WorldWideScience

Sample records for belt western greenland

  1. Source heterogeneity for the major components of ~3.7 Ga banded iron formations (Isua Greenstone Belt, Western Greenland)

    DEFF Research Database (Denmark)

    Frei, Robert; Polat, Ali

    2006-01-01

    of the depositional environment and to the understanding of depositional mechanisms of these earliest chemical sediments. Rare earth element (REE)-yttrium (Y) patterns of the individual mesobands show features of modern seawater with diagnostic cerium (Ce/Ce ), presodymium (Pr/Pr ) and Y/holmium (Ho) anomalies. Very......We report trace element, samarium (Sm)-neodymium (Nd) and lead (Pb) isotopic data for individual micro-and mesobands of the Earth's oldest Banded Iron Formation (BIF) from the  3.7-3.8 Ga Isua Greenstone Belt (IGB, West Greenland) in an attempt to contribute to the characterization...... low high field strength elements (HFSE) concentrations indicate essentially detritus-free precipitation. Uranogenic Pb isotope data define a correlation line with a slope of 3691 ± 41 Ma, indicating that the uranium (U)-lead (Pb) system remained closed after the formation of this BIF. High 207Pb/204Pb...

  2. Seabird Colonies in Western Greenland

    DEFF Research Database (Denmark)

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

    surveys of seabird colonies are needed, due to a lack of information or because the present information probably is outdated. The most immediate threats to the colonial seabirds in western Greenland during the breeding time is hunting and egging. Oil pollution is a minor threat to-day, but will increase...... if offshore areas with oil potential are explored and developed. Tab. 6 gives an overview of each species sensitivity to oil spills and the capacity to recover, as well as a comparison of the western Greenland population numbers to the North Atlantic population numbers. The most significant western Greenland...

  3. Holocene insect remains from south-western Greenland

    DEFF Research Database (Denmark)

    Bøcher, Jens Jensenius; Bennike, Ole; Wagner, Bernd

    2012-01-01

    Remains of plants and invertebrates from Holocene deposits in south-western Greenland include a number of insect fragments from Heteroptera and Coleoptera. Some of the finds extend the known temporal range of the species considerably back in time, and one of the taxa has not previously been found...... remains of terrestrial insects complement the scarce fossil Greenland record of the species concerned....

  4. The thrust belts of Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, F.C.

    1993-08-01

    Most of the Basin and Range physiographic province of western North America is now believed to be part of the overthrust. The more obvious overthrust belt along the eastern edge of the Basin and Range Province is named the Sevier orogenic belt, where older rocks are observed thrust onto younger rocks. More detailed surface geological mapping, plus deep multiple-fold geophysical work and many oil and gas wildcat wells, have confirmed an east-vergent shortened and stacked sequence is present in many places in the Basin and Range. This western compressive deformed area in east central Nevada is now named the Elko orogenic belt by the U.S. Geological Survey. This older compressed Elko orogenic belt started forming approximately 250 m.y. ago when the North American plate started to move west as the Pangaea supercontinent started to fragment. The North American plate moved west under the sediments of the Miogeocline that were also moving west. Surface-formed highlands and oceanic island arcs on the west edge of the North American plate restricted the westward movement of the sediments in the Miogeocline, causing east-vergent ramp thrusts to form above the westward-moving North American plate. The flat, eastward-up-cutting thrust assemblages moved on the detachment surfaces.

  5. Annual variations of frost table in Kangerlussuaq Airport, western Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas; Brock, Niels

    2007-01-01

    Ground-penetrating radar (GPR) has been used to study the annual variations of the frost table beneath the southern parking area at Kangerlussuaq Airport, western Greenland. In autumn 2000, three test areas were painted white in order to reduce further development of depressions in the asphalt...

  6. Geochemistry of Archaean supracrustal belts in SW Greenland

    DEFF Research Database (Denmark)

    Szilas, Kristoffer

    This PhD-thesis investigates the geological formation environment of c. 3200-3000 million-year-old volcanic rocks from SW Greenland, using whole-rock geochemical data in combination with U-Pb, Sm-Nd and Lu-Hf isotope data. The following three supracrustal areas were studied: (1) The Tartoq Group ...

  7. Lime stabilization of fine-grained sediments in western Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

    due to the cold climate, and it is therefore of great interest to study possible methods to improve the stability and strength properties. This project includes laboratory studies of lime stabilization on fine-grained marine sediments from Kangerlussuaq, western Greenland. The results have included...... tests to determine the optimum lime content and the strength development in relation to both reaction time and curing temperature. Hopefully the results from this project will lead to a future use of lime stabilization and make it possible to use/reuse materials of poor quality at construction sites...

  8. The Greenland analogue project. Geomodel version 1 of the Kangerlussuaq area on Western Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, J.; Paananen, M. [GTK Geological Survey of Finland, Espoo (Finland); Klint, K.E. [GEUS Geological Survey of Denmark and Greenland, Copenhagen (Denmark)

    2012-02-15

    During the 2nd annual Greenland Analogue Project modelling workshop in Toronto, November 2010, the hydrological modellers requested an updated geological map and structural model of the field area around Kangerlussuaq, Western Greenland. This report presents an updated GAP Geomodel which utilizes all available information in order to improve the accuracy of the model, especially beneath the ice-sheet. The modelling area was divided into two scales: The regional scale area and the site scale area. The site scale refers to the area were surface mapping has been performed, and where two drillholes (DH-GAP01 and DH-GAP03) were drilled during 2009. Geological and topographical maps from GEUS (sub-model 1) and data extracted from the Geophysical map, GEUS, (sub-model 2) were used in the process to develop GAP Geomodel version 1. These two interpretations were independent from each other and in the final stage these sub-models were integrated and developed into GAP Geological model version 1. The integration resulted in a total of 158 lineaments. These lineaments are referred in the final model as deformation zones and faults, where deformation zones are larger features and faults are single fractures indicating some sense of movement. Four different sets of deformation zones and faults were identified in the regional area. The most prominent feature is the ductile/brittle roughly ENE-WSW trending zones crosscutting the whole area; referred as Type 1. Type 2 and Type 3 zones are in general smaller scale than Type 1 and mostly dominated by brittle deformation. The Type 2 system generally trends NW-SE, while the Type 3 system generally trends NE-SW. The Type 4 features are a brittle and roughly N-S orientated younger system, thus crosscutting all other types. Confirmation and validation of the regional model is based on detailed surface-based examination of fractures within the site area, although the scale is different the same orientations were also identified in the

  9. The Greenland Analogue Project. Geomodel version 1 of the Kangerlussuaq area on Western Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Jon; Paananen, Markku (Geological Survey of Finland (Finland)); Klint, Knud Erik (The National Geological Survey of Denmark and Greenland (Denmark))

    2012-02-15

    During the 2nd annual Greenland Analogue Project modelling workshop in Toronto, November 2010, the hydrological modellers requested an updated geological map and structural model of the field area around Kangerlussuaq, Western Greenland. This report presents an updated GAP geomodel which utilizes all available information in order to improve the accuracy of the model, especially beneath the ice sheet. The modelling area was divided into two scales: The regional scale area and the site scale area. The site scale refers to the area were surface mapping has been performed, and where two boreholes (DH-GAP01 and DH-GAP03) were drilled during 2009. Geological and topographical maps from GEUS (sub-model 1) and data extracted from the geophysical map, GEUS, (sub-model 2) were used in the process to develop GAP geomodel version 1. These two interpretations were independent from each other and in the final stage these sub-models were integrated and developed into GAP geological model version 1. The integration resulted in a total of 158 lineaments. These lineaments are referred in the final model as deformation zones and faults, where deformation zones are larger features and faults are single fractures indicating some sense of movement. Four different sets of deformation zones and faults were identified in the regional area. The most prominent feature is the ductile/brittle roughly ENE-WSW trending zones crosscutting the whole area, referred as Type 1. Type 2 and Type 3 zones are in general smaller scale than Type 1 and mostly dominated by brittle deformation. The Type 2 system generally trends NW-SE, while the Type 3 system generally trends NE-SW. The Type 4 features are a brittle and roughly N-S orientated younger system, thus crosscutting all other types. Confirmation and validation of the regional model is based on detailed surface-based examination of fractures within the site area, although the scale is different the same orientations were also identified in the

  10. Hyperspectral and photogrammetric helicopter-based measurements over western Greenland

    Science.gov (United States)

    Tedesco, M.; Mote, T. L.; Smith, L. C.; Rennermalm, A. K.; Lampkin, D. J.

    2015-12-01

    We discuss the setup and results of an experiment aimed at collecting helicopter-based hyperspectral and photogrammetry measurements over the western Greenland ice sheet (GrIS) for studying the evolution of surface albedo and surface hydrological features. Data were collected during three days at the end of July 2015 concurrently with in-situ hydrological measurements of runoff and discharge of a supraglacial stream (Rio Behar) and along the K-transect up to an elevation of ~ 1500 m a.s.l. Hyperspectral measurements of incoming and outgoing radiation collected at a radiometric resolution of 10 nm were acquired in conjunction with geo-located images by means of a digital camera mounted on the same platform. Gyroscopes and 3-D accelerometers were also used to estimate the relative orientation of the sensors collecting the incoming and outgoing solar radiation. To our knowledge, despite their importance, it is the first time that such measurements have been collected over the Greenland ice sheet from an airborne platform. The sensors were installed inside a pod that was specifically modified for our purpose. The impact of the helicopter on the recorded incoming radiation was characterized by collecting measurements in the absence and presence of the helicopter when the rotors were either off or on. Moreover, the effect of the relative position of the helicopter with respect to the sun's position was also quantified by ad-hoc maneuvers during take off and landing with the helicopter spinning around the main rotor axis. The geo-referenced images collected by our instrument provide an unprecedented ground spatial resolution of ~ 6 cm, hence allowing us to study the spatial distribution of surface hydrological features, such as cryoconite holes, small order streams and cracks developing into larger moulins. Such images were also used to evaluate the application of RGB data to estimate streams and lakes surface area and depths. Our helicopter-based hyperspectral and

  11. Greenland

    Institute of Scientific and Technical Information of China (English)

    陈玮

    2002-01-01

    Greenland is the largest is land in the world.it is in the_____of Europe(欧洲)。Near Greenland is another island.it is small.its_____is lceland.do you think that greenland is green and warm? do you think that iceland is white with ice? if you do,you are______.

  12. Decreasing overweight and central fat patterning with Westernization among the Inuit in Greenland and Inuit migrants

    DEFF Research Database (Denmark)

    Bjerregaard, P; Jørgensen, M E; Andersen, S;

    2002-01-01

    OBJECTIVE: To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization. DESIGN: Cross-sectional, population-based epidemiological study. SUBJECTS: A total of 2046 adult Greenlanders (Inuit), 61% of those...... women. Adjusted for BMI, age and Inuit heritage waist circumference decreased with Westernization (among women), while hip circumference did not change. The differences were particularly pronounced for migrants compared with residents of Greenland. CONCLUSION: BMI and central fat patterning decrease...

  13. Greenland

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2014-01-01

    The relationship between Greenland and the European Union (EU) can best be understood by exploring the development from Danish colonialism to a future independent Greenlandic state. In 1985, Greenland became the first territory ever to leave the European Economic Community (EEC) when it opted...... in 1979 and made the 1985 withdrawal possible. On 25 November 2008, a majority of the people of Greenland voted in favour of enhanced home rule – ‘self-government’ – still within formal Danish sovereignty. Denmark and Greenland alike are preparing for a future envisioned as involving climate change......, intensive raw material extraction, new transportation corridors and new claims to sovereignty over the Arctic. Greenland uses this imagined future as a way of enhancing its subjectivity, not the least when dealing with the EU. This article analyses how the Greenlandic self-understanding as being on the way...

  14. Lacustrine Records of Holocene Mountain Glacier Fluctuations from Western Greenland

    Science.gov (United States)

    Schweinsberg, A.; Briner, J. P.; Bennike, O.

    2014-12-01

    Recent studies have focused on documenting fluctuations of the Greenland Ice Sheet margin throughout the Holocene but few data exist that constrain past changes of local glaciers independent of the ice sheet. Our research combines proglacial lake sediment analysis with cosmogenic 10Be dating of Holocene moraines and radiocarbon dating of ice-cap-killed vegetation with an overall objective to use this multi-proxy approach to generate a detailed record of the coupled climate-glacier system through the Holocene. Here, we present lacustrine records of mountain glacier variability from continuous pro-glacial lake sediment sequences recovered from two glaciated catchments in northeastern Nuussuaq, western Greenland. We use radiocarbon-dated sediments from Sikuiui and Pauiaivik lakes to reconstruct the timing of advance and retreat of local glaciers. Sediments were characterized with magnetic susceptibility (MS), gamma density, Itrax XRF and visible reflectance spectroscopy at 0.2 cm intervals and sediment organic matter at 0.5 cm intervals. Basal radiocarbon ages provide minimum-age constraints on deglaciation from Sikuiui and Pauiaivik lakes of ~9.6 and 8.7 ka, respectively. Organic-rich gyttja from deglaciation until ~5.0 ka in Pauiaivik Lake suggests minimal glacial extent there while slightly elevated MS values from ~9.0 - 7.0 ka in Sikuiui Lake may reflect early Holocene glacial advances. Minerogenic sediment input gradually increases starting at ~5.0 ka in Pauiaivik Lake, which we interpret as the onset of Neoglaciation in the catchment. Furthermore, a distinct episode of enhanced glacial activity from ~4.0 - 2.2 ka in Sikuiui Lake may be correlative to a period of persistent snowline lowering evidenced by radiocarbon dates of ice-killed vegetation from nearby ice cap margins. Results from these lacustrine records and our ice-killed vegetation dataset suggest a middle Holocene onset of Neoglaciation ~5.0 - 4.0 ka in this region. We are supplementing these records

  15. Tectonic Map of the Ellesmerian and Eurekan deformation belts on Svalbard, North Greenland and the Queen Elizabeth Islands (Canadian Arctic)

    Science.gov (United States)

    Piepjohn, Karsten; von Gosen, Werner; Tessensohn, Franz; Reinhardt, Lutz; McClelland, William C.; Dallmann, Winfried; Gaedicke, Christoph; Harrison, Christopher

    2016-04-01

    The tectonic map presented here shows the distribution of the major post-Ellesmerian and pre-Eurekan sedimentary basins, parts of the Caledonian Orogen, the Ellesmerian Fold-and-Thrust Belt, structures of the Cenozoic Eurekan deformation, and areas affected by the Eurekan overprint. The present continental margin of North America towards the Arctic Ocean between the Queen Elizabeth Islands and Northeast Greenland and the present west margin of the Barents Shelf are characterized by the Paleozoic Ellesmerian Fold-and-Thrust Belt, the Cenozoic Eurekan deformation, and, in parts, the Caledonian Orogen. In many areas, the structural trends of the Ellesmerian and Eurekan deformations are more or less parallel, and often, structures of the Ellesmerian Orogeny are affected or reactivated by the Eurekan deformation. While the Ellesmerian Fold-and-Thrust Belt is dominated by orthogonal compression and the formation of wide fold-and-thrust zones on Ellesmere Island, North Greenland and Spitsbergen, the Eurekan deformation is characterized by a complex network of regional fold-and-thrust belts (Spitsbergen, central Ellesmere Island), large distinct thrust zones (Ellesmere Island, North Greenland) and a great number of strike-slip faults (Spitsbergen, Ellesmere Island). The Ellesmerian Fold-and-Thrust Belt was most probably related to the approach and docking of the Pearya Terrane (northernmost part of Ellesmere Island) and Spitsbergen against the north margin of Laurasia (Ellesmere Island/North Greenland) in the earliest Carboniferous. The Eurekan deformation was related to plate tectonic movements during the final break-up of Laurasia and the opening of Labrador Sea/Baffin Bay west, the Eurasian Basin north, and the Norwegian/Greenland seas east of Greenland. The tectonic map presented here shows the German contribution to the Tectonic Map of the Arctic 1:5,000,000 (TeMAr) as part of the international project "Atlas of geological maps of Circumpolar Arctic at 1

  16. Greenland

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet

    2015-01-01

    the article includes updated informations regarding church-state relations in Greenland re the latest changes of the Church law......the article includes updated informations regarding church-state relations in Greenland re the latest changes of the Church law...

  17. A study of the dark region in the western ablation zone of the Greenland ice sheet

    NARCIS (Netherlands)

    Wientjes, I.G.M.

    2011-01-01

    The western ablation zone of the Greenland ice sheet contains a region that is darker than the surrounding ice. This region is several tens of kilometres wide and stretched parallel to the margin of the ice sheet for more than 350 kilometres. The dark appearance implies low radiance and therefore lo

  18. Oceanographic regime shift during 1997 in Disko Bay, Western Greenland

    DEFF Research Database (Denmark)

    Hansen, Marc Overgaard; Nielsen, Torkel Gissel; Stedmon, Colin A.;

    2012-01-01

    Data from a long time series of temperature, salinity, and nutrient measurements in Disko Bay (West Greenland) reveal a marked change in the water characteristics during recent years. Seasonal dynamics in the upper 150 m of the water column were highly affected by the seasonality in meteorologica...... bay, using inorganic nutrients. These changes in the oceanography of the bay will not only lead to further glacial retreat but will also affect the local marine ecosystem by changing the relative dominance of major copepod species that overwinter in bottom waters of the bay...

  19. Vitamin D insufficiency in Greenlanders on a westernized fare

    DEFF Research Database (Denmark)

    Rejnmark, Lars; Jorgensen, M.E.; Pedersen, M.B.;

    2004-01-01

    We studied the influence of age, gender, latitude, season, diet and ethnicity on plasma 25-hydroxyvitamin D 25 OHD, PTH, 1,25-dihydroxyvitamin D, vitamin D-binding protein, bone-specific alkaline phosphatase, and osteocalcin levels in 46 Greenlanders living in Nuuk (64 degrees N) on a traditional...... in all four study groups during summer (23-74%) and winter (42-81%). Compared to groups A and D, vitamin D insufficiency was significantly more frequent in groups B and C. In all groups, summer levels of 25 OHD were above winter levels. Multiple regression analysis revealed a significant effect...

  20. Arable weed flora in the Western Siberian grain belt

    Directory of Open Access Journals (Sweden)

    Kämpf, Immo

    2016-02-01

    Full Text Available Between Ekaterinburg and Nowosibirsk, in the Western Siberian grain belt, spring wheat is grown on fertile Chernozem soils. Field and farm sizes are large but the land-use intensity per area is low compared to Central Europe. Fertilizers and pesticides are applied only in low to moderate quantities and yields range between 10 and 20 dt ha-1. We studied the arable weed flora in the northern forest steppe zone of Tyumen region using a randomized sampling design. Surprisingly, the species richness was only moderate, on average 9.8 ± 3.8 species per 100 m². Compared to weed communities of Bashkiria (Southern Ural and less intensively used arable land of Central Europe these numbers are rather low. Moreover, most of the recorded species were cosmopolitans or widely distributed throughout the temperate zone. We suggest that the land use intensity was high enough to reduce the density of a number of weed species in a way that they were not registered by our random sampling design. The limited conservational value of the weed vegetation of large grain fields in Tyumen leads to the conclusion that if intensification of land use is unavoidable, it should be directed to arable land and not to ex-arable land or ancient grassland, which is of higher conservation value.

  1. Environmental and Physiological Controls on Plant Leaf Wax δD from Western Greenland

    Science.gov (United States)

    Berke, M. A.; Bush, R. T.; Cartagena Sierra, A.; Cheah, D.; Costello, C.; Muldoon, T.; Tillema, M.

    2015-12-01

    Hydrogen isotope ratios of leaf waxes are increasingly used to reconstruct past hydroclimate, but the interpretation of these signatures from ancient sedimentary archives relies on a thorough understanding of the drivers of isotope variability in modern environments. These studies are particularly valuable in the arctic and subarctic, regions particularly vulnerable to rapid climate change, but where modern vegetation is understudied compared to proxy applications reliant on vegetation. Here we present δD values from leaf wax compounds of tundra vegetation in the Kangerlussuaq area of western Greenland. We collected samples along a transect that follows 12 sites from the base of the Greenland Ice Sheet, around a small lake ('Bird Lake') and to the town of Kangerlussuaq, along the Sandflugtdalen ('Flying Sand Valley'). We collected a variety of common tundra species in these locations including dwarf shrubs (e.g. Betula nana, Rhododendron lapponica, and Salix glauca), forbs and graminoids (e.g. Calamagrostis lapponica and Eriophorum angustifolium), and horsetails (Equisetum arvense) to study possible interspecies isotopic variability. We measured leaf and stem waters of these plants to help constrain potential drivers of leaf wax n-alkane δD values across this transect. Results are discussed relative to local climate parameters and modelled precipitation values to elucidate source water contributions modified by evaporation and transpiration. This survey of δD values from leaf wax compounds and plant waters in western Greenland will extend stable isotope calibrations to tundra vegetation and provide insights into the use of sedimentary leaf wax compounds for reconstruction of paleohydroclimate.

  2. Geochemical Evidence for Subduction in the Early Archaean from Quartz-Carbonate-Fuchsite Mineralization, Isua Supracrustal Belt, West Greenland

    Science.gov (United States)

    Pope, E. C.; Rosing, M. T.; Bird, D. K.

    2011-12-01

    Quartz, carbonate and fuchsite (chromian muscovite) is a common metasomatic assemblage observed in orogenic gold systems, both in Phanerozoic convergent margin settings, and within supracrustal and greenstone belts of Precambrian rocks. Geologic and geochemical observations in younger orogenic systems suggest that ore-forming metasomatic fluids are derived from subduction-related devolitilization reactions, implying that orogenic Au-deposits in Archaean and Proterozoic supracrustal rock suites are related to subduction-style plate tectonics beginning early in Earth history. Justification of this metasomatic-tectonic relationship requires that 1) Phanerozoic orogenic Au-deposits form in subduction-zone environments, and 2) the geochemical similarity of Precambrian orogenic deposits to their younger counterparts is the result of having the same petro-genetic origin. Hydrogen and oxygen isotope compositions of fuchsite and quartz from auriferous mineralization in the ca. 3.8 Ga Isua Supracrustal Belt (ISB) in West Greenland, in conjunction with elevated concentrations of CO2, Cr, Al, K and silica relative to protolith assemblages, suggest that this mineralization shares a common petro-tectonic origin with Phanerozoic orogenic deposits and that this type of metasomatism is a unique result of subduction-related processes. Fuchsite from the ISB has a δ18O and δD of +7.7 to +17.9% and -115 to -61%, respectively. δ18O of quartz from the same rocks is between +10.3 and +18.6%. Muscovite-quartz oxygen isotope thermometry indicates that the mineralization occurred at 560 ± 90oC, from fluids with a δD of -73 to -49% and δ18O of +8.8 to +17.2%. Calculation of isotopic fractionation during fluid-rock reactions along hypothetical fluid pathways demonstrates that these values, as well as those in younger orogenic deposits, are the result of seawater-derived fluids liberated from subducting lithosphere interacting with ultramafic rocks in the mantle wedge and lower crust

  3. Study of movement of the western and central belts of Peninsular Malaysia using GPS data analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ramli, Siti Hafizah; Samsudin, Abdul Rahim [Geology Programme, School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    Since the large earthquakes in Sumatera and Nias, there were some tremors incidents at Bukit Tinggi. Therefore, a study on the earth’s crust movement and the effects of the earthquake in Indonesia on the tectonic blocks of Peninsular Malaysia have been carried out using GPS data analysis. GPS data from five MyRTKnet stations within Peninsular Malaysia have been analyzed to monitor the movement of two major tectonic blocks of Peninsular Malaysia which are the western belt represented by the Behrang (BEHR) and UPM Serdang (UPMS) stations and the central belt represented by Bentong (BENT), Jerantut (JRNT) and Temerloh (TLOH) stations. GPS data recorded from 2005 to 2010 were analysed based on horizontal and vertical displacements of the respective stations by using Trimble Business Centre (TBC) software. Based on the results of accumulated displacements of recorded GPS data from January 2006 to December 2013, it shows that the western belt which represented by UPMS has shifted 0.096m towards northwest with changes of ellipsoidal height of +0.030m while the central belt which represented by TLOH has shifted 0.080m towards northwest with changes of ellipsoidal height of −0.015m. Meanwhile, BENT station which is located on the Bentong-Raub suture zone turns to its original position as well as JRNT station. However, BEHR station which are located in western belt do not show any movements. All of these movements may be due to the influence of reactive faults in the stations area stimulated by several large earthquakes that occurred in 2005 to 2010. Study on using the GPS data analysis and combine with integrated geophysical methods are necessary to understand in detail about the tectonic evolution of Peninsular Malaysia.

  4. Study of movement of the western and central belts of Peninsular Malaysia using GPS data analysis

    International Nuclear Information System (INIS)

    Since the large earthquakes in Sumatera and Nias, there were some tremors incidents at Bukit Tinggi. Therefore, a study on the earth’s crust movement and the effects of the earthquake in Indonesia on the tectonic blocks of Peninsular Malaysia have been carried out using GPS data analysis. GPS data from five MyRTKnet stations within Peninsular Malaysia have been analyzed to monitor the movement of two major tectonic blocks of Peninsular Malaysia which are the western belt represented by the Behrang (BEHR) and UPM Serdang (UPMS) stations and the central belt represented by Bentong (BENT), Jerantut (JRNT) and Temerloh (TLOH) stations. GPS data recorded from 2005 to 2010 were analysed based on horizontal and vertical displacements of the respective stations by using Trimble Business Centre (TBC) software. Based on the results of accumulated displacements of recorded GPS data from January 2006 to December 2013, it shows that the western belt which represented by UPMS has shifted 0.096m towards northwest with changes of ellipsoidal height of +0.030m while the central belt which represented by TLOH has shifted 0.080m towards northwest with changes of ellipsoidal height of −0.015m. Meanwhile, BENT station which is located on the Bentong-Raub suture zone turns to its original position as well as JRNT station. However, BEHR station which are located in western belt do not show any movements. All of these movements may be due to the influence of reactive faults in the stations area stimulated by several large earthquakes that occurred in 2005 to 2010. Study on using the GPS data analysis and combine with integrated geophysical methods are necessary to understand in detail about the tectonic evolution of Peninsular Malaysia

  5. Quaternary evolution and ice sheet history of contrasting landscapes in Uummannaq and Sukkertoppen, western Greenland

    Science.gov (United States)

    Beel, C. R.; Lifton, N. A.; Briner, J. P.; Goehring, B. M.

    2016-10-01

    Constraining the history of the Greenland Ice Sheet (GIS) is important for improving our understanding of ice sheet dynamics and landscape evolution processes. We analyzed in situ cosmogenic 10Be and 26Al in 26 rock samples from two high-elevation landscapes adjacent to the GIS, minimally eroded by past glaciations and of differing character in Uummannaq (n = 16) and Sukkertoppen (n = 10), western Greenland. The Uummannaq region is characterized by a marine embayment with islands and peninsulas, where the margin of the GIS is marine-based, whereas the Sukkertoppen landscape resides within the wide terrestrial fringe outboard of the land-terminating portion of the southwestern GIS margin. We targeted landscapes for sampling with highly weathered surfaces adjacent to cold-based portions of extant ice caps (indicated by preservation of fragile, dead vegetation emerging from beneath retreating ice margins). Paired isotope results require differing surface histories between the two areas. Many surfaces in the Uummannaq region have minimum exposure durations up to ca. 300 kyr, but with no significant burial. Most surfaces in the Sukkertoppen region, however, yield complex exposure histories with minimum cumulative exposure durations up to ca. 100 kyr and minimum cumulative burial durations up to ca. 400 kyr, yielding minimum total surface histories of up to 500 ka. These findings suggest that parts of the Uummannaq landscape may have been continuously exposed throughout much of the middle and late Quaternary. On the other hand, the high-altitude surfaces in the Sukkertoppen region were largely preserved beneath minimally-erosive, cold-based ice during the same period. Data from the Uummannaq region thus stand in contrast not only to the Sukkertoppen region, but also to other sites surrounding Baffin Bay reported in previous studies. We hypothesize that surfaces in the Uummannaq region may have remained as nunataks above the Last Glacial Maximum (LGM) ice sheet surface

  6. Molecular and biogeochemical evidence for methane cycling beneath the western margin of the Greenland Ice Sheet.

    Science.gov (United States)

    Dieser, Markus; Broemsen, Erik L J E; Cameron, Karen A; King, Gary M; Achberger, Amanda; Choquette, Kyla; Hagedorn, Birgit; Sletten, Ron; Junge, Karen; Christner, Brent C

    2014-11-01

    Microbial processes that mineralize organic carbon and enhance solute production at the bed of polar ice sheets could be of a magnitude sufficient to affect global elemental cycles. To investigate the biogeochemistry of a polar subglacial microbial ecosystem, we analyzed water discharged during the summer of 2012 and 2013 from Russell Glacier, a land-terminating outlet glacier at the western margin of the Greenland Ice Sheet. The molecular data implied that the most abundant and active component of the subglacial microbial community at these marginal locations were bacteria within the order Methylococcales (59-100% of reverse transcribed (RT)-rRNA sequences). mRNA transcripts of the particulate methane monooxygenase (pmoA) from these taxa were also detected, confirming that methanotrophic bacteria were functional members of this subglacial ecosystem. Dissolved methane ranged between 2.7 and 83 μM in the subglacial waters analyzed, and the concentration was inversely correlated with dissolved oxygen while positively correlated with electrical conductivity. Subglacial microbial methane production was supported by δ(13)C-CH4 values between -64‰ and -62‰ together with the recovery of RT-rRNA sequences that classified within the Methanosarcinales and Methanomicrobiales. Under aerobic conditions, >98% of the methane in the subglacial water was consumed over ∼30 days incubation at ∼4 °C and rates of methane oxidation were estimated at 0.32 μM per day. Our results support the occurrence of active methane cycling beneath this region of the Greenland Ice Sheet, where microbial communities poised in oxygenated subglacial drainage channels could serve as significant methane sinks.

  7. Rock Series and Genetic Types of Granitoids in the Western Kunlun Orogenic Belt, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A systematic geological and geochemical study was conducted for the granitoids of different periods in the western Kunlun orogenic belt. The study indicates that the granitoids belong to tholeiitic, calc-alkaline, high-K calc-alkaline, alkaline and shoshonitic series, and that there are 5 genetic types, i.e., I-, S-, M-, A- and SH-type, of which SH-type is first put forward in this paper, which corresponds to shoshonitic granitoids.

  8. Effects of a future warmer ocean on the coexisting copepods Calanus finmarchicus and C. glacialis in Disko Bay, Western Greenland

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Dünweber, Michael; Swalethorp, Rasmus;

    2012-01-01

    The effects of temperature and food was examined for Calanus finmarchicus and C. glacialis during 3 phases of the phytoplankton spring bloom in Disko Bay, western Greenland. The 2 species were collected during pre-bloom, bloom, and post-bloom and exposed to temperatures from 0 to 10°C, combined w...... production. Our results suggest that a future warmer ocean will reduce the advantage of early spawning by C. glacialis and that C. finmarchicus will become increasingly prevalent...

  9. Distribution and behaviour of passerines around peregrine Falco peregrinus eyries in western Greenland

    Science.gov (United States)

    Meese, R.J.; Fuller, M.R.

    1989-01-01

    This paper describes the distribution and behavior of passerine birds within 1 km of Peregrine Falcon Falco peregrinus eyries in western Greenland. Passerine populations were censused in 1983 around six cliffs occupied by nesting Peregrines and at six sites on the open tundra, and in 1984 at two unoccupied sites suitable for Peregrine nesting. Four passerine species accounted for over 90% of birds seen. Within 400 m of Peregrine occupied cliffs, three species, Lapland Longspur Calcarius lapponicus. Northern Wheatear Oenanthe oenanthe, and Common Redpoll Carduelisflammea, were found in lower than average abundance while the fourth, Snow Bunting Plectrophenax nivalis, was found in increased abundance. Our indirect tests suggest that Peregrine presence, rather than direct predation, was responsible for the distributions of the first three species. The Snow Bunting, however, behaviourally adapts to Peregrine presence in order to exploit nesting habitat available at the cliff base. These results contrast strongly with those reported by other Arctic workers, where increased abundances of potential prey were observed in close proximity to nesting Peregrines.

  10. Measured basal water pressure variability of the western Greenland Ice Sheet: Implications for hydraulic potential

    Science.gov (United States)

    Wright, Patrick J.; Harper, Joel T.; Humphrey, Neil F.; Meierbachtol, Toby W.

    2016-06-01

    The gradient of the hydraulic potential field at the ice-bedrock interface beneath the Greenland Ice Sheet (GrIS) dictates the routing and energetics of subglacial water, thereby influencing drainage system characteristics and sliding dynamics. In the ablation zone of the GrIS, variable water pressure due to an active subglacial drainage system and basal topography with high relief potentially interact to drive unknown spatial patterns and temporal changes in the hydraulic potential field. Here we present a suite of water pressure measurements collected in 13 boreholes along a 46 km transect on the western GrIS to investigate the role of spatial and temporal basal water pressure adjustments in hydraulic potential gradient dynamics. All borehole sites show pressures with similar seasonality, having relatively steady and high values during winter, variable and irregular behavior during spring and fall, and diurnal cycles that can persist for multiple weeks during the peak melt season. Despite much higher variability during the melt season, the median pressure of the summer period is nearly the same as the median pressure of the winter period. However, time variability of water pressure due to basal drainage processes can force changes in the magnitude and orientation of the hydraulic potential field over diurnal periods. We find that the basal water pressure across the transect generally mimics the ice thickness field but with superimposed large pressure gradients that develop at shorter scales within the basal drainage system. This leads to a complex hydraulic potential field across regions of similar ice thickness.

  11. Soil carbon storage and respiration potential across a landscape age and climate gradient in western Greenland

    Science.gov (United States)

    Bradley-Cook, J. I.; Virginia, R. A.; Hammond Wagner, C.; Racine, P. E.

    2013-12-01

    = 22.8). While soil respiration rates were significantly highest in the surface soils at the wettest coastal site, we observed high variation in respiration potential indicating that small-scale variation in carbon quality and other soil properties is high. This study informs our understanding of regional variation of carbon storage and turnover in western Greenland and provides important information for the parameterization of landscape scale models of soil carbon dynamics in the Arctic tundra.

  12. Annual changes in the song of the bowhead whale Balaena mysticetus in Disko Bay, Western Greenland

    DEFF Research Database (Denmark)

    Miller, Lee

    presented by Outi at: Acoustic Communication by Animals, 2nd International Conference, August 12-15, 2008, Oregon State University, Corvallis, Oregon, USAAnnual changes in the song of the bowhead whale Balaena mysticetusin Disko Bay, Western GreenlandOuti Tervo and Mads F. Christoffersen, Arctic...... (n=659) and song notes (n=4394). All call types were present in the repertoire each year. Songs were composed of repetitive units referred here as song notes and were the most frequently documented type of vocalisation every year. Song notes had a stereotyped frequency contour and formed trains...

  13. Development of bearing capacity of fine grained permafrost deposits in western greenland urban areas subject to soil temperature changes

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas

    2012-01-01

    The bearing capacity of frozen soils is high, compared to non-frozen soils of same composition. Projected climatic warming in the Arctic will increase the soil temperature, thus affecting the bearing capacity and the deformation properties. Western Greenland temperatures are projected to increase...... excess ice free samples. Unfrozen water contents are seen to be directly inversely proportional to the undrained shear strength when both are normalized, which may reduce costs for establishing reliable soil strength parameters. It is suggested that a relation to deformation parameters are investigated...

  14. Long-term erosion and interglacial period exposure in Western Greenland from meteoric 10Be in ice-bound sediment

    Science.gov (United States)

    Graly, J. A.; Corbett, L.; Bierman, P. R.; Neumann, T.; Rood, D. H.; Finkel, R. C.

    2010-12-01

    To examine the history of surface exposure and erosion in areas of Western Greenland presently covered by ice, we measured the concentration of meteoric 10Be in ice-bound fine sediment at three locations: Kangerlussuaq (67.1°N), Ilulissat (69.4°N), and Upernavik (72.5°N). Meteoric 10Be concentrations at Ilulissat and Upernavik range from 2×106 to 2×108 atoms/g and are statistically indistinguishable from each other. Meteoric 10Be concentrations at Kangerlussuaq range from 2×106 to 5×107 atoms/g and are significantly lower than the values found at the northern two sites. Through comparison to typical meteoric 10Be distribution in soils, source soil ages can be estimated at each of these locations. These estimates suggest on the order of 105 years of exposure at the northern sites and on the order of 104 years of exposure at Kangerlussuaq. Because meteoric 10Be is lost from the soil system both by erosion and isotope decay, these exposure ages represent a minimum length of cumulative interglacial exposure. This exposure signal likely developed over several Late Pliocene and Pleistocene interglacial periods and prior to the onset of Northern hemisphere glaciation, ~2.7 Ma before present. To further constrain the glacial history of Western Greenland implied from the meteoric 10Be data, we constructed forward models of interglacial period exposure and glacial period erosion. The high levels of meteoric 10Be at Upernavik and Ilulissat imply erosion rates below 5 m/My and some preservation of pre-glacial regolith. The lower levels of meteoric 10Be at Kangerlussuaq can be explained with erosion rates as high as 20 m/My. Because of the substantial debris fluxes in modern Kangerlussuaq glaciers [Knight, et al., 2002], erosion rates greater than 10 m/My are likely. Meteoric 10Be inventories at Kangerlussuaq under 10-20 m/My of long-term erosion imply substantial interglacial exposure and the slow evacuation of sediment by glacial transport. These results suggest that

  15. THE TECTONOPHYSICAL RESEARCHES OF THE SEMISAMSKAYA ANTICLINE (NORTH-WESTERN CAUCASUS FOLD AND THRUST BELT

    Directory of Open Access Journals (Sweden)

    A. V. Marinin

    2015-09-01

    Full Text Available Structural paragenetic and cataclastic analysis methods were applied to study tectonic fracturing within one of the folds of the southern wing of the North-Western Caucasus fold-and-thrust belt. The object of the study was the Semisamskaya anticline (Fig. 1 and 2 comprising the Upper Cretaceous and Paleogenic layered terrigenic-carbonate sediments that contain various well-developed geological indicators of palaeostresses (Fig. 3, 5, 7, and 9.In the folded structure under study, a paragenesis is revealed which is associated with the effect of sub-horizontal minimum compression (deviator extension stresses of the north-western orientation (NW 320° and traced by detached normal fault systems striking in the north-eastern direction (Fig. 6, 8, 10, 11, and 17. Upthrust-overthrust systems of the north-western strike (NW–SE, which are of importance for the whole folded structure of the North-Western Caucasus, are mainly manifested in the wings of the Semisamskaya anticline (Fig. 6, 12, and 13.The overall field of stresses related to formation of the folded structure is significantly variable as evidenced by the pattern of local parameters of the paleostress field, which are calculated by the cataclastic analysis method (Figure 15, 16, and 17.It is established that the geodynamic regime within the anticline is considerably variable by types (Fig. 18. Areas with horizontal extension in the axial part of the fold are replaced by areas of horizontal compression at its wings (Fig. 19.  

  16. Field and geochemical characterisitics of the Mesoarchean (~3075 ma) Ivisaartoq greenstone belt, southern West Greenland: Evidence for seafloor hydrothermal alteration in a supra-subduction oceanic crust

    DEFF Research Database (Denmark)

    Polat, A.; Appel, P.W.U.; Frei, Robert;

    2006-01-01

    The Mesoarchean (ca. 3075 Ma) Ivisaartoq greenstone belt in southern West Greenland includes variably deformed and metamorphosed pillow basalts, ultramafic flows (picrites), serpentinized ultramafic rocks, gabbros, sulphide-rich siliceous layers, and minor siliciclastic sedimentary rocks. Primary....... The belt underwent at least two stages of calc-silicate metasomatic alteration and polyphase deformation between 2963 and 3075 Ma. The stage I metasomatic assemblage is composed predominantly of epidote (now mostly diopside) + quartz + plagioclase ± hornblende ± scapolite, and occurs mainly in pillow cores...... + garnet + amphibole + plagioclase + quartz ± vesuvianite ± scapolite ± epidote ± titanite ± calcite ± scheelite. Given that the second stage of metasomatism is closely associated with shear zones and replaced rocks with an early metamorphic fabric, its origin is attributed to regional dynamothermal metamorphism. The least altered pillow basalts, picrites, gabbros, and diorites are characterized by LREE...

  17. Spatial and temporal variability of lake ontogeny in south-western Greenland

    Science.gov (United States)

    Law, A. C.; Anderson, N. J.; McGowan, S.

    2015-10-01

    Holocene palaeolimnological records of diatoms and β carotene (a proxy for aquatic production) from four lakes in the low Arctic region of south-western Greenland were used to investigate the role of climate on lake ontogeny. Two of the lakes are located in the maritime, coastal region near Sisimiut and two inland close to the head of Kangerlussuaq fjord, where there is a more continental climate. Diatom records from the four lakes (AT1, AT4, SS1381, SS8) had similar long-term ontogeny trends, independent of climatic setting and the changes are interpreted as responses to first order weathering controls on catchment/lake chemistry. Short-term excursions from these broad trends occurred in one coastal site (AT4) caused by intense erosion of the steep catchment, and at inland sites where temporary hydrological closure and lake level decline occurred during the mid-Holocene (˜8000 - 5000 cal a BP). Algal production (as β carotene) was more closely and consistently correlated with climatic changes; it peaked during the mid-Holocene, the warmest period of the Holocene, at all sites and there were transient increases in production in inland lakes during the Medieval Climate Anomaly and Little Ice Age because of fertilization through increased aeolian dust deposition. A synthesis of seven palaeolimnological records from this region identified that only the mid-Holocene was correlated with diatom stratigraphic zones and there was considerable among-site variability in later Holocene lake response to climate forcing in this area. Comparable long-term trends in species assemblage turnover (DCA/CA axis 1 scores) clearly demonstrate that lakes have predictable ontogeny trends in this region, characterised by maximum alkalinity and nutrient availability in the first few millennia followed by progressive oligotrophication and alkalinity loss. However, individual lake and catchment characteristics (lake morphology, catchment geomorphology), when modified by climatic change

  18. Recent land use change in the Western Corn Belt threatens grasslands and wetlands.

    Science.gov (United States)

    Wright, Christopher K; Wimberly, Michael C

    2013-03-01

    In the US Corn Belt, a recent doubling in commodity prices has created incentives for landowners to convert grassland to corn and soybean cropping. Here, we use land cover data from the National Agricultural Statistics Service Cropland Data Layer to assess grassland conversion from 2006 to 2011 in the Western Corn Belt (WCB): five states including North Dakota, South Dakota, Nebraska, Minnesota, and Iowa. Our analysis identifies areas with elevated rates of grass-to-corn/soy conversion (1.0-5.4% annually). Across the WCB, we found a net decline in grass-dominated land cover totaling nearly 530,000 ha. With respect to agronomic attributes of lands undergoing grassland conversion, corn/soy production is expanding onto marginal lands characterized by high erosion risk and vulnerability to drought. Grassland conversion is also concentrated in close proximity to wetlands, posing a threat to waterfowl breeding in the Prairie Pothole Region. Longer-term land cover trends from North Dakota and Iowa indicate that recent grassland conversion represents a persistent shift in land use rather than short-term variability in crop rotation patterns. Our results show that the WCB is rapidly moving down a pathway of increased corn and soybean cultivation. As a result, the window of opportunity for realizing the benefits of a biofuel industry based on perennial bioenergy crops, rather than corn ethanol and soy biodiesel, may be closing in the WCB.

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

    DEFF Research Database (Denmark)

    Petersen, Thomas Guldborg

    This thesis contains a detailed interpretation of seismic facies of the Paleogene sedimentary succession on the Northeast Greenland Shelf. Based on this, a model for the depostional environment and its interplay with the large scale plate tectonic evolution is produced. The model suggests...

  20. Were last glacial climate events simultaneous between Greenland and western Europe?

    Directory of Open Access Journals (Sweden)

    M. Blaauw

    2008-10-01

    Full Text Available During the last glacial period, several large abrupt climate fluctuations took place on the Greenland ice cap and elsewhere. Often these Dansgaard/Oeschger events are assumed to have been synchronous, and then used as tie-points to link chronologies between the proxy archives. However, if temporally separate events are lumped into one illusionary event, climatic interpretations of the tuned events will obviously be flawed. Here, we compare Dansgaard/Oeschger-type events in a well-dated record from south-eastern France with those in Greenland ice cores. Instead of assuming simultaneous climate events between both archives, we keep their age models independent. Even these well-dated archives possess large chronological uncertainties, that prevent us from inferring synchronous climate events at decadal to multi-centennial time scales. If possible, tuning of proxy archives should be avoided.

  1. An overview of the lithological and geochemical characteristics of the Mesoarchean (ca. 3075) Ivisaartoq greenstone belt, southern West Greenland

    DEFF Research Database (Denmark)

    Polat, A.; Frei, Robert; Appel, P.W.U.;

    2008-01-01

    -silicate metasomatism, between 3075 and 2961 Ma. The trace element systematics of the least altered rocks are consistent with a subduction zone geodynamic setting. On the basis of lithological similarities between the Ivisaartoq greenstone belt and Phanerozoic forearc/backarc ophiolites, and intra-oceanic island arcs......, we suggest that the Ivisaartoq greenstone belt represents a relic of dismembered Mesoarchean suprasubduction zone oceanic crust. The Sm-Nd isotope system appears to have remained relatively undisturbed in picrites, tholeiitic pillow lavas, gabbros, and diorites. As a group, picrites have more...... depleted initial Nd isotopic signatures ( Nd = +4.2 to +5.0) than gabbros, diorites, and tholeiitic basalts ( Nd = +0.3 to +3.1), consistent with a strongly depleted mantle source. In some areas gabbros include up to 15 cm long white inclusions (xenoliths). These inclusions are composed primarily (>90...

  2. Climatology of increased temperatures and melt at Swiss Camp, western slope of Greenland ice sheet, 1991-2012

    Science.gov (United States)

    Steffen, K.; McGrath, D.

    2013-12-01

    Climate observations (1991-2012) will be discussed from the Swiss Camp (69deg 33‧53″N, 49deg 19‧51″W, 1176 m), located at the western slope of the Greenland ice sheet, 60 km inland from Ilulissat. The mean annual temperature of -12 C increased 3.6 C between 1991 and 2012 (1.7 C per decade) with large interannual variability in all seasons. The mean spring temperature increased from -16.0 C to -13.8 C, and the fall temperature increased from -12.4 C to -11.3 C in the same time. The winter temperature showed the largest increase of 6.5 C, whereas summer temperatures increased 3.0 C during the 21 years (1991 - 2012). Radiation has been monitored continuously at Swiss Camp since 1993. Net radiation of 50 W/ m2 was recorded in 2012, the warmest summer month on record. The entire annual snow cover melted at Swiss Camp, reducing the monthly albedo value to 0.4 with bare ice exposed. Interannual variability of snow accumulation ranged between 0.07 and 0.70 m water equivalent, whereas annual snow and ice ablation varied between +0.35 (net gain) and -1.8 m (net loss) for the time period 1991-2012. The equilibrium line altitude (ELA) is no longer located at Swiss Camp (1176 m elevation) with a net surface lowering of 9.5 m since 1991. Increasing summer air temperatures have resulted in an upward migration of both the percolation facies and ablation area of the Greenland ice sheet. The 0°C isothermal migrated upward at a rate of 35 m/a over the 1995-2012 period in West Greenland. There is a 50% probability of the mean annual dry snow line migrating above Summit by 2025, at which time Summit will experience routine melt on an annual basis. The surface mass balance observations similarly indicate that the ELA has migrated upwards at a rate of 44 m/a over the 1997-2011 period in West Greenland, resulting in a more than doubling of the ablation zone width during this period. Inter-annual variability of monthly mean albedo at the Swiss Camp (1993 - 2012). Albedo at 0.5 is

  3. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century

    DEFF Research Database (Denmark)

    Hollesen, Jorgen; Buchwal, Agata; Rachlewicz, Grzegorz;

    2015-01-01

    Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100years long Betulanana ring-width chronology from Disko Island in western Greenland that demonstrates...... a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betulanana growth is especially pronounced during the periods from 1910-1930 to 1990-2011 that were dominated by significant winter warming...... of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates...

  4. Inuit health in Greenland

    DEFF Research Database (Denmark)

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

    2003-01-01

    During 1997-2001 a population survey was carried out amongst Greenland Inuit living in Denmark and West Greenland (Nuuk, Sisimiut, Qasigiannguit and four villages in Uummannaq municipality). Data collection comprised an interview, a questionnaire, clinical examinations and sampling of biological...... specimens (blood, urine, subcutaneous fat tissue). The clinical examinations included anthropometric measurements, an oral glucose tolerance test, ECG, ultrasound of thyroid gland and carotid arteries, a skin prick test, and lung function. The data collection areas in Greenland ranged from the westernized...

  5. Origin and source regions of nodule-bearing kimberlites and ultramafic lamprophyres in southern Western Greenland

    DEFF Research Database (Denmark)

    Pilbeam, Llewellyn Howard

    High precision high resolution electron microprobe traverses of olivine grains in the Majuagaa kimberlite sensu stricto from southern West Greenland show that the olivine crystallisation is coupled to digestion of xenocrystic orthopyroxene into the melt. This process was previously suspected...... but unconfirmed in kimberlite sensu stricto magmas. It is here termed digestion fractional crystallisation (DFC) and it is argued that the DFC process may account for much of the global varia-bility in kimberlite compositions. The bulk rock trace element geochemistry of the Majuagaa kimberlite is used...

  6. Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic)

    OpenAIRE

    Baron, I.; Agliardi, F.; Ambrosi, C.; Crosta, G.B.

    2005-01-01

    International audience Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM) of continua (Flac 4.0). We confirmed that such large mass movements could be triggered by water saturation of the bedrock...

  7. Petrogenesis and geodynamic significance of silicic volcanism in the western Trans-Mexican Volcanic Belt

    Science.gov (United States)

    Petrone, C. M.; Ferrari, L.; Orozco, M. A.; Lopez Martinez, M.

    2012-04-01

    Silicic volcanism in the western Trans-Mexican Volcanic Belt (WTMVB) was defined a Pliocene ignimbrite flare-up associated with the rifting of the Jalisco block from mainland Mexico (Frey et al., 2007; GSAB). With the integration of new and published geochronologic, geochemical, and isotope data we revise this interpretation and propose a new petrogenetic model. The oldest silicic volcanism consists of large silicic domes and minor pyroclastic flows (~370 km3) emplaced to the north of Guadalajara above a thick succession of ~11 to 8.7 Ma basaltic lavas, which yielded Ar-Ar and obsidian FT ages of ~7.5 to 5 Ma. Shortly after (4.9 to 2.9 Ma) large amount of rhyolitic lavas and ash flow tuffs (~500 km3) were emplaced in a WNW-ESE trending belt from Guadalajara to Compostela. Rhyolitic domes and flows (~430 km3) were emplaced also in the Pleistocene mostly between Tequila and Guadalajara with the late Pleistocene La Primavera caldera (~35 km3) as the sole explosive volcanic episodes. As a whole, silicic volcanism occurred from Late Miocene to the Pleistocene, and was dominated by dome and lava flows. Most rhyolites have high LILE/HFSE values and negative spikes at Nb, P and Ti. They also show the same Ba/Nb and K/Rb values and slightly higher Rb/Sr ratios as the 11-8 Ma basalts. Rhyolite Sr isotope data (87Sr/86Sr init = 0.70371 - 070598) are only slightly more radiogenic than the 11-8 basalts (87Sr/86Sr init = 0.70349-0.70410), whereas Nd isotope ratios are indistinguishable from them. Sr and Nd isotope ratios of the rhyolites are also similar to the crust nearby, indicating that they can be compatible either with fractional crystallization (FC) of basalts or with crust assimilation/melting. However REE contents are too low to be the result of basalt FC. Isotope and REE data can be successfully modelled with an initial crustal melt which subsequently undergone fractional crystallization of feldspar and quartz. Late Miocene slab detachment and subsequent slab rollback

  8. Analysis of methanogenic and methanotrophic activity at the western margin of the Greenland Ice Sheet

    Science.gov (United States)

    Broemsen, E. L.; Webster, K. D.; Dieser, M.; Pratt, L. M.; Christner, B. C.

    2012-12-01

    Anoxic conditions in environments beneath the world's glaciers and ice sheets provide plausible habitats supporting the microbial production of methane. Recent reports of potential methane sources beneath the Greenland Ice Sheet (GrIS) suggest in situ production by an active community of methanogens. Beneath the GrIS, microbially derived methane can be dissolved in subglacial water, and during periods of melting, can exchange with the atmosphere at sites of subglacial discharge. Transfer of methane from subglacial fluids to the atmosphere could be a significant climate factor, but few data are available to make such assessments. The specific aim of this study was to characterize the composition and activity of methanogens and methanotrophs present in samples of subglacial outflow at the ice sheet margin near Kangerlussuaq, Greenland. Subglaical water was collected twice-weekly over a nine week period (mid July to mid September of 2012) and the dissolved methane concentration in the samples was determined via gas chromatography. Extracted RNA and DNA from the subglacial water was analyzed by analysis of 16s rRNA and rRNA genes present in the subglacial assemblages. From the molecular results we infer the presence of active methanogens related to the order Methanosarcinales. Further, locally elevated concentrations of atmospheric methane as high as 1.92 ± 0.03 ppmv, were detected in the ice tunnel of the subglacial outflow using open-path laser spectrometry. From these data we estimate rates of methane release at the ice sheet margin during the summer melt months at this geographical location. The results provide a context for addressing the impact that deglaciation will have on the release of greenhouse gases from ice sheets on a warming Earth.

  9. The Majorqaq Belt: A record of Neoarchaean orogenesis during final assembly of the North Atlantic Craton, southern West Greenland

    Science.gov (United States)

    Dyck, Brendan; Reno, Barry L.; Kokfelt, Thomas F.

    2015-04-01

    Over the past 4.5 billion years (Ga) the Earth has undergone a secular change in tectonic regimes. Archaean tectonics was a markedly different process than observed today, involving a hotter planet with a thinner lithosphere, thicker oceanic crust, and smaller proto-continents. The transition to a more modern type of plate tectonics required the initiation of subduction of oceanic lithosphere. The onset of subduction in the Meso- to Neoarchaean (ca. 3.2 to 2.5 Ga) is shown by geochemical signatures indicative of crustal recycling and petrologic evidence of tectonically driven thickening of the continental crust. This transition is recorded in the rock record of the North Atlantic Craton, which preserves a history of crust formation through to terrane accretion and the collision of crustal blocks. Here we present petrologic, chronologic, chemical and geophysical evidence from the Majorqaq Belt, a ~ 100 km wide east-west striking zone, defined by a high gravity anomaly, voluminous metasedimentary units, olivine-rich ultramafic enclaves, and anomalously high K2O, Ni, and MgO stream-sediment chemistry. We use a 207Pb/206Pb zircon LA-ICP-MS age of 2.557 ± 0.005 Ga (2σ) from an upper-amphibolite facies metapelitic migmatite to propose Neoarchaean suturing of the Maniitsoq crustal block to the North Atlantic Craton. Ti-in-zircon temperatures and zircon-garnet REE distribution coefficients constrain zircon crystallisation to 815-729 °C, which is at, or near the solidus during leucosome crystallisation. Our data reveal a clockwise P-T path with a high-pressure assemblage of garnet-kyanite-plagioclase-rutile-biotite-quartz which grew at an apparent thermal gradient of ~ 660 °C/GPa during subduction-driven compression of surface-derived sediments to a minimum-peak-pressure of ~ 1.15 GPa at ~ 760 °C followed by the growth of gedrite-cordierite-sillimanite-ilmenite at minimum-peak-temperature conditions of ~ 810 °C at ~ 0.94 GPa. We propose the evolution of the Majorqaq

  10. Occurrence of Tourmaline in Metasedimentary Rocks of the Isua Supracrustal Belt, Greenland: Implications for Ribose Stabilization in Hadean Marine Sediments

    Science.gov (United States)

    Mishima, Shinpei; Ohtomo, Yoko; Kakegawa, Takeshi

    2016-06-01

    Abiotic formation of RNA was important for the emergence of terrestrial life, but the acknowledged difficulties of generating and stabilizing ribose have often raised questions regarding how the first RNA might have formed. Previous researchers have proposed that borate could have stabilized ribose; however, the availability of borate on the early Earth has been the subject of intense debate. In order to examine whether borate was available on the early Earth, this study examined metasedimentary rocks from the Isua Supracrustal Belt. Garnet, biotite, and quartz comprise the major constituents of the examined rocks. Field relationships and the chemical compositions of the examined rocks suggest sedimentary origin. The present study found that garnet crystals contain a number of inclusions of tourmaline (a type of borosilicate mineral). All tourmaline crystals are Fe-rich and categorized as schorl. Both garnet and tourmaline often contain graphite inclusions and this close association of tourmaline with garnet and graphite has not been recognized previously. Garnet-biotite and graphite geothermometers suggest that the tourmaline in garnet experienced peak metamorphic conditions (~500 °C and 5 kbar). The mineralogical characteristics of the tourmaline and the whole rock composition indicate that the tourmaline formed authigenically in the sediment during diagenesis and/or early metamorphism. Clay minerals in modern sediments have the capability to adsorb and concentrate borate, which could lead to boron enrichment during diagenesis, followed by tourmaline formation under metamorphic conditions. Clay minerals, deposited on the early Archean seafloor, were the precursors of the garnet and biotite in the examined samples. The studied tourmaline crystals were most likely formed in the same way as modern tourmaline in marine sediments. Therefore, boron enrichment by clays must have been possible even during the early Archean. Thus, similar enrichment could have been

  11. Occurrence of Tourmaline in Metasedimentary Rocks of the Isua Supracrustal Belt, Greenland: Implications for Ribose Stabilization in Hadean Marine Sediments.

    Science.gov (United States)

    Mishima, Shinpei; Ohtomo, Yoko; Kakegawa, Takeshi

    2016-06-01

    Abiotic formation of RNA was important for the emergence of terrestrial life, but the acknowledged difficulties of generating and stabilizing ribose have often raised questions regarding how the first RNA might have formed. Previous researchers have proposed that borate could have stabilized ribose; however, the availability of borate on the early Earth has been the subject of intense debate. In order to examine whether borate was available on the early Earth, this study examined metasedimentary rocks from the Isua Supracrustal Belt. Garnet, biotite, and quartz comprise the major constituents of the examined rocks. Field relationships and the chemical compositions of the examined rocks suggest sedimentary origin. The present study found that garnet crystals contain a number of inclusions of tourmaline (a type of borosilicate mineral). All tourmaline crystals are Fe-rich and categorized as schorl. Both garnet and tourmaline often contain graphite inclusions and this close association of tourmaline with garnet and graphite has not been recognized previously. Garnet-biotite and graphite geothermometers suggest that the tourmaline in garnet experienced peak metamorphic conditions (~500 °C and 5 kbar). The mineralogical characteristics of the tourmaline and the whole rock composition indicate that the tourmaline formed authigenically in the sediment during diagenesis and/or early metamorphism. Clay minerals in modern sediments have the capability to adsorb and concentrate borate, which could lead to boron enrichment during diagenesis, followed by tourmaline formation under metamorphic conditions. Clay minerals, deposited on the early Archean seafloor, were the precursors of the garnet and biotite in the examined samples. The studied tourmaline crystals were most likely formed in the same way as modern tourmaline in marine sediments. Therefore, boron enrichment by clays must have been possible even during the early Archean. Thus, similar enrichment could have been

  12. Using Remote Sensing and Rpas for Archaeology and Monitoring in Western Greenland

    Science.gov (United States)

    Pavelka, K.; Šedina, J.; Matoušková, E.; Faltýnová, M.; Hlaváčová, I.

    2016-06-01

    Since 2002, German low-cost scientific expeditions to Greenland have been performed. The objective was a geodetic survey and glaciology with GNSS technology - mainly the measurement of glacier profiles (height). The same glacier profiles along the route were measured during German expeditions in 2006, 2010, 2012 and 2015. The last international expedition was supplemented with RPAS (UAV) measurement, the testing of small corner reflectors for Terra SAR X satellite measurement and the use of image based modelling technology for historical monuments documentation, all in specific arctic conditions. The RPAS measurement was focused on the documentation of existing valuable archaeological sites near Ilulissat city and the testing of RPAS technology for the monitoring of the face of the moving glacier. Two typical church wooden constructions were documented by simple photogrammetric technology based on image correlation. Both experiments were evaluated as successfully case projects. The last part of the experiments deals with the monitoring of a moving inland glacier using SAR technology; four corner reflectors were installed on the glacier and on a massive nearby rock. Two ascending and two descending overflights of the Terra SAR X satellite in fine resolution mode were performed. The InSAR technology give inconclusive results, but some movements were detected; small and inexpensive corner reflectors of our own production have proven suitable. Experience and expertise from the measurement such as the first outputs from the expedition are the content of the present article.

  13. Estimating supraglacial lake depth in western Greenland using Landsat 8 and comparison with other multispectral methods

    Directory of Open Access Journals (Sweden)

    A. Pope

    2015-06-01

    Full Text Available Liquid water stored on the surface of ice sheets and glaciers impacts surface mass balance, ice dynamics, and heat transport. Supraglacial lakes, therefore, play a significant role in ice sheet behavior as a surface expression of the glacial hydrological system. Multispectral remote sensing can be used to detect supraglacial lakes and estimate their depth and area. In this study, we use in situ spectral and bathymetric data to assess lake depth retrieval using the recently launched Landsat 8 Operational Land Imager (OLI. We also extend our analysis to other multispectral sensors to evaluate their performance with similar methods. Digital elevation models derived from WorldView stereo imagery (pre-lake filling and post-drainage are used to validate spectrally derived depths, combined with a lake edge determination from imagery. The optimal supraglacial lake depth retrieval is a physically based single-band model applied to two OLI bands independently (red and panchromatic that are then averaged together. When OLI- and WorldView-derived depths are differenced, they yield a mean and standard deviation of 0.0 ± 1.6 m. This method is then applied to OLI data for the Sermeq Kujalleq (Jakobshavn Isbrae region of Greenland to study the spatial and intra-seasonal variability of supraglacial lakes during summer 2014. We also give coefficients for estimating supraglacial lake depth using a similar method as OLI with other multispectral sensors.

  14. Accumulation and Melt Variability at the Western Slope of the Greenland Ice Sheet at Swiss Camp: 1990 - 2005

    Science.gov (United States)

    Steffen, K.

    2005-12-01

    The Swiss Camp was established at the equilibrium line altitude (ELA) near Jakobshavn (~ 70° N), along the western slope of the Greenland ice sheet in spring 1990. Long-term glaciological measurements from the Danes predicted the ELA for this region. The elevation variability of the ELA will be discussed for the 1990 - 2005 time period. The surface slope of the ice sheet in this region is 1-2 degrees with large scale undulations (5 km wave length). The Swiss Camp was located in the accumulation regions during the first five years of the last decade, whereas in the later part of the 90's the camp was located at the ELA. The ELA moved to higher elevations during this decade due to increased melting. The fall-winter-spring accumulation variability and the summer melt will be discussed for the 15-year time record. The annual snow accumulation varied between 18 cm water equivalent (w.e.) to 75 cm w.e. during that period. Further, the sensitivity of albedo-feedback (snow fall events) on summer melt will be discussed based on in-situ data. Air temperature and accumulation records will be used to explain the variation of the ELA.

  15. Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic)

    OpenAIRE

    Baron, I.; Agliardi, F.; Ambrosi, C.; Crosta, G.B.

    2005-01-01

    Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM) of continua (Flac 4.0). We confirmed that such large mass movements could be triggered by water saturation of the bedrock in the three particular g...

  16. Tectonothermal evolution in the core of an arcuate fold and thrust belt: the south-eastern sector of the Cantabrian Zone (Variscan belt, north-western Spain)

    Science.gov (United States)

    Valín, María Luz; García-López, Susana; Brime, Covadonga; Bastida, Fernando; Aller, Jesús

    2016-07-01

    The tectonothermal evolution of an area located in the core of the Ibero-Armorican Arc (Variscan belt) has been determined by using the conodont colour alteration index (CAI), Kübler index of illite (KI), the Árkai index of chlorite (AI) and the analysis of clay minerals and rock cleavage. The area is part of the Cantabrian Zone (CZ), which represents the foreland fold and thrust belt of the orogen. It has been thrust by several large units of the CZ, what resulted in the generation of a large number of synorogenic Carboniferous sediments. CAI, KI and AI values show an irregular distribution of metamorphic grade, independent of stratigraphic position. Two tectonothermal events have been distinguished in the area. The first one, poorly defined, is mainly located in the northern part. It gave rise to very-low-grade metamorphism in some areas and it was associated with a deformation event that resulted in the emplacement of the last large thrust unit and development of upright folds and associated cleavage (S1). The second tectonothermal event gave rise to low-grade metamorphism and cleavage (S2) crosscutting earlier upright folds in the central, western and southern parts of the study area. The event continued with the intrusion of small igneous rock bodies, which gave rise to contact metamorphism and hydrothermal alteration. This event was linked to an extensional episode due to a gravitational instability at the end of the Variscan deformation. This tectonothermal evolution occurred during the Gzhelian-Sakmarian. Subsequently, several hydrothermal episodes took place and local crenulation cleavage developed during the Alpine deformation.

  17. Use of the Cropland Data Layer to monitor grassland conversion in the U.S. Western Corn Belt (Invited)

    Science.gov (United States)

    Wright, C.; Wimberly, M. C.

    2013-12-01

    The U.S. Department of Agriculture's Cropland Data Layer (CDL) provides new opportunities for monitoring land cover/land use change (LCLUC) related to U.S. agricultural policy, bioenergy development, and recent commodity price increases. We used the CDL to assess the conversion of grasslands to corn/soy cultivation along the western periphery of the U.S. Corn Belt. Here, we find rapid grassland conversion (1-5% annually) as the Corn Belt expands westward and northward into North Dakota and South Dakota. This LCLUC is occurring in close proximity to wetlands in the Prairie Pothole Region. In most counties in the eastern Dakotas, grassland conversion exceeds declines in land area enrolled in the Conservation Reserve Program (CRP). Within the core corn/soy growing area in Iowa and southern Minnesota, LCLUC is occurring on marginal lands characterized by high erosion potential and less-productive soils. In Minnesota, particularly, corn/soy production is increasing on lands previously too wet to farm without an expansion of agricultural drainage practices. Over the period 2006-2011, we estimate a net greenhouse gas impact of grassland conversion in the Western Corn Belt of approximately 4*106 metric tons CO2-equivalent. Although not designed for monitoring grasslands, we suggest that the CDL can be used judiciously to identify grassland conversion at farm- to sub-county scales, and, in conjunction with other national-level datasets (e.g., the National Wetlands Inventory and SSURGO database), to provide timely feedback to policymakers and the public on likely environmental impacts of U.S. agricultural policies and shifting market forces.

  18. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century

    Science.gov (United States)

    Hollesen, Jørgen; Buchwal, Agata; Rachlewicz, Grzegorz; Hansen, Birger U; Hansen, Marc O; Stecher, Ole; Elberling, Bo

    2015-01-01

    Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100 years long Betula nana ring-width chronology from Disko Island in western Greenland that demonstrates a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth is especially pronounced during the periods from 1910–1930 to 1990–2011 that were dominated by significant winter warming. To explain the strong winter importance on growth, we assessed the importance of different environmental factors using site-specific measurements from 1991 to 2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results show a strong positive growth response to the amount of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates. Data also reveal a clear shift within the last 20 years from a period with thick snow depths (1991–1996) and a positive effect on Betula nana radial growth, to a period (1997–2011) with generally very shallow snow depths and no significant growth response towards snow. During this period, winter and spring soil temperatures have increased significantly suggesting that the most recent increase in Betula nana radial growth is primarily triggered by warmer winter and spring air temperatures causing earlier snowmelt that allows the soils to drain and warm quicker. The presented results may help to explain the recently observed ‘greening of the Arctic’ which may further accelerate in future years due to both direct and indirect effects of winter warming. PMID:25788025

  19. Upper-mantle P- and S-wave velocities below Scandinavia and East Greenland from teleseismic traveltime tomography

    DEFF Research Database (Denmark)

    Hejrani, Babak

    2014-01-01

    north. The UMVB was resolved in P-and S-velocity as well as the VP/VS anomaly. From the Oslo Graben the UMVB follows the western edge of the Trans-scandinavian Igneous Belt to the Atlantic coast, from where where it continues northward sub-parallel to the coast. Third study compiled all data in the......This dissertation deals with the resolution of P- and S-velocity variations in the upper mantle (down to 600 km) using teleseismic P- and S-wave arrival times. The natural laboratory is the land areas bordering the North Atlantic; the Scandinavian and East Greenland Caledonides and the Northern...... first two studies with permanent station data from the North Atlantic and Greenland, and a dense temporary profile, the East Greenland Caledonian Central Fjord Array (EGCFA). EGCFA resolves low upper-mantle velocities close to the east coast of Greenland and high mantle velocities below the high...

  20. First results from Acoustic Doppler Current Profiler measurements of meltwater flux in a large supraglacial river in western Greenland compared with downstream proglacial river outflow

    Science.gov (United States)

    Pitcher, L. H.; Smith, L. C.; Overstreet, B. T.; Chu, V. W.; Rennermalm, A. K.; Cooper, M. G.; Gleason, C. J.; Yang, K.

    2015-12-01

    A vast network of seasonally evolving, thermally eroding supraglacial rivers on the southwestern Greenland Ice Sheet (GrIS) is the preeminent transporter of meltwater across this area of the ablation zone. Supraglacial rivers are important for estimating surface water storage and transport into moulins and into the en-, sub-, and proglacial environments. Yet, little is known about their role in the GrIS cryo-hydrologic system. To that end, supraglacial river discharge in a large river, the "Rio Behar" (67.05°, -49.02°; ~75 km from the Kangerlussuaq International Airport), was measured in situ over 300 times: approximately four times per hour over three consecutive days from July 19 - 22, 2015. The Rio Behar drains a ~ 70 km2 ice catchment and enters a large moulin in the Watson River land-ice watershed in western Greenland. River discharge was measured using a Sontek M9 Acoustic Doppler Current Profiler. Each profile records water temperature, depth-integrated velocity, channel width and channel bathymetry. This novel dataset can be used to assess diurnal variations in river discharge, slope, velocity, stream power, and channel incision in order to enhance process-level understanding of GrIS meltwater routing, storage and transport. Future work will compare supraglacial river discharge in the Rio Behar with in situ estimates of proglacial river outflow upstream of the Watson River bridge in Kangerlussuaq, Greenland.

  1. IceBridge Radar as a Tool for Understanding Accumulation Variability throughout the Western Greenland Ice Sheet

    Science.gov (United States)

    Lewis, G.; Hawley, R. L.; Osterberg, E. C.; Marshall, H. P.

    2015-12-01

    Understanding the mass balance of the Greenland Ice Sheet (GIS) in a warming climate is of critical interest to scientists and the general public in the context of future sea-level rise. The mass balance of the GIS has been increasingly negative over recent decades, with a conservative estimate of ice sheet mass loss of 2000 Gt yr-1 over the 1988-2014 period. Snow accumulation, the critical input to surface mass balance, varies through time and regionally around Greenland and from the coast to interior, but is constrained by relatively few observations. An improved understanding of temporal and spatial snow accumulation variability will thus reduce uncertainties in GIS mass balance models and sea-level rise projections. Here we quantify spatial and temporal variations in snow accumulation in central and southwest Greenland using data from NASA's Operation IceBridge Accumulation Radar. We estimate depth-density and depth-age relationships using a Herron-Langway density model and Nye flow model, which are iteratively calculated at 50 km intervals along each radar line. We then trace isochrones to calculate spatial and temporal variability in average snow accumulation along several flight paths throughout central and southwestern Greenland. Depth-density, depth-age, and snow accumulation calculations are calibrated at Summit using data from the GISP2, Katie, and SM07C ice cores. Accumulation results will be verified by a series of snow pits, shallow firn cores, and ice-penetrating radar profiles collected on the Greenland Traverse for Accumulation and Climate Studies (GreenTrACS) through southwest Greenland during spring 2016 and 2017.

  2. Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic)

    Science.gov (United States)

    Baron, I.; Agliardi, F.; Ambrosi, C.; Crosta, G. B.

    2005-04-01

    Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM) of continua (Flac 4.0). We confirmed that such large mass movements could be triggered by water saturation of the bedrock in the three particular geological and geomorphic settings. Such situation could have been caused by heavy rainfalls in humid phases of the Holocene or permafrost melting in Late Glacial. The effects of faulting, very deep weathering of the bedrock, low geotechnical parameters of smectite-rich material and the local slope geometry have also been accounted for in numerical models, as well as the other triggering factors of slope instability. FDM modelled shear zones are in agreement with observations.

  3. Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic

    Directory of Open Access Journals (Sweden)

    I. Baron

    2005-01-01

    Full Text Available Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM of continua (Flac 4.0. We confirmed that such large mass movements could be triggered by water saturation of the bedrock in the three particular geological and geomorphic settings. Such situation could have been caused by heavy rainfalls in humid phases of the Holocene or permafrost melting in Late Glacial. The effects of faulting, very deep weathering of the bedrock, low geotechnical parameters of smectite-rich material and the local slope geometry have also been accounted for in numerical models, as well as the other triggering factors of slope instability. FDM modelled shear zones are in agreement with observations.

  4. Juxtaposition of Neoproterozoic units along the Baruda - Tulu Dimtu shear-belt in the East African Orogen of western Ethiopia

    Science.gov (United States)

    Braathen, A.; Grenne, Tor; Selassie, M.G.; Worku, T.

    2001-01-01

    Amalgamation of East and West Gondwanaland during the Neoproterozoic East African Orogen is recorded by several shear-belts or 'suture zones', some of which are associated with ultramafic and mafic complexes that have been interpreted as ophiolite fragments. The Baruda shear-belt is a major structure of this type that belongs to the N-S trending Barka - Tulu Dimtu zone. The significance of this zone has been studied within a transect in western Ethiopia which covers a variety of metasedimentary and metavolcanic sequences, ultramafic rocks and synkinematic intrusive complexes. All rocks participated in the regional D1 event as reflected in a penetrative steep foliation in supracrustal rocks and marginal parts of the intrusions. Highly strained rocks contain a stretching lineation that plunge to the east. The several-km thick Baruda shear-belt, comprising mylonitic supracrustal and plutonic rocks including mafic-ultramafic mega-lenses, is the most prominent expression of this event. Shear-sense indicators demonstrate top-to-the-west shear. Subsequent D2 deformation is recorded in 2-300 m wide, N-S striking, subvertical shear-zones with subhorizontal stretching lineation relatable to sinistral transcurrent movements. Our data indicate that rock units on either side of the Baruda shear-belt are related, rather than being exotic to each other as implied in suture zone models, since there is no major lithologic or metamorphic difference, geochemical data on metavolcanic rocks and pre-tectonic intrusions suggest a paleotectonic link, and style and extent of deformation is similar across the shear-belt. A tentative model for the transect suggests an arc and back-arc setting which experienced later continental collision and tectonic shortening. The initial setting was that of a shallow marine platform characterised by carbonates and sandstones, which covered extensive areas prior to break-up of a pre-existing supercontinent. Continental convergence is first recorded in high

  5. Age and sex distributions in the catches of belugas, Delphinapterus leucas , in West Greenland and in western Russia

    DEFF Research Database (Denmark)

    Heide-Jørgensen, M.P.; Lockyer, C.

    2001-01-01

    Age and sex were determined for belugas or white whales, Delphinapterus leucas, harvested in West Greenland in 1985-86 and 1989-1997. There was a clear segregation of whales in the drive fishery conducted during autumn in Qaanaaq and Upernavik. Primarily immature whales of both sexes together wit...

  6. From folding to transpressional faulting: the Cenozoic Fusha structural belt in front of the Western Kunlun Orogen, northwestern Tibetan Plateau

    Science.gov (United States)

    Wang, Cong; Cheng, Xiao-Gan; Chen, Han-Lin; Li, Kang; Fan, Xiao-Gen; Wang, Chun-Yang

    2016-07-01

    Fusha structural belt (FSB) is one of the most important tectonic units in front of the Western Kunlun Orogen, northwestern Tibetan Plateau (NW China), in which the Kekeya oil field was discovered in 1971. However, there is no new oil field discovered since then due to the unclarity of the intense and complex Cenozoic deformation in this area. Based on field investigation, seismic interpretation and Continuous Electromagnetic Profile data, we analyze in detail the Cenozoic deformation history, emphasizing on the spatial and temporal variation of the deformation of the FSB in this paper. The result suggests that the FSB was dominated by two deformation events, (1) early (Miocene-early Pliocene) folding event expressed by anticline, with the western segment E-W orienting, while the eastern segment NWW-SEE orienting and (2) later (since late Pliocene) transpressional faulting event that destroyed and divided the earlier anticline into a number of fault blocks. The transpressional faulting caused dextral strike-slip reverse fault, with the dip angles decreasing eastward from ~90° to <45°. The dextral strike-slip reverse fault developed in the core of the anticline in the western part which caused the anticline into several fault blocks, while in the eastern part, the fault developed in the north limb of the anticline with the core of the anticline reserved. Based on the spatial variation of structural characteristics, we propose that the fault block traps and anticline traps in the eastern segment and fault block traps in western segment are favorable for hydrocarbon accumulation.

  7. Devonian to Triassic Successions of the Changning-Menglian Belt,Western Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    JIN Xiaochi; WANG Yizhao; XIE Guanglian

    2003-01-01

    Phanerozoic strata are distributed in several north-south trending zones in the central part of the Changning-Menglian Belt. Four types of Devonian to Triassic stratigraphic successions can be identified: (1) clastics with limestonelenses in the mid-section, changing up-section into alternations of fine clastics and cherts; (2) clastics with chertintercalations and limestone lenses, and topped by Permian basic volcanics; (3) clastics-basicvolcanics-carbonates-clastics; and (4) limestones, dolomitic limestones-dark gray thin-bedded limestones, argillaceouslimestones, mudstones and siliceous mudstones. Devonian to Triassic cherts occur in different horizons and differentzones from east to west. These cherts are usually transitional to their neighboring clastics. There is no continuousDevonian to Middle Triassic chert sequence in the central zone of the Changning-Menglian Belt as Liu et al. (1991, 1993)reported. Volcanics and the overlying carbonates described by some workers as "seamount" sequences are more likely tohave formed in a marine environment on continental crust. Succession (4) is newly recognized in the area from Menglai toYong'an in Cangyuan County and further north to Padi of Gengma County. Basalts, cherts and clastics also appear in thisarea. Mid-Triassic (very probably Ladinian) radiolarians extracted from bedded cherts in the Ganzhejidi section indicatethat they are in higher stratigraphic positions. The change from bedded cherts via siltstones to thick-bedded sandstoneswith thin-bedded fine intercalations in the Ganzhejidi section and (some other outcrops along the road from Cangyuan toGengma) suggests a fundamental change of sedimentary environment caused by a rapid increase of a large quantity ofdetritus supply. These siliciclastic sediments are possibly syn-orogenic deposits.

  8. Possible Greenland

    DEFF Research Database (Denmark)

    2012-01-01

    Organizing in Greenland is a complex matter. We have been on an arctic odyssey exploring the different aspects of the Greenlandic reality and have created a publication in which a wide range of Greenlandic and international profiles and stakeholders give their opinion and visions for the future...... development in Greenland. By creating a platform for a wide range of ideas about the Possible Greenland to be discussed now and in the future, we give Greenlanders and Greenlandic decision makers access to the greatest amount of possible solutions to the challenges they are facing. We look more closely...... at Greenland's structure, and ask some threshold questions. Which aspects of society are rooted in our human hardware? And, if we had the rare opportunity to build a new nation, what would we choose for ourselves? We hope this will inspire an open, imaginative and thoroughly human discussion about how...

  9. Envisioning Greenland

    DEFF Research Database (Denmark)

    Ren, Carina Bregnholm

    2012-01-01

    Currently, the traditional ‘cool’ representation of Greenland as a frozen landscape devoid of people and human structures is being challenged by an emerging vision of Greenland as ‘hot’. This article presents and describes these two versions of Greenland, showing how demarcations of what is ‘nature...

  10. In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

    OpenAIRE

    Tedesco, M.; Steiner, N.

    2011-01-01

    Supraglacial lakes form from meltwater on the Greenland ice sheet in topographic depressions on the surface, affecting both surface and sub-glacial processes. As the reflectance in the visible and near-infrared regions of a column of water is modulated by its height, retrieval techniques using spaceborne remote sensing data (e.g. Landsat, MODIS) have been proposed in the literature for the detection of lakes and estimation of their volume. These techniques require basic assumptions on the spe...

  11. In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

    OpenAIRE

    Tedesco, M.; Steiner, N.

    2011-01-01

    We report concurrent in-situ multi-spectral and depth measurements over a supraglacial lake in West Greenland, collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer. We focus our attention on the analysis of some of the key parameters widely used for multispectral spaceborne bathymetry, namely the lake bottom albedo and the water attenuation coefficient. The analysis of in-situ data highlights the exponential trend of the water-leaving reflectance wi...

  12. Andesite petrogenesis in a hybrid arc-rift setting: the Western Trans-Mexican Volcanic Belt

    Science.gov (United States)

    Gómez-Tuena, A.; Vázquez-Duarte, A.; Díaz-Bravo, B.; Mori, L.

    2011-12-01

    The western sector of the Mexican subduction zone is characterized by the steep subduction of one of the youngest slabs on the planet (Rivera plate), and by the existence of a continental rift at ~230 km to the north from the trench (the so-called Tepic-Zacoalco rift, TZR), under which the subducted slab is either extremely deep or even absent (>250 km). The volcanic front is located at ~170 km from the trench and contains abundant potassic-alkaline lamprophyres with strong subduction (Ba/Ta= 1600-6000) and garnet signatures (Gd/Yb= 2-8), that have been recently interpreted as influenced by deep K2O-rich slab melts or supercritical fluids (Gómez-Tuena et al., 2011, GCA). In contrast, the most mafic rocks within the TZR are high-Nb, intraplate-like basalts that appear to derive from low extents of melting of a dryer (Ba/Ta= 800-60) and shallower (Gd/Yb= 2-2.5) mantle source. Even though a simple transition from an arc environment to an extensional tectonic regime is apparent when only the most primitive volcanic rocks are taken into account, the scenario becomes more complicated since at least five stratovolcanoes have been erupting typical arc andesites within the TZR over the last million years (San Juan, Sanganguey, Tepetiltic, Ceboruco and Tequila). Surprisingly, true calc-alkaline basalts that could be parental to andesites have not been found, indicating that andesites may have a direct mantle origin. Indeed, mayor and trace element compositions of volcanic rocks from western Mexico arrange in discrete suites with linear trends that are indicative of mixing, but they form sub-parallel arrays that do not converge to a common primitive basaltic melt, and often follow diverging trends in trace element-ratio plots. Melt-crust interactions likely occurred during magma ascent, since the volcanic rocks frequently include xenoliths and disequilibrium textures, but correlations among isotopic compositions and indexes of fractionation are not clearly observed in the

  13. New paleomagnetic Data from Mid-Jurassic to Early Cretaceous Sequence of the Eastern Pieniny Klippen Belt (Western Ukraine)

    Science.gov (United States)

    Lewandowski, M.; Krobicki, M.; Matyja, B. A.; Wierzbowski, A.

    2003-04-01

    We report on first results of palaeomagnetic studies, undertaken on the Middle Jurassic to Early Cretaceous carbonates of the Pieniny Klippen Belt (PKB) of the southern-western Ukraine. Targeted rocks, dipping to SSW by 70 deg., are cropping out in the quarry of Kamenec near Novoselica, being easily accessible due to the wire-cut technique of mining. Almost 180 individually oriented cores were collected from a 40 m-thick carbonate succession, sampling density dependent on an inferred sedimentation rate. All cores were subjected to stepwise AF and temperature demagnetization. Thermomagnetic analysis is indicative of magnetite as a main magnetic carrier. Stable, high-blocking temperature NRM component shows dual polarity distribution and is considered primary. Polarity distribution along the sequence enabled us to recognize 20 polarity zones that could be correlated with biostratigraphic scale. Since we have identified two main sedimentary gaps (other being plausible), obtained sequence of reversals could not be considered complete. Paleomagnetic inclinations point to ca. 600 km separation between an original place of deposition and the northern shelf of Thetys. Palaeomagnetic declinations suggest anticlockwise, ca. 130 deg. vertical-axis rotation of the Kamenec succession before Tertiary. A low-blocking temperature, normal polarity component, is similar in-situ to the early Tertiary directions of European Craton.

  14. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional seafood items from western Greenland.

    Science.gov (United States)

    Carlsson, Pernilla; Herzke, Dorte; Kallenborn, Roland

    2014-03-01

    In this study, contamination levels were determined for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional Greenland seafood items, such as raw and smoked fish fillet (salmon and halibut), whale and seal meat and narwhal mattak (skin and blubber). The daily intake of PCBs, PBDEs and PFASs through traditional seafood items in Greenland was assessed. Based on the presented levels of contaminants, in combination with earlier food intake studies, suggests that the daily exposure was below the tolerable daily intake threshold for all compounds. BDE-47 was the only PBDE-congener detected in all food items, except in smoked halibut. The levels of BDE-47 varied from < LOD in smoked halibut up to 18 ng/g lw in narwhal mattak and 21 ng/g lw in whale beef. ∑PCB were lowest in smoked halibut (37 ng/g lw) and highest in narwhal mattak with 1,146 ng/g lw. Perfluorooctane sulfonate (PFOS) was the most common of the PFASs. However, ΣPFASs were below detection limits in most fish fillet samples, and varied from 2.9 ng/g ww in whale beef to 13.5 ng/g ww in seal beef. The present study shows that the exclusion from the diet of local food items such as intestines and blubber have a strong positive effect for the reduction of POPs levels in food, without a reducing the health benefits of traditional food intake considerably.

  15. In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

    Directory of Open Access Journals (Sweden)

    M. Tedesco

    2011-02-01

    Full Text Available We report concurrent in-situ multi-spectral and depth measurements over a supraglacial lake in West Greenland, collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer. We focus our attention on the analysis of some of the key parameters widely used for multispectral spaceborne bathymetry, namely the lake bottom albedo and the water attenuation coefficient. The analysis of in-situ data highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor are obtained from in-situ data and compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow-waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.

  16. In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

    Directory of Open Access Journals (Sweden)

    M. Tedesco

    2011-05-01

    Full Text Available Supraglacial lakes form from meltwater on the Greenland ice sheet in topographic depressions on the surface, affecting both surface and sub-glacial processes. As the reflectance in the visible and near-infrared regions of a column of water is modulated by its height, retrieval techniques using spaceborne remote sensing data (e.g. Landsat, MODIS have been proposed in the literature for the detection of lakes and estimation of their volume. These techniques require basic assumptions on the spectral properties of the water as well as the bottom of the lake, among other things. In this study, we report results obtained from the analysis of concurrent in-situ multi-spectral and depth measurements collected over a supraglacial lake during early July 2010 in West Greenland (Lake Olivia, 69°36'35" N, 49°29'40" W and aim to assess some of the underlying hypotheses in remote sensing based bathymetric approaches. In particular, we focus our attention on the analysis of the lake bottom albedo and of the water attenuation coefficient. The analysis of in-situ data (collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor obtained from in-situ data are compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.

  17. The Jurassic of Denmark and Greenland: The Middle Jurassic of western and northern Europe: its subdivisions, geochronology and correlations

    Directory of Open Access Journals (Sweden)

    Callomon, John H.

    2003-10-01

    Full Text Available The palaeogeographic settings of Denmark and East Greenland during the Middle Jurassic are outlined. They lay in the widespread epicontinental seas that covered much of Europe in the post-Triassic transgression. It was a period of continuing eustatic sea-level rise, with only distant connections to world oceans: to the Pacific, via the narrow Viking Straits between Greenland and Norway and hence the arctic Boreal Sea to the north; and to the subtropical Tethys, via some 1200 km of shelf-seas to the south. The sedimentary history of the region was strongly influenced by two factors: tectonism and climate. Two modes of tectonic movement governed basinal evolution: crustal extension leading to subsidence through rifting, such as in the Viking and Central Grabens of the North Sea; and subcrustal thermal upwelling, leading to domal uplift and the partition of marine basins through emergent physical barriers, as exemplified by the Central North Sea Dome with its associated volcanics. The climatic gradient across the 30º of temperate latitude spanned by the European seas governed biotic diversity and biogeography, finding expression in rock-forming biogenic carbonates that dominate sediments in the south and give way to largely siliciclastic sediments in the north. Geochronology of unrivalled finesse is provided by standard chronostratigraphy based on the biostratigraphy of ammonites. The Middle Jurassic saw the onset of considerable bioprovincial endemisms in these guide-fossils, making it necessary to construct parallel standard zonations for Boreal, Subboreal or NW European and Submediterranean Provinces, of which the NW European zonation provides the primary international standard. The current versions of these zonations are presented and reviewed.

  18. Tectonics Along Western-Central Part of the Trans Mexican Volcanic Belt as Inferred From Palaeomagnetic Data: A Summary

    Science.gov (United States)

    Rosas-Elguera, J.; Goguichaisvilli, A.; Alva-Valdivia, L.; Urrutia-Fucugauchi, J.

    2007-05-01

    The Trans-Mexican Volcanic Belt (TMVB), one of the largest continental volcanic arcs built on the North America plate, spans about 1000 km and crosses central Mexico from the Pacific Ocean to the Gulf of Mexico. The initial stage of the TMVB is marked by widespread Miocene basaltic volcanism, emplaced from the Nayarit state, in the west, to the longitude of Mexico City. This volcanism is characterized by plateau-like structures resulting from the shield volcanoes and fissure lava flows, which have an estimated aggregate volume ranging between 3200 and 6800 km3. The western-central Mexico has been affected by right-lateral transtension within the western TMVB but previous paleomagnetic studies indicate some 15-20° anticlockwise tectonic rotations for the Rio Grande de Santiago canyon and surrounding areas, in accordance with a Miocene left-lateral transtensional tectonic regime. We present a summary of paleomagnetic and rock-magnetic studies of that Miocene volcanic succession from the TMVB. A total of 114 consecutive basaltic lava flows (more than 550 oriented samples) were collected from four localities: Tepic, Guadalajara, Los Altos, and Queretaro which span from 11 to 7.5 Ma. The mean paleodirection obtained for Tepic area is I = 33.7°, D = 358.4°, k = 140, á95 = 3.0°, N = 17. These directions are in perfect agreement with the expected paleodirections for late Miocene time, as derived from reference poles given by Besse and Courtillot (1991) for North America.. The mean paleodirection obtained for Guadalajara is I = 31.1°, D = 354.6°, k = 124, 95 = 2.1°, which corresponds to the mean paleomagnetic pole position Plat = 84°, Plong = 129.8°, k = 29, 95 = 4.4°. These directions are in reasonably good agreement with the expected paleodirections for middle Miocene time. The mean paleomagnetic direction calculated for Los Altos and Queretaro is I = 32.46°, D = 341.2°, k = 7.2 and 95 = 11.6°. Thus, our results suggest that no major block rotation has

  19. Geochemical and Rock Magnetic Properties of a Purple Sand Belt on Cedar Beach, Western Lake Erie, Ontario, Canada

    Science.gov (United States)

    Zhang, S.; Cioppa, M. T.; Zhang, S.

    2009-05-01

    Limited environmental magnetic studies have been carried out on beaches and shoreline processes. Therefore, we initiated a rock magnetic study at Cedar Beach on the north shore of western Lake Erie (42°N, 81°W) and noted the highest susceptibility values (9.6 x 10-2 SI) occurred in a purple sand belt that is 200m in length and 3.5m in width and located just outside the swash zone. To understand the rock magnetic properties of these purple sands, we systematically performed frequency-dependence of low-field susceptibility (Kfd%), partial anhysteretic remanent magnetization (pARM) spectra, saturation isothermal remanent magnetization (SIRM) acquisition, S-ratio, hysteresis measurements and Curie-point determinations for a set of representative purple sand samples. Most Kfd% values are lower than 1%, indicating that the dominant magnetic minerals fall in the large pseudo-single domain (PSD) to multidomain (MD) magnetic size, while single domain/super paramagnetic (SD/SP) grains are rare. pARM curves show only one group with a peak in the pARM spectra at 10 mT, indicating a low coercivity and a PSD to MD grain size (around 4 um). However, in a few samples, the pARM spectra at high coercivities (> 90mT) is not zero, suggesting the presence of either fine magnetic grains (SD magnetites) or high coercivity minerals (hematite or maghemite). Most IRM acquisition spectra show 95% of the magnetization gained below 200 mT, and S-300 ratios close to one, indicating the presence of fully saturated, coarse and fine magnetite. Some samples did not saturate until after 800 mT and showed two saturation levels, suggesting the presence of high coercivity minerals. High temperature susceptibility curves (K-T) and magnetization curves (Js-T) show Curie points (Tc) around 585°C, suggesting magnetite is the main magnetic mineral. The Js-T cycles are almost reversible, indicating that magnetic minerals have not been created or destroyed. Hysteresis curves are normally wasp- waisted

  20. Late 18th to early 19th century sea-level history and inter-seismic behavior along the western Myanmar plate boundary belt recorded by coral microatolls

    Science.gov (United States)

    Liu, Sze-Chieh; Shyu, J. Bruce H.

    2016-04-01

    Along the western Myanmar plate boundary belt, the Indian-Australian plate is subducting obliquely beneath the Burma micro-plate at a rate of about 23 mm/yr. Although information about the 1762 Arakan earthquake, the only major historical event occurred along this plate boundary belt, has been delineated recently from uplifted coastal features, constraints on the inter-seismic behavior of this belt is still very limited, due to the lack of high resolution instrumental records in the area. Therefore, we utilized coral microatolls to analyze relative sea level history, in order to obtain potential information of land-level change along the western coast of Myanmar. Our sample was collected from northwestern Ramree Island, approximately 80 km away from the trench. Previous studies suggest that the coral was uplifted and killed during a local earthquake event in 1848, and recorded relative sea level history of ~80 years prior to that event. Since the highest level of survival (HLS) of coral microatolls is constrained within a few centimeters of the lowest tide level of the area, the patterns of annual growth bands of the coral microatoll in x-radiograph provide us yearly record of relative sea level, and we used U-Th dating technique to constrain the age of the coral. Our results show that this coral microatoll may have recorded the inter-seismic subsidence of northwestern Ramree Island, punctuated by several climatic events that produced die-down records of the coral growth bands. We hope the data obtained from this coral microatoll, combined with previously reported information of the area, will enable us to further understand the seismic behavior of this major plate boundary belt.

  1. Multi-phase Uplift of the Indo-Burman Ranges and Western Thrust Belt of Minbu Sub-basin (West Myanmar): Constraints from Apatite Fission Track Data

    Science.gov (United States)

    Zhang, P.; Qiu, H.; Mei, L.

    2015-12-01

    The forearc regions in active continental margins are important keys to analysis geodynamic processes such as oceanic crust oblique subduction, mechanism of subduction zone, and sediments recycling. The West Myanmar, interpreted as forearc silver, is the archetype example of such forearc regions subordinate to Sunda arc-trench system, and is widely debated when and how its forearc regions formed. A total of twenty-two samples were obtained from the Indo-Burman Ranges and western thrust belt of Minbu Sub-basin along Taungup-Prome Road in Southwestern Myanmar (Figure 1), and five sandstone samples of them were performed at Apatite to Zircon, Inc. Three samples (M3, M5, and M11) collected from Eocene flysch and metamorphic core at the Indo-Burman Ranges revealed apatite fission track (AFT) ages ranging from 19 to 9 Ma and 6.5 to 2 Ma. Two samples (M20 and M21) acquired from the western thrust belt of Minbu Sub-basin yielded AFT ages ranging from 28 to 13.5 Ma and 7.5 to 3.5 Ma. Time-temperature models based on AFT data suggest four major Cenozoic cooling episodes, Late Oligocene, Early to Middle Miocene, Late Miocene, and Pliocene to Pleistocene. The first to third episode, models suggest the metamorphic core of the Indo-Burman Ranges has experienced multi-phase rapidly uplifted during the early construction of the forearc regions. The latest episode, on which this study focused, indicated a fast westward growth of the Palaeogene accretionary wedge and a eastward propagation deformation of folding and thrusting of the western thrust belt of Minbu Sub-basin. We argued that above multi-phase uplifted and deformation of the forearc regions were results of India/West Burma plate's faster oblique convergence and faster sedimentation along the India/Eurasia suture zone.

  2. Enantiomer-selective and quantitative trace analysis of selected persistent organic pollutants (POP) in traditional food from western Greenland.

    Science.gov (United States)

    Carlsson, Pernilla; Herzke, Dorte; Kallenborn, Roland

    2014-01-01

    Enantiomeric fractions (EF) are today considered a powerful tool to elucidate selective uptake processes of chiral contaminants in biota. In this study, concentration levels and EF were determined by gas chromatograph-mass spectrometer (GC/MS) for α-hexachlorocyclohexane (α-HCH) and trans-, cis-, and oxychlordane in selected Greenlandic traditional food items, collected at the local market in Nuuk in 2010. The food items selected were raw and smoked fish (salmon and halibut, n = 6), whale meat (n = 8), seal meat (n = 2) and narwhal mattak (skin and blubber, n = 6). The EF were nonracemic (≠0.5) for all samples except for α-HCH in narwhal, trans-chlordane in whale and smoked salmon, and cis- and oxychlordane in seal. The EF for α-HCH were significant for all fish samples, but not for mammalian samples. Data indicate that different uptake and/or transformation mechanisms may be responsible for nonracemic distributions of chiral pesticides in mammals and fish species analyzed. There were no general enantiomer-selective transformation/accumulation trends found for chlordanes. Data indicate that enantiomer-specific properties are an important prerequisite for interaction of chiral contaminant with internal metabolic processes. However, marked differences within these groups were identified. The EF in ringed seals were racemic for most of the analyzed pesticides (i.e., chlordanes). However, narwhal were characterized by nonracemic EF for all chiral pesticides analyzed. Median levels of α-HCH ranged from 2 to 24 ng/g lw and from 15.1 to 626.6 ng/g lw for trans-nonachlor, with lowest levels observed in smoked salmon and highest levels in narwhal mattak. This study confirmed that concentration levels of analyzed pesticides in the investigated food items were below the tolerable daily intake (TDI) threshold. PMID:24754396

  3. Enantiomer-selective and quantitative trace analysis of selected persistent organic pollutants (POP) in traditional food from western Greenland.

    Science.gov (United States)

    Carlsson, Pernilla; Herzke, Dorte; Kallenborn, Roland

    2014-01-01

    Enantiomeric fractions (EF) are today considered a powerful tool to elucidate selective uptake processes of chiral contaminants in biota. In this study, concentration levels and EF were determined by gas chromatograph-mass spectrometer (GC/MS) for α-hexachlorocyclohexane (α-HCH) and trans-, cis-, and oxychlordane in selected Greenlandic traditional food items, collected at the local market in Nuuk in 2010. The food items selected were raw and smoked fish (salmon and halibut, n = 6), whale meat (n = 8), seal meat (n = 2) and narwhal mattak (skin and blubber, n = 6). The EF were nonracemic (≠0.5) for all samples except for α-HCH in narwhal, trans-chlordane in whale and smoked salmon, and cis- and oxychlordane in seal. The EF for α-HCH were significant for all fish samples, but not for mammalian samples. Data indicate that different uptake and/or transformation mechanisms may be responsible for nonracemic distributions of chiral pesticides in mammals and fish species analyzed. There were no general enantiomer-selective transformation/accumulation trends found for chlordanes. Data indicate that enantiomer-specific properties are an important prerequisite for interaction of chiral contaminant with internal metabolic processes. However, marked differences within these groups were identified. The EF in ringed seals were racemic for most of the analyzed pesticides (i.e., chlordanes). However, narwhal were characterized by nonracemic EF for all chiral pesticides analyzed. Median levels of α-HCH ranged from 2 to 24 ng/g lw and from 15.1 to 626.6 ng/g lw for trans-nonachlor, with lowest levels observed in smoked salmon and highest levels in narwhal mattak. This study confirmed that concentration levels of analyzed pesticides in the investigated food items were below the tolerable daily intake (TDI) threshold.

  4. South Greenland

    DEFF Research Database (Denmark)

    This report is a preliminary strategic environmental impact assessment of activities related to exploration, development and exploitation of oil in the Greenland sector of the Labrador Sea and the southeast Davis Strait......This report is a preliminary strategic environmental impact assessment of activities related to exploration, development and exploitation of oil in the Greenland sector of the Labrador Sea and the southeast Davis Strait...

  5. Geologic and geochemical insights into the formation of the Taiyangshan porphyry copper–molybdenum deposit, Western Qinling Orogenic Belt, China

    Science.gov (United States)

    Kun-Feng Qiu,; Taylor, Ryan D.; Yao-Hui Song,; Hao-Cheng Yu,; Kai-Rui Song,; Nan Li,

    2016-01-01

    Taiyangshan is a poorly studied copper–molybdenum deposit located in the Triassic Western Qinling collisional belt of northwest China. The intrusions exposed in the vicinity of the Taiyangshan deposit record episodic magmatism over 20–30 million years. Pre-mineralization quartz diorite porphyries, which host some of the deposit, were emplaced at 226.6 ± 6.2 Ma. Syn-collisional monzonite and quartz monzonite porphyries, which also host mineralization, were emplaced at 218.0 ± 6.1 Ma and 215.0 ± 5.8 Ma, respectively. Mineralization occurred during the transition from a syn-collisional to a post-collisional setting at ca. 208 Ma. A barren post-mineralization granite porphyry marked the end of post-collisional magmatism at 200.7 ± 5.1 Ma. The ore-bearing monzonite and quartz monzonite porphyries have a εHf(t) range from − 2.0 to + 12.5, which is much more variable than that of the slightly older quartz diorite porphyries, with TDM2 of 1.15–1.23 Ga corresponding to the positive εHf(t) values and TDM1 of 0.62–0.90 Ga corresponding to the negative εHf(t) values. Molybdenite in the Taiyangshan deposit with 27.70 to 38.43 ppm Re suggests metal sourced from a mantle–crust mixture or from mafic and ultramafic rocks in the lower crust. The δ34S values obtained for pyrite, chalcopyrite, and molybdenite from the deposit range from + 1.3‰ to + 4.0‰, + 0.2‰ to + 1.1‰, and + 5.3‰ to + 5.9‰, respectively, suggesting a magmatic source for the sulfur. Calculated δ18Ofluid values for magmatic K-feldspar from porphyries (+ 13.3‰), hydrothermal K-feldspar from stockwork veins related to potassic alteration (+ 11.6‰), and hydrothermal sericite from quartz–pyrite veins (+ 8.6 to + 10.6‰) indicate the Taiyangshan deposit formed dominantly from magmatic water. Hydrogen isotope values for hydrothermal sericite ranging from − 85 to − 50‰ may indicate that magma degassing progressively depleted residual liquid in

  6. Origin and tectonic implications of the ∼200 Ma, collision-related Jerai pluton of the Western Granite Belt, Peninsular Malaysia

    Science.gov (United States)

    Jamil, Azmiah; Ghani, Azman A.; Zaw, Khin; Osman, Syamir; Quek, Long Xiang

    2016-09-01

    Triassic granitoids (∼200-225 Ma) are widespread in the Western Belt of Peninsular Malaysia. The Main Range granite is the biggest batholith in the Western Belt composed of peraluminous to metaluminous granite and granodiorite and displays typical ilmenite-series characteristics. Jerai granitic pluton occurs at the northwestern part of the Main Range granite batholith. The Jerai granite can be divided into three facies: (i) biotite-muscovite granite; (ii) tourmaline granite; and (iii) pegmatite and aplopegmatite. Biotite-muscovite granite accounts for 90% of the Jerai pluton, and the rest is tourmaline granite. Geochemical data reveal that pegmatite and tourmaline granite are more differentiated than biotite-muscovite granite. Both pegmatite and tourmaline granite have a higher SiO2 content (70.95-83.94% versus 69.45-73.35%) and a more pronounced peraluminous character. The U-Pb zircon geochronology of the Jerai granite gave an age ranging from 204 ± 4.3 Ma, 205 ± 4 Ma and 205 ± 2 Ma for pegmatite biotite-muscovite granite and tourmaline granite, respectively. The biotite-muscovite Jerai granites are similar to S-type Main Range granite, but the tourmaline granite has a signature of late-stage hydrothermal fluid interaction such as tourmaline quartz pods, the accumulation of large pegmatitic K-feldspar, pronounced peraluminous character, higher SiO2 content. Age evidence of these two granitic facies suggest that they are from the same magma.

  7. Compressional and extensional tectonics inside collisional belts: the case of the western portion of the Northern Apennines

    OpenAIRE

    Carlini, Mirko

    2013-01-01

    Coeval extensional and compressional tectonics are a common feature in orogenic belts, especially in post-collisional phases. The attempt to constrain their relative timing and the responsible mechanisms led to several models taking into account different geodynamic contexts of various mountain chains. In peri-Mediterranean collisional orogens, extension and compression are commonly associated and coeval to the emplacement of far-travelled/allochthonous units. The deformation acquired by thes...

  8. First oceanographic observations on the Wandel Sea shelf in Northeast Greenland: Tracing the Arctic Ocean outflow through the western Fram Strait

    Science.gov (United States)

    Dmitrenko, Igor A.; Kirillov, Sergei A.; Rudels, Bert; Babb, David G.; Pedersen, Leif T.; Rysgaard, Soeren; Kristoffersen, Yngve; Barber, David G.

    2016-04-01

    The first-ever conductivity-temperature-depth (CTD) observations on the Wandel Sea shelf in North Eastern Greenland were collected from the land-fast ice in April-May 2015 as a part of the Arctic Science Partnership collaboration during the first research campaign at the Villum Research Station. They were complemented by (i) the ice-tethered profiler (ITP) and Acoustic Dopler Current Profiler (ADCP) mooring observations in ~300 m of the tidewater glacier outlet from the Flade Isblink Ice Cap and (ii) CTDs taken in June-July 2015 along the Wandel Sea continental slope during the Norwegian FRAM 2014-15 sea ice drift. The CTD profiles deeper than 100 m are used to reveal the origin of water masses and determine the extent to which these water masses have interacted with ambient water from the continental slope. The subsurface water layer from ~20-70 m depth is comprised of freshened water (30-32 psu) that is likely associated with the Pacific Water outflow from the Arctic Ocean through the western Fram Strait. The underlying halocline layer centered at ~80 m (~33 psu) separates the Pacific Water layer from a deeper (<140 m) layer of modified Polar Water that has interacted with the warm Atlantic Water outflow through Fram Strait. The Atlantic Water layer with temperature above 0°C is recorded below 140 m. Over the outer shelf, the halocline layer shows numerous cold density-compensated intrusions indicating lateral interaction with an ambient Polar Water mass across the continental slope. Mooring data shows an enhanced shelf-slope interaction responding the storm event in 23-24 April 2015 with northerly winds exceeding 10 m/s. The on-shelf transport of a cold and turbid water from the upper continental slope results in enhanced interleaving within the depth range of the halocline layer (~70-100 m). Our observations of Pacific Water in the Wandel Sea subsurface layer are set in the context of upstream observations in the Beaufort Sea for 2002-2011 and downstream

  9. Magmatic Gold Mineralization in the Western Qinling Orogenic Belt:Geology and Metallogenesis of the Baguamiao, Liba and Xiaogouli Gold Deposits

    Institute of Scientific and Technical Information of China (English)

    FENG Jianzhong; WANG Dongbo; WANG Xueming; ZENG Yishan; Li Tiefeng

    2004-01-01

    The superlarge Baguamiao, large Liba and Xiaogouli gold deposits represent three typical gold deposits different from the Carlin type in the western Qinling Orogenic Belt. Based on Ar-Ar dating of quartz from ores, U-Pb dating of single zircon from granite, tracing of H and O isotopes and studies on the mineralogy and texture of spots and bleached alteration developed in wall rocks, this paper focuses the relations between gold deposits and granite to clarify the origin of gold deposits and the metallogenesis in the tectonic evolution of the Qinling Orogenic Belt. The comprehensive studies show that the age of the granite (148.1-244 Ma) is identical with that of the gold deposits (131.91-232.56 Ma). It is suggested that the granite has close temporal, spatial and genetic relationship with the gold deposits. The granite provides a heat source, water source and considerable amount of ore-forming material. Finally, it is concluded that the orogeny by collision, emplacement of the granite and positioning of the gold deposits represent a successive process. Both the granite and gold deposits resulted from the syn-orogeny and post-orogeny tectonic evolution.

  10. The peopling of Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

    The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence...

  11. Tectonic evolution of the Western Kunlun orogenic belt in northern Qinghai-Tibet Plateau: Evidence from zircon SHRIMP and LA-ICP-MS U-Pb geochronology

    Institute of Scientific and Technical Information of China (English)

    ZHANG ChuanLin; LU SongNian; YU HaiFeng; YE HaiMin

    2007-01-01

    The Western Kunlun Range in northern Qinghai-Tibet Plateau is composed of the North Kunlun Terrane,the South Kunlun Terrane and the Karakorum-Tianshuihai Terrane. Here we report zircon SHRIMP and LA-ICP-MS U-Pb ages of some metamorphic and igneous rocks and field observations in order to provide a better understanding of their Precambrian and Palaeozoic-early Mesozoic tectonic evolution.Based on these data we draw the following conclusions: (1) The paragneisses in the North Kunlun Terrane are likely of late Mesoproterozoic age rather than Palaeoproterozoic age as previously thought,representing tectonothermal episodes at 1.0-0.9 Ga and ~0.8 Ga. (2) The North Kunlun Terrane was an orogenic belt accreted to the southern margin of Tarim during late Mesoproterozoic to early Neoproterozoic, the two episodes of metamorphisms correspond to the assemblage and breakup of Rodinia respectively. (3) The Bulunkuole Group in western South Kunlun Terrane, which was considered to be the Palaeoproterozoic basement of the South Kunlun Terrane by previous studies, is now subdivided into the late Neoproterzoic to early Palaeozoic paragneisses (khondalite) and the early Mesozoic metamorphic volcano-sedimentary series; the paragneisses were thrust onto the metamorphic volcano-sedimentary series from south to north, with two main teconothermal episodes (i.e., Caledonian,460-400 Ma, and Hercynian-Indosinian, 340-200 Ma), and have been documented by zircon U-Pb ages.(4) In the eastern part of the South Kunlun Terrane, a gneissic granodiorite pluton, which intruded the khondalite, was crystallized at ca. 505 Ma and metamorphosed at ca. 240 Ma. In combination with geochronology data of the paragneiss, we suggest that the South Kunlun Terrane was a Caledonian accretionary orogenic belt and overprinted by late Paleozoic to early Mesozoic arc magmatism.

  12. Tectonic evolution of the Western Kunlun orogenic belt in northern Qinghai-Tibet Plateau:Evidence from zircon SHRIMP and LA-ICP-MS U-Pb geochronology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Western Kunlun Range in northern Qinghai-Tibet Plateau is composed of the North Kunlun Terrane,the South Kunlun Terrane and the Karakorum-Tianshuihai Terrane. Here we report zircon SHRIMP and LA-ICP-MS U-Pb ages of some metamorphic and igneous rocks and field observations in order to pro-vide a better understanding of their Precambrian and Palaeozoic-early Mesozoic tectonic evolution. Based on these data we draw the following conclusions: (1) The paragneisses in the North Kunlun Terrane are likely of late Mesoproterozoic age rather than Palaeoproterozoic age as previously thought,representing tectonothermal episodes at 1.0―0.9 Ga and ~0.8 Ga. (2) The North Kunlun Terrane was an orogenic belt accreted to the southern margin of Tarim during late Mesoproterozoic to early Neopro-terozoic,the two episodes of metamorphisms correspond to the assemblage and breakup of Rodinia respectively. (3) The Bulunkuole Group in western South Kunlun Terrane,which was considered to be the Palaeoproterozoic basement of the South Kunlun Terrane by previous studies,is now subdivided into the late Neoproterzoic to early Palaeozoic paragneisses (khondalite) and the early Mesozoic metamorphic volcano-sedimentary series; the paragneisses were thrust onto the metamorphic vol-cano-sedimentary series from south to north,with two main teconothermal episodes (i.e.,Caledonian,460―400 Ma,and Hercynian-Indosinian,340―200 Ma),and have been documented by zircon U-Pb ages. (4) In the eastern part of the South Kunlun Terrane,a gneissic granodiorite pluton,which intruded the khondalite,was crystallized at ca. 505 Ma and metamorphosed at ca. 240 Ma. In combination with geochronology data of the paragneiss,we suggest that the South Kunlun Terrane was a Caledonian accretionary orogenic belt and overprinted by late Paleozoic to early Mesozoic arc magmatism.

  13. Detrital zircon provenance constraints on the initial uplift and denudation of the Chinese western Tianshan after the assembly of the southwestern Central Asian Orogenic Belt

    Science.gov (United States)

    Han, Yigui; Zhao, Guochun; Sun, Min; Eizenhöfer, Paul R.; Hou, Wenzhu; Zhang, Xiaoran; Liu, Dongxing; Wang, Bo

    2016-06-01

    U-Pb and Lu-Hf isotopic data of detrital zircons from late Paleozoic and Mesozoic strata along the southern flank of the Chinese western Tianshan enable to identify provenance changes and reconstruct early stage uplift and denudation history of the Tianshan range. Detrital zircons from Permian and Early-Middle Triassic siliciclastic rocks show two prominent age populations at 500-390 Ma and 310-260 Ma, and subordinate Precambrian ages at ~ 2.5 Ga, 2.0-1.7 Ga, 1.2-0.9 Ga and 900-600 Ma, with rare ages between 390 and 310 Ma. These characteristics and zircon εHf(t) data consistently suggest a sediment source predominantly from the Tarim Craton, rather than the Central Tianshan-Yili Block. In contrast, Late Triassic to Cretaceous strata additionally contain abundant 390-310 Ma and 260-220 Ma detrital zircons, implying multiple source regions from the Central Tianshan-Yili Block, Tarim Craton, and Western Kunlun Orogen. A significant switch of sedimentary provenances occurred in the mid-Triassic and is consistent with contemporaneous change of paleocurrent directions and the onset of intense tectonothermal events in the broad region of the Chinese western Tianshan and Kyrgyz Tianshan. These data collectively indicate that the significant surface uplift and denudation of the Tianshan range were probably initiated in the mid-Triassic (~ 240 Ma) after the assembly of the southwestern Central Asian Orogenic Belt. This uplifting event represents an intracontinental orogeny most likely in response to the collision between the Qiangtang Block and southern Eurasia, following the closure of the western part of the Paleo-Tethys Ocean.

  14. Nuuk, Greenland

    Science.gov (United States)

    2008-01-01

    Nuuk (or Gadthab) is the capital and largest city of Greenland. It is located at the mouth of the Nuup Kangerlua inlet on the west coast of Greenland. It has a population of about 15,000. The site has a long history of different inhabitation: first by the Inuit people around 2000 B.C., later by Viking explorers in the 10th century. Inuit and Vikings lived together for about 500 years until about 1500, when human habitation suddenly stopped, most likely due to change in climate and vegetation. The image was acquired August 2, 2004, covers an area of 22.7 x 26 km, and is located at 64.2 degrees north latitude, 51.8 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  15. Cretaceous sedimentation and metamorphism of the western Alpine Schist protoliths associated with the Pounamu Ultramafic Belt, Westland, New Zealand

    International Nuclear Information System (INIS)

    The Pounamu Ultramafic Belt (PUB), part of the Alpine Schists, comprises a metamorphosed ophiolitic sequence overlain by a thin pelagic unit, a massive quartzofeldspathic biotite rock and quartzofeldspathic turbidites derived from a Torlesse/Otago Schist source. Constituent zircon populations from the biotite rock are euhedral/prismatic and are unabraded. One sample is near unimodal, with a U-Pb SHRIMP age of 106.6 ± 1.4 Ma (2σm), while the other has two peaks at 108.0 ± 1.6 Ma and 71.9 ± 1.8 Ma. The older age is interpreted to represent the age of igneous activity and sedimentation, while the younger peak is interpreted to represent the age of subsequent metamorphism. The whole-rock geochemistry of the biotite rock, its field distribution and zircon morphology are consistent with an origin by eruption of a dacitic air-fall tuff. The base of the Pounamu sequence divides predominantly psammitic Triassic metasediments to the east from intensely deformed, but regionally west-facing, Cretaceous metasediments to the west. These Cretaceous metasediments have undergone multiphase deformation and metamorphism by 72 Ma, a timing that contrasts markedly with previous interpretations for Jurassic amalgamation of the Haast Schists. (author)

  16. Andean Basin Evolution Associated with Hybrid Thick- and Thin-Skinned Deformation in the Malargüe Fold-Thrust Belt, Western Argentina

    Science.gov (United States)

    Horton, B. K.; Fuentes, F.

    2015-12-01

    Andean deformation and basin evolution in the Malargüe fold-thrust belt of western Argentina (34-36°S) has been dominated by basement faults influenced by pre-existing Mesozoic rift structures of the hydrocarbon-rich Neuquen basin. However, the basement structures diverge from classic inversion structures, and the associated retroarc basin system shows a complex Mesozoic-Cenozoic history of mixed extension and contraction, along with an enigmatic early Cenozoic stratigraphic hiatus. New results from balanced structural cross sections (supported by industry seismic, well data, and surface maps), U-Pb geochronology, and foreland deposystem analyses provide improved resolution to examine the duration and kinematic evolution of Andean mixed-mode deformation. The basement structures form large anticlines with steep forelimbs and up to >5 km of structural relief. Once the propagating tips of the deeper basement faults reached cover strata, they fed slip to shallow thrust systems that were transported in piggyback fashion by newly formed basement structures, producing complex structural relationships. Detrital zircon U-Pb ages for the 5-7 km-thick basin fill succession reveal shifts in sedimentation pathways and accumulation rates consistent with (1) local basement sources during Early-Middle Jurassic back-arc extension, (2) variable cratonic and magmatic arc sources during Late Jurassic-Cretaceous postrift thermal subsidence, and (3) Andean arc and thrust-belt sources during irregular Late Cretaceous-Cenozoic shortening. Although pulses of flexural subsidence can be attributed to periods of fault reactivation (inversion) and geometrically linked thin-skinned thrusting, fully developed foreland basin conditions were only achieved in Late Cretaceous and Neogene time. Separating these two contractional episodes is an Eocene-lower Miocene (roughly 40-20 Ma) depositional hiatus within the Cenozoic succession, potentially signifying forebulge passage or neutral to

  17. Norse Greenland

    DEFF Research Database (Denmark)

    Arneborg, Jette

    2015-01-01

    human agency, landscape changes, climate changes, resilience, sustainability and adaptation are key words and research has moved from local to more global perspectives. New results from research projects in recent years have diversified the discussion claiming that the Norse Greenlanders created...... a flexible and successful subsistence system that responded effectively to the major environmental challenges they faced. In a recent paper it has been argued (Dugmore et al 2012) that abandonment should be explained by a combination of external factors (climate changes; changes in European trade systems...

  18. P- T- t constraints on the development of the Doi Inthanon metamorphic core complex domain and implications for the evolution of the western gneiss belt, northern Thailand

    Science.gov (United States)

    Macdonald, A. S.; Barr, S. M.; Miller, B. V.; Reynolds, P. H.; Rhodes, B. P.; Yokart, B.

    2010-01-01

    The western gneiss belt in northern Thailand is exposed within two overlapping Cenozoic structural domains: the extensional Doi Inthanon metamorphic core complex domain located west of the Chiang Mai basin, and the Mae Ping strike-slip fault domain located west of the Tak batholith. New P- T estimates and U-Pb and 40Ar/ 39Ar age determinations from the Doi Inthanon domain show that the gneiss there records a complex multi-stage history that can be represented by a clockwise P- T- t path. U-Pb zircon and titanite dating of mylonitic calc-silicate gneiss from the Mae Wang area of the complex indicates that the paragneissic sequence experienced high-grade, medium-pressure metamorphism (M1) in the Late Triassic - Early Jurassic (ca. 210 Ma), in good agreement with previously determined zircon ages from the underlying core orthogneiss exposed on Doi Inthanon. Late Cretaceous monazite ages of 84 and 72 Ma reported previously from the core orthogneiss are attributed to a thermal overprint (M2) to upper-amphibolite facies in the sillimanite field. U-Pb zircon and monazite dating of granitic mylonite from the Doi Suthep area of the complex provides an upper age limit of 40 Ma (Late Eocene) for the early stage(s) of development of the actual core complex, by initially ductile, low-angle extensional shearing under lower amphibolite-facies conditions (M3), accompanied by near-isothermal diapiric rise and decompression melting. 40Ar/ 39Ar laserprobe dating of muscovite from both Doi Suthep and Doi Inthanon provided Miocene ages of ca. 26-15 Ma, representing cooling through the ca. 350 °C isotherm and marking late-stage development of the core complex by detachment faulting of the cover rocks and isostatic uplift of the sheared core zone and mantling gneisses in the footwall. Similarities in the thermochronology of high-grade gneisses exposed in the core complex and shear zone domains in the western gneiss belt of northern Thailand (and also in northern Vietnam, Laos, Yunnan

  19. Hydromorphological parameters of natural channel behavior in conditions of the Hercynian System and the flysch belt of the Western Carpathians on the territory of the Czech Republic

    Science.gov (United States)

    Kujanová, Kateřina; Matoušková, Milada; Kliment, Zdeněk

    2016-04-01

    A fundamental prerequisite for assessing the current ecological status of streams is the establishment of reference conditions for each stream type that serve as a benchmark. The hydromorphological reference conditions reflect the natural channel behavior, which is extremely variable. Significant parameters of natural channel behavior were determined using a combination of four selected statistical methods: Principal Component Analysis, Agglomerative Hierarchical Clustering, correlation, and regression. Macroscale analyses of data about altitude, stream order, channel slope, valley floor slope, sinuosity, and characteristics of the hydrological regime were conducted for 3197 reaches of major rivers in the Czech Republic with total length of 15,636 km. On the basis of selected significant parameters and their threshold values, channels were classified into groups of river characteristics based on shared behaviors. The channel behavior within these groups was validated using hydromorphological characteristics of natural channels determined during field research at reference sites. Classification of channels into groups confirmed the fundamental differences between channel behavior under conditions of the Hercynian System and the flysch belt of the Western Carpathians in the Czech Republic and determined a specific group in the flattened high areas of mountains in the Bohemian Massif. Validating confirmed the distinctions between groups of river characteristics and the uniqueness of each one; it also emphasized the benefits of using qualitative data and riparian zone characteristics for describing channel behavior. Channel slope, entrenchment ratio, bed structure, and d50 were determined as quantitative characteristics of natural channel behavior.

  20. Lithosphere, crust and basement ridges across Ganga and Indus basins and seismicity along the Himalayan front, India and Western Fold Belt, Pakistan

    Science.gov (United States)

    Ravi Kumar, M.; Mishra, D. C.; Singh, B.

    2013-10-01

    Spectral analysis of the digital data of the Bouguer anomaly of North India including Ganga basin suggest a four layer model with approximate depths of 140, 38, 16 and 7 km. They apparently represent lithosphere-asthenosphere boundary (LAB), Moho, lower crust, and maximum depth to the basement in foredeeps, respectively. The Airy's root model of Moho from the topographic data and modeling of Bouguer anomaly constrained from the available seismic information suggest changes in the lithospheric and crustal thicknesses from ˜126-134 and ˜32-35 km under the Central Ganga basin to ˜132 and ˜38 km towards the south and 163 and ˜40 km towards the north, respectively. It has clearly brought out the lithospheric flexure and related crustal bulge under the Ganga basin due to the Himalaya. Airy's root model and modeling along a profile (SE-NW) across the Indus basin and the Western Fold Belt (WFB), (Sibi Syntaxis, Pakistan) also suggest similar crustal bulge related to lithospheric flexure due to the WFB with crustal thickness of 33 km in the central part and 38 and 56 km towards the SE and the NW, respectively. It has also shown the high density lower crust and Bela ophiolite along the Chamman fault. The two flexures interact along the Western Syntaxis and Hazara seismic zone where several large/great earthquakes including 2005 Kashmir earthquake was reported. The residual Bouguer anomaly maps of the Indus and the Ganga basins have delineated several basement ridges whose interaction with the Himalaya and the WFB, respectively have caused seismic activity including some large/great earthquakes. Some significant ridges across the Indus basin are (i) Delhi-Lahore-Sargodha, (ii) Jaisalmer-Sibi Syntaxis which is highly seismogenic. and (iii) Kachchh-Karachi arc-Kirthar thrust leading to Sibi Syntaxis. Most of the basement ridges of the Ganga basin are oriented NE-SW that are as follows (i) Jaisalmer-Ganganagar and Jodhpur-Chandigarh ridges across the Ganga basin intersect

  1. Reconstructing multiple arc-basin systems in the Altai-Junggar area (NW China): Implications for the architecture and evolution of the western Central Asian Orogenic Belt

    Science.gov (United States)

    Li, Di; He, Dengfa; Tang, Yong

    2016-05-01

    The Altai-Junggar area in northwestern China is a critical region to gain insights on the tectonic framework and geological evolution of the western Central Asian Orogenic Belt (CAOB). In this study, we report results from integrated geological, geochemical and geophysical investigations on the Wulungu Depression of the Junggar Basin to determine the basement nature of the basin and understand its amalgamation history with the Chinese Altai, within the broad tectonic evolution of the Altai-Junggar area. Based on borehole and seismic data, the Wulungu Depression is subdivided into two NW-trending tectonic units (Suosuoquan Sag and Hongyan High) by southward-vergent thrust faults. The Suosuoquan Sag consists of the Middle-Late Devonian basaltic andesite, andesite, dacite, tuff, tuffaceous sandstone and tuffite, and the overlying Early Carboniferous volcano-sedimentary sequence with lava flows and shallow marine sediments from a proximal juvenile provenance (zircon εHf(t) = 6.0-14.9), compared to the Late Carboniferous andesite and rhyolite in the Hongyan High. Zircon SIMS U-Pb ages for dacites and andesites indicate that these volcanics in the Suosuoquan Sag and Hongyan High erupted at 376.3 Ma and 313.4 Ma, respectively. The Middle-Late Devonian basaltic andesites from well LC1 are calc-alkaline and exhibit primitive magma-like MgO contents (7.9-8.6%) and Mg# values (66-68), with low initial 87Sr/86Sr (0.703269-0.704808) and positive εNd(t) values (6.6-7.6), and relatively high Zr abundance (98.2-116.0 ppm) and Zr/Y ratios (5.1-5.4), enrichment in LREEs and LILEs (e.g., Th and U) and depletion in Nb, Ta and Ti, suggesting that they were probably derived from a metasomatized depleted mantle in a retro-arc extensional setting. The well LC1 andesitic tuffs, well L8 dacites, well WL1 dacitic tuffs and well L5 andesites belong to calc-alkaline and metaluminous to peraluminous (A/CNK = 0.8-1.7) series, and display low Mg# values (35-46) and variably positive εNd(t) (4

  2. Evaluation of the ongoing rifting and subduction processes in the geochemistry of magmas from the western part of the Mexican Volcanic Belt

    Science.gov (United States)

    Verma, Surendra P.; Pandarinath, Kailasa; Rivera-Gómez, M. Abdelaly

    2016-03-01

    A compilation of new and published geochemical data for 1512 samples of volcanic rocks from the western part of the Mexican Volcanic Belt was first subdivided according to the age group (136 samples of Miocene and 1376 samples of Pliocene-Holocene). Rocks of the younger group were then subdivided as Rift (1014 samples from the triple-rift system) and No Rift (362 samples outside of the triple-rift system) or Near Trench (937 samples) and Far Trench (439 samples) magmas. These subdivisions were considered separately as basic, intermediate, and acid magmatic rocks. The application of the conventional and multidimensional techniques confirmed the great tectonic and geochemical complexity of this region. The presence of oceanic-type basalts suggested to result from a mantle plume was not confirmed from the tectonomagmatic multidimensional diagrams. The Miocene rocks, which are present at the surface far from the Middle-America Trench, showed a likely continental rift setting in most diagrams for basic rocks and a continental arc setting for intermediate rocks. These differences can be explained in terms of the petrogenetic origin of the magmas. Unlike the current thinking, the triple-rift system seems to have influenced the chemistry of Pliocene-Holocene basic rocks, which indicated a continental rift setting. The Pliocene-Holocene intermediate and acid rocks, however, did not show such an influence. The Pliocene-Holocene basic rocks indicated a continental rift setting, irrespective of the Near Trench and Far Trench subdivision because numerous Near Trench rocks also lie in the triple-rift and graben systems. However, the intermediate rocks having a crustal component in their genesis indicated a continental arc (Near Trench) or a transitional arc to within-plate setting (Far Trench). The acid rocks having a crustal component also suggested a continental arc (Near Trench) or a transitional setting (Far Trench). The application of the tectonomagmatic multidimensional

  3. High-Resolution Reconstruction of Late Holocene Sea-ice Distribution and Primary Production on the East Greenland Shelf and the NW Fram Strait.

    Science.gov (United States)

    Stein, R. H.; Kolling, H. M.; Fahl, K.

    2014-12-01

    Over the last decades, the extent and thickness of Arctic sea ice has changed dramatically and much more rapidly than predicted by climate models. Based on this alarming observation, the reconstruction of natural variability of past sea-ice cover and its forcing became a major focus of international scientific research. Here, we present a high-resolution biomarker approach over the last 4 ka from the East Greenland Shelf to investigate the interrelationship between sea-ice cover, meltwater/freshwater discharge and primary productivity. The phytoplankton-derived sea-ice proxy IP25 (Belt et al., 2007) points to a late Holocene cooling trend initiated around 1.5 ka which is interrupted by a period of reduced sea-ice cover centred around 1 ka. The latter might be related to the well known Medieval Warm Period. Our new results from the East Greenland Shelf will be compared with similar records from the Fram Strait area published by Müller et al., (2012). These data give information about differences and/or similarities of sea-ice variability and changes in productivity in the area influenced by the cold East Greenland Current and the warm Westspitsbergen Current, respectively. First data suggest a time lag of the Neoglacial cooling between western (Greenland side) and eastern (Westspitsbergen-side) of Fram Strait, as also proposed by Müller et al. (2012). ReferencesBelt., S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, C., LeBlanc, B., 2007. A novel chemical fossil of paleo sea ice: IP25. Organic Geochemistry 38, 16-27 Müller, J., Werner, K., Stein, R., Fahl, K., Moros, M., Jansen, E., 2012. Holocene cooling culminates in sea ice oscillations in Fram Strait. Quaternay Science Reviews 47, 1-14

  4. Sea-ice distribution and primary production on the East Greenland Shelf and the NW Fram Strait - a high resolution study of the last 5.2 ka

    Science.gov (United States)

    Kolling, Henriette Marie; Stein, Ruediger; Fahl, Kirsten

    2015-04-01

    Over the last decades, the extent and thickness of Arctic sea ice has changed dramatically and much more rapidly than predicted by climate models. Based on this alarming observation, the reconstruction of natural variability of past sea-ice cover and its forcing became a major focus of international scientific research. Here, we present a high-resolution biomarker approach over the last 4 ka from the East Greenland Shelf to investigate the interrelationship between sea-ice cover, meltwater/freshwater discharge and primary productivity. The phytoplankton-derived sea-ice proxy IP25 (Belt et al., 2007) points to a late Holocene cooling trend initiated around 1.5 ka which is interrupted by a period of reduced sea-ice cover centred around 1 ka. The latter might be related to the well known Medieval Warm Period. Our new results from the East Greenland Shelf will be compared with similar records from the Fram Strait area published by Müller et al., (2012). These data give information about differences and/or similarities of sea-ice variability and changes in productivity in the area influenced by the cold East Greenland Current and the warm Westspitsbergen Current, respectively. First data suggest a time lag of the Neoglacial cooling between western (Greenland side) and eastern (Westspitsbergen-side) of Fram Strait, as also proposed by Müller et al. (2012). References Belt., S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, C., LeBlanc, B., 2007. A novel chemical fossil of paleo sea ice: IP25. Organic Geochemistry 38, 16-27 Müller, J., Werner, K., Stein, R., Fahl, K., Moros, M., Jansen, E., 2012. Holocene cooling culminates in sea ice oscillations in Fram Strait. Quaternay Science Reviews 47, 1-14

  5. Popular music from Greenland

    DEFF Research Database (Denmark)

    Otte, Andreas Roed

    Popular music from Greenland – Globalization, nationalism and performance of place. This thesis is based on fieldwork done within the popular music scene in Greenland from 2008 to 2014. It engages with the question of how music and conceptions of the nation (Greenland) affect each other in social...... spaces, and analyses on how popular music can be used to construct senses of place and situate individuals within these places. The thesis is centered on four articles that engage with Greenlandic popular music from different perspectives. The first article looks at the historical development in inducing...... a sense of place in popular music. The second probes different strategies for co-branding popular music and Greenland. The third is concerned with music consumption patterns among Greenlandic youth. And the fourth article engages with an alternative form of nationalism found within the Nuuk underground...

  6. First Younger Dryas moraines in Greenland

    Science.gov (United States)

    Funder, Svend; Larsen, Nicolaj K.; Linge, Henriette; Möller, Per; Schomacker, Anders; Fabel, Derek; Kjær, Kurt H.; Xu, Sheng

    2016-04-01

    Over the Greenland ice sheet the Younger Dryas (YD) cold climate oscillation (12.9-11.7 kaBP) began with up to 10°C drop in temperatures and ended with up to 12°C abrupt warming. In the light of the present warming and melting of the ice sheet, and its importance for future climate change, the ice sheet's response to these dramatic changes in the past is of great interest. However, even though much effort has gone into charting YD ice margin behaviour around Greenland in recent years, no clear-cut signal of response to the oscillation has been uncovered. Here we show evidence to suggest that three major outlets from a local ice cap at Greenland's north coast advanced and retreated synchronously during YD. The evidence comprises OSL (optically stimulated luminescence) dates from a marine transgression of the coastal valleys that preceded the advance, and exposure ages from boulders on the moraines, formed by glaciers that overrode the marine sediment. The OSL ages suggest a maximum age of 12.4 ±0.6 kaBP for the marine incursion, and 10 exposure ages on boulders from the three moraines provide an average minimum age of 12.5 ±0.7 kaBP for the moraines, implying that the moraines were formed within the interval 11.8-13.0 kaBP. Elsewhere in Greenland evidence for readvance has been recorded in two areas. Most notably, in the East Greenland fjord zone outlet glaciers over a stretch of 800 km coast advanced through the fjords. In Scoresby Sund, where the moraines form a wide belt, an extensive 14C and exposure dating programme has shown that the readvance here probably culminated before YD, while cessation of moraine formation and rapid retreat from the moraine belt did not commence until c. 11.5 kaBP, but no moraines have so far been dated to YD. Readvance is also seen in Disko Bugt, the largest ice sheet outlet in West Greenland. However, here the advance and retreat of the ice stream took place in mid YD times, and lasted only a few hundred years, while YD in

  7. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

    The Greenland development is a story about: Having a hinterland position in relation to the global development. An indigenous people achieving more political influence. How conflicts and discussions on power and ownership of the subsurface resources between a state and an autonomy (Home Rule) can...... Greenland policy can delay and maybe change the future of the forecasted development of the use of natural resources. This book is relevant for anyone interested in Greenland in general and the development of Greenland both politically and economically and in relation natural resources....

  8. The summer 2012 Greenland heat wave

    DEFF Research Database (Denmark)

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

    2015-01-01

    in Bermuda Island, South Greenland coast (Ivittuut), and northwest Greenland ice sheet (NEEM), as well as remote sensing observations (Infrared Atmospheric Sounding Interferometer (IASI) instrument on board MetOp-A), depicting propagation of similar surface and midtropospheric humidity and δD signals....... Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM....... At Ivittuut, surface air temperature, humidity, and δD increases are observed. At NEEM, similar temperature increase is associated with a large and long-lasting ∼100‰δD enrichment and ∼15‰ deuterium excess decrease, thereby reaching Ivittuut level. We assess the simulation of this event in two isotope...

  9. Petrology and provenance of the Neogene fluvial succession in Pishin Belt (Katawaz Basin) western Pakistan: Implications for sedimentation in peripheral forelands basins

    DEFF Research Database (Denmark)

    Kasi, Aimal Khan; Kassi, Aktar Muhammad; Friis, Henrik;

    2016-01-01

    Sandstones and conglomerates of the fluvial Neogene succession in Pishin Belt (Katawaz Basin), Pakistan were studied first time to understand the composition, provenance and tectonic settings of the source areas. Sandstones of the Miocene Dasht Murgha group and Pliocene Malthanai formation are cl...

  10. Xenoliths From Isla Isabel, Nayarit, Mexico: The Nature of the Upper Mantle Underneath the Western Part of the Mexican Volcanic Belt

    Science.gov (United States)

    Housh, T. B.; Aranda-Gomez, J. J.; Luhr, J. F.

    2007-12-01

    Isla Isabel is located ~65 km NW of San Blas (Nayarit), off the Pacific coast of central Mexico. The island is a Quaternary (Ar/Ar < 0.7 Ma) volcanic complex built atop attenuated continental crust. Isabel lies on the east side of the mouth of the Gulf of California, near the area previously occupied (early Pliocene) by Los Cabos Block. Southeast of Isabel, on the mainland, is the NW-trending Tepic-Zacoalco rift, a major volcano-tectonic structure in the western part of the Mexican Volcanic Belt. On land, the rift is the boundary between the Jalisco and Sierra Madre Occidental blocks, and Isabel lies along its projection. Immediately S of Isabel is the San Blas Trough, a swale that trends NW-SE, co-linear with a gravity lineation parallel to the Tamayo and San Blas fault zones, which are the transform boundaries between the northern Rivera and North American plates. Plio-Quaternary alkaline and calc-alkaline lavas have erupted contemporaneously in the Tepic-Zacoalco rift, but so far no mantle xenoliths have been reported in them. Isabel's rocks are intra-plate type alkaline basalts to trachybasalts, with 5-6%\\ normative Ne. Primary paragenesis in the lavas is: Ol + Pl + Cpx + TMt. Small (< 5 cm) peridotite xenoliths, and xenocrysts derived from them, are ubiquitous in the rocks. Eleven xenoliths were studied comprising 3 dunites, 7 harzburgites (one Pl-bearing), and 1 gabbro. Compared to other Mexican xenolith localities N of the MVB, they are refractory as they are depleted in, or lack, Cpx. Ol crystals in xenoliths are homogenous and their Mg#\\ s range as follows: peridotites (92-88), gabbro (84), and Pl-harzburgite (80). Cores of primary Ol phenocrysts (90.5-86.5) in Isabel's volcanic rocks are significantly higher in Mg#\\ s than in Ol from other Mexican xenolith localities (max. 86) and overlap with the associated peridotite xenoliths. Such overlap has not been reported for other Mexican xenolith localities. Xenolith equilibration temperatures for 5

  11. West Greenlandic Eskimo

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann; Fortescue, Michael David

    the principal economic activity. Research projects and language initiatives currently in progress within Greenland will be touched upon, as will the possibilities of communication with North American Inuit. West Greenlandic is unique among the native languages of the North American Arctic and Sub...

  12. Health expectancy in Greenland

    DEFF Research Database (Denmark)

    Iburg, K M; Brønnum-Hansen, Henrik; Bjerregaard, P

    2001-01-01

    Mortality and disease patterns in Greenland have greatly changed since the 1950s. Infectious diseases have decreased markedly; chronic diseases, suicides and violent deaths have increased.......Mortality and disease patterns in Greenland have greatly changed since the 1950s. Infectious diseases have decreased markedly; chronic diseases, suicides and violent deaths have increased....

  13. Tectonic and thermal history of the western Serrania del Interior foreland fold and thrust belt and Guarico Basin, north central Venezuela: Implications of new apatite fission track analysis and seismic interpretation

    Science.gov (United States)

    Perez de Armas, Jaime Gonzalo

    Structural analysis, interpretation of seismic reflection lines, and apatite fission-track analysis in the Western Serrania del Interior fold and thrust belt and in the Guarico basin of north-central Venezuela indicate that the area underwent Mesozoic and Tertiary-to-Recent deformation. Mesozoic deformation, related to the breakup of Pangea, resulted in the formation of the Espino graben in the southernmost portion of the Guarico basin and in the formation of the Proto-Caribbean lithosphere between the diverging North and South American plates. The northern margin of Venezuela became a northward facing passive margin. Minor normal faults formed in the Guarico basin. The most intense deformation took place in the Neogene when the Leeward Antilles volcanic island arc collided obliquely with South America. The inception of the basal foredeep unconformity in the Late Eocene-Early Oligocene marks the formation of a perisutural basin on top of a buried graben system. It is coeval with minor extension and possible reactivation of Cretaceous normal faults in the Guarico basin. It marks the deepening of the foredeep. Cooling ages derived from apatite fission-tracks suggest that the obduction of the fold and thrust belt in the study area occurred in the Late Oligocene through the Middle Miocene. Field data and seismic interpretations suggest also that contractional deformation began during the Neogene, and specifically during the Miocene. The most surprising results of the detrital apatite fission-track study are the ages acquired in the sedimentary rocks of the easternmost part of the study area in the foreland fold and thrust belt. They indicate an Eocene thermal event. This event may be related to the Eocene NW-SE convergence of the North and South American plates that must have caused the Proto-Caribbean lithosphere to be shortened. This event is not related to the collision of the arc with South America, as the arc was far to the west during the Eocene.

  14. Conceptualizing and contextualizing food insecurity among Greenlandic children

    DEFF Research Database (Denmark)

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

    2013-01-01

    security among Inuit in Arctic regions was found to be very similar and connected to a westernization of the diet and contamination of the traditional diet. The major challenges are contamination, economic access to healthy food and socio-demographic differences in having a healthy diet. The literature...... on outcomes related to food insecurity in children in Western societies was reviewed and grouped based on 8 domains. Using data from the Greenlandic HBSC data from 2010, the item on food security showed negative associations on central items in all these domains. Focus group interviews with children revealed......OBJECTIVE: To review the context of food insecurity in Greenlandic children, to review and compare the outcomes related to food insecurity in Greenlandic children, in other Arctic child populations and in other western societies, and to explore the measure used by the Health Behaviour in School...

  15. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

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

  16. Cool or hot Greenland?

    DEFF Research Database (Denmark)

    Ren, Carina Bregnholm

    2016-01-01

    In a current stage of ‘Arctic fever’, former representations of Greenland as ‘cool’ are increasingly joined by ‘hot’ scenarios based on an assumption of the nation as a ‘climate winner’. Using examples from the exhibition ‘Possible Greenland’ at the Venice Architectural Biennale of 2012, this paper...... shows how a Greenland of the future is portrayed and branded as a sustainable nation and destination through future scenarios. The performative approach to the exhibition and its scenarios displays how issues related to all three sides of sustainability e people, planet and profit e are enrolled...... in an attempt to brand Greenland, but also to motivate and carry out decisions. Two scenarios from the exhibition are used to show howdiverging strategies are deployed in order to envision Greenland as sustainable. Where one seeks to embrace disagreement and complexity in its inclusive approach, the other...

  17. The Greenland ice sheet and the climate – a review

    DEFF Research Database (Denmark)

    Funder, Svend Visby; Kjeldsen, Kristian Kjellerup; Kjær, Kurt H.;

    During LGM the margins of the Greenland ice sheet around the whole perimeter stood on the shelf – but where? The first estimates had to be based on evidence from land such as weathering limits on coastal mountains, major moraine belts, and altitudes of marine limits. Still the estimates ranged fr...... climate change during and after LGM, and that coverage of the shelf may have been variable from one sector to another. Will the margin respond with similar complexity to global warming?...

  18. Q fever in Greenland

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  19. The Greenland Ramsar Sites

    DEFF Research Database (Denmark)

    Egevang, C.; Boertmann, D.

    The eleven Ramsar sites in Greenland are reviewed in terms of their status as habitats for waterbirds and other fauna. Management and monitoring is proposed, as well as revisions of their boundaries. A number of potential new Ramsar sites are described......The eleven Ramsar sites in Greenland are reviewed in terms of their status as habitats for waterbirds and other fauna. Management and monitoring is proposed, as well as revisions of their boundaries. A number of potential new Ramsar sites are described...

  20. Human antibody recognition of Anisakidae and Trichinella spp. in Greenland

    DEFF Research Database (Denmark)

    Møller, L N; Krause, T Grove; Koch, A;

    2007-01-01

    High levels of total IgE are observed among children in Greenland. To evaluate the extent to which Anisakidae and Trichinella spp. contribute to the high total IgE level, an ELISA and a western blot were developed for the detection of IgG antibodies to Anisakidae, based on excretory/secretory ant......High levels of total IgE are observed among children in Greenland. To evaluate the extent to which Anisakidae and Trichinella spp. contribute to the high total IgE level, an ELISA and a western blot were developed for the detection of IgG antibodies to Anisakidae, based on excretory...

  1. Contaminants in the Greenland terrestrial and freshwater environment. National assessment

    International Nuclear Information System (INIS)

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

  2. Compositional variations in the Mesoarchean chromites of the Nuggihalli schist belt, Western Dharwar Craton (India): potential parental melts and implications for tectonic setting

    DEFF Research Database (Denmark)

    Mukherjee, R.; Mondal, S.K.; Rosing, M.T.;

    2010-01-01

    -98)) and pyroxene grains (Mg-numbers = 97-99). Compositional variability on the scale of a single chromite grain occurs in the form of zoning, and it is common in the accessory chromite grains in serpentinite and in the altered grains in chromitite. In the zoned grains, the composition of the core is modified....... In some occurrences, the ferritchromit rim is very well developed, and only a small relict core appears to remain in the chromite grain. However, complete alteration of the chromite grains to ferritchromit without any remnant core is also present. The regular, well-developed and continuous occurrence...... of ferritchromit rims around the chromite grain boundaries, the complete alteration of the chromite grains and the modification of the core composition indicate the alteration in the Nuggihalli schist belt to be intense, pervasive and affected by later low-grade metamorphism. The primary composition of chromite...

  3. Greenland Ice Sheet Mass Balance

    Science.gov (United States)

    Reeh, N.

    1984-01-01

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

  4. Arctic Ocean UNCLOS Article 76 Work for Greenland Starts on Land

    Science.gov (United States)

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

    2005-12-01

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

  5. An early Holocene Greenland whale from Melville Bugt, Greenland

    Science.gov (United States)

    Bennike, Ole

    2008-01-01

    Radiocarbon age determination of a Greenland whale ( Balaena mysticetus) vertebra from Melville Bugt in northwestern Greenland yields an age of 9259-8989 cal yr BP. The margin of the Greenland Ice Sheet in Melville Bugt was situated behind its AD 1950-2000 position in the early Holocene, at a similar position to that being reached following rapid retreat in recent years. Such an early deglaciation of areas close to the Greenland Ice Sheet is unusual. This probably reflects the unique glaciological setting resulting from the narrow fringe of ice-free islands and peninsulas and offshore waters with deep areas that characterize this part of Greenland. The timing of Greenland Ice Sheet retreat to its present margin varies significantly around Greenland.

  6. How Greenland melts

    Directory of Open Access Journals (Sweden)

    van den Broeke M.R.

    2010-12-01

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

  7. Greenland climate change

    DEFF Research Database (Denmark)

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

    2012-01-01

    Climate archives available from deep-sea and marine shelf sediments, glaciers, lakes and ice cores in and around Greenland allow us to place the current trends in regional climate, ice sheet dynamics, and land surface changes in a broader perspective. We show that during the last decade (2000s...... during the last 10 000 years, highlighting the role of soil dynamics in past vegetation changes, and stressing the growing anthropogenic impacts on soil erosion during recent decades. Furthermore, past and present changes in atmospheric and oceanic heat advection appear to severely influence both...... regional climate and ice sheet dynamics. The magnitude and rate of future changes in Greenland temperature, in response to increasing greenhouse gas emissions, may be faster than any past abrupt events occurring under interglacial conditions. Projections indicate that within one century Greenland may...

  8. Retrieval of soil erosion relevant parameters in the Western Australian wheat belt region from VNIR-SWIR and TIR spectral signatures

    OpenAIRE

    Andreas Eisele; Sabine Chabrillat; I. Lau; Kobayashi, C.; B. Wheaton; Carter, D.; Kashimura, O.; Kato, M.; Ong, C.; R. Hewson; Cudahy, T.; Hermann Kaufmann

    2011-01-01

    With the focus on new available hyperspectral imaging sensors sensitive within the thermal infrared (TIR) wavelength region, this study is testing the ability of the TIR in deriving soil erosion relevant parameters (e.g. texture, organic carbon content) from soil spectral measurements with the respect to commonly used VNIR-SWIR spectrometers. Therefore a study site was chosen located within an agricultural area in Western Australia, which is suffering from soil loss through wind erosion proce...

  9. Petrography and chemical evidence for multi-stage emplacement of western Buem volcanic rocks in the Dahomeyide orogenic belt, southeastern Ghana, West Africa

    Science.gov (United States)

    Nude, Prosper M.; Kwayisi, Daniel; Taki, Naa A.; Kutu, Jacob M.; Anani, Chris Y.; Banoeng-Yakubo, Bruce; Asiedu, Daniel K.

    2015-12-01

    The volcanic rocks of the Buem Structural Unit in the Dahomeyide orogenic belt of southeastern Ghana, constitute a unique assemblage among the monocyclic sedimentary formations of this structural unit. Representative volcanic rock samples were collected from the Asukawkaw, Bowiri-Odumase and Nkonya areas which form a roughly north-south trend. The volcanic rocks comprise spherulitic, amygdaloidal, vesicular, phyric and aphyric varieties. Whole rock geochemistry shows that these volcanic rocks exhibit both alkaline and subalkaline characteristics. The alkaline varieties are relatively enriched in REE and incompatible trace element concentrations, similar to OIB; the subalkaline varieties show E-MORB and N-MORB REE and incompatible element characteristics. The rocks have low La/Nb (<1), low K/Nb (<450) and high Nb/U (averagely 47.3) values, suggesting no significant effect of crustal contamination. The key characteristics of these volcanic rocks are the distinct petrography and geochemistry, shown from the three separate localities, which may suggest source fractionation at different depths or modes of emplacement. The association of volcanic rocks of OIB, E-MORB and N-MORB affinities, with no significant crustal contamination, may suggest mantle derived magma that may have been related to rifting event and eventual emplacement at the eastern passive margin of the West African Craton.

  10. New paleomagnetic results from the Upper Cretaceous red marls of the Pieniny Klippen Belt, Western Carpathians: Evidence for general CCW rotation and implications for the origin of the structural arc formation

    Science.gov (United States)

    Márton, Emő; Grabowski, Jacek; Plašienka, Dušan; Túnyi, Igor; Krobicki, Michał; Haas, János; Pethe, Mihály

    2013-04-01

    The Pieniny Klippen Belt (PKB) is a narrow arcuate structure separating the Central and Outer Western Carpathians formed during several Cenozoic deformational stages. The primary aim of this study was to obtain paleomagnetic constraints for the mechanism of formation of the arc. We investigate Albian-Santonian red pelagic marls from 14 localities, distributed along a strike length of ca. 400 km. AMS measurements reveal a pattern characteristic of weakly deformed sedimentary rocks and magnetic lineations do not correlate with the general strike of the PKB. Paleomagnetic analysis revealed well defined hematite-based ancient magnetization components at 13 localities, which are dated using fold- and inclination tests. A within-locality fold test is negative for two localities exhibiting large CCW rotations of similar magnitude situated at the two ends of the PKB. Remanences of pre-folding age were documented for 11 localities, with an overall mean paleomagnetic direction of D = 311°, I = 53°, and α95 = 11°. The indicated general CCW rotation most probably took place during the Miocene, together with Western Central and Outer Carpathians. Paleolatitudes for the PKB indicate a considerable separation from the southern margin of stable Europe leaving space for coordinated rotation. A paleomagnetic oroclinal test involving all localities with primary magnetizations was negative. When localities with monoclinal steep dips are omitted due to possible declination bias, the overall mean paleomagentic direction does not change significantly, but correlation is observed between the general trend of the PKB and the paleomagnetic declinations. Thus, we conclude that the present shape of the arc can be partly due to oroclinal bending. This must have happened before Oligocene since paleomagnetic declinations for neighboring Paleogene basins in the Central and Outer Western Carpathians reveal a uniform CCW rotation of ca. 50° magnitude, irrespective of the position of the

  11. Geology, Distribution and Classification of Gold Deposits in the Western Qinling Belt, Central China%西秦岭地区造山型与卡林型金矿床

    Institute of Scientific and Technical Information of China (English)

    毛景文

    2001-01-01

    Gold deposits of the western Qinling belt comprising Carlin-typeand orogenic type gold deposits. Carlin-like gold deposits are abundant (1) along a westward extension of the southern zone defined by a window of early Paleozoic clastic rocks extending into the basin to the west and (2) within the easternmost margin of the basinal rocks, south of the extension, and in adjacent cover rocks of the Yangtze craton. Triassic and Early Jurassic synkinematic granitoids are widespread across the central and southern zones, as well as in the Songpan-Ganzi basin and northern margin of the Yangtze craton.Orogenic lode gold deposits sited along brittle-ductile shear zones occur throughout the central zone within greenschist-facies, highly-deformed, Devonian and younger clastic rocks. Mainly coarse-grained gold, along with pyrite, pyrrhotite, arsenopyrite, and minor base metal sulfides, occur in networks of quartz veinlets, brecciated wallrock, and disseminated in altered wallrock. Isotopic dates suggest that the deposits formed during the Late Triassic to Middle Jurassic as the leading edge of the Yangtze craton was thrust beneath rocks of the western Qinling belt.Both Carlin-and orogenic types of gold deposits formed during extensional period of post-orogenesis, aged mainly from 210-180 Ma.%西秦岭金矿床分为卡林型和造山型两类。卡林型金矿床麇集于南秦岭和松潘—甘孜造山带的东北部。三叠纪和早侏罗世的同构造花岗闪长岩广泛分布于西秦岭中部和南部、松潘—甘孜盆地以及扬子克拉通边缘。造山型脉状金矿床主要分布于西秦岭造山带中的脆韧性剪切带内。大部分粗粒金主要赋存在网格状石英细脉和角砾状围岩中的黄铁矿、磁黄铁矿、毒砂和少量贱金属硫化物中和以分散状分布在蚀变围岩中。同位素资料表明晚三叠世-中侏罗世与扬子克拉通俯冲有关的作用控制了造山型金矿床的形成。

  12. Belt attachment and system

    Science.gov (United States)

    Schneider, Abraham D.; Davidson, Erick M.

    2016-02-02

    Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

  13. Studying health in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Mulvad, Gert; Olsen, Jørn

    2003-01-01

    Health research in Greenland has contributed with several findings of interest for the global scientific community and has documented health problems and risk factors of importance for planning the local health care system. The study of how health develops in small, scattered communities during...

  14. China and Greenland

    DEFF Research Database (Denmark)

    Jakobsen, Uffe

    2014-01-01

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

  15. Commentary: Future Greenland 2015

    DEFF Research Database (Denmark)

    Bjørst, Lill Rastad

    2015-01-01

    Every second year the Greenlandic Business Association host the two-day conference “Future Greenland” in Nuuk. The main theme of this year conference was “Growth and welfare – scenarios for the development of Greenland”. The conference had more than 400 participants - mostly from Denmark and Gree...

  16. APISSEQ Sisimiut – Greenland

    DEFF Research Database (Denmark)

    Kotol, Martin

    This report summarizes the very first survey of the engineering dormitory Apisseq in Sisimiut, Greenland. The dormitory was inaugurated in August 2010 and the survey was performed in March 2011. The experienced problems and their possible causes are explained in the report. Furthermore possible...

  17. Neoproterozoic diamictite-bearing sedimentary rocks in the northern Yili Block and their constraints on the Precambrian evolution of microcontinents in the Western Central Asian Orogenic Belt

    Science.gov (United States)

    He, Jingwen; Zhu, Wenbin; Zheng, Bihai; Wu, Hailin; Cui, Xiang; Lu, Yuanzhi

    2015-12-01

    The origin and tectonic setting of Precambrian sequences in the Central Asian Orogenic Belt (CAOB) have been debated due to a lack of high resolution geochronological data. Answering this question is essential for the understanding of the tectonic framework and Precambrian evolution of the blocks within the CAOB. Here we reported LA-ICP-MS detrital zircon U-Pb ages and in-situ Hf isotopic data for Neoproterozoic sedimentary cover in the northern Yili Block, an important component of the CAOB, in order to provide information on possible provenance and regional tectonic evolution. A total of 271 concordant U-Pb zircon ages from Neoproterozoic sedimentary cover in the northern Yili Block define three major age populations of 1900-1400 Ma, 1300-1150 Ma and 700-580 Ma, which are quite different from cratons and microcontinents involved in the CAOB. Although it is not completely consistent with the local basement ages, an autochthonous provenance interpretation is more suitable. Some zircon grains show significant old Hf model ages (TDMC; 3.9-2.4 Ga) and reveal continental crust as old as Paleoarchean probably existed. Continuous Mesoproterozoic zircon age populations exhibit large variations in the εHf(t) ratios, suggesting the long-time involvement of both reworked ancient crust and juvenile material. Similar Mesoproterozoic evolution pattern is identified in many continental terranes involved in the CAOB that surround the Tarim Craton. Based on our analysis and published research, we postulate that the northern Yili Block, together with Chinese Central Tianshan, Kyrgyz North Tianshan and some other microcontinents surrounding the Tarim Craton, once constituted the continental margin of the Tarim Craton in the Mesoproterozoic, formed by long-lived accretionary processes. Most of the late Neoproterozoic zircons exhibit significant positive εHf(t) ratios, suggesting the addition of juvenile crust. It is consistent with the tectonic event related to the East Africa

  18. Petrogenesis and ore genesis of the Permian Huangshanxi sulfide ore-bearing mafic-ultramafic intrusion in the Central Asian Orogenic Belt, western China

    Science.gov (United States)

    Mao, Ya-Jing; Qin, Ke-Zhang; Li, Chusi; Xue, Sheng-Chao; Ripley, Edward M.

    2014-07-01

    The Permian Huangshanxi mafic-ultramafic intrusion hosts one of the two largest magmatic sulfide deposits in the Eastern Tianshan which is situated in the southern margin of the Central Asian Orogenic Belt. In this paper we use mineral compositions and whole-rock geochemical data to decipher the genetic relationship between magma evolution and sulfide mineralization. The Huangshanxi intrusion consists of three separate intrusive units. Important sulfide mineralization occurs in the base of the last intrusive unit, an elongated, layered ultramafic body composed of lherzolite at the bottom, olivine websterite in the middle and websterite at the top. Based on olivine-liquid equilibria and mass balance, the MgO and FeO contents in the parental magma for a lherzolite sample are estimated to be 8.71 and 8.36 wt.%, respectively. The Huangshanxi mafic-ultramafic intrusive rocks and the estimated "trapped liquids" for several olivine-orthopyroxene cumulate rocks all show light rare earth element enrichments relative to heavy rare earth elements and significant Nb depletions relative to Th and La, which are similar to the characteristics of coeval basalts in the region. The arc-like geochemical features are attributed to pre-Permian mantle metasomatism by slab-derived fluids. Partial melting of the previously-modified mantle is thought to have resulted from heating by upwelling asthenosphere associated with post-subduction lithosphere delamination or by mantle plume activity. The relationship between the Fo and Ni contents of olivine crystals from the Huangshanxi sulfide-poor ultramafic rocks (< 1 wt.% S) indicates cotectic sulfide segregation during olivine crystallization. Significant depletions in platinum group elements (PGE) relative to Ni and Cu in the bulk sulfide ores of the Huangshanxi deposit are likely due to sulfide retention in the source mantle. Stratigraphic reversals in olivine Fo contents and bulk sulfide PGE tenors suggest that multiple magma replenishments

  19. Uplift and late orogenic deformation of the Central European Variscan belt as revealed by sediment provenance and structural record in the Carboniferous foreland basin of western Poland

    Science.gov (United States)

    Mazur, S.; Aleksandrowski, P.; Turniak, K.; Krzemiński, L.; Mastalerz, K.; Górecka-Nowak, A.; Kurowski, L.; Krzywiec, P.; Żelaźniewicz, A.; Fanning, M. C.

    2010-01-01

    The Carboniferous foreland basin of western Poland contains a coherent succession of late Viséan through Westphalian turbidites derived from a uniform group of sources located within a continental magmatic arc. Detrital zircon geochronology indicates that two main crustal components were present in the source area of Namurian A sediments. They represent Late Devonian and Early Carboniferous ages, respectively. The detritus from Westphalian D beds is much more diversified and contains admixture of Late Carboniferous zircons suggesting rapid unroofing of Variscan igneous intrusions in the hinterland between Namurian A and Westphalian D times. Tectonic repetitions of tens of metres thick fault-bounded stratigraphic intervals, recorded in several wells, provide evidence for compressional regime that occurred in the SW part of the Carboniferous basin not earlier than during the Westphalian C and produced NW-SE trending folds, concordant with the structural grain of the adjacent, NE part of the Bohemian Massif.

  20. Growth performance of Avicennia officinalis L. and the effect of spacing on growth and yield of trees planted in the Western coastal belt of Bangladesh

    Institute of Scientific and Technical Information of China (English)

    Md. Abdul Quddus Miah; Sk. Ahiul Islam; Md. Ahsan Habib; Md. Golam Moula

    2014-01-01

    A trial of Avicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline (Patuakhali district) of Bangladesh since 1993 to assess growth perform-ance and the effect of spacing on tree growth. Data on tree density, height, diameter, bole height, crown diameter were recorded and ana-lyzed when the stand was 19 years old. Mean height ranged from 12.89-13.52 m and diameter at breast height (dbh) from 26.57-32.16 cm in plots of different spacings. The mean annual height increment ranged from 0.67-0.71 m, mean annual diameter increment from 1.40-1.69 cm and wood volume from 6.02-10.04 m3⋅ha-1⋅a-1 in different treatments. Significantly greater diameter (32.16 cm) and wood volume (10.04 m3⋅ha-1⋅a-1) were obtained with wider (2.13 m × 2.13 m) spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from other A. officinalis plantations raised by Forest Department (FD) on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, mean annual height incre-ment ranged from 0.33-0.62 m, mean annual diameter increment from 0.72-1.37 cm and wood volume from 1.55-5.73 m3⋅ha-1⋅a-1. The growth performance of A. officinalis indicated that the newly accreted lands along the western shoreline may be suitable for raising Avicennia planta-tions for the enrichment of coastal vegetation.

  1. FORMATION AND EVOLUTION OF THE CENOZOIC THRUST FOLD BELT IN JINPING, SICHUAN

    Institute of Scientific and Technical Information of China (English)

    LIAO Zhongli; DENG Yongfu; LIAO Guangyu

    2003-01-01

    The Jinping orogenic belt in Sichuan, China consists mainly of the Jinpingshan intracontinental thrust-nappe belt, foreland thrust-nappe belt and foreland uplift belt. Based on analyses about the characteristics of the structural units in this area, the authors propose in this paper that Chapuzi-Bazhe revival fault belt is the regional boundary fault, and points out that after the formation of the Pre-Sinian basement, the western edge of the Yangtze paraplatform was turned into the passive continental margin in Sinian to Triassic, then into the Mesozoic collision orogenic belt, and finally into the Cenozoic orogenic belt through intracontinental orogeny.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    of positive results on the modified CAGE test, measuring alcohol dependence, were also seen in large communities in Greenland. We found no statistically significant differences in alcohol intake between Inuit living in large and small communities in Greenland. When comparing Inuit living in Denmark according...... and in Greenland respectively, differs in relation to total intake, drinking patterns and a measure of alcohol dependence. Whether this may be attributed to urbanization, or to migration, is not clear.......OBJECTIVE: To analyse the effects of migration and urbanisation on alcohol intake among a population of Greenland Inuit. STUDY DESIGN: Population-based cross-sectional study of 4,139 Inuit randomly selected from Denmark and four areas of western Greenland. Data collection was based on interviews...

  3. Crustal structure beneath Eastern Greenland

    DEFF Research Database (Denmark)

    Reiche, Sönke; Thybo, H.; Kaip, G.;

    2011-01-01

    by the presence of an up to 4 km thick ice sheet, permanently covering the largest part of the land mass. Hence previous seismic surveys have only been carried out offshore and near the coast of Greenland, where little information about the continental part of the crust could be gained. To get...... insight into crustal thickness and composition below the Greenland ice sheet, the TopoGreenland project collects the first ever seismic data onshore Greenland. Wide-angle data was acquired along an EW-trending profile, extending 350 km inland from the approximate edge of the stable ice cap near Scoresby...

  4. Late Paleozoic closure of the Ob-Zaisan Ocean along the Irtysh/Chara shear zone and implications for arc amalgamation and oroclinal bending in the western Central Asian Orogenic Belt

    Science.gov (United States)

    Li, Pengfei; Sun, Min; Rosenbaum, Gideon

    2016-04-01

    The Irtysh/Chara Shear Zone is one of the largest strike-slip systems in the Central Asian Orogenic Belt (CAOB). It records collisional processes of the peri-Siberian orogenic system with the West Junggar-Kazakhstan-Tianshan orogenic system following the closure of the Ob-Zaisan Ocean, but the exact timing of these events remains enigmatic. We conducted detailed structural analysis along the Irtysh Shear Zone (NW China), which together with new geochronological data allows us to reconstruct the tectonic evolution during the final closure of the Ob-Zaisan Ocean. Our results showed that subduction-accretion processes lasted at least until the Late Carboniferous in the Chinese Altai and the East/West Junggar. The subsequent arc amalgamation is characterized by a cycle of crustal thickening, orogenic collapse and transpressional thickening. On a larger scale, the West Junggar- Kazakhstan -Tianshan orogenic system defines a U-shape oroclinal structure (e.g. Xiao et al., 2010). A major phase of oroclinal bending that involved ~110° rotation may have occurred during the Late Devonian to Early Carboniferous (Levashova et al., 2012). Previous authors have linked oroclinal bending with the late Paleozoic amalgamation of the western CAOB, and proposed that a quasi-linear West Junggar- Kazakhstan -Tianshan orogenic system was buckled during the convergence of the Siberian and Tarim cratons following the closure of the Ob-Zaisan Ocean (in the north) and the South Tianshan Ocean (in the south) (e.g. Abrajevitch et al., 2008). This model, however, is not supported by our new data that constrain the closure of the Ob-Zaisan Ocean to the Late Carboniferous. Alternatively, we propose that oroclinal bending may have involved two phases of bending, with the ~110° rotation in the Late Devonian to Early Carboniferous possibly associated with trench retreat. Further tightening may have occurred in response to the convergence of the Siberian and Tarim cratons during the Late

  5. Atuarfitsialak: Greenland's Cultural Compatible Reform

    Science.gov (United States)

    Wyatt, Tasha R.

    2012-01-01

    In 2002, Greenlandic reform leaders launched a comprehensive, nation-wide reform to create culturally compatible education. Greenland's reform work spans the entire educational system and includes preschool through higher education. To assist their efforts, reform leaders adopted the Standards for Effective Pedagogy developed at the Center for…

  6. Greenlandic adoptees' psychiatric inpatient contact. A comparative register-based study

    DEFF Research Database (Denmark)

    Laubjerg, Merete; Petersson, Birgit

    2010-01-01

    .4 (CI 95% 1.8 - 6.6). The most frequent diagnosis is ‘Inherent or acquired brain suffering'. The findings open up possibilities for new hypotheses as to reasons for adoptees' reverse health outcomes in the Western world. Epidemiological and medical contact recording do not exist outside central hospital...... level in Greenland, therefore, in order to put psychiatric contact patterns into perspective, in depth field studies are required in close collaboration with the local Greenlandic population...

  7. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: A lead isotope study of an Archaean gold prospect in the Attu region, Nagssugtoqidian orogen, West Greenland

    OpenAIRE

    Stendal, Henrik; Frei, Robert; Stensgaard, Bo Møller

    2006-01-01

    This paper presents a lead isotope investigation of a gold prospect south of the village Attu in the northern part of the Nagssugtoqidian orogen in central West Greenland. The Attu gold prospect is a replacement gold occurrence, related to a shear/mylonite zone along a contact between orthogneissand amphibolite within the Nagssugtoqidian orogenic belt. The mineral occurrence is small, less than 0.5 m wide, and can be followed along strike for several hundred metres. The mineral assemblage is ...

  8. Adventure Learning @ Greenland

    Science.gov (United States)

    Miller, B. G.; Cox, C. J.; Hougham, J.; Walden, V. P.; Eitel, K.; Albano, A.

    2013-12-01

    Teaching the general public and K-12 communities about scientific research has taken on greater importance as climate change increasingly impacts the world we live in. Science researchers and the educational community have a widening responsibility to produce and deliver curriculum and content that is timely, scientifically sound and engaging. To address this challenge, in the summer of 2012 the Adventure Learning @ Greenland (AL@GL) project, a United States' National Science Foundation (NSF) funded initiative, used hands-on and web-based climate science experiences for high school students to promote climate and science literacy. This presentation will report on an innovative approach to education and outreach for environmental science research known as Adventure Learning (AL). The purpose of AL@GL was to engage high school students in the US, and in Greenland, in atmospheric research that is being conducted in the Arctic to enhance climate and science literacy. Climate and science literacy was explored via three fundamental concepts: radiation, the greenhouse effect, and climate vs. weather. Over the course of the project, students in each location engaged in activities and conducted experiments through the use of scientific instrumentation. Students were taught science research principles associated with an atmospheric observatory at Summit Station, Greenland with the objective of connecting climate science in the Arctic to student's local environments. Summit Station is located on the Greenland Ice Sheet [72°N, 38°W, 3200 m] and was the primary location of interest. Approximately 35 students at multiple locations in Idaho, USA, and Greenland participated in the hybrid learning environments as part of this project. The AL@GL project engaged students in an inquiry-based curriculum with content that highlighted a cutting-edge geophysical research initiative at Summit: the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at

  9. Greenland Telescope (GLT Project

    Directory of Open Access Journals (Sweden)

    Nakamura M.

    2013-12-01

    Full Text Available The GLT project is deploying a new submillimeter (submm VLBI station in Greenland. Our primary scientific goal is to image a shadow of the supermassive black hole (SMBH of six billion solar masses in M87 at the center of the Virgo cluster of galaxies. The expected SMBH shadow size of 40-50 μas requires superbly high angular resolution, suggesting that the submm VLBI would be the only way to obtain the shadow image. The Summit station in Greenland enables us to establish baselines longer than 9,000 km with ALMA in Chile and SMA in Hawaii as well as providing a unique u–v coverage for imaging M87. Our VLBI network will achieve a superior angular resolution of about 20 μas at 350 GHz, corresponding to ∼ 2.5 times of the Schwarzschild radius of the supermassive black hole in M87. We have been monitoring the atmospheric opacity at 230 GHz since August. 2011; we have confirmed the value on site during the winter season is comparable to the ALMA site thanks to high altitude of 3,200 m and low temperature of −50°C. We will report current status and future plan of the GLT project towards our expected first light on 2015–2016.

  10. Permafrost degradation in West Greenland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2012-01-01

    and the first author has been involved since 1970 in engineering geology, geotechnical engineering and permafrost related studies for foundation construction and infrastructures in towns and communities mainly in West Greenland. We have since 2006 together with the Danish Meteorological Institute, Greenland...... Survey (ASIAQ) and the University of Alaska Fairbanks carried out the US NSF funded project ARC-0612533: Recent and future permafrost variability, retreat and degradation in Greenland and Alaska: An integrated approach. This contribution will present data and observations from the towns Ilulissat...

  11. Lifestyle, reproductive factors and food intake in Greenlandic pregnant women: The ACCEPT – sub-study

    Directory of Open Access Journals (Sweden)

    Ane-Kersti Skaarup Knudsen

    2015-11-01

    Full Text Available Background: In the past decades, Greenland has changed from a hunter society to a more western lifestyle, causing less intake of traditional food, such as marine mammals, fish and seabirds. These changes in the living conditions and food habits might impact the maternal health in Greenland. Objectives: To describe lifestyle, reproductive factors and food intake in Greenlandic pregnant women, and to assess possible age and geographical differences. Design: Cross-sectional study of 189 Greenlandic pregnant women. Inclusion criteria were ≥18 years and lived >50% of their life in Greenland. Data were collected in 2010–2011, and information was obtained from lifestyle and food frequency questionnaires. Two age groups for comparison were given for the pregnant women (25.0 kg/m2, 46.3% were current smokers in the beginning of their pregnancy and few participants consumed alcohol during pregnancy. Women 50% in North, South and West had a higher alcohol intake during pregnancy. Women in North had the fewest breastfeeding plans. Women in Disko Bay had the lowest intake of terrestrial species. No significant geographical differences were found for intake of marine mammals or seabirds. Conclusions: The present study found relatively high BMI level and high smoking frequency in Greenlandic pregnant women. Age and region differences were found for alcohol consumption, breastfeeding plans and food intake profile. Further research is needed to implement relevant maternal health intervention programs in Greenland.

  12. Early Archean serpentine mud volcanoes at Isua, Greenland, as a niche for early life

    OpenAIRE

    Pons, Marie-Laure; Quitté, Ghylaine; Fujii, Toshiyuki; Rosing, Minik T.; Reynard, Bruno; Moynier, Frederic; Douchet, Chantal; Albarède, Francis

    2011-01-01

    The Isua Supracrustal Belt, Greenland, of Early Archean age (3.81–3.70 Ga) represents the oldest crustal segment on Earth. Its complex lithology comprises an ophiolite-like unit and volcanic rocks reminiscent of boninites, which tie Isua supracrustals to an island arc environment. We here present zinc (Zn) isotope compositions measured on serpentinites and other rocks from the Isua supracrustal sequence and on serpentinites from modern ophiolites, midocean ridges, and the Mariana forearc. In ...

  13. Why is Transparency Greenland Necessary?

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2012-01-01

    Greenland is facing significant changes in the composition of its economy, and is moving rapidly in the direction of becoming a commodities economy. Studies conducted by Transparency International in other parts of the world suggest that oil exploration and mining are among the areas of economic...... activity, which carry the greatest risk of corruption. It is therefore important that Greenlandic society is prepared for the new economic players, and the risks this may entail....

  14. Wastewater Treatment in Greenland

    DEFF Research Database (Denmark)

    Gunnarsdottir, Ragnhildur

    treatment in these regions. However, designing, constructing and operating wastewater collection systems in the Arctic is challenging because of e.g. permafrost conditions, hard rock surfaces, freezing, limited quantity of water and high costs of electricity, fuel and transportation, as well as a settlement...... collection systems, and be more economically and environmentally sustainable than traditional wastewater collection and treatment systems. Possible alternative wastewater treatment methods for Greenlandic communities are dry composting or anaerobic digestion of excreta, collected at household level using dry...... alternative could be to use small and simple biogas plants, followed by dewatering of the degassed biomass, either by utilizing possible surplus of energy from the biogas plant or natural freezing, which might be a more cost-effective way. After dewatering the liquid part can be treated by filtration...

  15. Post-colonial identity in Greenland?

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2009-01-01

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

  16. Problems concerning musk oxen in Greenland

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the range of muskox in Greenland. The predominant habitat of the muskox is in northern and northeastern Greenland; however, it has appeared...

  17. Inuit dietary patterns in modern Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Jeppesen, Charlotte

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kalsbeek, Feiko

    2009-11-01

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

  19. Imersuaq - Hydropower potential in Greenland; Imersuaq - Vandkraftpotentiale i Groenland

    Energy Technology Data Exchange (ETDEWEB)

    Egede Boeggild, C.; Ahlstroem, A.P. [Danmark og Groenlands Geologiske Undersoegelse (GEUS), Copenhagen (Denmark); Tvis Knudsen, N. [Aarhus Univ., Geologisk Inst., Aarhus (Denmark)

    2001-07-01

    The project aims at a more precise estimate of the contribution from the icesheet to hydropower potentials, based on the largest bassin in Western Greenland 'Tasersiaq', situated between the cities of Maniitsoq and Kangerlussuaq. New methods are applied: 1) Detailed mapping of the icemargin using radar measurements from satellite. 2) Airborne radio-echo soundings, precisely estimating the ice thickness and bedrock topography. 3)Accurate determination of the aircraft's position by means of GPS and laser altimetry of the aircraft altitude above the ice. Furthermore, fully automatic climate stations on the surface provides in situ climate data for calculation of the snowmelt. The insight gained from combining the extensive data set with the broad range of expertise available within the project, is to be condensed into a strong scientific tool, which can be applied when the prospects for new hydropower plants in Greenland has to be assessed. (LN)

  20. A Comparison of Geoid Undulations for West Central Greenland

    Science.gov (United States)

    Roman, Daniel R.; Csatho, Beata; Jezek, Kenneth C.; Thomas, Robert H.; Krabill, William B.; vonFrese, Ralph R. B.; Forsberg, Rene

    1997-01-01

    The accuracy of a new local gravity field model, GEOID94A, is examined at a site on the western Greenland ice sheet. The model, developed by the Danish National Survey and Cadastre, incorporates several new gravity data sets including an extensive amount of airborne gravity data. Model-derived geoid undulations were compared to independently determined undulations found by differencing the elevations from Global Positioning System controlled airborne laser altimetry and optical leveling surveys. Differences between the two sets of undulations were less than +/- 6 cm RMS. The comparison improved (+/- 5 cm RMS) when GEOID94A undulations were adjusted by local gravity observations also acquired at the site. Our comparisons demonstrate that GEOID94A adequately models the long to intermediate wavelengths of the gravity field. We conclude that GEOID94A constitutes a reliable reference model for studies of Greenland's gravity field.

  1. Environmental radioactivity in Greenland in 1982

    International Nuclear Information System (INIS)

    Measurements of fallout radioactivity in Greenland in 1982 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in the human diet in Greenland in 1982. The report contains results from sampling expeditions to East Greenland as well as West Greenland waters in 1982. Brown algae collected in East Greenland in 1969 were analysed for 90Sr. (author)

  2. The Greenland Telescope

    Science.gov (United States)

    Grimes, Paul; Blundell, Raymond

    2012-09-01

    In the spring of 2010, the Academia Sinica Institute of Astronomy and Astrophysics, and the Smithsonian Astrophysical Observatory, acquired the ALMA North America prototype antenna - a state-of-the-art 12-m diameter dish designed for submillimeter astronomy. Together with the MIT-Haystack Observatory and the National Radio Astronomy Observatory, the plan is to retrofit this antenna for cold-weather operation and equip it with a suite of instruments designed for a variety of scientific experiments and observations. The primary scientific goal is to image the shadow of the Super-Massive Black Hole in M87 in order to test Einstein’s theory of relativity under extreme gravity. This requires the highest angular resolution, which can only be achieved by linking this antenna with others already in place to form a telescope almost the size of the Earth. We are therefore developing plans to install this antenna at the peak of the Greenland ice-sheet. This location will produce an equivalent North-South separation of almost 9,000 km when linked to the ALMA telescope in Northern Chile, and an East-West separation of about 6,000 km when linked to SAO and ASIAA’s Submillimeter Array on Mauna Kea, Hawaii, and will provide an angular resolution almost 1000 times higher than that of the most powerful optical telescopes. Given the quality of the atmosphere at the proposed telescope location, we also plan to make observations in the atmospheric windows at 1.3 and 1.5 THz. We will present plans to retrofit the telescope for cold-weather operation, and discuss potential instrumentation and projected time-line.

  3. Lime Stabilization of Fine-Grained Greenlandic Sediments in Relation to Construction Projects

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas; Nielsen, Hans Rasmus;

    2010-01-01

    Thick deposits of fine-grained marine sediments exist in large areas of western Greenland. Many places these sediments are located above sea-level, and now complicate construction projects in urban areas. The mineralogy of the sediments is very different from that of European sediments, mainly due...

  4. Sustained high basal motion of the Greenland ice sheet revealed by borehole deformation

    DEFF Research Database (Denmark)

    Ryser, Claudia; Luethi, Martin P.; Andrews, Lauren C.;

    2014-01-01

    Ice deformation and basal motion characterize the dynamical behavior of the Greenland ice sheet (GrIS). We evaluate the contribution of basal motion from ice deformation measurements in boreholes drilled to the bed at two sites in the western marginal zone of the GrIS. We find a sustained high am...

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

    Science.gov (United States)

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

    2015-12-01

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

  6. The Braconidae (Hymenoptera) of Greenland

    NARCIS (Netherlands)

    Achterberg, van C.

    2006-01-01

    Thirty species belonging to 16 genera of the family Braconidae (Hymenoptera) are reported from Greenland. Seven are new species described and illustrated below: Dacnusa groenlandica spec. nov.; Aphidius tarsalis spec. nov.; Praon brevistigma spec. nov.; Blacus (B.) groenlandicus spec. nov.; Cotesia

  7. The Pedagogical Situation in Greenland.

    Science.gov (United States)

    Gunther, Bent

    The history of Greenland's educational activities began in 1721 with the work of a missionary who encouraged the people to learn to read and write. A century later, higher education became available. In 1905, legislation was enacted that served as a milestone of progress for the growth of education. Separation from Denmark, which was leading…

  8. Health and society in Greenland

    OpenAIRE

    Kjeldsen, Anne B,

    2005-01-01

    Greenland is the largest island in the world covering 2,2 mill sq kilometers of which 90 % is covered by ice and 10 % is a narrow strip of land along the coastline.(Int J Circumpolar Health 2005; 64(3):257-259)

  9. Dynamic characteristics of conveyor belts

    Institute of Scientific and Technical Information of China (English)

    HOU You-fu; MENG Qing-rui

    2008-01-01

    The dynamic characteristics of a belt conveyor are determined to a large extent by the properties of the belt. This paper describes experiments designed to establish the dynamic properties of belting material. The dynamic elastic modulus, viscous damping and theological constants of the belt were measured. Several properties were studied as a function of the tensile loading on the belt. These included longitudinal vibration, the natural vibration frequency in the transverse direction and the response to an impulse excitation. Vibration response was observed under several different excitation frequencies. Most of these properties have not been tested previously under conditions appropriate for the ISO/DP9856 standard. Two types of belt were tested, a steel reinforced belt and a fabric reinforced belt. The test equipment was built to provide data appropriate for designing belt conveyors. It was observed that the stress wave propagation speed increased with tensile load and that tensile load was the main factor influencing longitudinal vibrations.

  10. Cenozoic intracontinental deformation of the Kopeh Dagh Belt, Northeastern Iran

    Science.gov (United States)

    Chu, Yang; Wan, Bo; Chen, Ling; Talebian, Morteza

    2016-04-01

    Compressional intracontinental orogens represent large tectonic zones far from plate boundaries. Since intracontinental mountain belts cannot be framed in the conventional plate tectonics theory, several hypotheses have been proposed to account for the formations of these mountain belts. The far-field effect of collision/subduction at plate margins is now well accepted for the origin and evolution of the intracontinental crust thickening, as exemplified by the Miocene tectonics of central Asia. In northern Iran, the Binalud-Alborz mountain belt witnessed the Triassic tectonothermal events (Cimmerian orogeny), which are interpreted as the result of the Paleotethys Ocean closure between the Eurasia and Central Iran blocks. The Kopeh Dagh Belt, located to the north of the Binalud-Alborz Belt, has experienced two significant tectonic phases: (1) Jurassic to Eocene rifting with more than 7 km of sediments; and (2) Late Eocene-Early Oligocene to Quaternary continuous compression. Due to the high seismicity, deformation associated with earthquakes has received more and more attention; however, the deformation pattern and architecture of this range remain poorly understood. Detailed field observations on the Cenozoic deformation indicate that the Kopeh Dagh Belt can be divided into a western zone and an eastern zone, separated by a series of dextral strike-slip faults, i.e. the Bakharden-Quchan Fault System. The eastern zone characterized by km-scale box-fold structures, associated with southwest-dipping reverse faults and top-to-the NE kinematics. In contrast, the western zone shows top-to-the SW kinematics, and the deformation intensifies from NE to SW. In the northern part of this zone, large-scale asymmetrical anticlines exhibit SW-directed vergence with subordinate thrusts and folds, whereas symmetrical anticlines are observed in the southern part. In regard to its tectonic feature, the Kopeh Dagh Belt is a typical Cenozoic intracontinental belt without ophiolites or

  11. Evidence of meltwater retention within the Greenland ice sheet

    Directory of Open Access Journals (Sweden)

    A. K. Rennermalm

    2012-08-01

    Full Text Available Greenland ice sheet mass losses have increased in recent decades with approximately half of these attributed to increased surface meltwater runoff. However, controls on ice sheet water release, and the magnitude of englacial storage, firn densification, internal refreezing and other hydrologic processes that delay or reduce true water export to the global ocean remain poorly understood. This problem is amplified by scant hydrometerological measurements. Here, ice sheet surface meltwater runoff and proglacial river discharge determined between 2008 and 2010 for three sites near Kangerlussuaq, western Greenland were used to establish the water budget for a small ice sheet watershed. The water budget could not be closed in the three years, even when uncertainty ranges were considered. Instead between 12% and 53% of ice sheet surface runoff is retained within the glacier each melt year (time between onset of ice sheet runoff in two consecutive years. Evidence of the ice sheet summer meltwater escaping during the cold-season suggests that the Greenland ice sheet cryo-hydrologic system may remain active year round.

  12. Plate Tectonics at 3.8-3.7 Ga: Field Evidence from the Isua Accretionary Complex, Southern West Greenland.

    Science.gov (United States)

    Komiya; Maruyama; Masuda; Nohda; Hayashi; Okamoto

    1999-09-01

    A 1&rcolon;5000 scale mapping was performed in the Isukasia area of the ca. 3.8-Ga Isua supracrustal belt, southern West Greenland. The mapped area is divided into three units bounded by low-angle thrusts: the Northern, Middle, and Southern Units. The Southern Unit, the best exposed, is composed of 14 subunits (horses) with similar lithostratigraphy, bound by layer-parallel thrusts. Duplex structures are widespread in the Isua belt and vary in scale from a few meters to kilometers. Duplexing proceeded from south to north and is well documented in the relationship between link- and roof-thrusts. The reconstructed lithostratigraphy of each horse reveals a simple pattern, in ascending order, of greenstone with low-K tholeiitic composition with or without pillow lava structures, chert/banded iron-formation, and turbidites. The cherts and underlying low-K tholeiites do not contain continent- or arc-derived material. The lithostratigraphy is quite similar to Phanerozoic "oceanic plate stratigraphy," except for the abundance of mafic material in the turbidites. The evidence of duplex structures and oceanic plate stratigraphy indicates that the Isua supracrustal belt is the oldest accretionary complex in the world. The dominantly mafic turbidite composition suggests that the accretionary complex was formed in an intraoceanic environment comparable to the present-day western Pacific Ocean. The duplex polarity suggests that an older accretionary complex should occur to the south of the Isua complex. Moreover, the presence of seawater (documented by a thick, pillow, lava unit at the bottom of oceanic plate stratigraphy) indicates that the surface temperature was less than ca. 100 degrees C in the Early Archean. The oceanic geotherm for the Early Archean lithosphere as a function of age was calculated based on a model of transient half-space cooling at given parameters of surface and mantle temperatures of 100 degrees and 1450 degrees C, respectively, suggesting that the

  13. Structure sismique du socle paléozoïque du bassin des Doukkala, Môle côtier, Maroc occidental. Indication en faveur de l'existence d'une phase éo-varisqueSeismic structure of the Doukkala basin, Palaeozoic basement, western Morocco: a hint for an Eovariscan fold-and-thrust belt

    Science.gov (United States)

    Echarfaoui, Hassan; Hafid, Mohamed; Salem, Abdallah Aı̈t

    2002-01-01

    Seismic profiles and well data from the Doukkala basin unravel the structure of the Palaeozoic basement and suggest that this coastal zone of western Morocco was affected by a compressive phase during the Frasnian. This resulted in the formation of upright, plurikilometric folds associated with reverse faults (North Doukkala), and of asymmetrical folds associated with mostly west verging ramps (South Doukkala). Folding involved all pre-Upper Frasnian formations and caused partial or total hiatus of Upper Frasnian-Strunian strata. This event can be correlated with the orogenic phase reported from more internal domains of the Morocco Hercynian belt, where it is referred to as the 'Bretonne' or 'Eovariscan' phase. To cite this article: H. Echarfaoui et al., C. R. Geoscience 334 (2002) 13-20

  14. Lithofacies Associations and Depositional Environments of the Neogene Molasse succession, Pishin Belt, northwestern Pakistan

    DEFF Research Database (Denmark)

    Kasi, Aimal K.; Kassi, Akhtar M.; Friis, Henrik;

    The Pishin Belt is a NE-SW trending mixed flysch and molasse basin, situated at the northwestern part of Pakistan, bordered by Afghan Block of the Eurasian Plate in the west and Indian Plate in the east. Western boundary of the belt is marked by the well-known Chaman Transform Fault, whereas the ...

  15. Retroflection of part of the east Greenland current at Cape Farewell

    Science.gov (United States)

    Holliday, N. Penny; Meyer, Amélie; Bacon, Sheldon; Alderson, Steven G.; de Cuevas, Beverly

    2007-04-01

    The east Greenland current (EGC) and the smaller east Greenland coastal current (EGCC) provide the major conduit for cold fresh polar water to enter the lower latitudes of the North Atlantic. They flow equatorward through the western Irminger Basin and around Cape Farewell into the Labrador Sea. The surface circulation and transport of the Cape Farewell boundary current region in summer 2005 is described. The EGCC merges with Arctic waters of the EGC to the south of Cape Farewell, forming the west Greenland current. The EGC transport decreases from 15.5 Sv south of Cape Farewell to 11.7 Sv in the eastern Labrador Sea (where the water becomes known as Irminger Sea Water). The decrease in EGC transport is balanced by the retroflection of a substantial proportion of the boundary current (5.1 Sv) into the central Irminger Basin; a new pathway for fresh water into the interior of the subpolar gyre.

  16. Inuit Health in Transition - the diet of young Inuit in Greenland

    DEFF Research Database (Denmark)

    Jeppesen, Charlotte

    Inuit Health in Transition - the diet of young Inuit in Greenland Charlotte Jeppesen, National Institute of Public Health, Copenhagen, Denmark OBJECTIVE The traditional diet of Inuit living in Greenland consists of marine mammals, reindeer, wild fowls and fish. Within the last 50 years consumption...... of imported Western foods has increased, as have the prevalence of diabetes and cardiovascular disease. This study aims to investigate whether the contribution of traditional foods to the dietary macronutrient composition differs across gender and age. METHODS Data were collected in a cross-sectional study...... is influenced both by sex and age. The macronutrients in the diet of young Greenlanders are mainly contributed by imported foods. These findings support the hypothesis that young Inuit are moving toward a westernised diet, which can lead to public health consequences in the future....

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

    Science.gov (United States)

    Bourgain, Pascaline

    2015-04-01

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

  18. Multibeam Mapping of Remote Fjords in Southeast-Greenland

    Science.gov (United States)

    Weinrebe, W.; Kjaer, K. H.; Kjeldsen, K. K.; Bjork, A. A.

    2015-12-01

    The fjords of Southeast-Greenland are among the most remote areas of the Northern Hemisphere. Access to this area is hampered by a broad belt of sea ice floating along the East-Greenland coast from North to South. Consequently, the majority of those fjords have never been surveyed in detail until now. During an expedition by the Center of GeoGenetics of the University of Copenhagen in summer of 2014 we were able to map the Skjoldungen Fjord system with multibeam bathymetry. The topsail schooner ACTIV, built 1951 as a cargo ship to supply remote settlements in Greenland was chosen for the expedition. Though a vintage vessel, the ACTIV was well suited to cross the belt of sea ice and to cruise the ice covered fjords. A portable ELAC-Seabeam 1050 multibeam system was temporarily installed on the vessel. The two transducer of the system were mounted at the lower end of a 6 m long pole attached outboard at port side to the hull of the vessel. Though the installation was quite demanding without any winches or cranes, the construction was sufficiently stable and easy to manage throughout the entire cruise. Nearly the entire fjord system, leaving only a small gap of 5 km at the innermost part and small stripes close to the shorelines could be surveyed during the cruise. For the first time, a comprehensive map of Skjoldungen Fjord is now available. The map displays water depths from close to zero up to 800 m, the deepest part along a stretch of about 10 km in the Southwest. The bathymetry of the northern fjord is remarkably different from the southern fjord: the southern fjord features an outer deep part showing water depths between 500 m and 800 m and a shallow inner part with depths less than 300 m and a prominent sill in between. The northern fjord shows a more gradual increase of water depths from 200 m in the inner part to 600 m at the entrance.

  19. Rethinking bilingualism : a sociolinguistic analysis of language planning and education legislation in Greenland

    OpenAIRE

    Pedersen, Ivalu Søvndahl

    2009-01-01

    Many indigenous peoples’ languages in the world are endangered. But the special case in Greenland is the fact that Greenlandic is not an endangered language, even though less than 56,000 people speak Greenlandic. In fact, Greenlandic is spreading in Greenlandic society. The challenge in Greenland is rather how to educate Greenlanders to become functionally bilingual in Greenlandic and Danish, considering the vast varieties of bilingual skills that exist. Greenland has been a Danish colon...

  20. Lead sources in human diet in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert;

    2004-01-01

    Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eid...

  1. Improving the Greenlandic Greenhouse Gas Inventory

    DEFF Research Database (Denmark)

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

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

  2. Impact of public health research in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Curtis, Tine

    2004-01-01

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

  3. Environmental radioactivity in Greenland in 1978

    International Nuclear Information System (INIS)

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

  4. Balance velocities of the Greenland ice sheet

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  5. The Greenlandic Economy – Structure and Prospects

    DEFF Research Database (Denmark)

    Andersen, Torben M.

    Greenland is a vast country with a small and geographically dispersed population. These conditioning factors pose a particular challenge for a natural resource-based economy. Greenland is thus in many respects unique and yet has to find a way to ensure a self-sustaining economy. This requires an ...

  6. Belt-up!

    Energy Technology Data Exchange (ETDEWEB)

    Woof, M.

    1999-07-01

    Advanced control systems, improved materials and new dust control systems have turned the humble conveyor belt into a sophisticated method for transporting materials. RJB Mining has improved productivity at the Price of Wales colliery in Yorkshire, UK, with the installation of Alstom`s VDM drive system; Qualter Hall`s upgraded conveyor system at the Rugely Power Station in the UK is proving its ability to minimise coal spillage. The article highlights advances by several manufacturers in conveyor technology. 5 photos.

  7. Studying health in Greenland: Obligations and challenges

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Mulvad, Gert; Olsen, Jørn

    2003-01-01

    Health research in Greenland has contributed with several findings of interest for the global scientific community and has documented health problems and risk factors of importance for planning the local health care system. The study of how health develops in small, scattered communities during...... to that of the industrialized world, while still including local outbreaks of tuberculosis. Health research in Greenland is logistically difficult and costly, but offers opportunities not found elsewhere in the world. A long tradition of registration enhances the possibilities for research. A number of research institutions...... in Denmark and Greenland have conducted health research in Greenland for many years in cooperation with, among others, researchers in Canada and Alaska. National and international cooperation is supported by the Danish/Greenlandic Society for Circumpolar Health, the International Union for Circumpolar Health...

  8. Active predation by Greenland shark Somniosus microcephalus

    DEFF Research Database (Denmark)

    Nielsen, Julius; hedeholm, Rasmus; Simon, Malene;

    2013-01-01

    Dansk Havforskermøde 2013 Julius Nielsen, Rasmus Hedeholm, Malene Simon og John Fleng Steffensen The Greenland shark is ubiquitous in the northern part of the North Atlantic ranging from eastern Canada to northwest Russia . Although knowledge is scarce it is believed to be abundant and potentially...... important part of the ecosystem. Whether Greenland sharks in general should be considered opportunistic scavengers or active predators is therefore important in understanding ecosystem dynamics. Due to its sluggish appearance and a maximum reported swimming speed of 74 cm per second scavenging seems...... the most likely feeding strategy. However, recent studies suggest that Greenland sharks in some areas feed actively upon seals . Feeding ecology is poorly described in Greenland waters. In this study we provide information on feeding habits of 29 sharks caught in Greenland waters in the summer 2012...

  9. Greenland mass balance from GRACE

    OpenAIRE

    Velicogna, I.; Wahr, J.

    2005-01-01

    We use 22 monthly GRACE (Gravity Recovery and Climate Experiment) gravity fields to estimate the linear trend in Greenland ice mass during 2002-2004. We recover a decrease in total ice mass of 82 ± 28 km3 of ice per year, consistent with estimates from other techniques. Our uncertainty estimate is dominated by the effects of GRACE measurement errors and errors in our post glacial rebound (PG) correction. The main advantages of GRACE are that it is sensitive to the entire ice sheet, and that i...

  10. The Greenland Ice Mapping Project

    Science.gov (United States)

    Joughin, I.; Smith, B.; Howat, I. M.; Moon, T. A.; Scambos, T. A.

    2015-12-01

    Numerous glaciers in Greenland have sped up rapidly and unpredictably during the first part of the 21st Century. We started the Greenland Ice Mapping Project (GIMP) to produce time series of ice velocity for Greenland's major outlet glaciers. We are also producing image time series to document the advance and retreat of glacier calving fronts and other changes in ice-sheet geometry (e.g., shrinking ice caps and ice shelves). When the project began, there was no digital elevation model (DEM) with sufficient accuracy and resolution to terrain-correct the SAR-derived products. Thus, we also produced the 30-m GIMP DEM, which, aside from improving our processing, is an important product in its own right. Although GIMP focuses on time series, complete spatial coverage for initializing ice sheet models also is important. There are insufficient data, however, to map the full ice sheet in any year. There is good RADARSAT coverage for many years in the north, but the C-band data decorrelate too quickly to measure velocity in the high accumulation regions of the southeast. For such regions, ALOS data usually correlate well, but speckle-tracking estimates at L-band are subject to large ionospheric artifacts. Interferometric phase data are far less sensitive to the effect of the ionosphere, but velocity estimates require results from crossing orbits. Thus, to produce a nearly complete mosaic we used data from multiple sensors, beginning with ERS-1/2 data from the mid 1990s. By using a primarily phase-only solution for much of the interior, we have reduced the velocity errors to ~1-3 m/yr. For the faster moving ice-sheet margin where phase data cannot be unwrapped, we used speckle-tracking data. In particular, we have relied on TerraSAR-X for many fast-moving glaciers because the ionosphere far less affects X-band data. This pan-Greenland velocity map as well as many of the time series would not have been possible without an extensive archive of data collected using six

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

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

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

    International Nuclear Information System (INIS)

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

  13. Lap belt injuries in children.

    LENUS (Irish Health Repository)

    McGrath, N

    2010-07-01

    The use of adult seat belts without booster seats in young children may lead to severe abdominal, lumbar or cervical spine and head and neck injuries. We describe four characteristic cases of lap belt injuries presenting to a tertiary children\\'s hospital over the past year in addition to a review of the current literature. These four cases of spinal cord injury, resulting in significant long-term morbidity in the two survivors and death in one child, arose as a result of lap belt injury. These complex injuries are caused by rapid deceleration characteristic of high impact crashes, resulting in sudden flexion of the upper body around the fixed lap belt, and consequent compression of the abdominal viscera between the lap belt and spine. This report highlights the dangers of using lap belts only without shoulder straps. Age-appropriate child restraint in cars will prevent these injuries.

  14. Belt conveyor for recycle aggregate

    OpenAIRE

    Bezrodný, Roman

    2014-01-01

    This bachelor thesis deals with the belt conveyor for the transport of recycled aggregate in an oblique direction. The aim is to find constructional solutions to the belt conveyor for the assigned transport capacity of 95 000 kg per hour, and the assigned axial distance of 49 m and different height of 12 m. The thesis contains a brief description of the belt conveyor and a description of basic constructional components. It also contains a functional calculation of the capacity and forces acco...

  15. SLH Timing Belt Powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abe

    2014-04-09

    The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon- fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning

  16. Global Warming and the Greenland Ice Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Chylek, P. [Space and Remote Sensing Sciences, Los Alamos National Laboratory, Mail Stop D436, Los Alamos, NM 87545, and Department of Physics, New Mexico State University, Las Cruces, NM (United States); Box, J.E. [Byrd Polar Research Center, Ohio State University, Columbus, OH 43210 (United States); Lesins, G. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS (Canada)

    2004-07-01

    The Greenland coastal temperatures have followed the early 20th century global warming trend. Since 1940, however, the Greenland coastal stations data have undergone predominantly a cooling trend. At the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2C per decade since the beginning of the measurements in 1987. This suggests that the Greenland ice sheet and coastal regions are not following the current global warming trend. A considerable and rapid warming over all of coastal Greenland occurred in the 1920s when the average annual surface air temperature rose between 2 and 4C in less than ten years (at some stations the increase in winter temperature was as high as 6C). This rapid warming, at a time when the change in anthropogenic production of greenhouse gases was well below the current level, suggests a high natural variability in the regional climate. High anti correlations (r = -0.84 to -0.93) between the NAO (North Atlantic Oscillation) index and Greenland temperature time series suggest a physical connection between these processes. Therefore, the future changes in the NAO and Northern Annular Mode may be of critical consequence to the future temperature forcing of the Greenland ice sheet melt rates.

  17. Holocene temperature shifts around Greenland: Paleolimnological approaches to quantifying past warmth and documenting its consequences

    Science.gov (United States)

    Axford, Y.; Lasher, G. E.; McFarlin, J. M.; Francis, D. R.; Kelly, M. A.; Langdon, P. G.; Levy, L.; Osburn, M. R.; Osterberg, E. C.

    2015-12-01

    Insolation-driven warmth across the Arctic during the early to middle Holocene (the Holocene Thermal Maximum, or HTM) represents a geologically accessible analog for future warming and its impacts. Improved constraints on the magnitude and seasonality of HTM warmth around Greenland's margins can advance the use of paleoclimate data to test and improve climate and ice sheet models. Here we present an overview of our recent efforts to reconstruct climate through the Holocene around the margins of the Greenland Ice Sheet using multiple proxies in lake sediments. We use insect (chironomid) assemblages to derive quantitative estimates of Holocene temperatures at sites with minimal soil and vegetation development near the eastern, northwestern and western margins of the ice sheet. Our chironomid-based temperature reconstructions consistently imply HTM July air temperatures 3 to 4.5 °C warmer than the pre-industrial late Holocene in these sectors of Greenland. The timing of reconstructed peak warmth differs between sites, with onset varying from ~10 ka to ~6.5 ka, but in good agreement with glacial geology and other evidence from each region. Our reconstructed temperature anomalies are larger than those typically inferred from annually-integrated indicators from the ice sheet itself, but comparable to the few other quantitative summer temperature estimates available from beyond the ice sheet on Greenland. Additional records are needed to confirm the magnitude of HTM warmth and to better define its seasonality and spatial pattern. To provide independent constraints on paleotemperatures and to elucidate additional aspects of Holocene paleoclimate, we are also employing oxygen isotopes of chironomid remains and other aquatic organic materials, and molecular organic proxies, in parallel (see Lasher et al. and McFarlin et al., this meeting). Combined with glacial geologic evidence, these multi-proxy records elucidate diverse aspects of HTM climate around Greenland - including

  18. Environmental radioactivity in Greenland in 1981

    International Nuclear Information System (INIS)

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

  19. Homicide in Greenland 1985-2010

    DEFF Research Database (Denmark)

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

    2016-01-01

    PURPOSE: Homicide in Greenland has not often been investigated. The latest published study documented a dramatic rise in the homicide rate from around 1/100,000 inhabitants to more than 23/100,000 inhabitants from 1946 to 1984. The aim of our study was to characterize homicides in Greenland from...... dominated homicide methods (41 and 29 % respectively), with sharp force deaths increasing throughout the investigation period. Altercations were the main motive (49 %). Alcohol-related homicides decreased in our study period. CONCLUSIONS: While the Greenlandic homicide rate has decreased, it is markedly...

  20. Inuit dietary patterns in modern Greenland

    OpenAIRE

    Bjerregaard, Peter; Jeppesen, Charlotte

    2012-01-01

    Objectives. The purpose of the study was to apply two different approaches of dietary pattern definition to data from Greenland and to analyse the contemporary dietary patterns of the Inuit in Greenland in relation to urbanization and socio-economic positions. Study design. Cross-sectional population survey. Methods. A total of 2,247 Inuit aged 18+ from 15 towns and villages in West Greenland (25% of all communities) were interviewed about their diet as part of a general health survey. A 67-i...

  1. Chronic suppurative otitis media in a birth cohort of children in Greenland

    DEFF Research Database (Denmark)

    Koch, Anders; Homøe, Preben; Pipper, Christian Bressen;

    2011-01-01

    Inuits of the Arctic experience very high rates of chronic suppurative otitis media (CSOM), yet world-wide, very little is known about the epidemiology of CSOM. The study aims were to determine incidence, median age at debut, risk factors, and associated population attributable risks for CSOM...... in young children in Sisimiut, the second biggest town of Greenland (population 5400), where living conditions are relatively western and approximately 90% are Inuits....

  2. Timing of the Little Ice Age in southern Greenland

    Science.gov (United States)

    Kjær, Kurt H.; Kjeldsen, Kristian K.; Bjørk, Anders A.; Khan, Shfaqat A.; Korsgaard, Niels J.; Funder, Svend; Larsen, Nicolaj K.; Vinther, Bo; Andresen, Camilla S.; Long, Antony J.; Woodroffe, Sarah A.; Steen Hansen, Eric; Olsen, Jesper

    2013-04-01

    Northern hemisphere temperatures reached their Holocene minimum and most glaciers reached their maximum during The Little Ice Age (LIA), but the timing of specific cold intervals is site-specific. In southern Greenland, we have compiled data from organic matter incorporated in LIA sediments, used as a signal for ice-free terrain being overridden by LIA glacier advances, and data from threshold lakes showing the onset of glacier-fed lakes, thus revealing the advance-maximum phase initiating the LIA. Finally, we have compiled lichenometry results indicating the onset of bedrock vegetation succeeding ice retreat. Our results show that the advance of glaciers during the LIA occurs early after the Medieval Warm Period terminating soon after 1200 AD and culminates c. 1500-1600 AD. Historical maps also show that many glaciers on the western coast occupy a still-stand near the LIA maximum until 1900 AD before retreat commence. Thus in southern Greenland, we define LIA as the period between the first signs of Late Holocene glacier readvance and the latest onset of retreat - i.e. from ca. 1200 to c. 1900. During this period northern hemisphere annual mean temperatures, although fluctuating, were generally below the 1961-1990 average, with the coldest interval between c. 1600 and 1800. Even though winter temperatures may have dominated the cooling, also the summer temperatures which are most closely correlated with glacier mass balances, dropped, to c. 0.6° below the average in the northern hemisphere including the Arctic. Furthermore, the glacier response seems to be mirrored by a oceanic cooling between 500-1000 AD, followed by onset of the LIA at 1150-1250 AD as seen in the relative strength of warm subsurface water and the influence of the East Greenland Current.

  3. Outburst flood evolution at Russell Glacier, western Greenland

    DEFF Research Database (Denmark)

    Carrivick, Jonathan; Russell, Andrew; Ingeman-Nielsen, Thomas;

    2013-01-01

    of the evolution of a bedrockchannelled outburst flood. Channel topography was obtained from digitised aerial photographs, a 5m grid resolution DEM and bathymetric surveys. Flood inundation was measured in the field from dGPS measurements. Flood evolution was analysed with application of a numerical model. Novel...

  4. Outburst flood evolution at Russell Glacier, western Greenland

    DEFF Research Database (Denmark)

    Carrivick, Jonathan L.; Turner, Andy G.D.; Russell, Andrew J.;

    2013-01-01

    quantification of the evolution of a bedrock-channelled outburst flood. Channel topography was obtained from digitised aerial photographs, a 5 m grid resolution DEM and bathymetric surveys. Flood inundation was measured in the field from dGPS measurements. Flood evolution was analysed with application...

  5. Geography of the asteroid belt

    Science.gov (United States)

    Zellner, B. H.

    1978-01-01

    The CSM classification serves as the starting point on the geography of the asteroid belt. Raw data on asteroid types are corrected for observational biases (against dark objects, for instance) to derive the distribution of types throughout the belt. Recent work on family members indicates that dynamical families have a true physical relationship, presumably indicating common origin in the breakup of a parent asteroid.

  6. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

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

  7. Physical activity in Greenland - a methodological perspective

    DEFF Research Database (Denmark)

    Dahl-Petersen, Inger

    Title: Physical activity in Greenland - a methodical perspective Inger Dahl-Petersen, National Institute of Public Health, Copenhagen, Denmark Purpose:   The present study is the first population-based study in Greenland with information on physical activity using The International Physical...... expenditure used on physical activity. However the total energy expenditure in Greenland estimated by IPAQ is surprisingly high, in particular for respondents living in villages, indicating some methodological challenges when applying IPAQ in a non-European setting. Validation of IPAQ by an objective measure...... Participants in a cross-sectional population survey representative of towns and villages in West Greenland completed an interviewer-administered questionnaire about their physical activity. The long version of The International Physical Activity Questionnaire (IPAQ) was used to measure time spent on physical...

  8. Trends of cervical cancer in Greenland

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  9. Alcohol in Greenland 1951-2010

    DEFF Research Database (Denmark)

    Aage, Hans

    2012-01-01

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

  10. Developing renewable energy in discontiguous Greenland

    DEFF Research Database (Denmark)

    Carruth, Susan

    2016-01-01

    Infrastructural Urbanism’s advocacy of creating synergies between technological, economical, and ecological processes holds great potential for guiding domestic energy planning in a transforming Greenland. However, the movement has largely been conceived in the context of regional paradigms very...

  11. Hepatitis B prevalence and incidence in Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

    Greenland remains a highly endemic area for hepatitis B virus (HBV) infection. This is in sharp contrast to other modern societies, such as Denmark. To address this discrepancy, we investigated the natural history of HBV infection in Greenland by estimating the age-specific incidence of HBV...... infection, the proportion of chronic carriers, and the rates of hepatitis B surface antigen seroclearance. In total, 8,879 Greenlanders (16% of the population) from population-based surveys conducted in 1987 and 1998 were followed through March 2010. Data on HBV status were supplemented by HBV test results...... from all available HBV registries in Greenland to determine changes in HBV status over time. Incidence rates of HBV infection and hepatitis B surface antigen seroclearance were estimated after taking into account interval censoring. The incidence of HBV infection in 5-14-year-old subjects was less than...

  12. IceBridge BedMachine Greenland

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains bed topography beneath the Greenland Ice Sheet based on mass conservation derived from airborne radar tracks and satellite radar. The data...

  13. Land Ice: Greenland & Antarctic ice mass anomaly

    Data.gov (United States)

    National Aeronautics and Space Administration — Data from NASA's Grace satellites show that the land ice sheets in both Antarctica and Greenland are losing mass. The continent of Antarctica (left chart) has been...

  14. Environmental radioactivity in Greenland in 1979

    International Nuclear Information System (INIS)

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

  15. Shrub expansion in SW Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Rasmus Halfdan

    Arctic regions have experienced higher temperatures in recent decades, and the warming trend is projected to continue in the coming years. Arctic ecosystems are considered to be particularly vulnerable to climate change. Expansion of shrubs has been observed widely in tundra areas across the Arctic......, and has a range of ecosystem effects where it occurs. Shrub expansion has to a large extend been attributed to increasing temperatures over the past century, while grazing and human disturbance have received less attention. Alnus viridis ssp. crispa is a common arctic species that contributes...... information on changes in shrub cover, and a long and complex land use history has to be taken into account. In this thesis a combination of descriptive and experimental approaches are used to investigate: I. Whether landscape scale shrub expansion occurred in SW Greenland, and to what extend it is influenced...

  16. The north-east Baffin Bay region, offshore Greenland - a new frontier petroleum exploration region

    Energy Technology Data Exchange (ETDEWEB)

    Gregersen, U. (Geological Survey of Denmark and Greenland, Copenhagen (Denmark))

    2008-07-15

    In recent years the Arctic has come into focus for hydrocarbon exploration, and areas offshore both West and East Greenland have been evaluated as promising frontier hydrocarbon provinces. Seven hydrocarbon exploration and exploitation licenses were awarded in 2007-2008 offshore the Disko-Nuussuaq region, and two more have been awarded in the open-door region offshore south-western Greenland. In 2007, an extensive amount of new seismic and aero-magnetic data was acquired by the TGS-NOPEC Geophysical Company in the north-eastern Baffin Bay region. Geophysical mapping has been initiated by the Geological Survey of Denmark and Greenland (GEUS) in the Melville Bugt region offshore North-West Greenland with the purpose of evaluating the hydrocarbon prospectivity. Initial interpretation of seismic and gravity data suggests the presence of deep sedimentary basins separated by structural highs. Geological information on source rock, reservoir rock and seal intervals from surrounding regions suggest that the Melville Bugt region is likely to have a significant petroleum potential. The study is based on public domain magnetic and gravity data, and all proprietary and public 2-D seismic data acquired before 2003. Seismic horizons from the 'seismic basement' to 'base Quaternary' are being interpreted regionally. Based on the seismic interpretation, a structural element map, depth-structure maps and isopach maps will be produced in order to assess the prospectivity of the Melville Bugt region. (au)

  17. Airborne ICESat-2 simulator (MABEL) results from Greenland

    Science.gov (United States)

    Neumann, T.; Markus, T.; Brunt, K. M.; Walsh, K.; Hancock, D.; Cook, W. B.; Brenner, A. C.; Csatho, B. M.; De Marco, E.

    2012-12-01

    The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is a next-generation laser altimeter designed to continue key observations of sea ice freeboard, ice sheet elevation change, vegetation canopy height, earth surface elevation and sea surface heights. Scheduled for launch in mid-2016, ICESat-2 will collect data between 88 degrees north and south using a high-repetition rate (10 kHz) laser operating at 532nm, and using a photon-counting detection strategy. Our airborne simulator, the Multiple Altimeter Beam Experimental Lidar (MABEL) uses a similar photon-counting measurement strategy, operates at 532nm (16 beams) and 1064 nm (8 beams) to collect similar data to what we expect for ICESat-2. The comparison between frequencies allows for studies of possible penetration of green light into water or snow. MABEL collects more spatially-dense data than ICESat-2 (2cm along-track vs. 70 cm along track for ICESat-2, and has a smaller footprint than ICESat-2 (2m nominal diameter vs. 10m nominal diameter for ICESat-2) requiring geometric and radiometric scaling to relate MABEL data to simulate ICESat-2 data. We based MABEL out of Keflavik, Iceland during April 2012, and collected ~ 100 hours of data from 20km altitude over a variety of targets. MABEL collected sea ice data over the Nares Strait, and off the east coast of Greenland, the later flight in coordination with NASA's Operation IceBridge, which collected ATM data along the same track within 90 minutes of MABEL data collection. MABEL flew a variety of lines over Greenland in the southwest, Jakobshavn region, and over the ice sheet interior, including 4 hours of coincident data with Operation IceBridge in southwest Greenland. MABEL flew a number of calibration sites, including corner cubes in Svalbard, Summit Station (where a GPS survey of the surface elevation was collected within an hour of our overflight), and well-surveyed targets in Iceland and western Greenland. In this presentation, we present an overview of

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  19. Traditional and modern Greenlandic food - Dietary composition, nutrients and contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Deutch, Bente [Centre for Arctic Environmental Medicine, Aarhus University, Building 260, Vennelyst Boulevard 6, DK-8000, Aarhus (Denmark)], E-mail: bd@mil.au.dk; Dyerberg, Jorn [Capio Diagnostic, a.s., Nygaardsvej 32, DK-2100, Copenhagen O (Denmark); Pedersen, Henning Sloth [Centre for Arctic Environmental Medicine, Aarhus University, Building 260, Vennelyst Boulevard 6, DK-8000, Aarhus (Denmark); Centre of Primary Health Care, Box 1001, DK-3900 Nuuk, Greenland (Denmark); Aschlund, Ejner; Hansen, Jens C. [Centre for Arctic Environmental Medicine, Aarhus University, Building 260, Vennelyst Boulevard 6, DK-8000, Aarhus (Denmark)

    2007-10-01

    Objectives: High levels of n-3 fatty acids and other nutrients in traditional Inuit food appear to provide some protection against the typical diseases of affluent industrialized societies: cardiovascular diseases and type 2 diabetes. An increased intake of imported food among Inuits will probably increase their frequency of these diseases. However, since the 1970s it has become evident that the marine-based Inuit diet also contains high levels of potentially toxic lipophilic organic pollutants and heavy metals. Since these two food related opposing health effects appear to be inseparable, the phenomenon has been known as 'The Arctic Dilemma'. However, both the fatty acid composition and the contaminant levels vary in Greenlandic food items. Thus in principle it is possible to compose a diet where the benefits and risks are better balanced. Our objectives of this study were to compare traditional and modern meals in Greenland concerning the dietary composition, nutrients, and health indicators among the consumers. Study design: The present study was a cross-sectional dietary survey as part of the Arctic Monitoring and Assessment, Human Health Programme (AMAP). These results were compared with older dietary surveys in Greenland. Methods: Dietary components, fatty acids, and nutrients in 90 local meals collected by duplicate portion method in Uummannaq town, north Greenland 2004 and in Narsaq, south Greenland 2006, were compared with 177 duplicate meals sampled in the village of Igdslorsuit, Uummannaq, district, 1976 and also compared with other dietary studies in Greenland 1953-1987. Anthropometric measures (weight, height, and body mass index, BMI) and blood lipids were measured as health indicators among the participants. Results: Between the traditional foods sampled or analysed 30-50 years ago and the modern food from 2004 to 2006, significant differences were found in the dietary composition. The percentage of local food had decreased, to a present

  20. Traditional and modern Greenlandic food - Dietary composition, nutrients and contaminants

    International Nuclear Information System (INIS)

    Objectives: High levels of n-3 fatty acids and other nutrients in traditional Inuit food appear to provide some protection against the typical diseases of affluent industrialized societies: cardiovascular diseases and type 2 diabetes. An increased intake of imported food among Inuits will probably increase their frequency of these diseases. However, since the 1970s it has become evident that the marine-based Inuit diet also contains high levels of potentially toxic lipophilic organic pollutants and heavy metals. Since these two food related opposing health effects appear to be inseparable, the phenomenon has been known as 'The Arctic Dilemma'. However, both the fatty acid composition and the contaminant levels vary in Greenlandic food items. Thus in principle it is possible to compose a diet where the benefits and risks are better balanced. Our objectives of this study were to compare traditional and modern meals in Greenland concerning the dietary composition, nutrients, and health indicators among the consumers. Study design: The present study was a cross-sectional dietary survey as part of the Arctic Monitoring and Assessment, Human Health Programme (AMAP). These results were compared with older dietary surveys in Greenland. Methods: Dietary components, fatty acids, and nutrients in 90 local meals collected by duplicate portion method in Uummannaq town, north Greenland 2004 and in Narsaq, south Greenland 2006, were compared with 177 duplicate meals sampled in the village of Igdslorsuit, Uummannaq, district, 1976 and also compared with other dietary studies in Greenland 1953-1987. Anthropometric measures (weight, height, and body mass index, BMI) and blood lipids were measured as health indicators among the participants. Results: Between the traditional foods sampled or analysed 30-50 years ago and the modern food from 2004 to 2006, significant differences were found in the dietary composition. The percentage of local food had decreased, to a present average of

  1. Surface and sub-surface multi-proxy reconstruction of middle to late Holocene palaeoceanographic changes in Disko Bugt, West Greenland

    Science.gov (United States)

    Moros, Matthias; Lloyd, Jeremy M.; Perner, Kerstin; Krawczyk, Diana; Blanz, Thomas; de Vernal, Anne; Ouellet-Bernier, Marie-Michele; Kuijpers, Antoon; Jennings, Anne E.; Witkowski, Andrzej; Schneider, Ralph; Jansen, Eystein

    2016-01-01

    We present new surface water proxy records of meltwater production (alkenone derived), relative sea surface temperature (diatom, alkenones) and sea ice (diatoms) changes from the Disko Bugt area off central West Greenland. We combine these new surface water reconstructions with published proxy records (benthic foraminifera - bottom water proxy; dinocyst assemblages - surface water proxy), along with atmospheric temperature from Greenland ice core and Greenland lake records. This multi-proxy approach allows us to reconstruct centennial scale middle to late Holocene palaeoenvironmental evolution of Disko Bugt and the Western Greenland coastal region with more detail than previously available. Combining surface and bottom water proxies identifies the coupling between ocean circulation (West Greenland Current conditions), the atmosphere and the Greenland Ice Sheet. Centennial to millennial scale changes in the wider North Atlantic region were accompanied by variations in the West Greenland Current (WGC). During periods of relatively warm WGC, increased surface air temperature over western Greenland led to ice sheet retreat and significant meltwater flux. In contrast, during periods of cold WGC, atmospheric cooling resulted in glacier advances. We also identify potential linkages between the palaeoceanography of the Disko Bugt region and key changes in the history of human occupation. Cooler oceanographic conditions at 3.5 ka BP support the view that the Saqqaq culture left Disko Bugt due to deteriorating climatic conditions. The cause of the disappearance of the Dorset culture is unclear, but the new data presented here indicate that it may be linked to a significant increase in meltwater flux, which caused cold and unstable coastal conditions at ca. 2 ka BP. The subsequent settlement of the Norse occurred at the same time as climatic amelioration during the Medieval Climate Anomaly and their disappearance may be related to harsher conditions at the beginning of the

  2. Timing of the Little Ice Age in southern Greenland

    DEFF Research Database (Denmark)

    Kjær, Kurt H.; Kjeldsen, Kristian Kjellerup; Bjørk, Anders Anker;

    Northern hemisphere temperatures reached their Holocene minimum and most glaciers reached their maximum during The Little Ice Age (LIA), but the timing of specific cold intervals is site-specific. In southern Greenland, we have compiled data from organic matter incorporated in LIA sediments, used...... as a signal for ice-free terrain being overridden by LIA glacier advances, and data from threshold lakes showing the onset of glacier-fed lakes, thus revealing the advance-maximum phase initiating the LIA. Finally, we have compiled lichenometry results indicating the onset of bedrock vegetation...... succeeding ice retreat. Our results show that the advance of glaciers during the LIA occurs early after the Medieval Warm Period terminating soon after 1200 AD and culminates c. 1500-1600 AD. Historical maps also show that many glaciers on the western coast occupy a still-stand near the LIA maximum until...

  3. Geophysical Investigations of Saline Permafrost at Ilulissat, Greenland

    DEFF Research Database (Denmark)

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

    2008-01-01

    The technical properties and general state of permafrost in Greenland is not well documented. A new coordinated investigation has been initiated, for ground temperature measurements and permafrost mapping in Greenlandic towns in sporadic, discontinuous and continuous permafrost zones. We present ...

  4. Nivation forms and processes in unconsolidated sediments, NE Greenland

    DEFF Research Database (Denmark)

    Christiansen, Hanne Hvidtfeldt

    1998-01-01

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

  5. Physical activity patterns in Greenland: A country in transition

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  6. Modern solar maximum forced late twentieth century Greenland cooling

    OpenAIRE

    T. Kobashi; Box, J. E.; Vinther, B. M.; K. Goto-Azuma; T. Blunier; J. W. C. White; Nakaegawa, T.; Andresen, C. S.

    2015-01-01

    The abrupt Northern Hemispheric warming at the end of the twentieth century has been attributed to an enhanced greenhouse effect. Yet Greenland and surrounding subpolar North Atlantic remained anomalously cold in 1970s to early 1990s. Here we reconstructed robust Greenland temperature records (North Greenland Ice Core Project and Greenland Ice Sheet Project 2) over the past 2100 years using argon and nitrogen isotopes in air trapped within ice cores and show that this cold anomaly was part of...

  7. Chaos on the conveyor belt

    CERN Document Server

    Sándor, Bulcsú; Tél, Tamás; Néda, Zoltán

    2013-01-01

    The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by spring to an external static point, and due to the dragging effect of the belt the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can only be achieved by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a function of the velocity of the conveyor belt and the noise strength, the system exhibits complex, self-organized critical, sometimes chaotic dynamics and phase transition-like behavior. Noise induced chaos and intermittency is also observed. Simulations suggest that the maximum complexity of the dynamical states is achieved for a relatively small number of blocks, around five.

  8. 21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Greenland turbot (Reinhardtius hippoglossoides... for Specific Nonstandardized Foods § 102.57 Greenland turbot (Reinhardtius hippoglossoides). “Greenland turbot” is the common or usual name of the food fish Reinhardtius hippoglossoides, a species...

  9. Reuse of harbour sediments in the Greenlandic construction industry

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Stig Andersen

    2013-08-01

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

  11. Avoidable deaths in Greenland 1968-1985

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Juel, K

    1990-01-01

    The concept of avoidable deaths suggests that certain deaths ought not occur in a given society because it is possible to prevent or treat the disease or condition. A list of avoidable deaths is time and community specific as it reflects the socioeconomic conditions, professional medical capacity...... and alcohol related diseases were high in the capital and East Greenland and low in West Greenlandic settlements. It is concluded that further studies on preventable diseases and causes of death, in particular certain infectious diseases, accidents and suicides, are needed....... and political will of the society. A list of avoidable deaths is proposed for Greenland which includes, inter alia, meningitis, lung cancer, acute respiratory infections, suicides, boat accidents and alcohol related diseases and accidents. All were considerably more common in Greenland than in Denmark...... and several showed an increasing time trend. The regional patterns were particularly clear for infectious diseases and accidents, which showed low mortality rates in the capital and other towns and high mortality rates in settlements and in the remote East Greenland, while mortality rates from suicides...

  12. Polar continental margins: Studies off East Greenland

    Science.gov (United States)

    Mienert, J.; Thiede, J.; Kenyon, N. H.; Hollender, F.-J.

    The passive continental margin off east Greenland has been shaped by tectonic and sedimentary processes, and typical physiographic patterns have evolved over the past few million years under the influence of the late Cenozoic Northern Hemisphere glaciations. The Greenland ice shield has been particularly affected.GLORIA (Geological Long Range Inclined Asdic), the Institute of Oceanographic Sciences' (IOS) long-range, side-scan sonar, was used on a 1992 RV Livonia cruise to map large-scale changes in sedimentary patterns along the east Greenland continental margin. The overall objective of this research program was to determine the variety of large-scale seafloor processes to improve our understanding of the interaction between ice sheets, current regimes, and sedimentary processes. In cooperation with IOS and the RV Livonia, a high-quality set of seafloor data has been produced. GLORIA'S first survey of east Greenland's continental margin covered several 1000- × 50-km-wide swaths (Figure 1) and yielded an impressive sidescan sonar image of the complete Greenland Basin and margin (about 250,000 km2). A mosaic of the data was made at a scale of 1:375,000. The base map was prepared with a polar stereographic projection having a standard parallel of 71°.

  13. Destabilization of the Northeast Greenland Ice Stream

    Science.gov (United States)

    Korsgaard, N. J.; Khan, S. A.; Kjaer, K.; Bevis, M. G.; Bamber, J. L.; Kjeldsen, K. K.; Bjork, A. A.; Wahr, J. M.; Stearns, L. A.; van den Broeke, M. R.; Muresan, I. S.; Larsen, N. K.

    2013-12-01

    The Greenland Ice Sheet (GrIS) has been one of the largest contributors to global sea level rise over the last 20 years, accounting for c. 0.5 of a total of c. 3.2 mm yr-1. A significant portion of this contribution is associated with the speed up of glaciers in southeast and northwest Greenland. Here, we reveal that the Northeast Greenland Ice Stream (NEGIS), which extends more than 600 km into the interior of the ice sheet, is now undergoing dynamic thinning after more than a quarter of a century of stability. This sector of the GrIS is of particular interest in sea level projections, because the glacier flows into a large submarine basin with a negative bed slope near the grounding line. Our findings unfold the next step in mass loss of the GrIS as we show a heightened risk of rapid sustained loss from Northeast Greenland on top of the thinning in Southeast and Northwestern Greenland.

  14. Clouds enhance Greenland ice sheet meltwater runoff.

    Science.gov (United States)

    Van Tricht, K; Lhermitte, S; Lenaerts, J T M; Gorodetskaya, I V; L'Ecuyer, T S; Noël, B; van den Broeke, M R; Turner, D D; van Lipzig, N P M

    2016-01-12

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m(-2). Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  15. Optimization of Industrial Structure of Western Economic Uplift Belt in Shandong Based on SSM Method%基于动态 SSM 空间模型的山东西部经济隆起带产业结构优化研究

    Institute of Scientific and Technical Information of China (English)

    张芬芬; 孙希华

    2015-01-01

    为促进山东西部经济隆起带成为省经济发展的增长极,在经济文化强省建设中发挥更大作用,本文在分析西部经济隆起带三次产业结构演变特征的基础上,以山东省的平均发展水平为标准,利用偏离—份额分析法(SSM)分析了该区域2005~2013年在产业结构方面的状况.结果表明,西部经济隆起带各产业发展不均衡,第一产业空间结构偏离分量平均为-102.40亿元,第二产业空间结构偏离分量平均为-101.87亿元,第三产业空间结构偏离分量平均为193.56亿元,第三产业处于结构优势,研究期间西部经济隆起带第三产业对经济增长的贡献比较大,在此基础上提出了促进西部经济隆起带产业发展、产业结构优化以及提高产业发展潜力的政策性建议.%In order to promote the western economy belt of Shandong Province to become the economic growth polar which plays a greater role in the construction of economic and cultural strong province,this thesis analy-zes the status of the industrial structure from 2005 to 2013 based on the analysis of the three industrial struc-ture evolution characteristics by following the principles of average level of Shandong development. It turns out that the development of the western economy belt is unbalanced. The average deviation amounts of spatial structure of the primary industry and secondary industry are about -10. 24 billion,and -10. 187 billion,re-spectively,and the average deviation amount of tertiary industry is 19. 356 billion,which enjoys the structural advantage. In the process of the study,the contribution of the tertiary industry to economic growth is greater. This thesis puts forward some policy suggestions to promote the development of industries,optimization of in-dustrial structure and upgrade of the potential development of industries.

  16. Anomalous subglacial heat flow in central Greenland induced by the Iceland plume.

    Science.gov (United States)

    Petrunin, Alexey G.; Rogozhina, Irina; Kaban, Mikhail K.; Vaughan, Alan P. M.; Steinberger, Bernhard; Johnson, Jesse; Koulakov, Ivan; Thomas, Maik

    2013-04-01

    3000 m of ice sheet thickness has ensured that central Greenland has kept it geothermal heat flow (GHF) distribution enigmatic. Some few direct ice temperature measurements from deep ice cores reveal a GHF of 50 to 60 mW/m² in the Summit region and this is noticeably above what would be expected for the underlying Early Proterozoic lithosphere. In addition, indirect estimates from zones of rapid basal melting suggest extreme anomalies 15 to 30 times continental background. Subglacial topography indicates caldera like topographic features in the zones hinting at possible volcanic activity in the past [1], and all of these observations combined hint at an anomalous lithospheric structure. Further supporting this comes from new high-resolution P-wave tomography, which shows a strong thermal anomaly in the lithosphere crossing Greenland from east to west [2]. Rock outcrops at the eastern and western end of this zone indicate significant former magmatic activity, older in the east and younger in the west. Additionally, plate modelling studies suggest that the Greenland plate passed over the mantle plume that is currently under Iceland from late Cretaceous to Neogene times, consistent with the evidence from age of magmatism. Evidence of rapid basal melt revealed by ice penetrating radar along the hypocentre of the putative plume track indicates that it continues to affect the Greenland continental geotherm today. We analyse plume-induced thermal disturbance of the present-day lithosphere and their effects on the central Greenland ice sheet by using a novel evolutionary model of the climate-ice-lithosphere-upper mantle system. Our results indicate that mantle plume-induced erosion of the lithosphere has occurred, explaining caldera-type volcanic structures, the GHF anomaly, and requiring dyke intrusion into the crust during the early Cenozoic. The residual thermo-mechanical effect of the mantle plume has raised deep-sourced heat flow by over 25 mW/m² since 60 Ma and

  17. Paleo-Eskimo kitchen midden preservation in permafrost under future climate conditions at Qajaa, West Greenland

    DEFF Research Database (Denmark)

    Elberling, Bo; Matthiesen, Henning; Jørgensen, Christian Juncher;

    2011-01-01

    Remains from Paleo-Eskimo cultures are well-documented, but complete preservation is rare. Two kitchen middens in Greenland are known to hold extremely well-preserved organic artefacts. Here, we assess the fate of the Qajaa site in Western Greenland under future climate conditions based on site...... characteristics measured in situ and from permafrost cores. Measurements of thermal properties, heat generation, oxygen consumption and CO2 production show that the kitchen midden can be characterized as peat but produces 4–7 times more heat than natural sediment. An analytical model from permafrost research has...... been applied to assess future thawing of the midden. Results show that the preservation conditions are controlled by freezing temperatures and a high water/ice content limiting the subsurface oxygen availability. Threats to the future preservation are related to thawing followed by drainage...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior......Intense rainfall events significantly affect Alpine and Alaskan glaciers through enhanced melting, ice-flow acceleration and subglacial sediment erosion, yet their impact on the Greenland ice sheet has not been assessed. Here we present measurements of ice velocity, subglacial water pressure....... We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern...

  19. Remote Estimation of Greenland Ice Sheet Supraglacial River Discharge using GIS Modeling and WorldView-2 Satellite Imagery

    Science.gov (United States)

    Chu, V. W.; Smith, L. C.; Yang, K.; Gleason, C. J.; Rennermalm, A. K.; Pitcher, L. H.; Legleiter, C. J.; Forster, R. R.

    2014-12-01

    Increasing surface melting on the Greenland ice sheet and rising sea level have heightened the need for understanding the complex pathways transporting meltwater from the ice sheet surface to the ice edge and the ocean. Satellite images show supraglacial rivers abundantly covering the western ablation zone throughout the melt season, transporting large volumes of meltwater into moulins and to the ice edge, yet these rivers remain poorly studied. Here, a GIS modeling framework is developed to estimate supraglacial river discharge by spatially adapting Manning's equation for use with remotely sensed imagery and is applied to supraglacial rivers on the Greenland Ice Sheet. This framework incorporates high-resolution visible/near-infrared WorldView-2 (WV2) satellite imagery, the Greenland Ice Mapping Project (GIMP) DEM, and a field-calibrated WV2 river bathymetry retrieval algorithm and channel roughness parameter. Orthogonal cross-sections are simulated along river centerlines to extract cross-sectional discharge using Manning's equation for open channel flow. A total of 1,629,502 reach-averaged points were retrieved over 465 river networks of western Greenland in 2012, including attributes of width, depth, velocity, slope, wetted perimeter, hydraulic radius, and discharge. This work provides a method for producing spatially extensive, high-resolution estimates of supraglacial meltwater flux in river networks and into the ice sheet.

  20. The Migration Characteristics of Strong Earthquakes on the North-South Seismic Belt and Its Relation with the South Asia Seismic Belt

    Institute of Scientific and Technical Information of China (English)

    Wang Yipeng; Ma Jin; Li Chuanyou

    2008-01-01

    Migration of strong earthquakes (M≥7.0) along the North-South Seismic Belt of China since 1500 AD shows three patterns: Approximately equal time and distance interval migration from N to S, varied patterns of migration from S to N and grouped strong earthquake activity in a certain period over the entire seismic belt. Analysis of strong earthquakes in the past hundred years shows that the seismicity on the North-South Seismic Belt is also associated with strong earthquake activities on the South Asia Seismic Belt which extends from Myanmar to Sumatra, Indonesia. Strong earthquakes on the former belt often lag several months or years behind the quakes occurring on the later belt. So, after the occurrence of the December 26, 2004 M8.7 great earthquake off the western coast of Sumatra, Indonesia, the possibility of occurrence of strong earthquakes on the North-South Seismic Belt of China cannot be ignored. The above-mentioned migration characteristics of strong earthquakes are related to the northeastward collision and subduction of the India Plate as well as the interaction between the Qinghai-Xizang (Tibet) Plateau and the stable and hard Ordos and Alashan Massifs at its northeastern margin.

  1. Destabilization of the Northeast Greenland Ice Stream

    DEFF Research Database (Denmark)

    Korsgaard, N. J.; Khan, Shfaqat Abbas; Kjaer, K. H.;

    The Greenland Ice Sheet (GrIS) has been one of the largest contributors to global sea level rise over the last 20 years, accounting for c. 0.5 of a total of c. 3.2 mm yr-1. A significant portion of this contribution is associated with the speed up of glaciers in southeast and northwest Greenland....... Here, we reveal that the Northeast Greenland Ice Stream (NEGIS), which extends more than 600 km into the interior of the ice sheet, is now undergoing dynamic thinning after more than a quarter of a century of stability. This sector of the GrIS is of particular interest in sea level projections, because...

  2. Mineral exploitation and development in Greenland

    DEFF Research Database (Denmark)

    Hendriksen, Kåre; Hoffmann, Birgitte; Jørgensen, Ulrik

    2014-01-01

    for the Greenlandic society. This point to a need for plans and the organisation of mineral exploitations that operate based on coupling local settlements and resources with mining and other forms of activities. This demands new perspectives on the content of social impact assessments as well as new criteria......The key question of the paper is how to plan and organize mining projects in Greenland in ways that involve local workforce and develop business as well as settlement potentials. The paper outlines a concept of flexible settlements with the aim to build a socio-economic sustainable future...... extraction based on a workforce that is working temporarily at the mining sites poses a threat to employment in Greenland. At the same time, attracting mineral resource based industries is key to overcome the economic challenges. Mining companies envisage potentials for a fast extraction of the resources...

  3. Improvements in Spatiotemporal Ecosystem Monitoring in Greenland

    DEFF Research Database (Denmark)

    Westergaard-Nielsen, Andreas

    ecosystem monitoring at several spatial scales are consequently of great importance when evaluating methods to adapt to and mitigate climatic changes in the Arctic. This PhD defense will focus on the use and scaling of multiplatform remotely sensed data in the monitoring of snow cover dynamics, vegetation...... productivity and phenology in Greenland. Specifically, emphasis will be put on: the application of broad band digital cameras in the monitoring of Arctic phenology; the use of digital camera data as a proxy for ecosystem productivity in sparsely vegetated biomes; investigations of the interactions between snow...... cover distribution and vegetation growth patterns; evaluation of the future ecosystem productivity in Southwest Greenland and the possible consequences for farming in the region; the assessment the representativeness of single research sites in Northeast Greenland in an upscaling of gas fluxes....

  4. Vitamins and minerals in the traditional Greenland diet

    DEFF Research Database (Denmark)

    Andersen, S. M.

    The relative importance of traditional Greenlandic food items has diminished during the last decades. Today these account for 25% of the Greenland diet with a dominance of fish, seabirds, and marine mammals. This report synthesises the available information on concentrations of vitamins and miner......The relative importance of traditional Greenlandic food items has diminished during the last decades. Today these account for 25% of the Greenland diet with a dominance of fish, seabirds, and marine mammals. This report synthesises the available information on concentrations of vitamins...... of contaminants, the information about vitamins and minerals will potentially make it possible to adjust the diet in Greenland, taking both nutrients and contaminants into account...

  5. Towards Greenland Glaciation: cumulative or abrupt transition?

    Science.gov (United States)

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

    2016-04-01

    During the mid-Pliocene warming period (3-3.3 Ma BP), global annual mean temperature is warmer by 2-3 degree than pre-industrial. Greenland ice sheet volume is supposed to be a 50% reduction compared to nowadays [Haywood et al. 2010]. Around 2.7-2.6 Ma BP, just ~ 500 kyr after the warming peak of mid-Pliocene, there is already full Greenland Glaciation [Lunt et al. 2008]. How does Greenland ice sheet evolve from a half size to a glaciation level during 3 Ma - 2.5 Ma? Data show that there is a decreasing trend of atmospheric CO2 concentration from 3 Ma to 2.5 Ma [Seki et al.2010; Bartoli et al. 2011; Martinez et al. 2015]. However, a recent study [Contoux et al. 2015] suggests that a lowering of CO2 is not sufficient to initiate a perennial glaciation on Greenland and must be combined to low summer insolation, to preserve the ice sheet during insolation maximum, suggesting a cumulative process. In order to diagnose whether the ice sheet build-up is an abrupt event or a cumulative process, we carry on, for the first time, a transient simulation of climate and ice sheet evolutions from 3 Ma to 2.5 Ma. This strategy enables to investigate waxing and waning of the ice sheet during several orbital cycles. To reach this goal, we use a tri-dimensional interpolation method designed by Ladant et al. (2014) which combines the evolution of CO2 concentration, orbital parameters and Greenland ice sheet sizes in an off-line way by interpolating snapshots simulations. Thanks to this new method, we can build a transient like simulation through asynchronous coupling between GCM and ice sheet model. With this method, we may consistently answer the question of the build-up of Greenland: abrupt or cumulative process.

  6. Changes in the firn structure of the Greenland Ice Sheet caused by recent warming

    Directory of Open Access Journals (Sweden)

    S. de la Peña

    2015-01-01

    Full Text Available Atmospheric warming over the Greenland Ice Sheet during the last two decades has increased the amount of surface meltwater production, resulting in the migration of melt and percolation regimes to higher altitudes and an increase in the amount of solid ice from refrozen meltwater found in the firn above the equilibrium line. Here we present observations of near-surface (0–20 m firn conditions in western Greenland obtained from campaigns between 1998 and 2014. We find a sharp increase in firn ice content in the form of thick widespread layers in the percolation zone, which decreases the capacity of the firn to store meltwater. The estimated total annual ice content retained in the firn in areas with positive surface mass balance west of the ice divide in Greenland reached a maximum of 74 ± 25 Gt in 2012, compared to the 1958–1999 average of 13 ± 2 Gt, while the percolation zone area more than doubled between 2003 and 2012. Increased melt and column densification resulted in surface lowering averaging −0.80 ± 0.39 m yr−1 between 1800 and 2800 m in the accumulation zone of western Greenland. Since 2007, annual melt and refreezing rates in the percolation zone at elevations below 2100 m surpass the annual snowfall from the previous year, implying that mass gain in the region is now in the form of refrozen meltwater. If current melt trends over high elevation regions continue, subsequent changes in firn structure will have implications for the hydrology of the ice sheet and related abrupt seasonal densification could become increasingly significant for altimetry-derived ice sheet mass balance estimates.

  7. Environmental radioactivity in Greenland in 1980

    International Nuclear Information System (INIS)

    Measurements of fallout radioactivity in Greenland in 1980 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in the human diet in Greenland in 1980. Provisional results of the 239Pu, 240Pu and 241Am measurements on samples from the expedition to Thule in August 1979 and from the Swedish YMER expedition in 1980 are presented. (author)

  8. Clouds enhance Greenland ice sheet meltwater runoff

    OpenAIRE

    Van Tricht, K.; S. Lhermitte; J. T. M. Lenaerts; Gorodetskaya, I. V.; L'Ecuyer, T. S.; Noël, B.; van den Broeke, M. R.; D. D. Turner; N. P. M. van Lipzig

    2016-01-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2)Wm-2. Co...

  9. Weather Test Reference Year of Greenland

    DEFF Research Database (Denmark)

    Kragh, Jesper; Pedersen, Frank; Svendsen, Svend

    2005-01-01

    The building code of Greenland from 1982 is to be revised in the coming years fulfilling the increased demand of more energy efficient buildings. To establish appropriate levels of energy consumption for heating the weather conditions have to be analyzed. The purpose of this paper is to describe...... test reference year is constructed using measurements from the town Uummannaq located in the north part of Greenland on the west coast. The construction of the test reference years fulfills the procedures described in the standard EN ISO 15927-4 using the following main weather parameters: Dry bulb...

  10. Ice age plant refugia in East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1979-01-01

    From the distribution of plants it has been inferred by some botanists that ice-free areas existed in East Greenland accommodating a flora which survived one or several ice ages in the area. Comparing this evidence with recent information on the chronology of glaciations and post-glacial vegetation...... of Greenland. 14 C dating and amino-acid age estimates of marine sediments show that lowland areas near the outer coast have been ice-free for at least 40,000 years. The vegetation history, as reflected in pollen diagrams extending back to ca. 10,000 yr. B.P., has shown that many of the extant species...

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  12. Glucose intolerance and its relation to cardiovascular risk factors among Greenland Inuit. The Greenland Population Study

    OpenAIRE

    Jørgensen, Marit Eika

    2004-01-01

    Objectives. Until recently it has been a widely accepted opinion that the incidence of diabetes among Inuit in Greenland was low. More recent studies from Canada and Alaska have demonstrated that diabetes is increasingly common among Inuit, similar to global trends for indigenous people, and genetic studies have indicated that the Inuit may have an increased risk of developing diabetes and insulin resistance related disease. This was the background for the initiation of the Greenland Populati...

  13. Allergen sensitization and allergen exposure in Greenlander Inuit residing in Denmark and Greenland.

    Science.gov (United States)

    Porsbjerg, C; Linstow, M L; Nepper-christensen, S C; Rasmussen, A; Korsgaard, J; Nolte, H; Backer, V

    2002-09-01

    The aim of this study was to estimate the prevalence of allergic sensitization and possible risk factors in a genetically homogenous Inuit population living under widely differing climatic and cultural conditions. A written questionnaire and skin prick test for 10 aeroallergens were obtained from 1119 adult Greenlanders residing in Denmark, Nuuk (main city in Southern Greenland) and Uummannaq (rural settlement in Northern Greenland). Allergen exposure was assessed by pollen counts, questions on pet keeping and counts of house dust mites in dust samples. The overall prevalence of at least one positive skin prick test was 22.8% in Denmark, 10.6% in Nuuk, and 6.4% in Uummannaq. In Denmark, the total birch pollen counts were 40-1000 times higher compared to Nuuk, whereas the grass pollen count was 13-30 times higher in Denmark compared to Nuuk. Dogs were held indoor with a similar frequency in Denmark and Nuuk, but much less frequently in Uummannaq. In Denmark, house dust mites were found in 72% of house holds (>10/0.1 g dust). Less than 15% of households in Greenland had measurable levels of house dust mites. The prevalence of sensitization to aeroallergens in Inuit Greenlanders differed significantly between Denmark, Nuuk and Uummannaq. These findings correlated with the observed differences in population allergen exposure in the three regions. Furthermore, differences in lifestyle factors such as educational level, stress and ethnic self-identification seemed to be associated with the risk of allergic sensitization in Greenland.

  14. Kuiper Belts Around Nearby Stars

    CERN Document Server

    Nilsson, R; Brandeker, A; Olofsson, G; Pilbratt, G L; Risacher, C; Rodmann, J; Augereau, J -C; Bergman, P; Eiroa, C; Fridlund, M; Thébault, P; White, G J

    2010-01-01

    In order to detect and characterise cold extended circumstellar dust originating from collisions of planetesimal bodies in disks, belts, or rings at Kuiper-Belt distances (30--50\\,AU or beyond) sensitive submillimetre observations are essential. Measurements of the flux densities at these wavelengths will extend existing IR photometry and permit more detailed modelling of the Rayleigh-Jeans tail of the disks spectral energy distribution (SED), effectively constraining dust properties and disk extensions. By observing stars spanning from a few up to several hundred Myr, the evolution of debris disks during crucial phases of planet formation can be studied. // We have performed 870\\,$\\mu$m observations of 22 exo-Kuiper-Belt candidates, as part of a Large Programme with the LABOCA bolometer at the APEX telescope. Dust masses (or upper limits) were calculated from integrated 870\\,$\\mu$m fluxes, and fits to the SED of detected sources revealed the fractional dust luminosities $f_{\\mathrm{dust}}$, dust temperatures...

  15. Periodicity in tree rings from the corn belt.

    Science.gov (United States)

    Meko, D M; Stockton, C W; Blasing, T J

    1985-07-26

    Previous tree-ring studies indicated that the total area affected by drought in the western United States has rhythmically expanded and contracted over the past 300 years, with a period near the 18.6-year lunar nodal and 22-year double-sunspot cycles. Recently collected tree-ring data from the U.S. Corn Belt for the years 1680 to 1980 were examined for evidence of either of these cycles on a regional scale. Spectral analysis indicated no periodicity in the eastern part of the Corn Belt, but a significant 18.33-year period in the western part. The period length changed from 17.60 to 20.95 years between the first 150 years and the last 151. High-resolution frequency analysis showed that the structure of the 18.33-year spectral peak was complex, with contributions from several frequencies near both the lunar nodal and double-sunspot periods. A t-test of difference of means in reconstructed annual precipitation weakly corroborated a previous finding of an association between drought area and the phase of the double-sunspot cycle. Both the high-resolution frequency analysis and the t-test results indicate that the periodic component of drought near 20 years is too weak and irregular to be of use in drought forecasting for the Corn Belt.

  16. Cultural change and mental health in Greenland

    DEFF Research Database (Denmark)

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

    2002-01-01

    In Greenland, the rapid sociocultural change of the last 50 years has been paralleled by an epidemiological transition characterized by a reduction in infectious diseases, an increase in cancer and cardiovascular diseases, and an increased prevalence of mental health problems. During 1993-94 and ...

  17. Geodetic measurements of postglacial adjustments in Greenland

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Wahr, J.; Leuliette, E.;

    2008-01-01

    We analyze data from seven continuous Global Positioning System ( GPS) receivers and one tide gauge, all located along the edge of the Greenland ice sheet, to determine vertical uplift rates. We compare our results with predictions based on the ICE-5G deglaciation model of Peltier ( 2004). Results...

  18. Population surveys in Greenland 1993-2009

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Pedersen, Henning Sloth; Nielsen, Nina O;

    2013-01-01

    The purpose of the study was to analyse temporal trends (1993-2009) of the concentrations of organochlorine contaminants (14 congeners of polychlorinated biphenyls (PCB) and 11 pesticides) in the blood of Greenland Inuit according to age and urbanisation. Statistical determinants for the contamin...

  19. Fatal outbreak of botulism in Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  20. Greenland ice sheet mass balance: a review

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Aschwanden, Andy; Bjørk, Anders A.;

    2015-01-01

    Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance...

  1. Regional mapping of hydrothermally altered igneous rocks along the Urumieh-Dokhtar, Chagai, and Alborz Belts of western Asia using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operators: a tool for porphyry copper exploration and assessment: Chapter O in Global mineral resource assessment

    Science.gov (United States)

    Mars, John L.; Zientek, M.L.; Hammarstrom, J.M.; Johnson, K.M.; Pierce, F.W.

    2014-01-01

    Regional maps of phyllic and argillic hydrothermal alteration were compiled using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and logical operator algorithms. The area mapped extends from northwestern Iran to southeastern Pakistan and includes volcanic and magmatic arcs that make up the Urumieh-Dokhtar volcanic belt (UDVB), the Chagai volcanic belt (CVB), and the central part of the Alborz magmatic belt (AMB). The volcanic belts span the Zagros-Makran transform zone and the present day Baluchistan (Makran) volcanic arc. ASTER visible near infrared (VNIR) data contain three bands between 0.52 and 0.86 micrometers (μm) and the short-wave infrared (SWIR) data consist of six bands spanning 1.6 to 2.43 μm with 15-meter (m), and 30-m resolution, respectively.

  2. The Greenland Ice Sheet Monitoring Network (GLISN)

    Science.gov (United States)

    Anderson, K. R.; Beaudoin, B. C.; Butler, R.; Clinton, J. F.; Dahl-Jensen, T.; Ekstrom, G.; Giardini, D.; Govoni, A.; Hanka, W.; Kanao, M.; Larsen, T.; Lasocki, S.; McCormack, D. A.; Mykkeltveit, S.; Nettles, M.; Agostinetti, N. P.; Stutzmann, E.; Tsuboi, S.; Voss, P.

    2010-12-01

    The GreenLand Ice Sheet monitoring Network (GLISN) is an international, broadband seismic capability for Greenland, being installed and implemented through the collaboration of Denmark, Canada, Germany, Italy, Japan, Norway, Poland, Switzerland, and USA. GLISN is a real-time sensor array of seismic stations to enhance and upgrade the performance of the sparse Greenland seismic infrastructure for detecting, locating, and characterizing glacial earthquakes and other cryo-seismic phenomena, and contributing to our understanding of Ice Sheet dynamics. Complementing data from satellites, geodesy, and other sources, and in concert with these technologies, GLISN will provide a powerful tool for detecting change, and will advance new frontiers of research in the glacial systems; the underlying geological and geophysical processes affecting the Greenland Ice Sheet; interactions between oceans, climate, and the cryosphere; and other multidisciplinary areas of interest to geoscience and climate dynamics. The glacial processes that induce seismic events (internal deformation, sliding at the base, disintegration at the calving front, drainage of supra-glacial lakes) are all integral to the overall dynamics of glaciers, and seismic observations of glaciers therefore provide a quantitative means for monitoring changes in their behavior over time. Long-term seismic monitoring of the Greenland Ice Sheet will contribute to identifying possible unsuspected mechanisms and metrics relevant to ice sheet collapse, and will provide new constraints on Ice Sheet dynamic processes and their potential roles in sea-level rise during the coming decades. GLISN will provide a new, fiducial reference network in and around Greenland for monitoring these phenomena in real-time, and for the broad seismological study of Earth and earthquakes. The 2010 summer field season saw the installation or upgrade of 9 stations in the GLISN network. Sites visited under the GLISN project include Station Nord (NOR

  3. Comparing dust flux records from the Subarctic North Pacific and Greenland: Implications for atmospheric transport to Greenland and for the application of dust as a chronostratigraphic tool

    Science.gov (United States)

    Serno, Sascha; Winckler, Gisela; Anderson, Robert F.; Maier, Edith; Ren, Haojia; Gersonde, Rainer; Haug, Gerald H.

    2015-06-01

    We present a new record of eolian dust flux to the western Subarctic North Pacific (SNP) covering the past 27,000 years based on a core from the Detroit Seamount. Comparing the SNP dust record to the North Greenland Ice Core Project (NGRIP) ice core record shows significant differences in the amplitude of dust changes to the two regions during the last deglaciation, while the timing of abrupt changes is synchronous. If dust deposition in the SNP faithfully records its mobilization in East Asian source regions, then the difference in the relative amplitude must reflect climate-related changes in atmospheric dust transport to Greenland. Based on the synchronicity in the timing of dust changes in the SNP and Greenland, we tie abrupt deglacial transitions in the 230Th-normalized 4He flux record to corresponding transitions in the well-dated NGRIP dust flux record to provide a new chronostratigraphic technique for marine sediments from the SNP. Results from this technique are complemented by radiocarbon dating, which allows us to independently constrain radiocarbon paleoreservoir ages. We find paleoreservoir ages of 745 ± 140 years at 11,653 year B.P., 680 ± 228 years at 14,630 year B.P., and 790 ± 498 years at 23,290 year B.P. Our reconstructed paleoreservoir ages are consistent with modern surface water reservoir ages in the western SNP. Good temporal synchronicity between eolian dust records from the Subantarctic Atlantic and equatorial Pacific and the ice core record from Antarctica supports the reliability of the proposed dust tuning method to be used more widely in other global ocean regions.

  4. Geologic Assessment of Undiscovered Oil and Gas Resources of the West Greenland-East Canada Province

    Science.gov (United States)

    Schenk, Christopher J.

    2010-01-01

    The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the West Greenland-East Canada Province as part of the USGS Circum-Arctic Resource Appraisal program. The province lies in the offshore area between western Greenland and eastern Canada and includes Baffin Bay, Davis Strait, Lancaster Sound, and Nares Strait west of and including part of Kane Basin. A series of major tectonic events led to the formation of several distinct structural domains that are the geologic basis for defining five assessment units (AU) in the province, all of which are within the Mesozoic-Cenozoic Composite Total Petroleum System (TPS). Potential petroleum source rocks within the TPS include strata of Ordovician, Early and Late Cretaceous, and Paleogene ages. The five AUs defined for this study-the Eurekan Structures AU, Northwest Greenland Rifted Margin AU, Northeast Canada Rifted Margin AU, Baffin Bay Basin AU, and the Greater Ungava Fault Zone AU-encompass the entire province and were assessed for undiscovered, technically recoverable resources.

  5. French experience in seat belt use.

    NARCIS (Netherlands)

    Lassarre, S. & Page, Y.

    1992-01-01

    This paper concerns the French experience in seat belt use. As well as the seat belt regulations, the strategies employed to reinforce the wearing of seat belts by using information and encouragement campaigns and checks by the police and gendarmerie are described here along with their timetables an

  6. Study of thermal conditions at belt slippage

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, R.; Pampel, W.; Pfleger, P.

    1987-04-01

    Conveyor belt slippage experiments are carried out on the Chrudim (Czechoslovakia) industrial sized test stand for belt widths up to 1 m and driving drum forces up to 400 kW. The stand is operated jointly by TAKRAF (GDR) and VITKOVICE VUTZ, Prague. From 1972 to 1981, 7 belt conveyor fires occurred in GDR brown coal surface mines due to belt slippage. One of these cases led to a belt fire after only 15 s at 100% belt slippage. Aim of the study was to determine accurate permissible slippage values. Design of the test stand is explained as well as test procedures with belt slippage at the driving drum varying between 10 and 100%. Belt driving parameters were measured along with temperature of the drum surface. The heat penetration parameter b (in kJ/m/sup 2/) was calculated. Maximum temperatures up to 150 C were measured on the drum during partial slippage and 370 C at 100% belt slippage. The ignition temperature of rubber abrasion fines was also analyzed and found to vary between 40 and 318 C, i.e. substantially lower than belt and drum layer ignition temperatures. Graphs and diagram of slippage measurement results are calculated. Values for permissible maximum slippage time for operating belt slippage monitoring devices are shown. These devices are required to be installed in the GDR at heavy mine belt conveyors with driving forces exceeding 500 kW. 8 refs.

  7. The intercultural challenges of engineering education in a Greenlandic context

    DEFF Research Database (Denmark)

    Hendriksen, Kåre; Christensen, Hans Peter

    2014-01-01

    for this program: to educate professionals with a deep understanding of the Arctic, and to give the Greenlandic youth a better chance of getting a higher education. To align the teaching philosophy with the Greenlandic students’ cultural background, the curriculum structure has large interdisciplinary courses...... based on authentic local cases and intercultural group work. This paper will focus on the challenges caused by many of the Greenlandic students’ weak academic preparation, and the fact that the cultural background embedded in the Greenlandic language can make it very difficult to comprehend topics...... at an abstract level. Additionally, the group work and the class teaching are challenging due to the culturally -based reticence and conflict -averse nature of many of the Greenlandic students, which gives the Danish students a dominant position. This often creates a negative spiral, where many Greenlandic...

  8. Tectonic Evolution of an Early Precambrian High-Pressure Granulite Belt in the North China Craton

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A large-scale high-pressure granulite belt (HPGB), more than 700 km long, is recognized within the metamorphic basement of the North China craton. In the regional tectonic framework, the Hengshan-Chengde HPGB is located in the central collision belt between the western block and eastern block, and represents the deep crustal structural level. The typical high-pressure granulite (HPG) outcrops are distributed in the Hengshan and Chengde areas. HPGs commonly occur as mafic xenoliths within ductile shear zones, and underwent multipile deformations. To the south, the Hengshan-Chengde HPGB is juxtaposed with the Wutai greenstone belt by several strike-slip shear zones. Preliminary isotopic age dating indicates that HPGs from North China were mainly generated at the end of the Neoarchaean, assocaited with tectonic assembly of the western and esatern blocks.

  9. Numerical simulation of a rainfall event in Greenland during 10-13 July 2012 using Non-hydrostatic Regional Model

    Science.gov (United States)

    Hashimoto, A.; Niwano, M.; Aoki, T.

    2015-12-01

    On 12 July 2012, extensive surface melt occurred across much of the Greenland ice sheet. During this event, the expeditionary team of Snow Impurity and Glacial Microbe effects on the Arctic (SIGMA) project experienced unexpectedly heavy rainfall at their campsite on the northwestern Greenland ice sheet. We tried to reproduce the rainfall event by using the Japan Meteorological Agency Non-Hydrostatic Model (JMA-NHM) with 5-km horizontal resolution to characterize the temporal and spatial variation of the types of precipitation. The simulated results well agreed with observational data from surface stations and space-borne radar. According to the simulated results, the areas where the 1-h rainfall exceeded 0.1 mm at least once during the event accounted for 48% of the entire area of the Greenland ice sheet. In the coastal regions of western Greenland, precipitation during the event was composed of liquid hydrometeors, whereas in high-elevation regions, it was composed mainly of solid hydrometeors. Over intermediate regions, the phase of the precipitation changed temporally and spatially among liquid, solid, and a mixture of both. These phase transitions of the precipitation are very likely to affect the surface radiative properties of the ice sheet as well as the heat and mass balance at the surface of the ice sheet during the study period and afterward.

  10. Atmospheric and oceanic climate forcing of the exceptional Greenland Ice Sheet surface melt in summer 2012

    Science.gov (United States)

    Hanna, Edward; Fettweis, Xavier; Mernild, Sebastian; Cappelen, John; Ribergaard, Mads; Shuman, Christopher; Steffen, Konrad; Wood, Len; Mote, Thomas

    2013-04-01

    The NASA announcement of record surface melting of the Greenland ice sheet in July 2012 led us to examine the atmospheric and oceanic climatic anomalies that are likely to have contributed to these exceptional conditions and also to ask the question of how unusual these anomalies were compared to available records. Our analysis allows us to assess the relative contributions of these two key influences to both the extreme melt event and ongoing climate change. In 2012, as in recent warm summers since 2007, a blocking high pressure feature, associated with negative NAO conditions, was present in the mid-troposphere over Greenland for much of the summer. This circulation pattern advected relatively warm southerly winds over the western flank of the ice sheet, forming a "heat dome" over Greenland that led to the widespread surface melting. Both sea-surface temperature and sea-ice cover anomalies seem to have played a minimal role in this record melt, relative to atmospheric circulation. Two representative coastal climatological station averages and several individual stations in S, W and NW Greenland set new surface air temperature records for May, June, July and the whole (JJA) summer. The unusually warm summer 2012 conditions extended to the top of the ice sheet at Summit, where our reanalysed (1994-2012) DMI Summit weather station summer (JJA) temperature series set new record high mean and extreme temperatures in 2012; 3-hourly instantaneous 2-m temperatures reached an exceptional value of 2.2degC at Summit on 11 July 2012. These conditions translated into the record observed ice-sheet wide melt during summer 2012. However, 2012 seems not to be climatically representative of future "average" summers projected this century.

  11. Modelling snow accumulation on Greenland in Eemian, glacial inception, and modern climates in a GCM

    Directory of Open Access Journals (Sweden)

    H. J. Punge

    2012-11-01

    Full Text Available Changing climate conditions on Greenland influence the snow accumulation rate and surface mass balance (SMB on the ice sheet and, ultimately, its shape. This can in turn affect local climate via orography and albedo variations and, potentially, remote areas via changes in ocean circulation triggered by melt water or calving from the ice sheet. Examining these interactions in the IPSL global model requires improving the representation of snow at the ice sheet surface. In this paper, we present a new snow scheme implemented in LMDZ, the atmospheric component of the IPSL coupled model. We analyse surface climate and SMB on the Greenland ice sheet under insolation and oceanic boundary conditions for modern, but also for two different past climates, the last glacial inception (115 kyr BP and the Eemian (126 kyr BP. While being limited by the low resolution of the general circulation model (GCM, present-day SMB is on the same order of magnitude as recent regional model findings. It is affected by a moist bias of the GCM in Western Greenland and a dry bias in the north-east. Under Eemian conditions, the SMB decreases largely, and melting affects areas in which the ice sheet surface is today at high altitude, including recent ice core drilling sites as NEEM. In contrast, glacial inception conditions lead to a higher mass balance overall due to the reduced melting in the colder summer climate. Compared to the widely applied positive degree-day (PDD parameterization of SMB, our direct modelling results suggest a weaker sensitivity of SMB to changing climatic forcing. For the Eemian climate, our model simulations using interannually varying monthly mean forcings for the ocean surface temperature and sea ice cover lead to significantly higher SMB in southern Greenland compared to simulations forced with climatological monthly means.

  12. Holocene paleoceanography of Disko Bugt area, west Greenland

    Science.gov (United States)

    Ouellet-Bernier, Marie-Michèle; de Vernal, Anne; Moros, Matthias; Hillaire-Marcel, Claude

    2014-05-01

    Micropaleontological, palynological and isotopic analyses of sediment core MSM343300 (68° 28,311'N, 54° 00,118'W; 519 m water depth) raised off Disko Bugt area (West Greenland) were undertaken in order to document Holocene paleoceanographical changes in the Eastern Baffin bay, at a site now influenced by the Western Greenland Current. Palynological analyses were performed with special attention paid to dinocysts in order to characterize sea-surface conditions whereas isotopic analyses on benthic foraminifers aimed at documenting the "deep" water mass bathing the shelf edge. Palynological assemblages are largely dominated by dinocysts, which suggest high pelagic productivity during the Middle and Late Holocene. The assemblages are dominated by Islandinium minutum accompanied of the cyst of Pentapharsodinium dalei, Brigantedinium spp., Operculodinium centrocarpum, Spiniferites elongatus, Selenopemphix quanta and Islandinium? cezare. The application of the Modern analogue technique (MAT) highlighted a major change in sea-surface conditions at ~7300 cal. yr BP. Harsh conditions with dense sea-ice cover, low temperature and low productivity prevailed at surface from at least ~ 10 000 (age of core bottom) until ~7300 cal. yr BP with a large dominance of Islandinium minutum in the dinocyst assemblages. The overall low productivity resulted in low benthic foraminiferal abundances. However a few benchmark isotopic values could be obtained. At ~10 000 cal. yr BP, delta 18O values near +4o pointed to the presence of cold and relatively saline waters at the sea floor. A short interval corresponding to a large amplitude 13C excursion is recorded at ~8200 cal. yr BP, with deltagalues as low as -4.5 and -6.03o in Islandiella norcrossi and Nonionella labradorica, respectively, whereas 13C content in total sedimentary organic carbon did not vary much from the background value of ~ -22o . We tentatively concluded at some linkage with a sea floor methane burst. Postglacial

  13. Marginal thinning in Northwest Greenland during 2002-2011

    OpenAIRE

    Khan, Shfaqat Abbas; K. H. Kjær; J. M. Wahr; Bevis, M; Korsgaard, N; A. A. Bjørk; Kjeldsen, K. K.; Timm, L. M.; Dam, T. v.

    2012-01-01

    Many glaciers along the southeast and northwest coast of Greenland have accelerated, increasing the Greenland ice sheet's (GrIS) contribution to global sea-level rise. Here, we map elevation changes in northwest Greenland during 2003-2009 using high-resolution Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data (Zwally, 2010) supplemented with altimeter surveys from NASA's Airborne Topographic Mapper (ATM) during 2002-2011 (Krabill, 2011). We use the measurements of elevatio...

  14. Radiostratigraphy and age structure of the Greenland Ice Sheet

    OpenAIRE

    MacGregor, JA; Fahnestock, MA; Catania, GA; Paden, JD; Prasad Gogineni, S; Young, SK; Rybarski, SC; Mabrey, AN; Wagman, BM; Morlighem, M.

    2015-01-01

    Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the Greenland Ice Sheet from airborne deep ice-penetrating radar data collected over Greenland by The University of Kansas between 1993 and 2013. T...

  15. Building sustained partnerships in Greenland through shared science

    Science.gov (United States)

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

    2013-12-01

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

  16. East Greenland Ridge in the North Atlantic Ocean

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  17. Resilience and Renewable Energy Planning in Greenland

    DEFF Research Database (Denmark)

    Carruth, Susan

    2014-01-01

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

  18. Increasing mass loss from Greenland's Mittivakkat Gletscher

    DEFF Research Database (Denmark)

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

    2011-01-01

    Warming in the Arctic during the past several decades has caused glaciers to thin and retreat, and recent mass loss from the Greenland Ice Sheet is well documented. Local glaciers peripheral to the ice sheet are also retreating, but few mass-balance observations are available to quantify...... balance and glacier front fluctuations. We attribute this mass loss primarily to record high mean summer (June–August) temperatures in combination with lower-than-average winter precipitation. Also, we use the 15-yr mass-balance record to estimate present-day and equilibrium accumulation-area ratios...... for the MG. We show that the glacier is significantly out of balance and will likely lose at least 70% of its current area and 80% of its volume even in the absence of further climate changes. Temperature records from coastal stations in Southeast Greenland suggest that recent MG mass losses are not merely...

  19. Resilience and Renewable Energy Planning in Greenland

    DEFF Research Database (Denmark)

    Carruth, Susan

    2014-01-01

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

  20. Holocene deceleration of the Greenland Ice Sheet.

    Science.gov (United States)

    MacGregor, Joseph A; Colgan, William T; Fahnestock, Mark A; Morlighem, Mathieu; Catania, Ginny A; Paden, John D; Gogineni, S Prasad

    2016-02-01

    Recent peripheral thinning of the Greenland Ice Sheet is partly offset by interior thickening and is overprinted on its poorly constrained Holocene evolution. On the basis of the ice sheet's radiostratigraphy, ice flow in its interior is slower now than the average speed over the past nine millennia. Generally higher Holocene accumulation rates relative to modern estimates can only partially explain this millennial-scale deceleration. The ice sheet's dynamic response to the decreasing proportion of softer ice from the last glacial period and the deglacial collapse of the ice bridge across Nares Strait also contributed to this pattern. Thus, recent interior thickening of the Greenland Ice Sheet is partly an ongoing dynamic response to the last deglaciation that is large enough to affect interpretation of its mass balance from altimetry. PMID:26912699

  1. Alcohol in Greenland 1951-2010

    DEFF Research Database (Denmark)

    Aage, Hans

    2012-01-01

    time series for Denmark 1906-2010 are presented for comparison. Results. The trends in alcohol prices and consumption followed each other rather closely until the 1990s in Greenland and the 1980s in Denmark. At this time, consumption stabilised while prices decreased further, but the effect of prices...... upon consumption is strong, also in recent years. A trend in Greenlandic mortality similar to consumption is discernible, but not significant. Among alcohol-related deaths cirrhosis of the liver is less prevalent whilst accidents are more prevalent than in Denmark. Conclusions. The effect of alcohol...... excise taxes and rationing upon consumption is evident. The stabilisation and subsequent decline in consumption since the mid-1990s, while alcohol prices decreased persistently, does not preclude continued effects of prices. On the contrary, price effects have been neutralised by other stronger causes...

  2. Extensive Admixture and Selective Pressure Across the Sahel Belt.

    Science.gov (United States)

    Triska, Petr; Soares, Pedro; Patin, Etienne; Fernandes, Veronica; Cerny, Viktor; Pereira, Luisa

    2015-11-26

    Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection).

  3. Late Ordovician brachiopods from eastern North Greenland

    DEFF Research Database (Denmark)

    Mac Ørum Rasmussen, Christian

    2013-01-01

    Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the BOrglum River Formation of the Centrum SO area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna is...... invasion of migrants from Baltica that arrived later during the Hirnantian. The offshore migration of this atypical Hiscobeccus fauna likely demonstrates the path of warm-water currents as the Centrum SO locality was located at the equator during the Late Ordovician....

  4. Violence, sexual abuse and health in Greenland

    OpenAIRE

    Curtis, Tine; Larsen, Finn B.; Helweg-Larsen, Karin; Bjerregaard, Peter

    2002-01-01

    The purposes of the study were to analyse the lifetime prevalence of violence and sexual abuse among the Inuit in Greenland and to study the associations between health and having been the victim of violence or sexual abuse. Associations were studied with specific attention to possible differences between women and men. Further, response rates were analysed specifically in order to understand consequences of including questions on violence and sexual abuse in the questionnaire survey. The ana...

  5. Driving forces in the Greenlandic urbanization

    DEFF Research Database (Denmark)

    Hendriksen, Kåre

    2014-01-01

    . This centralization has left geographical regions with limited livelihood and at the same time a lack of utilization of local resources and trade opportunities. Additionally the Greenlandic so called larger cities are ended in an un-sustainable economical situation manly depending on public financed jobs or social...... support and with limited export oriented value creation. It will be disused how the previous and present urbanization interact with a sustainable development and what is the core prerequisites for sustainable towns and settlements....

  6. Iron status markers in 224 indigenous Greenlanders

    DEFF Research Database (Denmark)

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

    2001-01-01

    OBJECTIVE: To evaluate iron status in indigenous Greenlanders and its relationship to gender, age and intake of traditional Greenlandic foods. Methods: Serum ferritin, serum transferrin saturation and haemoglobin were evaluated in a population survey in 1993-1994 comprising 224 Greenlandic...... of iron deficiency anaemia (ferritin iron-replete men and women) was 0.92% in men and 0.87% in women. Correlations between age and ferritin were lowest in Nuuk (men, r(s)=0.26, p=0.2; women, r(s)=0.50, p=0.001) intermediary in Ilulissat (men, r(s)=0.37, p=0...... ferritin levels were lowest in Nuuk (men, 92 microg/L; women, 40 microg/L), higher in Ilulissat (men, 104 microg/L; women, 69 microg/L) and in Uummannaq (men, 118 microg/L; women, 46 microg/L) (piron load (ferritin >200 microg/L) was lowest in Nuuk (men: 13.8%, women: 2...

  7. Uncertainty in Greenland glacial isostatic adjustment (Invited)

    Science.gov (United States)

    Milne, G. A.; Lecavalier, B.; Kjeldsen, K. K.; Kjaer, K.; Wolstencroft, M.; Wake, L. M.; Simpson, M. J.; Long, A. J.; Woodroffe, S.; Korsgaard, N. J.; Bjork, A. A.; Khan, S. A.

    2013-12-01

    It is well known that the interpretation of geodetic data in Greenland to constrain recent ice mass changes requires knowledge of isostatic land motion associated with past changes in the ice sheet. In this talk we will consider a variety of factors that limit how well the signal due to past mass changes (commonly referred to as glacial isostatic adjustment (GIA)) can be defined. Predictions based on a new model of Greenland GIA will be shown. Using these predictions as a reference, we will consider the influence of plausible variations in some key aspects of both the Earth and ice load components of the GIA model on predictions of land motion and gravity changes. The sensitivity of model output to plausible variations in both depth-dependent and lateral viscosity structure will be considered. With respect to the ice model, we will compare the relative contributions of loading during key periods of the ice history with a focus on the past few thousand years. In particular, we will show predictions of contemporary land motion and gravity changes due to loading changes following the Little Ice Age computed using a new reconstruction of ice thickness changes based largely on empirical data. A primary contribution of this work will be the identification of dominant sources of uncertainty in current models of Greenland GIA and the regions most significantly affected by this uncertainty.

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

    DEFF Research Database (Denmark)

    Homøe, Preben; Andersen, Ture; Grøntved, Aksel;

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Preben Homøe

    2013-08-01

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

  10. Lomonosov Ridge off Greenland (LOMROG) 2007

    Science.gov (United States)

    Marcussen, C.; Jakobsson, M.

    2007-12-01

    The Lomonosov Ridge off Greenland was the primary focus for the LOMROG expedition. This part of the Arctic is virtually unexplored as difficult sea ice conditions have made it inaccessible for surface vessels. With Swedish icebreaker /Oden/ supported by new Russian nuclear icebreaker /50 Let Pobedy/, LOMROG managed to reach the southern most tip of the Lomonosov Ridge off Greenland to carry out multibeam mapping, subbottom and seismic reflection profiling, gravity measurements, geological coring and oceanographic station work. The LOMROG expedition is a Swedish/Danish collaboration project with participating scientists also from Canada, Finland, and USA. The data collection was made for the purpose of studying paleoceanography/oceanography, glacial history and the tectonic evolution of the of the Arctic Ocean as well as for Denmark's Continental Shelf Project under the United Nations Convention on the Law of the Sea Article 76. One of the reasons for targeting the ice-infested area north of Greenland was that it likely holds answers to key questions regarding the glacial history of the Arctic Ocean, such as whether immense ice shelves existed in the Arctic Ocean during past glacial periods./ /Previous expeditions with /Oden/ in 1996 and the US nuclear submarine /Hawkbill/ in 1999, have demonstrated the occurrence of ice grounding down to 1000 m present water depth at about 87°N 145°E on the Lomonosov Ridge crest. If this ice grounding event resulted from a much debated, but supposedly coherent and large floating ice shelf, the Lomonosov Ridge north of Greenland must also be scoured. To test the hypothesis of a huge Arctic Ocean ice shelf LOMROG mapped the areas of the Lomonosov Ridge north of Greenland using the new EM120 multibeam bathymetry and SBP120 subbottom profiling system installed on the /Oden/ during the spring of 2007. Glacial erosion was indeed found at water depth shallower than approximately 800 m and two sediment cores retrieved from the glacially

  11. Perfluorinated compounds are related to breast cancer risk in greenlandic inuit: A case control study

    Directory of Open Access Journals (Sweden)

    Mulvad Gert

    2011-10-01

    Full Text Available Abstract Background Breast cancer (BC is the most common cancer for women in the western world. From very few cases an extraordinary increase in BC was observed in the Inuit population of Greenland and Canada although still lower than in western populations. Previous data suggest that exposure to persistent organic pollutants (POPs might contribute to the risk of BC. Rat studies showed that perfluorinated compounds (PFCs cause significantly increase in mammary fibroadenomas. This study aimed at evaluating the association between serum levels of POPs/PFCs in Greenlandic Inuit BC cases and their controls, and whether the combined POP related effect on nuclear hormone receptors affect BC risk. Methods Thirty-one BC cases and 115 controls were sampled during 2000-2003 from various Greenlandic districts. The serum levels of POPs, PFCs, some metals and the combined serum POP related effect on estrogen- (ER, androgen- (AR and Ah-receptor (AhR transactivity were determined. Independent student t-test was used to compare the differences and the odds ratios were estimated by unconditional logistic regression models. Results We observed for the very first time a significant association between serum PFC levels and the risk of BC. The BC cases also showed a significantly higher concentration of polychlorinated biphenyls at the highest quartile. Also for the combined serum POP induced agonistic AR transactivity significant association to BC risk was found, and cases elicited a higher frequency of samples with significant POP related hormone-like agonistic ER transactivity. The AhR toxic equivalent was lowest in cases. Conclusions The level of serum POPs, particularly PFCs, might be risk factors in the development of BC in Inuit. Hormone disruption by the combined serum POP related xenoestrogenic and xenoandrogenic activities may contribute to the risk of developing breast cancer in Inuit. Further investigations are needed to document these study conclusions.

  12. The Mantle Transition Zone in Central-Eastern Greenland

    Science.gov (United States)

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

    2015-12-01

    We present results of a Receiver Function (RF) study of the mantle transition zone (TZ) in Central-Eastern Greenland. The base of this study is data from 19 broad-band seismometers, which were temporarily installed from 2009 to 2012 in the region between Scoresbysund and Summit (~ 70º N) plus 5 permanent stations from the GLISN network. One half of these stations were installed on the ice, the other half on bedrock.Our analysis is based on low frequency PRF, which use the difference in travel times between converted and not converted phasesat discontinuities. Most of our RFs show clear signals for P410s and P660s. Their delay times suggest a surprisingly thin mantle transition zone for most parts of the study area in comparison to standard Earth models, and much thinner than below other continental shield and platform areas. This could indicate a fairly recent heating of the TZ. Another observation is an M-shaped signal around the 410 km - discontinuity at some of the stations mainly in the western part around Summit. This observation is contrary to the expected simple negative signal. It may indicate a thin low velocity layer between 410 km and 520 km, as it has previously been observed in several settings based on converted waves and also explosion data. Most of our stations show positive travel time anomalies for the upper mantle, which again is contrary to simple models of old continental shields.

  13. Geology and Mineral Resources Characteristics in Greenland and Main Metal Minerals Prospecting Orientation%格陵兰地质矿产特征及主要金属矿产找矿方向

    Institute of Scientific and Technical Information of China (English)

    杨霄; 黄亚松

    2013-01-01

    Greenland is situated on a Precambrian shield, outcropped rocks are mainly gneiss and supracrustal rocks formed in a series of collision orogenic events during Archean and Proterozoic eras. Proterozoic-Mesozoic sedimentary formations and basins were widely developed on the western, eastern and northern shield margins. Magmatic activities were occurred throughout Archean to Cenozoic eras and formed diversified magmatic rocks with different dimensions. Greenland possesses abundant iron, gold, lead-zinc, rare RE, plati-num group metals, copper, nickel and other mineral resources. An analysis has shown that the banded iron formations distributed in southwest, midwest and north parts are favorable targets to find BIF type iron ore deposits. Southwestern Archean greenstone belt and southern Ketilidian mobile belt have potential to find greenstone type and orogenic belt type gold ore deposits. Southwestern carbon-atite, alkaline rock masses are main targets to find rare RE metallic ore deposits. Sedimentary basins and strata developed in northwest and northeast parts and are favorable areas to find SEDEX and MVT typed lead-zinc ore deposits and SST typed copper ore deposits. Archean-Proterozoic basic and ultrabasic rocks distributed in southwest and southeast parts are favorable targets to find platinum group metals and nickel ore deposits.%格陵兰为前寒武纪地盾区,出露的岩石以片麻岩和上壳岩为主,形成于太古代和元古代一系列碰撞造山环境;在地盾西部、东部和北部边缘广泛发育了元古代-中生代的沉积地层和盆地;岩浆活动贯穿于太古代至新生代,形成了岩性多样、规模不一的岩浆岩。格陵兰矿产资源丰富,已发现铁、金、铅锌、稀有稀土、铂族、铜、镍等多种矿产资源。分析表明,格陵兰西南部、中西部和北部分布的条带状含铁建造是寻找BIF型铁矿的有利靶区;西南部太古代绿岩带、南部凯蒂利屯活动带具

  14. Seismic tomography beneath the orogenic belts and adjacent basins of northwestern China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Three-dimensional velocity images of the crust and upper mantlebeneath orogenic belts and adjacent basins of the northwestern continent of China are reconstructed by seismic tomography, based on arrival data of P wave recorded in seismic networks in Xinjiang, Qinghai, Gansu of China and Kyrgyzstan. The velocity images of upper crust demonstrate the tectonic framework on the ground surface. High velocities are observed beneath orogenic belts, and low velocities are observed in the basins and depressions that are obviously related to unconsolidated sediments. The velocity image in mid-crust maintains the above features, and in addition low velocities appear in some earthquake regions and a low velocity boundary separates the western Tianshan Mts. from eastern Tianshan Mts. The orogenic belts and the northern Tibetan plateau have a Moho depth over 50 km, whereas the depths of the Moho in basins and depressions are smaller than 50 km. The velocity images of upper mantle clearly reveal the colliding relationship and location of deep boundaries of the continental blocks in northwestern China, indicating a weakness of the upper mantle structure of orogenic belts. The top depth of upper mantle asthenosphere varies from place to place. It seems shallower under the northern Tibetan plateau, Altay and Qilian Mts., and deeper under the Tarim and Tianshan regions. Hot mantle probably rose to the bottom of some orogenic belts along tectonic boundaries when continental blocks collided to each other. Therefore their dynamic features are closely correlated to the formation and evolution of orogenic belts in northwestern China.

  15. A checklist of the fish fauna of Greenland waters

    DEFF Research Database (Denmark)

    Møller, Peter R.; Nielsen, Jørgen G.; Knudsen, Steen W.;

    2010-01-01

    Although the Greenland fish fauna has been studied for more than 200 years, new species continue to be discovered. We here take the opportunity of the International Polar Year 2007-08 (IPY) to present an updated check-list of the fishes of Greenland and discuss whether the growing diversity can...

  16. Risk factors for Mycobacterium tuberculosis infection among children in Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  17. Important Summer Concentrations of Seaducks in West Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.

    Aerial surveys for seaducks were conducted in West Greenland in July 1998 and 1999. Important concentrations of harlequin ducks, common eiders and red-breasted mergansers were located in central and southern West Greenland, while only few king eiders had yet arrived to the moulting grounds in cen...

  18. Greenland surface albedo changes 1981-2012 from satellite observations

    Science.gov (United States)

    Significant melt over Greenland has been observed during the last several decades associated with extreme warming events over the northern Atlantic Ocean. An analysis of surface albedo change over Greenland is presented, using a 32-year consistent satellite albedo product from the Global Land Surfac...

  19. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  20. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: Zircon geochronology from the Kangaatsiaq–Qasigiannguit region, the northern part of the 1.9–1.8 Ga Nagssugtoqidian orogen, West Greenland

    Directory of Open Access Journals (Sweden)

    Conelly, James N.

    2006-12-01

    Full Text Available The Kangaatsiaq–Qasigiannguit region in the northern part of the Palaeoproterozoic Nagssugtoqidian orogen of West Greenland consists of poly-deformed orthogneisses and minor occurrences of interleaved, discontinuous supracrustal belts. Laser ablation ICP-MS 207Pb/206Pb analyses of detrital zircons from four metasedimentary rocks (supplemented by ion probe analysis of one sample and igneous zircons from six granitoid rocks cutting metasedimentary units indicate that the supracrustal rocks in the Kangaatsiaq–Qasigiannguit (Christianshåb region are predominantly Archaean in age. Four occurrences of metasedimentary rocks are clearly Archaean, two have equivocal ages, and only one metasedimentary unit, from within the Naternaq (Lersletten supracrustal belt, is demonstrably Palaeoproterozoic and readily defines a large fold complex of this age at Naternaq. The 2.9–2.8 Ga ages of detrital Archaean grains are compatible with derivation from the local basement orthogneisses within the Nagssugtoqidian orogen. The detrital age patterns are similar to those of metasediments within the central Nagssugtoqidian orogen but distinct from age patterns in metasediments of the Rinkian belt to the north, where there is an additional component of pre-2.9 Ga zircons. Synkinematic intrusive granitoid rocks constrain the ages of some Archaean deformation at 2748 ± 19 Ma and some Palaeoproterozoic deformation at 1837 ± 12 Ma.

  1. Brief communication "The aerophotogrammetric map of Greenland ice masses"

    Directory of Open Access Journals (Sweden)

    M. Citterio

    2012-09-01

    Full Text Available The PROMICE (Programme for Monitoring of the Greenland Ice Sheet aerophotogrammetric map of Greenland ice masses is the first high resolution dataset documenting the mid-1980's extent of the Greenland Ice Sheet and all the local glaciers and ice caps. The total glacierized area was 1 804 638 km2 ± 2178 km2, of which 88 083 ± 1240 km2 belonged to local glaciers and ice caps (GIC substantially independent from the Greenland Ice Sheet. This new result of GIC glacierized area is higher than most previous estimates, and is in line with contemporary findings based on independent data sources. Comparison between our map and the recently released GIMP (Greenland Mapping Project Ice Cover Mask (Howat and Negrete, 2012 show potential for change assessment studies.

  2. Brief communication "The aerophotogrammetric map of Greenland ice masses"

    Directory of Open Access Journals (Sweden)

    M. Citterio

    2013-03-01

    Full Text Available The PROMICE (Programme for Monitoring of the Greenland Ice Sheet aerophotogrammetric map of Greenland ice masses is the first high resolution dataset documenting the mid-1980s areal extent of the Greenland Ice Sheet and all the local glaciers and ice caps. The total glacierized area excluding nunataks was 1 804 638 km2 ± 2178 km2, of which 88 083 ± 1240 km2 belonged to local glaciers and ice caps (GIC substantially independent from the Greenland Ice Sheet. This new result of GIC glacierized area is higher than most previous estimates, 81% greater than Weng's (1995 measurements, but is in line with contemporary findings based on independent data sources. A comparison between our map and the recently released Rastner et al. (2012 inventory and GIMP (Greenland Ice Mapping Project Ice-Cover Mask (Howat and Negrete, 2013 shows potential for change-assessment studies.

  3. Brief communication "The aerophotogrammetric map of Greenland ice masses"

    Science.gov (United States)

    Citterio, M.; Ahlstrøm, A. P.

    2013-03-01

    The PROMICE (Programme for Monitoring of the Greenland Ice Sheet) aerophotogrammetric map of Greenland ice masses is the first high resolution dataset documenting the mid-1980s areal extent of the Greenland Ice Sheet and all the local glaciers and ice caps. The total glacierized area excluding nunataks was 1 804 638 km2 ± 2178 km2, of which 88 083 ± 1240 km2 belonged to local glaciers and ice caps (GIC) substantially independent from the Greenland Ice Sheet. This new result of GIC glacierized area is higher than most previous estimates, 81% greater than Weng's (1995) measurements, but is in line with contemporary findings based on independent data sources. A comparison between our map and the recently released Rastner et al. (2012) inventory and GIMP (Greenland Ice Mapping Project) Ice-Cover Mask (Howat and Negrete, 2013) shows potential for change-assessment studies.

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

    Directory of Open Access Journals (Sweden)

    Smith, M. Paul

    2004-12-01

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

  5. Accumulation rates in Northwest Greenland from continuous GPR profiling along the Greenland Inland Traverse

    Science.gov (United States)

    Hawley, R. L.; Courville, Z.; Kehrl, L. M.; Lutz, E.; Osterberg, E. C.; Overly, T. B.; Wong, G. J.

    2012-12-01

    Snow accumulation is one of the fundamental parameters governing the mass balance of the Greenland Ice Sheet. While many point measurements of accumulation exist from shallow and deep ice cores, there are few spatially extensive and continuous records of accumulation in Greenland, particularly in the northwest quadrant. In April and May 2011, the Greenland Inland Traverse traveled via tractor train from Thule Air Base in northwest Greenland to Summit Station, at the center of the ice sheet. The science team on the traverse collected both point and profile measurements along the route. Kinematic GPS and 400 MHz GPR profiles provide geolocated subsurface stratigraphy. Density measurements from snowpits and shallow cores on the profile allow us to determine the true depth of radar reflecting horizons, commonly interpreted to be isochrons. We use three ice cores collected at the beginning, the end, and roughly the middle of the route to date horizons. We traced strong reflecting horizons along the entire route. From the combination of dated, traced horizons, density measurements, and position measurements, we determine accumulation rates continuously along the traverse route. We find our traverse route begins in a high-accumulation area, and accumulation decreases as we cross to the east side of the summit ridge. Accumulation then climbs again as we approach summit (directly on the summit ridge). We compare our accumulation rates with previous studies, both measurements (traverse and point measurements) and models.

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

    DEFF Research Database (Denmark)

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

    1997-01-01

    During the GRIP deep drilling in Central Greenland, the ice sheet topography and surface movement at Summit has been mapped with GPS. Measurements of the surface velocity are presented for a strain net consisting of 13 poles at distances of 25-60 km from the GRIP site. Some results are: The GRIP...

  7. Structuring of zooplankton and fish larvae assemblages in a freshwater-influenced Greenlandic fjord- influence from hydrography and prey availability

    DEFF Research Database (Denmark)

    Swalethorp, Rasmus; Malanski, Evandro; Munk, Peter;

    2015-01-01

    The recent increase in temperature and freshwater runoff in the Arctic will influence the functioning of the plankton ecosystem and hence the life of the fish larvae residing in these areas. Here, we studied the strength of physical– biological linkages and the adaptability of individual larval...... fish species to changing hydrographical and feeding environments in a sub-Arctic area in Greenland. The study was carried out along a transect covering a wide range of physical conditions from the deep ocean to the icecap in the Godtha°bsfjord on the south-western Greenland coast. Along the transect......, we identified a series of distinct zooplankton and larval fish assemblages which showed linkage to water mass characteristics, to the presence of frontal structures and to availability of preferred prey. Spawning site location and water circulation was also likely to influence distributional patterns...

  8. Last Interglacial (MIS5e) hydrographic shifts linked to meltwater discharges from the East Greenland margin

    Science.gov (United States)

    Zhuravleva, Anastasia; Bauch, Henning A.; Van Nieuwenhove, Nicolas

    2016-04-01

    The East Greenland Current (EGC) plays a key role in transporting polar water from the Arctic to convectional sites of the Iceland and Labrador seas. Ongoing melting of the Greenland Ice Sheet (GIS) as well as the Arctic sea ice prompts freshening of the EGC and accumulation of low-density water in the subpolar North Atlantic, thus affecting the stabilities of water mass overturning and subsequent northward heat transfer. To assess natural eastern GIS dynamics and possible freshwater-induced regional oceanic reorganizations we analyzed several sediment sequences from the poorly investigated area along the eastern Greenland margin and the western Nordic Seas. Records span the last interglacial (LIG, MIS5e) cycle, including deglacial Termination 2 and the LIG climatic optimum. On a global scale, the latter is believed to have been warmer than present, with a higher sea level, and may, therefore, serve as a promising analogue for future hydrographic changes. Based on various proxy data (stable isotopes, planktic foraminiferal assemblages, ice-rafted debris) our reconstructions support the notion of a "two-step development" of Termination 2 which underwent severe surface freshening in the subpolar North Atlantic. This is shown in extremely light oxygen isotopic values registered all along the eastern Greenland margin during early MIS5e, which are indicative for pronounced eastern/central GIS retreat and a further propagation of the resulting meltwater southward via the EGC. In addition, we find compelling evidence for at least two separate meltwater episodes in proximity of the eastern GIS during early MIS5e. The climatic episode in between is correlated with an early LIG warm peak, which may be linked to enhanced presence of Atlantic water in the central Nordic Seas (Bauch et al., 2012) and further downstream along southern Greenland (Hillaire-Marcel et al., 1994, Irvali et al., 2012). Our data, therefore, reveal a complex and variable dynamic of the EGC during MIS5e

  9. Spatiotemporal variability of oxygen isotope compositions in three contrasting glacier river catchments in Greenland

    Directory of Open Access Journals (Sweden)

    J. C. Yde

    2015-06-01

    Full Text Available Analysis of stable oxygen isotope (δ18O characteristics is a useful tool to investigate water provenance in glacier river systems. In order to attain knowledge on the diversity of spatio-temporal δ18O variations in glacier rivers, we have examined three glacierized catchments in Greenland with different areas, glacier hydrology and thermal regimes. At Mittivakkat Gletscher River, a small river draining a local temperate glacier in southeast Greenland, diurnal oscillations in δ18O occur with a three-hour time lag to the diurnal oscillations in runoff. Throughout the peak flow season the δ18O composition is controlled by the proportion between snowmelt and ice melt with episodic inputs of rainwater and occasional storage and release of a specific water component due to changes in the subglacial drainage system. At Kuannersuit Glacier River on the island Qeqertarsuaq, the δ18O characteristics were examined after the major 1995–1998 glacier surge event. Despite large variations in the δ18O values of glacier ice on the newly formed glacier tongue, there were no diurnal oscillations in the bulk meltwater emanating from the glacier in the post-surge years 2000–2001. In 2002 there were indications of diurnal oscillations, and in 2003 there were large diurnal fluctuations in δ18O. At Watson River, a large catchment at the western margin of the Greenland Ice Sheet, the spatial distribution of δ18O in the river system was applied to fingerprint the relative runoff contributions from sub-catchments. Spot sampling indicates that during the early melt season most of the river water (64–73 % derived from the Qinnguata Kuussua tributary, whereas the water flow on 23 July 2009 was dominated by bulk meltwater from the Akuliarusiarsuup Kuua tributary (where 7 and 67 % originated from the Russell Glacier and Leverett Glacier sub-catchments, respectively. A comparison of the δ18O compositions from glacial river water in Greenland shows distinct

  10. The East Greenland Ridge - a continental sliver along the Greenland Fracture Zone

    Science.gov (United States)

    Gerlings, Joanna; Funck, Thomas; Castro, Carlos F.; Hopper, John R.

    2014-05-01

    The East Greenland Ridge (EGR), situated along the Greenland Fracture Zone in the northern part of the Greenland-Norwegian Sea, is a NW-SE trending 250-km-long and up to 50-km-wide bathymetric high that separates the Greenland Basin in the south from the Boreas Basin in the north. Previous seismic work established that the EGR is primarily continental in nature. Detailed swath bathymetric data revealed a complex internal structure of the ridge with two main overstepping ridge segments. These segments were not adequately covered by the GEUS2002NEG seismic survey as the detailed structure was not known at that time. The crustal affinity of the northwestern, landward-most ridge segment, and how it is attached to the Northeast Greenland continental shelf, remained unclear. The GEUS-EAGER2011 survey was designed to address these issues and to provide further constraints on the structural development of the EGR. During the GEUS-EAGER2011 survey, additional seismic refraction and reflection data were acquired on the EGR and the Northeast Greenland shelf. The data set consists of two strike lines covering the seaward-most part of the Northeast Greenland shelf and the landward-most part of the EGR, and one cross line extending from the Boreas Basin, across the ridge and into the Greenland Basin. A total of 15 ocean bottom seismometers and 46 sonobuoys were deployed along the three seismic refraction lines. P-wave velocity models for the crust and upper mantle were derived by forward and inverse modelling of the travel times of the observed seismic phases using the raytracing algorithm RAYINVR. Seismic reflection data, coinciding with the seismic refraction data were used to guide the modelling of the sedimentary layers down to basement. The velocity models confirm that the crust has a continental nature along both ridge segments with a velocity structure that significantly differs from that of normal oceanic crust. The models also show that the crust of the EGR is linked to

  11. Insight into biogeochemical inputs and composition of Greenland Ice Sheet surface snow and glacial forefield river catchment environments.

    Science.gov (United States)

    Cameron, Karen; Hagedorn, Birgit; Dieser, Markus; Christner, Brent; Choquette, Kyla; Sletten, Ronald; Lui, Lu; Junge, Karen

    2014-05-01

    The volume of freshwater transported from Greenland to surrounding marine waters has tended to increase annually over the past four decades as a result of warmer surface air temperatures (Bamber et al 2012, Hanna et al 2008). Ice sheet run off is estimated to make up approximately of third of this volume (Bamber et al 2012). However, the biogeochemical composition and seeding sources of the Greenland Ice Sheet supraglacial landscape is largely unknown. In this study, the structure and diversity of surface snow microbial assemblages from two regions of the western Greenland Ice Sheet ice-margin was investigated through the sequencing of small subunit rRNA genes. Furthermore, the origins of microbiota were investigated by examining correlations to molecular data obtained from marine, soil, freshwater and atmospheric environments and to geochemical analytes measured in the snow. Snow was found to contain a diverse assemblage of bacteria (Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria) and eukarya (Alveolata, Fungi, Stramenopiles and Viridiplantae). Phylotypes related to archaeal Thaumarchaeota and Euryarchaeota phyla were also identified. The structure of microbial assemblages was found to have strong similarities to communities sampled from marine and air environments, and sequences obtained from the South-West region, near Kangerlussuaq, which is bordered by an extensive periglacial expanse, had additional resemblances to soil originating communities. Strong correlations were found between bacterial beta diversity and Na+ and Cl- concentrations. These data suggest that surface snow from western regions of Greenland contain microbiota that are most likely derived from exogenous, wind transported sources. Downstream of the supraglacial environment, Greenland's rivers likely influence the ecology of localized estuary and marine systems. Here we characterize the geochemical and biotic composition of a glacial and glacial forefield fed river catchment in

  12. NONLINEAR DYNAMIC BEHAVIOR OF VISCOELATIC TRANSMISSION BELT

    Institute of Scientific and Technical Information of China (English)

    Li Yinghui; Gao Qing; Jian Kailin; Yin Xuegang

    2003-01-01

    The nonlinear dynamic responses of viscoelastic axially transmission belts are investigated and the Kelvin viscoelastic differential constitutive model is employed to characterize the material property of belts. The generalized equation of motion is obtained for a viscoelatic axially transmission belts with geometric nonlinearity first, and then is reduced to be a set of second-order nonlinear ordinary differential equations by applying Galerkin's method. Finally, the effects of viscosity parameter and elastic parameter and the moving velocity of the belts on the transient responses are investigated by the research of digital simulation.

  13. PRELIMINARY DISCUSSION ON METALLOGENESIS OF LANCANGJIANG RIVER TRANSITIONAL FIELD TECTONIC ZONE IN WESTERN YUNNAN

    Institute of Scientific and Technical Information of China (English)

    HU Bin; DAI Tagen; HU Ruizhong; GUO Qun

    2004-01-01

    Applying the crustobody geotectonic theory to geological prospecting at the Lancangjiang river metallogenic belt in western Yunnan province, and on the basis of the basic geological background of western Yunnan and the space-time evolution-movement historical-dynamic features of the Lancangjiang river tectonic belt, the author has discussed firstly the metallogenesis of the Lancangjiang river transitional field tectonic zone, which can provide a new theoretical foundation for exploring the space-time laws of mineralization in this region.

  14. A review of structural patterns and melting processes in the Archean craton of West Greenland: Evidence for crustal growth at convergent plate margins as opposed to non-uniformitarian models

    Science.gov (United States)

    Polat, Ali; Wang, Lu; Appel, Peter W. U.

    2015-11-01

    The Archean craton of West Greenland consists of many fault-bounded Eoarchean to Neoarchean tectonic terranes (crustal blocks). These tectonic terranes are composed mainly of tonalite-trondhjemite-granodiorite (TTG) gneisses, granitic gneisses, metavolcanic-dominated supracrustal belts, layered anorthositic complexes, and late- to post-tectonic granites. Rock assemblages and geochemical signatures in these terranes suggest that they represent fragments of dismembered oceanic island arcs, consisting mainly of TTG plutons, tholeiitic to calc-alkaline basalts, boninites, picrites, and cumulate layers of ultramafic rocks, gabbros, leucogabbros and anorthosites, with minor sedimentary rocks. The structural characteristics of the terrane boundaries are consistent with the assembly of these island arcs through modern style of horizontal tectonics, suggesting that the Archean craton of West Greenland grew at convergent plate margins. Several supracrustal belts that occur at or near the terrane boundaries are interpreted as relict accretionary prisms. The terranes display fold and thrust structures and contain numerous 10 cm to 20 m wide bifurcating, ductile shear zones that are characterized by a variety of structures including transposed and redistributed isoclinal folds. Geometrically these structures are similar to those occurring on regional scales, suggesting that the Archean craton of West Greenland can be interpreted as a continental scale accretionary complex, such as the Paleozoic Altaids. Melting of metavolcanic rocks during tectonic thickening in the arcs played an important role in the generation of TTGs. Non-uniformitarian models proposed for the origin of Archean terranes have no analogs in the geologic record and are inconsistent with structural, lithological, petrological and geochemical data collected from Archean terranes over the last four decades. The style of deformation and generation of felsic rocks on outcrop scales in the Archean craton of West

  15. The Greenland analogue project. Yearly report 2010

    Energy Technology Data Exchange (ETDEWEB)

    Harper, J.; Brinkerhoff, D.; Johnson, J. [University of Montana, Missoula (United States); Ruskeeniemi, T.; Engstroem, J.; Kukkonen, I. [Geological Survey of Finland (Finland)] [and others

    2012-04-15

    A four-year field and modelling study of the Greenland ice sheet and subsurface conditions, Greenland Analogue Project (GAP), has been initiated collaboratively by SKB, Posiva and NWMO to advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository. The study site encompasses a land terminus portion of the Greenland ice sheet, east of Kangerlussuaq, and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project begins in 2009 and is scheduled for completion in 2012. Our current understanding of the hydrological, hydrogeological and hydrogeochemical processes associated with cold climate conditions and glacial cycles, and their impact on the long-term performance of deep geological repositories for spent nuclear fuel, will be significantly improved by studying a modern analogue. The GAP will conduct the first in situ investigations of some of the parameters and processes needed to achieve a better understanding of how an ice sheet may impact a deep repository, and will provide measurements, observations and data that may significantly improve our safety assessments and risk analyses of glaciation scenarios. This report was produced by the GAP team members and presents an overview of the activities within the GAP during the interval January 1 to December 31, 2010, as well as research results obtained during this time frame. Research for the GAP is ongoing, and additional results related to the data presented here may become available in the future and will be presented in subsequent annual reports. (orig.)

  16. The Greenland analogue project. Yearly report 2010

    International Nuclear Information System (INIS)

    A four-year field and modelling study of the Greenland ice sheet and subsurface conditions, Greenland Analogue Project (GAP), has been initiated collaboratively by SKB, Posiva and NWMO to advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository. The study site encompasses a land terminus portion of the Greenland ice sheet, east of Kangerlussuaq, and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project begins in 2009 and is scheduled for completion in 2012. Our current understanding of the hydrological, hydrogeological and hydrogeochemical processes associated with cold climate conditions and glacial cycles, and their impact on the long-term performance of deep geological repositories for spent nuclear fuel, will be significantly improved by studying a modern analogue. The GAP will conduct the first in situ investigations of some of the parameters and processes needed to achieve a better understanding of how an ice sheet may impact a deep repository, and will provide measurements, observations and data that may significantly improve our safety assessments and risk analyses of glaciation scenarios. This report was produced by the GAP team members and presents an overview of the activities within the GAP during the interval January 1 to December 31, 2010, as well as research results obtained during this time frame. Research for the GAP is ongoing, and additional results related to the data presented here may become available in the future and will be presented in subsequent annual reports. (orig.)

  17. The recent warming trend in North Greenland

    Science.gov (United States)

    Orsi, Anais; Kawamura, Kenji; Masson-Delmotte, Valerie; Landais, Amaelle; Severinghaus, Jeff

    2015-04-01

    The arctic is the fastest warming region on Earth, but it is also one where there is little historical data. Although summer warming causes melt, the annual temperature trend is dominated by the winter and fall season, which are much less well documented. In addition, the instrumental record relies principally on coastal weather stations, and there are very few direct temperature observations in the interior dating back more than 30 years, especially in North Greenland, where the current warming trend is the largest. Here, we present a temperature reconstruction from NEEM (51°W, 77°N), in North Greenland, for the last 100 years, which allows us to put the recent trend in the context of the longer term climate. We use a combination of two independent proxies to reconstruct the temperature history at NEEM: borehole temperature and inert gas isotope measurements in the firn. Borehole temperature takes advantage of the low temperature diffusivity of the snow and ice, which allows the temperature history to be preserved in the ice for several centuries. Temperature gradients in the firn (old snow above the ice) influence the gas isotopic composition: thermal fractionation causes heavy isotopes to concentrate on the cold end of the firn column. We measured the isotopes of inert gases (N2, Ar and Kr), which have a constant atmospheric composition through time, and use the thermal fractionation signal as an additional constraint on the temperature history at the site. We find that NEEM has been warming by 0.86±0.22°C/decade over the past 30 years, from -28.55±0.29°C for the 1900-1970 average to -26.77±0.16°C for the 2000-2010 average. The warming rate at NEEM is similar to that of Greenland Summit, and confirms the large warming trends in North Greenland (polar amplification) and high altitude sites (tropospheric rather than surface warming). Water isotopes show that the recent past has not met the level of the 1928 anomaly; but the average of the past 30 years has

  18. Characterization of household waste in Greenland

    DEFF Research Database (Denmark)

    Eisted, Rasmus; Christensen, Thomas Højlund

    2011-01-01

    by magazine type paper) and glass (7%) were other important material fractions of the household waste. The remaining approximately 10% constituted of steel (1.5%), aluminum (0.5%), plastic (2.4%), wood (1.0%), non-combustible waste (1.8%) and household hazardous waste (1.2%). The high content of biowaste...... and the low content of paper make Greenlandic waste much different from Danish household waste. The moisture content, calorific value and chemical composition (55 elements, of which 22 were below detection limits) were determined for each material fraction. These characteristics were similar to what has been...

  19. Greenlandic qajaq as heritage, activity and tourism

    OpenAIRE

    Lennert, Frederik Adam

    2015-01-01

    I will be using the Greenlandic name to what you know, as “kayak” which for me will be qajaq. (Note on Inuit terms: The word “kayak” is the English equivalent for a word spoken by Native Inuit. The word is made with the tongue against the uvula to produce a “q” sound (instead of a “k”). The “a” sounds are pronounced like the “a” in “father”. The word for Inuit watercraft should be spelled “qayaq” in English, or “qajaq” in Danish or German). My late grandfather was raised to become a hunte...

  20. Uncertainty in Greenland glacial isostatic adjustment

    DEFF Research Database (Denmark)

    Milne, G. A.; Lecavalier, B.; Kjeldsen, K. K.;

    changes (commonly referred to as glacial isostatic adjustment (GIA)) can be defined. Predictions based on a new model of Greenland GIA will be shown. Using these predictions as a reference, we will consider the influence of plausible variations in some key aspects of both the Earth and ice load components...... of the GIA model on predictions of land motion and gravity changes. The sensitivity of model output to plausible variations in both depth-dependent and lateral viscosity structure will be considered. With respect to the ice model, we will compare the relative contributions of loading during key periods...

  1. Greenland Ice Sheet: Increased coastal thinning

    OpenAIRE

    Krabill, W.; Hanna, E.; Huybrechts, Philippe; W. Abdalati; Cappelen, J.; Csatho, B.; Frederick, E; Manizade, S; Martin, C; Sonntag, J; Swift, R.; Thomas, R.; Yungel, J.

    2004-01-01

    Repeated laser-altimeter surveys and modelled snowfall/summer melt show average ice loss from Greenland between 1997 and 2003 was 80 ± 12 km3 yr, compared to about 60 km3 yr 1 for 1993/41998/9. Half of the increase was from higher summer melting, with the rest caused by velocities of some glaciers exceeding those needed to balance upstream snow accumulation. Velocities of one large glacier almost doubled between 1997 and 2003, resulting in net loss from its drainage basin by about 20 km of ic...

  2. What Darkens the Greenland Ice Sheet?

    OpenAIRE

    Tedesco, M.; Doherty, S; Warren, S; Tranter, M.; J. Stroeve; Fettweis, Xavier; Alexander, P.

    2015-01-01

    Most of the massive ice sheet that covers roughly four fifths of Greenland melts at the surface in summer. As long as the ice sheet regains its mass in the winter, this is not catastrophic. However, if the ice sheet melted entirely, sea levels would rise by more than 7 meters, with obvious and severe consequences for human civilization. Not surprisingly, scientists are working hard to determine if and when the ice sheet will transition (or if it has already transitioned) from a stable sta...

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

    OpenAIRE

    Laura Ghigliotti; Julius Nielsen; Jorgen Schou Christiansen; Eva Pisano

    2015-01-01

    The Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801) is the largest predatory fish in Arctic waters. The socio-economic significance of Greenland shark is demonstrated by its impact on the fishing cultures in Greenland, Scandinavia and Iceland for centuries. The fundamental biology and ecological role of Greenland shark, on the other hand, is virtually unknown. Although knowledge of its life history is limited, increasing evidence indicates that the Greenland shark may unde...

  4. Towards Introducing a Geocoding Information System for Greenland

    Science.gov (United States)

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

    2011-08-01

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

  5. Public Consultation Processes in Greenland Regarding the Mining Industry

    Directory of Open Access Journals (Sweden)

    Maria Ackrén

    2016-05-01

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

  6. Success and failure of reindeer herding in Greenland

    Directory of Open Access Journals (Sweden)

    Christine Cuyler

    1999-04-01

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

  7. Apparatus for heat treating plastic belts

    Science.gov (United States)

    Topits, A., Jr.

    1975-01-01

    Apparatus performs programed rotating, stretching/shrinking and heat treatment necessary to fabrication of high-performance plastic belts. Belts can be treated in lengths varying from 7 to 48 in., in widths up to 1 in., and in thicknesses up to approximately 0.003 in.

  8. Understanding Quaternions and the Dirac Belt Trick

    Science.gov (United States)

    Staley, Mark

    2010-01-01

    The Dirac belt trick is often employed in physics classrooms to show that a 2n rotation is not topologically equivalent to the absence of rotation whereas a 4n rotation is, mirroring a key property of quaternions and their isomorphic cousins, spinors. The belt trick can leave the student wondering if a real understanding of quaternions and spinors…

  9. Parameters affecting seat belt use in Greece.

    Science.gov (United States)

    Yannis, G; Laiou, A; Vardaki, S; Papadimitriou, E; Dragomanovits, A; Kanellaidis, G

    2011-09-01

    The objective of this research is the exploration of seat belt use in Greece and particularly the identification of the parameters affecting seat belt use in Greece. A national field survey was conducted for the analytical recording of seat belt use. A binary logistic regression model was developed, and the impact of each parameter on seat belt use in Greece was quantified. Parameters included in the model concern characteristics of car occupants (gender, age and position in the car), the type of the car and the type of the road network. The data collection revealed that in Greece, the non-use of seat belt on the urban road network was higher than on the national and rural road network and young and older men use seat belts the least. The developed model showed that travelling on a national road is negative for not wearing the seat belt. Finally, the variable with the highest impact on not wearing a seat belt is being a passenger on the back seats. PMID:21452095

  10. Anthropogenic carbon in the East Greenland Current

    Science.gov (United States)

    Jutterström, Sara; Jeansson, Emil

    2008-07-01

    Sections of dissolved inorganic anthropogenic carbon ( CTanthro) based on 2002 data in the East Greenland Current (EGC) are presented. The CTanthro has been estimated using a model based on optimum multiparameter analysis with predefined source water types. Values of CTanthro have been assigned to the source water types through age estimations based on the transit time distribution (TTD) technique. The validity of this approach is discussed and compared to other methods. The results indicated that the EGC had rather high levels of CTanthro in the whole water column, and the anthropogenic signal of the different source areas were detected along the southward transit. We estimated an annual transport of CTanthro with the Denmark Strait overflow ( σθ > 27.8 kg m -3) of ∼0.036 ± 0.005 Gt C y -1. The mean CTanthro concentration in this density range was ∼30 μmol kg -1. The main contribution was from Atlantic derived waters, the Polar Intermediate Water and the Greenland Sea Arctic Intermediate Water.

  11. Robots could assist scientists working in Greenland

    Science.gov (United States)

    Showstack, Randy

    2011-07-01

    GREENLAND—Tom Lane and Suk Joon Lee, recent graduates of Dartmouth University's Thayer School of Engineering, in Hanover, N. H., are standing outside in the frigid cold testing an autonomous robot that could help with scientific research and logistics in harsh polar environments. This summer, Lane, Lee, and others are at Summit Station, a U.S. National Science Foundation (NSF)-sponsored scientific research station in Greenland, fine-tuning a battery-powered Yeti robot as part of a team working on the NSF-funded Cool Robot project. The station, also known as Summit Camp, is located on the highest point of the Greenland Ice Sheet (72°N, 38°W, 3200 meters above sea level) near the middle of the island. It is a proving ground this season for putting the approximately 68-kilogram, 1-cubic-meter robot through its paces, including improving Yeti's mobility capabilities and field-testing the robot. (See the electronic supplement to this Eos issue for a video of Yeti in action (http://www.agu.org/eos_elec/).) During field-testing, plans call for the robot to collect data on elevation and snow surface characteristics, including accumulation. In addition, the robot will collect black carbon and elemental carbon particulate matter air samples around Summit Camp's power generator to help study carbon dispersion over snow.

  12. Instrument for Analysis of Greenland's Glacier Mills

    Science.gov (United States)

    Behar, Alberto E.; Matthews, Jaret B.; Tran, Hung B.; Steffen, Konrad; McGrath, Dan; Phillips, Thomas; Elliot, Andrew; OHern, Sean; Lutz, Colin; Martin, Sujita; Wang, Henry

    2010-01-01

    A new instrument is used to study the inner workings of Greenland s glacier mills by riding the currents inside a glacier s moulin. The West Greenland Moulin Explorer instrument was deployed into a tubular shaft to autonomously record temperature, pressure, 3D acceleration, and location. It is built with a slightly positive buoyancy in order to assist in recovery. The unit is made up of several components. A 3-axis MEMS (microelectromechanical systems) accelerometer with 0.001-g resolution forms the base of the unit. A pressure transducer is added that is capable of withstanding 500 psi (=3.4 MPa), and surviving down to -40 C. An Iridium modem sends out data every 10 minutes. The location is traced by a GPS (Global Positioning System) unit. This GPS unit is also used for recovery after the mission. Power is provided by a high-capacity lithium thionyl chloride D-sized battery. The accelerometer is housed inside a cylindrical, foot-long (=30 cm) polyvinyl chloride (PVC) shell sealed at each end with acrylic. The pressure transducer is attached to one of these lids and a MEMS accelerometer to the other, recording 100 samples per second per axis.

  13. Diabetes in Population Isolates: Lessons from Greenland.

    Science.gov (United States)

    Grarup, Niels; Moltke, Ida; Albrechtsen, Anders; Hansen, Torben

    2015-01-01

    Type 2 diabetes (T2D) is an increasing health problem worldwide with particularly high occurrence in specific subpopulations and ancestry groups. The high prevalence of T2D is caused both by changes in lifestyle and genetic predisposition. A large number of studies have sought to identify the genetic determinants of T2D in large, open populations such as Europeans and Asians. However, studies of T2D in population isolates are gaining attention as they provide several advantages over open populations in genetic disease studies, including increased linkage disequilibrium, homogeneous environmental exposure, and increased allele frequency. We recently performed a study in the small, historically isolated Greenlandic population, in which the prevalence of T2D has increased to more than 10%. In this study, we identified a common nonsense variant in TBC1D4, which has a population-wide impact on glucose-stimulated plasma glucose, serum insulin levels, and T2D. The variant defines a specific subtype of non-autoimmune diabetes characterized by decreased post-prandial glucose uptake and muscular insulin resistance. These and other recent findings in population isolates illustrate the value of performing medical genetic studies in genetically isolated populations. In this review, we describe some of the advantages of performing genetic studies of T2D and related cardio-metabolic traits in a population isolate like the Greenlandic, and we discuss potentials and perspectives for future research into T2D in this population. PMID:27111118

  14. Radiation belt dynamics during solar minimum

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G. (Geophysics Lab., Air Force Systems Command, Hanscom AFB, MA (US)); Holeman, E. (Physics Dept., Boston College, Chestnut Hill, MA (US))

    1989-12-01

    Two types of temporal variation in the radiation belts are studied using low altitude data taken onboard the DMSP F7 satellite: those associated with the solar cycle and those associated with large magnetic storm effects. Over a three-year period from 1984 to 1987 and encompassing solar minimum, the protons in the heart of the inner belt increased at a rate of approximately 6% per year. Over the same period, outer zone electron enhancements declined both in number and peak intensity. During the large magnetic storm of February 1986, following the period of peak ring current intensity, a second proton belt with energies up to 50 MeV was found at magnetic latitudes between 45{degrees} and 55{degrees}. The belt lasted for more than 100 days. The slot region between the inner and outer electron belts collapsed by the merging of the two populations and did not reform for 40 days.

  15. The East Greenland rifted volcanic margin

    Directory of Open Access Journals (Sweden)

    C. Kent Brooks

    2011-12-01

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

  16. A first isotopic dietary study of the Greenlandic Thule Culture

    DEFF Research Database (Denmark)

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

    2012-01-01

    The isotopic dietary method has been applied to samples of some 65 Thule Culture individuals from existing archaeological collections of Greenlandic human skeletal material. The aim was to use the Greenlandic Thule Culture as a test of the isotopic method, in that we know they were heavily...... was used as the basis for analysis. As expected, the results indicate that these people were almost entirely dependent on the marine biosphere for their protein. An exception is those from Northeast Greenland, whose isotopic signatures show evidence for consumption of terrestrial protein as well...

  17. Present conditions in Greenland and the Kangerlussuaq area

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, A. B. (Geological Survey of Denmark and Greenland, Copenhagen (Denmark))

    2010-01-15

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

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

    Science.gov (United States)

    Koenig, Lora

    2009-01-01

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

  19. Greenlandic postcoloniality and the predicament of prosperity inducing climate change

    DEFF Research Database (Denmark)

    Jensen, Lars

    mining consultant who used to work for the Greenlandic government to collaborate with the Greenlandic self-government. This requires us to think across a huge complexity of race, whiteness, climate change – and the postcolonial condition. I haven’t decided on the precise focus yet, as the case...... Greenland’s independence from its former colonial power, Denmark. In Denmark there has been an equally intense debate, which unsurprisingly is of a very different nature. Part of the debate here has been over, whether Greenland has indeed the right to decide over its resources, something agreed...

  20. Present conditions in Greenland and the Kangerlussuaq area

    International Nuclear Information System (INIS)

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

  1. Marginal thinning in Northwest Greenland during 2002-2011

    DEFF Research Database (Denmark)

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

    2012-01-01

    Many glaciers along the southeast and northwest coast of Greenland have accelerated, increasing the Greenland ice sheet's (GrIS) contribution to global sea-level rise. Here, we map elevation changes in northwest Greenland during 2003-2009 using high-resolution Ice, Cloud and land Elevation...... with independent measurements from GPS and the Gravity Recovery and Climate Experiment (GRACE) satellite gravity mission, launched in March, 2002. The GRACE results provide a direct measure of mass loss averaged over the entire northwest sector, while the GPS data are used to monitor crustal uplift caused by ice...

  2. Predicting spectral and PAR light attenuation in Greenlandic coastal waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Markager, Stiig; Stedmon, Colin

    present models for spectral and PAR (photosynthetically active radiation) attenuation in two contrasting Greenlandic fjords, Godthåbsfjord (SW Greenland) and Young Sound (NE Greenland). The fjords differ in the character and concentrations of optically active components present: dissolved organic material...... (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  3. Predicting Spectral and PAR Light Attenuation in Greenlandic Coastal Waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Stedmon, Colin A.; Markager, Stiig

    present models for spectral and PAR (photosynthetically active radiation) attenuation in two contrasting Greenlandic fjords, Godthåbsfjord (SW Greenland) and Young Sound (NE Greenland). The fjords differ in the character and concentrations of optically active components present: dissolved organic material...... (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  4. Brief communication "The aerophotogrammetric map of Greenland ice masses"

    OpenAIRE

    Citterio, M.; A. P. Ahlstrøm

    2012-01-01

    The PROMICE (Programme for Monitoring of the Greenland Ice Sheet) aerophotogrammetric map of Greenland ice masses is the first high resolution dataset documenting the mid-1980's extent of the Greenland Ice Sheet and all the local glaciers and ice caps. The total glacierized area was 1 804 638 km2 ± 2178 km2, of which 88 083 ± 1240 km2 belonged to local glaciers and ice caps (GIC) substantially independent from the Greenl...

  5. Greenland Halibut in Upernavik: a preliminary study of the importance of the stock for the fishing populace:A study undertaken under the Greenland Climate Research Centre

    OpenAIRE

    Delaney, Alyne E.; Becker Jakobsen, Rikke; Hendriksen, Kåre

    2012-01-01

    This report presents research undertaken with the belief that a need exists for better understanding of the social and cultural importance of the Greenland Halibut (Reinhardtius hippoglossoides) fishery to Greenlanders. It was decided the research would focus on one of three coastal Greenland Halibut fishery districts: Upernavik. Upernavik was chosen mgiven the critical importance of Greenland halibut for local fishers and area residents. The best method for presenting a combination of social...

  6. New Findings in High-Pressure and Ultrahigh-Pressure Metamorphic Belt of Tongbaishan-Dabieshan Regions, Central China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Tongbai-Dabieshan high-pressure (HP) and ultrahigh-pressure (UHP) belt is sandwiched between the Yangtze and the Sinokorean cratons. It connects the Qinling orogenic belt in the west and links toward the east to the Sulu ultrahigh-pressure (UHP) belt. At present there is a consensus that the UHP metamorphic rocks are the products of the oblique collision between the Yangtze and Sinokorean cratons during the Triassic. However, there is still a lot of controversies about the formation and exhumation of the HP- and UHP-metamorphic belts. The present research work on the composition and the structural geometry and kinetics of the HP- and UHP- metamorphic belt has shown the following new results: (1) The overall structural geometry pattern of Dabieshan is similar to the metamorphic core complex developed in the western North America; (2) The discoveries of HP and UHP metamorphic rocks in the north of Dabieshan indicate that the significance of Shuihou-Wuhe fault should be re-evaluated; (3) A series of micro-structural evidence, including the newly-found retrograde granulite facies assemblages in the garnet pyroxenites, substantiate the extensional processes following the collision event; (4) The discovery of partial melting phenomena in the UHP-metamorphic belts illuminates the relationship between the HP- and UHP metamorphic rocks and their associated granite gneiss. All of these new findings will greatly improve our understanding of the formation and exhumation of the high-pressure and ultrahigh pressure metamorphic belts.

  7. The western Greenland Sea. A preliminary strategic environmental impact assessment of hydrocarbon activities in the KANUMAS East area; Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Boertmann, D.; Johansen, K.; Maltha Rasmussen, L.; Schiedek, D.; Ugarte, F.; Mosbech, A.; Frederiksen, M.; Bjerrum, M.

    2009-05-15

    The environmental impacts of exploration activities will mainly be disturbance from activities creating noise such as seismic surveys and drilling. The impacts are expected to be relatively small, local and temporary, because of the intermittent nature of the exploration activities. Furthermore, the season for exploration activities is very short and limited to the few months with light ice conditions (June-October). The activities during development, production and transport are on the other hand long-lasting, and there are several activities which have the potential to cause severe environmental impacts. Careful Health, Safety and Environment (HSE) procedures, application of Best Available Technique (BAT) and Best Environmental Practice (BEP), zero-discharge policy and planning in combination with thorough background studies and application of the Precautionary Principle can mitigate most of these. The environmentally most severe accident would be a large oil spill. This has the potential to impact the marine ecosystem on all levels from primary production to the top predators. Oil spill trajectory modelling was carried out by DMI as a part of this SEIA. In most of the modelled oil spill drift scenarios oil does not reach the coasts, but stays offshore. However, three of the 24 scenarios indicate 11 that under certain conditions, oil may reach shores up to several hundred kilometres from the spill site. (ln)

  8. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: A lead isotope study of an Archaean gold prospect in the Attu region, Nagssugtoqidian orogen, West Greenland

    Directory of Open Access Journals (Sweden)

    Stendal, Henrik

    2006-12-01

    Full Text Available This paper presents a lead isotope investigation of a gold prospect south of the village Attu in the northern part of the Nagssugtoqidian orogen in central West Greenland. The Attu gold prospect is a replacement gold occurrence, related to a shear/mylonite zone along a contact between orthogneissand amphibolite within the Nagssugtoqidian orogenic belt. The mineral occurrence is small, less than 0.5 m wide, and can be followed along strike for several hundred metres. The mineral assemblage is pyrite, chalcopyrite, magnetite and gold. The host rocks to the gold prospect are granulite facies ‘brown gneisses’ and amphibolites. Pb-isotopic data on magnetite from the host rocks yield an isochron in a 207Pb/204Pb vs. 206Pb/204Pb diagram, giving a date of 3162 ± 43 Ma (MSWD = 0.5. This date is interpreted to represent the age of the rocks in question, and is older than dates obtained from rocks elsewhere within the Nagssugtoqidian orogen. Pb-isotopic data on cataclastic magnetite from the shear zone lie close to this isochron, indicating a similar origin. The Pb-isotopic compositions of the ore minerals are similar to those previously obtained from the close-by ~2650 Ma Rifkol granite, and suggest a genetic link between the emplacement of this granite and the formation of the ore minerals in the shear/mylonite zone. Consequently, the age of the gold mineralisation is interpreted tobe late Archaean.

  9. Chronic suppurative otitis media in a birth cohort of children in Greenland: population-based study of incidence and risk factors

    DEFF Research Database (Denmark)

    Koch, Anders; Homøe, Preben; Pipper, Christian Bressen;

    2011-01-01

    Inuits of the Arctic experience very high rates of chronic suppurative otitis media (CSOM), yet world-wide, very little is known about the epidemiology of CSOM. The study aims were to determine incidence, median age at debut, risk factors, and associated population attributable risks for CSOM...... in young children in Sisimiut, the second biggest town of Greenland (population 5400), where living conditions are relatively western and approximately 90% are Inuits....

  10. A Palaeoproterozoic multi-stage hydrothermal alteration system at Nalunaq gold deposit, South Greenland

    Science.gov (United States)

    Bell, Robin-Marie; Kolb, Jochen; Waight, Tod Earle; Bagas, Leon; Thomsen, Tonny B.

    2016-07-01

    Nalunaq is an orogenic, high gold grade deposit situated on the Nanortalik Peninsula, South Greenland. Mineralisation is hosted in shear zone-controlled quartz veins, located in fine- and medium-grained amphibolite. The deposit was the site of Greenland's only operating metalliferous mine until its closure in 2014, having produced 10.67 t of gold. This study uses a combination of field investigation, petrography and U/Pb zircon and titanite geochronology to define a multi-stage hydrothermal alteration system at Nalunaq. A clinopyroxene-plagioclase-garnet(-sulphide) alteration zone (CPGZ) developed in the Nanortalik Peninsula, close to regional peak metamorphism and prior to gold-quartz vein formation. The ca. 1783-1762-Ma gold-quartz veins are hosted in reactivated shear zones with a hydrothermal alteration halo of biotite-arsenopyrite-sericite-actinolite-pyrrhotite(-chlorite-plagioclase-löllingite-tourmaline-titanite), which is best developed in areas of exceptionally high gold grades. Aplite dykes dated to ca. 1762 Ma cross-cut the gold-quartz veins, providing a minimum age for mineralisation. A hydrothermal calcite-titanite alteration assemblage is dated to ca. 1766 Ma; however, this alteration is highly isolated, and as a result, its field relationships are poorly constrained. The hydrothermal alteration and mineralisation is cut by several generations of ca. 1745-Ma biotite granodiorite accompanied by brittle deformation. A ca. 1745-Ma lower greenschist facies hydrothermal epidote-calcite-zoisite alteration assemblage with numerous accessory minerals forms halos surrounding the late-stage fractures. The contrasting hydrothermal alteration styles at Nalunaq indicate a complex history of exhumation from amphibolite facies conditions to lower greenschist facies conditions in an orogenic belt which resembles modern Phanerozoic orogens.

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

    Science.gov (United States)

    Steffen, Konrad; Box, Jason

    2003-01-01

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

  12. Feeding ecology of Greenland halibut and sandeel larvae off West Greenland

    DEFF Research Database (Denmark)

    Stenberg, Claus; Munk, Peter; Folkvord, A.;

    2006-01-01

    Feeding ecology of Greenland halibut (Gr. halibut) (Reinhardtius hippoglossoides) and sandeel (Ammodytes sp.) larvae on the West Greenland shelf was studied during the main part of the productive season (May, June and July). Copepods were the main prey item for larval Gr. halibut and sandeel......, constituting between 88 and 99% of the ingested prey biomass. For both species, absolute size of preferred prey increased during ontogeny. However, preferred copepod size in relation to larval length differed markedly. In Gr. halibut, the relative size of the prey declined during growth of the larvae, while...... it remained constant for sandeel at a level of 2.7% of larval length. This led to a reduction in prey niche overlap between the two species. The available prey copepod biomass differed distinctly across the shelf area. In May, the prey density of Gr. halibut was the highest in the off-shelf area in Davis...

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

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2014-01-01

    Until present, seismic surveys have only been carried out offshore and near the coasts of Greenland, where the crustal structure is affected by oceanic break-up. We present the deep seismic structure of the crust of the interior of Greenland, based on the new and the only existing so far seismic...... developed an automatic routine to check the amplitudes and spectra of the selected seismic phases and to check the differences/challenges in making seismic experiments on ice and the effects of ice on data interpretation. Using tomographic inversion and forward ray tracing modelling we have obtained the two...... result from past collision tectonics or, alternatively, may be related to the speculated passage of the Iceland mantle plume. Comparison of our results with the new receiver function studies (Kraft et al., personal communication) suggests the possibility for a massive underplating along the profile...

  14. Killer whale depredation and associated costs to Alaskan sablefish, Pacific halibut and Greenland turbot longliners.

    Directory of Open Access Journals (Sweden)

    Megan J Peterson

    Full Text Available Killer whale (Orcinus orca depredation (whales stealing or damaging fish caught on fishing gear adversely impacts demersal longline fisheries for sablefish (Anoplopoma fimbria, Pacific halibut (Hippoglossus stenolepis and Greenland turbot (Reinhardtius hippoglossoides in the Bering Sea, Aleutian Islands and Western Gulf of Alaska. These interactions increase direct costs and opportunity costs associated with catching fish and reduce the profitability of longline fishing in western Alaska. This study synthesizes National Marine Fisheries Service observer data, National Marine Fisheries Service sablefish longline survey and fishermen-collected depredation data to: 1 estimate the frequency of killer whale depredation on longline fisheries in Alaska; 2 estimate depredation-related catch per unit effort reductions; and 3 assess direct costs and opportunity costs incurred by longliners in western Alaska as a result of killer whale interactions. The percentage of commercial fishery sets affected by killer whales was highest in the Bering Sea fisheries for: sablefish (21.4%, Greenland turbot (9.9%, and Pacific halibut (6.9%. Average catch per unit effort reductions on depredated sets ranged from 35.1-69.3% for the observed longline fleet in all three management areas from 1998-2012 (p<0.001. To compensate for depredation, fishermen set additional gear to catch the same amount of fish, and this increased fuel costs by an additional 82% per depredated set (average $433 additional fuel per depredated set. In a separate analysis with six longline vessels in 2011 and 2012, killer whale depredation avoidance measures resulted in an average additional cost of $494 per depredated vessel-day for fuel and crew food. Opportunity costs of time lost by fishermen averaged $522 per additional vessel-day on the grounds. This assessment of killer whale depredation costs represents the most extensive economic evaluation of this issue in Alaska to date and will help

  15. The Gould's Belt distance survey

    CERN Document Server

    Loinard, L; Torres, R M; Dzib, S; Rodriguez, L F; Boden, A F

    2011-01-01

    Very Long Baseline Interferometry (VLBI) observations can provide the position of compact radio sources with an accuracy of order 50 micro-arcseconds. This is sufficient to measure the trigonometric parallax and proper motions of any object within 500 pc of the Sun to better than a few percent. Because they are magnetically active, young stars are often associated with compact radio emission detectable using VLBI techniques. Here we will show how VLBI observations have already constrained the distance to the most often studied nearby regions of star-formation (Taurus, Ophiuchus, Orion, etc.) and have started to provide information on their internal structure and kinematics. We will then briefly describe a large project (called The Gould's Belt Distance Survey) designed to provide a detailed view of star-formation in the Solar neighborhood using VLBI observations.

  16. Binaries in the Kuiper Belt

    CERN Document Server

    Noll, K S; Chiang, E I; Margot, J L; Kern, S D; Noll, Keith S.; Grundy, William M.; Chiang, Eugene I.; Margot, Jean-Luc; Kern, Susan D.

    2007-01-01

    Binaries have played a crucial role many times in the history of modern astronomy and are doing so again in the rapidly evolving exploration of the Kuiper Belt. The large fraction of transneptunian objects that are binary or multiple, 48 such systems are now known, has been an unanticipated windfall. Separations and relative magnitudes measured in discovery images give important information on the statistical properties of the binary population that can be related to competing models of binary formation. Orbits, derived for 13 systems, provide a determination of the system mass. Masses can be used to derive densities and albedos when an independent size measurement is available. Angular momenta and relative sizes of the majority of binaries are consistent with formation by dynamical capture. The small satellites of the largest transneptunian objects, in contrast, are more likely formed from collisions. Correlations of the fraction of binaries with different dynamical populations or with other physical variabl...

  17. Upper-mantle velocity structure and its relation to topography across the Caledonides in Greenland and Norway

    DEFF Research Database (Denmark)

    Hejrani, Babak; Balling, N.; Jacobsen, B. H.;

    2015-01-01

    This study investigates the upper-mantle P- and S-wave velocity structure as well as structure in the VP/VS ratio across the high topography areas of north Atlantic Caledonides, integrating data from a new East Greenland Caledonide Central Fjord Array (EGCFA) with results of recent studies of the...... Igneous Belt and further north along the Norwegian coast. This boundary stands out clearly in the P-velocity and even clearer in the S-velocity. Compositional difference between the Baltic Shield and adjacent units is indicated by consistent VP/VS ratio anomalies. The new EGCFA profile reveals a similar...... three other regions bordering the North Atlantic. This result challenges the hypothesis of widespread Late Cenozoic uplift in this region....

  18. Strategy for replacing conveyor belts in complex haulage systems

    Energy Technology Data Exchange (ETDEWEB)

    Gladysiewicz, L.; Jurdziak, L.; Masella, J.

    1986-01-01

    Discusses service life and reliability of conveyor belts used for mine haulage in brown coal surface mining and a method for optimizing belt service life. Based on analysis of operation of 900-1,200 m long belt conveyors in the Konin surface mine, failure rates and factors that influence belt reliability were determined. Effects of joints, length of belt sections and service life of each belt section were analyzed. Formulae for determining the optimum time interval for replacing belt sections on a long belt conveyor were derived. The formulae consider cost of new belt sections, replacement cost and haulage losses associated with possible belt failure caused by excessive belt service life. The optimization procedure has been successfully tested at the Turow surface mine and power plant. 4 refs.

  19. The first glacier inventory for entire Greenland

    Science.gov (United States)

    Rastner, P.; Bolch, T.; Mölg, N.; Le Bris, R.; Paul, F.

    2012-04-01

    Detailed glacier data is becoming more and more important in the last decades to solve several research issues. One of the most prominent questions in this regard is the potential contribution of glaciers and icecaps (GIC) to global sea-level rise. Primarily, estimates are uncertain due to the globally still incomplete information about glacier location and size, as well as large uncertainties in future climate scenarios. Recent studies that calculate global sea-level rise from GIC have developed simplified approaches using information from glacier inventories or gridded data sets and a range of different global climate models and emission scenarios. However, for several strongly glacierized regions very rough assumptions about the ice distribution have to be made and an urgent demand for a globally complete glacier inventory is expressed. The GIC on Greenland are one of the regions with lacking information. Within the EU FP7 project ice2sea we mapped the GIC on Greenland using Landsat TM/ETM+ imagery acquired around the year 2000, along with an additional dataset in the North (DCW - Digital Chart of the World). A digital elevation model (DEM) with 90 m resolution (GIMP DEM) was used to derive drainage divides and henceforth topographic parameters for each entity. A major challenge in this regard is the application of a consistent strategy to separate the local GIC from the ice sheet. For this purpose we have defined different levels of connectivity (CL) of the local GIC with the ice sheet: CL0: Not connected. CL1: Connected but separable (either with drainage divides in the accumulation region or in touch only - and thus separable - in the ablation region). CL2: Connected but non-separable (the local GIC contribute to the flow of an ice sheet outlet in the ablation area). Up to now close to 12'000 GIC (only CL0 and CL1) with a total area of about 129'000 km2 have been mapped considering only entities larger than 0.1 km2. The area of the ice sheet itself is

  20. 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...

  1. Lifestyle, reproductive factors and food intake in Greenlandic pregnant women

    DEFF Research Database (Denmark)

    Knudsen, Ane-Kersti Skaarup; Long, Manhai; Pedersen, Henning S;

    2015-01-01

    in Disko Bay had the lowest intake of terrestrial species. No significant geographical differences were found for intake of marine mammals or seabirds. CONCLUSIONS: The present study found relatively high BMI level and high smoking frequency in Greenlandic pregnant women. Age and region differences were....... OBJECTIVES: To describe lifestyle, reproductive factors and food intake in Greenlandic pregnant women, and to assess possible age and geographical differences. DESIGN: Cross-sectional study of 189 Greenlandic pregnant women. Inclusion criteria were ≥18 years and lived >50% of their life in Greenland. Data...... were collected in 2010-2011, and information was obtained from lifestyle and food frequency questionnaires. Two age groups for comparison were given for the pregnant women (

  2. Greenland Snow Pit and Core Stratigraphy (Analog and Digital Formats)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is comprised of scientific field study notebooks from geologist Carl S. Benson describing his traverses of Greenland from 1952 to 1955. The notebooks...

  3. Greenland Ice Surface Elevations from NASA ATM Airborne Lidar

    Data.gov (United States)

    National Aeronautics and Space Administration — Scanning laser altimeters were flown over the Greenland icesheet during late spring or early summer from 1993 to 1999. Flights spanned the entire icesheet, sampling...

  4. Potential Environmental Impacts of Oil Spills in Greenland

    DEFF Research Database (Denmark)

    This report analyses information status and research needs in relation to potential environmental impacts of oil spills (offshore and onshore) in Greenland. The report assesses potential effects and potential mitigation and monitoring measures. Information gaps are identified and a number...

  5. Governance and Tradition in Nineteenth-Century Greenland

    DEFF Research Database (Denmark)

    Rud, Søren

    2014-01-01

    century reflect a fundamental shift in the rationality behind the colonial project in Greenland. This analytical point is reached through the deployment of the theoretical concept colonial governmentality. Following the work of scholars such as Nicholas Thomas, David Scott and Gyan Prakash, it is argued......: This article investigates the way in which the concept of tradition was evoked in the colonial policies in nineteenth-century Greenland. The author argues that ‘tradition’ provided colonial officials in Greenland with a strategy that enabled them to make fundamental changes appear as a...... that a significant shift toward social engineering techniques (of governance) happened in the period. The new techniques were employed in order to structure of the life world of the Greenlanders, and ultimately shape their individuality. Finally the article draws attention to the short and long term...

  6. High export of dissolved silica from the Greenland Ice Sheet

    Science.gov (United States)

    Meire, L.; Meire, P.; Struyf, E.; Krawczyk, D. W.; Arendt, K. E.; Yde, J. C.; Juul Pedersen, T.; Hopwood, M. J.; Rysgaard, S.; Meysman, F. J. R.

    2016-09-01

    Silica is an essential element for marine life and plays a key role in the biogeochemistry of the ocean. Glacial activity stimulates rock weathering, generating dissolved silica that is exported to coastal areas along with meltwater. The magnitude of the dissolved silica export from large glacial areas such as the Greenland Ice Sheet is presently poorly quantified and not accounted for in global budgets. Here we present data from two fjord systems adjacent to the Greenland Ice Sheet which reveal a large export of dissolved silica by glacial meltwater relative to other macronutrients. Upscaled to the entire Greenland Ice Sheet, the export of dissolved silica equals 22 ± 10 Gmol Si yr-1. When the silicate-rich meltwater mixes with upwelled deep water, either inside or outside Greenland's fjords, primary production takes place at increased silicate to nitrate ratios. This likely stimulates the growth of diatoms relative to other phytoplankton groups.

  7. Seat belt use law in developing countries

    Institute of Scientific and Technical Information of China (English)

    SangWanLee

    1999-01-01

    Objective:To highlight the way to successful implementation of mandantory seat belt use law in developing countries particulary where have significant increase in number or cars and subsequent increase in car occupant casualties.Methods:Literatures concerning seat belt use were reviewed and experiences of the world.Satisfactory or not,investigated.It summed up general aspects of seat belt use as well as benefits,attitude toward legislation and measures to enhance the usage.Results:Seat belt use has been proven and stood time tested as the most effective means to protect car occupants from road crash injuries.It appears to be arduous to achieve the golal of seat belt use law in developing countries. but possible via strategies appropriately leading to legislation and promotion of the belt usage.Conclusions:It is prime necessity for the government authorities to recognize the importance of seat belt use.There needs an organizational structure composed of relevant professional from both private and government sectors which is able to carry out every steps toward successful legislation and implementation:education,publicity,enforcement,evaluation and dissemination of the law's benefits.

  8. DYNAMIC RESPONSES OF VISCOELASTIC AXIALLY MOVING BELT

    Institute of Scientific and Technical Information of China (English)

    李映辉; 高庆; 蹇开林; 殷学纲

    2003-01-01

    Based on the Kelvin viscoelastic differential constitutive law and the motion equation of the axially moving belt, the nonlinear dynamic model of the viscoelastic axial moving belt was established. And then it was reduced to be a linear differential system which the analytical solutions with a constant transport velocity and with a harmonically varying transport velocity were obtained by applying Lie group transformations. According to the nonlinear dynamic model, the effects of material parameters and the steady-state velocity and the perturbed axial velocity of the belt on the dynamic responses of the belts were investigated by the research of digital simulation. The result shows: 1 ) The nonlinear vibration frequency of the belt will become small when the relocity of the belt increases. 2 ) Increasing the value of viscosity or decreasing the value of elasticity leads to a deceasing in vibration frequencies. 3 ) The most effects of the transverse amplitudes come from the frequency of the perturbed velocity when the belt moves with harmonic velocity.

  9. Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers

    Directory of Open Access Journals (Sweden)

    J. E. Box

    2012-08-01

    Full Text Available Greenland ice sheet mass loss has accelerated in the past decade responding to combined glacier discharge and surface melt water runoff increases. During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three amplifying mechanisms to maximize the albedo feedback: (1 increased warm (south air advection along the western ice sheet increased surface sensible heating that in turn enhanced snow grain metamorphic rates, further reducing albedo; (2 increased surface downward shortwave flux, leading to more surface heating and further albedo reduction; and (3 reduced snowfall rates sustained low albedo, maximizing surface solar heating, progressively lowering albedo over multiple years. The summer net infrared and solar radiation for the high elevation accumulation area approached

  10. The Influence of the Syn-kinematic Depositional Rate on the Compressional Deformation of Pre-existing Passive Salt Diapir:The Analysis and Analogue Modeling of Salt Structures in the Western Qiulitage Structural Belt, Kuqa Depression%同构造沉积速率对先存被动盐底辟挤压变形的影响:库车坳陷西秋里塔格构造带盐构造分析及物理模拟

    Institute of Scientific and Technical Information of China (English)

    谢会文; 吴珍云; 能源; 尹宏伟; Hemin Koyi

    2014-01-01

    Two scaled analogue models are constructed to simulate the evolution of thick-skinned shortening on salt-bearing basins with pre-existing passive salt diapirs. These models simulate the evolution of the Cenozoic salt-related structures in the Qiulitage structural belt, western Kuqa depression. Model results show that the syn-kinematic depositional rate has a major controlling influence on the differential structural deformation in different longitudinal segmentations from the Bozi-Quele area (the west part) to Qiulitage-Kelasu area (the east part) in the Qiulitage structural belt, western Kuqa depression. During the shortening, the slow syn-kinematic depositional rate caused the north flank (the south flank of the Baicheng sag) of the pre-existing passive salt diapir thrust onto the south flank (the north flank of the Misikantake salt anticline) and made the formation of the Quele salt nappe and the Misikantake salt anticline in the Bozi-Quele area;In contrast, the quick syn-kinematic depositional rate caused the south flank of the pre-existing passive salt diapir thrust onto the north flank (the south flank of the Baicheng sag), which made the formation of the south Qiulitage salt anticline in the Qiulitage-Kelasu area.%文中构建了两组构造物理实验,对存在先存被动盐底辟构造的含盐盆地的厚皮挤压构造演化特征进行模拟,研究揭示了库车坳陷西段秋里塔格构造带新生代盐相关构造演化过程。实验结果表明,同构造沉积速率对库车坳陷西段秋里塔格构造带博孜—却勒区域(西段)和秋里塔格—克拉苏区域(东段)盐相关构造横向分段差异变形具有重要的控制影响作用。在挤压过程中,博孜—却勒区域慢速同构造沉积使得先存被动盐底辟北翼(拜城凹陷南翼)向南逆冲到底辟南翼之上,并促使却勒盐推覆体和米斯坎塔克盐背斜形成;而秋里塔格—克拉苏区域快速

  11. Trends in physical activity in Greenlandic schoolchildren, 1994-2006

    OpenAIRE

    Vindfeld, Signe; Schnohr, Christina; Niclasen, Birgit

    2009-01-01

    Objectives. To describe trends in self-reported physical activity among Greenlandic schoolchildren from 1994 to 2006, and to analyse associations between physical activity and quality of life, health, academic achievement, school satisfaction and substance use. Study design. Trend analysis of the Greenlandic data reported in the Health Behaviour in School- Aged Children (HBSC) survey on 11 , 13 , and 15 years olds in 1994, 1998, 2002 and 2006. Methods. Analyses of associations data on all par...

  12. Notes on the Holocene marine fauna of eastern North Greenland

    DEFF Research Database (Denmark)

    Bennike, Ole; Funder, Svend Visby; Hjorth, Christian

    1986-01-01

    A list of invertebrates, notably molluscs, from the raised Holocene marine sedimets in eastern North Greenland is given. The faunas have low diversity, and contain an element of Arctic sublittoral and bathyal species indicative of cold surface water.......A list of invertebrates, notably molluscs, from the raised Holocene marine sedimets in eastern North Greenland is given. The faunas have low diversity, and contain an element of Arctic sublittoral and bathyal species indicative of cold surface water....

  13. Greenland ice core evidence of the 79 AD Vesuvius eruption

    OpenAIRE

    C. Barbante; N. M. Kehrwald; P. Marianelli; B. M. Vinther; Steffensen, J. P.; Cozzi, G; C. U. Hammer; Clausen, H. B.; M.-L. Siggaard-Andersen

    2012-01-01

    Volcanic tephra are indepenent age horizons and can synchronize strata of various paleoclimate records including ice and sediment cores. Before such paleoclimate records can be synchronized, it is essential to first confidently identify individual independent marker horizons. The Greenland Ice Core Project (GRIP) ice core from Central Greenland is often used as a "golden spike" to synchronize Northern Hemisphere paleoclimte records. The Holocene section of the GRIP ice core is dated by multi-...

  14. Using 10-Be in sediment to understand the long-term behavior of the Greenland Ice Sheet

    Science.gov (United States)

    Bierman, Paul; Rood, Dylan; Corbett, Lee; Nelson, Alice; Shakun, Jeremy

    2013-04-01

    We have used in situ and meteoric cosmogenic 10-Be, measured in sediment and rock, to understand better the history and erosional processes of the Greenland Ice Sheet over the many thousand to several million-year time scale. Measured concentrations of in situ 10-Be constrain Holocene emergence histories at the head of Igaliku fiord in southern Greenland. We sampled two well-preserved gravel beach ridges that are the highest marine deposits. Below one beach ridge, we sampled 4 quartzite outcrops at progressively lower elevations and above a nearby beach ridge, we sampled an erratic boulder and the underlying bedrock. We also sampled a beach ridge at a similar elevation at Qassiarsuk on Tunulliarfik Fiord about 20 km away. The data show rapid emergence after 11 ky. All three beach ridges (average and standard error of 6, 6 and 10 clast ages) have the same age (10.98±0.09, 11.07±0.51ky, and 10.96±0.33 ky). Ages of outcrops below the beach ridges are in stratigraphic order and show steady emergence; the outcrop just above modern high water has an age of 8.80 ky. The bedrock/boulder ages from above the beach ridge are slightly younger (10.45 and 10.73 ky, respectively), consistent with inheritance of about 1400 atoms/g 10-Be in beach clasts. Low levels of inheritance in deglacial beach gravels are consistent with the 10-Be content of clasts collected directly from the GIS in western Greenland. Most clasts have the equivalent of only a few hundred to a few thousand atoms/g 10-Be. Sand-sized sediment collected from outwash streams exiting the ice margin at Kangerlussuaq (western Greenland), Narsarsuaq (southern Greenland), and Tasilaq (eastern Greenland) has two to five thousand atoms/g of 10-Be - several times the median amount of in situ 10-Be measured in clasts collected from the ice. These data indicate efficient erosion by the ice sheet of both pre-glacial and interglacial regolith at least near the ice sheet margins. In contrast, chemical and meteoric 10-Be

  15. Freshwater fluxes in the East Greenland Current: A decade of observations

    Science.gov (United States)

    de Steur, L.; Hansen, E.; Gerdes, R.; Karcher, M.; Fahrbach, E.; Holfort, J.

    2009-12-01

    Over a decade of mooring measurements in the western Fram Strait at 78°50‧N shows that the annual mean liquid freshwater flux (FWF) in the East Greenland Current is relatively constant at -1274 ± 453 km3 yr-1 (-40.4 ± 14.4 mSv) despite the fact that the annual mean total volume transport of the EGC has more than doubled since 2001. This is shown to be due to an increase of the transport in the deeper ocean and the fact that the largest FW content is present on the East Greenland shelf and not in the core of the EGC. In order to capture the FWF on the shelf modeling results of NAOSIM are included showing that a mean contribution of FWF on the shelf of at least -807 ± 357 km3 yr-1 (-25.6 ± 11.3 mSv) should be added to the FWF obtained for the EGC. When compared to the extra input of freshwater required to account for the 1960-1990 freshening of the northern North Atlantic, the observed variations in the 1998-2008 EGC liquid freshwater fluxes are small.

  16. Alkaline intrusion in a granulite ensemble in the Eastern Ghats belt, India: Shear zone pathway and a pull-apart structure

    Indian Academy of Sciences (India)

    S Bhattacharya; Rajib Kar

    2004-03-01

    The alkaline complex of Koraput, Orissa, India, is one of several bodies in the high-grade Eastern Ghats belt, but this one is an integral part of the high-grade belt and remote from the western boundary against the Bastar craton. The Koraput complex forms a lozenge-shaped intrusion into the metapelitic granulites and is bounded by shear zones. The combined effect of movement along these shear zones, is a northeasterly elongated sygmoidal cavity with maximum width along the northwesterly trending Reidel shear. Thus the Koraput alkaline complex can be considered to have been emplaced in a pull-apart structure, developed in the granulitic country rocks. Moreover, in view of the fact that the western margin of the high-grade Eastern Ghats belt bears clear evidence of collisional features, rather than that of rifting or break-up, the rift-valley model for the alkaline magmatism in this high-grade belt appears untenable.

  17. Spatially extensive estimates of annual accumulation in the dry snow zone of the Greenland Ice Sheet determined from radar altimetry

    OpenAIRE

    Peña, S.; Nienow, P.; SHEPHERD, A; V. Helm; D Mair; Hanna, E.; Huybrechts, P.; Guo, Q.; Cullen, R; Wingham, D.

    2010-01-01

    We present estimates of accumulation rate along a 200 km transect ranging in elevation from 2750 to 3150 m in the dry snow zone on the western slope of the Greenland Ice Sheet. An airborne radar altimeter is used to estimate the thickness of annual internal layers and, in conjunction with ground based snow/firn density profiles, annual accumulation rates between 1998 and 2003 are derived. A clear gradient in the thickness of each layer observed by the radar altimeter and in the associated est...

  18. Computer-aided design of conveyor belts

    Energy Technology Data Exchange (ETDEWEB)

    Karolewski, B.; Pytel, J.

    1984-01-01

    Possibilities are discussed for using mathematical models of belt conveyors for development of computer-aided design of conveyors for coal mining. Examples of optimization tasks and methods for their solution using computerized simulation are analyzed. The analysis is illustrated by an algorithm used to design a starter for the drive system of a belt conveyor. Electromagnetic moment and starting current are used as optimization criteria. A simplified model of a belt conveyor is used. The model consists of an equation of motion with variable braking moment and variable moment of inertia. 3 references.

  19. Mercury in dated Greenland marine sediments

    DEFF Research Database (Denmark)

    Asmund, G.; Nielsen, S.P.

    2000-01-01

    Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age...... of the sediment for the youngest 100 years. As a rule the mercury decreased with depth in the sediment with various degrees of significance. The increase of the mercury flux during the last 100 years is roughly a doubling. The increase may be of anthropogenic origin as it is restricted to the last 100 years....... In four cores the concentration of manganese was found also to increase in the top layers indicating diagenesis. In the other cases the higher concentrations were not accompanied by higher manganese concentrations. The mercury flux to the sediment surface was generally proportional to the Pb-210 flux...

  20. The Greenland Analogue Project, Yearly Report 2009

    International Nuclear Information System (INIS)

    To advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository, the Greenland Analogue Project (GAP), a four-year field and modelling study of the Greenland ice sheet and sub-surface conditions, has been initiated collaboratively by SKB, Posiva and NWMO. The study site encompasses a land terminus portion of the Greenland ice sheet east of Kangerlussuaq and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project is planned to run from 2009 until 2012. The GAP will conduct the first in situ investigations of some of the parameters and processes needed to achieve a realistic understanding of how an ice sheet may impact a deep repository, and will provide measurements, observations and data that may significantly improve our safety assessments and risk analyses of glaciation scenarios. The project includes three sub-projects (A-C) with specific individual objectives, which collectively aim at contributing knowledge and input to the overall project aim. Three field campaigns were carried out in SPA during 2009. These campaigns focused on: (1) deployment and maintenance of AWS and GPS stations and to test the deep-look radar equipment; (2) investigating the hydrological processes and feedbacks and testing of passive seismic equipment; (3) downloading of weather station data and GPS data and winterizing the equipment. An extensive archive of real-time satellite remote sensing datasets has been obtained to be able to better constraint the surface elevation and dynamics of basal hydrological mechanisms. From this archive it has been possible to obtain Russell Glacier Cachment (RGC)-wide constraints on annual, seasonal and specific temporal snapshots of surface speed, initial lake and moulin distribution, drainage and network connections along with the temporal

  1. Evaluation of the Doll Project in Greenland

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2013-01-01

    supplemented with observations of teaching and personal interviews with the educators. Significant gains were found on the impact of the students perception of how early parenting affects their social and emotional life, and apprehension of the amount of responsibility involved in infant care. Parents......The Real Care Doll Program in Greenland intent to show students the amount of responsibility involved in caring for a baby. More than one thousands of predominantly eight- and ninth-grade students have been provided with an experience of being the parent of a ‘newborn infant’ by caring Real Care...... baby infant simulators. Throughout the 2 or 3 days, the students are responsible for the ‘baby’; an internal computer collects data about the students’ performance. Accompanying education helps students explore the physical, emotional, social, and financial consequences of parenthood. The general...

  2. The lithospheric mantle below southern West Greenland

    DEFF Research Database (Denmark)

    Sand, Karina Krarup; Waight, Tod Earle; Pearson, D. Graham;

    2009-01-01

    Geothermobarometry of primarily garnet lherzolitic xenoliths from several localities in southern West Greenland is applied to address the diamond potential, pressure and temperature distribution and the stratigraphy of the subcontinental lithospheric mantle ~600 Ma ago. The samples are from...... been conducted. No variation in P-T gradients between the three distinct crustal areas has been discerned. We find that the lithospheric mantle beneath this region extended to a depth of 215 km at the time of eruption, with a geotherm similar to those defined by peridotites from the Slave craton...... and the Kirkland Lake locality within the Superior craton. In supporting previous studies we find that the continental lithospheric mantle is layered and increases in fertility with depth. Twenty-five of 32 investigated samples are estimated to be derived from the diamond stability field that extends...

  3. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth;

    2007-01-01

    a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...... in liver and spleen and as little as 3% in kidney. In liver selenium was found in surplus to mercury on a molar basis. Mercury concentrations in the liver and kidneys of Greenlanders were elevated compared to levels in the general population in Japan, Korea and several European countries, except...

  4. Violence, sexual abuse and health in Greenland

    DEFF Research Database (Denmark)

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

    2002-01-01

    between women and men. Further, response rates were analysed specifically in order to understand consequences of including questions on violence and sexual abuse in the questionnaire survey. The analyses were based on material from a cross-sectional health interview survey conducted during 1993......-94 with participation from a random sample of the Inuit population in Greenland (N = 1393). The prevalence of ever having been a victim of violence was 47% among women and 48% among men. Women had more often than men been sexually abused (25% and 6%) (p ... and health was stronger for women than for men. It is possible to secure a reasonably high response rate in a general health survey that includes questions on violence and sexual abuse....

  5. Marginal thinning in Northwest Greenland during 2002-2011

    Science.gov (United States)

    Khan, S. A.; Kjær, K. H.; Wahr, J. M.; Bevis, M.; Korsgaard, N.; Bjørk, A. A.; Kjeldsen, K. K.; Timm, L. H.; Dam, T. v.

    2012-04-01

    Many glaciers along the southeast and northwest coast of Greenland have accelerated, increasing the Greenland ice sheet's (GrIS) contribution to global sea-level rise. Here, we map elevation changes in northwest Greenland during 2003-2009 using high-resolution Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data (Zwally, 2010) supplemented with altimeter surveys from NASA's Airborne Topographic Mapper (ATM) during 2002-2011 (Krabill, 2011). We use the measurements of elevation change to estimate catchment-wide ice volume loss (convert is to mass loss) and compare with independent measurements from GPS and the Gravity Recovery and Climate Experiment (GRACE) satellite gravity mission, launched in March, 2002. The GRACE results provide a direct measure of mass loss averaged over the entire northwest sector, while the GPS data are used to monitor crustal uplift caused by ice mass loss close to the sites. GPS data from a long term site at Thule Airbase show accelerated uplift starting in 2005 and a minor deceleration in 2009-2010. The deceleration is more dominant at GPS stations deployed in 2007 in northwest Greenland as part of the Greenland GPS Network (GNET). Independently, all three methods suggest increased ice loss in northwest Greenland starting in 2005 and a slowdown in 2009-2010.

  6. The South Greenland uranium exploration programme

    International Nuclear Information System (INIS)

    This is the final report of the reconnaissance phase of the SYDURAN Project which was initiated in 1st. December 1978 to outline areas of increased uranium potential where more detailed prospection would be warranted. Districts and smaller zones in South Greenland which have the potential for containing economically exploitable uranium occurrences were defined using airborne gamma-spectroscopic, reconnaissance geochemical and geological methods. Other districts and areas have been shown to have no uranium potential and can be eliminated. The three promising districts are: 1. a 2000 square kilometre sub-circular district surrounding Ilimaussaq complex in which there are small high grade pitchblende occurences in faults and fractures in the surrounding granite. 2. the eastern area of the Motzfeldt Centre where large parts of the centre is mineralised and may give rise to exploitable, large tonnage, low grade uranium ore with associated niobium and rare earth elements in extractable quantities. 3. uraniferous rich districts or zones associated with the migmatitic supracrustal units in the area between Kap Farvel and Lindenows Fjord. The areas which were eliminated from having any uranium potential include: the Ketilidian supracrustal unit. the Nunarssuit alkaline complex. The uranium mineralisation in South Greenland is confined to two Proterozoic episodes: a) a late phase of granitisation and migmatisation with the formation of disseminated uraninite in the Migmatite Complex in the south of the project area between 1700-1800 m.y. and, b) hydrothermal activity associated with Gardar magmatic events between 1090-1170 m.y. in the central Granite Zone. Future work should be directed towards the definition and location of drilling targets. (EG)

  7. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-07-01

    Full Text Available Fluctuations in terrestrial surface freshwater flux to Sermilik Fjord, SE Greenland, were simulated and analyzed. SnowModel, a state-of-the-art snow-evolution, snow and ice melt, and runoff modeling system, was used to simulate the temporal and spatial terrestrial runoff distribution to the fjord based on observed meteorological data (1999–2008 from stations located on and around the Greenland Ice Sheet (GrIS. Simulated runoff was compared and verified against independent glacier catchment runoff observations (1999–2005. Modeled runoff to Sermilik Fjord was highly variable, ranging from 2.9×109 m3 y−1 in 1999 to 5.9×109 m3 y−1 in 2005. The uneven spatial runoff distribution produced an areally-averaged annual maximum runoff at the Helheim glacier terminus of more than 3.8 m w.eq. The sub-catchment runoff of the Helheim glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage. To assess the Sermilik Fjord freshwater flux, simulated terrestrial runoff and net precipitation (precipitation minus evaporation and sublimation for the fjord area were combined with satellite-derived ice discharge and subglacial geothermal and frictional melting due to basal ice motion. A terrestrial freshwater flux of ~40.4×109 m3 y−1 was found for Sermilik Fjord, with an 11% contribution originated from surface runoff. For the Helheim glacier sub-catchment only 4% of the flux originated from terrestrial surface runoff.

  8. Western Samoa.

    Science.gov (United States)

    1985-12-01

    This discussion of Western Samoa, which lies 2575 km northeast of Auckland, New Zealand, focuses on the following: geography; the people; history; government; political conditions; the economy; foreign relations; and relations the US. The population of Western Samoa, as of 1985, totals 163,000 with an annual growth rate of 0.9%. The infant mortality rate is 13/1000; life expectancy is 65 years. The main islands are formed ranges of extinct volcanoes. Volcanic activity last occurred in 1911. More than 2000 years age, waves of Polynesians migrated from Southeast Asia to the Samoan Islands. Samoans are the 2nd largest Polynesian group, after the Maoris of New Zealand, and speak a Polynesian dialect. Samoans have tended to retain their traditional ways despite exposure to European influence for more than 150 years. Most Samoans live within the traditional social system based on an extended family group, headed by a chief. Western Samoans are Christian. Education is free but not compulsory. In 1967, 95% of the children of primary school age attended school. From 1947 to 1961, a series of constitutional advances, assisted by visits from UN missions, brought Western Samoa from dependent status to self-government and finally to independence. The 1960 constitution is based on the British pattern of parliamentary democracy, modified to take Samoan customs into account. The present head of state holds his position for life. Future heads of state will be elected by the Legislative Assembly for 5-year terms. The Parliament consists of the Legislative Assembly and the head of state. The Supreme Court is the superior court of record and has full jurisdiction in civil, criminal, and constitutional matters. The "matai" of chief system still dominates the politics of Western Samoa, although several political parties have been formed and seem to be taking root. The "matai" system is a predominantly conservative force but does provide for change. Western Samoa is predominantly

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    . During the period 1988–2011, population abundance and size composition changed as catch and effort in the Greenland halibut fishery increased. Two species showed a significant decrease in abundance, and four populations showed a significant reduction in mean weight of individuals (p , 0.05). Correlation......Since the late 1980s, a deep-sea fishery for Greenland halibut (Reinhardtius hippoglossoides) has been developing gradually in West Greenland. Deep-sea fish species are generally long-lived and characterized by late age of maturity, low fecundity, and slow growth, features that probably cause low...... resilience following overexploitation. In order to evaluate whether populations of nine potential bycatch species are negatively affected by the commercial fishery for Greenland halibut, scientific data from bottom-trawl surveys conducted in the same area and period as the commercial fishery were analysed...

  10. From transmission error measurement to Pulley-Belt slip determination in serpentine belt drives: influence of tensioner and belt characteristics

    OpenAIRE

    Manin, Lionel; Michon, Guilhem; Rémond, Didier; Dufour, Regis

    2007-01-01

    Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip: dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been u...

  11. Paleoproterozoic postcollisional magmatic belt of the southern Siberian craton

    Science.gov (United States)

    Salnikova, E. B.; Larin, A. M.; Kotov, A. B.; Levitsky, V. I.; Reznitsky, L. Z.; Kovach, V. P.; Yakovleva, S. Z.

    2003-04-01

    Paleoproterozoic time is characterized by large-scale collisional and postcollisional magmatic activity evidenced in the most of ancient cratons. This global event is related to the Arctic supercontinent assemblage (Rogers, 1996). The formation of postcollisional magmatic belt at 1.9-1.8 Ga within the south-west flanking of the Siberian craton is a remarkable example of these processes happened during overall lithospheric convergence. This belt is extends for about 3000 km from the southern Enisey ridge at the west to the central Aldan shield at the east. Within the central Aldan shield the latest collisional event occurred 1925+/-5 Ma (Kotov et al, 2003) and post-collisional subalkaline S- and I-type granites emplaced at 1916+/-10 Ma (Bibikova et al., 1989), 1901+/-1 Ma (Frost et al., 1998) and 1899+/-6 Ma (Kotov et al, 2003). However at the southern Olekma terrain (western Aldan shield) the syncollisional granites have formed at 1906+/-4 Ma and postcollisional Kodar granitoids were generated at 1876-1873 Ma (Larin et al., 2000). The is a tendency outlined in timing of postcollision processes to the west (in modern coordinates). Ages of postcollisional Kevakta granitoid plutons (1846+/-8 Ma) and volcanics of North-Baikal volcano-plutonic belt (1869+/-6 Ma 1856+/-3 Ma), Baikal folded area, support this tendency. Emplacement of the Primorsky complex postcollisional rapakivi-type granitoids (southern Baikal lake) occurred at 1859+/-16 Ma (Donskaya et al., 2002). New results of U-Pb single zircon and baddeleyite dating demonstrate that formation of late-synkinematic syenite, charnockite and pegmatitic veins (1856±12 Ma, 1853±20 Ma) and calciphyre (1868±2 Ma) within the eastern part of the Sharyzhalgay block (southern Baikal lake) occurred virtually within the same episode. Postcollisional intrusive charnockite of the Shumikha complex from the western Sharyzhalgay block dated at 1861±1 Ma (Donskaya et al., 2001) and 1871±17 Ma (Levitsky et al., 2002). Subalcaline

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

    Directory of Open Access Journals (Sweden)

    Higgins, Anthony K.

    2010-12-01

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

  13. The Compositional Structure of the Asteroid Belt

    CERN Document Server

    DeMeo, Francesca E; Walsh, Kevin J; Chapman, Clark R; Binzel, Richard P

    2015-01-01

    The past decade has brought major improvements in large-scale asteroid discovery and characterization with over half a million known asteroids and over 100,000 with some measurement of physical characterization. This explosion of data has allowed us to create a new global picture of the Main Asteroid Belt. Put in context with meteorite measurements and dynamical models, a new and more complete picture of Solar System evolution has emerged. The question has changed from "What was the original compositional gradient of the Asteroid Belt?" to "What was the original compositional gradient of small bodies across the entire Solar System?" No longer is the leading theory that two belts of planetesimals are primordial, but instead those belts were formed and sculpted through evolutionary processes after Solar System formation. This article reviews the advancements on the fronts of asteroid compositional characterization, meteorite measurements, and dynamical theories in the context of the heliocentric distribution of...

  14. Handbook Timing Belts Principles, Calculations, Applications

    CERN Document Server

    Perneder, Raimund

    2012-01-01

    Timing belts offer a broad range of innovative drivetrain solutions; they allow low-backlash operation in robot systems, they are widely used in automated processes and industrial handling involving highly dynamic start-up loads, they are low-maintenance solutions for continuous operation applications, and they can guarantee exact positioning at high operating speeds. Based on his years of professional experience, the author has developed concise guidelines for the dimensioning of timing belt drives and presents proven examples from the fields of power transmission, transport and linear transfer technology. He offers definitive support for dealing with and compensating for adverse operating conditions and belt damage, as well as advice on drive optimization and guidelines for the design of drivetrain details and supporting systems. All market-standard timing belts are listed as brand neutral. Readers will discover an extensive bibliography with information on the various manufacturers and their websites. This...

  15. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  16. Two Discrete UHP and HP Metamorphic Belts in the Central Orogenic Belt, China

    Institute of Scientific and Technical Information of China (English)

    Suo Shutian; Zhong Zengqiu; Zhang Li; Zhou Hanwen; You Zhendong

    2006-01-01

    An attempt is made to confirm the existence of the two discrete UHP and HP metamorphic belts in the central orogenic belt in China. Detailed geological mapping and structural and petrological analyses of the Kanfenggou (看丰沟) and Xiangfanggou ( 香坊沟 ) slices exposed in the eastern Qinling (秦岭) orogen indicate that they experienced ultrahigh pressure and high pressure metamorphism, respectively. The former, situated in northern Qinling, contains a large volume of fine-grained coesite and quartz pseudomorphs after coesite- and microdiamond-bearing eclogite lenses, whereas the latter, located in southern Qinling, preserves the relicts of a high pressure metamorphic mineral assemblage. Based on extensive fieldwork together with compilations at the scale of the orogenic belt, and a comparison of Pb isotopic compositions between the UHP metamorphic rocks from Kanfenggou slice and the Dabie UHP metamorphic belt, we propose that there are at least two discrete ultrahigh pressure metamorphic belts with different ages and tectonic evolution within the central orogenic belt in China. The first is the South Altun-North Qaidam-North Qinling ultrahigh pressure metamorphic belt of Early Paleozoic age (~ 500-400 Ma). The Kanfenggou ultrahigh pressure slab is located at its eastern segment. The second is the well constrained Dabie ( 大别 )-Sulu ( 苏鲁 ) ultrahigh/ high pressure metamorphic belt of Triassic age (~250-220 Ma). The Xiangfanggou high pressure metamorphic slab is a westward extension of the Dabie-Sulu ultrahigh/high pressure metamorphic belt. The Pb isotopic compositions of the UHP metamorphic rocks from Kanfenggou UHP fragment in East Qinling are different from those of the UHP rocks in Dabie UHP metamorphic belt, but are consistent with those of the rocks from the Qinling rock group and Erlangping (二郎坪) rock group. The East Qinling UHP metamorphic belt does not appear to link with the Dabie-Sulu UHP metamorphic belt. These two ultrahigh

  17. Role of Greenland meltwater in the changing Arctic

    Science.gov (United States)

    Dukhovskoy, Dmitry; Proshutinsky, Andrey; Timmermans, Mary-Louise; Myers, Paul; Platov, Gennady; Bamber, Jonathan; Curry, Beth; Somavilla, Raquel

    2016-04-01

    Observational data show that the Arctic ocean-ice-atmosphere system has been changing over the last two decades. Arctic change is manifest in the atypical behavior of the climate indices in the 21st century. Before the 2000s, these indices characterized the quasi-decadal variability of the Arctic climate related to different circulation regimes. Between 1948 and 1996, the Arctic atmospheric circulation alternated between anticyclonic circulation regimes and cyclonic circulation regimes with a period of 10-15 years. Since 1997, however, the Arctic has been dominated by an anticyclonic regime. Previous studies indicate that in the 20th century, freshwater and heat exchange between the Arctic Ocean and the sub-Arctic seas were self-regulated and their interactions were realized via quasi-decadal climate oscillations. What physical processes in the Arctic Ocean - sub-Arctic ocean-ice-atmosphere system are responsible for the observed changes in Arctic climate variability? The presented work is motivated by our hypothesis that in the 21st century, these quasi-decadal oscillations have been interrupted as a result of an additional freshwater source associated with Greenland Ice Sheet melt. Accelerating since the early 1990s, the Greenland Ice Sheet mass loss exerts a significant impact on thermohaline processes in the sub-Arctic seas. Surplus Greenland freshwater, the amount of which is about a third of the freshwater volume fluxed into the region during the 1970s Great Salinity Anomaly event, can spread and accumulate in the sub-Arctic seas influencing convective processes there. It is not clear, however, whether Greenland freshwater can propagate into the interior convective regions in the Labrador Sea and the Nordic Seas. In order to investigate the fate and pathways of Greenland freshwater in the sub-Arctic seas and to determine how and at what rate Greenland freshwater propagates into the convective regions, several numerical experiments using a passive tracer to

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  19. Common mental disorders among patients in primary health care in Greenland

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  20. Oil seepage onshore West Greenland: evidence of multiple source rocks and oil mixing

    Energy Technology Data Exchange (ETDEWEB)

    Bojesen-Koefoed, J.; Christiansen, F.G.; Nytoft, H.P.; Pedersen, A.K.

    1998-08-01

    Widespread oil seepage and staining are observed in lavas and hyaloclastites in the lower part of the volcanic succession on northwestern Disko and western Nuussuaq, central West Greenland. Chemical analyses suggest the existence of several petroleum systems in the underlying Cretaceous and Paleocene fluviodeltaic to marine sediments. Seepage and staining commonly occur within vesicular lava flow tops, and are often associated with mineral veins (mostly carbonates) in major fracture systems. Organic geochemical analyses suggest the existence of at least five distinct oil types: (1) a waxy oil, which on the basis of the presence of abundant angiosperm biological markers, is interpreted as generated from Paleocene mud-stones (the `Marraat type`); (2) a waxy oil, probably generated from coals and shales of the Cretaceous Atane formation (the `Kuugannguaq type`); (3) a low to moderately waxy oil containing 28,30-bisnorhopane, and abundant C{sub 27}-diasteranes and regular steranes (the `Itilli type`), possibly generated from presently unknown Cenomanian-Turonian marine modstones; (4) a low wax oil of marine, possibly lagoonal/saline lacustrine origin, containing ring-A methylated steranes and a previously unknown series of extended 28-norhopanes (the `Eqalulik type`); (5) a waxy oil with biological marker characteristics different from both the Kuugannguaq and Marraat oil types (the `Niaqornaarsuk type`), probably generated from Campanian mud-stones. The presence of widespread seepage and staining originating from several source rocks is encouraging for exploration in basins both on- and offshore western Greenland, where the existence of prolific source rocks has previously been the main exploration risk. (au) EFP-96. 34 refs.

  1. How warm was Greenland during the last interglacial period?

    Science.gov (United States)

    Landais, Amaelle; Masson-Delmotte, Valérie; Capron, Emilie; Langebroek, Petra M.; Bakker, Pepijn; Stone, Emma J.; Merz, Niklaus; Raible, Christoph C.; Fischer, Hubertus; Orsi, Anaïs; Prié, Frédéric; Vinther, Bo; Dahl-Jensen, Dorthe

    2016-09-01

    The last interglacial period (LIG, ˜ 129-116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 °C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning, suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Greenland surface warming using ice core air isotopic composition (δ15N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 °C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 °C warming initially determined from NEEM water isotopes but at the upper end of the preindustrial period to LIG temperature difference of +5.2 ± 2.3 °C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 °C) are produced in response to prescribed changes in sea ice extent and ice sheet topography.

  2. Victimisation and PTSD in a Greenlandic youth sample

    Directory of Open Access Journals (Sweden)

    Sidsel H. Karsberg

    2012-08-01

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

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

    OpenAIRE

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

    1999-01-01

    1. The paper focuses on the acculturation strategies employed by Greenlandic consumers living in Denmark and in particular how food products enter into a discourse of identity construction. The study of Greenlandic consumers in Denmark provides insight into acculturation processes for consumers with a more or less dual cultural background (due to the strong Danish cultural influence in Greenland). This duality of cultural identity means that Greenlandic immigrants' consumption reflects a well...

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

    OpenAIRE

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

    1999-01-01

    Executive summary 1. The paper focuses on the acculturation strategies employed by Greenlandic consumers living in Denmark and in particular how food products enter into a discourse of identity construction. The study of Greenlandic consumers in Denmark provides insight into acculturation processes for consumers with a more or less dual cultural background (due to the strong Danish cultural influence in Greenland). This duality of cultural identity means that Greenlandic immigrants’ consumpti...

  5. The Greenland Analogue Project. Yearly Report 2009

    International Nuclear Information System (INIS)

    A deep geological repository for spent nuclear fuel needs to be designed to keep used nuclear fuel isolated from mankind and the environment for a million years. Within this time frame glacial conditions are expected in regions that have been glaciated in the past two to ten million years. Climate induced changes such as the growth of ice sheets and permafrost will influence and alter the ground surface and subsurface environment, including its hydrology, which may impact repository safety. Glaciation impact assessments have to-date used over-simplified models and conservative assumptions, for example in the representation of ice sheet hydrology, that do not reflect the complexity of natural systems and processes. This is largely due to lack of direct observations of such processes from existing ice sheets, which if more readily available could help reduce uncertainties and provide a strong scientific basis for the treatment of glacial impacts in safety assessments. Our current understanding of the hydrological, hydrogeological and hydrogeochemical processes associated with glacial cycles and their impact on the long-term performance of deep geological repositories for spent nuclear fuel will be significantly improved by studying a modern analogue. To advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository, the Greenland Analogue Project (GAP), a four-year field and modelling study of the Greenland ice sheet and sub-surface conditions, has been initiated collaboratively by SKB, Posiva and NWMO. The study site encompasses a land terminus portion of the Greenland ice sheet east of Kangerlussuaq and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project is planned to run from 2009 until 2012. The GAP will conduct the first in situ investigations of some of

  6. The Greenland Analogue Project. Yearly Report 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    A deep geological repository for spent nuclear fuel needs to be designed to keep used nuclear fuel isolated from mankind and the environment for a million years. Within this time frame glacial conditions are expected in regions that have been glaciated in the past two to ten million years. Climate induced changes such as the growth of ice sheets and permafrost will influence and alter the ground surface and subsurface environment, including its hydrology, which may impact repository safety. Glaciation impact assessments have to-date used over-simplified models and conservative assumptions, for example in the representation of ice sheet hydrology, that do not reflect the complexity of natural systems and processes. This is largely due to lack of direct observations of such processes from existing ice sheets, which if more readily available could help reduce uncertainties and provide a strong scientific basis for the treatment of glacial impacts in safety assessments. Our current understanding of the hydrological, hydrogeological and hydrogeochemical processes associated with glacial cycles and their impact on the long-term performance of deep geological repositories for spent nuclear fuel will be significantly improved by studying a modern analogue. To advance the understanding of processes associated with glaciation and their impact on the long-term performance of a deep geological repository, the Greenland Analogue Project (GAP), a four-year field and modelling study of the Greenland ice sheet and sub-surface conditions, has been initiated collaboratively by SKB, Posiva and NWMO. The study site encompasses a land terminus portion of the Greenland ice sheet east of Kangerlussuaq and is in many ways considered to be an appropriate analogue of the conditions that are expected to prevail in much of Canada and Fennoscandia during future glacial cycles. The project is planned to run from 2009 until 2012. The GAP will conduct the first in situ investigations of some of

  7. Early Archean serpentine mud volcanoes at Isua, Greenland, as a niche for early life.

    Science.gov (United States)

    Pons, Marie-Laure; Quitté, Ghylaine; Fujii, Toshiyuki; Rosing, Minik T; Reynard, Bruno; Moynier, Frederic; Douchet, Chantal; Albarède, Francis

    2011-10-25

    The Isua Supracrustal Belt, Greenland, of Early Archean age (3.81-3.70 Ga) represents the oldest crustal segment on Earth. Its complex lithology comprises an ophiolite-like unit and volcanic rocks reminiscent of boninites, which tie Isua supracrustals to an island arc environment. We here present zinc (Zn) isotope compositions measured on serpentinites and other rocks from the Isua supracrustal sequence and on serpentinites from modern ophiolites, midocean ridges, and the Mariana forearc. In stark contrast to modern midocean ridge and ophiolite serpentinites, Zn in Isua and Mariana serpentinites is markedly depleted in heavy isotopes with respect to the igneous average. Based on recent results of Zn isotope fractionation between coexisting species in solution, the Isua serpentinites were permeated by carbonate-rich, high-pH hydrothermal solutions at medium temperature (100-300 °C). Zinc isotopes therefore stand out as a pH meter for fossil hydrothermal solutions. The geochemical features of the Isua fluids resemble the interstitial fluids sampled in the mud volcano serpentinites of the Mariana forearc. The reduced character and the high pH inferred for these fluids make Archean serpentine mud volcanoes a particularly favorable setting for the early stabilization of amino acids. PMID:22006301

  8. Early Archean serpentine mud volcanoes at Isua, Greenland, as a niche for early life.

    Science.gov (United States)

    Pons, Marie-Laure; Quitté, Ghylaine; Fujii, Toshiyuki; Rosing, Minik T; Reynard, Bruno; Moynier, Frederic; Douchet, Chantal; Albarède, Francis

    2011-10-25

    The Isua Supracrustal Belt, Greenland, of Early Archean age (3.81-3.70 Ga) represents the oldest crustal segment on Earth. Its complex lithology comprises an ophiolite-like unit and volcanic rocks reminiscent of boninites, which tie Isua supracrustals to an island arc environment. We here present zinc (Zn) isotope compositions measured on serpentinites and other rocks from the Isua supracrustal sequence and on serpentinites from modern ophiolites, midocean ridges, and the Mariana forearc. In stark contrast to modern midocean ridge and ophiolite serpentinites, Zn in Isua and Mariana serpentinites is markedly depleted in heavy isotopes with respect to the igneous average. Based on recent results of Zn isotope fractionation between coexisting species in solution, the Isua serpentinites were permeated by carbonate-rich, high-pH hydrothermal solutions at medium temperature (100-300 °C). Zinc isotopes therefore stand out as a pH meter for fossil hydrothermal solutions. The geochemical features of the Isua fluids resemble the interstitial fluids sampled in the mud volcano serpentinites of the Mariana forearc. The reduced character and the high pH inferred for these fluids make Archean serpentine mud volcanoes a particularly favorable setting for the early stabilization of amino acids.

  9. Seat belts, airbags and child protection devices. [previously: Seat belts and child restraint seats.

    NARCIS (Netherlands)

    2010-01-01

    In the Netherlands, the use of seat belts results in a yearly reduction of hundreds of fatalities. Seat belts reduce the risk of fatal injury by 37 to 48%, depending on the position in the car. At 50%, the effect of child protection devices is even slightly higher. When last measured (in 2010), 97%

  10. Timing of millennial-scale climate change in Antarctica and Greenland during the last glacial period

    DEFF Research Database (Denmark)

    Blunier, T; Brook, E J

    2001-01-01

    in Antarctica preceded the onset of Greenland warmings by 1500 to 3000 years. In general, Antarctic temperatures increased gradually while Greenland temperatures were decreasing or constant, and the termination of Antarctic warming was apparently coincident with the onset of rapid warming in Greenland...

  11. Segmentation of the eastern North Greenland oblique-shear margin – regional plate tectonic implications

    DEFF Research Database (Denmark)

    Andreasen, Arne Døssing; Stemmerik, Lars; Dahl-Jensen, T.;

    2010-01-01

    Late Cenozoic opening of the Fram Strait led to formation of the NW–SE striking, eastern North Greenland oblique-shear margin at transition from the Norwegian–Greenland Sea to the SW Eurasia Basin. Onshore geology exposed on large peninsulas in front of the major Greenland Inland Ice reveals a hi...

  12. Distribution and drift of Atlantic cod ( Gadus morhua ) eggs and larvae in Greenland offshore waters

    DEFF Research Database (Denmark)

    Wieland, Kai; Hovgård, Holger

    2002-01-01

    recruitment of the West Greenland cod stock. It is also shown that cod eggs and larvae occasionally drift from Southwest Iceland across the Denmark Strait to the East Greenland shelf from where a subsequent transport and immigration of juveniles to West Greenland waters can occur. Larval transport across the...

  13. Analysis of stress distribution of timing belts by FEM; Yugen yosoho ni yoru timing belt oryoku kaiseki (belt code oryoku bunpu kaiseki hokoku)

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Y.; Tomono, K.; Takahashi, H.; Uchida, T. [Honda R and D Co. Ltd., Tokyo (Japan)

    1997-10-01

    A model of the belt analyzed by-ABAQUS (: a general nonlinear finite element program) successfully confirmed the mechanism that generates the belt cord stress. A quite good agreement between experimental and computed results for the stress distribution of the belt cord. It is found that maximum stress of the cords occurs near the root of the tooth by calculation, where the belt cords break off. 3 refs., 9 figs.

  14. Resolving bathymetry from airborne gravity along Greenland fjords

    Science.gov (United States)

    Boghosian, Alexandra; Tinto, Kirsty; Cochran, James R.; Porter, David; Elieff, Stefan; Burton, Bethany L.; Bell, Robin E.

    2015-12-01

    Recent glacier mass loss in Greenland has been attributed to encroaching warming waters, but knowledge of fjord bathymetry is required to investigate this mechanism. The bathymetry in many Greenland fjords is unmapped and difficult to measure. From 2010 to 2012, National Aeronautics and Space Administration's Operation IceBridge collected a unique set of airborne gravity, magnetic, radar, and lidar data along the major outlet glaciers and fjords in Greenland. We applied a consistent technique using the IceBridge gravity data to create 90 bathymetric profiles along 54 Greenland fjords. We also used this technique to recover subice topography where warm or crevassed ice prevents the radar system from imaging the bed. Here we discuss our methodology, basic assumptions and error analysis. We present the new bathymetry data and discuss observations in six major regions of Greenland covered by IceBridge. The gravity models provide a total of 1950 line kilometers of bathymetry, 875 line kilometers of subice topography, and 12 new grounding line depths.

  15. Exploring Greenland: science and technology in Cold War settings.

    Science.gov (United States)

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

    2010-01-01

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

  16. Western blots.

    Science.gov (United States)

    Freeman, Lita A

    2013-01-01

    Western analysis of apolipoproteins, lipoproteins, and proteins involved in lipoprotein metabolism can be challenging due to their size, hydrophobic nature, and, in some cases, low abundance. Here we describe a Western blotting method that has been used successfully for many proteins involved in lipoprotein metabolism, as well as intact LDL or HDL particles. Proteins or lipoprotein particles separated by gel electrophoresis are transferred to a PVDF membrane in a Hoefer TE22 transfer tank with Tris-Glycine-SDS-Methanol transfer buffer. The membrane is blocked with 3 % BSA/5 % milk to prevent nonspecific binding of antibody to the membrane and is then incubated with primary antibody that binds specifically to the protein of interest. After washing away unbound primary antibody, the membrane is then incubated with an HRP-labeled secondary antibody that binds primary antibody. After washing away unbound secondary antibody, the membrane is then incubated with a substrate for HRP, generating a chemiluminescent signal at the location of the protein of interest. The protein is visualized by exposing the membrane to an autoradiography film or an imaging device. Information on the use of several human antibodies, including apoA-I, A-II, apoB, apoC-II, apoC-III, apoD, apoL1, apoM, PON1, SAA, ABCA1, nitrotyrosine, and LCAT, is provided. This method can be used for Western blotting of virtually any protein as well as native lipoprotein particles. PMID:23912997

  17. Contaminants in two West Greenland caribou populations.

    Science.gov (United States)

    Gamberg, Mary; Cuyler, Christine; Wang, Xiaowa

    2016-06-01

    Two caribou populations in West Greenland were sampled and the kidneys, liver and muscle analyzed for contaminants, including aluminum, arsenic, cadmium, copper, lead, mercury, selenium and zinc. Although close in proximity, the two populations are topographically separated by an ice cap, which creates different climates and vegetation types in each region. Contaminant levels reflected the differing diets of the two caribou populations. To the south in the wetter lichen-rich region, caribou had significantly more aluminum, arsenic, cadmium, lead, mercury, selenium and zinc, likely due to atmospheric deposition on lichens. To the north in the dry desert steppe where grasses predominate, caribou had higher levels of copper. Cows collected in late winter had significantly less hepatic copper, lead and mercury if pregnant, indicating placental transfer of these elements. Our results suggest that hepatic copper levels <200 μg g(-1) dry weight may result in copper depletion in pregnant cows and hepatic mercury concentrations above 0.5 μg g(-1) dry weight may negatively affect fertility in caribou cows. Hepatic mercury levels were negatively correlated with cow body weight, suggesting an adverse effect on body condition. Element concentrations found in tissues from these caribou are not considered to be of a health concern for those consuming this traditional food. PMID:26956180

  18. Bowhead whale springtime song off West Greenland.

    Science.gov (United States)

    Stafford, Kathleen M; Moore, Sue E; Laidre, Kristin L; Heide-Jørgensen, M P

    2008-11-01

    Three songs were recorded from bowhead whales (Balaena mysticetus) in Disko Bay, West Greenland, during 59 h of recordings via sonobuoys deployed on seven days between 5 and 14 April 2007. Song elements were defined by units following the protocol of previous description of bowhead whale song. The two most prominent songs were loud, complex, and repeated in long bouts on multiple recording days while the third song was much simpler and recorded on only one day. Bowhead whale simple calls and faint song elements were also recorded using digital audio tape recorders and a dipping hydrophone deployed from the sea ice approximately 100-150 km southwest of Disko Bay on three separate days suggesting that song is also produced in the central portion of Baffin Bay in winter. Songs recorded in Disko Bay are from an area where approximately 85% of the whales have been determined to be adult females. Although it is not known which sex was singing, we speculate that, as in humpback whales (Megaptera novaeangliae), male bowhead whales may sing to mediate sexual competition or mate selection behaviors. This is the first detailed description of springtime songs for bowhead whales in the eastern Arctic. PMID:19045814

  19. Permanent GPS and crustal deformation in Greenland

    Science.gov (United States)

    Khan, S. A.

    2003-12-01

    The National Survey and Cadastre - Denmark (KMS) is responsible for the geodetic definition of the reference network in Greenland. Permanent GPS plays an important role in the monitoring and maintenance of the geodetic network. Furthermore, KMS supports the international GPS infrastructure and research by supporting IGS. In October 1998 KMS has established a permanent GPS station THU2 at Thule Airbase. Besides THU2 the old permanent station THU1 is also running. The Thule stations are important because they are two of the few northernmost stations in the IGS network. THU2 has been operating since March 1999, and it is now a high quality and high performance station contributing to the IGS Low-Earth Orbiters (LEO) network. Besides the GPS stations in Thule, KMS is also running a permanent GPS station SCOB in Scoresbysund, which was established in August 1997, and in October 2001 a permanent station QAQ1 was established in Qaqortoq. This station is registered at IGS. Furthermore, University of Colorado operates the IGS station Kellyville near Kangerlussuaq and a station in Kulusuk. Using the BERNESE software, we have calculated daily baseline solutions between the GPS sites. The time series of the 3D crustal movements are analyzed due to post glacial rebound, plate tectonic and seasonal deformations (e.g. atmosphere loading). In addition, we have used the GIPSY OASIS II software to obtain similar time series. The results are compared with modeled estimates of the glacial rebound.

  20. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  1. Hydrocarbon prospectivity in Western Greece

    Energy Technology Data Exchange (ETDEWEB)

    Maravelis, Angelos; Makrodimitras, George; Zelilidis, Avraam [Patras Univ. (Greece). Lab. of Sedimentology

    2012-06-15

    The geology of Western Greece is dominated by the most external zones of the Hellenide fold-and-thrust belt, namely the Pre-Apulian (or Paxoi) and Ionian zones. With Western Greece and Albania having undergone, in broad terms, similar geological histories, also the hydrocarbon potentials of both areas may be compared. Likewise, the hydrocarbon potential of Italy's Apulian Platform, adjoining in the westerly offshore, may serve as an analogue. Three basin types within Western Greece that deserve hydrocarbon exploration have been examined and are grouped, correlated to major tectonic features, namely foreland (Ionian thrusts' foreland basin), piggy-back (Ionian thrusts' back-arc basin) and strike-slip basins. Additionally, strike-slip basins are further subdivided into the basin north of the Borsh-Khardhiqit strike-slip fault and the Preveza basin, north of Cephalonia transfer fault. Their filling histories suggest the occurrence of Mesozoic carbonate plays and Oligocene/Miocene sandstone plays both for oil and gas.

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

    Science.gov (United States)

    Pedersen, Michael Lynge; Olesen, Jesper; Jørgensen, Marit Eika; Damm, Peter

    2016-01-01

    Background Within the last 20 years, the prevalence of gestational diabetes mellitus (GDM) has been reported to be increasing worldwide in correlation with ethnic and geographic variations. The actual prevalence of GDM throughout all of Greenland remains unknown. Objective The aim of this study was to estimate the prevalence of GDM among Greenlanders and non-Greenlanders living in Greenland and to estimate the efficacy of testing for GDM. Design This study was performed as an observational, cross-sectional study including all women with permanent address in Greenland who had given birth to a singleton during 2014. The prevalence of GDM was calculated as the proportion of all pregnant women tested with a 75-g 2-h glucose tolerance test who had a 2-h capillary whole-blood glucose value of 8.5 mmol/l or above. Testing efficacy was calculated as the proportion of women who fulfilled the testing criteria who were actually tested in Greenland in 2014. Results A total of 794 women (727 Greenlanders and 67 non-Greenlanders) were included in the study. The prevalence of GDM among tested women was 3.3% (confidence interval, CI: 0.9–5.6) among Greenlanders and 12.5% (CI: 0–25.7) among non-Greenlanders, corresponding, respectively, to 1.0% (CI: 0.3–1.3) and 4.5% (CI: 0–9.4) of all singleton pregnancies in Greenland in 2014. The overall testing efficacy was 69.0% among all eligible residents of Greenland and 85.1% among eligible residents in the capital city, Nuuk. Conclusion In conclusion, the prevalence of GDM seems quite low in Greenland. Although diagnostic testing activity has improved within the last 6 years, still around one-third of all pregnant women in all Greenland fulfilling the testing criteria were not tested. Universal testing for GDM may be needed to improve testing of GDM in Greenland. PMID:27562574

  3. Spatiotemporal distribution of rabies in Arctic foxes in Greenland

    DEFF Research Database (Denmark)

    Raundrup, Katrine; Moshøj, Charlotte; Wennerberg, Sanne E.;

    2015-01-01

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

  4. North and northeast Greenland ice discharge from satellite radar interferometry

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  5. Violence- and alcohol-related acute healthcare visits in Greenland

    DEFF Research Database (Denmark)

    Nexøe, Jørgen; Wilche, Julie Præst; Niclasen, Birgit;

    2013-01-01

    Aims: The aim of this study was to describe emergency admissions in Greenland's healthcare system, and the extent to which admissions were associated with alcohol abuse or violence. Furthermore, we aimed to test whether data on emergencies in Greenland could be registered in a reliable way...... for presentation were mental or social problems, attempted suicide, accidents, or violence, 24, 50, 15, and 59% respectively were intoxicated. Alcohol intoxication was statistically significantly more often associated with advanced treatment (e.g. evacuation, hospitalisation, or follow up by doctor or nurse......). Conclusions: This study confirms that violence- and alcohol-related emergencies put a considerable strain on Greenland's healthcare system. Due to the short observation period, we have not been able to describe the actual extent of the problem in detail, nor was it possible to estimate whether this problem...

  6. Mountain building and the initiation of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

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

    2013-01-01

    by mapping the two main steps in the landscape that resulted from the two uplift phases. Ice sheet initiation is studied using the topography before uplift and after each phase of uplift by applying different forcing conditions relevant for the late Cenozoic, which was characterised by long-term cooling....... Under conditions that are colder than the present, the ice can overcome the Föhn effect, flow into the interior and form a coherent ice sheet. The results thus indicate that the Greenland Ice Sheet of today is a relict formed under colder conditions. The modelling results are consistent......The effects of a new hypothesis about mountain building in Greenland on ice sheet initiation are investigated using an ice sheet model in combination with a climate model. According to this hypothesis, low-relief landscapes near sea level characterised Greenland in Miocene times until two phases...

  7. Deformation Studies of NEEM, Greenland Basal Folded Ice

    Science.gov (United States)

    Keegan, K.; Dahl-Jensen, D.; Montagnat, M.; Weikusat, I.

    2015-12-01

    Deep Greenland ice cores and airborne radio echo sounding (RES) images have recently revealed that basal ice flow of the Greenland Ice Sheet is very unstable. In many locations, a basal layer of disturbed ice is observed. At the NEEM, Greenland site this folding occurs at the boundary between the Eemian and glacial ice regimes, indicating that differences in physical properties of the ice play a role in the disturbance. Past work in metallurgy and ice suggests that impurity content controls grain evolution and therefore deformation. We hypothesize that the differences in ice flow seen deep in the NEEM ice core are controlled by differences in the impurity content of the ice layers. Here we present results of fabric, grain size, impurity content, and deformation studies from samples above and below this unstable boundary in the ice sheet.

  8. Absolute gravimetry - for monitoring climate change and geodynamics in Greenland

    DEFF Research Database (Denmark)

    Nielsen, Jens Emil

    investigated come from geodynamical processes originating from ice mass changes. Two of the Earth’s properties give rise to two different geophysical signals. One of these is caused by the asthenosphere’s viscoelastic properties, while the other one is due to the lithosphere’s elastic properties...... about sea level change requires a knowledge of global ice masses, in this case the Greenland Ice Sheet. Global ice masses are estimated to contain 80% of the global fresh water resources, and the Greenland Ice Sheet holds enough water for an approximated 7m of sea level rise. For these reasons......, there is a large interest in studying the mass changes of the Greenland Ice Sheet. There are many geophysical methods which can be used to study climatic changes. However, the interpretation of these changes is complicated due to the presence of many different signals - not all of which are related to present...

  9. Y-chromosome STR haplotypes in males from Greenland.

    Science.gov (United States)

    Hallenberg, Charlotte; Tomas, Carmen; Simonsen, Bo; Morling, Niels

    2009-09-01

    A total of 272 males from Greenland were typed for 11 Y-chromosome STRs DYS19, DYS385a/b, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 with the PowerPlex Y System (Promega). A total of 146 different haplotypes were observed and the haplotype diversity was 0.9887. The number of haplotypes seen once was 108 and the most common haplotype was observed in 12 males. A significant F(ST) value was observed (F(ST)=0.012, P<0.00001) when comparing the population of 15 locations in Greenland assigned to 7 groups. The significance could mainly be attributed to the subpopulation of males from Tasiilaq (East of Greenland). The R(ST) value was not statistically significant (R(ST)=0.016, P=0.15). PMID:19647703

  10. Climate variability in West Greenland during the past 1500 years

    DEFF Research Database (Denmark)

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

    2012-01-01

    document late-Holocene climate variability in West Greenland as inferred from a marine sediment record from the outer Disko Bay. Organic-walled dinoflagellate cysts and other palynomorphs were used to reconstruct environmental changes in the area through the last c. 1500 years at 30–40 years resolution....... Sea ice cover and primary productivity were identified as the two main factors driving dinoflagellate cyst community changes through time. Our data provide evidence for an opposite climate trend in West Greenland relative to the NE Atlantic region from c. AD 500 to 1050. For the same period, sea......Ribeiro, S., Moros, M., Ellegaard, M. & Kuijpers, A. 2012 (January): Climate variability in West Greenland during the past 1500 years: evidence from a high-resolution marine palynological record from Disko Bay. Boreas, Vol. 41, pp. 68–83. 10.1111/j.1502-3885.2011.00216.x. ISSN 0300-9483. Here we...

  11. Greenland temperature response to climate forcing during the last deglaciation.

    Science.gov (United States)

    Buizert, Christo; Gkinis, Vasileios; Severinghaus, Jeffrey P; He, Feng; Lecavalier, Benoit S; Kindler, Philippe; Leuenberger, Markus; Carlson, Anders E; Vinther, Bo; Masson-Delmotte, Valérie; White, James W C; Liu, Zhengyu; Otto-Bliesner, Bette; Brook, Edward J

    2014-09-01

    Greenland ice core water isotopic composition (δ(18)O) provides detailed evidence for abrupt climate changes but is by itself insufficient for quantitative reconstruction of past temperatures and their spatial patterns. We investigate Greenland temperature evolution during the last deglaciation using independent reconstructions from three ice cores and simulations with a coupled ocean-atmosphere climate model. Contrary to the traditional δ(18)O interpretation, the Younger Dryas period was 4.5° ± 2°C warmer than the Oldest Dryas, due to increased carbon dioxide forcing and summer insolation. The magnitude of abrupt temperature changes is larger in central Greenland (9° to 14°C) than in the northwest (5° to 9°C), fingerprinting a North Atlantic origin. Simulated changes in temperature seasonality closely track changes in the Atlantic overturning strength and support the hypothesis that abrupt climate change is mostly a winter phenomenon.

  12. Netting and conventional tagging used to study movements of ringed seals (Phoca hispida in Greenland

    Directory of Open Access Journals (Sweden)

    Finn O Kapel

    2014-05-01

    Full Text Available Seven studies of netting and tagging of ringed seals (Phoca hispida in Greenland 1976-1997 are described. The areas of operation were: northern part of the Upernavik area (Northwest Greenland, Kong Oscars Fjord (Northeast Greenland, and Avanersuaq (Thule, North Greenland. Altogether, 135 seals were caught, of which 99 were tagged and released with Dalton Jumbo rototags. Recapture of 38 tagged seals has been reported to date. The recaptures demonstrate movements of ringed seals in Greenland of more than 100km within districts, as well as long-distance movementsof more than 1000km from the site of release.

  13. The Compositions of Kuiper Belt Objects

    CERN Document Server

    Brown, Michael E

    2011-01-01

    Objects in the Kuiper belt are small and far away thus difficult to study in detail even with the best telescopes available at earth. For much of the early history of the Kuiper belt, studies of the compositions of these objects were relegated to collections of moderate quality spectral and photometric data that remained difficult to interpret. Much early effort was put into simple correlations of surface colors and identifications of spectral features, but it was difficult to connect the observations to a larger understanding of the region. The last decade, however, has seen a blossoming in our understanding of the compositions of objects in the Kuiper belt. This blossoming is a product of the discoveries of larger -- and thus easier to study -- objects, continued dedication to the collection of a now quite large collection of high quality photometric and spectroscopic observations, and continued work at the laboratory and theoretical level. Today we now know of many processes which affect the surface compos...

  14. Perceptual findings on the broadway belt voice.

    Science.gov (United States)

    DeLeo LeBorgne, Wendy; Lee, Linda; Stemple, Joseph C; Bush, Heather

    2010-11-01

    The present study required raters (casting directors) to evaluate the belt voice quality of 20 musical theater majors who were proficient in the singing style referred to as belting. Two specified vocalizes and six short excerpts from the belting repertoire were used for rating purposes. The raters were asked to judge the belters on a set of seven perceptual parameters (loudness, vibrato, ring, timbre, focus, nasality, and registration breaks), and then report an overall score for these student belters. The four highest and lowest average scores were used to establish the elite and average student belters. A correlation analysis and linear regression analysis provided insight regarding which perceptual judgments correlated most highly with the elite and average scores. The present study found the perceptual ratings of vibrato and ring to be most highly correlated to the elite student belter. In addition, vibrato and ring were found to highly correlate with perceived loudness. PMID:19900789

  15. Smoking as a Determinant of High Organochlorine Levels in Greenland

    DEFF Research Database (Denmark)

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

    2003-01-01

    The authors investigated the accumulation of organochlorines among smoking and nonsmoking Inuit hunters (n = 48) in Uummanaq, Greenland, a population with high dietary exposure to persistent organic pollutants (POPs). Human plasma organochlorine levels were positively correlated with age, marine...... diet, and smoking or plasma cotinine in multiple linear-regression models (p < 0.001). Body mass index was inversely correlated with organochlorine accumulation, independent of smoking status. These findings confirm that the source of POPs among the Inuit in Greenland is diet, but smoking is an...

  16. Dynamics of the Greenland Ice Sheet over multiple timescales

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup

    behavior of the Greenland Ice Sheet on multiple timescales is investigated. These range from annual/decadal scale variations of ice surface heights and cyclic drainage patterns of ice-dammed lakes to long-term response of the ice sheet margin during the past 300,000 years. The results presented here show...... that the ice margin of the Greenland Ice Sheet responds highly dynamic and variable to climate change and oceanic forcing, with behavior additionally being governed by regional/local settings, e.g. topographical settings such as low-lying/mountainous areas and the presence or absence of deep fjords or shelf...

  17. Ionospheric travelling convection vortices observed by the Greenland magnetometer chain

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Stolle, Claudia; Friis-Christensen, Eigil;

    2013-01-01

    The Greenland magnetometer array continuously provides geomagnetic variometer data since the early eighties. With the polar cusp passing over it almost every day, the array is suitable to detect ionospheric traveling convection vortices (TCVs), which were rst detected by Friis-Christensen et al...... are discussed. Specifically, three years of magnetometer data, from 1986 to 1988, collected at seven stations at the West coast of Greenland are analysed and TCV events are identied and isolated. The events are classied with respect to their intensity, duration and time of occurrence and they are correlated...

  18. Offshore oil exploration and impact assessment in Greenland

    DEFF Research Database (Denmark)

    Hansen, Anne Merrild

    2016-01-01

    regulation system in relation to oil and gas projects to promote sustainable development. Additional Impact Benefit Agreements (IBA) have to be negotiated between the communities potentially affected, the Government and the oil companies to assure that social investments are made to secure long-term benefits...... benefits are expected to derive from oil and gas projects, but these benefits cannot be achieved without careful planning and project management. To secure that negative impacts are mitigated and that positive outcomes are achieved, Impact Assessments (IA) have been implemented as in the Greenlandic...... in Greenland. Finally I discuss challenges related to securing local benefits when implementing this new industry....

  19. GREENLAND ICE SHEET CHANGES FROM SPACE USING LASER, RADAR AND

    DEFF Research Database (Denmark)

    Sørensen, Louise Sandberg; Stenseng, Lars; Simonsen, Sebastian Bjerregaard;

    2010-01-01

    The Greenland cryosphere is undergoing rapid changes, and these are documented by remote sensing from space. In this paper, an inversion scheme is used to derive mass changes from gravity changes observed by GRACE, and to derive the mean annual mass loss for the Greenland Ice Sheet, which is...... estimated to be 204 Gt/yr for the period 2002-2010. NASA’s laser altimetry satellite ICESat has provided elevation estimates of the ice sheet since January 2003. In order to be able to compare GRACE and ICESat derived results, the ICESat volume change must be converted into a mass change estimate. Therefore...

  20. Age of the youngest Palaeogene flood basalts in East Greenland

    DEFF Research Database (Denmark)

    Heilmann-Clausen, C.; Piasecki, Stefan; Abrahamsen, Niels;

    2008-01-01

    Intra-basaltic sediments 50 m below the top of the Paleogene lava succession at Kap Dalton, East Greenland, contain dinoflagellate cysts of late Ypresian-earliest Lutetian age, while sediments immediately above the lavas contain an assemblage of early Lutetian age. Combined with paleomagnetic...... results, this constrains the termination of the East Greenland Paleogene Igneous Province to the Early-Middle Eocene transition (nannoplankton chronozones NP13-NP14/earliest NP15). This is 6-8 Ma younger than according to previous biostratigraphic age assignments. The new data show that flood basalt...

  1. An isotopic analysis of the diet of the Greenland Norse

    DEFF Research Database (Denmark)

    Nelson, D.E.; Heinemeier, Jan; Lynnerup, Niels;

    2012-01-01

    of Norse Greenlandic sites which have taken place over the past century. To obtain more detailed information on the diets of the Norse settlers in Greenland, measures of the stable carbon (δ C) and nitrogen (δ N) values of human bone collagen have been made for 80 individuals from an existing collection....... For the two Norse settlements taken as a whole, the basic dietary economy was based about as much on hunting as it was on their domestic animals. We see no evidence for real differences between the diets of men and women or between individuals of different ages. The large individual differences...

  2. Rapid dynamic thinning on Upernavik Icestream, West Greenland

    DEFF Research Database (Denmark)

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

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

  3. Greenland Ice sheet mass balance from satellite and airborne altimetry

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Bevis, M. G.; Wahr, J. M.;

    Ice loss from the Greenland Ice Sheet (GrIS) is dominated by loss in the marginal areas. Dynamic induced ice loss and its associated ice surface lowering is often largest close to the glacier calving front and may vary from rates of tens of meters per years to a few meters per year over relatively...... short distances. Hence, high spatial resolution data are required to accurately estimate volume changes. Here, we estimate ice volume change rate of the Greenland ice sheet using data from Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter during 2003-2009 and CryoSat-2 data during 2010...

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

    DEFF Research Database (Denmark)

    Larsen, Finn; Hammond, P.S.

    2004-01-01

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

  5. Satellite Tracking of Humpback Whales in West Greenland

    DEFF Research Database (Denmark)

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

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

  6. Brief communication: Historical glacier length changes in West Greenland

    Directory of Open Access Journals (Sweden)

    P. W. Leclercq

    2012-08-01

    Full Text Available Past glacier fluctuations provide insight into glacier dynamics, climate change, and the contribution of glaciers to sea-level rise. Here, the length fluctuations since the 19th century of 18 local glaciers in West and South Greenland are presented, extending and updating the study by Weidick (1968. The studied glaciers all show an overall retreat with an average of 1.2 ± 0.2 km over the 20th century, indicating a general rise of the equilibrium line along the west coast of Greenland during the last century. The rate of retreat was largest in the first half of the 20th century.

  7. Brief communication "Historical glacier length changes in West Greenland"

    Directory of Open Access Journals (Sweden)

    P. W. Leclercq

    2012-11-01

    Full Text Available Past glacier fluctuations provide insight into glacier dynamics, climate change, and the contribution of glaciers to sea-level rise. Here, the length fluctuations since the 19th century of 18 local glaciers in West and South Greenland are presented, extending and updating the study by Weidick (1968. The studied glaciers all showed an overall retreat with an average of 1.2 ± 0.2 km over the 20th century, indicating a general rise of the equilibrium line along the west coast of Greenland during the last century. Furthermore, the average rate of retreat was largest in the first half of the 20th century.

  8. Life history parameters of narwhals (Monodon monoceros) from Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

    assessed based on data from reproductive organs and was estimated to be 8–9 years for females and 12–20 years for males. Pregnancy rates for East and West Greenland were estimated to be 0.38–0.42 and 0.38, respectively. Maximum life span expectancy was found to be approximately 100 years. A population......Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007...

  9. Report on a Magnetotelluric Study in Kangerlussuaq, West Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  10. Hunting and fishing settlements in Upernavik district of Northern Greenland

    DEFF Research Database (Denmark)

    Hendriksen, Kåre; Jørgensen, Ulrik

    2015-01-01

    Inuit in the Upernavik district of Northern Greenland has in generations used the winter sea ice as the basis for the essential hunting of seals, white- and narwhales. Since the late 1980’ies hunting has been combined with increasing fishery of Greenland halibut during summer from dinghies and in...... government intent to allocate a larger part of the halibut quota to larger vessels not located in the district and at the same time reduce quota for dinghy and dog sledge based fishing due to limited or even misleading data of the local subsistence and money economy....

  11. Composite Microdiscs with a Magnetic Belt

    DEFF Research Database (Denmark)

    Knaapila, Matti; Høyer, Henrik; Helgesen, Geir

    2015-01-01

    We describe an emulsion-based preparation of patchy composite particles (diameter of 100-500 mu m) consisting of a disclike epoxy core and a belt of porous polystyrene particles (diameter of 30 mu m) with magnetite within the pores. Compared to the magnetically uniform polystyrene particles......, the spontaneous aggregation of composite particles is suppressed when dispersed into liquid, which is attributed to the increased particle size, reduced magnetic susceptibility, and the shape of the magnetic domain distribution within the particles (spherical versus a belt). When the composite particles...

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    Greenlanders have a lower rate of cardiovascular mortality and morbidity than Danes, possibly due to lower blood pressure. However, 24-h blood pressure has never been measured in Greenlanders. The aim of this study was to compare the 24-h blood pressure of Greenlanders and Danes, and to analyse....... Twenty-four-hour blood pressure was measured. It was found that 24-h diastolic blood pressure was lower in Greenlanders than in Danes for the whole 24-h period and during both day and night-time, whereas systolic blood pressure was the same (mean 24-h blood pressure with 95% CI: Danes 123/75 mmHg (120......, outdoor temperature, and lifestyle factors. Greenlanders have a lower 24-h diastolic blood pressure than Danes, and it is suggested that genetic factors are mainly responsible for the lower blood pressure level among Greenlanders. Twenty-four-hour blood pressure among Greenlanders and Danes: Relationship...

  13. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-10-01

    Full Text Available Terrestrial inputs of freshwater flux to Sermilik Fjord, SE Greenland, were estimated, indicating ice discharge to be the dominant source of freshwater. A freshwater flux of 40.4 ± 4.9×109 m3 y−1 was found (1999–2008, with an 85% contribution originated from ice discharge (65% alone from Helheim Glacier, 11% from terrestrial surface runoff (from melt water and rain, 3% from precipitation at the fjord surface area, and 1% from subglacial geothermal and frictional melting due to basal ice motion. The results demonstrate the dominance of ice discharge as a primary mechanism for delivering freshwater to Sermilik Fjord. Time series of ice discharge for Helheim Glacier, Midgård Glacier, and Fenris Glacier were calculated from satellite-derived average surface velocity, glacier width, and estimated ice thickness, and fluctuations in terrestrial surface freshwater runoff were simulated based on observed meteorological data. These simulations were compared and bias corrected against independent glacier catchment runoff observations. Modeled runoff to Sermilik Fjord was variable, ranging from 2.9 ± 0.4×109 m3 y−1 in 1999 to 5.9 ± 0.9×109 m3 y−1 in 2005. The sub-catchment runoff of the Helheim Glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage, indicating high runoff volumes, where glacier cover was present at low elevations.

  14. The South Greenland regional uranium exploration programme

    International Nuclear Information System (INIS)

    This report describes the work and results of the last two field seasons (1080 and 1982) of the Syduran Project. The field work was concentrated in the Motzfeldt Centre and the Granite zone with a short reconnaissance of five uranium anomalies in the Migmatite Complex. The results from the Motzfeldt Centre show that it is composed of at least 6 syenite units which can be divided into two major phases of igneous activity. The radioactive mineralisation has been mapped by gamma-spectrometer and has proved to be very extensive. Uranium mineral occurrences found in the Granite Zone occur in the many faults and fractures, which dissect the area. A study of the fractures and fault movements in the zone makes it possible to suggest an overall structural framework in which to place the uranium occurrences in the zone. Field work on the Igaliko peninsula was confined to a small area known as Puissagtag where four pitchblende veins have been discovered. Numerous uraniferous showings, associated with fractures, have been located in the Vatnaverfi peninsula south of the Igaliko Fjord. Mineralogical studies have shown that 12 of these showings contain pitchblende, that 7 of them contain coffinite and that most of them contain brannerite. The most interesting find during the 1982 field season was in the Migmatite Complex. Five anomalously high uranium areas in the complex were explored briefly with the helicopter-borne scintillometer. Near a place called Igdlorssuit, where a particlarly high gamma-spectrometer anomaly was found during the reconnaissance gamma-spectrometer survey, a large raft of meta-sediments in rapakivi granite was found, in which radioactive mineralisation occurred. This proved to be due to fine disseminated uraninite which occurs over some 150 m of strike length with a width of 1-2 m. The results confirm that there is a good possibility of finding exploitable uranium mineral occurrences in South Greenland. (author)

  15. Mycobacterium tuberculosis Outbreak Strain of Danish Origin Spreading at Worrying Rates among Greenland-Born Persons in Denmark and Greenland

    DEFF Research Database (Denmark)

    Lillebaek, T; Andersen, A B; Rasmussen, E M;

    2013-01-01

    origin has been transmitted to Greenland-born persons in Denmark and subsequently to Greenland, where it is spreading at worrying rates and adding to the already heavy tuberculosis burden in this population group. It is now clear that the C2/1112-15 strain is able to gain new territories using a new....../1112-15 into the Arctic circumpolar region is a worrying tendency which deserves attention. We need to monitor whether this strain already has, or will, spread to other countries....

  16. Greenland Ice Sheet Surface Elevation at Summit, Greenland: 2007-2013

    Science.gov (United States)

    Lutz, E.; Hawley, R. L.; Herring, T.

    2013-12-01

    Quantifying surface elevation change is essential for ice sheet mass balance estimates. We assessed surface elevation and elevation change of the Greenland Ice Sheet at a range of spatial scales using six years of monthly GPS surveys conducted near Summit between 8/2007 and 3/2013. The ~11 km route consists of 15 transects that run parallel and orthogonal to IceSat's groundtrack 412 and includes 121 repeat locations spatially distributed along the route (Figure 1). Horizontal velocities and velocity gradients derived from base station and transect positions agree closely with previous studies. At the survey scale, no significant linear elevation trend is evident over the study period. However, local- and transect-scale time series revealed significant elevation increases of 1--2 cm per year in the central and southern regions of the survey that spatially and temporally may correlate with wind transport events from Summit station. This finding illustrates how sample scale (e.g., density, location and extent) affects surface elevation estimates critical to remote sensing validation and mass balance estimation. Spectral time series analysis showed that the expected annual elevation cycle was dwarfed by a two-year periodicity that dominated nearly all time series. The elevation maximum of Winter 2012-2013 fell short of the expected elevation peak, possibly due to accelerated compaction forced by high temperatures in the preceding Summer of 2012. We also highlight spatial comparisons with elevation products from three NASA altimeters, including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experiment Lidar (MABEL). This unique long-term GPS dataset is valuable for assessing ice sheet elevation change at a range of spatial-temporal scales, and for validating remote sensing products. With continued effort this survey will provide invaluable ground-based observations linking ICESat, IceBridge and ICESat

  17. An eddy covariance derived annual carbon budget for an arctic terrestrial ecosystem (Disko, Greenland)

    Science.gov (United States)

    McConnell, Alistair; Lund, Magnus; Friborg, Thomas

    2016-04-01

    demonstrating that there was a net uptake of carbon by the ecosystem for the 2013-2014 year. Here we present inter annual variability in the exchange of CO2 from the an area of discontinuous permafrost and discuss the controlling factors. Ongoing work to model and upscale from our study site to Western Greenland and beyond will aid our understanding of what might happen over the coming decades and centuries, as vast volumes of permafrost across the world begin to thaw for the first time in millennia.

  18. Geochemical evidence for subduction in the early Archaean from quartz-carbonate-fuchsite mineralization, Isua Supracrustal Belt, West Greenland

    DEFF Research Database (Denmark)

    Pope, Emily Catherine; Rosing, Minik Thorleif; Bird, Dennis K.

    systems suggest that ore-forming metasomatic fluids are derived from subduction-related devolitilization reactions, implying that orogenic Au-deposits in Archaean and Proterozoic supracrustal rock suites are related to subduction-style plate tectonics beginning early in Earth history. Justification...

  19. Design aspects of multiple driven belt conveyors

    NARCIS (Netherlands)

    Nuttall, A.J.G.

    2007-01-01

    Worldwide belt conveyors are used to transport a great variety of bulk solid materials. The desire to carry higher tonnages over longer distances and more diverse routes, while keeping exploitation costs as low as possible, has fuelled many technological advances. An interesting development in the r

  20. Rerouting of subglacial water flow between neighboring glaciers in West Greenland

    Science.gov (United States)

    Chu, Winnie; Creyts, Timothy T.; Bell, Robin E.

    2016-05-01

    Investigations of the Greenland ice sheet's subglacial hydrological system show that the connectivity of different regions of the system influences how the glacier velocity responds to variations in surface melting. Here we examine whether subglacial water flow paths can be rerouted beneath three outlet glaciers in the ablation zone of western Greenland. We use Lamont-Doherty and Center for Remote Sensing of Ice Sheets of University of Kansas (CReSIS) ice-penetrating radar data to create a new ice thickness map. We then use a simple subglacial water flow model to examine whether flow paths can be rerouted and identify the topographic conditions that are sensitive to subglacial rerouting. By varying water pressures within an observationally constrained range, we show that moderate changes in pressure can cause flow paths to reroute and exchange water from one subglacial catchment to another. Flow across subglacial overdeepenings is particularly sensitive to rerouting. These areas have low hydraulic gradients driving flow, so subtle water pressure variations have a strong influence on water flow direction. Based on correlations between water flow paths and ice velocity changes, we infer that water piracy between neighboring catchments can result in a different spatial pattern of hydrologically induced ice velocity speedup depending on the amount and timing of surface melt. The potential for subglacial water to reroute across different catchments suggests that multiple hydrographs from neighboring glaciers are likely necessary to accurately ascertain melt budgets from proglacial point measurements. The relationship between surface runoff, ice dynamics, and proglacial discharge can be altered by rerouting of subglacial water flow within and across outlet glaciers.

  1. Tidewater Dynamics at Store Glacier, West Greenland from Daily Repeat UAV Survey

    Science.gov (United States)

    Hubbard, A., II; Ryan, J.; Toberg, N.; Todd, J.; Christoffersen, P.; Snooke, N.; Box, J. E.

    2015-12-01

    A significant component of the Greenland ice sheet's mass wasteage to sea level rise is attributed to the acceleration and dynamic thinning at its tidewater margins. To improve understanding of the rapid mass loss processes occurring at large tidewater glaciers, we conducted a suite of daily repeat aerial surveys across the terminus of Store Glacier, a large outlet draining the western Greenland Ice Sheet, from May to July 2014 (https://www.youtube.com/watch?v=-y8kauAVAfE). A suite flock of Unmanned Aerial Vehicles (UAVs) were equipped with digital cameras, which, in combination with onboard GPS, enabled production of high spatial resolution orthophotos and digital elevation models (DEMs) using standard structure-from-motion techniques. These data provide insight into the short-term dynamics of Store Glacier surrounding the break-up of the sea-ice mélange that occurred between 4 and 7 June. Feature tracking of the orthophotos reveals that mean speed of the terminus is 16 - 18 md-1, which was independently verified against a high temporal resolution time-series derived from an expendable/telemetric GPS deployed at the terminus. Differencing the surface area of successive orthophotos enable quantification of daily calving rates, which significantly increase just after melange break-up. Likewise, by differencing bulk freeboard volume of icebergs through time we could also constrain the magnitude and variation of submarine melt. We calculate a mean submarine melt rate of 0.18 md-1 throughout the spring period with relatively little supraglacial runoff and no active meltwater plumes to stimulate fjord circulation and upwelling of deeper, warmer water masses. Finally, we relate calving rates to the zonation and depth of water-filled crevasses, which were prominent across parts of the terminus from June onwards.

  2. Modelling the dynamic response of Jakobshavn Isbræ, West Greenland, to calving rate perturbations

    Directory of Open Access Journals (Sweden)

    J. H. Bondzio

    2015-10-01

    Full Text Available Calving is a major means of ice discharge of the Antarctic and Greenland Ice Sheets. The breaking off of icebergs changes the ice front configuration of marine terminating glaciers, which affects the stress regime of their upstream areas. Recent observations show the close correlation between the ice front position and the behaviour of many outlet glaciers. However, modelling of a glacier subject to calving poses various challenges. No universal calving rate parametrisation is known, and tracking of a moving ice front and the related boundary conditions in two or three spatial dimensions is non-trivial. Here, we present the theoretical and technical framework for a Level-Set Method, an implicit boundary tracking scheme, which we implemented into the Ice Sheet System Model (ISSM. The scheme allows us to study the dynamic response of a drainage basin to user-defined front ablation rates. We apply the method in a suite of experiments to Jakobshavn Isbræ, a major marine terminating outlet glacier of the western Greenland Ice Sheet. The model robustly reproduces the high sensitivity of the glacier to frontal ablation in form of calving. We find that enhanced calving is able to trigger significant acceleration of the ice stream. Upstream acceleration is sustained through a combination of various feedback mechanisms. However, lateral stress and ice influx into the trough are able to stabilise the ice stream. This study contributes to the present discussion on causes and effects of the continued changes occurring at Jakobshavn Isbræ, and emphasises that the incorporation of seasonal calving and dynamic lateral effects is key for realistic model projections of future global sea level rise on centennial time scales.

  3. The Quaternary geology of the Narssaq area, South Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1979-01-01

    The topography and glacial striations in th~ Narssaq area indicate that the ice age glacial regime in this part of Greenland was characterized by ice movement constrained by the local topography, and a shallow depth of the ice cover. Erratics observed 1200 m above sea level provide a minimum esti...

  4. Pastoral Settlement. Farming and Hierarchy in Norse Vatnahverfi, South Greenland

    DEFF Research Database (Denmark)

    Madsen, Christian Koch

    farming system relied on extensive land use practices organized around shielings, and apparently after unique Greenlandic patterns. A population estimate based on these settlement patterns implies an average population in Vatnahverfi of only ca. 225-550 people, and an average maximum population of ca...

  5. Improved ice loss estimate of the northwestern Greenland ice sheet

    NARCIS (Netherlands)

    Kjeldsen, K.K.; Khan, S.A.; van den Broeke, M.R.; van Angelen, J.H.

    2013-01-01

    We estimate ice volume change rates in the northwest Greenland drainage basin during 2003–2009 using Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Elevation changes are often reported to be largest near the frontal portion of outlet glaciers. To improve the volume change est

  6. Upper mantle and crustal structure of the East Greenland Caledonides

    DEFF Research Database (Denmark)

    Schiffer, Christian; Balling, N.; Jacobsen, B. H.;

    The East Greenland and Scandinavian Caledonides once formed a major coherent mountain range, as a consequence of the collision of the continents of Laurentia and Baltica. The crustal and upper mantle structure was furthermore influenced by several geodynamic processes leading to the formation...

  7. Greenland climate change: from the past to the future

    NARCIS (Netherlands)

    Masson-Delmotte, V.; Swingedouw, D.; van den Broeke, M.R.; Vinther, B.

    2012-01-01

    Climate archives available from deep sea and marine shelf sediments, glaciers, lakes, and ice cores in and around Greenland allow us to place the current trends in regional climate, ice sheet dynamics, and land surface changes in a broader perspective. We show that, during the last decade (2000s), a

  8. Environmental radioactive contamination in Greenland: A 35 years retrospect

    DEFF Research Database (Denmark)

    Aarkrog, A.; Dahlgaard, H.; Nielsen, S.P.

    2000-01-01

    Environmental studies of anthropogenic radionuclides in Greenland over four decades are reported. The studies have comprised the marine as well as the terrestrial environments and emphasis has been laid on measurements of Sr-90 and Cs-137. Th, temporal and the spatial trends of these radionuclide...

  9. Climate change in Greenland, Denmark and the Levant

    DEFF Research Database (Denmark)

    Schrøder, Niels

    . At the century scale there seems to be an opposite correlation in the trend in precipitation in Northern Europe (Denmark) and the Levant (Cyprus) but the trend in Greenland is positive, similar to the data for Denmark. For the Holocene it can be concluded that the Blytt-Sernander model fits very well...... Oscillation), archaeology, pollen, Blytt-Sernander model....

  10. Cultural adaptation, compounding vulnerabilities and conjunctures in Norse Greenland

    Science.gov (United States)

    Dugmore, Andrew J.; McGovern, Thomas H.; Vésteinsson, Orri; Arneborg, Jette; Streeter, Richard; Keller, Christian

    2012-01-01

    Norse Greenland has been seen as a classic case of maladaptation by an inflexible temperate zone society extending into the arctic and collapse driven by climate change. This paper, however, recognizes the successful arctic adaptation achieved in Norse Greenland and argues that, although climate change had impacts, the end of Norse settlement can only be truly understood as a complex socioenvironmental system that includes local and interregional interactions operating at different geographic and temporal scales and recognizes the cultural limits to adaptation of traditional ecological knowledge. This paper is not focused on a single discovery and its implications, an approach that can encourage monocausal and environmentally deterministic emphasis to explanation, but it is the product of sustained international interdisciplinary investigations in Greenland and the rest of the North Atlantic. It is based on data acquisitions, reinterpretation of established knowledge, and a somewhat different philosophical approach to the question of collapse. We argue that the Norse Greenlanders created a flexible and successful subsistence system that responded effectively to major environmental challenges but probably fell victim to a combination of conjunctures of large-scale historic processes and vulnerabilities created by their successful prior response to climate change. Their failure was an inability to anticipate an unknowable future, an inability to broaden their traditional ecological knowledge base, and a case of being too specialized, too small, and too isolated to be able to capitalize on and compete in the new protoworld system extending into the North Atlantic in the early 15th century. PMID:22371594

  11. Norse Greenland dietary economy ca. AD 980-ca. AD 1450

    DEFF Research Database (Denmark)

    Arneborg, J.; Lynnerup, Niels; Heinemeier, Jan;

    2012-01-01

    An initial study of the C values for human bone collagen of 27 Norse Greenlanders in the late 1990s suggested a change in the Norse diet from predominantly terrestrial to predominantly marine food. This shift may well indicate a change in diet; the question left open by the limited initial isotop...

  12. The Greenland ice sheet in a warming climate

    NARCIS (Netherlands)

    van Angelen, J.H.

    2013-01-01

    In this thesis we assess multiple aspects of the Greenland climate, including the surface energy and mass balance of the ice sheet for the contemporary and near future climate. For these purposes we used output of the extensively and well-evaluated regional atmospheric climate model RACMO2. The rela

  13. Recent changes in the freshwater composition east of Greenland

    NARCIS (Netherlands)

    de Steur, L.; Pickart, R.S.; Torres, D.J.; Valdimarsson, H.

    2015-01-01

    Results from three hydrographic surveys across the East Greenland Current between 2011 and 2013 are presented with focus on the freshwater sources. End-member analysis using salinity, d18O, and nutrient data shows that while meteoric water dominated the freshwater content, a significant amount of Pa

  14. Vegetation of the Angmagssalik District Southeast Greenland. I. Littoral vegetation

    NARCIS (Netherlands)

    Molenaar, de J.G.

    1974-01-01

    The present study deals with a part of the results of observations made during expeditions in 1968 and 1969 to the Angmagssalik District, the central and largest deglaciated area on the Southeast coast of Greenland; which journeys were preceded by a reconaissance in 1966. The Angmagssalik District i

  15. CT-scanning of ancient Greenlandic Inuit temporal bones

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Videbaek, H

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal...

  16. Evidence of meltwater retention within the Greenland ice sheet

    NARCIS (Netherlands)

    Rennermalm, A.K.; Smith, L.C.; Chu, V.W.; Box, J.E.; Forster, R.R.; van den Broeke, M.R.; van As, D.; Moustafa, S.E.

    2013-01-01

    Greenland ice sheet mass losses have increased in recent decades with more than half of these attributed to surface meltwater runoff. However, the magnitudes of englacial storage, firn retention, internal refreezing and other hydrologic processes that delay or reduce true water export to the global

  17. Environmental and Ethical Aspects of Sustainable Mining in Greenland

    DEFF Research Database (Denmark)

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

    2013-01-01

    The increased use of scarce metals in combination with climate changes pave way for extensive extraction of mineral resources in Greenland. The focus of this study is on environmental ethical aspects of mining activities in a vulnerable and unspoiled arctic nature. Mining can have several economi...

  18. Albedo decline on Greenland's Mittivakkat Gletscher in a warming climate

    DEFF Research Database (Denmark)

    Mernild, Sebastian H.; Malmros, Jeppe K.; Yde, Jacob C.;

    2015-01-01

    Albedo is one of the parameters that govern energy availability for snow and ice surface ablation, and subsequently the surface mass balance conditions of temperate glaciers and ice caps (GIC). Here, we document snow and ice albedo changes for Mittivakkat Gletscher (MG) in Southeast Greenland (20...

  19. Statistical Lineament Analysis in South Greenland Based on Landsat Imagery

    DEFF Research Database (Denmark)

    Conradsen, Knut; Nilsson, Gert; Thyrsted, Tage

    1986-01-01

    Linear features, mapped visually from MSS channel-7 photoprints (1: 1 000 000) of Landsat images from South Greenland, were digitized and analyzed statistically. A sinusoidal curve was fitted to the frequency distribution which was then divided into ten significant classes of azimuthal trends. Maps...

  20. Greenland's balance of Payments and Self-governance

    DEFF Research Database (Denmark)

    Aage, Hans

    Why is the current account of Greenland a topical issue, while those of Denmark and of the island of Bornholm in the Baltic Sea are not? Has the current account anything to do with future inde­pendence? It is ar­gued that balance of payments and foreign debt are closely connected to political...

  1. Supraglacial bacterial community structures vary across the Greenland ice sheet

    DEFF Research Database (Denmark)

    Cameron, Karen A.; Stibal, Marek; Zarsky, Jakub D.;

    2016-01-01

    The composition and spatial variability of microbial communities that reside within the extensive (>200 000 km(2)) biologically active area encompassing the Greenland ice sheet (GrIS) is hypothesized to be variable. We examined bacterial communities from cryoconite debris and surface ice across t...

  2. Greenland ice sheet melt from MODIS and associated atmospheric variability

    OpenAIRE

    Häkkinen, Sirpa; Hall, Dorothy K; Shuman, Christopher A; Worthen, Denise L; DiGirolamo, Nicolo E

    2014-01-01

    Daily June-July melt fraction variations over the Greenland ice sheet (GIS) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) (2000–2013) are associated with atmospheric blocking forming an omega-shape ridge over the GIS at 500 hPa height. Blocking activity with a range of time scales, from synoptic waves breaking poleward (

  3. The extreme melt across the Greenland ice sheet in 2012

    Science.gov (United States)

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

    2012-10-01

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

  4. Implementation and effectiveness of antiretroviral therapy in Greenland

    DEFF Research Database (Denmark)

    Lohse, N.; Ladefoged, K.; Obel, N.

    2008-01-01

    Analyses from the Danish HIV Cohort Study showed that, despite comparable economic means and general education of healthcare personnel, antiretroviral treatment of HIV in Greenland began later and has been implemented at a slower pace with lower therapeutic effectiveness than in Denmark. However...

  5. Greenland ice mass balance from GPS, GRACE and ICESat

    DEFF Research Database (Denmark)

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

    Global warming is predicted to have a profound impact on the Greenland Ice Sheet (GrIS) and its contribution to future sea-level rise. The GrIS has seen dramatic changes over the last two decades and mass loss has been accelerating, owing to a combination of increased runoff and discharge of ice ...

  6. History of the Greenland Ice Sheet: paleoclimatic insights

    DEFF Research Database (Denmark)

    Alley, Richard B.; Andrews, John Thomas; Brigham-Grette, Julia;

    2010-01-01

    Paleoclimatic records show that the Greenland Ice Sheet consistently has lost mass in response to warming, and grown in response to cooling. Such changes have occurred even at times of slow or zero sea-level change, so changing sea level cannot have been the cause of at least some of the ice-shee...

  7. First characterization of avian influenza viruses from Greenland 2014

    DEFF Research Database (Denmark)

    Hartby, Christina Marie; Krog, Jesper Schak; Ravn Merkel, Flemming;

    2016-01-01

    In late February 2014, unusually high numbers of wild birds, thick-billed murre (Uria lomvia), were found dead at the coast of South Greenland. To investigate the cause of death, 45 birds were submitted for laboratory examinations in Denmark. Avian influenza viruses (AIVs) with subtypes H11N2...

  8. 34 First Callisto solar burst spectrometer station in Greenland

    Science.gov (United States)

    Monstein, Christian

    2016-04-01

    In mid of March 2016 a new long wavelength station in Greenland was set into operation. It is a dual circular polarization, frequency agile solar radio burst spectrometer based on two Callisto spectrometers and the Long Wavelength Array antenna. During the commissioning phase several nice radio burst observations proved that the system works as expected.

  9. Representing Greenland ice sheet freshwater fluxes in climate models

    NARCIS (Netherlands)

    Lenaerts, Jan T M; Le Bars, Dewi; Van Kampenhout, Leo; Vizcaino, Miren; Enderlin, Ellyn M.; Van Den Broeke, Michiel R.

    2015-01-01

    Here we present a long-term (1850-2200) best estimate of Greenland ice sheet (GrIS) freshwater runoff that improves spatial detail of runoff locations and temporal resolution. Ice discharge is taken from observations since 2000 and assumed constant in time. Surface meltwater runoff is retrieved from

  10. Use of clay from kangerlussuaq in the Greenlandic construction industry

    DEFF Research Database (Denmark)

    Belmonte, Louise Josefine; Villumsen, Arne; Ottosen, Lisbeth M.;

    2010-01-01

    Clay material from Kangerlussuaq in West Greenland was characterised and its possible use for the production of bricks, expanded clay products and inert filler material was investigated. It was generally found that it was possible to use the clay in all of the above mentioned materials, although,...

  11. Greenland ice sheet motion insensitive to exceptional meltwater forcing.

    Science.gov (United States)

    Tedstone, Andrew J; Nienow, Peter W; Sole, Andrew J; Mair, Douglas W F; Cowton, Thomas R; Bartholomew, Ian D; King, Matt A

    2013-12-01

    Changes to the dynamics of the Greenland ice sheet can be forced by various mechanisms including surface-melt-induced ice acceleration and oceanic forcing of marine-terminating glaciers. We use observations of ice motion to examine the surface melt-induced dynamic response of a land-terminating outlet glacier in southwest Greenland to the exceptional melting observed in 2012. During summer, meltwater generated on the Greenland ice sheet surface accesses the ice sheet bed, lubricating basal motion and resulting in periods of faster ice flow. However, the net impact of varying meltwater volumes upon seasonal and annual ice flow, and thus sea level rise, remains unclear. We show that two extreme melt events (98.6% of the Greenland ice sheet surface experienced melting on July 12, the most significant melt event since 1889, and 79.2% on July 29) and summer ice sheet runoff ~3.9 σ above the 1958-2011 mean resulted in enhanced summer ice motion relative to the average melt year of 2009. However, despite record summer melting, subsequent reduced winter ice motion resulted in 6% less net annual ice motion in 2012 than in 2009. Our findings suggest that surface melt-induced acceleration of land-terminating regions of the ice sheet will remain insignificant even under extreme melting scenarios.

  12. A high-resolution record of Greenland mass balance

    Science.gov (United States)

    McMillan, Malcolm; Leeson, Amber; Shepherd, Andrew; Briggs, Kate; Armitage, Thomas W. K.; Hogg, Anna; Kuipers Munneke, Peter; Broeke, Michiel; Noël, Brice; Berg, Willem Jan; Ligtenberg, Stefan; Horwath, Martin; Groh, Andreas; Muir, Alan; Gilbert, Lin

    2016-07-01

    We map recent Greenland Ice Sheet elevation change at high spatial (5 km) and temporal (monthly) resolution using CryoSat-2 altimetry. After correcting for the impact of changing snowpack properties associated with unprecedented surface melting in 2012, we find good agreement (3 cm/yr bias) with airborne measurements. With the aid of regional climate and firn modeling, we compute high spatial and temporal resolution records of Greenland mass evolution, which correlate (R = 0.96) with monthly satellite gravimetry and reveal glacier dynamic imbalance. During 2011-2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland's area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.

  13. First indication of Storegga tsunami deposits from East Greenland

    NARCIS (Netherlands)

    Wagner, B.; Bennike, O.; Klug, M.; Cremer, H.

    2007-01-01

    A 2.73 m long sediment sequence from Loon Lake, located at 18m a.s.l. on outer Geographical Society Ø, East Greenland, was investigated for its chronology and changes in physical and biogeochemical properties, macrofossils, and grain-size distribution. The predominance of marine fossils throughout t

  14. Supporting an Externally Developed Model of Education in Greenland

    Science.gov (United States)

    Wyatt, Tasha R.

    2010-01-01

    This study investigated the adaptation process of an externally developed model of reform in Greenland's educational system. Under investigation was how reform leaders responded to the needs of the community after implementing an educational model developed in the United States by researchers at the Center for Research on Education, Diversity, and…

  15. Project CAP. Boston Mountains Educational Cooperative, Greenland, Arkansas.

    Science.gov (United States)

    Hamilton, Jack A.; Leffler, Jeanne

    This description of career education activities in Greenland, Arkansas, was prepared as part of a study conducted to identify evaluated, exemplary career education activities which represent the best of the current career education programs and practices referred to in Public Law 93-380. (See CE 018 212 for the final report of this study.) This…

  16. Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

    Science.gov (United States)

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

    2016-04-01

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

  17. The "Burgundian" hat from Herjolfsnes, Greenland: new discoveries, new dates

    DEFF Research Database (Denmark)

    Smith, Michèle Hayeur; Arneborg, Jette; Smith, Kevin

    2016-01-01

    of the Greenland Norse colony but also its enduring cultural links with continental European fashions, following a comment to this effect published by Nørlund himself. In 1996, the hat was dated to the early fourteenth century by Arneborg, a century earlier than Nørlund’s dating, based on stylistic comparisons...

  18. Greenland Ice Sheet Mass Loss from GRACE Monthly Models

    DEFF Research Database (Denmark)

    Sørensen, Louise Sandberg; Forsberg, René

    2010-01-01

    The Greenland ice sheet is currently experiencing a net mass loss. There are however large discrepancies between the published qualitative mass loss estimates, based on different data sets and methods. There are even large differences between the results based on the same data sources, as is the ...

  19. Eemian interglacial reconstructed from a Greenland folded ice core

    DEFF Research Database (Denmark)

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

    2013-01-01

    , the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during...

  20. Audit report from Greenland on nurses’ tasks and perceived competency

    DEFF Research Database (Denmark)

    Nexøe, Jørgen; Skifte, Ella; Niclasen, Birgit;

    2012-01-01

    Introduction: Despite all efforts, recruitment of healthcare personnel has become increasingly difficult in Greenland as in other remote areas. The aim of this observational study was to describe the extent of health care delivered by nurses in Greenland’s healthcare system. Reasons for encounter...