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Sample records for eldfell volcano iceland

  1. Eldfellite, NaFe(SO4)2, a new fumarolic mineral from Eldfell volcano, Iceland

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Garavelli, A.; Acquafredda, P.

    2009-01-01

    A new mineral, eldfellite, was found among fumarolic encrustations collected in 1990 on the Eldfell volcano, Heimaey Island, Iceland. Associated minerals are ralstonite, anhydrite, gypsum, bassanite, hematite, opal and tamarugite, as well as a presumably new mineral with the composition Na3Fe(SO4......)3. Along with opal and tamarugite, eldfellite forms soft and fragile aggregates built of thin, platy crystals of micrometre size. The mineral is yellowish-green to greenish-white, with a white streak. The calculated density is 3.062 g/cm3. Eldfellite is monoclinic, C2/m, a 8.043(4) Å, b 5.139(2) Å, c 7...

  2. Catalogue of Icelandic Volcanoes

    Science.gov (United States)

    Ilyinskaya, Evgenia; Larsen, Gudrún; Gudmundsson, Magnús T.; Vogfjörd, Kristin; Jonsson, Trausti; Oddsson, Björn; Reynisson, Vidir; Pagneux, Emmanuel; Barsotti, Sara; Karlsdóttir, Sigrún; Bergsveinsson, Sölvi; Oddsdóttir, Thorarna

    2017-04-01

    The Catalogue of Icelandic Volcanoes (CIV) is a newly developed open-access web resource (http://icelandicvolcanoes.is) intended to serve as an official source of information about volcanoes in Iceland for the public and decision makers. CIV contains text and graphic information on all 32 active volcanic systems in Iceland, as well as real-time data from monitoring systems in a format that enables non-specialists to understand the volcanic activity status. The CIV data portal contains scientific data on all eruptions since Eyjafjallajökull 2010 and is an unprecedented endeavour in making volcanological data open and easy to access. CIV forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the European Union funded effort FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. The supersite concept implies integration of space and ground based observations for improved monitoring and evaluation of volcanic hazards, and open data policy. This work is a collaboration of the Icelandic Meteorological Office, the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere.

  3. Oskarssonite, AlF3, a new fumarolic mineral from Eldfell volcano, Heimaey, Iceland

    DEFF Research Database (Denmark)

    Jacobsen, Morten Jølnæs; Balic Zunic, Tonci; Mitolo, Donatella

    2014-01-01

    with anhydrite, bassanite, gypsum, jarosite, anatase, hematite, opal, ralstonite, jakobssonite and meniaylovite. Chemical analyses by energy-dispersive spectrometry with a scanning electronmicroscope produced the following mean elemental composition: Al, 31.70; F, 58.41; O, 9.22; total 99.33 wt.%. The empirical...

  4. Silicic magma generation at Askja volcano, Iceland

    Science.gov (United States)

    Sigmarsson, O.

    2009-04-01

    Rate of magma differentiation is an important parameter for hazard assessment at active volcanoes. However, estimates of these rates depend on proper understanding of the underlying magmatic processes and magma generation. Differences in isotope ratios of O, Th and B between silicic and in contemporaneous basaltic magmas have been used to emphasize their origin by partial melting of hydrothermally altered metabasaltic crust in the rift-zones favoured by a strong geothermal gradient. An alternative model for the origin of silicic magmas in the Iceland has been proposed based on U-series results. Young mantle-derived mafic protolith is thought to be metasomatized and partially melted to form the silicic end-member. However, this model underestimates the compositional variations of the hydrothermally-altered basaltic crust. New data on U-Th disequilibria and O-isotopes in basalts and dacites from Askja volcano reveal a strong correlation between (230Th/232Th) and delta 18O. The 1875 AD dacite has the lowest Th- and O isotope ratios (0.94 and -0.24 per mille, respectively) whereas tephra of evolved basaltic composition, erupted 2 months earlier, has significantly higher values (1.03 and 2.8 per mille, respectively). Highest values are observed in the most recent basalts (erupted in 1920 and 1961) inside the Askja caldera complex and out on the associated fissure swarm (Sveinagja basalt). This correlation also holds for older magma such as an early Holocene dacites, which eruption may have been provoked by rapid glacier thinning. Silicic magmas at Askja volcano thus bear geochemical signatures that are best explained by partial melting of extensively hydrothermally altered crust and that the silicic magma source has remained constant during the Holocene at least. Once these silicic magmas are formed they appear to erupt rapidly rather than mixing and mingling with the incoming basalt heat-source that explains lack of icelandites and the bi-modal volcanism at Askja

  5. Imaging magma plumbing beneath Askja volcano, Iceland

    Science.gov (United States)

    Greenfield, Tim; White, Robert S.

    2015-04-01

    Volcanoes during repose periods are not commonly monitored by dense instrumentation networks and so activity during periods of unrest is difficult to put in context. We have operated a dense seismic network of 3-component, broadband instruments around Askja, a large central volcano in the Northern Volcanic Zone, Iceland, since 2006. Askja last erupted in 1961, with a relatively small basaltic lava flow. Since 1975 the central caldera has been subsiding and there has been no indication of volcanic activity. Despite this, Askja has been one of the more seismically active volcanoes in Iceland. The majority of these events are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes at 12-24km depth, situated in three distinct areas within the volcanic system. These earthquakes often show a frequency content which is lower than the shallower activity, but they still show strong P and S wave arrivals indicative of brittle failure, despite their location being well below the brittle-ductile boundary, which, in Askja is ~7km bsl. These earthquakes indicate the presence of melt moving or degassing at depth while the volcano is not inflating, as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. The lower frequency content must be the result of a slower source time function as earthquakes which are both high frequency and low frequency come from the same cluster, thereby discounting a highly attenuating lower crust. To image the plumbing system beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations

  6. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

    Science.gov (United States)

    Hudak, M. R.; Feineman, M. D.; La Femina, P. C.; Geirsson, H.

    2014-12-01

    Magmatic assimilation of felsic continental crust is a well-documented, relatively common phenomenon. The extent to which basaltic crust is assimilated by magmas, on the other hand, is not well known. Basaltic cannibalism, or the wholesale incorporation of basaltic crustal material into a basaltic magma, is thought to be uncommon because basalt requires more energy than higher silica rocks to melt. Basaltic materials that are unconsolidated, poorly crystalline, or palagonitized may be more easily ingested than fully crystallized massive basalt, thus allowing basaltic cannibalism to occur. Thrihnukagigur volcano, SW Iceland, offers a unique exposure of a buried cinder cone within its evacuated conduit, 100 m below the main vent. The unconsolidated tephra is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to a vent that produced lava and tephra during the ~4 Ka fissure eruption. Preliminary petrographic and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) analyses indicate that there are two populations of plagioclase present in the system - Population One is stubby (aspect ratio 2.1), subhedral to euhedral, and has much higher Ba/Sr ratios. Population One crystals are observed in the cinder cone, dike, and surface lavas, whereas Population Two crystals are observed only in the dike and surface lavas. This suggests that a magma crystallizing a single elongate population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the stubbier population of phenocrysts. This conceptual model for basaltic cannibalism is supported by field observations of large-scale erosion upward into the tephra, which is coated by magma flow-back indicating that magma was involved in the thermal etching. While the unique exposure at Thrihnukagigur makes it an exceptional place to investigate basaltic cannibalism, we suggest that it is not limited to this volcanic system. Rather it is a process that likely

  7. Jakobssonite, CaAlF5, a new mineral from fumaroles at the Eldfell and Hekla volcanoes, Iceland

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Garavelli, A.; Mitolo, D.

    2012-01-01

    (IMA2011-059), ralstonite, heklaite, anhydrite, gypsum, jarosite, hematite, opal and several fluoride minerals that have not been fully characterized. Jakobssonite occurs as soft white fragile crusts of acicular crystals

  8. New Proposed Drilling at Surtsey Volcano, Iceland

    Science.gov (United States)

    Jackson, Marie D.

    2014-12-01

    Surtsey, an isolated oceanic island and a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization, is a uniquely well-documented natural laboratory for investigating processes of rift zone volcanism, hydrothermal alteration of basaltic tephra, and biological colonization and succession in surface and subsurface pyroclastic deposits. Deposits from Surtsey's eruptions from 1963 to 1967 were first explored via a 181-meter hole drilled in 1979 by the U.S. Geological Survey and Icelandic Museum of Natural History.

  9. Geophysical Observations Supporting Research of Magmatic Processes at Icelandic Volcanoes

    Science.gov (United States)

    Vogfjörd, Kristín. S.; Hjaltadóttir, Sigurlaug; Roberts, Matthew J.

    2010-05-01

    Magmatic processes at volcanoes on the boundary between the European and North American plates in Iceland are observed with in-situ multidisciplinary geophysical networks owned by different national, European or American universities and research institutions, but through collaboration mostly operated by the Icelandic Meteorological Office. The terrestrial observations are augmented by space-based interferometric synthetic aperture radar (InSAR) images of the volcanoes and their surrounding surface. Together this infrastructure can monitor magma movements in several volcanoes from the base of the crust up to the surface. The national seismic network is sensitive enough to detect small scale seismicity deep in the crust under some of the voclanoes. High resolution mapping of this seismicity and its temporal progression has been used to delineate the track of the magma as it migrates upwards in the crust, either to form an intrusion at shallow levels or to reach the surface in an eruption. Broadband recording has also enabled capturing low frequency signals emanating from magmatic movements. In two volcanoes, Eyjafjallajökull and Katla, just east of the South Iceland Seismic Zone (SISZ), seismicity just above the crust-mantle boundary has revealed magma intruding into the crust from the mantle below. As the magma moves to shallower levels, the deformation of the Earth‘s surface is captured by geodetic systems, such as continuous GPS networks, (InSAR) images of the surface and -- even more sensitive to the deformation -- strain meters placed in boreholes around 200 m below the Earth‘s surface. Analysis of these signals can reveal the size and shape of the magma as well as the temporal evolution. At near-by Hekla volcano flanking the SISZ to the north, where only 50% of events are of M>1 compared to 86% of earthquakes in Eyjafjallajökull, the sensitivity of the seismic network is insufficient to detect the smallest seismicity and so the volcano appears less

  10. Inside the volcano: The how and why of Thrihnukagigur volcano, Iceland

    Science.gov (United States)

    LaFemina, Peter; Hudak, Michael; Feineman, Maureen; Geirsson, Halldor; Normandeau, Jim; Furman, Tanya

    2015-04-01

    The Thrihnukagigur volcano, located in the Brennisteinsfjöll fissure swarm on the Reykjanes Peninsula, Iceland, offers a unique exposure of the upper magmatic plumbing system of a monogenetic volcano. The volcano formed during a dike-fed strombolian eruption ~3500 BP with flow-back leaving an evacuated conduit, elongated parallel to the regional maximum horizontal stress. At least two vents were formed above the dike, as well as several small hornitos south-southwest of the main vent. In addition to the evacuated conduit, a cave exists 120 m below the vent. The cave exposes stacked lava flows and a buried cinder cone. The unconsolidated tephra of the cone is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to the vent that produced lava and tephra during the ~3500 BP fissure eruption. We present geochemical, petrologic and geologic observations, including a high-resolution three-dimensional scan of the system that indicate the dike intersected, eroded and assimilated unconsolidated tephra from the buried cinder cone, thus excavating a region along the dike, allowing for future slumping and cave formation. Two petrographically distinct populations of plagioclase phenocrysts are present in the system: a population of smaller (maximum length 1 mm) acicular phenocrysts and a population of larger (maximum length 10 mm) tabular phenocrysts that is commonly broken and displays disequilibrium sieve textures. The acicular plagioclase crystals are present in the dike and lavas while the tabular crystals are in these units and the buried tephra. An intrusion that appears not to have interacted with the tephra has only acicular plagioclase. This suggests that a magma crystallizing a single acicular population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the tabular population of phenocrysts from the cone. Petrographic thin-sections of lavas sampled near the vent show undigested fragments of tephra from

  11. Leonardsenite, MgAlF5(H2O)2, a new mineral species from Eldfell Volcano, Heimaey Island, Iceland

    DEFF Research Database (Denmark)

    Mitolo, Donatella; Garavelli, Anna; Balic Zunic, Tonci

    2013-01-01

    microscope produced a mean elemental composition as follows (wt.: Mg 14.66, Al 16.16, F 52.98, 0 15.88, H 1.78, total 101.46. The corresponding empirical formula, calculated on the basis of 2 cations pfu, is Mgi.00Ali 004.64(011)0.361E5.00(1420)1 29. On the basis of chemical analyses and X-ray diffraction...... data, leonardsenite corresponds to the synthetic compound MgAlF5(H2O)(2). The crystal structure of leonardsenite contains infinite chains of [A(1)F(6)] octahedra along the c-axis which are connected via common fluorine atoms to isolated [MgF4(H2O)(2)] octahedra. Leonardsenite is the first aluminum...

  12. Interaction between central volcanoes and regional tectonics along divergent plate boundaries: Askja, Iceland

    Science.gov (United States)

    Trippanera, Daniele; Ruch, Joël; Acocella, Valerio; Thordarson, Thor; Urbani, Stefano

    2018-01-01

    Activity within magmatic divergent plate boundaries (MDPB) focuses along both regional fissure swarms and central volcanoes. An ideal place to investigate their mutual relationship is the Askja central volcano in Iceland. Askja consists of three nested calderas (namely Kollur, Askja and Öskjuvatn) located within a hyaloclastite massif along the NNE-SSW trending Icelandic MDPB. We performed an extensive field-based structural analysis supported by a remote sensing study of tectonic and volcanic features of Askja's calderas and of the eastern flank of the hyaloclastite massif. In the massif, volcano-tectonic structures trend N 10° E to N 40° E, but they vary around the Askja caldera being both parallel to the caldera rim and cross-cutting on the Western side. Structural trends around the Öskjuvatn caldera are typically rim parallel. Volcanic vents and dikes are preferentially distributed along the caldera ring faults; however, they follow the NNE-SSW regional structures when located outside the calderas. Our results highlight that the Askja volcano displays a balanced amount of regional (fissure-swarm related) and local (shallow-magma-chamber related) tectonic structures along with a mutual interaction among these. This is different from Krafla volcano (to the north of Askja) dominated by regional structures and Grímsvötn (to the South) dominated by local structures. Therefore, Askja represents an intermediate tectono-magmatic setting for volcanoes located in a slow divergent plate boundary. This is also likely in accordance with a northward increase in the spreading rate along the Icelandic MDPB.

  13. Interaction between central volcanoes and regional tectonics along divergent plate boundaries: Askja, Iceland

    KAUST Repository

    Trippanera, Daniele

    2017-12-04

    Activity within magmatic divergent plate boundaries (MDPB) focuses along both regional fissure swarms and central volcanoes. An ideal place to investigate their mutual relationship is the Askja central volcano in Iceland. Askja consists of three nested calderas (namely Kollur, Askja and Öskjuvatn) located within a hyaloclastite massif along the NNE-SSW trending Icelandic MDPB. We performed an extensive field-based structural analysis supported by a remote sensing study of tectonic and volcanic features of Askja’s calderas and of the eastern flank of the hyaloclastite massif. In the massif, volcano-tectonic structures trend N 10° E to N 40° E, but they vary around the Askja caldera being both parallel to the caldera rim and cross-cutting on the Western side. Structural trends around the Öskjuvatn caldera are typically rim parallel. Volcanic vents and dikes are preferentially distributed along the caldera ring faults; however, they follow the NNE-SSW regional structures when located outside the calderas. Our results highlight that the Askja volcano displays a balanced amount of regional (fissure-swarm related) and local (shallow-magma-chamber related) tectonic structures along with a mutual interaction among these. This is different from Krafla volcano (to the north of Askja) dominated by regional structures and Grímsvötn (to the South) dominated by local structures. Therefore, Askja represents an intermediate tectono-magmatic setting for volcanoes located in a slow divergent plate boundary. This is also likely in accordance with a northward increase in the spreading rate along the Icelandic MDPB.

  14. Multiple ways of producing intermediate and silicic rocks within Thingmúli and other Icelandic volcanoes

    DEFF Research Database (Denmark)

    Charreteur, Gilles; Tegner, Christian; Haase, Karsten

    2013-01-01

    Major and trace element compositions of rocks and coexisting phenocrysts of the ThingmA(0)li volcano suggest a revision of the existing models for the formation of intermediate and silicic melts in Iceland. The new data define two compositional tholeiitic trends with a significant gap between the...... between the compositions of intermediate and silicic rocks and plate tectonic setting, therefore, should be avoided....

  15. Deep crustal melt plumbing of Bárðarbunga volcano, Iceland

    Science.gov (United States)

    Hudson, T. S.; White, R. S.; Greenfield, T.; Ágústsdóttir, T.; Brisbourne, A.; Green, R. G.

    2017-09-01

    Understanding magmatic plumbing within the Earth's crust is important for understanding volcanic systems and improving eruption forecasting. We discuss magma plumbing under Bárðarbunga volcano, Iceland, over a 4 year period encompassing the largest Icelandic eruption in 230 years. Microseismicity extends through the usually ductile region of the Earth's crust, from 7 to 22 km depth in a subvertical column. Moment tensor solutions for an example earthquake exhibits opening tensile crack behavior. This is consistent with the deep (>7 km) seismicity being caused by the movement of melt in the normally aseismic crust. The seismically inferred melt path from the mantle source is offset laterally from the center of the Bárðarbunga caldera by 12 km, rather than lying directly beneath it. It is likely that an aseismic melt feed also exists directly beneath the caldera and is aseismic due to elevated temperatures and pervasive partial melt under the caldera.

  16. The FUTUREVOLC Supersite's e-Infrastructure - A multidisciplinary data hub and data service for Icelandic Volcanoes

    Science.gov (United States)

    Vogfjörd, Kristín S.; Sigmundsson, Freysteinn; Sverrisson, Sverrir Th.; Sigurdsson, Sigurdur F.; Ófeigsson, Benedikt G.; Arnarsson, Ólafur S.; Kristinsson, Ingvar; Ilyinskaya, Evgenia; Oddsdóttir, Thorarna Ýr; Bergsveinsson, Sölvi Th.; Hjartansson, Kristján R.

    2014-05-01

    The FUTUREVOLC volanological supersite will establish a data hub and dataservice, where researchers, hazard managers and other stake holders can freely obtain access to multidisciplinary data and products on activity, unrest and eruptions at Icelandic volcanoes. The supersite is firmly founded on close interaction between the main Icelandic volcanological research and monitoring institutions, in coordination with expertise from European researchers participating in FUTUREVOLC. The hub is located at the Icelandic Meteorological Office (IMO), an institution responsible for monitoring and archiving data on all natural hazards in Iceland and, which also has a mandate as the state volcano observatory. This association will ensure a long-term sustainable data service. The data accessible at the hub include in-situ and space-based observations, products and models from all the relevant disciplines contributing to volcanological research and local as well as cross-border hazard management, i.e. Earth sciences, atmospheric science, hydrology, remote sensing and space science. Access to the data will be in compliance with the access policy of the GEO (Group on Earth Observations), providing registered users with easy and timely access to data and products of documented quality. This commitment has already led to the acceptance of FUTUREVOLC as a permanent geohazard supersite by CEOS (Committee on Earth Observation Satellites), which will ensure access to additional satellite data and products on Icelandic volcanoes. To facilitate services to seismological data at the supersite hub, the IMO is reconstructing its existing data base and utilizing the SeisComp3 software to manage waveform and parameter data. The accompanying ArcLink component will be used to provide access to event data and waveforms. Access to GPS data will be provided by the GSAC web service which has been installed at the IMO through collaboration with UNAVCO. If appropriate, the format and data base

  17. Crustal movements due to Iceland's shrinking ice caps mimic magma inflow signal at Katla volcano.

    Science.gov (United States)

    Spaans, Karsten; Hreinsdóttir, Sigrún; Hooper, Andrew; Ófeigsson, Benedikt Gunnar

    2015-05-20

    Many volcanic systems around the world are located beneath, or in close proximity to, ice caps. Mass change of these ice caps causes surface movements, which are typically neglected when interpreting surface deformation measurements around these volcanoes. These movements can however be significant, and may closely resemble movements due to magma accumulation. Here we show such an example, from Katla volcano, Iceland. Horizontal movements observed by GPS on the flank of Katla have led to the inference of significant inflow of magma into a chamber beneath the caldera, starting in 2000, and continuing over several years. We use satellite radar interferometry and GPS data to show that between 2001 and 2010, the horizontal movements seen on the flank can be explained by the response to the long term shrinking of ice caps, and that erratic movements seen at stations within the caldera are also not likely to signify magma inflow. It is important that interpretations of geodetic measurements at volcanoes in glaciated areas consider the effect of ice mass change, and previous studies should be carefully reevaluated.

  18. Geologic mapping of the Hekla volcano (Iceland) using integrated data sets from optic and radar sensors

    Science.gov (United States)

    Wever, Tobias; Loercher, Gerhard

    1994-12-01

    During the MAC-Europe campaign in June/July 1991 different airborne data sets (AIRSAR, TMS and AVIRIS) were collected over Iceland. One test site is situated around the Hekla-volcano in South Iceland. This area is characterised by a sequence of lava flows of different ages together with tuffs and ashes. This case study shall contribute to demonstrate the potential of MAC-Europe data for geological mapping. The optical- and the SAR data was analysed separately to elaborate the preferences of the different sensors. An approach was carried out to process an image representing the advantages of the respective sensors in only one presentation. The synergetic approach improves the separation of geological units clearly by combination of two completely different data sets due to the utilisation of spectral bands in the visible and infrared region on one side and on the other side in the microwave region. Beside the petrographical information extracted from optical data using spectral signatures the combination includes physical information like roughness and dielectricity of a target. The geologic setting of the test area is characterised by a very uniform petrography hence the spectral signatures are showing only little variations. Due to this fact, the differentiation of geological units using optical data is limited. The additional use of SAR data establishes the new dimension of the surface roughness which improves the discrimination clearly. This additional parameter presents a new information tool about the state of weathering, age and sequence of the different lava flows. The NASA/JPL AIRSAR system is very suitable for this kind of investigation due to its multifrequency and polarimetric capabilities. The three SAR frequencies (C-, L- and P-Band) enable the detection of a broad range of roughness differences. These results can be enhanced by comprising the full scattering matrix of the polarimetric AIRSAR data.

  19. Magma buoyancy and volatile ascent driving autocyclic eruptivity at Hekla Volcano (Iceland)

    Science.gov (United States)

    Hautmann, Stefanie; Sacks, I. Selwyn; Linde, Alan T.; Roberts, Matthew J.

    2017-09-01

    Volcanic eruptions are typically accompanied by ground deflation due to the withdrawal of magma from depth and its effusion at the surface. Here, based on continuous high-resolution borehole strain data, we show that ground deformation was absent during the major effusion phases of the 1991 and 2000 eruptions of Hekla Volcano, Iceland. This lack of surface deformation challenges the classic model of magma intrusion/withdrawal as source for volcanic ground uplift/subsidence. We incorporate geodetic and geochemical observables into theoretical models of magma chamber dynamics in order to constrain quantitatively alternative co- and intereruptive physical mechanisms that govern magma propagation and system pressurization. We find the lack of surface deformation during lava effusion to be linked to chamber replenishment from below whilst magma migrates as a buoyancy-driven flow from the magma chamber towards the surface. We further demonstrate that intereruptive pressure build-up is likely to be generated by volatile ascent within the chamber rather than magma injection. Our model explains the persistent periodic eruptivity at Hekla throughout historic times with self-initiating cycles and is conceptually relevant to other volcanic systems.

  20. Hekla Volcano, Iceland, in the 20th Century: Lava Volumes, Production Rates, and Effusion Rates

    Science.gov (United States)

    Pedersen, G. B. M.; Belart, J. M. C.; Magnússon, E.; Vilmundardóttir, O. K.; Kizel, F.; Sigurmundsson, F. S.; Gísladóttir, G.; Benediktsson, J. A.

    2018-02-01

    Lava flow thicknesses, volumes, and effusion rates provide essential information for understanding the behavior of eruptions and their associated deformation signals. Preeruption and posteruption elevation models were generated from historical stereo photographs to produce the lava flow thickness maps for the last five eruptions at Hekla volcano, Iceland. These results provide precise estimation of lava bulk volumes: V1947-1948 = 0.742 ± 0.138 km3, V1970 = 0.205 ± 0.012 km3, V1980-1981 = 0.169 ± 0.016 km3, V1991 = 0.241 ± 0.019 km3, and V2000 = 0.095 ± 0.005 km3 and reveal variable production rate through the 20th century. These new volumes improve the linear correlation between erupted volume and coeruption tilt change, indicating that tilt may be used to determine eruption volume. During eruptions the active vents migrate 325-480 m downhill, suggesting rough excess pressures of 8-12 MPa and that the gradient of this excess pressure increases from 0.4 to 11 Pa s-1 during the 20th century. We suggest that this is related to increased resistance along the eruptive conduit.

  1. A Seismological Portrait of the Anomalous 1996 Bardarbunga Volcano, Iceland, Earthquake (Invited)

    Science.gov (United States)

    Tkalcic, H.; Dreger, D. S.; Foulger, G. R.; Julian, B. R.; Fichtner, A.

    2009-12-01

    The Bardarbunga volcano lies beneath the 500-m-thick Vatnajokull icecap, the largest glacier in Europe. Earthquakes with atypical seismic radiation have occurred beneath the Bardarbunga caldera and have been routinely reported in the Global CMT catalog. An earthquake with Mw 5.6 and a strong non-double-couple (NDC) radiation pattern occurred beneath the caldera on 29 September, 1996. A peculiarity of that earthquake was that it was the first in a sequence of seismic and magmatic events and that it was followed, not preceded or accompanied, by a major eruption which ultimately led to a breakout flood from the subglacial caldera lake. The earthquake was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. One of the proposed hypotheses to explain the observed displacements and the sequence of events was the inflation of a shallow magma chamber that might have caused rupture on ring faults below the chamber. Iceland has a heterogeneous crust, with variable thickness, and thus a 1D structural model is not ideal for waveform modeling. We investigated the earthquake with a point-source complete moment-tensor (MT) inversion method using regional long-period seismic waveforms and a composite structural model of Iceland based on joint modeling of teleseismic receiver functions and surface-wave dispersion. When such a model is used, the waveform modeling yields a NDC solution with a strong, vertically oriented compensated linear vector dipole component and a statistically insignificant volumetric contraction. The absence of a volumetric component is surprising in the case of a large volcanic earthquake that cannot be explained by shear slip on a planar fault. A possible mechanism that can produce an earthquake without a volumetric component involves two offset sources with similar but opposite volume changes. We show that although such a model cannot be ruled out, it is unlikely. In order to investigate the hypothesis of a rupture occurring on a

  2. Volcanic ash and daily mortality in Sweden after the Icelandic volcano eruption of May 2011.

    Science.gov (United States)

    Oudin, Anna; Carlsen, Hanne K; Forsberg, Bertil; Johansson, Christer

    2013-12-10

    In the aftermath of the Icelandic volcano Grimsvötn's eruption on 21 May 2011, volcanic ash reached Northern Europe. Elevated levels of ambient particles (PM) were registered in mid Sweden. The aim of the present study was to investigate if the Grimsvötn eruption had an effect on mortality in Sweden. Based on PM measurements at 16 sites across Sweden, data were classified into an ash exposed data set (Ash area) and an unexposed data set (No ash area). Data on daily all-cause mortality were obtained from Statistics Sweden for the time period 1 April through 31 July 2011. Mortality ratios were calculated as the ratio between the daily number of deaths in the Ash area and the No ash area. The exposure period was defined as the week following the days with elevated particle concentrations, namely 24 May through 31 May. The control period was defined as 1 April through 23 May and 1 June through 31 July. There was no absolute increase in mortality during the exposure period. However, during the exposure period the mean mortality ratio was 2.42 compared with 2.17 during the control period, implying a relatively higher number of deaths in the Ash area than in the No ash area. The differences in ratios were mostly due to a single day, 31 May, and were not statistically significant when tested with a Mann-Whitney non-parametric test (p > 0.3). The statistical power was low with only 8 days in the exposure period (24 May through 31 May). Assuming that the observed relative differences were not due to chance, the results would imply an increase of 128 deaths during the exposure period 24-31 May. If 31 May was excluded, the number of extra deaths was reduced to 20. The results of the present study are contradicting and inconclusive, but may indicate that all-cause mortality was increased by the ash-fall from the Grimsvötn eruption. Meta-analysis or pooled analysis of data from neighboring countries might make it possible to reach sufficient statistical power to study effects

  3. Volcanic Ash and Daily Mortality in Sweden after the Icelandic Volcano Eruption of May 2011

    Science.gov (United States)

    Oudin, Anna; Carlsen, Hanne K.; Forsberg, Bertil; Johansson, Christer

    2013-01-01

    In the aftermath of the Icelandic volcano Grimsvötn’s eruption on 21 May 2011, volcanic ash reached Northern Europe. Elevated levels of ambient particles (PM) were registered in mid Sweden. The aim of the present study was to investigate if the Grimsvötn eruption had an effect on mortality in Sweden. Based on PM measurements at 16 sites across Sweden, data were classified into an ash exposed data set (Ash area) and an unexposed data set (No ash area). Data on daily all-cause mortality were obtained from Statistics Sweden for the time period 1 April through 31 July 2011. Mortality ratios were calculated as the ratio between the daily number of deaths in the Ash area and the No ash area. The exposure period was defined as the week following the days with elevated particle concentrations, namely 24 May through 31 May. The control period was defined as 1 April through 23 May and 1 June through 31 July. There was no absolute increase in mortality during the exposure period. However, during the exposure period the mean mortality ratio was 2.42 compared with 2.17 during the control period, implying a relatively higher number of deaths in the Ash area than in the No ash area. The differences in ratios were mostly due to a single day, 31 May, and were not statistically significant when tested with a Mann-Whitney non-parametric test (p > 0.3). The statistical power was low with only 8 days in the exposure period (24 May through 31 May). Assuming that the observed relative differences were not due to chance, the results would imply an increase of 128 deaths during the exposure period 24–31 May. If 31 May was excluded, the number of extra deaths was reduced to 20. The results of the present study are contradicting and inconclusive, but may indicate that all-cause mortality was increased by the ash-fall from the Grimsvötn eruption. Meta-analysis or pooled analysis of data from neighboring countries might make it possible to reach sufficient statistical power to study

  4. Habitat mapping using hyperspectral images in the vicinity of Hekla volcano in Iceland

    Science.gov (United States)

    Vilmundardóttir, Olga K.; Sigurmundsson, Friðþór S.; Pedersen, Gro B. M.; Falco, Nicola; Rustowicz, Rose; Gísladóttir, Guðrún; Benediktsson, Jón A.

    2016-04-01

    Hekla, one of the most active volcanoes in Iceland, has created a diverse volcanic landscape with lava flows, hyaloclastite and tephra fields. The variety of geological formations and different times of formation create diverse vegetation within Hekla's vicinity. The region is subjected to extensive loss of vegetation cover and soil erosion due to human utilization of woodlands and ongoing sheep grazing. The eolian activity and frequent tephra deposition has created vast areas of sparse vegetation cover. Over the 20th century, many activities have centered on preventing further loss of vegetated land and restoring ecosystems. The benefit of these activities is now noticeable in the increased vegetation and woodland cover although erosion is still active within the area. For mapping and monitoring this highly dynamic environment remote sensing techniques are extremely useful. One of the principal goals of the project 'Environmental Mapping and Monitoring of Iceland with Remote Sensing' (EMMIRS) is to use hyperspectral images and LiDAR data to classify and map the vegetation within the Hekla area. The data was collected in an aerial survey in summer 2015 by the Natural Environment Research Council (NERC), UK. The habitat type classification, currently being developed at the Icelandic Institute of Natural History and follows the structure of the EUNIS classification system, will be used for classifying the vegetation. The habitat map created by this new technique's outcome will be compared to the existent vegetation maps made by the conventional vegetation mapping method and the multispectral image classification techniques. In the field, vegetation cover, soil properties and spectral reflectance were measured within different habitat types. Special emphasis was on collecting data on vegetation and soil in the historical lavas from Hekla for assessing habitats forming over the millennia. A lava-chronosequence was established by measuring vegetation and soil in lavas

  5. Hydrothermal Alteration and Seawater Exchange at Surtsey Volcano, Iceland: New results from 1979 Surtsey Drill Core.

    Science.gov (United States)

    Rhodes, M.; Bryce, J. G.; Jercinovic, M. J.; Fahnestock, M. F.; Jackson, M. D.

    2017-12-01

    The archetypal volcano Surtsey erupted spectacularly out of the North Atlantic Ocean from November 1963 to June 1967, on the southern submarine extension of the E. Icelandic Rift Zone. Twelve years later, in 1979, the eastern cone (Surtur I) was drilled to a depth of 181 m to document the growth of the volcano and the interaction of basaltic tephra with seawater [1]. The present study is a pilot project for the International Continental Drilling Project on Surtsey, SUSTAIN, starting in August, 2017. The overall intent is to document the nature, extent and rates of hydrothermal and seawater reaction with tephra over the past 50 years. This work builds on the 1979 drilling studies through new electron microprobe and laser ablation (LA- ICPMS) analyses to document varying degrees of palagonitic alteration of volcanic glass and primary phases to form authigenic minerals (smectite, zeolites, Al-tobermorite, anhydrite) in the intervening 12 years since the eruption. Combined with modal data and inferred phase densities, the data documents the mass balance of major and trace elements among the phases and the relationship of these changes to core depth, temperature and porosity. Although hydrothermal alteration is extensive, especially in the hotter submarine intervals from 60 to 120 m, detailed whole-rock major, trace and isotopic data (Sr, Nd, Pb), show that, apart from hydration and oxidation, there is only modest exchange of elements between tephra and seawater, or hydrothermal fluids, in the upper 140 m of the core prior to 1979. Below 140 m, in a cooler zone of coarse, more porous tephra, extensive exchange of elements, involving hydrothermal introduction of sulfur and growth of anhydrite, is associated with the loss of Ca, K, Rb, Sr and addition of MgO and Na and seawater isotopic signatures. It is surely no coincidence that this zone of elemental and isotopic exchange supports active microbial colonies [2]. Our results serve as an important baseline for the 2017

  6. Fifty years of levelling measurements at Askja volcano, Iceland: New Bayesian interpretations of a unique dataset

    Science.gov (United States)

    Barnie, Talfan; Sigmundsson, Freysteinn; Sturkell, Erik

    2017-04-01

    The year 2016 marks the 50th anniversary of the start of geodetic levelling surveys at Askja volcano in the Northern Volcanic Zone of Iceland. Askja has produced frequent basaltic fissural eruptions and rarer silicic caldera forming eruptions during the Holocene, the most recent of each type in 1961 and 1875 respectively. The potential for widespread disruption from larger eruptions and the popularity of the site with tourists makes Askja an important target for observation. Geodetic monitoring started in 1966 with the installation of a 12 station survey line on the 1961 lava flow, which provided a stable, extensive surface close to the putative source of magma. This was infilled and extended over the following two decades to give a finished levelling line of 35 stations spaced approximately 50 m apart (Tryggvason, Nordic Volcanological Institute, 1989). With the exception of the period 1972 to 1983, this line has been surveyed every year, providing a unique record of post eruptive deformation at a spreading rift segment capable of capturing magma motions at depth and any potential recharging in anticipation of future activity. The levelling has so far revealed that after an initial period of complicated inflations and deflations the volcano settled into a pattern of slowly decaying deflation from 1983 onwards (Sturkell and Sigmundsson, JGR, 105, 2000), a pattern that has been confirmed by newer geodetic techniques as they have become available (e.g. Pagli et al., JVGR, 152, 2005). The strength of the levelling data at Askja is its long time span, high accuracy and same measurement type over a period of 50 years. However, the small extent of the levelling line limits the power of the network to resolve changes in the magma plumbing system and requires the addition of constraints from other sources. This lends itself to Bayesian modelling techniques where assumptions are made explicit as priors and uncertainties in retrieved parameters can be comprehensibly modelled

  7. Large explosive basaltic eruptions at Katla volcano, Iceland: Fragmentation, grain size and eruption dynamics

    Science.gov (United States)

    Schmith, Johanne; Höskuldsson, Ármann; Holm, Paul Martin; Larsen, Guðrún

    2018-04-01

    Katla volcano in Iceland produces hazardous large explosive basaltic eruptions on a regular basis, but very little quantitative data for future hazard assessments exist. Here details on fragmentation mechanism and eruption dynamics are derived from a study of deposit stratigraphy with detailed granulometry and grain morphology analysis, granulometric modeling, componentry and the new quantitative regularity index model of fragmentation mechanism. We show that magma/water interaction is important in the ash generation process, but to a variable extent. By investigating the large explosive basaltic eruptions from 1755 and 1625, we document that eruptions of similar size and magma geochemistry can have very different fragmentation dynamics. Our models show that fragmentation in the 1755 eruption was a combination of magmatic degassing and magma/water-interaction with the most magma/water-interaction at the beginning of the eruption. The fragmentation of the 1625 eruption was initially also a combination of both magmatic and phreatomagmatic processes, but magma/water-interaction diminished progressively during the later stages of the eruption. However, intense magma/water interaction was reintroduced during the final stages of the eruption dominating the fine fragmentation at the end. This detailed study of fragmentation changes documents that subglacial eruptions have highly variable interaction with the melt water showing that the amount and access to melt water changes significantly during eruptions. While it is often difficult to reconstruct the progression of eruptions that have no quantitative observational record, this study shows that integrating field observations and granulometry with the new regularity index can form a coherent model of eruption evolution.

  8. Radioactive secrets of Icelandic volcanoes: Eyjafjoll (March 2010) and Grimsvoetn (May 2011); Les secrets radioactifs des volcans islandais: Eyjafjoll (mars 2010) et Grimsvoetn (mai 2011)

    Energy Technology Data Exchange (ETDEWEB)

    Guiraud-Vitaux, F.; Pradel, J.; Colas-Linhart, N.

    2011-07-15

    This article recalls that volcanoes release huge quantities of radioactive nuclides during their eruption. In March 2010 the Eyjafjoll volcano (Iceland) ejected several hundred million tonnes of dust in the first 72 hours among which 400 tonnes of uranium-238 (20.000 billions Bq) and 1200 tonnes of natural thorium. Polonium-210 was also released in the atmosphere. Most part of the radioactivity fell on Icelandic soil and no sanitary measures were taken by the authorities because the resulting doses were too low to have hazardous effects. (A.C.)

  9. Magmatic emulsion texture formed by mixing during extrusion, Rauðafell composite complex, Breiðdalur volcano, eastern Iceland

    DEFF Research Database (Denmark)

    Charreteur, Gilles; Tegner, Christian

    2013-01-01

    The Rauoafell composite complex is part of the Neogene Breiodalur volcano, eastern Iceland and is composed of a composite feeder dyke, a vent structure and a composite flow. The two end-members of the composite complex are rhyolite and basalt, and both are rich in plagioclase macrocrysts: bytowni...

  10. European collaboration for improved monitoring of Icelandic volcanoes: Status of the FUTUREVOLC project after the initial 18 months

    Science.gov (United States)

    Dumont, Stéphanie; Parks, Michelle; Sigmundsson, Freysteinn; Vogfjörð, Kristín; Einarsdóttir, Heiðveig Maria; Tumi Gudmundsson, Magnús; Kristinsson, Ingvar; Loughlin, Sue; Ilyinskaya, Evgenia; Hooper, Andrew; Kylling, Arve; Witham, Claire; Bean, Chris; Braiden, Aoife; Ripepe, Maurizio; Prata, Fred; Pétur Heiðarsson, Einar; Other Members Of The Futurevolc Team

    2014-05-01

    The FUTUREVOLC project funded by the European Union (FP7) is devoted to volcanic hazard assessment and establishing an integrated volcanological monitoring procedure through a European collaboration. To reach these objectives the project combines broad expertise from 26 partners from 10 countries, focusing on the four most active volcanoes of Iceland: Grímsvötn, Katla, Hekla and Bárdarbunga. The geological setting of Iceland, the high rate of eruptions and the various eruption styles make this country an optimal natural laboratory to study volcanic processes from crustal depths to the atmosphere. The project, which began on 1 October 2012, integrates advanced monitoring and analytical techniques in an innovative way, focusing on (i) detailed monitoring to improve our understanding of the seismic/magmatic unrest, in order to estimate the amount of magma available for an eruption and to provide early warnings (ii) the dynamics of magma in the conduit and a near real time estimation of the mass eruption rate and (iii) observing and modelling the plume dynamics. The project design considers effective collaboration between partners and aims for efficient cross-disciplinary workflows. A major step during the first 18 months of the project was the installation of additional equipment in the volcanic regions of Iceland to reinforce and complement the existing monitoring. The instruments include: seismometers, GPS stations, MultigGAS detectors, DOAS, infrasonic arrays, electric field sensors, radars, and optical particle sizers. Data streaming is designed to withstand extreme weather conditions. The FUTUREVOLC project has an open data policy for real and near-time data. Implementation of a data hub is currently under way, based on open access to data from the 2010 Eyjafjallajökull eruption. Access to volcano monitoring data through a common interface will allow timely information on magma movements facilitated through combined analysis. A key part of the project is to

  11. Warming, Sheep and Volcanoes: Land Cover Changes in Iceland Evident in Satellite NDVI Trends

    Directory of Open Access Journals (Sweden)

    Martha Raynolds

    2015-07-01

    Full Text Available In a greening Arctic, Iceland stands out as an area with very high increases in the AVHRR Normalized Difference Vegetation Index (NDVI, 1982–2010. We investigated the possible sources of this anomalous greening in Iceland’s dynamic landscape, analyzing changes due to volcanism and warming temperatures, and the effects of agricultural and industrial land use changes. The analysis showed the increases were likely due to reductions in grazing in erosion-prone rangelands, extensive reclamation and afforestation efforts, as well as a response to warming climate, including glacial retreat. Like Scandinavia and much of the rest of the Arctic, Iceland has shown a recent reduction in NDVI since 2002, but still above pre-2000 levels. Theil-Sen robust regression analysis of MODIS NDVI trends from 2002 to 2013 showed Iceland had a slightly negative NDVI trend of 0.003 NDVI units/year (p < 0.05, with significant decreases in an area three times greater (29,809 km2 than that with increases (9419 km2. Specific areas with large decreases in NDVI during the last decade were due to the formation of a large reservoir as a part of a hydroelectric power project (Kárahnjúkar, 2002–2009, and due to ashfall from two volcanic eruptions (Eyjafjallajökull, 2010; Grímsvötn, 2011. Increases in NDVI in the last decade were found in erosion control areas, around retreating glaciers, and in other areas of plant colonization following natural disturbance. Our analysis demonstrates the effectiveness of MODIS NDVI for identifying the causes of changes in land cover, and confirms the reduction in NDVI in the last decade using both the AVHRR and MODIS satellite data.

  12. Modelling the effects of ice-sheet activity on CO2 outgassing by Icelandic volcanoes

    Science.gov (United States)

    Armitage, J. J.; Ferguson, D.; Petersen, K. D.; Creyts, T. T.

    2017-12-01

    Glacial cycles may play a significant role in mediating the flux of magmatic CO2 between the Earth's mantle and atmosphere. In Iceland, it is thought that late-Pleistocene deglaciation led to a significant volcanic pulse, evidenced by increased post-glacial lava volumes and changes in melt chemistry consistent with depressurization. Investigating the extent to which glacial activity may have affected volcanic CO2 emissions from Iceland, and crucially over what timescale, requires detailed knowledge of how the magma system responded to the growth and collapse of the ice-sheet before and after the LGM. To investigate this, we coupled a model of magma generation and transport with a history of ice-sheet activity. Our results show that the emplacement and removal of the LGM ice-sheet likely led to two significant pulses of magmatic CO2. The first, and most significant of these, is associated with ice-sheet growth and occurs as the magma system recovers from glacial loading. This recovery happens from the base of the melting region upwards, producing a pulse of CO2 rich magma that is predicted to reach the surface around 20 ka after the loading event, close in time to the LGM. The second peak in CO2 output occurs abruptly following deglaciation as a consequence of increased rates of melt generation and transport in the shallow mantle. Although these post-glacial melts are relatively depleted in CO2, the increase in magma flux leads to a short-lived period of elevated CO2 emissions. Our results therefore suggest a negative feedback, whereby ice-sheet growth produces a delayed pulse of magmatic CO2, which, in addition to increased geothermal heat flux, may contribute towards driving deglaciation, which itself then causes further magmatism and CO2 outgassing. This model is consistent with the seismic structure of the asthenosphere below Iceland, and the established compositional and volumetric trends for sub- and post-glacial volcanism in Iceland. These trends show that

  13. Time dependence of volcano inflation: mass influx or viscoelastic relaxation? Insights from Grímsvötn volcano, Iceland

    Science.gov (United States)

    Segall, P.

    2017-12-01

    Distinguishing magma chamber pressurization from relaxation of a viscoelastic aureole surrounding the chamber based on geodetic measurements has remained challenging. Elastic models with mass inflow proportional to the pressure difference between the chamber and a deep reservoir predict exponentially decaying flux. For a spherical chamber surrounded by a Maxwell viscoelastic shell with pressure dependent recharge, the surface deformation is the sum of two exponentials (Segall, 2016). GPS displacements following eruptions of Grímsvötn, Iceland in 2004 and 2011 exhibit rapid post-eruptive inflation (time scale of 0.1 yr), followed by inflation with a much longer time constant. Markov Chain Monte Carlo inversion with the viscoelastic model shows the GPS time series can be fit with viscosity of 2e16 Pa-s, and a relatively incompressible magma, B = beta_c/ (beta_m + beta_c) > 0.6, where beta_m and beta_c are chamber and magma compressibility. The latter appears to conflict with the ratio of erupted volume to geodetically inferred source volume change, rv 10, obtained for the best fitting spherical (Mogi ) source (Hreinsdóttir, 2014). Since rv = 1/B, this implies a relatively compressible melt, B 0.1. Reexamination of the co-eruptive GPS and tilt data with the more general ellipsoidal model of Cervelli (2013), reveals that the best fitting sources are oblate (b/a 3), deeper, and with larger volume changes, rv 3, relative to spherical models. Oblate magma chambers are consistent with seismic tomography. FEM calculations including free surface effects lead to even larger co-eruptive volume changes, smaller rv and hence larger B. I conclude that the data are consistent with rapid post-eruptive inflation driven by viscoelastic relaxation with a relatively incompressible magma, although other interpretations will be discussed.

  14. Integration of micro-gravity and geodetic data to constrain shallow system mass changes at Krafla Volcano, N Iceland

    Science.gov (United States)

    de Zeeuw-van Dalfsen, Elske; Rymer, Hazel; Williams-Jones, Glyn; Sturkell, Erik; Sigmundsson, Freysteinn

    2006-04-01

    New and previously published micro-gravity data are combined with InSAR data, precise levelling and GPS measurements to produce a model for the processes operating at Krafla volcano, 20 years after its most recent eruption. The data have been divided into two periods: from 1990 to 1995 and from 1996 to 2003 and show that the rate of deflation at Krafla is decaying exponentially. The net micro-gravity change at the centre of the caldera is shown, using the measured free air gradient, to be -85 μGal for the first and -100 μGal for the second period. After consideration of the effects of water extraction by the geothermal power station within the caldera, the net gravity decreases are -73±17 μGal for the first and -65±17 μGal for the second period. These decreases are interpreted in terms of magma drainage. Following a Mogi point source model, we calculate the mass decrease to be ˜2×1010 kg/year reflecting a drainage rate of ˜0.23 m3/s, similar to the ˜0.13 m3/s drainage rate previously found at Askja volcano, N. Iceland. Based on the evidence for deeper magma reservoirs and the similarity between the two volcanic systems, we suggest a pressure-link between Askja and Krafla at deeper levels (at the lower crust or the crust-mantle boundary). After the Krafla fires, co-rifting pressure decrease of a deep source at Krafla stimulated the subsequent inflow of magma, eventually affecting conditions along the plate boundary in N. Iceland, as far away as Askja. We anticipate that the pressure of the deeper reservoir at Krafla will reach a critical value and eventually magma will rise from there to the shallow magma chamber, possibly initiating a new rifting episode. We have demonstrated that by examining micro-gravity and geodetic data, our knowledge of active volcanic systems can be significantly improved.

  15. An overview of the Icelandic Volcano Observatory response to the on-going rifting event at Bárðarbunga (Iceland) and the SO2 emergency associated with the gas-rich eruption in Holuhraun

    Science.gov (United States)

    Barsotti, Sara; Jonsdottir, Kristin; Roberts, Matthew J.; Pfeffer, Melissa A.; Ófeigsson, Benedikt G.; Vögfjord, Kristin; Stefánsdóttir, Gerður; Jónasdóttir, Elin B.

    2015-04-01

    On 16 August, 2014, Bárðarbunga volcano entered a new phase of unrest. Elevated seismicity in the area with up to thousands of earthquakes detected per day and significant deformation was observed around the Bárðarbunga caldera. A dike intrusion was monitored for almost two weeks until a small, short-lived effusive eruption began on 29 August in Holuhraun. Two days later a second, more intense, tremendously gas-rich eruption started that is still (as of writing) ongoing. The Icelandic Volcano Observatory (IVO), within the Icelandic Meteorological Office (IMO), monitors all the volcanoes in Iceland. Responsibilities include evaluating their related hazards, issuing warnings to the public and Civil Protection, and providing information regarding risks to aviation, including a weekly summary of volcanic activity provided to the Volcanic Ash Advisory Center in London. IVO has monitored the Bárðarbunga unrest phase since its beginning with the support of international colleagues and, in collaboration with the University of Iceland and the Environment Agency of Iceland, provides scientific support and interpretation of the ongoing phenomena to the local Civil Protection. The Aviation Color Code, for preventing hazards to aviation due to ash-cloud encounter, has been widely used and changed as soon as new observations and geophysical data from the monitoring network have suggested a potential evolution in the volcanic crisis. Since the onset of the eruption, IVO is monitoring the gas emission by using different and complementary instrumentations aimed at analyzing the plume composition as well as estimating the gaseous fluxes. SO2 rates have been measured with both real-time scanning DOASes and occasional mobile DOAS traveses, near the eruption site and in the far field. During the first month-and-a-half of the eruption, an average flux equal to 400 kg/s was registered, with peaks exceeding 1,000 kg/s. Along with these measurements the dispersal model CALPUFF has

  16. Hydrovolcanic and Hydrothermal Biomediated Mineral Growth in Basaltic Tuff, Surtsey Volcano, Iceland

    Science.gov (United States)

    Jackson, M. D.; Couper, S.; Ivarsson, M.; Stan, C. V.; Tamura, N.; Miyagi, L. M.; Moore, J. G.

    2017-12-01

    this hypothesis. Hydrovolcanic fragmentation apparently increased ingress of seawater from the marine biosphere. Both eruptive and hydrothermal water-rock interactions influenced palagonitic alteration at the submillimeter scale during diverse temperature chronologies in the very young volcano.

  17. Constraints on Pressure-Driven Flow Beneath Askja Volcano, Iceland, from Microgravity and InSAR Measurements

    Science.gov (United States)

    Giniaux, J. M.; Hooper, A. J.; Dumont, S.; Bagnardi, M.; Drouin, V.; Sigmundsson, F.

    2017-12-01

    Askja is an active volcano in the Northern Volcanic Zone of Iceland, lying within a spreading segment of the mid-Atlantic ridge. There have been at least 40 eruptions in the last 1100 years, including the 1875 VEI-5 caldera-forming Plinian event. However the current state of the complex magmatic system and the probability of an eruption in the near future are not well understood. Steadily decaying subsidence within the main caldera has been recorded with a variety of geodetic measurements since at least 1983. It has been postulated that rifting extension and shallow magmatic processes, e.g. outflow and/or crystallisation, could be responsible for this subsidence. All models using surface deformation data agree that there is at least one shallow source at 2-2.5 km b.s.l. (3-3.5 km below the surface), shrinking at a rate of approximately -1.4 to -2.1x106 km3yr-1. This depth is consistent with results from seismic tomography, which also reveal the presence of two melt storage regions at about 5-7 and 9-11 km b.s.l. The subsidence has been accompanied by a gravity decrease (mass loss) since at least 1988, except for a measured increase between 2007 and 2008. These gravity signals have been interpreted as the result of magma drainage and magma intrusion, respectively. Here, we present new gravity results from 2015-2017, measured over an extended network within the caldera, together with new InSAR time series results. We use these data to model the location, depth, volume and mass changes beneath Askja from 2002-2017. Our results show a gravity decrease over a larger area than previously recognised, implying greater mass loss than previously thought. The InSAR results show a gradually decreasing rate of subsidence, consistent with earlier results from levelling and GPS, but the spatial pattern is more complicated than a simple spherical source would imply. Taken together the volume and mass decreases can be explained by magmatic drainage from shallow to deeper reservoirs

  18. Volcanoes

    Science.gov (United States)

    ... rock, steam, poisonous gases, and ash reach the Earth's surface when a volcano erupts. An eruption can also cause earthquakes, mudflows and flash floods, rock falls and landslides, acid rain, fires, and even tsunamis. Volcanic gas ...

  19. Magmatic emulsion texture formed by mixing during extrusion, Rauðafell composite complex, Breiðdalur volcano, eastern Iceland

    Science.gov (United States)

    Charreteur, Gilles; Tegner, Christian

    2013-06-01

    The Rauðafell composite complex is part of the Neogene Breiðdalur volcano, eastern Iceland and is composed of a composite feeder dyke, a vent structure and a composite flow. The two end-members of the composite complex are rhyolite and basalt, and both are rich in plagioclase macrocrysts: bytownite in basalt and oligoclase in rhyolite. The rhyolite also includes ferroaugite macrocrysts. The mixed rocks are separated in three textural groups related to mixing proportions. When the basaltic end-member is dominant, a hybrid texture with a homogeneous matrix is observed and the only evidence of mixing is the presence of antecrysts of both end-members. When the basaltic end-member represents c. 65 to 30 % of the mixture, we observe emulsion textures composed of finely co-mingled basalt and rhyolite. The difference between these two textural expressions of mixing is due to effects of diffusion. The third texture shows mafic enclaves suspended in a rhyolitic matrix. In these rocks, the proportion of the basaltic end-member is inferior to 30 %, implying that the basalt froze solid in contact with the rhyolite. Zoning of plagioclase shows that the mixing processes are driven initially by highly efficient micro-mingling; the emulsification is possibly a result of compositional gradient stresses (Korteweg stress) between miscible basalt and rhyolite. This is followed by chemical diffusion (hybridisation) and tend to protect antecrysts from reaction with the primitive magmas. When antecrysts originated in the evolved magma, they undergo dissolution due to thermal disequilibrium during mingling and chemical disequilibrium during hybridisation. We argue that such mixing processes are important in producing intermediate rocks in Iceland and elsewhere that shows only the chemical attributes of an origin by mixing. The preservation of emulsion textures is rare and highly dependent on cooling history.

  20. Modulation of glacier ablation by tephra coverage from Eyjafjallajökull and Grímsvötn volcanoes, Iceland: an automated field experiment

    Science.gov (United States)

    Möller, Rebecca; Möller, Marco; Kukla, Peter A.; Schneider, Christoph

    2018-01-01

    We report results from a field experiment investigating the influence of volcanic tephra coverage on glacier ablation. These influences are known to be significantly different from those of moraine debris on glaciers due to the contrasting grain size distribution and thermal conductivity. Thus far, the influences of tephra deposits on glacier ablation have rarely been studied. For the experiment, artificial plots of two different tephra types from Eyjafjallajökull and Grímsvötn volcanoes were installed on a snow-covered glacier surface of Vatnajökull ice cap, Iceland. Snow-surface lowering and atmospheric conditions were monitored in summer 2015 and compared to a tephra-free reference site. For each of the two volcanic tephra types, three plots of variable thickness ( ˜ 1.5, ˜ 8.5 and ˜ 80 mm) were monitored. After limiting the records to a period of reliable measurements, a 50-day data set of hourly records was obtained, which can be downloaded from the Pangaea data repository (pangaea.de" target="_blank">https://www.pangaea.de; doi:10.1594/PANGAEA.876656). The experiment shows a substantial increase in snow-surface lowering rates under the ˜ 1.5 and ˜ 8.5 mm tephra plots when compared to uncovered conditions. Under the thick tephra cover some insulating effects could be observed. These results are in contrast to other studies which depicted insulating effects for much thinner tephra coverage on bare-ice glacier surfaces. Differences between the influences of the two different petrological types of tephra exist but are negligible compared to the effect of tephra coverage overall.

  1. Total grain-size distribution of four subplinian-Plinian tephras from Hekla volcano, Iceland: Implications for sedimentation dynamics and eruption source parameters

    Science.gov (United States)

    Janebo, Maria H.; Houghton, Bruce F.; Thordarson, Thorvaldur; Bonadonna, Costanza; Carey, Rebecca J.

    2018-05-01

    The size distribution of the population of particles injected into the atmosphere during a volcanic explosive eruption, i.e., the total grain-size distribution (TGSD), can provide important insights into fragmentation efficiency and is a fundamental source parameter for models of tephra dispersal and sedimentation. Recent volcanic crisis (e.g. Eyjafjallajökull 2010, Iceland and Córdon Caulle 2011, Chile) and the ensuing economic losses, highlighted the need for a better constraint of eruption source parameters to be used in real-time forecasting of ash dispersal (e.g., mass eruption rate, plume height, particle features), with a special focus on the scarcity of published TGSD in the scientific literature. Here we present TGSD data associated with Hekla volcano, which has been very active in the last few thousands of years and is located on critical aviation routes. In particular, we have reconstructed the TGSD of the initial subplinian-Plinian phases of four historical eruptions, covering a range of magma composition (andesite to rhyolite), eruption intensity (VEI 4 to 5), and erupted volume (0.2 to 1 km3). All four eruptions have bimodal TGSDs with mass fraction of fine ash (primary fragmentation. Due to differences in plume height, this contrast is not seen in samples from individual sites, especially in the near field, where lapilli have a wider spatial coverage in the Plinian deposits. The distribution of pyroclast sizes in Plinian versus subplinian falls reflects competing influences of more efficient fragmentation (e.g., producing larger amounts of fine ash) versus more efficient particle transport related to higher and more vigorous plumes, displacing relatively coarse lapilli farther down the dispersal axis.

  2. Hydro-morphodynamic modelling of a volcano-induced sediment-laden outburst flood at Sólheimajökull, Iceland

    Science.gov (United States)

    Guan, M.; Wright, N.; Sleigh, P. A.; Carrivick, J.; Staines, K.

    2013-12-01

    Outburst floods are one of the most catastrophic natural hazards for populations and infrastructure. Such high-magnitude sudden onset floods generally comprise of an advancing intense kinematic water wave that can induce considerable sediment transport. The exploration and investigation of sediment-laden outburst floods cannot be limited solely to water flow but must also include the flood-induced sediment transport. Understanding the complex flow-bed interaction process in large (field) scale outburst floods is still limited, not least due to a lack of well-constrained field data, but also because consensus on appropriate modelling schemes has yet to be decided. In recent years, attention has focussed on the numerical models capable of describing the process of erosion, transport and deposition in such flows and they are now at a point at which they provide useful quantitative data. Although the "exact" measure of bed change is still unattainable the numerical models enhance and improve insights into large outburst flood events. In this study, a volcano-induced jökulhlaup or glacial outburst flood (GLOF) at Sólheimajökull, Iceland is reproduced by novel 2D hydro-morphodynamic model that considers both bedload and suspended load based on shallow water theory. The simulation of sediment-laden outburst flood is shown to perform well, with further insights into the flow-bed interaction behaviour obtained from the modelling output. These results are beneficial to flood risk management and hazard prevention and mitigation. In summary, the modelling outputs show that (1) the quantity of bed erosion and deposition are sensitive to the sediment gain size, yet, the influences are not so significant when considering flow discharge; (2) finer resolution of topography increases the computational time significantly yet the results are not affected correspondingly; (3) the bed changes simulated by the present model achieves reasonably good agreement with those by the

  3. Exploring Geology on the World-Wide Web--Volcanoes and Volcanism.

    Science.gov (United States)

    Schimmrich, Steven Henry; Gore, Pamela J. W.

    1996-01-01

    Focuses on sites on the World Wide Web that offer information about volcanoes. Web sites are classified into areas of Global Volcano Information, Volcanoes in Hawaii, Volcanoes in Alaska, Volcanoes in the Cascades, European and Icelandic Volcanoes, Extraterrestrial Volcanism, Volcanic Ash and Weather, and Volcano Resource Directories. Suggestions…

  4. Crustal thermal state and origin of silicic magma in Iceland: the case of Torfajökull, Ljósufjöll and Snæfellsjökull volcanoes

    Science.gov (United States)

    Martin, E.; Sigmarsson, O.

    2007-05-01

    Pleistocene and Holocene peralkaline rhyolites from Torfajökull (South Iceland Volcanic Zone) and Ljósufjöll central volcanoes and trachytes from Snæfellsjökull (Snæfellsnes Volcanic Zone) allow the assessment of the mechanism for silicic magma genesis as a function of geographical location and crustal geothermal gradient. The low δ18O (2.4‰) and low Sr concentration (12.2 ppm) measured in Torfajökull rhyolites are best explained by partial melting of hydrated metabasaltic crust followed by major fractionation of feldspar. In contrast, very high 87Sr/86Sr (0.70473) and low Ba (8.7 ppm) and Sr (1.2 ppm) concentrations measured in Ljósufjöll silicic lavas are best explained by fractional crystallisation and subsequent 87Rb decay. Snæfellsjökull trachytes are also generated by fractional crystallisation, with less than 10% crustal assimilation, as inferred from their δ18O. The fact that silicic magmas within, or close to, the rift zone are principally generated by crustal melting whereas those from off-rift zones are better explained by fractional crystallisation clearly illustrates the controlling influence of the thermal state of the crust on silicic magma genesis in Iceland.

  5. Physicochemical and toxicological profiling of ash from the 2010 and 2011 eruptions of Eyjafjallajökull and Grímsvötn volcanoes, Iceland using a rapid respiratory hazard assessment protocol.

    Science.gov (United States)

    Horwell, C J; Baxter, P J; Hillman, S E; Calkins, J A; Damby, D E; Delmelle, P; Donaldson, K; Dunster, C; Fubini, B; Kelly, F J; Le Blond, J S; Livi, K J T; Murphy, F; Nattrass, C; Sweeney, S; Tetley, T D; Thordarson, T; Tomatis, M

    2013-11-01

    The six week eruption of Eyjafjallajökull volcano in 2010 produced heavy ash fall in a sparsely populated area of southern and south eastern Iceland and disrupted European commercial flights for at least 6 days. We adopted a protocol for the rapid analysis of volcanic ash particles, for the purpose of informing respiratory health risk assessments. Ash collected from deposits underwent a multi-laboratory physicochemical and toxicological investigation of their mineralogical parameters associated with bio-reactivity, and selected in vitro toxicology assays related to pulmonary inflammatory responses. Ash from the eruption of Grímsvötn, Iceland, in 2011 was also studied. The results were benchmarked against ash from Soufrière Hills volcano, Montserrat, which has been extensively studied since the onset of eruptive activity in 1995. For Eyjafjallajökull, the grain size distributions were variable: 2-13 vol% of the bulk samples were <4 µm, with the most explosive phases of the eruption generating abundant respirable particulate matter. In contrast, the Grímsvötn ash was almost uniformly coarse (<3.5 vol%<4 µm material). Surface area ranged from 0.3 to 7.7 m2 g(-1) for Eyjafjallajökull but was very low for Grímsvötn (<0.6 m2 g(-1)). There were few fibre-like particles (which were unrelated to asbestos) and the crystalline silica content was negligible in both eruptions, whereas Soufrière Hills ash was cristobalite-rich with a known potential to cause silicosis. All samples displayed a low ability to deplete lung antioxidant defences, showed little haemolysis and low acute cytotoxicity in human alveolar type-1 like epithelial cells (TT1). However, cell-free tests showed substantial hydroxyl radical generation in the presence of hydrogen peroxide for Grímsvötn samples, as expected for basaltic, Fe-rich ash. Cellular mediators MCP-1, IL-6, and IL-8 showed chronic pro-inflammatory responses in Eyjafjallajökull, Grímsvötn and Soufrière Hills samples

  6. Anatomy of a volcano

    NARCIS (Netherlands)

    Hooper, A.; Wassink, J.

    2011-01-01

    The Icelandic volcano Eyjafjallajökull caused major disruption in European airspace last year. According to his co-author, Freysteinn Sigmundsson, the reconstruction published in Nature six months later by aerospace engineering researcher, Dr Andy Hooper, opens up a new direction in volcanology. “We

  7. A quantitative x-ray diffraction inventory of volcaniclastic inputs into the marine sediment archives off Iceland: a contribution to the Volcanoes in the Arctic System programme

    Directory of Open Access Journals (Sweden)

    Dennis D. Eberl

    2013-02-01

    Full Text Available This paper re-evaluates how well quantitative x-ray diffraction (qXRD can be used as an exploratory method of the weight percentage (wt% of volcaniclastic sediment, and to identify tephra events in marine cores. In the widely used RockJock v6 software programme, qXRD tephra and glass standards include the rhyodacite White River tephra (Alaska, a rhyolitic tephra (Hekla-4 and the basaltic Saksunarvatn tephra. Experiments of adding known wt% of tephra to felsic bedrock samples indicated that additions ≥10 wt% are accurately detected, but reliable estimates of lesser amounts are masked by amorphous material produced by milling. Volcaniclastic inputs range between 20 and 50 wt%. Primary tephra events are identified as peaks in residual qXRD glass wt% from fourth-order polynomial fits. In cores where tephras have been identified by shard counts in the >150 µm fraction, there is a positive correlation (validation with peaks in the wt% glass estimated by qXRD. Geochemistry of tephra shards confirms the presence of several Hekla-sourced tephras in cores B997-317PC1 and -319PC2 on the northern Iceland shelf. In core B997-338 (north-west Iceland, there are two rhyolitic tephras separated by ca. 100 cm with uncorrected radiocarbon dates on articulated shells of around 13 000 yr B.P. These tephras may be correlatives of the Borrobol and Penifiler tephras found in Scotland. The number of Holocene tephra events per 1000 yr was estimated from qXRD on 16 cores and showed a bimodal distribution with an increased number of events in both the late and early Holocene.

  8. Icelandic Geopower

    DEFF Research Database (Denmark)

    Maguire, James

    into these discussions through an ethnographic and practice based approach to the study of renewable energy. It does so by examining the production of geothermal energy in the Hengill volcanic zone in the southwest of Iceland. The analysis that is produced is based upon an engagement with the practices, ideas...... with those who make geothermal energy (geologists) as well as those who protest against its production (residents living in the vicinity of the volcanic zone) allows me to understand how geothermal energy is produced and resisted through particular sets of practices and technologies. At the same time it also....... Carrying out ethnographic fieldwork with key actors allows me to examine how this complex techno-political work is carried out and to what effects. However, drilling deep in the subterranean of a highly active seismic area is dangerous and risky. In producing geothermal energy, other consequences...

  9. Cultural Policy in Iceland

    DEFF Research Database (Denmark)

    Gudmundsson, Gestur

    2003-01-01

    on the continuing emphasis on central cultural institution and the Icelandic language. Since the 1970s Cold War conflicts have been replaced by a consensus on growing support to artists and an armth's length policy, and furthermore the 1990s have seen a strong move towards NPM and international participation.......The article examines the history of cultural policy in Iceland from a Nordic comparative perspective. National cultural policy takes form in the 19th and early 20th century as a part of the nation-building, emphasising the Icelandic language as the core of national identity, building cultural...

  10. Iceland country update

    International Nuclear Information System (INIS)

    Palmason, G.; Gudmundsson, A.

    1990-01-01

    This paper provides information on geothermal energy utilization in Iceland. Topics include: the present and planned production of electricity in Iceland, from all primary sources, the present and planned utilization of geothermal energy for electricity generation, the use of geothermal energy in all public district heating systems, high temperature geothermal localities, high-temperature wells drilled for electrical utilization and wells drilled for the combined use for district heating and power production, and wells drilled for direct use

  11. GLO polymorphism in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, S; Arnason, A; Jensson, O

    1980-01-01

    The phenotypes of red cell glyoxalase I (GLO) were determined in two Icelandic population samples using starch-gel electrophoresis and high-voltage agarose-gel electrophoresis. The gene frequencies of 178 unrelated individuals were 0.46 for GLO/sup 1/ and 0.54 for GLO/sup 2/. In a group of Icelandic insulin-dependent diabetics the gene frequencies were found to be very similar. The evaluation of 30 mother-child pairs is also shown.

  12. Oxygen isotope ratios of the Icelandic crust

    International Nuclear Information System (INIS)

    Hattori, K.; Muehlenbachs, K.

    1982-01-01

    Oxygen isotope ratios of hydrothermally altered basalts from depth of up to approx.3 km are reported from three localities in Iceland: International Research Drilling Project (IRDP) core at Reydarfjordur, eastern Iceland (Tertiary age); drill cuttings from Reykjavik (Plio-Pleistocene age); and Halocene drill cuttings from the active Krafla central volcano. Whole rock samples from these three localities have delta 18 O values averaging +3.9 +- 1.3, +2.4 +- 1.1, and -7.7 +- 2.4%, respectively. The observed values in the deeper samples from Krafla are as low as the values for any rocks previously reported. There seems to be a slight negative gradient in delta 18 O with depth at the former two localities and a more pronounced one at Krafla. Oxygen isotope fractionations between epidote and quartz and those between calcite and fluid suggests that the basalts were altered at temperatures of 300 0 --400 0 C. Low deltaD and delta 18 O of epidote and low delta 34 S of anhydrite indicate that the altering fluids in all three areas originated as meteoric waters and have undergone varied 'oxygen shifts'. Differences in the 18 O shift of the fluids are attributed to differences in hydrothermal systems; low water/rock ratios ( 5) at Krafla. The convective hydrothermal activity, which is probably driven by silicic magma beneath the central volcanoes, has caused strong subsolidus depletion of 18 O in the rocks. The primary-magnetic delta 18 O value of the rocks in the Tertiary IRDP core was about +3.9%, which is lower than that obtained for fresh basalt from other places. Such exceptionally low delta 18 O magmas are common in Iceland and may occur as the result of oxygen isotope exchange with or assimilation of altered rocks that form a thick sequence beneath the island due to isostatic subsidence

  13. Latin Hagiography in Medieval Iceland

    DEFF Research Database (Denmark)

    Jensson, Gottskálk

    2017-01-01

    I. INTRODUCTION A. Latin literacy in Iceland and the cult of saints B. Icelandic quasi-hagiography and the Christian monarchs of Norway II. THE ICELANDIC SAINTS AND THEIR LATIN TEXTS A. S. Thorlacus Scalotensis episcopus. – 1. The texts: the Latin hagiography about St Þorlákur. – 2. The historical...

  14. Erosive and Mechanical Tooth Wear in Viking Age Icelanders.

    Science.gov (United States)

    Richter, Svend; Eliasson, Sigfus Thor

    2017-08-29

    (1) Background: The importance of the Icelandic Sagas as a source of information about diet habits in medieval Iceland, and possibly other Nordic countries, is obvious. Extensive tooth wear in archaeological material worldwide has revealed that the main cause of this wear is believed to have been a coarse diet. Near the volcano Hekla, 66 skeletons dated from before 1104 were excavated, and 49 skulls could be evaluated for tooth wear. The purpose of this study was to determine the main causes of tooth wear in light of diet and beverage consumption described in the Sagas; (2) Materials and methods: Two methods were used to evaluate tooth wear and seven for age estimation; (3) Results: Extensive tooth wear was seen in all of the groups, increasing with age. The first molars had the highest score, with no difference between sexes. These had all the similarities seen in wear from a coarse diet, but also presented with characteristics that are seen in erosion in modern Icelanders, through consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and was used for the preservation of food in Iceland, until fairly recently; (4) Conclusions: It is postulated that the consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear seen in ancient Icelanders.

  15. The Icelandic ITQ System

    DEFF Research Database (Denmark)

    Christensen, Anne-Sofie; Hegland, Troels Jacob; Oddsson, Geir

    2009-01-01

    volume of landings is constituted by pelagic species. Cod, which is mainly caught in the Icelanders’ own exclusive economic zone, is the economically most important fish. The aim of this chapter is to evaluate the Icelandic individual transferable quota shares system with its management innovations, e.......g. harvest control rule for cod, cod equivalents, temporary closed areas, community quotas and features for regulation of quota concentration. The evaluation considers four possible fisheries management objectives, namely biological robustness, cost-effectiveness of management, economic efficiency......ABSTRACT: The fisheries sector is tremendously important for Iceland: the export of fish products accounts for a large part of the value of exported goods. Fisheries policy in Iceland is, consequently, of national importance to a degree that is not comparable to any of the EU member states...

  16. Energy taxes in Iceland

    International Nuclear Information System (INIS)

    Vilhjalmsson, A.

    1991-01-01

    A detailed survey, including data, of energy taxation, and related reforms and plans for reforms, in Iceland is presented. The current energy tax system here is mostly connected with consumption. There is as yet no taxation on air pollutants from fuel combustion. (AB)

  17. The Icelandic ITQ System

    DEFF Research Database (Denmark)

    Christensen, Anne-Sofie; Hegland, Troels Jacob; Oddsson, Geir

    2009-01-01

    volume of landings is constituted by pelagic species. Cod, which is mainly caught in the Icelanders’ own exclusive economic zone, is the economically most important fish. The aim of this chapter is to evaluate the Icelandic individual transferable quota shares system with its management innovations, e...

  18. Field Comparisons of Three Biomarker Detection Methods in Icelandic Mars Analogue Environments

    Science.gov (United States)

    Gentry, D.; Amador, E. S.; Cable, M. L.; Chaudry, N.; Cullen, T.; Jacobsen, M.; Murusekan, G.; Schwieterman, E.; Stevens, A.; Stockton, A.; Yin, C.; Cullen, D.; Geppert, W.

    2014-12-01

    The ability to estimate the spatial and temporal distributions of biomarkers has been identified as a key need for planning life detection strategies. In a typical planetary exploration scenario, sampling site selection will be informed only by remote sensing data; however, if a difference of a few tens of meters, or centimeters, makes a significant difference in the results, science objectives may not be met. We conducted an analogue planetary expedition to test the correlation of three common biomarker detection methods -- cell counts through fluorescence microscopy, ATP quantification, and quantitative PCR with universal primer sets (bacteria, archaea, and fungi) -- and their spatial scale representativeness. Sampling sites in recent Icelandic lava fields (Fimmvörđuháls and Eldfell) spanned four nested spatial scales: 1 m, 10 m, 100 m, and > 1 km. Each site was homogeneous at typical 'remote sampling' resolution (overall temperature, apparent moisture content, and regolith grain size). No correlation between cell counts and either ATP or qPCR data was significant at any distance scale; ATP quantification and the archaeal and fungal qPCR data showed a marginal negative correlation at the 1 m level. Visible cell count data was statistically site-dependent for sites 10 m and 100 m apart, but not for sites > 1 km apart, whereas ATP results and qPCR data showed site dependence at all four scales. Distance had no significant effect on variability in cell counts and qPCR data, but was positively correlated with ATP variability. These results highlight the difficulty of choosing a 'good' biomarker: not only may different methods yield conflicting results, but they may also be differentially representative of the overall area. We intend to expand on this work with a follow-up campaign using comprehensive assays of physicochemical site properties to better distinguish between effects of environmental variability and intrinsic biomarker variability.

  19. The Icelandic volcanological data node and data service

    Science.gov (United States)

    Vogfjord, Kristin; Sigmundsson, Freysteinn; Futurevolc Team

    2013-04-01

    Through funding from the European FP7 programme, the International Civil Aviation Authority (ICAO), as well as the local Icelandic government and RANNÍS research fund, the establishment of the Icelandic volcano observatory (VO) as a cross-disciplinary, international volcanological data node and data service is starting to materialize. At the core of this entity is the close collaboration between the Icelandic Meteorological Office (IMO), a natural hazard monitoring and research institution, and researchers at the Earth Science Institute of the University of Iceland, ensuring long-term sustainable access to research quality data and products. Existing Icelandic Earth science monitoring and research infrastructures are being prepared for integration with the European EPOS infrastructure. Because the VO is located at a Met Office, this infrastructure also includes meteorological infrastructures relevant to volcanology. Furthermore, the FP7 supersite project, FUTUREVOLC cuts across disciplines to bring together European researchers from Earth science, atmospheric science, remote sensing and space science focussed on combined processing of the different data sources and results to generate a multiparametric volcano monitoring and early warning system. Integration with atmospheric and space science is to meet the need for better estimates of the volcanic eruption source term and dispersion, which depend not only on the magma flow rate and composition, but also on atmosphere-plume interaction and dispersion. This should lead to better estimates of distribution of ash in the atmosphere. FUTUREVOLC will significantly expand the existing Icelandic EPOS infrastructure to an even more multidisciplinary volcanological infrastructure. A central and sustainable part of the project is the establishment of a research-quality data centre at the VO. This data centre will be able to serve as a volcanological data node within EPOS, making multidisciplinary data accessible to

  20. What Are Volcano Hazards?

    Science.gov (United States)

    ... Sheet 002-97 Revised March 2008 What Are Volcano Hazards? Volcanoes give rise to numerous geologic and ... as far as 15 miles from the volcano. Volcano Landslides A landslide or debris avalanche is a ...

  1. Establishment, test and evaluation of a prototype volcano surveillance system

    Science.gov (United States)

    Ward, P. L.; Eaton, J. P.; Endo, E.; Harlow, D.; Marquez, D.; Allen, R.

    1973-01-01

    A volcano-surveillance system utilizing 23 multilevel earthquake counters and 6 biaxial borehole tiltmeters is being installed and tested on 15 volcanoes in 4 States and 4 foreign countries. The purpose of this system is to give early warning when apparently dormant volcanoes are becoming active. The data are relayed through the ERTS-Data Collection System to Menlo Park for analysis. Installation was completed in 1972 on the volcanoes St. Augustine and Iliamna in Alaska, Kilauea in Hawaii, Baker, Rainier and St. Helens in Washington, Lassen in California, and at a site near Reykjavik, Iceland. Installation continues and should be completed in April 1973 on the volcanoes Santiaguito, Fuego, Agua and Pacaya in Guatemala, Izalco in El Salvador and San Cristobal, Telica and Cerro Negro in Nicaragua.

  2. Morphometry of terrestrial shield volcanoes

    Science.gov (United States)

    Grosse, Pablo; Kervyn, Matthieu

    2018-03-01

    Shield volcanoes are described as low-angle edifices built primarily by the accumulation of successive lava flows. This generic view of shield volcano morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galápagos). Here, the morphometry of 158 monogenetic and polygenetic shield volcanoes is analyzed quantitatively from 90-meter resolution SRTM DEMs using the MORVOLC algorithm. An additional set of 24 lava-dominated 'shield-like' volcanoes, considered so far as stratovolcanoes, are documented for comparison. Results show that there is a large variation in shield size (volumes from 0.1 to > 1000 km3), profile shape (height/basal width (H/WB) ratios mostly from 0.01 to 0.1), flank slope gradients (average slopes mostly from 1° to 15°), elongation and summit truncation. Although there is no clear-cut morphometric difference between shield volcanoes and stratovolcanoes, an approximate threshold can be drawn at 12° average slope and 0.10 H/WB ratio. Principal component analysis of the obtained database enables to identify four key morphometric descriptors: size, steepness, plan shape and truncation. Hierarchical cluster analysis of these descriptors results in 12 end-member shield types, with intermediate cases defining a continuum of morphologies. The shield types can be linked in terms of growth stages and shape evolution, related to (1) magma composition and rheology, effusion rate and lava/pyroclast ratio, which will condition edifice steepness; (2) spatial distribution of vents, in turn related to the magmatic feeding system and the tectonic framework, which will control edifice plan shape; and (3) caldera formation, which will condition edifice truncation.

  3. A new method for monitoring global volcanic activity. [Alaska, Hawaii, Washington, California, Iceland, Guatemala, El Salvador, and Nicaragua

    Science.gov (United States)

    Ward, P. L.; Endo, E.; Harlow, D. H.; Allen, R.; Eaton, J. P.

    1974-01-01

    The ERTS Data Collection System makes it feasible for the first time to monitor the level of activity at widely separated volcanoes and to relay these data rapidly to one central office for analysis. While prediction of specific eruptions is still an evasive goal, early warning of a reawakening of quiescent volcanoes is now a distinct possibility. A prototypical global volcano surveillance system was established under the ERTS program. Instruments were installed in cooperation with local scientists on 15 volcanoes in Alaska, Hawaii, Washington, California, Iceland, Guatemala, El Salvador and Nicaragua. The sensors include 19 seismic event counters that count four different sizes of earthquakes and six biaxial borehole tiltmeters that measure ground tilt with a resolution of 1 microradian. Only seismic and tilt data are collected because these have been shown in the past to indicate most reliably the level of volcano activity at many different volcanoes. Furthermore, these parameters can be measured relatively easily with new instrumentation.

  4. The Crash Course from Iceland

    Directory of Open Access Journals (Sweden)

    Huginn Freyr Þorsteinsson

    2014-11-01

    Full Text Available The years between 2006 and 2008 are key in understanding the Icelandic economic crisis. One of the main questions one gets when discussing the lessons from Iceland is: Was the quick recovery due to how the country 'burned' the creditors? Myth has it that when things got tough for the banks, the Icelandic government denied to bail them out and the country therefore escaped the difficult long-term consequence felt by, for example, Ireland. But that is a serious distortion of what happened. The Icelandic banks were on Central Bank life support from 2006 to 2008. It was only when the CBI ran out of steam that an alternative approach in crisis management was put in place. For admirers of historical contingencies, this case is of interest. Iceland did not take a calculated decision to let the banks fail, but an attempted bail-out failed. This meant that that its tackling of a banking crisis took an unexpected turn as banks were put into administration; a move only considered in the face of failure. And despite the route taken by Iceland, the total cost of the economic crisis for the State has surpassed Ireland's and is one of the costliest any sovereign has faced in the ongoing crisis. This is interesting, given the ongoing discussion about the Icelandic 'miraculous' escape from an economic crisis and that the possibilities countries face during crisis management may be many more than those that are discussed.

  5. Moral panic in Icelandic society: Arrival of ecstasy to Iceland

    Directory of Open Access Journals (Sweden)

    Jónas Orri Jónasson

    2014-12-01

    Full Text Available The use of illegal drugs has often been shown to ignite fear and insecurity in society. When a new drug appears the media typically reports on this drug and the risk it poses. Soon after ecstasy appeared in Iceland in the 1990s its use created a major public uproar and insecurity in Icelandic society. In the article the theory of moral panic will be used to examine if the arrival of ecstasy to Iceland ignited a moral panic. Media reports on ecstasy, public reactions, interest groups and government institutions will be analysed. Discourse analysis is employed on newspaper reporting on ecstasy between 1985 and 1997 to detect signs of moral panic. The main conclusion is that evidence suggests that a moral panic existed in Iceland as described in well-known theories on the subject.

  6. Wind Diagrams in Medieval Iceland

    DEFF Research Database (Denmark)

    Kedwards, Dale

    2014-01-01

    This article presents a study of the sole wind diagram that survives from medieval Iceland, preserved in the encyclopaedic miscellany in Copenhagen's Arnamagnæan Institute with the shelf mark AM 732b 4to (c. 1300-25). It examines the wind diagram and its accompanying text, an excerpt on the winds...... from Isidore of Seville's Etymologies. It also examines the perimeter of winds on two medieval Icelandic world maps, and the visual traditions from which they draw....

  7. Volcanic systems of Iceland and their magma source

    Science.gov (United States)

    Sigmarsson, Olgeir

    2017-04-01

    Several active hot-spot volcanoes produce magma from mantle sources which composition varies on decadal time scale. This is probably best demonstrated by the recent work of Pietruszka and collaborators on Kilauea, Hawaii. In marked contrast, basalt lavas from volcanic system in Iceland located above the presumed centre of the Iceland mantle plume have uniform isotope composition over the last 10 thousand years. Volcanic systems are composed of a central volcano and a fissure swarm, or a combination of both and they represent a fundamental component of the neovolcanic zones in Iceland. Four such systems, those of Askja, Bárðarbunga, Kverkfjöll and Grímsvötn in central Iceland were chosen for investigation. The last three have central volcanoes covered by the Vatnajökull ice-sheet whereas part of their fissure swarms is ice-free. Tephra produced during subglacial eruptions together with lavas from the fissure swarms of Holocene age have been collected and analysed for Sr, Nd and Th isotope ratios. Those volcanic formations that can be univocally correlated to a given volcanic system display uniform isotope ratio but different from one volcanic system to another. An exception to this regularity is that Askja products have isotope ratios indistinguishable from those of Gímsvötn, but since these volcanic systems lies far apart their lava fields do not overlap. A practical aspect of these findings was demonstrated during the rifting event of Bárðarbunga and fissure eruption forming the Holuhraun lava field. Relatively low, O isotope ratios in these basalts and heterogeneous macrocrystal composition have been ascribed to important metabasaltic crustal contamination with or without crystal mush recycling. In that case a surprisingly efficient magma mixing and melt homogenization must have occurred in the past beneath the volcanic systems. One possibility is that during the rapid deglaciation much mantle melting occurred and melts accumulated at the mantle

  8. Alteration in the IRDP drill hole compared with other drill holes in Iceland

    Science.gov (United States)

    Kristmannsdóttir, Hrefna

    1982-08-01

    The overall alteration pattern in the drill hole at Reydarfjördur is very similar to alteration patterns observed in Icelandic geothermal areas and in low-grade metamorphosed basalts in deep crustal sections elsewhere in Iceland. However more detail is obtained by the study of the IRDP drill core than by study of drill cuttings sampled in previous drill holes in Iceland. A comparatively high fossil thermal gradient is obtained at Reydarfjördur by a combination of mineral stability data and the observed occurence of secondary minerals. This high gradient is consistent with the measured dike dilation at the drill site and the location of the drill site adjacent to a central volcano.

  9. Amphipod family distributions around Iceland

    Directory of Open Access Journals (Sweden)

    Saskia Brix

    2018-01-01

    Full Text Available Amphipod crustaceans were collected at all 55 stations sampled with an epibenthic sledge during two IceAGE expeditions (Icelandic marine Animals: Genetics and Ecology in 2011 and 2013. In total, 34 amphipod families and three superfamilies were recorded in the samples. Distribution maps are presented for each taxon along with a summary of the regional taxonomy for the group. Statistical analyses based on presence/absence data revealed a pattern of family distributions that correlated with sampling depth. Clustering according to the geographic location of the stations (northernmost North Atlantic Sea and Arctic Ocean can also be observed. IceAGE data for the Amphilochidae and Oedicerotidae were analysed on species level; in case of the Amphilochidae they were compared to the findings from a previous Icelandic benthic survey, BIOICE (Benthic Invertebrates of Icelandic waters, which also identified a high abundance of amphipod fauna.

  10. Global Volcano Model

    Science.gov (United States)

    Sparks, R. S. J.; Loughlin, S. C.; Cottrell, E.; Valentine, G.; Newhall, C.; Jolly, G.; Papale, P.; Takarada, S.; Crosweller, S.; Nayembil, M.; Arora, B.; Lowndes, J.; Connor, C.; Eichelberger, J.; Nadim, F.; Smolka, A.; Michel, G.; Muir-Wood, R.; Horwell, C.

    2012-04-01

    Over 600 million people live close enough to active volcanoes to be affected when they erupt. Volcanic eruptions cause loss of life, significant economic losses and severe disruption to people's lives, as highlighted by the recent eruption of Mount Merapi in Indonesia. The eruption of Eyjafjallajökull, Iceland in 2010 illustrated the potential of even small eruptions to have major impact on the modern world through disruption of complex critical infrastructure and business. The effects in the developing world on economic growth and development can be severe. There is evidence that large eruptions can cause a change in the earth's climate for several years afterwards. Aside from meteor impact and possibly an extreme solar event, very large magnitude explosive volcanic eruptions may be the only natural hazard that could cause a global catastrophe. GVM is a growing international collaboration that aims to create a sustainable, accessible information platform on volcanic hazard and risk. We are designing and developing an integrated database system of volcanic hazards, vulnerability and exposure with internationally agreed metadata standards. GVM will establish methodologies for analysis of the data (eg vulnerability indices) to inform risk assessment, develop complementary hazards models and create relevant hazards and risk assessment tools. GVM will develop the capability to anticipate future volcanism and its consequences. NERC is funding the start-up of this initiative for three years from November 2011. GVM builds directly on the VOGRIPA project started as part of the GRIP (Global Risk Identification Programme) in 2004 under the auspices of the World Bank and UN. Major international initiatives and partners such as the Smithsonian Institution - Global Volcanism Program, State University of New York at Buffalo - VHub, Earth Observatory of Singapore - WOVOdat and many others underpin GVM.

  11. EROI and the Icelandic society

    DEFF Research Database (Denmark)

    Atlason, Reynir Smari

    2018-01-01

    In this paper, the societal Energy Return on Investment (EROIsoc) is estimated for Iceland between 1960 and the present. The results indicate that the overall EROIsoc was around 27:1 in the early 1960s, and was volatile for a period of time before stabilizing at around 45:1 in 1974 after establis...

  12. Pectinoidea (Mollusca: Bivalvia) from Iceland

    NARCIS (Netherlands)

    Dijkstra, H.H.; Waren, A.; Gudmundsson, G.

    2009-01-01

    The Icelandic pectinoid fauna is reviewed, based on material from the benthic survey programme BIOICE and 17 species are recorded. Similipecten oskarssoni is proposed as a replacement name for Pecten groenlandicus var. minor Locard, 1898 (Propeamussiidae), which is considered a valid species.

  13. Hydrogeology of the Krafla geothermal system, northeast Iceland

    DEFF Research Database (Denmark)

    Pope, Emily Catherine; Bird, D. K.; Arnórsson, S.

    2016-01-01

    The Krafla geothermal system is located in Iceland's northeastern neovolcanic zone, within the Krafla central volcanic complex. Geothermal fluids are superheated steam closest to the magma heat source, two-phase at higher depths, and sub-boiling at the shallowest depths. Hydrogen isotope ratios...... of geothermal fluids range from -87‰, equivalent to local meteoric water, to -94‰. These fluids are enriched in 18O relative to the global meteoric line by +0.5-3.2‰. Calculated vapor fractions of the fluids are 0.0-0.5 wt% (~0-16% by volume) in the northwestern portion of the geothermal system and increase...... the benefits of combining phase segregation effects in two-phase systems during analysis of wellhead fluid data with stable isotope values of hydrous alteration minerals when evaluating the complex hydrogeology of volcano-hosted geothermal systems....

  14. Psychotropic drug use among Icelandic children

    DEFF Research Database (Denmark)

    Zoëga, Helga; Baldursson, Gísli; Hrafnkelsson, Birgir

    2009-01-01

    OBJECTIVE: The aim of this study was to investigate psychotropic drug use among children in Iceland between 2003 and 2007. METHODS: A nationwide population-based drug use study covering the total pediatric population (ages 0-17) in Iceland. Information was obtained from the National Medicines Reg...... extensive psychotropic drug use among children in Iceland between 2003 and 2007. Further scrutiny is needed to assess the rationale behind this widespread use....

  15. Global Volcano Locations Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  16. A Scientific Excursion: Volcanoes.

    Science.gov (United States)

    Olds, Henry, Jr.

    1983-01-01

    Reviews an educationally valuable and reasonably well-designed simulation of volcanic activity in an imaginary land. VOLCANOES creates an excellent context for learning information about volcanoes and for developing skills and practicing methods needed to study behavior of volcanoes. (Author/JN)

  17. Life Interpretation and Religion among Icelandic Teenagers

    Science.gov (United States)

    Gunnarsson, Gunnar J.

    2009-01-01

    Does religion play any specific part in Icelandic teenagers' life interpretation? This paper examines Icelandic teenagers' talk about religion and presents some of the findings in interviews with teenagers in a qualitative research project. The focus is especially on how three individuals express themselves about the influence of religion on their…

  18. FUTUREVOLC: A European volcanological supersite in Iceland, a monitoring system and network for the future (Invited)

    Science.gov (United States)

    Sigmundsson, F.; Vogfjord, K. S.; Gudmundsson, M. T.; Kristinsson, I.; Loughlin, S. C.; Ilyinskaya, E.; Hooper, A. J.; Kylling, A.; Witham, C. S.; Bean, C. J.; Braiden, A.; Ripepe, M.; Prata, F.; Jordan, C. J.; Team, F.

    2013-12-01

    FUTURVOLC is a collaborative project funded through a FP7 Environment 'supersite' call of the European Union, with 26 partners in 10 countries. The main objectives of FUTUREVOLC are to establish an integrated volcanological monitoring procedure, develop new methods to evaluate volcanic crises, increase scientific understanding of magmatic processes and improve delivery of relevant information to civil protection and authorities. To reach these objectives the project combines broad expertise in seismology, volcano deformation, volcanic gas and geochemistry, infrasound, eruption monitoring, physical volcanology, satellite studies of plumes, meteorology, ash dispersal forecasting, and civil protection. The consortium members together with a more extensive group of collaborators, has applied to CEOS for making the Iceland volcanoes a permanent geohazard supersite. In summer 2013 FUTUREVOLC partners improved volcano monitoring in Iceland by installing new equipment, including seismometers, GPS receivers, an infrasound array, and electrical sensors. A key element of the project is to combine Icelandic ground based monitoring data with satellite observations in an improved manner. This applies to different disciplines, including e.g. deformation from ground observations and InSAR, and quantification of volcanic ash clouds during eruptions by combining measurements from ground based infrared (IR) cameras and satellite microwave and IR detectors. The FUTUREVOLC project has open data policy for real-time data streams, near real-time data and science products. Implementation of a data hub will begin in 2013 with making available data for the 2010 Eyjafjallajökull eruption. Access of monitoring data through one common interface will allow timely information on magma movements from combined interpretation of relocated earthquake sources, magma sources inferred from ground and space geodetic data, and measurements of volcanic volatiles. For better response during eruptions, the

  19. EROI and the Icelandic society

    DEFF Research Database (Denmark)

    Atlason, Reynir Smari

    2018-01-01

    In this paper, the societal Energy Return on Investment (EROIsoc) is estimated for Iceland between 1960 and the present. The results indicate that the overall EROIsoc was around 27:1 in the early 1960s, and was volatile for a period of time before stabilizing at around 45:1 in 1974 after...... the standard of living greatly. For policymakers in island nations, attention should be given to this relationship between high-EROI energy sources with low price volatility and the standard of living....

  20. Quantifying Variability and Correlation in Biomarker and Mineralogical Measurements: Lessons from Five Astrobiological Mars Analogue Expeditions in Iceland

    Science.gov (United States)

    Gentry, D.; Amador, E. S.; Cable, M. L.; Cantrell, T.; Chaudry, N.; Duca, Z. A.; Jacobsen, M. B.; Kirby, J.; McCaig, H. C.; Murukesan, G.; Rader, E.; Cullen, T.; Rennie, V.; Schwieterman, E. W.; Stevens, A. H.; Sutton, S. A.; Tan, G.; Yin, C.; Cullen, D.; Geppert, W.; Stockton, A. M.

    2017-12-01

    Studies in planetary analogue sites correlating remote imagery, mineralogy, and biomarker assay results help predict biomarker distribution and preservation. The FELDSPAR team has conducted five expeditions (2012-2017) to Icelandic Mars analogue sites with an increasingly refined battery of physicochemical measurements and biomarker assays. Two additional expeditions are planned; here we report intermediate results.The biomarker assays performed represent a diversity of potential biomarker types: ATP, cell counts, qPCR with domain-level primers, and DNA content. Mineralogical, chemical, and physical measurements and observations include temperature, pH, moisture content, and Raman, near-IR reflectance, and X-ray fluorescence spectra. Sites are geologically recent basaltic lava flows (Fimmvörðuháls, Eldfell, Holuhraun) and barren basaltic sand plains (Mælifellssandur, Dyngjusandur). All samples were 'homogeneous' at the 1 m to 1 km scale in apparent color, morphology, and grain size.[1]Sample locations were arranged in hierarchically nested grids at 10 cm, 1 m, 10 m, 100 m, and >1 km scales. Several measures of spatial distribution and variability were derived: unbiased sample variance, F- and pairwise t-tests with Bonferroni correction, and the non-parametric H- and u-tests. All assay results, including preliminary mineralogical information in the form of notable spectral bands, were then tested for correlation using the non-parametric Spearman's rank test.[2] For Fimmvörðuháls, four years of data were also examined for temporal trends.Biomarker quantification (other than cell count) was generally well correlated, although all assays showed notable variability even at the smallest examined spatial scale. Pairwise comparisons proved to be the most intuitive measure of variability; non-parametric characterization indicated trends at the >100 m scale, but required more replicates than were feasible at smaller scales. Future work will integrate additional

  1. Volcano seismology

    Science.gov (United States)

    Chouet, B.

    2003-01-01

    A fundamental goal of volcano seismology is to understand active magmatic systems, to characterize the configuration of such systems, and to determine the extent and evolution of source regions of magmatic energy. Such understanding is critical to our assessment of eruptive behavior and its hazardous impacts. With the emergence of portable broadband seismic instrumentation, availability of digital networks with wide dynamic range, and development of new powerful analysis techniques, rapid progress is being made toward a synthesis of high-quality seismic data to develop a coherent model of eruption mechanics. Examples of recent advances are: (1) high-resolution tomography to image subsurface volcanic structures at scales of a few hundred meters; (2) use of small-aperture seismic antennas to map the spatio-temporal properties of long-period (LP) seismicity; (3) moment tensor inversions of very-long-period (VLP) data to derive the source geometry and mass-transport budget of magmatic fluids; (4) spectral analyses of LP events to determine the acoustic properties of magmatic and associated hydrothermal fluids; and (5) experimental modeling of the source dynamics of volcanic tremor. These promising advances provide new insights into the mechanical properties of volcanic fluids and subvolcanic mass-transport dynamics. As new seismic methods refine our understanding of seismic sources, and geochemical methods better constrain mass balance and magma behavior, we face new challenges in elucidating the physico-chemical processes that cause volcanic unrest and its seismic and gas-discharge manifestations. Much work remains to be done toward a synthesis of seismological, geochemical, and petrological observations into an integrated model of volcanic behavior. Future important goals must include: (1) interpreting the key types of magma movement, degassing and boiling events that produce characteristic seismic phenomena; (2) characterizing multiphase fluids in subvolcanic

  2. Assessing hazards to aviation from sulfur dioxide emitted by explosive Icelandic eruptions

    OpenAIRE

    Schmidt, A; Witham, CS; Theys, N; Richards, NAD; Thordarson, T; Szpek, K; Feng, W; Hort, MC; Woolley, AM; Jones, AR; Redington, AL; Johnson, BT; Hayward, CL; Carslaw, KS

    2014-01-01

    Volcanic eruptions take place in Iceland about once every 3 to 5 years. Ash emissions from these eruptions can cause significant disruption to air traffic over Europe and the North Atlantic as is evident from the 2010 eruption of Eyjafjallajökull. Sulfur dioxide (SO2) is also emitted by volcanoes, but there are no criteria to define when airspace is considered hazardous or nonhazardous. However, SO2 is a well-known ground-level pollutant that can have detrimental effects on human health. We h...

  3. Self Censorship among Icelandic Journalists

    Directory of Open Access Journals (Sweden)

    Birgir Guðmundsson

    2015-06-01

    Full Text Available The discussion on media self-censorship has flourished in Iceland after the attacks on the Charlie Hebdo editorial offices in January 2015 and after some dramatic changes in the top management and owner-groups of some of the media firms. But what is this experience that journalists describe as self censorship? This paper attempts to answer two main research questions. On the one hand the question how journalists understand the concept of selfcensorship. On the other hand the question: what is the experience of Icelandic journalist of self-censorship? The approach is the one of a qualitative research and is based on interviews with six experienced journalists. The main findings suggest important influence of the social discourse on news and news values of journalists and their tendency for self-censorship. This discourse is partly directed by politicians and influential bloggers and also by a massive discussion by active social media users. Furthermore the findings suggest, that ownership and the location of the particular medium where a journalist works in the lineup of different commercial-political blocks in the media market, is important for self-censorship. Finally it seems that journalists understand the concept selfcensorship in a different manner and that it is important to define the term carefully if it is to be used as an analytical tool.

  4. Volcanoes: Nature's Caldrons Challenge Geochemists.

    Science.gov (United States)

    Zurer, Pamela S.

    1984-01-01

    Reviews various topics and research studies on the geology of volcanoes. Areas examined include volcanoes and weather, plate margins, origins of magma, magma evolution, United States Geological Survey (USGS) volcano hazards program, USGS volcano observatories, volcanic gases, potassium-argon dating activities, and volcano monitoring strategies.…

  5. Antarctic volcanoes: A remote but significant hazard

    Science.gov (United States)

    Geyer, Adelina; Martí, Alex; Folch, Arnau; Giralt, Santiago

    2017-04-01

    Ash emitted during explosive volcanic eruptions can be dispersed over massive areas of the globe, posing a threat to both human health and infrastructures, such as the air traffic. Some of the last eruptions occurred during this decade (e.g. 14/04/2010 - Eyjafjallajökull, Iceland; 24/05/2011-Grímsvötn, Iceland; 05/06/2011-Puyehue-Cordón Caulle, Chile) have strongly affected the air traffic in different areas of the world, leading to economic losses of billions of euros. From the tens of volcanoes located in Antarctica, at least nine are known to be active and five of them have reported volcanic activity in historical times. However, until now, no attention has been paid to the possible social, economical and environmental consequences of an eruption that would occur on high southern latitudes, perhaps because it is considered that its impacts would be minor or local, and mainly restricted to the practically inhabited Antarctic continent. We show here, as a case study and using climate models, how volcanic ash emitted during a regular eruption of one of the most active volcanoes in Antarctica, Deception Island (South Shetland Islands), could reach the African continent as well as Australia and South America. The volcanic cloud could strongly affect the air traffic not only in the region and at high southern latitudes, but also the flights connecting Africa, South America and Oceania. Results obtained are crucial to understand the patterns of volcanic ash distribution at high southern latitudes with obvious implications for tephrostratigraphical and chronological studies that provide valuable isochrones with which to synchronize palaeoclimate records. This research was partially funded by the MINECO grants VOLCLIMA (CGL2015-72629-EXP)and POSVOLDEC(CTM2016-79617-P)(AEI/FEDER, UE), the Ramón y Cajal research program (RYC-2012-11024) and the NEMOH European project (REA grant 34 agreement n° 289976).

  6. Deep Drilling into a Mantle Plume Volcano: The Hawaii Scientific Drilling Project

    Directory of Open Access Journals (Sweden)

    Donald M. Thomas

    2009-03-01

    Full Text Available Oceanic volcanoes formed by mantle plumes, such as those of Hawaii and Iceland, strongly influence our views about the deep Earth (Morgan, 1971; Sleep, 2006. These volcanoes are the principal geochemical probe into the deep mantle, a testing ground for understanding mantle convection, plate tectonics and volcanism, and an archive of information on Earth’s magnetic field and lithospheredynamics. Study of the petrology, geochemistry, and structure of oceanic volcanoes has contributed immensely to our present understanding of deep Earth processes, but virtually all of this study has been concentrated on rocks available at the surface. In favorable circumstances, surface exposures penetrate to a depth of a few hundred meters, which is a small fraction of the 10- to 15-kilometer height of Hawaiian volcanoes above the depressed seafloor (Moore, 1987; Watts, 2001.

  7. Volcanoes: observations and impact

    Science.gov (United States)

    Thurber, Clifford; Prejean, Stephanie G.

    2012-01-01

    Volcanoes are critical geologic hazards that challenge our ability to make long-term forecasts of their eruptive behaviors. They also have direct and indirect impacts on human lives and society. As is the case with many geologic phenomena, the time scales over which volcanoes evolve greatly exceed that of a human lifetime. On the other hand, the time scale over which a volcano can move from inactivity to eruption can be rather short: months, weeks, days, and even hours. Thus, scientific study and monitoring of volcanoes is essential to mitigate risk. There are thousands of volcanoes on Earth, and it is impractical to study and implement ground-based monitoring at them all. Fortunately, there are other effective means for volcano monitoring, including increasing capabilities for satellite-based technologies.

  8. Continuous monitoring of volcanoes with borehole strainmeters

    Science.gov (United States)

    Linde, Alan T.; Sacks, Selwyn

    Monitoring of volcanoes using various physical techniques has the potential to provide important information about the shape, size and location of the underlying magma bodies. Volcanoes erupt when the pressure in a magma chamber some kilometers below the surface overcomes the strength of the intervening rock, resulting in detectable deformations of the surrounding crust. Seismic activity may accompany and precede eruptions and, from the patterns of earthquake locations, inferences may be made about the location of magma and its movement. Ground deformation near volcanoes provides more direct evidence on these, but continuous monitoring of such deformation is necessary for all the important aspects of an eruption to be recorded. Sacks-Evertson borehole strainmeters have recorded strain changes associated with eruptions of Hekla, Iceland and Izu-Oshima, Japan. Those data have made possible well-constrained models of the geometry of the magma reservoirs and of the changes in their geometry during the eruption. The Hekla eruption produced clear changes in strain at the nearest instrument (15 km from the volcano) starting about 30 minutes before the surface breakout. The borehole instrument on Oshima showed an unequivocal increase in the amplitude of the solid earth tides beginning some years before the eruption. Deformational changes, detected by a borehole strainmeter and a very long baseline tiltmeter, and corresponding to the remote triggered seismicity at Long Valley, California in the several days immediately following the Landers earthquake are indicative of pressure changes in the magma body under Long Valley, raising the question of whether such transients are of more general importance in the eruption process. We extrapolate the experience with borehole strainmeters to estimate what could be learned from an installation of a small network of such instruments on Mauna Loa. Since the process of conduit formation from the magma sources in Mauna Loa and other

  9. Iceland's Economic Eruption and Meltdown

    DEFF Research Database (Denmark)

    Nielsson, Ulf; Torfason, Bjarni K.

    2012-01-01

    The Icelandic financial collapse, which occurred in the fall of 2008, is without precedent. Never before in modern history has an entire financial system of a developed country collapsed so dramatically. This paper describes the country's path towards financial liberalisation and the economic...... background that lead to an initially flourishing banking sector. In doing so, the paper elaborates on the economic oversights that were made during the financial build-up of the country and how such mistakes contributed to the crash. The focus is thus on identifying the main factors that contributed...... to the financial collapse and on drawing conclusions about how these missteps could have been avoided. Also summarised are the mistakes that followed in the attempted rescue phase after the disaster had struck. The paper discusses these issues from a general perspective to provide an overview of the pitfalls...

  10. Medical isotope applications in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-10-15

    About $ 12 000 worth of equipment and the services of an expert in the medical applications of radioisotopes were provided by IAEA to the Government of Iceland. The expert was primarily concerned with the establishment of a medical radioisotope laboratory at the State Hospital, Reykjavik. His specific tasks included the setting up of the equipment furnished by IAEA for radioactive measurements in medical work, the establishment of techniques for the routine uses of radioisotopes in medicine, and the training of personnel. The apparatus installed includes a well-type scintillation counter for small samples, a directional scintillation counter, and Geiger counters of different types. The laboratory is thus well equipped for nearly all the conventional applications of radioisotopes in medicine, except those involving very soft beta-ray emitting isotopes

  11. Geomagnetic polarity zones for icelandic lavas

    Science.gov (United States)

    Dagley, P.; Wilson, R.L.; Ade-Hall, J. M.; Walker, G.P.L.; Haggerty, S.E.; Sigurgeirsson, T.; Watkins, N.D.; Smith, P.J.; Edwards, J.; Grasty, R.L.

    1967-01-01

    Analysis of cores collected from a sequence of lavas in Eastern Iceland has made possible an accurate calculation of the average rate of reversal of the Earth's magnetic field. ?? 1967 Nature Publishing Group.

  12. Building Information Modelling in Denmark and Iceland

    DEFF Research Database (Denmark)

    Jensen, Per Anker; Jóhannesson, Elvar Ingi

    2013-01-01

    with BIM is studied. Based on findings from both parts, ideas and recommendations are put forward for the Icelandic building industry about feasible ways of implementing BIM. Findings – Among the results are that the use of BIM is very limited in the Icelandic companies compared to the other Nordic...... for making standards and guidelines related to BIM. Public building clients are also encouraged to consider initiating projects based on making simple building models of existing buildings in order to introduce the BIM technology to the industry. Icelandic companies are recommended to start implementing BIM...... countries. Research limitations/implications – The research is limited to the Nordic countries in Europe, but many recommendations could be relevant to other countries. Practical implications – It is recommended to the Icelandic building authorities to get into cooperation with their Nordic counterparts...

  13. Geothermal and hydropower production in Iceland

    International Nuclear Information System (INIS)

    Rosa, D.J.

    1993-01-01

    This paper analyzes the impact of current and future development of geothermal and hydropower production on the economy of Iceland. Natural conditions in Iceland favor the increased utilization and development of both of these abundant power sources. The mean surface run-off in Iceland is about 50 l/s/km 2 (liters per second per square kilometer), with a large part of the country consisting of a plateau more than 400 meters above sea level. More than half of the country is above 500 meters above sea level. ne technically harnessable hydropower potential is estimated at 64 TWh/year (terawatthours per year), of which 30 TWh/year is considered economically and environmentally harnessable. In addition, Iceland has abundant geothermal energy sources. A quarter of the entire country is a volcanic area. Keeping in mind that geothermal resources are not strictly renewable, it is estimated that the potential power production from this source is 20 TWh/year. Present utilization of these two resources totals only 4.2 TWh/year, or only about 8% of Iceland's aggregate potential. There are many issues facing Iceland today as it considers development opportunities utilizing both of these abundant power supplies. This paper will first consider the technical aspects of both hydropower and geothermal power production in Iceland. Then, the economic consequences of alternative utilization of these energy sources will be evaluated. The first alternative to be considered will be the direct export of power by HVDC submarine cable to other countries, such as Scotland or the United Kingdom. Iceland could, as a second alterative, concentrate its efforts on bringing in energy intensive industries into the country

  14. Investigations of Very High Enthalpy Geothermal Resources in Iceland.

    Science.gov (United States)

    Elders, W. A.; Fridleifsson, G. O.

    2012-12-01

    The Iceland Deep Drilling Project (IDDP) is investigating the economic feasibility of producing electricity from supercritical geothermal reservoirs. Earlier modeling indicates that the power output of a geothermal well producing from a supercritical reservoir could potentially be an order of magnitude greater than that from a conventional hot geothermal reservoir, at the same volumetric flow rate. However, even in areas with an unusually high geothermal gradient, for normal hydrostatic pressure gradients reaching supercritical temperatures and pressures will require drilling to depths >4 km. In 2009 the IDDP attempted to drill the first deep supercritical well, IDDP-01, in the caldera of the Krafla volcano, in NE Iceland. However drilling had to be terminated at only 2.1 km depth when ~900°C rhyolite magma flowed into the well. Our studies indicate that this magma formed by partial melting of hydrothermally altered basalts within the Krafla caldera. Although this well was too shallow to reach supercritical pressures, it is highly productive, and is estimated to be capable of generating up to 36 MWe from the high-pressure, superheated steam produced from the upper contact zone of the intrusion. With a well-head temperature of ~440°C, it is at present apparently the hottest producing geothermal well in the world. A pilot plant is investigating the optimal utilization of this magmatically heated resource. A special issue of the journal Geothermics with 16 papers reporting on the IDDP-01 is in preparation. However, in order to continue the search for supercritical geothermal resources, planning is underway to drill a 4.5 km deep well at Reykjanes in SW Iceland in 2013-14. Although drilling deeper towards the heat source of this already developed high-temperature geothermal field will be more expensive, if a supercritical resource is found, this cost increase should be offset by the considerable increase in the power output and lifetime of the Reykjanes geothermal

  15. Icelandic occupational therapists' attitudes towards educational issues.

    Science.gov (United States)

    Asmundsd ttir, ELIN EBBA; Kaplan, SUSAN

    2001-01-01

    The purpose of this study was to assess the readiness of occupational therapists in Iceland to accept a professional as opposed to a technical view of the profession. Most Icelandic occupational therapists were educated in other countries, with little emphasis on liberal arts, sciences and research. The first Icelandic occupational therapy programme, a university-level programme, was founded in 1997. All Icelandic occupational therapists were surveyed. Eighty-seven questionnaires were sent out and 80 (92%) were returned and used for statistical analysis. The results of the study showed that Icelandic occupational therapists valued academic skills over technical skills, emphasizing occupational therapy theory unique to the profession and research to validate practice. More recognition among other health professionals was considered the most needed change in the profession. The results of the study showed that the clinicians' attitudes confirmed in general what is emphasized in the curriculum and in students' fieldwork. Further research is needed to explore whether the Icelandic occupational therapy profession succeeds in promoting research and recognition by other health professions.

  16. New concepts in hydrogen production in Iceland

    International Nuclear Information System (INIS)

    Arnason, B.; Sigfusson, T.I.; Jonsson, V.K.

    1993-01-01

    The paper presents some new concepts of hydrogen production in Iceland for domestic use and export. A brief overview of the Icelandic energy consumption and available resources is given. The cost of producing hydrogen by electrolysis is calculated for various alternatives such as plant size, load factors and electricity cost. Comparison is made between the total cost of liquid hydrogen delivered to Europe from Iceland and from Northern America, showing that liquid hydrogen delivered to Europe from Iceland would be 9% less expensive. This assumes conventional technology. New technologies are suggested in the paper and different scenarios for geothermally assisted hydrogen production and liquefaction are discussed. It is estimated that the use of geothermal steam would lead to 19% lower hydrogen gas production costs. By analysing the Icelandic fishing fleet, a very large consumer of imported fuel, it is argued that a transition of fuel technology from oil to hydrogen may be a feasible future option for Iceland and a testing ground for changing fuel technology. (Author)

  17. Volcano-ice interactions on Mars

    International Nuclear Information System (INIS)

    Allen, C.C.

    1979-01-01

    Central volcanic eruptions beneath terrestrial glaciers have built steep-sided, flat-topped mountains composed of pillow lava, glassy tuff, capping flows, and cones of basalt. Subglacial fissure eruptions produced ridges of similar compostion. In some places the products from a number of subglacial vents have combined to form widespread deposits. The morphologies of these subglacial volcanoes are distinctive enough to allow their recognition at the resolutions characteristic of Viking orbiter imagery. Analogs to terrestrial subglacial volcanoes have been identified on the northern plains and near the south polar cap of Mars. The polar feature provides probable evidence of volcanic eruptions beneath polar ice. A mixed unit of rock and ice is postulated to have overlain portions of the northern plains, with eruptions into this ground ice having produced mountains and ridges analogous to those in Iceland. Subsequent breakdown of this unit due to ice melting revealed the volcanic features. Estimated heights of these landforms indicate that the ice-rich unit once ranged from approximately 100 to 1200 m thick

  18. Visions of Volcanoes

    Directory of Open Access Journals (Sweden)

    David M. Pyle

    2017-12-01

    Full Text Available The long nineteenth century marked an important transition in the understanding of the nature of combustion and fire, and of volcanoes and the interior of the earth. It was also a period when dramatic eruptions of Vesuvius lit up the night skies of Naples, providing ample opportunities for travellers, natural philosophers, and early geologists to get up close to the glowing lavas of an active volcano. This article explores written and visual representations of volcanoes and volcanic activity during the period, with the particular perspective of writers from the non-volcanic regions of northern Europe. I explore how the language of ‘fire’ was used in both first-hand and fictionalized accounts of peoples’ interactions with volcanoes and experiences of volcanic phenomena, and see how the routine or implicit linkage of ‘fire’ with ‘combustion’ as an explanation for the deep forces at play within and beneath volcanoes slowly changed as the formal scientific study of volcanoes developed. I show how Vesuvius was used as a ‘model’ volcano in science and literature and how, later, following devastating eruptions in Indonesia and the Caribbean, volcanoes took on a new dimension as contemporary agents of death and destruction.

  19. Present day geodynamics in Iceland monitored by a permanent network of continuous GPS stations

    Science.gov (United States)

    Völksen, Christof; Árnadóttir, Thóra; Geirsson, Halldór; Valsson, Guðmundur

    2009-12-01

    Iceland is located on the Mid-Atlantic Ridge and thereby offers a rare opportunity to study crustal movements at a divergent plate boundary. Iceland is not only characterized by the divergence of the Eurasian and North American Plates, as several active volcanoes are located on the island. Moderate size earthquakes occur in the transform zones, causing measurable crustal deformation. In 1999 the installation of a permanent network of continuous GPS stations (ISGPS) was initiated in order to observe deformation due to unrest in the Hengill volcanic system and at the Katla volcano. The ISGPS network has been enlarged over the years and consists today of more than 25 CGPS stations. Most of the stations are located along the plate boundary, where most of the active deformation takes place. Uplift due to post-glacial rebound due to the melting of the largest glacier in Europe, Vatnajökull, is also detected by the ISGPS network. This study presents results from analysis of 9 years of data from the ISGPS network, in the global reference frame PDR05, which has been evaluated by the Potsdam-Dresden-Reprocessing group with reprocessed GPS data only. We thus determine subsidence or land uplift in a global frame. The horizontal station velocities clearly show spreading across the plate boundary of about 20 mm/a. Stations in the vicinity of the glacier Vatnajökull indicate uplift in the range of 12 mm/a, while a station in the central part of Iceland shows uplift rates of about 25 mm/a. Tide gauge readings in Reykjavik and current subsidence rates observed with CGPS agree also quite well.

  20. Framework for foreign investment in Iceland

    International Nuclear Information System (INIS)

    Ingvarsson, G.; Svanbjoernson, A.

    1992-01-01

    Iceland possesses a wealth of hydro power and geothermal energy. No less than 50,000 GWh/year of power are estimated to be producible from hydro and geothermal in Iceland at a sufficiently low cost to be of interest to power-intensive industries and for export. Only a fraction of this energy potential has been developed or some 5,000 GWh/year. The power resources of Iceland represent one of the country's best opportunities for large scale development and economic growth and their utilization is high on the Government's priority list. In the past Iceland has run a successful campaign attracting foreign investors in power intensive industries and about half of the electric production today is consumed by power intensive industries. New industries can be sure of highly competitive power prices compared with Europe and North America for new contracts. Many other reasons for locating energy intensive industry in Iceland are outlined in the paper, such as the educated work-force, European culture and political stability, Mid-Atlantic location and proximity to markets, good transport and communication facilities, abundance of fresh water, good industrial sites with a large extension potential and excellent harbors for large vessels. The future prospects for hydro and geothermal energy include large greenfield aluminium smelters, direct export of electricity by submarine cables to the European continent and industries using geothermal steam for process application. The Icelandic Energy Marketing Unit, established in 1988 is mandated to promote and market Iceland's energy resources and seek investors in the field of power intensive industries. Currently marketing efforts are being undertaken to promote the direct use of geothermal steam for industrial application

  1. Thirteen million years of silicic magma production in Iceland: Links between petrogenesis and tectonic settings

    Science.gov (United States)

    Martin, E.; Sigmarsson, O.

    2010-04-01

    The origin of the Quaternary silicic rocks in Iceland is thought to be linked to the thermal state of the crust, which in turn depends on the regional tectonic settings. This simple model is tested here on rocks from the Miocene to present, both to suggest an internally consistent model for silicic magma formation in Iceland and to constrain the link between tectonic settings and silicic magma petrogenesis. New major and trace-element compositions together with O-, Sr- and Nd-isotope ratios have been obtained on silicic rocks from 19 volcanic systems ranging in age from 13 Ma to present. This allows us to trace the spatial and temporal evolution of both magma generation and the corresponding sources. Low δ18O (geothermal gradient. But later than 5.5 Ma they were produced in a flank zone environment by fractional crystallisation alone, probably due to decreasing geothermal gradient, of basalts derived from a mantle source with lower 143Nd/ 144Nd. This is in agreement with an eastwards rift-jump, from Snæfellsnes towards the present Reykjanes Rift Zone, between 7 and 5.5 Ma. In the South Iceland Volcanic Zone (SIVZ), the intermediate Nd-signature observed in silicic rocks from the Torfajökull central volcano reflects the transitional character of the basalts erupted at this propagating rift segment. Therefore, the abundant evolved rocks at this major silicic complex result from partial melting of the transitional alkaline basaltic crust (Iceland can, therefore, be used for deciphering past geodynamic settings characterized by rift- and off-rift zones resulting from interaction of a mantle plume and divergent plate boundaries.

  2. Strength and deformation properties of volcanic rocks in Iceland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Andreassen, Katrine Alling

    2016-01-01

    rock from Iceland has been the topic for rock mechanical studies carried out by Ice-landic guest students at the Department of Civil Engineering at the Technical University of Den-mark over a number of years in cooperation with University of Iceland, Vegagerðin (The Icelandic Road Directorate......) and Landsvirkjun (The National Power Company of Iceland). These projects involve engineering geological properties of volcanic rock in Iceland, rock mechanical testing and parameter evaluation. Upscaling to rock mass properties and modelling using Q- or GSI-methods have been studied by the students......Tunnelling work and preinvestigations for road traces require knowledge of the strength and de-formation properties of the rock material involved. This paper presents results related to tunnel-ling for Icelandic water power plants and road tunnels from a number of regions in Iceland. The volcanic...

  3. Earthquake Prediction Research In Iceland, Applications For Hazard Assessments and Warnings

    Science.gov (United States)

    Stefansson, R.

    Earthquake prediction research in Iceland, applications for hazard assessments and warnings. The first multinational earthquake prediction research project in Iceland was the Eu- ropean Council encouraged SIL project of the Nordic countries, 1988-1995. The path selected for this research was to study the physics of crustal processes leading to earth- quakes. It was considered that small earthquakes, down to magnitude zero, were the most significant for this purpose, because of the detailed information which they pro- vide both in time and space. The test area for the project was the earthquake prone region of the South Iceland seismic zone (SISZ). The PRENLAB and PRENLAB-2 projects, 1996-2000 supported by the European Union were a direct continuation of the SIL project, but with a more multidisciplinary approach. PRENLAB stands for "Earthquake prediction research in a natural labo- ratory". The basic objective was to advance our understanding in general on where, when and how dangerous NH10earthquake motion might strike. Methods were devel- oped to study crustal processes and conditions, by microearthquake information, by continuous GPS, InSAR, theoretical modelling, fault mapping and paleoseismology. New algorithms were developed for short term warnings. A very useful short term warning was issued twice in the year 2000, one for a sudden start of an eruption in Volcano Hekla February 26, and the other 25 hours before a second (in a sequence of two) magnitude 6.6 (Ms) earthquake in the South Iceland seismic zone in June 21, with the correct location and approximate size. A formal short term warning, although not going to the public, was also issued before a magnitude 5 earthquake in November 1998. In the presentation it will be shortly described what these warnings were based on. A general hazard assessmnets was presented in scientific journals 10-15 years ago assessing within a few kilometers the location of the faults of the two 2000 earthquakes and suggesting

  4. Individualistic Vikings: Culture, Economics and Iceland

    Directory of Open Access Journals (Sweden)

    Már Wolfgang Mixa

    2015-12-01

    Full Text Available Icelandic culture has generally been considered to share many similarities to the Nordic cultures. However, the financial crisis in 2008 painted a completely different picture, with the Nordic nations faring much less worse than Iceland, which saw its banking system becoming almost entirely worthless. Looking at traditional cultural yardsticks in the vein of the most commonly used research in the field of business and organizational management, generally linked to Hofstede´s dimensional studies, one would at first glance conclude that Icelanders would have behaved in a similar manner as people in the Nordic nations. By focusing on savings ratio, it is shown that Icelanders were much more risk-seeking during the prelude of the crisis. Many nations badly hit during the 2008 financial crisis have a high level of individualism inherent in their culture. Iceland fits this scenario. Thus while general cultural characteristics may lack explanatory power regarding economic behavior of people between cultures, the individual/collective cultural dimension may provide clues of what dangers (and possible strengths lurk within societies from a financial point of view. Such developments may affect the financial stability of nations, especially those with a high level of individualism where financial liberalization with possible abuses is occurring.

  5. Planetary geomorphology field studies: Iceland and Antarctica

    Science.gov (United States)

    Malin, M. C.

    1984-01-01

    Field studies of terrestrial landforms and the processes that shape them provide new directions to the study of planetary features. These studies, conducted in Iceland and in Antarctica, investigated physical and chemical weathering mechanisms and rates, eolitan processes, mudflow phenomena, drainage development, and catastrophic fluvial and volcanic phenomena. Continuing investigations in Iceland fall in three main catagories: (1) catastrophic floods of the Jokulsa a Fjollum, (2) lahars associated with explosive volcanic eruptions of Askja caldera, and (3) rates of eolian abrasion in cold, volcanic deserts. The ice-free valleys of Antarctica, in particular those in South Victoria Land, have much is common with the surface of Mars. In addition to providing independent support for the application of the Iceland findings to consideration of the martian erosional system, the Antarctic observations also provide analogies to other martian phenomena. For example, a family of sand dunes in Victoria Valley are stabilized by the incorporation of snow as beds.

  6. Gendering in one Icelandic preschool

    Directory of Open Access Journals (Sweden)

    Gudrun Alda Hardardottir

    2014-05-01

    Full Text Available The aim of this article is to shed light on gendering in preschool. It analyzes the opinions and beliefs of preschool teachers with regard to boys and girls in one Icelandic preschool, and how gender performative acts are manifested in the preschool’s children. The preschool, which was observed for one school year, comprised 60 children, aged 18 months to five years, and 20 employees, of which eight were qualified teachers. The research material is analyzed in terms of Judith Butler’s gender constructivism. Butler contends that gender is constituted by, and is a product of, society, and that the individual’s empowerment is therefore limited in relation to society, with individuals typically seeking to identify themselves with the dominant norms concerning gender. The main conclusions suggest that “gendering” is prominent within the preschool. There is a strong tendency among the preschool teachers to classify the children into categories of boys/masculine and girls/feminine, and specific norms direct the children into the dominant feminine and masculine categories, thus maintaining and reinforcing their gender stereotypes. The children used symbols such as colors, locations and types of play as means to instantiate the “girling” and the “boying”. These findings are consistent with previous Nordic research and indicate a prevailing essentialist perspective towards both girls and boys. The originality of the research, however, lies in focusing on children’s gender from the individual’s perspective and how the individual child generally enacts gender performatively within the confines of society’s norms.

  7. Strategy for larch breeding in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Eysteinsson, T. [Iceland Forest Service, Egilsstadir (Iceland)

    1995-12-31

    An accelerated breeding program for Siberian larch was initiated in Iceland in 1992. Siberian larch is an important exotic species, but not fully adapted to Icelandic conditions. Selections are made based on adaptive traits such as growth rhythm and resistance to damage as well as form and growth rate. Seed will be produced in containerised, greenhouse orchards, necessitating selection for fecundity to best use expensive greenhouse space. Research will concentrate on developing flower induction treatments for Siberian larch and ways to maximize seed production and viability. 19 refs

  8. The Wind Energy Potential of Iceland

    DEFF Research Database (Denmark)

    Nawri, Nikolai; Petersen, Guðrún Nína; Björnsson, Halldór

    2014-01-01

    Downscaling simulations performed with theWeather Research and Forecasting (WRF) model were used to determine the large-scale wind energy potential of Iceland. Local wind speed distributions are represented by Weibull statistics. The shape parameter across Iceland varies between 1.2 and 3...... is higher by 100 e700 W m_2 than that of offshore winds. Based on these results, 14 test sites were selected for more detailed analyses using the Wind Atlas Analysis and Application Program (WAsP). © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license...

  9. Iceland blasts millennium bugs in speed governors

    Energy Technology Data Exchange (ETDEWEB)

    Gislason, Gisli [Landsvirkjun, Reykjavik (Iceland). Electromechanical Dept.; Ferme, J.-M. [Voith Hydro, Heidenheim (Germany)

    1999-11-01

    This article focuses on the examination of distribution management systems to identify any potential problems related to the year 2000 (Y2K) that would affect the operation of speed governors with date management capacity at Iceland's hydroelectric power plants. Details are given of the work carried out by Landsvirkjun, Iceland's main power generator, the use of date for monitoring functions, the different governor models, the testing of the digital speed governors, and the modification of software in cases where protection relays were untestable.

  10. Strategy for larch breeding in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Eysteinsson, T [Iceland Forest Service, Egilsstadir (Iceland)

    1996-12-31

    An accelerated breeding program for Siberian larch was initiated in Iceland in 1992. Siberian larch is an important exotic species, but not fully adapted to Icelandic conditions. Selections are made based on adaptive traits such as growth rhythm and resistance to damage as well as form and growth rate. Seed will be produced in containerised, greenhouse orchards, necessitating selection for fecundity to best use expensive greenhouse space. Research will concentrate on developing flower induction treatments for Siberian larch and ways to maximize seed production and viability. 19 refs

  11. Iceland as a Landscape Investigation Pattern

    Directory of Open Access Journals (Sweden)

    Campanini, Manuela Silvia

    2007-03-01

    Full Text Available Nowadays Icelanders continue an ancient dialogue. Nature is part of their soul and they take with them bits of their terrestrial landscape when they move to the elsewhere. When they move out in the sea they often name their ships or boats after natural spots (waterfalls, mountains, etc., Moving to the town, architects build monuments inspired by wild nature like Hallgrimskirkja (inspired by Hraundrangar and the columnar basalt or Perlan (inspired by the Geysir and the geothermal water. This is the way Icelanders compensate and take care of their perennial landscape nostalgia.

  12. Nation in a sheep’s coat: The Icelandic sweater

    Directory of Open Access Journals (Sweden)

    Gudrun Helgadottir

    2011-12-01

    Full Text Available The Icelandic sweater is presented and received as being traditional—even ancient—authentically Icelandic and hand made by Icelandic women from the wool of Icelandic sheep. Even so, the sweater type, the so-called ‘Icelandic sweater’ in English, only dates back to the mid-20th century and is not necessarily made in Iceland nor from indigenous wool. Nevertheless, the sweater is a successful invention of a tradition (Hobsbawm & Ranger, 1983, popular among Icelanders and tourists alike since its introduction in the mid-20th century. It has gained ground as a national symbol, particularly in times of crisis for example in the reconstruction of values in the aftermath of the Icelandic bank collapse of 2008. I traced the development of the discourse about wool and the origins of the Icelandic sweater by looking at publications of the Icelandic National Craft Association, current design discourse in Iceland and its effect on the development of the wool industry. I then tied these factors to notions of tradition, authenticity, national culture, image and souvenirs.

  13. Volcano morphometry and volume scaling on Venus

    Science.gov (United States)

    Garvin, J. B.; Williams, R. S., Jr.

    1994-01-01

    A broad variety of volcanic edifices have been observed on Venus. They ranged in size from the limits of resolution of the Magellan SAR (i.e., hundreds of meters) to landforms over 500 km in basal diameter. One of the key questions pertaining to volcanism on Venus concerns the volume eruption rate or VER, which is linked to crustal productivity over time. While less than 3 percent of the surface area of Venus is manifested as discrete edifices larger than 50 km in diameter, a substantial component of the total crustal volume of the planet over the past 0.5 Ga is related to isolated volcanoes, which are certainly more easily studied than the relatively diffusely defined plains volcanic flow units. Thus, we have focused our efforts on constraining the volume productivity of major volcanic edifices larger than 100 km in basal diameter. Our approach takes advantage of the topographic data returned by Magellan, as well as our database of morphometric statistics for the 20 best known lava shields of Iceland, plus Mauna Loa of Hawaii. As part of this investigation, we have quantified the detailed morphometry of nearly 50 intermediate to large scale edifices, with particular attention to their shape systematics. We found that a set of venusian edifices which include Maat, Sapas, Tepev, Sif, Gula, a feature at 46 deg S, 215 deg E, as well as the shield-like structure at 10 deg N, 275 deg E are broadly representative of the approx. 400 volcanic landforms larger than 50 km. The cross-sectional shapes of these 7 representative edifices range from flattened cones (i.e., Sif) similar to classic terrestrial lava shields such as Mauna Loa and Skjaldbreidur, to rather dome-like structures which include Maat and Sapas. The majority of these larger volcanoes surveyed as part of our study displayed cross-sectional topographies with paraboloidal shaped, in sharp contrast with the cone-like appearance of most simple terrestrial lava shields. In order to more fully explore the

  14. Doing Business Economy Profile 2015 : Iceland

    OpenAIRE

    World Bank Group

    2014-01-01

    This economy profile for Doing Business 2015 presents the 11 Doing Business indicators for Iceland. To allow for useful comparison, the profile also provides data for other selected economies (comparator economies) for each indicator. Doing Business 2015 is the 12th edition in a series of annual reports measuring the regulations that enhance business activity and those that constrain it. E...

  15. Esperanto and Icelandic: Two Contrasting Lexical Systems

    Science.gov (United States)

    Gutmans, Theodore

    1972-01-01

    The article comprises a table listing Esperanto words conveying international concepts, accompained by equivalents in English, French, German, Russian, Hungarian, Hebrew and Icelandic, representing various language groups. The comparison shows that although the world language would opt for international terms, a language making no claims on…

  16. Recent saltmarsh foraminiferal assemblages from Iceland

    Science.gov (United States)

    Lübbers, Julia; Schönfeld, Joachim

    2018-01-01

    This study reports for the first time boreal to subarctic intertidal foraminiferal assemblages from saltmarshes at Borgarnes and Faskrudsfjördur on Iceland. The composition of living and dead foraminiferal assemblages was investigated along transects from the tidal flat to the highest reach of halophytic plants. The foraminiferal assemblages from Borgarnes showed 18 species in the total foraminiferal assemblage of which only 7 species were recorded in the living fauna. The assemblages were dominated by agglutinated taxa, whereas 3 calcareous species were recorded, of which only Haynesina orbicularis was found in the living fauna. The distribution limit of calcifying species corresponds to the lower boundary of the lower saltmarsh vegetation zone. Furthermore, calcareous tests showed many features of dissolution, which is an indication of a carbonate corrosive environment. The species forming the dead assemblages were mainly derived from the ambient intertidal areas and were displaced by tidal currents into the saltmarsh. The foraminiferal assemblages from Faskrudsfjördur showed two species, of which only one species was recorded in the living fauna. The assemblage was dominated by the agglutinated foraminifer Trochaminita irregularis. The foraminiferal species recorded on Iceland were the same as commonly found elsewhere in Europa. Since no species was found which is endemic to North America, Iceland is considered part of the European bio province. The foraminiferal could have been immigrated to Iceland from Europe through warm water currents, migratory birds or marine traffic since the last Ice Age.

  17. Characterization of Genetic Variation in Icelandic Cattle

    DEFF Research Database (Denmark)

    Holm, Lars-Erik; Das, Ashutosh; Momeni, Jamal

    Identification of genetic variation in cattle breeds using next-generation sequencing technology has focused on the modern production cattle breeds. We focused on one of the oldest indigenous breeds, the Icelandic cattle breed. Sequencing of two individuals enabled identification of more than 8...

  18. Physical properties of suspended dust in Iceland

    Czech Academy of Sciences Publication Activity Database

    Dagsson-Waldhauserova, P.; Olafsson, H.; Arnalds, O.; Škrabalová, L.; Sigurdardottir, G.; Braniš, M.; Hladil, Jindřich; Chadimová, Leona; Navrátil, Tomáš; von Lowis of Menar, S.; Thorsteinsson, T.

    2014-01-01

    Roč. 16, - (2014), s. 8565-8565 ISSN 1607-7962. [ European Geosciences Union General Assembly. 27.04.2014-02.05.2014, Vienna] Institutional support: RVO:67985831 Keywords : dust * volcanology * Iceland http://meetingorganizer.copernicus.org/EGU2014/EGU2014-8565.pdf

  19. Geothermal Cogeneration: Iceland's Nesjavellir Power Plant

    Science.gov (United States)

    Rosen, Edward M.

    2008-01-01

    Energy use in Iceland (population 283,000) is higher per capita than in any other country in the world. Some 53.2% of the energy is geothermal, which supplies electricity as well as heated water to swimming pools, fish farms, snow melting, greenhouses, and space heating. The Nesjavellir Power Plant is a major geothermal facility, supplying both…

  20. Cost containment of pharmaceutical use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, Anna Birna; Morgall, Janine Marie; Grímsson, A

    2000-01-01

    Iceland was the first Nordic country to liberalise its drug distribution system, in March 1996. Subsequent regulation in January 1997 increased patients' share of drug costs. The objectives of this study were to test the assumptions that liberalizing community pharmacy ownership would lower reimb...

  1. Seismic Tomography in Reykjanes , SW Iceland

    NARCIS (Netherlands)

    Jousset, Philippe; Blanck, Hanna; Franke, Steven; Metz, M.; Águstsson, K.; Verdel, Arie; Ryberg, T.; Hersir, Gylfi Páll; Weemstra, C.; Bruhn, D.F.; Flovenz, Olafur G

    2016-01-01

    We present tomographic results obtained around geothermal reservoirs using seismic data recorded both on-land Reykjanes, SW-Iceland and offshore along Reykjanes Ridge. We gathered records from a network of 83 seismic stations (including 21 Ocean Bottom Seismometers) deployed between April 2014 and

  2. Historic magmatism on the Reykjanes Peninsula, Iceland

    DEFF Research Database (Denmark)

    Peate, David W.; Baker, Joel A.; Jakobssen, Sveinn P.

    2009-01-01

    We present new compositional data on a suite of historic lava flows from the Reykjanes Peninsula, Iceland. They were erupted over a short time period between c. 940 and c. 1340 AD and provide a snap-shot view of melt generation and evolution processes beneath this onshore, 65 km long, ridge segment...

  3. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  4. Volcanoes: Coming Up from Under.

    Science.gov (United States)

    Science and Children, 1980

    1980-01-01

    Provides specific information about the eruption of Mt. St. Helens in March 1980. Also discusses how volcanoes are formed and how they are monitored. Words associated with volcanoes are listed and defined. (CS)

  5. Long-term variability of dust-storms in Iceland

    Science.gov (United States)

    Dagsson-Waldhauserová, Pavla; Ólafsson, Haraldur; Arnalds, Ólafur

    2013-04-01

    Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland are volcanic sandy deserts. Natural emissions from these sources influenced by strong winds affect not only regional air quality in Iceland ("Reykjavik haze") but dust particles are transported over the Atlantic ocean and Arctic Ocean > 1000 km at times. The study places Icelandic dust production area into international perspective, present long term frequency of dust storm events in NE Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in NE Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the NE erosion area, indicating extreme dust plume activity and erosion within the NE deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and aeolian transport during dust/volcanic ash storms in Iceland which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust is not only a substantial source for regional air pollution, but may be considered to contribute to the Arctic haze phenomena and Arctic air pollution.

  6. Organizational changes at Earthquakes & Volcanoes

    Science.gov (United States)

    Gordon, David W.

    1992-01-01

    Primary responsibility for the preparation of Earthquakes & Volcanoes within the Geological Survey has shifted from the Office of Scientific Publications to the Office of Earthquakes, Volcanoes, and Engineering (OEVE). As a consequence of this reorganization, Henry Spall has stepepd down as Science Editor for Earthquakes & Volcanoes(E&V).

  7. Hawaii's volcanoes revealed

    Science.gov (United States)

    Eakins, Barry W.; Robinson, Joel E.; Kanamatsu, Toshiya; Naka, Jiro; Smith, John R.; Takahashi, Eiichi; Clague, David A.

    2003-01-01

    Hawaiian volcanoes typically evolve in four stages as volcanism waxes and wanes: (1) early alkalic, when volcanism originates on the deep sea floor; (2) shield, when roughly 95 percent of a volcano's volume is emplaced; (3) post-shield alkalic, when small-volume eruptions build scattered cones that thinly cap the shield-stage lavas; and (4) rejuvenated, when lavas of distinct chemistry erupt following a lengthy period of erosion and volcanic quiescence. During the early alkalic and shield stages, two or more elongate rift zones may develop as flanks of the volcano separate. Mantle-derived magma rises through a vertical conduit and is temporarily stored in a shallow summit reservoir from which magma may erupt within the summit region or be injected laterally into the rift zones. The ongoing activity at Kilauea's Pu?u ?O?o cone that began in January 1983 is one such rift-zone eruption. The rift zones commonly extend deep underwater, producing submarine eruptions of bulbous pillow lava. Once a volcano has grown above sea level, subaerial eruptions produce lava flows of jagged, clinkery ?a?a or smooth, ropy pahoehoe. If the flows reach the ocean they are rapidly quenched by seawater and shatter, producing a steep blanket of unstable volcanic sediment that mantles the upper submarine slopes. Above sea level then, the volcanoes develop the classic shield profile of gentle lava-flow slopes, whereas below sea level slopes are substantially steeper. While the volcanoes grow rapidly during the shield stage, they may also collapse catastrophically, generating giant landslides and tsunami, or fail more gradually, forming slumps. Deformation and seismicity along Kilauea's south flank indicate that slumping is occurring there today. Loading of the underlying Pacific Plate by the growing volcanic edifices causes subsidence, forming deep basins at the base of the volcanoes. Once volcanism wanes and lava flows no longer reach the ocean, the volcano continues to submerge, while

  8. Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: a study of archived basaltic to rhyolitic ash samples.

    Science.gov (United States)

    Damby, David E; Horwell, Claire J; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

    2017-09-11

    The eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland's volcanoes to Icelandic and Northern European populations. A physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. Icelandic ash can be of a respirable size (up to 11.3 vol.% fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m 2  g -1 , which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO • ), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after 'refreshing' sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m -2 , with mafic samples releasing more iron than silicic samples. All samples were non-reactive in a test of red blood cell-membrane damage. The primary particle-specific concern is the potential for future eruptions of Iceland's volcanoes to generate fine, respirable material and, thus, to

  9. Inter-Rifting and Inter-Seismic Strain Accumulation in a Propagating Ridge System: A Geodetic Study from South Iceland

    Science.gov (United States)

    Travis, M. E.; La Femina, P. C.; Geirsson, H.

    2012-12-01

    The Mid-Atlantic Ridge, a slow spreading (~19 mm/yr) mid-ocean ridge boundary between the North American and Eurasian plates, is exposed subaerially in Iceland as the result of ridge-hotspot interaction. Plate spreading in Iceland is accommodated along neovolcanic zones comprised of central volcanoes and their fissure swarms. In south Iceland plate motion is partitioned between the Western Volcanic Zone (WVZ) and Eastern Volcanic Zone (EVZ). The EVZ is propagating to the southwest, while the WVZ is dying out from the northeast. Plate motion across both systems has been accommodated by repeated rifting events and fissure eruptions. In this study we investigate whether the WVZ is active and accumulating strain, and how strain is partitioned between the WVZ and EVZ. We also test how strain is accumulating along fissure swarms within the EVZ (i.e. is strain accumulation localized to one fissure swarm, or are multiple systems active?). We use GPS data and elastic block models run using the program DEFNODE to investigate these issues. GPS data are processed using the GIPSY-OASIS II software, and have been truncated to the 2000.5-2011 time period to avoid co-seismic displacement from the two June 2000 South Iceland Seismic Zone earthquakes. We also truncate the time series for sites within 20 km of Eyjafjallajökull to the beginning of 2010 to eliminate deformation associated with the March 2010 eruption of that volcano. We correct for co-seismic displacement from the two May 2008 SISZ earthquakes, inflation at Hekla volcano and the horizontal component of glacial isostatic rebound (GIA). Our best-fit model for inter-rifting and inter-seismic elastic strain accumulation suggests 80-90% of spreading is accommodated in the EVZ with the other 10-20% accommodated by the WVZ. The best-fit location of the EVZ is between Veidivotn and Lakigigar in an area of no Holocene volcanic activity. We suggest the WVZ is only active at Hengill and its associated fissure swarm. Geologic and

  10. Validity of Type D personality in Iceland

    DEFF Research Database (Denmark)

    Svansdottir, Erla; Karlsson, Hrobjartur D; Gudnason, Thorarinn

    2012-01-01

    was 26-29%, and assessment of Type D personality was not confounded by severity of underlying coronary artery disease. Regarding risk markers, Type D patients reported more psychopharmacological medication use and smoking, but frequency of previous mental problems was similar across groups. Type D......Type D personality has been associated with poor prognosis in cardiac patients. This study investigated the validity of the Type D construct in Iceland and its association with disease severity and health-related risk markers in cardiac patients. A sample of 1,452 cardiac patients completed...... the Type D scale (DS14), and a subgroup of 161 patients completed measurements for the five-factor model of personality, emotional control, anxiety, depression, stress and lifestyle factors. The Icelandic DS14 had good psychometric properties and its construct validity was confirmed. Prevalence of Type D...

  11. The electric power sector in Iceland

    International Nuclear Information System (INIS)

    Ingimarsson, J.

    1992-01-01

    In Iceland the government must give permission for the building of a power station etc. but in practise the power plant administrators determine the tariffs. The structure of electric power supply mirrors a strong engagement on the part of the state and the local authorities. Almost all the power plants and distribution systems are state owned or owned by both the state and the local authorities, and so constitute a monopoly, producing 93% of the total amount of electricity supply. Government policy in this field, the Icelandic electric power distribution system and the setting of electricity prices are briefly described. It is claimed that there would be economical advantages in restructuring the distribution network and that the government favours an increase in possibilities for competition and making legislative changes. This will mean that in the future the market will play a more important role and that power plant administrators must review their duties regarding consumer satisfaction, tariffs etc. (AB)

  12. Maximizing industrial infrastructure efficiency in Iceland

    Science.gov (United States)

    Ingason, Helgi Thor; Sigfusson, Thorsteinn I.

    2010-08-01

    As a consequence of the increasing aluminum production in Iceland, local processing of aluminum skimmings has become a feasible business opportunity. A recycling plant for this purpose was built in Helguvik on the Reykjanes peninsula in 2003. The case of the recycling plant reflects increased concern regarding environmental aspects of the industry. An interesting characteristic of this plant is the fact that it is run in the same facilities as a large fishmeal production installation. It is operated by the same personnel and uses—partly—the same equipment and infrastructure. This paper reviews the grounds for these decisions and the experience of this merger of a traditional fish melting industry and a more recent aluminum melting industry after 6 years of operation. The paper is written by the original entrepreneurs behind the company, who provide observations on how the aluminum industry in Iceland has evolved since the starting of Alur’s operation and what might be expected in the near future.

  13. Characteristic of 120 degree C thermoluminescence peak of iceland spar

    International Nuclear Information System (INIS)

    Lu Xinwei; Han Jia

    2006-01-01

    The basic characteristic of 120 degree C thermoluminescence peak of iceland spar was studied. The experimental result indicates the longevity of 120 degree C thermoluminescence peak of iceland spar is about 2 h under 30 degree C. The thermoluminescence peak moves to the high temperature when the heating speed increasing. The intensity of 120 degree C thermoluminescence peak of iceland spar is directly proportional to radiation dose under 15 Gy. (authors)

  14. Food 
Security
 in
 Iceland

    Directory of Open Access Journals (Sweden)

    Alyson J.K. Bailes

    2011-12-01

    Full Text Available The concept of food security applies in both poor and rich societies and concerns the steady availability of food in the right quantity and quality, at the right price. Globally, policies to assure it remain confused and world food prices are rising. Despite large exports of fish, Iceland produces only around half of its inhabitants’ nutritional needs and relies significantly on imports, also for food production inputs like fodder and seeds. Icelandic supplies are affected by oligopoly in the retail market, and could be put at risk by events in other security dimensions ranging from natural disasters and infrastructure failures to terrorism, neighbouring conflicts and other people’s shortages. Icelandic farmers have used the terminology of ‘food security’ to press their claims for more home-grown production, and more recently also in their campaign against EU membership. The general public however shows little sign of security-awareness in this field. The government possesses suitable non-military security frameworks to address food-related risks and has initiated useful, general and specific, studies. Yet it has not developed a strategy or contingency plan for food security, even following the lessons of the 2008 economic crash and 2010-2011 eruptions. Suitable remedies would include larger emergency stocks and a range of measures to reduce vulnerability and improve resilience in crises. Above all, Iceland needs a balanced and open policy-making process to decide what its general future strategy should be as a food-producing and -importing nation. Food security could then be more precisely defined and pursued with the aim of minimizing threats and risks to that agreed vision.

  15. Spying on volcanoes

    Science.gov (United States)

    Watson, Matthew

    2017-07-01

    Active volcanoes can be incredibly dangerous, especially to those who live nearby, but how do you get close enough to observe one in action? Matthew Watson explains how artificial drones are providing volcanologists with insights that could one day save human lives

  16. Geology of kilauea volcano

    Science.gov (United States)

    Moore, R.B.; Trusdell, F.A.

    1993-01-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower cast rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. ?? 1993.

  17. The passive of reflexive verbs in Icelandic

    Directory of Open Access Journals (Sweden)

    Hlíf Árnadóttir

    2011-10-01

    Full Text Available The Reflexive Passive in Icelandic is reminiscent of the so-called New Passive (or New Impersonal in that the oblique case of a passivized object NP is preserved. As is shown by recent surveys, however, speakers who accept the Reflexive Passive do not necessarily accept the New Passive, whereas conversely, speakers who accept the New Passive do also accept the Reflexive Passive. Based on these results we suggest that there is a hierarchy in the acceptance of passive sentences in Icelandic, termed the Passive Acceptability Hierarchy. The validity of this hierarchy is confirmed by our diachronic corpus study of open access digital library texts from Icelandic journals and newspapers dating from the 19th and 20th centuries (tímarit.is. Finally, we sketch an analysis of the Reflexive Passive, proposing that the different acceptability rates of the Reflexive and New Passives lie in the argument status of the object. Simplex reflexive pronouns are semantically dependent on the verbs which select them, and should therefore be analyzed as syntactic arguments only, and not as semantic arguments of these verbs.

  18. Icelandic: A Lesser-Used Language in the Global Community

    Science.gov (United States)

    Holmarsdottir, Halla B.

    2001-07-01

    A small nation in the middle of the North Atlantic, Iceland currently has a population of 265,000 (1996). The Iceland language has changed very little since the island was settled some 11 centuries ago. Despite the relatively small number of people who speak the language and irrespective of the globalisation efforts by the international community, which includes the ever-increasing influence of English worldwide, the Icelandic language and culture are stronger than ever. The current volume and variety of publications of Icelandic works in all areas have never been as great. Icelandic is a living and growing language. Growth in vocabulary, in response to recent phenomena like the introduction of new technology, has primarily come about with the development of new words from the language's roots. The near absence of Latin, Greek and, more recently, English or Danish words in Icelandic, is striking. Iceland's language policy is not only a governmental policy. It is a policy that comes from the grassroots with the government and official institutions viewing their job as one of service to the people of Iceland. Icelanders are very proud of their language and are extremely determined to continually develop and preserve it for future generations.

  19. Corporate taxation in Iceland and the international challenge

    Directory of Open Access Journals (Sweden)

    Agnarsdóttir Fjóla

    2014-11-01

    Full Text Available This article aims to describe the development in the field of corporate tax law in Iceland, from both legal and economic point of view, with a focus on measures taken to protect the tax base and in order to try to make Iceland an attractive place for investment and establishment companies. First, there will be a brief general description of the development of the corporate tax rate in Iceland since 2004 and an overview of new taxes that have been introduced for companies over the past ten years. Second, there will be an analysis of how the Icelandic legal framework provides for incentives for investment and establishment of companies in Iceland. Third, this discussion is to be followed by a section on the steps Iceland has taken in order to combat tax avoidance. Fourth, there is a general description of the economic development for the corporate taxation in Iceland since 1990 and fifth, there is brief discussion of the development of revenues from the corporate tax. Sixth, a short overview of the real investment in the Icelandic economy is given, and finally, the main conclusions of this article will be summed up with a short discussion on the main challenges Iceland is currently facing in the field of corporate taxation in today’s globalised economy.

  20. Petrologic Constraints on Iceland's Lower Crust

    Science.gov (United States)

    Kelley, D. F.; Leftwich, T. E.; Barton, M.

    2005-05-01

    Iceland is an area of relatively thick ocean crust that straddles the spreading MAR. Iceland was created by seafloor spreading originating about 55 Ma above abnormally hot mantle. The high temperatures resulted in greater melt volumes that enhanced crustal thickening. Geophysical investigations provide fundamental insight on crustal features, but results are contradictory. Early seismic, magneto-telluric, and resistivity studies predicted thin crust with partial melt regions at depths of 10-15 km beneath the neovolcanic zones. Reinterpretations based on recent seismic studies suggest thicker and cooler crust. These studies have shown magma lenses at shallow depths beneath volcanic centers, but cannot confirm their presence in the lower crust. Knowledge of the depth of magma chambers is critical to constrain the geothermal gradients in Icelandic crust and to resolve discrepancies in interpretation of geophysical data. Analyses of glasses in Icelandic lavas erupted from 11 volcanic centers throughout the rift zones have been compiled. The pressures of equilibration of these liquids with ol, high-Ca pyx, and plag were estimated qualitatively from projections into the pseudoternary system Ol-Di-Qtz. The results (ca. 0.6 GPa) indicate crystallization in magma chambers located at about 20 km depth. Equilibrium pressures also have been calculated quantitatively. These results (0.6±0.2 GPa) indicate magma chambers at 19.8±6.5 km depth beneath the volcanic centers. Magma chamber at these depths are located in the lower crust inferring that it must be relatively warm. Geothermal gradients have been calculated using the depths of the sourcing magma chambers and any shallow seismically detected magma chambers at each location. An average crustal composition has been calculated from the compiled geochemical data and was used to calculate density variations and seismic velocities along the geotherms. The distribution of sample locations in this study provides sufficient data

  1. Forecasting deflation, intrusion and eruption at inflating volcanoes

    Science.gov (United States)

    Blake, Stephen; Cortés, Joaquín A.

    2018-01-01

    A principal goal of volcanology is to successfully forecast the start of volcanic eruptions. This paper introduces a general forecasting method, which relies on a stream of monitoring data and a statistical description of a given threshold criterion for an eruption to start. Specifically we investigate the timing of intrusive and eruptive events at inflating volcanoes. The gradual inflation of the ground surface is a well-known phenomenon at many volcanoes and is attributable to pressurised magma accumulating within a shallow chamber. Inflation usually culminates in a rapid deflation event caused by magma escaping from the chamber to produce a shallow intrusion and, in some cases, a volcanic eruption. We show that the ground elevation during 15 inflation periods at Krafla volcano, Iceland, increased with time towards a limiting value by following a decaying exponential with characteristic timescale τ. The available data for Krafla, Kilauea and Mauna Loa volcanoes show that the duration of inflation (t*) is approximately equal to τ. The distribution of t* / τ values follows a log-logistic distribution in which the central 60% of the data lie between 0.99 deflation event starting during a specified time interval to be estimated. The time window in which there is a specified probability of deflation starting can also be forecast, and forecasts can be updated after each new deformation measurement. The method provides stronger forecasts than one based on the distribution of repose times alone and is transferable to other types of monitoring data and/or other patterns of pre-eruptive unrest.

  2. Geographic Names of Iceland's Glaciers: Historic and Modern

    Science.gov (United States)

    Sigurðsson, Oddur; Williams, Richard S.

    2008-01-01

    Climatic changes and resulting glacier fluctuations alter landscapes. In the past, such changes were noted by local residents who often documented them in historic annals; eventually, glacier variations were recorded on maps and scientific reports. In Iceland, 10 glacier place-names are to be found in Icelandic sagas, and one of Iceland's ice caps, Snaefellsjokull, appeared on maps of Iceland published in the 16th century. In the late 17th century, the first description of eight of Iceland's glaciers was written. Therefore, Iceland distinguishes itself in having a more than 300-year history of observations by Icelanders on its glaciers. A long-term collaboration between Oddur Sigurdsson and Richard S. Williams, Jr., led to the authorship of three books on the glaciers of Iceland. Much effort has been devoted to documenting historical glacier research and related nomenclature and to physical descriptions of Icelandic glaciers by Icelanders and other scientists from as far back as the Saga Age to recent (2008) times. The first book, Icelandic Ice Mountains, was published by the Icelandic Literary Society in 2004 in cooperation with the Icelandic Glaciological Society and the International Glaciological Society. Icelandic Ice Mountains was a glacier treatise written by Sveinn Palsson in 1795 and is the first English translation of this important scientific document. Icelandic Ice Mountains includes a Preface, including a summary of the history and facsimiles of page(s) from the original manuscript, a handwritten copy, and an 1815 manuscript (without maps and drawings) by Sveinn Palsson on the same subject which he wrote for Rev. Ebenezer Henderson; an Editor's Introduction; 82 figures, including facsimiles of Sveinn Palsson's original maps and perspective drawings, maps, and photographs to illustrate the text; a comprehensive Index of Geographic Place-Names and Other Names in the treatise; References, and 415 Endnotes. Professional Paper 1746 (this book) is the second

  3. Geodetic measurements and models of rifting in Northern Iceland for 1993-1998 (Invited)

    Science.gov (United States)

    Ali, T.; Feigl, K.; Thurber, C. H.; Masterlark, T.; Carr, B.; Sigmundsson, F.

    2010-12-01

    Rifting occurs as episodes of active deformation in individual rift segments of the Northern Volcanic Zone (NVZ) in Iceland. Here we simulate deformation around the Krafla central volcano and rift system in NVZ in order to explain InSAR data acquired between 1993 and 1998. The General Inversion for Phase Technique (GIPhT) is used to model the InSAR phase data directly, without unwrapping [Feigl and Thurber, Geophys. J. Int., 2009]. Using a parallel simulated annealing algorithm, GIPhT minimizes the non-linear cost function that quantifies the misfit between observed and modeled values of the phase. We test the hypothesis that the observed deformation can be explained by a combination of at least three processes including: (i) secular plate spreading, (ii) post rifting relaxation following the Krafla rifting episode (1975-1984), and (iii) deflation of a shallow magma chamber beneath the central volcano. The calibration parameters include material properties of upper/lower crust and mantle as well as flux rates for the elements of the plumbing system. The best fitting Maxwell model favors a stronger lower crust (~1.0E+20 Pa.s) and a mantle viscosity of ~1.0E+18 Pa.s as well as a shallow deflating magma chamber. The deformation appears to be linear in time over the observed interval.

  4. Explaining Gender Inequality in Iceland: What Makes the Difference?

    Science.gov (United States)

    Heijstra, Thamar M.; O'Connor, Pat; Rafnsdóttir, Gudbjörg Linda

    2013-01-01

    This article examines the explanations offered by men and women, at different academic ranks, for the scarcity of women in full professorial positions in Icelandic universities. Data derive from interviews and a survey involving the total Icelandic academic population. We test three hypotheses: Firstly, academics will not see family…

  5. Plastic ingestion by the northern fulmar (Fulmarus glacialis) in Iceland

    NARCIS (Netherlands)

    Kuehn, S.; Franeker, van J.A.

    2012-01-01

    In 2011, northern fulmars (Fulmarus glacialis) from Iceland were used to test the hypothesis that plastic debris decreases at northern latitudes in the Atlantic when moving away from major human centres of coastal and marine activities. Stomach analyses of Icelandic fulmars confirm that plastic

  6. The Origin of Noble Gas Isotopic Heterogeneity in Icelandic Basalts

    Science.gov (United States)

    Dixon, E. T.; Honda, M.; McDougall, I.

    2001-01-01

    Two models for generation of heterogeneous He, Ne and Ar isotopic ratios in Icelandic basalts are evaluated using a mixing model and the observed noble gas elemental ratios in Icelandic basalts,Ocean island Basalt (OIBs) and Mid-Ocean Ridge Basalt (MORBs). Additional information is contained in the original extended abstract.

  7. Interventions to curb rising pharmaceutical costs in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, Anna Birna; Grímsson, Almar; Björnsdóttir, Ingunn

    2003-01-01

    . The cancellation of reimbursement for antibiotics in 1991 resulted in a slight decrease in sales. The change in the list of "hospital only" medicines caused massive protests from pharmacists and physicians. The pharmaceutical policy in Iceland has been problematic in its formulations and implementations....... Recommendations in the light of the problems of Icelandic pharmaceutical policies have been provided in the article....

  8. Geology of Kilauea volcano

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.B. (Geological Survey, Denver, CO (United States). Federal Center); Trusdell, F.A. (Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory)

    1993-08-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.

  9. Heat flow and geothermal processes in Iceland

    Science.gov (United States)

    Flóvenz, Ólafur G.; Saemundsson, Kristján

    1993-09-01

    Heat flow values, derived from temperature measurements in shallow boreholes in Iceland, vary substantially across the country. The near-surface temperature gradients range from almost 0 to 500°C/km. The thermal conductivity of water-saturated rocks varies from 1.6 to 2.0 W/m°C. The temperature gradient in Iceland is mainly dependent on four factors: (1) the regional heat flow through the crust, (2) hydrothermal activity, (3) the permeability of the rock, and (4) residual heat in extinct volcanic centers. As Iceland is mainly made of basaltic material the radiogenic heat production is almost negligible. The thermal conductivity is, on the other hand, mainly influenced by the porosity of the rock; it increases as the porosity decreases. Iceland is made of sequences of flood basalts that formed within the volcanic rift zone—a continuation of the axis of the Mid-Atlantic ridge—and subsequently drifted sideways. Fresh basaltic lava is usually highly porous (30%) and fractured, and heat is mainly transported by convection. Therefore, a very low or even no temperature gradient is observed at shallow levels within the volcanic rift zone. As the basalt becomes buried the pores close due to lithostatic pressure and formation of secondary minerals. Below 500-1000 m depth in an uneroded lava pile, the heat is mainly transported by conduction. In the lowlands and valleys of Iceland outside the volcanic rift zone, 1000-1500 m of the original lava pile has been eroded, leaving thermal conduction as the most important heat transport mechanism. The regional temperature gradient has been measured in drillholes in dense and poorly permeable rocks away from the geothermal fields. The results show that the temperature gradient varies from 50 to 150°C/km. The highest values are found close to the volcanic rift zone and the gradient decreases with distance from the spreading axis. This result is mainly based on numerous shallow boreholes (60-500 m) but in some cases the results

  10. Galactic Super-volcano in Action

    Science.gov (United States)

    2010-08-01

    A galactic "super-volcano" in the massive galaxy M87 is erupting and blasting gas outwards, as witnessed by NASA's Chandra X-ray Observatory and NSF's Very Large Array. The cosmic volcano is being driven by a giant black hole in the galaxy's center and preventing hundreds of millions of new stars from forming. Astronomers studying this black hole and its effects have been struck by the remarkable similarities between it and a volcano in Iceland that made headlines earlier this year. At a distance of about 50 million light years, M87 is relatively close to Earth and lies at the center of the Virgo cluster, which contains thousands of galaxies. M87's location, coupled with long observations over Chandra's lifetime, has made it an excellent subject for investigations of how a massive black hole impacts its environment. "Our results show in great detail that supermassive black holes have a surprisingly good control over the evolution of the galaxies in which they live," said Norbert Werner of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University and the SLAC National Accelerator Laboratory, who led one of two papers describing the study. "And it doesn't stop there. The black hole's reach extends ever farther into the entire cluster, similar to how one small volcano can affect practically an entire hemisphere on Earth." The cluster surrounding M87 is filled with hot gas glowing in X-ray light, which is detected by Chandra. As this gas cools, it can fall toward the galaxy's center where it should continue to cool even faster and form new stars. However, radio observations with the Very Large Array suggest that in M87 jets of very energetic particles produced by the black hole interrupt this process. These jets lift up the relatively cool gas near the center of the galaxy and produce shock waves in the galaxy's atmosphere because of their supersonic speed. The scientists involved in this research have found the interaction of this cosmic

  11. Lithium Isotopes in Geothermal Fluids from Iceland

    Science.gov (United States)

    Millot, R.; Asmundsson, R.; Sanjuan, B.

    2008-12-01

    One of the main objectives of the HITI project (HIgh Temperature Instruments for supercritical geothermal reservoir characterization and exploitation), partially funded by the European Union, is to develop methods to characterize the reservoir and fluids of deep and very high temperature geothermal systems. The chemical composition of geothermal waters in terms of major and trace elements is related to the temperature, the degree of water/rock interaction and the mineralogical assemblage of the bedrock. Traditional geothermometers, such as silica, Na-K, Na-K-Ca or K-Mg applied to geothermal waters, make it possible to estimate the temperature at depth of the reservoir from which the waters are derived. However, the values estimated for deep temperature are not always concordant. The chemical geothermometer Na/Li which presents the singularity of associating two chemical elements, one a major element (sodium) and the other a trace element (Li), can be also used and gives an additional temperature estimation. The primary objective of this work was to better understand the behavior of this last geothermometer using the isotopic systematics of Li in order to apply it at very high temperature Icelandic geothermal systems. One particularly important aspect was to establish the nature, extent and mechanism of Li isotope fractionation between 100 and 350°C during water/rock interaction. For that purpose, we measured Li isotopes of about 25 geothermal waters from Iceland by using a Neptune MC-ICP-MS that enabled the analysis of Li isotopic ratios in geothermal waters with a level of precision of ±0.5‰ (2 standard deviations) on quantities of 10-50 ng of Li. Geothermal waters from Reykjanes, Svartsengi, Nesjavellir, Hveragerdi, Namafjall and Krafla geothermal systems were studied and particular emphasis was placed on the characterization of the behavior of Li isotopes in this volcanic context at high temperature with or without the presence of seawater during water

  12. Should Iceland engage in policy dialogue with developing countries?

    Directory of Open Access Journals (Sweden)

    Hilmar Þór Hilmarsson

    2007-12-01

    Full Text Available This article provides a brief overview of the current status of Icelandic development cooperation, bilaterally and multilaterally, and argues that it is time for Iceland to become more engaged in policy dialogue with developing countries on issues related to public sector reform and economic policy. Iceland should also in the authors view take more advantages of the extensive knowledge that Icelandic experts possess, and the experience they have gained, both in Iceland and internationally. Iceland should be more active in offering exerts in the public service, in the academia, as well as in the private sector to provide policy advise and technical assistance to developing countries that are implementing complex economic and public sector reforms. A number of those exerts have also gained considerable international experience in implementing policy reform programs. The article then discusses two cases: (i the case of Latvia where Iceland rushed to recognize its independence, but did little to assist the country in the post independence period, and (ii, the case of Vietnam where a country like Iceland could provide valuable assistance to a country that is achieving remarkable progress in poverty reduction, implementing important public sector reforms and creating a better business environment for foreign investors. This article is based on the authors experience as chairman of the Board of the Icelandic International Development Agency (ICEIDA and as Special Advisor to the Minister for Foreign Affairs in Iceland from 1995 to 1999, and as World Bank specialist at the Bank’s Head Quarters in Washington DC from 1990 to 1995, in Latvia from 1999 to 2003 and in Vietnam from 2003 to 2006.

  13. The Relevance of English Language Instruction in a Changing Linguistic Environment in Iceland: The L2 Self of Young Icelanders

    Science.gov (United States)

    Jeeves, Anna

    2014-01-01

    In this study perceptions of post-compulsory school studies in Iceland were investigated through semi-structured interviews. While colloquial English suffices for entertainment, hobbies and Internet use in Iceland, a high level of proficiency is required for employment and tertiary study. School learners and young people in tertiary study and…

  14. Icelandic: Linguistic Maintenance or Change? The Role of English. Occasional Paper.

    Science.gov (United States)

    Hilmarsson-Dunn, Amanda

    The Icelandic language has a long and stable history, and Old Icelandic is still accessible to modern day Icelanders. This is despite being ruled from Denmark, with influence by the Danish language, for about 500 years. Icelandic may now be under a more serious threat from the onslaught of English. This paper evaluates the linguistic situation in…

  15. Mantle and crustal contribution in the genesis of Recent basalts from off-rift zones in Iceland: Constraints from Th, Sr and O isotopes

    Science.gov (United States)

    Sigmarsson, Olgeir; Condomines, Michel; Fourcade, Serge

    1992-05-01

    Along the two volcanic off-rift zones in Iceland, the Sn˦fellsnes volcanic zone (SNVZ) and the South Iceland volcanic zone (SIVZ), geochemical parameters vary regularly along the strike towards the centre of the island. Recent basalts from the SNVZ change from alkali basalts to tholeiites where the volcanic zone reaches the active rift axis, and their 87Sr/ 86Sr and Th/U ratios decrease in the same direction. These variations are interpreted as the result of mixing between mantle melts from two distinct reservoirs below Sn˦fellsnes. The mantle melt would be more depleted in incompatible elements, but with a higher 3He/ 4He ratio ( R/Ra≈ 20) beneath the centre of Iceland than at the tip of the Sn˦fellsnes volcanic zone ( R/Ra≈ 7.5). From southwest to northeast along the SIVZ, the basalts change from alkali basalts to FeTi basalts and quartz-normative tholeiites. The Th/U ratio of the Recent basalts increases and both ( 230Th/ 232Th ) and δ 18O values decrease in the same direction. This reflects an important crustal contamination of the FeTi-rich basalts and the quartz tholeiites. The two types of basalts could be produced through assimilation and fractional crystallization in which primary alkali basaltic and olivine tholeiitic melts 'erode' and assimilate the base of the crust. The increasingly tholeiitic character of the basalts towards the centre of Iceland, which reflects a higher degree of partial melting, is qualitatively consistent with increasing geothermal gradient and negative gravity anomaly. The highest Sr isotope ratio in Recent basalts from Iceland is observed inÖr˦fajökull volcano, which has a 3He/ 4He ratio ( R/Ra≈ 7.8) close to the MORB value, and this might represent a mantle source similar to that of Mauna Loa in Hawaii.

  16. Epidemiology of organising pneumonia in Iceland

    Science.gov (United States)

    Gudmundsson, G; Sveinsson, O; Isaksson, H J; Jonsson, S; Frodadottir, H; Aspelund, T

    2006-01-01

    Background Cryptogenic organising pneumonia (COP) has also been called idiopathic bronchiolitis obliterans organising pneumonia. In secondary organising pneumonia (SOP) the causes can be identified or it occurs in a characteristic clinical context. The aim of this study was to determine the incidence and epidemiological features of COP and SOP nationwide in Iceland over an extended period. Methods A retrospective study of organising pneumonia (OP) in Iceland over 20 years was conducted and the epidemiology and survival were studied. All pathological reports of patients diagnosed with or suspected of having COP or SOP in the period 1984–2003 were identified and the pathology samples were re‐evaluated using strict diagnostic criteria. Results After re‐evaluation, 104 patients fulfilled the diagnostic criteria for OP (58 COP and 46 SOP). The mean annual incidence of OP was 1.97/100 000 population (1.10/100 000 for COP and 0.87/100 000 for SOP). The mean age at diagnosis was 67 years with a wide age range. The most common causes of death were lung diseases other than OP, and only one patient died from OP. Patients with OP had a lower rate of survival than the general population, but there was no statistical difference between COP and SOP. Conclusions The incidence of OP is higher than previously reported, suggesting that OP needs to be considered as a diagnosis more often than has been done in the past. PMID:16809413

  17. Evolution of Icelandic Central Volcanoes: Evidence from the Austurhorn Plutonic and Vestmannaeyjar Volcanic Complexes

    Science.gov (United States)

    1989-09-01

    complex (figure 3.2; Blake, 1964, 1970). They consist of basic, intermediate and acid lavas as well as pyroclastic deposits. Early propylitic ...hypothesis because dikes are heavily fractured and commonly show incipient propylitization along fracture surfaces. Mafic dikes exhibit a sharp maximum in

  18. Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow.

    Science.gov (United States)

    Gudmundsson, Magnús T; Jónsdóttir, Kristín; Hooper, Andrew; Holohan, Eoghan P; Halldórsson, Sæmundur A; Ófeigsson, Benedikt G; Cesca, Simone; Vogfjörd, Kristín S; Sigmundsson, Freysteinn; Högnadóttir, Thórdís; Einarsson, Páll; Sigmarsson, Olgeir; Jarosch, Alexander H; Jónasson, Kristján; Magnússon, Eyjólfur; Hreinsdóttir, Sigrún; Bagnardi, Marco; Parks, Michelle M; Hjörleifsdóttir, Vala; Pálsson, Finnur; Walter, Thomas R; Schöpfer, Martin P J; Heimann, Sebastian; Reynolds, Hannah I; Dumont, Stéphanie; Bali, Eniko; Gudfinnsson, Gudmundur H; Dahm, Torsten; Roberts, Matthew J; Hensch, Martin; Belart, Joaquín M C; Spaans, Karsten; Jakobsson, Sigurdur; Gudmundsson, Gunnar B; Fridriksdóttir, Hildur M; Drouin, Vincent; Dürig, Tobias; Aðalgeirsdóttir, Guðfinna; Riishuus, Morten S; Pedersen, Gro B M; van Boeckel, Tayo; Oddsson, Björn; Pfeffer, Melissa A; Barsotti, Sara; Bergsson, Baldur; Donovan, Amy; Burton, Mike R; Aiuppa, Alessandro

    2016-07-15

    Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption. We use multiparameter geophysical and geochemical data to show that the 110-square-kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014-2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, near-exponential decline of both collapse rate and the intensity of the 180-day-long eruption. Copyright © 2016, American Association for the Advancement of Science.

  19. Ruiz Volcano: Preliminary report

    Science.gov (United States)

    Ruiz Volcano, Colombia (4.88°N, 75.32°W). All times are local (= GMT -5 hours).An explosive eruption on November 13, 1985, melted ice and snow in the summit area, generating lahars that flowed tens of kilometers down flank river valleys, killing more than 20,000 people. This is history's fourth largest single-eruption death toll, behind only Tambora in 1815 (92,000), Krakatau in 1883 (36,000), and Mount Pelée in May 1902 (28,000). The following briefly summarizes the very preliminary and inevitably conflicting information that had been received by press time.

  20. Archaeal diversity in Icelandic hot springs

    DEFF Research Database (Denmark)

    Kvist, Thomas; Ahring, Birgitte Kiær; Westermann, Peter

    2007-01-01

    Whole-cell density gradient extractions from three solfataras (pH 2.5) ranging in temperature from 81 to 90 degrees C and one neutral hot spring (81 degrees C, pH 7) from the thermal active area of Hveragerethi (Iceland) were analysed for genetic diversity and local geographical variation...... of Archaea by analysis of amplified 16S rRNA genes. In addition to the three solfataras and the neutral hot spring, 10 soil samples in transects of the soil adjacent to the solfataras were analysed using terminal restriction fragment length polymorphism (t-RFLP). The sequence data from the clone libraries...... enzymes AluI and BsuRI. The sequenced clones from this solfatara belonged to Sulfolobales, Thermoproteales or were most closest related to sequences from uncultured Archaea. Sequences related to group I.1b were not found in the neutral hot spring or the hyperthermophilic solfatara (90 degrees C)....

  1. Assessing the long-term probabilistic volcanic hazard for tephra fallout in Reykjavik, Iceland: a preliminary multi-source analysis

    Science.gov (United States)

    Tonini, Roberto; Barsotti, Sara; Sandri, Laura; Tumi Guðmundsson, Magnús

    2015-04-01

    Icelandic volcanism is largely dominated by basaltic magma. Nevertheless the presence of glaciers over many Icelandic volcanic systems results in frequent phreatomagmatic eruptions and associated tephra production, making explosive eruptions the most common type of volcanic activity. Jökulhlaups are commonly considered as major volcanic hazard in Iceland for their high frequency and potentially very devastating local impact. Tephra fallout is also frequent and can impact larger areas. It is driven by the wind direction that can change with both altitude and season, making impossible to predict a priori where the tephra will be deposited during the next eruptions. Most of the volcanic activity in Iceland occurs in the central eastern part, over 100 km to the east of the main population centre around the capital Reykjavík. Therefore, the hazard from tephra fallout in Reykjavík is expected to be smaller than for communities settled near the main volcanic systems. However, within the framework of quantitative hazard and risk analyses, less frequent and/or less intense phenomena should not be neglected, since their risk evaluation depends on the effects suffered by the selected target. This is particularly true if the target is highly vulnerable, as large urban areas or important infrastructures. In this work we present the preliminary analysis aiming to perform a Probabilistic Volcanic Hazard Assessment (PVHA) for tephra fallout focused on the target area which includes the municipality of Reykjavík and the Keflavík international airport. This approach reverts the more common perspective where the hazard analysis is focused on the source (the volcanic system) and it follows a multi-source approach: indeed, the idea is to quantify, homogeneously, the hazard due to the main hazardous volcanoes that could pose a tephra fallout threat for the municipality of Reykjavík and the Keflavík airport. PVHA for each volcanic system is calculated independently and the results

  2. Eruptive viscosity and volcano morphology

    International Nuclear Information System (INIS)

    Posin, S.B.; Greeley, R.

    1988-01-01

    Terrestrial central volcanoes formed predominantly from lava flows were classified as shields, stratovolcanoes, and domes. Shield volcanoes tend to be large in areal extent, have convex slopes, and are characterized by their resemblance to inverted hellenic war shields. Stratovolcanoes have concave slopes, whereas domes are smaller and have gentle convex slopes near the vent that increase near the perimeter. In addition to these differences in morphology, several other variations were observed. The most important is composition: shield volcanoes tend to be basaltic, stratovolcanoes tend to be andesitic, and domes tend to be dacitic. However, important exceptions include Fuji, Pico, Mayon, Izalco, and Fuego which have stratovolcano morphologies but are composed of basaltic lavas. Similarly, Ribkwo is a Kenyan shield volcano composed of trachyte and Suswa and Kilombe are shields composed of phonolite. These exceptions indicate that eruptive conditions, rather than composition, may be the primary factors that determine volcano morphology. The objective of this study is to determine the relationships, if any, between eruptive conditions (viscosity, erupted volume, and effusion rate) and effusive volcano morphology. Moreover, it is the goal of this study to incorporate these relationships into a model to predict the eruptive conditions of extraterrestrial (Martian) volcanoes based on their morphology

  3. Macroeconomic conditions and population health in Iceland

    Directory of Open Access Journals (Sweden)

    Kristín Helga Birgisdóttir

    2017-09-01

    Full Text Available Background: Results from recent research on the impact of economic cycles and population health have been mixed, with results appearing to be context-sensitive. Objective: We examine the long-term relationship between economic conditions and population health in Iceland, which has experienced some economically turbulent times in the last years and decades. Methods: We use aggregate annual data for 1981‒2014. We use three aggregate indicators of economic activity to proxy the economic cycle: unemployment rate, real GDP per capita, and real GDP. Life expectancy at birth, infant mortality, and total mortality as well as four cause-specific mortality rates were used as outcome measures. Results: Our results do not suggest a statistically significant relationship between economic conditions and total mortality, infant mortality, or life expectancy. Different responses between causes of death are found, and in some instances between genders, although statistical significance is low. We do, however, find a consistent and statistically significant relationship for females aged 45‒64, where economic downturns are associated with lower all-cause mortality. Conclusions: For the time period studied we do not find a significant relationship between economic cycles and population health, where health is proxied by mortality rates, life expectancy at birth, and infant mortality. Further studies using less extreme health outcomes, such as morbidity rates, are warranted. Contribution: This type of study has not been performed using Icelandic data before and provides a comparison to research from other countries where the relationship has been explored more. Additionally, one of the contributions of this paper is to use a variety of economic indicators as proxies for economic cycles in a study examining their relationship with population health.

  4. Multigenerational information: the example of the Icelandic Genealogy Database.

    Science.gov (United States)

    Tulinius, Hrafn

    2011-01-01

    The first part of the chapter describes the Icelandic Genealogical Database, how it was created, what it contains, and how it operates. In the second part, an overview of research accomplished with material from the database is given.

  5. 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...

  6. Soufriere Hills Volcano

    Science.gov (United States)

    2002-01-01

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA

  7. Learning from Bjartur About Today's Icelandic Economic Crisis

    Directory of Open Access Journals (Sweden)

    Maria Pia Paganelli

    2010-03-01

    Full Text Available Economies are complex systems resulting from human action but not from human design. The economic success of Iceland in recent decades was the result of the development of good institutions combined with a positive global economic climate. The recent economic downturn, not just in Iceland but around the world, should be a reminder that good institutions matter and should serve as an exhortation to continue building good institutions rather than dismissing them in favor of institutions that generate poverty.

  8. Icelandic Inland Wetlands: Characteristics and Extent of Draining

    OpenAIRE

    Gudmundsson, Jon; Brink, Sigmundur H.; Arnalds, Olafur; Gisladottir, Fanney O.; Oskarsson, Hlynur

    2016-01-01

    Iceland has inland wetland areas with soils exhibiting both Andosol and Histosol properties which are uncommon elsewhere on Earth. They are generally fertile, with higher bird-nest densities than in similar wetlands in the neighboring countries, with nutrients released by rapid weathering of aeolian materials of basaltic nature. Icelandic inland wetlands cover about 9000 km2 constituting 19.4 % of the vegetated surfaces of the island. The wetland soils are often 1–3 m thick and store 33 to >1...

  9. [Effects of volcanic eruptions on human health in Iceland. Review].

    Science.gov (United States)

    Gudmundsson, Gunnar; Larsen, Guðrun

    2016-01-01

    Volcanic eruptions are common in Iceland and have caused health problems ever since the settlement of Iceland. Here we describe volcanic activity and the effects of volcanic gases and ash on human health in Iceland. Volcanic gases expelled during eruptions can be highly toxic for humans if their concentrations are high, irritating the mucus membranes of the eyes and upper respiratory tract at lower concentrations. They can also be very irritating to the skin. Volcanic ash is also irritating for the mucus membranes of the eyes and upper respiratory tract. The smalles particles of volcanic ash can reach the alveoli of the lungs. Described are four examples of volcanic eruptions that have affected the health of Icelanders. The eruption of Laki volcanic fissure in 1783-1784 is the volcanic eruption that has caused the highest mortality and had the greatest effects on the well-being of Icelanders. Despite multiple volcanic eruptions during the last decades in Iceland mortality has been low and effects on human health have been limited, although studies on longterm effects are lacking. Studies on the effects of the Eyjafjallajökul eruption in 2010 on human health showed increased physical and mental symptoms, especially in those having respiratory disorders. The Directorate of Health in Iceland and other services have responded promptly to recurrent volcanic eruptions over the last few years and given detailed instructions on how to minimize the effects on the public health. Key words: volcanic eruptions, Iceland, volcanic ash, volcanic gases, health effects, mortality. Correspondence: Gunnar Guðmundsson, ggudmund@landspitali.is.

  10. Making Earth's earliest continental crust - an analogue from voluminous Neogene silicic volcanism in NE-Iceland

    Science.gov (United States)

    Berg, Sylvia E.; Troll, Valentin R.; Burchardt, Steffi; Riishuus, Morten S.; Deegan, Frances M.; Harris, Chris; Whitehouse, Martin J.; Gústafsson, Ludvik E.

    2014-05-01

    Borgarfjörður Eystri in NE-Iceland represents the second-most voluminous exposure of silicic eruptive rocks in Iceland and is a superb example of bimodal volcanism (Bunsen-Daly gap), which represents a long-standing controversy that touches on the problem of crustal growth in early Earth. The silicic rocks in NE-Iceland approach 25 % of the exposed rock mass in the region (Gústafsson et al., 1989), thus they significantly exceed the usual ≤ 12 % in Iceland as a whole (e.g. Walker, 1966; Jonasson, 2007). The origin, significance, and duration of the voluminous (> 300 km3) and dominantly explosive silicic activity in Borgarfjörður Eystri is not yet constrained (c.f. Gústafsson, 1992), leaving us unclear as to what causes silicic volcanism in otherwise basaltic provinces. Here we report SIMS zircon U-Pb ages and δ18O values from the region, which record the commencement of silicic igneous activity with rhyolite lavas at 13.5 to 12.8 Ma, closely followed by large caldera-forming ignimbrite eruptions from the Breiðavik and Dyrfjöll central volcanoes (12.4 Ma). Silicic activity ended abruptly with dacite lava at 12.1 Ma, defining a ≤ 1 Myr long window of silicic volcanism. Magma δ18O values estimated from zircon range from 3.1 to 5.5 (± 0.3; n = 170) and indicate up to 45 % assimilation of a low-δ18O component (e.g. typically δ18O = 0 ‰, Bindeman et al., 2012). A Neogene rift relocation (Martin et al., 2011) or the birth of an off-rift zone to the east of the mature rift associated with a thermal/chemical pulse in the Iceland plume (Óskarsson & Riishuus, 2013), likely brought mantle-derived magma into contact with fertile hydrothermally-altered basaltic crust. The resulting interaction triggered large-scale crustal melting and generated mixed-origin silicic melts. Such rapid formation of silicic magmas from sustained basaltic volcanism may serve as an analogue for generating continental crust in a subduction-free early Earth (e.g. ≥ 3 Ga, Kamber et

  11. Underemployment of Immigrant Women in Iceland – A case study

    Directory of Open Access Journals (Sweden)

    Aija Burdikova

    2018-03-01

    Full Text Available The number of immigrants living in Iceland has been steadily on the rise for the last decade; between 2007 and 2017, the percentage of immigrants living in Iceland has increased from 7.6 % to 11.9%. Akureyri, the largest town in the North of Iceland with considerable industry and service, has seen its immigrant population double in the last decade, and is now home to 931 immigrants for a total of 18 488 inhabitants. New research from the University of Akureyri[1]shows that immigrant women are the most vulnerable people in the labour market in Iceland. Many occupy positions that do not fit with their level of education; despite having received higher education than men. For example, in the survey conducted 30% of immigrant women in Akureyri answered that they are in employment that does not suit their background, compared to the same answer by only 8% of Icelandic women. This difference has a direct impact on the income: just 11% of immigrant women answered that they earn 300 000 ISK or more per month, compared to 37% for Icelandic women and 22% for immigrant men.

  12. Inventory of gas flux measurements from volcanoes of the global Network for Observation of Volcanic and Atmospheric Change (NOVAC)

    Science.gov (United States)

    Galle, B.; Arellano, S.; Norman, P.; Conde, V.

    2012-04-01

    NOVAC, the Network for Observation of Volcanic and Atmospheric Change, was initiated in 2005 as a 5-year-long project financed by the European Union. Its main purpose is to create a global network for the monitoring and research of volcanic atmospheric plumes and related geophysical phenomena by using state-of-the-art spectroscopic remote sensing technology. Up to 2012, 64 instruments have been installed at 24 volcanoes in 13 countries of Latin America, Italy, Democratic Republic of Congo, Reunion, Iceland, and Philippines, and efforts are being done to expand the network to other active volcanic zones. NOVAC has been a pioneer initiative in the community of volcanologists and embraces the objectives of the Word Organization of Volcano Observatories (WOVO) and the Global Earth Observation System of Systems (GEOSS). In this contribution, we present the results of the measurements of SO2 gas fluxes carried out within NOVAC, which for some volcanoes represent a record of more than 7 years of continuous monitoring. The network comprises some of the most strongly degassing volcanoes in the world, covering a broad range of tectonic settings, levels of unrest, and potential risk. We show a global perspective of the output of volcanic gas from the covered regions, specific trends of degassing for a few selected volcanoes, and the significance of the database for further studies in volcanology and other geosciences.

  13. Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Founded in 1912 at the edge of the caldera of Kīlauea Volcano, HVO was the vision of Thomas A. Jaggar, Jr., a geologist from the Massachusetts Institute of Technology, whose studies of natural disasters around the world had convinced him that systematic, continuous observations of seismic and volcanic activity were needed to better understand—and potentially predict—earthquakes and volcanic eruptions. Jaggar summarized the aim of HVO by stating that “the work should be humanitarian” and have the goals of developing “prediction and methods of protecting life and property on the basis of sound scientific achievement.” These goals align well with those of the USGS, whose mission is to serve the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage natural resources; and enhance and protect our quality of life.

  14. Volcanoes, Third Edition

    Science.gov (United States)

    Nye, Christopher J.

    It takes confidence to title a smallish book merely “Volcanoes” because of the impliction that the myriad facets of volcanism—chemistry, physics, geology, meteorology, hazard mitigation, and more—have been identified and addressed to some nontrivial level of detail. Robert and Barbara Decker have visited these different facets seamlessly in Volcanoes, Third Edition. The seamlessness comes from a broad overarching, interdisciplinary, professional understanding of volcanism combined with an exceptionally smooth translation of scientific jargon into plain language.The result is a book which will be informative to a very broad audience, from reasonably educated nongeologists (my mother loves it) to geology undergraduates through professional volcanologists. I bet that even the most senior professional volcanologists will learn at least a few things from this book and will find at least a few provocative discussions of subjects they know.

  15. Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: A study of archived basaltic to rhyolitic ash samples

    Science.gov (United States)

    Damby, David; Horwell, Claire J.; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

    2017-01-01

    BackgroundThe eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland’s volcanoes to Icelandic and Northern European populations. MethodsA physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. ResultsIcelandic ash can be of a respirable size (up to 11.3 vol.% < 4 μm), but the samples did not display physicochemical characteristics of pathogenic particulate in terms of composition or morphology. Ash particles were generally angular, being composed of fragmented glass and crystals. Few fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m2 g−1, which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO•), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after ‘refreshing’ sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m−2, with mafic samples releasing more iron

  16. Volcanoes in Eruption - Set 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  17. Volcanoes in Eruption - Set 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  18. Volcano warning systems: Chapter 67

    Science.gov (United States)

    Gregg, Chris E.; Houghton, Bruce F.; Ewert, John W.

    2015-01-01

    Messages conveying volcano alert level such as Watches and Warnings are designed to provide people with risk information before, during, and after eruptions. Information is communicated to people from volcano observatories and emergency management agencies and from informal sources and social and environmental cues. Any individual or agency can be both a message sender and a recipient and multiple messages received from multiple sources is the norm in a volcanic crisis. Significant challenges to developing effective warning systems for volcanic hazards stem from the great diversity in unrest, eruption, and post-eruption processes and the rapidly advancing digital technologies that people use to seek real-time risk information. Challenges also involve the need to invest resources before unrest to help people develop shared mental models of important risk factors. Two populations of people are the target of volcano notifications–ground- and aviation-based populations, and volcano warning systems must address both distinctly different populations.

  19. GLACIERS OF THE KORYAK VOLCANO

    Directory of Open Access Journals (Sweden)

    T. M. Manevich

    2012-01-01

    Full Text Available The paper presents main glaciological characteristics of present-day glaciers located on the Koryaksky volcano. The results of fieldwork (2008–2009 and high-resolution satellite image analysis let us to specify and complete information on modern glacial complex of Koryaksky volcano. Now there are seven glaciers with total area 8.36 km2. Three of them advance, two are in stationary state and one degrades. Moreover, the paper describes the new crater glacier.

  20. Radon emanometry in active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M. (CNRS, IN2P3, BP45/F63170 Aubiere (France)); Cejudo, J. (Instituto Nacional de Investigaciones Nucleares, Mexico City)

    1984-01-01

    Radon emission measurements from active volcanoes has, since 1981, been continuously measured at monitoring stations in Mexico and in Costa Rica. Counting of etched alpha tracks on cellulose nitrate LR-115 detectors give varying results at the several stations. Radon emanation at Chichon, where an explosive eruption occurred in 1982, fell down. Radon detection at the active volcano in Colima shows a pattern of very low emission. At the Costa Rica stations located at Poas, Arenal and Irazu, the radon emanation shows regularity.

  1. Vertical Motions of Oceanic Volcanoes

    Science.gov (United States)

    Clague, D. A.; Moore, J. G.

    2006-12-01

    Oceanic volcanoes offer abundant evidence of changes in their elevations through time. Their large-scale motions begin with a period of rapid subsidence lasting hundreds of thousands of years caused by isostatic compensation of the added mass of the volcano on the ocean lithosphere. The response is within thousands of years and lasts as long as the active volcano keeps adding mass on the ocean floor. Downward flexure caused by volcanic loading creates troughs around the growing volcanoes that eventually fill with sediment. Seismic surveys show that the overall depression of the old ocean floor beneath Hawaiian volcanoes such as Mauna Loa is about 10 km. This gross subsidence means that the drowned shorelines only record a small part of the total subsidence the islands experienced. In Hawaii, this history is recorded by long-term tide-gauge data, the depth in drill holes of subaerial lava flows and soil horizons, former shorelines presently located below sea level. Offshore Hawaii, a series of at least 7 drowned reefs and terraces record subsidence of about 1325 m during the last half million years. Older sequences of drowned reefs and terraces define the early rapid phase of subsidence of Maui, Molokai, Lanai, Oahu, Kauai, and Niihau. Volcanic islands, such as Maui, tip down toward the next younger volcano as it begins rapid growth and subsidence. Such tipping results in drowned reefs on Haleakala as deep as 2400 m where they are tipped towards Hawaii. Flat-topped volcanoes on submarine rift zones also record this tipping towards the next younger volcano. This early rapid subsidence phase is followed by a period of slow subsidence lasting for millions of years caused by thermal contraction of the aging ocean lithosphere beneath the volcano. The well-known evolution along the Hawaiian chain from high to low volcanic island, to coral island, and to guyot is due to this process. This history of rapid and then slow subsidence is interrupted by a period of minor uplift

  2. Chiliques volcano, Chile

    Science.gov (United States)

    2002-01-01

    A January 6, 2002 ASTER nighttime thermal infrared image of Chiliques volcano in Chile shows a hot spot in the summit crater and several others along the upper flanks of the edifice, indicating new volcanic activity. Examination of an earlier nighttime thermal infrared image from May 24,2000 showed no thermal anomaly. Chiliques volcano was previously thought to be dormant. Rising to an elevation of 5778 m, Chiliques is a simple stratovolcano with a 500-m-diameter circular summit crater. This mountain is one of the most important high altitude ceremonial centers of the Incas. It is rarely visited due to its difficult accessibility. Climbing to the summit along Inca trails, numerous ruins are encountered; at the summit there are a series of constructions used for rituals. There is a beautiful lagoon in the crater that is almost always frozen.The daytime image was acquired on November 19, 2000 and was created by displaying ASTER bands 1,2 and 3 in blue, green and red. The nighttime image was acquired January 6, 2002, and is a color-coded display of a single thermal infrared band. The hottest areas are white, and colder areas are darker shades of red. Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U

  3. Holocene eruption history in Iceland - Eruption frequency vs. Tephra layer frequency

    Science.gov (United States)

    Oladottir, B. A.; Larsen, G.

    2012-12-01

    Volcanic deposits of all kinds are used to reconstruct eruption history of volcanoes and volcanic zones. In Iceland tephra is the ideal volcanic deposit to study eruption history as two out of every three eruptions taking place there during the last 11 centuries have been explosive, leaving tephra as their only product. If eruptions producing both lava and tephra are included three out of every four eruptions have produced tephra. Tephra dispersal and deposition depends on factors such as eruption magnitude, eruption cloud height, duration of eruption and prevailing wind directions at the time of eruption. Several outcrops around a particular volcano must therefore be measured to obtain optimal information of its eruption history. Vegetation in the area of deposition is also of great importance for its preservation. Tephra deposited on un-vegetated land is rapidly eroded by wind and water, and deposits up to few tens of cm thickness may be lost from the record. Such tephra deposited on grassy or forested land is at least partly sheltered from the wind after deposition. Soon after tephra deposition (how soon depends on tephra thickness) the root system of the vegetation creates an even better shelter for the tephra and when this stage is reached the tephra is preserved in the soil for millennia, given that no soil erosion takes place. Vegetation is often boosted in the first years after tephra deposition which in turn helps tephra preservation. A setback of using soil sections for reconstructing Holocene eruption history is the lack of soil at the beginning of the era but for that time period tephra records in lake and marine sediments can be used. When tephra stratigraphy in soil sections is measured to study eruption history and eruption frequency of a volcano it must be kept in mind that what is seen is in fact the tephra layer frequency. One section only shows tephra layers deposited in that location and more importantly only the layers preserved there. The

  4. Geothermal electric power generation in Iceland for the proposed Iceland/United Kingdom HVDC power link

    International Nuclear Information System (INIS)

    Hammons, T.J.; Palmason, G.; Thorhallsson, S.

    1991-01-01

    The paper reviews geothermal electric power potential in Iceland which could economically be developed to supplement hydro power for the proposed HVDC Power Link to the United Kingdom, and power intensive industries in Iceland, which are envisaged for development at this time. Technically harnessable energy for electricity generation taking account of geothermal resources down to an assumed base depth, temperature distribution in the crust, probable geothermal recovery factor, and accessibility of the field, has been assessed. Nineteen known high-temperature fields and 9 probable fields have been identified. Technically harnessable geo-heat for various areas is indicated. Data on high temperature fields suitable for geothermal electric power generation, and on harnessable energy for electric power generation within volcanic zones, is stated, and overall assessments are made. The paper then reviews how the potential might be developed, discussing preference of possible sites, and cost of the developments at todays prices. Cost of geothermal electric power generation with comparative costs for hydro generation are given. Possible transmission system developments to feed the power to the proposed HVDC Link converter stations are also discussed

  5. Magmatic densities control erupted volumes in Icelandic volcanic systems

    Science.gov (United States)

    Hartley, Margaret; Maclennan, John

    2018-04-01

    Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ). By studying subaerial flows of known age and volume, we are able to directly relate erupted volumes to magmatic physical properties, a task that has been near-impossible when dealing with submarine samples dredged from mid-ocean ridges. We find a strong correlation between magmatic density and observed erupted volumes on the NVZ. Over 85% of the total volume of erupted material lies close to a density and viscosity minimum that corresponds to the composition of basalts at the arrival of plagioclase on the liquidus. These magmas are buoyant with respect to the Icelandic upper crust. However, a number of small-volume eruptions with densities greater than typical Icelandic upper crust are also found in Iceland's neovolcanic zones. We use a simple numerical model to demonstrate that the eruption of magmas with higher densities and viscosities is facilitated by the generation of overpressure in magma chambers in the lower crust and uppermost mantle. This conclusion is in agreement with petrological constraints on the depths of crystallisation under Iceland.

  6. Magmatic Densities Control Erupted Volumes in Icelandic Volcanic Systems

    Directory of Open Access Journals (Sweden)

    Margaret Hartley

    2018-04-01

    Full Text Available Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ. By studying subaerial flows of known age and volume, we are able to directly relate erupted volumes to magmatic physical properties, a task that has been near-impossible when dealing with submarine samples dredged from mid-ocean ridges. We find a strong correlation between magmatic density and observed erupted volumes on the NVZ. Over 85% of the total volume of erupted material lies close to a density and viscosity minimum that corresponds to the composition of basalts at the arrival of plagioclase on the liquidus. These magmas are buoyant with respect to the Icelandic upper crust. However, a number of small-volume eruptions with densities greater than typical Icelandic upper crust are also found in Iceland's neovolcanic zones. We use a simple numerical model to demonstrate that the eruption of magmas with higher densities and viscosities is facilitated by the generation of overpressure in magma chambers in the lower crust and uppermost mantle. This conclusion is in agreement with petrological constraints on the depths of crystallization under Iceland.

  7. The development of the suffix –erni in Icelandic

    DEFF Research Database (Denmark)

    Jóhannsson, Ellert Þór

    This paper investigates the suffix –erni in Icelandic, its origin, and development from the period of Old Norse to Modern Icelandic. This suffix is most often used to derive a neuter noun from nouns and adjectives with the meaning ‘belonging to’ e.g. faðir ‘father’ => faðerni ‘fatherhood’. By tak......This paper investigates the suffix –erni in Icelandic, its origin, and development from the period of Old Norse to Modern Icelandic. This suffix is most often used to derive a neuter noun from nouns and adjectives with the meaning ‘belonging to’ e.g. faðir ‘father’ => faðerni ‘fatherhood...... stages to establish a clear derivational pattern that is productively used in the language to form new words. Having access to continuous written material in Icelandic from ca. 1200 to 2011 gives us the possibility to track this process through time and follow each step in the development....

  8. Global Volcano Mortality Risks and Distribution

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Volcano Mortality Risks and Distribution is a 2.5 minute grid representing global volcano mortality risks. The data set was constructed using historical...

  9. Additional Workload or a Part of the Job? Icelandic Teachers' Discourse on Inclusive Education

    Science.gov (United States)

    Gunnþórsdóttir, Hermína; Jóhannesson, Ingólfur Ásgeir

    2014-01-01

    The aim of this article is to examine the discourse of Icelandic compulsory school teachers on inclusive education. From 1974 and onwards, the education policy in Iceland has been towards inclusion, and Iceland is considered to be an example of a highly inclusive education system with few segregated resources for students with special educational…

  10. Re-Thinking Sustainable Education Systems in Iceland: The Net-University Project

    Science.gov (United States)

    Rennie, Frank; Johannesdottir, Sigurbjorg

    2011-01-01

    The recent economic crisis in Iceland has raised issues of the sustainability of Icelandic higher education to new levels of importance. A key strategy in relation to this economic crisis is to consider the merger of the four public universities in Iceland and to introduce a much higher engagement with online and open delivery methods of higher…

  11. Melt inclusion constraints on petrogenesis of the 2014-2015 Holuhraun eruption, Iceland

    Science.gov (United States)

    Hartley, Margaret E.; Bali, Enikö; Maclennan, John; Neave, David A.; Halldórsson, Sæmundur A.

    2018-02-01

    The 2014-2015 Holuhraun eruption, on the Bárðarbunga volcanic system in central Iceland, was one of the best-monitored basaltic fissure eruptions that has ever occurred, and presents a unique opportunity to link petrological and geochemical data with geophysical observations during a major rifting episode. We present major and trace element analyses of melt inclusions and matrix glasses from a suite of ten samples collected over the course of the Holuhraun eruption. The diversity of trace element ratios such as La/Yb in Holuhraun melt inclusions reveals that the magma evolved via concurrent mixing and crystallization of diverse primary melts in the mid-crust. Using olivine-plagioclase-augite-melt (OPAM) barometry, we calculate that the Holuhraun carrier melt equilibrated at 2.1 ± 0.7 kbar (7.5 ± 2.5 km), which is in agreement with the depths of earthquakes (6 ± 1 km) between Bárðarbunga central volcano and the eruption site in the days preceding eruption onset. Using the same approach, melt inclusions equilibrated at pressures between 0.5 and 8.0 kbar, with the most probable pressure being 3.2 kbar. Diffusion chronometry reveals minimum residence timescales of 1-12 days for melt inclusion-bearing macrocrysts in the Holuhraun carrier melt. By combining timescales of diffusive dehydration of melt inclusions with the calculated pressure of H2O saturation for the Holuhraun magma, we calculate indicative magma ascent rates of 0.12-0.29 m s-1. Our petrological and geochemical data are consistent with lateral magma transport from Bárðarbunga volcano to the eruption site in a shallow- to mid-crustal dyke, as has been suggested on the basis of seismic and geodetic datasets. This result is a significant step forward in reconciling petrological and geophysical interpretations of magma transport during volcano-tectonic episodes, and provides a critical framework for the interpretation of premonitory seismic and geodetic data in volcanically active regions.

  12. Subsidence of Surtsey volcano, 1967-1991

    Science.gov (United States)

    Moore, J.G.; Jakobsson, S.; Holmjarn, J.

    1992-01-01

    The Surtsey marine volcano was built on the southern insular shelf of Iceland, along the seaward extension of the east volcanic zone, during episodic explosive and effusive activity from 1963 to 1967. A 1600-m-long, east-west line of 42 bench marks was established across the island shortly after volcanic activity stopped. From 1967 to 1991 a series of leveling surveys measured the relative elevation of the original bench marks, as well as additional bench marks installed in 1979, 1982 and 1985. Concurrent measurements were made of water levels in a pit dug on the north coast, in a drill hole, and along the coastline exposed to the open ocean. These surveys indicate that the dominant vertical movement of Surtsey is a general subsidence of about 1.1??0.3 m during the 24-year period of observations. The rate of subsidence decreased from 15-20 cm/year for 1967-1968 to 1-2 cm/year in 1991. Greatest subsidence is centered about the eastern vent area. Through 1970, subsidence was locally greatest where the lava plain is thinnest, adjacent to the flanks of the eastern tephra cone. From 1982 onward, the region closest to the hydrothermal zone, which is best developed in the vicinity of the eastern vent, began showing less subsidence relative to the rest of the surveyed bench marks. The general subsidence of the island probably results from compaction of the volcanic material comprising Surtsey, compaction of the sea-floor sediments underlying the island, and possibly downwarping of the lithosphere due to the laod of Surtsey. The more localized early downwarping near the eastern tephra cone is apparently due to greater compaction of tephra relative to lava. The later diminished local subsidence near the hydrothermal zone is probably due to a minor volume increase caused by hydrous alteration of glassy tephra. However, this volume increase is concentrated at depth beneath the bottom of the 176-m-deep cased drillhole. ?? 1992 Springer-Verlag.

  13. Isotope heterogeneity of Pre-Holocene groundwater in Iceland

    DEFF Research Database (Denmark)

    Sveinbjörnsdóttir, Á.E.; Arnorsson, S.; Heinemeier, Jan

    2007-01-01

    In recent years, it has been shown that groundwater with a Pre-Holocene component is more common in the Icelandic bedrock than previously thought. Some of the Pre-Holocene water samples are more depleted in delta H-2 and delta O-18 than any mean annual precipitation in Iceland today due to the cold...... climate at that time. However, most often Pre-Holocene water components cannot be detected based on the water isotopes alone due to mixing with younger and isotopically heavier water. The Cl concentration in relation to the water isotopes in specific areas has proved to be a good indicator of a Pre......-Holocene component in the groundwater. The deuterium excess value may also help to identify water from a different climate regime, if no oxygen shift has occurred. The relative abundance of a Pre-Holocene water component of the Icelandic groundwater has led to the understanding that combined interpretation of water...

  14. Relative chronology of Martian volcanoes

    International Nuclear Information System (INIS)

    Landheim, R.; Barlow, N.G.

    1991-01-01

    Impact cratering is one of the major geological processes that has affected the Martian surface throughout the planet's history. The frequency of craters within particular size ranges provides information about the formation ages and obliterative episodes of Martian geologic units. The Barlow chronology was extended by measuring small craters on the volcanoes and a number of standard terrain units. Inclusions of smaller craters in units previously analyzed by Barlow allowed for a more direct comparison between the size-frequency distribution data for volcanoes and established chronology. During this study, 11,486 craters were mapped and identified in the 1.5 to 8 km diameter range in selected regions of Mars. The results are summarized in this three page report and give a more precise estimate of the relative chronology of the Martian volcanoes. Also, the results of this study lend further support to the increasing evidence that volcanism has been a dominant geologic force throughout Martian history

  15. Porosity evolution in Icelandic hydrothermal systems

    Science.gov (United States)

    Thien, B.; Kosakowski, G.; Kulik, D. A.

    2014-12-01

    Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced hydrothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems, grant number CRSII2_141843/1) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. These are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. These shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. Field observations suggest that active and fossil Icelandic hydrothermal systems are built from a superposition of completely altered and completely unaltered layers. With help of 1D and 2D reactive transport models (OpenGeoSys-GEM code), we investigate the reasons for this finding, by studying the mineralogical evolution of protoliths with different initial porosities at different temperatures and pressures, different leaching water composition and gas content, and different porosity geometries (i.e. porous medium versus fractured medium). From this study, we believe that the initial porosity of protoliths and volume changes due to their transformation into secondary minerals are key factors to explain the different alteration extents observed in field studies. We also discuss how precipitation and dissolution kinetics can influence the alteration time scales.

  16. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)

    1999-08-01

    Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

  17. Edible wild plant use in the Faroe Islands and Iceland

    Directory of Open Access Journals (Sweden)

    Ingvar Svanberg

    2012-11-01

    Full Text Available This paper reviews the use of wild edible plants in the Faroe Islands and Iceland from the times of the first settlement of Norse people in the Viking age until today, with a special emphasis on the 18th, 19th and 20th centuries. Animal products have been an important source of nutrients for the islanders of northern Atlantic. Cultivation of cereals on the other hand has played a minor role, and had already been abandoned by late medieval times in Iceland and by the early 20th century on the Faroes. Crops such as potatoes, turnips and other roots were only grown in the small patches of cultivated soil. Wild plants have therefore been of some importance for the Faroese people and the Icelanders; in the last centuries especially for the rural poor and during times of recessions. The native Angelica archangelica L. was gathered in the wild and also cultivated in gardens for centuries. A few species have been part of the regular food staple. Some plants are still gathered and made into food products by small companies, especially in Iceland. In the Faroes, the economic aspect of edible wild plant taxa is mostly of historical interest, although a few products of A. archangelica are sometimes available. Two taxa have been exploited as regular food exclusively in Iceland: Cetraria islandica (L. Arch. and Elymus arenarius L. Icelanders have used C. islandica from the early settlement days and continue to do so today, E. arenarius became obsolete as a food plant a century ago.

  18. Multiphase modelling of mud volcanoes

    Science.gov (United States)

    Colucci, Simone; de'Michieli Vitturi, Mattia; Clarke, Amanda B.

    2015-04-01

    Mud volcanism is a worldwide phenomenon, classically considered as the surface expression of piercement structures rooted in deep-seated over-pressured sediments in compressional tectonic settings. The release of fluids at mud volcanoes during repeated explosive episodes has been documented at numerous sites and the outflows resemble the eruption of basaltic magma. As magma, the material erupted from a mud volcano becomes more fluid and degasses while rising and decompressing. The release of those gases from mud volcanism is estimated to be a significant contributor both to fluid flux from the lithosphere to the hydrosphere, and to the atmospheric budget of some greenhouse gases, particularly methane. For these reasons, we simulated the fluid dynamics of mud volcanoes using a newly-developed compressible multiphase and multidimensional transient solver in the OpenFOAM framework, taking into account the multicomponent nature (CH4, CO2, H2O) of the fluid mixture, the gas exsolution during the ascent and the associated changes in the constitutive properties of the phases. The numerical model has been tested with conditions representative of the LUSI, a mud volcano that has been erupting since May 2006 in the densely populated Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industry, farmland, and over 10,000 homes. The activity of LUSI mud volcano has been well documented (Vanderkluysen et al., 2014) and here we present a comparison of observed gas fluxes and mud extrusion rates with the outcomes of numerical simulations. Vanderkluysen, L.; Burton, M. R.; Clarke, A. B.; Hartnett, H. E. & Smekens, J.-F. Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia) Geochem. Geophys. Geosyst., Wiley-Blackwell, 2014, 15, 2932-2946

  19. Superhot Drilling in Iceland, the Experience of the Iceland Deep Drilling Project.

    Science.gov (United States)

    Elders, W. A.; Friðleifsson, G. Ó.; Zierenberg, R. A.; Fowler, A. P.

    2017-12-01

    The Iceland Deep Drilling Project aims to improve geothermal economics by producing supercritical fluids (www.iddp.is). Supercritical wells could yield an order of magnitude more usable energy than that from conventional geothermal wells because of higher enthalpy and enhanced flow properties. In 2009, the IDDP-1 well failed to reach supercritical conditions in the Krafla caldera in NE Iceland, after encountering rhyolite magma at only 2.1 km depth. The completed geothermal well became the world's hottest and produced superheated steam with a wellhead temperature of 452°C and flow sufficient to generate 35 MWe. The IDDP next moved SW to the Reykjanes Peninsula, the landward extension of the Mid-Atlantic Ridge, where it is possible to study an analog of the roots of a black smoker. Reykjanes is unique among Icelandic geothermal systems in being recharged by seawater, which has a critical point of 406°C at 298 bars. Drilling began by deepening an existing 2.5 km deep production well to 3 km depth, and then angling it towards the main upflow zone of the system, for a total slant depth of 4,659 m. Total circulation losses were encountered below 3 km that could not be cured by lost circulation materials or by multiple cement jobs. Accordingly, drilling continued to total depth without return of drill cuttings. We attempted 13 core runs below 3 km depth, only half of which recovered core. The cores are basalts and dolerites with alteration ranging from lower greenschist facies to lower amphibolite facies, suggesting formation temperatures >450°C. After the end of drilling in January 2017, following only six days of heating, supercritical conditions (426°C at 340 bars) were measured in the well at a depth of 4.5 km. The well has not yet been allowed to equilibrate to full in situ temperature. A perforated liner was inserted to 4,570 m, depth to facilitate temperature cycling to enhance permeability at depth through thermal cracking. In 2018 this will be followed by a

  20. Meteorological buoy measurements in the Iceland Sea, 2007-2009

    Science.gov (United States)

    Nína Petersen, Guðrún

    2017-10-01

    The Icelandic Meteorological Office (IMO) conducted meteorological buoy measurements in the central Iceland Sea in the time period 2007-2009, specifically in the northern Dreki area on the southern segment of the Jan Mayen Ridge. Due to difficulties in deployment and operations, in situ measurements in this region are sparse. Here the buoy, deployment and measurements are described with the aim of giving a future user of the data set information that is as comprehensive as possible. The data set has been quality-checked, suspect data removed and the data set made publicly available from PANGAEA Data Publisher (PANGAEA.876206" target="_blank">https://doi.org/10.1594/PANGAEA.876206).

  1. Holocene and latest Pleistocene climate and glacier fluctuations in Iceland

    Science.gov (United States)

    Geirsdóttir, Áslaug; Miller, Gifford H.; Axford, Yarrow; Ólafsdóttir, Sædís

    2009-10-01

    Multiproxy climate records from Iceland document complex changes in terrestrial climate and glacier fluctuations through the Holocene, revealing some coherent patterns of change as well as significant spatial variability. Most studies on the Last Glacial Maximum and subsequent deglaciation reveal a dynamic Iceland Ice Sheet (IIS) that responded abruptly to changes in ocean currents and sea level. The IIS broke up catastrophically around 15 ka as the Polar Front migrated northward and sea level rose. Indications of regional advance or halt of the glaciers are seen in late Alleröd/early Younger Dryas time and again in PreBoreal time. Due to the apparent rise of relative sea level in Iceland during this time, most sites contain evidence for fluctuating, tidewater glacier termini occupying paleo fjords and bays. The time between the end of the Younger Dryas and the Preboreal was characterized by repeated jökulhlaups that eroded glacial deposits. By 10.3 ka, the main ice sheet was in rapid retreat across the highlands of Iceland. The Holocene thermal maximum (HTM) was reached after 8 ka with land temperatures estimated to be 3 °C higher than the 1961-1990 reference, and net precipitation similar to modern. Such temperatures imply largely ice-free conditions across Iceland in the early to mid-Holocene. Several marine and lacustrine sediment climate proxies record substantial summer temperature depression between 8.5 and 8 ka, but no moraines have been detected from that time. Termination of the HTM and onset of Neoglacial cooling took place sometime after 6 ka with increased glacier activity between 4.5 and 4.0 ka, intensifying between 3.0 and 2.5 ka. Although a distinct warming during the Medieval Warm Period is not dramatically apparent in Icelandic records, the interval from ca AD 0 to 1200 is commonly characterized by relative stability with slow rates of change. The literature most commonly describes Little Ice Age moraines (ca AD 1250-1900) as representing the

  2. High resolution modelling of the North Icelandic Irminger Current (NIIC

    Directory of Open Access Journals (Sweden)

    K. Logemann

    2006-01-01

    Full Text Available The northward inflow of Atlantic Water through Denmark Strait – the North Icelandic Irminger Current (NIIC – is simulated with a numerical model of the North Atlantic and Arctic Ocean. The model uses the technique of adaptive grid refinement which allows a high spatial resolution (1 km horizontal, 10 m vertical around Iceland. The model is used to assess time and space variability of volume and heat fluxes for the years 1997–2003. Passive tracers are applied to study origin and composition of NIIC water masses. The NIIC originates from two sources: the Irminger Current, flowing as part of the sub-polar gyre in 100–500 m depth along the Reykjanes Ridge and the shallow Icelandic coastal current, flowing north-westward on the south-west Icelandic shelf. The ratio of volume flux between the deep and shallow branch is around 2:1. The NIIC continues as a warm and saline branch northward through Denmark Strait where it entrains large amounts of polar water due to the collision with the southward flowing East Greenland Current. After passing Denmark Strait, the NIIC follows the coast line eastward being an important heat source for north Icelandic waters. At least 60% of the temporal temperature variability of north Icelandic waters is caused by the NIIC. The NIIC volume and heat transport is highly variable and depends strongly on the wind field north-east of Denmark Strait. Daily means can change from 1 Sv eastward to 2 Sv westward within a few days. Highest monthly mean transport rates occur in summer when winds from north are weak, whereas the volume flux is reduced by around 50% in winter. Summer heat flux rates can be even three times higher than in winter. The simulation also shows variability on the interannual scale. In particular weak winds from north during winter 2002/2003 combined with mild weather conditions south of Iceland led to anomalous high NIIC volume (+40% and heat flux (+60% rates. In this period, simulated north Icelandic

  3. Progress report on research on human genetics in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-31

    Records of the Icelandic population are being used to investigate the possible inheritance of disabilities and diseases as well as other characteristics and the effect of environment on man. The progress report of research covers the period from 1977 to 1980. The investigation was begun in 1965 by the Genetical Committee of the University of Iceland and the materials used are demographic records from the year 1840 to present and various medical information. The records are being computerized and linked together to make them effective for use in hereditary studies.

  4. Research on human genetics in Iceland. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-31

    Records of the Icelandic Population are being used to investigate the possible inheritance of disabilities and diseases as well as other characters and the effect of environment on man. The progress report of research covers the period 1977 to 1980. The investigation was begun in 1965 by the Genetical Committee of the University of Iceland and the materials used are demographic records from the year 1840 to present and various medical information. The records are being computerized and linked together to make them effective for use in hereditary studies.

  5. Alaska volcanoes guidebook for teachers

    Science.gov (United States)

    Adleman, Jennifer N.

    2011-01-01

    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  6. Petrography and petrology of the Nornahraun eruption of the Bárðarbunga volcanic system, Iceland

    Science.gov (United States)

    Guðfinnsson, Guðmundur H.; Halldórsson, Sæmundur Ari; Bali, Enikő; Jakobsson, Sigurður; Sverrisdóttir, Guðrún; Höskuldssson, Ármann; Riishuus, Morten S.; Þórðarson, Þorvaldur; The 2014 Nornahraun Eruption Team

    2015-04-01

    The on-going fissure eruption north of Dyngjujökull is becoming the largest of its kind in Iceland since the 1783-84 Laki eruption. The erupted lava is olivine tholeiite, containing up to 5% normative olivine. It is relatively macrocryst-poor, initially containing less than 1% phenocrysts by volume, increasing to over 1% as the eruption has progressed. Plagioclase is the dominant macrocryst phase but olivine and augite are also present. In most of the samples, crystallization of the groundmass is substantial, with plagioclase and augite as the key groundmass minerals and minor olivine. It features subophitic texture, typical for olivine tholeiites, where the interstitial glass contains dendritic Fe-Ti oxide. During the first two months of the eruption, magma composition has been constant, displaying uniform major and trace element composition and nearly uniform isotopic compositions (Halldórsson et al. (a), this session). The major and trace element contents, in addition to the isotope ratios of lead, are indistinguishable from basalts in the Bárðarbunga volcanic system (Halldórsson et al. (b), this session). The compositional trends are consistent with crystallization along the ol-plag-cpx cotectic. Crystallization depth estimates, based on the pressure dependence of the cotectic (Yang et al., 1996), indicate that the magma equilibrated at a minimum depth between 6-9 km, consistent with depth estimates derived from CO2-bearing fluid inclusions trapped in plagioclase phenocrysts (Bali et al., this session). The bulk of the earthquakes associated with this volcano-tectonic episode are also in this range (e.g., Sigmundsson et al., 2015). Calculations with several different magma geothermometers suggest that the temperature of the magma as it rises to the surface is about 1170-1180°C, in good agreement with on-site measurements by thermal imaging cameras. The eruption has been characterized by steady, high emission of SO2. The sulfur-rich nature of the lava is

  7. Overview of gas flux measurements from volcanoes of the global Network for Observation of Volcanic and Atmospheric Change (NOVAC)

    Science.gov (United States)

    Galle, Bo; Arellano, Santiago; Conde, Vladimir

    2015-04-01

    NOVAC, the Network for Observation of Volcanic and Atmospheric Change, was initiated in 2005 as a 5-years-long project financed by the European Union. Its main purpose is to create a global network for the study of volcanic atmospheric plumes and related geophysical phenomena by using state-of-the-art spectroscopic remote sensing technology. Up to 2014, 67 instruments have been installed at 25 volcanoes in 13 countries of Latin America, Italy, Democratic Republic of Congo, Reunion, Iceland, and Philippines, and efforts are being done to expand the network to other active volcanic zones. NOVAC has been a pioneer initiative in the community of volcanologists and embraces the objectives of the Word Organization of Volcano Observatories (WOVO) and the Global Earth Observation System of Systems (GEOSS). In this contribution, we present the results of the measurements of SO2 gas fluxes carried out within NOVAC, which for some volcanoes represent a record of more than 8 years of semi-continuous monitoring. The network comprises some of the most strongly degassing volcanoes in the world, covering a broad range of tectonic settings, levels of unrest, and potential risk. Examples of correlations with seismicity and other geophysical phenomena, environmental impact studies and comparisons with previous global estimates will be discussed as well as the significance of the database for further studies in volcanology and other geosciences.

  8. Laboratory volcano geodesy

    Science.gov (United States)

    Færøvik Johannessen, Rikke; Galland, Olivier; Mair, Karen

    2014-05-01

    intrusion can be excavated and photographed from several angles to compute its 3D shape with the same photogrammetry method. Then, the surface deformation pattern can be directly compared with the shape of underlying intrusion. This quantitative dataset is essential to quantitatively test and validate classical volcano geodetic models.

  9. What Happened to Our Volcano?

    Science.gov (United States)

    Mangiante, Elaine Silva

    2006-01-01

    In this article, the author presents an investigative approach to "understanding Earth changes." The author states that students were familiar with earthquakes and volcanoes in other regions of the world but never considered how the land beneath their feet had experienced changes over time. Here, their geology unit helped them understand…

  10. [Accidents on Iceland's most dangerous roads].

    Science.gov (United States)

    Bjarnason, Thóroddur; Arnarsson, Sveinn

    2012-02-01

    The objective of this paper was to identify the most dangerous segments of the Icelandic road system in terms of the number of accidents pr km and the rate of accidents pr million km travelled. First to identify the segments where the number of accidents is highest and where the risk of the individual traveller is the greatest. Second to evaluate if the association between the number and the rate of accidents is positive or negative. Third to identify the road segments that are the most dangerous in the sense of many accidents and great risk to individual travellers. Main roads outside urban centers were divided into 45 segments that were on average 78 km in length. Infrequently travelled roads and roads within urban centers were omitted. Information on the length of roads, traffic density and number of accidents was used to calculate the number of accidents per km and the rate of accidents per million km travelled. The correlation between the number and rate of accidents was calculated and the most dangerous road segments were identified by the average rank order on both dimensions. Most accidents pr km occurred on the main roads to and from the capital region, but also east towards Hvolsvöllur, north towards Akureyri and in the Mideast region of the country. The rate of accidents pr million km travelled was highest in the northeast region, in northern Snæfellsnes and in the Westfjords. The most dangerous roads on both dimensions were in Mideast, northern Westfjords, in the north between Blönduós and Akureyri and in northern Snæfellsnes. Most accidents pr km occurred on roads with a low accident rate pr million km travelled. It is therefore possible to reduce accidents the most by increasing road safety where it is already the greatest but that would however increase inequalities in road safety. Policy development in transportation is therefore in part a question of priorities in healthcare. Individual equality in safety and health are not always fully

  11. [Tablets and tablet production - with special reference to Icelandic conditions].

    Science.gov (United States)

    Skaftason, Jóhannes F; Jóhannesson, Thorkell

    2013-04-01

    Modern tablet compression was instituted in England in 1844 by William Brockedon (1787-1854). The first tablets made according to Brockedon´s procedures contained watersoluble salts and were most likely compressed without expedients. In USA a watershed occurred around 1887 when starch (amylum maydis) was introduced to disperse tablets in aqueous milieu in order to corroborate bioavailability of drugs in the almentary canal. About the same time great advances in tablet production were introduced by the British firm Burroughs Wellcome and Co. In Denmark on the other hand tablet production remained on low scale until after 1920. As Icelandic pharmacies and drug firms modelled themselves mostly upon Danish firms tablet production was first instituted in Iceland around 1930. The first tablet machines in Iceland were hand-driven. More efficent machines came after 1945. Around 1960 three sizeable tablet producers were in Iceland; now there is only one. Numbers of individual tablet species (generic and proprietary) on the market rose from less than 10 in 1913 to 500 in 1965, with wide variations in numbers in between. Tablets have not wiped out other medicinal forms for peroral use but most new peroral drugs have been marketed in the form of tablets during the last decades.

  12. Injury Pattern in Icelandic Elite Male Handball Players.

    Science.gov (United States)

    Rafnsson, Elis Thor; Valdimarsson, Örnólfur; Sveinsson, Thorarinn; Árnason, Árni

    2017-10-10

    To examine the incidence, type, location, and severity of injuries in Icelandic elite male handball players and compare across factors like physical characteristics and playing position. Prospective cohort study. The latter part of the preseason and the competitive season of Icelandic male handball. Eleven handball teams (185 players) from the 2 highest divisions in Iceland participated in the study. Six teams (109 players) completed the study. Injuries were recorded by the players under supervision from their team physiotherapists or coaches. Coaches recorded training exposure, and match exposure was obtained from the Icelandic and European Handball Federations. The players directly recorded potential risk factors, such as age, height, weight, previous injuries, and player position. Injury incidence and injury location and number of injury days. Recorded time-loss injuries were 86, of which 53 (62%) were acute and 33 (38%) were due to overuse. The incidence of acute injuries was 15.0 injuries/1000 hours during games and 1.1 injuries/1000 hours during training sessions. No significant difference was found in injury incidence between teams, but number of injury days did differ between teams (P = 0.0006). Acute injuries were most common in knees (26%), ankles (19%), and feet/toes (17%), but overuse injuries occurred in low back/pelvic region (39%), shoulders (21%), and knees (21%). Previous knee injuries were the only potential risk factor found for knee injury. The results indicate a higher rate of overuse injuries in low back/pelvic region and shoulders than in comparable studies.

  13. Broadcasting in Iceland: Cultural Protectionism and U.S. Influence.

    Science.gov (United States)

    Hudson, Tim

    Icelanders are a highly literate people, their culture tied together by perhaps the most complete written tradition of any modern nation. No wonder, then, that the tiny island country seemed in no rush to develop a television broadcasting system. Indeed, it is questionable whether television would have been in demand at all if not for outside…

  14. Iceland's Central Highlands: Nature conservation, ecotourism, and energy resource utilization

    Science.gov (United States)

    Bjorn Gunnarsson; Maria-Victoria Gunnarsson

    2002-01-01

    Iceland’s natural resources include an abundance of geothermal energy and hydropower, of which only 10 to 15 percent is currently being utilized. These are clean, renewable sources of energy. The cost to convert these resources to electricity is relatively low, making them attractive and highly marketable for industrial development, particularly for heavy industry....

  15. Primitive off-rift basalts from Iceland and Jan Mayen

    DEFF Research Database (Denmark)

    Debaille, Vinciane; Trønnes, Reidar G.; Brandon, Alan D.

    2009-01-01

    to a hybrid mixture between the depleted-MORB mantle and the enriched Iceland mantle plume, itself resulting from mixing between recycled oceanic crust and depleted lower mantle. This hybrid accounts for the high 3He/4He (28 Ra), high 143Nd/144Nd (0.5132), high 187Os/188Os (0.14) and low 87Sr/86Sr (0...

  16. Students' Attitudes towards Craft and Technology in Iceland and Finland

    Science.gov (United States)

    Thorsteinsson, Gísli; Ólafsson, Brynjar; Autio, Ossi

    2012-01-01

    Craft education in both Finland and Iceland originated over 140 years ago and was influenced by the Scandinavian Sloyd pedagogy. Since then, the subject has moved away from craft and towards technology, with the aim being to increase students' technological abilities. In the beginning, the subject largely focused on the students copying artefacts,…

  17. Pressure Algometry in Icelandic Horses : Interexaminer and Intraexaminer Reliability

    NARCIS (Netherlands)

    Menke, Eveline S.; Blom, Guy; van Loon, Johannes P A M; Back, Willem

    2016-01-01

    Reliability of pressure algometry as an outcome measure in equine research and therapy needs to be studied. The aim of the present study was to establish interexaminer and intraexaminer reliability of pressure algometry in Icelandic horses and to determine reference mechanical nociceptive threshold

  18. The thirteenth-century runic revival in Denmark and Iceland

    DEFF Research Database (Denmark)

    Wills, Tarrin Jon

    2016-01-01

    alphabet. This paper examines a number of runic phenomenon from the thirteenth and early fourteenth centuries in Denmark and Iceland to argue that they belong to a cultural revival movement rather than forming part of a continuous runic tradition stretching back into the early Middle Ages. Some...

  19. Island connections: Icelandic spatiality in the wake of worldly linkages

    Directory of Open Access Journals (Sweden)

    David Bjarnason

    2010-11-01

    Full Text Available The notions and materiality of connections, through electronic networks as well as modes of mobility, play an ever-increasing role in how we define, understand, engage and experience the world we live in and the islands we live on. This article presents an account of Icelandic encounters with technologies of telecommunication and explores how electronic connections have participated in formulating a particularly connected, island spatiality. It is argued that an island can be regarded as a kind of connected laboratory suitable for studying how associations form around technologies of connections, which can be traced through various actors. For this purpose, the historical genealogy of connections and telecommunication in Iceland is analyzed, as well as more contemporary ideas and representations of mobile phone usage and network connectivity. It is maintained that connections have fundamentally altered the spatiality as well as representations of Iceland. While still an island in a geographical sense, and in that manner remote and isolated, the social space of the island now denies such connotations in many respects, valorizing the connectivity of Iceland and its people.

  20. Iceland and European Union accession - the whaling issue

    OpenAIRE

    Davies, Peter G.G.

    2011-01-01

    This article seeks to assess one of the important questions regarding Iceland’s potential accession to the EU, namely, whether Iceland could legitimately continue its whaling operations under current EU environmental law if it becomes a member of the regional economic integration organization

  1. Curriculum Analysis and Education for Sustainable Development in Iceland

    Science.gov (United States)

    Johannesson, Ingolfur Asgeir; Norodahl, Kristin; Oskarsdottir, Gunnhildur; Palsdottir, Auour; Petursdottir, Bjorg

    2011-01-01

    The article explores how the Icelandic public school curriculum for early childhood, compulsory and upper secondary school deals with education for sustainable development. As the curriculum does not often mention the term sustainability, a key with which to investigate signs of education for sustainable development in the three curricula was…

  2. Over-the-counter codeine use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, Anna Birna; Grímsson, Almar

    2000-01-01

    Background: The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine. Methods: Based on this assumption we built and tested a model using an interru...

  3. The effect of silica in washing with geothermal water, Iceland

    International Nuclear Information System (INIS)

    Lindal, B.

    1992-01-01

    Industrial washing operation using geothermal water in Iceland are reported and testing designed to explain the beneficial effect of geothermal water for washing described. The findings indicate, that the silica content of the water may be the principal component for a superior washing quality

  4. Iridium emissions from Hawaiian volcanoes

    International Nuclear Information System (INIS)

    Finnegan, D.L.; Zoller, W.H.; Miller, T.M.

    1988-01-01

    Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes

  5. Iridium emissions from Hawaiian volcanoes

    Science.gov (United States)

    Finnegan, D. L.; Zoller, W. H.; Miller, T. M.

    1988-01-01

    Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes.

  6. Strain Anomalies during an Earthquake Sequence in the South Iceland Seismic Zone

    Science.gov (United States)

    Arnadottir, T.; Haines, A. J.; Geirsson, H.; Hreinsdottir, S.

    2017-12-01

    The South Iceland Seismic Zone (SISZ) accommodates E-W translation due to oblique spreading between the North American/Hreppar microplate and Eurasian plate, in South Iceland. Strain is released in the SISZ during earthquake sequences that last days to years, at average intervals of 80-100 years. The SISZ is currently in the midst of an earthquake sequence that started with two M6.5 earthquakes in June 2000, and continued with two M6 earthquakes in May 2008. Estimates of geometric strain accumulation, and seismic strain release in these events indicate that they released at most only half of the strain accumulated since the last earthquake cycle in 1896-1912. Annual GPS campaigns and continuous measurements during 2001-2015 were used to calculate station velocities and strain rates from a new method using the vertical derivatives of horizontal stress (VDoHS). This new method allows higher resolution of strain rates than other (older) approaches, as the strain rates are estimated by integrating VDoHS rates obtained by inversion rather than differentiating interpolated GPS velocities. Estimating the strain rates for eight 1-2 year intervals indicates temporal and spatial variation of strain rates in the SISZ. In addition to earthquake faulting, the strain rates in the SISZ are influenced by anthropogenic signals due to geothermal exploitation, and magma movements in neighboring volcanoes - Hekla and Eyjafjallajökull. Subtle signals of post-seismic strain rate changes are seen following the June 2000 M6.5 main shocks, but interestingly, much larger strain rate variations are observed after the two May 2008 M6 main shocks. A prominent strain anomaly is evident in the epicentral area prior to the May 2008 earthquake sequence. The strain signal persists over at least 4 years in the epicentral area, leading up to the M6 main shocks. The strain is primarily extension in ESE-WNW direction (sub-parallel to the direction of plate spreading), but overall shear across the N

  7. Long-term variability of dust events in Iceland (1949-2011)

    Science.gov (United States)

    Dagsson-Waldhauserova, P.; Arnalds, O.; Olafsson, H.

    2014-12-01

    The long-term frequency of atmospheric dust observations was investigated for the southern part of Iceland and interpreted together with earlier results obtained from northeastern (NE) Iceland (Dagsson-Waldhauserova et al., 2013). In total, over 34 dust days per year on average occurred in Iceland based on conventionally used synoptic codes for dust observations. However, frequent volcanic eruptions, with the re-suspension of volcanic materials and dust haze, increased the number of dust events fourfold (135 dust days annually). The position of the Icelandic Low determined whether dust events occurred in the NE (16.4 dust days annually) or in the southern (S) part of Iceland (about 18 dust days annually). The decade with the most frequent dust days in S Iceland was the 1960s, but the 2000s in NE Iceland. A total of 32 severe dust storms (visibility typically warm, occurring during summer/autumn (May-September) and during mild southwesterly winds, while the subarctic dust events (S Iceland) were mainly cold, occurring during winter/spring (March-May) and during strong northeasterly winds. About half of the dust events in S Iceland occurred in winter or at sub-zero temperatures. A good correlation was found between particulate matter (PM10) concentrations and visibility during dust observations at the stations Vík and Stórhöfði. This study shows that Iceland is among the dustiest areas of the world and that dust is emitted year-round.

  8. Aleutian Islands Coastal Resources Inventory and Environmental Sensitivity Maps: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains point locations of active volcanoes as compiled by Motyka et al., 1993. Eighty-nine volcanoes with eruptive phases in the Quaternary are...

  9. Subglacial hydrothermal alteration minerals in Jökulhlaup deposits of Southern Iceland, with implications for detecting past or present habitable environments on Mars.

    Science.gov (United States)

    Warner, Nicholas H; Farmer, Jack D

    2010-06-01

    Jökulhlaups are terrestrial catastrophic outfloods, often triggered by subglacial volcanic eruptions. Similar volcano-ice interactions were likely important on Mars where magma/lava may have interacted with the planet's cryosphere to produce catastrophic floods. As a potential analogue to sediments deposited during martian floods, the Holocene sandurs of Iceland are dominated by basaltic clasts derived from the subglacial environment and deposited during jökulhlaups. Palagonite tuffs and breccias, present within the deposits, represent the primary alteration lithology. The surface abundance of palagonite on the sandurs is 1-20%. X-ray diffraction (XRD) analysis of palagonite breccias confirms a mineral assemblage of zeolites, smectites, low-quartz, and kaolinite. Oriented powder X-ray diffractograms (habitable environments for microbial life may be found.

  10. Flank tectonics of Martian volcanoes

    International Nuclear Information System (INIS)

    Thomas, P.J.; Squyres, S.W.; Carr, M.H.

    1990-01-01

    On the flanks of Olympus Mons is a series of terraces, concentrically distributed around the caldera. Their morphology and location suggest that they could be thrust faults caused by compressional failure of the cone. In an attempt to understand the mechanism of faulting and the possible influences of the interior structure of Olympus Mons, the authors have constructed a numerical model for elastic stresses within a Martian volcano. In the absence of internal pressurization, the middle slopes of the cone are subjected to compressional stress, appropriate to the formation of thrust faults. These stresses for Olympus Mons are ∼250 MPa. If a vacant magma chamber is contained within the cone, the region of maximum compressional stress is extended toward the base of the cone. If the magma chamber is pressurized, extensional stresses occur at the summit and on the upper slopes of the cone. For a filled but unpressurized magma chamber, the observed positions of the faults agree well with the calculated region of high compressional stress. Three other volcanoes on Mars, Ascraeus Mons, Arsia Mons, and Pavonis Mons, possess similar terraces. Extending the analysis to other Martian volcanoes, they find that only these three and Olympus Mons have flank stresses that exceed the compressional failure strength of basalt, lending support to the view that the terraces on all four are thrust faults

  11. Long-term dust aerosol production from natural sources in Iceland.

    Science.gov (United States)

    Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur

    2017-02-01

    Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland is volcanic sandy deserts. Not only do natural emissions from these sources influenced by strong winds affect regional air quality in Iceland ("Reykjavik haze"), but dust particles are transported over the Atlantic ocean and Arctic Ocean >1000 km at times. The aim of this paper is to place Icelandic dust production area into international perspective, present long-term frequency of dust storm events in northeast Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in northeast Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the northeastern erosion area, indicating extreme dust plume activity and erosion within the northeastern deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and Aeolian transport during dust/volcanic ash storms in Iceland, which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust may contribute to the Arctic air pollution. Long-term records of meteorological dust observations from Northeast Iceland indicate the frequency of dust events from Icelandic deserts. The research involves a 60-year period and

  12. Restoring ecosystem functions and services by overcoming soil threats - The case of Mt. Hekla area in Iceland

    Science.gov (United States)

    Thorsson, Johann; Petursdottir, Thorunn

    2015-04-01

    Soils are one of the main fundamental bodies of terrestrial ecosystems. Soil functions contribute substantially to the ecosystem services humans and all other living beings depend on. Current soil threats are in most cases related to anthropogenic impacts and derived environmental pressures. For instance, overexploitation has in many cases damaged ecosystem resilience, affected current equilibrium and caused severe soil degradation. The resulting dysfunctional ecosystems are incapable of providing necessary ecosystem services. In such cases ecosystem restoration is necessary to restore ecosystem functions and ecological succession. The Mt. Hekla area in Iceland is an example of land suffering from accelerated erosion amplified by anthropogenic impacts. The area is 900 km2 located in South Iceland in the vicinity of the volcano Mt. Hekla. Today over 40% of the area is classified as eroded but historical documents indicate that vast part of the area were fertile and vegetated at the time of settlement, 1100 years ago; hence was able to withstand the geological disturbances occurring prior to the arrival of man as is obvious from the pristine woody patches still remaining. Severe soil degradation followed the large-scale deforestation and overgrazing that took place within the area. The initial land degradation event is considered to have occurred in the 11th century, but has been ongoing since then in several episodes. The Þjórsá glacial river flows through the area and carries enormous amounts of sediments every year. After the deforestation, the ecosystem resilience was damaged and the land left exposed to the elements. Eventually large scale wind erosion started, followed with water erosion and increased impact of freeze-thaw processes. The Soil Conservation Service of Iceland started working in the area in the early 20th century and land reclamation operations have been ongoing until this day. Considerable successes have been made as is manifested in the fact

  13. Patterns in the Physical, Chemical, and Biological Composition of Icelandic Lakes and the Dominant Factors Controlling Variability Across Watersheds

    Science.gov (United States)

    Greco, A.; Strock, K.; Edwards, B. R.

    2017-12-01

    Fourteen lakes were sampled in the southern and western area of Iceland in June of 2017. The southern systems, within the Eastern Volcanic Zone, have minimal soil development and active volcanoes that produce ash input to lakes. Lakes in the Western Volcanic Zone were more diverse and located in older bedrock with more extensively weathered soil. Physical variables (temperature, oxygen concentration, and water clarity), chemical variables (pH, conductivity, dissolved and total nitrogen and phosphorus concentrations, and dissolved organic carbon concentration), and biological variables (algal biomass) were compared across the lakes sampled in these geographic regions. There was a large range in lake characteristics, including five to eighteen times higher algal biomass in the southern systems that experience active ash input to lakes. The lakes located in the Eastern Volcanic Zone also had higher conductivity and lower pH, especially in systems receiving substantial geothermal input. These results were analyzed in the context of more extensive lake sampling efforts across Iceland (46 lakes) to determine defining characteristics of lakes in each region and to identify variables that drive heterogeneous patterns in physical, chemical, and biological lake features within each region. Coastal systems, characterized by high conductivity, and glacially-fed systems, characterized by high iron concentrations, were unique from lakes in all other regions. Clustering and principal component analyses revealed that lake type (plateau, valley, spring-fed, and direct-runoff) was not the primary factor explaining variability in lake chemistry outside of the coastal and glacial lake types. Instead, lakes differentiated along a gradient of iron concentration and total nitrogen concentration. The physical and chemical properties of subarctic lakes are especially susceptible to both natural and human-induced environmental impacts. However, relatively little is known about the

  14. Drilling into Rhyolitic Magma at Shallow depth at Krafla Volcanic Complex, NE-Iceland

    Science.gov (United States)

    Mortensen, A. K.; Markússon, S. H.; Gudmundsson, Á.; Pálsson, B.

    2017-12-01

    Krafla volcanic complex in NE-Iceland is an active volcano but the latest eruption was the Krafla Fires in 1975-1984. Though recent volcanic activity has consisted of basaltic fissure eruptions, then it is rhyolitic magma that has been intercepted on at least two occasions while drilling geothermal production wells in the geothermal field suggesting a layered magma plumbing system beneath the Krafla volcanic complex. In 2008 quenched rhyolitic glass was retrieved from the bottom of well KJ-39, which is 2865 m deep ( 2571 m true vertical depth). In 2009 magma was again encountered at an even shallower depth and in more than 2,5 km distance from the bottom of well KJ-39, but in 2009 well IDDP-1 was drilled into magma three times just below 2100 m depth. Only on the last occasion was quenched glass retrieved to confirm that magma had been encountered. In well KJ-39 the quenched glass was rhyolitic in composition. The glass contained resorbed minerals of plagioclase, clinopyroxene and titanomagnetite, but the composition of the glass resembles magma that has formed by partial melting of hydrated basalt. The melt was encountered among cuttings from impermeable, coarse basaltic intrusives at a depth, where the well was anticipated to penetrate the Hólseldar volcanic fissure. In IDDP-1 the quenched glass was also rhyolitic in composition. The glass contained less than 5% of phenocrysts, but the phenocryst assemblage included andesine plagioclase, augite, pigeonite, and titanomagnetite. At IDDP-1 the melt was encountered below a permeable zone composed of fine to coarse grained felsite and granophyre. The disclosure of magma in two wells at Krafla volcanic complex verify that rhyolitic magma can be encountered at shallow depth across a larger area within the caldera. The encounter of magma at shallow depth conforms with that superheated conditions have been found at >2000 m depth in large parts of Krafla geothermal field.

  15. Meteorological buoy measurements in the Iceland Sea, 2007–2009

    Directory of Open Access Journals (Sweden)

    G. N. Petersen

    2017-10-01

    Full Text Available The Icelandic Meteorological Office (IMO conducted meteorological buoy measurements in the central Iceland Sea in the time period 2007–2009, specifically in the northern Dreki area on the southern segment of the Jan Mayen Ridge. Due to difficulties in deployment and operations, in situ measurements in this region are sparse. Here the buoy, deployment and measurements are described with the aim of giving a future user of the data set information that is as comprehensive as possible. The data set has been quality-checked, suspect data removed and the data set made publicly available from PANGAEA Data Publisher (https://doi.org/10.1594/PANGAEA.876206.

  16. Application of subsurface temperature measurements in geothermal prospecting in Iceland

    Science.gov (United States)

    Flóvenz, Ólafur G.

    1985-12-01

    In geothermal areas in Iceland aquifers are in most cases found to occur in highly permeable near-vertical fractures in the low permeability basaltic crust. Therefore heat transfer in the rocks surrounding the aquifers is mainly conductive. Temperature profiles in shallow non-flowing boreholes are used to construct a two dimensional model of the temperature distribution in the vicinity of near vertical aquifers. This is done by finite element solution of the equation of heat transfer which requires knowledge of the regional temperature gradient outside the area of geothermal activity and some constraints on the temperature within the aquifers. The model is helpful in estimating dip and location of near-vertical water bearing fractures and thus in siting production wells. An example of successful use to the method and of soil temperature measurements from a geothermal field in North-Iceland is demonstrated.

  17. Icelandic Public Pensions: Why time is running out

    Directory of Open Access Journals (Sweden)

    Ólafur Ísleifsson

    2011-12-01

    Full Text Available The aim of this paper is to analyse the Icelandic public sector pension system enjoying a third party guarantee. Defined benefit funds fundamentally differ from defined contribution pension funds without a third party guarantee as is the case with the Icelandic general labour market pension funds. We probe the special nature of the public sector pension funds and make a comparison to the defined contribution pension funds of the general labour market. We explore the financial and economic effects of the third party guarantee of the funds, their investment performance and other relevant factors. We seek an answer to the question why time is running out for the country’s largest pension fund that currently faces the prospect of becoming empty by the year 2022.

  18. 230Th-238U disequilibria in historical lavas from Iceland

    International Nuclear Information System (INIS)

    Condomines, M.; Morand, P.; Alleegre, C.J.; Sigvaldason, G.

    1981-01-01

    The 230 Th- 238 U disequilibrium studies on historical lavas from Iceland show a relative homogeneity for Th/U ratios and also a variation for ( 230 Th/ 232 Th) activity ratios at the scale of the island. The ( 230 Th/ 238 U) disequilibrium ratio is always greater than 1 which indicates that partial melting produces magmas with Th/U ratios greater than those of the mantle source. Furthermore, there seems to be a correlation between the variations of ( 230 Th/ 232 Th) (and delta 18 O) ratios and the geographical location of the samples along the active zones of Iceland. We develop and discuss several models in order to explain these variations. (orig.)

  19. 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.

  20. The assent of a nation: genethics and Iceland.

    Science.gov (United States)

    McInnis, M G

    1999-04-01

    The Icelandic parliament passed legislation authorizing the establishment of a national health sector database which will be sponsored financially by private enterprises through DeCode Genetics Inc. Health related data will be gathered from patients, without their informed consent, from all points of contact with Icelandic public and private health care providers. A centralized data curator will 'non-personalize' the identity of the subjects in a one-way coding system which the government and DeCode Genetics argue overrides the need for informed consent. This legislation is in conflict with the European Data Protection Act, which requires informed consent for the collection of personal data. The law raises many ethical questions regarding the central tenets of informed consent, the power of government, the rights of the human subject, and finally, the responsibility of the clinician balancing commitments of the patient and research.

  1. Legalizing altruistic surrogacy in response to evasive travel? An Icelandic proposal

    OpenAIRE

    Kristinsson, Sigurður

    2017-01-01

    Surrogate motherhood has been prohibited by Icelandic law since 1996, but in recent years, Icelandic couples have sought transnational surrogacy in India and the United States despite uncertainties about legal parental status as they return to Iceland with infants born to surrogate mothers. This reflects global trends of increased reproductive tourism, which forces restrictive regimes not only to make decisions concerning the citizenship and parentage of children born to surrogate mothers abr...

  2. Long-term variability of dust events in Iceland (1949-2011)

    OpenAIRE

    Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Ólafsson, Haraldur

    2014-01-01

    The long-term frequency of atmospheric dust observations was investigated for the southern part of Iceland and interpreted together with earlier results obtained from northeastern (NE) Iceland (Dagsson-Waldhauserova et al., 2013). In total, over 34 dust days per year on average occurred in Iceland based on conventionally used synoptic codes for dust observations. However, frequent volcanic eruptions, with the re-suspension of volcanic materials and dust haze, increased the n...

  3. Icelandic boom and bust - Immigration and the housing market

    OpenAIRE

    Lúðvík Elíasson

    2014-01-01

    Possible explanations for the rapid increase in house prices and housing investment in Iceland between 2004 and 2007 and the subsequent market crash are studied. The boom was driven in part by banking liberalisation, international financial conditions, and domestic policies. A simple demand and supply model, based on the study by Elíasson and Pétursson (2009), is fitted to data through the recent boom-bust period. The model is remarkably robust through the cycle despite its unprecedented ampl...

  4. Alcohol and labor supply: the case of Iceland.

    Science.gov (United States)

    Asgeirsdottir, Tinna Laufey; McGeary, Kerry Anne

    2009-10-01

    At a time when the government of Iceland is considering privatization of alcohol sales and a reduction of its governmental fees, it is timely to estimate the potential effects of this policy change. Given that the privatization of sales coupled with a tax reduction should lead to a decrease in the unit price of alcohol, one would expect the quantity consumed to increase. While it is of interest to project the impact of the proposed bill on the market for alcohol, another important consideration is the impact that increased alcohol consumption and, more specifically, probable alcohol misuse would have on other markets in Iceland. The only available study on this subject using Icelandic data yields surprising results. Tómasson et al. (Scand J Public Health 32:47-52, 2004) unexpectedly found no effect of probable alcohol abuse on sick leave. A logical next step would be to examine the effect of probable alcohol abuse on other important labor-market outcomes. Nationally representative survey data from 2002 allow for an analysis of probable misuse of alcohol and labor-supply choices. Labor-supply choices are considered with reference to possible effects of policies already in force, as well as proposed changes to current policies. Contrary to intuition, but in agreement with the previously mentioned Icelandic study, the adverse effects of probable misuse of alcohol on employment status or hours worked are not confirmed within this sample. The reasons for the results are unclear, although some suggestions are hypothesized. Currently, data to test those theories convincingly are not available.

  5. Servant leadership and job satisfaction in the University of Iceland

    OpenAIRE

    Guðjón Ingi Guðjónsson; Sigrún Gunnarsdóttir

    2014-01-01

    Servant leadership is a philosophy of communication and leadership whith focus on decentralization, autonomy, mutual respect and commitment to society. In light of universities’ important societal role and importance of equality of academic staff it is presumed that servant leadership suits a university. Prior research indicates the value of servant leadership for universities’ performance. The purpose of the study was to assess servant leadership in the University of Iceland and its correlat...

  6. Servant leadership and job satisfaction in the University of Iceland

    Directory of Open Access Journals (Sweden)

    Guðjón Ingi Guðjónsson

    2014-12-01

    Full Text Available Servant leadership is a philosophy of communication and leadership whith focus on decentralization, autonomy, mutual respect and commitment to society. In light of universities’ important societal role and importance of equality of academic staff it is presumed that servant leadership suits a university. Prior research indicates the value of servant leadership for universities’ performance. The purpose of the study was to assess servant leadership in the University of Iceland and its correlation with staff job satisfaction using a new Dutch instrument (SLS measuring participants’ attitudes to their next superior. A single item job satisfaction question was included. Results showed considerable practice of servant leadership or 4,19 (scale: 1-6 and the strongest servant leadership characteristic was stewardship, followed by forgiveness and empowerment. 82,6% of participants reported job satisfaction with significant positive correlation with servant leadership. The relatively high degree of servant leadership supports previous study of the uiniversity’s working environment but not recent American studies indicating universities’ a low degree of servant leadership. The degree of servant leadership in the University of Iceland was lower compared to grammar schools (6,46 and general hospital wards (4,33 but identical to hospital emergency care units (4,19. Significant positive correlation of servant leadership with job satisfaction, confirms similar relationships in US universities and in various institutions in Iceland. Results indicate the importance of servant leadership for employees’ job satisfaction, not least empowerment and courage, and this has the potential to support peer management, employee independence and social responsibility of the University of Iceland.

  7. Cereal production, high status and climate in Medieval Iceland

    Science.gov (United States)

    Erlendsson, Egill; Riddell, Scott

    2017-04-01

    At Hrísbrú (formerly the medieval Mosfell estate) in the Mosfell Valley, southwest Iceland, archaeologists have excavated a medieval skáli (hall) proposed to be the high status residence of a chieftain. This is indicated by the size of the skáli, artefacts (foreign goods), archaeofaunal (cattle/sheep bone) ratios and macrobotanical remains (cereal grain). The analysis of pollen from nearby natural contexts suggests that cereals were grown locally. Using multiple profile palynological approach, this paper examines if the apparent cereal production is representative of high status in the Icelandic context. First as a correlate by confirming that cereals were grown in association with the archaeological features characteristic of high status; secondly, as an indicator in its own right through comparison with other palynological datasets from inferred lower status farms. The presence or absence of cereal-type pollen (cf. barley) and other arable correlates was examined for each site. The results suggest that medieval cereal cultivation in the Mosfell Valley was confined to the landholding of the medieval Mosfell estate. This feature is seen as an attribute of the locale's greater status in relation to the other farms in Mosfell Valley. The abandonment of cereal cultivation at the Mosfell estate around AD 1200 is probably associated with interactions between changes in the nation's social power structure and how marginal cereal production in Iceland was (and is) in terms of climate.

  8. The involvement of family in child protection cases in Iceland

    Directory of Open Access Journals (Sweden)

    Anni Haugen

    2015-07-01

    Full Text Available The aim of this study is to examine the involvement of families in child protection cases in Iceland, as well as to shed light on the attitudes of child protection workers on the importance of including families while working on child protection cases. The study is part of an international comparative analysis called: Social Work with Families: Social Workers’ Constructions of Family in Professional Practice. This article only addresses the Icelandic segment of the research. In the study, qualitative methods were used and three focus groups were conducted, in which the same three-step vignette about a child protection case was presented. The findings highlighted how difficult child protection workers found it to define the family. The main element is that family are those individuals closest to the child and connected to them through emotional ties, as Icelandic child protection workers seem to strive to involve family in child protection cases. However, there are signs which show that when working with more complicated cases the definition of a family becomes narrower, and involvement is restricted mostly to parents and grandparents. The findings also show that attitudes toward fathers differ from those toward mothers. The mother is expected to support and create security for the child, while the father is judged mostly on his violent behaviour and is not automatically regarded as providing support or actively taking responsibility for his child.

  9. [Organising Pneumonia - a review and results from Icelandic studies].

    Science.gov (United States)

    Sveinsson, Olafur A; Isaksson, Helgi J; Gudmundsson, Gunnar

    2008-01-01

    Organising pneumonia (OP) is a relatively rare interstitial lung disease. It s definition is based on a characteristic histological pattern in the presence of certain clinical and radiological features. Organising pneumonia represents also what has been called Bronchiolitis Obliterans Organising Pneumonia (BOOP). Recently it has been recommended to call OP cryptogenic organising pneumonia (COP) when no definite cause or characteristic clinical context is found and secondary organising pneumonia (SOP) when causes can be identified such as infection or it occurs in a characteristic clinical context such as connective tissue disorder. The most common clinical symptoms are dyspnea, cough, fever and general malaise. It is common that symptoms have been present for some weeks before the diagnosis is made. Patients commonly have lowered PO2 and a mildly restrictive spirometry. Radiographic features are most often patchy bilateral airspace opacities but an interstitial pattern or focal opacities can also be seen. Most of patients respond well to steroids but relapses are quite common. The aim of this paper is to present an overview of the disease and the main results from studies on OP in Iceland. The mean annual incidence for OP in Iceland was 1.97/100,000 inhabitants. Annual incidence for COP was 1.10/100,000 and 0.87/100,000 for SOP. This is higher than in most other studies. In Iceland patients with OP had a higher standardized mortality ratio than the general population despite good clinical responses. No clinical symptoms could separate between SOP and COP.

  10. Gudmundur Finnbogason, "sympathetic understanding," and early Icelandic psychology.

    Science.gov (United States)

    Pind, Jörgen L

    2008-05-01

    Gudmundur Finnbogason (1873-1944) was a pioneer of Icelandic psychology. He was educated at the University of Copenhagen where he finished his M.A. in 1901 in philosophy, specializing in psychology. During the years 1901-1905, Finnbogason played a major role in establishing and shaping the future of primary education in Iceland. He defended his doctoral thesis on "sympathetic understanding" at the University of Copenhagen in 1911. This work deals with the psychology of imitation. In it Finnbogason defends the view that imitation is basically perception so that there is a direct link from perception to motor behavior. Through imitation people tend to assume the countenance and demeanor of other people, thus showing, in Finnbogason's terminology, "sympathetic understanding." Finnbogason's theory of imitation in many respects anticipates contemporary approaches to the psychology of imitation. In 1918 Finnbogason became professor of applied psychology at the recently founded University of Iceland. Here he attempted to establish psychology as an independent discipline. In this he was unsuccessful; his chair was abolished in 1924.

  11. Midwifery in Iceland: From vocational training to university education.

    Science.gov (United States)

    Olafsdottir, Olof A; Kristjansdottir, Hildur; Halfdansdottir, Berglind; Gottfredsdottir, Helga

    2018-04-03

    Midwifery education is a foundation for health professionals' competence in providing quality healthcare for the benefit of women, their families and society. This paper describes midwifery and the development of midwifery education in Iceland. It examines policy and extensive reforms, from hospital-based vocational training in midwifery to an academic university education, and the impact on the scope of midwifery practice in Iceland. The university-based programme, with its emphasis on autonomy of the midwife, seems to have affected the context of home birth and strengthened midwives' role in primary healthcare. Education reform with a focus on evidence-based practice and midwife-led continuity of care has had limited influence within the hospital system, where the structure of care is fragmented and childbirth is under threat of increasing interventions. Research is needed on the role of education in supporting evidence-based practice, normal childbirth and reproductive health in the Icelandic context. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. K-Ar ages of the Hiruzen volcano group and the Daisen volcano

    International Nuclear Information System (INIS)

    Tsukui, Masashi; Nishido, Hirotsugu; Nagao, Keisuke.

    1985-01-01

    Seventeen volcanic rocks of the Hiruzen volcano group and the Daisen volcano, in southwest Japan, were dated by the K-Ar method to clarify the age of volcanic activity in this region and the evolution of these composite volcanoes. The eruption ages of the Hiruzen volcano group were revealed to be about 0.9 Ma to 0.5 Ma, those of the Daisen volcano to be about 1 Ma to very recent. These results are consistent with geological and paleomagnetic data of previous workers. Effusion of lavas in the area was especially vigorous at 0.5+-0.1 Ma. It was generally considered that the Hiruzen volcano group had erupted during latest Pliocene to early Quaternary and it is older than the Daisen volcano, mainly from their topographic features. However, their overlapping eruption ages and petrographical similarities of the lavas of the Hiruzen volcano group and the Daisen volcano suggest that they may be included in the Daisen volcano in a broad sense. The aphyric andesite, whose eruption age had been correlated to Wakurayama andesite (6.34+-0.19 Ma) in Matsue city and thought to be the basement of the Daisen volcano, was dated to be 0.46+-0.04 Ma. It indicates that petrographically similar aphyric andesite erupted sporadically at different time and space in the San'in district. (author)

  13. Depths of Magma Chambers in the Icelandic Crust

    Science.gov (United States)

    Kelley, D. F.; Kapostasy, D. D.; Barton, M.

    2004-05-01

    There is considerable interest in the structure and thermal state of the crust in Iceland, which lies across the Mid Atlantic Ridge. However, interpretations of seismic and gravity data yield conflicting views of the nature of the lower crust. Some interpretations prefer a model in which the lower crust (15-25 km) is relatively cool and solid, whereas other interpretations, based largely on gravity data, prefer a model in which the lower crust is relatively warm and possibly partially molten. Knowledge of the depth of magma chambers is critical to constrain the geothermal gradient in Icelandic crust and to resolve discrepancies in interpretation of geophysical data. Analyses of aphyric lavas and of glasses in Icelandic lavas erupted from 11 volcanic centers have been compiled. The compositions are picritic and basaltic with SiO2 - 47 to 50 wt%, MgO - 6 to 15wt%, FeO - 8 to 14wt%, to, Na2O - 1.3 to 3.3 wt%, and K2O - 0.03-46 wt%. The pressures of equilibration of these liquids with ol, high-Ca pyx and plag were estimated qualitatively from projections into the pseudoternary system Ol-Di-Silica using methods described by Walker and coworkers and Grove and coworkers. The results (ca. 0.5 GPa) indicate crystallization in magma chambers located at about 16 km depth. Equilibration pressures were also calculated using the method described by Yang and coworkers and by a modified version of this method. Calculated pressures (0.45±0.15 GPa) indicate magma chambers located at 15±4 km depth. Equilibration pressures for Rekjanes Ridge glasses determined using the same techniques are 0.2±0.1 GPa, corresponding to depths of 7.6±3 km. The results indicate the presence of magma chambers in the deep Icelandic crust and that the latter is relatively warm. Shallower chambers (3-7 km) have been identified from seismic studies suggesting a complex magma plumbing system. The results also confirm that magma chambers beneath Iceland are located at greater depths than those beneath the

  14. Geoflicks Reviewed--Films about Hawaiian Volcanoes.

    Science.gov (United States)

    Bykerk-Kauffman, Ann

    1994-01-01

    Reviews 11 films on volcanic eruptions in the United States. Films are given a one- to five-star rating and the film's year, length, source and price are listed. Top films include "Inside Hawaiian Volcanoes" and "Kilauea: Close up of an Active Volcano." (AIM)

  15. Orographic Flow over an Active Volcano

    Science.gov (United States)

    Poulidis, Alexandros-Panagiotis; Renfrew, Ian; Matthews, Adrian

    2014-05-01

    Orographic flows over and around an isolated volcano are studied through a series of numerical model experiments. The volcano top has a heated surface, so can be thought of as "active" but not erupting. A series of simulations with different atmospheric conditions and using both idealised and realistic configurations of the Weather Research and Forecast (WRF) model have been carried out. The study is based on the Soufriere Hills volcano, located on the island of Montserrat in the Caribbean. This is a dome-building volcano, leading to a sharp increase in the surface skin temperature at the top of the volcano - up to tens of degrees higher than ambient values. The majority of the simulations use an idealised topography, in order for the results to have general applicability to similar-sized volcanoes located in the tropics. The model is initialised with idealised atmospheric soundings, representative of qualitatively different atmospheric conditions from the rainy season in the tropics. The simulations reveal significant changes to the orographic flow response, depending upon the size of the temperature anomaly and the atmospheric conditions. The flow regime and characteristic features such as gravity waves, orographic clouds and orographic rainfall patterns can all be qualitatively changed by the surface heating anomaly. Orographic rainfall over the volcano can be significantly enhanced with increased temperature anomaly. The implications for the eruptive behaviour of the volcano and resulting secondary volcanic hazards will also be discussed.

  16. Volcanic Hazard Education through Virtual Field studies of Vesuvius and Laki Volcanoes

    Science.gov (United States)

    Carey, S.; Sigurdsson, H.

    2011-12-01

    Volcanic eruptions pose significant hazards to human populations and have the potential to cause significant economic impacts as shown by the recent ash-producing eruptions in Iceland. Demonstrating both the local and global impact of eruptions is important for developing an appreciation of the scale of hazards associated with volcanic activity. In order to address this need, Web-based virtual field exercises at Vesuvius volcano in Italy and Laki volcano in Iceland have been developed as curriculum enhancements for undergraduate geology classes. The exercises are built upon previous research by the authors dealing with the 79 AD explosive eruption of Vesuvius and the 1783 lava flow eruption of Laki. Quicktime virtual reality images (QTVR), video clips, user-controlled Flash animations and interactive measurement tools are used to allow students to explore archeological and geological sites, collect field data in an electronic field notebook, and construct hypotheses about the impacts of the eruptions on the local and global environment. The QTVR images provide 360o views of key sites where students can observe volcanic deposits and formations in the context of a defined field area. Video sequences from recent explosive and effusive eruptions of Carribean and Hawaiian volcanoes are used to illustrate specific styles of eruptive activity, such as ash fallout, pyroclastic flows and surges, lava flows and their effects on the surrounding environment. The exercises use an inquiry-based approach to build critical relationships between volcanic processes and the deposits that they produce in the geologic record. A primary objective of the exercises is to simulate the role of a field volcanologist who collects information from the field and reconstructs the sequence of eruptive processes based on specific features of the deposits. Testing of the Vesuvius and Laki exercises in undergraduate classes from a broad spectrum of educational institutions shows a preference for the

  17. Volcano geodesy: The search for magma reservoirs and the formation of eruptive vents

    Science.gov (United States)

    Dvorak, J.J.; Dzurisin, D.

    1997-01-01

    Routine geodetic measurements are made at only a few dozen of the world's 600 or so active volcanoes, even though these measurements have proven to be a reliable precursor of eruptions. The pattern and rate of surface displacement reveal the depth and rate of pressure increase within shallow magma reservoirs. This process has been demonstrated clearly at Kilauea and Mauna Loa, Hawaii; Long Valley caldera, California; Campi Flegrei caldera, Italy; Rabaul caldera, Papua New Guinea; and Aira caldera and nearby Sakurajima, Japan. Slower and lesser amounts of surface displacement at Yellowstone caldera, Wyoming, are attributed to changes in a hydrothermal system that overlies a crustal magma body. The vertical and horizontal dimensions of eruptive fissures, as well as the amount of widening, have been determined at Kilauea, Hawaii; Etna, Italy; Tolbachik, Kamchatka; Krafla, Iceland; and Asal-Ghoubbet, Djibouti, the last a segment of the East Africa Rift Zone. Continuously recording instruments, such as tiltmeters, extensometers, and dilatometers, have recorded horizontal and upward growth of eruptive fissures, which grew at rates of hundreds of meters per hour, at Kilauea; Izu-Oshima, Japan; Teishi Knoll seamount, Japan; and Piton de la Fournaise, Re??union Island. In addition, such instruments have recorded the hour or less of slight ground movement that preceded small explosive eruptions at Sakurajima and presumed sudden gas emissions at Galeras, Colombia. The use of satellite geodesy, in particular the Global Positioning System, offers the possibility of revealing changes in surface strain both local to a volcano and over a broad region that includes the volcano.

  18. Characteristics of Helicopter-Generated and Volcano-Related Seismic Tremor Signals

    Science.gov (United States)

    Eibl, Eva P. S.; Lokmer, Ivan; Bean, Christopher J.; Akerlie, Eggert; Vogfjörd, Kristin S.

    2017-04-01

    In volcanic environments it is crucial to distinguish between man-made seismic signals and signals created by the volcano. We compare volcanic, seismic signals with helicopter generated, seismic signals recorded in the last 2.5 years in Iceland. In both cases a long-lasting, emergent seismic signal, that can be referred to as seismic tremor, was generated. In the case of a helicopter, the rotating blades generate pressure pulses that travel through the air and excite Rayleigh waves at up to 40 km distance depending on wind speed, wind direction and topographic features. The longest helicopter related seismic signal we recorded was at the order of 40 minutes long. The tremor usually has a fundamental frequency of more than 10 Hz and overtones at integers of the fundamental frequency. Changes in distance lead to either increases or decreases of the frequency due to the Doppler Effect and are strongest for small source-receiver distances. The volcanic tremor signal was recorded during the Bardarbunga eruption at Holuhraun in 2014/15. For volcano-related seismic signals it is usually more difficult to determine the source process that generated the tremor. The pre-eruptive tremor persists for 2 weeks, while the co-eruptive tremor lasted for 6 months. We observed no frequency changes, most energy between 1 and 2 Hz and no or very little energy above 5 Hz. We compare the different characteristics of helicopter-related and volcano-related seismic signals and discuss how they can be distinguished. In addition we discuss how we can determine if a frequency change is related to a moving source or change in repeat time or a change in the geometry of the resonating body.

  19. Two weather radar time series of the altitude of the volcanic plume during the May 2011 eruption of Grímsvötn, Iceland

    Directory of Open Access Journals (Sweden)

    G. N. Petersen

    2012-10-01

    Full Text Available The eruption of Grímsvötn volcano in Iceland in 2011 lasted for a week, 21–28 May. The eruption was explosive and peaked during the first hours, with the eruption plume reaching 20–25 km altitude. The height of the plume was monitored every 5 min with a C-band weather radar located at Keflavík International Airport and a mobile X-band radar, 257 km and 75 km distance from the volcano respectively. In addition, photographs taken during the first half-hour of the eruption give information regarding the initial rise. Time series of the plume-top altitude were constructed from the radar observations. This paper presents the two independent radar time series. The series have been cross validated and there is a good agreement between them. The echo top radar series of the altitude of the volcanic plume are publicly available from the Pangaea Data Publisher (doi:10.1594/PANGAEA.778390.

  20. The 2014 eruptions of Pavlof Volcano, Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Haney, Matthew M.; Wallace, Kristi; Cameron, Cheryl E.; Schneider, David J.

    2017-12-22

    Pavlof Volcano is one of the most frequently active volcanoes in the Aleutian Island arc, having erupted more than 40 times since observations were first recorded in the early 1800s . The volcano is located on the Alaska Peninsula (lat 55.4173° N, long 161.8937° W), near Izembek National Wildlife Refuge. The towns and villages closest to the volcano are Cold Bay, Nelson Lagoon, Sand Point, and King Cove, which are all within 90 kilometers (km) of the volcano (fig. 1). Pavlof is a symmetrically shaped stratocone that is 2,518 meters (m) high, and has about 2,300 m of relief. The volcano supports a cover of glacial ice and perennial snow roughly 2 to 4 cubic kilometers (km3) in volume, which is mantled by variable amounts of tephra fall, rockfall debris, and pyroclastic-flow deposits produced during historical eruptions. Typical Pavlof eruptions are characterized by moderate amounts of ash emission, lava fountaining, spatter-fed lava flows, explosions, and the accumulation of unstable mounds of spatter on the upper flanks of the volcano. The accumulation and subsequent collapse of spatter piles on the upper flanks of the volcano creates hot granular avalanches, which erode and melt snow and ice, and thereby generate watery debris-flow and hyperconcentrated-flow lahars. Seismic instruments were first installed on Pavlof Volcano in the early 1970s, and since then eruptive episodes have been better characterized and specific processes have been documented with greater certainty. The application of remote sensing techniques, including the use of infrasound data, has also aided the study of more recent eruptions. Although Pavlof Volcano is located in a remote part of Alaska, it is visible from Cold Bay, Sand Point, and Nelson Lagoon, making distal observations of eruptive activity possible, weather permitting. A busy air-travel corridor that is utilized by a numerous transcontinental and regional air carriers passes near Pavlof Volcano. The frequency of air travel

  1. Icelandic National Culture compared to National Cultures of 25 OECD member states using VSM94

    Directory of Open Access Journals (Sweden)

    Svala Guðmundsdóttir

    2015-06-01

    Full Text Available Researchers such as Hofstede (2002 and House, Hanges, Javidan, Dorfman and Gupta, (2004 have defined well-known cultural clusters such as, Anglo, Germanic, and Nordic cultural clusters. However, Iceland was not incorporated in these studies and therefore the research question of this paper is: In relation to Hofstede´s five cultural dimensions where does Iceland differ in relation to 25 of the OECD member states using VSM94? A questionnaire was sent to students at the University of Iceland, School of Social Sciences by e-mail in October 2013. The five dimensions of national culture were measured using scales developed by Hofstede called VSM 94. The results indicated that Iceland differs considerably from nations such as Slovakia, Japan, India, Thailand and China, which were found high in PDI and the MAS dimension while Iceland was found to be high in IDV and low in PDI. When considering the 25 OECD countries, Iceland is more similar to the Anglo cluster, C3, Canada, New Zealand, United Kingdon, Australia and United States than the Nordic cluster, C1 i.e. Denmark, Sweden and Norway. Iceland is similar to those countries in relation to high IDV, low PDI but differs in the dimensions MAS and UAI where Iceland scores higher.

  2. Holland in Iceland Revisited: An Emic Approach to Evaluating U.S. Vocational Interest Models

    Science.gov (United States)

    Einarsdottir, Sif; Rounds, James; Su, Rong

    2010-01-01

    An emic approach was used to test the structural validity and applicability of Holland's (1997) RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) model in Iceland. Archival data from the development of the Icelandic Interest Inventory (Einarsdottir & Rounds, 2007) were used in the present investigation. The data…

  3. Development of Indigenous Basic Interest Scales: Re-Structuring the Icelandic Interest Space

    Science.gov (United States)

    Einarsdottir, Sif; Eyjolfsdottir, Katrin Osk; Rounds, James

    2013-01-01

    The present investigation used an emic approach to develop a set of Icelandic indigenous basic interest scales. An indigenous item pool that is representative of the Icelandic labor market was administered to three samples (N = 1043, 1368, and 2218) of upper secondary and higher education students in two studies. A series of item level cluster and…

  4. Spring production of Calanus finmarchicus at the Iceland-Scotland Ridge

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Richardson, K.; Heath, M.R.

    2008-01-01

    Distribution and reproduction activity of the calanoid copepod Calanus finmarchicus were studied in the waters between Scotland and Iceland in April 1997 during the expected time of the animals' ascent to surface waters following diapause. Ascent was taking place on both sides of the Iceland-Scot...

  5. Report on a Survey Project in Iceland on the Use of Radiation Pasteurization of Various Seafoods

    Energy Technology Data Exchange (ETDEWEB)

    Hannesson, G.; Dagbjartsson, B. [Icelandic Fisheries Laboratories, Reykjavik (Iceland)

    1970-11-15

    A survey project on the irradiation preservation of seafoods, sponsored by the Government of Iceland, the International Atomic Energy Agency and the United States Atomic Energy Commission has been carried out at the Icelandic Fisheries Laboratories. A summary of results obtained on Norway lobster tails, deep-sea shrimp and cod fish is given in this paper. (author)

  6. Geophysical Exploration on the Structure of Volcanoes: Two Case Histories

    Energy Technology Data Exchange (ETDEWEB)

    Furumoto, A. S.

    1974-01-01

    Geophysical methods of exploration were used to determine the internal structure of Koolau Volcano in Hawaii and of Rabaul Volcano in New Guinea. By use of gravity and seismic data the central vent or plug of Koolau Volcano was outlined. Magnetic data seem to indicate that the central plug is still above the Curie Point. If so, the amount of heat energy available is tremendous. As for Rabaul Volcano, it is located in a region characterized by numerous block faulting. The volcano is only a part of a large block that has subsided. Possible geothermal areas exist near the volcano but better potential areas may exist away from the volcano.

  7. Instrumentation Recommendations for Volcano Monitoring at U.S. Volcanoes Under the National Volcano Early Warning System

    Science.gov (United States)

    Moran, Seth C.; Freymueller, Jeff T.; LaHusen, Richard G.; McGee, Kenneth A.; Poland, Michael P.; Power, John A.; Schmidt, David A.; Schneider, David J.; Stephens, George; Werner, Cynthia A.; White, Randall A.

    2008-01-01

    As magma moves toward the surface, it interacts with anything in its path: hydrothermal systems, cooling magma bodies from previous eruptions, and (or) the surrounding 'country rock'. Magma also undergoes significant changes in its physical properties as pressure and temperature conditions change along its path. These interactions and changes lead to a range of geophysical and geochemical phenomena. The goal of volcano monitoring is to detect and correctly interpret such phenomena in order to provide early and accurate warnings of impending eruptions. Given the well-documented hazards posed by volcanoes to both ground-based populations (for example, Blong, 1984; Scott, 1989) and aviation (for example, Neal and others, 1997; Miller and Casadevall, 2000), volcano monitoring is critical for public safety and hazard mitigation. Only with adequate monitoring systems in place can volcano observatories provide accurate and timely forecasts and alerts of possible eruptive activity. At most U.S. volcanoes, observatories traditionally have employed a two-component approach to volcano monitoring: (1) install instrumentation sufficient to detect unrest at volcanic systems likely to erupt in the not-too-distant future; and (2) once unrest is detected, install any instrumentation needed for eruption prediction and monitoring. This reactive approach is problematic, however, for two reasons. 1. At many volcanoes, rapid installation of new ground-1. based instruments is difficult or impossible. Factors that complicate rapid response include (a) eruptions that are preceded by short (hours to days) precursory sequences of geophysical and (or) geochemical activity, as occurred at Mount Redoubt (Alaska) in 1989 (24 hours), Anatahan (Mariana Islands) in 2003 (6 hours), and Mount St. Helens (Washington) in 1980 and 2004 (7 and 8 days, respectively); (b) inclement weather conditions, which may prohibit installation of new equipment for days, weeks, or even months, particularly at

  8. Iceland as a demonstrator for a transition to low carbon economy?

    Science.gov (United States)

    Asbjornsson, Einar Jon; Stefansson, Hlynur; Finger, David Christian

    2017-04-01

    The energy supply in Iceland is quite unique, about 85% of the total primary energy is coming from renewable resources. Nevertheless, the ecological footprint of an average Icelander is with 6.5 worlds, one of the highest worldwide and the energy consumption per capita is about 7 times higher than the European average. Recent developments have shown that there is a great potential to reduce the footprint and develop towards low carbon economy. With its small population, well educated and governed society and clear system boundaries to the outside world, Iceland is a good research laboratory and an ideal demonstrator for a transition towards a low carbon economy. This presentation will outline how several innovative research projects at Reykjavik University could lead Iceland towards a sustainable and low carbon economy. The presentations will conclude with a visionary outlook how Iceland can become a demonstration nation towards a prosperous, low carbon and sustainable economy, helping stabilize global warming at an acceptable level.

  9. Is earthquake rate in south Iceland modified by seasonal loading?

    Science.gov (United States)

    Jonsson, S.; Aoki, Y.; Drouin, V.

    2017-12-01

    Several temporarily varying processes have the potential of modifying the rate of earthquakes in the south Iceland seismic zone, one of the two most active seismic zones in Iceland. These include solid earth tides, seasonal meteorological effects and influence from passing weather systems, and variations in snow and glacier loads. In this study we investigate the influence these processes may have on crustal stresses and stressing rates in the seismic zone and assess whether they appear to be influencing the earthquake rate. While historical earthquakes in the south Iceland have preferentially occurred in early summer, this tendency is less clear for small earthquakes. The local earthquake catalogue (going back to 1991, magnitude of completeness M6+ earthquakes, which occurred in June 2000 and May 2008. Standard Reasenberg earthquake declustering or more involved model independent stochastic declustering algorithms are not capable of fully eliminating the aftershocks from the catalogue. We therefore inspected the catalogue for the time period before 2000 and it shows limited seasonal tendency in earthquake occurrence. Our preliminary results show no clear correlation between earthquake rates and short-term stressing variations induced from solid earth tides or passing storms. Seasonal meteorological effects also appear to be too small to influence the earthquake activity. Snow and glacier load variations induce significant vertical motions in the area with peak loading occurring in Spring (April-May) and maximum unloading in Fall (Sept.-Oct.). Early summer occurrence of historical earthquakes therefore correlates with early unloading rather than with the peak unloading or unloading rate, which appears to indicate limited influence of this seasonal process on the earthquake activity.

  10. The Last Glacial in Northern Iceland: geothermal and permafrost controls

    Science.gov (United States)

    Gudmundsson, A.; van Vliet-Lanoë, B.; Bourgeois, O.; Dauteuil, O.; Embry, J. C.; Guillou, H.; Schneider, J. L.

    2003-04-01

    This paper provides arguments for a multi-advance model of Weichselian glaciation-deglaciation of Northern Iceland considering the influence of the geothermal gradient and of the ice sheds on the different ice-stream outlets. This paper is based on morphological mapping , SPOT images analysis high resolution stratigraphy, palaeopedology, tephra petrography and Ar/K dating. The Last Glaciation Maximum has a limited extend in Northern Iceland, with cold-based characteristics, except in sectors of high thermal gradient which supported low profile ice streams, a main difference with MIS6. Ice sheet building started from MIS 5d with a limited extent. At MIS 5b the thickness of the ice is enough to enable the activity of the eastern hyalocastite ridge in the NVZ. The maximal extent is reached abruptly at the boundary stage 3/2, probably in relation with increased precipitation, with development of H3, followed by a drastic retreat, controlled by very low precipitation rate and cold-based glaciers. This period is responsible for long periglacial morphogenesis inland, on the nunataks and ice free areas, and for starved sedimentation on the shelf and in the fjords. From 17 ka or H2, precipitation rose again and a second maximal extent, the Fnjoskadalur Stadial, the so-called "Old Dryas", in retreat from the former one. The main deglaciation took place at the onset of the Bölling. A late glacial pulse of minimal intensity occurred with the Younger Dryas. The Pre-Boreal stadial is extremely limited in the North of Iceland in relation with the lower and colder conditions compared to the south coast inflenced by the Irminger current.

  11. Variation in the crustal structure across central Iceland

    Science.gov (United States)

    Du, Zhijun; Foulger, G. R.

    2001-04-01

    We determine the crustal structures beneath 12 broad-band seismic stations deployed in a swath across central Iceland along and around the ICEMELT explosion seismic profile by combining teleseismic receiver functions, surface wave dispersion curves and the waveforms of a large, local event in Iceland. By using teleseisms that approach from different backazimuths, we study lateral structural variability out of the line of the ICEMELT profile. Beneath Tertiary areas, the thickness of the upper crust, as defined by the 6.5kms-1 velocity horizon, is ~8km and the depth to the base of the lower crust, as defined by the 7.2kms-1 velocity horizon, is ~29-32km. Beneath the currently active rift zone the upper crust thins to ~6.0km and the depth to the base of the lower crust increases to ~35-40km. A substantial low-velocity zone underlies the Middle Volcanic Zone in the lower crust, which may indicate anomalously high geothermal gradients there. This suggests that the large-scale thermal centre of the hotspot may be more westerly than northwest Vatnajokull, where it is generally assumed to lie. Simplified description of the results notwithstanding, there is substantial variability in the overall style of crustal structure throughout Iceland, and a clear, tripartite division into upper and lower crusts and a sharp Moho is poorly supported by many of our results. The nature, distinctiveness and continuity of the Moho is variable and in many areas the crust-mantle transition is a zone with enhanced velocity gradients several kilometres thick.

  12. [Fluctuations in unemployment and disability in Iceland 1992-2006].

    Science.gov (United States)

    Thorlacius, Sigurdur; Olafsson, Stefán

    2008-03-01

    To examine and explain the effect of unemployment on the number of disability pensioners in Iceland by examining changes in this relationship from 1992 to 2006. Information on gender and place of residence of new recipients of disability pension in Iceland and corresponding information on unemployment for each year in the period 1992 to 2006. The variables were correlated and disaggregated by gender and regions within Iceland. Two big fluctuations occurred in the rate of new disability pension receivers during the study period, with significant increases in disability from 1993 to 1995 and again from 2003 onwards. Both of these fluctuations are associated with considerable increases in the unemployment rate. The extent of new disability pensioners declined again when the level of unemployment went down, even though not to the same relative extent. In the upswing from 2003 a delay of about a year in the increase of disability pensioners' numbers, following the rise in unemployment rate, became more prominent and the overall rate of new disability pensioners reached new highs. The relationship applies equally to the capital area as well as the provincial areas as a whole. There is though a small deviation in three of the seven provincial areas, with less decline of the disability rate on the downswing. Health and capability condition determine the overall disability rate, but fluctuations over time are related to environmental conditions in the labour market, especially the unemployment rate. The features of the welfare system, especially the benefit and rehabilitation system, as well as the extent and character of activation measures in the labour market also influence the number of disability pensioners. A new method of disability assessment from late 1999 may have had some influence on the relationship during the latter part of the period and increasing applications from people with mental and psychiatric deficiencies seems to have had a significant influence on

  13. Money Talks: Gender Budgeting in the University of Iceland

    Directory of Open Access Journals (Sweden)

    Finnborg S. Jónasdóttir

    2016-06-01

    Full Text Available The article addresses the financial framework, decision-making and budgeting processes of the University of Iceland from a gender perspective. The newly appointed rector of the University of Iceland (elected 2015 together with the university council is currently revising the UI system of the distribution formula of budget allocation. This provides an opportunity to examine the system which is inspired by New Public Management, with emphasis on global competition and performance based indicators. The aim of the article is to scrutinize the current system of budget allocation and distribution and its significance when it comes to gender. We ask how the, allegedly gender neutral, system plays out for different schools and disciplines and for academics in different ranks, when the gender dimension is taken into account. We draw on empirical data collected as part of the GARCIA research project, Gendering the Academy and Research combating Career Instability and Asymmetries, which is supported by the 7th Framework Programme of the European Union. To shed a light on the process we focus on the male-dominated School of Engineering and Natural Sciences (SENS and the more feminised School of Social Sciences (SSS. The exploration shows that the financial framework, decision-making and budgeting processes at the University of Iceland are rather non-transparent, and biased in favour of the natural sciences. This applies to funding from the state; third party funding; the allocation of funding in the teaching part of the budgeting, as well as the research part. From the article it can be concluded that the current system contains an internal, though unintended, gender bias that needs to be corrected.

  14. Unzipping of the volcano arc, Japan

    Science.gov (United States)

    Stern, R.J.; Smoot, N.C.; Rubin, M.

    1984-01-01

    A working hypothesis for the recent evolution of the southern Volcano Arc, Japan, is presented which calls upon a northward-progressing sundering of the arc in response to a northward-propagating back-arc basin extensional regime. This model appears to explain several localized and recent changes in the tectonic and magrnatic evolution of the Volcano Arc. Most important among these changes is the unusual composition of Iwo Jima volcanic rocks. This contrasts with normal arc tholeiites typical of the rest of the Izu-Volcano-Mariana and other primitive arcs in having alkaline tendencies, high concentrations of light REE and other incompatible elements, and relatively high silica contents. In spite of such fractionated characteristics, these lavas appear to be very early manifestations of a new volcanic and tectonic cycle in the southern Volcano Arc. These alkaline characteristics and indications of strong regional uplift are consistent with the recent development of an early stage of inter-arc basin rifting in the southern Volcano Arc. New bathymetric data are presented in support of this model which indicate: 1. (1) structural elements of the Mariana Trough extend north to the southern Volcano Arc. 2. (2) both the Mariana Trough and frontal arc shoal rapidly northwards as the Volcano Arc is approached. 3. (3) rugged bathymetry associated with the rifted Mariana Trough is replaced just south of Iwo Jima by the development of a huge dome (50-75 km diameter) centered around Iwo Jima. Such uplifted domes are the immediate precursors of rifts in other environments, and it appears that a similar situation may now exist in the southern Volcano Arc. The present distribution of unrifted Volcano Arc to the north and rifted Mariana Arc to the south is interpreted not as a stable tectonic configuration but as representing a tectonic "snapshot" of an arc in the process of being rifted to form a back-arc basin. ?? 1984.

  15. Volcanoes

    Science.gov (United States)

    ... Extreme Heat Older Adults (Aged 65+) Infants and Children Chronic Medical Conditions Low Income Athletes Outdoor Workers Pets Hot Weather Tips Warning Signs and Symptoms FAQs Social Media How to Stay Cool Missouri Cooling Centers Extreme ...

  16. Environmental mapping and monitoring of Iceland by remote sensing (EMMIRS)

    Science.gov (United States)

    Pedersen, Gro B. M.; Vilmundardóttir, Olga K.; Falco, Nicola; Sigurmundsson, Friðþór S.; Rustowicz, Rose; Belart, Joaquin M.-C.; Gísladóttir, Gudrun; Benediktsson, Jón A.

    2016-04-01

    Iceland is exposed to rapid and dynamic landscape changes caused by natural processes and man-made activities, which impact and challenge the country. Fast and reliable mapping and monitoring techniques are needed on a big spatial scale. However, currently there is lack of operational advanced information processing techniques, which are needed for end-users to incorporate remote sensing (RS) data from multiple data sources. Hence, the full potential of the recent RS data explosion is not being fully exploited. The project Environmental Mapping and Monitoring of Iceland by Remote Sensing (EMMIRS) bridges the gap between advanced information processing capabilities and end-user mapping of the Icelandic environment. This is done by a multidisciplinary assessment of two selected remote sensing super sites, Hekla and Öræfajökull, which encompass many of the rapid natural and man-made landscape changes that Iceland is exposed to. An open-access benchmark repository of the two remote sensing supersites is under construction, providing high-resolution LIDAR topography and hyperspectral data for land-cover and landform classification. Furthermore, a multi-temporal and multi-source archive stretching back to 1945 allows a decadal evaluation of landscape and ecological changes for the two remote sensing super sites by the development of automated change detection techniques. The development of innovative pattern recognition and machine learning-based approaches to image classification and change detection is one of the main tasks of the EMMIRS project, aiming to extract and compute earth observation variables as automatically as possible. Ground reference data collected through a field campaign will be used to validate the implemented methods, which outputs are then inferred with geological and vegetation models. Here, preliminary results of an automatic land-cover classification based on hyperspectral image analysis are reported. Furthermore, the EMMIRS project

  17. Semi-supervised morphosyntactic classification of Old Icelandic.

    Science.gov (United States)

    Urban, Kryztof; Tangherlini, Timothy R; Vijūnas, Aurelijus; Broadwell, Peter M

    2014-01-01

    We present IceMorph, a semi-supervised morphosyntactic analyzer of Old Icelandic. In addition to machine-read corpora and dictionaries, it applies a small set of declension prototypes to map corpus words to dictionary entries. A web-based GUI allows expert users to modify and augment data through an online process. A machine learning module incorporates prototype data, edit-distance metrics, and expert feedback to continuously update part-of-speech and morphosyntactic classification. An advantage of the analyzer is its ability to achieve competitive classification accuracy with minimum training data.

  18. Family counts: deciding when to murder among the Icelandic Vikings

    OpenAIRE

    Palmstierna, Markel; Frangou, Anna; Wallette, Anna; Dunbar, Robin

    2017-01-01

    In small scale societies, lethal attacks on another individual usually invite revenge by the victim's family. We might expect those who perpetrate such attacks to do so only when their own support network (mainly family) is larger than that of the potential victim so as to minimise the risk of retaliation. Using data from Icelandic family sagas, we show that this prediction holds whether we consider biological kin or affinal kin (in-laws): on average, killers had twice as many relatives as th...

  19. Common processes at unique volcanoes – a volcanological conundrum

    OpenAIRE

    Katharine eCashman; Juliet eBiggs

    2014-01-01

    An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behavior over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behavior (or “personali...

  20. Linking space observations to volcano observatories in Latin America: Results from the CEOS DRM Volcano Pilot

    Science.gov (United States)

    Delgado, F.; Pritchard, M. E.; Biggs, J.; Arnold, D. W. D.; Poland, M. P.; Ebmeier, S. K.; Wauthier, C.; Wnuk, K.; Parker, A. L.; Amelug, F.; Sansosti, E.; Mothes, P. A.; Macedo, O.; Lara, L.; Zoffoli, S.; Aguilar, V.

    2015-12-01

    Within Latin American, about 315 volcanoes that have been active in the Holocene, but according to the United Nations Global Assessment of Risk 2015 report (GAR15) 202 of these volcanoes have no seismic, deformation or gas monitoring. Following the 2012 Santorini Report on satellite Earth Observation and Geohazards, the Committee on Earth Observation Satellites (CEOS) has developed a 3-year pilot project to demonstrate how satellite observations can be used to monitor large numbers of volcanoes cost-effectively, particularly in areas with scarce instrumentation and/or difficult access. The pilot aims to improve disaster risk management (DRM) by working directly with the volcano observatories that are governmentally responsible for volcano monitoring, and the project is possible thanks to data provided at no cost by international space agencies (ESA, CSA, ASI, DLR, JAXA, NASA, CNES). Here we highlight several examples of how satellite observations have been used by volcano observatories during the last 18 months to monitor volcanoes and respond to crises -- for example the 2013-2014 unrest episode at Cerro Negro/Chiles (Ecuador-Colombia border); the 2015 eruptions of Villarrica and Calbuco volcanoes, Chile; the 2013-present unrest and eruptions at Sabancaya and Ubinas volcanoes, Peru; the 2015 unrest at Guallatiri volcano, Chile; and the 2012-present rapid uplift at Cordon Caulle, Chile. Our primary tool is measurements of ground deformation made by Interferometric Synthetic Aperture Radar (InSAR) but thermal and outgassing data have been used in a few cases. InSAR data have helped to determine the alert level at these volcanoes, served as an independent check on ground sensors, guided the deployment of ground instruments, and aided situational awareness. We will describe several lessons learned about the type of data products and information that are most needed by the volcano observatories in different countries.

  1. Hydrothermal systems and volcano geochemistry

    Science.gov (United States)

    Fournier, R.O.

    2007-01-01

    The upward intrusion of magma from deeper to shallower levels beneath volcanoes obviously plays an important role in their surface deformation. This chapter will examine less obvious roles that hydrothermal processes might play in volcanic deformation. Emphasis will be placed on the effect that the transition from brittle to plastic behavior of rocks is likely to have on magma degassing and hydrothermal processes, and on the likely chemical variations in brine and gas compositions that occur as a result of movement of aqueous-rich fluids from plastic into brittle rock at different depths. To a great extent, the model of hydrothermal processes in sub-volcanic systems that is presented here is inferential, based in part on information obtained from deep drilling for geothermal resources, and in part on the study of ore deposits that are thought to have formed in volcanic and shallow plutonic environments.

  2. New voices in Iceland young adults with disabilities in Iceland: The importance of relationships and natural supports

    OpenAIRE

    Bjarnason, Dóra S.

    2009-01-01

    This paper deals with young adults’ perspectives and experiences of growing up with a variety of impairments in Iceland, and how they impact the young disabled adults’ approach to the status of adulthood. The paper is based on a qualitative study that explored perspectives and experiences of 36 young disabled adults (16–24 years old), their parents, friends and teachers. The purpose of this paper is to share themes related to the way that choices made by and for disabled children and young pe...

  3. Lahar hazards at Mombacho Volcano, Nicaragua

    Science.gov (United States)

    Vallance, J.W.; Schilling, S.P.; Devoli, G.

    2001-01-01

    Mombacho volcano, at 1,350 meters, is situated on the shores of Lake Nicaragua and about 12 kilometers south of Granada, a city of about 90,000 inhabitants. Many more people live a few kilometers southeast of Granada in 'las Isletas de Granada and the nearby 'Peninsula de Aseses. These areas are formed of deposits of a large debris avalanche (a fast moving avalanche of rock and debris) from Mombacho. Several smaller towns with population, in the range of 5,000 to 12,000 inhabitants are to the northwest and the southwest of Mombacho volcano. Though the volcano has apparently not been active in historical time, or about the last 500 years, it has the potential to produce landslides and debris flows (watery flows of mud, rock, and debris -- also known as lahars when they occur on a volcano) that could inundate these nearby populated areas. -- Vallance, et.al., 2001

  4. Analysis of volcano rocks by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Dekan, J.

    2012-01-01

    In this work we have analysed the basalt rock from Mount Ba tur volcano situated on the Island of Bali in Indonesia.We compared our results with composition of basalt rocks from some other places on the Earth. (authors)

  5. Moessbauer Spectroscopy study of Quimsachata Volcano materials

    International Nuclear Information System (INIS)

    Dominguez, A.G.B.

    1988-01-01

    It has been studied volcanic lava from Quimsachata Volcano in Pem. Moessbauer Spectroscopy, X-ray diffraction, electronic and optical microscopy allowed the identification of different mineralogical phases. (A.C.AS.) [pt

  6. Lahar hazards at Agua volcano, Guatemala

    Science.gov (United States)

    Schilling, S.P.; Vallance, J.W.; Matías, O.; Howell, M.M.

    2001-01-01

    At 3760 m, Agua volcano towers more than 3500 m above the Pacific coastal plain to the south and 2000 m above the Guatemalan highlands to the north. The volcano is within 5 to 10 kilometers (km) of Antigua, Guatemala and several other large towns situated on its northern apron. These towns have a combined population of nearly 100,000. It is within about 20 km of Escuintla (population, ca. 100,000) to the south. Though the volcano has not been active in historical time, or about the last 500 years, it has the potential to produce debris flows (watery flows of mud, rock, and debris—also known as lahars when they occur on a volcano) that could inundate these nearby populated areas.

  7. Food appearances in children's television programmes in Iceland.

    Science.gov (United States)

    Olafsdottir, Steingerdur; Berg, Christina

    2017-11-01

    Exposure to advertisements cannot fully explain the associations between young children's dietary intake and the time they spend in front of the television. It is therefore of importance to study television content other than advertisements in this aspect. The present study aimed to examine the nature and extent of verbal and visual appearances of foods and beverages in children's television programmes on Icelandic public service television. A total of 27 h of children's programmes (domestic and internationally produced) were watched. All verbal and visual appearances of foods and beverages were coded, as well as the context in which the foods/beverages were discussed or appeared. Children's programmes on Icelandic public service television. Two food groups were of special interest for their importance from a public health perspective: high-calorie and low-nutrient (HCLN) foods and fruits and vegetables (F&V). The χ 2 test and logistic regression were performed to analyse if the occurrence of the two groups was associated with the context where foods/beverages appeared. Of the 125 different programmes, a food or beverage appeared in 86 %. Of the total food appearances (n 599), HCLN foods accounted for 26 % and F&V for 23 %. HCLN foods were presented as desirable by appearing more frequently with child characters (Pfood and eating is presented in children's programmes, as young childhood is a critical period for founding healthy habits for later life.

  8. Changes in groundwater chemistry before two consecutive earthquakes in Iceland

    KAUST Repository

    Skelton, Alasdair

    2014-09-21

    Groundwater chemistry has been observed to change before earthquakes and is proposed as a precursor signal. Such changes include variations in radon count rates1, 2, concentrations of dissolved elements3, 4, 5 and stable isotope ratios4, 5. Changes in seismic wave velocities6, water levels in boreholes7, micro-seismicity8 and shear wave splitting9 are also thought to precede earthquakes. Precursor activity has been attributed to expansion of rock volume7, 10, 11. However, most studies of precursory phenomena lack sufficient data to rule out other explanations unrelated to earthquakes12. For example, reproducibility of a precursor signal has seldom been shown and few precursors have been evaluated statistically. Here we analyse the stable isotope ratios and dissolved element concentrations of groundwater taken from a borehole in northern Iceland between 2008 and 2013. We find that the chemistry of the groundwater changed four to six months before two greater than magnitude 5 earthquakes that occurred in October 2012 and April 2013. Statistical analyses indicate that the changes in groundwater chemistry were associated with the earthquakes. We suggest that the changes were caused by crustal dilation associated with stress build-up before each earthquake, which caused different groundwater components to mix. Although the changes we detect are specific for the site in Iceland, we infer that similar processes may be active elsewhere, and that groundwater chemistry is a promising target for future studies on the predictability of earthquakes.

  9. Icelandic media firms viewed from the perspective of agency theory

    Directory of Open Access Journals (Sweden)

    Guðbjörg Hildur Kolbeins

    2015-06-01

    Full Text Available It has previously been proposed that agency theory (principal-agent approach might be applied to media organizations to understand how media owners make sure that their companies are managed according to their wishes. Thus, the purpose of the present study was to investigate: a whether agency theory is applicable to three Icelandic media companies, and b how the theory manifests itself in the management practices of these companies. The media companies that were examined were: the Icelandic National Broadcasting Service (RÚV ohf., 365 miðlar ehf. and Árvakur hf. Qualitative interviews were conducted with three editors-in-chief, two CEOs/publishers, the director general of RÚV and the news director of RÚV in May of 2012. Two of the interviewees were also part- owners of the media companies. The results indicated that it is, indeed, possible to analyze management practices of media organizations from the perspective of agency theory. However, it varies how much the companies are driven by profit maximization, for instance – on which agency theory places an optimum emphasis. The media house 365 miðlar ehf. turned out to be the best example of how the underlying constructs of agency theory are incorporated into the management practices of a media organization.

  10. Over-the-counter codeine use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, A B; Grimsson, A

    2000-01-01

    BACKGROUND: The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine. METHODS: Based on this assumption we built and tested a model using an interru......BACKGROUND: The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine. METHODS: Based on this assumption we built and tested a model using...... an interrupted time series design that contrasts the monthly sales data for over-the-counter pain relievers containing codeine before and after the legislation took effect. RESULTS: The total use of over-the-counter pain relievers containing codeine as well as those containing paracetamol and codeine has risen...... leads to irrational use of over-the-counter medicines is not substantiated in the case of over-the-counter pain relievers containing codeine....

  11. Changes in groundwater chemistry before two consecutive earthquakes in Iceland

    KAUST Repository

    Skelton, Alasdair; André n, Margareta; Kristmannsdó ttir, Hrefna; Stockmann, Gabrielle; Mö rth, Carl-Magnus; Sveinbjö rnsdó ttir, Á rny; Jonsson, Sigurjon; Sturkell, Erik; Guð rú nardó ttir, Helga Rakel; Hjartarson, Hreinn; Siegmund, Heike; Kockum, Ingrid

    2014-01-01

    Groundwater chemistry has been observed to change before earthquakes and is proposed as a precursor signal. Such changes include variations in radon count rates1, 2, concentrations of dissolved elements3, 4, 5 and stable isotope ratios4, 5. Changes in seismic wave velocities6, water levels in boreholes7, micro-seismicity8 and shear wave splitting9 are also thought to precede earthquakes. Precursor activity has been attributed to expansion of rock volume7, 10, 11. However, most studies of precursory phenomena lack sufficient data to rule out other explanations unrelated to earthquakes12. For example, reproducibility of a precursor signal has seldom been shown and few precursors have been evaluated statistically. Here we analyse the stable isotope ratios and dissolved element concentrations of groundwater taken from a borehole in northern Iceland between 2008 and 2013. We find that the chemistry of the groundwater changed four to six months before two greater than magnitude 5 earthquakes that occurred in October 2012 and April 2013. Statistical analyses indicate that the changes in groundwater chemistry were associated with the earthquakes. We suggest that the changes were caused by crustal dilation associated with stress build-up before each earthquake, which caused different groundwater components to mix. Although the changes we detect are specific for the site in Iceland, we infer that similar processes may be active elsewhere, and that groundwater chemistry is a promising target for future studies on the predictability of earthquakes.

  12. Geodetic Measurements and Numerical Models of Rifting in Northern Iceland for 1993-1999

    Science.gov (United States)

    Ali, T.; Feigl, K.; Masterlark, T.; Carr, B. B.; Sigmundsson, F.; Thurber, C. H.

    2009-12-01

    Rifting occurs as episodes of active deformation in individual rift segments of the Northern Volcanic Zone (NVZ) of Iceland. To measure the deformation, we use interferometric analysis of synthetic aperture radar (InSAR) data acquired between 1993 and 1999. Preliminary results suggest that a complex interplay of multiple inflating and deflating sources at depth is required to account for the observed deformation. In an effort to integrate heterogeneous constraining information (kinematic plate spreading, seismic tomography and anisotropy, and thermal and rheologic structures), we develop finite element models that simulate the underlying sources and processes associated with rifting events to quantitatively understand the magmatic plumbing system beneath Krafla central volcano and rift segment, the site of the most recent rifting episode in the NVZ. Calibration parameters include the positions, geometries, and flux rates for elements of the plumbing system, as well as material properties. The General Inversion for Phase Technique (GIPhT) [Feigl and Thurber, Geophys. J. Int., 2009] is used to model the InSAR phase data directly, without unwrapping parameters. It operates on wrapped phase values ranging from -1/2 to +1/2 cycles. By defining a cost function that quantifies the misfit between observed and modeled values in terms of wrapped phase, GIPhT can estimate parameters in a geophysical model by minimizing the cost function. Since this approach can handle noisy, wrapped phase data, it avoids the pitfalls of phase-unwrapping approaches. Consequently, GIPhT allows the analysis, interpretation and modeling of more interferometric pairs than approaches that require unwrapping. GIPhT also allows statistical testing of hypotheses because the wrapped phase residuals follow a Von Mises distribution. As a result, the model parameters estimated by GIPhT include formal uncertainties. We test the hypothesis that deformation in the rift zone occurred at a constant (secular

  13. The Tephra Layer From the Plinian Eruption in ™r‘faj”kull 1362, Southeast Iceland

    Science.gov (United States)

    Selbekk, R. S.

    2002-12-01

    Pyroclastic fallout from the 1362 eruption of ™r‘faj”kull forms one of the volcanic marker horizons of the North Atlantic. This contribution reports the mineralogical and geochemical characteristics of the ™r‘faj”kull 1362 fallout and its grain-size distribution. A non-rifting 120 km long volcanic lineament some 50 km east of the Eastern Rift-Zone of Iceland is defined by transitional and alkalic volcanic rocks resting unconformably on late Tertiary strata. ™r‘faj”kull which forms the southern termination of this off-rift liniment is an ice-covered stratovolcano (2200 masl) composed mostly of subglacially formed hyaloclastite ranging from basalts to rhyolites. The two historical (1100 yrs) eruptions of ™r‘faj”kull include a small explosive eruption in 1727 and a large devastating Plinian eruption associated with major lahars and a caldera collapse in 1362. Between 1 and 2 km3 dense rock equivalent or 5-10 km3 of rhyolitic pumice was erupted and the fallout was mainly towards ESE. Tentative modelling of the PT-conditions of the magma formation, based on glass/mineral equilibria, indicates that the source was a near-eutectic melt in equilibrium with fayalite, hedenbergite, oligoclase and hematite at some 0.2 GPa pressure. A profile through the fallout was sampled at elevation of about 1100 masl on the SE flank of the volcano. A deposit of 1.8 m thickness was collected in 14 units for examination of composition, mineralogy and grain-size distribution during the eruption. In the profile the fallout is fine grained vesicular glass (1-3% minerals, 3% lithic fragments) with bubble wall thickness in the low micron range. The high and even vesiculation of the glass indicates fast magma ascent and explains the extreme mechanical fragmentation within the eruptive column, yielding between 50 and 80 wt% of less than 0.25 mm grain size. A reconstruction of the Plinian phase, based on grain-size analysis and abundance of lithic fragments, reveals that the

  14. Controlling factors on earthquake swarms associated with magmatic intrusions; constraints from Iceland

    Science.gov (United States)

    Pedersen, R.; Sigmundsson, F.; Einarsson, P.; Brandsdottir, B.; Arnadottir, T.

    2005-12-01

    Intrusion of magma into the Earth's crust is frequently associated with seismic activity, often occurring as distinct earthquake swarms. Understanding the nature of these swarms is important for evaluating crisis situations in volcanic areas. However, there often seem to be little correlation between the amount of seismic energy release, the spatial extent of the volume of rock affected by the stress perturbations, and the volume of magma on the move, which complicates the immediate risk evaluation. A number of factors may influence the evolution of a magmatically induced seismic swarm and the resulting seismic energy release. A number of factors need to be evaluated in each individual case. These are, in random order: the crustal thickness, presence/absence of a crustal magma chamber, geothermal gradient, magmatic flow rate/stressing rate, intrusion volume, depth of intrusion, tectonic setting of the intruded area, regional stresses and tectonic history. Based on three case studies, where seismic swarm activities have been confirmed through deformation measurements to be related to magmatic movements, we attempt to evaluate the relative importance of the assumed controlling factors. All case examples are located within Iceland, but in different tectonic settings. 1. The Hengill triple junction, situated where two extensional plate boundaries join a transform zone. The area experienced a period of unusually persistent earthquake activity from 1994 to 1999, contemporaneously with ground uplift at a rate of 1-2 cm/yr. The uplift was modeled as a response to magma injection at about 7 km depth. 2. The Eyjafjallajokull volcano, situated in a volcanic flank zone where extensional fractures are only poorly developed. Two minor seismic swarms, in 1994 and 1999; were associated with a cumulative surface uplift of more than 35 cm. The two uplift events were modeled as sill intrusions at depths of 4.5 to 6.5 km. 3. The Krafla rift segment, forming part of an extensional

  15. Present kinematics of the Tjornes Fracture Zone, North Iceland, from campaign and continuous GPS measurements

    KAUST Repository

    Metzger, S.

    2012-11-19

    The Tjörnes Fracture Zone (TFZ), North Iceland, is a 120 km transform offset of the Mid-Atlantic-Ridge that accommodates 18 mm yr−1 plate motion on two parallel transform structures and connects the offshore Kolbeinsey Ridge in the north to the on-shore Northern Volcanic Zone (NVZ) in the south. This transform zone is offshore except for a part of the right-lateral strike-slip Húsavík-Flatey fault (HFF) system that lies close to the coastal town of Húsavík, inducing a significant seismic risk to its inhabitants. In our previous work we constrained the locking depth and slip-rate of the HFF using 4 yr of continuous GPS measurements and found that the accumulated slip-deficit on the fault is equivalent to a Mw6.8 ± 0.1 earthquake, assuming a complete stress release in the last major earthquakes in 1872 and a steady accumulation since then. In this paper we improve our previous analysis by adding 44 campaign GPS (EGPS) data points, which have been regularly observed since 1997. We extract the steady-state interseismic velocities within the TFZ by correcting the GPS data for volcanic inflation of Theistareykir—the westernmost volcano of the NVZ—using a model with a magma volume increase of 25 × 106 m3, constrained by InSAR time-series analysis results. The improved velocity field based on 58 GPS stations confirms the robustness of our previous model and allows to better constrain the free model parameters. For the HFF we find a slightly shallower locking depth of ∼6.2 km and a slightly higher slip-rate of ∼6.8 mm yr−1 that again result in the same seismic potential equivalent to a Mw6.8 earthquake. The much larger number of GPS velocities improves the statistically estimated model parameter uncertainties by a factor of two, when compared to our previous study, a result that we validate using Bayesian estimation.

  16. Intercomparison of Metop-A SO2 measure- ments during the 2010- 2011 Icelandic eruptions

    Directory of Open Access Journals (Sweden)

    Maria Elissavet Koukouli

    2015-03-01

    Full Text Available The European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Avi­ ation Hazards, was introduced after the eruption of the Icelandic volcano Eyjafjallajökull in the spring of 2010 to facilitate the development of an optimal End­to­End System for Volcanic Ash Plume Monitoring and Predic­ tion. The Eyjafjallajökull plume drifted towards Europe and caused major disruptions of European air traffic for several weeks affecting the everyday life of millions of people. The limitations in volcanic plume monitoring and prediction capabilities gave birth to this observational system which is based on comprehensive satellite­derived ash plume and sulphur dioxide [SO2] level estimates, as well as a widespread validation using supplementary satellite, aircraft and ground­based measurements. Inter­comparison of the volcanic total SO2 column and plume height observed by GOME­2/Metop­A and IASI/Metop­A are shown before, during and after the Eyjaf­ jallajökull 2010 eruptions as well as for the 2011 Grímsvötn eruption. Co­located ground­based Brewer Spectro­ photometer data extracted from the World Ozone and Ultraviolet Radiation Data Centre for de Bilt, the Nether­ lands, are also compared to the different satellite estimates. Promising agreement is found for the two different types of instrument for the SO2 columns with linear regression coefficients ranging around from 0.64 when comparing the different instruments and 0.85 when comparing the two different IASI algorithms. The agree­ ment for the plume height is lower, possibly due to the major differences between the height retrieval part of the GOME2 and IASI algorithms. The comparisons with the Brewer ground­based station in de Bilt, The Nether­ lands show good qualitative agreement for the peak of the event however stronger eruptive signals are required for a longer quantitative comparison. 

  17. Effects of Accelerated Deglaciation on Chemical Characteristics of Sub-arctic Lakes and Rivers in South and West Iceland

    Science.gov (United States)

    Ritter, M.; Strock, K.; Edwards, B. R.

    2017-12-01

    Glaciers and their associated paraglacial landscapes have changed rapidly over the past century, and may see increased rates of melt as temperatures increase in high latitude environments. As glaciers recede, glacial meltwater subsidies increase to inland freshwater systems, influencing their structure and function. Evidence suggests melting ice influences the chemical characteristics of systems by providing nutrient subsidies, while inputs of glacial flour influence their physical structure by affecting temperature, reducing water clarity and increasing turbidity. Together, changes in physical and chemical structure of these systems have subsequent effects on biota, with the potential to lower taxonomic richness. This study characterized the chemistry of rivers and lakes fed by glacial meltwater in sub-arctic environments of Iceland, where there is limited limnological data. The survey characterized nutrient chemistry, dissolved organic carbon, and ion chemistry. We surveyed glacial meltwater from six glaciers in south and west Iceland, using the drainage basin of Gigjökull glacier along the southern coast as a detailed study area to examine the interactions between groundwater and surface runoff. The southern systems, within the Eastern Volcanic Zone, have minimal soil development and active volcanoes produce ash input to lakes. Lakes in the Western Volcanic Zone were more diverse, located in older bedrock with more extensively weathered soil. Key differences were observed between aquatic environments subsidized with glacial meltwater and those without. This included physical effects, such as lower temperatures and chemical effects such as lower conductivity and higher pH in glacially fed systems. In the drainage basin of Gigjökull glacier, lakes formed after the former lagoon was emptied and then partly refilled with debris from jokulhlaups during the 2010 Eyjafjallajökull eruption. These newly formed lakes resembled non-glacial melt systems despite receiving

  18. The Role of Business Schools in Ethics Education in Iceland

    DEFF Research Database (Denmark)

    Sigurjonsson, Throstur Olaf; Vaiman, Vlad; Arnardottir, Audur Arna

    2014-01-01

    should not be held responsible for employees’ unethical behavior. Nevertheless, managers believe that business schools should assist future employees in understanding ethics by including business ethics in teaching curricula. Second, managers believe that the workplace is not where ethics are learned......This article explores managers’ views on various ways in which business schools can contribute to providing solid ethics education to their students, who will ultimately become the next generation of business leaders. One thousand top level managers of Icelandic firms were approached and asked......, while also insisting that former students should already have strong ethical standards when entering the workplace. Third, managers call for business schools not only to contribute more to influencing students’ ethical standards, but also to reshape the knowledge and capabilities of practicing managers...

  19. Effects of handling on fear reactions in young Icelandic horses

    DEFF Research Database (Denmark)

    Marsbøll, Anna Feldberg; Christensen, Janne Winther

    2015-01-01

    To investigate the effect of a short-term standardised handling procedure on reactions of young horses in 2 types of fear tests (including and excluding human handling). Study design An experimental study with 3-year-old Icelandic horses (n = 24). Methods Handled horses (n = 12) were trained according...... to a standardised handling procedure whereas controls (n = 12) remained untrained. Behavioural and heart rate responses in a novel object test and 2 handling fear tests (HFTs) were measured. The HFTs were conducted with both an unknown (HFT-unknown) and a known handler (HFT-known). Results There was no effect...... correlated significantly between tests. Conclusions Previous handling may affect the behavioural fear response of horses when handled by their usual handler, whereas this effect did not apply to an unknown handler. Heart rates appeared unaffected by handling and may be a more reliable indicator...

  20. Inflection of modern Icelandic nouns, adjectives and adverbs

    Directory of Open Access Journals (Sweden)

    Janez Orešnik

    1976-12-01

    Full Text Available The present paper is a list of Modern Icelandic nouns, adjectives, and adverbs, analysed into their respective stems and endings; the declension of the suffixed definite article is also included. Under each item it is stated which rules, if any, apply in the derivation of its grammatical forms. The following items of the list should be consulted for new phonological rules: (3, (11, (12, and (133. A grammatical innovation has been implemented in the list, namely the so-called REPLACING ENDINGS. These are not added after the last segment of the stem, as endings usually are, but replace the last segment(s of the stem. More is said on replacing endings in the Introduction.

  1. Fractionation of boron isotopes in Icelandic hydrothermal systems

    International Nuclear Information System (INIS)

    Aggarwal, J.K.

    1995-01-01

    Boron isotope ratios have been determined in a variety of different geothermal waters from hydrothermal systems across Iceland. Isotope ratios from the high temperature meteoric water recharged systems reflect the isotope ratio of the host rocks without any apparent fractionation. Seawater recharged geothermal systems exhibit more positive δ 1 1B values than the meteoric water recharged geothermal systems. Water/rock ratios can be assessed from boron isotope ratios in the saline hydrothermal systems. Low temperature hydrothermal systems also exhibit more positive δ 1 1B than the high temperature systems, indicating fractionation of boron due to absorption of the lighter isotope onto secondary minerals. Fractionation of boron in carbonate deposits may indicate the level of equilibrium attained within the systems. (author). 14 refs., 2 figs

  2. A Saga for Dinner: Landscape and Nationality in Icelandic Literature

    Directory of Open Access Journals (Sweden)

    Reinhard Hennig

    2011-01-01

    Full Text Available Iceland’s attempted industrialisation through an expansion of hydropower andaluminium smelters can lead to a significant reshaping of the country’slandscapes. There has been considerable resistance against such plans since the1970s, culminating in the debate about the Kárahnjúkar project between 2001and 2006. The book Draumalandið. Sjálfshjálparbók handa hræddri þjóð[Dreamland. A Self-Help Manual for a Frightened Nation] by the writer AndriSnær Magnason has been particularly influential. It combines ecologicalconsciousness with an appreciation of Iceland‘s literary tradition and history.Thus it displays a view of landscape which connects nature preservation closelyto cultural achievements and to national sovereignty. This perception oflandscape originates from the assumption that Iceland experienced a golden agefrom the beginning of colonisation in the Viking age until the subordinationunder the Norwegian and later Danish kings in the 13th century, which led to anall-embracing degeneration. Nationalist poets such as Jónas Hallgrímsson inthe 19th century based their demands for independence on Iceland‘s medievalsaga literature and the country‘s landscapes. These seemed to provide evidencefor a high culture in unity with nature during the time of the Commonwealth.Although the historical reliability of the sagas is doubtful, they are still used asan important argument in Draumalandið. Now the narratives as such are put inthe foreground, as they can give value and meaning to the landscapes and placesthey describe. Thus a turn from a realistic to a more constructivist perception oflandscape can be observed in contemporary Icelandic environmental literature.

  3. Effects of Volcanoes on the Natural Environment

    Science.gov (United States)

    Mouginis-Mark, Peter J.

    2005-01-01

    The primary focus of this project has been on the development of techniques to study the thermal and gas output of volcanoes, and to explore our options for the collection of vegetation and soil data to enable us to assess the impact of this volcanic activity on the environment. We originally selected several volcanoes that have persistent gas emissions and/or magma production. The investigation took an integrated look at the environmental effects of a volcano. Through their persistent activity, basaltic volcanoes such as Kilauea (Hawaii) and Masaya (Nicaragua) contribute significant amounts of sulfur dioxide and other gases to the lower atmosphere. Although primarily local rather than regional in its impact, the continuous nature of these eruptions means that they can have a major impact on the troposphere for years to decades. Since mid-1986, Kilauea has emitted about 2,000 tonnes of sulfur dioxide per day, while between 1995 and 2000 Masaya has emotted about 1,000 to 1,500 tonnes per day (Duffel1 et al., 2001; Delmelle et al., 2002; Sutton and Elias, 2002). These emissions have a significant effect on the local environment. The volcanic smog ("vog" ) that is produced affects the health of local residents, impacts the local ecology via acid rain deposition and the generation of acidic soils, and is a concern to local air traffic due to reduced visibility. Much of the work that was conducted under this NASA project was focused on the development of field validation techniques of volcano degassing and thermal output that could then be correlated with satellite observations. In this way, we strove to develop methods by which not only our study volcanoes, but also volcanoes in general worldwide (Wright and Flynn, 2004; Wright et al., 2004). Thus volcanoes could be routinely monitored for their effects on the environment. The selected volcanoes were: Kilauea (Hawaii; 19.425 N, 155.292 W); Masaya (Nicaragua; 11.984 N, 86.161 W); and Pods (Costa Rica; 10.2OoN, 84.233 W).

  4. Climate-driven vertical acceleration of Icelandic crust measured by continuous GPS geodesy

    KAUST Repository

    Compton, Kathleen; Bennett, Richard A.; Hreinsdó ttir, Sigrú n

    2015-01-01

    © 2015 The Authors. Earth's present-day response to enhanced glacial melting resulting from climate change can be measured using Global Positioning System (GPS) technology. We present data from 62 continuously operating GPS instruments in Iceland. Statistically significant upward velocity and accelerations are recorded at 27 GPS stations, predominantly located in the Central Highlands region of Iceland, where present-day thinning of the Iceland ice caps results in velocities of more than 30mm/yr and uplift accelerations of 1-2mm/yr2. We use our acceleration estimates to back calculate to a time of zero velocity, which coincides with the initiation of ice loss in Iceland from ice mass balance calculations and Arctic warming trends. We show, through a simple inversion, a direct relationship between ice mass balance measurements and vertical position and show that accelerated unloading is required to reproduce uplift observations for a simple elastic layer over viscoelastic half-space model.

  5. Acetylcholinesterase inhibitory activity of lycopodane-type alkaloids from the Icelandic Lycopodium annotinum ssp. alpestre

    DEFF Research Database (Denmark)

    Halldórsdóttir, Elsa Steinunn; Jaroszewski, Jerzy W; Olafsdottir, Elin Soffia

    2010-01-01

    The aim of this study was to investigate structures and acetylcholinesterase inhibitory activities of lycopodane-type alkaloids isolated from an Icelandic collection of Lycopodium annotinum ssp. alpestre. Ten alkaloids were isolated, including annotinine, annotine, lycodoline, lycoposerramine M...

  6. Volcanoes in the Classroom--an Explosive Learning Experience.

    Science.gov (United States)

    Thompson, Susan A.; Thompson, Keith S.

    1996-01-01

    Presents a unit on volcanoes for third- and fourth-grade students. Includes demonstrations; video presentations; building a volcano model; and inviting a scientist, preferably a vulcanologist, to share his or her expertise with students. (JRH)

  7. Volcanostratigraphic Approach for Evaluation of Geothermal Potential in Galunggung Volcano

    Science.gov (United States)

    Ramadhan, Q. S.; Sianipar, J. Y.; Pratopo, A. K.

    2016-09-01

    he geothermal systems in Indonesia are primarily associated with volcanoes. There are over 100 volcanoes located on Sumatra, Java, and in the eastern part of Indonesia. Volcanostratigraphy is one of the methods that is used in the early stage for the exploration of volcanic geothermal system to identify the characteristics of the volcano. The stratigraphy of Galunggung Volcano is identified based on 1:100.000 scale topographic map of Tasikmalaya sheet, 1:50.000 scale topographic map and also geological map. The schematic flowchart for evaluation of geothermal exploration is used to interpret and evaluate geothermal potential in volcanic regions. Volcanostratigraphy study has been done on Galunggung Volcano and Talaga Bodas Volcano, West Java, Indonesia. Based on the interpretation of topographic map and analysis of the dimension, rock composition, age and stress regime, we conclude that both Galunggung Volcano and Talaga Bodas Volcano have a geothermal resource potential that deserve further investigation.

  8. Guðrún Johnsen: Bringing Down the Banking System: Lessons from Iceland

    Directory of Open Access Journals (Sweden)

    Maximilian Conrad

    2014-12-01

    Full Text Available Considering the myths that have been spun not only on the causes of the crisis, but maybe more importantly on the democratic awakening in Icelandic society in the aftermath, it is evident that a much broader audience – especially outside Iceland – should have a keen interest in understanding the political and societal climate that facilitated the emergence of the phenomenon that has also been termed "Viking Capitalism".

  9. The association between lifting an administrative restriction on antidepressant dispensing and treatment patterns in Iceland

    DEFF Research Database (Denmark)

    Thengilsdottir, G; Gardarsdottir, H; Almarsdóttir, Anna Birna

    2013-01-01

    On March 1st 2009, restrictions on the dispensing of selective serotonin reuptake inhibitors (SSRI) in Iceland were lifted. Incident rates and changes in early discontinuation and switching before and after the change were investigated.......On March 1st 2009, restrictions on the dispensing of selective serotonin reuptake inhibitors (SSRI) in Iceland were lifted. Incident rates and changes in early discontinuation and switching before and after the change were investigated....

  10. Deformation derived from GPS geodesy associated with Bárðarbunga 2014 rifting event in Iceland

    KAUST Repository

    Ofeigsson, Benedikt Gunnar; Hreinsdó ttir, Sigrú n; Sigmundsson, Freysteinn; Frið riksdó ttir, Hildur; Parks, Michelle; Dumont, Stephanie; Á rnadó ttir, Þ ó ra; Geirsson, Halldó r; Hooper, Andrew; Roberts, Matthew; Bennett, Rick; Sturkell, Erik; Jó nsson, Sigurjó n|

    2015-01-01

    On August 16, 2014 an intense seismic swarm started below the eastern part of Bárðarbunga Caldera in the north-western corner of Vatnajökull ice-cap, Iceland, marking the onset of the first rifting event in Iceland since the Krafla fires (1975-1984). The migration of the seismicity was corroborated by ground deformation in areas outside the ice cap and on nunataks within the ice cap suggesting a lateral propagation of magma, from the Bárðabunga system. The sesimicity migrated out of the caldera forming a dyke with roughly three segments, changing direction each time until August 28 when the migration stopped around 10 km south of Askja Volcano, eventually leading to a short lived eruption in Holuhraun north of Dyngjujökull. A second fissure eruption started in Holuhraun on August 31 which is still ongoing at the time of this writing. In the months prior to the onset of the activity, subtle signs of inflation where observed on continuous GPS sites around the Bárðarbunga indicating a volume increase in the roots of the volcanic system. When the activity started on August 16, the deformation pattern indicated a simultaneous deflation centered within the caldera and a lateral growth of a dyke also reflected in the migration of seismicity along segments of variable strike. A maximum widening of 1.3 m occurred between stations on opposite sides of the dyke spaced 25 km apart. Significant movements where detected on GPS site more then 80 km away from the tip of dyke. Displacements indicated the fastest rate of widening at any time in the most distal segment of the dyke throughout its evolution. After the dyke stopped propagating, the inflation continued, decaying exponentialy with time. On September 4, five days into the second fissure eruption, the movements associated with the dyke where no longer significant. As the fissure eruption continues, a slowly decaying contraction is observed around the Bárðarbunga central volcano, both shown in the piston like

  11. Deformation derived from GPS geodesy associated with Bárðarbunga 2014 rifting event in Iceland

    KAUST Repository

    Ofeigsson, Benedikt Gunnar

    2015-04-01

    On August 16, 2014 an intense seismic swarm started below the eastern part of Bárðarbunga Caldera in the north-western corner of Vatnajökull ice-cap, Iceland, marking the onset of the first rifting event in Iceland since the Krafla fires (1975-1984). The migration of the seismicity was corroborated by ground deformation in areas outside the ice cap and on nunataks within the ice cap suggesting a lateral propagation of magma, from the Bárðabunga system. The sesimicity migrated out of the caldera forming a dyke with roughly three segments, changing direction each time until August 28 when the migration stopped around 10 km south of Askja Volcano, eventually leading to a short lived eruption in Holuhraun north of Dyngjujökull. A second fissure eruption started in Holuhraun on August 31 which is still ongoing at the time of this writing. In the months prior to the onset of the activity, subtle signs of inflation where observed on continuous GPS sites around the Bárðarbunga indicating a volume increase in the roots of the volcanic system. When the activity started on August 16, the deformation pattern indicated a simultaneous deflation centered within the caldera and a lateral growth of a dyke also reflected in the migration of seismicity along segments of variable strike. A maximum widening of 1.3 m occurred between stations on opposite sides of the dyke spaced 25 km apart. Significant movements where detected on GPS site more then 80 km away from the tip of dyke. Displacements indicated the fastest rate of widening at any time in the most distal segment of the dyke throughout its evolution. After the dyke stopped propagating, the inflation continued, decaying exponentialy with time. On September 4, five days into the second fissure eruption, the movements associated with the dyke where no longer significant. As the fissure eruption continues, a slowly decaying contraction is observed around the Bárðarbunga central volcano, both shown in the piston like

  12. Volcano Trial Case on GEP: Systematically processing EO data

    OpenAIRE

    Baumann, Andreas Bruno Graziano

    2017-01-01

    Volcanoes can be found all over the world; on land and below water surface. Even nowadays not all volcanoes are known. About 600 erupted in geologically recent times and about 50-70 volcanoes are currently active. Volcanoes can cause earthquakes; throw out blasts and tephras; release (toxic) gases; lava can flow relatively slow down the slopes; mass movements like debris avalanches, and landslides can cause tsunamis; and fast and hot pyroclastic surge, flows, and lahars can travel fast down ...

  13. Photosynthesis within Mars' volcanic craters?: Insights from Cerro Negro Volcano, Nicaragua

    Science.gov (United States)

    Rogers, K. L.; Hynek, B. M.; McCollom, T. M.

    2011-12-01

    Discrete locales of sulfate-rich bedrocks exist on Mars and in many cases represent the products of acid-sulfate alteration of martian basalt. In some places, the products have been attributed to hydrothermal processes from local volcanism. In order to evaluate the habitability of such an environment, we are investigating the geochemical and biological composition of active fumaroles at Cerro Negro Volcano, Nicaragua, where fresh basaltic cinders similar in composition to martian basalts are altered by acidic, sulfur-bearing gases. Temperatures at active fumaroles can reach as high as 400°C and the pH of the steam ranges from Cyanobacteria and Ktedonobacteria, however Actinobacteria, alpha-Proteobacteria and Acidobacteria were also identified. Many of the cyanobacterial sequences were similar to those of the eukaryotic Cyanidiales, red algae that inhabit acidic, geothermal environments. Many of sequences related to Ktedonobacteria and Actinobacteria have also been found in acid mine drainage environments. The Archaeal community was far less diverse, with sequences matching those of unclassified Desulfurococcales and unclassified Thermoprotei. These sequences were more distant from isolated species than the bacterial sequences. Similar bacterial and archaeal communities have been found in hot spring environments in Yellowstone National Park, Greenland, Iceland, New Zealand and Costa Rica. Some of Mars' volcanoes were active for billions of years and by analogy to Cerro Negro, may have hosted photosynthetic organisms that could have been preserved in alteration mineral assemblages. Even on a generally cold and dry Mars, volcanic craters likely provided long-lived warm and wet conditions and should be a key target for future exploration assessing habitability.

  14. Drilling Magma for Science, Volcano Monitoring, and Energy

    Science.gov (United States)

    Eichelberger, J. C.; Lavallée, Y.; Blankenship, D.

    2017-12-01

    Magma chambers are central to understanding magma evolution, formation of continental crust, volcanism, and renewal of hydrothermal systems. Information from geology, petrology, laboratory experiments, and geophysical imagery has led to little consensus except a trend to see magma systems as being crystal-dominant (mush) rather than melt dominant. At high melt viscosities, crystal-liquid fractionation may be achieved by separation of melt from mush rather than crystals from liquid suspension. That the dominant volume has properties more akin to solid than liquid might explain the difficulty in detecting magma geophysically. Recently, geothermal drilling has intersected silicic magma at the following depths and SiO2 contents are: Puna, Hawaii, 2.5 km, 67 wt%; Menengai, Kenya 2.1 km, 67 wt%; Krafla, Iceland, 2.1 km, 75 wt%. Some similarities are: 1) Drillers encountered a "soft", sticky formation; 2) Cuttings or chips of clear quenched glass were recovered; 3) The source of the glass flowed up the well; 4) Transition from solid rock to recovering crystal-poor glass occurred in tens of meters, apparently without an intervening mush zone. Near-liquidus magma at the roof despite rapid heat loss there presents a paradox that may be explained by very recent intrusion of magma, rise of liquidus magma to the roof replacing partially crystallized magma, or extremely skewed representation of melt over mush in cuttings (Carrigan et al, this session). The latter is known to occur by filter pressing of ooze into lava lake coreholes (Helz, this session), but cannot be verified in actual magma without coring. Coring to reveal gradients in phase composition and proportions is required for testing any magma chamber model. Success in drilling into and controlling magma at all three locations, in coring lava lakes to over 1100 C, and in numerical modeling of coring at Krafla conditions (Su, this session) show this to be feasible. Other unprecedented experiments are using the known

  15. Weathering The Storm – Icelandic Municipalities’ Handling of an Unprecedented Economic Crisis

    Directory of Open Access Journals (Sweden)

    Magnús Árni Skjöld MAGNÚSSON

    2016-04-01

    Full Text Available Within a few days in October 2008, following serious turmoil on financial markets worldwide, some 85% of the Icelandic banking sector collapsed, together with the Icelandic currency, the króna. Almost all the rest followed early in 2009. The Icelandic stock market took a nosedive. The Republic of Iceland had entered the worst economic crisis of its history. Icelandic municipalities, which had taken on an increasing burden of running the welfare state, were hard hit financially, without the ability of the state to help out. In fact, some of the post-crisis actions of the state, under IMF direction, were difficult for the municipalities. It did not make things easier that the crisis had been precluded by an unprecedented period of growth, encouraging the municipalities to borrow in international markets and invest in infrastructure that turned out to be superfluous in the post-crisis period. This paper will look at the reactions of the Icelandic municipalities to the crisis, the political implications of it, where they are now and if there are lessons that can be learned from the difficult years in the last decade.

  16. Fingerprinting North Atlantic water masses near Iceland using Nd-isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Norbert [Institut fuer Umweltphysik, INF229, Heidelberg (Germany); Waldner, Astrid [Paul Scherrer Institute, Villigen (Switzerland); Montagna, Paolo [CNR - ISMAR, Bologna (Italy); Colin, Christophe [IDES, Universite de Paris-Sud, Orsay (France); Wu, Qiong [State Key Laboratory, Tongji University, Shanghai (China)

    2015-07-01

    The radiogenic {sup 143}Nd/{sup 144}Nd ratio of seawater is a valuable tracer of north Atlantic circulation pathways, driven by continental runoff (freshwater and Aeolian dust), boundary exchange and advection and thus mixing patterns. A region of particular interest in the North Atlantic is the overflow across the Iceland-Scotland Ridge injecting water from the Arctic Ocean into the Iceland basin (Iceland Scotland Overflow Water). However, Iceland itself constitutes a local source for Nd due to possible leaching of young volcanic basalts adding radiogenic {sup 143}Nd/{sup 144}Nd to seawater. We have conducted an intense survey of physical properties and Nd-isotope composition between Iceland and the Azores that allows to fingerprint different water masses of the North Atlantic through the {sup 143}Nd/{sup 144}Nd ratio and that demonstrates the very local influence of volcanic material to the seawater Nd cycle. A first local transect is achieved from the open ocean to the outflow of the Vatnajoekull glacier. Runoff influences seawater Nd in close vicinity (< 40 km near the outflow). A along shelf transect provide a similar observation. From Iceland to the Azores, however, water masses of the sub-tropical and sub-polar gyre are clearly distinguishable.

  17. Do body weight and gender shape the work force? The case of Iceland.

    Science.gov (United States)

    Asgeirsdottir, Tinna Laufey

    2011-03-01

    Most studies of the relationship between body weight - as well as its corollary, beauty - and labor-market outcomes have indicated that it is a function of a gender bias, the negative relationship between excess weight or obesity and labor-market outcomes being greater for women than for men. Iceland offers an exceptional opportunity to examine this hypothesis, given that it scores relatively well on an index of gender equality comprising economic, political, educational, labor-market, and health-based criteria. Equipped with an advanced level of educational attainment, on average, women are well represented in Iceland's labor force. When it comes to women's presence in the political sphere, Iceland is out of the ordinary as well; that Icelanders were the first in the world to elect a woman to be president may suggest a relatively gender-blind assessment in the labor market. In the current study, survey data collected by Gallup Iceland in 2002 are used to examine the relationship between weight and employment within this political and social setting. Point estimates indicate that, despite apparently lesser gender discrimination in Iceland than elsewhere, the bias against excess weight and obesity remains gender-based, showing a slightly negative relationship between weight and the employment rate of women, whereas a slightly positive relationship was found for men. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Preferences, power and policy outcomes in public policy in Iceland: The Icelandic Housing Fund fiasco 2003-2005

    Directory of Open Access Journals (Sweden)

    Sigurbjörg Sigurgeirsdóttir

    2014-12-01

    Full Text Available This research focuses on the interplay of politics, bureaucracies and markets in Iceland. It aims to explain theoretically how politics and bureaucracies operate when a coalition government makes and implements decisions in a policy environment in which decisions and their effects intersect public bureaucracies’ and markets’ boundaries. The decision to raise the limits of Housing Fund mortgages in 2003 is a case examined by agenda-setting theories in public policy. The research is based on the data from parliamentary Special Investigation reports on the collapse of the Icelandic banks and the Housing Fund as well as the author’s interviews home and abroad. The research shows that, when made, the decision ignited competition between the Housing Fund and the recently privatized banks and that between the banks themselves. The Independence Party’s attempts to delay implementation of the decision involved system change backed by an instrument designed to stem a run on the Fund. The impact of this instrument (a tax on pre-payments was incompatible with the Progressive Party’s political interests. In a hasty attempt to implement its election promises, the Progressive Party ignored the fact that the Fund was operating within a transformed financial system. The conclusions indicate that those who think long-term in politics make policies by changing system dynamics, those who think short-term change programmes. System dynamics, however, change the balance of power and influence between actors, leaving legacies which curb the government’s attempt at change, unless consolidated and sustained political authority and will are established to see changes through.

  19. Volcano Geodesy: Recent developments and future challenges

    Science.gov (United States)

    Fernandez, Jose F.; Pepe, Antonio; Poland, Michael; Sigmundsson, Freysteinn

    2017-01-01

    Ascent of magma through Earth's crust is normally associated with, among other effects, ground deformation and gravity changes. Geodesy is thus a valuable tool for monitoring and hazards assessment during volcanic unrest, and it provides valuable data for exploring the geometry and volume of magma plumbing systems. Recent decades have seen an explosion in the quality and quantity of volcano geodetic data. New datasets (some made possible by regional and global scientific initiatives), as well as new analysis methods and modeling practices, have resulted in important changes to our understanding of the geodetic characteristics of active volcanism and magmatic processes, from the scale of individual eruptive vents to global compilations of volcano deformation. Here, we describe some of the recent developments in volcano geodesy, both in terms of data and interpretive tools, and discuss the role of international initiatives in meeting future challenges for the field.

  20. Soil radon response around an active volcano

    International Nuclear Information System (INIS)

    Segovia, N.; Valdes, C.; Pena, P.; Mena, M.; Tamez, E.

    2001-01-01

    Soil radon behavior related to the volcanic eruptive period 1997-1999 of Popocatepetl volcano has been studied as a function of the volcanic activity. Since the volcano is located 60 km from Mexico City, the risk associated with an explosive eruptive phase is high and an intense surveillance program has been implemented. Previous studies in this particular volcano showed soil radon pulses preceding the initial phase of the eruption. The radon survey was performed with LR-115 track detectors at a shallow depth and the effect of the soil moisture during the rainy season has been observed on the detectors response. In the present state of the volcanic activity the soil radon behavior has shown more stability than in previous eruptive stages

  1. Predicting the Timing and Location of the next Hawaiian Volcano

    Science.gov (United States)

    Russo, Joseph; Mattox, Stephen; Kildau, Nicole

    2010-01-01

    The wealth of geologic data on Hawaiian volcanoes makes them ideal for study by middle school students. In this paper the authors use existing data on the age and location of Hawaiian volcanoes to predict the location of the next Hawaiian volcano and when it will begin to grow on the floor of the Pacific Ocean. An inquiry-based lesson is also…

  2. Interdisciplinary studies of eruption at Chaiten Volcano, Chile

    Science.gov (United States)

    John S. Pallister; Jon J. Major; Thomas C. Pierson; Richard P. Hoblitt; Jacob B. Lowenstern; John C. Eichelberger; Lara. Luis; Hugo Moreno; Jorge Munoz; Jonathan M. Castro; Andres Iroume; Andrea Andreoli; Julia Jones; Fred Swanson; Charlie Crisafulli

    2010-01-01

    There was keen interest within the volcanology community when the first large eruption of high-silica rhyolite since that of Alaska's Novarupta volcano in 1912 began on 1 May 2008 at Chaiten volcano, southern Chile, a 3-kilometer-diameter caldera volcano with a prehistoric record of rhyolite eruptions. Vigorous explosions occurred through 8 May 2008, after which...

  3. How Do Volcanoes Affect Human Life? Integrated Unit.

    Science.gov (United States)

    Dayton, Rebecca; Edwards, Carrie; Sisler, Michelle

    This packet contains a unit on teaching about volcanoes. The following question is addressed: How do volcanoes affect human life? The unit covers approximately three weeks of instruction and strives to present volcanoes in an holistic form. The five subject areas of art, language arts, mathematics, science, and social studies are integrated into…

  4. Living with Volcanoes: Year Eleven Teaching Resource Unit.

    Science.gov (United States)

    Le Heron, Kiri; Andrews, Jill; Hooks, Stacey; Larnder, Michele; Le Heron, Richard

    2000-01-01

    Presents a unit on volcanoes and experiences with volcanoes that helps students develop geography skills. Focuses on four volcanoes: (1) Rangitoto Island; (2) Lake Pupuke; (3) Mount Smart; and (4) One Tree Hill. Includes an answer sheet and resources to use with the unit. (CMK)

  5. Volcanoes muon imaging using Cherenkov telescopes

    International Nuclear Information System (INIS)

    Catalano, O.; Del Santo, M.; Mineo, T.; Cusumano, G.; Maccarone, M.C.; Pareschi, G.

    2016-01-01

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  6. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Catalano, O. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Del Santo, M., E-mail: melania@ifc.inaf.it [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Mineo, T.; Cusumano, G.; Maccarone, M.C. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Pareschi, G. [INAF Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807, Merate (Italy)

    2016-01-21

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  7. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin

    2017-01-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  8. The origin of the Hawaiian Volcano Observatory

    International Nuclear Information System (INIS)

    Dvorak, John

    2011-01-01

    I first stepped through the doorway of the Hawaiian Volcano Observatory in 1976, and I was impressed by what I saw: A dozen people working out of a stone-and-metal building perched at the edge of a high cliff with a spectacular view of a vast volcanic plain. Their primary purpose was to monitor the island's two active volcanoes, Kilauea and Mauna Loa. I joined them, working for six weeks as a volunteer and then, years later, as a staff scientist. That gave me several chances to ask how the observatory had started.

  9. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael P.; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Ben

    2017-08-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  10. Volcanology and volcano sedimentology of Sahand region

    International Nuclear Information System (INIS)

    Moine Vaziri, H.; Amine Sobhani, E.

    1977-01-01

    There was no volcano in Precambrian and Mesozoic eras in Iran, but in most place of Iran during the next eras volcanic rocks with green series and Dacites were seen. By the recent survey in Sahand mountain in NW of Iran volcanography, determination of rocks and the age of layers were estimated. The deposits of Precambrian as sediment rocks are also seen in the same area. All of volcanic periods in this place were studied; their extrusive rocks, their petrography and the result of their analytical chemistry were discussed. Finally volcano sedimentology of Sahand mountain were described

  11. The origin of the Hawaiian Volcano Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dvorak, John [University of Hawaii' s Institute for Astronomy (United States)

    2011-05-15

    I first stepped through the doorway of the Hawaiian Volcano Observatory in 1976, and I was impressed by what I saw: A dozen people working out of a stone-and-metal building perched at the edge of a high cliff with a spectacular view of a vast volcanic plain. Their primary purpose was to monitor the island's two active volcanoes, Kilauea and Mauna Loa. I joined them, working for six weeks as a volunteer and then, years later, as a staff scientist. That gave me several chances to ask how the observatory had started.

  12. The Political Economy of Joining the European Union : Iceland's Position at the Beginning of the 21st Century

    OpenAIRE

    Bjarnason, Magnus

    2010-01-01

    Iceland can consider its participation in the European Economic Area (EEA) as an associate membership of the European Union (EU). Under the EEA agreement, Iceland participates in the EU free movement of capital, persons, services and industrial goods, along with cooperation in social policy and related fields. However, Iceland does not participate in the EU Common Fisheries Policy (CFP), the EU Common Agricultural Policy (CAP), the European Economic and Monetary Union (EMU), or in the EU Cust...

  13. Recent Inflation of Kilauea Volcano

    Science.gov (United States)

    Miklius, A.; Poland, M.; Desmarais, E.; Sutton, A.; Orr, T.; Okubo, P.

    2006-12-01

    Over the last three years, geodetic monitoring networks and satellite radar interferometry have recorded substantial inflation of Kilauea's magma system, while the Pu`u `O`o eruption on the east rift zone has continued unabated. Combined with the approximate doubling of carbon dioxide emission rates at the summit during this period, these observations indicate that the magma supply rate to the volcano has increased. Since late 2003, the summit area has risen over 20 cm, and a 2.5 km-long GPS baseline across the summit area has extended almost half a meter. The center of inflation has been variable, with maximum uplift shifting from an area near the center of the caldera to the southeastern part of the caldera in 2004-2005. In 2006, the locus of inflation shifted again, to the location of the long-term magma reservoir in the southern part of the caldera - the same area that had subsided more than 1.5 meters during the last 23 years of the ongoing eruption. In addition, the southwest rift zone reversed its long-term trend of subsidence and began uplifting in early 2006. The east rift zone has shown slightly accelerated rates of extension, but with a year-long hiatus following the January 2005 south flank aseismic slip event. Inflation rates have varied greatly. Accelerated rates of extension and uplift in early 2005 and 2006 were also associated with increased seismicity. Seismicity occurred not only at inflation centers, but was also triggered on the normal faulting area northwest of the caldera and the strike-slip faulting area in the upper east rift zone. In early 2006, at about the time that we started recording uplift on the southwest rift zone, the rate of earthquakes extending from the summit into the southwest rift zone at least quadrupled. The most recent previous episode of inflation at Kilauea, in 2002, may have resulted from reduced lava- transport capacity, as it was associated with decreased outflow at the eruption site. In contrast, eruption volumes

  14. Human induced impacts on soil organic carbon in southwest Iceland

    Science.gov (United States)

    Gísladóttir, Guðrún; Erlendsson, Egill; Lal, Rattan

    2013-04-01

    The Icelandic environment has been strongly influenced by natural processes during the Holocene. Since settlement in AD 874, the introduction of grazing animals and other land use has drastically affected the natural environment. This includes the diminishing of vegetative cover, which has led to soil exposure and accelerated erosion over large areas, especially when in conjunction with harsh climate. This has specifically impacted processes and properties of volcanic soils (Andosols), which are subject to accelerated erosion by wind and water. While approximately 46% of the land surface in Iceland has sustained continuous vegetation cover, large areas have lost some or all of their soil cover formed during the postglacial era. Elsewhere, remaining soils have sparse or no vegetation cover, thus impairing soil carbon (C) sequestration. Among their multifunctional roles, soils support plant growth, increase soil biotic activity, enhance nutrient storage and strengthen the cycling of water and nutrients. In contrast, soil degradation by accelerated erosion and other processes impairs soil quality, reduces soil structure and depletes the soil organic matter (SOM) pool. Depletion of the SOM pool has also global implications because the terrestrial C pool is the third largest pool and strongly impacts the global C cycle. Erosional-depositional processes may deplete soil organic C (SOC) by erosion and increase by deposition. Some SOC-enriched sediments are redistributed over the landscape, while others are deposited in depression sites and transported into aquatic ecosystems. SOC decomposition processes are severely constrained in some environmental settings and any SOC buried under anaerobic conditions is protected against decomposition. Yet, the impact of the SOC transported by erosional processes and redistributed over the landscape is not fully understood because the variability in its turnover characteristics has not been widely studied. Thus, the fate of C

  15. COTHERM: Modelling fluid-rock interactions in Icelandic geothermal systems

    Science.gov (United States)

    Thien, Bruno; Kosakowski, Georg; Kulik, Dmitrii

    2014-05-01

    Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced geothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. We model the mineralogical and porosity evolution of Icelandic geothermal systems with 1D and 2D reactive transport models. These geothermal systems are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. The shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. We investigate two contrasting geothermal systems: Krafla, for which the water recharge consists of meteoritic water; and Reykjanes, for which the water recharge mainly consists of seawater. The initial rock composition is a fresh basalt. We use the GEM-Selektor geochemical modeling package [1] for calculation of kinetically controlled mineral equilibria between the rock and the ingression water. We consider basalt minerals dissolution kinetics according to Palandri & Kharaka [2]. Reactive surface areas are assumed to be geometric surface areas, and are corrected using a spherical-particle surface/mass relationship. For secondary minerals, we consider the partial equilibrium assuming that the primary mineral dissolution is slow, and the secondary mineral precipitation is fast. Comparison of our modeling results with the mineralogical assemblages observed in the

  16. Growth and degradation of Hawaiian volcanoes: Chapter 3 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Clague, David A.; Sherrod, David R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    The 19 known shield volcanoes of the main Hawaiian Islands—15 now emergent, 3 submerged, and 1 newly born and still submarine—lie at the southeast end of a long-lived hot spot chain. As the Pacific Plate of the Earth’s lithosphere moves slowly northwestward over the Hawaiian hot spot, volcanoes are successively born above it, evolve as they drift away from it, and eventually die and subside beneath the ocean surface.

  17. Bryophyte colonization history of the virgin volcanic island Surtsey, Iceland

    Directory of Open Access Journals (Sweden)

    G. V. Ingimundardóttir

    2014-08-01

    Full Text Available The island Surtsey was formed in a volcanic eruption south of Iceland in 1963–1967 and has since then been protected and monitored by scientists. The first two moss species were found on Surtsey as early as 1967 and several new bryophyte species were discovered every year until 1973 when regular sampling ended. Systematic bryophyte inventories in a grid of 100 m × 100 m quadrats were made in 1971 and 1972: the number of observed species doubled, with 36 species found in 1971 and 72 species in 1972. Here we report results from an inventory in 2008, when every other of the grid's quadrats were searched for bryophytes. Despite lower sampling intensity than in 1972, distributional expansion and contraction of earlier colonists was revealed as well as the presence of new colonists. A total of 38 species were discovered, 15 of those were not encountered in 1972 and eight had never been reported from Surtsey before (Bryum elegans, Ceratodon heterophyllus, Didymodon rigidulus, Eurhynchium praelongum, Schistidium confertum, S. papillosum, Tortula hoppeana and T. muralis. Habitat loss due to erosion and reduced thermal activity in combination with successional vegetation changes are likely to have played a significant role in the decline of some bryophyte species which were abundant in 1972 (Leptobryum pyriforme, Schistidium apocarpum coll., Funaria hygrometrica, Philonotis spp., Pohlia spp, Schistidium strictum, Sanionia uncinata while others have continued to thrive and expand (e.g. Schistidium maritimum, Racomitrium lanuginosum, R. ericoides, R. fasciculare and Bryum argenteum. Some species (especially Bryum spp. benefit from the formation of new habitats, such as grassland within a gull colony, which was established in 1984. Several newcomers are rarely producing sporophytes on Iceland and are unlikely to have been dispersed by airborne spores. They are more likely to have been introduced to Surtsey by seagulls in the form of vegetative fragments

  18. Bryophyte colonization history of the virgin volcanic island Surtsey, Iceland

    Science.gov (United States)

    Ingimundardóttir, G. V.; Weibull, H.; Cronberg, N.

    2014-08-01

    The island Surtsey was formed in a volcanic eruption south of Iceland in 1963-1967 and has since then been protected and monitored by scientists. The first two moss species were found on Surtsey as early as 1967 and several new bryophyte species were discovered every year until 1973 when regular sampling ended. Systematic bryophyte inventories in a grid of 100 m × 100 m quadrats were made in 1971 and 1972: the number of observed species doubled, with 36 species found in 1971 and 72 species in 1972. Here we report results from an inventory in 2008, when every other of the grid's quadrats were searched for bryophytes. Despite lower sampling intensity than in 1972, distributional expansion and contraction of earlier colonists was revealed as well as the presence of new colonists. A total of 38 species were discovered, 15 of those were not encountered in 1972 and eight had never been reported from Surtsey before (Bryum elegans, Ceratodon heterophyllus, Didymodon rigidulus, Eurhynchium praelongum, Schistidium confertum, S. papillosum, Tortula hoppeana and T. muralis). Habitat loss due to erosion and reduced thermal activity in combination with successional vegetation changes are likely to have played a significant role in the decline of some bryophyte species which were abundant in 1972 (Leptobryum pyriforme, Schistidium apocarpum coll., Funaria hygrometrica, Philonotis spp., Pohlia spp, Schistidium strictum, Sanionia uncinata) while others have continued to thrive and expand (e.g. Schistidium maritimum, Racomitrium lanuginosum, R. ericoides, R. fasciculare and Bryum argenteum). Some species (especially Bryum spp.) benefit from the formation of new habitats, such as grassland within a gull colony, which was established in 1984. Several newcomers are rarely producing sporophytes on Iceland and are unlikely to have been dispersed by airborne spores. They are more likely to have been introduced to Surtsey by seagulls in the form of vegetative fragments or dispersal agents

  19. Floating like a cork: The importance of glacial isostasy in the deglaciation progress in Iceland

    Science.gov (United States)

    Norddahl, H.; Ingolfsson, O.

    2016-12-01

    Being positioned on top of a hotspot and between two spreading ocean plates explains rheological structure of Iceland and the properties of a 30-35 km thick lithosphere, possibly with high proportion of partial melt, on top of a low viscous asthenosphere below Iceland, in the middle of the North Atlantic Ocean. Rapid variations in glacier loading on the Iceland crust have been proved to generate more or less an instantaneous depression or uplift of the crust and, thus, uphold both temporal and spacial glacio-isostatic equilibrium. Formation of a shoreline requires at least temporal equilibrium between glacial isostasy and eustasy. Eminent raised shorelines - found throughout Iceland - were formed during two separate but consecutive culmination of climatically induced glacier re-advance and consequent transgression of relative sea-level in Younger Dryas and Preboreal times (12.0 and 11.3 kcal BP). A Marine Limit shoreline in W Iceland was formed at 14.7 kcal BP, subsequent to a collapse-like retreat of the marine based part of the Icelandic Ice Sheet (IIS) and just prior to the onset of the Bølling warming, i.e. during a period of anticipated rapid isostatic uplift. A temporary glacio-isostatic equilibrium at that time is best explained by changes in the mode of deglaciation generating dynamic changes within the Ice Sheet itself, changes that resulted in reduced rates of mass-loss and glacio-isostatic uplift to such a degree that a temporal quasi-equilibrium between eustatic rise and isostatic uplift was established. Formation of well-developed raised shoreline is generally regarded as a deglaciation proxy signaling large ice volume changes. Formation of the ML shoreline in W Iceland during the rapid climatic improvement at the beginning of the Bølling/Allerød Interstadial underlines the importance of, beside the geological data, also to take into consideration physical properties of both the lithosphere and asthenosphere in each location.

  20. Iceland as the largest source of natural air pollution in the Arctic

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Meinander, Outi; Olafsson, Haraldur; Arnalds, Olafur

    2017-04-01

    Arctic aerosols are often attributed to the Arctic Haze and long-range transport tracers. There is, however, an important dust source in the Arctic/Sub-arctic region which should receive more attention. The largest desert in the Arctic as well as in the Europe is Iceland with > 40,000 km2 of desert areas. The mean dust suspension frequency was 135 dust days annually in 1949-2012 with decreasing numbers in 2013-2015. The annual dust deposition was calculated as 31-40 million tons yr-1 affecting the area of > 500,000 km2. Satelite MODIS pictures have revealed dust plumes traveling > 1000 km at times. The physical properties of Icelandic dust showed differences in mineralogy, geochemical compositions, shapes, sizes, and colour, compared to the crustal mineral dust. Icelandic dust is of volcanic origin, dark in colour with sharp-tipped shards and large bubbles. About 80% of the particulate matter is volcanic glass rich in heavy metals, such as iron and titanium. Suspended dust measured at the glacial dust source consisted of such high number of close-to-ultrafine particles as concentrations during active eruptions. Generally, about 50% of the suspended PM10 are submicron particles in Iceland. Contrarily, suspended grains > 2 mm were captured during severe dust storm after the 2010 Eyjafjallajokull eruption when the aeolian transport exceeded 11 t m-1 of materials and placed this storms among the most extreme wind erosion events recorded on Earth. Our reflectance measurements showed that Icelandic dust deposited on snow lowers the snow albedo and reduces the snow density as much as Black Carbon. Icelandic volcanic dust tends to act as a positive climate forcing agent, both directly and indirectly, which is different to what generally concluded for crustal dust in the 2013 IPCC report. The high frequency, severity and year-round activity of volcanic dust emissions suggest that Icelandic dust may contribute to Arctic warming.

  1. Carbonate assimilation at Merapi volcano, Java Indonesia

    DEFF Research Database (Denmark)

    Chadwick, J.P; Troll, V.R; Ginibre,, C.

    2007-01-01

    Recent basaltic andesite lavas from Merapi volcano contain abundant, complexly zoned, plagioclase phenocrysts, analysed here for their petrographic textures, major element composition and Sr isotope composition. Anorthite (An) content in individual crystals can vary by as much as 55 mol% (An40^95...

  2. Probing magma reservoirs to improve volcano forecasts

    Science.gov (United States)

    Lowenstern, Jacob B.; Sisson, Thomas W.; Hurwitz, Shaul

    2017-01-01

    When it comes to forecasting eruptions, volcano observatories rely mostly on real-time signals from earthquakes, ground deformation, and gas discharge, combined with probabilistic assessments based on past behavior [Sparks and Cashman, 2017]. There is comparatively less reliance on geophysical and petrological understanding of subsurface magma reservoirs.

  3. Biological Studies on a Live Volcano.

    Science.gov (United States)

    Zipko, Stephen J.

    1992-01-01

    Describes scientific research on an Earthwatch expedition to study Arenal, one of the world's most active volcanoes, in north central Costa Rica. The purpose of the two-week project was to monitor and understand the past and ongoing development of a small, geologically young, highly active stratovolcano in a tropical, high-rainfall environment.…

  4. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    , at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

  5. Geophysical monitoring of the Purace volcano, Colombia

    Directory of Open Access Journals (Sweden)

    M. Arcila

    1996-06-01

    Full Text Available Located in the extreme northwestern part of the Los Coconucos volcanic chain in the Central Cordillera, the Purace is one of Colombia's most active volcanoes. Recent geological studies indicate an eruptive history of mainly explosive behavior which was marked most recently by a minor ash eruption in 1977. Techniques used to forecast the renewal of activity of volcanoes after a long period of quiescence include the monitoring of seismicity and ground deformation near the volcano. As a first approach toward the monitoring of the Purace volcano, Southwest Seismological Observatory (OSSO, located in the city of Cali, set up one seismic station in 1986. Beginning in June 1991, the seismic signals have also been transmitted to the Colombian Geological Survey (INGEOMINAS at the Volcanological and Seismological Observatory (OVS-UOP, located in the city of Popayan. Two more seismic stations were installed early in 1994 forming a minimum seismic network and a geodetic monitoring program for ground deformation studies was established and conducted by INGEOMINAS.

  6. Muons reveal the interior of volcanoes

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    The MU-RAY project has the very challenging aim of providing a “muon X-ray” of the Vesuvius volcano (Italy) using a detector that records the muons hitting it after traversing the rock structures of the volcano. This technique was used for the first time in 1971 by the Nobel Prize-winner Louis Alvarez, who was searching for unknown burial chambers in the Chephren pyramid.   The location of the muon detector on the slopes of the Vesuvius volcano. Like X-ray scans of the human body, muon radiography allows researchers to obtain an image of the internal structures of the upper levels of volcanoes. Although such an image cannot help to predict ‘when’ an eruption might occur, it can, if combined with other observations, help to foresee ‘how’ it could develop and serves as a powerful tool for the study of geological structures. Muons come from the interaction of cosmic rays with the Earth's atmosphere. They are able to traverse layers of ro...

  7. False Color Image of Volcano Sapas Mons

    Science.gov (United States)

    1991-01-01

    This false-color image shows the volcano Sapas Mons, which is located in the broad equatorial rise called Atla Regio (8 degrees north latitude and 188 degrees east longitude). The area shown is approximately 650 kilometers (404 miles) on a side. Sapas Mons measures about 400 kilometers (248 miles) across and 1.5 kilometers (0.9 mile) high. Its flanks show numerous overlapping lava flows. The dark flows on the lower right are thought to be smoother than the brighter ones near the central part of the volcano. Many of the flows appear to have been erupted along the flanks of the volcano rather than from the summit. This type of flank eruption is common on large volcanoes on Earth, such as the Hawaiian volcanoes. The summit area has two flat-topped mesas, whose smooth tops give a relatively dark appearance in the radar image. Also seen near the summit are groups of pits, some as large as one kilometer (0.6 mile) across. These are thought to have formed when underground chambers of magma were drained through other subsurface tubes and lead to a collapse at the surface. A 20 kilometer-diameter (12-mile diameter) impact crater northeast of the volcano is partially buried by the lava flows. Little was known about Atla Regio prior to Magellan. The new data, acquired in February 1991, show the region to be composed of at least five large volcanoes such as Sapas Mons, which are commonly linked by complex systems of fractures or rift zones. If comparable to similar features on Earth, Atla Regio probably formed when large volumes of molten rock upwelled from areas within the interior of Venus known as'hot spots.' Magellan is a NASA spacecraft mission to map the surface of Venus with imaging radar. The basic scientific instrument is a synthetic aperture radar, or SAR, which can look through the thick clouds perpetually shielding the surface of Venus. Magellan is in orbit around Venus which completes one turn around its axis in 243 Earth days. That period of time, one Venus day

  8. Hazard maps of Colima volcano, Mexico

    Science.gov (United States)

    Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Escudero Ayala, C. R.

    2011-12-01

    Colima volcano, also known as Volcan de Fuego (19° 30.696 N, 103° 37.026 W), is located on the border between the states of Jalisco and Colima and is the most active volcano in Mexico. Began its current eruptive process in February 1991, in February 10, 1999 the biggest explosion since 1913 occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching attitudes between 4,500 and 9,000 m.a.s.l., further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events ash emissions were generated in all directions reaching distances up to 100 km, slightly affected nearby villages as Tuxpan, Tonila, Zapotlán, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During the 2005 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano due to low population density and low socio-economic activities at the time. Shows the updating of the volcanic hazard maps published in 2001, where we identify whit SPOT satellite imagery and Google Earth, change in the land use on the slope of volcano, the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano, the population inhabiting the area is approximately 517,000 people, and growing at an annual rate of 4.77%, also the region that has shown an increased in the vulnerability for the development of economic activities, supported by the construction of highways, natural gas pipelines and electrical infrastructure that connect to the Port of Manzanillo to Guadalajara city. The update the hazard maps are: a) Exclusion areas and moderate hazard for explosive events

  9. Mauna Kea volcano's ongoing 18-year swarm

    Science.gov (United States)

    Wech, A.; Thelen, W. A.

    2017-12-01

    Mauna Kea is a large postshield-stage volcano that forms the highest peak on Hawaii Island. The 4,205-meter high volcano erupted most recently between 6,000 and 4,500 years ago and exhibits relatively low rates of seismicity, which are mostly tectonic in origin resulting from lithospheric flexure under the weight of the volcano. Here we identify deep repeating earthquakes occurring beneath the summit of Mauna Kea. These earthquakes, which are not part of the Hawaiian Volcano Observatory's regional network catalog, were initially detected through a systematic search for coherent seismicity using envelope cross-correlation, and subsequent analysis revealed the presence of a long-term, ongoing swarm. The events have energy concentrated at 2-7 Hz, and can be seen in filtered waveforms dating back to the earliest continuous data from a single station archived at IRIS from November 1999. We use a single-station (3 component) match-filter analysis to create a catalog of the repeating earthquakes for the past 18 years. Using two templates created through phase-weighted stacking of thousands of sta/lta-triggers, we find hundreds of thousands of M1.3-1.6 earthquakes repeating every 7-12 minutes throughout this entire time period, with many smaller events occurring in between. The earthquakes occur at 28-31 km depth directly beneath the summit within a conspicuous gap in seismicity surrounding the flanks of the volcano. Magnitudes and periodicity are remarkably stable long-term, but do exhibit slight variability and occasionally display higher variability on shorter time scales. Network geometry precludes obtaining a reliable focal mechanism, but we interpret the frequency content and hypocenters to infer a volcanic source distinct from the regional tectonic seismicity responding to the load of the island. In this model, the earthquakes may result from the slow, persistent degassing of a relic magma chamber at depth.

  10. Geochemical studies on island arc volcanoes

    International Nuclear Information System (INIS)

    Notsu, Kenji

    1998-01-01

    This paper summarizes advances in three topics of geochemical studies on island arc volcanoes, which I and my colleagues have been investigating. First one is strontium isotope studies of arc volcanic rocks mainly from Japanese island arcs. We have shown that the precise spatial distribution of the 87 Sr/ 86 Sr ratio reflects natures of the subduction structure and slab-mantle interaction. Based on the 87 Sr/ 86 Sr ratio of volcanic rocks in the northern Kanto district, where two plates subduct concurrently with different directions, the existence of an aseismic portion of the Philippine Sea plate ahead of the seismic one was suggested. Second one is geochemical monitoring of active arc volcanoes. 3 He/ 4 He ratio of volcanic volatiles was shown to be a good indicator to monitor the behavior of magma: ascent and drain-back of magma result in increase and decrease in the ratio, respectively. In the case of 1986 eruptions of Izu-Oshima volcano, the ratio began to increase two months after big eruptions, reaching the maximum and decreased. Such delayed response is explained in terms of travelling time of magmatic helium from the vent area to the observation site along the underground steam flow. Third one is remote observation of volcanic gas chemistry of arc volcanoes, using an infrared absorption spectroscopy. During Unzen eruptions starting in 1990, absorption features of SO 2 and HCl of volcanic gas were detected from the observation station at 1.3 km distance. This was the first ground-based remote detection of HCl in volcanic gas. In the recent work at Aso volcano, we could identify 5 species (CO, COS, CO 2 , SO 2 and HCl) simultaneously in the volcanic plume spectra. (author)

  11. [Lung volume reduction surgery for severe pulmonary emphysema in Iceland].

    Science.gov (United States)

    Gunnarsson, Sverrir I; Johannsson, Kristinn B; Guðjónsdóttir, Marta; Jónsson, Steinn; Beck, Hans J; Magnusson, Bjorn; Gudbjartsson, Tomas

    2011-12-01

    Lung volume reduction surgery (LVRS) can benefit patients with severe emphysema. The aim of this study was to evaluate the outcome of LVRS performed in Iceland. A prospective study of 16 consecutive patients who underwent bilateral LVRS through median sternotomy between January 1996 and December 2008. All patients had disabling dyspnea, lung hyperinflation, and emphysema with upper lobe predominance. Preoperatively all patients underwent pulmonary rehabilitation. Spirometry, lung volumes, arterial blood gases and exercise capacity were measured before and after surgery. Mean follow-up time was 8.7 years. Mean age was 59.2 ± 5.9 years. All patients had a history of heavy smoking. There was no perioperative mortality and survival was 100%, 93%, and 63% at 1, 5, and 10 years, respectively. The forced expiratory volume in 1 second (FEV1) and the forced vital capacity (FVC) improved significantly after surgery by 35% (plung capacity, residual volume and partial pressure of CO2 also showed statistically significant improvements but exercise capacity, O2 consumption and diffusing capacity of the lung for CO did not change. Prolonged air leak (≥ 7 days) was the most common complication (n=7). Five patients required reoperation, most commonly for sternal dehiscence (n=4). In this small prospective study, FEV1 and FVC increased and lung volumes and PaCO2 improved after LVRS. Long term survival was satisfactory although complications such as reoperations for sternal dehiscence were common and hospital stay therefore often prolonged.

  12. Cultivating Communication: Participatory Approaches in Land Restoration in Iceland

    Directory of Open Access Journals (Sweden)

    Brita Berglund

    2013-06-01

    Full Text Available Stakeholder participation in environmental management is increasing. Staff of environmental agencies, however, often lack training in communication and in conducting participatory processes. Their interpretation of "participation" is of interest because interpretation affects how participation is practiced. We explored how participation was interpreted within the Soil Conservation Service of Iceland and how the interpretation affected how participation was carried out in two land restoration projects. Our methods included semi-structured interviews with agency staff and involved stakeholders, participant observations, and document review. The findings showed that participation was seen as a method to accomplish the agency's tasks, and the focus was primarily on the outputs, or products, of the participatory processes. This interpretation worked well and created positive outcomes as long as process factors, such as interaction with other stakeholders and shared influence, were adequately attended to and joint gains were assured, but other stakeholders expressed dissatisfaction when they were not. We conclude that, although tangible outcomes are necessary for environmental agencies, maintaining a balance between product and process focus in participatory projects is important for optimal results. To increase their ability to deal with process factors, environmental agencies, and ultimately environmental management, would benefit from enhancing their personnel's understanding of participation, and capacity to conduct participatory processes. To facilitate participation, this understanding should also be integrated in the institutional framework the agencies work within.

  13. Xylanases of thermophilic bacteria from Icelandic hot springs

    Energy Technology Data Exchange (ETDEWEB)

    Pertulla, M; Raettoe, M; Viikari, L [VTT, Biotechnical Lab., Espoo (Finland); Kondradsdottir, M [Dept. of Biotechnology, Technological Inst. of Iceland, Reykjavik (Iceland); Kristjansson, J K [Dept. of Biotechnology, Technological Inst. of Iceland, Reykjavik (Iceland) Inst. of Biotechnology, Iceland Univ., Reykjavik (Iceland)

    1993-02-01

    Thermophilic, aerobic bacteria isolated from Icelandic hot springs were screened for xylanase activity. Of 97 strains tested, 14 were found to be xylanase positive. Xylanase activities up to 12 nkat/ml were produced by these strains in shake flasks on xylan medium. The xylanases of the two strains producing the highest activities (ITI 36 and ITI 283) were similar with respect to temperature and pH optima (80deg C and pH 8.0). Xylanase production of strain ITI 36 was found to be induced by xylan and xylose. Xylanase activity of 24 nkat/ml was obtained with this strain in a laboratory-scale-fermentor cultivation on xylose medium. [beta]-Xylosidase activity was also detected in the culture filtrate. The thermal half-life of ITI 36 xylanase was 24 h at 70deg C. The highest production of sugars from hydrolysis of beech xylan was obtained at 70deg C, although xylan depolymerization was detected even up to 90deg C. (orig.).

  14. Political control and perceptions of corruption in Icelandic local government

    Directory of Open Access Journals (Sweden)

    Gunnar Helgi Kristinsson

    2015-06-01

    Full Text Available Political control is an important value of democratic governance and without it democratic accountability can hardly mean much. This is why a number of authors have seen politicization of public service appointments and greater control by the centre as a potential counterweight against trends in recent decades towards more networked and less hierarchical organizational forms of directing public policy. It may help to reassert democratic control. The option of strengthening political control, however, has not been much studied with regard to its likely effects on corruption. Power has the potential to corrupt unless adequately controlled and strengthening political power in a networked environment may create a structure of temptation which conventional deterrents to corruption are unable to curb. The impact of strong political leadership on corruption is here studied in the context of Icelandic local government, making use of institutional variations in the office of Mayor, which provide a unique opportunity for testing the effects of strong political control on corruption. The analysis indicates that municipalities with strong political mayors are likely to be associated with perceptions of corruption even when other factors, such as the structure of temptation and deterrents, are accounted for.

  15. The Impact of Amalgamations on Services in Icelandic Municipalities

    Directory of Open Access Journals (Sweden)

    Grétar Thór Eythórsson

    2018-03-01

    Full Text Available This article deals with answering the question whether municipal amalgamations can meet the wishes at the root of the most common motives behind them: to gain cost-efficiency and more quality in the municipal services. The analysis is partly based on a survey among Icelandic local leaders in 2015 and partly on survey among citizens in 8 recently amalgamated municipalities collected with a snowball method through Facebook in the spring and summer 2013. The main results are that the impact of amalgamations on municipal services seems to depend on whether we look at the central or peripheral parts of the municipality. Both leaders and citizens seem to perceive developments of services differently depending on the position in the municipality. In the peripheries, they have significantly more negative view than in the service centres. This has to do with both their evaluation of specific services and their general evaluation of service development. However, in the general evaluation the difference is significantly larger.

  16. Magma-Hydrothermal Transition: Basalt Alteration at Supercritical Conditions in Drill Core from Reykjanes, Iceland, Iceland Deep Drilling Project.

    Science.gov (United States)

    Zierenberg, R. A.; Fowler, A. P.; Schiffman, P.; Fridleifsson, G. Ó.; Elders, W. A.

    2017-12-01

    The Iceland Deep Drilling Project well IDDP-2, drilled to 4,659 m in the Reykjanes geothermal system, the on-land extension of the Mid Atlantic Ridge, SW Iceland. Drill core was recovered, for the first time, from a seawater-recharged, basalt-hosted hydrothermal system at supercritical conditions. The well has not yet been allowed to heat to in situ conditions, but temperature and pressure of 426º C and 340 bar was measured at 4500 m depth prior to the final coring runs. Spot drill cores were recovered between drilling depths of 3648.00 m and 4657.58 m. Analysis of the core is on-going, but we present the following initial observations. The cored material comes from a basaltic sheeted dike complex in the brittle-ductile transition zone. Felsic (plagiogranite) segregation veins are present in minor amounts in dikes recovered below 4300 m. Most core is pervasively altered to hornblende + plagioclase, but shows only minor changes in major and minor element composition. The deepest samples record the transition from the magmatic regime to the presently active hydrothermal system. Diabase near dike margins has been locally recrystallized to granoblastic-textured orthopyroxene-clinopyroxe-plagioclase hornfels. High temperature hydrothermal alteration includes calcic plagioclase (up to An100) and aluminous hornblende (up to 11 Wt. % Al2O3) locally intergrown with hydrothermal biotite, clinopyroxene, orthopyroxene and/or olivine. Hydrothermal olivine is iron-rich (Mg # 59-64) compared to expected values for igneous olivine. Biotite phenocrysts in felsic segregation veins have higher Cl and Fe compared to hydrothermal biotites. Orthopyroxene-clinopyroxene pairs in partially altered quench dike margins give temperature of 955° to 1067° C. Orthopyroxene-clinopyroxene pairs from hornfels and hydrothermal veins and replacements give temperature ranging from 774° to 888° C. Downhole fluid sampling is planned following thermal equilibration of the drill hole. Previous work

  17. Comparison of grass haylage digestibility and metabolic plasma profile in Icelandic and Standardbred horses.

    Science.gov (United States)

    Ragnarsson, S; Jansson, A

    2011-06-01

    The aim of the present study was to compare digestibility and metabolic response in Icelandic and Standardbred horses fed two grass haylages harvested at different stages of maturity. Six horses of each breed were used in a 24-day change-over design. A total collection of faeces was made on days 15-17 and 22-24. Blood samples were collected on day 24 of each period and analysed for total plasma protein (TPP), plasma urea, non-esterified fatty acids, cortisol and insulin concentration. There were no differences in digestibility coefficients of crude protein, neutral detergent fibre or energy between breeds but organic matter digestibility was higher in the Standardbred horses. On both haylages, the Icelandic horses gained weight whereas the Standardbred horses lost weight. The Icelandic horses had higher TPP, plasma insulin and lower plasma urea concentrations. Our results indicate that the Icelandic horse may be more prone to maintain positive energy balance in relation to the Standardbred horse, but there were no indication of a better digestive capacity in the Icelandic horses. © 2010 Blackwell Verlag GmbH.

  18. Legalizing altruistic surrogacy in response to evasive travel? An Icelandic proposal

    Directory of Open Access Journals (Sweden)

    Sigurður Kristinsson

    2016-12-01

    Full Text Available Surrogate motherhood has been prohibited by Icelandic law since 1996, but in recent years, Icelandic couples have sought transnational surrogacy in India and the United States despite uncertainties about legal parental status as they return to Iceland with infants born to surrogate mothers. This reflects global trends of increased reproductive tourism, which forces restrictive regimes not only to make decisions concerning the citizenship and parentage of children born to surrogate mothers abroad, but also to confront difficult moral issues concerning surrogacy, global justice, human rights and exploitation. In March 2015, a legislative proposal permitting altruistic surrogacy, subject to strict regulation and oversight, and prohibiting the solicitation of commercial surrogacy abroad, was presented in the Icelandic Parliament. The proposal aims to protect the interest of the child first, respect the autonomy of the surrogate second, and accommodate the intended parents’ wishes third. After a brief overview of the development of the surrogacy issue in Iceland, this article describes the main features of this legislative proposal and evaluates it from an ethical and global justice perspective. It concludes that the proposed legislation is a response to problems generated by cross-border surrogacy in the context of evolving public attitudes toward the issue, and constitutes a valid attempt to reduce the moral hazards of surrogacy consistent with insights from current bioethical literature. Although the proposed legislation arguably represents an improvement over the current ban, however, difficult problems concerning evasive travel and global injustice are likely to persist until effective international coordination is achieved.

  19. Legalizing altruistic surrogacy in response to evasive travel? An Icelandic proposal.

    Science.gov (United States)

    Kristinsson, Sigurður

    2016-12-01

    Surrogate motherhood has been prohibited by Icelandic law since 1996, but in recent years, Icelandic couples have sought transnational surrogacy in India and the United States despite uncertainties about legal parental status as they return to Iceland with infants born to surrogate mothers. This reflects global trends of increased reproductive tourism, which forces restrictive regimes not only to make decisions concerning the citizenship and parentage of children born to surrogate mothers abroad, but also to confront difficult moral issues concerning surrogacy, global justice, human rights and exploitation. In March 2015, a legislative proposal permitting altruistic surrogacy, subject to strict regulation and oversight, and prohibiting the solicitation of commercial surrogacy abroad, was presented in the Icelandic Parliament. The proposal aims to protect the interest of the child first, respect the autonomy of the surrogate second, and accommodate the intended parents' wishes third. After a brief overview of the development of the surrogacy issue in Iceland, this article describes the main features of this legislative proposal and evaluates it from an ethical and global justice perspective. It concludes that the proposed legislation is a response to problems generated by cross-border surrogacy in the context of evolving public attitudes toward the issue, and constitutes a valid attempt to reduce the moral hazards of surrogacy consistent with insights from current bioethical literature. Although the proposed legislation arguably represents an improvement over the current ban, however, difficult problems concerning evasive travel and global injustice are likely to persist until effective international coordination is achieved.

  20. Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt

    International Nuclear Information System (INIS)

    Ulmer, G.C.; Grandstaff, D.E.

    1984-01-01

    Analog studies of Icelandic geothermal fields have shown that the design of nuclear waste repositories in basalt can benefit by comparison to the data base already available from the development of these geothermal fields. A high degree of similarity exists between these two systems: their petrology, groundwater geochemistry, mineral solubilities, hydrologic parameters, temperature ranges, water-rock redox equilibria, hydrothermal pH values, and secondary mineralogies all show considerable overlap in the range of values. The experimentally-simulated hydrothermal studies of the basaltic nuclear waste repository rocks have, at this time, produced a data base that receives a strong confirmation from the Icelandic analog. Furthermore, the Icelandic analog should eventually be employed to extrapolate into higher and lower temperatures, into longer time-base chemical comparisons, and into more realistic mineral deposition studies, than have been possible in the laboratory evaluations of the nuclear waste repository designs. This eventual use of the Icelandic analog will require cooperative work with the Icelandic Geological Survey. 46 refs., 4 figs., 2 tabs

  1. Iceland as a western country. How to classify medieval church law in the vernacular

    Directory of Open Access Journals (Sweden)

    Lára Magnúsardóttir

    2015-12-01

    Full Text Available Iceland’s subjection to the king of Norway in 1262-64 was followed by a legislation in which a law book for Church and spiritual matters was composed in the vernacular for each country. Such law was implemented in Iceland in 1275 along with a separate secular law book in 1281. Both books remained in force until the middle of the 16th century. A church law that was separate, both from the secular law and that of Roman Church appears to set Iceland apart from other Western European countries where spiritual matters were governed according to the Latin law of the Roman Church. This has been viewed as an indication of constant rivalry between the religious and secular authorities, usually presenting the Church as an overreaching and even oppressive institution against which laity struggled. But a comparison of Icelandic Church law with the Latin Canon law shows that the Church in Iceland submitted entirely to the authority of the Roman Church and thus shows that the Icelandic Church law was, despite its obscure language, a specific representation of the law of the Roman Church. A Norwegian concordat from 1277 shows the king’s recognition of separate spiritual and temporal jurisdictions. This cooperation is readily apparent in later court cases.

  2. Re-Thinking Sustainable Education Systems in Iceland: The Net-University Project

    Directory of Open Access Journals (Sweden)

    Frank Rennie

    2011-05-01

    Full Text Available The recent economic crisis in Iceland has raised issues of the sustainability of Icelandic higher education to new levels of importance. A key strategy in relation to this economic crisis is to consider the merger of the four public universities in Iceland and to introduce a much higher enegagement with online and open delivery methods of higher education. The Net-University Project was an EU Leonardo-funded initiative to compare approaches to open and distance education in Iceland, Sweden, and Scotland, with additional lessons from Atlantic Canada. In particular, it sought to focus on the transfer of innovation in continuing university education, with particular emphasis on the development and delivery of online higher education courses throughout rural Iceland (i.e., outside of Reykjavik. The partners concentrated on how knowledge and experience about distributed and distance learning models could be transferred between the partner countries and how such models can be integrated into the education system to better support higher education and lifelong learning. There was a particular interest in the practical use of open educational resources (OER for course design and in the sharing of these course modules among university partners. Some good practice and lessons from OER use in course creation are listed.

  3. Avian influenza virus ecology in Iceland shorebirds: intercontinental reassortment and movement

    Science.gov (United States)

    Hall, Jeffrey S.; Hallgrimsson, Gunnar Thor; Suwannanarn, Kamol; Sreevatsen, Srinand; Ip, Hon S.; TeSlaa, Joshua L.; Nashold, Sean W.; Dusek, Robert J.

    2014-01-01

    Shorebirds are a primary reservoir of avian influenza viruses (AIV). We conducted surveillance studies in Iceland shorebird populations for 3 years, documenting high serological evidence of AIV exposure in shorebirds, primarily in Ruddy Turnstones (Arenaria interpres; seroprevalence = 75%). However, little evidence of virus infection was found in these shorebird populations and only two turnstone AIVs (H2N7; H5N1) were able to be phylogenetically examined. These analyses showed that viruses from Iceland shorebirds were primarily derived from Eurasian lineage viruses, yet the H2 hemagglutinin gene segment was from a North American lineage previously detected in a gull from Iceland the previous year. The H5N1 virus was determined to be low pathogenic, however the PB2 gene was closely related to the PB2 from highly pathogenic H5N1 isolates from China. Multiple lines of evidence suggest that the turnstones were infected with at least one of these AIV while in Iceland and confirm Iceland as an important location where AIV from different continents interact and reassort, creating new virus genomes. Mounting data warrant continued surveillance for AIV in wild birds in the North Atlantic, including Canada, Greenland, and the northeast USA to determine the risks of new AI viruses and their intercontinental movement in this region.

  4. Economic conditions, hypertension, and cardiovascular disease: analysis of the Icelandic economic collapse.

    Science.gov (United States)

    Birgisdóttir, Kristín Helga; Jónsson, Stefán Hrafn; Ásgeirsdóttir, Tinna Laufey

    2017-12-01

    Previous research has found a positive short-term relationship between the 2008 collapse and hypertension in Icelandic males. With Iceland's economy experiencing a phase of economic recovery, an opportunity to pursue a longer-term analysis of the collapse has emerged. Using data from a nationally representative sample, fixed-effect estimations and mediation analyses were performed to explore the relationship between the Icelandic economic collapse in 2008 and the longer-term impact on hypertension and cardiovascular health. A sensitivity analysis was carried out with pooled logit models estimated as well as an alternative dependent variable. Our attrition analysis revealed that results for cardiovascular diseases were affected by attrition, but not results from estimations on the relationship between the economic crisis and hypertension. When compared to the boom year 2007, our results point to an increased probability of Icelandic women having hypertension in the year 2012, when the Icelandic economy had recovered substantially from the economic collapse in 2008. This represents a deviation from pre-crisis trends, thus suggesting a true economic-recovery impact on hypertension.

  5. The impact of divergence time on the nature of population structure: an example from Iceland.

    Directory of Open Access Journals (Sweden)

    Alkes L Price

    2009-06-01

    Full Text Available The Icelandic population has been sampled in many disease association studies, providing a strong motivation to understand the structure of this population and its ramifications for disease gene mapping. Previous work using 40 microsatellites showed that the Icelandic population is relatively homogeneous, but exhibits subtle population structure that can bias disease association statistics. Here, we show that regional geographic ancestries of individuals from Iceland can be distinguished using 292,289 autosomal single-nucleotide polymorphisms (SNPs. We further show that subpopulation differences are due to genetic drift since the settlement of Iceland 1100 years ago, and not to varying contributions from different ancestral populations. A consequence of the recent origin of Icelandic population structure is that allele frequency differences follow a null distribution devoid of outliers, so that the risk of false positive associations due to stratification is minimal. Our results highlight an important distinction between population differences attributable to recent drift and those arising from more ancient divergence, which has implications both for association studies and for efforts to detect natural selection using population differentiation.

  6. The Spatial Variation of Dust Particulate Matter Concentrations during Two Icelandic Dust Storms in 2015

    Directory of Open Access Journals (Sweden)

    Pavla Dagsson-Waldhauserova

    2016-06-01

    Full Text Available Particulate matter mass concentrations and size fractions of PM1, PM2.5, PM4, PM10, and PM15 measured in transversal horizontal profile of two dust storms in southwestern Iceland are presented. Images from a camera network were used to estimate the visibility and spatial extent of measured dust events. Numerical simulations were used to calculate the total dust flux from the sources as 180,000 and 280,000 tons for each storm. The mean PM15 concentrations inside of the dust plumes varied from 10 to 1600 µg·m−3 (PM10 = 7 to 583 µg·m−3. The mean PM1 concentrations were 97–241 µg·m−3 with a maximum of 261 µg·m−3 for the first storm. The PM1/PM2.5 ratios of >0.9 and PM1/PM10 ratios of 0.34–0.63 show that suspension of volcanic materials in Iceland causes air pollution with extremely high PM1 concentrations, similar to polluted urban areas in Europe or Asia. Icelandic volcanic dust consists of a higher proportion of submicron particles compared to crustal dust. Both dust storms occurred in relatively densely inhabited areas of Iceland. First results on size partitioning of Icelandic dust presented here should challenge health authorities to enhance research in relation to dust and shows the need for public dust warning systems.

  7. Avian influenza virus ecology in Iceland shorebirds: intercontinental reassortment and movement.

    Science.gov (United States)

    Hall, Jeffrey S; Hallgrimsson, Gunnar Thor; Suwannanarn, Kamol; Sreevatsen, Srinand; Ip, Hon S; Magnusdottir, Ellen; TeSlaa, Joshua L; Nashold, Sean W; Dusek, Robert J

    2014-12-01

    Shorebirds are a primary reservoir of avian influenza viruses (AIV). We conducted surveillance studies in Iceland shorebird populations for 3 years, documenting high serological evidence of AIV exposure in shorebirds, primarily in Ruddy Turnstones (Arenaria interpres; seroprevalence=75%). However, little evidence of virus infection was found in these shorebird populations and only two turnstone AIVs (H2N7; H5N1) were able to be phylogenetically examined. These analyses showed that viruses from Iceland shorebirds were primarily derived from Eurasian lineage viruses, yet the H2 hemagglutinin gene segment was from a North American lineage previously detected in a gull from Iceland the previous year. The H5N1 virus was determined to be low pathogenic, however the PB2 gene was closely related to the PB2 from highly pathogenic H5N1 isolates from China. Multiple lines of evidence suggest that the turnstones were infected with at least one of these AIV while in Iceland and confirm Iceland as an important location where AIV from different continents interact and reassort, creating new virus genomes. Mounting data warrant continued surveillance for AIV in wild birds in the North Atlantic, including Canada, Greenland, and the northeast USA to determine the risks of new AI viruses and their intercontinental movement in this region. Published by Elsevier B.V.

  8. Space Radar Image of Colombian Volcano

    Science.gov (United States)

    1999-01-01

    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations ofColombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of

  9. Common processes at unique volcanoes – a volcanological conundrum

    Directory of Open Access Journals (Sweden)

    Katharine eCashman

    2014-11-01

    Full Text Available An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behaviour over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behaviour (or personality. In contrast, volcano classification schemes define eruption styles referenced to type volcanoes (e.g. Plinian, Strombolian, Vulcanian; this approach implicitly assumes that common processes underpin volcanic activity and can be used to predict the nature, extent and ensuing hazards of individual volcanoes. Actual volcanic eruptions, however, often include multiple styles, and type volcanoes may experience atypical eruptions (e.g., violent explosive eruptions of Kilauea, Hawaii1. The volcanological community is thus left with a fundamental conundrum that pits the uniqueness of individual volcanic systems against generalization of common processes. Addressing this challenge represents a major challenge to volcano research.

  10. Tax Evasion, Tax Avoidance and The Influence of Special Interest Groups: Taxation in Iceland from 1930 to the Present

    Directory of Open Access Journals (Sweden)

    Karlsson Johannes

    2015-12-01

    Full Text Available This paper focuses on tax evasion and tax avoidance in Iceland, and on how special interest groups have shaped the taxation system to serve their own ends. The period covered is from 1930, when the present Icelandic system of power was established, to the present.

  11. Imaging of bone spavin. A radiographic and scintigraphic study of degenerative joint disease in the distal tarsus in Icelandic horses

    International Nuclear Information System (INIS)

    Eksell, P.

    2000-01-01

    Radiography and scintigraphy are commonly used for the diagnosis of skeletal disorders in horses. Icelandic Horses have a high prevalence of degenerative joint disease of the distal tarsus, generally known as bone spavin (BS). The purpose of this study was to evaluate and develop the use of radiography and scintigraphy for the detection of BS in Icelandic Horses

  12. Soot on snow in Iceland: First results on black carbon and organic carbon in Iceland 2016 snow and ice samples, including the glacier Solheimajökull

    Science.gov (United States)

    Meinander, Outi; Dagsson-Waldhauserova, Pavla; Gritsevich, Maria; Aurela, Minna; Arnalds, Olafur; Dragosics, Monika; Virkkula, Aki; Svensson, Jonas; Peltoniemi, Jouni; Kontu, Anna; Kivekäs, Niku; Leppäranta, Matti; de Leeuw, Gerrit; Laaksonen, Ari; Lihavainen, Heikki; Arslan, Ali N.; Paatero, Jussi

    2017-04-01

    New results on black carbon (BC) and organic carbon (OC) on snow and ice in Iceland in 2016 will be presented in connection to our earlier results on BC and OC on Arctic seasonal snow surface, and in connection to our 2013 and 2016 experiments on effects of light absorbing impurities, including Icelandic dust, on snow albedo, melt and density. Our sampling included the glacier Solheimajökull in Iceland. The mass balance of this glacier is negative and it has been shrinking during the last 20 years by 900 meters from its southwestern corner. Icelandic snow and ice samples were not expected to contain high concentrations of BC, as power generation with domestic renewable water and geothermal power energy sources cover 80 % of the total energy consumption in Iceland. Our BC results on filters analyzed with a Thermal/Optical Carbon Aerosol Analyzer (OC/EC) confirm this assumption. Other potential soot sources in Iceland include agricultural burning, industry (aluminum and ferroalloy production and fishing industry), open burning, residential heating and transport (shipping, road traffic, aviation). On the contrary to low BC, we have found high concentrations of organic carbon in our Iceland 2016 samples. Some of the possible reasons for those will be discussed in this presentation. Earlier, we have measured and reported unexpectedly low snow albedo values of Arctic seasonally melting snow in Sodankylä, north of Arctic Circle. Our low albedo results of melting snow have been confirmed by three independent data sets. We have explained these low values to be due to: (i) large snow grain sizes up to 3 mm in diameter (seasonally melting snow); (ii) meltwater surrounding the grains and increasing the effective grain size; (iii) absorption caused by impurities in the snow, with concentration of elemental carbon (black carbon) in snow of 87 ppb, and organic carbon 2894 ppb. The high concentrations of carbon were due to air masses originating from the Kola Peninsula, Russia

  13. Darwin's triggering mechanism of volcano eruptions

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

    Charles Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…' and ‘…a power, I may remark, which acts in paroxysmal upheavals like that of Concepcion, and in great volcanic eruptions,…'. Darwin reports that ‘…several of the great chimneys in the Cordillera of central Chile commenced a fresh period of activity ….' In particular, Darwin reported on four-simultaneous large eruptions from the following volcanoes: Robinson Crusoe, Minchinmavida, Cerro Yanteles and Peteroa (we cite the Darwin's sentences following his The Voyage of the Beagle and researchspace. auckland. ac. nz/handle/2292/4474). Let us consider these eruptions taking into account the volcano shape and the conduit. Three of the volcanoes (Minchinmavida (2404 m), Cerro Yanteles (2050 m), and Peteroa (3603 m)) are stratovolcanos and are formed of symmetrical cones with steep sides. Robinson Crusoe (922 m) is a shield volcano and is formed of a cone with gently sloping sides. They are not very active. We may surmise, that their vents had a sealing plug (vent fill) in 1835. All these volcanoes are conical. These common features are important for Darwin's triggering model, which is discussed below. The vent fill material, usually, has high level of porosity and a very low tensile strength and can easily be fragmented by tension waves. The action of a severe earthquake on the volcano base may be compared with a nuclear blast explosion of the base. It is known, that after a underground nuclear explosion the vertical motion and the surface fractures in a tope of mountains were observed. The same is related to the propagation of waves in conical elements. After the explosive load of the base. the tip may break and fly off at high velocity. Analogous phenomenon may be generated as a result of a

  14. Antibacterial use in the Faroe Islands, Iceland, and Denmark 1999-2011

    DEFF Research Database (Denmark)

    Magnussen, Marita Debess; Gudnason, Thorolfur; Jensen, Ulrich Stab

    2014-01-01

    BACKGROUND: The Faroe Islands, Iceland, and Denmark are neighbouring Nordic countries with great ethnic, cultural, and political similarities and are relatively homogeneous. Important information about prescribing practices can be obtained by comparing the antibacterial use in these countries...... in the Faroe Islands and Iceland, whereas in Denmark it increased gradually from 13.5 DID in 1999 to 19.5 DID in 2011. The higher use in Iceland can be explained by much higher consumption of tetracyclines. There was also considerable variation in the use of individual penicillins and macrolides between...... the countries. CONCLUSIONS: Despite the great ethnic and cultural similarities of these 3 countries, we found marked differences in total antibacterial use and important differences in the use of individual antibacterials....

  15. Network analysis of the Íslendinga sögur - the Sagas of Icelanders

    Science.gov (United States)

    Mac Carron, P.; Kenna, R.

    2013-10-01

    The Íslendinga sögur - or Sagas of Icelanders - constitute a collection of medieval literature set in Iceland around the late 9th to early 11th centuries, the so-called Saga Age. They purport to describe events during the period around the settlement of Iceland and the generations immediately following and constitute an important element of world literature thanks to their unique narrative style. Although their historicity is a matter of scholarly debate, the narratives contain interwoven and overlapping plots involving thousands of characters and interactions between them. Here we perform a network analysis of the Íslendinga sögur in an attempt to gather quantitative information on interrelationships between characters and to compare saga society to other social networks.

  16. 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...

  17. Iceland and the EU’s Common Security and Defence Policy: Challenge or Opportunity?

    Directory of Open Access Journals (Sweden)

    Alyson J.K. Bailes

    2012-06-01

    Full Text Available Iceland had initial misgivings about the EU’s capacity created in 1999 for military crisis management. In the current debate over Iceland’s EU application, questions have been raised about the possible impact of CSDP on the nation’s non-military status. In fact the CSDP is designed to respect national choices in defence; requires unanimity on new actions; and allows case-by-case decisions on participation. Preliminary study of six other small states in the EU suggests that none of them has been obliged by membership to abandon national preferences in this field, though all have made special efforts to support EU police and civilian operations - an area where Iceland is also well qualified to contribute. The more significant effects of EU membership for Icelandic security might in fact come in other, ‘softer’ areas including EU obligations for mutual assistance in civil emergencies.

  18. Geographical, and seasonal variation in the diet of harbour porpoises (Phocoena phocoena in Icelandic coastal waters

    Directory of Open Access Journals (Sweden)

    Gísli A Víkingsson

    2003-07-01

    Overall capelin (Mallotus villosus comprised the predominant prey, followed by sandeel (Ammodytidae sp., then gadids, cephalopods and redfish (Sebastes marinus, while other taxa were of less importance. Differences were detected in diet composition among 5 areas around Iceland with redfish and gadids more prominent in the northern areas. Off SW Iceland there was considerable seasonal variation in the porpoise diet, where capelin appeared to be dominant in late winter and spring and sandeel in the summer through early winter. Predominance of capelin in the diet coincided with the spawning migration of capelin from northern waters along the east, south and west coasts of Iceland. Mature females appeared to have a more diverse diet than other reproductive classes. The length distributions of fish consumed by the porpoises ranged from 1 to 51 cm although most fish prey were less than 30 cm.

  19. Post-partum reproductive performance of the Icelandic dairy cow

    International Nuclear Information System (INIS)

    Eldon, J.; Olafsson, T.; Thorsteinsson, T.

    1990-01-01

    The aim of the studies was to monitor the reproductive performance of Icelandic dairy cow herds with and without histories of fertility problems under normal farming conditions. Artificial inseminations and calvings were recorded, pregnancy was diagnosed by rectal palpation, and progesterone concentration was measured by radioimmunoassay in sequential samples of milk. Blood samples were collected at regular intervals and the concentrations of glucose, urea, calcium and magnesium were determined. Clinical ketosis and low glucose were found in one third of the cows on problem farms. The mean time of first post-partum ovulation was 49 days for cows with ketosis, compared with 34 days for cows free of ketosis. Cows in the normal herds ovulated considerably later than is reported for many other breeds of dairy cows; however, the time of first post-partum AI, the time of conception and the conception rate were similar to those reported for other breeds. The effects of season and herd were statistically significant for the time of first post-partum ovulation, AI and conception; the effect of area was highly significant for the time of ovulation. Progesterone profiles showed that over 50% of the first post-partum ovarian cycles were short and had low progesterone concentrations. Season had significant effects on the length of the interval from calving to first post-partum ovulation, AI and conception, on the conception rate to first AI and consequently on the number of AIs per conception, and on the blood levels of glucose, urea and calcium. (author). 28 refs, 3 figs, 3 tabs

  20. Reconciling biodiversity conservation and agricultural expansion in the subarctic environment of Iceland

    Directory of Open Access Journals (Sweden)

    Lilja Jóhannesdóttir

    2017-03-01

    Full Text Available Intensified agricultural practices have driven biodiversity loss throughout the world, and although many actions aimed at halting and reversing these declines have been developed, their effectiveness depends greatly on the willingness of stakeholders to take part in conservation management. Knowledge of the willingness and capacity of landowners to engage with conservation can therefore be key to designing successful management strategies in agricultural land. In Iceland, agriculture is currently at a relatively low intensity but is very likely to expand in the near future. At the same time, Iceland supports internationally important breeding populations of many ground-nesting birds that could be seriously impacted by further expansion of agricultural activities. To understand the views of Icelandic farmers toward bird conservation, given the current potential for agricultural expansion, 62 farms across Iceland were visited and farmers were interviewed, using a structured questionnaire survey in which respondents indicated of a series of future actions. Most farmers intend to increase the area of cultivated land in the near future, and despite considering having rich birdlife on their land to be very important, most also report they are unlikely to specifically consider bird conservation in their management, even if financial compensation were available. However, as no agri-environment schemes are currently in place in Iceland, this concept is highly unfamiliar to Icelandic farmers. Nearly all respondents were unwilling, and thought it would be impossible, to delay harvest, but many were willing to consider sparing important patches of land and/or maintaining existing pools within fields (a key habitat feature for breeding waders. Farmers' views on the importance of having rich birdlife on their land and their willingness to participate in bird conservation provide a potential platform for the codesign of conservation management with landowners

  1. 87Sr/86Sr isotope fingerprinting of Scottish and Icelandic migratory shorebirds

    International Nuclear Information System (INIS)

    Evans, Jane; Bullman, Rhys

    2009-01-01

    Biosphere Sr isotope composition data from Iceland and Scotland suggest that terrestrially feeding birds from these two countries will have significantly different 87 Sr/ 86 Sr isotope composition in their tissues. The aim of this study is to test if these differences can be measured within the bone and feather of migratory wading birds, who feed terrestrially as juveniles, thus providing a provenance tool for these birds. The study shows that birds can be distinguished on the basis of the Sr isotope composition of their bone. The field for Icelandic birds is defined by data from juvenile common redshank (Tringa totanus) and whimbrel (Numenius phaeopus) which give 0.7056 ± 0.0012, (2σ, n = 7). The majority of Scottish birds in this study are from coastal regions and have a signature close to that of seawater of 0.7095 ± 0.0006 (2σ, n = 9). The Sr ratios in the body tissue of these two populations of all Icelandic and Scottish adult and juvenile birds analysed are significantly different (p 87 Sr/ 86 Sr values as high as 0.7194 which reflect their non-marine diet. Icelandic redshank (Tringa totanus robusta) that have flown to Scotland and returned to Iceland show the effect of the Scottish contribution to their diet with elevated values of 0.7086 ± 0.0004, (2σ, n = 6). Redshank found in Scotland that cannot be classified on the basis biometric analysis are shown to be of Icelandic origin and analysis of the primary feathers from two birds demonstrates that isotope variation between feathers could be used to track changes in diet related to the timing of individual feather growth.

  2. Non-native species in the vascular flora of highlands and mountains of Iceland

    Directory of Open Access Journals (Sweden)

    Pawel Wasowicz

    2016-01-01

    Full Text Available The highlands and mountains of Iceland are one of the largest remaining wilderness areas in Europe. This study aimed to provide comprehensive and up-to-date data on non-native plant species in these areas and to answer the following questions: (1 How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2 Do temporal trends in the immigration of alien species to Iceland differ between highland and lowland areas? (3 Does the incidence of alien species in the disturbed and undisturbed areas within Icelandic highlands differ? (4 Does the spread of non-native species in Iceland proceed from lowlands to highlands? and (5 Can we detect hot-spots in the distribution of non-native taxa within the highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive. Results showed that temporal trends in alien species immigration to highland and lowland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. Non-native plants tended to occur close to man-made infrastructure and buildings including huts, shelters, roads etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were identified using the Getis-Ord Gi* statistic and these were linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Iceland’s highlands and mountain areas.

  3. Decision Analysis Tools for Volcano Observatories

    Science.gov (United States)

    Hincks, T. H.; Aspinall, W.; Woo, G.

    2005-12-01

    Staff at volcano observatories are predominantly engaged in scientific activities related to volcano monitoring and instrumentation, data acquisition and analysis. Accordingly, the academic education and professional training of observatory staff tend to focus on these scientific functions. From time to time, however, staff may be called upon to provide decision support to government officials responsible for civil protection. Recognizing that Earth scientists may have limited technical familiarity with formal decision analysis methods, specialist software tools that assist decision support in a crisis should be welcome. A review is given of two software tools that have been under development recently. The first is for probabilistic risk assessment of human and economic loss from volcanic eruptions, and is of practical use in short and medium-term risk-informed planning of exclusion zones, post-disaster response, etc. A multiple branch event-tree architecture for the software, together with a formalism for ascribing probabilities to branches, have been developed within the context of the European Community EXPLORIS project. The second software tool utilizes the principles of the Bayesian Belief Network (BBN) for evidence-based assessment of volcanic state and probabilistic threat evaluation. This is of practical application in short-term volcano hazard forecasting and real-time crisis management, including the difficult challenge of deciding when an eruption is over. An open-source BBN library is the software foundation for this tool, which is capable of combining synoptically different strands of observational data from diverse monitoring sources. A conceptual vision is presented of the practical deployment of these decision analysis tools in a future volcano observatory environment. Summary retrospective analyses are given of previous volcanic crises to illustrate the hazard and risk insights gained from use of these tools.

  4. Radiographic closure time of appendicular growth plates in the Icelandic horse

    Directory of Open Access Journals (Sweden)

    Huse-Olsen Lisel

    2007-07-01

    Full Text Available Abstract Background The Icelandic horse is a pristine breed of horse which has a pure gene pool established more than a thousand years ago, and is approximately the same size as living and extinct wild breeds of horses. This study was performed to compare the length of the skeletal growth period of the "primitive" Icelandic horse relative to that reported for large horse breeds developed over the recent centuries. This information would provide practical guidance to owners and veterinarians as to when the skeleton is mature enough to commence training, and would be potentially interesting to those scientists investigating the pathogenesis of osteochondrosis. Interestingly, osteochondrosis has not been documented in the Icelandic horse. Methods The radiographic closure time of the appendicular growth plates was studied in 64 young Icelandic horses. The results were compared with previously published closure times reported for other, larger horse breeds. The radiographs were also examined for any signs of developmental orthopaedic diseases. In order to describe further the growth pattern of the Icelandic horse, the total serum alkaline phosphatase (ALP activity was determined and the height at the withers was measured. Results Most of the examined growth plates were fully closed at the age of approximately three years. The horses reached adult height at this age; however ALP activity was still mildly increased over baseline values. The growth plates in the digits were the first to close at 8.1 to 8.5 months of age, and those in the regions of the distal radius (27.4 to 32.0 months, tuber olecrani (31.5 to 32.2 months, and the stifle (27.0 to 40.1 months were the last to close. No horse was found to have osteochondrosis type lesions in the neighbouring joints of the evaluated growth plates. Conclusion The Icelandic horse appears to have similar radiographic closure times for most of the growth plates of its limbs as reported for large new breeds of

  5. Geothermal Exploration of Newberry Volcano, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Waibel, Albert F. [Columbia Geoscience, Pasco, WA (United States); Frone, Zachary S. [Southern Methodist Univ., Dallas, TX (United States); Blackwell, David D. [Southern Methodist Univ., Dallas, TX (United States)

    2014-12-01

    Davenport Newberry (Davenport) has completed 8 years of exploration for geothermal energy on Newberry Volcano in central Oregon. Two deep exploration test wells were drilled by Davenport on the west flank of the volcano, one intersected a hydrothermal system; the other intersected isolated fractures with no hydrothermal interconnection. Both holes have bottom-hole temperatures near or above 315°C (600°F). Subsequent to deep test drilling an expanded exploration and evaluation program was initiated. These efforts have included reprocessing existing data, executing multiple geological, geophysical, geochemical programs, deep exploration test well drilling and shallow well drilling. The efforts over the last three years have been made possible through a DOE Innovative Exploration Technology (IET) Grant 109, designed to facilitate innovative geothermal exploration techniques. The combined results of the last 8 years have led to a better understanding of the history and complexity of Newberry Volcano and improved the design and interpretation of geophysical exploration techniques with regard to blind geothermal resources in volcanic terrain.

  6. Electrical structure of Newberry Volcano, Oregon

    Science.gov (United States)

    Fitterman, D.V.; Stanley, W.D.; Bisdorf, R.J.

    1988-01-01

    From the interpretation of magnetotelluric, transient electromagnetic, and Schlumberger resistivity soundings, the electrical structure of Newberry Volcano in central Oregon is found to consist of four units. From the surface downward, the geoelectrical units are 1) very resistive, young, unaltered volcanic rock, (2) a conductive layer of older volcanic material composed of altered tuffs, 3) a thick resistive layer thought to be in part intrusive rocks, and 4) a lower-crustal conductor. This model is similar to the regional geoelectrical structure found throughout the Cascade Range. Inside the caldera, the conductive second layer corresponds to the steep temperature gradient and alteration minerals observed in the USGS Newberry 2 test-hole. Drill hole information on the south and north flanks of the volcano (test holes GEO N-1 and GEO N-3, respectively) indicates that outside the caldera the conductor is due to alteration minerals (primarily smectite) and not high-temperature pore fluids. On the flanks of Newberry the conductor is generally deeper than inside the caldera, and it deepens with distance from the summit. A notable exception to this pattern is seen just west of the caldera rim, where the conductive zone is shallower than at other flank locations. The volcano sits atop a rise in the resistive layer, interpreted to be due to intrusive rocks. -from Authors

  7. Monitoring active volcanoes: The geochemical approach

    Directory of Open Access Journals (Sweden)

    Takeshi Ohba

    2011-06-01

    Full Text Available

    The geochemical surveillance of an active volcano aims to recognize possible signals that are related to changes in volcanic activity. Indeed, as a consequence of the magma rising inside the volcanic "plumbing system" and/or the refilling with new batches of magma, the dissolved volatiles in the magma are progressively released as a function of their relative solubilities. When approaching the surface, these fluids that are discharged during magma degassing can interact with shallow aquifers and/or can be released along the main volcano-tectonic structures. Under these conditions, the following main degassing processes represent strategic sites to be monitored.

    The main purpose of this special volume is to collect papers that cover a wide range of topics in volcanic fluid geochemistry, which include geochemical characterization and geochemical monitoring of active volcanoes using different techniques and at different sites. Moreover, part of this volume has been dedicated to the new geochemistry tools.

  8. Nanoscale volcanoes: accretion of matter at ion-sculpted nanopores.

    Science.gov (United States)

    Mitsui, Toshiyuki; Stein, Derek; Kim, Young-Rok; Hoogerheide, David; Golovchenko, J A

    2006-01-27

    We demonstrate the formation of nanoscale volcano-like structures induced by ion-beam irradiation of nanoscale pores in freestanding silicon nitride membranes. Accreted matter is delivered to the volcanoes from micrometer distances along the surface. Volcano formation accompanies nanopore shrinking and depends on geometrical factors and the presence of a conducting layer on the membrane's back surface. We argue that surface electric fields play an important role in accounting for the experimental observations.

  9. The EVER-EST Virtual Research Environment for the European Volcano Supersites

    Science.gov (United States)

    Salvi, S.; Trasatti, E.; Rubbia, G.; Romaniello, V.; Marelli, F.

    2017-12-01

    EVER-EST (European Virtual Environment for Research - Earth Science Themes) is an European H2020 project (2015-2018) aimed at the creation of a Virtual Research Environment (VRE) for the Earth Sciences. The VRE is intended to enhance the ability to collaborate and share knowledge and experience among scientists. One of the innovations of the project is the exploitation of the "Research Object" concept (http://www.rohub.org). Research Objects encapsulate not only data and publications, but also algorithms, codes, results, and workflows that can be stored, shared and re-used. Four scientific communities are involved in the EVER-EST project: land monitoring, natural hazards, marine biology, and the GEO Geohazard Supersites community (http://www.earthobservations.org/gsnl.php). The latter is represented in the project by INGV and the University of Iceland, and has provided user requirements to tailor the VRE to the common needs of the worldwide Supersite communities. To develop and test the VRE we have defined user scenarios and created Research Objects embedding research activities and workflows on the Permanent Supersites Campi Flegrei, Mount Etna and Icelandic Volcanoes (http://vm1.everest.psnc.pl/supersites/). While these Supersites are test sites for the platform, during the last year of the project other Supersites may also be involved to demonstrate the added value of the collaborative environment in research activities aiming to support Disaster Risk Reduction. Using the VRE, scientists are able to collaborate with colleagues located in different parts of the world, in a simple and effective way. This includes being able to remotely access and share data, research results and ideas, to carry out training sessions and discussions, to compare different results and models, and to synthesize many different pieces of information in a single consensus product to be disseminated to end-users. In particular, a further need of the Supersite scientists, which can be

  10. Efficient inversion of volcano deformation based on finite element models : An application to Kilauea volcano, Hawaii

    Science.gov (United States)

    Charco, María; González, Pablo J.; Galán del Sastre, Pedro

    2017-04-01

    The Kilauea volcano (Hawaii, USA) is one of the most active volcanoes world-wide and therefore one of the better monitored volcanoes around the world. Its complex system provides a unique opportunity to investigate the dynamics of magma transport and supply. Geodetic techniques, as Interferometric Synthetic Aperture Radar (InSAR) are being extensively used to monitor ground deformation at volcanic areas. The quantitative interpretation of such surface ground deformation measurements using geodetic data requires both, physical modelling to simulate the observed signals and inversion approaches to estimate the magmatic source parameters. Here, we use synthetic aperture radar data from Sentinel-1 radar interferometry satellite mission to image volcano deformation sources during the inflation along Kilauea's Southwest Rift Zone in April-May 2015. We propose a Finite Element Model (FEM) for the calculation of Green functions in a mechanically heterogeneous domain. The key aspect of the methodology lies in applying the reciprocity relationship of the Green functions between the station and the source for efficient numerical inversions. The search for the best-fitting magmatic (point) source(s) is generally conducted for an array of 3-D locations extending below a predefined volume region. However, our approach allows to reduce the total number of Green functions to the number of the observation points by using the, above mentioned, reciprocity relationship. This new methodology is able to accurately represent magmatic processes using physical models capable of simulating volcano deformation in non-uniform material properties distribution domains, which eventually will lead to better description of the status of the volcano.

  11. Geologic map of Medicine Lake volcano, northern California

    Science.gov (United States)

    Donnelly-Nolan, Julie M.

    2011-01-01

    Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover more than 2,000 km2 east of the main axis of the Cascade Range in northern California. Across the Cascade Range axis to the west-southwest is Mount Shasta, its towering volcanic neighbor, whose stratocone shape contrasts with the broad shield shape of Medicine Lake volcano. Hidden in the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of Medicine Lake volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 8,000 ft (2,440 m). The maximum extent of lavas from this half-million-year-old volcano is about 80 km north-south by 45 km east-west. In postglacial time, 17 eruptions have added approximately 7.5 km3 to its total estimated volume of 600 km3, and it is considered to be the largest by volume among volcanoes of the Cascades arc. The volcano has erupted nine times in the past 5,200 years, a rate more frequent than has been documented at all other Cascades arc volcanoes except Mount St. Helens.

  12. The critical role of volcano monitoring in risk reduction

    Directory of Open Access Journals (Sweden)

    R. I. Tilling

    2008-01-01

    Full Text Available Data from volcano-monitoring studies constitute the only scientifically valid basis for short-term forecasts of a future eruption, or of possible changes during an ongoing eruption. Thus, in any effective hazards-mitigation program, a basic strategy in reducing volcano risk is the initiation or augmentation of volcano monitoring at historically active volcanoes and also at geologically young, but presently dormant, volcanoes with potential for reactivation. Beginning with the 1980s, substantial progress in volcano-monitoring techniques and networks – ground-based as well space-based – has been achieved. Although some geochemical monitoring techniques (e.g., remote measurement of volcanic gas emissions are being increasingly applied and show considerable promise, seismic and geodetic methods to date remain the techniques of choice and are the most widely used. Availability of comprehensive volcano-monitoring data was a decisive factor in the successful scientific and governmental responses to the reawakening of Mount St. elens (Washington, USA in 1980 and, more recently, to the powerful explosive eruptions at Mount Pinatubo (Luzon, Philippines in 1991. However, even with the ever-improving state-of-the-art in volcano monitoring and predictive capability, the Mount St. Helens and Pinatubo case histories unfortunately still represent the exceptions, rather than the rule, in successfully forecasting the most likely outcome of volcano unrest.

  13. Volcano-Monitoring Instrumentation in the United States, 2008

    Science.gov (United States)

    Guffanti, Marianne; Diefenbach, Angela K.; Ewert, John W.; Ramsey, David W.; Cervelli, Peter F.; Schilling, Steven P.

    2010-01-01

    The United States is one of the most volcanically active countries in the world. According to the global volcanism database of the Smithsonian Institution, the United States (including its Commonwealth of the Northern Mariana Islands) is home to about 170 volcanoes that are in an eruptive phase, have erupted in historical time, or have not erupted recently but are young enough (eruptions within the past 10,000 years) to be capable of reawakening. From 1980 through 2008, 30 of these volcanoes erupted, several repeatedly. Volcano monitoring in the United States is carried out by the U.S. Geological Survey (USGS) Volcano Hazards Program, which operates a system of five volcano observatories-Alaska Volcano Observatory (AVO), Cascades Volcano Observatory (CVO), Hawaiian Volcano Observatory (HVO), Long Valley Observatory (LVO), and Yellowstone Volcano Observatory (YVO). The observatories issue public alerts about conditions and hazards at U.S. volcanoes in support of the USGS mandate under P.L. 93-288 (Stafford Act) to provide timely warnings of potential volcanic disasters to the affected populace and civil authorities. To make efficient use of the Nation's scientific resources, the volcano observatories operate in partnership with universities and other governmental agencies through various formal agreements. The Consortium of U.S. Volcano Observatories (CUSVO) was established in 2001 to promote scientific cooperation among the Federal, academic, and State agencies involved in observatory operations. Other groups also contribute to volcano monitoring by sponsoring long-term installation of geophysical instruments at some volcanoes for specific research projects. This report describes a database of information about permanently installed ground-based instruments used by the U.S. volcano observatories to monitor volcanic activity (unrest and eruptions). The purposes of this Volcano-Monitoring Instrumentation Database (VMID) are to (1) document the Nation's existing

  14. Data assimilation strategies for volcano geodesy

    Science.gov (United States)

    Zhan, Yan; Gregg, Patricia M.

    2017-09-01

    Ground deformation observed using near-real time geodetic methods, such as InSAR and GPS, can provide critical information about the evolution of a magma chamber prior to volcanic eruption. Rapid advancement in numerical modeling capabilities has resulted in a number of finite element models targeted at better understanding the connection between surface uplift associated with magma chamber pressurization and the potential for volcanic eruption. Robust model-data fusion techniques are necessary to take full advantage of the numerical models and the volcano monitoring observations currently available. In this study, we develop a 3D data assimilation framework using the Ensemble Kalman Filter (EnKF) approach in order to combine geodetic observations of surface deformation with geodynamic models to investigate volcanic unrest. The EnKF sequential assimilation method utilizes disparate data sets as they become available to update geodynamic models of magma reservoir evolution. While the EnKF has been widely applied in hydrologic and climate modeling, the adaptation for volcano monitoring is in its initial stages. As such, our investigation focuses on conducting a series of sensitivity tests to optimize the EnKF for volcano applications and on developing specific strategies for assimilation of geodetic data. Our numerical experiments illustrate that the EnKF is able to adapt well to the spatial limitations posed by GPS data and the temporal limitations of InSAR, and that specific strategies can be adopted to enhance EnKF performance to improve model forecasts. Specifically, our numerical experiments indicate that: (1) incorporating additional iterations of the EnKF analysis step is more efficient than increasing the number of ensemble members; (2) the accuracy of the EnKF results are not affected by initial parameter assumptions; (3) GPS observations near the center of uplift improve the quality of model forecasts; (4) occasionally shifting continuous GPS stations to

  15. In situ measurement of the Icelandic Holuhraun/ Bárðarbunga volcanic plume in an early "young state" using a LOAC

    Science.gov (United States)

    Vignelles, Damien; Roberts, Tjarda; Carboni, Elisa; Ilyinskaya, Evgenia; Dagsson Waldhauserovà, Pavla; Berthet, Gwenael; Jegou, Fabrice; Baptiste Renard, Jean; Olafsson, Haraldur; Bergsson, Baldur; Yeo, Richard; Fannar Reynisson, Njall; Grainger, Roy; Pfeffer, Melissa; Lurton, Thibaut; Duverger, Vincent; Coute, Benoit

    2016-04-01

    Volcanic eruptions have huge societal and economic consequences. In Iceland, one of the best known examples is the Laki eruption (1783-84 CE) (Thordarson and Self, 2003) which caused the death of > 20% of the Icelandic populations and likely increased European levels of mortality through air pollution (Witham and Oppenheimer, 2004). The recent fissure eruption at Holuhraun (31 August 2014 - 27 February 2015) was a major source of sulfur gases and aerosols and caused also both local and European-wide deteriorations to air quality (Gislason et al. 2015; Schmidt et al. 2015). The capability of atmospheric models to predict volcanic plume impacts is limited by uncertainties in the near-source plume state. Most in-situ measurements of the elevated plume involve interception of aged plumes that have already chemically or physically evolved. Small portable sensors airborne drone or balloon platforms offer a new possibility to characterize volcano plumes near to source. We present the results of a balloon flight through the plume emitted by Baugur the main vent during the night of the January 22th 2015. The balloon carrying a LOAC (Renard et al. 2015) has intercepted the plume at 8km distance downwind from the crater which represents a plume age of approximately 15 minutes. The plume was located in altitude between 2 and 3.1km above the sea level. Two layers were observed, a non-condensed lower layer and a condensed upper layer. The lower layer of 400m thick was characterized by a mode of fine particles centered on 0.2μm in diameter and a second mode centered on 2.3μm in diameter and a total particle concentration around 100 particles per cubic centimeter. The upper layer of 800m thick was a cloud-like signature with droplets centered on 20 μm in diameter and a fine mode, the total particles concentrations was 10 times higher than the first layer. The plume top height was determined between 2.7 and 3.1 km, the plume height is in good agreement with an estimate made by

  16. Childbearing trends in Iceland, 1982-2013: Fertility timing, quantum, and gender preferences for children in a Nordic context

    Directory of Open Access Journals (Sweden)

    Ari Klængur Jónsson

    2017-07-01

    Full Text Available Background: Iceland is one of the most gender-equal countries in the world, but one that does not seem to have experienced the same fertility fluctuations as most other countries, following the enhanced role of women in society. Objective: In this study we examine the childbearing trends in Iceland during 1982-2013 by analysing the progressions to parities one, two, and three. We also investigate whether there is evidence of gender preferences for children among Icelandic parents. Methods: Official individual longitudinal register data is used, covering the total female population born in Iceland between 1941 and 1997. The data is analysed by means of event history analysis. Results: We find evidence of tendencies to postpone motherhood during the period, with increases in fertility for women in their 30s and 40s. The propensity to have a second and a third child has not declined; on the contrary, these birth intensities have increased since the mid-1980s. Estimates suggest that Icelandic parents prefer to have daughters. Conclusions: During a period of increased educational attainment and postponed family formation, the resilience of Icelandic fertility is intriguing. Contribution: The study provides the first comprehensive overview of fertility trends in Iceland.

  17. Climate-driven vertical acceleration of Icelandic crust measured by continuous GPS geodesy

    KAUST Repository

    Compton, Kathleen

    2015-02-06

    © 2015 The Authors. Earth\\'s present-day response to enhanced glacial melting resulting from climate change can be measured using Global Positioning System (GPS) technology. We present data from 62 continuously operating GPS instruments in Iceland. Statistically significant upward velocity and accelerations are recorded at 27 GPS stations, predominantly located in the Central Highlands region of Iceland, where present-day thinning of the Iceland ice caps results in velocities of more than 30mm/yr and uplift accelerations of 1-2mm/yr2. We use our acceleration estimates to back calculate to a time of zero velocity, which coincides with the initiation of ice loss in Iceland from ice mass balance calculations and Arctic warming trends. We show, through a simple inversion, a direct relationship between ice mass balance measurements and vertical position and show that accelerated unloading is required to reproduce uplift observations for a simple elastic layer over viscoelastic half-space model.

  18. Early Behavioral Self-Regulation, Academic Achievement, and Gender: Longitudinal Findings from France, Germany, and Iceland

    Science.gov (United States)

    Gestsdottir, Steinunn; von Suchodoletz, Antje; Wanless, Shannon B.; Hubert, Blandine; Guimard, Philippe; Birgisdottir, Freyja; Gunzenhauser, Catherine; McClelland, Megan

    2014-01-01

    Research suggests that behavioral self-regulation skills are critical for early school success, but few studies have explored such links among young children in Europe. This study examined the contribution of early self-regulation to academic achievement gains among children in France, Germany, and Iceland. Gender differences in behavioral…

  19. Internet Gambling and Problem Gambling among 13 to 18 Year Old Adolescents in Iceland

    Science.gov (United States)

    Olason, Daniel Thor; Kristjansdottir, Elsa; Einarsdottir, Hafdis; Haraldsson, Haukur; Bjarnason, Geir; Derevensky, Jeffrey L.

    2011-01-01

    This study reports findings on Internet gambling and problem gambling among Icelandic youth. Participants were 1.537 13-18 year-old students, 786 boys and 747 girls. Results revealed that 56.6% had gambled at least once in the past 12 months and 24.3% on the Internet. Gender and developmental differences were found for Internet gambling, as boys…

  20. The Role of Choral Singing in the Lives of Amateur Choral Singers in Iceland

    Science.gov (United States)

    Einarsdottir, Sigrun Lilja; Gudmundsdottir, Helga Rut

    2016-01-01

    The purpose of this study was to investigate what motivates people to sing in choirs as a leisure activity. Subjects were retrieved from members of 10 amateur choirs of various types in Iceland through a paper-based survey. Results indicated that participants gain both personal and social benefits from singing in a choir. Findings revealed…

  1. Interaction of the Faroe Bank Channel overflow with Iceland Basin intermediate waters

    Science.gov (United States)

    Ullgren, Jenny E.; Fer, Ilker; Darelius, Elin; Beaird, Nicholas

    2014-01-01

    The narrow and deep Faroe Bank Channel (FBC) is an important pathway for cold, dense waters from the Nordic Seas to flow across the Iceland-Scotland ridge into the North Atlantic. The swift, turbulent FBC overflow is associated with strong vertical mixing. Hydrographic profiles from a shipboard survey and two Slocum electric gliders deployed during a cruise in May-June 2012 show an intermediate water mass characterized by low salinity and low oxygen concentration between the upper waters of Atlantic origin and the dense overflow water. A weak low-salinity signal originating north-east of Iceland is discernible at the exit of the FBC, but smeared out by intense mixing. Further west (downstream) marked salinity and oxygen minima are found, which we hypothesize are indicators of a mixture of Labrador Sea Water and Intermediate Water from the Iceland Basin. Water mass characteristics vary strongly on short time scales. Low-salinity, low-oxygen water in the stratified interface above the overflow plume is shown to move along isopycnals toward the Iceland-Faroe Front as a result of eddy stirring and a secondary, transverse circulation in the plume interface. The interaction of low-salinity, low-oxygen intermediate waters with the overflow plume already at a short distance downstream of the sill, here reported for the first time, affects the final properties of the overflow waters through entrainment and mixing.

  2. Influence of Day Length and Physical Activity on Sleep Patterns in Older Icelandic Men and Women

    DEFF Research Database (Denmark)

    Brychta, Robert J; Arnardóttir, Nanna Ýr; Jóhannsson, Erlingur

    2016-01-01

    Study Objectives: To identify cross-sectional and seasonal patterns of sleep and physical activity (PA) in community-dwelling, older Icelandic adults using accelerometers. Methods: A seven-day free-living protocol of 244 (110 female) adults aged 79.7 +/- 4.9 years was conducted as part of a larger...

  3. Environmental Education. University Level. 10 Years Development; Recommendations. Denmark, Finland, Iceland, Norway, Sweden.

    Science.gov (United States)

    Nordic Council of Ministers, Copenhagen (Denmark).

    The Nordic countries have worked together over the last decade to enhance the efforts of environmental educators. This document details: (1) the history and activities of the group responsible for the coordination of efforts at the university level; (2) the types of environmental education occurring in Denmark, Iceland, Finland, Norway, and…

  4. Was it for walrus? Viking Age settlement and medieval walrus ivory trade in Iceland and Greenland

    DEFF Research Database (Denmark)

    Frei, Karin M.; Coutu, Ashley N.; Smiarowski, Konrad

    2015-01-01

    Walrus-tusk ivory and walrus-hide rope were highly desired goods in Viking Age north-west Europe. New finds of walrus bone and ivory in early Viking Age contexts in Iceland are concentrated in the south-west, and suggest extensive exploitation of nearby walrus for meat, hide and ivory during the ...

  5. The use of geothermal energy at a chieftan's farm in medieval Iceland

    Directory of Open Access Journals (Sweden)

    Gudrun Sveinbjarnardottir

    2003-10-01

    Full Text Available Archaeological investigations at the farm site of Reykholt, in the Reykholtsdalur valley in western Iceland (Fig. 1 , have produced evidence of sophisticated use of geothermal energy in the medieval period that is unmatched by comparable finds elsewhere in this geothermally and volcanically active country.

  6. Glacio-meteorological investigations on Vatnajökull, Iceland, summer 1996: an overview

    NARCIS (Netherlands)

    Oerlemans, J.; Björnsson, H.; Kuhn, M.; Obleitner, F.; Palsson, F.; Smeets, C.J.P.P.; Vugts, H.F.; Wolde, J. de

    1999-01-01

    We give an overview of a glacio-meteorological experiment carried out in the summer (melt season) of 1996 on the largest European ice cap, Vatnajökull, Iceland (area 8000 km2; altitude range: from sea level to about 2000 m). The main goal was to understand how the energy used in the melting of snow

  7. Design and Craft Education in Iceland, Pedagogical Background and Development: A Literature Review

    Science.gov (United States)

    Olafsson, Brynjar; Thorsteinsson, Gisli

    2009-01-01

    Sloyd pedagogy was introduced towards the close of the 18th century to Icelandic educators. Subsequently craft was established as a specific subject aimed at general education. In the beginning craft was called "school industry," to distinguish it from "home industry" whose aim was to help homes to be self-sufficient for…

  8. An Action Research Study in an Icelandic Preschool: Developing Consensus about Values and Values Education

    Science.gov (United States)

    Sigurdardottir, Ingibjorg; Einarsdottir, Johanna

    2016-01-01

    Values education is embedded in the curricula of all the Nordic countries. However, values education remains a neglected area for research and practice in early childhood education and care. This article reports on the aspects of an action research project conducted in a preschool in Iceland, across a period of 18 months. The study focused on the…

  9. Learning Icelandic Language and Culture in Virtual Reykjavik: Starting to Talk

    Science.gov (United States)

    Bédi, Branislav; Arnbjörnsdóttir, Birna; Vilhjálmsson, Hannes Högni; Helgadóttir, Hafdís Erla; Ólafsson, Stefán; Björgvinsson, Elías

    2016-01-01

    This paper describes how beginners of Icelandic as a foreign and second language responded to playing the first scene in Virtual Reykjavik, a video game-like environment where learners interact with virtual characters--Embodied Conversational Agents (ECAs). This game enables learners to practice speaking and listening skills, to learn about the…

  10. How to deal with the collapse of a banking system the Icelandic way

    DEFF Research Database (Denmark)

    Solnes, Valgerdur

    2016-01-01

    In the fall of 2008, a crisis materialized in the global financial markets, creating the imminent risk of collapse in Icelandic's largest financial institutions and the banking system as a whole. The perilous situation originated in similar conditions that formed overseas in the US and around...

  11. Paleomagnetism and geochronology of the Pliocene-Pleistocene lavas in Iceland

    NARCIS (Netherlands)

    McDougall, Ian; Wensink, H.

    Potassium-argon dates are reported on five basalt samples from the Pliocene-Pleistocene sequence of lavas in the Jökuldalur area, northeastern Iceland. These dates confirm the correlations previously made with the geological time scale by means of paleomagnetic stratigraphy. The R1 and N2 polarity

  12. Body condition score, morphometric measurements and estimation of body weight in mature Icelandic horses in Denmark

    DEFF Research Database (Denmark)

    Jensen, Rasmus Bovbjerg; Danielsen, Signe H.; Tauson, Anne-Helene

    2016-01-01

    Background: Obesity is related to the development of several diseases like insulin resistance and laminitis in horses. The prevalence of obesity among mature Icelandic horses in Denmark has not been investigated previously. This study aimed to find the prevalence of obesity, to compare body condi...

  13. Manifestations of Heterosexism in Icelandic Upper Secondary Schools and the Responses of LGBT Students

    Science.gov (United States)

    Kjaran, Jón Ingvar; Jóhannesson, Ingólfur Ásgeir

    2013-01-01

    How does institutionalized heterosexism manifest itself in Icelandic upper secondary schools and how do lesbian, gay, bisexual, and transgender (LGBT) students respond to these manifestations? In addressing these questions, interviews were conducted with six current and former LGBT upper secondary school students, using queer theory and thematic…

  14. Schooling Sexualities and Gendered Bodies. Experiences of LGBT Students in Icelandic Upper Secondary Schools

    Science.gov (United States)

    Kjaran, Jón Ingvar; Kristinsdóttir, Guðrún

    2015-01-01

    In this paper, we study how Lesbian, Gay, Bisexual and Transgender people (LGBT) students in Icelandic upper secondary schools interpret their experience of heteronormative environment and how they respond to it. The aim is to explore how sexualities and gendered bodies are constructed through "schooling". The article draws on interview…

  15. Leading the Small Rural School in Iceland and Australia: Building Leadership Capacity

    Science.gov (United States)

    Wildy, Helen; Siguräardóttir, Sigríäur Margrét; Faulkner, Robert

    2014-01-01

    This study builds on a set of Australian case studies exploring the impact of Place on the work of principals and of the importance of Place in the preparation and development of principals. The project compares the ways that principals in Iceland and Australia build leadership capacity in small rural schools. Leaders of small schools in both…

  16. CITY, COUNTRYSIDE AND NATURE AS DISCURSIVE DEVICES USED TO STRENGTHEN THE NATIONAL IDENTITY IN ICELANDIC CINEMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Jakub Sebastian Konefał

    2015-03-01

    Full Text Available Since its inception the Icelandic film industry has used the strategy of combining telluric elements with national- istic narratives. In many films one may also find visual structures that can be linked with the ‘tourist gaze’ – the term as we know it from the texts of John Urry. Despite a focus on some unique qualities of Icelandic nature and its cultural heritage (that can be attractive to foreign viewers the specificity of cinematic production processes on the island belong to the structure of local, national cinema. Moreover, the 1980s, considered as the time of the rebirth of the Icelandic film industry and its rapid modernization, are full of films containing conservative or leftist telluric topics which are difficult for foreign audiences to understand. A new, transnational quality of Icelandic film features began with the film debut of Friðrik Þór Friðriksson in 1987. His fusion of modernist and postmodernist plots has encouraged other filmmakers to start the process of re-interpretation of the classic narrative structures, and to render the ironic demystification of some nationalistic themes.

  17. Optimum Safety Levels and Design Rules for the Icelandic-Type Berm Breakwater

    DEFF Research Database (Denmark)

    Sigurdarson, Sigurdur; van der Meer, Jentsje W.; Burcharth, Hans F.

    2009-01-01

    strategies and possible failure with corresponding downtime have been taken into account, as well as actual market prices (in Iceland and Norway) for rack material and construction. Calculations show that low stability numbers for the largest rock armour layer give the optimal safety level....

  18. Kernel based pattern analysis methods using eigen-decompositions for reading Icelandic sagas

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman; Carstensen, Jens Michael

    We want to test the applicability of kernel based eigen-decomposition methods, compared to the traditional eigen-decomposition methods. We have implemented and tested three kernel based methods methods, namely PCA, MAF and MNF, all using a Gaussian kernel. We tested the methods on a multispectral...... image of a page in the book 'hauksbok', which contains Icelandic sagas....

  19. Development of Bioavailable Pools of Base Cations and P after Afforestation of Volcanic Soils in Iceland

    DEFF Research Database (Denmark)

    Ritter, Eva

    2009-01-01

    Few long-term studies have been conducted on changes in soil nutrients after afforestation in Iceland, a country with a young history of forest management. While fertilization was shown to improve survival of seedlings in the first years after planting on the nutrient limited soils, knowledge about...

  20. [Scientific articles in the Icelandic Medical Journal 2004-2008: an overview].

    Science.gov (United States)

    Gudbjartsson, Tómas; Sigurdsson, Engilbert

    2009-10-01

    In the past 5 years the Icelandic Medical Journal has undergone many changes during a period of flourishing research in Iceland. The process of reviewing and editing scientific articles has been revised since the Journal joined the Medline database in 2005 and the proportion of rejected articles has risen. New columns have been launched covering medical history, professionalism, ethics and hobbies of the medical profession. We categorized all scientific articles from the period 2004-2008, that is research articles, review articles, case reports and clinical guidelines, according to types of articles and to which medical speciality or subspeciality the publication should belong. The number of scientific articles rose during the period but the number of research articles remained around 20 most years during the period. The relative proportion of research articles therefore fell whereas the number and proportion of review articles and case reports increased. Clinical guidelines ceased to appear in the Journal. The contribution of individual specialities to the Journal varied widely. Researchers amongst doctors and related professions need be encouraged to submit scientific articles to the Journal. The publication of scientific articles in English in the web-based form of the Journal may prove to be stimulating in this regard for Icelandic doctors abroad as well as for some researchers in Iceland.

  1. A chironomid-based reconstruction of summer temperatures in NW Iceland since AD 1650

    Science.gov (United States)

    Langdon, P. G.; Caseldine, C. J.; Croudace, I. W.; Jarvis, S.; Wastegård, S.; Crowford, T. C.

    2011-05-01

    Few studies currently exist that aim to validate a proxy chironomid-temperature reconstruction with instrumental temperature measurements. We used a reconstruction from a chironomid percentage abundance data set to produce quantitative summer temperature estimates since AD 1650 for NW Iceland through a transfer function approach, and validated the record against instrumental temperature measurements from Stykkishólmur in western Iceland. The core was dated through Pb-210, Cs-137 and tephra analyses (Hekla 1693) which produced a well-constrained dating model across the whole study period. Little catchment disturbance, as shown through geochemical (Itrax) and loss-on-ignition data, throughout the period further reinforce the premise that the chironomids were responding to temperature and not other catchment or within-lake variables. Particularly cold phases were identified between AD 1683-1710, AD 1765-1780 and AD 1890-1917, with relative drops in summer temperatures in the order of 1.5-2°C. The timing of these cold phases agree well with other evidence of cooler temperatures, notably increased extent of Little Ice Age (LIA) glaciers. Our evidence suggests that the magnitude of summer temperature cooling (1.5-2°C) was enough to force LIA Icelandic glaciers into their maximum Holocene extent, which is in accordance with previous modelling experiments for an Icelandic ice cap (Langjökull).

  2. Volcanic risk and tourism in southern Iceland: Implications for hazard, risk and emergency response education and training

    Science.gov (United States)

    Bird, Deanne K.; Gisladottir, Gudrun; Dominey-Howes, Dale

    2010-01-01

    This paper examines the relationship between volcanic risk and the tourism sector in southern Iceland and the complex challenge emergency management officials face in developing effective volcanic risk mitigation strategies. An early warning system and emergency response procedures were developed for communities surrounding Katla, the volcano underlying the Mýrdalsjökull ice cap. However, prior to and during the 2007 tourist season these mitigation efforts were not effectively communicated to stakeholders located in the tourist destination of Þórsmörk despite its location within the hazard zone of Katla. The hazard zone represents the potential extent of a catastrophic jökulhlaup (glacial outburst flood). Furthermore, volcanic risk mitigation efforts in Þórsmörk were based solely on information derived from physical investigations of volcanic hazards. They did not consider the human dimension of risk. In order to address this gap and provide support to current risk mitigation efforts, questionnaire surveys were used to investigate tourists' and tourism employees' hazard knowledge, risk perception, adoption of personal preparedness measures, predicted behaviour if faced with a Katla eruption and views on education. Results indicate that tourists lack hazard knowledge and they do not adopt preparedness measures to deal with the consequences of an eruption. Despite a high level of risk perception, tourism employees lack knowledge about the early warning system and emergency response procedures. Results show that tourists are positive about receiving information concerning Katla and its hazards and therefore, the reticence of tourism employees with respect to disseminating hazard information is unjustified. In order to improve the tourism sector's collective capacity to positively respond during a future eruption, recommendations are made to ensure adequate dissemination of hazard, risk and emergency response information. Most importantly education campaigns

  3. Locking depth and slip-rate of the Húsavík Flatey fault, North Iceland, derived from continuous GPS data 2006-2010

    KAUST Repository

    Metzger, Sabrina

    2011-11-01

    Located at the northern shore of Iceland, the Tjörnes Fracture Zone (TFZ) is a 120 km offset in the mid-Atlantic Ridge that connects the offshore Kolbeinsey Ridge to the on-land Northern Volcanic Zone. This transform zone is seismically one of the most active areas in Iceland, exposing the population to a significant risk. However, the kinematics of the mostly offshore area with its complex tectonics have not been adequately resolved and the seismic potential of the two main transform structures within the TFZ, the Grímsey Oblique Rift (GOR) and the Húsavík Flatey Fault (HFF) in particular, is not well known. In summer 2006, we expanded the number of continuous GPS (CGPS) stations in the area from 4 to 14. The resulting GPS velocities after four years of data collection show that the TFZ accommodates the full plate motion as it is predicted by the MORVEL plate motion model. In addition, ENVISAT interferograms reveal a transient uplift signal at the nearby Theistareykir central volcano with a maximum line-of-sight uplift of 3 cm between summers of 2007 and 2008. We use a combination of an interseismic backslip and a Mogi model in a homogeneous, elastic half-space to describe the kinematics within the TFZ. With a non-linear optimization approach we fit the GPS observations and estimate the key model parameters and their uncertainties, which are (among others) the locking depth, the partition of the transform motion between the two transform structures within the TFZ and the slip rate on the HFF. We find a shallow locking depth of 6.3+1.7- 1.2 km and transform motion that is accommodated 34 ± 3 per cent by the HFF and 66 ± 3 per cent by the GOR, resulting in a slip velocity of 6.6 ± 0.6 mm yr-1 for the HFF. Assuming steady accumulation since the last two large M6.5 earthquakes in 1872 the seismic potential of the fault is equivalent to a Mw6.8 ± 0.1 event.

  4. Quantitative impact of hydrothermal alteration on electrical resistivity in geothermal systems from a joint analysis of laboratory measurements and borehole data in Krafla area, N-E Iceland

    Science.gov (United States)

    Lévy, Léa; Páll Hersir, Gylfi; Flóvenz, Ólafur; Gibert, Benoit; Pézard, Philippe; Sigmundsson, Freysteinn; Briole, Pierre

    2016-04-01

    Rock permeability and fluid temperature are the two most decisive factors for a successful geothermal drilling. While those parameters are only measured from drilling, they might be estimated on the basis of their impact on electrical resistivity that might be imaged from surface soundings, for example through TEM (Transient Electro Magnetic) down to one km depth. The electrical conductivity of reservoir rocks is the sum of a volume term depending on fluid parameters and a surface term related to rock alteration. Understanding the link between electrical resistivity and geothermal key parameters requires the knowledge of hydrothermal alteration and its petrophysical signature with the Cation Exchange Capacity (CEC). Fluid-rock interactions related to hydrothermal circulation trigger the precipitation of alteration minerals, which are both witnesses of the temperature at the time of reaction and new paths for the electrical current. Alteration minerals include zeolites, smectites, chlorites, epidotes and amphiboles among which low temperatures parageneses are often the most conductive. The CEC of these mineral phases contributes to account for surface conductivity occuring at the water-rock interface. In cooling geothermal systems, these minerals constitute in petrophysical terms and from surface electrical conduction a memory of the equilibrium phase revealed from electrical probing at all scales. The qualitative impact of alteration minerals on resistivity structure has been studied over the years in the Icelandic geothermal context. In this work, the CEC impact on pore surfaces electrical conductivity is studied quantitatively at the borehole scale, where several types of volcanic rocks are mixed together, with various degrees of alteration and porosity. Five boreholes located within a few km at the Krafla volcano, Northeast Iceland, constitute the basis for this study. The deepest and reference hole, KJ-18, provides cuttings of rock and logging data down to 2215

  5. Seasonal rural residence of Icelandic children Sendur í sveit

    Directory of Open Access Journals (Sweden)

    Jónína Einarsdóttir

    2012-06-01

    Full Text Available Research that focuses on children who migrate without a parent or legal guardian is most often carried out in low-income countries. Such migration is increasingly associated with child trafficking. In this article the Icelandic custom to send children to the country during the summer months in the last century will be examined. It is based on secondary documents such as journals, magazines, documents and reports from child protection authorities. The Icelandic population shared the opinion that seasonal rural residence for urban children was beneficial for the nation, the family and the child. In the country, the children would enjoy unspoiled nature, clean mountain air and nutritious food. In addition, they would learn to attend animals and proper work. Individuals, associations, charities and child protection authorities collaborated in an effort to organise rural residence for children during the summer months, either at farms or particular summer camps. Rural residence was considered to be particularly important for delinquent children, but also those who suffered from poverty, irresponsible parental behaviour and poor health. Data is lacking on the number of children sent to the country and their experiences however it is known to have varied greatly. Likewise, little is known about the considerations of the farmers who hosted the children and the children’s parents. This custom is typically per definition child migration without a parent or legal guardian. Care should be taken not to classify such customs routinely as child trafficking wherever they are practiced.Rannsóknir á búferlaflutningi barna til lengri eða skemmri tíma án samfylgdar foreldris eða löggilds forráðamanns beinast oftast að börnum sem flytja úr einum stað í annan innan eða milli lágtekjulanda. Slíkur flutningur er oft bendlaður við mansal. Hér er skoðaður siðurinn að senda íslensk börn í sveit þar sem þau dvöldu að sumri til hjá venslaf

  6. Preliminary Volcano-Hazard Assessment for Gareloi Volcano, Gareloi Island, Alaska

    Science.gov (United States)

    Coombs, Michelle L.; McGimsey, Robert G.; Browne, Brandon L.

    2008-01-01

    Gareloi Volcano (178.794 degrees W and 51.790 degrees N) is located on Gareloi Island in the Delarof Islands group of the Aleutian Islands, about 2,000 kilometers west-southwest of Anchorage and about 150 kilometers west of Adak, the westernmost community in Alaska. This small (about 8x10 kilometer) volcano has been one of the most active in the Aleutians since its discovery by the Bering expedition in the 1740s, though because of its remote location, observations have been scant and many smaller eruptions may have gone unrecorded. Eruptions of Gareloi commonly produce ash clouds and lava flows. Scars on the flanks of the volcano and debris-avalanche deposits on the adjacent seafloor indicate that the volcano has produced large landslides in the past, possibly causing tsunamis. Such events are infrequent, occurring at most every few thousand years. The primary hazard from Gareloi is airborne clouds of ash that could affect aircraft. In this report, we summarize and describe the major volcanic hazards associated with Gareloi.

  7. Volcano art at Hawai`i Volcanoes National Park—A science perspective

    Science.gov (United States)

    Gaddis, Ben; Kauahikaua, James P.

    2018-03-26

    Long before landscape photography became common, artists sketched and painted scenes of faraway places for the masses. Throughout the 19th century, scientific expeditions to Hawaiʻi routinely employed artists to depict images for the people back home who had funded the exploration and for those with an interest in the newly discovered lands. In Hawaiʻi, artists portrayed the broad variety of people, plant and animal life, and landscapes, but a feature of singular interest was the volcanoes. Painters of early Hawaiian volcano landscapes created art that formed a cohesive body of work known as the “Volcano School” (Forbes, 1992). Jules Tavernier, Charles Furneaux, and D. Howard Hitchcock were probably the best known artists of this school, and their paintings can be found in galleries around the world. Their dramatic paintings were recognized as fine art but were also strong advertisements for tourists to visit Hawaiʻi. Many of these masterpieces are preserved in the Museum and Archive Collection of Hawaiʻi Volcanoes National Park, and in this report we have taken the opportunity to match the artwork with the approximate date and volcanological context of the scene.

  8. Evolution of deep crustal magma structures beneath Mount Baekdu volcano (MBV) intraplate volcano in northeast Asia

    Science.gov (United States)

    Rhie, J.; Kim, S.; Tkalcic, H.; Baag, S. Y.

    2017-12-01

    Heterogeneous features of magmatic structures beneath intraplate volcanoes are attributed to interactions between the ascending magma and lithospheric structures. Here, we investigate the evolution of crustal magmatic stuructures beneath Mount Baekdu volcano (MBV), which is one of the largest continental intraplate volcanoes in northeast Asia. The result of our seismic imaging shows that the deeper Moho depth ( 40 km) and relatively higher shear wave velocities (>3.8 km/s) at middle-to-lower crustal depths beneath the volcano. In addition, the pattern at the bottom of our model shows that the lithosphere beneath the MBV is shallower (interpret the observations as a compositional double layering of mafic underplating and a overlying cooled felsic structure due to fractional crystallization of asthenosphere origin magma. To achieve enhanced vertical and horizontal model coverage, we apply two approaches in this work, including (1) a grid-search based phase velocity measurement using real-coherency of ambient noise data and (2) a transdimensional Bayesian joint inversion using multiple ambient noise dispersion data.

  9. Understanding cyclic seismicity and ground deformation patterns at volcanoes: Intriguing lessons from Tungurahua volcano, Ecuador

    Science.gov (United States)

    Neuberg, Jürgen W.; Collinson, Amy S. D.; Mothes, Patricia A.; Ruiz, Mario C.; Aguaiza, Santiago

    2018-01-01

    Cyclic seismicity and ground deformation patterns are observed on many volcanoes worldwide where seismic swarms and the tilt of the volcanic flanks provide sensitive tools to assess the state of volcanic activity. Ground deformation at active volcanoes is often interpreted as pressure changes in a magmatic reservoir, and tilt is simply translated accordingly into inflation and deflation of such a reservoir. Tilt data recorded by an instrument in the summit area of Tungurahua volcano in Ecuador, however, show an intriguing and unexpected behaviour on several occasions: prior to a Vulcanian explosion when a pressurisation of the system would be expected, the tilt signal declines significantly, hence indicating depressurisation. At the same time, seismicity increases drastically. Envisaging that such a pattern could carry the potential to forecast Vulcanian explosions on Tungurahua, we use numerical modelling and reproduce the observed tilt patterns in both space and time. We demonstrate that the tilt signal can be more easily explained as caused by shear stress due to viscous flow resistance, rather than by pressurisation of the magmatic plumbing system. In general, our numerical models prove that if magma shear viscosity and ascent rate are high enough, the resulting shear stress is sufficient to generate a tilt signal as observed on Tungurahua. Furthermore, we address the interdependence of tilt and seismicity through shear stress partitioning and suggest that a joint interpretation of tilt and seismicity can shed new light on the eruption potential of silicic volcanoes.

  10. High Proportions of Sub-micron Particulate Matter in Icelandic Dust Storms in 2015

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur; Magnusdottir, Agnes

    2017-04-01

    Iceland is extremely active dust region and desert areas of over 44,000 km2 acknowledge Iceland as the largest Arctic and European desert. Frequent dust events, up to 135 dust days annually, transport dust particles far distances towards the Arctic and Europe. Satellite MODIS pictures have revealed dust plumes exceeding 1,000 km. The annual dust deposition was calculated as 40.1 million tons yr-1. Two dust storms were measured in transverse horizontal profile about 90 km far from different dust sources in southwestern Iceland in the summer of 2015. Aerosol monitor DustTrak DRX 8533EP was used to measure PM mass concentrations corresponding to PM1, PM2.5, PM4, PM10 and the total PM15 at several places within the dust plume. Images from camera network operated by the Icelandic Road and Coastal Administration were used to estimate the visibility and spatial extent of measured dust events. A numerical simulation of surface winds was carried out with the numerical model HIRLAM with horizontal resolution of 5 km and used to calculate the total dust flux from the sources. The in situ measurements inside the dust plumes showed that aeolian dust can be very fine. The study highlights that suspended volcanic dust in Iceland causes air pollution with extremely high PM1 concentrations comparable to the polluted urban stations in Europe or Asia rather than reported dust event observations from around the world. The PM1/PM2.5 ratios are generally low during dust storms outside of Iceland, much lower than > 0.9 and PM1/PM10 ratios of 0.34-0.63 found in our study. It shows that Icelandic volcanic dust consists of higher proportion of submicron particles compared to crustal dust. The submicron particles are predicted to travel long distances. Moreover, such submicron particles pose considerable health risk because of high potential for entering the lungs. Icelandic volcanic glass has often fine pipe-vesicular structures known from asbestos and high content of heavy metals. Previous

  11. Volcano monitoring with an infrared camera: first insights from Villarrica Volcano

    Science.gov (United States)

    Rosas Sotomayor, Florencia; Amigo Ramos, Alvaro; Velasquez Vargas, Gabriela; Medina, Roxana; Thomas, Helen; Prata, Fred; Geoffroy, Carolina

    2015-04-01

    This contribution focuses on the first trials of the, almost 24/7 monitoring of Villarrica volcano with an infrared camera. Results must be compared with other SO2 remote sensing instruments such as DOAS and UV-camera, for the ''day'' measurements. Infrared remote sensing of volcanic emissions is a fast and safe method to obtain gas abundances in volcanic plumes, in particular when the access to the vent is difficult, during volcanic crisis and at night time. In recent years, a ground-based infrared camera (Nicair) has been developed by Nicarnica Aviation, which quantifies SO2 and ash on volcanic plumes, based on the infrared radiance at specific wavelengths through the application of filters. Three Nicair1 (first model) have been acquired by the Geological Survey of Chile in order to study degassing of active volcanoes. Several trials with the instruments have been performed in northern Chilean volcanoes, and have proven that the intervals of retrieved SO2 concentration and fluxes are as expected. Measurements were also performed at Villarrica volcano, and a location to install a ''fixed'' camera, at 8km from the crater, was discovered here. It is a coffee house with electrical power, wifi network, polite and committed owners and a full view of the volcano summit. The first measurements are being made and processed in order to have full day and week of SO2 emissions, analyze data transfer and storage, improve the remote control of the instrument and notebook in case of breakdown, web-cam/GoPro support, and the goal of the project: which is to implement a fixed station to monitor and study the Villarrica volcano with a Nicair1 integrating and comparing these results with other remote sensing instruments. This works also looks upon the strengthen of bonds with the community by developing teaching material and giving talks to communicate volcanic hazards and other geoscience topics to the people who live "just around the corner" from one of the most active volcanoes

  12. U-series radioactive disequilibria 238U-230Th-226Ra: discussions on sources and processes responsible for volcanism of the Andean cordillera and on the deglaciation in Iceland

    International Nuclear Information System (INIS)

    Chmeleff, J.

    2005-10-01

    Thanks to precise analyses of uranium series radioactive disequilibria, permitted by improvements of mass spectrometry data acquisition and optimization of chemistry, two questions were tackled and answers about the periods of glaciation in Iceland and the petrogenesis of Andean lavas were proposed. Two methods were used to date lava flows from the Reykjanes peninsula and the island of Heimaey, in Iceland, directly linked to the periods of deglaciation or reheating around the last ice age. An original method based on the use of segregation veins present in the lava flows has been developed. Thanks to the formation of this particular geological object this methods permits to be freed from xeno-crystals when using the internal isochron method in the 238 U- 230 Th system. Using this method some constraints are brought both on the quaternary geology of the area of Reykjavik and on the age of the end of the Wurm glaciation on Heirnaey. In parallel, due to the homogeneity of the historical and Holocene lavas of the Reykjanes peninsula, regarding the ( 230 Th/ 232 Th) and Th/U ratios, it is possible to derive the ( 230 Th/ 232 Th) ratio in time to determine the age of lava flows installed during the ice age. Thus we confirmed that the magnetic excursion recorded in the Skalamaelifell lava flow is most probably the same one as that of Laschamp-Olby and that at this time (approximately 48.000 years) the Reykjanes peninsula was entirely covered with a glacier. Thanks to this method the extent of the glacier was also constrained by dating of a picritic shield around 22.000 years, thus the peninsula has to be free of any ice cap despite the fact that glaciation is the most intense around this time.Then Andean arc magmas petrogenesis was constrained in time and space. Almost systematic excesses of 226 Ra compared to 230 Th in lavas of austral, southern and northern volcanic zones of the Andes (AVZ, SVZ and NVZ) constrain the ascending time from the source to the surface after

  13. Social correlates of cigarette smoking among Icelandic adolescents: A population-based cross-sectional study

    Directory of Open Access Journals (Sweden)

    Allegrante John P

    2008-03-01

    Full Text Available Abstract Background Previous research has shown that between 80 and 90 percent of adult smokers report having started smoking before 18 years of age. Several studies have revealed that multiple social factors influence the likelihood of smoking during adolescence, the period during which the onset of smoking usually occurs. To better understand the social mechanisms that influence adolescent smoking, we analyzed the relationship and relative importance of a broad spectrum of social variables in adolescent smoking in Iceland, a Nordic country with high per-capita income. Methods We used cross-sectional data from 7,430 14- to 16 year-old students (approximately 81% of all Icelanders in these age cohorts in the 2006 Youth in Iceland study. The Youth in Iceland studies are designed to investigate the role of several cognitive, behavioral, and social factors in the lives of adolescents, and the data collected are used to inform the design, implementation, and evaluation of substance use prevention programs that are being developed by Icelandic social scientists, policy makers, and practitioners. Results Our analysis revealed that friends' smoking behavior and attitude toward smoking were strongly associated with adolescent smoking and other tobacco use, as well as alcohol consumption during the previous 30 days. Main protective factors were parent's perceived attitude toward smoking, the quantity of time spent with parents, absence of serious verbal conflict between parents and adolescents, and participation in physical activity. Family structure was related to adolescent smoking to a small extent, but other background factors were not. Conclusion We conclude that multiple social factors are related to adolescent smoking. Parents and other primary preventive agents need to be informed about the complicated nature of the adolescent social world in order to maximize their impact.

  14. Local food in Iceland: identifying behavioral barriers to increased production and consumption

    Science.gov (United States)

    Ósk Halldórsdóttir, Þórhildur; Nicholas, Kimberly A.

    2016-11-01

    Increased production and consumption of local food may reduce the negative environmental, social, and economic impacts of industrialized and globalized food production. Here we examined potential barriers to increasing production and consumption of food produced in Iceland. First, we developed a new framework to address the behaviors of production and consumption simultaneously, to comprehensively analyze their potential barriers. We examined structural barriers by estimating the food production capacity of Iceland, and cultural and personal barriers through survey data on cultural norms and purchasing behavior from Matís, a research and development company. We found no structural barriers preventing Iceland from increasing production of local cereals, which would compliment current local production of meat and dairy and reduce reliance on imports, currently at 50% of the daily caloric intake. However, if food production became entirely local without changing the current mix of crops grown, there would be a 50% reduction in diversity (from 50 to 25 items in eight out of ten food categories). We did not identify any cultural barriers, as survey results demonstrated that consumers hold generally positive worldviews towards local food, with 88% satisfied with local food they had purchased. More than two-thirds of consumers regarded supporting the local farmer and considerations such as environmentally friendly production, fewer food miles, lower carbon footprint as important. However, they rated the local food they have access to as lower in meeting sustainability criteria, showing that they make justifications for not choosing local food in practice. This is a personal barrier to increased consumption of local food, and implies that marketing strategies and general knowledge connected to local food in Iceland might be improved. Although the results apply to the case of Iceland, the method of identifying behavioral barriers to change is applicable to other countries

  15. Mineralogical and geochemical study of mud volcanoes in north ...

    African Journals Online (AJOL)

    The gulf of Cadiz is one of the most interesting areas to study mud volcanoes and structures related to cold fluid seeps since their discovery in 1999. In this study, we present results from gravity cores collected from Ginsburg and Meknes mud volcanoes and from circular structure located in the gulf of Cadiz (North Atlantic ...

  16. Fuego Volcano eruption (Guatemala, 1974): evidence of a tertiary fragmentation?

    International Nuclear Information System (INIS)

    Brenes-Andre, Jose

    2014-01-01

    Values for mode and dispersion calculated from SFT were analyzed using the SFT (Sequential Fragmentation/Transport) model to Fuego Volcano eruption (Guatemala, 1974). Analysis results have showed that the ideas initially proposed for Irazu, can be applied to Fuego Volcano. Experimental evidence was found corroborating the existence of tertiary fragmentations. (author) [es

  17. 36 CFR 7.25 - Hawaii Volcanoes National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Hawaii Volcanoes National Park. 7.25 Section 7.25 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.25 Hawaii Volcanoes National Park. (a...

  18. Using Google Earth to Study the Basic Characteristics of Volcanoes

    Science.gov (United States)

    Schipper, Stacia; Mattox, Stephen

    2010-01-01

    Landforms, natural hazards, and the change in the Earth over time are common material in state and national standards. Volcanoes exemplify these standards and readily capture the interest and imagination of students. With a minimum of training, students can recognize erupted materials and types of volcanoes; in turn, students can relate these…

  19. Volcano ecology: Disturbance characteristics and assembly of biological communities

    Science.gov (United States)

    Volcanic eruptions are powerful expressions of Earth’s geophysical forces which have shaped and influenced ecological systems since the earliest days of life. The study of the interactions of volcanoes and ecosystems, termed volcano ecology, focuses on the ecological responses of organisms and biolo...

  20. Copahue volcano and its regional magmatic setting

    Science.gov (United States)

    Varekamp, J C; Zareski, J E; Camfield, L M; Todd, Erin

    2016-01-01

    Copahue volcano (Province of Neuquen, Argentina) has produced lavas and strombolian deposits over several 100,000s of years, building a rounded volcano with a 3 km elevation. The products are mainly basaltic andesites, with the 2000–2012 eruptive products the most mafic. The geochemistry of Copahue products is compared with those of the main Andes arc (Llaima, Callaqui, Tolhuaca), the older Caviahue volcano directly east of Copahue, and the back arc volcanics of the Loncopue graben. The Caviahue rocks resemble the main Andes arc suite, whereas the Copahue rocks are characterized by lower Fe and Ti contents and higher incompatible element concentrations. The rocks have negative Nb-Ta anomalies, modest enrichments in radiogenic Sr and Pb isotope ratios and slightly depleted Nd isotope ratios. The combined trace element and isotopic data indicate that Copahue magmas formed in a relatively dry mantle environment, with melting of a subducted sediment residue. The back arc basalts show a wide variation in isotopic composition, have similar water contents as the Copahue magmas and show evidence for a subducted sedimentary component in their source regions. The low 206Pb/204Pb of some backarc lava flows suggests the presence of a second endmember with an EM1 flavor in its source. The overall magma genesis is explained within the context of a subducted slab with sediment that gradually looses water, water-mobile elements, and then switches to sediment melt extracts deeper down in the subduction zone. With the change in element extraction mechanism with depth comes a depletion and fractionation of the subducted complex that is reflected in the isotope and trace element signatures of the products from the main arc to Copahue to the back arc basalts.

  1. Isotopic evolution of Mauna Loa volcano

    International Nuclear Information System (INIS)

    Kurz, M.D.; Kammer, D.P.

    1991-01-01

    In an effort to understand the temporal helium isotopic variations in Mauna Loa volcano, we have measured helium, strontium and lead isotopes in a suite of Mauna Loa lavas that span most of the subaerial eruptive history of the volcano. The lavas range in age from historical flows to Ninole basalt which are thought to be several hundred thousand years old. Most of the samples younger than 30 ka in age (Kau Basalt) are radiocarbon-dated flows, while the samples older than 30 ka are stratigraphically controlled (Kahuku and Ninole Basalt). The data reveal a striking change in the geochemistry of the lavas approximately 10 ka before present. The lavas older than 10 ka are characterized by high 3 He/ 4 He (≅ 16-20 times atmospheric), higher 206 Pb/ 204 Pb (≅ 18.2), and lower 87 Sr/ 86 Sr(≅ 0.70365) ratios than the younger Kau samples (having He, Pb and Sr ratios of approximately 8.5 x atmospheric, 18.1 and 0.70390, respectively). The historical lavas are distinct in having intermediate Sr and Pb isotopic compositions with 3 He/ 4 He ratios similar to the other young Kau basalt (≅ 8.5 x atmospheric). The isotopic variations are on a shorter time scale (100 to 10,000 years) than has previously been observed for Hawaiian volcanoes, and demonstrate the importance of geochronology and stratigraphy to geochemical studies. The data show consistency between all three isotope systems, which suggests that the variations are not related to magma chamber degassing processes, and that helium is not decoupled from the other isotopes. However, the complex temporal evolution suggests that three distinct mantle sources are required to explain the isotopic data. Most of the Mauna Loa isotopic variations could be explained by mixing between a plume type source, similar to Loihi, and an asthenospheric source with helium isotopic composition close to MORB and elevated Sr isotopic values. (orig./WL)

  2. Monte Carlo Volcano Seismic Moment Tensors

    Science.gov (United States)

    Waite, G. P.; Brill, K. A.; Lanza, F.

    2015-12-01

    Inverse modeling of volcano seismic sources can provide insight into the geometry and dynamics of volcanic conduits. But given the logistical challenges of working on an active volcano, seismic networks are typically deficient in spatial and temporal coverage; this potentially leads to large errors in source models. In addition, uncertainties in the centroid location and moment-tensor components, including volumetric components, are difficult to constrain from the linear inversion results, which leads to a poor understanding of the model space. In this study, we employ a nonlinear inversion using a Monte Carlo scheme with the objective of defining robustly resolved elements of model space. The model space is randomized by centroid location and moment tensor eigenvectors. Point sources densely sample the summit area and moment tensors are constrained to a randomly chosen geometry within the inversion; Green's functions for the random moment tensors are all calculated from modeled single forces, making the nonlinear inversion computationally reasonable. We apply this method to very-long-period (VLP) seismic events that accompany minor eruptions at Fuego volcano, Guatemala. The library of single force Green's functions is computed with a 3D finite-difference modeling algorithm through a homogeneous velocity-density model that includes topography, for a 3D grid of nodes, spaced 40 m apart, within the summit region. The homogenous velocity and density model is justified by long wavelength of VLP data. The nonlinear inversion reveals well resolved model features and informs the interpretation through a better understanding of the possible models. This approach can also be used to evaluate possible station geometries in order to optimize networks prior to deployment.

  3. The deep structure of Axial Volcano

    Science.gov (United States)

    West, Michael Edwin

    The subsurface structure of Axial Volcano, near the intersection of the Juan de Fuca Ridge and the Cobb-Eickelberg seamount chain in the northeast Pacific, is imaged from an active source seismic experiment. At a depth of 2.25 to 3.5 km beneath Axial lies an 8 km x 12 km region of very low seismic velocities that can only be explained by the presence of magma. In the center of this magma storage chamber at 2--3.5 km below sea floor, the crust is at least 10--20% melt. At depths of 4--5 km there is evidence of additional low concentrations of magma (a few percent) over a larger area. In total, 5--11 km3 of magma are stored in the mid-crust beneath Axial. This is more melt than has been positively identified under any basaltic volcano on Earth. It is also far more than the 0.1--0.2 km3 emplaced during the 1998 eruption. The implied residence time in the magma reservoir of a few hundred to a few thousand years agrees with geochemical trends which suggest prolonged storage and mixing of magmas. The large volume of melt bolsters previous observations that Axial provides much of the material to create crust along its 50 km rift zones. A high velocity ring-shaped feature sits above the magma chamber just outside the caldera walls. This feature is believed to be the result of repeated dike injections from the magma body to the surface during the construction of the volcanic edifice. A rapid change in crustal thickness from 8 to 11 km within 15 km of the caldera implies focused delivery of melt from the mantle. The high flux of magma suggests that melting occurs deeper in the mantle than along the nearby ridge. Melt supply to the volcano is not connected to any plumbing system associated with the adjacent segments of the Juan de Fuca Ridge. This suggests that, despite Axial's proximity to the ridge, the Cobb hot spot currently drives the supply of melt to the volcano.

  4. Cataloging tremor at Kilauea Volcano, Hawaii

    Science.gov (United States)

    Thelen, W. A.; Wech, A.

    2013-12-01

    Tremor is a ubiquitous seismic feature on Kilauea volcano, which emanates from at least three distinct sources. At depth, intermittent tremor and earthquakes thought to be associated with the underlying plumbing system of Kilauea (Aki and Koyanagi, 1981) occurs approximately 40 km below and 40 km SW of the summit. At the summit of the volcano, nearly continuous tremor is recorded close to a persistently degassing lava lake, which has been present since 2008. Much of this tremor is correlated with spattering at the lake surface, but tremor also occurs in the absence of spattering, and was observed at the summit of the volcano prior to the appearance of the lava lake, predominately in association with inflation/deflation events. The third known source of tremor is in the area of Pu`u `O`o, a vent that has been active since 1983. The exact source location and depth is poorly constrained for each of these sources. Consistently tracking the occurrence and location of tremor in these areas through time will improve our understanding of the plumbing geometry beneath Kilauea volcano and help identify precursory patterns in tremor leading to changes in eruptive activity. The continuous and emergent nature of tremor precludes the use of traditional earthquake techniques for automatic detection and location of seismicity. We implement the method of Wech and Creager (2008) to both detect and localize tremor seismicity in the three regions described above. The technique uses an envelope cross-correlation method in 5-minute windows that maximizes tremor signal coherency among seismic stations. The catalog is currently being built in near-realtime, with plans to extend the analysis to the past as time and continuous data availability permits. This automated detection and localization method has relatively poor depth constraints due to the construction of the envelope function. Nevertheless, the epicenters distinguish activity among the different source regions and serve as

  5. Geology of El Chichon volcano, Chiapas, Mexico

    Science.gov (United States)

    Duffield, Wendell A.; Tilling, Robert I.; Canul, Rene

    1984-03-01

    The (pre-1982) 850-m-high andesitic stratovolcano El Chichón, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, México. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chichón is built on Tertiary siltstone and sandstone, underlain by Cretaceous dolomitic limestone; a 4-km-deep bore hole near the east base of the volcano penetrated this limestone and continued 770 m into a sequence of Jurassic or Cretaceous evaporitic anhydrite and halite. The basement rocks are folded into generally northwest-trending anticlines and synclines. El Chichón is built over a small dome-like structure superposed on a syncline, and this structure may reflect cumulative deformation related to growth of a crustal magma reservoir beneath the volcano. The cone of El Chichón consists almost entirely of pyroclastic rocks. The pre-1982 cone is marked by a 1200-m-diameter (explosion?) crater on the southwest flank and a 1600-m-diameter crater apparently of similar origin at the summit, a lava dome partly fills each crater. The timing of cone and dome growth is poorly known. Field evidence indicates that the flank dome is older than the summit dome, and K-Ar ages from samples high on the cone suggest that the flank dome is older than about 276,000 years. At least three pyroclastic eruptions have occurred during the past 1250 radiocarbon years. Nearly all of the pyroclastic and dome rocks are moderately to highly porphyritic andesite, with plagioclase, hornblende and clinopyroxene the most common phenocrysts. Geologists who mapped El Chichón in 1980 and 1981 warned that the volcano posed a substantial hazard to the surrounding region. This warning was proven to be prophetic by violent eruptions that occurred in March and April of 1982. These eruptions blasted away nearly all of the summit dome, blanketed the surrounding region with tephra, and sent pyroclastic

  6. Degassing Processes at Persistently Active Explosive Volcanoes

    Science.gov (United States)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with Indonesia), a volcano that has been producing cycles of repeated explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range of conditions, for which the mass balance between magma flux and open-system gas escape repeatedly

  7. Mud Volcanoes as Exploration Targets on Mars

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy Z.

    2010-01-01

    Tens of thousands of high-albedo mounds occur across the southern part of the Acidalia impact basin on Mars. These structures have geologic, physical, mineralogic, and morphologic characteristics consistent with an origin from a sedimentary process similar to terrestrial mud volcanism. The potential for mud volcanism in the Northern Plains of Mars has been recognized for some time, with candidate mud volcanoes reported from Utopia, Isidis, northern Borealis, Scandia, and the Chryse-Acidalia region. We have proposed that the profusion of mounds in Acidalia is a consequence of this basin's unique geologic setting as the depocenter for the tune fraction of sediments delivered by the outflow channels from the highlands.

  8. Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments

    Directory of Open Access Journals (Sweden)

    Riad Hosein

    2014-10-01

    Full Text Available Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i Digity; (ii Piparo and (iii Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  9. Measurements of radon and chemical elements: Popocatepetl volcano

    International Nuclear Information System (INIS)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V.; Armienta, M.A.; Valdes, C.; Mena, M.; Seidel, J.L.; Monnin, M.

    2002-01-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  10. Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments

    Science.gov (United States)

    Hosein, Riad; Haque, Shirin; Beckles, Denise M.

    2014-01-01

    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region. PMID:25370529

  11. Tsunamis generated by eruptions from mount st. Augustine volcano, alaska.

    Science.gov (United States)

    Kienle, J; Kowalik, Z; Murty, T S

    1987-06-12

    During an eruption of the Alaskan volcano Mount St. Augustine in the spring of 1986, there was concern about the possibility that a tsunami might be generated by the collapse of a portion of the volcano into the shallow water of Cook Inlet. A similar edifice collapse of the volcano and ensuing sea wave occurred during an eruption in 1883. Other sea waves resulting in great loss of life and property have been generated by the eruption of coastal volcanos around the world. Although Mount St. Augustine remained intact during this eruptive cycle, a possible recurrence of the 1883 events spurred a numerical simulation of the 1883 sea wave. This simulation, which yielded a forecast of potential wave heights and travel times, was based on a method that could be applied generally to other coastal volcanos.

  12. Mud volcanoes of trinidad as astrobiological analogs for martian environments.

    Science.gov (United States)

    Hosein, Riad; Haque, Shirin; Beckles, Denise M

    2014-10-13

    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil's Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  13. Translating Volcano Hazards Research in the Cascades Into Community Preparedness

    Science.gov (United States)

    Ewert, J. W.; Driedger, C. L.

    2015-12-01

    Research by the science community into volcanic histories and physical processes at Cascade volcanoes in the states of Washington, Oregon, and California has been ongoing for over a century. Eruptions in the 20th century at Lassen Peak and Mount St. Helen demonstrated the active nature of Cascade volcanoes; the 1980 eruption of Mount St. Helens was a defining moment in modern volcanology. The first modern volcano hazards assessments were produced by the USGS for some Cascade volcanoes in the 1960s. A rich scientific literature exists, much of which addresses hazards at these active volcanoes. That said community awareness, planning, and preparation for eruptions generally do not occur as a result of a hazard analyses published in scientific papers, but by direct communication with scientists. Relative to other natural hazards, volcanic eruptions (or large earthquakes, or tsunami) are outside common experience, and the public and many public officials are often surprised to learn of the impacts volcanic eruptions could have on their communities. In the 1980s, the USGS recognized that effective hazard communication and preparedness is a multi-faceted, long-term undertaking and began working with federal, state, and local stakeholders to build awareness and foster community action about volcano hazards. Activities included forming volcano-specific workgroups to develop coordination plans for volcano emergencies; a concerted public outreach campaign; curriculum development and teacher training; technical training for emergency managers and first responders; and development of hazard information that is accessible to non-specialists. Outcomes include broader ownership of volcano hazards as evidenced by bi-national exchanges of emergency managers, community planners, and first responders; development by stakeholders of websites focused on volcano hazards mitigation; and execution of table-top and functional exercises, including evacuation drills by local communities.

  14. Shallow conduit processes of the 1991 Hekla eruption, Iceland

    Science.gov (United States)

    Gudnason, J.; Thordarson, T.; Houghton, B. F.

    2013-12-01

    ., et al., The 1991 eruption of Hekla, Iceland. Bulletin of Volcanology, 1992. 54(3): p. 238-246. 2. Höskuldsson, Á., Óskarsson, N., Pedersen, R., Grönvold, K., Vogfjörd, K. & Ólafsdóttir, R. 2007. The millennium eruption of Hekla in February 2000. Bull Volcanol, 70:169-182. 3. Larsen, G., E.G. Vilmundardóttir, and B. Thorkelsson, Heklugosid 1991: Gjóskufall og gjóskulagid frá fyrsta degi gossins. Náttúrufrædingurinn, 1992. 61(3-4): p. 159-176.

  15. A space-borne, multi-parameter, Virtual Volcano Observatory for the real-time, anywhere-anytime support to decision-making during eruptive crises

    Science.gov (United States)

    Ferrucci, F.; Tampellini, M.; Loughlin, S. C.; Tait, S.; Theys, N.; Valks, P.; Hirn, B.

    2013-12-01

    The EVOSS consortium of academic, industrial and institutional partners in Europe and Africa, has created a satellite-based volcano observatory, designed to support crisis management within the Global Monitoring for Environment and Security (GMES) framework of the European Commission. Data from 8 different payloads orbiting on 14 satellite platforms (SEVIRI on-board MSG-1, -2 and -3, MODIS on-board Terra and Aqua, GOME-2 and IASI onboard MetOp-A, OMI on-board Aura, Cosmo-SkyMED/1, /2, /3 and /4, JAMI on-board MTSAT-1 and -2, and, until April 8th2012, SCHIAMACHY on-board ENVISAT) acquired at 5 different down-link stations, are disseminated to and automatically processed at 6 locations in 4 countries. The results are sent, in four separate geographic data streams (high-temperature thermal anomalies, volcanic Sulfur dioxide daily fluxes, volcanic ash and ground deformation), to a central facility called VVO, the 'Virtual Volcano Observatory'. This system operates 24H/24-7D/7 since September 2011 on all volcanoes in Europe, Africa, the Lesser Antilles, and the oceans around them, and during this interval has detected, measured and monitored all subaerial eruptions occurred in this region (44 over 45 certified, with overall detection and processing efficiency of ~97%). EVOSS borne realtime information is delivered to a group of 14 qualified end users, bearing the direct or indirect responsibility of monitoring and managing volcano emergencies, and of advising governments in Comoros, DR Congo, Djibouti, Ethiopia, Montserrat, Uganda, Tanzania, France and Iceland. We present the full set of eruptions detected and monitored - from 2004 to present - by multispectral payloads SEVIRI onboard the geostationary platforms of the MSG constellation, for developing and fine tuning-up the EVOSS system along with its real-time, pre- and post-processing automated algorithms. The set includes 91% of subaerial eruptions occurred at 15 volcanoes (Piton de la Fournaise, Karthala, Jebel al

  16. The effect of signal leakage and glacial isostatic rebound on GRACE-derived ice mass changes in Iceland

    DEFF Research Database (Denmark)

    Sørensen, Louise Sandberg; Jarosch, Alexander H.; Adalgeirsdottir, Gudfinna

    2017-01-01

    Monthly gravity field models from the GRACE satellite mission are widely used to determine ice mass changes of large ice sheets as well as smaller glaciers and ice caps. Here, we investigate in detail the ice mass changes of the Icelandic ice caps as derived from GRACE data. The small size...... of the Icelandic ice caps, their location close to other rapidly changing ice covered areas and the low viscosity of the mantle below Iceland make this especially challenging. The mass balance of the ice caps is well constrained by field mass balance measurements, making this area ideal for such investigations. We...... the Little Ice Age (∼ 1890 AD). To minimize the signal that leaks towards Iceland from Greenland, we employ an independent mass change estimate of the Greenland Ice Sheet derived from satellite laser altimetry. We also estimate the effect of post Little Ice Age glacial isostatic adjustment, from knowledge...

  17. Three-dimensional stochastic adjustment of volcano geodetic network in Arenal volcano, Costa Rica

    Science.gov (United States)

    Muller, C.; van der Laat, R.; Cattin, P.-H.; Del Potro, R.

    2009-04-01

    Volcano geodetic networks are a key instrument to understanding magmatic processes and, thus, forecasting potentially hazardous activity. These networks are extensively used on volcanoes worldwide and generally comprise a number of different traditional and modern geodetic surveying techniques such as levelling, distances, triangulation and GNSS. However, in most cases, data from the different methodologies are surveyed, adjusted and analysed independently. Experience shows that the problem with this procedure is the mismatch between the excellent correlation of position values within a single technique and the low cross-correlation of such values within different techniques or when the same network is surveyed shortly after using the same technique. Moreover one different independent network for each geodetic surveying technique strongly increase logistics and thus the cost of each measurement campaign. It is therefore important to develop geodetic networks which combine the different geodetic surveying technique, and to adjust geodetic data together in order to better quantify the uncertainties associated to the measured displacements. In order to overcome the lack of inter-methodology data integration, the Geomatic Institute of the University of Applied Sciences of Western Switzerland (HEIG-VD) has developed a methodology which uses a 3D stochastic adjustment software of redundant geodetic networks, TRINET+. The methodology consists of using each geodetic measurement technique for its strengths relative to other methodologies. Also, the combination of the measurements in a single network allows more cost-effective surveying. The geodetic data are thereafter adjusted and analysed in the same referential frame. The adjustment methodology is based on the least mean square method and links the data with the geometry. Trinet+ also allows to run a priori simulations of the network, hence testing the quality and resolution to be expected for a determined network even

  18. Molecular epidemiology of HIV-1 in Iceland: Early introductions, transmission dynamics and recent outbreaks among injection drug users.

    Science.gov (United States)

    Sallam, Malik; Esbjörnsson, Joakim; Baldvinsdóttir, Guðrún; Indriðason, Hlynur; Björnsdóttir, Thora Björg; Widell, Anders; Gottfreðsson, Magnús; Löve, Arthur; Medstrand, Patrik

    2017-04-01

    The molecular epidemiology of HIV-1 in Iceland has not been described so far. Detailed analyses of the dynamics of HIV-1 can give insights for prevention of virus spread. The objective of the current study was to characterize the genetic diversity and transmission dynamics of HIV-1 in Iceland. Partial HIV-1 pol (1020bp) sequences were generated from 230 Icelandic samples, representing 77% of all HIV-1 infected individuals reported in the country 1985-2012. Maximum likelihood phylogenies were reconstructed for subtype/CRF assignment and determination of transmission clusters. Timing and demographic growth patterns were determined in BEAST. HIV-1 infection in Iceland was dominated by subtype B (63%, n=145) followed by subtype C (10%, n=23), CRF01_AE (10%, n=22), sub-subtype A1 (7%, n=15) and CRF02_AG (7%, n=15). Trend analysis showed an increase in non-B subtypes/CRFs in Iceland over the study period (p=0.003). The highest proportion of phylogenetic clustering was found among injection drug users (IDUs; 89%), followed by heterosexuals (70%) and men who have sex with men (35%). The time to the most recent common ancestor of the oldest subtype B cluster dated back to 1978 (median estimate, 95% highest posterior density interval: 1974-1981) suggesting an early introduction of HIV-1 into Iceland. A previously reported increase in HIV-1 incidence among IDUs 2009-2011 was revealed to be due to two separate outbreaks. Our study showed that a variety of HIV-1 subtypes and CRFs were prevalent in Iceland 1985-2012, with subtype B being the dominant form both in terms of prevalence and domestic spread. The rapid increase of HIV-1 infections among IDUs following a major economic crisis in Iceland raises questions about casual associations between economic factors, drug use and public health. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Changing epidemiology of methicillin-resistant Staphylococcus aureus in Iceland from 2000 to 2008: a challenge to current guidelines

    DEFF Research Database (Denmark)

    Holzknecht, B.J.; Hardardottir, H.; Haraldsson, Gustav Helgi

    2010-01-01

    and microbiological data of all MRSA patients from the years 2000 to 2008 were collected prospectively. Isolates were characterized by pulsed-field gel electrophoresis (PFGE), sequencing of the repeat region of the Staphylococcus protein A gene (spa typing), staphylococcal cassette chromosome mec (SCCmec) typing...... setting. However, MRSA in Iceland is now shifting into the community, challenging the current Icelandic guidelines, which are tailored to the health care system....

  20. Iceland Scotland Overflow Water flow through the Bight Fracture Zone in June-July 2015

    Science.gov (United States)

    Mercier, Herle; Petit, Tillys; Thierry, Virginie

    2017-04-01

    ISOW (Iceland Scotland Overflow Water) is the densest water in the northern Iceland Basin and a main constituent of the lower limb of the meridional overturning circulation (MOC). ISOW is the product of mixing of dense water originating from the Nordic Seas with Atlantic Water and Labrador Sea Water during its crossing of the Iceland-Faroe-Scotland Ridge and downstream acceleration. In the northern Iceland Basin, ISOW is characterized by potential density σ0 > 27.8 and salinity > 34.94. Downstream of the Iceland-Scotland Ridge, ISOW flows southwestward in a Deep Western Boundary Current along the eastern flank of the Reykjanes Ridge. Models and float trajectories previously suggested that part of the ISOW flow could cross the Reykjanes Ridge through the Bight Fracture Zone. However, no direct observations of the ISOW flow through the Bight Fracture Zone are available that would allow us to quantify its transport and water mass transformation. This lack of direct observations also prevents understanding the dynamics of the throughflow. In this study, we analyzed a set of CTDO2 and LADCP stations acquired in June-July 2015 during the Reykjanes Ridge Experiment cruise and provide new insights on the ISOW flow through the Bight Fracture Zone. The evolution of the properties as well as the velocity measurements confirm an ISOW flow from the Iceland Basin to the Irminger Sea. A main constrain to the throughflow is the presence of two sills of about 2150 m depth and two narrows. With potential densities between 27.8-27.87 kg m-3 and near bottom potential temperature of 3.02°C and salinity of 34.98, only the lightest variety of ISOW is found at the entrance of the BFZ east of the sills. In the central part of the Bight Fracture Zone, the evolution of ISOW is characterized by a decrease of 0.015 kg m-3 in the near bottom density, ascribed to the blocking of the densest ISOW variety by the sills and/or diapycnal mixing. To the West, at the exit of the BFZ, ISOW overlays

  1. Insights into Earth's Accretion and Mantle Structure from Neon and Xenon in Icelandic Basalt (Invited)

    Science.gov (United States)

    Mukhopadhyay, S.

    2010-12-01

    The noble gases provide important constraints for planet accretion models and understanding mantle structure and dynamics. Recent work based on continental well gases indicate that the MORB source 20Ne/22Ne ratio is similar to the Ne-B component in chondrites [1,2]. However, ratios higher than Ne-B have been reported in plume-derived Devonian rocks form the Kola Peninsula [3]. Here I report high-precision noble gas data in an Icelandic basaltic glass that demonstrate plumes have a different 20Ne/22Ne ratio than the MORB source. The highest measured 20Ne/22Ne ratio from Iceland is ~12.9, very similar to values in the Kola plume, but quite distinct from the convecting upper mantle as constrained from the well gases [1,2]. Hence, the Icelandic and Kola plume data indicate that OIBs and MORBs have different 20Ne/22Ne ratios. Since 20Ne/22Ne ratios in the mantle cannot change, Earth must have accreted volatiles from at least two separate reservoirs. The differences in 20Ne/22Ne ratios between OIBs and MORBs further indicate that early heterogeneities in the Earth’s mantle have not been wiped away by 4.5 Gyrs of mantle convection, placing strong constraints on mixing and mass flow in the mantle. The requirement of limited direct mixing between plumes and MORB source is supported by 129Xe, formed through radioactive decay of now extinct 129I. Combined He, Ne, and Xe measurements demonstrate that the Iceland plume has a lower 129Xe/130Xe ratio than MORBs because it evolved with a I/Xe ratio distinct from the MORB source and not because of recycled atmosphere (which has low 129/130Xe) in the plume source. Since 129I became extinct 80 Myrs after solar system formation, limited mixing between plume and MORB source is a stringent requirement. Additionally, the high-precision Xe measurements reveal for the first time that the Iceland plume source has significantly higher proportion of plutonium derived fission xenon than MORBs, requiring the plume source to be less degassed

  2. A first Event-tree for the Bárðarbunga volcanic system (Iceland): from the volcanic crisis in 2014 towards a tool for hazard assessment

    Science.gov (United States)

    Barsotti, Sara; Tumi Gudmundsson, Magnús; Jónsdottir, Kristín; Vogfjörd, Kristín; Larsen, Gudrun; Oddsson, Björn

    2015-04-01

    Bárdarbunga volcano is part of a large volcanic system that had its last confirmed eruption before the present unrest in 1910. This system is partially covered by ice within the Vatnajökull glacier and it extends further to the NNE as well as to SW. Based on historical data, its eruptive activity has been predominantly characterized by explosive eruptions, originating beneath the glacier, and important effusive eruptions in the ice-free part of the system itself. The largest explosive eruptions took place on the southern side of the fissure system in AD 1477 producing about 10 km3 of tephra. Due to the extension and location of this volcanic system, the range of potential eruptive scenarios and associated hazards is quite wide. Indeed, it includes: inundation, due to glacial outburst; tephra fallout, due to ash-rich plume generated by magma-water interaction; abundant volcanic gas release; and lava flows. Most importantly these phenomena are not mutually exclusive and might happen simultaneously, creating the premise for a wide spatial and temporal impact. During the ongoing volcanic crisis at Bárdarbunga, which started on 16 August, 2014, the Icelandic Meteorological Office, together with the University of Iceland and Icelandic Civil Protection started a common effort of drawing, day-by-day, the potential evolution of the ongoing rifting event and, based on the newest data from the monitoring networks, updated and more refined scenarios have been identified. Indeed, this volcanic crisis created the occasion for pushing forward the creation of the first Event-tree for the Bárðarbunga volcanic system. We adopted the approach suggested by Newhall and Pallister (2014) and a preliminary ET made of nine nodes has been constructed. After the two initial nodes (restless and genesis) the ET continues with the identification of the location of aperture of future eruptive vents. Due to the complex structure of the system and historical eruptions, this third node

  3. Applying 3D Dynamic Visualisation to (Palaeo) Geomorphic Reconstruction: Modelling a Tenth Century Jökulhlaup at Sólheimajökull Glacier, South Iceland.

    Science.gov (United States)

    Booth, Laura; Isaacs, John

    2014-05-01

    Jökulhlaup (glacial outburst floods) are caused by subglacial geothermal activity melting overlying ice, or by draining of ice-dammed lakes. They pose a recurring hazard along Iceland's south coast where volcano-glacial interactions create often unpredictable, high-magnitude floods. Gathering information about past floods is crucial for projecting findings to present day scenarios and developing future predictions for contemporary flood routes. Understanding the physical setting or surrounding environment is essential in palaeo-flood reconstruction as drainage routes are ultimately defined by local topography and changing ice cover. At Sólheimajökull glacier, which drains the southern portion of Mýrdalsjökull ice cap, field evidence has been collected of a Tenth Century flood, recorded in the Icelander's Landnámabók (Book of Settlements). It was an exceptional event in terms of generation, magnitude and geomorphic impact. Although now fragmented and piecemeal, many of its direct (and indirect) geomorphological and sedimentary markers are still relatively well preserved and have been identified, mapped and dated to unravel the sequence of events played out during this significant episode in the glacial history and complex regional flood chronology. VolcVis, an innovative, bespoke visualisation platform, is developed and applied for the first time in visualising volcanic jökulhlaup. The platform is created using the Microsoft XNA game development framework, which facilitates rapid game engine production by providing a set of tools utilising a managed runtime environment. VolcVis can render large amounts of data efficiently and still provide an extremely high level of interaction with the data being presented, including full freedom of motion. This enables synthesis and presentation of field results from Sólheimajökull in a novel way, creating an interactive, multi-perspective, three-dimensional (3D) prototype model. The platform combines Digital Elevation

  4. Contribution of the FUTUREVOLC project to the study of segmented lateral dyke growth in the 2014 rifting event at Bárðarbunga volcanic system, Iceland

    Science.gov (United States)

    Sigmundsson, Freysteinn; Hooper, Andrew; Hreinsdóttir, Sigrún; Vogfjörd, Kristín S.; Ófeigsson, Benedikt; Rafn Heimisson, Elías; Dumont, Stéphanie; Parks, Michelle; Spaans, Karsten; Guðmundsson, Gunnar B.; Drouin, Vincent; Árnadóttir, Thóra; Jónsdóttir, Kristín; Gudmundsson, Magnús T.; Samsonov, Sergey; Brandsdóttir, Bryndís; White, Robert S.; Ágústsdóttir, Thorbjörg; Björnsson, Helgi; Bean, Christopher J.

    2015-04-01

    The FUTUREVOLC project (a 26-partner project funded by FP7 Environment Programme of the European Commission, addressing topic "Long-term monitoring experiment in geologically active regions of Europe prone to natural hazards: the Supersite concept) set aims to (i) establish an innovative volcano monitoring system and strategy, (ii) develop new methods for near real-time integration of multi-parametric datasets, (iii) apply a seamless transdisciplinary approach to further scientific understanding of magmatic processes, and (iv) to improve delivery, quality and timeliness of transdisciplinary information from monitoring scientists to civil protection. The project duration is 1 October 2012 - 31 March 2016. Unrest and volcanic activity since August 2014 at one of the focus areas of the project in Iceland, at the Bárðarbunga volcanic system, near the middle of the project duration, has offered unique opportunities for this project. On 16 August 2014 an intense seismic swarm started in Bárðarbunga, the beginning of a major volcano-tectonic rifting event forming over 45 km long dyke extending from the caldera to Holuhraun lava field outside the northern margin of Vatnajökull. A large basaltic, effusive fissure eruption began in Holuhraun on 31 August which had by January formed a lava field with a volume in excess of one cubic kilometre. We document how the FUTUREVOLC project has contributed to the study and response to the subsurface dyke formation, through increased seismic and geodetic coverage and joint interpreation of the data. The dyke intrusion in the Bárðarbunga volcanic system, grew laterally for over 45 km at a variable rate, with an influence of topography on the direction of propagation. Barriers at the ends of each segment were overcome by the build-up of pressure in the dyke end; then a new segment formed and dyke lengthening temporarily peaked. The dyke evolution, which occurred over 14 days, was revealed by propagating seismicity, ground

  5. Plate boundary deformation in North Iceland during 1992–2009 revealed by InSAR time-series analysis and GPS

    KAUST Repository

    Metzger, Sabrina

    2014-08-20

    In North Iceland, extensional plate motion is accommodated by the Northern Volcanic Zone, a set of en-echelon volcanic systems, and the Tjörnes Fracture Zone, a transform offset in the mid-Atlantic Ridge consisting of two parallel transform lineaments. The southern lineament, the Húsavík–Flatey fault, is a 100 km-long right-lateral strike slip fault that has not ruptured for more than 140 years and poses a significant seismic hazard to Húsavík, a fishing town located by the fault, and to other coastal communities. We present results of InSAR time-series analysis data spanning almost two decades (1992–2009) that show extensional and interseismic deformation within the Northern Volcanic Zone and the on-shore part of the Tjörnes Fracture Zone. The results also exhibit transient inflation at Theistareykir volcano, deflation at Krafla central volcano and a broad uplift north of Krafla. The current plate extension is not uniform across the Northern Volcanic Zone, but concentrated at the western fissures of the Theistareykir volcanic system and the outermost fissures of the Krafla fissure swarm. We combine a back-slip plate boundary model with a set of point pressure sources representing volcanic changes to describe the current extensional plate boundary deformation and update the previous estimations of the locking depth and slip rate of the Húsavík–Flatey fault that were based on GPS data alone. Using different combinations of input data, we find that the Húsavík–Flatey fault has a locking depth of 6–10 km and, with a slip rate of 6–9 mm/yr, is accommodating about a third of the full transform motion. We furthermore show that while the InSAR data provide important constraints on the volcanic deformation within the NVZ, they do not significantly improve the model parameter estimation for the HFF, as the dense GPS network appears to better capture the deformation across the fault.

  6. Plate boundary deformation in North Iceland during 1992–2009 revealed by InSAR time-series analysis and GPS

    KAUST Repository

    Metzger, Sabrina; Jonsson, Sigurjon

    2014-01-01

    In North Iceland, extensional plate motion is accommodated by the Northern Volcanic Zone, a set of en-echelon volcanic systems, and the Tjörnes Fracture Zone, a transform offset in the mid-Atlantic Ridge consisting of two parallel transform lineaments. The southern lineament, the Húsavík–Flatey fault, is a 100 km-long right-lateral strike slip fault that has not ruptured for more than 140 years and poses a significant seismic hazard to Húsavík, a fishing town located by the fault, and to other coastal communities. We present results of InSAR time-series analysis data spanning almost two decades (1992–2009) that show extensional and interseismic deformation within the Northern Volcanic Zone and the on-shore part of the Tjörnes Fracture Zone. The results also exhibit transient inflation at Theistareykir volcano, deflation at Krafla central volcano and a broad uplift north of Krafla. The current plate extension is not uniform across the Northern Volcanic Zone, but concentrated at the western fissures of the Theistareykir volcanic system and the outermost fissures of the Krafla fissure swarm. We combine a back-slip plate boundary model with a set of point pressure sources representing volcanic changes to describe the current extensional plate boundary deformation and update the previous estimations of the locking depth and slip rate of the Húsavík–Flatey fault that were based on GPS data alone. Using different combinations of input data, we find that the Húsavík–Flatey fault has a locking depth of 6–10 km and, with a slip rate of 6–9 mm/yr, is accommodating about a third of the full transform motion. We furthermore show that while the InSAR data provide important constraints on the volcanic deformation within the NVZ, they do not significantly improve the model parameter estimation for the HFF, as the dense GPS network appears to better capture the deformation across the fault.

  7. Volcano hazards in the San Salvador region, El Salvador

    Science.gov (United States)

    Major, J.J.; Schilling, S.P.; Sofield, D.J.; Escobar, C.D.; Pullinger, C.R.

    2001-01-01

    San Salvador volcano is one of many volcanoes along the volcanic arc in El Salvador (figure 1). This volcano, having a volume of about 110 cubic kilometers, towers above San Salvador, the country’s capital and largest city. The city has a population of approximately 2 million, and a population density of about 2100 people per square kilometer. The city of San Salvador and other communities have gradually encroached onto the lower flanks of the volcano, increasing the risk that even small events may have serious societal consequences. San Salvador volcano has not erupted for more than 80 years, but it has a long history of repeated, and sometimes violent, eruptions. The volcano is composed of remnants of multiple eruptive centers, and these remnants are commonly referred to by several names. The central part of the volcano, which contains a large circular crater, is known as El Boquerón, and it rises to an altitude of about 1890 meters. El Picacho, the prominent peak of highest elevation (1960 meters altitude) to the northeast of the crater, and El Jabali, the peak to the northwest of the crater, represent remnants of an older, larger edifice. The volcano has erupted several times during the past 70,000 years from vents central to the volcano as well as from smaller vents and fissures on its flanks [1] (numerals in brackets refer to end notes in the report). In addition, several small cinder cones and explosion craters are located within 10 kilometers of the volcano. Since about 1200 A.D., eruptions have occurred almost exclusively along, or a few kilometers beyond, the northwest flank of the volcano, and have consisted primarily of small explosions and emplacement of lava flows. However, San Salvador volcano has erupted violently and explosively in the past, even as recently as 800 years ago. When such eruptions occur again, substantial population and infrastructure will be at risk. Volcanic eruptions are not the only events that present a risk to local

  8. Chemical compositions of lavas from Myoko volcano group

    International Nuclear Information System (INIS)

    Hasenaka, Toshiaki; Yoshida, Takeyoshi; Hayatsu, Kenji.

    1995-01-01

    In the volcanic rocks produced in island arc and continental margin arc, the phenomena of magma mixing is observed considerably generally. The research on these phenomena has been carried out also in Japan, and the periodically refilled magma chamber model has been proposed. In this report, the results of the photon activation analysis for the volcanic rock samples of Myoko volcano, for which the magma chamber model that the supply of basalt magma is periodically received was proposed, and of which the age of eruption and the stratigraphy are clearly known, are shown, and the above model is examined together with the published data of fluorescent X-ray analysis and others. The history of activities and the rate of magma extrusion of Myoko volcano group are described. The modal compositions of the volcanic rock samples of Myoko and Kurohime volcanos, for which photon activation analysis was carried out, are shown and discussed. The results of the analysis of the chemical composition of 39 volcanic rock samples from Myoko, Kurohime and Iizuna volcanos are shown. The primary magma in Myoko volcano group, the crystallization differentiation depth and moisture content of magma in Myoko and Kurohime volcanos, the presumption of Felsic and Mafic end-members in R type andesite in Myoko volcano group, and the change of magma composition with lapse of time are described. (K.I.)

  9. Chemical compositions of lavas from Myoko volcano group

    Energy Technology Data Exchange (ETDEWEB)

    Hasenaka, Toshiaki; Yoshida, Takeyoshi [Tohoku Univ., Sendai (Japan). Faculty of Science; Hayatsu, Kenji

    1995-08-01

    In the volcanic rocks produced in island arc and continental margin arc, the phenomena of magma mixing is observed considerably generally. The research on these phenomena has been carried out also in Japan, and the periodically refilled magma chamber model has been proposed. In this report, the results of the photon activation analysis for the volcanic rock samples of Myoko volcano, for which the magma chamber model that the supply of basalt magma is periodically received was proposed, and of which the age of eruption and the stratigraphy are clearly known, are shown, and the above model is examined together with the published data of fluorescent X-ray analysis and others. The history of activities and the rate of magma extrusion of Myoko volcano group are described. The modal compositions of the volcanic rock samples of Myoko and Kurohime volcanos, for which photon activation analysis was carried out, are shown and discussed. The results of the analysis of the chemical composition of 39 volcanic rock samples from Myoko, Kurohime and Iizuna volcanos are shown. The primary magma in Myoko volcano group, the crystallization differentiation depth and moisture content of magma in Myoko and Kurohime volcanos, the presumption of Felsic and Mafic end-members in R type andesite in Myoko volcano group, and the change of magma composition with lapse of time are described. (K.I.)

  10. Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai‘i

    Science.gov (United States)

    Orr, T.R.

    2011-01-01

    Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīlauea Volcano during November 2005–July 2006. During this period, tilt data, time-lapse images, and field observations showed that episodic tilt changes at the nearby Pu‘u ‘Ō‘ō cone, the shallow magmatic source reservoir, were directly related to fluctuations in the level of lava in the active lava tube, with periods of deflation at Pu‘u ‘Ō‘ō correlating with increases in the level of the lava stream surface. Increases in lava level are interpreted as increases in lava flux, and were coincident with lava breakouts from shatter rings constructed over the lava tube. The repetitive behavior of the lava flux changes, inferred from the nearly continuous tilt oscillations, suggests that shatter rings form from the repeated rise and fall of a portion of a lava tube roof. The locations of shatter rings along the active lava tube suggest that they form where there is an abrupt decrease in flow velocity through the tube, e.g., large increase in tube width, abrupt decrease in tube slope, and (or) sudden change in tube direction. To conserve volume, this necessitates an abrupt increase in lava stream depth and causes over-pressurization of the tube. More than a hundred shatter rings have been identified on volcanoes on Hawai‘i and Maui, and dozens have been reported from basaltic lava fields in Iceland, Australia, Italy, Samoa, and the mainland United States. A quick study of other basaltic lava fields worldwide, using freely available satellite imagery, suggests that they might be even more common than previously thought. If so, this confirms that episodic

  11. SAR interferometry applications on active volcanoes. State of the art and perspectives for volcano monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Puglisi, G.; Coltelli, M. [Istituto Nazionale di Geofisica e Vulcanologia, Catania (Italy)

    2001-02-01

    In this paper the application of the Synthetic Aperture Radar Interferometry (INSAR) on volcanology is analysed. Since it is not a real novelty among the different applications of INSAR in Earth Observation activities, at the beginning of this paper it is analysed the state of the art of the researches in this field. During the discussion, the point of view of volcanologists is favoured because it is considered that the first applications were often badly aimed. Consequently, the initial INSAR performances in volcanology were overrated with respect to the real capabilities of this technique. This fact lead to discover some unexpected limitations in INSAR usage in volcano monitoring, but, at the same time, spurred on scientists to overcome these drawbacks. The results achieved recently allow to better apply SAR to volcanology; in the paper a possible operative work-plan aimed at introducing INSAR in the volcano monitoring system is presented.

  12. Geologic Map of the Summit Region of Kilauea Volcano, Hawaii

    Science.gov (United States)

    Neal, Christina A.; Lockwood, John P.

    2003-01-01

    This report consists of a large map sheet and a pamphlet. The map shows the geology, some photographs, description of map units, and correlation of map units. The pamphlet gives the full text about the geologic map. The area covered by this map includes parts of four U.S. Geological Survey 7.5' topographic quadrangles (Kilauea Crater, Volcano, Ka`u Desert, and Makaopuhi). It encompasses the summit, upper rift zones, and Koa`e Fault System of Kilauea Volcano and a part of the adjacent, southeast flank of Mauna Loa Volcano. The map is dominated by products of eruptions from Kilauea Volcano, the southernmost of the five volcanoes on the Island of Hawai`i and one of the world's most active volcanoes. At its summit (1,243 m) is Kilauea Crater, a 3 km-by-5 km collapse caldera that formed, possibly over several centuries, between about 200 and 500 years ago. Radiating away from the summit caldera are two linear zones of intrusion and eruption, the east and the southwest rift zones. Repeated subaerial eruptions from the summit and rift zones have built a gently sloping, elongate shield volcano covering approximately 1,500 km2. Much of the volcano lies under water; the east rift zone extends 110 km from the summit to a depth of more than 5,000 m below sea level; whereas the southwest rift zone has a more limited submarine continuation. South of the summit caldera, mostly north-facing normal faults and open fractures of the Koa`e Fault System extend between the two rift zones. The Koa`e Fault System is interpreted as a tear-away structure that accommodates southward movement of Kilauea's flank in response to distension of the volcano perpendicular to the rift zones.

  13. Response of Eyjafjallajökull, Torfajökull and Tindfjallajökull ice caps in Iceland to regional warming, deduced by remote sensing

    Directory of Open Access Journals (Sweden)

    Jørgen Dall

    2011-07-01

    Full Text Available We assess the volume change and mass balance of three ice caps in southern Iceland for two periods, 1979–1984 to 1998 and 1998 to 2004, by comparing digital elevation models (DEMs. The ice caps are Eyjafjallajökull (ca. 81 km2, Tindfjallajökull (ca. 15 km2 and Torfajökull (ca. 14 km2. The DEMs were compiled using aerial photographs from 1979 to 1984, airborne Synthetic Aperture Radar (SAR images obtained in 1998 and two image pairs from the SPOT 5 satellite's high-resolution stereoscopic (HRS instrument acquired in 2004. The ice-free part of the accurate DEM from 1998 was used as a reference map for co-registration and correction of the vertical offset of the other DEMs. The average specific mass balance was estimated from the mean elevation difference between glaciated areas of the DEMs. The glacier mass balance declined significantly between the two periods: from −0.2 to 0.2 m yr−1 w. eq. during the earlier period (1980s through 1998 to −1.8 to −1.5 m yr−1 w. eq. for the more recent period (1998–2004. The declining mass balance is consistent with increased temperature over the two periods. The low mass balance and the small accumulation area ratio of Tindfjallajökull and Torfajökull indicate that they will disappear if the present-day climate continues. The future lowering rate of Eyjafjallajökull will, however, be influenced by the 2010 subglacial eruption in the Eyjafjallajökull volcano.

  14. Low-pressure differentiation of tholeiitic lavas as recorded in segregation veins from Reykjanes (Iceland), Lanzarote (Canary Islands) and Masaya (Nicaragua)

    Science.gov (United States)

    Martin, E.; Sigmarsson, O.

    2007-11-01

    Segregation veins are common in lava sheets and result from internal differentiation during lava emplacement and degassing. They consist of evolved liquid, most likely replaced by gas-filter pressing from a ˜50% crystallised host lava. Pairs of samples, host lavas and associated segregation veins from the Reykjanes Peninsula (Iceland), Lanzarote (Canary Islands) and the Masaya volcano (Nicaragua) show extreme mineralogical and compositional variations (MgO in host lava, segregation veins and interstitial glass ranges from 8-10 wt%, 3-6 wt%, and to less than 0.01 wt%, respectively). These samples allow the assessment of the internal lava flow differentiation mechanism, since both the parental and derived liquid are known in addition to the last magma drops in the form of late interstitial glasses. The mineralogical variation, mass-balance calculated from major- and trace element composition, and transitional metal partition between crystals and melts are all consistent with fractional crystallisation as the dominant differentiation mechanism. The interstitial glasses are highly silicic (SiO2 = 70-80 wt%) and represent a final product of high-degree (75-97%) fractional crystallisation of olivine tholeiite at a pressure close to one atmosphere. The tholeiitic liquid-line-of-decent and the composition of the residual melts are governed by the K2O/Na2O of the initial basaltic magma. The granitic minimum is reached if the initial liquid has a high K2O/Na2O whereas trondhjemitic composition is the final product of magma with low initial K2O/Na2O.

  15. Mount Meager Volcano, Canada: a Case Study for Landslides on Glaciated Volcanoes

    Science.gov (United States)

    Roberti, G. L.; Ward, B. C.; van Wyk de Vries, B.; Falorni, G.; Perotti, L.; Clague, J. J.

    2015-12-01

    Mount Meager is a strato-volcano massif in the Northern Cascade Volcanic Arc (Canada) that erupted in 2350 BP, the most recent in Canada. To study the stability of the Massif an international research project between France ( Blaise Pascal University), Italy (University of Turin) and Canada (Simon Fraser University) and private companies (TRE - sensing the planet) has been created. A complex history of glacial loading and unloading, combined with weak, hydrothermally altered rocks has resulted in a long record of catastrophic landslides. The most recent, in 2010 is the third largest (50 x 106 m3) historical landslide in Canada. Mount Meager is a perfect natural laboratory for gravity and topographic processes such as landslide activity, permafrost and glacial dynamics, erosion, alteration and uplift on volcanoes. Research is aided by a rich archive of aerial photos of the Massif (1940s up to 2006): complete coverage approximately every 10 years. This data set has been processed and multi-temporal, high resolution Orthophoto and DSMs (Digital Surface Models) have been produced. On these digital products, with the support on field work, glacial retreat and landslide activity have been tracked and mapped. This has allowed for the inventory of unstable areas, the identification of lava flows and domes, and the general improvement on the geologic knowledge of the massif. InSAR data have been used to monitor the deformation of the pre-2010 failure slope. It will also be used to monitor other unstable slopes that potentially can evolve to catastrophic collapses of up to 1 km3 in volume, endangering local communities downstream the volcano. Mount Meager is definitively an exceptional site for studying the dynamics of a glaciated, uplifted volcano. The methodologies proposed can be applied to other volcanic areas with high erosion rates such as Alaska, Cascades, and the Andes.

  16. 3D electrical conductivity tomography of volcanoes

    Science.gov (United States)

    Soueid Ahmed, A.; Revil, A.; Byrdina, S.; Coperey, A.; Gailler, L.; Grobbe, N.; Viveiros, F.; Silva, C.; Jougnot, D.; Ghorbani, A.; Hogg, C.; Kiyan, D.; Rath, V.; Heap, M. J.; Grandis, H.; Humaida, H.

    2018-05-01

    Electrical conductivity tomography is a well-established galvanometric method for imaging the subsurface electrical conductivity distribution. We characterize the conductivity distribution of a set of volcanic structures that are different in terms of activity and morphology. For that purpose, we developed a large-scale inversion code named ECT-3D aimed at handling complex topographical effects like those encountered in volcanic areas. In addition, ECT-3D offers the possibility of using as input data the two components of the electrical field recorded at independent stations. Without prior information, a Gauss-Newton method with roughness constraints is used to solve the inverse problem. The roughening operator used to impose constraints is computed on unstructured tetrahedral elements to map complex geometries. We first benchmark ECT-3D on two synthetic tests. A first test using the topography of Mt. St Helens volcano (Washington, USA) demonstrates that we can successfully reconstruct the electrical conductivity field of an edifice marked by a strong topography and strong variations in the resistivity distribution. A second case study is used to demonstrate the versatility of the code in using the two components of the electrical field recorded on independent stations along the ground surface. Then, we apply our code to real data sets recorded at (i) a thermally active area of Yellowstone caldera (Wyoming, USA), (ii) a monogenetic dome on Furnas volcano (the Azores, Portugal), and (iii) the upper portion of the caldera of Kīlauea (Hawai'i, USA). The tomographies reveal some of the major structures of these volcanoes as well as identifying alteration associated with high surface conductivities. We also review the petrophysics underlying the interpretation of the electrical conductivity of fresh and altered volcanic rocks and molten rocks to show that electrical conductivity tomography cannot be used as a stand-alone technique due to the non-uniqueness in

  17. Muon imaging of volcanoes with Cherenkov telescopes

    Science.gov (United States)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; La Parola, Valentina; La Rosa, Giovanni; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Sottile, Giuseppe; Zuccarello, Luciano

    2017-04-01

    The quantitative understanding of the inner structure of a volcano is a key feature to model the processes leading to paroxysmal activity and, hence, to mitigate volcanic hazards. To pursue this aim, different geophysical techniques are utilized, that are sensitive to different properties of the rocks (elastic, electrical, density). In most cases, these techniques do not allow to achieve the spatial resolution needed to characterize the shallowest part of the plumbing system and may require dense measurements in active zones, implying a high level of risk. Volcano imaging through cosmic-ray muons is a promising technique that allows to overcome the above shortcomings. Muons constantly bombard the Earth's surface and can travel through large thicknesses of rock, with an energy loss depending on the amount of crossed matter. By measuring the absorption of muons through a solid body, one can deduce the density distribution inside the target. To date, muon imaging of volcanic structures has been mainly achieved with scintillation detectors. They are sensitive to noise sourced from (i) the accidental coincidence of vertical EM shower particles, (ii) the fake tracks initiated from horizontal high-energy electrons and low-energy muons (not crossing the target) and (iii) the flux of upward going muons. A possible alternative to scintillation detectors is given by Cherenkov telescopes. They exploit the Cherenkov light emitted when charged particles (like muons) travel through a dielectric medium, with velocity higher than the speed of light. Cherenkov detectors are not significantly affected by the above noise sources. Furthermore, contrarily to scintillator-based detectors, Cherenkov telescopes permit a measurement of the energy spectrum of the incident muon flux at the installation site, an issue that is indeed relevant for deducing the density distribution inside the target. In 2014, a prototype Cherenkov telescope was installed at the Astrophysical Observatory of Serra

  18. Large-N in Volcano Settings: Volcanosri

    Science.gov (United States)

    Lees, J. M.; Song, W.; Xing, G.; Vick, S.; Phillips, D.

    2014-12-01

    We seek a paradigm shift in the approach we take on volcano monitoring where the compromise from high fidelity to large numbers of sensors is used to increase coverage and resolution. Accessibility, danger and the risk of equipment loss requires that we develop systems that are independent and inexpensive. Furthermore, rather than simply record data on hard disk for later analysis we desire a system that will work autonomously, capitalizing on wireless technology and in field network analysis. To this end we are currently producing a low cost seismic array which will incorporate, at the very basic level, seismological tools for first cut analysis of a volcano in crises mode. At the advanced end we expect to perform tomographic inversions in the network in near real time. Geophone (4 Hz) sensors connected to a low cost recording system will be installed on an active volcano where triggering earthquake location and velocity analysis will take place independent of human interaction. Stations are designed to be inexpensive and possibly disposable. In one of the first implementations the seismic nodes consist of an Arduino Due processor board with an attached Seismic Shield. The Arduino Due processor board contains an Atmel SAM3X8E ARM Cortex-M3 CPU. This 32 bit 84 MHz processor can filter and perform coarse seismic event detection on a 1600 sample signal in fewer than 200 milliseconds. The Seismic Shield contains a GPS module, 900 MHz high power mesh network radio, SD card, seismic amplifier, and 24 bit ADC. External sensors can be attached to either this 24-bit ADC or to the internal multichannel 12 bit ADC contained on the Arduino Due processor board. This allows the node to support attachment of multiple sensors. By utilizing a high-speed 32 bit processor complex signal processing tasks can be performed simultaneously on multiple sensors. Using a 10 W solar panel, second system being developed can run autonomously and collect data on 3 channels at 100Hz for 6 months

  19. Dynamic triggering of volcano drumbeat-like seismicity at the Tatun volcano group in Taiwan

    Science.gov (United States)

    Lin, Cheng-Horng

    2017-07-01

    Periodical seismicity during eruptions has been observed at several volcanoes, such as Mount St. Helens and Soufrière Hills. Movement of magma is often considered one of the most important factors in its generation. Without any magma movement, drumbeat-like (or heartbeat-like) periodical seismicity was detected twice beneath one of the strongest fumarole sites (Dayoukeng) among the Tatun volcano group in northern Taiwan in 2015. Both incidences of drumbeat-like seismicity were respectively started after felt earthquakes in Taiwan, and then persisted for 1-2 d afterward with repetition intervals of ∼18 min between any two adjacent events. The phenomena suggest both drumbeat-like (heartbeat-like) seismicity sequences were likely triggered by dynamic waves generated by the two felt earthquakes. Thus, rather than any involvement of magma, a simplified pumping system within a degassing conduit is proposed to explain the generation of drumbeat-like seismicity. The collapsed rocks within the conduit act as a piston, which was repeatedly lifted up by ascending gas from a deeper reservoir and dropped down when the ascending gas was escaping later. These phenomena show that the degassing process is still very strong in the Tatun volcano group in Taiwan, even though it has been dormant for about several thousand years.

  20. Ideological Cooperation versus Cold War Realpolitik - The SED and the Icelandic Socialist Party

    Directory of Open Access Journals (Sweden)

    Valur Ingimundarson

    2007-01-01

    Full Text Available The article deals with the relationship between the East German Socialist Unity Party (SED and the Icelandic Socialist Party (SEI during the Cold War. It details the structural limitations of ideological cooperation between the two parties – Iceland’s NATO membership and the U.S. military presence – as well as its possibilities, especially in the 1950s, through the governmental participation of the SEI. Special attention is devoted to the role played by Einar Olgeirsson, the chairman of the SEI 1939–1968, who was instrumental in forging and developing political, economic, and cultural ties with the SED and the German Democratic Republic. The article argues that this experiment in transnational solidarity between socialist parties from two radically different political systems failed in the end due to several factors, including ideological differences and the political and economic development in Iceland.

  1. Spatiotemporal evolution of the completeness magnitude of the Icelandic earthquake catalogue from 1991 to 2013

    Science.gov (United States)

    Panzera, Francesco; Mignan, Arnaud; Vogfjörð, Kristin S.

    2017-07-01

    In 1991, a digital seismic monitoring network was installed in Iceland with a digital seismic system and automatic operation. After 20 years of operation, we explore for the first time its nationwide performance by analysing the spatiotemporal variations of the completeness magnitude. We use the Bayesian magnitude of completeness (BMC) method that combines local completeness magnitude observations with prior information based on the density of seismic stations. Additionally, we test the impact of earthquake location uncertainties on the BMC results, by filtering the catalogue using a multivariate analysis that identifies outliers in the hypocentre error distribution. We find that the entire North-to-South active rift zone shows a relatively low magnitude of completeness Mc in the range 0.5-1.0, highlighting the ability of the Icelandic network to detect small earthquakes. This work also demonstrates the influence of earthquake location uncertainties on the spatiotemporal magnitude of completeness analysis.

  2. HACCP and water safety plans in Icelandic water supply: preliminary evaluation of experience.

    Science.gov (United States)

    Gunnarsdóttir, María J; Gissurarson, Loftur R

    2008-09-01

    Icelandic waterworks first began implementing hazard analysis and critical control points (HACCP) as a preventive approach for water safety management in 1997. Since then implementation has been ongoing and currently about 68% of the Icelandic population enjoy drinking water from waterworks with a water safety plan based on HACCP. Preliminary evaluation of the success of HACCP implementation was undertaken in association with some of the waterworks that had implemented HACCP. The evaluation revealed that compliance with drinking water quality standards improved considerably following the implementation of HACCP. In response to their findings, waterworks implemented a large number of corrective actions to improve water safety. The study revealed some limitations for some, but not all, waterworks in relation to inadequate external and internal auditing and a lack of oversight by health authorities. Future studies should entail a more comprehensive study of the experience with the use of HACCP with the purpose of developing tools to promote continuing success.

  3. Environmental Uncertainty, Performance Measure Variety and Perceived Performance in Icelandic Companies

    DEFF Research Database (Denmark)

    Rikhardsson, Pall; Sigurjonsson, Throstur Olaf; Arnardottir, Audur Arna

    and the perceived performance of the company. The sample was the 300 largest companies in Iceland and the response rate was 27%. Compared to other studies the majority of the respondents use a surprisingly high number of different measures – both financial and non-financial. This made testing of the three......The use of performance measures and performance measurement frameworks has increased significantly in recent years. The type and variety of performance measures in use has been researched in various countries and linked to different variables such as the external environment, performance...... measurement frameworks, and management characteristics. This paper reports the results of a study carried out at year end 2013 of the use of performance measures by Icelandic companies and the links to perceived environmental uncertainty, management satisfaction with the performance measurement system...

  4. Provenance variation in subalpine fir grown as an exotic tree species in Denmark and Iceland

    DEFF Research Database (Denmark)

    Skúlason, Brynjar

    Neonectria neomacrospora in Denmark. In Iceland the corkbark fir showed superior results, especially for survival rate and Christmas tree quality. The White River provenance from British Columbia is recommended for use in Denmark. The Mount Taylor provenance from the Cibola National Forest in New Mexico...... fir (A. lasiocarpa var. lasiocarpa) and corkbark fir (A. lasiocarpa var. arizonica (Merriam) Lemmon) was established at three sites in Denmark and at one site in Iceland in 1999. Adaptability, Christmas tree quality, growth rhythm and susceptibility to pests and pathogens were measured and assessed...... and the most spring frost damage on buds. The westernmost subalpine fir provenances from Washington state and British Columbia showed the overall best results in Denmark, with the highest survival (after 15 years), fastest height growth and highest Christmas tree quality and profitability, as well as both good...

  5. Survivel, growth, and nutrition of tree seedlings fertilized at planting on Andisol soils in Iceland

    DEFF Research Database (Denmark)

    Oskarsson, Hreinn; Sigurgeirsson, Adalsteinn; Raulund-Rasmussen, Karsten

    2006-01-01

    seedlings, compared to control seedlings. It is concluded that fertilization during afforestation in Iceland and other areas in the world with similar climatic and soil properties could make the difference between plantation success or failure. Growth; Survival; Foliar nutrient concentration; Frost heaving......A field trial was carried out in 1995 to study the effect of fertilization at planting on the survival, growth, and nutrition of tree seedlings planted on Andisol soils at two sites in South Iceland. Nine fertilizer treatments were tested on three tree species Betula pubescens Ehrh., Larix sibirica...... survival and growth. Larger amounts of N increased mortality during the first year. Fertilized trees were less subject to frost heaving than untreated trees. In the year following application of NPK fertilizer the effect was insignificant on the foliar concentration of macronutrients of the fertilized...

  6. Helium isotopes in geothermal systems: Iceland, The Geysers, Raft River and Steamboat Springs

    International Nuclear Information System (INIS)

    Torgersen, T.

    1982-01-01

    Helium isotope ratios have been measured in geothermal fluids from Iceland, The Geysers, Raft River, Steamboat Springs and Hawaii. These ratios have been interpreted in terms of the processes which supply He in distinct isotopic ratios and in terms of the processes which can alter the isotopic ratio. Using this interpretational scheme, Iceland is found to be an area of hot-spot magmatic He implying an active volcanic source although the data are suggestive of high-temperature weathering release of crustal He incorporated in the geothermal fluids. By comparison to fumarolic gases from Hawaii and Juan De Fuca and Cayman Trench basaltic glass samples, The Geysers contains MOR type magmatic He again implying an active volcanic source possibly a 'leaky' transform related to the San Andreas Fault System. Raft River contains only crustal He indicating no active volcanic sources. Steamboat Springs He isotope ratios are distinctly less than typical plate margin volcanics but must still have a magmatic source. (author)

  7. Effect of year of birth on the breast cancer age-incidence curve in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Bjarnason, O [Univ. of Iceland, Reykjavik; Day, N; Snaedal, G; Tulinius, H

    1974-01-01

    Among different populations, the shape of the age-incidence curve for breast cancer is strongly related to the overall incidence of breast cancer in the respective population. Data are available from Iceland for the period 1911--1972. These data show that breast cancer has increased very markedly in Iceland during this period, and that as the overall incidence has risen, so the age-incidence curve has changed in shape, the relation between the shape and the overall incidence being the same as that now observed in other countries. The change in shape is shown to be explicable entirely as a cohort phenomenon, each decade of birth cohort having an age-incidence curve of similar shape, but with different overall incidence. Data from some other regions of the world indicate that many of the present differences in the shape of the age-incidence curve may be the reflection of cohort phenomena.

  8. Effective Project Risk management in Micro Companies : Case study for Persona Optima Iceland ehf.

    OpenAIRE

    Bražinskaitė, Justina

    2011-01-01

    This study is meant to be a guide for micro companies regarding effective project risk management. The main purpose of this thesis is to introduce project risk management and build a user-friendly managerial model toward effective project risk management in micro companies. The research is based on a case company Persona Optima Iceland ehf. analysis. The study investigates risk management, uncertainties and risks in projects, project risk management, its models and particularities in orde...

  9. Optimum Safety Levels and Design Rules for the Icelandic Type Berm Breakwater

    DEFF Research Database (Denmark)

    Sigurdarson, Sigurdur; van der Meer, Jentsje W.; Burcharth, Hans F.

    2007-01-01

    Guidance on selection of breakwater types and related design safety levels for breakwaters are almost non-existent, which is the reason that PIANC has initiated working group 47 on this subject. This paper presents ongoing work particulary on the Icelandic type berm breakwater within the PIANC...... working group. It will concentrate on design guidance and on the optimum safety levels for this type of structure....

  10. Impact of soil warming on the plant metabolome of Icelandic grasslands

    Czech Academy of Sciences Publication Activity Database

    Gargallo-Garriga, A.; Ayala-Roque, M.; Sardans, J.; Bartrons, M.; Granda, V.; Sigurdsson, B. D.; Leblans, N. I.W.; Oravec, Michal; Urban, Otmar; Janssens, I. A.; Peñuelas, J.

    2017-01-01

    Roč. 7, č. 3 (2017), č. článku 44. E-ISSN 2218-1989 R&D Projects: GA MŠk(CZ) LM2015061; GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : Climate change * Geothermal bedrock channels * Grassland * Iceland * Metabolome * Warming Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)

  11. Social Media Used by Government Institutions in Iceland: Application, Role and Aims

    Directory of Open Access Journals (Sweden)

    Már Einarsson

    2014-12-01

    Full Text Available The purpose of this research was to study the use and role of social media hosted by government institutions in Iceland. The research was conducted using quantitative and qualitative research methods. A survey was sent electronically to all government institutions in Iceland and semi-structured interviews were conducted with specialists working for institutions. No research has been conducted on this subject in Iceland before. It was therefore considered timely that a research was conducted on the use of social media in public institutions, with the intention of adding new knowledge to the field. No similar research from outside of Iceland was found, but this research was based on related studies and sources from abroad. A little less than half of government institutions used social media as part of their activities and Facebook and YouTube were most widely used. Popularity, circulation, usefulness and convenience were the most important factors when choosing social media. The majority of institutions had neither defined social media goals nor the role and responsibility of employees when using social media. The institutions placed strong emphasis on publishing adverts and news items on the institutions’ activities via social media pages and there were a considerable number of references to material on other web pages. Among other things the interviewees said that the purpose of using social media was information dissemination, reception of information, more visibility, the opening of institutions to the public and increased transparency. They talked about the importance of being informal on social media, but they also pointed out that there had been some fear among institutions of using them, in particular fear of employees showing a human side via social media. There was minimal use of original material on institutions’ social media pages, while institutions were quite systematic in posting material from their website through social media

  12. Deep magma transport at Kilauea volcano, Hawaii

    Science.gov (United States)

    Wright, T.L.; Klein, F.W.

    2006-01-01

    The shallow part of Kilauea's magma system is conceptually well-understood. Long-period and short-period (brittle-failure) earthquake swarms outline a near-vertical magma transport path beneath Kilauea's summit to 20 km depth. A gravity high centered above the magma transport path demonstrates that Kilauea's shallow magma system, established early in the volcano's history, has remained fixed in place. Low seismicity at 4-7 km outlines a storage region from which magma is supplied for eruptions and intrusions. Brittle-failure earthquake swarms shallower than 5 km beneath the rift zones accompany dike emplacement. Sparse earthquakes extend to a decollement at 10-12 km along which the south flank of Kilauea is sliding seaward. This zone below 5 km can sustain aseismic magma transport, consistent with recent tomographic studies. Long-period earthquake clusters deeper than 40 km occur parallel to and offshore of Kilauea's south coast, defining the deepest seismic response to magma transport from the Hawaiian hot spot. A path connecting the shallow and deep long-period earthquakes is defined by mainshock-aftershock locations of brittle-failure earthquakes unique to Kilauea whose hypocenters are deeper than 25 km with magnitudes from 4.4 to 5.2. Separation of deep and shallow long-period clusters occurs as the shallow plumbing moves with the volcanic edifice, while the deep plumbing is centered over the hotspot. Recent GPS data agrees with the volcano-propagation vector from Kauai to Maui, suggesting that Pacific plate motion, azimuth 293.5?? and rate of 7.4 cm/yr, has been constant over Kilauea's lifetime. However, volcano propagation on the island of Hawaii, azimuth 325??, rate 13 cm/yr, requires southwesterly migration of the locus of melting within the broad hotspot. Deep, long-period earthquakes lie west of the extrapolated position of Kilauea backward in time along a plate-motion vector, requiring southwesterly migration of Kilauea's magma source. Assumed ages of 0

  13. Space Radar Image of Kilauea Volcano, Hawaii

    Science.gov (United States)

    1994-01-01

    This is a deformation map of the south flank of Kilauea volcano on the big island of Hawaii, centered at 19.5 degrees north latitude and 155.25 degrees west longitude. The map was created by combining interferometric radar data -- that is data acquired on different passes of the space shuttle which are then overlayed to obtain elevation information -- acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar during its first flight in April 1994 and its second flight in October 1994. The area shown is approximately 40 kilometers by 80 kilometers (25 miles by 50 miles). North is toward the upper left of the image. The colors indicate the displacement of the surface in the direction that the radar instrument was pointed (toward the right of the image) in the six months between images. The analysis of ground movement is preliminary, but appears consistent with the motions detected by the Global Positioning System ground receivers that have been used over the past five years. The south flank of the Kilauea volcano is among the most rapidly deforming terrains on Earth. Several regions show motions over the six-month time period. Most obvious is at the base of Hilina Pali, where 10 centimeters (4 inches) or more of crustal deformation can be seen in a concentrated area near the coastline. On a more localized scale, the currently active Pu'u O'o summit also shows about 10 centimeters (4 inches) of change near the vent area. Finally, there are indications of additional movement along the upper southwest rift zone, just below the Kilauea caldera in the image. Deformation of the south flank is believed to be the result of movements along faults deep beneath the surface of the volcano, as well as injections of magma, or molten rock, into the volcano's 'plumbing' system. Detection of ground motions from space has proven to be a unique capability of imaging radar technology. Scientists hope to use deformation data acquired by SIR-C/X-SAR and future imaging

  14. Element fluxes from Copahue Volcano, Argentina

    Science.gov (United States)

    Varekamp, J. C.

    2003-12-01

    Copahue volcano in Argentina has an active volcano-magmatic hydrothermal system that emits fluids with pH=0.3 that feed a river system. River flux measurements and analytical data provide element flux data from 1997 to 2003, which includes the eruptive period of July to December 2000. The fluids have up to 6.5 percent sulfate, 1 percent Cl and ppm levels of B, As, Cu, Zn and Pb. The hydrothermal system acts as a perfect scrubber for magmatic gases during the periods of passive degassing, although the dissolved magmatic gases are modified through water rock interaction and mineral precipitation. The magmatic SO2 disproportionates into sulfate and liquid elemental sulfur at about 300 C; the sulfate is discharged with the fluids, whereas the liquid sulfur is temporarily retained in the reservoir but ejected during phreatic and hydrothermal eruptions. The intrusion and chemical attack of new magma in the hydrothermal reservoir in early 2000 was indicated by strongly increased Mg concentrations and Mg fluxes, and higher Mg/Cl and Mg/K values. The hydrothermal discharge has acidified a large glacial lake (0.5 km3) to pH=2 and the lake effluents acidify the exiting river. Even more than 100 km downstream, the effects of acid pulses from the lake are evident from red coated boulders and fish die-offs. The river-bound sulfate fluxes from the system range from 70 to 200 kilotonnes/year. The equivalent SO2 output of the whole volcanic system ranges from 150 to 500 tonnes/day, which includes the fraction of native sulfur that formed inside the mountain but does not include the release of SO2 into the atmosphere during the eruptions. Trace element fluxes of the river will be scaled up and compared with global element fluxes from meteoric river waters (subterranean volcanic weathering versus watershed weathering).

  15. Geomechanical rock properties of a basaltic volcano

    Directory of Open Access Journals (Sweden)

    Lauren N Schaefer

    2015-06-01

    Full Text Available In volcanic regions, reliable estimates of mechanical properties for specific volcanic events such as cyclic inflation-deflation cycles by magmatic intrusions, thermal stressing, and high temperatures are crucial for building accurate models of volcanic phenomena. This study focuses on the challenge of characterizing volcanic materials for the numerical analyses of such events. To do this, we evaluated the physical (porosity, permeability and mechanical (strength properties of basaltic rocks at Pacaya Volcano (Guatemala through a variety of laboratory experiments, including: room temperature, high temperature (935 °C, and cyclically-loaded uniaxial compressive strength tests on as-collected and thermally-treated rock samples. Knowledge of the material response to such varied stressing conditions is necessary to analyze potential hazards at Pacaya, whose persistent activity has led to 13 evacuations of towns near the volcano since 1987. The rocks show a non-linear relationship between permeability and porosity, which relates to the importance of the crack network connecting the vesicles in these rocks. Here we show that strength not only decreases with porosity and permeability, but also with prolonged stressing (i.e., at lower strain rates and upon cooling. Complimentary tests in which cyclic episodes of thermal or load stressing showed no systematic weakening of the material on the scale of our experiments. Most importantly, we show the extremely heterogeneous nature of volcanic edifices that arise from differences in porosity and permeability of the local lithologies, the limited lateral extent of lava flows, and the scars of previous collapse events. Input of these process-specific rock behaviors into slope stability and deformation models can change the resultant hazard analysis. We anticipate that an increased parameterization of rock properties will improve mitigation power.

  16. Ash and Steam, Soufriere Hills Volcano, Monserrat

    Science.gov (United States)

    2002-01-01

    International Space Station crew members are regularly alerted to dynamic events on the Earth's surface. On request from scientists on the ground, the ISS crew observed and recorded activity from the summit of Soufriere Hills on March 20, 2002. These two images provide a context view of the island (bottom) and a detailed view of the summit plume (top). When the images were taken, the eastern side of the summit region experienced continued lava growth, and reports posted on the Smithsonian Institution's Weekly Volcanic Activity Report indicate that 'large (50-70 m high), fast-growing, spines developed on the dome's summit. These spines periodically collapsed, producing pyroclastic flows down the volcano's east flank that sometimes reached the Tar River fan. Small ash clouds produced from these events reached roughly 1 km above the volcano and drifted westward over Plymouth and Richmond Hill. Ash predominately fell into the sea. Sulfur dioxide emission rates remained high. Theodolite measurements of the dome taken on March 20 yielded a dome height of 1,039 m.' Other photographs by astronauts of Montserrat have been posted on the Earth Observatory: digital photograph number ISS002-E-9309, taken on July 9, 2001; and a recolored and reprojected version of the same image. Digital photograph numbers ISS004-E-8972 and 8973 were taken 20 March, 2002 from Space Station Alpha and were provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  17. The Icelandic economic collapse, smoking, and the role of labor-market changes.

    Science.gov (United States)

    Ólafsdóttir, Thorhildur; Hrafnkelsson, Birgir; Ásgeirsdóttir, Tinna Laufey

    2015-05-01

    Smoking is related to health deterioration through increased risk of various diseases. Changes in this health behavior could contribute to the documented health improvements during economic downturns. Furthermore, the reasons for changes in behavior are not well understood. We explore smoking behavior in Iceland before and after the sudden and unexpected economic crisis in 2008. Furthermore, to explore the mechanisms through which smoking could be affected we focus on the role of labor-market changes. Both real income and working hours fell significantly and economic theory suggests that such changes can affect health behaviors which in turn affect health. We use individual longitudinal data from 2007 to 2009, incidentally before and after the crisis hit. The data originates from a postal survey, collected by The Public Health Institute in Iceland. Two outcomes are explored: smoking participation and smoking intensity, using pooled ordinary least squares (OLS) and linear probability models. The detected reduction in both outcomes is not explained by the changes in labor-market variables. Other factors in the demand function for tobacco play a more important role. The most notable are real prices which increased in particular for imported goods because of the devaluation of the Icelandic currency as a result of the economic collapse.

  18. Levelized Cost of Energy Analysis of a Wind Power Generation System at Búrfell in Iceland

    Directory of Open Access Journals (Sweden)

    Birgir Freyr Ragnarsson

    2015-09-01

    Full Text Available Wind energy harnessing is a new energy production alternative in Iceland. Current installed wind power in Iceland sums to 1.8 MW, which in contrast is 0.1% of the country’s total electricity production. This article is dedicated to the exploration of the potential cost of wind energy production at Búrfell in the south of Iceland. A levelized cost of energy (LCOE approach was applied to the estimation of the potential cost. Weibull simulation is used to simulate wind data for calculations. A confirmation of the power law is done by comparing real data to calculated values. A modified Weibull simulation is verified by comparing results with actual on-site test wind turbines. A wind farm of 99MWis suggested for the site. Key results were the capacity factor (CF at Búrfell being 38.15% on average and that the LCOE for wind energy was estimated as 0.087–0.088 USD/kWh (assuming 10% weighted average cost of capital (WACC, which classifies Búrfell among the lowest LCOE sites for wind energy in Europe.

  19. Drivers of Ecological Restoration: Lessons from a Century of Restoration in Iceland

    Directory of Open Access Journals (Sweden)

    Ása L. Aradóttir

    2013-12-01

    Full Text Available We analyzed the main drivers for ecological restoration in Iceland from 1907 to 2010 and assessed whether the drivers have changed over time and what factors might explain the changes, if any. Our study was based on a catalogue of 100 restoration projects, programs, and areas, representing 75% to 85% of all restoration activities in Iceland. Catastrophic erosion was an early driver for soil conservation and restoration efforts that still ranked high in the 2000s, reflecting the immense scale of soil erosion and desertification in Iceland. Socioeconomic drivers such as farming and the provision of wood products were strong motivators of ecological restoration over most of the 20th century, although their relative importance decreased with time as the number and diversity of drivers increased. In the 1960s and 1970s, the construction of hard infrastructure, and moral values such as improving the aesthetics of the countryside and "repaying the debt to the land" emerged as motivations for restoration actions. In the late 1990s, the United Nations Climate Change Convention became a driver for restoration, and the importance of nature conservation and recreation increased. Technological development and financial incentives did not show up as drivers of ecological restoration in our study, although there are some indications of their influence. Furthermore, policy was a minor driver, which might reflect weak policy instruments for ecological restoration and some counteractive policies.

  20. Magma supply, storage, and transport at shield-stage Hawaiian volcanoes: Chapter 5 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Poland, Michael P.; Miklius, Asta; Montgomery-Brown, Emily K.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    The characteristics of magma supply, storage, and transport are among the most critical parameters governing volcanic activity, yet they remain largely unconstrained because all three processes are hidden beneath the surface. Hawaiian volcanoes, particularly Kīlauea and Mauna Loa, offer excellent prospects for studying subsurface magmatic processes, owing to their accessibility and frequent eruptive and intrusive activity. In addition, the Hawaiian Volcano Observatory, founded in 1912, maintains long records of geological, geophysical, and geochemical data. As a result, Hawaiian volcanoes have served as both a model for basaltic volcanism in general and a starting point for many studies of volcanic processes.