greenland's largest flux of precipitation occurs in its Southeast (SE) region. An understanding of the mechanisms controlling precipitation in this region is lacking despite its disproportionate importance in the mass balance of Greenland and the consequent contributions to sea level rise. We use weather station data from the Danish Meteorological Institute to reveal the governing influences on precipitation in SE Greenland during the winter and fall. We find that precipitation in the fall is significantly correlated to the longitude of the Icelandic Low and the NAO. Winter precipitation is correlated with the strength and longitude of the Icelandic Low, as well as the NAO. We show that in years of extreme high precipitation, onshore winds dominate, thereby advecting more moisture inland. In low precipitation years, winds are more westerly, approaching the stations from land. Understanding the controls of SE Greenland precipitation will help us predict how future precipitation in this key region may change in a warming climate.

Limited distortion in LSB steganography

Science.gov (United States)

Kim, Younhee; Duric, Zoran; Richards, Dana

2006-02-01

It is well known that all information hiding methods that modify the least significant bits introduce distortions into the cover objects. Those distortions have been utilized by steganalysis algorithms to detect that the objects had been modified. It has been proposed that only coefficients whose modification does not introduce large distortions should be used for embedding. In this paper we propose an effcient algorithm for information hiding in the LSBs of JPEG coefficients. Our algorithm uses parity coding to choose the coefficients whose modifications introduce minimal additional distortion. We derive the expected value of the additional distortion as a function of the message length and the probability distribution of the JPEG quantization errors of cover images. Our experiments show close agreement between the theoretical prediction and the actual additional distortion.

Catch history and status of the harbour seal (Phoca vitulina in Greenland

Directory of Open Access Journals (Sweden)

Aqqalu Rosving-Asvid

2010-09-01

Full Text Available The number of harbour seals (Phoca vitulina in West Greenland declined rapidly after the 1950s and the seals have now abandoned their traditional haulout locations along the Greenland west coast. However, in recent years, a previously undetected group of about 60-100 harbour seals has been observed approximately 80 km upstream in a large river, and some traditional hauloutlocations are still in use near the south-eastern tip of Greenland. A small number of harbour seals is caught annually far from any of these locations, indicating that other groups might live unnoticed. Catch statistics provide the best evidence of the presence and locations of these remnant harbour seals. Therefore efforts were made to validate the recent catch statistics and to describe the catch history for the past 60 years. The catch statistics were also used to estimate plausibleranges of past and present numbers of harbour seals based on the assumption that hunting has caused the observed decline. The total number of harbour seals in Greenland according to these estimates was about 3,000 in 1950 and fewer than 1,000 in 2007. The number of harbour seals caught in the southernmost part of Greenland has, unlike in the rest of Greenland, increased significantly in some of the recent years. This change seems to be related to changes in the amount of drift ice. Drift ice reduces the frequency of contact between hunters and harbour seals in South Greenland and above normal quantities of drift ice from the mid 1960s to the mid 1980s probably allowed these seals to increase in numbers. Record low inflow of drift ice in some of the recent years, however, has resulted in record high catches, which likely have reduced the seals again. The remaining harbour seals in Greenland are few and without protection these sealsare potentially in danger of extinction.

Risk factors for Mycobacterium tuberculosis infection among children in Greenland

DEFF Research Database (Denmark)

Søborg, Bolette; Andersen, Aase Bengaard; Melbye, Mads

2011-01-01

To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection.......To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection....

Firn thickness variations across the Northeast Greenland Ice Stream margins indicating nonlinear densification rates

Science.gov (United States)

Riverman, K. L.; Anandakrishnan, S.; Alley, R. B.; Peters, L. E.; Christianson, K. A.; Muto, A.

2013-12-01

Northeast Greenland Ice Stream (NEGIS) is the largest ice stream in Greenland, draining approximately 8.4% of the ice sheet's area. The flow pattern and stability mechanism of this ice stream are unique to others in Greenland and Antarctica, and merit further study to ascertain the sensitivity of this ice stream to future climate change. Geophysical methods are valuable tools for this application, but their results are sensitive to the structure of the firn and any spatial variations in firn properties across a given study region. Here we present firn data from a 40-km-long seismic profile across the upper reaches of NEGIS, collected in the summer of 2012 as part of an integrated ground-based geophysical survey. We find considerable variations in firn thickness that are coincident with the ice stream shear margins, where a thinner firn layer is present within the margins, and a thicker, more uniform firn layer is present elsewhere in our study region. Higher accumulation rates in the marginal surface troughs due to drift-snow trapping can account for some of this increased densification; however, our seismic results also highlight enhanced anisotropy within the firn and upper ice column that is confined to narrow bands within the shear margins. We thus interpret these large firn thickness variations and abrupt changes in anisotropy as indicators of firn densification dependent on the effective stress state as well as the overburden pressure, suggesting that the strain rate increases nonlinearly with stress across the shear margins. A GPS strain grid maintained for three weeks across both margins observed strong side shearing, with rapid stretching and then compression along particle paths, indicating large deviatoric stresses in the margins. This work demonstrates the importance of developing a high-resolution firn densification model when conducting geophysical field work in regions possessing a complex ice flow history; it also motivates the need for a more

Resilience and Renewable Energy Planning in Greenland

DEFF Research Database (Denmark)

Carruth, Susan

2014-01-01

Using a combination of thematic analysis and studio-based planning proposals in West Greenland, this paper proposes that there is more than one interpretation of resilience in renewable energy planning. All energy transitions, from one system to another, are protracted and unpredictable, and the ......Using a combination of thematic analysis and studio-based planning proposals in West Greenland, this paper proposes that there is more than one interpretation of resilience in renewable energy planning. All energy transitions, from one system to another, are protracted and unpredictable......, and the transition to a renewable energy system is proving no exception. Such a transition is particularly amplified in the context of Greenland – a country undergoing rapid transformation in many fields, including energy. Resilience theory offers an approach for how to plan for this energy transition, but how...... to translate resilience theory into planning practices remains underdeveloped. The paper begins by outlining some of the challenges in planning a transition to renewable energy, and sketching Greenland’s energy landscape. It then discusses the key characteristics of resilience thinking, before proposing...

Secret Science: Exploring Cold War Greenland

Science.gov (United States)

Harper, K.

2013-12-01

During the early Cold War - from the immediate postwar period through the 1960s - the United States military carried out extensive scientific studies and pursued technological developments in Greenland. With few exceptions, most of these were classified - sometimes because new scientific knowledge was born classified, but mostly because the reasons behind the scientific explorations were. Meteorological and climatological, ionospheric, glaciological, seismological, and geological studies were among the geophysical undertakings carried out by military and civilian scientists--some in collaboration with the Danish government, and some carried out without their knowledge. This poster will present some of the results of the Exploring Greenland Project that is coming to a conclusion at Denmark's Aarhus University.

A first isotopic dietary study of the Greenlandic Thule Culture

DEFF Research Database (Denmark)

Nelson, D.E.; Lynnerup, Niels; Arneborg, J.

2012-01-01

The isotopic dietary method has been applied to samples of some 65 Thule Culture individuals from existing archaeological collections of Greenlandic human skeletal material. The aim was to use the Greenlandic Thule Culture as a test of the isotopic method, in that we know they were heavily...... was used as the basis for analysis. As expected, the results indicate that these people were almost entirely dependent on the marine biosphere for their protein. An exception is those from Northeast Greenland, whose isotopic signatures show evidence for consumption of terrestrial protein as well....... Not expected were the observed differences at the regional and local levels....

Life history parameters of narwhals (Monodon monoceros) from Greenland

DEFF Research Database (Denmark)

Garde, Eva; Hansen, Steen H; Ditlevsen, Susanne

2015-01-01

Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007–...... projection matrix was parameterized with the data on age structure and fertility rates. The annual rate of increase of narwhals in East Greenland was estimated to be 3.8% while narwhals in West Greenland had a rate of increase at 2.6%. Key words:......Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007......–2010. Age estimates were based on the racemization of L-aspartic acid to D-aspartic acid in the nucleus of the eye lens. The ratio of D- and L-enantiomers was measured using high-performance liquid chromatography. The age equation used, 420.32X − 24.02·year where X is the D/L ratio, was determined from data...

Caribou, individual-based modeling and mega-industry in central West Greenland

DEFF Research Database (Denmark)

Raundrup, Katrine; Nymand, Josephine; Nabe-Nielsen, Jacob

in West Greenland. In a newly started PhD-project the focus will be the implementation of spatially explicit individual based modeling (IBM). The project relies on existing knowledge on caribou behavior and feeding ecology along with data on variations in the vegetation. By relating vegetation, snow......Spatial distribution of caribou (Rangifer tarandus groenlandicus) in West Greenland is a result of both short and long term changes in the Arctic landscape. To understand present distribution 40 satellite collars were deployed on 40 female caribou in the Akia-Maniitsoq herd, central West Greenland...... in an area. Further, enhanced or lowered hunting pressure, and changed weather conditions can be studied using IBM. Thus, both short and long term changes in the landscape will be studied and provide insights in how the specific spatial changes impact caribou in West Greenland....

Openness, transparency and public participation in the governance of uranium mining in Greenland:

DEFF Research Database (Denmark)

Pelaudeix, Cécile; Basse, Ellen Margrethe; Loukacheva, Natalia

2017-01-01

This article examines the implementation of the principles of openness, transparency and public participation in the decision-making regarding the conditions for uranium mining in Greenland from a legal and political perspective. The time frame covers the period from the exploration for minerals...... before the Second World War to 2016-17 where the current Greenlandic authorities prepared a license for a project of extraction of rare earth elements and uranium in Kvanefjeld. It is shown that the issue of openness, transparency and public participation in Greenland is a long-standing issue...... to it - has impacted the design of governance in Greenland, and that the constraints put today on a full implementation of the legal principles of openness, transparency and public participation in the governance of uranium mining in Greenland, amongst other factors, point to a current hybrid political...

Hunting and fishing settlements in Upernavik district of Northern Greenland

DEFF Research Database (Denmark)

Hendriksen, Kåre; Jørgensen, Ulrik

2015-01-01

Inuit in the Upernavik district of Northern Greenland has in generations used the winter sea ice as the basis for the essential hunting of seals, white- and narwhales. Since the late 1980’ies hunting has been combined with increasing fishery of Greenland halibut during summer from dinghies and in...

Depression, post-traumatic stress disorder, and life satisfaction in Greenlandic adults

DEFF Research Database (Denmark)

Zaragoza Scherman, Alejandra

2017-01-01

problems or a sense of wellbeing. In this study, a group of 137 Greenlandic adults completed measures of depression, PTSD, and life satisfaction. In addition, they also provided memories of traumatic or stressful and positive life events they had xperienced during their lives. No sex differences were found......Suicide is a major public health problem in Greenland. Despite the fact that suicide is highly associated with depression, posttraumatic stress disorder (PTSD), and life satisfaction there are virtually no data about the extent to which Greenlandic individuals experience these mental health...

Ice-sheet flow conditions deduced from mechanical tests of ice core

DEFF Research Database (Denmark)

Miyamoto, Atsushi; Narita, Hideki; Hondoh, Takeo

1999-01-01

Uniaxial compression tests were performed on samples of the Greenland Ice Core Project (GRIP) deep ice core, both in the field and later in a cold-room laboratory, in order to understand the ice-flow behavior of large ice sheets. Experiments were conducted under conditions of constant strain rate....... It was revealed that cloudy bands affect ice-deformation processes, but the details remain unclear. Udgivelsesdato: June......Uniaxial compression tests were performed on samples of the Greenland Ice Core Project (GRIP) deep ice core, both in the field and later in a cold-room laboratory, in order to understand the ice-flow behavior of large ice sheets. Experiments were conducted under conditions of constant strain rate......-core samples with basal planes parallel to the horizontal plane of the ice sheet. The ice-flow enhancement factors show a gradual increase with depth down to approximately 2000 m. These results can be interpreted in terms of an increase in the fourth-order Schmid factor. Below 2000 m depth, the flow...

Recent greenland accumulation estimated from regional climate model simulations and ice core analysis

DEFF Research Database (Denmark)

Dethloff, K.; Schwager, M.; Christensen, J. H.

2002-01-01

to precipitation. Maxima of precipitation and accumulation occur at the southwestern and southeastern coasts of Greenland and are connected with cyclonic activity and the main storm tracks around Greenland. The central region of the Greenland ice sheet acts as a blocking barrier on moving weather systems...... and prohibits cyclones moving from west to east across this region and, thus prevents moisture transports....

Gross morphology and histology of the olfactory organ of the Greenland shark Somniosus microcephalus

DEFF Research Database (Denmark)

Ferrando, S.; Gallus, L.; Ghigliotti, L.

2016-01-01

The Greenland shark (Somniosus microcephalus) is the largest predatory fish in Arctic waters. Knowledge of the fundamental biology and ecological role of the Greenland shark is limited, and the sensory biology of the Greenland shark has been poorly studied. Given the potential relevant contribution...... of chemoreception to the sensory capability of the Greenland shark to forage and navigate in low-light environments, we examined the architecture of the peripheral olfactory organ (the olfactory rosette) through morphological, histological and immunohistochemical assays. We found that each olfactory rosette...... neurons, presence of unusually large cells along the olfactory fiber bundles) deserve further investigation. Overall, the structure of the olfactory rosette suggests a well-developed olfactory capability for the Greenland shark coherent with a bentho-pelagic lifestyle....

Rapid dynamic thinning on Upernavik Icestream, West Greenland

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Kjær, Kurt H.; Korsgaard, Niels Jákup

2011-01-01

The main outlet glaciers in Greenland have more than doubled their contribution to global sea level rise over the last decade. Several studies have shown increase in ice discharge from the main outlet glaciers (notably Kangerdlugssuaq (KG) and Helheim glaciers (HG) in Southeast Greenland, and Jak......) laser altimetry data supplemented with altimeter surveys from NASA’s Airborne Topographic Mapper (ATM). To assess thinning prior to 2003, we analyze 1985 aerial photos and derived a 2x2 m grid digital elevation model (DEM)....

Report on a Magnetotelluric Study in Kangerlussuaq, West Greenland

DEFF Research Database (Denmark)

Kother, Livia Kathleen; Junge, A.; Löwer, A.

2011-01-01

Despite a well-mapped, interesting surface geology, deep sounding geophysical studies like seismics or magnetotellurics have been used very rarely in Greenland. The aim of this article is to present the preliminary results of a magnetotelluric study performed in the area of Kangerlussuaq, West Gr...... Greenland. The estimated transfer functions will be used in the future for 2-D and 3-D modelling of subsurface resistivity structures, the inuence of the electrically conductive ocean, as well as the source geometry in the auroral oval.......Despite a well-mapped, interesting surface geology, deep sounding geophysical studies like seismics or magnetotellurics have been used very rarely in Greenland. The aim of this article is to present the preliminary results of a magnetotelluric study performed in the area of Kangerlussuaq, West...

Environmental and Ethical Aspects of Sustainable Mining in Greenland

DEFF Research Database (Denmark)

Hansen, Sinne Hjælmsø; Pedersen, Lise Celine; Vilsgaard, Kristine Duelund

2013-01-01

The increased use of scarce metals in combination with climate changes pave way for extensive extraction of mineral resources in Greenland. The focus of this study is on environmental ethical aspects of mining activities in a vulnerable and unspoiled arctic nature. Mining can have several economic...... and social benefits for Greenland. On the other hand, the environmental impacts from mining are well known. Through DPSIR (Drivers, Pressures, States, Impacts, Responses) and Stakeholder analysis, we assess how future mining in Greenland can be sustainably implemented. The analysis revealed that numerous...... stakeholders have to be taken into consideration with a wide range of different interests. The DPSIR analysis clarified the availability of various potential political responses that could affect the drivers, pressures, states and impacts of mining mainly focused on implementation of effective environmental...

Verbal aspects in West Greenlandic

DEFF Research Database (Denmark)

Trondhjem, Naja Blytmann

2017-01-01

In this article, lexical aspectual types in West Greenlandic are investigated in the five aspectual types, states, achievements, semelfactives, activities and accomplishments. It is shown that derivational verbalizing affixes include aspectual type congruent with the lexical aspect and how the as...

Greenland ice core evidence for spatial and temporal variability of the Atlantic Multidecadal Oscillation

NARCIS (Netherlands)

Chylek, P.; Folland, C.K.; Frankcombe, L.M.; Dijkstra, H.A.; Lesins, G.; Dubey, M.

2012-01-01

[1] The Greenland δ18O ice core record is used as a proxy for Greenland surface air temperatures and to interpret Atlantic Multidecadal Oscillation (AMO) variability. An analysis of annual δ18O data from six Arctic ice cores (five from Greenland and one from Canada's Ellesmere Island) suggests a

Twenty-four-hour blood pressure among Greenlanders and Danes: relationship to diet and lifestyle

DEFF Research Database (Denmark)

Jørgensen, Marit Eika; Pedersen, M.B.; Siggaard, Cecilie

2002-01-01

Greenlanders have a lower rate of cardiovascular mortality and morbidity than Danes, possibly due to lower blood pressure. However, 24-h blood pressure has never been measured in Greenlanders. The aim of this study was to compare the 24-h blood pressure of Greenlanders and Danes, and to analyse t...

Brief communication: Improved simulation of the present-day Greenland firn layer (1960-2016)

Science.gov (United States)

Ligtenberg, Stefan R. M.; Kuipers Munneke, Peter; Noël, Brice P. Y.; van den Broeke, Michiel R.

2018-05-01

By providing pore space for storage or refreezing of meltwater, the Greenland ice sheet firn layer strongly modulates runoff. Correctly representing the firn layer is therefore crucial for Greenland (surface) mass balance studies. Here, we present a simulation of the Greenland firn layer with the firn model IMAU-FDM forced by the latest output of the regional climate model RACMO2, version 2.3p2. In the percolation zone, much improved agreement is found with firn density and temperature observations. A full simulation of Greenland firn at high temporal (10 days) and spatial (11 km) resolution is available for the period 1960-2016.

Export of Strongly Diluted Greenland Meltwater From a Major Glacial Fjord

Science.gov (United States)

Beaird, Nicholas L.; Straneo, Fiammetta; Jenkins, William

2018-05-01

The Greenland Ice Sheet has been, and will continue, losing mass at an accelerating rate. The influence of this anomalous meltwater discharge on the regional and large-scale ocean could be considerable but remains poorly understood. This uncertainty is in part a consequence of challenges in observing water mass transformation and meltwater spreading in coastal Greenland. Here we use tracer observations that enable unprecedented quantification of the export, mixing, and vertical distribution of meltwaters leaving one of Greenland's major glacial fjords. We find that the primarily subsurface meltwater input results in the upwelling of the deep fjord waters and an export of a meltwater/deepwater mixture that is 30 times larger than the initial meltwater release. Using these tracer data, the vertical structure of Greenland's summer meltwater export is defined for the first time showing that half the meltwater export occurs below 65 m.

Scale modeling flow-induced vibrations of reactor components

International Nuclear Information System (INIS)

Mulcahy, T.M.

1982-06-01

Similitude relationships currently employed in the design of flow-induced vibration scale-model tests of nuclear reactor components are reviewed. Emphasis is given to understanding the origins of the similitude parameters as a basis for discussion of the inevitable distortions which occur in design verification testing of entire reactor systems and in feature testing of individual component designs for the existence of detrimental flow-induced vibration mechanisms. Distortions of similitude parameters made in current test practice are enumerated and selected example tests are described. Also, limitations in the use of specific distortions in model designs are evaluated based on the current understanding of flow-induced vibration mechanisms and structural response

Experimental Investigation of a Forward Swept Rotor in a Multistage Fan with Inlet Distortion

Directory of Open Access Journals (Sweden)

Aspi R. Wadia

2011-01-01

Full Text Available Previous studies of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep to multistage configurations. The experimental investigation compare two builds of an advanced two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs. The presence of the inlet guide vanes had a profound impact in lowering the two-stage fan's sensitivity with inlet distortion.

Greenland Radar Ice Sheet Thickness Measurements

Data.gov (United States)

National Aeronautics and Space Administration — Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA...

Audit report from Greenland on nurses' tasks and perceived competency.

Science.gov (United States)

Nexøe, J; Skifte, E; Niclasen, B; Munck, A

2012-01-01

Despite all efforts, recruitment of healthcare personnel has become increasingly difficult in Greenland as in other remote areas. The aim of this observational study was to describe the extent of health care delivered by nurses in Greenland's healthcare system. Reasons for encounter, diagnostic procedures, treatments and need for a physician's assistance, as well as the nurses' self-perceived competency, were also analysed. A total of 42 nurses registered all patient encounters for 10 days in late autumn 2006 in 14 out of 16 healthcare districts in Greenland. Nurses treated 1117 encounters (60%) singlehandedly. The nurses felt competent in what they were doing in 1415 encounters (76%). In 525 encounters (31%), a physician's advice was sought. Either the physician was asked to come or the physician's advice was obtained by telephone. In four cases the nurses did not feel completely competent, but did not seek advice from the physician on call. Feeling competent did not depend on length of experience in Greenland. In Greenland, nurses independently receive, diagnose and treat a substantial number of primary healthcare patients. The nurses take care of the patients and perform a number of clinical and laboratory procedures with great confidence. There has been speculation that part of the difficulty in recruiting doctors and healthcare personnel in remote areas may be due to uneasiness about professional responsibilities and, to some extent, lack of confidence. At least among the registering nurses in this study, this did not seem to be a problem.

Abdominal Wall Defects in Greenland 1989-2015.

Science.gov (United States)

Bugge, Merete; Drachmann, Gitte; Kern, Peder; Budtz-Jørgensen, Esben; Eiberg, Hans; Olsen, Britta; Tommerup, Niels; Nielsen, Inge-Merete

2017-07-03

In the last decades, an increasing rate of gastroschisis but not of omphalocele has been reported worldwide. Greenland is the world's largest island, but 80% is covered by an ice cap, it has a small population of around 56,000 peoples (as of 2016). The occurrence of abdominal wall defects has never been investigated in Greenland. The present study is based on data retrieved from three nationwide and two local registries in the Greenlandic health care system over 27 years (1989-2015). We identified 33 infants with abdominal wall defects born in the study time period. All cases were reclassified to 28 cases of gastroschisis, four cases of omphalocele, and there was 1 infant in the indeterminate group. The point prevalence at birth for gastroschisis increased significantly from 8 to 35 (average 10.7) per 10,000 liveborn and -stillborn infants. Mothers below 20 years of age represented 23% of all cases and the prevalence for this group was 17 per 10,000 liveborn and stillborn. Perinatal mortality for infants with gastroschisis was high (18%), and 1 year survival was 71%. For omphalocele, the prevalence varied from 8 to 11 per 10,000 liveborn and stillborn infants. There was no increasing rate in the period, further highlighting an etiological difference between gastroschisis and omphalocele. This study confirms the increasing prevalence of gastroschisis in Greenland in the period from 1989 to 2015. The average was 10.7 per 10,000 liveborn and -stillborn infants and, to the best of our knowledge, this is the highest prevalence ever reported. Birth Defects Research 109:836-842, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Cardiovascular risk amongst migrant and non-migrant Greenland Inuit in a gender perspective

DEFF Research Database (Denmark)

Bjerregaard, Peter; Jørgensen, Marit Eika; Borch-Johnsen, Knut

2007-01-01

surveys among adult Inuit in Greenland and Inuit migrants in Denmark (n = 1542). General Linear Models adjusted for age, smoking, diet (seal, fish, and fruit), and alcohol consumption. RESULTS: Blood pressure was significantly higher among Inuit migrants of either sex than among the Inuit in Greenland....... Among women, HDL-cholesterol concentrations were 1.59 mmol/l in Greenland and 1.83 among migrants (pSmoking, diet, and alcohol...

Spatiotemporal distribution of rabies in Arctic foxes in Greenland

DEFF Research Database (Denmark)

Raundrup, Katrine; Moshøj, Charlotte Margaret; Wennerberg, Sanne

2015-01-01

The temporal occurrence, spatial distribution, spread, and prevalence of rabies in Arctic foxes, Vulpes lagopus, in Greenland were studied using historical observations from 1969 to 2011 and survey data collected in the winters 1992 and 1993. Regionally, the prevalence of rabies ranged between 0...... and 7.1 %. Wavelet analysis was used to identify periodicities in the abundance of rabies cases based on the historical observations. No general length of the cyclic interval of rabies occurrences in Greenland could be demonstrated. The frequency of outbreaks was found to be variable but can be grouped...... as short (less than 5 years), medium (5–10 years), and long (more than 10 years). Moreover, rabies outbreaks in neighboring regions were found to be more closely correlated compared to regions further apart. In West Greenland, the temporal outbreaks of rabies were found to occur along a north...

Models of brachial to finger pulse wave distortion and pressure decrement.

Science.gov (United States)

Gizdulich, P; Prentza, A; Wesseling, K H

1997-03-01

To model the pulse wave distortion and pressure decrement occurring between brachial and finger arteries. Distortion reversion and decrement correction were also our aims. Brachial artery pressure was recorded intra-arterially and finger pressure was recorded non-invasively by the Finapres technique in 53 adult human subjects. Mean pressure was subtracted from each pressure waveform and Fourier analysis applied to the pulsations. A distortion model was estimated for each subject and averaged over the group. The average inverse model was applied to the full finger pressure waveform. The pressure decrement was modelled by multiple regression on finger systolic and diastolic levels. Waveform distortion could be described by a general, frequency dependent model having a resonance at 7.3 Hz. The general inverse model has an anti-resonance at this frequency. It converts finger to brachial pulsations thereby reducing average waveform distortion from 9.7 (s.d. 3.2) mmHg per sample for the finger pulse to 3.7 (1.7) mmHg for the converted pulse. Systolic and diastolic level differences between finger and brachial arterial pressures changed from -4 (15) and -8 (11) to +8 (14) and +8 (12) mmHg, respectively, after inverse modelling, with pulse pressures correct on average. The pressure decrement model reduced both the mean and the standard deviation of systolic and diastolic level differences to 0 (13) and 0 (8) mmHg. Diastolic differences were thus reduced most. Brachial to finger pulse wave distortion due to wave reflection in arteries is almost identical in all subjects and can be modelled by a single resonance. The pressure decrement due to flow in arteries is greatest for high pulse pressures superimposed on low means.

Age of Tertiary volcanic rocks on the West Greenland continental margin

DEFF Research Database (Denmark)

Larsen, Lotte M.; Pedersen, Asger Ken; Tegner, Christian

2016-01-01

across the entire North Atlantic Igneous Province. A quiescent 58–56 Ma period correlates with similar periods in East Greenland and the Faroes, and the Naqerloq Formation is coeval with the Eocene basalts in East Greenland. The Paleocene and Eocene tholeiitic basalts are distinguishable chemically...

On the Origin of Multidecadal to Centennial Greenland Temperature Anomalies Over the Past 800 yr

Science.gov (United States)

Kobashi, T.; Shindell, D. T.; Kodera, K.; Box, J. E.; Nakaegawa, T.; Kawamura, K.

2013-01-01

The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies due to its association with sea level rise. However, the causes of multidecadal-to-centennial temperature changes in Greenland temperatures are not well understood, largely owing to short observational records. To examine these, we calculated the Greenland temperature anomalies (GTA[G-NH]) over the past 800 yr by subtracting the standardized northern hemispheric (NH) temperature from the standardized Greenland temperature. This decomposes the Greenland temperature variation into background climate (NH); polar amplification; and regional variability (GTA[G-NH]). The central Greenland polar amplification factor as expressed by the variance ratio Greenland/NH is 2.6 over the past 161 yr, and 3.3-4.2 over the past 800 yr. The GTA[G-NH] explains 31-35%of the variation of Greenland temperature in the multidecadal-to-centennial time scale over the past 800 yr. We found that the GTA[G-NH] has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO). Climate modeling and proxy temperature records indicate that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC) and associated changes in northward oceanic heat transport.

On the origin of multidecadal to centennial Greenland temperature anomalies over the past 800 yr

Directory of Open Access Journals (Sweden)

T. Kobashi

2013-03-01

Full Text Available The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies due to its association with sea level rise. However, the causes of multidecadal-to-centennial temperature changes in Greenland temperatures are not well understood, largely owing to short observational records. To examine these, we calculated the Greenland temperature anomalies (GTA[G-NH] over the past 800 yr by subtracting the standardized northern hemispheric (NH temperature from the standardized Greenland temperature. This decomposes the Greenland temperature variation into background climate (NH; polar amplification; and regional variability (GTA[G-NH]. The central Greenland polar amplification factor as expressed by the variance ratio Greenland/NH is 2.6 over the past 161 yr, and 3.3–4.2 over the past 800 yr. The GTA[G-NH] explains 31–35% of the variation of Greenland temperature in the multidecadal-to-centennial time scale over the past 800 yr. We found that the GTA[G-NH] has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO. Climate modeling and proxy temperature records indicate that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC and associated changes in northward oceanic heat transport.

Homicide in Greenland 1985-2010.

Science.gov (United States)

Christensen, Martin R; Thomsen, Asser H; Høyer, Christian B; Gregersen, Markil; Banner, Jytte

2016-03-01

Homicide in Greenland has not often been investigated. The latest published study documented a dramatic rise in the homicide rate from around 1/100,000 inhabitants to more than 23/100,000 inhabitants from 1946 to 1984. The aim of our study was to characterize homicides in Greenland from 1985 to 2010 and to compare trends during this period with those in previous studies and with homicide characteristics in Denmark, northern Europe, and other Arctic regions. We identified a total of 281 homicides by legal definition and 194 by medical definition, the latter from the years 1990 to 2010. We procured case files for a total of 129 victims (71 male, 58 female) and 117 perpetrators (85 male, 32 female). We identified an overall decrease in the homicide rate during our study period. The decrease in the medical homicide rate was significant (p = 0.007). The homicide rate ranged from 25/100,000 inhabitants to 13/100,000 inhabitants when results were grouped within 5-year periods. There were significantly more male perpetrators (p homicide methods (41 and 29% respectively), with sharp force deaths increasing throughout the investigation period. Altercations were the main motive (49%). Alcohol-related homicides decreased in our study period. While the Greenlandic homicide rate has decreased, it is markedly higher compared to that seen in Denmark and northern Europe. However, it resembles the rate seen in the rest of the Arctic. Liberal gun laws do not affect the proportion of gun-related killings. Despite the high homicide rate, women account for almost half the victims.

The peripheral olfactory organ in the Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801

Directory of Open Access Journals (Sweden)

Laura Ghigliotti

2015-11-01

Full Text Available The Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801 is the largest predatory fish in Arctic waters. The socio-economic significance of Greenland shark is demonstrated by its impact on the fishing cultures in Greenland, Scandinavia and Iceland for centuries. The fundamental biology and ecological role of Greenland shark, on the other hand, is virtually unknown. Although knowledge of its life history is limited, increasing evidence indicates that the Greenland shark may undertake long-distance migrations and perform vertical movements from the surface to the deep sea. It is an omnivorous species feeding on carrion and a wide variety of pelagic and bottom-dwelling organisms ranging from invertebrates to mammals, and including active species such as fishes and seals. Accordingly, Greenland shark should be recognized as a top predator, with a strong potential to influence the trophic dynamics of the Arctic marine ecosystem. The sensory biology of Greenland shark is scarcely studied, and considering the importance of olfaction in chemoreception, feeding and other behavioral traits, we examined the architecture of the peripheral olfactory organ where olfactory cues are received from the environment – the olfactory rosette. The structural organization of the olfactory rosette, in terms of histological features of the sensory epithelium, number of primary lamellae and total sensory surface area, provides a first proxy of the olfactory capability of Greenland shark. Based on own results and published studies, the overall morphology of the olfactory rosette is viewed in context of the functional and trophic ecology among other elasmobranch species.

Analysis of Brown camera distortion model

Science.gov (United States)

Nowakowski, Artur; Skarbek, Władysław

2013-10-01

Contemporary image acquisition devices introduce optical distortion into image. It results in pixel displacement and therefore needs to be compensated for many computer vision applications. The distortion is usually modeled by the Brown distortion model, which parameters can be included in camera calibration task. In this paper we describe original model, its dependencies and analyze orthogonality with regard to radius for its decentering distortion component. We also report experiments with camera calibration algorithm included in OpenCV library, especially a stability of distortion parameters estimation is evaluated.

Sensitivity of boundary-layer stability to base-state distortions at high Mach numbers

Science.gov (United States)

Park, Junho; Zaki, Tamer

2017-11-01

The stability diagram of high-speed boundary layers has been established by evaluating the linear instability modes of the similarity profile, over wide ranges of Reynolds and Mach numbers. In real flows, however, the base state can deviate from the similarity profile. Both the base velocity and temperature can be distorted, for example due to roughness and thermal wall treatments. We review the stability problem of high-speed boundary layer, and derive a new formulation of the sensitivity to base-state distortion using forward and adjoint parabolized stability equations. The new formulation provides qualitative and quantitative interpretations on change in growth rate due to modifications of mean-flow and mean-temperature in heated high-speed boundary layers, and establishes the foundation for future control strategies. This work has been funded by the Air Force Office of Scientific Research (AFOSR) Grant: FA9550-16-1-0103.

Gestational diabetes mellitus in Greenland

DEFF Research Database (Denmark)

Pedersen, Michael Lynge; Olesen, Jesper; Jørgensen, M. E.

2016-01-01

Background. Within the last 20 years, the prevalence of gestational diabetes mellitus (GDM) has been reported to be increasing worldwide in correlation with ethnic and geographic variations. The actual prevalence of GDM throughout all of Greenland remains unknown. Objective. The aim of this study...

Offshore oil exploration and impact assessment in Greenland

DEFF Research Database (Denmark)

Hansen, Anne Merrild

2016-01-01

Greenland needs development. Oil and mineral extraction is pursued as a means to achieve economical growth. Fisheries, hunting and tourism are the main pillars in the Greenland economy in 2015. These businesses are however sensitive to potential negative impacts from oil and gas development. Local...... regulation system in relation to oil and gas projects to promote sustainable development. Additional Impact Benefit Agreements (IBA) have to be negotiated between the communities potentially affected, the Government and the oil companies to assure that social investments are made to secure long-term benefits...

Effects of bending-torsional duct-induced swirl distortion on aerodynamic performance of a centrifugal compressor

Science.gov (United States)

Hou, Hongjuan; Wang, Leilei; Wang, Rui; Yang, Yanzhao

2017-04-01

A turbocharger compressor working in commercial vehicles, especially in some passenger cars, often works together with some pipes with complicated geometry as an air intake system, due to limit of available space in internal combustion engine compartments. These pipes may generate various distortions of physical parameters of the air at the inlet of the compressor and therefore the compressor aerodynamic performance deteriorates. Sometimes, the turbocharging engine fails to work at some operation points. This paper investigates the effects of various swirl distortions induced by different bending-torsional intake ducts on the aerodynamic performance of a turbocharger compressor by both 3D numerical simulations and experimental measurements. It was found that at the outlet of the pipes the different inlet ducts can generate different swirl distortions, twin vortices and bulk-like vortices with different rotating directions. Among them, the bulk-like vortices not only affect seriously the pressure distribution in the impeller domain, but also significantly deteriorate the compressor performance, especially at high flow rate region. And the rotating direction of the bulk-like vortices is also closely associated with the efficiency penalty. Besides the efficiency, the transient flow rate through a single impeller channel, or the asymmetric mass flow crossing the whole impeller, can be influenced by two disturbances. One is from the upstream bending-torsional ducts; other one is from the downstream volute.

Greenlandic water and sanitation systems-identifying system constellation and challenges

DEFF Research Database (Denmark)

Hendriksen, Kåre; Hoffmann, Birgitte

2017-01-01

" (United Nations 2015). This obviously raises the question of how this can be achieved considering the very different conditions and cultures around the globe. This article presents the Greenlandic context and elucidates the current Greenland water supply system and wastewater management system from......A good water supply and wastewater management is essential for a local sustainable community development. This is emphasized in the new global goals of the UN Sustainable Development, where the sixth objective is to: "Ensure availability and sustainable management of water and sanitation for all...... a socio-technical approach, focusing on the geographic, climatic and cultural challenges. The article identifies a diverse set of system constellations in different parts of Greenland and concludes with a discussion of health and quality of life implications....

Stable Isotopes and Oral Tori in Greenlandic Norse and Inuit

DEFF Research Database (Denmark)

Baumann, M.; Lynnerup, N.; Scott, G. R.

2017-01-01

Palatine (PT) and mandibular torus (MT) have long been of interest to dental researchers and anthropologists, but their aetiology remains unresolved. Some combination of genetic and environmental factors influences their expression, but the relative role of each remains contentious. Previous...... research has shown that the Greenlandic Norse exhibit exceptionally high frequencies and pronounced expressions of PT and MT. In this regard, they are significantly different from genetically related medieval Scandinavian populations, so environmental factors have to be considered. An earlier study...... that estimated stable carbon and nitrogen isotope compositions for a Greenlandic Norse sample makes it possible to compare directly PT and MT expression with the relative degree of marine protein intake. For comparative purposes, parallel observations were made on a Greenlandic Inuit sample. Some researchers...

Greenland deep boreholes inform on sliding and deformation of the basal ice

Science.gov (United States)

Dahl-Jensen, D.

2017-12-01

Repeated measurements of the deformation of the deep boreholes on the Greenland ice sheet informs on the basal sliding, near basal deformation and in general on the horizontal velocity through the ice. Results of the logging of the boreholes at Dye3, GRIP, NGRIP, NEEM and Camp Century through the last 40 years by the Danish Ice and Climate group will be presented and discussed. The results on the flow will be compared with the information on ice properties, impurity load and bedrock entrained material from the deep ice cores and the radio echo sounding images near the drill sites.The results show that the basal movement often happens in an impurity rich zone above the bedrock while pure basal sliding is limited even in the presence of basal water and significant basal melt.Most of the deep ice core sites are located close to ice divides where the surface velocity is limited so significant basal sliding is not expected. Exceptions are the surface velocities at Camp Century and Dye 3, both being 13 m/yr.Finally, the ongoing deep drilling at EGRIP will shortly be presented where we are drilling in the center of the North East Greenland Ice Stream (NEGIS).

Perfluorinated alkyl substances (PFAS) in terrestrial environments in Greenland and Faroe Islands.

Science.gov (United States)

Bossi, Rossana; Dam, Maria; Rigét, Frank F

2015-06-01

Perfluorinated alkylated substances (PFASs) have been measured in liver samples from terrestrial organisms from Greenland and the Faeroe Islands. Samples from ptarmigan (West Greenland), reindeer (southwest-Greenland), muskox (East Greenland), and land-locked Arctic char from southwest Greenland and the Faroe Islands were analyzed. In addition, PFASs levels in land-locked brown trout from Faroese lakes are reported. Of the 17 PFASs analyzed in the samples the following compounds were detected: PFOS, PFNA, PFDA, PFUnA, PFDoA, PFTrA, and PFTeA. PFNA was the compound detected in most samples and in all species. However, the compound detected at highest concentration was dependent on species, with overall highest concentrations of PFTrA and PFUnA being detected in trout liver from Lake á Mýranar (Faroe Islands). In muskox, the PFAS occurring at highest concentrations was PFDA, which was among the PFAS detected at lowest concentrations in freshwater fish, and was only detected in one individual ptarmigan. The concentration of PFOS, PFDoA and PFTrA in Arctic char from Greenland and Faroe Islands were similar, whereas the concentration of PFNA, PFDA and PFUnA were higher in Arctic char than those from Greenland. The opposite was observed for PFTeA. The PFASs occurring at highest concentrations in trout were PFTrA and PFUnA. Arctic char from Lake á Mýranar had much lower concentrations of PFTrA and PFUnA than in trout from the lakes analyzed, but a higher concentration of PFTeA than trout from the same lake. A clear pattern with odd-carbon number homologues concentrations higher than the next lower even homologue was observed in fish samples, which is consistent with the hypothesis of transport of volatile precursors to remote regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

A novel multispectral glacier mapping method and its performance in Greenland

Science.gov (United States)

Citterio, M.; Fausto, R. S.; Ahlstrom, A. P.; Andersen, S. B.

2014-12-01

Multispectral land surface classification methods are widely used for mapping glacier outlines. Significant post-classification manual editing is typically required, and mapping glacier outlines over larger regions remains a rather labour intensive task. In this contribution we introduce a novel method for mapping glacier outlines from multispectral satellite imagery, requiring only minor manual editing.Over the last decade GLIMS (Global Land Ice Measurements from Space) improved the availability of glacier outlines, and in 2012 the Randolph Glacier Inventory (RGI) attained global coverage by compiling existing and new data sources in the wake of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). With the launch of Landsat 8 in 2013 and the upcoming ESA (European Space Agency) Sentinel 2 missions, the availability of multispectral imagery may grow faster than our ability to process it into timely and reliable glacier outline products. Improved automatic classification methods would enable a full exploitation of these new data sources.We outline the theoretical basis of the proposed classification algorithm, provide a step by step walk-through from raw imagery to finished ice cover grids and vector glacier outlines, and evaluate the performance of the new method in mapping the outlines of glaciers, ice caps and the Greenland Ice Sheet from Landsat 8 OLI imagery. The classification output is compared against manually digitized ice margin positions, the RGI vectors, and the PROMICE (Programme for Monitoring of the Greenland Ice Sheet) aerophotogrammetric map of Greenland ice masses over a sector of the Disko Island surge cluster in West Greenland, the Qassimiut ice sheet lobe in South Greenland, and the A.P. Olsen ice cap in NE Greenland.

First record of Centromerus arcanus (O. P.-Cambridge, 1873) from Greenland (Araneae, Linyphiidae)

DEFF Research Database (Denmark)

Lissner, Jørgen; Gravesen, Eigil Vestergaard

2017-01-01

The linyphiid spider Centromerus arcanus (O. P.-Cambridge, 1873) is reported new to Greenland. A single female was pitfall trapped in South-West Greenland at Kobbefjord in the summer of 2016 constituting the first record of this species in the Nearctic ecozone. The habitat in which the Greenland...

A new regional high-resolution map of basal and surface topography for the Greenland ice-sheet margin at Paakitsoq, West Greenland

DEFF Research Database (Denmark)

Mottram, R.; Nielsen, C.; Ahlstrøm, A. P.

2009-01-01

In 2005 an airborne survey was carried out from a Twin Otter aircraft at Pâkitsup Akuliarusersua (Paakitsoq) near Ilulissat in West Greenland. The survey aimed to measure ice thickness with a 60 MHz cohrent radar and surface elevation with a scanning laser altimeter.......In 2005 an airborne survey was carried out from a Twin Otter aircraft at Pâkitsup Akuliarusersua (Paakitsoq) near Ilulissat in West Greenland. The survey aimed to measure ice thickness with a 60 MHz cohrent radar and surface elevation with a scanning laser altimeter....

Quality Evaluation and Nonuniform Compression of Geometrically Distorted Images Using the Quadtree Distortion Map

Directory of Open Access Journals (Sweden)

Cristina Costa

2004-09-01

Full Text Available The paper presents an analysis of the effects of lossy compression algorithms applied to images affected by geometrical distortion. It will be shown that the encoding-decoding process results in a nonhomogeneous image degradation in the geometrically corrected image, due to the different amount of information associated to each pixel. A distortion measure named quadtree distortion map (QDM able to quantify this aspect is proposed. Furthermore, QDM is exploited to achieve adaptive compression of geometrically distorted pictures, in order to ensure a uniform quality on the final image. Tests are performed using JPEG and JPEG2000 coding standards in order to quantitatively and qualitatively assess the performance of the proposed method.

Greenlandic Waste Incineration Fly And Bottom Ash As Secondary Resource In Mortar

DEFF Research Database (Denmark)

Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2016-01-01

Today, 900 tons incineration fly ash is shipped abroad annually from Greenland for deposits, whereas the 6,000 tons incineration bottom ash is deposited locally. These incineration ashes could be valuable in concrete production, where the cement has to be shipped to Greenland. For this purpose...... and cement with fly ash. Based on the compressive strength tests, it is found that using Greenlandic incineration ashes in mortar as 5% cement replacement could consume all ash instead of disposals, and could thus turn the ashes into a local resource and simultaneously reduce the import of cement....

GAD65 antibodies among Greenland Inuit and its relation to glucose intolerance

DEFF Research Database (Denmark)

Pedersen, Michael Lynge; Bjerregaard, Peter; Jørgensen, Marit Eika

2014-01-01

The aim of this study was to compare the prevalence of circulating Glutamin-Acid-decarboxylase 65 antibodies in a sample of Greenlanders (Inuit) with clinically verified diabetes with samples of participants from a population survey. The study population included participants with known diabetes.......3 % and less than 1 % among Greenlanders without diabetes (p = 0.001). The prevalence of circulating Glutamin-Acid-decarboxylase 65 antibodies among Greenlanders with and without diabetes is relatively low in a global perspective in accordance with one former study among Inuit. Autoimmune diabetes seems...

Mercury in dated Greenland marine sediments

DEFF Research Database (Denmark)

Asmund, G.; Nielsen, S.P.

2000-01-01

Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age of the sedi......Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age...... indicating that the mercury mainly originates from atmospheric washout. But the large variability indicates that other processes also influence the mercury flux to Arctic marine sediments. (C) 2000 Elsevier Science B.V. All rights reserved....

The summer 2012 Greenland heat wave

DEFF Research Database (Denmark)

Bonne, Jean-Louis; Steen-Larsen, Hans Christian; Risi, Camille

2015-01-01

During 7–12 July 2012, extreme moist and warm conditions occurred over Greenland, leading to widespread surface melt. To investigate the physical processes during the atmospheric moisture transport of this event, we study the water vapor isotopic composition using surface in situ observations....... Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM......-enabled atmospheric general circulation models (LMDz-iso and ECHAM5-wiso). LMDz-iso correctly captures the timing of propagation for this event identified in IASI data but depict too gradual variations when compared to surface data. Both models reproduce the surface meteorological and isotopic values during the event...

Why is Transparency Greenland Necessary?

DEFF Research Database (Denmark)

Jensen, Boris Brorman

2012-01-01

Greenland is facing significant changes in the composition of its economy, and is moving rapidly in the direction of becoming a commodities economy. Studies conducted by Transparency International in other parts of the world suggest that oil exploration and mining are among the areas of economic...

The extreme melt across the Greenland ice sheet in 2012

Science.gov (United States)

Nghiem, S. V.; Hall, D. K.; Mote, T. L.; Tedesco, M.; Albert, M. R.; Keegan, K.; Shuman, C. A.; DiGirolamo, N. E.; Neumann, G.

2012-10-01

The discovery of the 2012 extreme melt event across almost the entire surface of the Greenland ice sheet is presented. Data from three different satellite sensors - including the Oceansat-2 scatterometer, the Moderate-resolution Imaging Spectroradiometer, and the Special Sensor Microwave Imager/Sounder - are combined to obtain composite melt maps, representing the most complete melt conditions detectable across the ice sheet. Satellite observations reveal that melt occurred at or near the surface of the Greenland ice sheet across 98.6% of its entire extent on 12 July 2012, including the usually cold polar areas at high altitudes like Summit in the dry snow facies of the ice sheet. This melt event coincided with an anomalous ridge of warm air that became stagnant over Greenland. As seen in melt occurrences from multiple ice core records at Summit reported in the published literature, such a melt event is rare with the last significant one occurring in 1889 and the next previous one around seven centuries earlier in the Medieval Warm Period. Given its rarity, the 2012 extreme melt across Greenland provides an exceptional opportunity for new studies in broad interdisciplinary geophysical research.

Cognitive Distortions, Humor Styles, and Depression.

Science.gov (United States)

Rnic, Katerina; Dozois, David J A; Martin, Rod A

2016-08-01

Cognitive distortions are negative biases in thinking that are theorized to represent vulnerability factors for depression and dysphoria. Despite the emphasis placed on cognitive distortions in the context of cognitive behavioural theory and practice, a paucity of research has examined the mechanisms through which they impact depressive symptomatology. Both adaptive and maladaptive styles of humor represent coping strategies that may mediate the relation between cognitive distortions and depressive symptoms. The current study examined the correlations between the frequency and impact of cognitive distortions across both social and achievement-related contexts and types of humor. Cognitive distortions were associated with reduced use of adaptive Affiliative and Self-Enhancing humor styles and increased use of maladaptive Aggressive and Self-Defeating humor. Reduced use of Self-Enhancing humor mediated the relationship between most types of cognitive distortions and depressed mood, indicating that distorted negative thinking may interfere with an individual's ability to adopt a humorous and cheerful outlook on life (i.e., use Self-Enhancing humor) as a way of regulating emotions and coping with stress, thereby resulting in elevated depressive symptoms. Similarly, Self-Defeating humor mediated the association of the social impact of cognitive distortions with depression, such that this humor style may be used as a coping strategy for dealing with distorted thinking that ultimately backfires and results in increased dysphoria.

Distortion Control during Welding

NARCIS (Netherlands)

Akbari Pazooki, A.M.

2014-01-01

The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ

A tracer investigation of the atmospheric dispersion in the Dyrnaes Valley, Greenland

International Nuclear Information System (INIS)

Gryning, S.-E.; Lyck, E.

1983-02-01

Mining at Kvanefjeld, Greenland, will result in releases of air pollution gases. In order to measure the dilution of these gases tracer experiments were carried out in July-August 1981. Results from these experiments are described. The Kvanefjeld constitutes the northwestern side of a valley. The tracer was released at the Kvanefjeld during the night and sampled in the valley. The measured tracer concentrations were compared with those calculated by use of a conventional model of the dispersion of plumes. The dilution of the tracer was found to correspond to the dilution at ground level of a plume from a stack of 100-200 m height in atmospheric neutral conditions (wind speed 5 m/s). General aspects of the flow-field in the valley are discussed. It was observed that the flow direction in the valley shifts between downvalley and upvalley with a period of approximately 1 hour. It is suggested that this behaviour is caused by the interplay of a drainage flow and a sea-breeze. (author)

TPC track distortions IV: post tenebras lux

CERN Document Server

Ammosov, V; Boyko, I; Chelkov, G; Dedovitch, D; Dydak, F; Elagin, A; Gostkin, M; Guskov, A; Koreshev, V; Krumshtein, Z; Nefedov, Y; Nikolaev, K; Wotschack, J; Zhemchugov, A

2007-01-01

We present a comprehensive discussion and summary of static and dynamic track distortions in the HARP TPC in terms of physical origin, mathematical modelling and correction algorithms. `Static' distortions are constant with time, while `dynamic' distortions are distortions that occur only during the 400 ms long accelerator spill. The measurement of dynamic distortions, their mathematical modelling and the correction algorithms build on our understanding of static distortions. In the course of corroborating the validity of our static distortion corrections, their reliability and precision was further improved. Dynamic TPC distortions originate dominantly from the `stalactite' effect: a column of positive-ion charge starts growing at the begin of the accelerator spill, and continues growing with nearly constant velocity out from the sense-wire plane into the active TPC volume. However, the `stalactite' effect is not able to describe the distortions that are present already at the start of the spill and which ha...

Crustal structure beneath Eastern Greenland

DEFF Research Database (Denmark)

Reiche, Sönke; Thybo, H.; Kaip, G.

2011-01-01

is recorded by 350 Reftek Texan receivers for 10 equidistant shot points along the profile. We use forward ray tracing modelling to construct a two-dimensional velocity model from the observed travel times. These results show the first images of the subsurface velocity structure beneath the Greenland ice...

Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

Science.gov (United States)

Berkelhammer, Max; Noone, David C; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J; O'Neill, Michael S; Schneider, David; Steffen, Konrad; White, James W C

2016-04-01

Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland.

The public’s preferences for establishing nephrology facilities in Greenland

DEFF Research Database (Denmark)

Kjaer, T.; Bech, M.; Kronborg, C.

2013-01-01

in which they were asked to consider the trade-offs of establishing nephrology facilities in Greenland as opposed to the current situation. This involved trading off the benefits of having such facilities in their home country against the costs of the intervention. Besides including a payment attribute...... robust. Establishing facilities in Greenland therefore would appear to be welfare-improving, deriving positive net benefits. Despite the relatively narrow policy focus, we believe that our findings provide some insight into individuals' preferences for decentralization of public services and on citizens...... facilities in Greenland were preferred to the current treatment in Denmark. The welfare estimate from the DCE, at DKK 18.74 million, exceeds the estimated annual costs of establishing treatment facilities for patients with chronic renal failure. Given the estimated confidence interval this result seems...

Prevalence of gestational diabetes mellitus among women born in Greenland

DEFF Research Database (Denmark)

Jacobsen, Jytte Lindskov; Jørgensen, Marit Eika

2010-01-01

OBJECTIVES: To estimate the prevalence of gestational diabetes mellitus (GDM) among Greenlanders and to evaluate the quality of the current screening procedure for gestational diabetes. STUDY DESIGN: Observational retrospective study of consecutive birth-log data and medical records on pregnant....... However, only 54% of those women were screened. The prevalence of gestational diabetes was calculated to be 4.3% among high-risk Greenlandic pregnant women (2/46) (95% CI 0-10.0%). CONCLUSIONS: Despite a suboptimal screening rate, the prevalence of GDM among Greenlanders seems to be relatively low...... women who had given birth in Nuuk during 2008. METHODS: Information about maternal weight, weight gain in pregnancy, height, blood pressure, result of oral glucose tolerance test, family history of diabetes, smoking and alcohol habits, ethnicity, delivery and birth weight and length was collected...

Frequency modulation television analysis: Distortion analysis

Science.gov (United States)

Hodge, W. H.; Wong, W. H.

1973-01-01

Computer simulation is used to calculate the time-domain waveform of standard T-pulse-and-bar test signal distorted in passing through an FM television system. The simulator includes flat or preemphasized systems and requires specification of the RF predetection filter characteristics. The predetection filters are modeled with frequency-symmetric Chebyshev (0.1-db ripple) and Butterworth filters. The computer was used to calculate distorted output signals for sixty-four different specified systems, and the output waveforms are plotted for all sixty-four. Comparison of the plotted graphs indicates that a Chebyshev predetection filter of four poles causes slightly more signal distortion than a corresponding Butterworth filter and the signal distortion increases as the number of poles increases. An increase in the peak deviation also increases signal distortion. Distortion also increases with the addition of preemphasis.

THE ATTITUDES OF DANISH POLITICIANS TO THE PROSPECTS OF URANIUM MINING IN GREENLAND

OpenAIRE

Westerberg, Niklas; Szpisjak, Aron; Schow, Marco

2014-01-01

The following case study may well function as a basis or groundwork for another project on Greenland concerning natural resources. The study gathered data primarily from interviews with experts on the subject i.e. politicians. The main point of this study is the attitudes of the Danish party political spectrum to the prospect of uranium extraction in Greenland. The study discusses whether or not Greenland has jurisdiction over its own resources, as well as entailing a summary of the jurisdict...

How Will Sea Ice Loss Affect the Greenland Ice Sheet? On the Puzzling Features of Greenland Ice-Core Isotopic Composition

Science.gov (United States)

Pausata, Francesco S. R.; Legrande, Allegra N.; Roberts, William H. G.

2016-01-01

The modern cryosphere, Earth's frozen water regime, is in fast transition. Greenland ice cores show how fast theses changes can be, presenting evidence of up to 15 C warming events over timescales of less than a decade. These events, called Dansgaard/Oeschger (D/O) events, are believed to be associated with rapid changes in Arctic sea ice, although the underlying mechanisms are still unclear. The modern demise of Arctic sea ice may, in turn, instigate abrupt changes on the Greenland Ice Sheet. The Arctic Sea Ice and Greenland Ice Sheet Sensitivity (Ice2Ice Chttps://ice2ice.b.uib.noD) initiative, sponsored by the European Research Council, seeks to quantify these past rapid changes to improve our understanding of what the future may hold for the Arctic. Twenty scientists gathered in Copenhagen as part of this initiative to discuss the most recent observational, technological, and model developments toward quantifying the mechanisms behind past climate changes in Greenland. Much of the discussion focused on the causes behind the changes in stable water isotopes recorded in ice cores. The participants discussed sources of variability for stable water isotopes and framed ways that new studies could improve understanding of modern climate. The participants also discussed how climate models could provide insights into the relative roles of local and nonlocal processes in affecting stable water isotopes within the Greenland Ice Sheet. Presentations of modeling results showed how a change in the source or seasonality of precipitation could occur not only between glacial and modern climates but also between abrupt events. Recent fieldwork campaigns illustrate an important role of stable isotopes in atmospheric vapor and diffusion in the final stable isotope signal in ice. Further, indications from recent fieldwork campaigns illustrate an important role of stable isotopes in atmospheric vapor and diffusion in the final stable isotope signal in ice. This feature complicates

Greenland's balance of Payments and Self-governance

DEFF Research Database (Denmark)

Aage, Hans

Why is the current account of Greenland a topical issue, while those of Denmark and of the island of Bornholm in the Baltic Sea are not? Has the current account anything to do with future inde­pendence? It is ar­gued that balance of payments and foreign debt are closely connected to political and...... of produc­tion and living standards and large current account deficits. It is possible to remove the trade balance deficit and the need for Danish transfers simultaneously, but this would require higher tax rates and huge increases of exports.......Why is the current account of Greenland a topical issue, while those of Denmark and of the island of Bornholm in the Baltic Sea are not? Has the current account anything to do with future inde­pendence? It is ar­gued that balance of payments and foreign debt are closely connected to political...... and eco­nomic national identi­ty. Until recently Greenland's current account was positive by large amounts, which were unex­plained, as it proved impos­sible to uncover corresponding capital account defi­cits. However, im­proved balance of payments statistics together with sim­ple compu...

Satellite Tracking of Humpback Whales in West Greenland

DEFF Research Database (Denmark)

Dietz, R.; Teilmann, J.; Heide-Jørgensen, M.-P.

In June 2000, 6 humpback whales (Megaptere novaeangliae) were tagged with satellite transmitters off West Greenland. Contact remained for up to 42 days. The tagging revealed that within the month of June, humpback whales off West Greenland moved between Fiskenæs Banke, Fyllas Banke, Tovqussaq Banke......, Sukkertop Banke and Lille Hellefiske Banke. The whales showed a preference for the continental slopes with depths less than 200 m, however, few dives were recorded down to 500 m. The whales had a preference for dives lasting 7-8 min. (15%) and no dives lasted longer than 15 min....

Gastrointestinal helminths of arctic foxes (Alopex lagopus) from different bioclimatological regions in Greenland

DEFF Research Database (Denmark)

Kapel, C. M O; Nansen, P.

1996-01-01

Nine species of gastrointestinal helminths were recovered from 254 arctic foxes (Alopex lagopus) from 8 different localities in Greenland. Prevalences of infection with the helminth species differed from area to area: Toxascaris leonina (3968%), Strongyloides stercoralis (0-14%), Mesocestoides...... of Greenland. In general, the composition of the helminth fauna of arctic foxes in Greenland showed distinct differences geographically. Thus, the diversity of helminth species in foxes caught in the northern districts of Greenland seems lower than in the southern districts; only nematode species with direct...... life cycles were represented equally in all parts of the country. The diversity of the surrounding fauna, and thereby the food items available for the foxes, seems to determine the spectrum of helminth species. Helminths requiring rodents as intermediate hosts were absent on the west coast, even...

Generic distortion model for metrology under optical microscopes

Science.gov (United States)

Liu, Xingjian; Li, Zhongwei; Zhong, Kai; Chao, YuhJin; Miraldo, Pedro; Shi, Yusheng

2018-04-01

For metrology under optical microscopes, lens distortion is the dominant source of error. Previous distortion models and correction methods mostly rely on the assumption that parametric distortion models require a priori knowledge of the microscopes' lens systems. However, because of the numerous optical elements in a microscope, distortions can be hardly represented by a simple parametric model. In this paper, a generic distortion model considering both symmetric and asymmetric distortions is developed. Such a model is obtained by using radial basis functions (RBFs) to interpolate the radius and distortion values of symmetric distortions (image coordinates and distortion rays for asymmetric distortions). An accurate and easy to implement distortion correction method is presented. With the proposed approach, quantitative measurement with better accuracy can be achieved, such as in Digital Image Correlation for deformation measurement when used with an optical microscope. The proposed technique is verified by both synthetic and real data experiments.

Human papillomavirus and oropharyngeal cancer in Greenland in 1994–2010

Directory of Open Access Journals (Sweden)

Magnus Balslev Avnstorp

2013-11-01

Full Text Available Background. Oropharyngeal squamous cell carcinoma (OPSCC is associated with the sexually transmitted human papillomavirus (HPV, smoking and alcohol. In Greenland, a high rate of HPV-induced cervical cancer and venereal diseases are found, which exposes the population for high risk of HPV infection. In Greenland, only girls are included in the mandatory HPV vaccination program. Objective. To investigate the annual incidence of OPSCC and the proportion of HPV-associated OPSCC (HPV+ OPSCC in Greenland in 1994–2010. Design. At Rigshospitalet, University of Copenhagen, we identified all Greenlandic patients diagnosed and treated for OPSCC from 1994 to 2010. Sections were cut from the patient's paraffin-embedded tissue blocks and investigated for p16 expression by immunohistochemistry. HPV analyses were performed with 2 sets of general HPV primers and 1 set of HPV16-specific primer. HPV+ OPSCC was defined as both >75% p16+ cells and PCR positive for HPV. Results. Of 26 Greenlandic patients diagnosed with OPSCC, 17 were males and 9 were females. The proportion of HPV+ OPSCC in the total study period was 22%, without significant changes in the population in Greenland. We found an increase in the proportion of HPV+ OPSCC from 14% in 1994–2001 to 25% in 2002–2010 (p=0.51. Among males from 20 to 27% (p=0.63 and in females from 0 to 20% (p=0.71. The annual OPSCC incidence increased from 2.3/100,000 (CI=1.2–4.2 in 1994–2001 to 3.8/100,000 (CI=2.4–6.2 in 2002–2010: among males from 2.4/100,000 (CI=1.0–5.7 to 5.0/100,000 (CI=2.9–8.9. Conclusion. Even though the population is at high risk of HPV infection, the proportion of 22% HPV+ OPSCC in the total study period is low compared to Europe and the United States. This might be explained by our small study size and/or by ethnic, geographical, sexual and cultural differences. Continuing observations of the OPSCC incidence and the proportion of HPV+ OPSCC in Greenland are needed.

Characterization of household waste in Greenland

DEFF Research Database (Denmark)

Eisted, Rasmus; Christensen, Thomas Højlund

2011-01-01

The composition of household waste in Greenland was investigated for the first time. About 2tonnes of household waste was sampled as every 7th bag collected during 1week along the scheduled collection routes in Sisimiut, the second largest town in Greenland with about 5400 inhabitants....... The collection bags were sorted manually into 10 material fractions. The household waste composition consisted primarily of biowaste (43%) and the combustible fraction (30%), including anything combustible that did not belong to other clean fractions as paper, cardboard and plastic. Paper (8%) (dominated...... by magazine type paper) and glass (7%) were other important material fractions of the household waste. The remaining approximately 10% constituted of steel (1.5%), aluminum (0.5%), plastic (2.4%), wood (1.0%), non-combustible waste (1.8%) and household hazardous waste (1.2%). The high content of biowaste...

Possible contribution of ice-sheet/lithosphere interactions to past glaciological changes in Greenland

Science.gov (United States)

Alley, R. B.; Parizek, B. R.; Anandakrishnan, S.; Pollard, D.; Stevens, N. T.; Pourpoint, M.

2017-12-01

Ice-lithosphere interactions may have influenced the history of ice-sheet sensitivity to climate change. The Greenland ice sheet (GIS) is sensitive to warming, and is likely to be largely removed if subjected to relatively small additional temperature increases. The recent report (Schaefer et al., 2016, Nature) of near-complete GIS removal under modest Pleistocene forcing suggests that GIS sensitivity may be even greater than generally modeled, but lack of major Holocene retreat is more consistent with existing models. As shown by Stevens et al. (2016, JGR), peak lithospheric flexural stresses associated with ice-age GIS cycling are of the same order as dike-driving stresses in plutonic systems, and migrate over ice-age cycles. The full analysis by Stevens et al. suggests the possibility that the onset of cyclic ice-sheet loading allowed deep melt associated with the passage of the Icelandic hot spot beneath Greenland to work up though the crust to or near the base of the ice sheet, helping explain the anomalous geothermal heat fluxes observed at the head of the Northeast Greenland Ice Stream and elsewhere in the northern part of GIS. If ice-age cycling aided extraction of an existing reservoir of melted rock, then geothermal heat flux would have risen with the onset of extraction and migration, but with a subsequent fall associated with reservoir depletion. Simple parameterized flow-model simulations confirm intuition that a higher geothermal flux makes deglaciation easier, with the northern part of the ice sheet especially important. Large uncertainties remain in quantification, but we suggest the hypothesis that, following the onset of ice-age cycling, deglaciation of the GIS first became easier and then more difficult in response to feedbacks involving the ice sheet and the geological system beneath. In turn, this suggests that evidence of past deglaciation under moderate forcing is consistent with existing ice-sheet models.

Raised BMI cut-off for overweight in Greenland Inuit--a review.

Science.gov (United States)

Andersen, Stig; Fleischer Rex, Karsten; Noahsen, Paneeraq; Sørensen, Hans Christian Florian; Mulvad, Gert; Laurberg, Peter

2013-01-01

Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. This led us to reconsider the cut-off point for overweight among Inuit in Greenland. We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Defining overweight according to the WHO cut-off of a BMI above 25 kg/m(2) in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Greenlandic Peregrines will have normal eggshell thickness by mid 2030’ies

DEFF Research Database (Denmark)

Falk, Knud; Møller, Søren; Riget, Frank Farsø

haliaetus) in Europe have documented that it took 30 years from DDT was phased out until eggshell thickness was back to normal pre-DDT levels. In Greenland, the peregrine population has been the subject of long-term studies, and a previous study of eggshell thinning found a significant increase over time...... and reinterpreted data for a 43 year time span. Mean shell thickness was estimated for 184 clutches based on fragments from hatched eggs, and for 56 whole addled eggs from 44 clutches. During the period 1972-2014 there was a highly significant increasing trend in the average eggshell thickness of 0.25% per year...... recovery of the shell thickness in the Greenland population as compared to other studies is likely indicative of the slower phasing out of DDT in the Greenlandic peregrine’s wintering grounds in Latin America. The shell thinning in the Greenlandic population crossed the 17% “danger limit” associated...

Hydrologic Sub-basins of Greenland, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — The Hydrologic Sub-basins of Greenland data set contains Geographic Information System (GIS) polygon shapefiles that include 293 hydrologic sub-basins of the...

Level and Temporal Trend of Perfluoroalkyl Acids in Greenlandic Inuit

DEFF Research Database (Denmark)

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva Cecilie

bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Study design: Cross-section and temporal time trend survey. Methods: Serum PFAA levels were determined in 284 Inuit from different...... Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 19982005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Results: Serum PFAA levels were...... higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 19982005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs...

A common Greenlandic Inuit BRCA1 RING domain founder mutation

DEFF Research Database (Denmark)

Hansen, T.v.O.; Ejlertsen, B.; Albrechtsen, Anders

2009-01-01

of the families had members with ovarian cancer, suggesting that the RING domain may be an ovarian cancer hotspot. By SNP array analysis, we find that all 13 families share a 4.5 Mb genomic fragment containing the BRCA1 gene, showing that the mutation originates from a founder. Finally, analysis of 1152 Inuit......, representing almost ~2% of the total Greenlandic Inuit population, showed that the frequency of the mutation was 1.0%. We conclude that the BRCA1 nucleotide 234 T > G is a common Greenlandic Inuit founder mutation. The relative high frequency in the general population, together with the ease of screening...... and possibility to reduce mortality in gene carriers, may warrant screening of the Greenlandic Inuit population. Provided screening is efficient, about 5% of breast- and 13% of ovarian cancers, respectively, may be prevented Udgivelsesdato: 2009/5...

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit

DEFF Research Database (Denmark)

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva Cecilie

2012-01-01

bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Study design: Cross-section and temporal time trend survey. Methods: Serum PFAA levels were determined in 284 Inuit from different...... Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 19982005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Results: Serum PFAA levels were...... higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 19982005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs...

The intercultural challenges of engineering education in a Greenlandic context

DEFF Research Database (Denmark)

Hendriksen, Kåre; Christensen, Hans Peter

2014-01-01

Greenland is a modern society with Self Governance, but only half a century ago it was primarily a fishing and hunting society governed as a colony by a Danish elite. The rapid changes have left Greenland with many social problems, and compared to Western Europe relatively few finish education...... students tend to withdraw from discussions, which are an important part of the education. The paper will discuss our experiences with handling these challenges....

Interannual Variability of the Sea-Ice-Induced Salt Flux in the Greenland Sea

DEFF Research Database (Denmark)

Pedersen, Leif Toudal; Coon, M.D.

2001-01-01

The Greenland Sea is one of the few places in the World Ocean where deep convection takes place. The convection process is initiated by a density increase originating from rapid cooling and/or a salt flux to the upper layer of the ocean due to brine rejection from ice formation (Rudels, 1990......; Visbeck and others, 1995). The predominant ice types in the Greenland Sea arc frazil/grease ice and pancake ice. A numerical model has been developed relating ice formation and decay of these ice types as observed by the SMMR and SSM/I microwave radiometers and evaluating their contribution to salt...... redistribution in the Greenland Sea. The model has been used to calculate spatial distribution of the annual integrated net salt flux to the Greenland Sea from ice production and advection for the period 1979-97....

Time trend by region of suicides and suicidal thoughts among Greenland Inuit

Directory of Open Access Journals (Sweden)

Peter Bjerregaard

2015-02-01

Full Text Available Background: Suicides remain a major public health problem in Greenland. Their increase coincides with the modernization since 1950. Serious suicidal thoughts are reported by a significant proportion of participants in countrywide surveys. Objective: To analyze the time trend by region of suicides and suicidal thoughts among the Inuit in Greenland. Design: Data included the Greenland registry of causes of death for 1970–2011 and 2 cross-sectional health surveys carried out in 1993–1994 and 2005–2010 with 1,580 and 3,102 Inuit participants, respectively. Results: Suicide rates were higher among men than women while the prevalence of suicidal thoughts was higher among women. Suicide rates for men and women together increased from 1960 to 1980 and have remained around 100 per 100,000 person-years since then. The regional pattern of time trend for suicide rates varied with an early peak in the capital, a continued increase to very high rates in remote East and North Greenland and a slow increase in villages relative to towns on the West Coast. Suicidal thoughts followed the regional pattern for completed suicides. Especially for women there was a noticeable increasing trend in the villages. The relative risk for suicide was highest among those who reported suicidal thoughts, but most suicides happened outside this high-risk group. Conclusion: Suicide rates and the prevalence of suicidal thoughts remain high in Greenland but different regional trends point towards an increased marginalization between towns on the central West Coast, villages and East and North Greenland. Different temporal patterns call for different regional strategies of prevention.

Physical activity patterns in Greenland: a country in transition.

Science.gov (United States)

Dahl-Petersen, Inger K; Jørgensen, Marit E; Bjerregaard, Peter

2011-11-01

To examine differences in physical activity patterns among Inuit in Greenland in relation to social transition. The Inuit in Greenland are an indigenous population in the circumpolar north who are experiencing rapid social transition. Physical activity patterns were assessed by the International Physical Activity Questionnaire (long version). The population was divided into six groups according to different stages of social change, measured on the basis of education, current residence and occupation. Data were collected in a country-wide cross-sectional population survey among adult Inuit in Greenland from 2005 to 2009. Men with long vocational or academic education living in towns (latest stage of social change) spent significantly less time on occupational physical activity (p = 0.001) compared with hunters and fishermen in villages (earliest stage of social change) (trend test p = 0.01). Women in the latest stage of change spent significantly less time on domestic physical activity (p physical activity during transportation (p = 0.02 and p = 0.01 for men and women, respectively). No significant difference was found for leisure time physical activity. Men and women in the latest stage of social change spent more time on sedentary activity (p physical activity patterns among Inuit in Greenland included decreasing time spent on domestic and occupational physical activity and increasing time spent on sedentary activities along with social change. Knowledge of changes in physical activity patterns in relation to social transition is important in prevention of obesity, type 2 diabetes and lifestyle diseases.

Coupled European and Greenland last glacial dust activity driven by North Atlantic climate

DEFF Research Database (Denmark)

Újvári, Gábor; Stevens, Thomas; Molnár, Mihály

2017-01-01

Centennial-scale mineral dust peaks in last glacial Greenland ice cores match the timing of lowest Greenland temperatures, yet little is known of equivalent changes in dust-emitting regions, limiting our understanding of dust−climate interaction. Here, we present the most detailed and precise age...... model for European loess dust deposits to date, based on 125 accelerator mass spectrometry14C ages from Dunaszekcso, } Hungary. The record shows that variations in glacial dust deposition variability on centennial–millennial timescales in east central Europe and Greenland were synchronous within...

Environmental radioactivity in the North Atlantic region including the Faroe Islands and Greenland

International Nuclear Information System (INIS)

Aarkrog, A.; Chen, Q.J.; Dahlgaard, H.; Hansen, H.; Nielsen, S.P.; Buch, E.; Christensen, G.C.; Holm, E.

1992-01-01

Measurements of fallout radioactivity in the North Atlantic region including the Faroe Islands and Greenland are reported. Strontium-90, cesium-137 and cesium-134 were determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes), and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in human diet in the Faroes and Greenland in 1988 and 1989. 99 Tc data on marine samples, in particular sea water from the Greenland Sea, are reported. (au) (91 taps., 51 ills., 7 refs.)

Palaeogene tectono-stratigraphic evolution of the Western Barents Sea, Svalbard and Northeast Greenland

DEFF Research Database (Denmark)

Petersen, Thomas Guldborg

This thesis contains a detailed interpretation of seismic facies of the Paleogene sedimentary succession on the Northeast Greenland Shelf. Based on this, a model for the depostional environment and its interplay with the large scale plate tectonic evolution is produced. The model suggests...... is similar and by using the dated volcanic events onshore Greenland temporal constraints of the deposition on the Northeast Greenland Shelf are much improved. Based on this correlation, the succession can be subdivided into pre-, syn- and post- volcanic intervals. The provenance of the sedimentary succession...

Lime stabilization of fine-grained sediments in western Greenland

DEFF Research Database (Denmark)

Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas; Skels, Peteris

2011-01-01

Thick deposits of fine-grained marine sediments exist in large areas of western Greenland. Many places these sediments are located above sea-level, and now complicate construction projects in urban areas. The mineralogy of the fine-grained sediments is very different from European sediments, mainly...... due to the cold climate, and it is therefore of great interest to study possible methods to improve the stability and strength properties. This project includes laboratory studies of lime stabilization on fine-grained marine sediments from Kangerlussuaq, western Greenland. The results have included...

Fatal outbreak of botulism in Greenland

DEFF Research Database (Denmark)

Hammer, Tóra Hedinsdottir; Jespersen, Sanne; Kanstrup, Jakob

2015-01-01

respiratory muscle paralysis. We present five cases of foodborne botulism occurring in Greenland, two with fatal outcome, caused by ingestion of tradionally preserved eider fowl. In the cases of the survivors, antitoxin and supportive care, including mechanical ventilation, were administered. In these cases...

Use of Vortex Generators to Reduce Distortion for Mach 1.6 Streamline-Traced Supersonic Inlets

Science.gov (United States)

Baydar, Ezgihan; Lu, Frank; Slater, John W.; Trefny, Chuck

2016-01-01

Reduce the total pressure distortion at the engine-fan face due to low-momentum flow caused by the interaction of an external terminal shock at the turbulent boundary layer along a streamline-traced external-compression (STEX) inlet for Mach 1.6.

Challenges for Greenland-wide mass balance from Cryosat-2 radar-altimetry

DEFF Research Database (Denmark)

Simonsen, Sebastian Bjerregaard; Forsberg, René; Sørensen, Louise Sandberg

As the Greenland ice sheet warms, a change in the structure of the upper snow/firn occurs. This change further induces changes in the reflective properties of the firn seen from satellite radar altimetry. If not identified as changes in the reflective properties of the firn, these may be interpre......As the Greenland ice sheet warms, a change in the structure of the upper snow/firn occurs. This change further induces changes in the reflective properties of the firn seen from satellite radar altimetry. If not identified as changes in the reflective properties of the firn, these may...... be interpreted as actual surface elevation changes seen from the satellite radar altimetry (Nilsson et al., 2015).Here, we investigate how to correct the elevation change observed from the ESA Cryosat-2 radar altimetry mission to derive elevation change of the air/snow interface of the Greenland ice sheet....... The elevation change of this “real” physical surface is crucial, if the goal is to derive Greenland mass balance as done for LiDAR missions.The investigations look into waveform parameters to correct for the observed bias between Radar and LiDAR observations when using Croysat-2 level-2 data. Based...

The distribution of artificial radionuclides in the waters of the Norwegian-Greenland Sea in 1985

International Nuclear Information System (INIS)

Wedekind, C.; Gabriel, H.; Goroncy, I.; Framcke, G.

1997-01-01

In the summer of 1985, sea water samples were taken to determine 3 H, 90 Sr, 134 Cs, 137 Cs and transuranics within a grid of 165 stations including 16 depth series down to the seafloor, covering all ice-free areas. The distribution of the activity concentrations and the nuclide ratios reveal the contamination pathway into the surface and deeper layers of the Norwegian-Greenland Sea from nuclear weapon fallout and civil nuclear technology. Moreover, the investigations show that: (1) a yearly discharge of 1 TBq (10 12 Bq) 90 Sr into the Irish Sea (English Channel) is diluted on its way to the southern Norwegian Sea, raising the concentration by about 0.04 m Bql -1 ; (2) the drift time to this sea area is around 4 years; (3) about 40% of the 137 Cs discharged does not reach the Norwegian Sea and (4) a further 30% leaves the Norwegian-Greenland Sea via the North Cape and flows into the Barents Sea. Investigations into the vertical distribution and stratification of the radioactivity indicate the time scale on which the radionuclides travel to the deeper layers. (author)

West Greenland caribou explosion: What happened? What about the future?

Directory of Open Access Journals (Sweden)

Christine Cuyler

2007-04-01

Full Text Available In West Greenland, the 1993 caribou (Rangifer tarandus groenlandicus population size estimate was 7000 to 9000 animals. Eight years later in 2001, the estimate was ca. 140 000. Relatively rapid rise and fall cycles of abundance in West Greenland caribou have been noted since the 1700s. Caribou have no natural predators in West Greenland. Combined with their high fertility and recruitment, this suggests that overabundance might be their greatest threat to stability. The 2005 population surveys indicate poor recruitment in two major populations and decreasing abundance in one. Given stocking densities are three to six-times the value considered sustainable, we expect strong competition between individuals for available food resources. Although the management goal is sustainable harvest of natural resources, if populations continue at their current size or increase further, there is a clear risk of range overgrazing and trampling. Unsustainable range use may result in density-dependent forage limitation with subsequent relatively rapid population decline over a series of years, e.g. a decade. As in the past, populations are expected to recover, and if true to the past, recovery will take the better part of a century. Furthermore, the role of catastrophic weather events may be of major importance. Abrupt collapse could be precipitated by a disastrous single year event, e.g. thaw-freeze icing or deep snow, because possibilities for dispersal to new ranges are limited. Regardless of management initiatives taken now, population declines or crashes may be inevitable for some West Greenland herds in the foreseeable future, but accurate predictions about herd trends are impossible. To understand the potential impact of future developments, Greenland caribou and their range must be studied within the wider context of climate change.

Greenland and Antarctica Ice Sheet Mass Changes and Effects on Global Sea Level

DEFF Research Database (Denmark)

Forsberg, René; Sørensen, Louise Sandberg; Simonsen, Sebastian Bjerregaard

2017-01-01

Thirteen years of GRACE data provide an excellent picture of the current mass changes of Greenland and Antarctica, with mass loss in the GRACE period 2002–2015 amounting to 265 ± 25 GT/year for Greenland (including peripheral ice caps), and 95 ± 50 GT/year for Antarctica, corresponding to 0.......72 and 0.26 mm/year average global sea level change. A significant acceleration in mass loss rate is found, especially for Antarctica, while Greenland mass loss, after a corresponding acceleration period, and a record mass loss in the summer of 2012, has seen a slight decrease in short-term mass loss trend....... The yearly mass balance estimates, based on point mass inversion methods, have relatively large errors, both due to uncertainties in the glacial isostatic adjustment processes, especially for Antarctica, leakage from unmodelled ocean mass changes, and (for Greenland) difficulties in separating mass signals...

Guessing and compression subject to distortion

OpenAIRE

Hanawal, Manjesh Kumar; Sundaresan, Rajesh

2010-01-01

The problem of guessing a random string is revisited. The relation-ship between guessing without distortion and compression is extended to the case when source alphabet size is countably in¯nite. Further, similar relationship is established for the case when distortion allowed by establishing a tight relationship between rate distortion codes and guessing strategies.

Preliminary Data on the Effects of Inlet Pressure Distortions on the J57-P-1 Turbojet Engine

Science.gov (United States)

Wallner, Lewis E.; Lubick, Robert J.; Einstein, Thomas H.

1954-01-01

An investigation to determine the steady-state and surge characteristics of the J57-P-1 two-spool turbojet engine with various inlet air-flow distortions was conducted in the altitude wind tunnel at the NACA Lewis laboratory. Along with a uniform inlet total-pressure distribution, one circumferential and three radial pressure distortions were investigated. Data were obtained over a complete range of compressor speeds both with and without intercompressor air bleed at a flight Mach number of 0.8 and at altitudes of 35,000 and 50,000 feet. Total-pressure distortions of the magnitudes investigated had very little effect on the steady-state operating line for either the outer or inner compressor. The small radial distortions investigated also had engine over that obtained with the uniform inlet pressure distribution. The circumferential distortion, however, raised the minimum speed at which the engine could operate without encountering surge when the intercompressor bleeds were closed. This increase in minimum speed resulted in a substantial reduction in the operable speed range accompanied by a reduction in the altitude operating limit.

Meltwater-induced changes in the structure and behavior of Greenland's firn

Science.gov (United States)

MacFerrin, M. J.; Machguth, H.; van As, D.; Charalampidis, C.; Heilig, A.; Vandecrux, B.; Stevens, C.; Abdalati, W.

2017-12-01

As surface melt increases across the Greenland ice sheet in a warming climate, Greenland's accumulation zone has absorbed a progressively greater volume of water. In low-accumulation regions lacking perennial aquifers, this meltwater has refrozen into subsurface ice, which is now fundamentally altering the structure of near-surface firn layers. Here we present an extensive collection of firn cores, in situ radar, NASA IceBridge radar, thermistor string measurements, in situ FirnCover compaction data and regional climate model results to illustrate several distinct ways that Greenland's percolation zone is being fundamentally altered by increasing surface melt. The bulk density of the top 20 meters' firn in the wet-snow facies has increased by up to 40% in the past 50 years, due primarily to an up to six-fold increase in firn ice content. Firn compaction rates have changed both in their annual magnitude and have been delayed in their seasonal phase by up to three months, driven primarily by an increased release of latent heat as water refreezes at depth. When firn exceeds a threshold of excess melt in which seasonal snow can no longer accommodate summer melt, individual refrozen ice layers at depth have annealed together to form low-permeability ice slabs (LPISs). These multi-meter thick layers of ice perched over porous firn block percolation to depth and increase the size of the runoff zone. LPISs are a type of "hybrid facies" capable both of running water off the surface, while continuing to slowly compact porous firn at depth. Currently LPISs cover approximately 5% of Greenland's current accumulation zone, but we project them to extend across 15-50% of the accumulation zone by 2100 under different forcing scenarios. These observed changes in the structure and behavior of Greenland's firn have serious implications for future runoff of the ice sheet. Additionally, they challenge modern assumptions which we use to quantify the mass balance of the Greenland ice

An Improved Distortion Operator for Insurance Risks

Institute of Scientific and Technical Information of China (English)

GAO Jian-wei; QIU Wan-hua

2002-01-01

This paper reviews the distortion function approach developed in the actuarial literature for insurance risks. The main aim of this paper is to derive an extensive distortion operator, and to propose a new premium principle based on this extensive distortion operator. Furthermore, the non-robustness of general distortion operator is also discussed. Examples are provided using Bernoulli, Pareto, Lognormal and Gamma distribution assumptions.

Environmental radioactivity in the North Atlantic region. The Faroe Islands and Greenland included. 1983

International Nuclear Information System (INIS)

Aarkrog, A.; Boelskifte, S.; Buch, E.; Christensen, G.C.; Dahlgaard, H.; Hallstadius, L.; Hansen, H.; Holm, E.; Mattsson, S.; Meide, A.

1984-12-01

Measurements of fallout radioactivity in the North Atlantic region including the Faroe Islands and Greenland are reported. Strontium-90 and cesium-137 was determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes) and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in human diet in the Faroes and Greenland in 1983. Results from samplings of surface sea water and seaweed in the Norwegian and Greenland Seas and along the Norwegian and Greenland west coasts are reported. Beside radiocesium and 90 Sr some of these samples have also been anlysed for tritium,plutonium and americium. Finally technetium-99 data on seaweed samples collected in the North Atlantic region since the beginning of the sixties are presented. (author)

Environmental radioactivity in the North Atlantic region. The Faroe Islands and Greenland included. 1984

International Nuclear Information System (INIS)

Aarkrog, A.; Boelskifte, S.; Buch, E.; Christensen, G.C.; Dahlgaard, H.; Hallstadius, L.; Hansen, H.; Holm, E.

1985-12-01

Measurements of fallout radioactivity in the North Atlantic region including the Faroe Islands and Greenland are reported. Strontium-90 and cesium-137 was determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes) and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in human diet in the Faroes and Greenland in 1984. Results from samplings of surface sea water and seaweed in the Norwegian and Greenland Seas and along the Norwegian and Greenland west coasts are reported. Beside radiocesium and 90 Sr some of these samples have also been anlysed for tritium, polonium, plutonium and americium. Finally technetium-99 data on seaweed samples collected in the North Atlantic region since the beginning of the sixties are presented. (author)

Organotropism of persistent organic pollutants and heavy metals in the Greenland shark Somniosus microcephalus in NE Greenland

International Nuclear Information System (INIS)

Corsolini, Simonetta; Ancora, Stefania; Bianchi, Nicola; Mariotti, Giacomo; Leonzio, Claudio; Christiansen, Jørgen S.

2014-01-01

Highlights: • PCBs were more abundant in liver > muscle > fat and PBDEs in gonads > spleen > muscle. • Dioxin-like compounds and TEQs were lower than/comparable to those in Arctic species. • Cd and Se accumulated in the pancreas, mercury in muscle, lead in the skin. • The protective mechanism between Se and Hg is valid for this species. • First study on contaminant distribution across multiple tissues of Somniosus microcephalus. - Abstract: The Greenland shark Somniosus microcephalus is an opportunistic feeder, a top predator, and a very long-lived species. The brain, liver, red and white muscle, gonads, fat, skin, pancreas, and spleen of Greenland sharks from NE Greenland fjords were analysed for PCBs, PCDDs/DFs, PBDEs; DDT isomers; HCH isomers; dieldrin; endrin; HCB; Cd, Hg, Pb, and Se. PCBs (2.01–103 ng/g wet wt) and PBDEs (7.9–3050 pg/g wet wt) were detected in most of the samples. PCDDs/DFs showed high values when detected. DDTs, HCB and HCHs were only detected in some tissues. The ΣTEQ was 5.76 pg/g in muscle. Cadmium mainly accumulated in the pancreas and liver (19.6 and 10.7 mg/kg dry wt, respectively); mercury in red muscle (4.10–6.91 mg/kg dry wt); selenium in the pancreas (3.57 mg/kg dry wt) and spleen (1.95 mg/kg dry wt); lead in the skin (0.358 mg/kg dry wt). The selenium-mercury ratio in the liver was also evaluated

Recent trends of environmental radioactivity in Greenland and the Faroe Islands

DEFF Research Database (Denmark)

Nielsen, Sven Poul; Joensen, H.P.

2009-01-01

Environmental radioactivity in Greenland and the Faroe Islands was investigated from samples collected in 2004 of seawater, seaweed, marine fish, seal, whale, lake water, freshwater fish and total diet. Anthropogenic radionuclides in Greenland and the Faroe Islands are present due to long......-range transport by air and water mainly due to fallout from nuclear weapons testing, from the Chernobyl accident and discharges from European reprocessing facilities, Sellafield in the UK and La Hague in France. Concentrations of anthropogenic radionuclides in environment and food are low, however, and present...... insignificant health risks to humans. Naturally occurring radionuclides are present in the environment and human food and dominate the radiation dose from ingestion. Even in case of landlocked Arctic char from South Greenland showing elevated concentrations of anthropogenic 137Cs, the radiation doses to man...

Foraging strategy of little auks during chick rearing in northwest Greenland

DEFF Research Database (Denmark)

Mosbech, Anders; Møller, Eva Friis; Johansen, Kasper Lambert

of the ongoing warming of the Arctic. Here we present the first results from GPS tracking of breeding little auks in northwest Greenland, involving data from four different breeding colonies. We examine time budgets, foraging trip patterns and habitat preferences at foraging areas, including comparison......Foraging strategy of little auks during chick rearing in northwest Greenland Anders Mosbech, Kasper Johansen, Eva Friis Møller & Peter Lyngs Department of Biology and Arctic Center, Aarhus University, Denmark An estimated 80 % of the global little auk population breeds in the coastal landscape...... bordering the north water polynya in high Arctic northwest Greenland, and from this main breeding area very little is known on foraging behavior. Little auks are feeding on lipid-rich copepods associated with cold artic waters, and are potentially important for monitoring and assessing the impact...

Tributyltin accumulation and effects in marine molluscs from West Greenland

Energy Technology Data Exchange (ETDEWEB)

Strand, J.; Asmund, G

2003-05-01

Tributyltin is accumulated in marine molluscs living in Greenland, with the highest levels found in harbour areas. - The levels of the antifouling agent tributyltin (TBT) and its breakdown products in bivalves were investigated in 1999-2000 at six areas along the west coast of Greenland with focus on locations inside and outside harbours. In addition female gastropods were examined for the development of TBT-induced masculine characteristics in form of imposex or intersex. The highest TBT concentration, 254 ng g{sup -1} ww, was found in the bivalve Mytilus edulis sampled inside Nuuk harbour, but significant TBT concentrations were also present in bivalves from the other harbour areas. Only low levels of TBT were detected in bivalves sampled outside the harbours and in several of the samples the TBT level was below the detection limit. The examination of neogastropods like Buccinum revealed that imposex development occurred in all the harbours. In contrast, imposex was not found in any neogastropods sampled outside the harbour areas. However, the value of marine neogastropods as indicators of TBT contamination in West Greenland seems limited, because of large species diversity and the difficulties in sampling enough specimens at least with the current sampling strategy. No effects, which could be related to TBT contamination, were found in the most abundant tidal gastropod in West Greenland, Littorina saxatilis.

Tributyltin accumulation and effects in marine molluscs from West Greenland

International Nuclear Information System (INIS)

Strand, J.; Asmund, G.

2003-01-01

Tributyltin is accumulated in marine molluscs living in Greenland, with the highest levels found in harbour areas. - The levels of the antifouling agent tributyltin (TBT) and its breakdown products in bivalves were investigated in 1999-2000 at six areas along the west coast of Greenland with focus on locations inside and outside harbours. In addition female gastropods were examined for the development of TBT-induced masculine characteristics in form of imposex or intersex. The highest TBT concentration, 254 ng g -1 ww, was found in the bivalve Mytilus edulis sampled inside Nuuk harbour, but significant TBT concentrations were also present in bivalves from the other harbour areas. Only low levels of TBT were detected in bivalves sampled outside the harbours and in several of the samples the TBT level was below the detection limit. The examination of neogastropods like Buccinum revealed that imposex development occurred in all the harbours. In contrast, imposex was not found in any neogastropods sampled outside the harbour areas. However, the value of marine neogastropods as indicators of TBT contamination in West Greenland seems limited, because of large species diversity and the difficulties in sampling enough specimens at least with the current sampling strategy. No effects, which could be related to TBT contamination, were found in the most abundant tidal gastropod in West Greenland, Littorina saxatilis

Annual Greenland Accumulation Rates (2009-2012) from Airborne Snow Radar

Science.gov (United States)

Koenig, Lora S.; Ivanoff, Alvaro; Alexander, Patrick M.; MacGregor, Joseph A.; Fettweis, Xavier; Panzer, Ben; Paden, John D.; Forster, Richard R.; Das, Indrani; McConnell, Joseph R.;

Manganiferous minerals of the epidote group from the Archaean basement of West Greenland

DEFF Research Database (Denmark)

Katerinopoulou, Anna; Balic Zunic, Tonci; Kolb, Jochen

2014-01-01

The chemical compositions and crystal structures of Mn3+-containing minerals from the epidote group in Greenland rocks are investigated and described in detail. They occur in hydrothermally altered Archaean mafic sequences within the gneissic complex of the North Atlantic craton of West Greenland...

Resilience and Renewable Energy Planning in Greenland

DEFF Research Database (Denmark)

Carruth, Susan

2014-01-01

Using a combination of thematic analysis and studio-based planning proposals in West Greenland, this paper proposes that there is more than one interpretation of resilience in renewable energy planning. All energy transitions, from one system to another, are protracted and unpredictable......, and the transition to a renewable energy system is proving no exception. Such a transition is particularly amplified in the context of Greenland – a country undergoing rapid transformation in many fields, including energy. Resilience theory offers an approach for how to plan for this energy transition, but how...... to translate resilience theory into planning practices remains underdeveloped. The paper begins by outlining some of the challenges in planning a transition to renewable energy, and sketching Greenland’s energy landscape. It then discusses the key characteristics of resilience thinking, before proposing...

Observed runoff, jokulhlaups and suspended sediment load from the Greenland ice at Kangerlussuaq, West Greenland, 2007 and 2008

Energy Technology Data Exchange (ETDEWEB)

Mernild, Sebastian Haugard [Los Alamos National Laboratory; Hasholt, Bent [UNIV OF COPENHAGEN

2009-01-01

This study fills the gap in hydrologic measurements of runoff exiting a part of the Greenland Ice Sheet (GrIS), the Kangerlussuaq drainage area, West Greenland. The observations are of value for obtaining knowledge about the terrestrial freshwater and sediment output from part of the GrIS and the strip of land between the GrIS and the ocean, in the context of varying ice sheet surface melt and influx entering the ocean. High-resolution stage, discharge and suspended sediment load show a decrease in runoff of {approx} 25% and in sediment load of {approx} 40% from 2007 to 2008 in response to a decrease in the summer accumulated number of positive degree days. During the 2007 and 2008 runoff season, joekulhlaups are observed at Kangerlussuaq, drained from an ice-dammed lake at the margin of the GrIS.

Mitigation of Grid Current Distortion for LCL-Filtered Voltage Source Inverter with Inverter Current Feedback Control

DEFF Research Database (Denmark)

Xin, Zhen; Mattavelli, Paolo; Yao, WenLi

2018-01-01

LCL filters feature low inductance; thus, the injected grid current from an LCL-filtered Voltage Source Inverter (VSI) can be easily distorted by grid voltage harmonics. This problem is especially tough for the control system with Inverter-side Current Feedback (ICF), since the grid current...... harmonics can freely flow into the filter capacitor. In this case, because of the loss of harmonic information, traditional harmonic controllers fail to mitigate the grid current distortion. Although this problem may be avoided using the grid voltage feedforward scheme, the required differentiators may...

Volterra Series Based Distortion Effect

DEFF Research Database (Denmark)

Agerkvist, Finn T.

2010-01-01

A large part of the characteristic sound of the electric guitar comes from nonlinearities in the signal path. Such nonlinearities may come from the input- or output-stage of the amplier, which is often equipped with vacuum tubes or a dedicated distortion pedal. In this paper the Volterra series...... expansion for non linear systems is investigated with respect to generating good distortion. The Volterra series allows for unlimited adjustment of the level and frequency dependency of each distortion component. Subjectively relevant ways of linking the dierent orders are discussed....

En vellykket krisekommunikation? Air Greenlands krisekommunikation - internt og eksternt perspektiv

OpenAIRE

Christiansen, Jacob; Christiansen, Kristine; Petersen, Heidi Juul; Møller-Petersen, Allan; Wintlev-Jensen, Anette

2015-01-01

The majority of the investigations into crisis communication are studying crisis communication after the escalation of a crisis. In this thesis, we examine a case where the potential media crises did not evolve. The fact that a media crisis never occurred made us curious, and such a case may hold valuable information about the efficacy of crisis communication. On the 29th of January 2014 an aircraft from Air Greenland (AG) crashed in Greenland. This resulted in only minor casualties. As a con...

North and northeast Greenland ice discharge from satellite radar interferometry

DEFF Research Database (Denmark)

Rignot, E.J.; Gogineni, S.P.; Krabill, W.B.

1997-01-01

Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier...... front, because basal melting is extensive at the underside of the floating glacier sections. The results suggest that the north and northeast parts of the Greenland ice sheet may be thinning and contributing positively to sea-level rise....

Interdisciplinary Graduate Training in Polar Environmental Change: Field-based learning in Greenland

Science.gov (United States)

Virginia, R. A.; Holm, K.; Whitecloud, S.; Levy, L.; Kelly, M. A.; Feng, X.; Grenoble, L.

2009-12-01

The objective of the NSF-funded Integrative Graduate Education Research Traineeship (IGERT) program at Dartmouth College is to develop a new cohort of environmental scientists and engineers with an interdisciplinary understanding of polar regions and their importance to global environmental change. The Dartmouth IGERT challenges Ph.D. students to consider the broader dimensions of their research and to collaborate with scientists from other disciplines, educators, and policy makers. IGERT students will focus on research questions that are relevant to the needs of local people experiencing climate change and on understanding the ethical responsibilities and benefits of conducting research in partnership with northern residents and institutions. Seven Ph.D. students from the departments of Earth Sciences, Engineering, and Ecology and Evolutionary Biology at Dartmouth College make up the first IGERT cohort for the five-year program. The Dartmouth IGERT curriculum will focus on three main components of polar systems responding to recent climate change: the cryosphere, terrestrial ecosystems, and biogeochemical cycles. The integrating experience of the core curriculum is the Greenland Field Seminar that will take place in Kangerlussuaq (terrestrial and aquatic systems), Summit Camp (snow and ice) and Nuuk, Greenland (human dimensions of change). In Nuuk, IGERT students will share their science and develop partnerships with students, educators, and policy makers at the University of Greenland, the Inuit Circumpolar Council (ICC), and other Greenlandic institutions. In summer 2009 the authors conducted preliminary fieldwork near Kangerlussuaq, Greenland to develop aspects of the science curriculum for the 2010 Greenland Field Seminar and to explore research topics for IGERT Fellows (Levy and Whitecloud). Examples of results presented here are designed to develop field-based learning activities. These include soil and vegetation relationships as a function of aspect

Energy-efficient Building in Greenland: Investigation of the Energy Consumption and Indoor Climate

DEFF Research Database (Denmark)

Luc, Katarzyna Marta; Kotol, Martin; Lading, Tove

2015-01-01

Recently, a brand new single family home was built in Sisimiut, Greenland. The building was constructed as a wooden house typical for Greenland. However, some non-traditional measures were implemented in order to reduce the energy consumption and improve indoor air quality. Assessment of the infl...

Global climate model performance over Alaska and Greenland

DEFF Research Database (Denmark)

Walsh, John E.; Chapman, William L.; Romanovsky, Vladimir

2008-01-01

The performance of a set of 15 global climate models used in the Coupled Model Intercomparison Project is evaluated for Alaska and Greenland, and compared with the performance over broader pan-Arctic and Northern Hemisphere extratropical domains. Root-mean-square errors relative to the 1958...... to narrowing the uncertainty and obtaining more robust estimates of future climate change in regions such as Alaska, Greenland, and the broader Arctic....... of the models are generally much larger than the biases of the composite output, indicating that the systematic errors differ considerably among the models. There is a tendency for the models with smaller errors to simulate a larger greenhouse warming over the Arctic, as well as larger increases of Arctic...

High-resolution Moho model for Greenland from EIGEN-6C4 gravity data

DEFF Research Database (Denmark)

Steffen, Rebekka; Strykowski, Gabriel; Lund, Björn

2017-01-01

are difficult to obtain. Here, we take advantage of the global gravity model EIGEN-6C4, together with the Parker-Oldenburg algorithm, to estimate the depth to the Moho beneath Greenland and surroundings. The available free-air gravity data are corrected for the topographic effect and the effect of sedimentary...... basins. We also correct for the effect on gravity due to the weight of the ice sheet and the accompanying deflection of the Earth's surface, which has not previously been taken into account in gravity studies of currently glaciated regions. Our final Moho depth model for Greenland has an associated...... uncertainty of ±4.5 km for areas with sedimentary basins and ±4 km for areas without sedimentary basins. The model shows maximum Moho depths below east Greenland of up to 55 km and values less than 20 km offshore east Greenland. There is a marked increase in Moho depth of 10–15 km from northern to central...

Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Kjaer, Kurt H.; Bevis, Michael

2014-01-01

The Greenland ice sheet has been one of the largest contributors to global sea-level rise over the past 20 years, accounting for 0.5 mm yr(-1) of a total of 3.2 mm yr(-1). A significant portion of this contribution is associated with the speed-up of an increased number of glaciers in southeast...... and northwest Greenland. Here, we show that the northeast Greenland ice stream, which extends more than 600 km into the interior of the ice sheet, is now undergoing sustained dynamic thinning, linked to regional warming, after more than a quarter of a century of stability. This sector of the Greenland ice sheet...... is of particular interest, because the drainage basin area covers 16% of the ice sheet (twice that of Jakobshavn Isbrae) and numerical model predictions suggest no significant mass loss for this sector, leading to an under-estimation of future global sea-level rise. The geometry of the bedrock and monotonic trend...

Deglacial History and Paleoceanography of the Umanak System, West Greenland

DEFF Research Database (Denmark)

Sheldon, Christina; Jennings, Anne; Andrews, John

2012-01-01

A record of Greenland Ice Sheet (GIS) and ice-stream history, ice-sheet ocean interactions and paleoclimate from the Last Glacial Maximum to present is preserved in the sediments of the Umanak fjord, shelf trough and trough mouth fan system of central West Greenland. The objective of this study....... This evidence of Atlantic Water carried in the WGC precedes lithological evidence of ice stream retreat from the shelf edge (an influx of coarse IRD beginning 62 cm above the first Atlantic Water assemblage) indicating the presence of the WGC at the shelf edge prior to initial deglaciation. Both the slope...... is to document the timing and rate of ice retreat and the role of the West Greenland Current (WGC) in initiating or sustaining ice retreat. During cruise JR175 of the UK ship RRS James Clark Ross in 2009, sediment cores and geophysical data were collected from the Umanak System to document the glacial history...

Trends of perfluorochemicals in Greenland ringed seals and polar bears: indications of shifts to decreasing trends.

Science.gov (United States)

Rigét, Frank; Bossi, Rossana; Sonne, Christian; Vorkamp, Katrin; Dietz, Rune

2013-11-01

Time-series of perfluorinated alkylated substances (PFASs) in East Greenland polar bears and East and West Greenland ringed seals were updated in order to deduce whether a response to the major reduction in perfluoroalkyl production in the early 2000s had occurred. Previous studies had documented an exponential increase of perfluorooctane sulphonate (PFOS) in liver tissue from both species. In the present study, PFOS was still the far most dominant compound constituting 92% (West Greenland ringed seals), 88% (East Greenland ringed seals) and 85% (East Greenland polar bears). The PFOS concentrations increased up to 2006 with doubling times of approximately 6 years for the ringed seal populations and 14 years in case of polar bears. Since then a rapid decrease has occurred with clearing half-lives of approximately 1, 2 and 4 years, respectively. In polar bears perfluorohexane sulphonate (PFHxS) and perfluorooctane sulphonamide (PFOSA) also showed decreasing trends in recent years as do perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA). For the West Greenland ringed seal population perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), PFDA and PFUnA peaked in the mid 2000s, whereas PFNA, PFDA and PFUnA in the East Greenland population have been stable or increasing in recent years. The peak of PFASs in Greenland ringed seals and polar bears occurred at a later time than in Canadian seals and polar bears and considerably later than observed in seal species from more southern latitudes. We suggest that this could be explained by the distance to emission hot-spots and differences in long-range transport to the Arctic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aerial photographs reveal late-20th-century dynamic ice loss in northwestern greenland

DEFF Research Database (Denmark)

Kjær, Kurt H.; Khan, Shfaqat Abbas; Korsgaard, Niels J

2012-01-01

Global warming is predicted to have a profound impact on the Greenland Ice Sheet and its contribution to global sea-level rise. Recent mass loss in the northwest of Greenland has been substantial. Using aerial photographs, we produced digital elevation models and extended the time record of recent...

Super-energy wrap-up model for renovation of standard wooden houses in Greenland?

DEFF Research Database (Denmark)

Bjarløv, Søren Peter; Vladyková, Petra

2012-01-01

This paper is based on the developed theoretical practice of super-insulation solution for renovation of exiting standard wooden houses in Greenland built from 1950s until 2006, more than half the building stock in Arctic Greenland. From various perspectives, the wrap-up system is evaluated as a ...

Spatiotemporal Variability of Meltwater Refreezing in Southwest Greenland Ice Sheet Firn

Science.gov (United States)

Rennermalm, A. K.; Hock, R.; Tedesco, M.; Corti, G.; Covi, F.; Miège, C.; Kingslake, J.; Leidman, S. Z.; Munsell, S.

2017-12-01

A substantial fraction of the summer meltwater formed on the surface of the Greenland ice sheet is retained in firn, while the remaining portion runs to the ocean through surface and subsurface channels. Refreezing of meltwater in firn can create impenetrable ice lenses, hence being a crucial process in the redistribution of surface runoff. To quantify the impact of refreezing on runoff and current and future Greenland surface mass balance, a three year National Science Foundation funded project titled "Refreezing in the firn of the Greenland ice sheet: Spatiotemporal variability and implications for ice sheet mass balance" started this past year. Here we present an overview of the project and some initial results from the first field season in May 2017 conducted in proximity of the DYE-2 site in the percolation zone of the Southwest Greenland ice sheet at elevations between 1963 and 2355 m a.s.l.. During this fieldwork two automatic weather stations were deployed, outfitted with surface energy balance sensors and 16 m long thermistor strings, over 300 km of ground penetrating radar data were collected, and five 20-26 m deep firn cores were extracted and analyzed for density and stratigraphy. Winter snow accumulation was measured along the radar tracks. Preliminary work on the firn-core data reveals increasing frequency and thickness of ice lenses at lower ice-sheet elevations, in agreement with other recent work in the area. Data collected within this project will facilitate advances in our understanding of the spatiotemporal variability of firn refreezing and its role in the hydrology and surface mass balance of the Greenland Ice Sheet.

Greenland as a self-governing sub-national territory in international relations: past, current and future perspectives

DEFF Research Database (Denmark)

Ackrén, Maria; Jakobsen, Uffe

2015-01-01

Greenland was used by the US as a platform and as an extended arm within its security and foreign policy during the World War II and the cold war. After this things changed, although Greenland remained important in Danish-US relations under the umbrella of NATO. Nowadays, the geostrategic position...... of Greenland between North America and Europe is gaining fresh prominence in the race for natural resources in the Arctic. Many issues arise from the prospective opening of the Arctic, all of which may have fateful impacts on future development in the region. Climate change, claims related to the extension....... This article reviews developments from the World War II to the present regarding international relations from a Greenlandic perspective. As a self-governing sub-national territory within the realm of Denmark, Greenland does not have the ultimate decision-making power within foreign and security policy. The new...

Oceanic Transport of Surface Meltwater from the Southern Greenland Ice Sheet

Science.gov (United States)

Luo, Hao; Castelao, Renato M.; Rennermalm, Asa K.; Tedesco, Marco; Bracco, Annalisa; Yager, Patricia L.; Mote, Thomas L.

2016-01-01

The Greenland ice sheet has undergone accelerating mass losses during recent decades. Freshwater runoff from ice melt can influence fjord circulation and dynamic1 and the delivery of bioavailable micronutrients to the ocean. It can also have climate implications, because stratification in the adjacent Labrador Sea may influence deep convection and the strength of the Atlantic meridional overturning circulation. Yet, the fate of the meltwater in the ocean remains unclear. Here, we use a high-resolution ocean model to show that only 1-15% of the surface meltwater runoff originating from southwest Greenland is transported westwards. In contrast, up to 50-60% of the meltwater runoff originating from southeast Greenland is transported westwards into the northern Labrador Sea, leading to significant salinity and stratification anomalies far from the coast. Doubling meltwater runoff, as predicted in future climate scenarios, results in a more-than-double increase in anomalies offshore that persists further into the winter. Interannual variability in offshore export of meltwater is tightly related to variability in wind forcing. The new insight that meltwaters originating from the west and east coasts have different fates indicates that future changes in mass loss rates and surface runoff will probably impact the ocean differently, depending on their Greenland origins.

Ecosystem variability in west Greenland waters

DEFF Research Database (Denmark)

Buch, E.; Pedersen, Søren Anker; Ribergaard, M. H.

2004-01-01

A review of the climate conditions off West Greenland during the past 50 years shows large variability in the atmospheric, oceanographic and sea-ice variables, as well as in fish stocks. A positive relationship is found between water temperature and the recruitment of cod and redfish, whereas the...

Freshwater discharge and sediment transport to Kangerlussuaq Fjord, West Greenland

DEFF Research Database (Denmark)

Mikkelsen, Andreas Peter Bech

the deep inner basin of Kangerlussuaq Fjord. Different melt models were applied to the MIKE SHE and MIKE 11 water routing models in order to simulate the proglacial water flows. The best melt model was a surface energy balance model. The routing model improved the modelled proglacial discharge......The main objectives of this PhD study have been to quantify the large-scale hydrological and geomorphological processes and implications related to three large proglacial rivers draining into Kangerlussuaq Fjord from the Greenland Ice Sheet (GrIS). These rivers are Watson, Umivit and Sarfartoq...... River. Hydrological processes studied are: proglacial discharge volumes and timing of this, creation of runoff (i.e. melt), storage and release features such as ice dammed lakes (jökulhlaups lakes), the role of supraglacial lakes, storage and release inside or beneath the ice and the role of the so...

Spectral Distortion in Lossy Compression of Hyperspectral Data

Directory of Open Access Journals (Sweden)

Bruno Aiazzi

2012-01-01

Full Text Available Distortion allocation varying with wavelength in lossy compression of hyperspectral imagery is investigated, with the aim of minimizing the spectral distortion between original and decompressed data. The absolute angular error, or spectral angle mapper (SAM, is used to quantify spectral distortion, while radiometric distortions are measured by maximum absolute deviation (MAD for near-lossless methods, for example, differential pulse code modulation (DPCM, or mean-squared error (MSE for lossy methods, for example, spectral decorrelation followed by JPEG 2000. Two strategies of interband distortion allocation are compared: given a target average bit rate, distortion may be set to be constant with wavelength. Otherwise, it may be allocated proportionally to the noise level of each band, according to the virtually lossless protocol. Comparisons with the uncompressed originals show that the average SAM of radiance spectra is minimized by constant distortion allocation to radiance data. However, variable distortion allocation according to the virtually lossless protocol yields significantly lower SAM in case of reflectance spectra obtained from compressed radiance data, if compared with the constant distortion allocation at the same compression ratio.

Adverse health effects of experiencing food insecurity among Greenlandic school children

DEFF Research Database (Denmark)

Niclasen, B.; Petzold, M.; Schnohr, C. W.

2013-01-01

Background. In vulnerable populations, food security in children has been found to be associated with negative health effects. Still, little is known about whether the negative health effects can be retrieved in children at the population level. Objective. To examine food insecurity reported...... by Greenlandic school children as a predictor for perceived health, physical symptoms and medicine use. Design. The study is based on the Greenlandic part of the Health Behavior in School-aged Children survey. The 2010 survey included 2,254 students corresponding to 40% of all Greenlandic school children...... in Grade 5 through 10. The participation rate in the participating schools was 65%. Food insecurity was measured as going to bed or to school hungry because there was no food at home. Results. Boys, the youngest children (11-12 year-olds), and children from low affluence homes were at increased risk...

Urbanization, migration and alcohol use in a population of Greenland inuit

DEFF Research Database (Denmark)

Madsen, Marie Henriette; Grønbæk, Morten; Bjerregaard, Peter

2005-01-01

and self-administered questionnaires. METHODS: The association between different aspects of alcohol intake (quantity of intake, occasional heavy drinking, and the modified CAGE questionnaire) and place of living were analysed using a chi-square test and logistic regression analysis. RESULTS: The population...... living in Denmark had a higher mean alcohol intake than those living in Greenland. Drinking above the sensible drinking limits (21 drinks per week for men and 14 drinks per week for women; where one drink contains 12 g alcohol) was also more prevalent in the population living in Denmark, whereas a higher...... proportion of those living in Greenland was abstaining. In contrast to the higher alcohol intake in the population living in Denmark, a higher proportion of individuals with episodes of heavy drinking (binge drinking), was observed in both large and small communities in Greenland. A higher proportion...

Comparison of modelled runoff with observed proglacial discharge across the western margin of the Greenland ice sheet

Science.gov (United States)

Moustafa, S.; Rennermalm, A.; van As, D.; Overeem, I.; Tedesco, M.; Mote, T. L.; Koenig, L.; Smith, L. C.; Hagedorn, B.; Sletten, R. S.; Mikkelsen, A. B.; Hasholt, B.; Hall, D. K.; Fettweis, X.; Pitcher, L. H.; Hubbard, A.

2017-12-01

Greenland ice sheet surface ablation now dominates its total mass loss contributions to sea-level rise. Despite the increasing importance of Greenland's sea-level contribution, a quantitative inter-comparison between modeled and measured melt, runoff and discharge across multiple drainage basins is conspicuously lacking. Here we investigate the accuracy of model discharge estimates from the Modèle Atmosphérique Régionale (MAR v3.5.2) regional climate model by comparison with in situ proglacial river discharge measurements at three West Greenland drainage basins - North River (Thule), Watson River (Kangerlussuaq), and Naujat Kuat River (Nuuk). At each target catchment, we: 1) determine optimal drainage basin delineations; 2) assess primary drivers of melt; 3) evaluate MAR at daily, 5-, 10- and 20-day time scales; and 4) identify potential sources for model-observation discrepancies. Our results reveal that MAR resolves daily discharge variability poorly in the Nuuk and Thule basins (r2 = 0.4-0.5), but does capture variability over 5-, 10-, and 20-day means (r2 > 0.7). Model agreement with river flow data, though, is reduced during periods of peak discharge, particularly for the exceptional melt and discharge events of July 2012. Daily discharge is best captured by MAR across the Watson River basin, whilst there is lower correspondence between modeled and observed discharge at the Thule and Naujat Kuat River basins. We link the main source of model error to an underestimation of cloud cover, overestimation of surface albedo, and apparent warm bias in near-surface air temperatures. For future inter-comparison, we recommend using observations from catchments that have a self-contained and well-defined drainage area and an accurate discharge record over variable years coincident with a reliable automatic weather station record. Our study highlights the importance of improving MAR modeled surface albedo, cloud cover representation, and delay functions to reduce model

Peopling of the North Circumpolar Region--insights from Y chromosome STR and SNP typing of Greenlanders.

Directory of Open Access Journals (Sweden)

Jill Katharina Olofsson

Full Text Available The human population in Greenland is characterized by migration events of Paleo- and Neo-Eskimos, as well as admixture with Europeans. In this study, the Y-chromosomal variation in male Greenlanders was investigated in detail by typing 73 Y-chromosomal single nucleotide polymorphisms (Y-SNPs and 17 Y-chromosomal short tandem repeats (Y-STRs. Approximately 40% of the analyzed Greenlandic Y chromosomes were of European origin (I-M170, R1a-M513 and R1b-M343. Y chromosomes of European origin were mainly found in individuals from the west and south coasts of Greenland, which is in agreement with the historic records of the geographic placements of European settlements in Greenland. Two Inuit Y-chromosomal lineages, Q-M3 (xM19, M194, L663, SA01 and L766 and Q-NWT01 (xM265 were found in 23% and 31% of the male Greenlanders, respectively. The time to the most recent common ancestor (TMRCA of the Q-M3 lineage of the Greenlanders was estimated to be between 4,400 and 10,900 years ago (y. a. using two different methods. This is in agreement with the theory that the North Circumpolar Region was populated via a second expansion of humans in the North American continent. The TMRCA of the Q-NWT01 (xM265 lineage in Greenland was estimated to be between 7,000 and 14,300 y. a. using two different methods, which is older than the previously reported TMRCA of this lineage in other Inuit populations. Our results indicate that Inuit individuals carrying the Q-NWT01 (xM265 lineage may have their origin in the northeastern parts of North America and could be descendants of the Dorset culture. This in turn points to the possibility that the current Inuit population in Greenland is comprised of individuals of both Thule and Dorset descent.

Consumption of traditional food and adherence to nutrition recommendations in Greenland

DEFF Research Database (Denmark)

Jeppesen, Charlotte; Bjerregaard, Peter

2012-01-01

The purpose was to study the composition of the Inuit diet, to assess the adherence to nutritional recommendations among the Inuit in Greenland, and to discuss the potential role of traditional food in improving dietary quality.......The purpose was to study the composition of the Inuit diet, to assess the adherence to nutritional recommendations among the Inuit in Greenland, and to discuss the potential role of traditional food in improving dietary quality....

Bioaccumulation of nonylphenols and bisphenol A in the Greenland shark Somniosus microcephalus from the Greenland seawaters

DEFF Research Database (Denmark)

Ademollo, N.; Patrolecco, L.; Rauseo, J.

2018-01-01

and on the loss of biodiversity. In this work, we report the occurrence and bioaccumulation of selected endocrine-disrupting compounds (EDCs) in muscle and liver of the Greenland shark . Somniosus microcephalus, an arctic species of interest for biogeography, migration, physiology, long- and short...

Constraints on mineralisation and hydrothermal alteration in the Nalunaq gold deposit, South Greenland

DEFF Research Database (Denmark)

Bell, Robin-Marie Fairbairn

Summary: Nalunaq is located in South Greenland and is a small high gold-grade deposit, which for the majority of its operational life was Greenland's only metalliferous mine. Gold is hosted in narrow quartz veins which are cross-cut by late-stage faults. Gold-quartz veins are hosted by fine...

Causes of Greenland temperature variability over the past 4000 yr: implications for northern hemispheric temperature changes

Directory of Open Access Journals (Sweden)

T. Kobashi

2013-10-01

Full Text Available Precise understanding of Greenland temperature variability is important in two ways. First, Greenland ice sheet melting associated with rising temperature is a major global sea level forcing, potentially affecting large populations in coming centuries. Second, Greenland temperatures are highly affected by North Atlantic Oscillation/Arctic Oscillation (NAO/AO and Atlantic multidecadal oscillation (AMO. In our earlier study, we found that Greenland temperature deviated negatively (positively from northern hemispheric (NH temperature trend during stronger (weaker solar activity owing to changes in atmospheric/oceanic changes (e.g. NAO/AO over the past 800 yr (Kobashi et al., 2013. Therefore, a precise Greenland temperature record can provide important constraints on the past atmospheric/oceanic circulation in the region and beyond. Here, we investigated Greenland temperature variability over the past 4000 yr reconstructed from argon and nitrogen isotopes from trapped air in a GISP2 ice core, using a one-dimensional energy balance model with orbital, solar, volcanic, greenhouse gas, and aerosol forcings. The modelled northern Northern Hemisphere (NH temperature exhibits a cooling trend over the past 4000 yr as observed for the reconstructed Greenland temperature through decreasing annual average insolation. With consideration of the negative influence of solar variability, the modelled and observed Greenland temperatures agree with correlation coefficients of r = 0.34–0.36 (p = 0.1–0.04 in 21 yr running means (RMs and r = 0.38–0.45 (p = 0.1–0.05 on a centennial timescale (101 yr RMs. Thus, the model can explain 14 to 20% of variance of the observed Greenland temperature in multidecadal to centennial timescales with a 90–96% confidence interval, suggesting that a weak but persistent negative solar influence on Greenland temperature continued over the past 4000 yr. Then, we estimated the distribution of multidecadal NH and northern high

Active predation by Greenland shark Somniosus microcephalus

DEFF Research Database (Denmark)

Nielsen, Julius; hedeholm, Rasmus; Simon, Malene

2013-01-01

and show that the sharks catch epi-benthic species with Atlantic cod being the most important (% IRI = 56 ), followed by squid (% IRI= 13 ) and wolf fish (IRI=4). Furthermore seal was found in 50 % of all stomachs (% IRI= 13). In addition to providing new knowledge of feeding habits of this species......Dansk Havforskermøde 2013 Julius Nielsen, Rasmus Hedeholm, Malene Simon og John Fleng Steffensen The Greenland shark is ubiquitous in the northern part of the North Atlantic ranging from eastern Canada to northwest Russia . Although knowledge is scarce it is believed to be abundant and potentially...... important part of the ecosystem. Whether Greenland sharks in general should be considered opportunistic scavengers or active predators is therefore important in understanding ecosystem dynamics. Due to its sluggish appearance and a maximum reported swimming speed of 74 cm per second scavenging seems...

Violence, sexual abuse and health in Greenland

DEFF Research Database (Denmark)

Curtis, Tine; Larsen, Finn B; Helweg-Larsen, Karin

2002-01-01

The purposes of the study were to analyse the lifetime prevalence of violence and sexual abuse among the Inuit in Greenland and to study the associations between health and having been the victim of violence or sexual abuse. Associations were studied with specific attention to possible differences...... between women and men. Further, response rates were analysed specifically in order to understand consequences of including questions on violence and sexual abuse in the questionnaire survey. The analyses were based on material from a cross-sectional health interview survey conducted during 1993......-94 with participation from a random sample of the Inuit population in Greenland (N = 1393). The prevalence of ever having been a victim of violence was 47% among women and 48% among men. Women had more often than men been sexually abused (25% and 6%) (p sexually abused in childhood (8...

Evaluation of the Doll Project in Greenland

DEFF Research Database (Denmark)

Wistoft, Karen

2013-01-01

supplemented with observations of teaching and personal interviews with the educators. Significant gains were found on the impact of the students perception of how early parenting affects their social and emotional life, and apprehension of the amount of responsibility involved in infant care. Parents......The Real Care Doll Program in Greenland intent to show students the amount of responsibility involved in caring for a baby. More than one thousands of predominantly eight- and ninth-grade students have been provided with an experience of being the parent of a ‘newborn infant’ by caring Real Care...... objective of the evaluation study is to determine the short-term impact of the family and sex education including evaluating the effectiveness of this education strategy to influence Greenland teenagers' perceptions of pregnancy and parenting. The study is a pre-/posttest questionnaire survey design...

Violence, sexual abuse and health in Greenland

DEFF Research Database (Denmark)

Curtis, Tine; Larsen, Finn B; Helweg-Larsen, Karin

2002-01-01

The purposes of the study were to analyse the lifetime prevalence of violence and sexual abuse among the Inuit in Greenland and to study the associations between health and having been the victim of violence or sexual abuse. Associations were studied with specific attention to possible differences...... between women and men. Further, response rates were analysed specifically in order to understand consequences of including questions on violence and sexual abuse in the questionnaire survey. The analyses were based on material from a cross-sectional health interview survey conducted during 1993......-94 with participation from a random sample of the Inuit population in Greenland (N = 1393). The prevalence of ever having been a victim of violence was 47% among women and 48% among men. Women had more often than men been sexually abused (25% and 6%) (p abused in childhood (8...

TPC track distortions III: fiat lux

CERN Document Server

Boyko, I; Dydak, F; Elagin, A; Gostkin, M; Guskov, A; Koreshev, V; Nefedov, Y; Nikolaev, K; Veenhof, R; Wotschack, J; Zhemchugov, A

2005-01-01

We present a comprehensive overview and final summary of all four types of static track distortions seen in the HARP TPC, in terms of physical origins, mathematical modelling, and correction algorithms. 'Static'™ distortions are defined as not depending on the event time within the 400 ms long accelerator spill. Calculated static distortions are compared with measurements from cosmic-muon tracks. We characterize track distortions by the r phi residuals of cluster positions with respect to the transverse projection of a helical trajectory constrained by hits in the RPC overlap regions. This method provides a fixed TPC-external reference system (by contrast to the co-moving coordinate system associated with a fit) which solely permits to identify individually, and measure quantitatively, the static TPC track distortions arising from (i) the inhomogeneity of the solenoidal magnetic field, (ii) the inhomogeneity of the electric field from the high-voltage mismatch between the inner and outer TPC field cages, (...

Intermingling and seasonal migrations of Greenland halibut ( Reinhardtius hippoglossoides ) populations determined from tagging studies

DEFF Research Database (Denmark)

Boje, Jesper

2002-01-01

A total of 7244 Greenland halibut (Reinhardtius hippoglossoides' Walbaum) were tagged in Greenland waters between 1986 and 1998 to increase information on stock delineations, to clarify migration routes, and to describe the seasonal movements of cord populations. At present 517 recaptured Greenla...

Empirical Retrieval of Surface Melt Magnitude from Coupled MODIS Optical and Thermal Measurements over the Greenland Ice Sheet during the 2001 Ablation Season.

Science.gov (United States)

Lampkin, Derrick; Peng, Rui

2008-08-22

Accelerated ice flow near the equilibrium line of west-central Greenland Ice Sheet (GIS) has been attributed to an increase in infiltrated surface melt water as a response to climate warming. The assessment of surface melting events must be more than the detection of melt onset or extent. Retrieval of surface melt magnitude is necessary to improve understanding of ice sheet flow and surface melt coupling. In this paper, we report on a new technique to quantify the magnitude of surface melt. Cloud-free dates of June 10, July 5, 7, 9, and 11, 2001 Moderate Resolution Imaging Spectroradiometer (MODIS) daily reflectance Band 5 (1.230-1.250μm) and surface temperature images rescaled to 1km over western Greenland were used in the retrieval algorithm. An optical-thermal feature space partitioned as a function of melt magnitude was derived using a one-dimensional thermal snowmelt model (SNTHERM89). SNTHERM89 was forced by hourly meteorological data from the Greenland Climate Network (GC-Net) at reference sites spanning dry snow, percolation, and wet snow zones in the Jakobshavn drainage basin in western GIS. Melt magnitude or effective melt (E-melt) was derived for satellite composite periods covering May, June, and July displaying low fractions (0-1%) at elevations greater than 2500m and fractions at or greater than 15% at elevations lower than 1000m assessed for only the upper 5 cm of the snow surface. Validation of E-melt involved comparison of intensity to dry and wet zones determined from QSCAT backscatter. Higher intensities (> 8%) were distributed in wet snow zones, while lower intensities were grouped in dry zones at a first order accuracy of ~ ±2%.

Smoking as a Determinant of High Organochlorine Levels in Greenland

DEFF Research Database (Denmark)

Deutch, Bente; Pedersen, Henning Sloth; Bonefeld-Jørgensen, Eva Cecilie

2003-01-01

diet, and smoking or plasma cotinine in multiple linear-regression models (p smoking status. These findings confirm that the source of POPs among the Inuit in Greenland is diet, but smoking......The authors investigated the accumulation of organochlorines among smoking and nonsmoking Inuit hunters (n = 48) in Uummanaq, Greenland, a population with high dietary exposure to persistent organic pollutants (POPs). Human plasma organochlorine levels were positively correlated with age, marine...... is an important determinant of POP bioaccumulation. Smoking cessation may provide a means to lower the body burden of POPs....

Distribution and abundance of West Greenland humpback whales ( Megaptera novaeangliae )

DEFF Research Database (Denmark)

Larsen, Finn; Hammond, P.S.

2004-01-01

Photo-identification surveys of humpback whales Megaptera novaeangliae were conducted at West Greenland during 1988-93, the last 2 years of which were part of the internationally coordinated humpback whale research programme YoNAH, with the primary aim of estimating abundance for the West Greenland...... effort. A total of 670 groups of humpback whales was encountered leading to the identification of 348 individual animals. Three areas of concentration were identified: an area off Nuuk; an area at c. 63degrees30'N; and an area off Frederikshab. Sequential Petersen capture-recapture estimates of abundance...

Levels and trends of radioactive contaminants in the Greenland environment

DEFF Research Database (Denmark)

Dahlgaard, H.; Eriksson, M.; Nielsen, S.P.

2004-01-01

. The concentrations are expected to increase in the future, especially in East Greenland. The Bylot Sound at the Thule Airbase (Pituffik) in North-West Greenland was contaminated with plutonium and enriched uranium in a weapons accident in 1968. Biological activity has mixed accident plutonium efficiently...... into the new sediments resulting in continued high surface sediment concentrations three decades after the accident. Transfer of plutonium to benthic biota is low-and lower than observed in the Irish Sea. This is supposed to be caused by the physico-chemical form of the accident plutonium. A recent study...

Paleo-eskimo mtDNA genome reveals matrilineal discontinuity in Greenland

DEFF Research Database (Denmark)

Gilbert, Marcus Thomas Pius; Kivisild, Toomas; Grønnow, Bjarne

2008-01-01

a mitochondrial genome from a Paleo-Eskimo human by using 3400-to 4500-year-old frozen hair excavated from an early Greenlandic Saqqaq settlement. The sample is distinct from modern Native Americans and Neo-Eskimos, falling within haplogroup D2a1, a group previously observed among modern Aleuts and Siberian......The Paleo-Eskimo Saqqaq and Independence I cultures, documented from archaeological remains in Northern Canada and Greenland, represent the earliest human expansion into the New World's northern extremes. However, their origin and genetic relationship to later cultures are unknown. We sequenced...

Factors Controlling Methane in Arctic Lakes of Southwest Greenland.

Science.gov (United States)

Northington, Robert M; Saros, Jasmine E

2016-01-01

We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.

Assessment of consumption of marine food in Greenland by a food frequency questionnaire and biomarkers

DEFF Research Database (Denmark)

Jeppesen, Charlotte; Jørgensen, Marit Eika; Bjerregaard, Peter

2012-01-01

We studied the association and agreement between questionnaire data and biomarkers of marine food among Greenland Inuit.......We studied the association and agreement between questionnaire data and biomarkers of marine food among Greenland Inuit....

Distortions in Judged Spatial Relations.

Science.gov (United States)

Stevens, Albert

1978-01-01

Distortions in judgments of relative geographical relations were observed, particularly when the locations were in different geographical or political units. Subjects distorted the judged relation to conform with the relation of the superordinate political unit. A model for the hierachical storage of spatial information is presented. (Author/RD)

Waste management in Greenland: current situation and challenges

DEFF Research Database (Denmark)

Eisted, Rasmus; Christensen, Thomas Højlund

2011-01-01

Waste management in Greenland (56 000 inhabitants) is characterized by landfilling, incineration and export to Denmark of small quantities of metals and hazardous waste. The annual amount of waste is estimated to about 50 000 tons but actual data are scarce. Data on the waste composition is basic...... are small and equipped with only moderate flue gas cleaning technology. This report summarizes the current waste management situation in Greenland and identifies important challenges in improving the waste management....... is basically lacking. The scattered small towns and settlements, the climate and the long transport distances between towns and also to recycling industries abroad constitute a complex situation with respect to waste management. The landfills have no collection of gas and leachate and the incinerators...

Aeromechanics Analysis of a Distortion-Tolerant Fan with Boundary Layer Ingestion

Science.gov (United States)

Bakhle, Milind A.; Reddy, T. S. R.; Coroneos, Rula M.; Min, James B.; Provenza, Andrew J.; Duffy, Kirsten P.; Stefko, George L.; Heinlein, Gregory S.

2018-01-01

A propulsion system with Boundary Layer Ingestion (BLI) has the potential to significantly reduce aircraft engine fuel burn. But a critical challenge is to design a fan that can operate continuously with a persistent BLI distortion without aeromechanical failure -- flutter or high cycle fatigue due to forced response. High-fidelity computational aeromechanics analysis can be very valuable to support the design of a fan that has satisfactory aeromechanic characteristics and good aerodynamic performance and operability. Detailed aeromechanics analyses together with careful monitoring of the test article is necessary to avoid unexpected problems or failures during testing. In the present work, an aeromechanics analysis based on a three-dimensional, time-accurate, Reynolds-averaged Navier-Stokes computational fluid dynamics code is used to study the performance and aeromechanical characteristics of the fan in both circumferentially-uniform and circumferentially-varying distorted flows. Pre-test aeromechanics analyses are used to prepare for the wind tunnel test and comparisons are made with measured blade vibration data after the test. The analysis shows that the fan has low levels of aerodynamic damping at various operating conditions examined. In the test, the fan remained free of flutter except at one near-stall operating condition. Analysis could not be performed at this low mass flow rate operating condition since it fell beyond the limit of numerical stability of the analysis code. The measured resonant forced response at a specific low-response crossing indicated that the analysis under-predicted this response and work is in progress to understand possible sources of differences and to analyze other larger resonant responses. Follow-on work is also planned with a coupled inlet-fan aeromechanics analysis that will more accurately represent the interactions between the fan and BLI distortion.

Snow crab allergy and asthma among Greenlandic workers – a pilot study

Directory of Open Access Journals (Sweden)

Jakob Hjort Bønløkke

2012-08-01

Full Text Available Objectives. To study snow crab sensitization, occupational allergy and asthma in the snow crab industry in Greenland, as high rates have been found in Canada, but no reports have emerged from the same industry in Greenland. Study design. Pilot survey. Methods. Twenty workers (19 of Inuit and 1 of other origin in a snow crab (Chionoecetes opilio and Atlantic shrimp (Pandalus borealis processing plant in Greenland were assessed with skin prick tests (SPTs with common aeroallergens and specific allergens from snow crab and shrimp extracts, spirometry, blood sampling for total IgE and specific IgE determination. Eighteen workers contributed a questionnaire-based medical interview. Results. Positive skin prick test reactions were common to snow crab (40% and shrimp (20%. Specific IgE to snow crab were positive in 4 workers (21%. Two workers had elevated total IgE levels. Symptoms suggestive of asthma were common (45%. Work-related symptoms of skin rash, rhinitis, and/or conjunctivitis were reported by 50%, and symptoms from the lower airways by 39%. Combining history of work-related symptoms with results from specific SPTs and/or specific IgE determination suggested that 11 and 22% of workers suffered from probable and possible occupational asthma, respectively, whereas 22% had possible occupational dermatitis or rhinitis. Conclusions. Greenlander Inuit do not appear to be protected against sensitization to snow crab or shrimp when occupationally exposed to these. This pilot study suggests that occupational allergy and asthma may be as common a problem in Greenlandic workers as in Canadian.

Raised BMI cut-off for overweight in Greenland Inuit – a review

Science.gov (United States)

Andersen, Stig; Fleischer Rex, Karsten; Noahsen, Paneeraq; Sørensen, Hans Christian Florian; Mulvad, Gert; Laurberg, Peter

2013-01-01

Background Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. Objective This led us to reconsider the cut-off point for overweight among Inuit in Greenland. Design and findings We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Conclusion Defining overweight according to the WHO cut-off of a BMI above 25 kg/m2 in Greenland Inuit may overestimate the number of individuals with elevated BMI. PMID:23986904

Raised BMI cut-off for overweight in Greenland Inuit – a review

Directory of Open Access Journals (Sweden)

Stig Andersen

2013-08-01

Full Text Available Background. Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI, a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. Objective. This led us to reconsider the cut-off point for overweight among Inuit in Greenland. Design and findings. We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Conclusion. Defining overweight according to the WHO cut-off of a BMI above 25 kg/m2 in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Ventilation of the deep Greenland and Norwegian seas: evidence from krypton-85, tritium, carbon-14 and argon-39

International Nuclear Information System (INIS)

Smethie, W.M. Jr.; Ostlund, H.G.; Loosli, H.H.

1986-01-01

On leg 5 of the TTO expedition, the distributions of 85 Kr, tritium, 14 C, 39 Ar, temperature, salinity, oxygen, carbon dioxide and nutrients were measured in the Greenland and Norwegian seas. These observations support previous observations that Greenland Sea Deep Water is formed by a deep convective process within the Greenland gyre. They also support AAGAARD et al.'s (1985, Journal of Geophysical Research, 90, 4833-4846) new hypothesis that Norwegian Sea Deep Water forms from a mixture of Greenland Sea Deep Water and Eurasian Basin Deep Water. Volume transports estimated from the distributions of 85 Kr, tritium, 14 C and 39 Ar range from 0.53 to 0.74 Sv for exchange between the surface and deep Greenland Sea and from 0.9 to 1.47 Sv for exchange between the deep Greenland and deep Norwegian Seas. The residence time of water and the deep Greenland Sea with respect to exchange with surface water ranges from 24 to 34 years reported by PETERSON and ROOTH (1976, Deep-Sea Research, 23, 273-283) and 35-42 years reported by BULLISTER and WEISS (1983, Science, 221, 265-268). The residence time of water in the deep Norwegian Sea with respect to exchange with the deep Greenland Sea ranges from 19 to 30 years compared to 97-107 years reported by PETERSON and ROOTH (1976) and 10-28 years reported by BULLISTER and WEISS (1983). The oxygen consumption rate was estimated to be at most 1.04 μM kg -1 y -1 for the deep Greenland Sea and to be between 0.47 and 0.79 μM kg -1 y -1 for the deep Norwegian Sea. (author)

Probability based hydrologic catchments of the Greenland Ice Sheet

Science.gov (United States)

Hudson, B. D.

2015-12-01

Greenland Ice Sheet melt water impacts ice sheet flow dynamics, fjord and coastal circulation, and sediment and biogeochemical fluxes. Melt water exiting the ice sheet also is a key term in its mass balance. Because of this, knowledge of the area of the ice sheet that contributes melt water to a given outlet (its hydrologic catchment) is important to many ice sheet studies and is especially critical to methods using river runoff to assess ice sheet mass balance. Yet uncertainty in delineating ice sheet hydrologic catchments is a problem that is rarely acknowledged. Ice sheet catchments are delineated as a function of both basal and surface topography. While surface topography is well known, basal topography is less certain because it is dependent on radar surveys. Here, I a present a Monte Carlo based approach to delineating ice sheet catchments that quantifies the impact of uncertain basal topography. In this scheme, over many iterations I randomly vary the ice sheet bed elevation within published error bounds (using Morlighem et al., 2014 bed and bed error datasets). For each iteration of ice sheet bed elevation, I calculate the hydraulic potentiometric surface and route water over its path of 'steepest' descent to delineate the catchment. I then use all realizations of the catchment to arrive at a probability map of all major melt water outlets in Greenland. I often find that catchment size is uncertain, with small, random perturbations in basal topography leading to large variations in catchments size. While some catchments are well defined, others can double or halve in size within published basal topography error bars. While some uncertainty will likely always remain, this work points to locations where studies of ice sheet hydrology would be the most successful, allows reinterpretation of past results, and points to where future radar surveys would be most advantageous.

Flow tilt angles near forest edges - Part 1: Sonic anemometry

DEFF Research Database (Denmark)

Dellwik, Ebba; Mann, Jakob; Larsen, Klaus Steenberg

2010-01-01

distortion and vertical alignment, it was only possible to a limited extent to relate sonic anemometer flow tilt angles to upwind forest edges, but the results by the lidar indicated that an internal boundary layer affect flow tilt angles at 21m above the forest. This is in accordance with earlier studies......-flow angles were assumed for neutral flow, the data was interpreted in relation to upstream and downstream forest edges. Uncertainties caused by flow distortion, vertical misalignment and limited sampling time (statistical uncertainty) were evaluated and found to be highly significant. Since the attack angle...... balance, unless all terms in the carbon dioxide conservation equation can be precisely estimated....

A long-term increase in eggshell thickness of Greenlandic Peregrine Falcons Falco peregrinus tundrius

DEFF Research Database (Denmark)

Falk, Knud; Møller, Søren; Matox, William G.

2006-01-01

Thickness of eggshell fragments and whole eggs from the Peregrine Falcon Falco peregrinus collected in South and West Greenland between 1972 and 2003 was measured and compared to shell thickness of pre-DDT eggs, also collected in Greenland. Linear regression yields a significant increase...

Greenland Ice Sheet Monitoring Network (GLISN): Contributions to Science and Society

Science.gov (United States)

Anderson, K. R.; Bonaime, S.; Clinton, J. F.; Dahl-Jensen, T.; Debski, W. M.; Giardini, D.; Govoni, A.; Kanao, M.; Larsen, T. B.; Lasocki, S.; Lee, W. S.; McCormack, D. A.; Mykkeltveit, S.; Nettles, M.; Stutzmann, E.; Strollo, A.; Sweet, J. R.; Tsuboi, S.; Vallee, M.

2017-12-01

The Greenland Ice Sheet Monitoring Network (GLISN) is a broadband, multi-use seismological network, enhanced by selected geodetic observations, designed with the capability to allow researchers to understand the changes currently occurring in the Arctic, and with the operational characteristics necessary to enable response to those changes as understanding improves. GLISN was established through an international collaboration, with 10 nations coordinating their efforts to develop the current 34-station observing network during the last eight years. All of the data collected are freely and openly available in near-real time. The network was designed to transform the community capability for recording, analysis, and interpretation of seismic signals generated by discrete events in Greenland and the Arctic, as well as those traversing the region. Data from the network support a wide range of uses, including estimation of the properties of the solid Earth that control isostatic adjustment rates and set key boundary conditions for ice-sheet evolution; analysis of tectonic earthquakes throughout Greenland and the Arctic; study of the seismic signals associated with large calving events and changing glacier dynamics; and variations in ice and snow properties within the Greenland Ice Sheet. Recordings from the network have also provided invaluable data for rapid evaluation and understanding of the devastating landslide and tsunami that occurred near Nuugaatsiaq, Greenland, in June, 2017. The GLISN strategy of maximizing data quality from a network of approximately evenly distributed stations, delivering data in near-real time, and archiving a continuous data stream easily accessible to researchers, allows continuous discovery of new uses while also facilitating the generation of data products, such as catalogs of tectonic and glacial earthquakes and GPS-based estimates of snow height, that allow for assessment of change over time.

Spatial gradients of temperature, accumulation and δ18O-ice in Greenland over a series of Dansgaard–Oeschger events

Directory of Open Access Journals (Sweden)

M. Guillevic

2013-05-01

Full Text Available Air and water stable isotope measurements from four Greenland deep ice cores (GRIP, GISP2, NGRIP and NEEM are investigated over a series of Dansgaard–Oeschger events (DO 8, 9 and 10, which are representative of glacial millennial scale variability. Combined with firn modeling, air isotope data allow us to quantify abrupt temperature increases for each drill site (1σ = 0.6 °C for NEEM, GRIP and GISP2, 1.5 °C for NGRIP. Our data show that the magnitude of stadial–interstadial temperature increase is up to 2 °C larger in central and North Greenland than in northwest Greenland: i.e., for DO 8, a magnitude of +8.8 °C is inferred, which is significantly smaller than the +11.1 °C inferred at GISP2. The same spatial pattern is seen for accumulation increases. This pattern is coherent with climate simulations in response to reduced sea-ice extent in the Nordic seas. The temporal water isotope (δ18O–temperature relationship varies between 0.3 and 0.6 (±0.08 ‰ °C−1 and is systematically larger at NEEM, possibly due to limited changes in precipitation seasonality compared to GISP2, GRIP or NGRIP. The gas age−ice age difference of warming events represented in water and air isotopes can only be modeled when assuming a 26% (NGRIP to 40% (GRIP lower accumulation than that derived from a Dansgaard–Johnsen ice flow model.

Younger Dryas cooling and the Greenland climate response to CO2.

Science.gov (United States)

Liu, Zhengyu; Carlson, Anders E; He, Feng; Brady, Esther C; Otto-Bliesner, Bette L; Briegleb, Bruce P; Wehrenberg, Mark; Clark, Peter U; Wu, Shu; Cheng, Jun; Zhang, Jiaxu; Noone, David; Zhu, Jiang

2012-07-10

Greenland ice-core δ(18)O-temperature reconstructions suggest a dramatic cooling during the Younger Dryas (YD; 12.9-11.7 ka), with temperatures being as cold as the earlier Oldest Dryas (OD; 18.0-14.6 ka) despite an approximately 50 ppm rise in atmospheric CO(2). Such YD cooling implies a muted Greenland climate response to atmospheric CO(2), contrary to physical predictions of an enhanced high-latitude response to future increases in CO(2). Here we show that North Atlantic sea surface temperature reconstructions as well as transient climate model simulations suggest that the YD over Greenland should be substantially warmer than the OD by approximately 5 °C in response to increased atmospheric CO(2). Additional experiments with an isotope-enabled model suggest that the apparent YD temperature reconstruction derived from the ice-core δ(18)O record is likely an artifact of an altered temperature-δ(18)O relationship due to changing deglacial atmospheric circulation. Our results thus suggest that Greenland climate was warmer during the YD relative to the OD in response to rising atmospheric CO(2), consistent with sea surface temperature reconstructions and physical predictions, and has a sensitivity approximately twice that found in climate models for current climate due to an enhanced albedo feedback during the last deglaciation.

The East Greenland rifted volcanic margin

Directory of Open Access Journals (Sweden)

C. Kent Brooks

2011-12-01

Full Text Available The Palaeogene North Atlantic Igneous Province is among the largest igneous provinces in the world and this review of the East Greenland sector includes large amounts of information amassed since previous reviews around 1990.The main area of igneous rocks extends from Kangerlussuaq (c. 67°N to Scoresby Sund (c. 70°N, where basalts extend over c. 65 000 km2, with a second area from Hold with Hope (c. 73°N to Shannon (c. 75°N. In addition, the Ocean Drilling Project penetrated basalt at five sites off South-East Greenland. Up to 7 km thickness of basaltic lavas have been stratigraphically and chemically described and their ages determined. A wide spectrum of intrusions are clustered around Kangerlussuaq, Kialeeq (c. 66°N and Mesters Vig (c. 72°N. Layered gabbros are numerous (e.g. the Skaergaard and Kap Edvard Holm intrusions, as are under- and oversaturated syenites, besides small amounts of nephelinite-derived products, such as the Gardiner complex (c. 69°N with carbonatites and silicate rocks rich in melilite, perovskite etc. Felsic extrusive rocks are sparse. A single, sanidine-bearing tuff found over an extensive area of the North Atlantic is thought to be sourced from the Gardiner complex.The province is famous for its coast-parallel dyke swarm, analogous to the sheeted dyke swarm of ophiolites, its associated coastal flexure, and many other dyke swarms, commonly related to central intrusive complexes as in Iceland. The dyke swarms provide time markers, tracers of magmatic evolution and evidence of extensional events. A set of dykes with harzburgite nodules gives unique insight into the Archaean subcontinental lithosphere.Radiometric dating indicates extrusion of huge volumes of basalt over a short time interval, but the overall life of the province was prolonged, beginning with basaltic magmas at c. 60 Ma and continuing to the quartz porphyry stock at Malmbjerg (c. 72°N at c. 26 Ma. Indeed, activity was renewed in the Miocene with

Rapid dynamic thinning events during 1985-2010 on Upernavik Isstrøm, West Greenland

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Kjær, Kurt H.; Korsgaard, Niels Jákup

Many glaciers along the southeast and northwest coast of Greenland have accelerated, increasing the ice sheet's contribution to global sea-level rise. Here, we map elevation changes on Upernavik Isstrøm (UI), West Greenland, during 2003-2009 using high-resolution Ice, Cloud and land Elevation...

Physical Activity and Abdominal Fat Distribution in Greenland.

Science.gov (United States)

Dahl-Petersen, Inger Katrine; Brage, Søren; Bjerregaard, Peter; Tolstrup, Janne Schurmann; Jørgensen, Marit Eika

2017-10-01

We examined how total volume of physical activity and reallocation of time spent at various objectively measured intensities of physical activity (PA) were associated with overall and abdominal fat distribution in adult Inuit in Greenland. Data were collected as part of a countrywide cross-sectional health survey in Greenland. A combined accelerometer and HR monitor measured total physical activity energy expenditure (PAEE) and intensities of PA (N = 1536). Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by ultrasonography. Isotemporal substitution modeling was used to analyze the association between substitution of 1 h of sedentary time to light- or moderate-intensity PA and 1 h light-intensity PA to moderate- or vigorous-intensity PA in relation to body mass index (BMI), waist circumference (WC), SAT, and VAT. A negative linear association was found for total PAEE and BMI, WC, VAT, and SAT. Exchanging 1 h of sedentary time with light-intensity PA was associated with lower WC (-0.6 cm, P = 0.01), SAT (-0.08 cm, P abdominal fat distribution. Physical activity energy expenditure is associated with lower BMI, WC, and abdominal fat among Greenland Inuit. The importance of promoting an upward shift of the whole PA intensity distribution and to spur even short bouts of MVPA to limit excessive accumulation of SAT and VAT is highlighted.

Age determination of Precambrian rocks from Greenland: past and present

International Nuclear Information System (INIS)

Karlsbeek, F.

1997-01-01

For Precambrian rocks as well as for younger igneous intrusions, precise ages can only be obtained by isotopic analysis of minerals or rocks. Isotopic (radiometric) age determination of Greenland rocks began in the early 1960s and has continued since with gradually improving methods. In this contribution, the development of geochronological knowledge of the Precambrian of Greenland is described in historical perspective, and an outline of new results is given. The history of geochronology can be roughly divided into three periods: 1) a period of single-sample K-Ar and Rb-Sr mineral or whole-rock age determinations; 2) a time when most ages were determined with the help of Rb-Sr and Pb-Pb whole-rock isochrones and multi-grain zircon U-Pb isotope data; 3) the present, where 'single' zircon U-Pb data are the preferred method to obtain rock ages. These stages in the development of radiometric dating methods partly overlap in time, and each has yielded very significant contributions to the knowledge of Precambiran evolution in Greenland. (EG)

Vulnerability of Southeast Greenland Glaciers to Warm Atlantic Water From Operation IceBridge and Ocean Melting Greenland Data

Science.gov (United States)

Millan, R.; Rignot, E.; Mouginot, J.; Wood, M.; Bjørk, A. A.; Morlighem, M.

2018-03-01

We employ National Aeronautics and Space Administration (NASA)'s Operation IceBridge high-resolution airborne gravity from 2016, NASA's Ocean Melting Greenland bathymetry from 2015, ice thickness from Operation IceBridge from 2010 to 2015, and BedMachine v3 to analyze 20 major southeast Greenland glaciers. The results reveal glacial fjords several hundreds of meters deeper than previously thought; the full extent of the marine-based portions of the glaciers; deep troughs enabling warm, salty Atlantic Water (AW) to reach the glacier fronts and melt them from below; and few shallow sills that limit the access of AW. The new oceanographic and topographic data help to fully resolve the complex pattern of historical ice front positions from the 1930s to 2017: glaciers exposed to AW and resting on retrograde beds have retreated rapidly, while glaciers perched on shallow sills or standing in colder waters or with major sills in the fjords have remained stable.

Suicides in the midnight sun--a study of seasonality in suicides in West Greenland

DEFF Research Database (Denmark)

Björkstén, Karin Sparring; Bjerregaard, Peter; Kripke, Daniel F

2005-01-01

high rates in most age groups, up to 577 per 100,000 person-years in men aged 15-24 years in 1990, and up to 147 per 100,000 person-years in women aged 15-24 years in 1995. Violent methods of suicide were used by 93%. Depression has been reported uncommonly. High alcohol intake and extended periods......Greenland is the most extreme of human habitats in regard to annual changes in natural light. From being very low, the rate of suicides in Greenland has increased during the past few decades to be among the highest in the world. Several studies have shown seasonality in suicides with spring...... or summer peaks, but this has not been previously shown in Greenland. Official data from 1968 to 1995 from West Greenland were pooled. A significant seasonality in the 833 suicides was found using Rayleigh's test, a peak in June and a trough in the winter. Suicides increased during the period, and reached...

Mitigation of Grid-Current Distortion for LCL-Filtered Voltage-Source Inverter with Inverter-Current Feedback Control

DEFF Research Database (Denmark)

Xin, Zhen; Mattavelli, Paolo; Yao, WenLi

2018-01-01

harmonics can freely flow into the filter capacitor. In this case, because of the loss of harmonic information, traditional harmonic controllers fail to mitigate the grid current distortion. Although this problem may be avoided using the grid voltage feedforward scheme, the required differentiators may...

Zooplankton data: Vertical distributions of zooplankton in the Norweigian and Greenland Seas during summer, 1989

Energy Technology Data Exchange (ETDEWEB)

Lane, P.V.Z.; Smith, S.L.; Schwarting, E.M.

1993-08-01

Recent studies of zooplankton populations in the Greenland Sea have focused on processes at the Marginal Ice Zone (MIZ) and the areas immediately adjacent to it under the ice and in open water. These studies have shown a relatively short period of intense secondary productivity which is closely linked temporally and spatially to phytoplankton blooms occurring near the ice edge in spring and early summer. During the summer of 1989 we participated in a project focusing on benthic and water column processes in the basins of the Norwegian and Greenland Seas. This study allowed us to compare biological processes at the MIZ with those occurring in the open waters of the Greenland Sea, and to compare processes at both of these locations with those in the Norwegian Sea. The data presented in this report are the results of zooplankton net tows covering the upper 1000 meters of the water column over the Norwegian Sea basin and the Greenland Sea basin, and the upper 500 meters of open water adjacent to the MIZ in the Greenland Sea. Sampling was conducted between 12 and 29 July 1989.

Ecosystem vulnerability to climate change in Greenland and the Faroe Islands

Energy Technology Data Exchange (ETDEWEB)

Heide-Joergensen, H S; Johnsen, I [Koebenhavns Univ., Botanisk Inst., Oekologisk afd. (Denmark)

1998-12-31

An increase in the mean yearly temperature up to 3.6 deg. C may occur in North-Greenland by the end of the 21st century, while in south-Greenland temperature may remain stable or fall slightly. Consequences of this climate change for species diversity and the structure of terrestrial and marine ecosystems are discussed. For the Faroe Islands climate change is not expected to cause notable changes in terrestrial ecosystems, but in marine ecosystems changes are highly unpredictable. (au)

Ecosystem vulnerability to climate change in Greenland and the Faroe Islands

International Nuclear Information System (INIS)

Heide-Joergensen, H.S.; Johnsen, I.

1997-01-01

An increase in the mean yearly temperature up to 3.6 deg. C may occur in North-Greenland by the end of the 21st century, while in south-Greenland temperature may remain stable or fall slightly. Consequences of this climate change for species diversity and the structure of terrestrial and marine ecosystems are discussed. For the Faroe Islands climate change is not expected to cause notable changes in terrestrial ecosystems, but in marine ecosystems changes are highly unpredictable. (au)

Ecosystem vulnerability to climate change in Greenland and the Faroe Islands

Energy Technology Data Exchange (ETDEWEB)

Heide-Joergensen, H.S.; Johnsen, I. [Koebenhavns Univ., Botanisk Inst., Oekologisk afd. (Denmark)

1997-12-31

An increase in the mean yearly temperature up to 3.6 deg. C may occur in North-Greenland by the end of the 21st century, while in south-Greenland temperature may remain stable or fall slightly. Consequences of this climate change for species diversity and the structure of terrestrial and marine ecosystems are discussed. For the Faroe Islands climate change is not expected to cause notable changes in terrestrial ecosystems, but in marine ecosystems changes are highly unpredictable. (au)

Coral by-catch in shrimp bottom trawl surveys in West Greenland waters (2010 – 2012)

DEFF Research Database (Denmark)

Jørgensbye, Helle; Arboe, Nanette Hammeken

There have been zoological expeditions in Greenland waters since the 19th century documenting the sea life, including cold water corals. Coral trees (vernacular name for Paragorgia arborea) are mentioned as early as 1741 in the first natural history book about Greenland (Egede 1741). Due to the m......There have been zoological expeditions in Greenland waters since the 19th century documenting the sea life, including cold water corals. Coral trees (vernacular name for Paragorgia arborea) are mentioned as early as 1741 in the first natural history book about Greenland (Egede 1741). Due....... The identification of the corals is based on Kenchington et al. (2009). The identification of many specimens has further been verified by Ole Tendal (Zoological Museum, Copenhagen) on the basis of frozen samples. Few corals, mainly soft corals (Alcyonacea) and sea pens (Pennatulacea), were found in the depth range...

ASTER GDEM validation using LiDAR data over coastal regions of Greenland

DEFF Research Database (Denmark)

Hvidegaard, Sine Munk; Sørensen, Louise Sandberg; Forsberg, René

2011-01-01

Elevation data from airborne Light Detection and Ranging (LiDAR) campaigns are used in an attempt to evaluate the accuracy of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) global digital elevation model (GDEM) in Greenland. The LiDAR elevation data set is characterized...... of Greenland and the effect of the number of scenes used to generate the ASTER GDEM as well as relief are associated with the GDEM accuracy....

Setting the scene in Nuuk: Introducing the cast of characters in Greenlandic foreign policy narratives

DEFF Research Database (Denmark)

Jacobsen, Marc; Gad, Ulrik Pram

2017-01-01

Greenland has for decades worked towards enhanced independent agency in international politics. The renewed global interest in the Arctic has given new impetus to a strategy of diversifying its dependency relations as a way to postcoloniality. As the Government of Greenland puts it in its foreign...... - and infrequently clashes - with narratives of modernization in different ways when Greenland relates to Inuit kinsmen, Nordic siblings, the UN, the USA, the EU and Asian powers; the presentation of each character put in historical perspective. Theoretically, the analysis draws on a tradition of analysing...

Does Greenland need a guideline on how to deal with moisture in the construction phase?

DEFF Research Database (Denmark)

Hansen, Ernst Jan de Place

2012-01-01

. As the requirements concerning moisture control are function-based, the construction client and the authorities are entrusted with interpreting requirements in a specific case, which caused the introduction of a guideline based on humidity risk classes. This paper presents the Danish requirements and guideline...... and gives examples of moisture-related problems in buildings in Greenland. Requirements and guidelines are needed in Greenland in order to deal with moisture in the construction phase, but as the conditions for constructing houses and the way that houses are used in Greenland are different from Denmark...

Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

Directory of Open Access Journals (Sweden)

Dennis Hanke

2016-07-01

Full Text Available There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV lineage (arctic-3, but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4 with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population

Digital elevation model and orthophotographs of Greenland based on aerial photographs from 1978-1987

DEFF Research Database (Denmark)

Korsgaard, Niels J.; Nuth, Christopher; Khan, Shfaqat Abbas

2016-01-01

in general. We present a historical medium-resolution DEM and orthophotographs that consistently cover the entire surroundings and margins of the Greenland Ice Sheet 1978-1987. About 3,500 aerial photographs of Greenland are combined with field surveyed geodetic ground control to produce a 25 m gridded DEM...

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit.

Science.gov (United States)

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva C

2012-03-19

Perfluoroalkyl acids (PFAAs) have been detected in human blood, breast milk and umbilical cord blood across the globe. PFAAs do accumulate in the marine food chain in Arctic regions. In Greenland, increasing PFAA concentrations were observed during 1982-2006 in ringed seals and polar bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Cross-section and temporal time trend survey. Serum PFAA levels were determined in 284 Inuit from different Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 1998-2005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Serum PFAA levels were higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 1998-2005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs and legacy POPs was observed for Nuuk Inuit while for non-Nuuk Inuit this correlation was significant. No correlation between PFAAs and legacy POPs was found for male Inuit, whereas significant correlation was observed both for pooled female Inuit and for non-Nuuk Inuit females. We suggest that sources other than seafood intake might contribute to the observed higher PFAA levels in Nuuk Inuit compared to the pooled non-Nuuk Inuit.

The Distribution of Basal Water Beneath the Greenland Ice Sheet from Radio-Echo Sounding

Science.gov (United States)

Jordan, T.; Williams, C.; Schroeder, D. M.; Martos, Y. M.; Cooper, M.; Siegert, M. J.; Paden, J. D.; Huybrechts, P.; Bamber, J. L.

2017-12-01

There is widespread, but often indirect, evidence that a significant fraction of the Greenland Ice Sheet is thawed at the bed. This includes major outlet glaciers and around the NorthGRIP ice-core in the interior. However, the ice-sheet-wide distribution of basal water is poorly constrained by existing observations, and the spatial relationship between basal water and other ice-sheet and subglacial properties is therefore largely unexplored. In principle, airborne radio-echo sounding (RES) surveys provide the necessary information and spatial coverage to infer the presence of basal water at the ice-sheet scale. However, due to uncertainty and spatial variation in radar signal attenuation, the commonly used water diagnostic, bed-echo reflectivity, is highly ambiguous and prone to spatial bias. Here we introduce a new RES diagnostic for the presence of basal water which incorporates both sharp step-transitions and rapid fluctuations in bed-echo reflectivity. This has the advantage of being (near) independent of attenuation model, and enables a decade of recent Operation Ice Bride RES survey data to be combined in a single map for basal water. The ice-sheet-wide water predictions are compared with: bed topography and drainage network structure, existing knowledge of the thermal state and geothermal heat flux, and ice velocity. In addition to the fast flowing ice-sheet margins, we also demonstrate widespread water routing and storage in parts of the slow-flowing northern interior. Notably, this includes a quasi-linear `corridor' of basal water, extending from NorthGRIP to Petermann glacier, which spatially correlates with a region of locally high (magnetic-derived) geothermal heat flux. The predicted water distribution places a new constraint upon the basal thermal state of the Greenland Ice Sheet, and could be used as an input for ice-sheet model simulations.

Distortional Modes of Thin-Walled Beams

DEFF Research Database (Denmark)

Jönsson, Jeppe; Andreassen, Michael Joachim

2009-01-01

The classic thin-walled beam theory for open and closed cross-sections can be generalized by including distortional displacement modes. The introduction of additional displacement modes leads to coupled differential equations, which seems to have prohibited the use of exact shape functions...... in the modelling of coupled torsion and distortion. However, if the distortional displacement modes are chosen as those which decouple the differential equations as in non proportionally damped modal dynamic analysis then it may be possible to use exact shape functions and perform analysis on a reduced problem....... In the recently developed generalized beam theory (GBT) the natural distortional displacement modes are determined on the basis of a quadratic eigenvalue problem. However, as in linear modal dynamic analysis of proportionally damped structures this problem has been solved approximately using linear eigenvalue...

Remediation of Oil-Contaminated Soil in Greenland

DEFF Research Database (Denmark)

Fritt-Rasmussen, Janne; Jensen, Pernille Erland

2013-01-01

This paper present the recent research conducted at the Arctic Technology Centre, where different solutions for remediation of excavated oil contaminated soil in Greenlandic towns were tested. In the first work, soil polluted by light oil was treated with two different nutrient sources (substrate...

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...

A fossil subduction zone in the East Greenland Caledonides revealed by a Receiver Function analysis

DEFF Research Database (Denmark)

Schiffer, Christian; Jacobsen, B. H.; Balling, N.

Subsequent to their formation the East Greenland and Scandinavian Caledonides formed a major coherent mountain range. The understanding of the European Caledonides therefore naturally involves also the East Greenland Caledonides. The present-day topography and crustal and upper mantle structure i...

Greenlandic postcoloniality and the predicament of prosperity inducing climate change

DEFF Research Database (Denmark)

Jensen, Lars

Greenland’s independence from its former colonial power, Denmark. In Denmark there has been an equally intense debate, which unsurprisingly is of a very different nature. Part of the debate here has been over, whether Greenland has indeed the right to decide over its resources, something agreed...... to in the agreement laying the foundation for Greenland’s self-government (2009), another part has been whether Denmark should allow Chinese workers, not working under Danish conditions, to immigrate to Greenland – an area where Denmark can still exercise its sovereignty. And there are, of course, several other...

Greenland Ice sheet mass balance from satellite and airborne altimetry

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Bevis, M. G.; Wahr, J. M.

Ice loss from the Greenland Ice Sheet (GrIS) is dominated by loss in the marginal areas. Dynamic induced ice loss and its associated ice surface lowering is often largest close to the glacier calving front and may vary from rates of tens of meters per years to a few meters per year over relatively...... short distances. Hence, high spatial resolution data are required to accurately estimate volume changes. Here, we estimate ice volume change rate of the Greenland ice sheet using data from Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter during 2003-2009 and CryoSat-2 data during 2010...

GREENLAND ICE SHEET CHANGES FROM SPACE USING LASER, RADAR AND

DEFF Research Database (Denmark)

Sørensen, Louise Sandberg; Stenseng, Lars; Simonsen, Sebastian Bjerregaard

2010-01-01

The Greenland cryosphere is undergoing rapid changes, and these are documented by remote sensing from space. In this paper, an inversion scheme is used to derive mass changes from gravity changes observed by GRACE, and to derive the mean annual mass loss for the Greenland Ice Sheet, which...... is estimated to be 204 Gt/yr for the period 2002-2010. NASA’s laser altimetry satellite ICESat has provided elevation estimates of the ice sheet since January 2003. In order to be able to compare GRACE and ICESat derived results, the ICESat volume change must be converted into a mass change estimate. Therefore...

Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

Science.gov (United States)

Møller, Lone Nukâraq; Petersen, Eskild; Kapel, Christian M O; Melbye, Mads; Koch, Anders

2005-09-05

The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

Adverse metabolic risk profiles in Greenlandic Inuit children compared to Danish children.

Science.gov (United States)

Munch-Andersen, T; Sorensen, K; Andersen, L B; Aachmann-Andersen, N J; Aksglaede, L; Juul, A; Helge, J W

2013-06-01

During recent decades, the prevalence of metabolic morbidity has increased rapidly in adult Greenlandic Inuit. To what extent this is also reflected in the juvenile Inuit population is unknown. The objective was, therefore, in the comparison with Danish children, to evaluate metabolic profiles in Greenlandic Inuit children from the capital in the southern and from the northern most villages 187 Inuit and 132 Danish children were examined with anthropometrics, pubertal staging, fasting blood samples, and a maximal aerobic test. Both Inuit children living in Nuuk and the northern villages had significantly higher glucose, total cholesterol, apolipoprotein A1 levels, and diastolic blood pressure compared with Danish children after adjustment for differences in adiposity and aerobic fitness levels. The Inuit children living in Nuuk had significantly higher BMI, body fat %, HbA1 c, and significantly lower aerobic fitness and ApoA1 levels than northern living Inuit children. Greenlandic Inuit children had adverse metabolic health profile compared to the Danish children, the differences where more pronounced in Inuit children living in Nuuk. The tendencies toward higher prevalence of diabetes and metabolic morbidity in the adult Greenlandic Inuit population may also be present in the Inuit children population. Copyright © 2013 The Obesity Society.

Detection of chromatic and luminance distortions in natural scenes.

Science.gov (United States)

Jennings, Ben J; Wang, Karen; Menzies, Samantha; Kingdom, Frederick A A

2015-09-01

A number of studies have measured visual thresholds for detecting spatial distortions applied to images of natural scenes. In one study, Bex [J. Vis.10(2), 1 (2010)10.1167/10.2.231534-7362] measured sensitivity to sinusoidal spatial modulations of image scale. Here, we measure sensitivity to sinusoidal scale distortions applied to the chromatic, luminance, or both layers of natural scene images. We first established that sensitivity does not depend on whether the undistorted comparison image was of the same or of a different scene. Next, we found that, when the luminance but not chromatic layer was distorted, performance was the same regardless of whether the chromatic layer was present, absent, or phase-scrambled; in other words, the chromatic layer, in whatever form, did not affect sensitivity to the luminance layer distortion. However, when the chromatic layer was distorted, sensitivity was higher when the luminance layer was intact compared to when absent or phase-scrambled. These detection threshold results complement the appearance of periodic distortions of the image scale: when the luminance layer is distorted visibly, the scene appears distorted, but when the chromatic layer is distorted visibly, there is little apparent scene distortion. We conclude that (a) observers have a built-in sense of how a normal image of a natural scene should appear, and (b) the detection of distortion in, as well as the apparent distortion of, natural scene images is mediated predominantly by the luminance layer and not chromatic layer.

Prediction of transmission distortion for wireless video communication: analysis.

Science.gov (United States)

Chen, Zhifeng; Wu, Dapeng

2012-03-01

Transmitting video over wireless is a challenging problem since video may be seriously distorted due to packet errors caused by wireless channels. The capability of predicting transmission distortion (i.e., video distortion caused by packet errors) can assist in designing video encoding and transmission schemes that achieve maximum video quality or minimum end-to-end video distortion. This paper is aimed at deriving formulas for predicting transmission distortion. The contribution of this paper is twofold. First, we identify the governing law that describes how the transmission distortion process evolves over time and analytically derive the transmission distortion formula as a closed-form function of video frame statistics, channel error statistics, and system parameters. Second, we identify, for the first time, two important properties of transmission distortion. The first property is that the clipping noise, which is produced by nonlinear clipping, causes decay of propagated error. The second property is that the correlation between motion-vector concealment error and propagated error is negative and has dominant impact on transmission distortion, compared with other correlations. Due to these two properties and elegant error/distortion decomposition, our formula provides not only more accurate prediction but also lower complexity than the existing methods.

Ultrasonographic Findings of Mammographic Architectural Distortion

International Nuclear Information System (INIS)

Ma, Jeong Hyun; Kang, Bong Joo; Cha, Eun Suk; Hwangbo, Seol; Kim, Hyeon Sook; Park, Chang Suk; Kim, Sung Hun; Choi, Jae Jeong; Chung, Yong An

2008-01-01

To review the sonographic findings of various diseases showing architectural distortion depicted under mammography. We collected and reviewed architectural distortions observed under mammography at our health institution between 1 March 2004, and 28 February 2007. We collected 23 cases of sonographically-detected mammographic architectural distortions that confirmed lesions after surgical resection. The sonographic findings of mammographic architectural distortion were analyzed by use of the BI-RADS lexicon for shape, margin, lesion boundary, echo pattern, posterior acoustic feature and orientation. There were variable diseases that showed architectural distortion depicted under mammography. Fibrocystic disease was the most common presentation (n = 6), followed by adenosis (n = 2), stromal fibrosis (n = 2), radial scar (n = 3), usual ductal hyperplasia (n = 1), atypical ductal hyperplasia (n = 1) and mild fibrosis with microcalcification (n = 1). Malignant lesions such as ductal carcinoma in situ (DCIS) (n = 2), lobular carcinoma in situ (LCIS) (n = 2), invasive ductal carcinoma (n = 2) and invasive lobular carcinoma (n = 1) were observed. As observed by sonography, shape was divided as irregular (n = 22) and round (n = 1). Margin was divided as circumscribed (n = 1), indistinct (n = 7), angular (n = 1), microlobulated (n = 1) and sipculated (n = 13). Lesion boundary was divided as abrupt interface (n = 11) and echogenic halo (n = 12). Echo pattern was divided as hypoechoic (n = 20), anechoic (n = 1), hyperechoic (n = 1) and isoechoic (n = 1). Posterior acoustic feature was divided as posterior acoustic feature (n = 7), posterior acoustic shadow (n = 15) and complex posterior acoustic feature (n = 1). Orientation was divided as parallel (n = 12) and not parallel (n = 11). There were no differential sonographic findings between benign and malignant lesions. This study presented various sonographic findings of mammographic architectural distortion and that it is

Human exposure to contaminants in the traditional Greenland diet

International Nuclear Information System (INIS)

Johansen, Poul; Muir, Derek; Asmund, Gert; Riget, Frank

2004-01-01

The traditional diet is a significant source of contaminants to people in Greenland, although contaminant levels vary widely among species and tissue from very low in many to very high in a few. Our study has included cadmium, mercury, selenium, polychlorinated biphenyls (PCB), dichlorophenyltrichloroethane (DDT), chlordane, hexachlorocyclohexanes (HCH), chlorobenzenes, dieldrin and toxaphene in the major species and tissues consumed by Greenlanders. In general, the levels of these are very low in terrestrial species and in muscle of many marine species. High organochlorines concentrations are typically found in blubber of marine mammals and high metal levels in liver and kidney of seals and whales. In this study, the mean intakes of cadmium, chlordanes and toxaphene significantly exceed 'acceptable/tolerable intakes' (ADI/TDI) by a factor between 2.5 and 6. Mean intakes of mercury, PCB and dieldrin also exceed ADI/TDI by up to approximately 50%. However as these figures are mean intakes and as variation in both food intake and contaminant levels is large, the variation of contaminant intake among individuals is also large, and some individuals will be exposed to significantly higher intakes. The mean intakes of DDT, HCH and chlorobenzenes are well below the ADI/TDI values, and it seems unlikely that the TDI for these contaminants normally is exceeded in the Greenland population. The evaluation of contaminant intake in this study points to seal muscle, seal liver, seal kidney, seal blubber and whale blubber as the dominant contributors of contaminants in the traditional diet. Levels in liver from Greenland halibut, snow crab, king eider, kittiwake, beluga and narwhal and kidney of beluga and narwhal are also high but were, with the exception of toxaphene in Greenland halibut liver, not important sources in this study, because they were eaten in low quantities. A way to minimize contaminant intake would be to avoid or limit the consumption of diet items with high

Human exposure to contaminants in the traditional Greenland diet

Energy Technology Data Exchange (ETDEWEB)

Johansen, Poul; Muir, Derek; Asmund, Gert; Riget, Frank

2004-09-20

The traditional diet is a significant source of contaminants to people in Greenland, although contaminant levels vary widely among species and tissue from very low in many to very high in a few. Our study has included cadmium, mercury, selenium, polychlorinated biphenyls (PCB), dichlorophenyltrichloroethane (DDT), chlordane, hexachlorocyclohexanes (HCH), chlorobenzenes, dieldrin and toxaphene in the major species and tissues consumed by Greenlanders. In general, the levels of these are very low in terrestrial species and in muscle of many marine species. High organochlorines concentrations are typically found in blubber of marine mammals and high metal levels in liver and kidney of seals and whales. In this study, the mean intakes of cadmium, chlordanes and toxaphene significantly exceed 'acceptable/tolerable intakes' (ADI/TDI) by a factor between 2.5 and 6. Mean intakes of mercury, PCB and dieldrin also exceed ADI/TDI by up to approximately 50%. However as these figures are mean intakes and as variation in both food intake and contaminant levels is large, the variation of contaminant intake among individuals is also large, and some individuals will be exposed to significantly higher intakes. The mean intakes of DDT, HCH and chlorobenzenes are well below the ADI/TDI values, and it seems unlikely that the TDI for these contaminants normally is exceeded in the Greenland population. The evaluation of contaminant intake in this study points to seal muscle, seal liver, seal kidney, seal blubber and whale blubber as the dominant contributors of contaminants in the traditional diet. Levels in liver from Greenland halibut, snow crab, king eider, kittiwake, beluga and narwhal and kidney of beluga and narwhal are also high but were, with the exception of toxaphene in Greenland halibut liver, not important sources in this study, because they were eaten in low quantities. A way to minimize contaminant intake would be to avoid or limit the consumption of diet items

The potential and sustainability of agricultural land use in a changing ecosystem in southern Greenland

Science.gov (United States)

Hunziker, Matthias; Caviezel, Chatrina; Kuhn, Nikolaus J.

2015-04-01

Southern Greenland currently experiences an increase in summer temperatures and a prolonged growing season (Masson-Delmotte et al. 2012), resulting in an increased potential regarding agricultural land use. Subsequently, the agricultural sector is expected to grow. Thereby, a higher hay production and grazing capacity is pursued by applying more efficient farming practices (Greenland Agriculture Advisory Board 2009). However, agricultural potential at borderline ecotones is not only influenced by factors like temperature and growing season but also by other ecologic parameters. In addition, the intensification of land use in the fragile boreal - tundra border ecotone has various environmental impacts (Perren et al. 2012; Normand et al. 2013). Already the Norse settlers practiced animal husbandry in southern Greenland between 986-1450 AD. Several authors mention the unadapted land use as main reason for the demise of the Norse in Greenland, as grazing pressure exceeded the resilience of the landscape and pasture economy failed (Fredskild 1988; Perren et al. 2012). During the field work in summer 2014, we compared the pedologic properties of already used hay fields, grazed land, birch woodland and barren, unused land around Igaliku (South Greenland), in order to estimate the potential and the sustainability of the land use in southern Greenland. Beside physical soil properties, nutrient condition of the different land use types, the shrub woodland and barren areas was analyzed. The results of the study show that the most suitable areas for intensive agricultural activity are mostly occupied. Further on, the fields, which were used by the Norse, seem to be the most productive sites nowadays. Less productive hay fields are characterized by a higher coarse fraction, leading to a reduced ability to store water and to an unfavorable nutrient status. An intensification of the agricultural land use by applying fertilizer would lead to an increased environmental impact

Components of segregation distortion in Drosophila melanogaster

International Nuclear Information System (INIS)

Ganetzky, B.

1977-01-01

The segregation distorter (SD) complex is a naturally occurring meiotic drive system with the property that males heterozygous for an SD-bearing chromosome 2 and an SD+-bearing homolog transmit the SD-bearing chromosome almost exclusively. This distorted segregation is the consequence of an induced dysfunction of those sperm that receive the SD+ homolog. From previous studies, two loci have been implicated in this phenomenon: the Sd locus which is required to produce distortion, and the Responder (Rsp) locus that is the site at which Sd acts. There are two allelic alternatives of Rsp-sensitive (Rsp/sup sens/) and insensitive (Rsp/sup ins/); a chromosome carrying Rsp/sup ins/ is not distorted by SD. In the present study, the function and location of each of these elements was examined by a genetic and cytological characterization of x-ray-induced mutations at each locus. The results indicate the following: the Rsp locus is located in the proximal heterochromatin of 2R; a deletion for the Rsp locus renders a chromosome insensitive to distortion; the Sd locus is located to the left of pr (2-54.5), in the region from 37D2-D7 to 38A6-B2 of the salivary chromosome map; an SD chromosome deleted for Sd loses its ability to distort; there is another important component of the SD system, E(SD), in or near the proximal heterochromatin of 2L, that behaves as a strong enhancer of distortion. The results of these studies allow a reinterpretation of results from earlier analyses of the SD system and serve to limit the possible mechanisms to account for segregation distortion

Distribution and drift of Atlantic cod ( Gadus morhua ) eggs and larvae in Greenland offshore waters

DEFF Research Database (Denmark)

Wieland, Kai; Hovgård, Holger

2002-01-01

Catches of Atlantic cod (Gadus morhua) eggs and larvae from 45 national and international ichthyoplankton surveys conducted in Greenland offshore waters during the period 1950 to 1984 have been compiled and re-analysed. Southeast and Southwest Greenland were identified as im- portant spawning areas...

Using an SLR inversion to measure the mass balance of Greenland before and during GRACE

Science.gov (United States)

Bonin, Jennifer

2016-04-01

The GRACE mission has done an admirable job of measuring large-scale mass changes over Greenland since its launch in 2002. However before that time, measurements of large-scale ice mass balance were few and far between, leading to a lack of baseline knowledge. High-quality Satellite Laser Ranging (SLR) data existed a decade earlier, but normally has too low a spatial resolution to be used for this purpose. I demonstrate that a least squares inversion technique can reconstitute the SLR data and use it to measure ice loss over Greenland. To do so, I first simulate the problem by degrading today's GRACE data to a level comparable with SLR, then demonstrating that the inversion can re-localize Greenland's contribution to the low-resolution signal, giving an accurate time series of mass change over all of Greenland which compares well with the full-resolution GRACE estimates. I then utilize that method on the actual SLR data, resulting in an independent 1994-2014 time series of mass change over Greenland. I find favorable agreement between the pure-SLR inverted results and the 2012 Ice-sheet Mass Balance Inter-comparison Exercise (IMBIE) results, which are largely based on the "input-output" modeling method before GRACE's launch.

Symptoms and health-related quality of life in patients with advanced cancer - A population-based study in Greenland.

Science.gov (United States)

Augustussen, Mikaela; Sjøgren, Per; Timm, Helle; Hounsgaard, Lise; Pedersen, Michael Lynge

2017-06-01

The aims were to describe symptoms and health-related quality of life (HRQoL) in Greenlandic patients with advanced cancer and to assess the applicability and internal consistency of the Greenlandic version of the EORTC-QLQ-C30 core version 3.0. A Greenlandic version of the EORTC QLQ-C30 v.3.0 was developed. The translation process included independent forward translation, reconciliation and independent back translation by native Greenlandic-speaking translators who were fluent in English. After pilot testing, a population-based cross-sectional study of patients with advanced cancer receiving palliative treatment was conducted. Internal consistency was examined by calculating Cronbach's alpha coefficients for five function scales and three symptom scales. Of the 58 patients who participated in the study, 47% had reduced social functioning, 36% had reduced physical and role functioning and 19% had reduced emotional and cognitive functioning. Furthermore, 48% reported fatigue, and 33% reported financial problems. The Greenlandic version of the EORTC had good applicability in the assessment of symptoms and quality of life. Acceptable Cronbach's alpha coefficients (above 0.70) were observed for the physical, role and social functioning scales, the fatigue scale and the global health status scale. Patients with undergoing palliative treatment in Greenland for advanced cancer reported high levels of social and financial problems and reduced physical functioning. This indicates a potential for improving palliative care service and increasing the focus on symptom management. The Greenlandic version of the EORTC-QLQ-C30 represents an applicable and reliable tool to describe symptoms and health-related quality of life among Greenlandic patients with advanced cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rare ATGL haplotypes are associated with increased plasma triglyceride concentrations in the Greenland Inuit

DEFF Research Database (Denmark)

Johansen, Christopher T; Gallinger, Zane R; Wang, Jian

2010-01-01

To genotype common genetic variants found in the adipose triglyceride lipase (ATGL) gene and test them for association with cardiovascular disease risk factors in the Greenland Inuit.......To genotype common genetic variants found in the adipose triglyceride lipase (ATGL) gene and test them for association with cardiovascular disease risk factors in the Greenland Inuit....

Geodetic measurements of postglacial adjustments in Greenland

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Wahr, J.; Leuliette, E.

2008-01-01

We analyze data from seven continuous Global Positioning System ( GPS) receivers and one tide gauge, all located along the edge of the Greenland ice sheet, to determine vertical uplift rates. We compare our results with predictions based on the ICE-5G deglaciation model of Peltier ( 2004). Results...

Ice age plant refugia in East Greenland

DEFF Research Database (Denmark)

Funder, Svend Visby

1979-01-01

From the distribution of plants it has been inferred by some botanists that ice-free areas existed in East Greenland accommodating a flora which survived one or several ice ages in the area. Comparing this evidence with recent information on the chronology of glaciations and post-glacial vegetation...

High-elevation mass loss of Greenland increasing

DEFF Research Database (Denmark)

Andersen, M. L.; Andersen, S. B.; Ahlstrøm, A. P.

project, repeated airborne LIDAR and radar surveys were carried out along the entire margin of the Greenland ice sheet in the years 2007 and 2011, providing bed and surface elevation profiles. Using these profiles, we establish a flux gate along the flight path, passing through 19 drainage basins...

Greenland Regional and Ice Sheet-wide Geometry Sensitivity to Boundary and Initial conditions

Science.gov (United States)

Logan, L. C.; Narayanan, S. H. K.; Greve, R.; Heimbach, P.

2017-12-01

Ice sheet and glacier model outputs require inputs from uncertainly known initial and boundary conditions, and other parameters. Conservation and constitutive equations formalize the relationship between model inputs and outputs, and the sensitivity of model-derived quantities of interest (e.g., ice sheet volume above floatation) to model variables can be obtained via the adjoint model of an ice sheet. We show how one particular ice sheet model, SICOPOLIS (SImulation COde for POLythermal Ice Sheets), depends on these inputs through comprehensive adjoint-based sensitivity analyses. SICOPOLIS discretizes the shallow-ice and shallow-shelf approximations for ice flow, and is well-suited for paleo-studies of Greenland and Antarctica, among other computational domains. The adjoint model of SICOPOLIS was developed via algorithmic differentiation, facilitated by the source transformation tool OpenAD (developed at Argonne National Lab). While model sensitivity to various inputs can be computed by costly methods involving input perturbation simulations, the time-dependent adjoint model of SICOPOLIS delivers model sensitivities to initial and boundary conditions throughout time at lower cost. Here, we explore both the sensitivities of the Greenland Ice Sheet's entire and regional volumes to: initial ice thickness, precipitation, basal sliding, and geothermal flux over the Holocene epoch. Sensitivity studies such as described here are now accessible to the modeling community, based on the latest version of SICOPOLIS that has been adapted for OpenAD to generate correct and efficient adjoint code.

Elastic uplift in southeast Greenland due to rapid ice mass loss

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Van dam, Tonie; Hamilton, Gordon S.

2007-01-01

The rapid unloading of ice from the southeastern sector of the Greenland ice sheet between 2001 and 2006 caused an elastic uplift of 35 mm at a GPS site in Kulusuk. Most of the uplift results from ice dynamic-induced volume losses on two nearby outlet glaciers. Volume loss from Helheim Glacier...... between 62N and 66N. Citation: Khan, S. A., J. Wahr, L. A. Stearns, G. S. Hamilton, T. van Dam, K. M. Larson, and O. Francis (2007), Elastic uplift in southeast Greenland due to rapid ice mass loss....

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit

Directory of Open Access Journals (Sweden)

Manhai Long

2012-03-01

Full Text Available Objectives: Perfluoroalkyl acids (PFAAs have been detected in human blood, breast milk and umbilical cord blood across the globe. PFAAs do accumulate in the marine food chain in Arctic regions. In Greenland, increasing PFAA concentrations were observed during 1982–2006 in ringed seals and polar bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Study design: Cross-section and temporal time trend survey. Methods: Serum PFAA levels were determined in 284 Inuit from different Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 1998–2005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs were explored. Results: Serum PFAA levels were higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 1998–2005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs and legacy POPs was observed for Nuuk Inuit while for non-Nuuk Inuit this correlation was significant. No correlation between PFAAs and legacy POPs was found for male Inuit, whereas significant correlation was observed both for pooled female Inuit and for non-Nuuk Inuit females. Conclusions: We suggest that sources other than seafood intake might contribute to the observed higher PFAA levels in Nuuk Inuit compared to the pooled non-Nuuk Inuit.

The Greenland analogue project. Yearly report 2010

Energy Technology Data Exchange (ETDEWEB)

Harper, J; Brinkerhoff, D; Johnson, J [University of Montana, Missoula (United States); Ruskeeniemi, T; Engstroem, J; Kukkonen, I [Geological Survey of Finland (Finland); and others

2012-04-15

A four-year field and modelling study of the Greenland ice sheet and subsurface conditions, Greenland Analogue Project (GAP), has been initiated collaboratively by SKB, Posiva and NWMO to advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository. The study site encompasses a land terminus portion of the Greenland ice sheet, east of Kangerlussuaq, and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project begins in 2009 and is scheduled for completion in 2012. Our current understanding of the hydrological, hydrogeological and hydrogeochemical processes associated with cold climate conditions and glacial cycles, and their impact on the long-term performance of deep geological repositories for spent nuclear fuel, will be significantly improved by studying a modern analogue. The GAP will conduct the first in situ investigations of some of the parameters and processes needed to achieve a better understanding of how an ice sheet may impact a deep repository, and will provide measurements, observations and data that may significantly improve our safety assessments and risk analyses of glaciation scenarios. This report was produced by the GAP team members and presents an overview of the activities within the GAP during the interval January 1 to December 31, 2010, as well as research results obtained during this time frame. Research for the GAP is ongoing, and additional results related to the data presented here may become available in the future and will be presented in subsequent annual reports. (orig.)

The Greenland analogue project. Yearly report 2010

International Nuclear Information System (INIS)

Harper, J.; Brinkerhoff, D.; Johnson, J.; Ruskeeniemi, T.; Engstroem, J.; Kukkonen, I.

2012-04-01

A four-year field and modelling study of the Greenland ice sheet and subsurface conditions, Greenland Analogue Project (GAP), has been initiated collaboratively by SKB, Posiva and NWMO to advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository. The study site encompasses a land terminus portion of the Greenland ice sheet, east of Kangerlussuaq, and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project begins in 2009 and is scheduled for completion in 2012. Our current understanding of the hydrological, hydrogeological and hydrogeochemical processes associated with cold climate conditions and glacial cycles, and their impact on the long-term performance of deep geological repositories for spent nuclear fuel, will be significantly improved by studying a modern analogue. The GAP will conduct the first in situ investigations of some of the parameters and processes needed to achieve a better understanding of how an ice sheet may impact a deep repository, and will provide measurements, observations and data that may significantly improve our safety assessments and risk analyses of glaciation scenarios. This report was produced by the GAP team members and presents an overview of the activities within the GAP during the interval January 1 to December 31, 2010, as well as research results obtained during this time frame. Research for the GAP is ongoing, and additional results related to the data presented here may become available in the future and will be presented in subsequent annual reports. (orig.)

Estimating the future ice sheet hydropower potential in Paakitsoq, Ilulissat, West Greenland

DEFF Research Database (Denmark)

Ahlstrøm, Andreas P.; Mottram, R.H.; Nielsen, C.

2008-01-01

sheet has emphasized the risk of sudden changes in catchment supply. In this study, we present a thorough investigation of hydropower feasibility at the Paakitsoq basin, near Ilulissat in West Greenland. The catchment is completely dominated by the Greenland ice sheet which provides large quantities...... of meltwater during the summer season. However, geometrical changes in the ice sheet, for example due to a retreat or an advance of the ice sheet margin, could change the hydrological catchment within the ice sheet. Such a change would have a devastating economical impact as a hydropower plant is a significant...... long-term investment for an Arctic community of modest population. Here we present a new bedrock and surface map of the Paakitsoq/Swiss Camp part of the Greenland ice sheet and a prediction of the future discharge up to 2080 AD using regional climate model output, dynamic ice sheet modelling...

Time trend by region of suicides and suicidal thoughts among Greenland Inuit

DEFF Research Database (Denmark)

Bjerregaard, Peter; Larsen, Christina Viskum Lytken

2015-01-01

BACKGROUND: Suicides remain a major public health problem in Greenland. Their increase coincides with the modernization since 1950. Serious suicidal thoughts are reported by a significant proportion of participants in countrywide surveys. OBJECTIVE: To analyze the time trend by region of suicides...... and suicidal thoughts among the Inuit in Greenland. DESIGN: Data included the Greenland registry of causes of death for 1970-2011 and 2 cross-sectional health surveys carried out in 1993-1994 and 2005-2010 with 1,580 and 3,102 Inuit participants, respectively. RESULTS: Suicide rates were higher among men than...... women while the prevalence of suicidal thoughts was higher among women. Suicide rates for men and women together increased from 1960 to 1980 and have remained around 100 per 100,000 person-years since then. The regional pattern of time trend for suicide rates varied with an early peak in the capital...

Sonographic ally Detected Architectural Distortion: Clinical Significance

Energy Technology Data Exchange (ETDEWEB)

Kim, Shin Kee; Seo, Bo Kyoung; Yi, Ann; Cha, Sang Hoon; Kim, Baek Hyun; Cho, Kyu Ran; Kim, Young Sik; Son, Gil Soo; Kim, Young Soo; Kim, Hee Young [Korea University Ansan Hospital, Ansan (Korea, Republic of)

2008-12-15

Architectural distortion is a suspicious abnormality for the diagnosis of breast cancer. The aim of this study was to investigate the clinical significance of sonographic ally detected architectural distortion. From January 2006 to June 2008, 20 patients were identified who had sonographic ally detected architectural distortions without a history of trauma or surgery and abnormal mammographic findings related to an architectural distortion. All of the lesions were pathologically verified. We evaluated the clinical and pathological findings and then assessed the clinical significance of the sonographic ally detected architectural distortions. Based on the clinical findings, one (5%) of the 20 patients had a palpable lump and the remaining 19 patients had no symptoms. No patient had a family history of breast cancer. Based on the pathological findings, three (15%) patients had malignancies. The malignant lesions included invasive ductal carcinomas (n = 2) and ductal carcinoma in situ (n = 1). Four (20%) patients had high-risk lesions: atypical ductal hyperplasia (n = 3) and lobular carcinoma in situ (n = 1). The remaining 13 (65%) patients had benign lesions, however, seven (35%) out of 13 patients had mild-risk lesions (three intraductal papillomas, three moderate or florid epithelial hyperplasia and one sclerosing adenosis). Of the sonographic ally detected architectural distortions, 35% were breast cancers or high-risk lesions and 35% were mild-risk lesions. Thus, a biopsy might be needed for an architectural distortion without an associated mass as depicted on breast ultrasound, even though the mammographic findings are normal

Sonographic ally Detected Architectural Distortion: Clinical Significance

International Nuclear Information System (INIS)

Kim, Shin Kee; Seo, Bo Kyoung; Yi, Ann; Cha, Sang Hoon; Kim, Baek Hyun; Cho, Kyu Ran; Kim, Young Sik; Son, Gil Soo; Kim, Young Soo; Kim, Hee Young

2008-01-01

Architectural distortion is a suspicious abnormality for the diagnosis of breast cancer. The aim of this study was to investigate the clinical significance of sonographic ally detected architectural distortion. From January 2006 to June 2008, 20 patients were identified who had sonographic ally detected architectural distortions without a history of trauma or surgery and abnormal mammographic findings related to an architectural distortion. All of the lesions were pathologically verified. We evaluated the clinical and pathological findings and then assessed the clinical significance of the sonographic ally detected architectural distortions. Based on the clinical findings, one (5%) of the 20 patients had a palpable lump and the remaining 19 patients had no symptoms. No patient had a family history of breast cancer. Based on the pathological findings, three (15%) patients had malignancies. The malignant lesions included invasive ductal carcinomas (n = 2) and ductal carcinoma in situ (n = 1). Four (20%) patients had high-risk lesions: atypical ductal hyperplasia (n = 3) and lobular carcinoma in situ (n = 1). The remaining 13 (65%) patients had benign lesions, however, seven (35%) out of 13 patients had mild-risk lesions (three intraductal papillomas, three moderate or florid epithelial hyperplasia and one sclerosing adenosis). Of the sonographic ally detected architectural distortions, 35% were breast cancers or high-risk lesions and 35% were mild-risk lesions. Thus, a biopsy might be needed for an architectural distortion without an associated mass as depicted on breast ultrasound, even though the mammographic findings are normal

Chinese mineral dust and anthropogenic aerosol inter-continental transport: a Greenland perspective

Science.gov (United States)

Bory, A.; Abouchami, W.; Galer, S.; Svensson, A.; Biscaye, P.

2012-04-01

Impurities contained in snow and ice layers in Greenland provide a record of the history of atmospheric dustiness and pollution in the Northern Hemisphere. The source of the particles deposited onto the ice cap may be investigated using specific intrinsic tracers. Provenance discrimination may then provide valuable constraints for the validation of atmospheric transport models as well as for the monitoring of natural and anthropogenic aerosols emissions at a global scale. Clay mineralogy combined with the strontium and neodymium isotope composition of the insoluble particles extracted from recent snow deposits at NorthGRIP (75.1°N, 042.3°W), for instance, enabled us to demonstrate that the Taklimakan desert of North-western China was the main source of mineral dust reaching central Greenland at present [Bory et al., EPSL, 2002 ; GRL, 2003a]. Here we report the lead isotopic signature of these snow-pit samples, covering the 1989-1995 and 1998-2001 time periods. Unradiogenic lead isotopic composition of our Greenland samples, compared to Asian dust isotopic fingerprints, implies that most of the insoluble lead reaching the ice cap is of anthropogenic origin. Lead isotopes reveal likely contributions from European/Canadian and, to a lesser extent, US sources, as well as a marked overprinted signature typical of Chinese anthropogenic lead sources. The relative contribution of the latter appears to have been increasing steadily over the last decade of the 20th century. Quantitative estimates suggest that, in addition to providing most of the dust, China may have already become the most important supplier of anthropogenic lead deposited in Greenland by the turn of the 20th to the 21st century. The close timing between dust and anthropogenic particles deposition onto the ice cap provides new insights for our understanding of Chinese aerosols transport to Greenland.

Accelerated mass loss from Greenland ice sheet : Links to atmospheric circulation in the North Atlantic

NARCIS (Netherlands)

Seo, Ki-Weon; Waliser, Duane E.; Lee, Choon-Ki; Tian, Baijun; Scambos, Ted; Kim, Baek-Min; van Angelen, Jan H.; van den Broeke, Michiel R.

Understanding the mechanisms that drive the mass imbalance of the Greenland ice sheet (GrIS) is critical to the accurate projection of its contribution to future sea level rise. Greenland's ice mass loss has been accelerating recently. Using satellite Earth-gravity and regional climate model data,

Greenland ice sheet surface mass balance: evaluating simulations and making projections with regional climate models

NARCIS (Netherlands)

Rae, J.G.L.; Aðalgeirsdóttir, G.; Edwards, T.L.; Fettweis, X.; Gregory, J.M.; Hewitt, H.T.; Lowe, J.A.; Lucas-Picher, P.; Mottram, R.H.; Payne, A.J.; Ridley, J.K.; Shannon, S.R.; van de Berg, W.J.; van de Wal, R.S.W.; van den Broeke, M.R.

2012-01-01

Four high-resolution regional climate models (RCMs) have been set up for the area of Greenland, with the aim of providing future projections of Greenland ice sheet surface mass balance (SMB), and its contribution to sea level rise, with greater accuracy than is possible from coarser-resolution

Greenlandic water and sanitation-a context oriented analysis of system challenges towards local sustainable development.

Science.gov (United States)

Hendriksen, Kåre; Hoffmann, Birgitte

2017-08-28

Today, as Greenland focuses on more economic and cultural autonomy, the continued development of societal infrastructure systems is vital. At the same time, pressure is put on the systems by a lack of financial resources and locally based professional competences as well as new market-based forms of organization. Against this background, the article discusses the challenges facing Greenland's self-rule in relation to further develop the existing water and wastewater systems so that they can contribute to the sustainable development of Greenland. The article reviews the historical development of the water supply and wastewater system. This leads to an analysis of the sectorisation, which in recent decades has reorganized the Greenlandic infrastructures, and of how this process is influencing local sustainable development. The article discusses the socio-economic and human impacts and points to the need for developing the water and sanitation system to support not only hygiene and health, but also local sustainable development.

Modeling the response of Northwest Greenland to enhanced ocean thermal forcing and subglacial discharge

Science.gov (United States)

Morlighem, M.; Wood, M.; Seroussi, H. L.; Bondzio, J. H.; Rignot, E. J.

2017-12-01

Glacier-front dynamics is an important control on Greenland's ice mass balance. Warm and salty Atlantic water, which is typically found at a depth below 200-300 m, has the potential to trigger ice-front retreats of marine-terminating glaciers, and the corresponding loss in resistive stress leads to glacier acceleration and thinning. It remains unclear, however, which glaciers are currently stable but may retreat in the future, and how far inland and how fast they will retreat. Here, we quantify the sensitivity and vulnerability of marine-terminating glaciers along the Northwest coast of Greenland (from 72.5° to 76°N) to ocean forcing using the Ice Sheet System Model (ISSM), and its new ice front migration capability. We rely on the ice melt parameterization from Rignot et al. 2016, and use ocean temperature and salinity from high-resolution ECCO2 simulations on the continental shelf to constrain the thermal forcing. The ice flow model includes a calving law based on a Von Mises criterion. We investigate the sensitivity of Northwest Greenland to enhanced ocean thermal forcing and subglacial discharge. We find that some glaciers, such as Dietrichson Gletscher or Alison Gletscher, are sensitive to small increases in ocean thermal forcing, while others, such as Illullip Sermia or Qeqertarsuup Sermia, are very difficult to destabilize, even with a quadrupling of the melt. Under the most intense melt experiment, we find that Hayes Gletscher retreats by more than 50 km inland into a deep trough and its velocity increases by a factor of 10 over only 15 years. The model confirms that ice-ocean interactions are the triggering mechanism of glacier retreat, but the bed controls its magnitude. This work was performed at the University of California Irvine under a contract with the National Aeronautics and Space Administration, Cryospheric Sciences Program (#NNX15AD55G), and the National Science Foundation's ARCSS program (#1504230).

Decreasing overweight and central fat patterning with Westernization among the Inuit in Greenland and Inuit migrants

DEFF Research Database (Denmark)

Bjerregaard, P; Jørgensen, M E; Andersen, S

2002-01-01

OBJECTIVE: To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization. DESIGN: Cross-sectional, population-based epidemiological study. SUBJECTS: A total of 2046 adult Greenlanders (Inuit), 61% of those...... invited to participate, living in three areas of Greenland and in Denmark. MEASUREMENTS: Height, weight, waist and hip circumferences were measured and body mass index (BMI in kg/m(2)) and waist-hip ratio calculated. Sociocultural information was obtained by questionnaire and interview. Westernization...... was estimated by language and place of residence. RESULTS: The prevalence of obesity (>or=30 kg/m(2)) was 16 and 22% among men and women in Greenland (P=0.004), and 12 and 11%, respectively, in Denmark (NS). Westernization was accompanied by a decrease in the proportion of obese people, in particular among...

Glaciation and geosphere evolution - Greenland Analogue Project

International Nuclear Information System (INIS)

Hirschorn, S.; Vorauer, A.; Belfadhel, M.B.; Jensen, M.

2011-01-01

The deep geological repository concept for the long-term management of used nuclear fuel involves the containment and isolation of used nuclear fuel in a suitable geological formation. A key objective of the Canadian Nuclear Waste Management Organization (NWMO) geoscience technical research program is to advance the understanding of geosphere stability and its resilience to perturbations over time frames of relevance to a deep geological repository. Glaciation has been identified as the most probable and intense perturbation relevant to a deep geological repository associated with long-term climate change in northern latitudes. Given that the North American continent has been re-glaciated nine times over the past million years, it is strongly expected that a deep geological repository within a suitable crystalline or sedimentary rock formation in Canada will be subject to glaciation events associated with long-term climate change. As such, NWMO's geoscience research program has placed particular emphasis on investigations of the response of the geosphere to glaciations. As surface conditions change from present day conditions to periglacial, followed by ice-sheet cover of variable thickness and rapid glacial retreat, transient geochemical, hydraulic, mechanical and temperature conditions will be simultaneously imposed on groundwater systems. NWMO research activities related to glaciation events and their impacts on groundwater system evolution are being undertaken using a multi-disciplinary approach aimed at collecting multiple lines of evidence. These investigations include assessment of the: Impact of an ice sheet on groundwater composition at repository depth using the Greenland Ice Sheet as an analogue to future glaciations in North America; Expected physical and temporal surface boundary conditions related to potential future glaciation events by estimating the magnitude and time rate of change of ice sheet thickness, ground surface temperature and

Centi-pixel accurate real-time inverse distortion correction

CSIR Research Space (South Africa)

De Villiers, Johan P

2008-11-01

Full Text Available Inverse distortion is used to create an undistorted image from a distorted image. For each pixel in the undistorted image it is required to determine which pixel in the distorted image should be used. However the process of characterizing a lens...

Environmental radioactivity in the North Atlantic region including the Faroe Islands and Greenland. 1990 and 1991

International Nuclear Information System (INIS)

Aarkrog, A.; Chen, Q.J.; Dahlgaard, H.; Hansen, H.; Nielsen, S.P.; Strandberg, M.; Buch, E.; Christensen, G.C.; Holm, E.

1994-01-01

Measurements of fallout radioactivity in the North Atlantic region including Faroe Islands and Greenland are reported. Strontium-90, cesium-137 and cesium-134 were determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes), and drinking water. Estimates are given of the mean contents of 90 Sr and 137 Cs in human diet in the Faroes and Greenland in 1990 and 1991. 99 Tc data on marine samples, in particular sea water from the Greenland Sea, are reported. (au) (77 tabs., 46 ills., 8 refs.)

The lithospheric mantle below southern West Greenland

DEFF Research Database (Denmark)

Sand, Karina Krarup; Waight, Tod Earle; Pearson, D. Graham

2009-01-01

Geothermobarometry of primarily garnet lherzolitic xenoliths from several localities in southern West Greenland is applied to address the diamond potential, pressure and temperature distribution and the stratigraphy of the subcontinental lithospheric mantle ~600 Ma ago. The samples are from kimbe...... into the reworked Archean North of the Naqssugtoqidian deformation front....

Potential Environmental Impacts of Oil Spills in Greenland

DEFF Research Database (Denmark)

This report analyses information status and research needs in relation to potential environmental impacts of oil spills (offshore and onshore) in Greenland. The report assesses potential effects and potential mitigation and monitoring measures. Information gaps are identified and a number...

Quota disputes and subsistence whaling in Qeqertarsuaq, Greenland

DEFF Research Database (Denmark)

Tejsner, Pelle

2014-01-01

In Qeqertarsuaq (Disco Island), northwest Greenland, local disputes about the allocation of annual whaling quotas for beluga and narwhals feature as a source of conflict between state-imposed categories of occupational and non-occupational hunters. The national authorities’ co-management regime...

Soil-Snow-Vegetation Interactions at Zackenberg, Northeast Greenland

DEFF Research Database (Denmark)

Gacitua, Guisella

-term eects on the ecosystem function and dynamics. At the Zackenberg Research Station in Northeast Greenland ecosystem processes are routinely monitored through a comprehensive monitoring program. This PhD project investigates and discusses the interactions between climate, the physical components...

Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)

DEFF Research Database (Denmark)

Nielsen, Julius; Hedeholm, Rasmus B.; Heinemeier, Jan

2016-01-01

The Greenland shark (Somniosus microcephalus), an iconic species of the Arctic Seas, grows slowly and reaches >500 centimeters (cm) in total length, suggesting a life span well beyond those of other vertebrates. Radiocarbon dating of eye lens nuclei from 28 female Greenland sharks (81 to 502 cm i...

Higher surface mass balance of the Greenland ice sheet revealed by high - resolution climate modeling

NARCIS (Netherlands)

Ettema, Janneke; van den Broeke, Michiel R.; van Meijgaard, Erik; van de Berg, Willem Jan; Bamber, Jonathan L.; Box, Jason E.; Bales, Roger C.

2009-01-01

High‐resolution (∼11 km) regional climate modeling shows total annual precipitation on the Greenland ice sheet for 1958–2007 to be up to 24% and surface mass balance up to 63% higher than previously thought. The largest differences occur in coastal southeast Greenland, where the much higher

A Younger Dryas re-advance of local glaciers in north Greenland

DEFF Research Database (Denmark)

Larsen, Nicolaj K.; Funder, Svend; Linge, Henriette

2016-01-01

The Younger Dryas (YD) is a well-constrained cold event from 12,900 to 11,700 years ago but it remains unclear how the cooling and subsequent abrupt warming recorded in ice cores was translated into ice margin fluctuations in Greenland. Here we present 10Be surface exposure ages from three moraines...... in front of local glaciers on a 50 km stretch along the north coast of Greenland, facing the Arctic Ocean. Ten ages range from 11.6 ± 0.5 to 27.2 ± 0.9 ka with a mean age of 12.5 ± 0.7 ka after exclusion of two outliers. We consider this to be a minimum age for the abandonment of the moraines. The ages...... the interval 11.8-13.0 ka ago. This is the first time a synchronous YD glacier advance and subsequent retreat has been recorded for several independent glaciers in Greenland. In most other areas, there is no evidence for re-advance and glaciers were retreating during YD. We explain the different behaviour...

FSD: Frequency Space Differential measurement of CMB spectral distortions

Science.gov (United States)

Mukherjee, Suvodip; Silk, Joseph; Wandelt, Benjamin D.

2018-04-01

Although the Cosmic Microwave Background agrees with a perfect blackbody spectrum within the current experimental limits, it is expected to exhibit certain spectral distortions with known spectral properties. We propose a new method, Frequency Space Differential (FSD) to measure the spectral distortions in the CMB spectrum by using the inter-frequency differences of the brightness temperature. The difference between the observed CMB temperature at different frequencies must agree with the frequency derivative of the blackbody spectrum, in the absence of any distortion. However, in the presence of spectral distortions, the measured inter-frequency differences would also exhibit deviations from blackbody which can be modeled for known sources of spectral distortions like y & μ. Our technique uses FSD information for the CMB blackbody, y, μ or any other sources of spectral distortions to model the observed signal. Successful application of this method in future CMB missions can provide an alternative method to extract spectral distortion signals and can potentially make it feasible to measure spectral distortions without an internal blackbody calibrator.

Evaluation of harmonic distortions using small scale computers; Avaliacao de distorcoes harmonicas utilizando-se computadores de pequeno porte

Energy Technology Data Exchange (ETDEWEB)

Paschoareli, Junior, Dionizio

1991-12-01

The emergence more and more constant of non-linear loads in the power systems, with the consequent distortion in the voltage wave forms and of current, turns necessary complementary analyses in the planning of the systems, in way the if understands and to minimize the effects caused by the harmonic distortions. Among the methods used in this analysis are the computational programs that determine the flow of harmonic current and the voltages distorted in the buses. The objective of this work is the optimization of a program developed for large computers, turning possible its utilization in microcomputers. Besides, several models of components and two electric systems have its answers to the presence of multiple frequencies of the fundamental (harmonic frequency) evaluated and the results of the simulations will be presented. It also accomplishes simulations that make possible the visualization of the distortions in the voltage wave forms of the buses. Finally, the work offers a global and qualitative vision of this phenomenon that has been reason increasing preoccupation for mainly among the responsible for the quality of the supplied energy.

Magmatism and Eurekan deformation in the High Arctic Large Igneous Province: 40Ar–39Ar age of Kap Washington Group volcanics, North Greenland

DEFF Research Database (Denmark)

Tegner, Christian; Storey, Michael; Holm, Paul Martin

2011-01-01

The High Arctic Large Igneous Province is unusual on two counts: first, magmatism was prolonged and has been suggested to include an initial tholeiitic phase (130–80 Ma) and a second alkaline phase (85–60 Ma); second, it was subsequently deformed during the Eurekan Orogeny. New 40Ar–39Ar dating...... of alkaline volcanics from Kap Kane, part of the Kap Washington Group volcanics at the northern tip of Greenland, provides an emplacement age of 71.2±0.5 Ma obtained from amphibole in lapilli tuffs, and a thermal resetting age of 49–47 Ma obtained in feldspar and whole-rocks from trachyte flows. Patch...... in the Labrador Sea and the Baffin Bay, and to eastwards displacement of Greenland relative to North America. The alkaline suite, therefore, may be unrelated to the main tholeiitic phase of the High Arctic Large Igneous Province. The subsequent initiation of continental rifting and ensuing seafloor spreading...

Impacts of food web structure and feeding behavior on mercury exposure in Greenland Sharks (Somniosus microcephalus)

Energy Technology Data Exchange (ETDEWEB)

McMeans, Bailey C., E-mail: bcmcmeans@gmail.com [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); Arts, Michael T. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); National Water Research Institute, Environment Canada, 867 Lakeshore Road, PO Box 5050, Burlington, Ontario L7R 4A6 (Canada); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada)

2015-03-15

Benthic and pelagic food web components in Cumberland Sound, Canada were explored as sources of total mercury (THg) to Greenland Sharks (Somniosus microcephalus) via both bottom-up food web transfer and top-down shark feeding behavior. Log{sub 10}THg increased significantly with δ{sup 15}N and trophic position from invertebrates (0.01 ± 0.01 μg·g{sup −1} [113 ± 1 ng·g{sup −1}] dw in copepods) to Greenland Sharks (3.54 ± 1.02 μg·g{sup −1}). The slope of the log{sub 10}THg vs. δ{sup 15}N linear regression was higher for pelagic compared to benthic food web components (excluding Greenland Sharks, which could not be assigned to either food web), which resulted from THg concentrations being higher at the base of the benthic food web (i.e., in benthic than pelagic primary consumers). However, feeding habitat is unlikely to consistently influence shark THg exposure in Cumberland Sound because THg concentrations did not consistently differ between benthic and pelagic shark prey. Further, size, gender and feeding behavior (inferred from stable isotopes and fatty acids) were unable to significantly explain THg variability among individual Greenland Sharks. Possible reasons for this result include: 1) individual sharks feeding as generalists, 2) high overlap in THg among shark prey, and 3) differences in turnover time between ecological tracers and THg. This first assessment of Greenland Shark THg within an Arctic food web revealed high concentrations consistent with biomagnification, but low ability to explain intra-specific THg variability. Our findings of high THg levels and consumption of multiple prey types, however, suggest that Greenland Sharks acquire THg through a variety of trophic pathways and are a significant contributor to the total biotic THg pool in northern seas. - Highlights: • THg significantly increased with δ{sup 15}N from invertebrates to Greenland Sharks. • THg increased with δ{sup 15}N at a faster rate through the pelagic than

Impacts of food web structure and feeding behavior on mercury exposure in Greenland Sharks (Somniosus microcephalus)

International Nuclear Information System (INIS)

McMeans, Bailey C.; Arts, Michael T.; Fisk, Aaron T.

2015-01-01

Benthic and pelagic food web components in Cumberland Sound, Canada were explored as sources of total mercury (THg) to Greenland Sharks (Somniosus microcephalus) via both bottom-up food web transfer and top-down shark feeding behavior. Log 10 THg increased significantly with δ 15 N and trophic position from invertebrates (0.01 ± 0.01 μg·g −1 [113 ± 1 ng·g −1 ] dw in copepods) to Greenland Sharks (3.54 ± 1.02 μg·g −1 ). The slope of the log 10 THg vs. δ 15 N linear regression was higher for pelagic compared to benthic food web components (excluding Greenland Sharks, which could not be assigned to either food web), which resulted from THg concentrations being higher at the base of the benthic food web (i.e., in benthic than pelagic primary consumers). However, feeding habitat is unlikely to consistently influence shark THg exposure in Cumberland Sound because THg concentrations did not consistently differ between benthic and pelagic shark prey. Further, size, gender and feeding behavior (inferred from stable isotopes and fatty acids) were unable to significantly explain THg variability among individual Greenland Sharks. Possible reasons for this result include: 1) individual sharks feeding as generalists, 2) high overlap in THg among shark prey, and 3) differences in turnover time between ecological tracers and THg. This first assessment of Greenland Shark THg within an Arctic food web revealed high concentrations consistent with biomagnification, but low ability to explain intra-specific THg variability. Our findings of high THg levels and consumption of multiple prey types, however, suggest that Greenland Sharks acquire THg through a variety of trophic pathways and are a significant contributor to the total biotic THg pool in northern seas. - Highlights: • THg significantly increased with δ 15 N from invertebrates to Greenland Sharks. • THg increased with δ 15 N at a faster rate through the pelagic than benthic food web. • Benthic primary

Greenland ice sheet mass balance: a review

DEFF Research Database (Denmark)

Khan, Shfaqat Abbas; Aschwanden, Andy; Bjørk, Anders A.

2015-01-01

Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance...

Seismic structure of the crust and upper mantle in central-eastern Greenland

DEFF Research Database (Denmark)

Kraft, Helene Anja

Geophysical and geological knowledge of the interior of Greenland is very limited. The lack of knowledge arises mainly due to the logistical challenges related to conducting geophysical fieldwork on the up to 3400 m thick ice sheet, which covers around 80% of the land area. This PhD thesis is based...... on the very first regional passive seismic study in central-Eastern Greenland, focusing on the area between Scoresby Sund and Summit. The study aims to image the structure of subsurface Greenland starting from the crust and down to the mantle transition zone. Furthermore, the thesis links these observations....... The receiver functions were jointly inverted for the velocity structure of the crust and delay times, and shapes of signals originating at the mantle transition zone discontinuities, P410s and P660s, were analysed. The crustal models show a deepening of the Moho from east to west from less than 20 km depth...

A Younger Dryas re-advance of local glaciers in north Greenland

Science.gov (United States)

Larsen, Nicolaj K.; Funder, Svend; Linge, Henriette; Möller, Per; Schomacker, Anders; Fabel, Derek; Xu, Sheng; Kjær, Kurt H.

2016-09-01

The Younger Dryas (YD) is a well-constrained cold event from 12,900 to 11,700 years ago but it remains unclear how the cooling and subsequent abrupt warming recorded in ice cores was translated into ice margin fluctuations in Greenland. Here we present 10Be surface exposure ages from three moraines in front of local glaciers on a 50 km stretch along the north coast of Greenland, facing the Arctic Ocean. Ten ages range from 11.6 ± 0.5 to 27.2 ± 0.9 ka with a mean age of 12.5 ± 0.7 ka after exclusion of two outliers. We consider this to be a minimum age for the abandonment of the moraines. The ages of the moraines are furthermore constrained using Optically Stimulated Luminescence (OSL) dating of epishelf sediments, which were deposited prior to the ice advance that formed the moraines, yielding a maximum age of 12.4 ± 0.6 ka, and bracketing the formation and subsequent abandonment of the moraines to within the interval 11.8-13.0 ka ago. This is the first time a synchronous YD glacier advance and subsequent retreat has been recorded for several independent glaciers in Greenland. In most other areas, there is no evidence for re-advance and glaciers were retreating during YD. We explain the different behaviour of the glaciers in northernmost Greenland as a function of their remoteness from the Atlantic Meridional Overturning Circulation (AMOC), which in other areas has been held responsible for modifying the YD drop in temperatures.

Implementation and effectiveness of antiretroviral therapy in Greenland

DEFF Research Database (Denmark)

Lohse, N.; Ladefoged, K.; Obel, N.

2008-01-01

Analyses from the Danish HIV Cohort Study showed that, despite comparable economic means and general education of healthcare personnel, antiretroviral treatment of HIV in Greenland began later and has been implemented at a slower pace with lower therapeutic effectiveness than in Denmark. However...

Levels of ammonium, sulfate, chloride, calcium, and sodium in snow and ice from southern Greenland

International Nuclear Information System (INIS)

Busenberg, E.; Langway, C.C. Jr.

1979-01-01

Chemical analysis of surface snows and dated ice core samples from Dye 3, Greenland, suggests that the ammonium cation is a major constituent in all samples and that the annual ammonium levels present in the south Greenland samples have varied from 3.3 to 26.3 μg/kg between the seventeenth century and the present time. The annual range of 1974--1975 surface samples was between 3.8 and 8.8 μg/kg, while the mean was 5.7 +- 1.8 μ/kg. The recent large-scale uses of fixed nitrogen fertilizers and industrial pollution have apparently not affected the levels of ammonia reaching southern Greenland. The sodium and chloride present are predominantly derived from ocean spray, while more than 90% of the calcium is of continental origin. The levels of these three elements have not apparently been affected by human activity since the industrial revolution. Sulfate levels have increased dramatically since the industrial revolution, suggesting that sulfate of anthropogenic origin is the most important source of sulfate in modern snows from southern Greenland. The amount of the sulfuric acid neutralized by the ammonium cations was approximately 100% in the seventeenth and eighteenth centuries, dropping to approximately 20% in the 1974--1975 samples. These figures imply that there has been in increase in the acidity of precipitation in southern Greenland since the end of the eighteenth ce

Pb isotope evidence for contributions from different Iceland mantle components to Palaeogene East Greenland flood basalts

DEFF Research Database (Denmark)

Peate, David; Stecher, Ole

2003-01-01

We present new Pb isotope data on 21 samples of break-up-related flood basalts (56–54 Ma) from the Blosseville Kyst region of East Greenland. These samples show a considerable range in isotopic composition (206Pb/204Pb 17.6 to 19.3) that broadly correlates with compositional type. The ‘low-Ti’ type...... in the selected samples. Uncontaminated Palaeogene East Greenland flood basalts appear to have sampled the same broad range in mantle compositions seen in Recent Iceland basalts. In contrast to the peripheral lava suites from the British Isles and Southeast Greenland, where the inferred uncontaminated magmas have...... to the most radiogenic values found in recent Icelandic basalts. Furthermore, the main volume of lavas in East Greenland is displaced away from the NAEM towards this radiogenic Pb component. Thus, this ‘Iceland radiogenic Pb end-member’ component was a significant contributor to the break-up-related magmatism...

Greenland-Iceland-Norwegian Seas Regional Climatology (NODC Accession 0112824)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — To provide an improved oceanographic foundation and reference for multi-disciplinary studies of the Greenland-Iceland-Norwegian Seas (GINS), NODC developed a new set...

Interglacial insects and their possible survival in Greenland during the last glacial stage

DEFF Research Database (Denmark)

Bøcher, Jens Jensenius

2012-01-01

Sediments from the last interglacial (Eemian) in Jameson Land, East Greenland, and the Thule area, NW Greenland, have revealed a number of insect fragments of both arctic and more or less warmth-demanding species. Altogether, the interglacial fauna of Coleoptera (beetles) indicates boreal...... beetle species such as Amara alpina and Isochnus arcticus did not survive the last glacial stage in Greenland. Two factors that have not been sufficiently considered when discussing survival contra extinction are the importance of microclimate and the number of sun-hours during the Arctic summer. Even...... among the Coleoptera, which as a group fares quite badly in the Arctic, there might be survivors, at least among those found both during the interglacial and as fossils during the early Holocene. First of all, glacial survival applies to the seed bug Nysius groenlandicus, which was widespread during...

L3 English acquisition in Denmark and Greenland

DEFF Research Database (Denmark)

Spellerberg, Stine Marie

2011-01-01

This paper presents findings of gender-related tendencies found in a study of factors influential in third language acquisition of English in Denmark and Greenland. A survey consisting of a questionnaire and an English test was carried out amongst pupils in their last year of compulsory schooling...... in Copenhagen, Denmark, and Nuuk, Greenland. In total, responses from 187 pupils were included, some of which were responses from pupils learning English as a second language; these respondents were included for comparisons (Copenhagen: L2 learners N =59, L3 learners N=32; Nuuk: L3 learners N=96; age: 14......' degree of English classroom anxiety. The results differentiate the view that L3 learners as a group do less well in English than L2 learner peers, warranting further research into gender-related tendencies and extra focus on the English acquisition of L3 learner boys in particular in the Danish context....

Gender difference in health expectancy trends in Greenland

DEFF Research Database (Denmark)

Mairey, Isabelle; Bjerregaard, Peter; Brønnum-Hansen, Henrik

2014-01-01

longstanding illness supports the theory of compression of morbidity, but as the trend direction differs according to which measure for health is used, a definite conclusion cannot be drawn. The different rate of development of partial life expectancy and expected lifetime in good health between men and women......Background: The population of Greenland comprises almost 31 000 Inuit Greenlanders aged 20-65. The purpose of this study was to estimate trends in expected life years between age 20 and 65 in good and poor health, and to compare changes between men and women since the mid-1990s. Methods: Partial...... life expectancy was calculated and combined with prevalence data on self-rated health, longstanding illness and musculoskeletal diseases derived from health surveys carried out in 1993-94, 1999-2001 and 2005-10. Trends for men and women were compared and changes were decomposed into contributions from...

Self-inhibiting growth of the Greenland Ice Sheet

DEFF Research Database (Denmark)

Langen, Peter Lang; Solgaard, Anne Munck; Hvidberg, Christine Schøtt

2012-01-01

The build-up of the Greenland Ice Sheet (GrIS) from ice-free conditions is studied in an ice sheet model (ISM) driven by fields from an atmospheric general circulation model (GCM) to demonstrate the importance of coupling between the two components. Experiments where the two are coupled off-line...... are augmented by one where an intermediate ice sheet configuration is coupled back to the GCM. Forcing the ISM with GCM fields corresponding to the ice-free state leads to extensive regrowth which, however, is halted when the intermediate recoupling step is included. This inhibition of further growth is due...... to a Föhn effect of moist air parcels being lifted over the intermediate ice sheet and arriving in the low-lying Greenland interior with high temperatures. This demonstrates that two-way coupling between the atmosphere and the ice sheet is essential for understanding the dynamics and that large scale...

Impact of loudspeaker nonlinear distortion on personal sound zones

DEFF Research Database (Denmark)

Ma, Xiaohui; J. Hegarty, Patrick; Abildgaard Pedersen, Jan

2018-01-01

Personal sound zone systems aim at creating multiple listening zones within a shared space with minimum interference between zones, but the performance is often poorer than simulations predict and effects of nonlinear distortion are sometimes audible. This paper assesses the impact of nonlinear...... distortion on sound zones through simulations and measurements performed under anechoic conditions. Two sound zones, one bright and one dark, are created with acoustic contrast control using two loudspeaker arrays driven at 250 Hz. Nonlinear distortion is modelled using second or third order nonlinearities....... Simulations show that nonlinear distortion degrades the acoustic contrast, which is confirmed by experimental measurements. The harmonic distortion is audible in the dark zone. Frequency resolved measurements reveal that harmonic distortion contributes to contrast loss, but nonlinear effects...

The Greenland Analogue Project. Geomodel version 1 of the Kangerlussuaq area on Western Greenland