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Sample records for east greenland recorded

  1. The interglacial-glacial record at the mouth of Scoresby Sund, East Greenland

    DEFF Research Database (Denmark)

    Mangerud, Jan; Funder, Svend Visby

    1994-01-01

    Brewster (facing the open ocean) and till on top of the interglacial beds at Kikiakajik show that both an outlet from the Greenland Ice Sheet, and more local glaciers reached the continental shelf during the Weichselian. This glacial event is poorly dated, but tentatively correlated with the Flakkerhuk...... interglaciation ( "" isotope substage Se) on the basis of mollusc assemblages and luminescence dates. Abundant Balal/lls Crel/atlls, and several bivalves, show that the advection of warm Atlantic water to the East Greenland coast was higher during that interglacial than during the Holocene. Glacial striae at Kap...... stade ( "" 19-15 ka BP) when, from marine geological data, it is suggested that the Scoresby Sund glacier terminated c. 30 km east of Kap Brewster. During the Milne Land stade (c. 10 ka BP) there was a resurgence of local ice caps in the mountains both north and south of the fjord mouth, but Scoresby...

  2. Multi-decadal record of ice dynamics on Daugaard Jensen Gletscher, East Greenland, from satellite imagery and terrestrial measurements

    DEFF Research Database (Denmark)

    Stearns, L.A.; Hamilton, G.S.; Reeh, Niels

    2005-01-01

    The history of ice velocity and calving front position of Daugaard Jensen Gletscher, a large outlet glacier in East Greenland, is reconstructed from field measurements, aerial photography and satellite imagery for the period 1950-2001. The calving terminus of the glacier has remained in approxima......The history of ice velocity and calving front position of Daugaard Jensen Gletscher, a large outlet glacier in East Greenland, is reconstructed from field measurements, aerial photography and satellite imagery for the period 1950-2001. The calving terminus of the glacier has remained...

  3. Disentangling Diagenesis From the Rock Record: An Example From the Permo-Triassic Wordie Creek Formation, East Greenland

    Science.gov (United States)

    Roberts, J.; Turchyn, A. V.; Wignall, P. B.; Newton, R. J.; Vane, C. H.

    2018-01-01

    The measurement of isotope ratios in sedimentary rocks deposited over geological time can provide key insights to past environmental change over important intervals in the past. However, it is important to be aware that secondary alteration can overprint the original isotopic records. We demonstrate this principle using high-resolution carbon, sulfur, and oxygen isotope measurements in organic carbon, pyrite, and carbonate minerals (δ13Corg, δ34Spyr, δ34SCAS, δ13Ccarb, and δ18Ocarb) and kerogen analyses (HI and OI) from the Wordie Creek Formation, East Greenland. These sediments were initially deposited across the Permo-Triassic transition, but as we will show, the carbonate record has been altered by interaction with meteoric water significantly after initial deposition. Comparison of the better preserved organic carbon and pyrite records with a proximal Permo-Triassic sequence reveals significant pyrite-sulfur isotope variability across the Permo-Triassic transition. This regional heterogeneity argues against basin-wide euxinia and instead suggests localized changes in sulfur fractionation in response to variations in organic carbon flux. This hypothesis can be used to explain seemingly inconsistent regional trends in other sulfur isotopes across the Permo-Triassic transition.

  4. The Jurassic of Denmark and Greenland: The Jurassic of East Greenland: a sedimentary record of thermal subsidence, onset and culmination of rifting

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    Surlyk, Finn

    2003-10-01

    Full Text Available The Late Palaeozoic – Mesozoic extensional basin complex of East Greenland contains a record of deposition during a period of Rhaetian – Early Bajocian thermal subsidence, the onset of riftingin the Late Bajocian, its growth during the Bathonian–Kimmeridgian, culmination of rifting in the Volgian – Early Ryazanian, and waning in the Late Ryazanian – Hauterivian. The area was centred over a palaeolatitude of about 45°N in the Rhaetian and drifted northwards to about 50°N in the Hauterivian. A major climate change from arid to humid subtropical conditions took place at the Norian–Rhaetian transition. Deposition was in addition governed by a long-term sea-level rise with highstands in the Toarcian–Aalenian, latest Callovian and Kimmeridgian, and lowstands in the latest Bajocian – earliest Bathonian, Middle Oxfordian and Volgian.The Rhaetian – Lower Bajocian succession is considered the upper part of a megasequence, termed J1, with its base in the upper Lower Triassic, whereas the Upper Bajocian – Hauterivian succession forms a complete, syn-rift megasequence, termed J2. The southern part of the basin complex in Jameson Land contains a relatively complete Rhaetian–Ryazanian succession and underwent only minor tilting during Middle Jurassic – earliest Cretaceous rifting. Rhaetian – Lower Jurassic deposits are absent north of Jameson Land and this region was fragmented into strongly tilted fault blocks during the protracted rift event. The syn-rift successions of the two areas accordingly show different long-term trends in sedimentary facies. In the southern area, the J2 syn-rift megasequence forms a symmetrical regressive–transgressive–regressive cycle, whereas the J2 megasequence in the northern area shows an asymmetrical, stepwise deepening trend.A total of eight tectonostratigraphic sequences are recognised in the Rhaetian–Hauterivian interval. They reflect major changes in basin configuration, drainage systems

  5. Comparison of the glacial chronology of Eastern Baffin Island, East Greenland and Camp century accumulation record

    DEFF Research Database (Denmark)

    Andrews, John; Funder, Svend Visby; Hjort, Chritian

    1974-01-01

    ) an interval about 40,000 to 11,000 yr ago of restricted ice extent; and (5) a late glacial sladial belween 11,000 and 8,000 B.P. This record shows basic agreement with a chronology of snow accumulation at the Camp Century ice core site based on a revised chronostratigraphic interpretation. Fluctuations in sea...... level between 120,000 and 70,000 B.P. may well be related to glacierization of high arctic land masses under conditions of heavy snowfall. The subsequent reduction of accumulation in these high arctic areas then leads to a reduction of ice volume with a dry, cold interstadial correlative in time...

  6. 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...

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

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    Piasecki, Stefan

    2004-11-01

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

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

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    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.

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

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    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.

  10. The East Greenland rifted volcanic margin

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    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

  11. 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...

  12. East Greenland tetrapods are Devonian in age

    Science.gov (United States)

    Marshall, J. E. A.; Astin, T. R.; Clack, J. A.

    1999-07-01

    Palynological dates unambiguously resolve the stratigraphic age of the East Greenland sedimentary rocks containing the earliest well-preserved tetrapod remains. This is the first time that spore samples have been discovered in the sedimentary succession that has yielded Acanthostega and Ichthyostega, two tetrapods that are regarded as critically important taxa for our understanding of the origin and early evolution of the tetrapods. These palynological assemblages conclusively show that the rocks are Devonian in age. The evidence resolves a 60-year-old dispute regarding the age of these rocks and contradicts a recent controversial study suggesting a much younger (Carboniferous, Viséan) age for these tetrapods. Spore samples bracketing the in situ occurrences of both tetrapod genera place them securely within the Famennian Age of the Devonian Period and at least as old as Famennian 2b. The ages of all known Devonian tetrapods are reviewed and related to a common palynological standard. This review places Ichthyostega and Acanthostega as the earliest of the Famennian tetrapods.

  13. Hydrothermal flake graphite mineralisation in Paleoproterozoic rocks of south-east Greenland

    DEFF Research Database (Denmark)

    Rosing-Schow, Nanna; Bagas, Leon; Kolb, Jochen

    2017-01-01

    Flake graphite mineralisation is hosted in the Kuummiut Terrane of the Paleoproterozoic Nagssugtoqidian Orogen, south-east Greenland. Eclogite-facies peak-metamorphic assemblages record temperatures of 640–830 °C and pressures of 22–25 kbar, and are retrogressed in the high-pressure amphibolite-f...

  14. 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 of ...

  15. 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

  16. Age of the youngest Palaeogene flood basalts in East Greenland

    DEFF Research Database (Denmark)

    Heilmann-Clausen, C.; Piasecki, Stefan; Abrahamsen, Niels

    2008-01-01

    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...

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

    DEFF Research Database (Denmark)

    Døssing, Arne; Funck, T.

    2012-01-01

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

  18. Luminescence dating of Late Quaternary sediments from East Greenland

    DEFF Research Database (Denmark)

    Mejdahl, V.; Funder, Svend Visby

    1994-01-01

    Luminescence dating based on K-feldspars and using both TL and OSL methods have been performed on 94 sediment samples from East Greenland. The ages go back more than 380 ka, but are mainly from the last interglaciation and the subsequent period and include both shallow-marine/coastal-fluvial and ...... owing to incomplete bleaching. OSL may give better results than TL in these sediments...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  20. Comparison of satellite imagery and infrared aerial photography as vegetation mapping methods in an arctic study area: Jameson Land, East Greenland

    DEFF Research Database (Denmark)

    Hansen, Birger Ulf; Mosbech, Anders

    1994-01-01

    Remote Sensing, vegetation mapping, SPOT, Landsat TM, aerial photography, Jameson Land, East Greenland......Remote Sensing, vegetation mapping, SPOT, Landsat TM, aerial photography, Jameson Land, East Greenland...

  1. A fossil subduction zone in the East Greenland Caledonides revealed by a Receiver Function analysis

    DEFF Research Database (Denmark)

    Schiffer, Christian; Jacobsen, B. H.; Balling, N.

    Subsequent to their formation the East Greenland and Scandinavian Caledonides formed a major coherent mountain range. The understanding of the European Caledonides therefore naturally involves also the East Greenland Caledonides. The present-day topography and crustal and upper mantle structure i...

  2. Historical ablation rates on south-east Greenland glaciers measured in the 1933 warm summer

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    Bent Hasholt

    2016-07-01

    Full Text Available Ice ablation rates measured on four glaciers in south-east Greenland in summer 1933 are recovered from an old field book of geologist K. Milthers. These unpublished ablation data are among the first measured in Greenland and were obtained during a warm period comparable to that of recent years. Ablation rates of up to 45 mm ice eq. d−1 were observed. Using the Tasiilaq meteorological record, we calculate degree-day factors of ca. 3–5 mm ice eq. d−1°C−1. Comparing these results with 1996–2012 observations at one of Milthers’ glaciers (Mittivakkat, we find that ablation rates and degree-day factors are significantly higher (61±50% in recent years. We speculate this to be due to a reduction in surface albedo, and perhaps the retreat of the glaciers out of the cold maritime inversion layer. Our findings suggest that using a temperature-index method that assumes constant degree-day factors may produce inaccurate long-term ablation estimates for south-east Greenland glaciers, further emphasizing the value of the rare 1933 measurements for validation of ablation models.

  3. An Intensive Observation of Calving at Helheim Glacier, East Greenland

    Science.gov (United States)

    Holland, David M.; Voytenko, Denis; Christianson, Knut; Dixon, Timothy H.; Mei, M. Jeffrey; Parizek, Byron R.; Vankova, Irena; Walker, Ryan T.; Walter, Jacob I.; Nicholls, Keith; hide

    2016-01-01

    Calving of glacial ice into the ocean from the Greenland Ice Sheet is an important component of global sea-level rise. The calving process itself is relatively poorly observed, understood, and modeled; as such, it represents a bottleneck in improving future global sea-level estimates in climate models. We organized a pilot project to observe the calving process at Helheim Glacier in east Greenland in an effort to better understand it. During an intensive one-week survey, we deployed a suite of instrumentation, including a terrestrial radar interferometer, global positioning system (GPS) receivers, seismometers, tsunameters, and an automated weather station. We were fortunate to capture a calving process and to measure various glaciological, oceanographic, and atmospheric parameters before, during, and after the event. One outcome of our observations is evidence that the calving process actually consists of a number of discrete events, spread out over time, in this instance over at least two days. This time span has implications for models of the process. Realistic projections of future global sea level will depend on an accurate parametrization of calving, and we argue that more sustained observations will be required to reach this objective.

  4. 110 years of local glacier and ice cap changes in Central- and North East Greenland

    Science.gov (United States)

    Bjork, A. A.; Aagaard, S.; Kjaer, K. H.; Khan, S. A.; Box, J.

    2014-12-01

    The local glaciers and ice caps of Greenland are becoming more apparent players in global sea-level rise, and their contribution to future changes is significant. Very little information on their historical fluctuations exists as much of the focus has been on the Greenland Ice Sheet. Now, we can for the first time present historic data that spans 110 years for more than 200 of the local glaciers and ice caps covering this large and important region of the Arctic. The central- and north eastern part of Greenland is of particular interest as these areas are predicted to exhibit a more active behavior with higher mass loss in the future - simultaneously with an increase in precipitation. Our results show that the glaciers and ice caps in the region are responding very rapidly to changes in temperature and precipitation. The present retreat is the fastest observed within the last eight decades, only surpassed by the rapid post LIA retreat. The 1930s was the golden era for scientific exploration in Central- and North East Greenland as several large expeditions visited the area and photographed from land, sea and air. We use historic recordings from Danish and Norwegian aerial missions and terrestrial recordings from the renowned American Explorer Louise Boyd. These unique pictures from the early 1930s form the backbone of the study and are supplemented the more recent aerial photographs the 1940s and onwards and satellite imagery from the mid-1960s and up until present. From high resolution aerial photographs we are able to map the maximum extent of the glaciers during the LIA (Little Ice Age), from which retreat in this area is estimated to commence in 1900. Using a new SMB (Surface Mass Balance) model and its components covering the entire observational period along with high resolution DEMs and historic sea-ice records we are now able to extract valuable information on the past and present triggers of glacial change.

  5. Preliminary results of a geophysical study of the East Greenland Caledonides

    DEFF Research Database (Denmark)

    Schiffer, Christian; Jacobsen, B. H.; Balling, N.

    The present-day topography and crustal structure of the East Greenland Caledonides were intensively influenced by several constructive and destructive processes, including the Caledonian orogeny, the subsequent extensional collapse, continental breakup and fluvial and glacial erosional processes....

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  7. Pb isotope evidence for contributions from different Iceland mantle components to Palaeogene East Greenland flood basalts

    DEFF Research Database (Denmark)

    Peate, David; Stecher, Ole

    2003-01-01

    We present new Pb isotope data on 21 samples of break-up-related flood basalts (56–54 Ma) from the Blosseville Kyst region of East Greenland. These samples show a considerable range in isotopic composition (206Pb/204Pb 17.6 to 19.3) that broadly correlates with compositional type. The ‘low-Ti’ type...... in the selected samples. Uncontaminated Palaeogene East Greenland flood basalts appear to have sampled the same broad range in mantle compositions seen in Recent Iceland basalts. In contrast to the peripheral lava suites from the British Isles and Southeast Greenland, where the inferred uncontaminated magmas have...... to the most radiogenic values found in recent Icelandic basalts. Furthermore, the main volume of lavas in East Greenland is displaced away from the NAEM towards this radiogenic Pb component. Thus, this ‘Iceland radiogenic Pb end-member’ component was a significant contributor to the break-up-related magmatism...

  8. The Jurassic of Denmark and Greenland: Palynostratigraphy and palaeoenvironment of the Middle Jurassic Sortehat Formation (Neill Klinter Group, Jameson Land, East Greenland

    Directory of Open Access Journals (Sweden)

    Koppelhus, Eva B.

    2003-10-01

    Full Text Available The grey–black mudstones of the Sortehat Formation form part of the Middle Jurassic fill of the Jameson Land Basin in East Greenland. The formation is exposed in the southernmost part of the north–south-trending, Mesozoic rift system in East Greenland that was part of the epeiric seaway between East Greenland and Norway. Sedimentological observations of the Sortehat Formation indicate deposition in an offshore marine setting that was typically low energy and periodically oxygen-deficient but was influenced by storm currents on occasion. Detailed palynological studies of the Sortehat Formation have resulted in the definition of three palynological assemblage zones recognised at four localities, namely Enhjørningen Dal and Pelion (north Jameson Land, the type section at Sortehat (central Jameson Land and Albuen at Neill Klinter along Hurry Inlet(south-east Jameson Land. In stratigraphic order, these zones are termed the Botryococcus Assemblage Zone, the Nannoceratopsis gracilis – Nannoceratopsis senex Assemblage Zone, and the Sentusidinium pelionense Assemblage Zone. They are recognised on the basis of the identification of approximately 110 species of palynomorphs, including 45 species of spores, 30 of pollen, 22 of dinoflagellate cysts, 10 acritarch species, two species of algae, and some fungal spores. An Aalenian – ?Early Bajocian age is suggested for the Sortehat Formation on the basis of thepalynoflora.Interpretation of the palynomorph assemblages suggests that the formation accumulated in a shallow, brackish marine environment. A significant terrestrial input, including the freshwater greenalga Botryococcus, is recorded in the lower part of the formation and interpreted as an allochthonous accumulation in an offshore marine environment related to transgression of a low-lyingcoastal plain. A marked shift in the palynomorph assemblage seen by diversification of marine microplankton above the base of the formation, indicates an

  9. An isotope trace element study of the East Greenland Tertiary dyke swarm

    DEFF Research Database (Denmark)

    Hanghøj, Karen; Storey, Michael; Stecher, Ole

    2003-01-01

    Dykes of the East Greenland Tertiary dyke swarm can be divided into pre- and syn-break-up tholeiitic dykes, and post-break-up transitional dykes. Of the pre- and syn-break-up dykes, the most abundant group (Tholeiitic Series; TS) has major element compositions similar to the main part of the East...

  10. Bottom fish assemblages at the shelf and continental slope off East Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Ole A; Hvingel, Carsten; Møller, P.R.

    2015-01-01

    During 2006 and 2008 two bottom trawl surveys were conducted at East Greenland to 72°N covering depths down to 1500 m. In the 149 trawl hauls in total 113 fish species were recorded of which 37 were considered pelagic and excluded from the analyses. As a first step the abundance data for the 76...... benthic species were used for analyses of the fish fauna diversity and fish assemblages. Nine assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each...... distribution, species composition, temperature and depth. Three of the assemblages were located in the cold Iceland Sea while six were found in the somewhat warmer Irminger Sea...

  11. Cortisol levels in hair of East Greenland polar bears.

    Science.gov (United States)

    Bechshøft, T Ø; Sonne, C; Dietz, R; Born, E W; Novak, M A; Henchey, E; Meyer, J S

    2011-01-15

    To demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (HPA) axis activity in polar bears (Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3-19 years) and 10 male (6-19 years) East Greenland polar bears sampled in 1994-2006. The hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. The samples were categorized according to contamination: eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p=0.81) or sampling year (p=0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p=0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. No Abrupt Changes in redox conditions associated with the end-Permian marine ecosystem collapse in the east Greenland basin

    DEFF Research Database (Denmark)

    Nielsen, Jesper K.; Shen, Y; Piasecki, Stefan

    2010-01-01

    compositions of pyrites from the East Greenland Basin. The size distributions of framboidal pyrites in sediments from a continuous section across the Permian–Triassic boundary reveal that sulfidic conditions in water columns were established about 0.7 m above the extinction event in the East Greenland Basin...

  13. Xenoendocrine pollutants may reduce size of sexual organs in East Greenland polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Sonne, Christian; Leifsson, Páll Skuli; Dietz, Rune

    2006-01-01

    Reproductive organs from 55 male and 44 female East Greenland polar bears were examined to investigate the potential negative impact from organohalogen pollutants (OHCs). Multiple regressions normalizing for age showed a significant inverse relationship between OHCs and testis length and baculum.......01) and uterine horn length and HCB (p = 0.02). The study suggests thatthere is an impact from xenoendocrine pollutants on the size of East Greenland polar bear genitalia. This may pose a riskto this polar bear subpopulation in the future because of reduced sperm and egg quality/quantity and uterus and penis size...

  14. GJB2 (Connexin-26) mutations are not frequent among hearing impaired patients in East Greenland

    DEFF Research Database (Denmark)

    Homoe, P.; Koch, A.; Rendtorff, Nanna Dahl

    2012-01-01

    Objective: Investigate genetic causes of HI among the Inuit populations in the Arctic with a high prevalence of hearing impairment (HI). Design: A cross-sectional survey with population-based controls. Study sample: Forty-five patients, with sensorineural or mixed HI and an available blood sample...... for GJB2 sequencing from DNA, were selected from 166 East Greenlanders by specialist audiology examination, including pure-tone air and bone conduction audiometry from 125 Hz to 8000 Hz. Controls were 108 East- and 109 West-Greenlanders. Results: Forty-five patients with HI were included, 24 males and 21...

  15. Greenland

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2014-01-01

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

  16. Geophysical investigations of the East Greenland Caledonides using receiver functions, gravity and topography data

    DEFF Research Database (Denmark)

    Schiffer, Christian; Balling, N.; Jacobsen, B. H.

    The present-day topography and crustal structure of the East Greenland Caledonides are a product of various events, including the Caledonian orogeny, lithospheric extensional collapse, continental breakup and erosional processes. The topographic elevation appears high in this region, still after ...

  17. PREVALENCE OF ANTIBODIES AGAINST TOXOPLASMA GONDII IN POLAR BEARS (URSUS MARITIMUS) FROM SVALBARD AND EAST GREENLAND

    Science.gov (United States)

    Serum samples from 419 polar bears (Ursus maritimus) from Svalbard and the Barents Sea (collected 1990 - 2000) and 108 polar bears from East Greenland (collected 1999 - 2004) were assayed for antibodies against Toxoplasma gondii using the modified agglutination test (MAT). Antibody prevalences were ...

  18. Is Bone Mineral Composition Disrupted by Organochlorines in East Greenland Polar Bears (Ursus maritimus)?

    DEFF Research Database (Denmark)

    Sonne, C.; Dietz, R.; Born, E. W.

    2004-01-01

    We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs.......04) and SigmaCHL (p polar...... bears may have been caused by organochlorine exposure. Udgivelsesdato: 2004-Dec...

  19. Is bone mineral composition disrupted by organochlorines in east Greenland polar bears (Ursus maritimus)?

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, Rune; Born, Erik W

    2004-01-01

    We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs...

  20. Depleted basaltic lavas from the proto-Iceland plume, Central East Greenland

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Baker, Joel A.

    2012-01-01

    New geochemical and isotopic data are presented for volumetrically minor, depleted low-Ti basalts that occur in the Plateau Basalt succession of central East Greenland (CEG), formed during the initial stages of opening of the North Atlantic at 55 Ma. The basalts have MORB-like geochemistry (e.g. ...

  1. U–Pb geochronology of the Eocene Kærven intrusive complex, East Greenland

    DEFF Research Database (Denmark)

    Þórarinsson, Sigurjón Böðvar; Holm, Paul Martin; Tappe, Sebatstian

    2016-01-01

    Several major tholeiitic (e.g. the Skaergaard intrusion) and alkaline (e.g. the Kangerlussuaq Syenite) intrusive complexes of the North Atlantic Large Igneous Province are exposed along the Kangerlussuaq Fjord in East Greenland. The Kærven Complex forms a satellite intrusion to the Kangerlussuaq ...

  2. Observed increase in freshwater transport in the East Greenland Current north of Denmark Strait

    Science.gov (United States)

    de Steur, Laura; Pickart, Bob; Macrander, Andreas; Våge, Kjetil; Harden, Ben; Jonsson, Steingrimur; Østerhus, Svein; Valdimarsson, Hedinn

    2017-04-01

    We present liquid freshwater transports of the shelfbreak East Greenland Current (EGC) and the separated EGC determined from mooring records from the Kögur section north of Denmark Strait between August 2011 and July 2012. The 11-month mean freshwater transport (FWT) of these two branches was 65±11 mSv to the south (relative to a salinity of 34.8). Approximately 70% of this was associated with the shelfbreak EGC and the remaining 30% with the separated EGC. Very large southward FWT ranging from 160 mSv to 120 mSv was observed from September to mid-October 2011 and was foremost due to anomalously low upper-layer salinities. The FWT on the Greenland shelf was also estimated using additional inshore moorings deployed from 2012-2014. While the annual mean ranged from nearly zero during the first year to 18 mSv to the south during the second year, synoptically the FWT on the shelf can be significant. Furthermore, an anomalous event in autumn 2011 caused the shelfbreak EGC to reverse, leading to a large reduction in FWT. This reversed circulation was due to the passage of a large, 100 km wide anticyclone originating upstream from the shelfbreak. The late summer FWT of -131 mSv is two and a half times larger than earlier estimates based on sections in the late-1990s and early-2000s. This increase is likely the result of enhanced freshwater flux from the Arctic Ocean to the Nordic Seas during the early 2010s when also a significant increase of Pacific Water in the EGC was observed. Preliminary results obtained from the long-term ocean observing system in Fram Strait are included to compare the increased FWT seen in 2011-2012 with interannual variations in Arctic freshwater outflow during the last decade.

  3. 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

  4. Size and density of East Greenland polar bear (Ursus maritimus) skulls

    DEFF Research Database (Denmark)

    Sonne, Christian; Bechshoft, Thea Ø.; Rigét, Frank F.

    2013-01-01

    density (BMD) in 87 East Greenland male polar bears (Ursus maritimus) sampled in the time period of 1892-2010. The purpose of the study was to investigate if these measures are potential candidates as indicators for stress associated with climate change and long-range transported toxic industrial...... of the limited sample size in period 2 and lower mean age in period 4. Therefore, precautions should be taken towards a final conclusion on BMD and CBL as bioindicators for climate oscillations and exposure to toxic environmental chemicals. It is recommended that the sampling and archiving of East Greenland...... chemicals. The analyses showed that both BMD and CBL in polar bears sampled in period 4 (1999-2010, n = 57) were significantly lower when compared with period 2 (1920-1936, n = 19) (both p

  5. Xenoendocrine pollutants May Reduce Size of Sexual Organs in East Greenland Polar Bears (Ursus Maritimus)

    DEFF Research Database (Denmark)

    Sonne, Christian; Leifsson, Pall S.; Dietz, Rune

    2006-01-01

    .01) and uterine horn length and HCB (p = 0.02). The study suggests thatthere is an impact from xenoendocrine pollutants on the size of East Greenland polar bear genitalia. This may pose a riskto this polar bear subpopulation in the future because of reduced sperm and egg quality/quantity and uterus and penis size......Reproductive organs from 55 male and 44 female East Greenland polar bears were examined to investigate the potential negative impact from organohalogen pollutants (OHCs). Multiple regressions normalizing for age showed a significant inverse relationship between OHCs and testis length and baculum...... length and weight, respectively, and was found in both subadults (dichlorodiphenyl trichloroethanes, dieldrin, chlordanes, hexacyclohexanes, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs)) and adults (hexachlorobenzene [HCB]) (all p

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

    DEFF Research Database (Denmark)

    Lissner, Jørgen; Gravesen, Eigil Vestergaard

    2017-01-01

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

  7. Persistent organic pollutants, skull size and bone density of polar bears (Ursus maritimus) from East Greenland 1892–2015 and Svalbard 1964–2004

    DEFF Research Database (Denmark)

    Daugaard-Petersen, Tobias; Langebæk, Rikke; Rigét, Frank F.

    2018-01-01

    that the skull size of adult East Greenland females was negatively correlated with collection year 1892–2015 (linear regression: p = 0.06). No temporal change was found for BMD or skull size in Svalbard polar bears (ANOVA: all p > 0.05) nor was there any significant difference in BMD between Svalbard and East...... Greenland subpopulations. Skull size was larger in polar bears from Svalbard than from East Greenland (two-way ANOVA: p = 0.003). T-scores reflecting risk of osteoporosis showed that adult males from both East Greenland and Svalbard are at risk of developing osteopenia. Finally, when correcting for age...

  8. 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)

  9. Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Erdmann, Simon Erik; Dietz, Rune; Sonne, Christian

    2013-01-01

    The aims of the project were to (i) extract the lipophilic persistent organic pollutants (POPs) from the blood of 99 East Greenland polar bears and assess the combined mixture effect on the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR) mediated transactivity; (ii) To evaluate...... whether the receptor transactivities were associated with selected POP markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on Greenlandic Inuit. Lipophilic POPs were extracted using a combination of solid-phase extraction (SPE) and high performance liquid...... induced ER response. Positive correlations were found in subadult bears between XER and several POP biomarkers. XER and XERcomp correlated positively to each other. A total of 91% of the polar bear blood extracts elicited agonistic AhR transactivity. The AhR-TCDD equivalent (AhR-TEQ) median levels were...

  10. Late Pleistocene to early Holocene environmental changes on Store Koldewey, coastal north-east Greenland

    Directory of Open Access Journals (Sweden)

    Martin Klug

    2016-12-01

    Full Text Available A lake sediment sequence from southern Store Koldewey, north-east Greenland, has been investigated using a multidisciplinary approach, including geophysical, geochemical, biogeochemical, biological and sedimentological methods. Chronological constraints are provided by accelerator mass spectrometry (AMS 14C dating of bulk sediment and complemented with published water moss ages. The record consists of three major sediment units. Their individual structural, textural, geophysical and geochemical characteristics indicate variable input of sediment and meltwater due to variable proximity of the ice margin and therefore reflect the growth and decay of a local glacier during the late Weichselian. Radiocarbon dating of bulk sediment samples from the lowermost unit gave ages of 42 to 34 calibrated thousand years (cal Ky B.P. and indicates that this material is redeposited in the lake basin during or after the ice advance at the end of the Pleistocene. Increased meltwater and sediment input from a retreating ice margin following the Younger Dryas is indicated by the occurrence of a sandy to gravely section. Fine-grained and laminated sediments were deposited during the Pleistocene–Holocene transition and indicate calm sedimentation conditions with an ice margin outside of the lake catchment. The reoccurrence of coarse sediments during the early Holocene may indicate increased meltwater input in response to the cold spell at about 9.3 Kya with increased snow accumulation rather than fluctuations of local glaciers. The dating results furthermore show that AMS 14C dating of bulk sediment samples deposited during glacier decay in High Arctic environments can give problematic ages.

  11. Skull pathology in East Greenland and Svalbard polar bears (Ursus maritimus) during 1892 to 2002 in relation to organochlorine pollution

    International Nuclear Information System (INIS)

    Sonne, Christian; Riget, Frank F.; Dietz, Rune; Wiig, Oystein; Kirkegaard, Maja; Born, Erik W.

    2007-01-01

    East Greenland and Svalbard polar bears (Ursus maritimus) are heavily polluted with long-range transported organochlorines such as PCBs (polychlorinated biphenyls). To investigate the negative health impacts, a time-trend study of skull pathology was conducted on 269 East Greenland and 241 Svalbard polar bears. The skulls were sampled during 1892-2002 and 1964-1992, respectively. Seven different pathological changes were found: adonti, displacement of teeth, caries, osseous proliferations, exostosis, tooth wear and periodontitis. Only tooth wear and periodontitis was in a prevalence that allowed statistical treatment. The most severe cases of tooth wear and periodontitis were accompanied by a substantial loss of alveolar bone structure. The prevalence of tooth wear and periodontitis increased significantly with age (p < 0.001) with incisor wear being more severe than in canines, premolars and molars (p < 0.001). No sex difference was found for tooth wear (p = 0.22) while a significant difference between sexes was found for periodontitis (p = 0.01) with males having higher prevalence than females (odds ratio of 2.5 for males:females). In East Greenland, the prevalence of tooth wear was significantly higher in polar bears collected in the pre pollution period (< 1960) than in bears sampled during polluted periods (1960-1980 and 1981-2002) (p < 0.001). Regarding periodontitis, the prevalence was not significantly different between pre-pollution and pollution periods (p = 0.309). Polar bears from Svalbard had significantly higher prevalence of tooth wear (p < 0.001) and periodontitis (p = 0.02) than polar bears from East Greenland. The tooth wear and periodontitis odds ratios for Svalbard:East Greenland were 135 and 2.6, respectively. Hence, we found a clear age/sex link and geographical difference but no evidence for an association between skull pathology and exposure to organochlorines in East Greenland and Svalbard polar bears

  12. Skull pathology in East Greenland and Svalbard polar bears (Ursus maritimus) during 1892 to 2002 in relation to organochlorine pollution

    Energy Technology Data Exchange (ETDEWEB)

    Sonne, Christian [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark) and Department of Veterinary Basic Sciences, Royal Veterinary and Agricultural University, Buelowsvej 17, DK-1870 Frederiksberg C (Denmark)]. E-mail: csh@dmu.dk; Riget, Frank F. [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Dietz, Rune [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Wiig, Oystein [Natural History Museum, University of Oslo, PO Box 1172 Blindern, N-0562 Oslo (Norway); Kirkegaard, Maja [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Born, Erik W. [Greenland Institute of Natural Resources, PO Box 570, DK-3900 Nuuk, Greenland (Denmark)

    2007-01-01

    East Greenland and Svalbard polar bears (Ursus maritimus) are heavily polluted with long-range transported organochlorines such as PCBs (polychlorinated biphenyls). To investigate the negative health impacts, a time-trend study of skull pathology was conducted on 269 East Greenland and 241 Svalbard polar bears. The skulls were sampled during 1892-2002 and 1964-1992, respectively. Seven different pathological changes were found: adonti, displacement of teeth, caries, osseous proliferations, exostosis, tooth wear and periodontitis. Only tooth wear and periodontitis was in a prevalence that allowed statistical treatment. The most severe cases of tooth wear and periodontitis were accompanied by a substantial loss of alveolar bone structure. The prevalence of tooth wear and periodontitis increased significantly with age (p < 0.001) with incisor wear being more severe than in canines, premolars and molars (p < 0.001). No sex difference was found for tooth wear (p = 0.22) while a significant difference between sexes was found for periodontitis (p = 0.01) with males having higher prevalence than females (odds ratio of 2.5 for males:females). In East Greenland, the prevalence of tooth wear was significantly higher in polar bears collected in the pre pollution period (< 1960) than in bears sampled during polluted periods (1960-1980 and 1981-2002) (p < 0.001). Regarding periodontitis, the prevalence was not significantly different between pre-pollution and pollution periods (p = 0.309). Polar bears from Svalbard had significantly higher prevalence of tooth wear (p < 0.001) and periodontitis (p = 0.02) than polar bears from East Greenland. The tooth wear and periodontitis odds ratios for Svalbard:East Greenland were 135 and 2.6, respectively. Hence, we found a clear age/sex link and geographical difference but no evidence for an association between skull pathology and exposure to organochlorines in East Greenland and Svalbard polar bears.

  13. Using the magmatic record to constrain the growth of continental crust-The Eoarchean zircon Hf record of Greenland

    Science.gov (United States)

    Fisher, Christopher M.; Vervoort, Jeffrey D.

    2018-04-01

    Southern West Greenland contains some of the best-studied and best-preserved magmatic Eoarchean rocks on Earth, and these provide an excellent vantage point from which to view long-standing questions regarding the growth of the earliest continental crust. In order to address the questions surrounding early crustal growth and complementary mantle depletion, we present Laser Ablation Split Stream (LASS) analyses of the U-Pb and Hf isotope compositions of zircon from eleven samples of the least-altered meta-igneous rocks from the Itsaq (Amîtsoq) Gneisses of the Isukasia and Nuuk regions of southern West Greenland. This analytical technique allows a less ambiguous approach to determining the age and Hf isotope composition of complicated zircon. Results corroborate previous findings that Eoarchean zircon from the Itsaq Gneiss (∼3.85 Ga to ∼3.63 Ga) were derived from a broadly chondritic source. In contrast to the Sm-Nd whole rock isotope record for southern West Greenland, the zircon Lu-Hf isotope record provides no evidence for early mantle depletion, nor does it suggest the presence of crust older than ∼3.85 Ga in Greenland. Utilizing LASS U-Pb and Hf data from the Greenland zircons studied here, we demonstrate the importance of focusing on the magmatic (rather than detrital) zircon record to more confidently understand early crustal growth and mantle depletion. We compare the Greenland Hf isotope data with other Eoarchean magmatic complexes such as the Acasta Gneiss Complex, Nuvvuagittuq greenstone belt, and the gneissic complexes of southern Africa, and all lack zircons with suprachondritic Hf isotope compositions. In total, these data suggest only a very modest volume of crust was produced during (or survived from) the Hadean and earliest Eoarchean. There remains no record of planet-scale early Earth mantle depletion in the Hf isotope record prior to 3.8 Ga.

  14. Associations between complex OHC mixtures and thyroid and cortisol hormone levels in East Greenland polar bears.

    Science.gov (United States)

    Bechshøft, T Ø; Sonne, C; Dietz, R; Born, E W; Muir, D C G; Letcher, R J; Novak, M A; Henchey, E; Meyer, J S; Jenssen, B M; Villanger, G D

    2012-07-01

    The multivariate relationship between hair cortisol, whole blood thyroid hormones, and the complex mixtures of organohalogen contaminant (OHC) levels measured in subcutaneous adipose of 23 East Greenland polar bears (eight males and 15 females, all sampled between the years 1999 and 2001) was analyzed using projection to latent structure (PLS) regression modeling. In the resulting PLS model, most important variables with a negative influence on cortisol levels were particularly BDE-99, but also CB-180, -201, BDE-153, and CB-170/190. The most important variables with a positive influence on cortisol were CB-66/95, α-HCH, TT3, as well as heptachlor epoxide, dieldrin, BDE-47, p,p'-DDD. Although statistical modeling does not necessarily fully explain biological cause-effect relationships, relationships indicate that (1) the hypothalamic-pituitary-adrenal (HPA) axis in East Greenland polar bears is likely to be affected by OHC-contaminants and (2) the association between OHCs and cortisol may be linked with the hypothalamus-pituitary-thyroid (HPT) axis. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Early Holocene climate oscillations recorded in three Greenland ice cores

    DEFF Research Database (Denmark)

    Rasmussen, Sune Olander; Vinther, Bo Møllesøe; Clausen, Henrik Brink

    2007-01-01

    around 9.3 ka before present, and the Preboreal Oscillation during the first centuries of the Holocene. For each of these sections, we present a d18O anomaly curve and a common accumulation signal that represents regional changes in the accumulation rate over the Greenland ice cap....... and accumulation anomalies that are common to the three cores in the Early Holocene (7.9–11.7 ka before present). Three time periods with significant and synchronous anomalies in the d18O and accumulation signals stand out: the well-known 8.2 ka event, an event of shorter duration but of almost similar amplitude...

  16. Comparison of northern and central Greenland ice cores records of methanesulfonate covering the last glacial period

    DEFF Research Database (Denmark)

    Jonsell, U.; Hansson, M. E.; Siggaard-Andersen, M-L-

    2007-01-01

    Methanesulfonate (MS-) is measured in ice cores with the objective to obtain a proxy record of marine phytoplankton production of dimethylsulfide (DMS). We present a continuous MS- record covering the last glacial period from the North Greenland Ice Core Project (NGRIP) ice core and compare...... this record with the corresponding records previously presented from Greenland and, in particular, with the GISP2 ice core located 320 km south of NGRIP. Despite that the records have similar mean concentrations, their responses to climatic changes during the last glacial period are slightly different. NGRIP...... MS- concentrations were higher during the cold marine isotopic stages (MIS) 2 and 4 and lower during the warm MIS 5. This long-term trend in MS-, which is similar to the inverse of the corresponding trend in d 18O, is not detected in the GISP2 MS- record. A systematic response in MS- concentrations...

  17. First record of Taenia ovis krabbei muscle cysts in muskoxen from Greenland

    DEFF Research Database (Denmark)

    Raundrup, Katrine; Al-Sabi, Mohammad M; Kapel, Christian Moliin Outzen

    2012-01-01

    A first record of Taenia ovis krabbei muscle cysts in a muskoxen (Ovibos moschatus) from the Kangerlussuaq population in West Greenland suggests that introduced muskoxen now contributes to the transmission of this parasite in addition to previous observations from caribou (Rangtfer tarandus...

  18. A 600-year annual 10Be record from the NGRIP ice core, Greenland

    DEFF Research Database (Denmark)

    Berggren, A.M.; Johnsen, Sigfus Johann; Vinther, Bo Møllesøe

    2009-01-01

    in an ice core from the NGRIP site in Greenland. NGRIP and Dye-3 10Be exhibits similar long-term variability, although occasional short term differences between the two sites indicate that at least two high resolution 10Be records are needed to assess local variations and to confidently reconstruct past...

  19. Retrieving a common accumulation record from Greenland ice cores for the past 1800 years

    DEFF Research Database (Denmark)

    Andersen, Katrine K.; Ditlevsen, Peter D.; Rasmussen, Sune Olander

    2006-01-01

    In the accumulation zone of the Greenland ice sheet the annual accumulation rate may be determined through identification of the annual cycle in the isotopic climate signal and other parameters that exhibit seasonal variations. On an annual basis the accumulation rate in different Greenland ice...... cores is highly variable, and the degree of correlation between accumulation series from different ice cores is low. However, when using multiyear averages of the different accumulation records, the correlation increases significantly. A statistical model has been developed to estimate the common...

  20. A preliminary report on coprolites from the Late Triassic part of the Kap Stewart Formation, Jameson Land, East Greenland

    DEFF Research Database (Denmark)

    Milàn, Jesper; Clemmensen, Lars B; Adolphsen, Jan Schulz

    2012-01-01

    The basal part of the Triassic-Jurassic (Rhaetian-Sinemurian) Kap Stewart Formation, exposed at Jameson Land, East Greenland, yields an extensive coprolite collection from black, parallel-laminated mudstone (“paper shale”), representing an open lacustrine system. Preliminary investigations show t...

  1. Precambrain Rb-Sr isochron ages from the crystalline complexes of inner Forsblads Fjord, East Greenland fold belt

    International Nuclear Information System (INIS)

    Rex, D.C.; Gledhill, A.R.; Higgins, A.K.

    1977-01-01

    Several collections of samples were made from crystalline units in inner Forsblads Fjord in 1974. Results of whole rock Rb-Sr analyses on two of these collections are presented, and give an Archaean age for banded gneisses and a middle Proterozoic age for quartzitic metasediments. These ages confirm the occurence of major Precambrian complexes within the East Greenland Caledonian fold belt. (author)

  2. The Jurassic of Denmark and Greenland: Shallow marine syn-rift sedimentation: Middle Jurassic Pelion Formation, Jameson Land, East Greenland

    Directory of Open Access Journals (Sweden)

    Engkilde, Michael

    2003-10-01

    Full Text Available The Middle Jurassic Pelion Formation – Fossilbjerget Formation couplet of Jameson Land, East Greenland, is a well-exposed example of the Middle Jurassic inshore–offshore successions characteristicof the rifted seaways in the Northwest European – North Atlantic region. Early Jurassic deposition took place under relatively quiet tectonic conditions following Late Permian – earliest Triassic and Early Triassic rift phases and the Lower Jurassic stratal package shows an overall layer-cake geometry. A long-term extensional phase was initiated in Middle Jurassic (Late Bajocian time, culminated in the Late Jurassic (Kimmeridgian–Volgian, and petered out in the earliest Cretaceous (Valanginian. The Upper Bajocian – Middle Callovian early-rift succession comprises shallow marine sandstones of the Pelion Formation and correlative offshore siltstones of theFossilbjerget Formation. Deposition was initiated by southwards progradation of shallow marine sands of the Pelion Formation in the Late Bajocian followed by major backstepping in Bathonian–Callovian times and drowning of the sandy depositional system in the Middle–Late Callovian. Six facies associations are recognised in the Pelion–Fossilbjerget couplet, representing estuarine, shoreface, offshore transition zone and offshore environments. The north–southtrendingaxis of the Jameson Land Basin had a low inclination, and deposition was sensitive to even small changes in relative sea level which caused the shorelines to advance or retreat over tens to several hundreds of kilometres. Eight composite sequences, termed P1–P8, are recognised and are subdivided into a total of 28 depositional sequences. The duration of the two orders of sequences was about 1–2 Ma and 360,000 years, respectively. The Upper Bajocian P1–2 sequencesinclude the most basinally positioned shallow marine sandstones, deposited during major sealevel lowstands. The lowstands were terminated by significant marine

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

    Science.gov (United States)

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

    2016-04-01

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

  4. Periodic outburst floods from an ice-dammed lake in East Greenland.

    Science.gov (United States)

    Grinsted, Aslak; Hvidberg, Christine S; Campos, Néstor; Dahl-Jensen, Dorthe

    2017-08-30

    We report evidence of four cycles of outburst floods from Catalina Lake, an ice-dammed lake in East Greenland, identified in satellite imagery between 1966-2016. The lake measures 20-25 km 2 , and lake level drops 130-150 m in each event, corresponding to a water volume of 2.6-3.4 Gt, and a release of potential energy of 10 16  J, among the largest outburst floods reported in historical times. The drainage cycle has shortened systematically, and the lake filling rate has increased over each cycle, suggesting that the drainage pattern is changing due to climate warming with possible implications for environmental conditions in Scoresbysund fjord.

  5. Temporal Trends of Hexabromocyclododecane, Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls in Ringed Seals from East Greenland

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Riget, Frank Farsø; Bossi, Rossana

    2011-01-01

    also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding......Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. R-HBCD was the only diastereoisomer consistently above levels of quantification and showed...... on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which...

  6. Uranium and selected trace elements in granites from the Caledonides of East Greenland

    International Nuclear Information System (INIS)

    Steenfelt, A.

    1982-01-01

    The Caledonian fold belt of East Greenland contains calc-alkaline granite (sensu lato) intrusions with ages ranging from c.2000 Ma to c.350 Ma. The Proterozoic granites have low U contents and the pre-Devonian Caledonian granites contents of U corresponding to the clarke value for U in granites. Some aspects of the geochemistry of U are discussed using U-K/Rb, U-Sr, U-Zr, and U-Th diagrams. Secondary enrichment and mineralization occurs in fractured and hydrothermally altered granites and rhyolites situated in or near a major NNE fault zone. The U is associated with iron oxides or hydrocarbons. It is suggested that the source of the mineralization was Devonian acid magma, which also acted as a heat source for circulating hydrothermal fluids. (author)

  7. Modeling Population-Level Consequences of Polychlorinated Biphenyl Exposure in East Greenland Polar Bears.

    Science.gov (United States)

    Pavlova, Viola; Grimm, Volker; Dietz, Rune; Sonne, Christian; Vorkamp, Katrin; Rigét, Frank F; Letcher, Robert J; Gustavson, Kim; Desforges, Jean-Pierre; Nabe-Nielsen, Jacob

    2016-01-01

    Polychlorinated biphenyls (PCBs) can cause endocrine disruption, cancer, immunosuppression, or reproductive failure in animals. We used an individual-based model to explore whether and how PCB-associated reproductive failure could affect the dynamics of a hypothetical polar bear (Ursus maritimus) population exposed to PCBs to the same degree as the East Greenland subpopulation. Dose-response data from experimental studies on a surrogate species, the mink (Mustela vision), were used in the absence of similar data for polar bears. Two alternative types of reproductive failure in relation to maternal sum-PCB concentrations were considered: increased abortion rate and increased cub mortality. We found that the quantitative impact of PCB-induced reproductive failure on population growth rate depended largely on the actual type of reproductive failure involved. Critical potencies of the dose-response relationship for decreasing the population growth rate were established for both modeled types of reproductive failure. Comparing the model predictions of the age-dependent trend of sum-PCBs concentrations in females with actual field measurements from East Greenland indicated that it was unlikely that PCB exposure caused a high incidence of abortions in the subpopulation. However, on the basis of this analysis, it could not be excluded that PCB exposure contributes to higher cub mortality. Our results highlight the necessity for further research on the possible influence of PCBs on polar bear reproduction regarding their physiological pathway. This includes determining the exact cause of reproductive failure, i.e., in utero exposure versus lactational exposure of offspring; the timing of offspring death; and establishing the most relevant reference metrics for the dose-response relationship.

  8. Hepatic and renal histology and mercury concentrations of North West and North East Greenland narwhals (Monodon monoceros)

    DEFF Research Database (Denmark)

    Sonne, Christian; Leifsson, Pall S.; Sondergaard, Jens

    2018-01-01

    subadult females, 8 adult females, 3 subadult males, and 1 adult male) and compare data with previous observations of 12 North West Greenland specimens (1 subadult female, 4 adult females, 1 subadult male, and 6 adult males). The zoological length was significantly larger and hepatic and renal...... of glomerular lesions (capillary dilatation [0–100%], membrane thickening [0–100%], dilatation of space [0–80%], and sclerosis [0–70%]) and two tubular lesions (atrophy/hyalinization [0–40%] and casts [0–60%]). Hepatic tissues exhibited three portal lesions (fibrosis [0–33%], cell infiltrates [0–40%], and bile...... duct proliferation [0–40%]) and two parenchymal lesions (steatosis [83–100%] and lipid-filled Ito cells [0–33%]). All 12 lesions were found in adult whales from North West Greenland while eight were present in adult whales from North East Greenland. Six lesions were detected in subadults from North...

  9. Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Erdmann, Simon E; Dietz, Rune; Sonne, Christian; Bechshøft, Thea Ø; Vorkamp, Katrin; Letcher, Robert J; Long, Manhai; Bonefeld-Jørgensen, Eva C

    2013-07-01

    The aims of the project were to (i) extract the lipophilic persistent organic pollutants (POPs) from the blood of 99 East Greenland polar bears and assess the combined mixture effect on the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR) mediated transactivity; (ii) To evaluate whether the receptor transactivities were associated with selected POP markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on Greenlandic Inuit. Lipophilic POPs were extracted using a combination of solid-phase extraction (SPE) and high performance liquid chromatography (HPLC). ER mediated transactivity was determined using the ER luciferase reporter MVLN cell assay. The extracts were tested alone (XER) and together with 17β-estradiol (E2) as a physiological mimic (XERcomp). Dioxins and dioxin-like (DL) compounds were extracted by a combination of SPE and the Supelco Dioxin Prep System®. AhR mediated dioxin-like transactivity was determined using the AhR luciferase reporter Hepa 1.12cR cell assay. Agonistic ER transactivity was elicited by 19% of the samples, and a further increased E2 induced ER response was found for 52%, whereas 17% antagonized the E2 induced ER response. Positive correlations were found in subadult bears between XER and several POP biomarkers. XER and XERcomp correlated positively to each other. A total of 91% of the polar bear blood extracts elicited agonistic AhR transactivity. The AhR-TCDD equivalent (AhR-TEQ) median levels were higher among adult bears compared to subadult bears, but not significantly. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Organohalogen concentrations and a gross and histologic assessment of multiple organ systems in East Greenland polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Sonne, C.

    To investigate the relation between biological parameters, not earlier investigated in the polar bear, and organohalogen pollution in East Greenland polar bears, we initiated a sampling of adipose tissue, internal organs and skulls from more than 100 free-ranging polar bears killed by local...... in the adipose tissue and pathological changes in skulls and internal organs. Our results suggested a decrease in adipose tissue concentrations of organohalogens in East Greenland polar bears from 1990 to 1999-2001. Two of the biological effect parameters (FA and enlarged clitoris) did not indicate a link......, infectious agents, season and meaby chronic exposure to organohalogens. These result fill out an existing knowledge gap in potential effects of environmental, organic contaminants on fluctuating asymmetry, bone mineral density and functional anatomy (histology) in the polar bear. In addition, the results may...

  11. Tissue-specific congener composition of organohalogen and metabolite contaminants in East Greenland polar bears (Ursus maritimus)

    International Nuclear Information System (INIS)

    Gebbink, Wouter A.; Sonne, Christian; Dietz, Rune; Kirkegaard, Maja; Riget, Frank F.; Born, Erik W.; Muir, Derek C.G.; Letcher, Robert J.

    2008-01-01

    Congener patterns of the major organohalogen contaminant classes of PCBs, PBDEs and their metabolites and/or by-products (OH-PCBs, MeSO 2 -PCBs, OH-PBDEs and MeO-PBDEs) were examined in adipose tissue, liver, brain and blood of East Greenland polar bears (Ursus maritimus). PCB, OH-PCB, MeSO 2 -PCB and PBDE congener patterns showed significant differences (p ≤ 0.05) mainly in the liver and the brain relative to the adipose tissue and the blood. OH-PBDEs and MeO-PBDEs were not detected in the brain and liver, but had different patterns in blood versus the adipose tissue. Novel OH-polybrominated biphenyls (OH-PBBs), one tri- and two tetra-brominated OH-PBBs were detected in all tissues and blood. Congener pattern differences among tissues and blood are likely due to a combination of factors, e.g., biotransformation and retention in the liver, retention in the blood and blood-brain barrier transport. Our findings suggest that different congener pattern exposures to these classes of contaminants should be considered with respect to potential target tissue-specific effects in East Greenland polar bears. - Tissues-specific (adipose tissue, liver, brain and blood) differences exist for the congener patterns of PCBs, PBDEs and their metabolites/degradation products in East Greenland polar bears

  12. The crust and upper mantle of central East Greenland - implications for continental accretion and rift evolution

    Science.gov (United States)

    Schiffer, Christian; Balling, Niels; Ebbing, Jörg; Holm Jacobsen, Bo; Bom Nielsen, Søren

    2016-04-01

    The geological evolution of the North Atlantic Realm during the past 450 Myr, which has shaped the present-day topographic, crustal and upper mantle features, was dominated by the Caledonian orogeny and the formation of the North Atlantic and associated igneous activity. The distinct high altitude-low relief landscapes that accompany the North Atlantic rifted passive margins are the focus of a discussion of whether they are remnant and modified Caledonian features or, alternatively, recently uplifted peneplains. Teleseismic receiver function analysis of 11 broadband seismometers in the Central Fjord Region in East Greenland indicates the presence of a fossil subduction complex, including a slab of eclogitised mafic crust and an overlying wedge of hydrated mantle peridotite. This model is generally consistent with gravity and topography. It is shown that the entire structure including crustal thickness variations and sub-Moho heterogeneity gives a superior gravity and isostatic topographic fit compared to a model with a homogeneous lithospheric layer (1). The high topography of >1000 m in the western part of the area is supported by the c. 40 km thick crust. The eastern part requires buoyancy from the low velocity/low density mantle wedge. The geometry, velocities and densities are consistent with structures associated with a fossil subduction zone. The spatial relations with Caledonian structures suggest a Caledonian origin. The results indicate that topography is isostatically compensated by density variations within the lithosphere and that significant present-day dynamic topography seems not to be required. Further, this structure is suggested to be geophysically very similar to the Flannan reflector imaged north of Scotland, and that these are the remnants of the same fossil subduction zone, broken apart and separated during the formation of the North Atlantic in the early Cenozoic (2). 1) Schiffer, C., Jacobsen, B.H., Balling, N., Ebbing, J. and Nielsen, S

  13. Inverse stochastic-dynamic models for high-resolution Greenland ice core records

    DEFF Research Database (Denmark)

    Boers, Niklas; Chekroun, Mickael D.; Liu, Honghu

    2017-01-01

    as statistical properties such as probability density functions, waiting times and power spectra, with no need for any external forcing. The crucial ingredients for capturing these properties are (i) high-resolution training data, (ii) cubic drift terms, (iii) nonlinear coupling terms between the 18O and dust......Proxy records from Greenland ice cores have been studied for several decades, yet many open questions remain regarding the climate variability encoded therein. Here, we use a Bayesian framework for inferring inverse, stochastic-dynamic models from 18O and dust records of unprecedented, subdecadal...

  14. Large-scale evolution of the central-east Greenland margin: New insights to the North Atlantic glaciation history

    Science.gov (United States)

    Pérez, Lara F.; Nielsen, Tove; Knutz, Paul C.; Kuijpers, Antoon; Damm, Volkmar

    2018-04-01

    The continental shelf of central-east Greenland is shaped by several glacially carved transverse troughs that form the oceanward extension of the major fjord systems. The evolution of these troughs through time, and their relation with the large-scale glaciation of the Northern Hemisphere, is poorly understood. In this study seismostratigraphic analyses have been carried out to determine the morphological and structural development of this important sector of the East Greenland glaciated margin. The age of major stratigraphic discontinuities has been constrained by a direct tie to ODP site 987 drilled in the Greenland Sea basin plain off Scoresby Sund fan system. The areal distribution and internal facies of the identified seismic units reveal the large-scale depositional pattern formed by ice-streams draining a major part of the central-east Greenland ice sheet. Initial sedimentation along the margin was, however, mainly controlled by tectonic processes related to the margin construction, continental uplift, and fluvial processes. From late Miocene to present, progradational and erosional patterns point to repeated glacial advances across the shelf. The evolution of depo-centres suggests that ice sheet advances over the continental shelf have occurred since late Miocene, about 2 Myr earlier than previously assumed. This cross-shelf glaciation is more pronounced during late Miocene and early Pliocene along Blosseville Kyst and around the Pliocene/Pleistocene boundary off Scoresby Sund; indicating a northward migration of the glacial advance. The two main periods of glaciation were separated by a major retreat of the ice sheet to an inland position during middle Pliocene. Mounded-wavy deposits interpreted as current-related deposits suggest the presence of changing along-slope current dynamics in concert with the development of the modern North Atlantic oceanographic pattern.

  15. Application of geochemical exploration in the Kap Franklin Area, Northern East Greenland

    International Nuclear Information System (INIS)

    Kunzendorf, H.; Friedrich, G.H.W.; Koensler, W.; Steenfelt, A.

    1978-02-01

    More than 800 stream sediments, soil, seepage soil and water samples collected during the field seasons of 1974 and 1975 in the Kap Franklin area, northern East Greenland, were analysed for K, Ca, Ti, Mn, and Fe by radioisotope energy-dispersive X-ray fluorescence, and for U by delayed-neutron counting. Samples were also analysed for V, Cu, Zn and Pb by atomic absorption spectrophotometry. Areas with known mineralization are outlined by anomalous Zn and Pb contents in stream sediments and soils. A predominantly mechanical dispersion mechanism is deduced from the similarity in the chemistry of bedrock, stream sediments and soils. Narrow dispersion halos following from this observation suggest that dense sampling procedures are required. The usefulness of Cu, Zn and Pb water geochemistry is not proved. There is reasonable agreement between a reconnaissance study and detailed investigations carried out in 1974 and 1975, respectively. The distribution patterns for Cu, Zn, Pb, and U were more clearly displayed by means of the detailed sampling, and the metal contents in stream sediments were found to decrease rapidly downstream. Soil and seepage soil sampling between tributaries was shown to be advantageous. A test of daily and weekly variations of Cu, Zn, and Pb in stream sediments of selected sampling sites demonstrated changes in the metal contents of generally less than 10 per cent. Data from soil samples in the Randboeldal clearly outline the extent of U mineralisation. There is good correlation between U, and Zn and Pb in both stream sediments and soil. (author)

  16. Mapping tide-water glacier dynamics in east Greenland using landsat data

    Science.gov (United States)

    Dwyer, John L.

    1995-01-01

    Landsat multispectral scanner and thematic mapper images were co-registered For the Kangerdlugssuaq Fjord region in East Greenland and were used to map glacier drainage-basin areas, changes in the positions of tide-water glacier termini and to estimate surface velocities of the larger tide-water glaciers. Statistics were compiled to document distance and area changes to glacier termini. The methodologies developed in this study are broadly applicable to the investigation of tide-water glaciers in other areas. The number of images available for consecutive years and the accuracy with which images are co-registered are key factors that influence the degree to which regional glacier dynamics can be characterized using remotely sensed data.Three domains of glacier state were interpreted: net increase in terminus area in the southern part of the study area, net loss of terminus area for glaciers in upper Kangerdlugssuaq Fjord and a slight loss of glacier terminus area northward from Ryberg Fjord. Local increases in the concentrations of drifting icebergs in the fjords coincide with the observed extension of glacier termini positions Ice-surface velocity estimates were derived for several glaciers using automated image cross-correlation techniques The velocity determined for Kangerdlugssuaq Gletscher is approximately 5.0 km a−1 and that for Kong Christian IV Gletscher is 0.9 km a−1. The continuous presence of icebergs and brash ice in front of these glaciers indicates sustained rates of ice-front calving.

  17. Tissue-specific concentrations and patterns of perfluoroalkyl carboxylates and sulfonates in East Greenland polar bears.

    Science.gov (United States)

    Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune; Born, Erik W

    2012-11-06

    Several perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) of varying chain length are bioaccumulative in biota. However, wildlife reports have focused on liver and with very little examination of other tissues, and thus there is a limited understanding of their distribution and potential effects in the mammalian body. In the present study, the comparative accumulation of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, and select precursors were examined in the liver, blood, muscle, adipose, and brain of 20 polar bears (Ursus maritimus) from Scoresby Sound, Central East Greenland. Overall, PFSA and PFCA concentrations were highest in liver followed by blood > brain > muscle ≈ adipose. Liver and blood samples contained proportionally more of the shorter/medium chain length (C(6) to C(11)) PFCAs, whereas adipose and brain samples were dominated by longer chain (C(13) to C(15)) PFCAs. PFCAs with lower lipophilicities accumulated more in the liver, whereas the brain accumulated PFCAs with higher lipophilicities. The concentration ratios (±SE) between perfluorooctane sulfonate and its precursor perfluorooctane sulfonamide varied among tissues from 9 (±1):1 (muscle) to 36 (±7):1 (liver). PFCA and PFSA patterns in polar bears indicate that the pharmacokinetics of these compounds are to some extent tissue-specific, and are the result of several factors that may include differing protein interactions throughout the body.

  18. A 60-yr record of atmospheric carbon monoxide reconstructed from Greenland firn air

    Science.gov (United States)

    Petrenko, V. V.; Martinerie, P.; Novelli, P.; Etheridge, D. M.; Levin, I.; Wang, Z.; Blunier, T.; Chappellaz, J.; Kaiser, J.; Lang, P.; Steele, L. P.; Hammer, S.; Mak, J.; Langenfelds, R. L.; Schwander, J.; Severinghaus, J. P.; Witrant, E.; Petron, G.; Battle, M. O.; Forster, G.; Sturges, W. T.; Lamarque, J.-F.; Steffen, K.; White, J. W. C.

    2012-08-01

    We present a reconstruction of the Northern Hemisphere (NH) high latitude atmospheric carbon monoxide (CO) mole fraction from Greenland firn air. Firn air samples were collected at three deep ice core sites in Greenland (NGRIP in 2001, Summit in 2006 and NEEM in 2008). CO records from the three sites agree well with each other as well as with recent atmospheric measurements, indicating that CO is well preserved in the firn at these sites. CO atmospheric history was reconstructed back to the year 1950 from the measurements using a combination of two forward models of gas transport in firn and an inverse model. The reconstructed history suggests that Arctic CO was already higher in 1950 than it is today. CO mole fractions rose gradually until the 1970s and peaked in the 1970s or early 1980s, followed by a decline to today's levels. We compare the CO history with the atmospheric histories of methane, light hydrocarbons, molecular hydrogen, CO stable isotopes and hydroxyl radical (OH), as well as with published CO emission inventories and results of a historical run from a chemistry-transport model. We find that the reconstructed Greenland CO history cannot be reconciled with available emission inventories unless large changes in OH are assumed. We argue that the available CO emission inventories chronically underestimate NH emissions, and fail to capture the emission decline starting in the late 1970s, which was most likely due to reduced emissions from road transportation in North America and Europe.

  19. Increased Atmospheric SO2 Detected from Changes in Leaf Physiognomy across the Triassic–Jurassic Boundary Interval of East Greenland

    Science.gov (United States)

    Bacon, Karen L.; Belcher, Claire M.; Haworth, Matthew; McElwain, Jennifer C.

    2013-01-01

    The Triassic–Jurassic boundary (Tr–J; ∼201 Ma) is marked by a doubling in the concentration of atmospheric CO2, rising temperatures, and ecosystem instability. This appears to have been driven by a major perturbation in the global carbon cycle due to massive volcanism in the Central Atlantic Magmatic Province. It is hypothesized that this volcanism also likely delivered sulphur dioxide (SO2) to the atmosphere. The role that SO2 may have played in leading to ecosystem instability at the time has not received much attention. To date, little direct evidence has been presented from the fossil record capable of implicating SO2 as a cause of plant extinctions at this time. In order to address this, we performed a physiognomic leaf analysis on well-preserved fossil leaves, including Ginkgoales, bennettites, and conifers from nine plant beds that span the Tr–J boundary at Astartekløft, East Greenland. The physiognomic responses of fossil taxa were compared to the leaf size and shape variations observed in nearest living equivalent taxa exposed to simulated palaeoatmospheric treatments in controlled environment chambers. The modern taxa showed a statistically significant increase in leaf roundness when fumigated with SO2. A similar increase in leaf roundness was also observed in the Tr–J fossil taxa immediately prior to a sudden decrease in their relative abundances at Astartekløft. This research reveals that increases in atmospheric SO2 can likely be traced in the fossil record by analyzing physiognomic changes in fossil leaves. A pattern of relative abundance decline following increased leaf roundness for all six fossil taxa investigated supports the hypothesis that SO2 had a significant role in Tr–J plant extinctions. This finding highlights that the role of SO2 in plant biodiversity declines across other major geological boundaries coinciding with global scale volcanism should be further explored using leaf physiognomy. PMID:23593262

  20. Novel sedimentological fingerprints link shifting depositional processes to Holocene climate transitions in East Greenland

    Science.gov (United States)

    van der Bilt, Willem G. M.; Rea, Brice; Spagnolo, Matteo; Roerdink, Desiree L.; Jørgensen, Steffen L.; Bakke, Jostein

    2018-05-01

    The Arctic warms faster than any other region of our planet. Besides melting glaciers, thawing permafrost and decreasing sea-ice, this amplified response affects earth surface processes. This geomorphological expression of climate change may alter landscapes and increase the frequency and magnitude of geohazards like floods or mass-movements. Beyond the short span of sparse monitoring time series, geological archives provide a valuable long-term context for future risk assessment. Lake sediment sequences are particularly promising in this respect as continuous recorders of surface process change. Over the past decade, the emergence of new techniques that characterize depositional signatures in more detail has enhanced this potential. Here, we present a well-dated Holocene-length lake sediment sequence from Ammassalik Island on southeast Greenland. This area is particularly sensitive to regional shifts in the Arctic climate system due to its location near the sea-ice limit, the Greenland Ice Sheet and the convergence of polar and Atlantic waters. The expression of Holocene change is fingerprinted using physical (grain size, organic content, density), visual (3-D Computed Tomography) and geochemical (X-Ray Fluorescence, X-Ray Diffraction) evidence. We show that three sharp transitions characterize the Holocene evolution of Ymer Lake. Between 10 and 9.5 cal. ka BP, rapid local glacier loss from the lake catchment culminated in an outburst flood. Following a quiescent Holocene climatic optimum, Neoglacial cooling, lengthening lake ice cover and shifting wind patterns prompted in-lake avalanching of sediments from 4.2 cal. ka BP onwards. Finally, glaciers reformed in the catchment around 1.2 cal. ka BP. The timing of these shifts is consistent with the regional expression of deglaciation, Neoglacial cooling and Little Ice Age-type glacier growth, respectively. The novel multi-proxy approach applied in this study rigorously links depositional sediment signatures to

  1. Terra nullius, Inuit Habitation and Norse Occupation – With Special Emphasis on the 1933 East Greenland Case

    Directory of Open Access Journals (Sweden)

    Peter Thomas Ørebech

    2016-05-01

    Full Text Available Sovereignty acquired by occupation entails “recognize[d] title based on discovery,” “a reasonable period [of] … effective occupation of the region claimed to be discovered” and “the continuous and peaceful display of State authority.” Only terra nullius is subject to occupation. A territory inhabited by indigenous groups that sustain social and political organization may impede an occupying power because the terra nullius requirement fails. While sovereignty over thinly populated areas are often lax, case law requires less public involvement in these sparsely inhabited areas. This study reveals that the Dano-Norwegian Kings regarded the Inuit as “our subjects.” The Kings’ pretention of absolutum dominium and jurisdiction involved both the Norse and Inuit ethnic groups and “bygð ok ubygð” (settled and unsettled land. The exodus of the Norse peoples in 1450 AD for 200 years did not undermine the acquired sovereignty of the Dano-Norwegian Crown, which as a result, spoiled the 1931 Norwegian pretentions to legally occupy East-Greenland. Denmark's triumph in the 1933-East Greenland case resulted from a “zero-sum principle.” More than a 100 years earlier, the Danish Kingdom lost a succession of countries and dependencies. The 1814 Kiel Treaty transferred mainland Norway to Sweden, but explicitly states that none of the ancient Norwegian dependencies, Greenland, Iceland and Faroe Islands would follow suit. Thus, these territories remained part of the Kingdom of Denmark.

  2. Inverse stochastic–dynamic models for high-resolution Greenland ice core records

    Directory of Open Access Journals (Sweden)

    N. Boers

    2017-12-01

    Full Text Available Proxy records from Greenland ice cores have been studied for several decades, yet many open questions remain regarding the climate variability encoded therein. Here, we use a Bayesian framework for inferring inverse, stochastic–dynamic models from δ18O and dust records of unprecedented, subdecadal temporal resolution. The records stem from the North Greenland Ice Core Project (NGRIP, and we focus on the time interval 59–22 ka b2k. Our model reproduces the dynamical characteristics of both the δ18O and dust proxy records, including the millennial-scale Dansgaard–Oeschger variability, as well as statistical properties such as probability density functions, waiting times and power spectra, with no need for any external forcing. The crucial ingredients for capturing these properties are (i high-resolution training data, (ii cubic drift terms, (iii nonlinear coupling terms between the δ18O and dust time series, and (iv non-Markovian contributions that represent short-term memory effects.

  3. Inverse stochastic-dynamic models for high-resolution Greenland ice core records

    Science.gov (United States)

    Boers, Niklas; Chekroun, Mickael D.; Liu, Honghu; Kondrashov, Dmitri; Rousseau, Denis-Didier; Svensson, Anders; Bigler, Matthias; Ghil, Michael

    2017-12-01

    Proxy records from Greenland ice cores have been studied for several decades, yet many open questions remain regarding the climate variability encoded therein. Here, we use a Bayesian framework for inferring inverse, stochastic-dynamic models from δ18O and dust records of unprecedented, subdecadal temporal resolution. The records stem from the North Greenland Ice Core Project (NGRIP), and we focus on the time interval 59-22 ka b2k. Our model reproduces the dynamical characteristics of both the δ18O and dust proxy records, including the millennial-scale Dansgaard-Oeschger variability, as well as statistical properties such as probability density functions, waiting times and power spectra, with no need for any external forcing. The crucial ingredients for capturing these properties are (i) high-resolution training data, (ii) cubic drift terms, (iii) nonlinear coupling terms between the δ18O and dust time series, and (iv) non-Markovian contributions that represent short-term memory effects.

  4. Geology and assessment of undiscovered oil and gas resources of the West Greenland-East Canada Province, 2008

    Science.gov (United States)

    Schenk, Christopher J.; Moore, Thomas E.; Gautier, Donald L.

    2018-01-05

    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, Lower and Upper 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. The estimated mean volumes of undiscovered resources for the West GreenlandEast Canada Province are 10.7 billion barrels of oil, 75 trillion cubic feet of gas, and 1.7 billion barrels of natural gas liquids. For the part of the province that is north of the Arctic Circle, the estimated mean volumes of these undiscovered resources are 7.3 billion barrels of oil, 52 trillion cubic feet of natural gas, and 1.1 billion barrels of natural-gas liquids.

  5. Uranium geology and prospecting in Greenland

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  6. A screening of persistent organohalogenated contaminants in hair of East Greenland polar bears.

    Science.gov (United States)

    Jaspers, Veerle L B; Dietz, Rune; Sonne, Christian; Letcher, Robert J; Eens, Marcel; Neels, Hugo; Born, Erik W; Covaci, Adrian

    2010-10-15

    In this pilot study, we report on levels of persistent organohalogenated contaminants (OHCs) in hair of polar bears (Ursus maritimus) from East Greenland sampled between 1999 and 2001. To our knowledge, this is the first study on the validation of polar bear hair as a non-invasive matrix representative of concentrations and profiles in internal organs and blood plasma. Because of low sample weights (13-140mg), only major bioaccumulative OHCs were detected above the limit of quantification: five polychlorinated biphenyl (PCB) congeners (CB 99, 138, 153, 170 and 180), one polybrominated diphenyl ether (PBDE) congener (BDE 47), oxychlordane, trans-nonachlor and β-hexachlorocyclohexane. The PCB profile in hair was similar to that of internal tissues (i.e. adipose, liver, brain and blood), with CB 153 and 180 as the major congeners in all matrices. A gender difference was found for concentrations in hair relative to concentrations in internal tissues. Females (n=6) were found to display negative correlations, while males (n=5) showed positive correlations, although p-values were not found significant. These negative correlations in females may reflect seasonal OHC mobilisation from periphery adipose tissue due to, for example, lactation and fasting. The lack of significance in most correlations may be due to small sample sizes and seasonal variability of concentrations in soft tissues. Further research with larger sample weights and sizes is therefore necessary to draw more definitive conclusions on the usefulness of hair for biomonitoring OHCs in polar bears and other fur mammals. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. The Thermodynamic Structure of Arctic Coastal Fog Occurring During the Melt Season over East Greenland

    Science.gov (United States)

    Gilson, Gaëlle F.; Jiskoot, Hester; Cassano, John J.; Gultepe, Ismail; James, Timothy D.

    2018-05-01

    An automated method to classify Arctic fog into distinct thermodynamic profiles using historic in-situ surface and upper-air observations is presented. This classification is applied to low-resolution Integrated Global Radiosonde Archive (IGRA) soundings and high-resolution Arctic Summer Cloud Ocean Study (ASCOS) soundings in low- and high-Arctic coastal and pack-ice environments. Results allow investigation of fog macrophysical properties and processes in coastal East Greenland during melt seasons 1980-2012. Integrated with fog observations from three synoptic weather stations, 422 IGRA soundings are classified into six fog thermodynamic types based on surface saturation ratio, type of temperature inversion, fog-top height relative to inversion-base height and stability using the virtual potential temperature gradient. Between 65-80% of fog observations occur with a low-level inversion, and statically neutral or unstable surface layers occur frequently. Thermodynamic classification is sensitive to the assigned dew-point depression threshold, but categorization is robust. Despite differences in the vertical resolution of radiosonde observations, IGRA and ASCOS soundings yield the same six fog classes, with fog-class distribution varying with latitude and environmental conditions. High-Arctic fog frequently resides within an elevated inversion layer, whereas low-Arctic fog is more often restricted to the mixed layer. Using supplementary time-lapse images, ASCOS microwave radiometer retrievals and airmass back-trajectories, we hypothesize that the thermodynamic classes represent different stages of advection fog formation, development, and dissipation, including stratus-base lowering and fog lifting. This automated extraction of thermodynamic boundary-layer and inversion structure can be applied to radiosonde observations worldwide to better evaluate fog conditions that affect transportation and lead to improvements in numerical models.

  8. Prevalence of antibodies against Brucella spp. in West Greenland polar bears (Ursus maritimus) and East Greenland muskoxen (Ovibos moschatus)

    DEFF Research Database (Denmark)

    Sonne, Christian; Andersen-Ranberg, Emilie; Rajala, Elisabeth L.

    2018-01-01

    impact on human health due to consumption of raw meat or otherwise contact with tissues and fluids of infected game species such as muskoxen and polar bears. Here, we present serological results for Baffin Bay polar bears (Ursus maritimus) (n = 96) and North East Greenland muskoxen (Ovibos moschatus) (n...

  9. Regions of open water and melting sea ice drive new particle formation in North East Greenland.

    Science.gov (United States)

    Dall Osto, M; Geels, C; Beddows, D C S; Boertmann, D; Lange, R; Nøjgaard, J K; Harrison, Roy M; Simo, R; Skov, H; Massling, A

    2018-04-17

    Atmospheric new particle formation (NPF) and growth significantly influences the indirect aerosol-cloud effect within the polar climate system. In this work, the aerosol population is categorised via cluster analysis of aerosol number size distributions (9-915 nm, 65 bins) taken at Villum Research Station, Station Nord (VRS) in North Greenland during a 7 year record (2010-2016). Data are clustered at daily averaged resolution; in total, we classified six categories, five of which clearly describe the ultrafine aerosol population, one of which is linked to nucleation events (up to 39% during summer). Air mass trajectory analyses tie these frequent nucleation events to biogenic precursors released by open water and melting sea ice regions. NPF events in the studied regions seem not to be related to bird colonies from coastal zones. Our results show a negative correlation (r = -0.89) between NPF events and sea ice extent, suggesting the impact of ultrafine Arctic aerosols is likely to increase in the future, given the likely increased sea ice melting. Understanding the composition and the sources of Arctic aerosols requires further integrated studies with joint multi-component ocean-atmosphere observation and modelling.

  10. Temporal monitoring of liver and kidney lesions in contaminated East Greenland polar bears (Ursus maritimus) during 1999-2010.

    Science.gov (United States)

    Sonne, Christian; Letcher, Robert J; Leifsson, Pall S; Rigét, Frank F; Bechshøft, Thea Ø; Bossi, Rossana; Asmund, Gert; Dietz, Rune

    2012-11-01

    Organohalogen contaminants bioaccumulate to high concentrations in tissues of polar bears (Ursus maritimus). The exposure levels are in the order to be toxic to inner organs like liver and kidney. We therefore investigated the temporal development of lesions in liver (n=115) and kidney (n=122) samples from East Greenland polar bears taken over the 12 year period from 1999 to 2010. Seven liver and seven kidney lesions were observed of which six were age-related. Controlling for this, the analyses showed that hepatic steatosis and renal cell infiltrations, glomerular sclerosis and tubular hyperplasia decreased over the investigated time period (all ppolar bears. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. A 60 yr record of atmospheric carbon monoxide reconstructed from Greenland firn air

    Science.gov (United States)

    Petrenko, V. V.; Martinerie, P.; Novelli, P.; Etheridge, D. M.; Levin, I.; Wang, Z.; Blunier, T.; Chappellaz, J.; Kaiser, J.; Lang, P.; Steele, L. P.; Hammer, S.; Mak, J.; Langenfelds, R. L.; Schwander, J.; Severinghaus, J. P.; Witrant, E.; Petron, G.; Battle, M. O.; Forster, G.; Sturges, W. T.; Lamarque, J.-F.; Steffen, K.; White, J. W. C.

    2013-08-01

    We present the first reconstruction of the Northern Hemisphere (NH) high latitude atmospheric carbon monoxide (CO) mole fraction from Greenland firn air. Firn air samples were collected at three deep ice core sites in Greenland (NGRIP in 2001, Summit in 2006 and NEEM in 2008). CO records from the three sites agree well with each other as well as with recent atmospheric measurements, indicating that CO is well preserved in the firn at these sites. CO atmospheric history was reconstructed back to the year 1950 from the measurements using a combination of two forward models of gas transport in firn and an inverse model. The reconstructed history suggests that Arctic CO in 1950 was 140-150 nmol mol-1, which is higher than today's values. CO mole fractions rose by 10-15 nmol mol-1 from 1950 to the 1970s and peaked in the 1970s or early 1980s, followed by a ≈ 30 nmol mol-1 decline to today's levels. We compare the CO history with the atmospheric histories of methane, light hydrocarbons, molecular hydrogen, CO stable isotopes and hydroxyl radicals (OH), as well as with published CO emission inventories and results of a historical run from a chemistry-transport model. We find that the reconstructed Greenland CO history cannot be reconciled with available emission inventories unless unrealistically large changes in OH are assumed. We argue that the available CO emission inventories strongly underestimate historical NH emissions, and fail to capture the emission decline starting in the late 1970s, which was most likely due to reduced emissions from road transportation in North America and Europe.

  12. A 60 yr record of atmospheric carbon monoxide reconstructed from Greenland firn air

    Directory of Open Access Journals (Sweden)

    V. V. Petrenko

    2013-08-01

    Full Text Available We present the first reconstruction of the Northern Hemisphere (NH high latitude atmospheric carbon monoxide (CO mole fraction from Greenland firn air. Firn air samples were collected at three deep ice core sites in Greenland (NGRIP in 2001, Summit in 2006 and NEEM in 2008. CO records from the three sites agree well with each other as well as with recent atmospheric measurements, indicating that CO is well preserved in the firn at these sites. CO atmospheric history was reconstructed back to the year 1950 from the measurements using a combination of two forward models of gas transport in firn and an inverse model. The reconstructed history suggests that Arctic CO in 1950 was 140–150 nmol mol−1, which is higher than today's values. CO mole fractions rose by 10–15 nmol mol−1 from 1950 to the 1970s and peaked in the 1970s or early 1980s, followed by a ≈ 30 nmol mol−1 decline to today's levels. We compare the CO history with the atmospheric histories of methane, light hydrocarbons, molecular hydrogen, CO stable isotopes and hydroxyl radicals (OH, as well as with published CO emission inventories and results of a historical run from a chemistry-transport model. We find that the reconstructed Greenland CO history cannot be reconciled with available emission inventories unless unrealistically large changes in OH are assumed. We argue that the available CO emission inventories strongly underestimate historical NH emissions, and fail to capture the emission decline starting in the late 1970s, which was most likely due to reduced emissions from road transportation in North America and Europe.

  13. Greenland, my greenland

    DEFF Research Database (Denmark)

    Andersen, Astrid

    2016-01-01

    In 2012, Visit Greenland, the Greenlandic national tourist organisation, conducted a survey on Danish prejudices towards Greenland and Greenlanders. The survey, linked to an ambivalent nation-building strategy that pitched Greenland as ‘the pioneering nation’, was aimed both at challenging...... tourist audience more concerned with preserving whales than with accepting the sustainable visions of indigenous modernity that are currently being articulated by Greenlanders. Contemporary Greenlandic nation branding is a response to these internal and external dichotomies....

  14. Traditional Knowledge About Polar Bears (Ursus maritimus in East Greenland: Changes in the Catch and Climate Over Two Decades

    Directory of Open Access Journals (Sweden)

    Kristin L. Laidre

    2018-05-01

    Full Text Available In Greenland, polar bears (Ursus maritimus are nutritional, economic, and cultural subsistence resources for Inuit. Traditional Ecological Knowledge (TEK collected from subsistence hunters can provide important insights and improve management decisions when collected systematically. We report on the results of a TEK survey of subsistence polar bear hunters living in the areas around Tasiilaq and Ittoqqortoormiit, East Greenland. Twenty-five full-time polar bear hunters were interviewed between December 2014 and March 2015 in a conversation-style interview, where a local interviewer fluent in the East Greenlandic dialect asked a series of 55 predetermined questions. The primary goals were to (1 gather Inuit perspectives on polar bear subsistence quotas and hunting strategies, (2 understand how climate change is affecting the polar bear subsistence hunt, and (3 document observed changes in polar bear distribution, abundance, and biology. Approximately 40% of the Tasiilaq respondents had caught between 10 and 19 polar bears in their lifetime, while 67% of Ittoqqortoormiit respondents reported lifetime catches of ≥20 bears. In both areas, polar bears were most commonly hunted between February and April. Hunters noted large changes to the climate in the areas where they hunt polar bears. Most hunters reported loss of sea ice, receding glaciers, unstable weather, and warmer temperatures. In Tasiilaq 73% of the hunters said climate changes had affected the polar bear hunt and in Ittoqqortoormiit about 88% of respondents reported the same. Hunters indicated that sea ice loss has created more areas of open water so dog sledges have become unsafe for hunting transportation compared to 10–15 years ago (reported by 100% of hunters in Tasiilaq and 80% in Ittoqqortoormiit. In Ittoqqortoormiit, the distance traveled during polar bear hunting trips has decreased dramatically. In both areas hunters noted that more polar bears are coming into their

  15. Abrupt Greenland Ice Sheet runoff and sea water temperature changes since 1821, recorded by coralline algae

    Science.gov (United States)

    Kamenos, N.; Hoey, T.; Bedford, J.; Claverie, T.; Fallick, A. E.; Lamb, C. M.; Nienow, P. W.; O'Neill, S.; Shepherd, I.; Thormar, J.

    2012-12-01

    The Greenland Ice Sheet (GrIS) contains the largest store of fresh water in the northern hemisphere, equivalent to ~7.4m of eustatic sea level rise, but its impacts on current, past and future sea level, ocean circulation and European climate are poorly understood. Previous estimates of GrIS melt, from 26 years of satellite observations and temperature driven melt-models over 48 years, show a trend of increasing melt. There are however no runoff data of comparable duration with which to validate temperature-based runoff models, or relationships between the spatial extent of melt and runoff. Further, longer runoff records that extend GrIS melt records to centennial timescales will enable recently observed trends to be put into a better historical context. We measured Mg/Ca, δ18O and structural cell size in annual growth bands of red coralline algae to reconstruct: (1) near surface sea water temperature; and, (2) melt/runoff from the GrIS. (1) Temperature: we reconstructed the longest (1821-2009) sub-annual resolution record of water temperature in Disko Bugt (western Greenland) showing an abrupt change in temperature oscillation patterns during the 1920s which may be attributable to the interaction between atmospheric temperature and mass loss from Jakobshavn Isbrae glacier. (2) GrIS runoff: using samples from distal parts of Søndre Strømfjord we produced the first reconstruction of decadal (1939-2002) GrIS runoff. We observed significant negative relationships between historic runoff, relative salinity and marine summer temperature. Our reconstruction shows a trend of increasing reconstructed runoff since the mid 1980s. In situ summer marine temperatures followed a similar trend. We suggest that since 1939 atmospheric temperatures have been important in forcing runoff. Subject to locating in situ coralline algae samples, these methods can be applied across hundreds to thousands of years. These results show that our technique has significant potential to enhance

  16. Field metabolic rate and PCB adipose tissue deposition efficiency in East Greenland polar bears derived from contaminant monitoring data.

    Science.gov (United States)

    Pavlova, Viola; Nabe-Nielsen, Jacob; Dietz, Rune; Svenning, Jens-Christian; Vorkamp, Katrin; Rigét, Frank Farsø; Sonne, Christian; Letcher, Robert J; Grimm, Volker

    2014-01-01

    Climate change will increasingly affect the natural habitat and diet of polar bears (Ursus maritimus). Understanding the energetic needs of polar bears is therefore important. We developed a theoretical method for estimating polar bear food consumption based on using the highly recalcitrant polychlorinated biphenyl (PCB) congener, 2,2',4,4',55-hexaCB (CB153) in bear adipose tissue as an indicator of food intake. By comparing the CB153 tissue concentrations in wild polar bears with estimates from a purposely designed individual-based model, we identified the possible combinations of field metabolic rates (FMR) and CB153 deposition efficiencies in East Greenland polar bears. Our simulations indicate that if 30% of the CB153 consumed by polar bear individuals were deposited into their adipose tissue, the corresponding FMR would be only two times the basal metabolic rate. In contrast, if the modelled CB153 deposition efficiency were 10%, adult polar bears would require six times more energy than that needed to cover basal metabolism. This is considerably higher than what has been assumed for polar bears in previous studies though it is similar to FMRs found in other marine mammals. An implication of this result is that even relatively small reductions in future feeding opportunities could impact the survival of East Greenland polar bears.

  17. Field metabolic rate and PCB adipose tissue deposition efficiency in East Greenland polar bears derived from contaminant monitoring data.

    Directory of Open Access Journals (Sweden)

    Viola Pavlova

    Full Text Available Climate change will increasingly affect the natural habitat and diet of polar bears (Ursus maritimus. Understanding the energetic needs of polar bears is therefore important. We developed a theoretical method for estimating polar bear food consumption based on using the highly recalcitrant polychlorinated biphenyl (PCB congener, 2,2',4,4',55-hexaCB (CB153 in bear adipose tissue as an indicator of food intake. By comparing the CB153 tissue concentrations in wild polar bears with estimates from a purposely designed individual-based model, we identified the possible combinations of field metabolic rates (FMR and CB153 deposition efficiencies in East Greenland polar bears. Our simulations indicate that if 30% of the CB153 consumed by polar bear individuals were deposited into their adipose tissue, the corresponding FMR would be only two times the basal metabolic rate. In contrast, if the modelled CB153 deposition efficiency were 10%, adult polar bears would require six times more energy than that needed to cover basal metabolism. This is considerably higher than what has been assumed for polar bears in previous studies though it is similar to FMRs found in other marine mammals. An implication of this result is that even relatively small reductions in future feeding opportunities could impact the survival of East Greenland polar bears.

  18. Are liver and renal lesions in East Greenland polar bears (Ursus maritimus associated with high mercury levels?

    Directory of Open Access Journals (Sweden)

    Born Erik W

    2007-04-01

    Full Text Available Abstract Background In the Arctic, polar bears (Ursus maritimus bio-accumulate mercury as they prey on polluted ringed seals (Phoca hispida and bearded seals (Erignathus barbatus. Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arctic. It is unknown whether these levels are toxic to liver and kidney tissue. Methods We investigated the histopathological impact from anthropogenic long-range transported mercury on East Greenland polar bear liver (n = 59 and kidney (n = 57 tissues. Results Liver mercury levels ranged from 1.1–35.6 μg/g wet weight and renal levels ranged from 1–50 μg/g wet weight, of which 2 liver values and 9 kidney values were above known toxic threshold level of 30 μg/g wet weight in terrestrial mammals. Evaluated from age-correcting ANCOVA analyses, liver mercury levels were significantly higher in individuals with visible Ito cells (p Conclusion Based on these relationships and the nature of the chronic inflammation we conclude that the lesions were likely a result of recurrent infections and ageing but that long-term exposure to mercury could not be excluded as a co-factor. The information is important as it is likely that tropospheric mercury depletion events will continue to increase the concentrations of this toxic heavy metal in the Sub Arctic and Arctic marine food webs.

  19. Age and seasonal variability of polybrominated diphenyl ethers in free-ranging East Greenland polar bears (Ursus maritimus)

    International Nuclear Information System (INIS)

    Dietz, Rune; Riget, Frank F.; Sonne, Christian; Letcher, Robert J.; Backus, Sean; Born, Erik W.; Kirkegaard, Maja; Muir, Derek C.G.

    2007-01-01

    Polybrominated diphenyl ethers (PBDEs) were analysed in adipose tissue from 92 East Greenland polar bears (Ursus maritimus) sampled during 1999-2001. Mean ΣPBDE concentrations were 70 ng/g lipid weight (lw) (range: 22-192 ng/g lw) and showed no relationship with age or sex. Of the 32 analysed PBDE congeners; BDE47, BDE153, BDE99 and BDE100 dominated, and comprised 99.6% of the ΣPBDE concentration. The ΣPBDE concentration had a highly significant correlation with ΣPCB, ΣCHL, dieldrin, HCB and ΣHCH concentrations. We found a seasonal pattern of median ΣPBDE concentration with 1.2 to 1.8 times higher concentrations in March to July than the rest of the year. The seasonal variation also provides a clue to the seasonal exposure, bio-availability, toxic exposure and degradation. We suggest that future geographical PBDE data comparisons may not need corrections for sex or age, but such data sets should be corrected for seasonal variability, using the presented correctional trigonometric regression. - Mean ΣPBDE concentrations of East Greenland polar bears (Ursus maritimus) were 69.5 ng/g lw (range: 21.7-192 ng/g lw) and showed a seasonal pattern with no relationship with age and sex

  20. Three decades (1983-2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 2: brominated flame retardants.

    Science.gov (United States)

    Dietz, Rune; Rigét, Frank F; Sonne, Christian; Born, Erik W; Bechshøft, Thea; McKinney, Melissa A; Drimmie, Robert J; Muir, Derek C G; Letcher, Robert J

    2013-09-01

    Brominated flame retardants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Significant linear increases were found for sum polybrominated diphenyl ether (ΣPBDE), BDE100, BDE153, and hexabromocyclododecane (HBCD). Average increases of 5.0% per year (range: 2.9-7.6%/year) were found for the subadult polar bears. BDE47 and BDE99 concentrations did not show a significant linear trend over time, but rather a significant non-linear trend peaking between 2000 and 2004. The average ΣPBDE concentrations increased 2.3 fold from 25.0ng/g lw (95% C.I.: 15.3-34.7ng/g lw) in 1983-1986 to 58.5ng/g lw (95% C.I.: 43.6-73.4ng/g lw) in 2006-2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Analyses of δ(15)N and δ(13)C stable isotopes in hair revealed no clear linear temporal trends in trophic level or carbon source, respectively, and non-linear trends differed among sex and age groups. These increasing concentrations of organobromine contaminants contribute to complex organohalogen mixture, already causing health effects to the East Greenland polar bears. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Revised estimates of Greenland ice sheet thinning histories based on ice-core records

    DEFF Research Database (Denmark)

    Lecavalier, B.S.; Milne, G.A.; Fisher, D.A.

    2013-01-01

    -based reconstructions and, to some extent, the estimated elevation histories. A key component of the ice core analysis involved removing the influence of vertical surface motion on the dO signal measured from the Agassiz and Renland ice caps. We re-visit the original analysis with the intent to determine if the use...... of more accurate land uplift curves can account for some of the above noted discrepancy. To improve on the original analysis, we apply a geophysical model of glacial isostatic adjustment calibrated to sea-level records from the Queen Elizabeth Islands and Greenland to calculate the influence of land...... in this selection is further complicated by the possible influence of Innuitian ice during the early Holocene (12-8 ka BP). Our results indicate that a more accurate treatment of the uplift correction leads to elevation histories that are, in general, shifted down relative to the original curves at GRIP, NGRIP, DYE...

  2. Southwest Greenland's Alpine Glacier History: Recent Glacier Change in the Context of the Holocene Geologic Record

    Science.gov (United States)

    Larocca, L. J.; Axford, Y.; Lasher, G. E.; Lee, C. W.

    2017-12-01

    Due to anthropogenic climate change, the Arctic region is currently undergoing major transformation, and is expected to continue warming much faster than the global average. To put recent and future changes into context, a longer-term understanding of this region's past response to natural climate variability is needed. Given their sensitivity to modest climate change, small alpine glaciers and ice caps on Greenland's coastal margin (beyond the Greenland Ice Sheet) represent ideal features to record climate variability through the Holocene. Here we investigate the Holocene history of a small ( 160 square km) ice cap and adjacent alpine glaciers, located in southwest Greenland approximately 50 km south of Nuuk. We employ measurements on sediment cores from a glacier-fed lake in combination with geospatial analysis of satellite images spanning the past several decades. Sedimentary indicators of sediment source and thus glacial activity, including organic matter abundance, inferred chlorophyll-a content, sediment major element abundances, grain size, and magnetic susceptibility are presented from cores collected from a distal glacier-fed lake (informally referred to here as Per's Lake) in the summer of 2015. These parameters reflect changes in the amount and character of inorganic detrital input into the lake, which may be linked to the size of the upstream glaciers and ice cap and allow us to reconstruct their status through the Holocene. Additionally, we present a complementary record of recent changes in Equilibrium Line Altitude (ELA) for the upstream alpine glaciers. Modern ELAs are inferred using the accumulation area ratio (AAR) method in ArcGIS via Landsat and Worldview-2 satellite imagery, along with elevation data obtained from digital elevation models (DEMs). Paleo-ELAs are inferred from the positions of moraines and trim lines marking the glaciers' most recent expanded state, which we attribute to the Little Ice Age (LIA). This approach will allow us to

  3. Impact of recirculation on the East Greenland Current in Fram Strait: Results from moored current meter measurements between 1997 and 2009

    NARCIS (Netherlands)

    de Steur, L.; Hansen, E.; Mauritzen, C.; Beszczynska-Möller, A.; Fahrbach, E.

    2014-01-01

    Transports of total volume and water masses obtained from a mooring array in the East Greenland Current (EGC) in Fram Strait are presented for the period 1997–2009. The array in the EGC was moved along isobaths from 79°N to 78°50'N78°50'N in 2002 to line up with moorings in the eastern Fram Strait.

  4. Vegetation phenology gradients along the west and east coasts of Greenland from 2001 to 2015

    DEFF Research Database (Denmark)

    Karami, Mojtaba; Hansen, Birger Ulf; Westergaard-Nielsen, Andreas

    2017-01-01

    , as well as the climatic response. The date of the start of season (SOS) was significantly earlier (24 days), length of season longer (25 days), and time-integrated NDVI higher in West Greenland. The sea ice concentration during May was found to have a significant effect on the date of the SOS only in West...

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  6. New marine geophysical and sediment record of the Northeast Greenland Ice Stream.

    Science.gov (United States)

    Callard, L.; Roberts, D. H.; O'Cofaigh, C.; Lloyd, J. M.; Smith, J. A.; Dorschel, B.

    2017-12-01

    The NE Greenland Ice Stream (NEGIS) drains 16% of the Greenland Ice Sheet (GrIS) and has a sea-level equivalent of 1.1-1.4 m. Stabilised by two floating ice shelves, 79N and Zachariae Isstrom, until recently it has shown little response to increased atmospheric and oceanic warming. However, since 2010 it has experienced an accelerated rate of grounding line retreat ( 4 km) and significant ice shelf loss that indicates that this sector of the GrIS is now responding to current oceanic and/or climatic change and has the potential to be a major contributor to future global sea-level rise. The project `NEGIS', a collaboration between Durham University and AWI, aims to reconstruct the history of the NE Greenland Ice Stream from the Last Glacial Maximum (LGM) to present using both onshore and offshore geological archives to better understand past ice stream response to a warming climate. This contribution presents results and interpretations from an offshore dataset collected on the RV Polarstern, cruises PS100 and PS109 in 2016 and 2017. Gravity and box cores, supplemented by swath bathymetric and sub-bottom profiler data, were acquired and initial core analysis including x-radiographs and MSCL data logging has been performed. Data collection focused principally in the Norske Trough and the area directly in front of the 79N ice shelf, a sub-ice shelf environment as recently as two years ago. On the outer shelf streamlined subglacial bedforms, grounding-zone wedges and moraines as well as overconsolidated subglacial tills, record an extensive ice sheet advance to the shelf edge. On the inner shelf and in front of the 79N ice shelf, deep, glacially-eroded bedrock basins are infilled with stratified sediment. The stratified muds represent deglacial and Holocene glacimarine sedimentation, and capture the recent transition from sub-ice shelf to shelf free conditions. Multiproxy palaeoenvironmental reconstructions, including foraminifera and diatom analysis, and radiocarbon

  7. Wintertime re-ventilation of the East Greenland Current's Atlantic-origin Overflow Water in the western Iceland Sea

    Science.gov (United States)

    Våge, Kjetil; Håvik, Lisbeth; Papritz, Lukas; Spall, Michael; Moore, Kent

    2017-04-01

    The Deep Western Boundary Current constitutes the lower limb of the Atlantic Meridional Overturning Circulation, and, as such, is a crucial component of the Earth's climate system. The largest and densest contribution to the current stems from the overflow plume that passes through Denmark Strait. A main source of Denmark Strait Overflow Water (DSOW) is the East Greenland Current (EGC). The DSOW transported by the EGC originates from the Atlantic inflow into the Nordic Seas. This is then transformed into Atlantic-origin Overflow Water while progressing northward through the eastern part of the Nordic Seas. Here we show, using measurements from autonomous gliders deployed from fall 2015 to spring 2016, that the Atlantic-origin Overflow Water transported toward Denmark Strait by the EGC was re-ventilated while transiting the western Iceland Sea in winter. In summer, this region is characterized by an upper layer of cold, fresh Polar Surface Water that is thought to prevent convection. But in fall and winter this fresh water mass is diverted toward the Greenland shelf by enhanced northerly winds, which results in a water column that is preconditioned for convection. Severe heat loss from the ocean to the atmosphere offshore of the ice edge subsequently causes the formation of deep mixed layers. This further transforms the Atlantic-origin Overflow Water and impacts the properties of the DSOW, and hence the deepest and densest component of the lower limb of the Atlantic Meridional Overturning Circulation.

  8. Crestal unconformities on an exposed Jurassic tilted fault block, Wollaston Forland, East Greenland as an analogue for buried hydrocarbon traps

    DEFF Research Database (Denmark)

    Surlyk, Finn; Korstgård, J.

    2013-01-01

    The stratigraphy of successions exposed in footwall crests of tilted fault blocks is commonly highly complex. Crestal stratigraphy and structure are particularly difficult to unravel in the subsurface due to poor seismic resolution across fault zones, footwall collapse, and coalescing syn- and post......-rift unconformities. Crestal ridges are important elements in basin evolution, as they form drainage divides and sediment sources for aprons along footwall scarps and hangingwall deltas. A Middle Jurassic – lowermost Cretaceous footwall crest is exceptionally well exposed in the mountain Stratumbjerg in Wollaston...... Forland, East Greenland. Rifting and block tilting was initiated in the (?)Bajocian, intensified in the Oxfordian–Kimmeridgian, culminated in latest Jurassic, Volgian, time and faded out in the earliest Cretaceous. The main border faults of the westward tilted blocks trend roughly N–S. The first early syn...

  9. Three decades (1983-2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 2

    DEFF Research Database (Denmark)

    Dietz, Rune; Rigét, Frank F; Sonne, Christian

    2013-01-01

    Legacy organochlorine contaminants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Of 19 major legacy contaminants and congeners (ΣPCB, 4 PCB congeners (CB153, 180, 170/190), ΣDDT, p,p'-DDE, p,p' -DDD...... and p,p'-DDT, α- and β-hexachlorocyclohexane (HCH), HCB, octachlorostyrene, dieldrin, oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, heptachlor epoxide and BB-153), 18 showed statistically significant average yearly declines of -4.4% (range: -2.0 to -10.8%/year) among subadult polar...... bears (i.e. females...

  10. Pb isotopes during crustal melting and magma mingling - A cautionary tale from the Miki Fjord macrodike, central east Greenland

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Lesher, Charles

    2010-01-01

    Pb isotopic data are presented for hybrid rocks formed by mingling between mantle-derived tholeiitic magma of the Eocene Miki Fjord macrodike (East Greenland) and melt derived from the adjacent Precambrian basement. Bulk mixing and AFC processes between end-members readily identified in the field...... grain boundaries during disequilibrium melting of the host rock by the mafic magma. The crustal melt involved in magma interactions was therefore heterogeneous with respect to Pb isotopes on a metre-scale. These results illustrate the difficulties inherent in interpreting isotopic variations...... in contaminated mafic magmas even when the end-members are well constrained by field relations. We show that the Pb isotopic composition of the crustal contaminants and contamination trajectories for the Miki Fjord hybrid magmatic lithologies are markedly different from regional basement gneisses and contaminated...

  11. Source apportionment of particles at Station Nord, North East Greenland during 2008–2010 using COPREM and PMF analysis

    DEFF Research Database (Denmark)

    Nguyen, Quynh; Skov, Henrik; Sørensen, Lise Lotte

    2013-01-01

    In order to develop strategies for controlling and reducing Arctic air pollution, there is a need to understand the basic mechanisms for determining the fate of air pollution in the Arctic. Sources of atmospheric particles at Station Nord (81° 36' N, 16° 40' W) in North East Greenland were...... evaluated for a two-year period from March 2008 to February 2010. Source apportionment using Positive Matrix Factorization (PMF) and COnstrained Physical REceptor Model (COPREM) was based on measurements of black carbon, elements (Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr...... origins. Another anthropogenic source was characterised by high concentrations of Pb and As, which has been historically referred to as a Combustion source at Station Nord. The impacts of large-scale industry in Siberia, Russia were evident through high Cu concentrations in both the Combustion source...

  12. Three decades (1983-2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 1: legacy organochlorine contaminants.

    Science.gov (United States)

    Dietz, Rune; Rigét, Frank F; Sonne, Christian; Born, Erik W; Bechshøft, Thea; McKinney, Melissa A; Letcher, Robert J

    2013-09-01

    Legacy organochlorine contaminants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Of 19 major legacy contaminants and congeners (ΣPCB, 4 PCB congeners (CB153, 180, 170/190), ΣDDT, p,p'-DDE, p,p' -DDD and p,p'-DDT, α- and β-hexachlorocyclohexane (HCH), HCB, octachlorostyrene, dieldrin, oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, heptachlor epoxide and BB-153), 18 showed statistically significant average yearly declines of -4.4% (range: -2.0 to -10.8%/year) among subadult polar bears (i.e. femalespolar bear tissues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Grain size dependent magnetic discrimination of Iceland and South Greenland terrestrial sediments in the northern North Atlantic sediment record

    Science.gov (United States)

    Hatfield, Robert G.; Stoner, Joseph S.; Reilly, Brendan T.; Tepley, Frank J.; Wheeler, Benjamin H.; Housen, Bernard A.

    2017-09-01

    We use isothermal and temperature dependent in-field and magnetic remanence methods together with electron microscopy to characterize different sieved size fractions from terrestrial sediments collected in Iceland and southern Greenland. The magnetic fraction of Greenland silts (3-63 μm) and sands (>63 μm) is primarily composed of near-stoichiometric magnetite that may be oxidized in the finer clay (samples, in contrast to coarser PSD and multi-domain (MD) discrete magnetites from southern Greenland. We demonstrate the potential of using magnetic properties of the silt fraction for source unmixing by creating known endmember mixtures and by using naturally mixed marine sediments from the Eirik Ridge south of Greenland. We develop a novel approach to ferrimagnetic source unmixing by using low temperature magnetic susceptibility curves that are sensitive to the different crystallinity and cation substitution characteristics of the different source regions. Covariation of these properties with hysteresis parameters suggests sediment source changes have driven the magnetic mineral variations observed in Eirik Ridge sediments since the last glacial maximum. These observations assist the development of a routine method and interpretative framework to quantitatively determine provenance in a geologically realistic and meaningful way and assess how different processes combine to drive magnetic variation in the North Atlantic sediment record.

  14. Millennial oscillations in greenland dust and Eurasian Aeolian records - a paleosol-loess perspective (Hans Oeschger Medal Lecture)

    Science.gov (United States)

    Rousseau, Denis-Didier

    2017-04-01

    Considerable interest is brought on the abrupt climate changes that punctuated the last glacial period (˜110.6-14.62 ka). Originating in the North-Atlantic area, they have been recorded in ice, marine and terrestrial records all over the world, and especially in the Northern Hemisphere, with various environmental implications. The ice-core records, of increasingly high resolution, allow specifying more precisely the timing of these abrupt changes, which have occurred within intervals equivalent to present human generations. The continental records have been mainly interpreted so far in terms of temperature, precipitation or vegetation changes between the relatively warm ("Greenland Interstadial" - GI) and the cold ("Greenland Stadial" - GS) North-Atlantic climate phases. In this presentation records from Greenland ice and northwestern European eolian deposits are compared in order to establish a link between GI and the soil development in European mid-latitudes, as recorded in loess sequences. For the different types of observed paleosols, the precise correlation with the Greenland records is applied to propose estimates of the maximum time lapses needed to achieve the different degrees of maturation and development. To identify these time lapses more precisely, two independent ice-core records are compared: δ180 and dust concentration, indicating variations of temperature and atmospheric dustiness respectively in the Greenland area. This method slightly differs from the definition of a GI event duration applied in other studies where the sharp end of the δ18O decrease gives the end of a GI. The same methodology is applied to both records (i.e., the GI last from the beginning of the abrupt δ18O increase or dust concentration decrease until when δ18O or dust reach again their initial value) determined both visually and algorithmically, and compare them to GI published estimates. Focusing on the eolian/dust intervals, the analysis of δ18O and dust in the

  15. Coastal glaciers advanced onto Jameson Land, East Greenland during the late glacial–early Holocene Milne Land Stade

    Directory of Open Access Journals (Sweden)

    Helena Alexanderson

    2014-01-01

    Full Text Available We report on 10Be and optically stimulated luminescence ages from moraines and glaciolacustrine sediments on eastern Jameson Land, East Greenland. Sampled landforms and sediment are associated with advances of outlet glaciers from the local Liverpool Land ice cap situated in the coastal Scoresby Sund region. Previous studies have tentatively correlated these advances with the Milne Land Stade moraines, which are prominent moraine sets deposited by mountain glaciers in the inner Scoresby Sund region. Recent constraints on the formation of the outer and inner of these moraines have suggested two advances of local glaciers, one prior to or during the Younger Dryas and another during the Preboreal. In this paper, we test the correlation of the Liverpool Land glacial advance with the Milne Land Stade. Our results show that outlet glaciers from the Liverpool Land ice cap reached ice-marginal positions marked by moraines in east-facing valleys on Jameson Land sometime during late glacial–early Holocene time (ca. 13–11 Kya. This confirms the correlation of these moraines with the Milne Land Stade moraines described elsewhere in the Scoresby Sund region.

  16. Three new fern records for Kilimanjaro | Hemp | Journal of East ...

    African Journals Online (AJOL)

    Working on the flora and vegetation of Mt. Kilimanjaro, Tanzania, three ferns in three families were found that are not yet recorded for the floral region T2. The altitudinal range, localities and habitat description are given for Adiantum reniforme, Azolla africana and Trichomanes radicans. Journal of East African Natural History ...

  17. Of Images, Archives, and Anonymity: Glacier Photographs from Louise Arner Boyd's East Greenland Expeditions, 1933, 1937, and 1938

    Science.gov (United States)

    Nelson, F. E.; Peschel, S. M.; Hall, D. K.

    2010-12-01

    Louise A. Boyd (1887-1972) was raised to wealth and privilege in San Raphael, CA. Her inherited fortune allowed unlimited travel, and in 1924 she arrived in Spitsbergen as a tourist. Infatuated by Arctic landscapes, Boyd resolved to return north in a more assertive role and ran three "preliminary" expeditions to Greenland, in 1926, 1928, and 1931. Boyd’s expeditions to East Greenland in 1933, 1937, and 1938 were predictive of the type of campaign that after WWII would characterize government-sponsored and international scientific efforts. “Planned as a unit,” these campaigns, sponsored by the American Geographical Society (AGS), were thoroughly integrated scientific expeditions incorporating glaciology, periglacial and glacial geomorphology, bedrock geology, botany, hydrography, topographic surveys, tides and currents, and magnetic observations within representative areas. The goal of the expeditions was to provide comprehensive characterization of the physical environment. The volumes resulting from this work contain many large-scale hydrographic and topographic maps, photomosaics, glacier maps, and chapters on the geology, glacial history, botany, and hydrology of the region. Boyd received extensive publicity for her Arctic expeditions, although much of it was concerned with the novelty of expeditions to remote locations being led by a woman. Boyd’s expeditions employed scientists who eventually became highly influential in their respective fields. Boyd employed, among others, the earth scientists J.H. Bretz, R.F. Flint, and A.L. Washburn. Other important personnel on these expeditions included AGS cartographer/surveyor O.M. Miller and his assistant, W.A. Wood, who employed novel ground-based photogrammetric techniques to construct a series of glacier maps at scales as large as 1:5000. The maps featured detailed error analyses, and are probably the first large-scale maps of known accuracy to be made of the Greenland Ice Sheet’s outlet glaciers. Boyd

  18. Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling

    DEFF Research Database (Denmark)

    Sonne, Christian; Gustavson, Kim; Rigét, Frank F.

    2009-01-01

    Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health...... effects, including reproductive, were conducted during 1990–2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk......, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79–1271 ng g−1 lw) and PCBs (range: 4128–53 923 ng g−1 lw) reported...

  19. Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker responses in east Greenland polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Pedersen, Kathrine Eggers; Basu, Niladri; Letcher, Robert J.

    2015-01-01

    to bioaccumulate in lipid rich tissues of the brain among other tissues such as liver, and can reach high concentrations in top predators including the polar bear. PFCA and PFSA bioaccummulation in the brain has the potential to pose neurotoxic effects and therefore we conducted a study to investigate...... if variations in neurochemical transmitter systems i.e. the cholinergic, glutaminergic, dopaminergic and GABAergic, could be related to brain-specific bioaccumulation of PFASs in East Greenland polar bears. Nine brain regions from nine polar bears were analyzed for enzyme activity (monoamine oxidase (MAO...... regions, whereas GS activity was positively correlated with PFASs primarily in occipital lobe. Results from the present study support the hypothesis that PFAS concentrations in polar bears from East Greenland have exceeded the threshold limits for neurochemical alterations. It is not known whether...

  20. East Greenland and Barents Sea polar bears (Ursus maritimus): adaptive variation between two populations using skull morphometrics as an indicator of environmental and genetic differences.

    Science.gov (United States)

    Pertoldi, Cino; Sonne, Christian; Wiig, Øystein; Baagøe, Hans J; Loeschcke, Volker; Bechshøft, Thea Østergaard

    2012-06-01

    A morphometric study was conducted on four skull traits of 37 male and 18 female adult East Greenland polar bears (Ursus maritimus) collected 1892-1968, and on 54 male and 44 female adult Barents Sea polar bears collected 1950-1969. The aim was to compare differences in size and shape of the bear skulls using a multivariate approach, characterizing the variation between the two populations using morphometric traits as an indicator of environmental and genetic differences. Mixture analysis testing for geographic differentiation within each population revealed three clusters for Barents Sea males and three clusters for Barents Sea females. East Greenland consisted of one female and one male cluster. A principal component analysis (PCA) conducted on the clusters defined by the mixture analysis, showed that East Greenland and Barents Sea polar bear populations overlapped to a large degree, especially with regards to females. Multivariate analyses of variance (MANOVA) showed no significant differences in morphometric means between the two populations, but differences were detected between clusters from each respective geographic locality. To estimate the importance of genetics and environment in the morphometric differences between the bears, a PCA was performed on the covariance matrix derived from the skull measurements. Skull trait size (PC1) explained approx. 80% of the morphometric variation, whereas shape (PC2) defined approx. 15%, indicating some genetic differentiation. Hence, both environmental and genetic factors seem to have contributed to the observed skull differences between the two populations. Overall, results indicate that many Barents Sea polar bears are morphometrically similar to the East Greenland ones, suggesting an exchange of individuals between the two populations. Furthermore, a subpopulation structure in the Barents Sea population was also indicated from the present analyses, which should be considered with regards to future management

  1. The last glacial cycles in East Greenland, an overVIew

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1994-01-01

    /glacial cycle. The stratigraphical scheme is based on studies on the Jameson Land peninsula, and contains five glacial stages and stades with the Greenland ice sheet or its outlets reaching the outer coasts. Individual sites are correlated and dated by a combination of biostratigraphy, luminescence dating...... ( ~ Eemian) the advection of warm Atlantic water was higher than during the Holocene, and the terrestrial flora and insect faullas show that summer temperatures were 3-4"C higher than during the Holocene optimum. There is no unambiguous evidence for cooling in the sediments from this interval. Later......, in isotope stage 5, there were apparently two ice-free periods. During the Hugin Sa interstade, stable Polar water dominated Scoresby Sund, and the terrestrial flora suggests summer temperatures 2"_3" lower than the present. The marine and fluvial sediments from the second ice-free period, the Manselv...

  2. Exposure to mixtures of organohalogen contaminants and associative interactions with thyroid hormones in East Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Villanger, Gro D; Jenssen, Bjørn M; Fjeldberg, Rita R; Letcher, Robert J; Muir, Derek C G; Kirkegaard, Maja; Sonne, Christian; Dietz, Rune

    2011-05-01

    We investigated the multivariate relationships between adipose tissue residue levels of 48 individual organohalogen contaminants (OHCs) and circulating thyroid hormone (TH) levels in polar bears (Ursus maritimus) from East Greenland (1999-2001, n=62), using projection to latent structure (PLS) regression for four groupings of polar bears; subadults (SubA), adult females with cubs (AdF_N), adult females without cubs (AdF_S) and adult males (AdM). In the resulting significant PLS models for SubA, AdF_N and AdF_S, some OHCs were especially important in explaining variations in circulating TH levels: polybrominated diphenylether (PBDE)-99, PBDE-100, PBDE-153, polychlorinated biphenyl (PCB)-52, PCB-118, cis-nonachlor, trans-nonachlor, trichlorobenzene (TCB) and pentachlorobenzene (QCB), and both negative and positive relationships with THs were found. In addition, the models revealed that DDTs had a positive influence on total 3,5,3'-triiodothyronine (TT3) in AdF_S, and that a group of 17 higher chlorinated ortho-PCBs had a positive influence on total 3,5,3',5'-tetraiodothyronine (thyroxine, TT4) in AdF_N. TH levels in AdM seemed less influenced by OHCs because of non-significant PLS models. TH levels were also influenced by biological factors such as age, sex, body size, lipid content of adipose tissue and sampling date. When controlling for biological variables, the major relationships from the PLS models for SubA, AdF_N and AdF_S were found significant in partial correlations. The most important OHCs that influenced TH levels in the significant PLS models may potentially act through similar mechanisms on the hypothalamic-pituitary-thyroid (HPT) axis, suggesting that both combined effects by dose and response addition and perhaps synergistic potentiation may be a possibility in these polar bears. Statistical associations are not evidence per se of biological cause-effect relationships. Still, the results of the present study indicate that OHCs may affect circulating

  3. 500-year climate cycles stacking of recent centennial warming documented in an East Asian pollen record

    Science.gov (United States)

    Xu, Deke; Lu, Houyuan; Chu, Guoqiang; Wu, Naiqin; Shen, Caiming; Wang, Can; Mao, Limi

    2014-01-01

    Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake in East Asia (EA). Pollen record reflected the dynamics of vertical vegetation zones and temperature change. Spectral analysis on pollen percentages/concentrations of Pinus and Quercus, and a temperature proxy, revealed ~500-year quasi-periodic cold-warm fluctuations during the past 5350 years. This ~500-year cyclic climate change occurred in EA during the mid-late Holocene and even the last 150 years dominated by anthropogenic forcing. It was almost in phase with a ~500-year periodic change in solar activity and Greenland temperature change, suggesting that ~500-year small variations in solar output played a prominent role in the mid-late Holocene climate dynamics in EA, linked to high latitude climate system. Its last warm phase might terminate in the next several decades to enter another ~250-year cool phase, and thus this future centennial cyclic temperature minimum could partially slow down man-made global warming. PMID:24402348

  4. Validation of a Climate-Data Record of the "Clear-Kky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Box, Jason E.; Koenig, Lora S.; DiGirolamo, Nicolo E.; Comiso, Josefino C.; Shuman, Christopher A.

    2011-01-01

    Surface temperatures on the Greenland Ice Sheet have been studied on the ground, using automatic weather station (AWS) data from the Greenland-Climate Network (GC-Net), and from analysis of satellite sensor data. Using Advanced Very High Frequency Radiometer (AVHRR) weekly surface temperature maps, warming of the surface of the Greenland Ice Sheet has been documented since 1981. We extended and refined this record using higher-resolution Moderate-Resolution Imaging Spectroradiometer (MODIS) data from March 2000 to the present. We developed a daily and monthly climate-data record (CDR) of the "clear-sky" surface temperature of the Greenland Ice Sheet using an ice-surface temperature (1ST) algorithm developed for use with MODIS data. Validation of this CDR is ongoing. MODIS Terra swath data are projected onto a polar stereographic grid at 6.25-km resolution to develop binary, gridded daily and mean-monthly 1ST maps. Each monthly map also has a color-coded image map that is available to download. Also included with the monthly maps is an accompanying map showing number of days in the month that were used to calculate the mean-monthly 1ST. This is important because no 1ST decision is made by the algorithm for cells that are considered cloudy by the internal cloud mask, so a sufficient number of days must be available to produce a mean 1ST for each grid cell. Validation of the CDR consists of several facets: 1) comparisons between ISTs and in-situ measurements; 2) comparisons between ISTs and AWS data; and 3) comparisons of ISTs with surface temperatures derived from other satellite instruments such as the Thermal Emission and Reflection Radiometer (ASTER) and Enhanced Thematic Mapper Plus (ETM+). Previous work shows that Terra MODIS ISTs are about 3 C lower than in-situ temperatures measured at Summit Camp, during the winter of 2008-09 under clear skies. In this work we begin to compare surface temperatures derived from AWS data with ISTs from the MODIS CDR. The

  5. Brain region distribution and patterns of bioaccumulative perfluoroalkyl carboxylates and sulfonates in east greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune

    2013-03-01

    The present study investigated the comparative accumulation of perfluoroalkyl acids (PFAAs) in eight brain regions of polar bears (Ursus maritimus, n = 19) collected in 2006 from Scoresby Sound, East Greenland. The PFAAs studied were perfluoroalkyl carboxylates (PFCAs, C(6) -C(15) chain lengths) and sulfonates (C(4) , C(6) , C(8) , and C(10) chain lengths) as well as selected precursors including perfluorooctane sulfonamide. On a wet-weight basis, blood-brain barrier transport of PFAAs occurred for all brain regions, although inner regions of the brain closer to incoming blood flow (pons/medulla, thalamus, and hypothalamus) contained consistently higher PFAA concentrations compared to outer brain regions (cerebellum, striatum, and frontal, occipital, and temporal cortices). For pons/medulla, thalamus, and hypothalamus, the most concentrated PFAAs were perfluorooctane sulfonate (PFOS), ranging from 47 to 58 ng/g wet weight, and perfluorotridecanoic acid, ranging from 43 to 49 ng/g wet weight. However, PFOS and the longer-chain PFCAs (C(10) -C(15) ) were significantly (p  0.05) different among brain regions. The burden of the sum of PFCAs, perfluoroalkyl sulfonates, and perfluorooctane sulfonamide in the brain (average mass, 392 g) was estimated to be 46 µg. The present study demonstrates that both PFCAs and perfluoroalkyl sulfonates cross the blood-brain barrier in polar bears and that wet-weight concentrations are brain region-specific. Copyright © 2012 SETAC.

  6. Immunomodulatory effects of exposure to polychlorinated biphenyls and perfluoroalkyl acids in East Greenland ringed seals (Pusa hispida)

    International Nuclear Information System (INIS)

    Levin, Milton; Gebhard, Erika; Jasperse, Lindsay; Desforges, Jean-Pierre; Dietz, Rune; Sonne, Christian; Eulaers, Igor; Covaci, Adrian; Bossi, Rossana; De Guise, Sylvain

    2016-01-01

    To better elucidate the potential immune-related health effects of exposure to environmentally persistent organic pollutants (POP), such as polychlorinated biphenyls (PCBs) and perfluoroalkyl substances (PFASs), in ringed seals (Pusa hispida), a sentinel Arctic species, we assessed 1) associations between mitogen-induced lymphocyte proliferation and in vivo tissue contaminant burdens, and 2) the concentration-response effects of in vitro exposure to PFASs and PCB congeners on mitogen-induced lymphocyte proliferation. Upon in vitro contaminant exposure, the non-coplanar PCB congeners CB 138, 153, and 180, but not the coplanar CB 169, significantly reduced lymphocyte proliferation between 10 and 20 µg g −1 ww. The respective in vitro EC 50 values for these congeners were 13.3, 20.7, 20.8, and 54.6 µg g −1 ww. No modulation of lymphocyte proliferation was observed upon in vitro exposure to two individual PFASs, perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA), at concentrations up to 1000 ng g-1. In addition, no significant correlations were found between lymphocyte proliferation and any blood or blubber contaminant measured. Taken together, these data suggest this population of ringed seals is not currently at high risk of altered lymphocyte proliferation from exposure to the POPs or PFASs in this study. - Highlights: • Assess relationships between tissue contaminants and changes in immune function. • Risk for contaminant-induced immunotoxicity in East Greenland ringed seal is low. • Weight of evidence suggest non-coplanar PCBs are immunotoxic at high concentrations.

  7. A multidisciplinary study of Holocene sediment records from Hjort Sø on Store Koldewey, Northeast Greenland

    NARCIS (Netherlands)

    Wagner, B.; Bennike, O.; Bos, J.A.A.; Cremer, H.; Lotter, A.F.; Melles, M.

    2008-01-01

    Two sediment cores of 70 and 252 cm length were recovered from Hjort Sø, a small lake on Store Koldewey, Northeast Greenland, and studied with a multidisciplinary approach in order to reconstruct the local environmental history and to test the relevance of proxies for paleoenvironmental information.

  8. Millennia of magmatism recorded in crustal xenoliths from alkaline provinces in Southwest Greenland

    DEFF Research Database (Denmark)

    Smit, Matthijs; Waight, Tod Earle; Nielsen, Troels

    2016-01-01

    Neoproterozoic alkaline provinces in West Greenland: 1)Sarfartôq, which overlies Archean ultra-depleted SCLM and yielded ultra-deep mineral indicators, and 2)Sisimiut, where the SCLM is refertilized and deep xenoliths (>120km) are lacking. We focused on the rare and understudied crustal xenoliths, which preserve...

  9. Climatic signals in multiple highly resolved stable isotope records from Greenland

    DEFF Research Database (Denmark)

    Vinther, Bo Møllesøe; Dahl-Jensen, Dorthe; Johnsen, Sigfus Johann

    2010-01-01

    are found to correspond better with winter stable isotope data than with summer or annual average stable isotope data it is suggested that a strong local Greenland temperature signal can be extracted from the winter stable isotope data even on centennial to millennial time scales. Udgivelsesdato: Feb....

  10. Ocean tides modulation of flow at Helheim Glacier, East Greenland, observed using GPS

    DEFF Research Database (Denmark)

    de Juan, Julia; Elosegui, P.; Nettles, M.

    Observations at high spatial and temporal resolution could be key for improving our understanding of the physical processes that govern outlet-glacier flow variations. We collected simultaneous high-rate GPS observations at several locations distributed along and across Helheim Glacier, East...

  11. Use and Limitations of a Climate-Quality Data Record to Study Temperature Trends on the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Comiso, Josefino C.; Shuman, Christopher A.; Koenig, Lora S.; DiGirolamo, Nicolo E.

    2011-01-01

    Enhanced melting of the Greenland Ice Sheet has been documented in recent literature along with surface-temperature increases measured using infrared satellite data since 1981. Using a recently-developed climate-quality data record, 11- and 12-year trends in the clear-sky ice-surface temperature (IST) of the Greenland Ice Sheet have been studied using the Moderate-Resolution Imaging Spectroradiometer (MODIS) IST product. Daily and monthly MODIS ISTs of the Greenland Ice Sheet beginning on 1 March 2000 and continuing through 31 December 2010 are now available at 6.25-km spatial resolution on a polar stereographic grid as described in Hall et al. (submitted). This record will be elevated in status to a climate-data record (CDR) when more years of data become available either from the MODIS on the Terra or Aqua satellites, or from the Visible Infrared Imager Radiometer Suite (VIIRS) to be launched in October 2011. Maps showing the maximum extent of melt for the entire ice sheet and for the six major drainage basins have been developed from the MODIS IST dataset. Twelve-year trends of the duration of the melt season on the ice sheet vary in different drainage basins with some basins melting progressively earlier over the course of the study period. Some (but not all) of the basins also show a progressively-longer duration of melt. IST 12-year trends are compared with in-situ data, and climate data from the Modern Era Retrospective-Analysis for Research and Applications (MERRA) Reanalysis.

  12. Limnological controls on stable isotope records of late-holocene palaeoenvironment change in sw greenland: A paired lake study

    DEFF Research Database (Denmark)

    Olsen, Jesper; John Anderson, N.; Leng, M.J.

    2013-01-01

    Stable isotope records are increasingly being used in palaeoenvironmental studies of Arctic lakes. Here we compare stable isotope and elemental records (δ13C, δ15N, C/N) with high resolution XRF-derived geochemical and colour data from low Arctic lakes (SS1220 and SS85) in southwest Greenland. Lake...... SS1220 sediments are laminated gyttja whereas SS85 consist of homogeneous gyttja, both records cover the last c. 5000 years. d13C and carbon content suggest that organic matter in both lakes is predominantly autochthonous. The C/N variability, ranging between 11 and 15, is interpreted...... composition of lake sediments when there is a reasonable understanding of limnological processes, and records may be lake specific....

  13. Late-Holocene environment and climatic changes in Ameralik Fjord, southwest Greenland: evidence from the sedimentary record

    DEFF Research Database (Denmark)

    Møller, Henrik S.; Jensen, Karin G.; Kuijpers, Antoon

    2006-01-01

      Sedimentological and geochemical (XRF) data together with information from diatom and benthic foraminifera records of a 3.5 m long gravity core from Ameralik fjord, southern West Greenland, is used for reconstructing late Holocene environmental changes in this area. The changes are linked...... to large-scale North Atlantic ocean and climate variability. AMS 14C-dating of benthic foraminifera indicates that the sediment core covers the last 4400 years and may include the termination of the Holocene Thermal Maximum (HTM). The late HTM (4.4-3.2 ka BP) is characterized by high accumulation rates...

  14. The Jurassic of Denmark and Greenland: Palynostratigraphy and palaeoenvironments of the Rævekløft, Gule Horn and Ostreaelv Formations (Lower–Middle Jurassic, Neill Klinter Group, Jameson Land, East Greenland

    Directory of Open Access Journals (Sweden)

    Koppelhus, Eva B.

    2003-10-01

    Full Text Available The Neill Klinter Group of Jameson Land, East Greenland contains rich and diverse palynomorph assemblages. Spores, pollen and freshwater algae dominate most of the samples, but dinoflagellatecysts and acritarchs also form important components. The ages suggested by the palynomorphs from the Rævekløft, Gule Horn and Ostreaelv Formations span the period from the Early Pliensbachian to the early Aalenian. The number of palynomorphs identified totals 136,including 83 miospore and 53 microplankton species; they are grouped into seven palynological assemblage zones.In general, there is good agreement between the palynological and sedimentological data, and the palynological data has refined the understanding of the depositional palaeoenvironments ofthe Neill Klinter Group. In some cases, the boundaries of the palynological assemblage zones are congruent with major sequence stratigraphic surfaces and the palynological data thus supportthe sequence stratigraphic interpretation. In other cases, however, regional correlation indicates that the zone boundaries cross important sequence stratigraphic surfaces, such as sequenceboundaries; such behaviour is thought to reflect the facies-dependent nature of certain of the palynological assemblage zones. The pattern of palynological events in East Greenland has alsobeen recognised on the mid-Norwegian shelf.

  15. Synchronizing Greenland ice-core records and the Meerfelder maar sediment record via the global cosmogenic radionuclide signature and insights on climate around 11,230 years BP

    Science.gov (United States)

    Mekhaldi, F.; Czymzik, M.; Brauer, A.; Martin-Puertas, C.; Aldahan, A.; Possnert, G.; Muscheler, R.

    2017-12-01

    The causal investigation of multiple paleoclimate records relies on the accuracy of their respective chronostratigraphy. To achieve relative synchronization, cosmogenic radionuclides are an excellent tool because their common signature is global and can be retrieved and measured in different paleoclimate archives. For instance, 10Be can be measured in both ice cores and lake sediments (Berggren et al., 2013; Czymzik et al., 2016) which allows for both archives to be anchored onto radiocarbon timescales by synchronizing 10Be with 14C. We investigate the period 11,500-11,000 years BP when a short cold climate spell is known, from ice-core proxy records, to have occurred in Greenland shortly after the onset of the Holocene - the Preboreal Oscillation (PBO). This period also coincides with one of the largest and longest-lived increase in 14C production rate during the Holocene, which most likely corresponds to a grand solar minimum (around 11,230-11,000 years BP). In consequence, this period ideally illustrates the potential of using a known and clear signal in the production rate of cosmogenic radionuclides as a synchronizing tool, such as caused by large variations in solar activity. Here we measure 10Be in Meerfelder Maar (a well-dated and widely used sediment record from Germany) around 11,230 years BP which allows us to align the 10Be signal in both the Meerfelder Maar (MFM) sediment record and the GRIP ice core to IntCal13. Doing so, we report that i) the structure of the grand solar minimum is well-preserved in the 10Be signal of MFM sediments, ii) the PBO in Greenland occurs during high levels of solar activity and is not clearly observed in MFM, and iii) the PBO in Greenland ends precisely at the onset of the grand solar minimum at 11,230 years BP which also corresponds to a depositional change in MFM sediments (Martin-Puertas et al., 2017). These results thus suggest that changes in solar activity could have been a forcing at play eventually resulting in the

  16. High Arctic Holocene temperature record from the Agassiz ice cap and Greenland ice sheet evolution.

    Science.gov (United States)

    Lecavalier, Benoit S; Fisher, David A; Milne, Glenn A; Vinther, Bo M; Tarasov, Lev; Huybrechts, Philippe; Lacelle, Denis; Main, Brittany; Zheng, James; Bourgeois, Jocelyne; Dyke, Arthur S

    2017-06-06

    We present a revised and extended high Arctic air temperature reconstruction from a single proxy that spans the past ∼12,000 y (up to 2009 CE). Our reconstruction from the Agassiz ice cap (Ellesmere Island, Canada) indicates an earlier and warmer Holocene thermal maximum with early Holocene temperatures that are 4-5 °C warmer compared with a previous reconstruction, and regularly exceed contemporary values for a period of ∼3,000 y. Our results show that air temperatures in this region are now at their warmest in the past 6,800-7,800 y, and that the recent rate of temperature change is unprecedented over the entire Holocene. The warmer early Holocene inferred from the Agassiz ice core leads to an estimated ∼1 km of ice thinning in northwest Greenland during the early Holocene using the Camp Century ice core. Ice modeling results show that this large thinning is consistent with our air temperature reconstruction. The modeling results also demonstrate the broader significance of the enhanced warming, with a retreat of the northern ice margin behind its present position in the mid Holocene and a ∼25% increase in total Greenland ice sheet mass loss (∼1.4 m sea-level equivalent) during the last deglaciation, both of which have implications for interpreting geodetic measurements of land uplift and gravity changes in northern Greenland.

  17. Evidence of Influence of Human Activities and Volcanic Eruptions on Environmental Perchlorate from a 300-Year Greenland Ice Core Record.

    Science.gov (United States)

    Cole-Dai, Jihong; Peterson, Kari Marie; Kennedy, Joshua Andrew; Cox, Thomas S; Ferris, David G

    2018-06-26

    A 300-year (1700-2007) chronological record of environmental perchlorate, reconstructed from high-resolution analysis of a central Greenland ice core, shows that perchlorate levels in the post-1980 atmosphere were two-to-three times those of the pre-1980 environment. While this confirms recent reports of increased perchlorate in Arctic snow since 1980 compared with the levels for the prior decades (1930-1980), the longer Greenland record demonstrates that the Industrial Revolution and other human activities, which emitted large quantities of pollutants and contaminants, did not significantly impact environmental perchlorate, as perchlorate levels remained stable throughout the eighteenth, nineteenth, and much of the twentieth centuries. The increased levels since 1980 likely result from enhanced atmospheric perchlorate production, rather than from direct release from perchlorate manufacturing and applications. The enhancement is probably influenced by the emission of organic chlorine compounds in the last several decades. Prior to 1980, no significant long-term temporal trends in perchlorate concentration are observed. Brief (a few years) high concentration episodes appear frequently over an apparently stable and low background (~1 ng kg‒1). Several such episodes coincide in time with large explosive volcanic eruptions including the 1912 Novarupta/Katmai eruption in Alaska. It appears that atmospheric perchlorate production is impacted by large eruptions in both high and low latitudes, but not by small eruptions and non-explosive degassing.

  18. Validation of a Climate-Data Record of the "Clear-Sky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Box, Jason E.; Koenig, Lora S.; DiGirolamo, Nicolo E.; Comiso, Josefino C.; Shuman, Christopher A.

    2011-01-01

    Surface temperatures on the Greenland Ice Sheet have been studied on the ground, using automatic weather station (AWS) data from the Greenland-Climate Network (GC-Net), and from analysis of satellite sensor data. Using Advanced Very High Frequency Radiometer (AVHRR) weekly surface temperature maps, warming of the surface of the Greenland Ice Sheet has been documented since 1981. We extended and refined this record using higher-resolution Moderate-Resolution Imaging Spectroradiometer (MODIS) data from March 2000 to the present. We developed a daily and monthly climate-data record (CDR) of the "clear-sky" surface temperature of the Greenland Ice Sheet using an ice-surface temperature (1ST) algorithm developed for use with MODIS data. Validation of this CDR is ongoing. MODIS Terra swath data are projected onto a polar stereographic grid at 6.25-km resolution to develop binary, gridded daily and mean-monthly 1ST maps. Each monthly map also has a color-coded image map that is available to download. Also included with the monthly maps is an accompanying map showing number of days in the month that were used to calculate the mean-monthly 1ST. This is important because no 1ST decision is made by the algorithm for cells that are considered cloudy by the internal cloud mask, so a sufficient number of days must be available to produce a mean 1ST for each grid cell. Validation of the CDR consists of several facets: 1) comparisons between ISTs and in-situ measurements; 2) comparisons between ISTs and AWS data; and 3) comparisons of ISTs with surface temperatures derived from other satellite instruments such as the Thermal Emission and Reflection Radiometer (ASTER) and Enhanced Thematic Mapper Plus (ETM+). Previous work shows that Terra MODIS ISTs are about 3 C lower than in-situ temperatures measured at Summit Camp, during the winter of 2008-09 under clear skies. In this work we begin to compare surface temperatures derived from AWS data with ISTs from the MODIS CDR.

  19. Decade-centenary resolution records of climate changes in East Siberia from elements in the bottom sediments of lake Baikal for the last 150 kyr

    International Nuclear Information System (INIS)

    Goldberg, E.L.; Phedorin, M.A.; Chebykin, E.P.; Zolotarev, K.B; Zhuchenko, N.A.

    2007-01-01

    High-resolution scanning Synchrotron Radiation X-ray Fluorescence Analysis (SRXFA) was applied to investigate the downcore distribution of elements in the sediments from Lake Baikal (East Siberia). The obtained multi-element time series reveal the presence of abrupt climate shifts in East Siberia which were synchronous with the abrupt warming events in the North Atlantic and Greenland (Dansgaard-Oeschges events (D/O) during the last ice age 24-75 kyr BP. We show here the set of climatic indicators reveals all globally known climate changes from dry and cool or glacial climates to humid and warm ones, which were recorded in Northern Atlantic and East Siberia both on the orbital and millennial time scales during the last 150 kyr

  20. Decade-centenary resolution records of climate changes in East Siberia from elements in the bottom sediments of lake Baikal for the last 150 kyr

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, E.L. [Limnological Institute of the SB RAS, 664033 Irkutsk (Russian Federation)]. E-mail: gold@econova.nsk.su; Phedorin, M.A. [Limnological Institute of the SB RAS, 664033 Irkutsk (Russian Federation); Chebykin, E.P. [Limnological Institute of the SB RAS, 664033 Irkutsk (Russian Federation); Zolotarev, K.B [Budker Institute of Nuclear Physics of SB RAS, Lavrentyev prospect -11, 630090 Novosibirsk (Russian Federation); Zhuchenko, N.A. [Limnological Institute of the SB RAS, 664033 Irkutsk (Russian Federation)

    2007-05-21

    High-resolution scanning Synchrotron Radiation X-ray Fluorescence Analysis (SRXFA) was applied to investigate the downcore distribution of elements in the sediments from Lake Baikal (East Siberia). The obtained multi-element time series reveal the presence of abrupt climate shifts in East Siberia which were synchronous with the abrupt warming events in the North Atlantic and Greenland (Dansgaard-Oeschges events (D/O) during the last ice age 24-75 kyr BP. We show here the set of climatic indicators reveals all globally known climate changes from dry and cool or glacial climates to humid and warm ones, which were recorded in Northern Atlantic and East Siberia both on the orbital and millennial time scales during the last 150 kyr.

  1. Immunomodulatory effects of exposure to polychlorinated biphenyls and perfluoroalkyl acids in East Greenland ringed seals (Pusa hispida)

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Milton, E-mail: Milton.levin@uconn.edu [Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269-3089 (United States); Gebhard, Erika; Jasperse, Lindsay [Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269-3089 (United States); Desforges, Jean-Pierre; Dietz, Rune; Sonne, Christian; Eulaers, Igor [Department of Bioscience, Arctic Research Centre (ARC), Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde (Denmark); Covaci, Adrian [Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, BE-2610 Wilrijk (Belgium); Bossi, Rossana [Department of Environmental Science, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde (Denmark); De Guise, Sylvain [Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269-3089 (United States)

    2016-11-15

    To better elucidate the potential immune-related health effects of exposure to environmentally persistent organic pollutants (POP), such as polychlorinated biphenyls (PCBs) and perfluoroalkyl substances (PFASs), in ringed seals (Pusa hispida), a sentinel Arctic species, we assessed 1) associations between mitogen-induced lymphocyte proliferation and in vivo tissue contaminant burdens, and 2) the concentration-response effects of in vitro exposure to PFASs and PCB congeners on mitogen-induced lymphocyte proliferation. Upon in vitro contaminant exposure, the non-coplanar PCB congeners CB 138, 153, and 180, but not the coplanar CB 169, significantly reduced lymphocyte proliferation between 10 and 20 µg g{sup −1} ww. The respective in vitro EC{sub 50} values for these congeners were 13.3, 20.7, 20.8, and 54.6 µg g{sup −1} ww. No modulation of lymphocyte proliferation was observed upon in vitro exposure to two individual PFASs, perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA), at concentrations up to 1000 ng g-1. In addition, no significant correlations were found between lymphocyte proliferation and any blood or blubber contaminant measured. Taken together, these data suggest this population of ringed seals is not currently at high risk of altered lymphocyte proliferation from exposure to the POPs or PFASs in this study. - Highlights: • Assess relationships between tissue contaminants and changes in immune function. • Risk for contaminant-induced immunotoxicity in East Greenland ringed seal is low. • Weight of evidence suggest non-coplanar PCBs are immunotoxic at high concentrations.

  2. Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling.

    Science.gov (United States)

    Sonne, Christian; Gustavson, Kim; Rigét, Frank F; Dietz, Rune; Birkved, Morten; Letcher, Robert J; Bossi, Rossana; Vorkamp, Katrin; Born, Erik W; Petersen, Gitte

    2009-12-01

    Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990-2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p'-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79-1271 ng g(-1) lw) and PCBs (range: 4128-53,923 ng g(-1) lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs > or = 1). Similar results were found for PCBs (range: 1928-17,376 ng g(-1) lw) and PFOS (range: 104-2840 ng g(-1) ww) in the year 2000 and for dieldrin (range: 43-640 ng g(-1) lw), PCBs (range: 3491-13,243 ng g(-1) lw) and PFOS (range: 1332-6160 ng g(-1) ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQspolar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife.

  3. Measuring environmental stress in East Greenland polar bears, 1892-1927 and 1988-2009: what does hair cortisol tell us?

    Science.gov (United States)

    Bechshøft, T Ø; Rigét, F F; Sonne, C; Letcher, R J; Muir, D C G; Novak, M A; Henchey, E; Meyer, J S; Eulaers, I; Jaspers, V L B; Eens, M; Covaci, A; Dietz, R

    2012-09-15

    Hair sampled from 96 East Greenland polar bears (Ursus maritimus) over the periods 1892-1927 and 1988-2009 was analyzed for cortisol as a proxy to investigate temporal patterns of environmental stress. Cortisol concentration was independent of sex and age, and was found at significantly higher (ppolar bear hair appears to be a relatively poor indicator of the animal's general POP load in adipose tissue. However, further investigations are warranted to explore the reasons for the temporal decrease found in the bears' hair cortisol levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. The endocrine disruption properties of an adipose contaminant mixture extracted from East Greenland polar bears studied in the H295R cell line

    DEFF Research Database (Denmark)

    Hjorth, R.; Letcher, R. J.; Blair, D.

    been well described and especially the polar bear (Ursus maritimus) is recognized as being one of the most contaminated species in the Arctic. The present study investigated the in vitro endocrine disruptive effects of the POP mixture found in adipose tissue from 10 East Greenland polar bears collected...... (dehydroepiandrosterone and androstenedione). These results demonstrated comprehensive in vitro effects of POPs extracted from polar bear adipose tissue on key elements in the steroidogenesis, and identifies disruption of CYP17 activity as a mode of action. A POP-induced interference with CYP17 can potentially explain...... previously observed hormone levels in polar bears and could pose a risk to their reproductive health....

  5. The Aucellaelv stade at Aucellaelv, the first Weichselian glacier advance in Scoresby Sund, East Greenland

    DEFF Research Database (Denmark)

    Israelson, Carsten; Funder, Svend Visby; Kelly, Michael

    1994-01-01

    of the Aucellaelv. Jameson Land, which contain a scquence of shallow marine, fluvial and glacigene sediments extending from the Scoresby Sund glaciation (Saalian) to the Flakkerhuk stade (Late Weichselian). The sequence is dated by palaeoceanographic correlation with the deep-sea record, U/Th and luminescence...

  6. Holocene stratigraphy and vegetation history in the Scoresby Sund area, East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1978-01-01

    The Holocene stratigraphy in Scoresby Sund is based on climatic change as reflected by fluctuations in fjord and valley glaciers, immigration and extinction of marine molluscs, and the vegetation history recorded in pollen diagrams from five lakes. The histories are dated by C-14, and indirectly...

  7. A 40-year record of Northern Hemisphere atmospheric carbon monoxide concentration and isotope ratios from the firn at Greenland Summit.

    Science.gov (United States)

    Place, P., Jr.; Petrenko, V. V.; Vimont, I.; Buizert, C.; Lang, P. M.; Edwards, J.; Harth, C. M.; Hmiel, B.; Mak, J. E.; Novelli, P. C.; Brook, E.; Weiss, R. F.; Vaughn, B. H.; White, J. W. C.

    2014-12-01

    Carbon Monoxide (CO) is an important atmospheric trace gas that affects the oxidative capacity of the atmosphere and contributes indirectly to climate forcing by being a major sink of tropospheric OH. A good understanding of the past atmospheric CO budget is therefore important for climate models attempting to characterize recent changes in the atmosphere. Previous work at NEEM, Greenland provided the first reconstructions of Arctic atmospheric history of CO concentration and stable isotope ratios (δC18O and δ13CO) from firn air, dating to the 1950s. In this new study, firn air was sampled from eighteen depth levels through the firn column at Summit, Greenland (in May 2013), yielding a second, independent record of Arctic CO concentration and isotopic ratios. Carbon monoxide stable isotope ratios were analyzed on replicate samples and using a newly developed system with improved precision allowing for a more robust reconstruction. The new CO concentration and stable isotope results overall confirm the earlier findings from NEEM, with a CO concentration peak around the 1970s and higher δC18O and δ13CO values associated with peak CO. Modeling and interpretation of the data are in progress.

  8. Late-Holocene environment and climatic changes in Ameralik Fjord, southwest Greenland: evidence from the sedimentary record

    DEFF Research Database (Denmark)

    Møller, Henrik S.; Jensen, Karin G.; Kuijpers, Antoon

    2006-01-01

      Sedimentological and geochemical (XRF) data together with information from diatom and benthic foraminifera records of a 3.5 m long gravity core from Ameralik fjord, southern West Greenland, is used for reconstructing late Holocene environmental changes in this area. The changes are linked...... to large-scale North Atlantic ocean and climate variability. AMS 14C-dating of benthic foraminifera indicates that the sediment core covers the last 4400 years and may include the termination of the Holocene Thermal Maximum (HTM). The late HTM (4.4-3.2 ka BP) is characterized by high accumulation rates...... conditions were further characterised by limited sea ice probably related to a mild and relatively windy winter climate. After 3.2 ka BP lower fine-grained sedimentation rates, but a larger input from sea-ice rafted or aeolian coarse material prevailed. This can be related to colder atmospheric conditions...

  9. Polyhalogenated compounds (PCBs, chlordanes, HCB and BFRs) in four polar bears (Ursus maritimus) that swam malnourished from East Greenland to Iceland.

    Science.gov (United States)

    Vetter, Walter; Gall, Vanessa; Skírnisson, Karl

    2015-11-15

    Levels of organohalogen compounds (PCBs, chlordane, PBB 153, PBDEs, HCB) were determined in adipose tissue, liver, kidney and muscle of four polar bears which swam and/or drifted to Iceland in extremely malnourished condition. Since the colonization in the 9th century polar bears have been repeatedly observed in Iceland. However, in recent years three of the animals have clearly left their natural habitat in poor condition in May or June, i.e. at the end of the major feeding season. The fourth bear is believed to have drifted with melting ice to North-Eastern Iceland in mid-winter. The concentrations of the POPs were within the range or higher than the typical concentrations measured in polar bears from the East Greenland population. In addition to the targeted compounds, we tentatively detected Dechlorane 602 and its potential hydrodechlorinated Cl11-metabolite in all samples. Moreover, a polychlorinated compound which partly co-eluted with PCB 209 was detected in all liver samples but not in adipose tissue, kidney or muscle. The mass spectrum of the potential metabolite did not allow determining its structure. Polar bears are good swimmers and can reach Iceland from the ice edge of East Greenland within a few days. Potential reasons for the swims are briefly discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Source apportionment of particles at Station Nord, North East Greenland during 2008–2010 using COPREM and PMF analysis

    Directory of Open Access Journals (Sweden)

    Q. T. Nguyen

    2013-01-01

    Full Text Available In order to develop strategies for controlling and reducing Arctic air pollution, there is a need to understand the basic mechanisms for determining the fate of air pollution in the Arctic. Sources of atmospheric particles at Station Nord (81° 36' N, 16° 40' W in North East Greenland were evaluated for a two-year period from March 2008 to February 2010. Source apportionment using Positive Matrix Factorization (PMF and COnstrained Physical REceptor Model (COPREM was based on measurements of black carbon, elements (Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr, Pb and inorganic ions (SO2, SO42−, Na+, NH4+, NO3, Cl2−. In general, source apportionment results by PMF and COPREM showed good agreement. Five sources adequately explained the measurements, which included a Marine and a Soil source of natural origin and three additional anthropogenic sources, which were all influenced by metal industries. One anthropogenic source was dominated by Zn of which air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT model suggested a Canadian Arctic origin, despite certain influences from Southern and Eastern origins. Another anthropogenic source was characterised by high concentrations of Pb and As, which has been historically referred to as a Combustion source at Station Nord. The impacts of large-scale industry in Siberia, Russia were evident through high Cu concentrations in both the Combustion source and an additional Cu/Ni source.

    Br correlated well with the anthropogenic species S and Pb though the elements are unlikely to have a common origin. More likely, sulphuric acid aerosols serve as transport containers for Br species of marine origin. Of particular relevance to climate, sources of black carbon were identified to be

  11. Global change effects on the long-term feeding ecology and contaminant exposures of East Greenland polar bears.

    Science.gov (United States)

    McKinney, Melissa A; Iverson, Sara J; Fisk, Aaron T; Sonne, Christian; Rigét, Frank F; Letcher, Robert J; Arts, Michael T; Born, Erik W; Rosing-Asvid, Aqqalu; Dietz, Rune

    2013-08-01

    Rapid climate changes are occurring in the Arctic, with substantial repercussions for arctic ecosystems. It is challenging to assess ecosystem changes in remote polar environments, but one successful approach has entailed monitoring the diets of upper trophic level consumers. Quantitative fatty acid signature analysis (QFASA) and fatty acid carbon isotope (δ(13) C-FA) patterns were used to assess diets of East Greenland (EG) polar bears (Ursus maritimus) (n = 310) over the past three decades. QFASA-generated diet estimates indicated that, on average, EG bears mainly consumed arctic ringed seals (47.5 ± 2.1%), migratory subarctic harp (30.6 ± 1.5%) and hooded (16.7 ± 1.3%) seals and rarely, if ever, consumed bearded seals, narwhals or walruses. Ringed seal consumption declined by 14%/decade over 28 years (90.1 ± 2.5% in 1984 to 33.9 ± 11.1% in 2011). Hooded seal consumption increased by 9.5%/decade (0.0 ± 0.0% in 1984 to 25.9 ± 9.1% in 2011). This increase may include harp seal, since hooded and harp seal FA signatures were not as well differentiated relative to other prey species. Declining δ(13) C-FA ratios supported shifts from more nearshore/benthic/ice-associated prey to more offshore/pelagic/open-water-associated prey, consistent with diet estimates. Increased hooded seal and decreased ringed seal consumption occurred during years when the North Atlantic Oscillation (NAO) was lower. Thus, periods with warmer temperatures and less sea ice were associated with more subarctic and less arctic seal species consumption. These changes in the relative abundance, accessibility, or distribution of arctic and subarctic marine mammals may have health consequences for EG polar bears. For example, the diet change resulted in consistently slower temporal declines in adipose levels of legacy persistent organic pollutants, as the subarctic seals have higher contaminant burdens than arctic seals. Overall, considerable changes are occurring in the EG

  12. Holocene stratigraphy and vegetation history in the Scoresby Sund area, East Greenland

    International Nuclear Information System (INIS)

    Funder, S.

    1978-01-01

    The Holocene stratigraphy in Scoresby Sund is based on climatic change reflected by fluctuations in fjord and valley glaciers, immigration and extinction of marine molluscs, and the vegetation history recorded in pollen diagrams from five lakes. The histories are dated by C-14, and indirectly by emergence curves showing the patterns of isostatic uplift. From c. 10100-10400 to 9400 yr BP the major fjord glaciers showed oscillatory retreat with abundant moraine formation, the period of the Milne Land Moraines. The vegetation in the ice free areas was a sparse type of fell field vetetation but with thermophilous elements indicating temperatures similar to the present. From 9400 yr BP the fjord glaciers retreated rapidly in the narrow fjords, the few moraines formed are referred to the Roedefjord stages and indicate topographically conditioned stillstands. At 8000 yr BP the low arctic Betula nana imigrated into the area, and in the period until 5000 yr BP dense dwarf shrub heat grew in areas where it is now absent. In the fjords the subarctic Mytilus edulis and Pecten islandia lived, suggesting a climate warmer than the present. From c. 5000 yr BP the dense dwarf shrub heath began to disappear in the coastal areas, and a ''poor'' heat dominated by the high arctic Salix Arctica and Cassiope tetragona expanded. These two species, which are now extremely common, apparently did not grow in the area until c. 6000 yr BP. In lakes in the coastal area minerogenic sedimentation at c. 2800 yr BP, reflecting the general climatic deterioration. (author)

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

    DEFF Research Database (Denmark)

    Újvári, Gábor; Stevens, Thomas; Molnár, Mihály

    2017-01-01

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

  14. Ice stratigraphy at the Pakitsoq ice margin, West Greenland, derived from gas records

    DEFF Research Database (Denmark)

    Schaefer, H.; Petrenko, V. V.; Brook, E. J.

    2009-01-01

    at Pakitsoq. Sections containing ice from every distinct climatic interval during Termination I, including Last Glacial Maximum, Bolling/Allerod, Younger Dryas and the early Holocene, are identified. In the early Holocene, we find evidence for climatic fluctuations similar to signals found in deep ice cores...... from Greenland. A second glacial-interglacial transition exposed at the extreme margin of the ice is identified as another outcrop of Termination I (rather than the onset of the Eemian interglacial as postulated in earlier work). Consequently, the main structural feature at Pakitsoq is a large......-scale anticline with accordion-type folding in both exposed sequences of the glacial-Holocene transition, leading to multiple layer duplications and age reversals....

  15. Falsifying the Sikussak-Oasis Hypothesis for the Tillite Group, East Greenland: Implications for Trezona-like Carbon Isotope Excursions Beneath Neoproterozoic Glacials

    Science.gov (United States)

    Hoffman, P. F.; Domack, E. W.; Maloof, A. C.; Halverson, G. P.

    2006-05-01

    In Neoproterozoic time, East Greenland and East Svalbard (EGES) occupied landward and seaward positions, respectively, on the southern subtropical margin of Laurentia. In both areas, thick clastic-to-carbonate successions are overlain by two discrete glacial and/or periglacial formations, separated by fine basinal clastics. In Svalbard, the younger glacial has a characteristic Marinoan (basal Ediacaran) cap dolostone, but the older glacial is underlain by a 10-permil negative carbon isotope excursion that is indistinguishable from excursions observed exclusively beneath Marinoan glacials in Australia, Namibia and western Laurentia. This led us to propose (Basin Research 16, 297-324, 2004) that the paired glacials in EGES represent the onset and climax of a single, long-lived, Marinoan glaciation. The intervening fine clastics, which contain ikaite pseudomorphs, presumptively accumulated beneath permanent shorefast sea ice (sikussak), analogous to East Greenland fjords during the Younger Dryas and Little Ice Age. In this model, the top of the older glacial signals the start of Snowball Earth. We conducted a preliminary field test of the sikussak hypothesis in Strindberg Land (SL), Andrée Land (AL) and Ella O (EO), East Greenland. We confirmed the correlation of the paired glacials and the Marinoan cap dolostone (missing on EO). In SL, the older glacial (Ulveso Fm) is a thin diamictite overlain by conglomerate lag and a set of megavarves composed of alternating siltstone and ice-rafted debris. In AL and EO, the Ulveso is a sub-glacial diamictite overlain by aeolian and/or marine sandstone. In Bastion Bugt on EO, it is a transgressive shoreface sandstone. This proves that glacial recession occurred under open-water conditions and did not result from permanent sea-ice formation, as stipulated in the sikussak model. There is no evidence that the fine clastic sequence between the glacials formed under an ice cover, or for a single glacial period. This brings us back to

  16. A Climate-Data Record (CDR) of the "Clear-Sky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Comiso, Josefino C.; DiGirolamo, Nocolo E.; Shuman, Christopher A.

    2011-01-01

    We have developed a climate-data record (CDR) of "clear-sky" ice-surface temperature (IST) of the Greenland Ice Sheet using Moderate-Resolution Imaging Spectroradiometer (MODIS) data. The CDR provides daily and monthly-mean IST from March 2000 through December 2010 on a polar stereographic projection at a resolution of 6.25 km. The CDR is amenable to extension into the future using Visible/Infrared Imager Radiometer Suite (VIIRS) data. Regional "clear-sky" surface temperature increases since the early 1980s in the Arctic, measured using Advanced Very High Resolution Radiometer (AVHRR) infrared data, range from 0.57 +/- 0.02 to 0.72 +/- 0.1 c per decade. Arctic warming has important implications for ice-sheet mass balance because much of the periphery of the Greenland Ice Sheet is already near O C during the melt season, and is thus vulnerable to rapid melting if temperatures continue to increase. An increase in melting of the ice sheet would accelerate sea-level rise, an issue affecting potentially billions of people worldwide. The IST CDR will provide a convenient data set for modelers and for climatologists to track changes of the surface temperature of the ice sheet as a whole and of the individual drainage basins on the ice sheet. The daily and monthly maps will provide information on surface melt as well as "clear-sky" temperature. The CDR will be further validated by comparing results with automatic-weather station data and with satellite-derived surface-temperature products.

  17. A Climate-Data Record (CDR) of the "Clear Sky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Comiso, J. C.; DiGirolamo, N. E.; Shuman, C. A.

    2011-01-01

    To quantify the ice-surface temperature (IST) we are developing a climate-data record (CDR) of monthly IST of the Greenland ice sheet, from 1982 to the present using Advanced Very High Resolution Radiometer (AVHRR) and Moderate-Resolution Imaging Spectroradiometer (MODIS) data at 5-km resolution. "Clear-sky" surface temperature increases have been measured from the early 1980s to the early 2000s in the Arctic using AVHRR data, showing increases ranging from 0.57-0.02 (Wang and Key, 2005) to 0.72 0.10 deg C per decade (Comiso, 2006). Arctic warming has implications for ice-sheet mass balance because much of the periphery of the ice sheet is near 0 deg C in the melt season and is thus vulnerable to more extensive melting (Hanna et al., 2008). The algorithm used for this work has a long history of measuring IST in the Arctic with AVHRR (Key and Haefliger, 1992). The data are currently available from 1981 to 2004 in the AVHRR Polar Pathfinder (APP) dataset (Fowler et al., 2000). J. Key1NOAA modified the AVHRR algorithm for use with MODIS (Hall et al., 2004). The MODIS algorithm is now being processed over Greenland. Issues being addressed in the production of the CDR are: time-series bias caused by cloud cover, and cross-calibration between AVHRR and MODIS instruments. Because of uncertainties, time series of satellite ISTs do not necessarily correspond with actual surface temperatures. The CDR will be validated by comparing results with in-situ (see Koenig and Hall, in press) and automatic-weather station data (e.g., Shuman et al., 2001).

  18. Lipid Biomarker Records Across the Permian-Triassic Boundary from Kap Stosch, Greenland

    Science.gov (United States)

    Hays, L. E.; Love, G. D.; Foster, C. B.; Grice, K.; Summons, R. E.

    2006-12-01

    The end-Permian extinction was the most severe in the past 500 million years of the Earth's history and evidence that an oceanic anoxic event (OAE) occurred contemporaneously has been presented previously [1,2]. OAEs have, therefore, been proposed as responsible for the mass mortality, and if the anoxic ocean was also euxinic, the release of hydrogen sulfide during upwelling and/or transgression provides an extinction agent in the ocean as well as on land. Chlorobiaceae, as indicators of photic zone euxinia (PZE), utilize hydrogen sulfide as an electron donor for anoxygenic photosynthesis. The detection of isorenieratane and a series of short-chain monoaromatic aryl isoprenoids, biomarkers for Chlorobiaceae, in sediments indicates the presence of hydrogen sulfide in the photic zone of the water column during sediment deposition. The Kap Stosch area in Eastern Greenland was identified as a Permian-Triassic boundary (PTB) outcrop of homogeneous shale, silty shale, and siltstone facies [3]. Another late Permian section in Eastern Greenland, the Ravnefjeld Formation, has framboidal pyrites indicative of sulfidic deep water [4]. A sample suite from the Kap Stosch region was studied using standard organic geochemistry methods including stable isotopic analyses of organic carbon, Rock-Eval pyrolysis, and biomarker hydrocarbon analysis. Aryl isoprenoids, including isorenieratane, were present in all samples studied and the concentrations were observed to fluctuate in tandem with TOC, similar to other Mesozoic OAEs. The molecular ratios of pristane/phytane and hopanes/steranes as well as the 2-methyl-hopane index (2-MHI) fluctuated dramatically through this section as they do at the type section at Meishan and in the Perth Basin [5]. The 2-MHI shows an inverse pattern to the total aryl isoprenoids, perhaps indicative of instability in the form of primary productivity in the water column during euxinic episodes. This can result in nitrogen limitation and a competitive

  19. Bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from East Greenland.

    Science.gov (United States)

    Letcher, Robert J; Gebbink, Wouter A; Sonne, Christian; Born, Erik W; McKinney, Melissa A; Dietz, Rune

    2009-11-01

    We report on the comparative bioaccumulation, biotransformation and/or biomagnification from East Greenland ringed seal (Pusa hispida) blubber to polar bear (Ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (PCBs), chlordanes (CHLs), hydroxyl (OH-) and methylsulfonyl (MeSO(2)-) PCBs, polybrominated biphenyls (PBBs), OH-PBBs, polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants and OH- and methoxyl (MeO-) PBDEs, 2,2-dichloro-bis(4-chlorophenyl)ethene (p,p'-DDE), 3-MeSO(2)-p,p'-DDE, pentachlorophenol (PCP) and 4-OH-heptachlorostyrene (4-OH-HpCS). We detected all of the investigated contaminants in ringed seal blubber with high frequency, the main diet of East Greenland bears, with the exception of OH-PCBs and 4-OH-HpCS, which indicated that these phenolic contaminants were likely of metabolic origin and formed in the bears from accumulated PCBs and octachlorostyrene (OCS), respectively, rather than being bioaccumulated from a seal blubber diet. For all of the detectable sum of classes or individual organohalogens, in general, the ringed seal to polar bear mean BMFs for SigmaPCBs, p,p'-DDE, SigmaCHLs, SigmaMeSO(2)-PCBs, 3-MeSO(2)-p,p'-DDE, PCP, SigmaPBDEs, total-(alpha)-HBCD, SigmaOH-PBDEs, SigmaMeO-PBDEs and SigmaOH-PBBs indicated that these organohalogens bioaccumulate, and in some cases there was tissue-specific biomagnification, e.g., BMFs for bear adipose and liver ranged from 2 to 570. The blood-brain barrier appeared to be effective in minimizing brain accumulation as BMFs were bear tissues appeared to be mainly accumulated from the seal blubber rather than being metabolic formed from PBDEs in the bears. In vitro PBDE depletion assays using polar bear hepatic microsomes, wherein the rate of oxidative metabolism of PBDE congeners was very slow, supported the probability that accumulation

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

    Science.gov (United States)

    Shulgin, Alexey; Thybo, Hans; Field Team TopoGreenland

    2013-04-01

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

  1. Vitamins A and E in liver, kidney, and whole blood of East Greenland polar bears sampled 1994–2008: reference values and temporal trends

    DEFF Research Database (Denmark)

    Bechshoft, T.; Sonne, C.; Jakobsen, Jette

    2015-01-01

    on this health issue in polar bears (Ursus maritimus). The aim of this study was thus to provide reference values for concentrations of vitamin A in liver, kidney cortex, and whole blood and vitamin E in kidney cortex and whole blood from 166 East Greenland polar bears, as well as to assess the relationship...... that POPs could be disrupting polar bear vitamin status. However, while the observed temporal increases in vitamin concentrations were likely POP related, the question remains as to whether they stem from influence of contaminants only or also, e.g., changes in prey species. Further studies are needed...... between POPs and vitamin concentrations. In addition, vitamin concentrations were analyzed for temporal trends (1994–2008). Results showed vitamin A in liver to be higher in adult bears and the concentrations of vitamin E in kidney and blood to likewise be generally higher in adult bears. In addition, all...

  2. Persistent organic pollutants and penile bone mineral density in East Greenland and Canadian polar bears (Ursus maritimus) during 1996-2015.

    Science.gov (United States)

    Daugaard-Petersen, Tobias; Langebæk, Rikke; Rigét, Frank F; Dyck, Markus; Letcher, Robert J; Hyldstrup, Lars; Jensen, Jens-Erik Bech; Dietz, Rune; Sonne, Christian

    2018-05-01

    Persistent organic pollutants (POPs) are long-range transported to the Arctic via atmospheric and oceanic currents, where they biomagnify to high concentrations in the tissues of apex predators such as polar bears (Ursus maritimus). A major concern of POP exposure is their physiological effects on vital organ-tissues posing a threat to the health and survival of polar bears. Here we examined the relationship between selected POPs and baculum bone mineral density (BMD) in the East Greenland and seven Canadian subpopulations of polar bears. BMD was examined in 471 bacula collected between years 1996-2015 while POP concentrations in adipose tissue were determined in 67-192 of these individuals collected from 1999 to -2015. A geographical comparison showed that baculum BMD was significantly lowest in polar bears from East Greenland (EG) when compared to Gulf of Boothia (GB), Southern Hudson (SH) and Western Hudson (WH) Bay subpopulations (all p bears as a reference group gave a T-score of -1.44 which indicate risk of osteopenia. Concentrations of ΣPCB 74 (polychlorinated biphenyls), ΣDDT 3 (dichlorodiphenyltrichloroethanes), p,p'-DDE (dichlorodiphenyldichloroethylene), ΣHCH 3 (hexachlorohexane) and α-HCH was significantly highest in EG bears while ΣPBDE (polybrominated diphenyl ethers), BDE-47 and BDE-153 was significantly highest in SH bears (all p polar bears despite the positive statistical correlations of BMD vs. POPs. Other important factors such as nutritional status, body mass and body condition was not available for the statistical modelling. Since on-going environmental changes are known to affect these, future studies need to incorporate nutritional, endocrine and genetic parameters to further understand how POP exposure may disrupt bone homeostasis and affect baculum BMD across polar bear subpopulations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Organophosphate esters in East Greenland polar bears and ringed seals: Adipose tissue concentrations and in vitro depletion and metabolite formation.

    Science.gov (United States)

    Strobel, Adelle; Willmore, William G; Sonne, Christian; Dietz, Rune; Letcher, Robert J

    2018-04-01

    East Greenland is a contamination "hot spot" for long-range transported anthropogenic chemicals, including organophosphate esters (OPEs). High concentrations of OPEs have been reported in arctic air while very little is known for wildlife where OPE tissue residues levels appear to be strongly influenced by biotransformation. In the present study, the hepatic in vitro metabolism of six environmentally relevant organophosphate (OP) triesters and corresponding OP diester formation were investigated in East Greenland polar bears (PBs) and ringed seals (RSs). The in vitro metabolism assay results were compared to adipose levels in field samples from the same individuals. In vitro OP triester metabolism was generally rapid and structure-dependent, where PBs metabolized OPEs more rapidly than RSs. Exceptions were the lack of triethyl phosphate (TEP) metabolism and slow metabolism of tris(2-ethylhexyl) phosphate (TEHP) in both species. OP diester metabolites were also formed with the exception of TEP which was not metabolized at all. Tris(1,3-dichloro-2-propyl) phosphate was completely converted to its corresponding diester. However, the mass balances showed that OP diester formation corresponding to TEHP, tri(n-butyl) phosphate, and tris(2-butyoxyethyl) phosphate did not account for 100% of the OP triester depletion, which indicated alternate pathways of OP triester metabolism had occurred. Triphenyl phosphate was completely converted to its OP diester metabolite in PBs but not in RSs suggesting species-specific differences. The results demonstrated that OP triester bioaccumulation and fate in PBs versus their RS prey is substantially influenced by biotransformation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. 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...

  5. Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity.

    Science.gov (United States)

    McConnell, Joseph R; Wilson, Andrew I; Stohl, Andreas; Arienzo, Monica M; Chellman, Nathan J; Eckhardt, Sabine; Thompson, Elisabeth M; Pollard, A Mark; Steffensen, Jørgen Peder

    2018-05-29

    Lead pollution in Arctic ice reflects midlatitude emissions from ancient lead-silver mining and smelting. The few reported measurements have been extrapolated to infer the performance of ancient economies, including comparisons of economic productivity and growth during the Roman Republican and Imperial periods. These studies were based on sparse sampling and inaccurate dating, limiting understanding of trends and specific linkages. Here we show, using a precisely dated record of estimated lead emissions between 1100 BCE and 800 CE derived from subannually resolved measurements in Greenland ice and detailed atmospheric transport modeling, that annual European lead emissions closely varied with historical events, including imperial expansion, wars, and major plagues. Emissions rose coeval with Phoenician expansion, accelerated during expanded Carthaginian and Roman mining primarily in the Iberian Peninsula, and reached a maximum under the Roman Empire. Emissions fluctuated synchronously with wars and political instability particularly during the Roman Republic, and plunged coincident with two major plagues in the second and third centuries, remaining low for >500 years. Bullion in silver coinage declined in parallel, reflecting the importance of lead-silver mining in ancient economies. Our results indicate sustained economic growth during the first two centuries of the Roman Empire, terminated by the second-century Antonine plague.

  6. Records: East African Rarities Committee report and change of remit ...

    African Journals Online (AJOL)

    Scopus: Journal of East African Ornithology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 29 (2009) >. Log in or Register to get access to full text downloads.

  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......), atmospheric and sea-surface temperatures are reaching levels last encountered millennia ago when northern high latitude summer insolation was higher due to a different orbital configuration. Concurrently, records from lake sediments in southern Greenland document major environmental and climatic conditions...... regional climate and ice sheet dynamics. The magnitude and rate of future changes in Greenland temperature, in response to increasing greenhouse gas emissions, may be faster than any past abrupt events occurring under interglacial conditions. Projections indicate that within one century Greenland may...

  8. Using Classroom Recordings in Educational History Research. An East German Civics Lesson

    Science.gov (United States)

    Jehle, May; Blessing, Benita

    2014-01-01

    Students learned in civics lessons in the German Democratic Republic (GDR, or East Germany) that their socialist society uniquely guaranteed all individuals the right to work, and that, as good socialists, they had the duty to take on socially meaningful work. Using the example of a video recording of an East German civics lesson and its…

  9. A Satellite-Derived Climate-Quality Data Record of the Clear-Sky Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Comiso, Josefino C.; DiGirolamo, Nikolo E.; Shuman, Christopher A.; Key, Jeffrey R.; Koenig, Lora S.

    2012-01-01

    We have developed a climate-quality data record of the clear-sky surface temperature of the Greenland Ice Sheet using the Moderate-Resolution Imaging Spectroradiometer (MODIS) ice-surface temperature (1ST) algorithm. A climate-data record (CDR) is a time series of measurements of sufficient length, consistency, and continuity to determine climate variability and change. We present daily and monthly MODIS ISTs of the Greenland Ice Sheet beginning on 1 March 2000 and continuing through 31 December 2010 at 6.25-km spatial resolution on a polar stereographic grid. This record will be elevated in status to a CDR when at least nine more years of data become available either from MODIS Terra or Aqua, or from the Visible Infrared Imager Radiometer Suite (VIIRS) to be launched in October 2011. Our ultimate goal is to develop a CDR that starts in 1981 with the Advanced Very High Resolution (AVHRR) Polar Pathfinder (APP) dataset and continues with MODIS data from 2000 to the present, and into the VIIRS era. Differences in the APP and MODIS cloud masks have so far precluded the current 1ST records from spanning both the APP and MODIS time series in a seamless manner though this will be revisited when the APP dataset has been reprocessed. The complete MODIS 1ST daily and monthly data record is available online.

  10. Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker responses in east Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Eggers Pedersen, Kathrine; Basu, Niladri; Letcher, Robert; Greaves, Alana K; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

    2015-04-01

    Perfluoroalkyl substances (PFASs) is a growing class of contaminants in the Arctic environment, and include the established perfluorinated sulfonates (PFSAs; especially perfluorooctane sulfonate (PFOS)) and carboxylic acids (PFCAs). PFSAs and PFCAs of varying chain length have been reported to bioaccumulate in lipid rich tissues of the brain among other tissues such as liver, and can reach high concentrations in top predators including the polar bear. PFCA and PFSA bioaccummulation in the brain has the potential to pose neurotoxic effects and therefore we conducted a study to investigate if variations in neurochemical transmitter systems i.e. the cholinergic, glutaminergic, dopaminergic and GABAergic, could be related to brain-specific bioaccumulation of PFASs in East Greenland polar bears. Nine brain regions from nine polar bears were analyzed for enzyme activity (monoamine oxidase (MAO), acetylcholinesterase (AChE) and glutamine synthetase (GS)) and receptor density (dopamine-2 (D2), muscarinic cholinergic (mAChR) and gamma-butyric acid type A (GABA-A)) along with PFSA and PFCA concentrations. Average brain ∑PFSA concentration was 25ng/g ww where PFOS accounted for 91%. Average ∑PFCA concentration was 88ng/g ww where PFUnDA, PFDoDA and PFTrDA combined accounted for 79%. The highest concentrations of PFASs were measured in brain stem, cerebellum and hippocampus. Correlative analyses were performed both across and within brain regions. Significant positive correlations were found between PFASs and MAO activity in occipital lobe (e.g. ∑PFCA; rp=0.83, p=0.041, n=6) and across brain regions (e.g. ∑PFCA; rp=0.47, p=0.001, ∑PFSA; rp=0.44, p>0.001; n=50). GABA-A receptor density was positively correlated with two PFASs across brain regions (PFOS; rp=0.33, p=0.02 and PFDoDA; rp=0.34, p=0.014; n=52). Significant negative correlations were found between mAChR density and PFASs in cerebellum (e.g. ∑PFCA; rp=-0.95, p=0.013, n=5) and across brain regions (e.g.

  11. Discussion on final rifting evolution and breakup : insights from the Mid Norwegian - North East Greenland rifted system

    Science.gov (United States)

    Peron-Pinvidic, Gwenn; Terje Osmundsen, Per

    2016-04-01

    In terms of rifted margin studies, the characteristics of the distal and outer domains are among the today's most debated questions. The architecture and composition of deep margins are rarely well constrained and hence little understood. Except from in a handful number of cases (eg. Iberia-Newfoundland, Southern Australia, Red Sea), basement samples are not available to decipher between the various interpretations allowed by geophysical models. No consensus has been reached on the basement composition, tectonic structures, sedimentary geometries or magmatic content. The result is that non-unique end-member interpretations and models are still proposed in the literature. So, although these domains mark the connection between continents and oceans, and thus correspond to unique stages in the Earth's lithospheric life cycle, their spatial and temporal evolution are still unresolved. The Norwegian-Greenland Sea rift system represents an exceptional laboratory to work on questions related to rifting, rifted margin formation and sedimentary basin evolution. It has been extensively studied for decades by both the academic and the industry communities. The proven and expected oil and gas potentials led to the methodical acquisition of world-class geophysical datasets, which permit the detailed research and thorough testing of concepts at local and regional scales. This contribution is issued from a three years project funded by ExxonMobil aiming at better understanding the crustal-scale nature and evolution of the Norwegian-Greenland Sea. The idea was to take advantage of the data availability on this specific rift system to investigate further the full crustal conjugate scale history of rifting, confronting the various available datasets. In this contribution, we will review the possible structural and sedimentary geometries of the distal margin, and their connection to the oceanic domain. We will discuss the definition of 'breakup' and introduce a first order conceptual

  12. Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records

    DEFF Research Database (Denmark)

    Walker, Mike; Johnsen, Sigfus Johann; Rasmussen, Sune Olander

    2009-01-01

    The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene-Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs...... the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) has been ratified by the International Union of Geological Sciences. Five auxiliary stratotypes for the Pleistocene-Holocene boundary have also been recognised....

  13. An immunohistochemical study of retinol-binding protein (RBP) in livers of free-living polar bears (Ursus maritimus) from east Greenland.

    Science.gov (United States)

    Heier, Annabelle; Sonne, Christian; Gröne, Andrea; Leifsson, Pall S; Dietz, Rune; Born, Erik W; Bacciarini, Luca N

    2005-09-01

    From 1999 to 2002 samples from 114 free-ranging polar bears (Ursus maritimus) were collected in the municipality of Scoresby Sound, East Greenland, to detect levels of organochlorines and potential histopathologic changes. Livers of 16 female polar bears from this group were evaluated histologically and analyzed for hepatic retinol-binding protein by immunohistochemistry. Retinol-binding protein is the main transport protein for retinol, an important vitamin A metabolite in the polar bear. Only mild pathologic changes were noted on histologic evaluation of the livers. Small lymphocytic or lymphohistiocytic infiltrates were present in all the livers. Small lipid granulomas, mild periportal fibrosis, and bile duct proliferation were found in several cases. Immunohistochemistry for retinol-binding protein of hepatic tissue from free-ranging polar bears showed no distinct difference in staining intensity by a number of criteria: age, season (fasting and nonfasting), or lactation status. The staining was diffuse to finely stippled in the cytoplasm and showed very little variation among the animals. Because of the lack of macroscopic changes and the absence of severe histologic liver lesions, these polar bears were assumed to be healthy. The diffuse cytoplasmic retinol-binding protein staining in hepatocytes of free-ranging polar bears varies markedly from the prominent granular, less intense staining of captive polar bears investigated previously.

  14. A tentative record of the last 1,000 years of Greenland temperature from occluded air in the GISP2 ice core

    Science.gov (United States)

    Kobashi, T.; Severinghaus, J. P.; Barnola, J.; Kawamura, K.; Beaudette, R.

    2005-12-01

    Ice borehole temperature inversion has been used to reconstruct Greenland surface temperature during the last millennium (Dahl-Jensen et al, Science, 1998). However, this technique does not preserve high frequencies because of diffusion of heat in the ice. Here, we present a tentative reconstruction of the past 1,000 years of central Greenland temperature using nitrogen and argon isotopes from occluded air in the GISP2 ice core. This technique preserves decadal-to-centennial-scale temperature variations and complements the borehole technique. Nitrogen and argon isotopes in the porous snow layer (~80m) experience two isotopic fractionations by gravitation and temperature gradients (ΔT) between the top and bottom of the snow layer. The simultaneous analysis of argon and nitrogen isotopes allows us to separate these two effects, and obtain a history of ΔT in the layer. To a first approximation, ΔT change on decadal to centennial time scales is a surface temperature history because the heat conductivity of snow is much smaller than that of ice, and the heat capacity of the ice sheet is quite large. The preliminary ΔT history (20-year interval) shows a Medieval Warm Period in the 11th to 12th centuries and the Little Ice Age in the 15th to 19th centuries. Furthermore, the record shows a clear similarity with the Be-10 record (a proxy for solar activity) with Wolf, Sporer, Maunder, and Dalton minima clearly seen in the cold periods. This finding is consistent with the hypothesis that solar activity influenced Greenland temperature during the past 1000 years.

  15. New fern records for Kilimanjaro | Hemp | Journal of East African ...

    African Journals Online (AJOL)

    Working on the flora and vegetation of Mt Kilimanjaro, Tanzania, 17 ferns in 10 families were found that had not yet been recorded for the floral region T2. The altitudinal range, localities and habitat description are given for Adiantum raddianum, Asplenium bugoiense, Blechnum ivohibense, Blotiella stipitata, Dryopteris ...

  16. Records of ectoparasites on humans and sheep from Viking-age deposits in the former western settlement of Greenland.

    Science.gov (United States)

    Sadler, J P

    1990-07-01

    During recent archaeological excavations in Viking Greenland, specimens of the human flea, Pulex irritans L., and the body louse, Pediculus humanus humanus L., were recovered from several farmsteads. Bovicola ovis (Schrank) and the sheep ked, Melophagus ovinus (L.), also were found in associated deposits. The specimens were dated from about AD 990 to AD 1350. These finds raise questions about the levels of hygiene of the Viking farmers and open some interesting medical and biogeographical conundrums.

  17. Avoidable deaths in Greenland 1968-1985

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Juel, K

    1990-01-01

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

  18. Crustal and mantle structure of the greater Jan Mayen-East Greenland region (NE Atlantic) from combined 3D structural, S-wave velocity, and gravity modeling

    Science.gov (United States)

    Tan, P.; Sippel, J.; Scheck-Wenderoth, M.; Meeßen, C.; Breivik, A. J.

    2016-12-01

    The study area is located between the Jan Mayen Ridge and the east coast of Greenland. It has a complex geological setting with the ultraslow Kolbeinsey and Mohn's spreading ridges, the anomalously shallow Eggvin Bank, the Jan Mayen Microcontinent (JMMC), and the tectonically active West Jan Mayen Fracture Zone (WJMFZ). In this study, we present the results of forward 3D structural, S-wave velocity, and gravity modeling which provide new insights into the deep crust and mantle structure and the wide-ranging influence of the Iceland Plume. The crustal parts of the presented 3D structural model are mainly constrained by local seismic refraction and reflection data. Accordingly, greatest crustal thicknesses (24 km) are observed on the northern boundary of the JMMC, while the average crustal thickness is 8.5 km and 4 km in the Kolbeinsey and Mohn's Ridge, respectively. The densities of the crustal parts are from previous studies. Additionally, the mantle density is derived from S-wave velocity data (between 50 and 250 km depth), while densities of the lithospheric mantle between the Moho and 50 km are calculated assuming isostatic equilibrium at 250 km depth. This is used as a starting density model which is further developed to obtain a reasonable fit between the calculated and measured (free-air) gravity fields. The observed S-wave tomographic data and the gravity modeling prove that the Iceland plume anomaly in the asthenosphere affects the lithospheric thickness and temperature, from the strongly influenced Middle Kolbeinsey Ridge, to the less affected North Kolbeinsey Ridge (Eggvin Bank), and to the little impacted Mohn's Ridge. Thus, the age-temperature relations of the different mid-ocean ridges of the study area are perturbed to different degrees controlled by the distance from the Iceland Plume. Furthermore, we find that the upper 50 km of lithospheric mantle are thermally affected by the plume only in the southwestern parts of the study area.

  19. 3D Density Structure of Oceanic Lithosphere Affected by A Plume: A Case Study from the Greater Jan Mayen-East Greenland Region (NE Atlantic)

    Science.gov (United States)

    Tan, P.; Sippel, J.; Breivik, A. J.; Scheck-Wenderoth, M.; Meeßen, C.

    2017-12-01

    Unraveling the density structure of the oceanic lithosphere north of Iceland is key for understanding the effects of the Iceland Plume on the mid-ocean ridges of the greater Jan Mayen-East Greenland Region. We use a data-integrative approach for 3D gravity modeling to develop new insights into the crust and upper mantle density structure of this region. First, we obtain the 3D density structure of the sediments and crust from interpretations of regional reflection and refraction seismic lines. Then, the temperature and density structure of the mantle between 50 and 250 km are derived from a published shear-wave velocity (Vs) tomography model. To assess the density configuration between the Moho and 50 km depth, we follow a combined forward and inverse 3D gravity modeling approach. The Vs tomography and derived density of the deeper mantle (>50 km depth) reveal that the low-density anomaly related to the Iceland plume gets weaker with increasing distance from the plume, i.e. from the strongly influenced Middle Kolbeinsey Ridge (MKR) to the Mohn's Ridge. The West Jan Mayen Fracture Zone is identified as a main mantle density contrast, indicative of differences in the thermal evolution of the ridge systems it separates. Beneath the MKR region, the low-density anomaly at depths of >50 km continues upwards into the uppermost mantle, where its lateral dimensions narrow considerably. This elongated density anomaly is consistent with a basement high and indicates a channelization of the Iceland plume effects. The NE-SW elongated mantle anomaly does not, however, coincide with the topographical NNE-SSW striking ridge axis. Thus, the modelled plume-affected oceanic lithosphere reveals discrepancies with the half-space cooling model. We discuss the 3D density model in terms of such spatial relations between deeper mantle anomalies and the shallow crustal structure.

  20. Thyroid hormones and deiodinase activity in plasma and tissues in relation to high levels of organohalogen contaminants in East Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Gabrielsen, Kristin Møller; Krokstad, Julie Stene; Villanger, Gro Dehli; Blair, David A D; Obregon, Maria-Jesus; Sonne, Christian; Dietz, Rune; Letcher, Robert J; Jenssen, Bjørn Munro

    2015-01-01

    Previous studies have shown relationships between organohalogen contaminants (OHCs) and circulating levels of thyroid hormones (THs) in arctic wildlife. However, there is a lack of knowledge concerning the possible functional effects of OHCs on TH status in target tissues for TH-dependent activity. The relationships between circulating (plasma) levels of OHCs and various TH variables in plasma as well as in liver, muscle and kidney tissues from East Greenland sub-adult polar bears (Ursus maritimus) sampled in 2011 (n=7) were therefore investigated. The TH variables included 3.3',5.5'-tetraiodothyronine or thyroxine (T4), 3.3',5-triiodothyronine (T3) and type 1 (D1) and type 2 (D2) deiodinase activities. Principal component analysis (PCA) combined with correlation analyses demonstrated negative relationships between individual polychlorinated biphenyls (PCBs) and their hydroxylated (OH-) metabolites and T4 in both plasma and muscle. There were both positive and negative relationships between individual OHCs and D1 and D2 activities in muscle, liver and kidney tissues. In general, PCBs, OH-PCBs and polybrominated dipehenyl ethers (PBDEs) were positively correlated to D1 and D2 activities, whereas organochlorine pesticides and byproducts (OCPs) were negatively associated with D1 and D2 activities. These results support the hypothesis that OHCs can affect TH status and action in the target tissues of polar bears. TH levels and deiodinase activities in target tissues can be sensitive endpoints for exposure of TH-disrupting compounds in arctic wildlife, and thus, tissue-specific responses in target organs should be further considered when assessing TH disruption in wildlife studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Historical records of organic matter supply and degradation status in the East Siberian Sea

    DEFF Research Database (Denmark)

    Bröder, Lisa; Tesi, Tommaso; Andersson, August

    2016-01-01

    biomarkers were used to construct two centennial records in the East Siberian Sea. Differences in topsoil and Pleistocene Ice Complex Deposit permafrost concentrations, modeled using δ13C and δ14C, were larger between inner and outer shelf than the changes over time. Similarly, lignin-derived phenol...

  2. An independently dated 2000-yr volcanic record from Law Dome, East Antarctica, including a new perspective on the dating of the 1450s CE eruption of Kuwae, Vanuatu

    Directory of Open Access Journals (Sweden)

    C. T. Plummer

    2012-11-01

    Full Text Available Volcanic eruptions are an important cause of natural climate variability. In order to improve the accuracy of climate models, precise dating and magnitude of the climatic effects of past volcanism are necessary. Here we present a 2000-yr record of Southern Hemisphere volcanism recorded in ice cores from the high accumulation Law Dome site, East Antarctica. The ice cores were analysed for a suite of chemistry signals and are independently dated via annual layer counting, with 11 ambiguous years at 23 BCE, which has presently the lowest error of all published long Antarctic ice cores. Independently dated records are important to avoid circular dating where volcanic signatures are assigned a date from some external information rather than using the date it is found in the ice core. Forty-five volcanic events have been identified using the sulphate chemistry of the Law Dome record. The low dating error and comparison with the NGRIP (North Greenland Ice Core Project volcanic records (on the GICC05 timescale suggest Law Dome is the most accurately dated Antarctic volcanic dataset, which will improve the dating of individual volcanic events and potentially allow better correlation between ice core records, leading to improvements in global volcanic forcing datasets. One of the most important volcanic events of the last two millennia is the large 1450s CE event, usually assigned to the eruption of Kuwae, Vanuatu. In this study, we review the evidence surrounding the presently accepted date for this event, and make the case that two separate eruptions have caused confusion in the assignment of this event. Volcanic sulphate deposition estimates are important for modelling the climatic response to eruptions. The largest volcanic sulphate events in our record are dated at 1458 CE (Kuwae?, Vanuatu, 1257 and 422 CE (unidentified.

  3. Seabird Colonies in Western Greenland

    DEFF Research Database (Denmark)

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

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

  4. Rapid response of Helheim Glacier in Greenland to climate variability over the past century

    DEFF Research Database (Denmark)

    Andresen, Camilla Snowman; Straneo, Fiammetta; Ribergaard, Mads Hvid

    2012-01-01

    a common climate forcing. Increasing air(6) and ocean(7,8) temperatures have been indicated as potential triggers. Here, we present a record of calving activity of Helheim Glacier, East Greenland, that extends back to about AD 1890, based on an analysis of sedimentary deposits from Sermilik Fjord, where...... of large-scale oceanic and atmospheric conditions, on timescales of 3-10 years....

  5. 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...

  6. Possible Greenland

    DEFF Research Database (Denmark)

    2012-01-01

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

  7. Environmental radioactivity in Greenland in 1981

    International Nuclear Information System (INIS)

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

    1982-07-01

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

  8. Identification and synchronization of the common cosmic-ray signal in the IntCal13 14C calibration and the Greenland ice-core 10Be records

    Science.gov (United States)

    Muscheler, Raimund; Adolphi, Florian; Bronk Ramsey, Christopher; Rasmussen, Sune; Hughen, Konrad; Cooper, Alan; Turney, Chris

    2017-04-01

    The production rates of cosmogenic radionuclides (such as 10Be and 14C) are modulated by the solar and geomagnetic shielding of galactic cosmic rays. In addition, 14C and 10Be are influenced by the carbon cycle and the atmospheric transport and deposition, respectively. Isolating and identifying the common production signal allows us to synchronize ice core 10Be and tree ring 14C records during the Holocene (Adolphi and Muscheler, 2016), thereby connecting ice core climate records with 14C-dated records. Extending this comparison further back in time is challenging due to deteriorating quality of the 14C calibration record, IntCal13, (Reimer et al., 2013) and possible unidentified climate influences on the ice-core 10Be records. Nevertheless, by focusing on the most prominent production-rate features this comparison can be extended far back into the last glacial where, for example, the linkage of tree-ring based Kauri 14C data and the Greenland ice-core time scale (GICC05) suggested unresolved data and/or time scale differences around the period of the Laschamp geomagnetic field minimum at about 42000 yrs BP (Muscheler et al., 2014). Here we show that the data underlying the IntCal13 14C record and the ice-core 10Be records exhibit common variability that allows us to tentatively link the ice core GICC05 time scale to the radiocarbon time scale for almost the complete radiocarbon dating range. The observed time scale differences could be related to uncertainties in both the U/Th-based dating of the IntCal13 calibration data set and the GICC05 time scale, and we show that the two can be reconciled within the uncertainties of the ice-core layer counting. This direct comparison between IntCal13 and 10Be also suggests that the 14C differences shown in (Muscheler et al., 2014) around the Laschamp geomagnetic field minimum can be reduced by moderate adjustments to the GICC05 time scale. References: Adolphi, F., and Muscheler, R., 2016, Synchronizing the Greenland ice

  9. Spirometry in Greenland

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  10. Local processes and regional patterns - Interpreting a multi-decadal altimetry record of Greenland Ice Sheet changes

    Science.gov (United States)

    Csatho, B. M.; Schenk, A. F.; Babonis, G. S.; van den Broeke, M. R.; Kuipers Munneke, P.; van der Veen, C. J.; Khan, S. A.; Porter, D. F.

    2016-12-01

    This study presents a new, comprehensive reconstruction of Greenland Ice Sheet elevation changes, generated using the Surface Elevation And Change detection (SERAC) approach. 35-year long elevation-change time series (1980-2015) were obtained at more than 150,000 locations from observations acquired by NASA's airborne and spaceborne laser altimeters (ATM, LVIS, ICESat), PROMICE laser altimetry data (2007-2011) and a DEM covering the ice sheet margin derived from stereo aerial photographs (1970s-80s). After removing the effect of Glacial Isostatic Adjustment (GIA) and the elastic crustal response to changes in ice loading, the time series were partitioned into changes due to surface processes and ice dynamics and then converted into mass change histories. Using gridded products, we examined ice sheet elevation, and mass change patterns, and compared them with other estimates at different scales from individual outlet glaciers through large drainage basins, on to the entire ice sheet. Both the SERAC time series and the grids derived from these time series revealed significant spatial and temporal variations of dynamic mass loss and widespread intermittent thinning, indicating the complexity of ice sheet response to climate forcing. To investigate the regional and local controls of ice dynamics, we examined thickness change time series near outlet glacier grounding lines. Changes on most outlet glaciers were consistent with one or more episodes of dynamic thinning that propagates upstream from the glacier terminus. The spatial pattern of the onset, duration, and termination of these dynamic thinning events suggest a regional control, such as warming ocean and air temperatures. However, the intricate spatiotemporal pattern of dynamic thickness change suggests that, regardless of the forcing responsible for initial glacier acceleration and thinning, the response of individual glaciers is modulated by local conditions. We use statistical methods, such as principal

  11. Holocene changes in climate and vegetation in the Ammassalik area, East Greenland, recorded in lake sediments and soil profiles

    DEFF Research Database (Denmark)

    Jakobsen, Bjarne Holm; Fredskild, Bent; Pedersen, Jørn Bjarke Torp

    2008-01-01

    , appears to have experienced the warmest Holocene summer conditions, ice-free seas and limited snow covers. The climate situation seems to have been to a considerable extent based on internal regional meteorological processes and largely without strong and regular cyclonic impacts from lower latitudes...

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  13. Evidence for Isostatic Emergence and Holocene Environmental Change Recorded in Chironomid Assemblages and Sediment Composition of Coastal Lake T1 in SW Greenland

    Science.gov (United States)

    Berman, K.; Axford, Y.; Lasher, G. E.

    2017-12-01

    Multi-proxy analysis of a coastal lake in southwest Greenland near Nuuk provides evidence for regional environmental changes, including the timing of isostatic rebound and the temperature history of the area. T1 (informal name) is a small lake 50 km south of Nuuk, at 17.5 m elevation and currently isolated from glacial meltwater drainage. The lake's sediment record begins approximately 9500 cal years BP, when the site was submerged beneath sea level due to glacial isostatic depression following the Last Glacial Maximum. The record captures the transition of the environment from a submerged, glacially-influenced marine site to a non-glacially fed (and initially meromictic) freshwater lake 8600 cal years BP. Magnetic susceptibility, a proxy for sediment minerogenic content, decreased rapidly from 9500 to 8600 years BP, before abruptly stabilizing and remaining relatively low and steady for the rest of the record. The transition to a lacustrine environment was characterized by a rapid and relatively simultaneous increase in primary productivity (inferred from biogenic silica concentrations) and shift towards terrestrial versus marine sources of organic matter (inferred from carbon:nitrogen ratios and nitrogen isotopes) between 8700 and 8400 years BP. Together, these proxies and the presence of marine shells below the transition provide robust evidence for the transition from a marine environment to a freshwater lake in response to regional postglacial isostatic rebound. Within the Holocene, measures of bulk sediment composition (e.g., biogenic silica, loss-on-ignition and magnetic susceptibility) are relatively stable. Chironomid (Insecta: Diptera: Chironomidae) assemblages, which in some environments are quantitative proxies for summer temperature changes, show species-level shifts within the Holocene that will be interpreted in this presentation alongside indicators of landscape change including carbon:nitrogen ratios, bulk sediment spectral reflectance and bulk

  14. An approach to estimate the freshwater contribution from glacial melt and precipitation in East Greenland shelf waters using colored dissolved organic matter (CDOM)

    DEFF Research Database (Denmark)

    Stedmon, Colin; Granskog, Mats A.; Dodd, Paul A.

    2015-01-01

    Changes in the supply and storage of freshwater in the Arctic Ocean and its subsequent export to the North Atlantic can potentially influence ocean circulation and climate. In order to understand how the Arctic freshwater budget is changing and the potential impacts, it is important to develop......, and precipitation) and sea ice melt. We develop this approach further and investigate the use of an additional tracer, colored dissolved organic matter (CDOM), which is largely specific to freshwater originating from Arctic rivers. A robust relationship between the freshwater contribution from meteoric water...... processes (riverine input and sea ice formation), while previously, these waters where thought to be derived from open sea processes (cooling and sea ice formation) in the northern Barents and Kara Seas. In Greenlandic coastal waters the meteoric water contribution is influenced by Greenland ice sheet...

  15. Electronic health records approaches and challenges: a comparison between Malaysia and four East Asian countries.

    Science.gov (United States)

    Abd Ghani, Mohd Khanapi; Bali, Rajeev K; Naguib, Raouf N G; Marshall, Ian M

    2008-01-01

    An integrated Lifetime Health Record (LHR) is fundamental for achieving seamless and continuous access to patient medical information and for the continuum of care. However, the aim has not yet been fully realised. The efforts are actively progressing around the globe. Every stage of the development of the LHR initiatives had presented peculiar challenges. The best lessons in life are those of someone else's experiences. This paper presents an overview of the development approaches undertaken by four East Asian countries in implementing a national Electronic Health Record (EHR) in the public health system. The major challenges elicited from the review including integration efforts, process reengineering, funding, people, and law and regulation will be presented, compared, discussed and used as lessons learned for the further development of the Malaysian integrated LHR.

  16. Crustal structure beneath Eastern Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  17. Warble infestations by Hypoderma tarandi (Diptera; Oestridae) recorded for the first time in West Greenland muskoxen

    DEFF Research Database (Denmark)

    Samuelsson, Frederik; Nejsum, Peter; Raundrup, Katrine

    2013-01-01

    as a zoonosis infecting humans. In February 2012, concurrent with the hunting of muskoxen, we examined carcasses for muscle and tissue parasites, and recorded warble larvae infestations. DNA extracted from samples of larvae was amplified targeting 579. bp of the COI gene, and subsequently sequenced...

  18. Molecular records of continental air temperature and monsoon precipitation variability in East Asia spanning the past 130,000 years

    NARCIS (Netherlands)

    Peterse, F.; Martínez-García, A.; Zhou, B.; Beets, C.J.; Prins, M.A.; Zheng, H.; Eglinton, T.I.

    2014-01-01

    Our current understanding of past changes in East Asian summer monsoon (EASM) precipitation intensity derives from several loess–paleosol sequences and oxygen isotope (δ18O) records of well-dated stalagmites. Although temperature is generally presumed to have had minimal impact on EASM records, past

  19. The glacial inception as recorded in the NorthGRIP Greenland ice core: timing, structure and associated abrupt temperature changes

    Energy Technology Data Exchange (ETDEWEB)

    Landais, Amaelle [UMR CEA-CNRS, CEA Saclay, IPSL/Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur -Yvette (France); Hebrew University, Institute of Earth Sciences, Givat Ram, Jerusalem (Israel); Masson-Delmotte, Valerie; Jouzel, Jean; Minster, Benedicte [UMR CEA-CNRS, CEA Saclay, IPSL/Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur -Yvette (France); Raynaud, Dominique [LGGE, UMR CNRS-UJF, St Martin d' Heres (France); Johnsen, Sigfus [University of Copenhagen, Department of Geophysics, Copenhagen (Denmark); Huber, Christof; Leuenberger, Markus; Schwander, Jakob [University of Bern, Physics Institute, Bern (Switzerland)

    2006-02-01

    The mechanisms involved in the glacial inception are still poorly constrained due to a lack of high resolution and cross-dated climate records at various locations. Using air isotopic measurements in the recently drilled NorthGRIP ice core, we show that no evidence exists for stratigraphic disturbance of the climate record of the last glacial inception ({proportional_to}123-100 kyears BP) encompassing Dansgaard-Oeschger events (DO) 25, 24 and 23, even if we lack sufficient resolution to completely rule out disturbance over DO 25. We quantify the rapid surface temperature variability over DO 23 and 24 with associated warmings of 10{+-}2.5 and 16{+-}2.5 C, amplitudes which mimic those observed in full glacial conditions. We use records of {delta}{sup 18}O of O{sub 2} to propose a common timescale for the NorthGRIP and the Antarctic Vostok ice cores, with a maximum uncertainty of 2,500 years, and to examine the interhemispheric sequence of events over this period. After a synchronous North-South temperature decrease, the onset of rapid events is triggered in the North through DO 25. As for later events, DO 24 and 23 have a clear Antarctic counterpart which does not seem to be the case for the very first abrupt warming (DO 25). This information, when added to intermediate levels of CO{sub 2} and to the absence of clear ice rafting associated with DO 25, highlights the uniqueness of this first event, while DO 24 and 23 appear similar to typical full glacial DO events. (orig.)

  20. Response of northern hemisphere environmental and atmospheric conditions to climate changes using Greenland aerosol records from the Eemian to the Holocene

    Science.gov (United States)

    Fischer, H.

    2017-12-01

    The Northern Hemisphere experienced dramatic climate changes over the last glacial cycle, including vast ice sheet expansion and frequent abrupt climate events. Moreover, high northern latitudes during the last interglacial (Eemian) were warmer than today and may provide guidance for future climate change scenarios. However, little evidence exists regarding the environmental alterations connected to these climate changes. Using aerosol concentration records in decadal resolution from the North Greenland Eemian Ice Drilling (NEEM) over the last 128,000 years we extract quantitative information on environmental changes, including the first comparison of northern hemisphere environmental conditions between the warmer than present Eemian and the early Holocene. Separating source changes from transport effects, we find that changes in the ice concentration greatly overestimate the changes in atmospheric concentrations in the aerosol source region, the latter mirroring changes in aerosol emissions. Glacial times were characterized by a strong reduction in terrestrial biogenic emissions (only 10-20% of the early Holocene value) reflecting the net loss of vegetated area in mid to high latitudes, while rapid climate changes during the glacial had essentially no effect on terrestrial biogenic aerosol emissions. An increase in terrestrial dust emissions of approximately a factor of eight during peak glacial and cold stadial intervals indicates higher aridity and dust storm activity in Asian deserts. Glacial sea salt aerosol emissions increased only moderately (by approximately 50%), likely due to sea ice expansion, while marked stadial/interstadial variations in sea salt concentrations in the ice reflect mainly changes in wet deposition en route. Eemian ice contains lower aerosol concentrations than ice from the early Holocene, due to shortened atmospheric residence time during the warmer Eemian, suggesting that generally 2°C warmer climate in high northern latitudes did not

  1. Age of Tertiary volcanic rocks on the West Greenland continental margin

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  2. NEW AND NOTEWORTHY BIRD RECORDS FROM THE EAST SLOPE OF THE ANDES OF COLOMBIA

    Directory of Open Access Journals (Sweden)

    SALAMAN PAUL G.W.

    2002-06-01

    Full Text Available We present significant new information on the distribution and status of 138 speciesof birds from the Andean East Slope of Colombia, based upon fieldwork between1990 and 2000 at 28 sites from central Dpto. Boyacá south to the Ecuador border.The first Colombian specimens of two species (Campylopterus villaviscensio, NapoSabrewing; Myrmotherula spodionota, Foothill Antwren are reported. Three othertaxa (Ocreatus underwoodii addae, Piculus leucolaemus leucolaemus andMyiophobus p. phoenicomitra, the first two sometimes considered species distinctfrom known Colombian forms, represent first reports from Colombia based uponsightings or photographs; we add several more sightings of two species (Pipreolachlorolepidota, Iridisornis analis previously known from single sight records. Inall, we report 35 species from the Andean East Slope of Colombia for the first time,southward range extensions on this slope for 47 species, northward extensions for21, upward or downward altitudinal extensions for 19, filling in of major discontinuitiesin distribution for 22; for ten of the latter, known from very few reports, new informationindicates a continuous distribution and far greater abundance than previouslysupposed. Range extensions and previously undiscovered populations of severalrestricted-range, Vulnerable, Near-threatened and Threatened species help toemphasize the importance of implementing conservation measures in the face of the increasing colonization pressures and insecurity. Based on our observations, wepresent several recommendations for setting conservation priorities in this rich butstill relatively poorly known region.

  3. A Newly Recorded Sea Cucumber (Holothuroidea: Aspidochirotida: Synallactidae from East Sea, Korea

    Directory of Open Access Journals (Sweden)

    Lee, Taekjun

    2014-04-01

    Full Text Available Five sea cucumbers were collected from Gisamun and Gonghyeonjin of Gangwon-do, in the East Sea, Korea from 27 December 2009 to 14 November 2012. These specimens were classified as Synallactes nozawai Mitsukuri, 1912 belonging to the family Synallactidae of order Aspidochirotida based on morphological characteristics. The family, genus and species are recorded for the first time from Korea. The distinct morphological characteristics of this species are as follows: body flexible, with thin gelatinous body wall; presence of numerous tubercles along dorsal ambulacra table of body wall consisted of three- or four-armed disk and a spire-form pillar. This species usually inhabits the deep sea and is distributed in the Northwest Pacific from northern Japan to Bering Sea.

  4. Electrical conductivity measurements from the GISP2 and GRIP Greenland ice cores

    DEFF Research Database (Denmark)

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

    1993-01-01

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

  5. Metal residues, histopathology and presence of parasites in the liver and gills of fourhorn sculpin (Myoxocephalus quadricornis) and shorthorn sculpin (Myoxocephalus scorpius) near a former lead-zinc mine in East Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Mai [Institute of Marine and Antarctic Studies University of Tasmania, Launceston, Tasmania 7250 (Australia); Nørregaard, Rasmus; Bach, Lis; Sonne, Christian; Søndergaard, Jens; Gustavson, Kim; Aastrup, Peter [Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde (Denmark); Nowak, Barbara, E-mail: B.Nowak@utas.edu.au [Institute of Marine and Antarctic Studies University of Tasmania, Launceston, Tasmania 7250 (Australia)

    2017-02-15

    Fourhorn sculpins (Myoxocephalus quadricornis) and shorthorn sculpins (Myoxocephalus scorpius) have been considered suitable local bioindicators for environmental monitoring studies in the Arctic. Because these species share many characteristics, data from the two species have previously been pooled when assessing marine metal contamination. A chemical and histological study was conducted on fourhorn and shorthorn sculpins collected around a contaminated lead-zinc mine at East Greenland to investigate whether there were any differences in the residues of metals, histopathology and parasites in liver and gills between the two sculpin species. The results demonstrated that concentrations of copper (Cu), zinc (Zn), mercury (Hg) and lead (Pb) were significantly higher in the fourhorn sculpins (p<0.001) while there were no significant differences for arsenic (As) or cadmium (Cd). Furthermore, density of blood vessel fibrosis (p=0.028), prevalence and density of chondroplasia (p=0.002 and p=0.005, respectively), number of mucin-containing mucous cells (p<0.001) and chloride cells (p<0.001) and mean intensity of colonial Peritricha (p<0.001) were significantly higher in fourhorn sculpin. Based on these results we suggest that pooling the two species when conducting environmental assessments is not recommended as it can lead to incorrect conclusions. We propose that a larger study investigating the biological effects of zinc-lead mining in Greenland is needed. - Highlights: • Fourhorn sculpins (Myoxocephalus quadricornis) more sensitive to pollution than shorthorn sculpins (Myoxocephalus scorpius). • Metal residues, histological changes and presence of parasites were species-specific. • Different sculpin species should not be pooled together as pollution biomarkers.

  6. Correlation of Greenland ice-core isotope profiles and the terrestrial record of the Alpine Rhine glacier for the period 32-15 ka

    NARCIS (Netherlands)

    de Jong, M.G.G.; de Graaff, L.W.S.; Seijmonsbergen, A.C.; Böhm, A.R.

    2011-01-01

    We present a newly extended stratigraphic subdivision of the Greenland NGRIP, GRIP and GISP2 ice cores for the period 32-15 ka. Our classification emphasizes the multiscale nature of the climatic oscillations. Spectral trend analysis of isotopic data supports this interpretation. We compare this

  7. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

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

  8. West Greenlandic Eskimo

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann; Fortescue, Michael David

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

  9. Molecular records of climate variability and vegetation response since the Late Pleistocene in the Lake Victoria basin, East Africa

    NARCIS (Netherlands)

    Berke, M.A.; Johnson, T.C.; Werne, J.P.; Grice, K.; Schouten, S.; Sinninghe Damsté, J.S.

    2012-01-01

    New molecular proxies of temperature and hydrology are helping to constrain tropical climate change and elucidate possible forcing mechanisms during the Holocene. Here, we examine a similar to 14,000 year record of climate variability from Lake Victoria, East Africa, the world's second largest

  10. 77 FR 52053 - Notice of Availability of the Record of Decision for San Diego Gas and Electric's East County...

    Science.gov (United States)

    2012-08-28

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [CACA-51625, LLCAD07000, L51010000, ER0000, LVRWB10B3800] Notice of Availability of the Record of Decision for San Diego Gas and Electric's East County...&E filed right-of-way (ROW) application CACA-51625 for the ECO Substation Project. The ECO Substation...

  11. 78 FR 33101 - Notice of Availability of the Record of Decision for the Alta East Wind Project, Kern County...

    Science.gov (United States)

    2013-06-03

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [CACA-052537, LLCAD05000, L51010000.LVRWB11B4520.FX0000] Notice of Availability of the Record of Decision for the Alta East Wind Project, Kern County, California AGENCY: Bureau of Land Management, Interior. ACTION: Notice of Availability. SUMMARY...

  12. Geologic mapping in Greenland with polarimetric SAR

    DEFF Research Database (Denmark)

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

    1995-01-01

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

  13. The peopling of Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  14. Terrestrial mollusk records from Chinese loess sequences and changes in the East Asian monsoonal environment

    Science.gov (United States)

    Wu, Naiqin; Li, Fengjiang; Rousseau, Denis-Didier

    2018-04-01

    The terrestrial mollusk fossils found in Chinese loess strata have been studied for over one hundred years. However, the greatest progress in these studies has been made only in the last two decades. In this paper, we review the advancements, advantages and limitations of terrestrial mollusk studies in Chinese loess deposits. Improvements in research methods and approaches have allowed the extraction of more detailed paleoenvironmental and paleoclimatic information from mollusk assemblages. The broadened research scope and content have yielded many new findings and results. The mollusk record has thus become one of the most important proxies in the paleoenvironmental and paleoclimatic reconstruction of loess-paleosol sequences in China. The greatest progress in the studies of terrestrial mollusks in Chinese loess sequences can be summarized as follows: (1) modern mollusk assemblages can be classified into four ecotypes, based on their temperature and humidity requirements, including eurytopic, semi-aridiphilous and sub-humidiphilous, cold-aridiphilous, and thermo-humidiphilous types; (2) Quaternary mollusk assemblages can be modified into the following three ecological types: glacial loess, interglacial paleosol, and interstadial weakly-developed paleosol assemblages; (3) mollusk records successfully reveal long-term climatic and environmental changes reflective of the history of East Asian monsoonal variations since the Late Cenozoic, and the succession of mollusk species also indicate short-term environmental changes such as millennial climate variability during Last Glacial Maximum and unstable climatic fluctuations during glacial and interglacial periods; and (4) more recently, new analytical approaches have offered increased research potential in areas such as paleotemperature reconstruction using the isotopic compositions of modern and fossil mollusk shells, combined with higher accuracy 14C dating of Quaternary loess deposits, which will greatly improve

  15. Anthropogenic contributions to atmospheric Hg, Pb and As accumulation recorded by peat cores from southern Greenland and Denmark dated using the 14C "bomb pulse curve"

    Science.gov (United States)

    Shotyk, W.; Goodsite, M. E.; Roos-Barraclough, F.; Frei, R.; Heinemeier, J.; Asmund, G.; Lohse, C.; Hansen, T. S.

    2003-11-01

    Mercury concentrations are clearly elevated in the surface and sub-surface layers of peat cores collected from a minerotrophic ("groundwater-fed") fen in southern Greenland (GL) and an ombrotrophic ("rainwater-fed") bog in Denmark (DK). Using 14C to precisely date samples since ca. AD 1950 using the "atmospheric bomb pulse," the chronology of Hg accumulation in GL is remarkably similar to the bog in DK where Hg was supplied only by atmospheric deposition: this suggests not only that Hg has been supplied to the surface layers of the minerotrophic core (GL) primarily by atmospheric inputs, but also that the peat cores have preserved a consistent record of the changing rates of atmospheric Hg accumulation. The lowest Hg fluxes in the GL core (0.3 to 0.5 μg/m 2/yr) were found in peats dating from AD 550 to AD 975, compared to the maximum of 164 μg/m 2/yr in AD 1953. Atmospheric Hg accumulation rates have since declined, with the value for 1995 (14 μg/m 2/yr) comparable to the value for 1995 obtained by published studies of atmospheric transport modelling (12 μg/m 2/yr). The greatest rates of atmospheric Hg accumulation in the DK core are also found in the sample dating from AD 1953 and are comparable in magnitude (184 μg/m 2/yr) to the GL core; again, the fluxes have since gone into strong decline. The accumulation rates recorded by the peat core for AD 1994 (14 μg/m 2/yr) are also comparable to the value for 1995 obtained by atmospheric transport modelling (18 μg/m 2/yr). Comparing the Pb/Ti and As/Ti ratios of the DK samples with the corresponding crustal ratios (or "natural background values" for preanthropogenic peat) shows that the samples dating from 1953 also contain the maximum concentration of "excess" Pb and As. The synchroneity of the enrichments of all three elements (Hg, Pb, and As) suggests a common source, with coal-burning the most likely candidate. Independent support for this interpretation was obtained from the Pb isotope data ( 206Pb/ 207Pb

  16. Migration and breeding biology of arctic terns in Greenland

    DEFF Research Database (Denmark)

    Egevang, Carsten

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  18. East African Soil Erosion Recorded in a 300 Year old Coral Colony From Kenya

    Science.gov (United States)

    Dunbar, R. B.; Fleitmann, D.; McCulloch, M.; Mudelsee, M.; Vuille, M.; McClanahan, T.; Cole, J.; Eggins, S.

    2006-12-01

    Soil erosion threatens the food security of 2.6 billion people worldwide. The situation is particularly dire in East and Sub-Saharan Africa where per capita food production has declined over the past 45 years. Erosion and the resultant loss of fertile soil is a key socio-economic and ecological problem in Kenya, affecting all sectors of its economy and damaging marine and terrestrial ecosystems. The temporal pattern of soil erosion is almost unknown and currently only sparse and rather anecdotal information exists. To aid in filling this gap of knowledge, we present a 300-year long Barium record from two Kenyan coral colonies (Porites sp., 3°15'S, 40°9' E; Malindi Marine National Park) that documents a dynamic history of soil erosion in the Sabaki river drainage basin. To reconstruct Sabaki River sediment flux to the Malindi coral reef Ba/Ca ratios were measured in the skeleton of two Porites colonies (Mal 96-1 and Mal 95-3). Well-developed annual bands allow us to develop annually precise chronologies. Ba/Ca ratios were measured in core Mal 96-1 at continuous 40 μm intervals (~400 to 500 samples yr-1) using laser-ablation inductively coupled plasma mass spectrometry (LA- ICP-MS). To test for reproducibility and accuracy of the Mal 96-1 Ba/Ca profile, coral core Mal 95-3 was analyzed at lower resolution (1 to 12 samples yr-1) using discrete micro-drill sampling and isotope dilution ICP-MS. The close similarity between both coral Ba/Ca profiles, in absolute values as well as general pattern, underscores the accuracy of the LA-ICP-MS technique and adds confidence to our interpretation of the 300 year long Mal 96-1 Ba/Ca profile. The Ba/Ca coral proxy record shows that while the sediment flux from the Sabaki River is nearly constant between 1700 and 1900, a continuous rise in sediment flux is observed since 1900, reflecting steadily increasing demographic pressure on land use. The peak in suspended sediment load and hence soil erosion recorded at the Malindi reef

  19. Eemian interglacial reconstructed from a Greenland folded ice core

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  20. Climate variability in West Greenland during the past 1500 years

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  1. Polar Ice Caps: a Canary for the Greenland Ice Sheet

    Science.gov (United States)

    Honsaker, W.; Lowell, T. V.; Sagredo, E.; Kelly, M. A.; Hall, B. L.

    2010-12-01

    Ice caps are glacier masses that are highly sensitive to climate change. Because of their hypsometry they can have a binary state. When relatively slight changes in the equilibrium line altitude (ELA) either intersect or rise above the land the ice can become established or disappear. Thus these upland ice masses have a fast response time. Here we consider a way to extract the ELA signal from independent ice caps adjacent to the Greenland Ice Sheet margin. It may be that these ice caps are sensitive trackers of climate change that also impact the ice sheet margin. One example is the Istorvet Ice Cap located in Liverpool Land, East Greenland (70.881°N, 22.156°W). The ice cap topography and the underlying bedrock surface dips to the north, with peak elevation of the current ice ranging in elevation from 1050 to 745 m.a.s.l. On the eastern side of the ice mass the outlet glaciers extending down to sea level. The western margin has several small lobes in topographic depressions, with the margin reaching down to 300 m.a.s.l. Topographic highs separate the ice cap into at least 5 main catchments, each having a pair of outlet lobes toward either side of the ice cap. Because of the regional bedrock slope each catchment has its own elevation range. Therefore, as the ELA changes it is possible for some catchments of the ice cap to experience positive mass balance while others have a negative balance. Based on weather observations we estimate the present day ELA to be ~1000 m.a.s.l, meaning mass balance is negative for the majority of the ice cap. By tracking glacier presence/absence in these different catchments, we can reconstruct small changes in the ELA. Another example is the High Ice Cap (informal name) in Milne Land (70.903°N, 25.626°W, 1080 m), East Greenland. Here at least 4 unconformities in ice layers found near the southern margin of the ice cap record changing intervals of accumulation and ablation. Therefore, this location may also be sensitive to slight

  2. Toxaphene in the aquatic environment of Greenland

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  3. Telemedicine in Greenland

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  4. Evaluating the Duration and Continuity of Potential Climate Records From the Allan Hills Blue Ice Area, East Antarctica

    Science.gov (United States)

    Kehrl, Laura; Conway, Howard; Holschuh, Nicholas; Campbell, Seth; Kurbatov, Andrei V.; Spaulding, Nicole E.

    2018-05-01

    The current ice core record extends back 800,000 years. Geologic and glaciological evidence suggests that the Allan Hills Blue Ice Area, East Antarctica, may preserve a continuous record that extends further back in time. In this study, we use ice-penetrating radar and existing age constraints to map the internal stratigraphy and age structure of the Allan Hills Main Ice Field. The dated isochrones provide constraints for an ice flow model to estimate the age of ice near the bed. Previous drilling in the region recovered stratigraphically disturbed sections of ice up to 2.7 million years old. Our study identifies a site 5 km upstream, which likely preserves a continuous record through Marine Isotope Stage 11 with the possibility that the record extends back 1 million years. Such records would provide new insight into the past climate and glacial history of the Ross Sea Sector.

  5. 100,000-year-long terrestrial record of millennial-scale linkage between eastern North American mid-latitude paleovegetation shifts and Greenland ice-core oxygen isotope trends

    Science.gov (United States)

    Litwin, Ronald J.; Smoot, Joseph P.; Pavich, Milan J.; Markewich, Helaine Walsh; Brook, George; Durika, Nancy J.

    2013-01-01

    We document frequent, rapid, strong, millennial-scale paleovegetation shifts throughout the late Pleistocene, within a 100,000+ yr interval (~ 115–15 ka) of terrestrial sediments from the mid-Atlantic Region (MAR) of North America. High-resolution analyses of fossil pollen from one core locality revealed a continuously shifting sequence of thermally dependent forest assemblages, ranging between two endmembers: subtropical oak-tupelo-bald cypress-gum forest and high boreal spruce-pine forest. Sedimentary textural evidence indicates fluvial, paludal, and loess deposition, and paleosol formation, representing sequential freshwater to subaerial environments in which this record was deposited. Its total age"depth model, based on radiocarbon and optically stimulated luminescence ages, ranges from terrestrial oxygen isotope stages (OIS) 6 to 1. The particular core sub-interval presented here is correlative in trend and timing to that portion of the oxygen isotope sequence common among several Greenland ice cores: interstades GI2 to GI24 (≈ OIS2–5 d). This site thus provides the first evidence for an essentially complete series of "Dansgaard"Oeschger" climate events in the MAR. These data reveal that the ~ 100,000 yr preceding the Late Glacial and Holocene in the MAR of North America were characterized by frequently and dynamically changing climate states, and by vegetation shifts that closely tracked the Greenland paleoclimate sequence.

  6. Present conditions in Greenland and the Kangerlussuaq area

    International Nuclear Information System (INIS)

    Nielsen, A. B.

    2010-01-01

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

  7. 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 ...

  8. Popular music from Greenland

    DEFF Research Database (Denmark)

    Otte, Andreas Roed

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

  9. Middle Holocene Organic Carbon and Biomarker Records from the South Yellow Sea: Relationship to the East Asian Monsoon

    Science.gov (United States)

    Zou, Liang; Hu, Bangqi; Li, Jun; Dou, Yanguang; Xie, Luhua; Dong, Liang

    2018-03-01

    The East Asian monsoon system influences the sedimentation and transport of organic matter in East Asian marginal seas that is derived from both terrestrial and marine sources. In this study, we determined organic carbon (OC) isotope values, concentrations of marine biomarkers, and levels of OC and total nitrogen (TN) in core YSC-1 from the central South Yellow Sea (SYS). Our objectives were to trace the sources of OC and variations in palaeoproductivity since the middle Holocene, and their relationships with the East Asian monsoon system. The relative contributions of terrestrial versus marine organic matter in core sediments were estimated using a two-end-member mixing model of OC isotopes. Results show that marine organic matter has been the main sediment constituent since the middle Holocene. The variation of terrestrial organic carbon concentration (OCter) is similar to the EASM history. However, the variation of marine organic carbon concentration (OCmar) is opposite to that of the EASM curve, suggesting OCmar is distinctly influenced by terrestrial material input. Inputs of terrestrial nutrients into the SYS occur in the form of fluvial and aeolian dust, while concentrations of nutrients in surface water are derived mainly from bottom water via the Yellow Sea circulation system, which is controlled by the East Asian winter monsoon (EAWM). Variations in palaeoproductivity represented by marine organic matter and biomarker records are, in general, consistent with the recent EAWM intensity studies, thus, compared with EASM, EAWM may play the main role to control the marine productivity variations in the SYS.

  10. High-Arctic climate conditions for the last 7000 years inferred from multi-proxy analysis of the Bliss Lake record, North Greenland

    DEFF Research Database (Denmark)

    Olsen, Jesper; Kjær, Kurt H.; Funder, Svend Visby

    2012-01-01

    , Peary Land, Greenland. The early Holocene (10 850–10 480 cal. a BP) is characterized by increased erosion and gradually more marine conditions. Full marine conditions developed from 10 480 cal. a BP until the lake was isolated at 7220 cal. a BP. From its marine isolation at 7220 cal. a BP Bliss Lake...... becomes a lacustrine environment. Evidence from geochemical proxies (δ13C and total organic carbon) suggests that warmer conditions prevailed between 7220 and 6500 cal. a BP, corresponding to the Holocene thermal maximum, and from 3300 until 910 cal. a BP. From 850 to 500 cal. a BP colder climate...

  11. Trends in precipitation extremes and long-term memory of runoff records in Zhejiang, East China

    NARCIS (Netherlands)

    Tian, Y.; Tian, Ye; Xu, YuePing; Booij, Martijn J.; Zhang, Qingqing; Lin, Shengji; Franks, Steward W.; Boegh, Eva; Blyth, Eleanor; Hannah, David M.; Yilmaz, Koray K.

    2011-01-01

    Extreme weather events have a huge impact on human beings and therefore it is of vital importance to investigate trends in relevant climatological and hydrological variables. In this study, precipitation and streamflow trends in Zhejiang Province in east China are analysed. Trends in annual and

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  13. Uncovering the genetic history of the present-day greenlandic population

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  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. The Greenland shark

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  17. 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....

  18. Tectonics, topography, and river system transition in East Tibet: Insights from the sedimentary record in Taiwan

    Science.gov (United States)

    Lan, Qing; Yan, Yi; Huang, Chi-Yue; Clift, Peter D.; Li, Xuejie; Chen, Wenhuang; Zhang, Xingchang; Yu, Mengming

    2014-09-01

    The Cenozoic in East Asia is marked by major changes in tectonics, landscapes, and river systems, although the timing and nature of such changes remains disputed. We investigate the geochemistry and neodymium isotope character of Cenozoic mudstones spanning the breakup unconformity in the Western Foothills of Taiwan in order to constrain erosion and drainage development in southern China during the opening of the South China Sea. The La/Lu, Eu/Eu*, Th/Sc, Th/La, Cr/Th, and ɛNd values in these rocks show an abrupt change between ˜31 and 25 Ma. Generally the higher ɛNd values in sediments deposited prior to 31 Ma indicate erosion from Phanerozoic granitic sources exposed in coastal South China, whereas the lower ɛNd values suggest that the main sources had evolved to inland southern China by ˜25 Ma. The SHRIMP U-Pb ages of zircons from a tuff, together with biostratigraphy data constrain the breakup unconformity to be between ˜39 and 33 Ma, suggesting that the seafloor spreading in the South China Sea commenced before ˜33 Ma. This is significantly older than most of the oceanic crust preserved in the deeper part of the basin. Diachronous westward younging of the breakup unconformities and provenance changes of basins are consistent with seafloor spreading propagating from east to west. Initial spreading of the South China Sea prior to ˜33 Ma corresponds to tectonic adjustment in East Asia, including extrusion of the Indochina block and the rotation and eastward retreat of the subducting Pacific Plate.

  19. New record of Clypeasterophilus stebbingi (Rathbun, 1918 (Decapoda: Brachyura: Pinnotheridae from the east coast of Nicaragua

    Directory of Open Access Journals (Sweden)

    Michel E. Hendrickx

    Full Text Available The pinnotherid crab Clypeasterophilus stebbingi (Rathbun, 1918, previously known from Florida, USA, Colombia and Brazil, is reported for the first time from Central America, on the east coast of Nicaragua. A single female specimen was collected on the sand dollar Clypeaster subdepressus (Gray, 1825, at 4 m depth, among turtle grass on sandy bottom. The specimen fits well with the description provided by M.J. Rathbun and observations made on photographs of the male holotype. Comparison of the material described from Florida (including the type material, Colombia and Brazil to the Nicaragua specimen, however, indicates that C. stebbingi shows some variation in the shape of the third maxilliped.

  20. Distance learning in the arctic wilderness of northeast Greenland

    DEFF Research Database (Denmark)

    Langebæk, Rikke

    2011-01-01

    ABSTRACT In North East Greenland, the Danish Sirius Sledge Patrol conducts long-range patrolling in pairs of two soldiers and a team of sled dogs. Trips last 4 months or more and soldiers have no outside human contact. Each year seven new soldiers are selected to undergo seven months training bef...

  1. 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.

  2. Crustal surface wave velocity structure of the east Albany-Fraser Orogen, Western Australia, from ambient noise recordings

    Science.gov (United States)

    Sippl, C.; Kennett, B. L. N.; Tkalčić, H.; Gessner, K.; Spaggiari, C. V.

    2017-09-01

    Group and phase velocity maps in the period range 2-20 s for the Proterozoic east Albany-Fraser Orogen, Western Australia, are extracted from ambient seismic noise recorded with the 70-station ALFREX array. This 2 yr temporary installation provided detailed coverage across the orogen and the edge of the Neoarchean Yilgarn Craton, a region where no passive seismic studies of this scale have occurred to date. The surface wave velocities are rather high overall (>3 km s-1 nearly everywhere), as expected for exposed Proterozoic basement rocks. No clear signature of the transition between Yilgarn Craton and Albany-Fraser Orogen is observed, but several strong anomalies corresponding to more local geological features were obtained. A prominent, NE-elongated high-velocity anomaly in the northern part of the array is coincident with a Bouguer gravity high caused by the upper crustal metamorphic rocks of the Fraser Zone. This feature disappears towards longer periods, which hints at an exclusively upper crustal origin for this anomaly. Further east, the limestones of the Cenozoic Eucla Basin are clearly imaged as a pronounced low-velocity zone at short periods, but the prevalence of low velocities to periods of ≥5 s implies that the uppermost basement in this area is likewise slow. At longer periods, slightly above-average surface wave velocities are imaged below the Eucla Basin.

  3. Greenland plateau jets

    Directory of Open Access Journals (Sweden)

    George William Kent Moore

    2013-08-01

    Full Text Available The high ice-covered topography of Greenland represents a significant barrier to atmospheric flow and, as a direct and indirect result, it plays a crucial role in the coupled climate system. The wind field over Greenland is important in diagnosing regional weather and climate, thereby providing information on the mass balance of the ice sheet as well as assisting in the interpretation of ice core data. Here, we identify a number of hitherto unrecognised features of the three-dimensional wind field over Greenland; including a 2500-km-long jet along the central ice sheet's western margin that extends from the surface into the middle-troposphere, as well as a similar but smaller scale and less intense feature along its eastern margin. We refer to these features as Greenland Plateau Jets. The jets are coupled to the downslope katabatic flow and we argue that they are maintained by the zonal temperature gradients associated with the strong temperature inversion over the central ice sheet. Their importance for Greenland's regional climate is discussed.

  4. Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences

    Directory of Open Access Journals (Sweden)

    H. Angot

    2016-07-01

    Full Text Available Under the framework of the Global Mercury Observation System (GMOS project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0 has been gathered at Dumont d'Urville (DDU, 66°40′ S, 140°01′ E, 43 m above sea level on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0 at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L−1 as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg(0 concentrations. The open ocean may represent a source of atmospheric Hg(0 in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0. This paper also discusses implications for coastal Antarctic ecosystems and for the cycle of atmospheric mercury in high southern latitudes.

  5. 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.

  6. Full-vector geomagnetic field records from the East Eifel, Germany

    Science.gov (United States)

    Monster, Marilyn W. L.; Langemeijer, Jaap; Wiarda, Laura R.; Dekkers, Mark J.; Biggin, Andy J.; Hurst, Elliot A.; Groot, Lennart V. de

    2018-01-01

    To create meaningful models of the geomagnetic field, high-quality directional and intensity input data are needed. However, while it is fairly straightforward to obtain directional data, intensity data are much scarcer, especially for periods before the Holocene. Here, we present data from twelve flows (age range ∼ 200 to ∼ 470 ka) in the East Eifel volcanic field (Germany). These sites had been previously studied and are resampled to further test the recently proposed multi-method palaeointensity approach. Samples are first subjected to classic palaeomagnetic and rock magnetic analyses to optimise the subsequent palaeointensity experiments. Four different palaeointensity methods - IZZI-Thellier, the multispecimen method, calibrated pseudo-Thellier, and microwave-Thellier - are being used in the present study. The latter should be considered as supportive because only one or two specimens per site could be processed. Palaeointensities obtained for ten sites pass our selection criteria: two sites are successful with a single approach, four sites with two approaches, three more sites work with three approaches, and one site with all four approaches. Site-averaged intensity values typically range between 30 and 35 μT. No typically low palaeointensity values are found, in line with paleodirectional results which are compatible with regular palaeosecular variation of the Earth's magnetic field. Results from different methods are remarkably consistent and generally agree well with the values previously reported. They appear to be below the average for the Brunhes chron; there are no indications for relatively higher palaeointensities for units younger than 300 ka. However, our young sites could be close in age, and therefore may not represent the average intensity of the paleofield. Three of our sites are even considered coeval; encouragingly, these do yield the same palaeointensity within uncertainty bounds.

  7. Trace elements records from vermetids aragonite as millennial paleo-oceanographic archives in the South-East Mediterranean

    Science.gov (United States)

    Jacobson, Yitzhak; Yam, Ruth; Shemesh, Aldo

    2017-04-01

    The Mediterranean Sea is a region under high anthropogenic stress, thus a hotspot for climate change studies. Natural conditions, such as SST, productivity, precipitation and dust fluxes along with human induced activity affect seawater chemistry. We study millennial variability of trace elements in East Mediterranean Sea high-resolution records, in attempt to connect them to environmental factors. The Mediterranean reef builder Vermetid, D. petraeum is a sessile gastropod, secreting its aragonite shells in tidal zones. Cores of Vermetid reefs from the South Eastern Mediterranean (Israel) were previously analyzed by Sisma?Ventura et al. (2014) to reconstruct seawater surface temperature (SST) and δ13C of dissolved inorganic carbon (DIC). In this study we analyzed trace elements of these vermetid cores, and reconstructed millennial records of elements to calcium (el/Ca) molar ratios. Vermetid trace element contents from recent decades are mostly in agreement with known values for marine biogenic aragonites from corals and mollusk. We divide vermetid trace element records into three element groups: 1) Sr and U are related to SST and DIC. These elements correlate with major climatic events of the last millennium, such as the Medieval Warm Period (900-1300 AD) and the Little Ice Age (1450-1850 AD). 2) Pb and Cd are related to anthropogenic pollution and demonstrate industrial sourced trends throughout the anthropocene (since 1750 AD). 3) Terrogenous elements, including Fe, Al, Mn and V. Al in seawater and sediments has been used to trace water masses and land derived sediment source. We observe a major change in average vermetid Al/Fe ratios from 0.5 to 2.5 over the recorded period (n=72). This vermetid Al/Fe change points at a possible shift from Nilotic sediments (0.1-0.5 Al/Fe molar ratio) to Saharan dust ratio (2-4 Al/Fe molar ratio). Mn and V show a similar variability to Fe. Understanding the variability of vermetid TE can help us interpret the relative

  8. Levels and trends of radioactive contaminants in the Greenland environment

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  9. Life history parameters of narwhals (Monodon monoceros) from Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  10. Bourdieu in Greenland

    DEFF Research Database (Denmark)

    Hussain, Naimah

    2017-01-01

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

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

    Science.gov (United States)

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

    2013-11-01

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

  12. Nephila clavata L Koch, the Joro Spider of East Asia, newly recorded from North America (Araneae: Nephilidae

    Directory of Open Access Journals (Sweden)

    E. Richard Hoebeke

    2015-02-01

    Full Text Available Nephila clavata L Koch, known as the Joro spider and native to East Asia (Japan, China, Korea, and Taiwan, is newly reported from North America. Specimens from several locations in northeast Georgia were collected from around residential properties in Barrow, Jackson, and Madison counties in late October and early November 2014. These are the first confirmed records of the species in the New World. Our collections, along with confirmed images provided by private citizens, suggest that the Joro spider is established in northeast Georgia. Genomic sequence data for the COI gene obtained from two specimens conforms to published sequences for N. clavata, providing additional confirmation of species identity. Known collection records are listed and mapped using geocoding. Our observations are summarized along with published background information on biology in Asia and we hypothesize on the invasion history and mode of introduction into North America. Recognition features are given and photographic images of the male and female are provided to aid in their differentiation from the one native species of the genus (Nephila clavipes in North America.

  13. 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...

  14. Greenlandic Sovereignty in Practice

    DEFF Research Database (Denmark)

    Kristensen, Kristian S.; Rahbek-Clemmensen, Jon

    2018-01-01

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

  15. Cool or hot Greenland?

    DEFF Research Database (Denmark)

    Ren, Carina Bregnholm

    2016-01-01

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

  16. Telemedicine in Greenland: Citizens' Perspectives.

    Science.gov (United States)

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

    2017-05-01

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

  17. Des-A-lupane in an East African lake sedimentary record as a new proxy for the stable carbon isotopic composition of C3 plants

    NARCIS (Netherlands)

    van Bree, Loes G.J.; Rijpstra, W. Irene C; Al-Dhabi, N.A.; Verschuren, D.; Sinninghe Damste, J.S.; de Leeuw, J.W.

    2016-01-01

    We studied the high-resolution and well-dated 25,000 year sedimentary record of Lake Challa, a deep tropical crater lake in equatorial East Africa, to explore new proxies for paleoenvironmental and paleohydrological change. Sedimentary biomarker analysis revealed the presence of des-A-triterpenoids

  18. Climatic differences and similarities between Indian and East Asian Monsoon regions of China over the last millennium: a perspective based mainly on stalagmite records.

    Directory of Open Access Journals (Sweden)

    Ming Tan

    2007-07-01

    Full Text Available Cave sediments, especially stalagmites, have been providing absolute dated climate records that can extend from the present to over 500,000 years ago. Based on the reconstructed temperature time series, a comprehensive overview of the climatic differences and similarities between the Indian and the East Asian Monsoon regions of China over the last millennium is presented. Evidence from accurately dated and high-resolution records including stalagmites, ice cores and tree rings show that there was a “Medieval Warm Period” (around 1000 to 1400 AD in north and east China where climate is dominated by the East Asian monsoon; whilst no such interval is evident in the records including stalagmites and ice cores from southwest China where climate is dominated by the Indian monsoon. However, both regions underwent a significant cooling during the Little Ice Age (around the mid 1500s to the 1800s. The result achieved here may allow a possibility of distinguishing the boundary between Indian monsoon and East Asian monsoon regions over the last millennium with increase of climate records, especially stalagmites that are mostly suitable for accurate U/Th dating and/or lamina counting.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  20. Temporal Trends and Future Predictions of Mercury Concentrations in Northwest Greenland Polar Bear (Ursus maritimus) Hair

    DEFF Research Database (Denmark)

    Dietz, Rune; Born, E.W.; Riget, Frank Farsø

    2011-01-01

    -2008 concentrations ofHg in Northwest Greenland polar bear hair exceeded the general guideline values of 20-30 μg/g dry weight for terrestrial wildlife, whereas the neurochemical effect level of 5.4 μg Hg/g dry weight proposed for East Greenland polar bears was exceeded in 93.5% of the cases. These results call......Hair samples from 117 Northwest Greenland polar bears (Ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafterHg). The sample represented 28 independent years and the aim of the study was to analyze for temporal Hg trends. Mercury concentrations showed yearly...

  1. 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.

  2. Continuous 1.3-million-year record of East African hydroclimate, and implications for patterns of evolution and biodiversity.

    Science.gov (United States)

    Lyons, Robert P; Scholz, Christopher A; Cohen, Andrew S; King, John W; Brown, Erik T; Ivory, Sarah J; Johnson, Thomas C; Deino, Alan L; Reinthal, Peter N; McGlue, Michael M; Blome, Margaret W

    2015-12-22

    The transport of moisture in the tropics is a critical process for the global energy budget and on geologic timescales, has markedly influenced continental landscapes, migratory pathways, and biological evolution. Here we present a continuous, first-of-its-kind 1.3-My record of continental hydroclimate and lake-level variability derived from drill core data from Lake Malawi, East Africa (9-15° S). Over the Quaternary, we observe dramatic shifts in effective moisture, resulting in large-scale changes in one of the world's largest lakes and most diverse freshwater ecosystems. Results show evidence for 24 lake level drops of more than 200 m during the Late Quaternary, including 15 lowstands when water levels were more than 400 m lower than modern. A dramatic shift is observed at the Mid-Pleistocene Transition (MPT), consistent with far-field climate forcing, which separates vastly different hydroclimate regimes before and after ∼800,000 years ago. Before 800 ka, lake levels were lower, indicating a climate drier than today, and water levels changed frequently. Following the MPT high-amplitude lake level variations dominate the record. From 800 to 100 ka, a deep, often overfilled lake occupied the basin, indicating a wetter climate, but these highstands were interrupted by prolonged intervals of extreme drought. Periods of high lake level are observed during times of high eccentricity. The extreme hydroclimate variability exerted a profound influence on the Lake Malawi endemic cichlid fish species flock; the geographically extensive habitat reconfiguration provided novel ecological opportunities, enabling new populations to differentiate rapidly to distinct species.

  3. Ice Velocity Variations of the Polar Record Glacier (East Antarctica Using a Rotation-Invariant Feature-Tracking Approach

    Directory of Open Access Journals (Sweden)

    Tingting Liu

    2017-12-01

    Full Text Available In this study, the ice velocity changes from 2004 to 2015 of the Polar Record Glacier (PRG in East Antarctica were investigated based on a feature-tracking method using Landsat-7 enhanced thematic mapper plus (ETM+ and Landsat-8 operational land imager (OLI images. The flow field of the PRG curves make it difficult to generate ice velocities in some areas using the traditional normalized cross-correlation (NCC-based feature-tracking method. Therefore, a rotation-invariant parameter from scale-invariant feature transform (SIFT is introduced to build a novel rotation-invariant feature-tracking approach. The validation was performed based on multi-source images and the making earth system data records for use in research environments (MEaSUREs interferometric synthetic aperture radar (InSAR-based Antarctica ice velocity map data set. The results indicate that the proposed method is able to measure the ice velocity in more areas and performs as well as the traditional NCC-based feature-tracking method. The sequential ice velocities obtained present the variations in the PRG during this period. Although the maximum ice velocity of the frontal margin of the PRG and the frontal iceberg reached about 900 m/a and 1000 m/a, respectively, the trend from 2004 to 2015 showed no significant change. Under the interaction of the Polar Times Glacier and the Polarforschung Glacier, both the direction and the displacement of the PRG were influenced. This impact also led to higher velocities in the western areas of the PRG than in the eastern areas. In addition, elevation changes and frontal iceberg calving also impacted the ice velocity of the PRG.

  4. Stratigraphy and palynology of the Lower Carboniferous Sortebakker Formation, Wandel Sea Basin, eastern North Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Dalhoff, F.; Stemmerik, L. [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Vigran, J.O. [IKU Petroleum Research, Trondheim (Norway)

    2000-07-01

    Two palynological assemblages of Early Carboniferous age have been recorded from the upper parts of the non-marine, fluvial-dominated Sortebakker Formation in the Wandel Sea Basin. The stratigraphically lower assemblage includes poorly preserved Cingulizonates spp., Densosporites spp., Lycospora spp. and Schulzospora spp. whereas the upper assemblage contains a more diversified microflora including the stratigraphically important Tripartites distinctus, Potoniespores delicatus and Savitrisporites spp. The microflora enables correlation and dating of the succession to the late Visean Perotrilites tessellatus - Schulzospora campyloptera (TC) and Raistrickia nigra - Triquitrites marginatus (NM) miospore Biozones of western Europe. The depositional facies correspond to those seen in time equivalent deposits from East Greenland, Svalbard, Bjoernoeya and the Barents Sea. (au)

  5. Lake sediment multi-taxon DNA from North Greenland records early post-glacial appearance of vascular plants and accurately tracks environmental changes

    DEFF Research Database (Denmark)

    Epp, L. S.; Gussarova, C.; Boessenkool, S.

    2015-01-01

    temperatures. Lake sediments contain DNA paleorecords of the surrounding ecosystems and can be used to retrieve a variety of organismal groups from a single sample. In this study, we analyzed vascular plant, bryophyte, algal (in particular diatom) and copepod DNA retrieved from a sediment core spanning...... phases, and distinct temporal changes in plant presence were recovered. The plant DNA was mostly in agreement with expected vegetation history, but very early occurrences of vascular plants, including the woody Empetrum nigrum, document terrestrial vegetation very shortly after glacial retreat. Our study...... core. Our DNA record was stratigraphically coherent, with no indication of leaching between layers, and our cross-taxon comparisons were in accordance with previously inferred local ecosystem changes. Authentic ancient plant DNA was retrieved from nearly all layers, both from the marine and the limnic...

  6. Studying health in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Mulvad, Gert; Olsen, Jørn

    2003-01-01

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

  7. Children in Greenland

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  8. Modelling Greenland icebergs

    Science.gov (United States)

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

    2017-04-01

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

  9. 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

  10. Environmental radioactivity in Greenland 1977

    International Nuclear Information System (INIS)

    Aarkrog, A.; Lippert, J.

    1978-07-01

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

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

    Directory of Open Access Journals (Sweden)

    T. Kobashi

    2013-03-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  13. When Does the Warmest Water Reach Greenland?

    Science.gov (United States)

    Grist, J. P.; Josey, S. A.; Boehme, L.; Meredith, M. P.; Laidre, K. L.; Heide-Jørgensen, M. P.; Kovacs, K. M.; Lydersen, C.; Davidson, F. J. M.; Stenson, G. B.; Hammill, M. O.; Marsh, R.; Coward, A.

    2016-02-01

    The warmest water reaching the east and west coast of Greenland is found between 200 and 600 m, in the warm Atlantic Water Layer (WL). Temperature changes within the WL have been highlighted as a possible cause of accelerated melting of tidewater glaciers and therefore are an important consideration for understanding global sea level rise. However, a limited number of winter observations of the WL have prohibited determining its seasonal variability. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database, and unprecedented coverage from marine-mammal borne sensors have been analyzed for the period 2002-2011. A significant seasonal range in temperature ( 1-2°C) is found in the warm layer, in contrast to most of the surrounding ocean. The magnitude of the seasonal cycle is thus comparable with the 1990s warming that was associated with an increased melt rate in a marine terminating glacier of West Greenland. The phase of the seasonal cycle exhibits considerable spatial variability; with high-resolution ocean model trajectory analysis suggesting it is determined by the time taken for waters to be advected from the subduction site in the Irminger Basin. For western Greenland, the annual temperature maximum occurs near or after the turn of the calendar year. This is significant because a recent study suggested that it is in the non-summer months when fjord-shelf exchanges allow the WL to most strongly influence glacier melt rate. However this is also the time of the year when the WL is least well observed. It is therefore clear that year-round subsurface temperature measurements are still required for a complete description of the WL seasonality, and in particular to ensure that the ice-melting potential of the WL is not underestimated.

  14. 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.)

  15. The Greenland analogue project. Yearly report 2010

    International Nuclear Information System (INIS)

    Harper, J.; Brinkerhoff, D.; Johnson, J.; Ruskeeniemi, T.; Engstroem, J.; Kukkonen, I.

    2012-04-01

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

  16. 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

  17. Temperature and conductivity data collected by CTDs on moored buoys in the Sermilik Fjord, Greenland from 2008-07 to 2009-08 (NODC Accession 0123217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data included in this dataset were collected in the Sermilik Fjord, located in East Greenland in the Ammassalik district close to the town of Tasiilaq. Data...

  18. Polarimetric signatures of sea ice in the Greenland Sea

    DEFF Research Database (Denmark)

    Skriver, Henning; Pedersen, Leif Toudal

    1995-01-01

    Polarimetric SAR data of sea ice have been acquired by the Danish polarimetric SAR (EMISAR) during a mission at the Greenland Sea in August 1994. Video recordings from a low-altitude acquisition have been used for interpretation of the SAR data. Also, ERS-1 SAR data and NOAA AVHRR-data have been...

  19. 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...

  20. A synthesis of Plio-Pleistocene leaf wax biomarker records of hydrological variation in East Africa and their relationship with hominin evolution

    Science.gov (United States)

    Lupien, R.; Russell, J. M.; Campisano, C. J.; Feibel, C. S.; Deino, A. L.; Kingston, J.; Potts, R.; Cohen, A. S.

    2017-12-01

    Climate change is thought to play a critical role in human evolution. However, the mechanisms behind this relationship are difficult to test due to a lack of long, high-quality paleoclimate records from hominin fossil locales. We improve the understanding of this relationship by examining Plio-Pleistocene lake sediment cores from East Africa that were drilled by the Hominin Sites and Paleolakes Drilling Project, an international effort to study the environment in which our hominin ancestors evolved and dispersed. We have analyzed organic geochemical signals of climate from drill cores from Ethiopia and Kenya spanning the Pliocene to recent time (from north to south: paleolake Hadar, Lake Turkana, Lake Baringo, and paleolake Koora). Specifically, we analyzed the hydrogen isotopic composition of terrestrial leaf waxes, which records changes in regional atmospheric circulation and hydrology. We reconstructed quantitative records of rainfall amount at each of the study sites, which host sediment spanning different geologic times and regions. By compiling these records, we test hominin evolutionary hypotheses as well as crucial questions about climate trend and variability. We find that there is a gradual or step-wise enrichment in δDwax, signifying a trend from a wet to dry climate, from the Pliocene to the Pleistocene, perhaps implying an influence of global temperature, ice sheet extent, and/or atmospheric greenhouse gas concentrations on East African climate. However, the shift is small relative to the amplitude of orbital-scale isotopic variations. The records indicate a strong influence of eccentricity-modulated orbital precession, and imply that local insolation effects are the likely cause of East African precipitation. Several of the intervals of high isotopic variability coincide with key hominin fossil or technological transitions, suggesting that climate variability plays a key role in hominin evolution.

  1. 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....

  2. Volcanic influence on centennial to millennial Holocene Greenland temperature change.

    Science.gov (United States)

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

    2017-05-03

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

  3. Ecosystem responses during Late Glacial period recorded in the sediments of Lake Łukie (East Poland)

    Science.gov (United States)

    Zawiska, Izabela; Słowiński, Michał; Correa-Metrio, Alex; Obremska, Milena; Luoto, Tomi; Nevalainen, Liisa; Woszczyk, Michał; Milecka, Krystyna

    2014-05-01

    The main objectives of this study was to reconstruct climate impact on the functioning of Lake Łukie and its catchment (Łęczna Włodawa Lake District, East European Plain) during Late Glacial period. In order to reconstruct climatic fluctuations and corresponding ecosystem responses, we analysed lake sediments for pollen, subfossil Cladocera, plant macrofossils and chemical composition of the sediment. Of these, plant macrofossils and Cladocera were used to infer minimum and mean July temperatures and ordination analysis was used to examine biotic community shifts. Multiproxy analyses of late-glacial sediments of Lake Łukie clearly show that the main driver of aquatic and terrestrial ecosystems as well as geomorphological processes in the catchment was climate variation. The history of the lake initiated during the Older Dryas. In that period, Łęczna Włodawa Lake District was covered by open habitats dominated by grasses (Poaceae), humid sites were occupied by tundra plant communities with less clubmoss (Selaginella selaginoides), dry sites by dominated by steppe-like vegetation with light-demanding species such as Helianthemum, Artemisia, Chenopodiaceae, and juniper bushes (Juniperus). Cold climate limited the growth and development of organisms in the lake, Cladocera community species composition was poor, with only few species present there all the time. During this time period, permafrost was still present in the ground limiting infiltration of rainwater and causing high erosion in the catchment area. Surface runoff is confirmed by the presence of sclerotia of Cenococcum geophilum and high terrigenous silica content. The warming of the early Allerød caused a remarkable change in the natural environment of this area. This is in accordance with the temperature rise reconstructed with the use of plant macrofossils though the Cladocera reconstruction did not recorded the rise than. This temperature increase resulted in turnover of vegetation in the

  4. Trichinella infections in arctic foxes from Greenland

    DEFF Research Database (Denmark)

    Kapel, C. M O; Henriksen, S. A.; Berg, T. B.

    1995-01-01

    Studies were carried out to determine the predilection sites of Trichinella nativa muscle larvae in arctic foxes (Alopex lagopus) caught in Greenland. The highest number of larvae per gram of tissue was found in the muscles of the eyes and the legs. With regard to predilection sites no significant...... differences were demonstrated either between age groups or between foxes with high and low total parasite burdens. Predilection sites were comparable with those recorded earlier in experimentally infected caged foxes and in other carnivorous species. Hypotheses on predilection sites of Trichinella muscle...

  5. Deglacial History and Paleoceanography of the Umanak System, West Greenland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Jennings, Anne; Andrews, John

    2012-01-01

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

  6. Prevalence of gestational diabetes mellitus among women born in Greenland

    DEFF Research Database (Denmark)

    Jacobsen, Jytte Lindskov; Jørgensen, Marit Eika

    2010-01-01

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

  7. Permafrost degradation in West Greenland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2012-01-01

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

  8. Regional and inter annual patterns of heavy metals, organochlorines and stable isotopes in narwhals (Monodon monoceros) from West Greenland

    DEFF Research Database (Denmark)

    Dietz, R.; Riget, F.; Hobson, K.A.

    2004-01-01

    Samples of 150 narwhals obtained in different years from two West Greenland areas, Avanersuaq and Uummannaq, were compared for concentrations of and regional differences in heavy metals and organochlorines and stable-carbon and nitrogen isotopes. Cadmium, Hg, and Se concentrations increased....../age composition of the data. PCB and DDT concentrations in West Greenland narwhals were half those found in East Greenland and Svalbard. Stable-carbon isotope ratios in muscle of 150 narwhals showed a decreasing trend in the first year when they gradually reduced their dependency on mother's milk, after which...... between stable isotope ratios and metal and OC concentrations....

  9. An evaluation of teeth of ringed seals (Phoca hispida) from Greenland as a matrix to monitor spatial and temporal trends of mercury and stable isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Aubail, Aurore, E-mail: aaubail@yahoo.fr [National Environmental Research Institute, Aarhus University, Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde (Denmark); Littoral, Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17000 La Rochelle (France); Dietz, Rune; Riget, Frank [National Environmental Research Institute, Aarhus University, Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde (Denmark); Simon-Bouhet, Benoit; Caurant, Florence [Littoral, Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17000 La Rochelle (France)

    2010-10-01

    Total mercury (Hg) concentrations were measured in teeth of ringed seals from Qeqertarsuaq, central West Greenland (1982 to 2006) and Ittoqqortoormiit, central East Greenland (1986 to 2006). Stable isotopic ratios of carbon ({sup 13}C/{sup 12}C) and nitrogen ({sup 15}N/{sup 14}N) were determined as well to provide insights into diet variations between regions or through time. Mercury concentrations decreased the first years of life of the animals suggesting that Hg had been transferred from the mother to the foetus and newborn. The Hg concentrations in teeth were significantly lesser in ringed seals from central West Greenland compared to those from central East Greenland. Carbon and nitrogen stable isotopic values measured in the animals differed also significantly between the two regions. Increasing temporal trends of dental Hg concentrations between 1994 and 2006 were observed in ringed seals from both central West Greenland and central East Greenland. These increases were attributed to global changes in environmental Hg levels since no temporal trends in {delta}{sup 15}N values were found to support the hypothesis of a diet shift over time. Furthermore, a decreasing temporal trend in {delta}{sup 13}C values was observed in the teeth of seals from central East Greenland, and explained by a likely change over time towards more pelagic feeding habits; alternatively, the so-known Seuss effect was thought to be responsible for this decrease. Finally, it was concluded that the tooth of ringed seal was a good monitoring tissue to assess Hg trends.

  10. 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...... or water saving toilets. This opens up for co-treatment of organic waste fractions. Freezing and thawing has also been recognised as being a cost-effective wastewater treatment method in cold regions. Thus it was chosen to concentrate on the effect of the mentioned processes, namely freezing, anaerobic...... spreading of nutrients, diseases and potential pollution issues. Due to the above mentioned challenges alternative treatment methods are needed, especially in small and remotely located communities. Decentralized solutions are well suited for Greenland. Ideal solutions should reduce the need for expensive...

  11. Gastrointestinal Parasites of Two Populations of Arctic Foxes (Vulpes lagopus) from Northeast Greenland

    DEFF Research Database (Denmark)

    Andreassen, P.N.S.; Schmidt, Niels Martin; Kapel, Christian M. O.

    2017-01-01

    Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps...

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

    Science.gov (United States)

    Shulgin, Alexey; Thybo, Hans

    2014-05-01

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

  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...... refraction/wide-angle reflection profile. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass, made...... acquisition of geophysical data logistically complicated. The profile extends 310 km inland in E-W direction from the approximate edge of the stable ice cap near the Scoresby Sund across the center of the ice cap. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along...

  14. Growth of wild muskoxen under two nutritional regimes in Greenland

    Directory of Open Access Journals (Sweden)

    Carsten Riis Olesen

    1994-12-01

    Full Text Available Growth of muskoxen in Jameson Land, East Greenland (EG and in Angujaartorfiup Nunaa, West Greenland (WG is affected by the different nutritional conditions in the two areas. The abundance and availability of forage plants is highest in WG. Muskoxen in WG reach sexual maturity one year earlier than muskoxen in EG. A significant proportion of female muskoxen in WG conceive at the age of 16 months and give birth to their first calf as two years olds. The horn bases of the muskox bulls in WG are fully developed during their third year of life, but their maximum body weight (BW is attained at the age of six. Average BW of adult bulls (4 yr+ in WG is 306 kg which is 23 % greater than in adult bulls in EG. BW is seasonally more variable in EG than in WG owing to greater seasonal fluctuation in food supply.

  15. Holocene environmental changes and climate development in Greenland

    International Nuclear Information System (INIS)

    Engels, Stefan; Helmens, Karin

    2010-12-01

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

  16. Holocene environmental changes and climate development in Greenland

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  17. Hydrologic Outlets of the Greenland Ice Sheet

    Data.gov (United States)

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

  18. Post-colonial identity in Greenland?

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2009-01-01

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

  19. 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....

  20. Mass accumulation rate and monsoon records from Xifeng, Chinese Loess Plateau, based on a luminescence age model

    DEFF Research Database (Denmark)

    Stevens, Thomas; Buylaert, Jan-Pieter; Lu, Huayu

    2016-01-01

    common than previously realized. MARs from undisturbed portions of Xifeng vary dramatically, with peaks potentially matching the timing of Heinrich events. The last glacial maximum peak MAR (22–27 ka) matches the Pacific and Greenland dust flux records, although appears earlier than peak MARs seen...... in many other OSL‐dated Loess Plateau sites. East Asian monsoon grain‐size and magnetic susceptibility records also show several differences between independently dated loess sites. This complicates our understanding of any lag between insolation forcing and monsoon response. Nevertheless, the Xifeng...

  1. 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

    A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings in A....... This pattern provides further evidence for the operation of a "bipolar see-saw" in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales....

  2. The climatic record of the earliest spring in Romania, regarding the south-east part of the country – spring 2016

    Directory of Open Access Journals (Sweden)

    I. OCTAVIA BOGDAN

    2016-11-01

    Full Text Available The climatic record of the earliest spring in Romania, regarding the south-east part of the country – Spring 2016. In the past 30 years it has been an increasing frequency of early SPRING ARRIVAL. Therefore, vegetation development started in early February. In March, the warm weather continued almost throughout the month, and the hoarfrosts from March became hereby destructive. Frequently, the vegetation in April was in very advanced stages. Even though the temperatures rose in April, cooling in April and late spring hoarfrosts have occurred and caused considerable damage. In this study we analyze the climatic macroprocesses that led to the apparition of an absolute climate record for the earliest spring arrival in 2016. The work is useful to anyone interested in climate change in Romania.

  3. The Melbourne East Monash General Practice Database (MAGNET: Using data from computerised medical records to create a platform for primary care and health services research

    Directory of Open Access Journals (Sweden)

    Danielle Mazza

    2016-07-01

    Full Text Available The Melbourne East MonAsh GeNeral PracticE DaTabase (MAGNET research platform was launched in 2013 to provide a unique data source for primary care and health services research in Australia.  MAGNET contains information from the computerised records of 50 participating general practices and includes data from the computerised medical records of more than 1,100,000 patients.  The data extracted is patient-level episodic information and includes a variety of fields related to patient demographics and historical clinical information, along with the characteristics of the participating general practices.  While there are limitations to the data that is currently available, the MAGNET research platform continues to investigate other avenues for improving the breadth and quality of data, with the aim of providing a more comprehensive picture of primary care in Australia

  4. The Melbourne East Monash General Practice Database (MAGNET): Using data from computerised medical records to create a platform for primary care and health services research.

    Science.gov (United States)

    Mazza, Danielle; Pearce, Christopher; Turner, Lyle Robert; De Leon-Santiago, Maria; McLeod, Adam; Ferriggi, Jason; Shearer, Marianne

    2016-07-04

    The Melbourne East MonAsh GeNeral PracticE DaTabase (MAGNET) research platform was launched in 2013 to provide a unique data source for primary care and health services research in Australia.  MAGNET contains information from the computerised records of 50 participating general practices and includes data from the computerised medical records of more than 1,100,000 patients.  The data extracted is patient-level episodic information and includes a variety of fields related to patient demographics and historical clinical information, along with the characteristics of the participating general practices.  While there are limitations to the data that is currently available, the MAGNET research platform continues to investigate other avenues for improving the breadth and quality of data, with the aim of providing a more comprehensive picture of primary care in Australia.

  5. High-resolution records of the beryllium-10 solar activity proxy in ice from Law Dome, East Antarctica: measurement, reproducibility and principal trends

    Directory of Open Access Journals (Sweden)

    J. B. Pedro

    2011-07-01

    Full Text Available Three near-monthly resolution 10Be records are presented from the Dome Summit South (DSS ice core site, Law Dome, East Antarctica. The chemical preparation and Accelerator Mass Spectrometer (AMS measurement of these records is described. The reproducibility of 10Be records at DSS is assessed through intercomparison of the ice core data with data from two previously published and contemporaneous snow pits. We find generally good agreement between the five records, comparable to that observed between other trace chemical records from the site. This result allays concerns raised by a previous Antarctic study (Moraal et al., 2005 about poor reproducibility of ice core 10Be records. A single composite series is constructed from the three ice cores providing a monthly-resolved record of 10Be concentrations at DSS over the past decade (1999 to 2009. To our knowledge, this is the first published ice core data spanning the recent exceptional solar minimum of solar cycle 23. 10Be concentrations are significantly correlated to the cosmic ray flux recorded by the McMurdo neutron monitor (rxy = 0.64, with 95 % CI of 0.53 to 0.71, suggesting that solar modulation of the atmospheric production rate may explain up to ~40 % of the variance in 10Be concentrations at DSS. Sharp concentration peaks occur in most years during the summer-to-autumn, possibly caused by stratospheric incursions. Our results underscore the presence of both production and meteorological signals in ice core 10Be data.

  6. Vegetation, climate and fire-dynamics in East Africa inferred from the Maundi crater pollen record from Mt Kilimanjaro during the last glacial-interglacial cycle

    Science.gov (United States)

    Schüler, Lisa; Hemp, Andreas; Zech, Wolfgang; Behling, Hermann

    2012-04-01

    The pollen, charcoal and sedimentological record from the Maundi crater, located at 2780 m elevation on the south-eastern slope of Mt Kilimanjaro, is one of the longest terrestrial records in equatorial East Africa, giving an interesting insight into the vegetation and climate dynamics back to the early last Glacial period. Our sediment record has a reliable chronology until 42 ka BP. An extrapolation of the age-depth model, as well as matching with other palaeo-records from tropical East Africa, suggest a total age of about 90 ka BP at the bottom of the record. During the last Glacial the distribution as well as the composition of the vegetation belts classified as colline savanna, submontane woodland, montane forest, ericaceous belt, and alpine vegetation changed. The early last Glacial is characterized by high amounts of Poaceae and Asteraceae pollen suggesting a climatically dry but stable phase. Based on the absence of pollen grains in samples deposited around 70 ka BP, we assume the occurrence of distinct drought periods. During the pre-LGM (Last Glacial Maximum) a higher taxa diversity of the ericaceous and montane zone is recorded and suggests a spread of forest and shrub vegetation, thus indicating a more humid period. The taxa diversity increases steadily during the recorded time span. The decent of vegetation zones indicate dry and cold conditions during the LGM and seem to have been detrimental for many taxa, especially those of the forest vegetation; however, the early last Glacial seems to have been markedly drier than the LGM. The reappearance of most of the taxa (most importantly Alchemilla, Araliaceae, Dodonea, Hagenia, Ilex, Myrsine, Moraceae, Piperaceae) during the deglacial and Holocene period suggest a shift into humid conditions. An increase in ferns and the decrease in grasses during the Holocene also indicate increasing humidity. Fire played an important role in controlling the development and elevation of the ericaceous zone and the tree

  7. Population Structure of West Greenland Narwhals

    DEFF Research Database (Denmark)

    Riget, F.; Dietz, R.; Møller, P.

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

  8. Sustainable Mobile Tourist Hut for Greenland

    DEFF Research Database (Denmark)

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

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

  9. Environmental radioactivity in Greenland in 1974

    International Nuclear Information System (INIS)

    Aarkrog, A.; Lippert, J.

    1975-07-01

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

  10. New Records of Hippolytid Shrimps, Lebbeus speciosus and Lebbeus comanthi (Crustacea: Decapoda: Caridea from the East Sea, Korea

    Directory of Open Access Journals (Sweden)

    Chu Lee

    2013-01-01

    Full Text Available Two species of the hippolytid shrimps, Lebbeus speciosus and Lebbeus comanthi, are described and illustrated for the first time in Korea. They were collected from the East Sea. Lebbeus speciosus was found in a scallop farm of Jumunjin, Gangneung, and L. comanthi associated with crinoids, was found in Gampo, Gyeongju. The difference between these two related species is in the number of dorsal teeth of the rostrum, five teeth in L. speciosus and a single tooth in L. comanthi. The Korean Lebbeus species has increased to 6 species by the present report. They are L. grandimana, L. polaris, L. unalaskensis, L. groenlandicus, L. speciosus, and L. comanthi.

  11. Speleothem stable isotope records for east-central Europe: resampling sedimentary proxy records to obtain evenly spaced time series with spectral guidance

    Science.gov (United States)

    Gábor Hatvani, István; Kern, Zoltán; Leél-Őssy, Szabolcs; Demény, Attila

    2018-01-01

    Uneven spacing is a common feature of sedimentary paleoclimate records, in many cases causing difficulties in the application of classical statistical and time series methods. Although special statistical tools do exist to assess unevenly spaced data directly, the transformation of such data into a temporally equidistant time series which may then be examined using commonly employed statistical tools remains, however, an unachieved goal. The present paper, therefore, introduces an approach to obtain evenly spaced time series (using cubic spline fitting) from unevenly spaced speleothem records with the application of a spectral guidance to avoid the spectral bias caused by interpolation and retain the original spectral characteristics of the data. The methodology was applied to stable carbon and oxygen isotope records derived from two stalagmites from the Baradla Cave (NE Hungary) dating back to the late 18th century. To show the benefit of the equally spaced records to climate studies, their coherence with climate parameters is explored using wavelet transform coherence and discussed. The obtained equally spaced time series are available at PANGAEA.875917" target="_blank">https://doi.org/10.1594/PANGAEA.875917.

  12. Solitary Waves of Ice Loss Detected in Greenland Crustal Motion

    Science.gov (United States)

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

    2017-12-01

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

  13. 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...... strong upper-mantle velocity boundary under the East Greenland Caledonides. However, the contrast in the VP/VS ratio is not as clear at this location. A correlation study of topography versus upper-mantle velocity revealed positive correlation in southern Norway but negative or absent correlation...

  14. Planation surfaces as a record of medium to large wavelength deformation: the example of the Lake Albert Rift (Uganda) on the East African Dome

    Science.gov (United States)

    Brendan, Simon; François, Guillocheau; Cécile, Robin; Jean, Braun; Olivier, Dauteuil; Massimo, Dall'Asta

    2016-04-01

    African relief is characterized by planation surfaces, some of them of continental scale. These surfaces are slightly deformed according to different wavelengths (x10 km; x100 km, x1000 km) which record both mantle dynamics (very long wavelength, x 1000 km) and lithosphere deformation (long wavelength deformation, x 100 km). Different types of these planation surfaces are recognized: - Etchplains capped by iron-duricrust which correspond to erosional nearly flat weathered surfaces resulting from the growth of laterites under warm and humid conditions. - Pediments which define mechanical erosional surfaces with concave or rectilinear profiles delimited by upslope scarps connected upstream with the upper landforms. We here focused on the Lake Albert Rift at the northern termination of the western branch of the East African Rift System of which the two branches are surimposed on the East-African Dome. Different wavelengths of deformation were characterized based on the 3D mapping of stepped planation surfaces: (1) very long wavelength deformations resulting from the uplift of the East African Dome; (2) long wavelength deformations resulting from the opening of the eastern branch and (3) medium wavelength deformations represented by the uplift of rift shoulders like the Rwenzori Mountains. The paleo-landscape reconstruction of Uganda shows the existence of four generations of landforms dated according to their geometrical relationships with volcanic rocks. A four stepped evolution of the Ugandan landforms is proposed: • 70 - 22 Ma: generation of two weathered planation surfaces (etchplain Uw and Iw). The upper one (Uw) records a very humid period culminating at time of the Early Eocene Climatic Optimum (70-45 Ma). It corresponds to the African Surface. A first uplift of the East African Dome generates a second lower planation surface (Iw) connected to the Atlantic Ocean base level; • 17-2.7 Ma: planation of large pediplains connected to the local base level induced

  15. A geochemical record of the link between chemical weathering and the East Asian summer monsoon during the late Holocene preserved in lacustrine sediments from Poyang Lake, central China

    Science.gov (United States)

    Huang, Chao; Wei, Gangjian; Li, Wuxian; Liu, Ying

    2018-04-01

    This paper presents relatively high-resolution geochemical records spanning the past 4000 cal yr BP obtained from the lacustrine sediments of Poyang Lake in central China. The variations in the intensity of the East Asian summer monsoon (EASM) are traced using the K/Na, Ti/Na, Al/K, kaolinite/illite and clay/feldspar ratios, together with the chemical index of alteration (CIA), as indicators of chemical weathering. During the last 4000 years, the proxy records of chemical weathering from Poyang Lake exhibit an overall enhanced trend, consistent with regional hydrological changes in previous independent records. Further comparisons and analyses demonstrate that regional moisture variations in central China is inversely correlated with the EASM intensity, with weak EASM generating high precipitation in central China. Our data reveal three intervals of dramatically dry climatic conditions (i.e., ca. 4000-3200 cal yr BP, ca. 2800-2400 cal yr BP, and ca. 500-200 cal yr BP). A period of weak chemical weathering, related to cold and dry climatic conditions, occurred during the Little Ice Age (LIA), whereas more intense chemical weathering, reflecting warm and humid climatic conditions, was recorded during the Medieval Warm Period (MWP). Besides, an intensification of chemical weathering in Poyang Lake during the late Holocene agrees well with strong ENSO activity, suggesting that moisture variations in central China may be predominantly driven by ENSO variability.

  16. Environmental magnetic and petroleum hydrocarbons records in sediment cores from the north east coast of Tamilnadu, Bay of Bengal, India.

    Science.gov (United States)

    Venkatachalapathy, R; Veerasingam, S; Basavaiah, N; Ramkumar, T; Deenadayalan, K

    2011-04-01

    In this study, mineral magnetic properties and petroleum hydrocarbons were statistically analysed in four sediment cores (C1, A1, T1 and K1) from the north east coast of Tamilnadu, India to examine the feasibility of PHC concentrations assessment using magnetic susceptibility. The C1 and A1 cores reveal a clear horizon of increase in PHC above 35 and 50 cm respectively suggesting the excess anthropogenic loading occurred in the recent past. Magnetic properties which were enhanced in the upper part of the sediment cores were the result of ferrimagnetic minerals from anthropogenic sources. Factor analysis confirmed that the input of magnetic minerals and petroleum hydrocarbons in Chennai coastal sediments are derived from the same sources. The present study shows that instead of expensive and destructive PHC chemical methods, magnetic susceptibility is found to be a suitable, cheap and rapid method for detailed study of petroleum hydrocarbon contamination in marine sediments. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Low-high latitude interaction forcing on the evolution of the 400 kyr cycle in East Asian winter monsoon records during the last 2.8 Myr

    Science.gov (United States)

    Li, Dawei; Zhao, Meixun; Tian, Jun

    2017-09-01

    Variability of the East Asian winter monsoon (EAWM), stronger during glacials and weaker during interglacials, has been tightly linked to the wax and wane of the Northern Hemisphere ice sheets (NHIS) via the Siberian High over the last 2.8 million years (Myr). However, the long eccentricity cycle (ca. 400 kyr) in the EAWM record from the late Pliocene to early-Pleistocene (2.8-1.2 Ma) could not be linked to NHIS changes, which lacked the long eccentricity cycle in the Pleistocene. Here, we present the first low latitude EAWM record of the last 2.8 Myr using surface and subsurface temperature difference from the northern South China Sea to evaluate interactions between tropical ocean and EAWM changes. The results show that the EAWM variability displayed significant 400 kyr cycle between 2.8 Ma and 1.2 Ma, with weak (strong) EAWM during high (low) earth orbital eccentricity state. A super El Niño-Southern Oscillation (ENSO) proxy record, calculated using west-east equatorial Pacific sea surface temperature differences, revealed 400 kyr cycles throughout the last 2.8 Myr with warm phase during high eccentricity state. Thus, we propose that super ENSO mean state strongly modulated the EAWM strength through remote forcing to generate the 400 kyr cycle between 2.8 Ma and 1.2 Ma, while low NHIS volume was not sufficient to dominate the EAWM variation as it did over the last 0.9 Myr with 100 kyr cycles in dominance.

  19. Temperature and conductivity, and water currents data collected by CTDs and current meters on moored buoys in the Sermilik Fjord, Greenland from 2010-08 to 2011-08 (NODC Accession 0123282)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data included in this dataset were collected in Sermilik Fjord, located in East Greenland in the Ammassalik district close to the town of Tasiilaq. Data...

  20. Water Temperature, conductivity, and currents data collected by CTDs and current meters on moored buoys in the Sermilik Fjord, Greenland from 2012-09-18 to 2013-08-20 (NCEI Accession 0127325)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data included in this dataset were collected in the Sermilik Fjord, located in East Greenland in the Ammassalik district close to the town of Tasiilaq. Data...

  1. Temperature, conductivity, and water currents data collected by CTDs and current meters on moored buoys in the Sermilik Fjord, Greenland from 2011-08-20 to 2012-09-16 (NODC Accession 0126772)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data included in this dataset were collected in the Sermilik Fjord, located in East Greenland in the Ammassalik district close to the town of Tasiilaq. Data...

  2. 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).

  3. The Greenland Telescope (GLT): antenna status and future plans

    Science.gov (United States)

    Raffin, Philippe; Algaba-Marcosa, Juan Carlos; Asada, Keiichi; Blundell, Raymond; Burgos, Roberto; Chang, Chih-Cheng; Chen, Ming-Tang; Christensen, Robert; Grimes, Paul K.; Han, C. C.; Ho, Paul T. P.; Huang, Yau-De; Inoue, Makoto; Koch, Patrick M.; Kubo, Derek; Leiker, Steve; Liu, Ching-Tang; Martin-Cocher, Pierre; Matsushita, Satoki; Nakamura, Masanori; Nishioka, Hiroaki; Nystrom, George; Paine, Scott N.; Patel, Nimesh A.; Pradel, Nicolas; Pu, Hung-Yi; Shen, H.-Y.; Snow, William; Sridharan, Tirupati K.; Srinivasan, Ranjani; Tong, Edward; Wang, Jackie

    2014-07-01

    The ALMA North America Prototype Antenna was awarded to the Smithsonian Astrophysical Observatory (SAO) in 2011. SAO and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), SAO's main partner for this project, are working jointly to relocate the antenna to Greenland to carry out millimeter and submillimeter VLBI observations. This paper presents the work carried out on upgrading the antenna to enable operation in the Arctic climate by the GLT Team to make this challenging project possible, with an emphasis on the unexpected telescope components that had to be either redesigned or changed. Five-years of inactivity, with the antenna laying idle in the desert of New Mexico, coupled with the extreme weather conditions of the selected site in Greenland have it necessary to significantly refurbish the antenna. We found that many components did need to be replaced, such as the antenna support cone, the azimuth bearing, the carbon fiber quadrupod, the hexapod, the HVAC, the tiltmeters, the antenna electronic enclosures housing servo and other drive components, and the cables. We selected Vertex, the original antenna manufacturer, for the main design work, which is in progress. The next coming months will see the major antenna components and subsystems shipped to a site of the US East Coast for test-fitting the major antenna components, which have been retrofitted. The following step will be to ship the components to Greenland to carry out VLBI

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  5. Greenland ice mass balance from GPS, GRACE and ICESat

    DEFF Research Database (Denmark)

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

    Greenland, using stereoscopic coverage by aerial photographs recorded in 1985, and subsequent comparative surface elevation data from ICESat (Ice, Cloud and land Elevation Satellite) and ATM (Airborne Topographic Mapper) supplemented with 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, while the GPS data are used to monitor crustal uplift caused by ice mass loss close to the GPS sites....

  6. 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...

  7. Verbal aspects in West Greenlandic

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann

    2017-01-01

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

  8. Gestational diabetes mellitus in Greenland

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Aqqalu Rosving-Asvid

    2010-09-01

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

  10. Seismic structure of the crust and upper mantle in central-eastern Greenland

    DEFF Research Database (Denmark)

    Kraft, Helene Anja

    Geophysical and geological knowledge of the interior of Greenland is very limited. The lack of knowledge arises mainly due to the logistical challenges related to conducting geophysical fieldwork on the up to 3400 m thick ice sheet, which covers around 80% of the land area. This PhD thesis is based...... on the very first regional passive seismic study in central-Eastern Greenland, focusing on the area between Scoresby Sund and Summit. The study aims to image the structure of subsurface Greenland starting from the crust and down to the mantle transition zone. Furthermore, the thesis links these observations....... The receiver functions were jointly inverted for the velocity structure of the crust and delay times, and shapes of signals originating at the mantle transition zone discontinuities, P410s and P660s, were analysed. The crustal models show a deepening of the Moho from east to west from less than 20 km depth...

  11. Interglacial insects and their possible survival in Greenland during the last glacial stage

    DEFF Research Database (Denmark)

    Bøcher, Jens Jensenius

    2012-01-01

    Sediments from the last interglacial (Eemian) in Jameson Land, East Greenland, and the Thule area, NW Greenland, have revealed a number of insect fragments of both arctic and more or less warmth-demanding species. Altogether, the interglacial fauna of Coleoptera (beetles) indicates boreal...... beetle species such as Amara alpina and Isochnus arcticus did not survive the last glacial stage in Greenland. Two factors that have not been sufficiently considered when discussing survival contra extinction are the importance of microclimate and the number of sun-hours during the Arctic summer. Even...... among the Coleoptera, which as a group fares quite badly in the Arctic, there might be survivors, at least among those found both during the interglacial and as fossils during the early Holocene. First of all, glacial survival applies to the seed bug Nysius groenlandicus, which was widespread during...

  12. Reconstruction of Antarctic climate change using ice core proxy records from the coastal Dronning Maud Land, East Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Thamban, M.; Laluraj, C.M.; Naik, S.S.; Chaturvedi, A.

    the austral summer of 2003. The retrieved ice core samples were labelled, packed in good quality LDPE containers and subsequently shipped in -20ºC deep freezer facilities. These cores were archived in frozen conditions in custom-made expanded polypropylene...: Glaciochemistry, Stable isotope, Ice core, Solar activity, Dronning Maud Land, Antarctica. regions offer continuous and highly resolved long-term records of reliable information on major atmospheric parameters like temperature, composition and trace gases. Among...

  13. Infectious diseases in Greenlanders of Upernavik

    DEFF Research Database (Denmark)

    Bjerregaard, P

    1985-01-01

    During one year, 1979-80, all the contacts between the 836 inhabitants of Upernavik town and the local medical officers were recorded. In the 737 native Greenlanders 1006 contacts (41%) were caused by infectious diseases, representing 705 episodes of disease. The number of contacts per episode...... infections during winter was noted. The contact rate for all infectious diseases together was slightly higher than in Danish general practice, and infectious diseases also accounted for a larger proportion of all registered contacts. Contacts due to chronic respiratory infections, skin infections...... of disease was similar in all age groups. Of these contacts 26% were caused by acute upper respiratory tract infections, 8% by other acute respiratory infections, 10% by chronic respiratory infections, 24% by non-traumatic skin infections, 7% by post-traumatic skin infections, 8% by sexually transmitted...

  14. A 242-year seasonal-resolved speleothem record from Hainan Island: A window into variability of the precipitation δ18O in East Asia

    Science.gov (United States)

    Cai, Y.; An, Z.; Cheng, H.; Edwards, R. L.; Fung, I. Y.; Zhang, H.; Tan, L.; Bi, H.

    2016-12-01

    Hainan Island is located at the gateway of East Asian summer monsoon to the continent. The typical tropical monsoon climate at Hainan island is characterized by wet season during the summer and autumn and dry season during the winter and spring. Here, we present a seasonal resolved speleothem record spanning 242 years ( 50-292 AD) from Xianren Cave (E109°25`, N18°34`), which is situated in the Baoting County, Hainan Province. The monitoring inside the cave shows that the relative humidity kept saturated during the observed periods (one and half years) while the temperature varied seasonally following the temperature changes outside the cave, but with much smaller amplitude. Monthly observation of drip water inside the cave indicates that the isotope composition of drip water mainly responds to the changes in the precipitation isotope composition with less than two months' resident time. The visible annual lamination and distinct fluctuations of calcite Mg, Sr and Ba concentrations corroborate that the high-frequency oscillations of calcite δ18O largely capture the seasonal variation of the isotope composition of precipitation, although the temperature effect cannot be excluded. By setting the heaviest value of annual variation of calcite δ18O as the beginning of each annual cycle, we transferred the δ18O record of 11.2 cm in depth to a δ18O record of 242-year in age. The δ18O record of stalagmite XR-3 demonstrate clearly the annual, decadal and multi-decadal variations of amplitude from 2 to 4‰, in addition to the seasonal oscillation of amplitude varied from 1.5 to 2.5‰. The ensemble empirical mode decomposition results show that the dominant variability (54.6% of the total variance) is captured by the components at the timescale of 3-7 year, while the components on timescales of 22-24 -year, 80-year and 120-year capture 35.0%, 7.0% and 3.4% of the variance, respectively. We contribute the variability of speleothem δ18O at the timescale of 3-7 -year to

  15. The Greenland Analogue Project, Yearly Report 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-08-15

    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

  16. The Greenland Analogue Project, Yearly Report 2009

    International Nuclear Information System (INIS)

    2011-08-01

    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

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

    Directory of Open Access Journals (Sweden)

    Peter Bjerregaard

    2015-02-01

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

  18. Resolving climate change in the period 15-23 ka in Greenland ice cores: A new application of spectral trend analysis

    NARCIS (Netherlands)

    de Jong, M.G.G.; Nio, D.S.; Böhm, A.R.; Seijmonsbergen, H.C.; de Graaff, L.W.S.

    2009-01-01

    Northern Hemisphere climate history through and following the Last Glacial Maximum is recorded in detail in ice cores from Greenland. However, the period between Greenland Interstadials 1 and 2 (15-23 ka), i.e. the period of deglaciation following the last major glaciation, has been difficult to

  19. Long term variations of chlorine-36 input signal to groundwater as recorded in deep unsaturated zones, south-east Australia

    International Nuclear Information System (INIS)

    Le Gal La Salle, C.; Herczeg, A.L.; Leaney, F.W.; Fifield, L.K.; Cresswell, R.G.; Kellet, J.

    1997-01-01

    The use of chlorine-36 is increasing in hydrology as its long half-life (3x10 5 a), allows useful long-term investigations into groundwater systems. Because chloride is very hydrophillic, the chlorine-36 signal should not be affected by geochemical processes in most aquatic systems. Nevertheless, over long periods of time, the chlorine-36 input to groundwater systems may vary due to factors such as: changes of production of chlorine-36 and/or changes of its distribution in the atmosphere. For instance the production of chlorine-36 might be governed by long-term terrestrial magnetic dipole strength variations as suggested for other radiogenic isotopes. Variations of the input signal of chlorine-36 should be recorded in pore waters of deep unsaturated zones. In this system, the time scale is approximated by the cumulative chloride content with depth assuming a constant input of chloride. Long-term records of chloride and chlorine-36 in two deep unsaturated-zone profiles, situated in the semi-arid Murray Basin in Australia, are presented. The two profiles record periods of approximately 20±1 to 27±2 ka and 100±5 to 220±10 ka respectively. The range of variation of the recorded time at each site is related to the estimated range of chloride deposition rate. The recharge rates are constant in both profiles with values approximating 0.4 and less than 0.1 mm.a -1 respectively. The linear relationship between chlorine-36 and stable chloride indicates that variations of chlorine-36 are governed by evapotranspiration, with a concentration factor of up to 2. Therefore the chlorine-36 is normalised to chloride to take account of the evapotranspiration process. In the soil profile at Kaniva, Western Victoria, 36 Cl/Cl'- ratio shows an increase of approximately 20% down profile. The second profile at Boree Plains, Wester, NSW, shows variations of 36 Cl/Cl'- ratio of 40% with a decreasing trend down profile. The input signal of chlorine-36/chloride is calculated by correction

  20. Insights on nitrate sources at Dome C (East Antarctic Plateau from multi-year aerosol and snow records

    Directory of Open Access Journals (Sweden)

    Rita Traversi

    2014-06-01

    Full Text Available Here we present the first multi-year record of nitrate in the atmospheric aerosol (2005–2008 and surface snow (2006–08 from central Antarctica. PM10 and size-segregated aerosol, together with superficial snow, have been collected all year-round at high resolution (daily for all the snow samples and for most of aerosol samples at Dome C since the 2004/05 field season and analysed for main and trace ionic markers. The suitability of the sampling location in terms of possible contamination from the base is shown in detail. In spite of the relevance of nitrate in Antarctic atmosphere, both for better understanding the chemistry of N cycle in the plateau boundary layer and for improving the interpretation of long-term nitrate records from deep ice core records, nitrate sources in Antarctica are not well constrained yet, neither in extent nor in timing. A recurring seasonal pattern was pointed out in both aerosol and snow records, showing summer maxima and winter minima, although aerosol maxima lead the snow ones of 1–2 months, possibly due to a higher acidity in the atmosphere in mid-summer, favouring the repartition of nitrate as nitric acid and thus its uptake by the surface snow layers. On the basis of a meteorological analysis of one major nitrate event, of data related to PSC I extent and of irradiance values, we propose that the high nitrate summer levels in aerosol and snow are likely due to a synergy of enhanced source of nitrate and/or its precursors (such as the stratospheric inputs, higher solar irradiance and higher oxidation rates in this season. Moreover, we show here a further evidence of the substantial contribution of HNO3/NOx re-emission from the snowpack, already shown in previous works, and which can explain a significant fraction of atmospheric nitrate, maintaining the same seasonal pattern in the snow. As concerning snow specifically, the presented data suggest that nitrate is likely to be controlled mainly by atmospheric

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

    Science.gov (United States)

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

    2015-06-01

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

  2. Multi-decadal dynamic thinning on the northwest margin of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

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

    records with a 25 m grid resolution and vertical uncertainty of 4.6m. Comparative DEMs were derived from laser altimetry data recorded in 2005 and 2010. Ice loss from the Greenland Ice Sheet (GrIS) can be partitioned into surface mass balance (SMB) processes (runoff and precipitation) and ice dynamics...

  3. Biogeochemical cycling in a subarctic fjord adjacent to the Greenland Ice Sheet

    NARCIS (Netherlands)

    Meire, L.

    2016-01-01

    Temperatures in the Arctic have increased rapidly in recent years resulting in the melting of sea ice and glaciers at unprecedented rates. In 2012, sea ice extent across the Arctic reached a record minimum and the melt extent of Greenland Ice Sheet reached a record maximum. The accelerated mass loss

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  5. A 350 ka record of climate change from Lake El'gygytgyn, Far East Russian Arctic: refining the pattern of climate modes by means of cluster analysis

    Directory of Open Access Journals (Sweden)

    U. Frank

    2013-07-01

    Full Text Available Rock magnetic, biochemical and inorganic records of the sediment cores PG1351 and Lz1024 from Lake El'gygytgyn, Chukotka peninsula, Far East Russian Arctic, were subject to a hierarchical agglomerative cluster analysis in order to refine and extend the pattern of climate modes as defined by Melles et al. (2007. Cluster analysis of the data obtained from both cores yielded similar results, differentiating clearly between the four climate modes warm, peak warm, cold and dry, and cold and moist. In addition, two transitional phases were identified, representing the early stages of a cold phase and slightly colder conditions during a warm phase. The statistical approach can thus be used to resolve gradual changes in the sedimentary units as an indicator of available oxygen in the hypolimnion in greater detail. Based upon cluster analyses on core Lz1024, the published succession of climate modes in core PG1351, covering the last 250 ka, was modified and extended back to 350 ka. Comparison to the marine oxygen isotope (δ18O stack LR04 (Lisiecki and Raymo, 2005 and the summer insolation at 67.5° N, with the extended Lake El'gygytgyn parameter records of magnetic susceptibility (κLF, total organic carbon content (TOC and the chemical index of alteration (CIA; Minyuk et al., 2007, revealed that all stages back to marine isotope stage (MIS 10 and most of the substages are clearly reflected in the pattern derived from the cluster analysis.

  6. World Record Earned Value Management System Certification for Cleanup of the East Tennessee Technology Park, Oak Ridge, Tennessee, USA - 13181

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, Ray; Hirschy, Anita [URS - CH2M Oak Ridge, LLC (UCOR), East Tennessee Technology Park D and D and Environmental Remediation Project, Oak Ridge, Tennessee 37830 (United States)

    2013-07-01

    On projects that require Earned Value Management (EVMS) Certification, it is critical to quickly prepare for and then successfully obtain certification. This is especially true for government contracts. Projects that do poorly during the review are subject to financial penalties to their company and they lose creditability with their customer creating problems with the project at the outset. At East Tennessee Technology Park (ETTP), we began preparing for Department of Energy (DOE) certification early during proposal development. Once the contract was awarded, while still in transition phase from the previous contractor to our new company, we immediately began reviewing the project controls systems that were in place on the project and determined if any replacements needed to be made immediately. The ETTP contract required the scheduling software to be upgraded to Primavera P6 and we determined that no other software changes would be done prior to certification. Next, preparation of the Project Controls System Description (PCSD) and associated procedures began using corporate standards as related to the project controls systems. During the transition phase, development was started on the Performance Measurement Baseline which is the resource loaded schedule used to measure our performance on the project and which is critical to good Earned Value Management of the project. Early on, and throughout the baseline review, there was positive feedback from the Department of Energy that the quality of the new baseline was good. Having this superior baseline also contributed to our success in EVMS certification. The combined companies of URS and CH2M Hill had recent experience with certifications at other Department of Energy sites and we were able to capitalize on that knowledge and experience. Generic PCSD and procedures consistent with our co-operations approach to Earned Value Management were available to us and were easily tailorable to the specifics of our contract

  7. World Record Earned Value Management System Certification for Cleanup of the East Tennessee Technology Park, Oak Ridge, Tennessee, USA - 13181

    International Nuclear Information System (INIS)

    Haynes, Ray; Hirschy, Anita

    2013-01-01

    On projects that require Earned Value Management (EVMS) Certification, it is critical to quickly prepare for and then successfully obtain certification. This is especially true for government contracts. Projects that do poorly during the review are subject to financial penalties to their company and they lose creditability with their customer creating problems with the project at the outset. At East Tennessee Technology Park (ETTP), we began preparing for Department of Energy (DOE) certification early during proposal development. Once the contract was awarded, while still in transition phase from the previous contractor to our new company, we immediately began reviewing the project controls systems that were in place on the project and determined if any replacements needed to be made immediately. The ETTP contract required the scheduling software to be upgraded to Primavera P6 and we determined that no other software changes would be done prior to certification. Next, preparation of the Project Controls System Description (PCSD) and associated procedures began using corporate standards as related to the project controls systems. During the transition phase, development was started on the Performance Measurement Baseline which is the resource loaded schedule used to measure our performance on the project and which is critical to good Earned Value Management of the project. Early on, and throughout the baseline review, there was positive feedback from the Department of Energy that the quality of the new baseline was good. Having this superior baseline also contributed to our success in EVMS certification. The combined companies of URS and CH2M Hill had recent experience with certifications at other Department of Energy sites and we were able to capitalize on that knowledge and experience. Generic PCSD and procedures consistent with our co-operations approach to Earned Value Management were available to us and were easily tailorable to the specifics of our contract

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

    DEFF Research Database (Denmark)

    Steffen, Rebekka; Strykowski, Gabriel; Lund, Björn

    2017-01-01

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

  9. Gastrointestinal Parasites of Two Populations of Arctic Foxes (Vulpes lagopus) from Northeast Greenland

    DEFF Research Database (Denmark)

    Andreassen, P.N.S.; Schmidt, Niels Martin; Kapel, Christian M. O.

    2017-01-01

    Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps...

  10. Temporal and spatial variations in wildlife population fluctuations in Greenland; The effect of climate, environment and man

    DEFF Research Database (Denmark)

    Moshøj, Charlotte Margaret; Forchhammer, Mads C.; Forbes, Valery E.

    2009-01-01

    Temporal and spatial variations in wildlife population fluctuations in Greenland; The effect of climate, environment and man Moshøj, C.M, M.C.Forchhammer and V.E. Forbes Temporal and spatial variations in wildlife population fluctuations in Greenland; The effect of climate, environment and man...... and mammals display distinct population fluctuations of varying temporal and spatial scale. In Greenland, historical records, archaeological findings and oral accounts passed on from Inuit elders all document that the presence of wildlife species and their population sizes have undergone pronounced....... The results of this study will model future predictions of wildlife populations under changing climate variables and human hunting pressure....

  11. Validation of strong-motion stochastic model using observed ground motion records in north-east India

    Directory of Open Access Journals (Sweden)

    Dipok K. Bora

    2016-03-01

    Full Text Available We focused on validation of applicability of semi-empirical technique (spectral models and stochastic simulation for the estimation of ground-motion characteristics in the northeastern region (NER of India. In the present study, it is assumed that the point source approximation in far field is valid. The one-dimensional stochastic point source seismological model of Boore (1983 (Boore, DM. 1983. Stochastic simulation of high frequency ground motions based on seismological models of the radiated spectra. Bulletin of Seismological Society of America, 73, 1865–1894. is used for modelling the acceleration time histories. Total ground-motion records of 30 earthquakes of magnitudes lying between MW 4.2 and 6.2 in NER India from March 2008 to April 2013 are used for this study. We considered peak ground acceleration (PGA and pseudospectral acceleration (response spectrum amplitudes with 5% damping ratio at three fundamental natural periods, namely: 0.3, 1.0, and 3.0 s. The spectral models, which work well for PGA, overestimate the pseudospectral acceleration. It seems that there is a strong influence of local site amplification and crustal attenuation (kappa, which control spectral amplitudes at different frequencies. The results would allow analysing regional peculiarities of ground-motion excitation and propagation and updating seismic hazard assessment, both the probabilistic and deterministic approaches.

  12. Understanding Recent Mass Balance Changes of the Greenland Ice Sheet

    Science.gov (United States)

    vanderVeen, Cornelius

    2003-01-01

    The ultimate goal of this project is to better understand the current transfer of mass between the Greenland Ice Sheet, the world's oceans and the atmosphere, and to identify processes controlling the rate of this transfer, to be able to predict with greater confidence future contributions to global sea level rise. During the first year of this project, we focused on establishing longer-term records of change of selected outlet glaciers, reevaluation of mass input to the ice sheet and analysis of climate records derived from ice cores, and modeling meltwater production and runoff from the margins of the ice sheet.

  13. Climate change in Greenland, Denmark and the Levant

    DEFF Research Database (Denmark)

    Schrøder, Niels

    presented their isotopic records it was clear that the records were similar showing a series of climatic fluctuations (Dansgaard/Oescher events) We have re-examined the Yarbrud site in Syria (OSL dating and pollen analysis) in the hope that we could correlate the 25 cultural layers here (Rust 1950......), with the Dansgaard/Oescher events. It is concluded that: The effect of the NAO (North Atlantic Oscillation), given rise to opposite climate conditions in Denmark (NW Europe), the Levant and Greenland in the observation based climatic overview showis an interannual to decadal correlation of the climate...... Oscillation), archaeology, pollen, Blytt-Sernander model....

  14. Coral Geochemical Proxy Records Of The East Asian Winter Monsoon And Hydrological Conditions In The Central Vietnam From 1978-2004 AD

    Science.gov (United States)

    Chang, C.; Shen, C.; Chen, Y.; Chiang, H.; Lam, D. D.; Ngai, N.

    2007-12-01

    Monthly-resolution geochemical proxies, including δ18O, δ13C, Sr/Ca, and Ba/Ca, in a living Porites coral head, collected from Son Tra Island, a near-shore island located at the north tip of Vung Da Nang Bay, central Vietnam (16°12'59.4", 108°1'57.1"), was used to quantitatively reconstruct records of sea surface temperature (SST), sea surface salinity (SSS), seasonality of rainfall, and regional terrestrial input during a period of 1978-2004 AD. By comparing the 1/4-century geochemical data, five features are exhibited. (1) The coral Sr/Ca-inferred summer SSTs correspond well with the 1°x1° instrumental data to suggest that the regional SST record can be retrieved from this local coral head. (2) Interannual variation of coral winter SST data does not follow regional instrumental values. The harmonic phenomenon between coral inferred winter SST dynamic and the surface pressure difference, between the southern South China Sea (SCS) (0-10°N, 105-115°E) and the northern SCS (22.5-32.5°N, 112-122°E), indicating that the cold local SST induced by East Asian winter monsoon was addressed in the Son Tra coral. (3) 1‰ seasonal anomaly of δ18O residual (Δδ18O) suggests a 2-4-psu seasonal salinity change between dry and wet seasons. (4) The synchronous intra-annual changes of δ18O and Ba/Ca data suggest that the rainy season is from late summer to winter, which is consistent with the meteorological record. (5) The high Ba/Ca background level of 10 μmol/mol in 1992-2004, 2-3 times larger than the averaged value of 4 μmol/mol in 1978-1992, indicates an enhanced terrestrial sediment discharge into the bay over the past 10 years. Ba records probably reflect an impact of human activity on hydrological change since the Vietnam War.

  15. 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...

  16. 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...

  17. 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 ...

  18. Environmental radioactivity in Greenland in 1976

    International Nuclear Information System (INIS)

    Aarkrog, A.; Lippert, J.

    1977-07-01

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

  19. 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....

  20. Environmental radioactivity in Greenland in 1978

    International Nuclear Information System (INIS)

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

    1979-07-01

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

  1. Environmental radioactivity in Greenland in 1975

    International Nuclear Information System (INIS)

    Aarkrog, A.; Lippert, J.

    1976-07-01

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

  2. Cultural noise and the night-day asymmetry of the seismic activity recorded at the Bunker-East (BKE) Vesuvian Station

    Science.gov (United States)

    Scafetta, Nicola; Mazzarella, Adriano

    2018-01-01

    Mazzarella and Scafetta (2016) showed that the seismic activity recorded at the Bunker-East (BKE) Vesuvian station from 1999 to 2014 suggests a higher nocturnal seismic activity. However, this station is located at about 50 m from the main road to the volcano's crater and since 2009 its seismograms also record a significant diurnal cultural noise due mostly to tourist tours to Mt. Vesuvius. Herein, we investigate whether the different seismic frequency between day and night times could be an artifact of the peculiar cultural noise that affects this station mostly from 9:00 am to 5:00 pm from spring to fall. This time-distributed cultural noise should evidently reduce the possibility to detect low magnitude earthquakes during those hours but not high magnitude events. Using hourly distributions referring to different magnitude thresholds from M = 0.2 to M = 2.0, the Gutenberg-Richter magnitude-frequency diagram applied to the day and night-time sub-catalogs and Montecarlo statistical modeling, we demonstrate that the day-night asymmetry persists despite an evident disruption induced by cultural noise during day-hours. In particular, for the period 1999-2017, and for earthquakes with M ≥ 2 we found a Gutenberg-Richter exponent b = 1.66 ± 0.07 for the night-time events and b = 2.06 ± 0.07 for day-time events. Moreover, we repeat the analysis also for an older BKE catalog covering the period from 1992 to 2000 when cultural noise was not present. The analysis confirms a higher seismic nocturnal activity that is also characterized by a smaller Gutenberg-Richter exponent b for M ≥ 2 earthquakes relative to the day-time activity. Thus, the found night-day seismic asymmetric behavior is likely due to a real physical feature affecting Mt. Vesuvius.

  3. Paleoenvironmental Reconstruction of the North Atlantic Current Variations from MIS 3 to Holocene Based on Multiproxy Record from the North-East Scotland Continental Margin.

    Science.gov (United States)

    Ovsepyan, Y.; Tikhonova, A.; Novichkova, E.; Gupta, R. M.; Korsun, S.; Matul, A.

    2017-12-01

    In order to reconstruct the history of water mass interaction between the North Atlantic and the Nordic Seas since MIS 3 to the present, the sediment core from the North-East Scotland continental slope was investigated. The site of core AI-3521 (59°30.009 N, 7°20.062 E) from the 1051 m water depth is located beneath the pathway of the North Atlantic current which transports warm and saline Atlantic surface water to the Norwegian Sea. The age model of the sequence is based on stable isotope record of benthic Cassidulina neoteretis and planktic Neogloboquadrina pachyderma sin. and Globigerina bulloides. The Holocene interval of the upper 1.5 m is characterized by high sedimentation rates and the high biodiversity of microfauna. The distribution of ice rafted debris and CaCO3 content; benthic and planktic foraminiferal assemblages; oxygen, carbon and boron isotopes, Mg/Ca ratio were used to reconstruct the regional paleoceanographic conditions (bioproductivity, temperature, salinity) and to compare with the paleoclimatic events in the subpolar North Atlantic in the frame of the global environmental changes during the Late Pleistocene and Holocene. The research was supported by Russian Science Foundation projects 16-47-02009 and 14-50-00095.

  4. 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

  5. The Greenland Analogue Project. Yearly Report 2009

    International Nuclear Information System (INIS)

    2010-12-01

    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 Northeast Greenland Shelf - Evidence of the existence of a pronounced salt-province

    Science.gov (United States)

    Schmitz, T.; Jokat, W.

    2003-04-01

    The Northeast Greenland shelf (NEGS) is the part of the continental margin of east Greenland located between the Jan Mayen Fracture Zone at about 72°N in the south and the Spitzbergen Fracture Zone at 81°N in the north. The eastern boundary, at the shelf edge, is the approximate position of the boundary between continental and oceanic crust and the western boundary is the coastline of Greenland. The shelf has a N-S orientation, is about 1000 km long, and between 125 km (southern part) and 380 km (at 78°N) wide. Based on present data the NEGS can be subdivided into a southern part influenced by Tertiary tectonism and volcanism (approx. 72°N to 75°N) and a northern, nonvolcanic, part (approx. 75°N to 81°N). Today the sedimentary history, stratigraphy, structure and origin of the basement below the sedimentary shelf south of 74°N are reasonable known, but only sparse information exists about the northern part of the shelf. Until 1990 there weren't any seismic lines north of 74°N, and all interpretations of stratigraphy and basin structures of the northern part of the NEGS were based on aeromagnetic data. During the last decade, the first seismic lines were shot over the northern part of the shelf to give more detailed information about sediment thickness, stratigraphy, and the structure of the sedimentary shelf. The area under investigation lies on the nonvolcanic northern part of the shelf between 78°30'N and 81°N. The sea floor topography indicates some submarine banks with water depth as shallow as 30 m, which are separated by valleys up to 500 m deep. These valleys were formed through erosion processes caused by cyclic movements of big grounded glacier tongues during the last ice-ages with a maximum expansion during the Wisconsin-Weichselian glaciation. During two scientific expeditions with the German research icebreaker Polarstern in 1997 and 1999, more than 1100 km of multichannel seismic data were collected. The cruise tracks during seismic

  7. A 15-year record (2001–2015 of the ratio of nitrate to non-sea-salt sulfate in precipitation over East Asia

    Directory of Open Access Journals (Sweden)

    S. Itahashi

    2018-02-01

    Full Text Available Acidifying species in precipitation can have severe impacts on ecosystems. The chemical composition of precipitation is directly related to the amount of precipitation; accordingly, it is difficult to identify long-term variation in chemical concentrations. The ratio of the nitrate (NO3− to non-sea-salt sulfate (nss-SO42− concentration in precipitation on an equivalent basis (hereinafter, Ratio is a useful index to investigate the relative contributions of these acidifying species. To identify the long-term record of acidifying species in precipitation over East Asia, the region with the highest emissions worldwide, we compiled ground-based observations of the chemical composition of precipitation over China, Korea, and Japan from 2001 to 2015 based on the Acid Deposition Monitoring Network in East Asia (EANET. The spatial coverage was limited, but additional monitoring data for Japan, southern China, and northern China around Beijing were utilized. The period of analysis was divided into three phases: Phase I (2001–2005, Phase II (2006–2010, and Phase III (2011–2015. The behaviors of NO3− and nss-SO42− concentrations and hence the Ratio in precipitation were related to these precursors. The anthropogenic NOx and SO2 emissions and the NOx ∕ SO2 emission ratio were analyzed. Further, satellite observations of the NO2 and SO2 column density to capture the variation in emissions were applied. We found that the long-term trend in the NO3− concentration in precipitation was not related to the variation in NOx emission and the NO2 column. In comparison, the nss-SO42− concentration in precipitation over China, Korea, and Japan was partially connected to the changes in SO2 emissions from China, but the trends were not significant. The long-term trends of Ratio over China, Korea, and Japan were nearly flat during Phase I, increased significantly during Phase II, and were essentially flat again during Phase III. This

  8. The East Greenland Caledonides—teleseismic signature, gravity and isostasy

    DEFF Research Database (Denmark)

    Schiffer, Christian; Jacobsen, Bo Holm; Balling, Niels

    2015-01-01

    The large-scale geological evolution of the North Atlantic Realm during the past 450 Myr is largely understood, but crucial elements remain uncertain. These involve the Caledonian orogeny, the formation of the North Atlantic and accompanying igneous activity, and the present-day high topography s...

  9. The Neoproterozoic Tillite Group from Ella Ø, East Greenland

    DEFF Research Database (Denmark)

    Buchardt, Bjørn; Kristiansen, Kasper K.; Houmark-Nielsen, Michael

    values of carbonates in Bed Group 19 are close to -10‰. Organic carbon from Bed Group 19 has d13C values close to -34‰ indicating a carbonate to organic carbon fractionation of ~25‰ similar to present-day conditions. Similar depleted carbon isotope compositions are found in the Arena Fm between the two...... the Storeelv should be of Marinoan age. We have performed carbon isotope analyses of carbonates and organic carbon throughout the Tillite Group at Ella Ø and from the uppermost 600 m of underlying carbonates (Bed Group 18) and shales (Bed group 19) of the Eleonora Bay Supergroup. The carbon isotope...... Fm consisting of organic-rich black shales and fine-grained sandstones. The age of the Tillite Group has not been established with certainty, but an Ediacaran age has been suggested. Based on correlations to similar deposits on Svalbard the lower Ulvesø Fm has been assigned a Sturtian age while...

  10. Rapid population increase in an introduced muskox population, West Greenland

    Directory of Open Access Journals (Sweden)

    Carsten Riis Olesen

    1993-10-01

    Full Text Available In 1962 and 1965, 27 (13 and 14 muskox yearlings were translocated from East Greenland (71°N to the Angujaartorfiup Nunaa range in West Greenland (67°N. Angujaartorfiup Nunaa is a 6600 km2 icefree, continental area where caribou are indigenous. The climate is strictly continental with a minimum of precipitation but with abundant vegetation. Aerial surveys in 1990 documented that the muskox population has increased to 2600 heads despite quota-based harvesting since 1988. The annual quota was 200, 300 and 400 for 1988, 1989 and 1990, respectively. Distribution of muskoxen shows a significant preference for low altitude habitats southeast of Kangerlussuaq Airport and around Arnangarnup Qoorua (Paradise valley. Annual population increment averages 30% and the calf crop is around 24% of the population. Yearling recruitment in the population reveals that calf mortality during winter is very limited. About half of the 1-year-old females are served and they eventually give birth to their first calf when they turn 2 years old. With half of the 2-year-old females reproducing, the calf/cow ration ranges between 0.9 and 1.0.

  11. A new fossil cichlid from the Middle Miocene in the East African Rift Valley (Tugen Hills, Central Kenya: First record of a putative Ectodini

    Directory of Open Access Journals (Sweden)

    Melanie Altner

    2015-11-01

    Full Text Available Identification of fossil cichlids is difficult, because the currently used diagnostic morphological characters for living cichlids are mostly soft tissue based and such characters are hardly preserved in fossils. During our recent fieldwork in the Central Kenya Rift (E-Africa, we discovered several exceptionally well-preserved fossil cichlids, which can be assigned to different lineages among the African Pseudocrenilabrinae. Here we present one of those new specimens. Its most conspicuous character is a lateral line divided into three segments. This specimen was found in the lacustrine sediments of the Middle Miocene site Waril, Tugen Hills, Kenya. The site represents the deposits of an ancient freshwater lake ca. 9-10 million years ago. Previous work on fossil leaves from the same site allow for the reconstruction of open vegetation surrounding the lake and pronounced dry seasons. Among the main further characteristics of the new fossil cichlid is a lachrimal with six lateral line canals, big cycloid scales and a low number of dorsal fin spines (XIII. The latter two characters are traceable in several members of tribes within the Pseudocrenilabrinae. However, a lachrimal with six lateral line canals is exclusively found in certain tribes of the EAR (East African Radiation within the Pseudocrenilabrinae. Moreover, the unique lateral line pattern is solely present in two genera of the EAR tribe Ectodini. However, the fossil shows cycloid scales, while modern Ectodini have ctenoid scales. Taken all evidence together, this fossil may perhaps represent an ancient lineage related to the Ectodini. Up to date, there is no definite fossil record of the members of the EAR. Our fossil may represent the first reliable calibration point for this group, which would be consistent with the previously reconstructed diversification time of the H-lineage (EAR tribes, except Boulengerochromini, Bathybatini, Trematocarini and Lamprologini and the Lamprologini ca

  12. Balance Velocities of the Greenland Ice Sheet

    Science.gov (United States)

    Joughin, Ian; Fahnestock, Mark; Ekholm, Simon; Kwok, Ron

    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 altimetry data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail the location of an ice stream in northeastern Greenland, which was only recently discovered using satellite imagery. Enhanced flow associated with all of the major outlets is clearly visible, although small errors in the source data result in less accurate estimates of the absolute flow speeds. Nevertheless, the balance map is useful for ice-sheet modelling, mass balance studies, and field planning.

  13. Developing renewable energy in discontiguous Greenland

    DEFF Research Database (Denmark)

    Carruth, Susan

    2016-01-01

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

  14. Destabilization of the Northeast Greenland Ice Stream

    DEFF Research Database (Denmark)

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

    . 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....

  15. Impact of public health research in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Curtis, Tine

    2004-01-01

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

  16. Hepatitis B prevalence and incidence in Greenland

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  17. Episodes of subsidence and uplift of the conjugate margins of Greenland and Norway after opening of the NE Atlantic

    Science.gov (United States)

    Japsen, Peter; Green, Paul F.; Bonow, Johan M.; Chalmers, James A.

    2015-04-01

    We have undertaken a regional study of the thermo-­tectonic development of East Greenland (68-75°N) and of southern Norway (58-64°N). We take advantage of the general observation that that the effects of uplift often are reflected more clearly onshore than offshore, and of the specific condition that the mountains of southern East Greenland expose thick basalts that were extruded onto a largely horizontal lava plain near sea level during breakup of the NE Atlantic at the Paleocene-Eocene transition. It is thus clear that the present-­day elevation of these basalts up to 3.7 km a.s.l. were reached after breakup. Our results based on apatite fission-­track analysis (AFTA) data from East Greenland reveal a long history of post-­Palaeozoic burial and exhumation across the region and show that the terrains of Palaeozoic and older rocks were buried below a 2-3 km­-thick cover prior to a series of Mesozoic events of uplift and exhumation. The AFTA results from southern Norway reveal events of Mesozoic uplift and exhumation that are broadly simultaneous with those in Greenland. Volcanic and sedimentary rocks accumulated on the subsiding, East Greenland margin during and following breakup and then began to be exhumed during late Eocene uplift that preceded a major, early Oligocene plate reorganization in the NE Atlantic. The Norwegian margin also experienced Eocene subsidence and burial. Our AFTA data from southern Norway show evidence of an event of mid­Cenozoic uplift and exhumation that overlap with the early Oligocene onset of progradation of clastic wedges towards the south and with the formation of a major, late Eocene unconformity along the NW European margin. The uplift event at the Eocene-Oligocene transition that affected wide areas in the NE Atlantic domain was followed by two regional events of uplift and incision of the East Greenland margin in the late Miocene and Pliocene whereas the Neogene uplift of southern Norway began in the early Miocene and was

  18. Temporal trends and future predictions of mercury concentrations in Northwest Greenland polar bear (Ursus maritimus) hair.

    Science.gov (United States)

    Dietz, R; Born, E W; Rigét, F; Aubail, A; Sonne, C; Drimmie, R; Basu, N

    2011-02-15

    Hair samples from 117 Northwest Greenland polar bears (Ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafter Hg). The sample represented 28 independent years and the aim of the study was to analyze for temporal Hg trends. Mercury concentrations showed yearly significant increases of 1.6-1.7% (p polar bear Hg exposure is 95.6-96.2% anthropogenic in its origin. Assuming a continued anthropogenic increase, this model estimated concentrations in 2050 and 2100 will be 40- and 92-fold the baseline concentration, respectively, which is equivalent to a 97.5 and 98.9% man-made contribution. None of the 2001-2008 concentrations of Hg in Northwest Greenland polar bear hair exceeded the general guideline values of 20-30 μg/g dry weight for terrestrial wildlife, whereas the neurochemical effect level of 5.4 μg Hg/g dry weight proposed for East Greenland polar bears was exceeded in 93.5% of the cases. These results call for detailed effect studies in main target organs such as brain, liver, kidney, and sexual organs in the Northwest Greenland polar bears.

  19. Atlantic water variability on the SE Greenland continental shelf and its relationship to SST

    Science.gov (United States)

    Sutherland, D. A.; Straneo, F.; Rosing-Asvid, A.; Stenson, G.; Davidson, F. J.; Hammill, M.

    2012-12-01

    Interaction of warm, Atlantic-origin water (AW) and colder, polar origin water (PW) advecting southward in the East Greenland Current (EGC) influences the heat content of water entering Greenland's outlet glacial fjords. Here we use depth and temperature data derived from deep-diving seals to map out water mass variability across the continental shelf and to augment existing bathymetric products. We find two dominant modes in the vertical temperature structure: a cold mode, with the typical AW/PW layering observed in the EGC, and a warm mode, where AW is present throughout the water column. The prevalence of these modes varies seasonally and spatially across the continental shelf, implying distinct AW pathways. In addition, we find that satellite sea surface temperatures (SST) correlate significantly with temperatures in the upper 50 m (R=0.54), but this correlation decreases with depth (R=0.22 at 200 m), and becomes insignificant below 250 m. Thus, care must be taken in using SST as a proxy for heat content, as AW mainly resides in these deeper layers. Regional map showing the location of all seal tracks originating from Canada and Greenland (stars). Tracks passing inside (red) or outside (blue) the SE Greenland region (black) were subdivided into continental shelf regions (green boxes) near Sermilik Fjord (SF), Cape Farewell (CF) and Kangerdlugssuaq Fjord (KG). GEBCO bathymetry is contoured at 200, 1000, 2000, and 3000 m.

  20. Oceanic Transport of Surface Meltwater from the Southern Greenland Ice Sheet

    Science.gov (United States)

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

    2016-01-01

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

  1. Ultratrace analysis for organolead compounds in Greenland snow

    International Nuclear Information System (INIS)

    Lobinski, R.; Szpunar-Lobinska, J.; Adams, F.C.

    1994-01-01

    The degradation products of tetraalkyllead compounds used as antiknock additives are unique indicators of automotive environmental pollution by lead. Recent dramatic improvements in species-specific ultrasensitive analytical procedures enabled the identification and quantification of organolead compounds in ancient Greenland snow which is considered as the archives of northern hemispheric pollution records. Organolead species determined in fresh and ancient polar snow demonstrate unambiguously the global range of petrol-related pollution not only with ionic Pb 2+ but also with more toxic metalloorganic compounds. (authors). 9 refs., 5 figs

  2. Transuranic depositional history in South Greenland firn layers

    International Nuclear Information System (INIS)

    Koide, M.; Goldberg, E.D.; Herron, M.M.; Langway, C.C. Jr.

    1977-01-01

    It is stated that the surface layers of the Greenland ice sheet have preserved a continuous and detailed record of atmospheric fallout of transuranic nuclides from weapons tests over the past 30 yr. It was found that fallout maxima occurred in the 1950s and 1960s for sup(239+240)Pu and in 1965-66 for 238 Pu. This work may be extended by using alpine glaciers in mid-latitudes for a reconstruction of fallout patterns over the past three decades for an evaluation of present day dispersions of these nuclides as a consequence of atmospheric fallout and other possible entries. (author)

  3. Dynamics of the Greenland Ice Sheet over multiple timescales

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup

    to further constrain the individual components of the current budget, and in conjunction with longer records, it is important to provide a trustworthy basis for future projections. In this thesis, using airborne- and satellite derived data combined with terrestrial and marine observations, the dynamic...... become grounded and also assuming a similar warming pattern. This thesis implies that in order to investigate the response of the Greenland Ice Sheet to future climate change much is to be gained by merging and incorporating data from both marine and terrestrial geology, combined with air- and satellite...

  4. Seasonal and interannual variability of the Mid-Holocene East Asian monsoon in coral δ18O records from the South China Sea

    Science.gov (United States)

    Sun, Donghuai; Gagan, Michael K.; Cheng, Hai; Scott-Gagan, Heather; Dykoski, Carolyn A.; Edwards, R. Lawrence; Su, Ruixia

    2005-08-01

    Understanding the full range of past monsoon variability, with reference to specific monsoon seasons, is essential to test coupled climate models and improve their predictive capabilities. We present a 54-year long, high-resolution skeletal oxygen isotope (δ18O) record extracted from a well-preserved, massive Porites sp. coral at Hainan Island, South China Sea, to investigate East Asian monsoon variability during summer and winter ∼4400 calendar yr ago. Analysis of modern coral δ18O confirms that Porites from Hainan Island are well positioned to record winter monsoon forcing of sea surface temperature (SST), as well as the influence of summer monsoon rainfall on sea surface salinity (SSS). The coral record for ∼4400 yr ago shows ∼9% amplification of the annual cycle of δ18O, in good agreement with coupled ocean-atmosphere models showing higher summer rainfall (lower coral δ18O) and cooler winter SSTs (higher coral δ18O) in response to greater Northern Hemisphere insolation seasonality during the Middle Holocene. Mean SSTs in the South China Sea during the Mid-Holocene were within 0.5 °C of modern values, yet the mean δ18O for the fossil coral is ∼0.6‰ higher than that for the modern coral, suggesting that the δ18O of surface seawater was higher by at least ∼0.5‰, relative to modern values. The 18O-enrichment is likely to be driven by greater advection of moisture towards the Asian landmass, enhanced monsoon wind-induced evaporation and vertical mixing, and/or invigorated advection of saltier 18O-enriched Pacific water into the relatively fresh South China Sea. The 18O-enrichment of the northern South China Sea ∼4400 yr ago contributes to mounting evidence for recent freshening of the tropical Western Pacific. Today, winter SST and summer SSS variability in the South China Sea reflect the interannual influence of ENSO and the biennial variability inherent to monsoon precipitation. Spectral analysis of winter SSTs ∼4400 yr ago reveals a

  5. New records of water mites of the family Torrenticolidae (Acari, Hydrachnidia) with descriptions of two new species from Nanshih River system in Taiwan and redescription of Torrenticola ussuriensis (Sokolow, 1940) from the Russian Far East

    Science.gov (United States)

    Pešić, Vladimir; Semenchenko, Ksenia A.; Chatterjee, Tapas; Yam, Rita S.W.; Chan, Benny K.K.

    2011-01-01

    Abstract New records of torrenticolid water mites (Acari: Hydrachnidia, Torrenticolidae) from Nanshih River, Taiwan, are presented. Two new species are described: Torrenticola nanshihensis and Torrenticola taiwanicus; the latter species is compared with Torrenticola ussuriensis (Sokolow, 1940), a poorly known species which is re-described based on a new material from the Russian Far East; Monatractides cf. circuloides (Halík, 1930)is reported for the first time for Taiwan. PMID:21998497

  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. Hydrologic Sub-basins of Greenland

    Data.gov (United States)

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

  8. 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...

  9. Weather Test Reference Year of Greenland

    DEFF Research Database (Denmark)

    Kragh, Jesper; Pedersen, Frank; Svendsen, Svend

    2005-01-01

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

  10. Trends of cervical cancer in Greenland

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  11. Future markers of the West Greenlandic

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann

    2010-01-01

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

  12. Explanation of Significant Differences for the Record of Decision for Interim Actions in Zone 1, East Tennessee Technology Park, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Jacobs

    2011-02-01

    Zone 1 is a 1400-acre area outside the fence of the main plant at The East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. The Record of Decision for Interim Actions in Zone, ETTP (Zone 1 Interim ROD) (DOE 2002) identifies the remedial actions for contaminated soil, buried waste, and subsurface infrastructure necessary to protect human health and to limit further contamination of groundwater. Since the Zone 1 Interim Record of Decision (ROD) was signed, new information has been obtained that requires the remedy to be modified as follows: (1) Change the end use in Contractor's Spoil Area (CSA) from unrestricted industrial to recreational; (2) Remove Exposure Units (EU5) ZI-50, 51, and 52 from the scope of the Zone I Interim ROD; (3) Change the end use of the duct bank corridor from unrestricted industrial to restricted industrial; and (4) Remove restriction for the disturbance of soils below 10 feet in Exposure Unit (EU) Z1-04. In accordance with 40 Code of Federal Regulations (CFR) 300.435, these scope modifications are a 'significant' change to the Zone 1 Interim ROD. In accordance with CERCLA Sect. 117 (c) and 40 CFR 300.435 (c)(2)(i), such a significant change is documented with an Explanation of Significant Differences (ESD). The purpose of this ESD is to make the changes listed above. This ESD is part of the Administrative Record file, and it, and other information supporting the selected remedy, can be found at the DOE Information Center, 475 Oak Ridge Turnpike, Oak Ridge, Tennessee 37830, from 8:00 a.m. to 5:00 p.m., Monday through Friday. The ORR is located in Roane and Anderson counties, within and adjacent to the corporate city limits of Oak Ridge, Tennessee. ETTP is located in Roane County near the northwest corner of the ORR. ETTP began operation during World War II as part of the Manhattan Project. The original mission of ETTP was to produce enriched uranium for use in atomic weapons. The plant produced enriched uranium from

  13. A New Oceanic Anoxic Event 2 record from the Central North Atlantic at South East Newfoundland Ridge, IODP Expedition 342, Newfoundland Drifts

    Science.gov (United States)

    Junium, C. K.; Bornemann, A.; Bown, P. R.; Friedrich, O.; Moriya, K.; Kirtland Turner, S.; Whiteside, J. H.

    2013-12-01

    The recovery of Cretaceous, Cenomanian-Turonian black shales deposited during Oceanic Anoxic Event 2 (OAE 2) at Site U1407, South East Newfoundland Ridge (SENR), was an unexpected but fortuitous discovery that fills a gap in the pelagic Tethyan and North Atlantic geologic records. Drilling operations recovered the OAE sequence in all three holes drilled at Site U1407 defined initially on the basis of lithology and calcareous nannofossil biostratigraphy and confirmed by carbon isotope stratigraphy post-expedition. The SENR OAE 2 sequence is a classic chalk sequence punctuated by a prominent black band. Prior to OAE 2, greenish white pelagic carbonate is interrupted by thin, 2 to 5 cm thick organic-rich, gray calcareous clays. A sharp transition from greenish-white chalk to carbonate-poor sediments marks the occurrence of the organic carbon-rich black band. Within the black band are finely laminated to massive, pyritic black shales and laminated gray clays that are relatively organic carbon-lean, free of preserved benthic foraminifera and rich in radiolarians. Finely laminated greenish-gray marls overlay the black band and grade into approximately 1 meter of greenish white chalks with common 1cm chert layers and nodules. The remainder of the Turonian sequence is characterized by a notable transition to pink chalks. The thickness of the black band ranges from 15-40 cm between Holes A through C. The differences in the thickness of beds between Holes is due in part to drilling disturbances and mass wasting indicated by slump features in the overlying Turonian strata. Core scanning XRF and carbon isotopes can help resolve the nature of these differences and inform future sampling and study. Carbonate and organic carbon isotopes reveal that the δ13C excursion marking the initiation of OAE 2 is below the base of the black band. At U1407A the δ13C rise is immediately below (3 cm) the black shale, with δ13C maxima in the black band. At U1407C the initial δ13C rise is

  14. Scientific activities in and about Greenland

    DEFF Research Database (Denmark)

    Graversen, Ebbe Krogh; Pedersen, Asger Dalsgaard

    2018-01-01

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

  15. Environmental radioactivity in Greenland in 1979

    International Nuclear Information System (INIS)

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

    1980-07-01

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

  16. Determining counselling communication strategies associated with successful quits in the National Health Service community pharmacy Stop Smoking programme in East London: a focused ethnography using recorded consultations.

    Science.gov (United States)

    Rivas, Carol; Sohanpal, Ratna; MacNeill, Virginia; Steed, Liz; Edwards, Elizabeth; Antao, Laurence; Griffiths, Chris; Eldridge, Sandra; Taylor, Stephanie; Walton, Robert

    2017-10-27

    To determine communication strategies associated with smoking cessation in the National Health Service community pharmacy Stop Smoking programme. 11 community pharmacies in three inner east London boroughs. 9 stop smoking advisers and 16 pairs of smokers who either quit or did not quit at 4 weeks, matched on gender, ethnicity, age and smoking intensity. 1-3 audio-recorded consultations between an adviser and each pair member over 5-6 weeks were analysed using a mixed-method approach. First a content analysis was based on deductive coding drawn from a theme-oriented discourse analysis approach and the Roter Interaction Analysis System. Core themes were identified through this quantification to explore in detail the qualitative differences and similarities between quitters and non-quitters. Quantitative analysis revealed advisers used a core set of counselling strategies that privileged the 'voice of medicine' and often omitted explicit motivational interviewing. Smokers tended to quit when these core strategies were augmented by supportive talk, clear permission for smokers to seek additional support from the adviser between consultations, encouragement for smokers to use willpower. The thematic analysis highlighted the choices made by advisers as to which strategies to adopt and the impacts on smokers. The first theme 'Negotiating the smoker-adviser relationship' referred to adviser judgements about the likelihood the smoker would quit. The second theme, 'Roles of the adviser and smoker in the quit attempt', focused on advisers' counselling strategies, while the third theme, 'Smoker and adviser misalignment on reasons for smoking, relapsing and quitting', concerned inconsistencies in the implementation of National Centre for Smoking Cessation and Training recommendations. Advisers in community pharmacies should use the advantages of their familiarity with smokers to ensure appropriate delivery of patient-centred counselling strategies and reflect on the impact on

  17. Modelling the response of stable water isotopes in Greenland precipitation to orbital configurations of the previous interglacial

    Directory of Open Access Journals (Sweden)

    Jesper Sjolte

    2014-09-01

    Full Text Available The relation between δ 18O of precipitation and temperature has been used in numerous studies to reconstruct past temperatures at ice core sites in Greenland and Antarctica. During the past two decades, it has become clear that the slope between δ 18O and temperature varies in both space and time. Here, we use a general circulation model driven by changes in orbital parameters to investigate the Greenland δ 18O–temperature relation for the previous interglacial, the Eemian. In our analysis, we focus on changes in the moisture source regions, and the results underline the importance of taking the seasonality of climate change into account. The orbitally driven experiments show that continental evaporation over North America increases during summer in the warm parts of the Eemian, while marine evaporation decreases. This likely flattens the Greenland δ 18O response to temperature during summer. Since the main climate change in the experiments occurs during summer this adds to a limited response of δ 18O, which is more strongly tied to temperature during winter than during summer. A south–west to north–east gradient in the δ 18O–temperature slope is also evident for Greenland, with low slopes in the south–west and steeper slopes in the north–east. This probably reflects the proportion of continental moisture and Arctic moisture arriving in Greenland, with more continental moisture in the south–west and less in the north–east, and vice versa for the Arctic moisture.

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

    Directory of Open Access Journals (Sweden)

    T. Kobashi

    2013-10-01

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

  20. Paleoenvironmental evolution and geomorphic dynamics recorded in the Homo-bearing Pleistocene stratigraphic succession of Aalat (Eritrea, East Africa): A pedological perspective

    Science.gov (United States)

    Scarciglia, Fabio; Mercatante, Giuseppe; Donato, Paola; Ghinassi, Massimiliano; Carnevale, Giorgio; Delfino, Massimo; Oms, Oriol; Papini, Mauro; Pavia, Marco; Sani, Federico; Rook, Lorenzo

    2017-04-01

    these cemented horizons with layers affected by local to extensive staining of the matrix with reddish to yellowish iron-oxides/hydroxides, suggests cyclical changes from dry to wet environmental conditions. This pattern is quite consistent with the main Pleistocene climate oscillations evidenced in global-scale paleoclimatic curves, where glacial/interglacial cycles of higher latitudes well correspond to the formation of carbonate- or gypsum-cemented and the iron-stained layers, respectively. In addition, some carbonate parent material enhancing secondary carbonate dynamics within the soil system, dominated by siliciclastic grains sourced from the metamorphic basement rocks prevailing in the Dandiero basin, could have been supplied as eolian dust during dryer (glacial) periods. A comparison of the different evolutionary (maturity-related) stages of calcic/petrocalcic and petrogypsic horizons of the chronologically well-constrained Aalat succession suggests that their time ranges of development were between 102 - 103 years and a few tens of thousands years. Further investigations are required to assess the potential role of paleoenvironmental changes recorded in the Dandiero basin fill on human settlement, dispersal and evolution in East Africa during the Early-Middle Pleistocene transition.

  1. The isotope X-ray fluorescence analysis and its application in geochemical investigations in Greenland

    International Nuclear Information System (INIS)

    Kunzendorf, H.

    1973-01-01

    The applicability of the isotope X-ray fluorescence analysis (IRFA) in the geochemical exploration was investigated. Detection limits of about 0.1% for the elements Ti, Zr, Nb, Mo and La+Ce were achieved in terrain measurements. Detection limits of 0.05% were found in the analysis of Cr, Ni, Cu, Zn, Zr, Nb, Mo, La+Ce and Pb in finely grinded rock samples. Geochemical investigations were carried out in the Ilimaussag-Intrusion in south Greenland as well as on the Mo deposits Malmbjerg and the heavy mineral occurence 'kote 800' in East Greenland. The use of portable IRFA equipment proved to be particularly suitable in the analysis of bed rocks, loose rock samples such as moraine material, in the semi-quantitative analysis of heavy mineral concentrates, the analysis of bored cores during the boring programme, as well as the analysis of finely grinded rock samples. (ORU) [de

  2. 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...

  3. Hydrologic Outlets of the Greenland Ice Sheet, Version 1

    Data.gov (United States)

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

  4. A Case of Greenlandic Fisheries Co-Politics

    DEFF Research Database (Denmark)

    Jacobsen, Rikke Becker; Raakjær, Jesper

    2012-01-01

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

  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. Periodontal status among patients with diabetes in Nuuk, Greenland

    Directory of Open Access Journals (Sweden)

    Amanda Lamer Schjetlein

    2014-12-01

    Full Text Available Background: Diabetes is becoming more common in the Greenlandic population. Patients with diabetes are more prone to periodontal disease. Periodontal status may have an effect on metabolic control. Objective: The aim of this study was to estimate the prevalence of periodontitis amongst patients with diabetes in Nuuk, Greenland, and secondly, to observe if dental care was associated with improved periodontal status and metabolic control. Study design: Observational cross-sectional study and a pilot study of a dental care intervention. Methods: Sixty-two Greenlandic patients with diabetes were included in the study. Data were collected from the Electronic Medical Records (EMR, in addition to a telephone interview. Patients were offered 3 dental examinations with a 3-month interval. The dental examinations consisted of a full-mouth assessment of number of remaining teeth and assessment of periodontal status. Patients received scaling and root planing, together with information and instructions on oral hygiene. Information on glycated haemoglobin (HbA1C values was collected from the EMR at each dental examination. Results: In this study, 21.0% (13/62 of patients with diabetes had periodontitis. About 42% had less than 20 teeth. The association between diabetes and periodontitis was known by 20 out of the 62 patients. Over half of the patients had been to a dental examination within the last year. The prevalence of periodontitis decreased significantly from 21.0 to 0% (p<0.001 after 3 dental examinations. No change in HbA1C levels was observed (p=0.440. Conclusion: Periodontitis was common among patients with diabetes in Nuuk. Dental health status based on Periodontal Screening Index (PSI and bleeding on probing (BOP seemed to improve after dental health care, indicating a need for increased awareness among patients and health care professionals. HbA1C levels were not improved among the patients.

  7. Validation of cardiovascular diagnoses in the Greenlandic Hospital Discharge Register for epidemiological use

    DEFF Research Database (Denmark)

    Tvermosegaard, Maria; Ronn, Pernille Falberg; Pedersen, Michael Lynge

    2018-01-01

    not previously been validated specifically. The objective of the study was to validate diagnoses of CVD in GHDR. The study was conducted as a validation study with primary investigator comparing information in GHDR with information in medical records. Diagnoses in GHDR were considered correct and thus valid......Cardiovascular disease (CVD) is one of the leading causes of death worldwide. In Greenland, valid estimates of prevalence and incidence of CVD do not exist and can only be calculated if diagnoses of CVD in the Greenlandic Hospital Discharge Register (GHDR) are correct. Diagnoses of CVD in GHDR have...... if they matched the diagnoses or the medical information in the medical records. A total of 432 online accessible medical records with a cardiovascular diagnosis according to GHDR from Queen Ingrid's Hospital from 2001 to 2013 (n=291) and from local health care centres from 2007 to 2013 (n=141) were reviewed...

  8. Marginal thinning in Northwest Greenland during 2002-2011

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  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. Pneumatization and otitis media in Greenlandic Inuit before European colonization

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Skovgaard, L T

    1995-01-01

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

  11. Reconstructing surface elevation changes for the Greenland Ice Sheet (1993-2013) and analysis of Zachariae Isstrom, northeast Greenland

    Science.gov (United States)

    Duncan, Kyle

    Previous studies investigating the velocity and elevation change records of the Greenland Ice Sheet (GrIS) revealed rapid and complex changes. It is therefore imperative to determine changes with both high spatial and temporal resolutions. By fusing multiple laser altimetry data sets, the Surface Elevation Reconstruction and Change (SERAC) program is capable of reconstructing surface elevation changes with high spatial and temporal resolution over the entire GrIS. The input data include observations from NASA's Ice, Cloud and land Elevation Satellite (ICESat) mission (2003-2009) as well as data collected by NASA's Airborne Topographic Mapper (ATM) (1993-2013) and Land, Vegetation and Ice Sensor (LVIS) (2007-2012) airborne laser altimetry systems. This study extends the record of surface elevation changes over the GrIS by adding 2012 and 2013 laser altimetry data to the previous 1993-2011 record. Extending the record leads to a new, more accurate and detailed altimetry record for 1993-2013. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Models (DEMs) are fused with laser altimetry data over Zachariae Isstrom, northeast Greenland to analyze surface elevation changes and associated thinning rates during 1978-2014. Little to no elevation change occurred over Zachariae Isstrom from 1978-1999, however, from 1999-2014 elevation changes near the calving front became increasingly negative and accelerated. Calving front position showed steady retreat and grounding line position has been retreating towards the interior of the ice sheet at an increasing rate from 2010-2014 when compared to the 1996-2010 period. The measured elevation changes near the calving front have brought a large portion of the glacier close to the height of flotation. If the current thinning trend continues this portion of the glacier will reach flotation within the next 2-5 years allowing for further retreat and increased vulnerability to retreat for sections of

  12. Gastrointestinal Parasites of Two Populations of Arctic Foxes (Vulpes lagopus) from Northeast Greenland

    DEFF Research Database (Denmark)

    Andreassen, P.N.S.; Schmidt, Niels Martin; Kapel, Christian M. O.

    2017-01-01

    Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps......, Taenia serialis, Toxascaris leonina, Eucoleus boehmi, Physalopteridae and Ancylostomatidae, and Strongyloides-like larvae. As long-term ecological studies are conducted at both sampling locations, the present findings constitute a baseline data set for further parasitological monitoring....

  13. Continuous methane measurements from a late Holocene Greenland ice core

    DEFF Research Database (Denmark)

    Rhodes, R.H.; Mitchell, L.E.; Brook, E.J.

    2013-01-01

    Ancient air trapped inside bubbles in ice cores can now be analysed for methane concentration utilising a laser spectrometer coupled to a continuous melter system. We present a new ultra-high resolution record of atmospheric methane variability over the last 1800yr obtained from continuous analysis...... of a shallow ice core from the North Greenland Eemian project (NEEM-2011-S1) during a 4-week laboratory-based measurement campaign. Our record faithfully replicates the form and amplitudes of multi-decadal oscillations previously observed in other ice cores and demonstrates the detailed depth resolution (5.3cm......), rapid acquisition time (30mday) and good long-term reproducibility (2.6%, 2s) of the continuous measurement technique.In addition, we report the detection of high frequency ice core methane signals of non-atmospheric origin. Firstly, measurements of air from the firn-ice transition region...

  14. Uranium districts in South Greenland

    International Nuclear Information System (INIS)

    Armour-Brown, A.; Tukiainen, T.; Wallin, B.

    1981-01-01

    A short review is given of reconnaissance work in South Greenland. The work has demonstrated that there are areas in the Motzfeldt centre of at least 1 km 2 with continuously high radioactivity. If the uranium content of these radioactive zones are sufficiently high, then potential ore tonnages could prove to be substantial. The reconnaissance exploration has proved that uranium mineralization is widely distributed in the Narssaq-Narssarssuaq district. It is, no doubt, responsible for the high uranium values in the exploration geochemical samples. Although the size of the pitchblende occurences which have been found so far are small, the high grade of the mineralisation, the great frequency of the fracturing and the evidence for an all pervasive mineralising event over a wide area indicate that there is a good possibility of finding economic mineralisation within the Narssaq-Narssarssuaq area. The area as a whole may, perhaps, be termed a ''uranium mineral district''. As the potential targets are small, only detailed follow-up exploration will establish this. At the same time more detailed work on individual showings, and geological mapping to demonstrate the relative ages of the various petrological and mineralising events, will establish the possible origin of this uranium mineralisation. (author)

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  16. Greenland unveils terms for offshore licenses

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

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

  17. Cultural change and mental health in Greenland

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  18. Iron status markers in 224 indigenous Greenlanders

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  19. Lead sources in human diet in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert

    2004-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  1. 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.

  2. Younger Dryas cooling and the Greenland climate response to CO2.

    Science.gov (United States)

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

    2012-07-10

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

  3. Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

    Science.gov (United States)

    Møller, Lone Nukâraq; Petersen, Eskild; Kapel, Christian M O; Melbye, Mads; Koch, Anders

    2005-09-05

    The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

  4. Increasing mass loss from Greenland's Mittivakkat Gletscher

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  5. Small-scale fisheries in Greenlandic planning

    DEFF Research Database (Denmark)

    Jacobsen, Rikke Becker

    2013-01-01

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

  6. TALDICE-1 age scale of the Talos Dome deep ice core, East Antarctica

    Directory of Open Access Journals (Sweden)

    D. Buiron

    2011-01-01

    Full Text Available A new deep ice core drilling program, TALDICE, has been successfully handled by a European team at Talos Dome, in the Ross Sea sector of East Antarctica, down to 1620 m depth. Using stratigraphic markers and a new inverse method, we produce the first official chronology of the ice core, called TALDICE-1. We show that it notably improves an a priori chronology resulting from a one-dimensional ice flow model. It is in agreement with a posteriori controls of the resulting accumulation rate and thinning function along the core. An absolute uncertainty of only 300 yr is obtained over the course of the last deglaciation. This uncertainty remains lower than 600 yr over Marine Isotope Stage 3, back to 50 kyr BP. The phasing of the TALDICE ice core climate record with respect to the central East Antarctic plateau and Greenland records can thus be determined with a precision allowing for a discussion of the mechanisms at work at sub-millennial time scales.

  7. Vitamins and minerals in the traditional Greenland diet

    DEFF Research Database (Denmark)

    Andersen, S. M.

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

  8. A cascade of warming impacts brings bluefin tuna to Greenland waters

    DEFF Research Database (Denmark)

    MacKenzie, Brian R.; Payne, Mark R.; Boje, Jesper

    2014-01-01

    Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species in ec...... impacts is restructuring the food web in east Greenland waters.......Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species...

  9. Age distributions of Greenlandic dwarf shrubs support concept of negligible actuarial senescence

    DEFF Research Database (Denmark)

    Dahlgren, Johan; Rizzi, Silvia; Schweingruber, Fritz

    2016-01-01

    shrub species from 863 taproot samples collected in coastal east Greenland. Penalized composite link models (pclm) were used to fill gaps in the observed age ranges, caused by low species-specific sample sizes in relation to life span. Resulting distributions indicate that mortality patterns...... are independent of age. Actuarial senescence is thus negligible in these dwarf shrub populations. We suggest that smoothing techniques such as pclm enable consideration of noisy age data for determining age distributions. These distributions may, in turn, reveal age effects on demographic rates. Moreover, age...

  10. 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...

  11. THE BAFFIN BAY REGION DURING THE LAST INTERGLACIATION: EVIDENCE FROM NORTHWEST GREENLAND

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1989-01-01

    Coastal sections in the Thule area, northwest Greenland, provide a recordof last interglacial glacial and oceanographic events on the northern perimeter of Baffin Bay. The record is dated by a combination of thermoluminescence and 14C dating; local and regional correlation is provided by amino acid...... for the last nterglacial/glacial cycle was attained during Middle Sangamonian times, and a smaller advance took place in the Late Wisconsinan. In beween ice coverage was similar to the present, or smaller. The record provides a link between events in Arctic Canada and northern Greenland, and shows...... analyses of mollusc shells, and periods of penetration by warm subarctic water have been identified by their foraminifera and mollusc faunas. Subarclic water reached the area on three occasions: during the Holocene, and in the Early and Late Sangamonian. Maximum, although restricted, ice coverage...

  12. DNA evidence of bowhead whale exploitation by Greenlandic Paleo-Inuit 4,000 years ago

    Science.gov (United States)

    Seersholm, Frederik Valeur; Pedersen, Mikkel Winther; Søe, Martin Jensen; Shokry, Hussein; Mak, Sarah Siu Tze; Ruter, Anthony; Raghavan, Maanasa; Fitzhugh, William; Kjær, Kurt H.; Willerslev, Eske; Meldgaard, Morten; Kapel, Christian M. O.; Hansen, Anders Johannes

    2016-11-01

    The demographic history of Greenland is characterized by recurrent migrations and extinctions since the first humans arrived 4,500 years ago. Our current understanding of these extinct cultures relies primarily on preserved fossils found in their archaeological deposits, which hold valuable information on past subsistence practices. However, some exploited taxa, though economically important, comprise only a small fraction of these sub-fossil assemblages. Here we reconstruct a comprehensive record of past subsistence economies in Greenland by sequencing ancient DNA from four well-described midden deposits. Our results confirm that the species found in the fossil record, like harp seal and ringed seal, were a vital part of Inuit subsistence, but also add a new dimension with evidence that caribou, walrus and whale species played a more prominent role for the survival of Paleo-Inuit cultures than previously reported. Most notably, we report evidence of bowhead whale exploitation by the Saqqaq culture 4,000 years ago.

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

    Science.gov (United States)

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

    2017-11-01

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

  14. Snapshots of circum-Greenland elevation change, viewed from the PROMICE airborne surveys in 2007, 2011, and 2015

    DEFF Research Database (Denmark)

    Simonsen, Sebastian Bjerregaard; Forsberg, René; Hvidegaard, Sine Munk

    For the Greenland ice sheet, the period from 2007-2015 is characterized by a large variability in climate conditions, with record-breaking melt in 2010 and 2012 and minor net mass loss in 2013. As a part of the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) funded by the Danish...... along the flight-path. As the only one of its kind, the repeat surveys have been performed in late summer, to coincide with the end of the balance year. With the third survey successfully conducted in 2015, a unique opportunity for evaluating elevation changes at a consistent and tailored circum...... observations from satellites to target the balance year....

  15. 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...

  16. The lithospheric mantle below southern West Greenland

    DEFF Research Database (Denmark)

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

    2009-01-01

    Geothermobarometry of primarily garnet lherzolitic xenoliths from several localities in southern West Greenland is applied to address the diamond potential, pressure and temperature distribution and the stratigraphy of the subcontinental lithospheric mantle ~600 Ma ago. The samples are from kimbe...... into the reworked Archean North of the Naqssugtoqidian deformation front....

  17. 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...

  18. Characterization of household waste in Greenland

    International Nuclear Information System (INIS)

    Eisted, Rasmus; Christensen, Thomas H.

    2011-01-01

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

  19. 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...

  20. Ecosystem variability in west Greenland waters

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  1. East India Company Logbooks - Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection consists of images of 1,235 ship logbooks created during British East India Company voyages. Period of record 1786-1834, peaking in 1804. The...

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

    Directory of Open Access Journals (Sweden)

    S. L. Bevan

    2012-09-01

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

  3. Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States

    International Nuclear Information System (INIS)

    Rush, Scott A.; Borga, Katrine; Dietz, Rune; Born, Erik W.; Sonne, Christian; Evans, Thomas; Muir, Derek C.G.; Letcher, Robert J.; Norstrom, Ross J.; Fisk, Aaron T.

    2008-01-01

    To assess geographic distributions of elements in the Arctic we compared essential and non-essential elements in the livers of polar bears (Ursus maritimus) collected from five regions within Canada in 2002, in Alaska between 1994 and 1999 and from the northwest and east coasts of Greenland between 1988 and 2000. As, Hg, Pb and Se varied with age, and Co and Zn with gender, which limited spatial comparisons across all populations to Cd, which was highest in Greenland bears. Collectively, geographic relationships appeared similar to past studies with little change in concentration over time in Canada and Greenland for most elements; Hg and Se were higher in some Canadian populations in 2002 as compared to 1982 and 1984. Concentrations of most elements in the polar bears did not exceed toxicity thresholds, although Cd and Hg exceeded levels correlated with the formation of hepatic lesions in laboratory animals. - Geographical trends were observed for a number of elements in livers, including mercury, of polar bears collected across Alaska, Canada and Greenland and were similar to those observed in the early 1980s

  4. Chinese mineral dust and anthropogenic aerosol inter-continental transport: a Greenland perspective

    Science.gov (United States)

    Bory, A.; Abouchami, W.; Galer, S.; Svensson, A.; Biscaye, P.

    2012-04-01

    Impurities contained in snow and ice layers in Greenland provide a record of the history of atmospheric dustiness and pollution in the Northern Hemisphere. The source of the particles deposited onto the ice cap may be investigated using specific intrinsic tracers. Provenance discrimination may then provide valuable constraints for the validation of atmospheric transport models as well as for the monitoring of natural and anthropogenic aerosols emissions at a global scale. Clay mineralogy combined with the strontium and neodymium isotope composition of the insoluble particles extracted from recent snow deposits at NorthGRIP (75.1°N, 042.3°W), for instance, enabled us to demonstrate that the Taklimakan desert of North-western China was the main source of mineral dust reaching central Greenland at present [Bory et al., EPSL, 2002 ; GRL, 2003a]. Here we report the lead isotopic signature of these snow-pit samples, covering the 1989-1995 and 1998-2001 time periods. Unradiogenic lead isotopic composition of our Greenland samples, compared to Asian dust isotopic fingerprints, implies that most of the insoluble lead reaching the ice cap is of anthropogenic origin. Lead isotopes reveal likely contributions from European/Canadian and, to a lesser extent, US sources, as well as a marked overprinted signature typical of Chinese anthropogenic lead sources. The relative contribution of the latter appears to have been increasing steadily over the last decade of the 20th century. Quantitative estimates suggest that, in addition to providing most of the dust, China may have already become the most important supplier of anthropogenic lead deposited in Greenland by the turn of the 20th to the 21st century. The close timing between dust and anthropogenic particles deposition onto the ice cap provides new insights for our understanding of Chinese aerosols transport to Greenland.

  5. Linkage of the king eider population in Northeast Greenland: Migration, moult and discovery of a new offshore wintering area at Spitsbergenbanken

    DEFF Research Database (Denmark)

    Mosbech, Anders; Johansen, Kasper Lambert; Sonne, Christian

    In late July 2009, two female king eiders were caught on the breeding grounds in Myggbukta, Northeast Greenland and equipped with satellite transmitters. Both individuals were tracked for approximately two years. The birds remained in the Myggbukta area until the onset of the autumn migration...... arrival 6 April) where they stayed for some time before returning on the spring migration to Greenland. During a ship-based survey in the offshore winter location at Spitsbergenbanken in April 2013, a previously unknown wintering ground with approximately 10.000 king eiders was discovered. The birds were...... concentrated in a partly ice-covered area 79 km from shore and of about 20 m depth. The number of king eiders indicated that Spitsbergenbanken is a wintering area for both the East Greenland and the Svalbard breeding populations. The discovery has important conservation implications due to the expanding...

  6. 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.

  7. TopoGreenland: Lithospheric structure and topography in Central-Eastern Greenland

    Science.gov (United States)

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

    2017-12-01

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

  8. Pollen record of the mid- to late-Holocene centennial climate change on the East coast of South Korea and its influential factors

    Science.gov (United States)

    Song, Bing; Yi, Sangheon; Jia, Hongjuan; Nahm, Wook-Hyun; Kim, Jin-Cheul; Lim, Jaesoo; Lee, Jin-Young; Sha, Longbin; Mao, Limi; Yang, Zhongyong; Nakanishi, Toshimichi; Hong, Wan; Li, Zhen

    2018-01-01

    To understand historical climate change in western Pacific coastal areas, a sediment core (SOJ-2) from the stable sedimentary environment of the Songjiho Lagoon on the east coast of South Korea was obtained for centennial-resolution palynological analysis. The ages of the SOJ-2 core is well controlled by carbon 14 dating with high-resolution accelerator mass spectrometry (AMS), and the results indicated a general warm to cold climate trend from the mid-Holocene to the present, which can be divided into two different stages: a warmer stage between 6842 and 1297 cal yr BP and a colder stage from 1297 cal yr BP to the present, with fluctuations during these stages. The climate was wetter from 6842 to 6227 cal yr BP and 4520 to 1297 cal yr BP and was drier from 6227 to 4520 cal yr BP. The climate changed to cold and dry during the period from 1297-425 cal yr BP. The impact of human activity on the climate began at approximately 1297 cal yr BP and became pronounced starting in 425 cal yr BP. The general cooling trend may represent a response to decreasing solar insolation; however, the relative dryness or wetness of the climate may have been co-determined by westerlies and the East Asian summer monsoon (EASM). The climate had a teleconnection with the North Atlantic region, resulting from changes in solar activity. Nevertheless, EI Niño-Southern Oscillation (ENSO) activity played an important role in impacting the EASM changes in western Pacific coastal areas.

  9. Magmatic record of Late Devonian arc-continent collision in the northern Qiangtang, Tibet: Implications for the early evolution of East Paleo-Tethys Ocean

    Science.gov (United States)

    Dan, Wei; Wang, Qiang; Zhang, Xiu-Zheng; Zhang, Chunfu; Tang, Gong-Jian; Wang, Jun; Ou, Quan; Hao, Lu-Lu; Qi, Yue

    2018-05-01

    Recognizing the early-developed intra-oceanic arc is important in revealing the early evolution of East Paleo-Tethys Ocean. In this study, new SIMS zircon U-Pb dating, O-Hf isotopes, and whole-rock geochemical data are reported for the newly-discovered Late Devonian-Early Carboniferous arc in Qiangtang, central Tibet. New dating results reveal that the eastern Riwanchaka volcanic rocks were formed at 370-365 Ma and were intruded by the 360 Ma Gangma Co alkali feldspar granites. The volcanic rocks consist of basalts, andesites, dacites, and rhyodacites, whose geochemistry is similar to that typical of subduction-related volcanism. The basalts and andesites were generated by partial melting of the fluid and sediment-melt metasomatized mantle, respectively. The rhyodacites and dacites were probably derived from the fractional crystallization of andesites and from partial melting of the juvenile underplated mafic rocks, respectively. The Gangma Co alkali feldspar granites are A-type granites, and were possibly derived by partial melting of juvenile underplated mafic rocks in a post-collisional setting. The 370-365 Ma volcanic arc was characterized by basalts with oceanic arc-like Ce/Yb ratios and by rhyodacites with mantle-like or slightly higher zircon δ18O values, and it was associated with the contemporary ophiolites. Thus, we propose that it is the earliest intra-oceanic arc in the East Paleo-Tethys Ocean, and was accreted to the Northern Qiangtang Terrane during 365-360 Ma.

  10. Observations of runoff and sediment and dissolved loads from the Greenland Ice Sheet at Kangerlussuaq, West Greenland, 2007 to 2010

    DEFF Research Database (Denmark)

    Hasholt, Bent; Mikkelsen, Andreas Peter Bech; Nielsen, Morten Holtegaard

    2012-01-01

    Observations from 2007 to 2010 of runoff, sediment and solute delivery from a segment of the Greenland Ice Sheet (GrIS) and the proglacial landscape draining into the fjord at Kangerlussuaq are presented. The observations include at least three jökulhlaups and extreme recordings from 2010...... previously published for 2007 and 2008. The average effective erosion from the catchment was 0.28 mm (min. 0.18 and max. 0.45 mm). The erosion is larger than indicated from most other locations along the GrIS, but in the same order of magnitude as erosion in other glaciated areas at the same latitude, e.......g. Norway. The sandur in the proglacial area acts as a sediment sink for a lot of the sediments from the GrIS....

  11. Liver biochemistry and associations with alcohol intake, hepatitis B virus infection and Inuit ethnicity: a population-based comparative epidemiological survey in Greenland and Denmark.

    Science.gov (United States)

    Rex, Karsten Fleischer; Krarup, Henrik Bygum; Laurberg, Peter; Andersen, Stig

    2016-01-01

    Hepatitis B virus (HBV) infection is common in Arctic populations and high alcohol intake has been associated with an increased risk of a number of diseases. Yet, a description of the influence of alcohol intake in persons with HBV infection on liver biochemistry is lacking. We aimed to describe the association between reported alcohol intake and liver biochemistry taking into account also HBV infection, ethnicity, Inuit diet, body mass index (BMI), gender and age in an Arctic population. Population-based investigation of Inuit (n=441) and non-Inuit (94) in Greenland and Inuit living in Denmark (n=136). Participants filled in a questionnaire on alcohol intake and other life style factors. Blood samples were tested for aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin, albumin, hepatitis B surface antigen, hepatitis B surface antibody and hepatitis B core antibody. We also performed physical examinations. Participation rate was 95% in Greenland and 52% in Denmark. An alcohol intake above the recommended level was reported by 12.9% of non-Inuit in Greenland, 9.1% of Inuit in East Greenland, 6.1% of Inuit migrants and 3.4% of Inuit in the capital of Greenland (p=0.035). Alcohol intake was associated with AST (pbiochemistry. Non-Inuit in Greenland reported a higher alcohol intake than Inuit. Ethnic origin was more markedly associated with liver biochemistry than was alcohol intake, and Greenlandic ethnicity modified the effect of alcohol intake on AST. HBV infection was slightly associated with ALP but not with other liver biochemistry parameters.

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

    Directory of Open Access Journals (Sweden)

    Jill Katharina Olofsson

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

  13. Markers of futurity and aspect in West Greenlandic

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann

    2014-01-01

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

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

    DEFF Research Database (Denmark)

    Hansen, Birger Ulf

    1991-01-01

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

  15. Towards Greenland Glaciation: cumulative or abrupt transition?

    Science.gov (United States)

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

    2017-04-01

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

  16. Towards a new common Greenland Ice Core Chronology for the last 5000 years

    Science.gov (United States)

    Winstrup, Mai; Olander Rasmussen, Sune; Møllesøe Vinther, Bo; Cook, Eliza; Svensson, Anders; McConnell, Joe; Steffensen, Jørgen Peder

    2017-04-01

    Since the development of the Greenland Ice Core Chronology 2005 (GICC05), it has been widely used as a reference chronology in paleoclimate research. However, recent research (Sigl et al, 2015) demonstrated that this timescale has small, but significant, issues over historical time. These discrepancies was found by counting annual layers in high-resolution chemistry records from the NEEM S1 shallow core, and confirmed by linking via 10Be marker horizons to the layer-counted WAIS Divide ice core, Antarctica, and accurately-dated tree-ring series. This work showed that a revision of GICC05 is required prior to 1250AD. We here refine and extend this work. Layer-counting in a single core will always involve some uncertainty, and we hence use data from multiple Greenland ice cores, for which high-resolution impurity records recently have been measured. These ice cores have been synchronized using volcanic marker horizons, and the layer-counting is performed automatically using the StratiCounter algorithm (Winstrup et al, 2012), while ensuring that the number of layers between volcanic horizons are the same in all cores. Based on this extended multiple-core data set, we are further able to extend the new Greenland timescale another few thousand years back in time. This will, among others, provide a new ice-core date for the catastrophic volcanic eruption ( 1600 BC) that destroyed the Greek Minoan culture, an important time marker in Greek history.

  17. A Younger Dryas re-advance of local glaciers in north Greenland

    DEFF Research Database (Denmark)

    Larsen, Nicolaj K.; Funder, Svend; Linge, Henriette

    2016-01-01

    The Younger Dryas (YD) is a well-constrained cold event from 12,900 to 11,700 years ago but it remains unclear how the cooling and subsequent abrupt warming recorded in ice cores was translated into ice margin fluctuations in Greenland. Here we present 10Be surface exposure ages from three moraines...... in front of local glaciers on a 50 km stretch along the north coast of Greenland, facing the Arctic Ocean. Ten ages range from 11.6 ± 0.5 to 27.2 ± 0.9 ka with a mean age of 12.5 ± 0.7 ka after exclusion of two outliers. We consider this to be a minimum age for the abandonment of the moraines. The ages...... the interval 11.8-13.0 ka ago. This is the first time a synchronous YD glacier advance and subsequent retreat has been recorded for several independent glaciers in Greenland. In most other areas, there is no evidence for re-advance and glaciers were retreating during YD. We explain the different behaviour...

  18. 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

  19. Uranium-bearing metasediment and granite in the Tasermiut area, South Greenland

    International Nuclear Information System (INIS)

    Leth Nielsen, B.; Tukiainen, T.

    1981-01-01

    Regional exploration for uranium was carried out in South Greenland in 1979 and 1980. From the planning stage the area between the fjords Tasermiut and Soendre Sermilik was considered a favourable target because deposits from geological environments of similar age, structure and lithology are known, e.g. the Makkovik Bay area in Labrador. The deposits sought were mainly pegmatitic or vein type deposits related to a Proterozoic unconformity. During the South Greenland uranium exploration project the area was covered in 1979 by a regional reconnaissance gamma-spectrometric survey and by drainage geochemistry (stream sediments and stream waters). Several areas of anomalous radioactivity were recorded, and on the basis of this and short field visit in 1979 it was decided to undertake a more systematic follow-up in 1980. The preliminary results of this work are reported below. (author)

  20. Mass balance of Greenland and the Canadian Ice Caps from combined altimetry and GRACE inversion

    DEFF Research Database (Denmark)

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

    The combination of GRACE and altimetry data may yield a high resolution mass balance time series of the Greenlandice sheet, highlighting the varying individual mass loss behaviour of major glaciers. By including the Canadian arctic ice caps in the estimation, a more reliable estimate of the mass...... loss of both Greenlandand the Canadian ice caps may be obtained, minimizing the leakage errors otherwise unavoidable by GRACE. Actually, the absolute value of the Greenlandice sheet mass loss is highly dependent on methods and how the effects of Arctic Canadian ice caps are separated in the GRACE...... loss of the ice caps and ice sheet basins for the period 2003-15. This period shows a marked increase of ice sheet melt, especially in NW and NE Greenland, but also show large variability, with the melt anomaly year of 2012 showing a record mass loss, followed by 2013 with essentially no Greenland mass...

  1. Early mantle dynamics inferred from 142Nd variations in Archean rocks from southwest Greenland

    DEFF Research Database (Denmark)

    Rizo, Hanika; Boyet, Maud; Blichert-Toft, Janne

    2013-01-01

    of the Greenland samples from a source formed in the Hadean. This mantle source is the oldest yet identified on Earth and therefore provides key information about the nature and evolution of early-differentiated reservoirs. In contrast, modern mantle-derived rocks from around the world do not have Nd-142 anomalies......The composition and evolution of the silicate Earth during Hadean/Eoarchean times are widely debated and largely unknown due to the sparse geological record preserved from Earth's infancy. The short-lived Sm-146-Nd-142 chronometer applied to 3.8-3.7 Ga old mantle-derived amphibolites from the Isua...... Supracrustal Belt (ISB) in southwest Greenland has revealed ubiquitous Nd-142 excesses in these rocks compared to modern samples and terrestrial Nd standards. Because the parent isotope, Sm-146, was extant only during the first few hundred million years of Solar System history, this implies derivation...

  2. Sea ice and primary production proxies in surface sediments from a High Arctic Greenland fjord

    DEFF Research Database (Denmark)

    Ribeiro, Sofia; Sejr, Mikael K; Limoges, Audrey

    2017-01-01

    Monitoring Programme. Clear spatial gradients in organic carbon and biogenic silica contents reflected marine influence, nutrient availability and river-induced turbidity, in good agreement with in situ measurements. The sea ice proxy IP25 was detected at all sites but at low concentrations, indicating...... that IP25 records from fjords need to be carefully considered and not directly compared to marine settings. The sea ice-associated biomarker HBI III revealed an open-water signature, with highest concentrations near the mid-July ice edge. This proxy evaluation is an important step towards reliable......In order to establish a baseline for proxy-based reconstructions for the Young Sound–Tyrolerfjord system (Northeast Greenland), we analysed the spatial distribution of primary production and sea ice proxies in surface sediments from the fjord, against monitoring data from the Greenland Ecosystem...

  3. Ancient Biomolecules from Deep Ice Cores Reveal a Forested Southern Greenland

    Science.gov (United States)

    Willerslev, Eske; Cappellini, Enrico; Boomsma, Wouter; Nielsen, Rasmus; Hebsgaard, Martin B.; Brand, Tina B.; Hofreiter, Michael; Bunce, Michael; Poinar, Hendrik N.; Dahl-Jensen, Dorthe; Johnsen, Sigfus; Steffensen, Jørgen Peder; Bennike, Ole; Schwenninger, Jean-Luc; Nathan, Roger; Armitage, Simon; de Hoog, Cees-Jan; Alfimov, Vasily; Christl, Marcus; Beer, Juerg; Muscheler, Raimund; Barker, Joel; Sharp, Martin; Penkman, Kirsty E.H.; Haile, James; Taberlet, Pierre; Gilbert, M. Thomas P.; Casoli, Antonella; Campani, Elisa; Collins, Matthew J.

    2009-01-01

    One of the major difficulties in paleontology is the acquisition of fossil data from the 10% of Earth’s terrestrial surface that is covered by thick glaciers and ice sheets. Here we reveal that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores and allow reconstructions of past flora and fauna. We show that high altitude southern Greenland, currently lying below more than two kilometers of ice, was once inhabited by a diverse array of conifer trees and insects that may date back more than 450 thousand years. The results provide the first direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections. PMID:17615355

  4. Vitamin D-rich marine Inuit diet and markers of inflammation - a population-based survey in Greenland

    DEFF Research Database (Denmark)

    Schæbel, Louise Kærholm; Bonefeld-Jørgensen, Eva Cecilie; Laurberg, Peter

    2015-01-01

    The traditional Inuit diet in Greenland consists mainly of fish and marine mammals, rich in vitamin D. Vitamin D has anti-inflammatory capacity but markers of inflammation have been found to be high in Inuit living on a marine diet. Yet, the effect of vitamin D on inflammation in Inuit remains...... unsettled. This led us to investigate the association between vitamin D and markers of inflammation in a population with a high intake of a marine diet. We studied 535 Inuit and non-Inuit living in West and East Greenland. Information concerning dietary habits was obtained by interview-based FFQ. Blood...... samples were drawn for analysis of 25-hydroxyvitamin D, high-sensitivity C-reactive protein (hsCRP) and chitinase-3-like protein 1(YKL-40). Participants were divided into three groups based on degree of intake of the traditional Inuit diet. The diet groups (Inuit diet/mixed diet/imported foods) were...

  5. Characterization of household waste in Greenland

    DEFF Research Database (Denmark)

    Eisted, Rasmus; Christensen, Thomas Højlund

    2011-01-01

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

  6. Mercury in dated Greenland marine sediments

    DEFF Research Database (Denmark)

    Asmund, G.; Nielsen, S.P.

    2000-01-01

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

  7. Violence, sexual abuse and health in Greenland

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  8. Violence, sexual abuse and health in Greenland

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  9. Active predation by Greenland shark Somniosus microcephalus

    DEFF Research Database (Denmark)

    Nielsen, Julius; hedeholm, Rasmus; Simon, Malene

    2013-01-01

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

  10. Secret Science: Exploring Cold War Greenland

    Science.gov (United States)

    Harper, K.

    2013-12-01

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

  11. Evaluation of the Doll Project in Greenland

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2013-01-01

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

  12. 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...

  13. The summer 2012 Greenland heat wave

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  14. A Younger Dryas re-advance of local glaciers in north Greenland

    Science.gov (United States)

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

    2016-09-01

    The Younger Dryas (YD) is a well-constrained cold event from 12,900 to 11,700 years ago but it remains unclear how the cooling and subsequent abrupt warming recorded in ice cores was translated into ice margin fluctuations in Greenland. Here we present 10Be surface exposure ages from three moraines in front of local glaciers on a 50 km stretch along the north coast of Greenland, facing the Arctic Ocean. Ten ages range from 11.6 ± 0.5 to 27.2 ± 0.9 ka with a mean age of 12.5 ± 0.7 ka after exclusion of two outliers. We consider this to be a minimum age for the abandonment of the moraines. The ages of the moraines are furthermore constrained using Optically Stimulated Luminescence (OSL) dating of epishelf sediments, which were deposited prior to the ice advance that formed the moraines, yielding a maximum age of 12.4 ± 0.6 ka, and bracketing the formation and subsequent abandonment of the moraines to within the interval 11.8-13.0 ka ago. This is the first time a synchronous YD glacier advance and subsequent retreat has been recorded for several independent glaciers in Greenland. In most other areas, there is no evidence for re-advance and glaciers were retreating during YD. We explain the different behaviour of the glaciers in northernmost Greenland as a function of their remoteness from the Atlantic Meridional Overturning Circulation (AMOC), which in other areas has been held responsible for modifying the YD drop in temperatures.

  15. Divergent influences of the Greenland and Antarctica climates on the Asian monsoon during a stadial to interstadial cycle

    Science.gov (United States)

    Duan, Fucai; Wang, Yongjin; Liao, Zebo; Chen, Shitao; Zhang, Weihong; Shao, Qingfeng

    2018-06-01

    Despite the links of Asian monsoon with climates at high northern and southern latitudes, it remains unclear that at which time and to what extent the Asian monsoon variation is dominated by one of the two drivers throughout a Greenland Stadial (GS) to Greenland Interstadial (GI) cycle. Here we provide a Chinese stalagmite δ18O record to study their teleconnections throughout the GS-6 to GI-5.2 cycle. The resemblance between the stalagmite and Greenland records, in timing, duration and abruptness of GI-5.2, supports that the occurrence and termination of GIs are paced by the northern driving force. During the intervals of GI-5.2 and GS-6, however, the Asian monsoon fluctuated concomitantly with variation in temperature over Antarctica, instead of over Greenland. This covariation indicates dominant influences of the Antarctic climate during the climatically stable intervals of stadials and interstadials. This study updates our knowledge on mechanical dynamics of the Asian monsoon change and global climate change throughout a GS to GI cycle.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  17. Resilience and Renewable Energy Planning in Greenland

    DEFF Research Database (Denmark)

    Carruth, Susan

    2014-01-01

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

  18. Reproductive factors, lifestyle and dietary habits among pregnant women in Greenland: The ACCEPT sub-study 2013-2015.

    Science.gov (United States)

    Terkelsen, Anne Seneca; Long, Manhai; Hounsgaard, Lise; Bonefeld-Jørgensen, Eva Cecilie

    2018-03-01

    During past decades the formerly active lifestyle in Greenland has become sedentary, and the intake of traditional food has gradually been replaced with imported food. These lifestyle and dietary habits may affect pregnant women. To describe age and regional differences in reproductive factors, lifestyle and diet among Greenlandic pregnant women in their first trimester. A cross-sectional study during 2013-2015 including 373 pregnant women was conducted in five Greenlandic regions (West, Disko Bay, South, North and East). Interview-based questionnaires on reproductive factors, lifestyle and dietary habits were compared in relation to two age groups (median age ≤28 years and >28 years). In total, 72.4% were Inuit, 46.6% had BMI >25.0 kg/m 2 , 29.0% were smoking during pregnancy and 54.6% had used hashish. BMI, educational level, personal income, previous pregnancies and planned breastfeeding period were significantly higher in the age group >28 years of age compared to the age group ≤28 years of age. In region Disko Bay, 90.9% were Inuit, in region South more had a university degree (37.9%) and region East had the highest number of previous pregnancies, the highest number of smokers during pregnancy and the most frequent intake of sauce with hot meals and fast-food. Overall a high BMI and a high smoking frequency were found. Age differences were found for BMI and planned breastfeeding period, while regional differences were found for smoking and intake of sauce with hot meals and fast-food. Future recommendations aimed at pregnant women in Greenland should focus on these health issues.

  19. Vertical land motion controls regional sea level rise patterns on the United States east coast since 1900

    Science.gov (United States)

    Piecuch, C. G.; Huybers, P. J.; Hay, C.; Mitrovica, J. X.; Little, C. M.; Ponte, R. M.; Tingley, M.

    2017-12-01

    Understanding observed spatial variations in centennial relative sea level trends on the United States east coast has important scientific and societal applications. Past studies based on models and proxies variously suggest roles for crustal displacement, ocean dynamics, and melting of the Greenland ice sheet. Here we perform joint Bayesian inference on regional relative sea level, vertical land motion, and absolute sea level fields based on tide gauge records and GPS data. Posterior solutions show that regional vertical land motion explains most (80% median estimate) of the spatial variance in the large-scale relative sea level trend field on the east coast over 1900-2016. The posterior estimate for coastal absolute sea level rise is remarkably spatially uniform compared to previous studies, with a spatial average of 1.4-2.3 mm/yr (95% credible interval). Results corroborate glacial isostatic adjustment models and reveal that meaningful long-period, large-scale vertical velocity signals can be extracted from short GPS records.

  20. 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...

  1. 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

  2. New geothermal heat flux map of Greenland and the Iceland hotspot track

    Science.gov (United States)

    Martos, Y. M.; Jordan, T. A.; Catalan, M.; Jordan, T. M.; Bamber, J. L.; Vaughan, D. G.

    2017-12-01

    Greenland is the second largest reservoir of water on Earth and about 80% of its surface is covered by ice. It is mainly composed of Archean blocks that collided during the Early Proterozoic. Indirect methods have been used to study its subglacial thermal conditions, geology and lithospheric structure. Numerous regions of basal melting are identified in the central and north Greenland but their relationship with geothermal heat flux is not yet clear. Crustal thickness derived by seismology and gravity data are consistent, showing no significant lateral variations, and providing average values of about 40 and 36 km respectively. Even though Greenland is considered a craton its crust has been affected by the presume passage of the Iceland hotspot since at least 100 Ma. Here we present the newest and highest resolution Curie Depth and geothermal heat flux maps for Greenland as well as their associated uncertainties. For estimating the Curie Depths we applied spectral methods to aeromagnetic data from the World Digital Magnetic Anomaly Map WDMAM2.0. Calculated Curie Depths vary from 25 to 50 km with shallower values located to the east. A thermal model is built based on the 1D heat conduction equation and considering steady state conditions. The thermal parameters are then optimized using local values derived from direct measurements, temperature profiles and more indirect methods such as radar imaging. The heat flux distribution shows higher spatial variability and a very different pattern than previously proposed and with values of 50-80 mW/m2. We identify a NW-SE high heat flux feature crossing Greenland which we correlate with the Iceland hotspot track. Additionally, to evaluate the lithospheric structure we calculate the Bouguer anomaly from GOCO5s satellite free air data and construct several gravity models across the proposed hotspot track. We show that a dense lower crust body in the same location the high heat flux trend is permissible from a gravimetric

  3. Regional drought shifts (1710-2010) in East Central Asia and linkages with atmospheric circulation recorded in tree-ring δ18O

    Science.gov (United States)

    Xu, Guobao; Liu, Xiaohong; Trouet, Valerie; Treydte, Kerstin; Wu, Guoju; Chen, Tuo; Sun, Weizhen; An, Wenling; Wang, Wenzhi; Zeng, Xiaomin; Qin, Dahe

    2018-04-01

    Drought occurrence and duration in central Asia are of important socioeconomic, ecological, and geophysical significance and have received increasing research attention in recent years. Understanding long-term drought trends and their driving forces require reliable records of past drought variability with broad spatial representativeness. Here, we compiled four tree-ring δ18O records from eastern central Asia (ECA) and composited them into a drought-sensitive proxy to explore regional ECA moisture variations over the past 301 years (1710-2010 CE). A robust regional standardized precipitation-evapotranspiration index (SPEI) reconstruction was established based on the tree-ring cellulose δ18O fractionation mechanism and statistically significant proxy-climate relationships. We identified prominent droughts in 1710-1770, 1810-1830, and the beginning of the twenty-first century, and a regime shift to a persistently wet period from the 1880s to 2000. Our reconstruction reveals the impact of drought and pluvial patterns on the decline of Zhungar Empire, and on historical agricultural and socio-economical activities, including increased migration into ECA during the 1770-1800 pluvial. Our findings also suggest that wet conditions in the twentieth century in ECA were related to a strengthening of the westerly circulation and thus shed light on large-scale atmospheric circulation dynamics in central Asia.

  4. Multi-proxy Organic Geochemical Reconstruction of Holocene Hydroclimate Near the Western Greenland Ice Sheet Margin

    Science.gov (United States)

    Cluett, A.; Thomas, E. K.

    2017-12-01

    Anthropogenic warming is projected to drive profound change to the Arctic hydrological cycle within the century, most notably in the intensification of rainfall, with potential feedbacks to the climate system and cryosphere. However, the relationship between hydroclimate and cryosphere variability is poorly constrained in the long-term due to a scarcity of high-resolution hydroclimate records from the Arctic. We analyze the stable hydrogen isotopes (dD) of leaf wax biomarkers from lacustrine sediments spanning the Holocene to 9000 cal. year B.P. from Lake Gus (67.032ºN, 52.427ºW, 300 m a.s.l.; informal name), a small lake approximately 90 km from the modern western margin of the Greenland Ice Sheet. We interpret the signal of aquatic leaf wax isotopes in the context of a survey of 100 modern lake water samples from western Greenland across an aridity gradient to better understand the combined climatological and hydrological controls on lake water dD in the study area. We compare variability of aquatic and terrestrial leaf wax isotopes to infer changes in relative moisture throughout the Holocene, and complement our leaf wax record with analysis of glycerol dialkyl glycerol tetraethers (GDGTs) and alkenones, to produce records of summer temperature. Pairing temperature and leaf wax isotope records provides a means to constrain the changing dD-temperature relationship throughout the Holocene and infer moisture source variability. In combination, these proxies produce a comprehensive hydroclimate record at approximately centennial scale to evaluate shifts in relative moisture, temperature, and moisture source, and to investigate the interaction between hydroclimate and Greenland Ice Sheet margin fluctuations through the Holocene.

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

    Science.gov (United States)

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

    2016-01-01

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

  6. Measured and modelled absolute gravity changes in Greenland

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  7. 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...

  8. Uncovering the Genetic History of the Present Day Greenlandic Population

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  9. Continuity and discontinuity in the Inuit culture of Greenland

    NARCIS (Netherlands)

    Kylstra, Hans P.

    1977-01-01

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

  10. 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....

  11. Climate Change and Baleen Whale Trophic Cascades in Greenland

    Science.gov (United States)

    2009-09-30

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

  12. Conceptualizing and contextualizing food insecurity among Greenlandic children

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  13. Cadmium toxicity to ringed seals (Phoca hispida): an epidemiological study of possible cadmium-induced nephropathy and osteodystrophy in ringed seals (Phoca hispida) from Qaanaaq in Northwest Greenland

    DEFF Research Database (Denmark)

    Sonne-Hansen, C; Dietz, R; Leifsson, P S

    2002-01-01

    The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose of the st......The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose...... of the study was to determine whether cadmium-induced damage in the kidneys and the skeletal system could be detected among 100 ringed seals from Northwest Greenland. The cadmium concentrations in the kidney cortex ranged from 0 to 248 microg/g wet weight (mean=44.5, N=100) in the 99 kidneys examined....... Experience from cadmium-poisoned humans and laboratory mammals indicates that concentrations above 50-200 microg/g wet wt. may induce histopathological changes. Overall, 31 of the ringed seals had cadmium concentrations in the kidney cortex above 50 microg/g wet wt., 11 had concentrations above 100 and one...

  14. Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

    Science.gov (United States)

    Maselli, Olivia J.; Chellman, Nathan J.; Grieman, Mackenzie; Layman, Lawrence; McConnell, Joseph R.; Pasteris, Daniel; Rhodes, Rachael H.; Saltzman, Eric; Sigl, Michael

    2017-01-01

    Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750-2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

  15. Birth weight and risk of adiposity among adult Inuit in Greenland.

    Directory of Open Access Journals (Sweden)

    Pernille Falberg Rønn

    Full Text Available OBJECTIVE: The Inuit population in Greenland has undergone rapid socioeconomic and nutritional changes simultaneously with an increasing prevalence of obesity. Therefore, the objective was to examine fetal programming as part of the aetiology of obesity among Inuit in Greenland by investigating the association between birth weight and measures of body composition and fat distribution in adulthood. METHODS: The study was based on cross-sectional data from a total of 1,473 adults aged 18-61 years in two population-based surveys conducted in Greenland between 1999-2001 and 2005-2010. Information on birth weight was collected from birth records. Adiposity was assessed by anthropometry, fat mass index (FMI, fat-free mass index (FFMI, and visceral (VAT and subcutaneous adipose tissue (SAT estimated by ultrasound. The associations to birth weight were analyzed using linear regression models and quadratic splines. Analyses were stratified by sex, and adjusted for age, birthplace, ancestry and family history of obesity. RESULTS: Spline analyses showed linear relations between birth weight and adult adiposity. In multiple regression analyses, birth weight was positively associated with BMI, waist circumference, FMI, FFMI and SAT with generally weaker associations among women compared to men. Birth weight was only associated with VAT after additional adjustment for waist circumference and appeared to be specific and inverse for men only. CONCLUSIONS: Higher birth weight among Inuit was associated with adiposity in adulthood. More studies are needed to explore a potential inverse association between birth size and VAT.

  16. Spirometry in Greenland: a cross-sectional study on patients treated with medication targeting obstructive pulmonary disease.

    Science.gov (United States)

    Nielsen, Lasse Overballe; Olsen, Sequssuna; Jarbøl, Dorte Ejg; Pedersen, Michael Lynge

    2016-01-01

    Chronic obstructive pulmonary disease (COPD) is globally increasing in frequency and is expected to be the third largest cause of death by 2020. Smoking is the main risk factor of developing COPD. In Greenland, more than half of the adult population are daily smokers, and COPD may be common. International guidelines recommend the usage of spirometry as a golden standard for diagnosing COPD. The current number of spirometries performed among patients treated with medication targeting obstructive pulmonary disease in Greenland remains unexplored. To estimate the prevalence of patients aged 50 years or above treated with medication targeting obstructive pulmonary disease and the extent to which spirometry was performed among them within 2 years. An observational, cross-sectional study based on the review of data obtained from electronic medical records in Greenland was performed. The inclusion criterion was that patients must have been permanent residents aged 50 years or above who had medication targeting obstructive pulmonary disease prescribed within a period of 15 months prior to data extraction. A full review of electronic patient records was done on each of the identified users of medication targeting obstructive pulmonary disease. Information on age, gender, town and spirometry was registered for each patient within the period from October 2013 to October 2015. The prevalence of patients treated with medication targeting obstructive pulmonary disease aged 50 years or above was 7.9%. Of those, 34.8% had spirometry performed within 2 years and 50% had a forced expiratory volume (1 sec)/ forced vital capacity (FEV1/FVC) under 70% indicating obstructive pulmonary disease. The use of medication targeting obstructive pulmonary disease among patients over 50 years old is common in Greenland. About one third of the patients had a spirometry performed within 2 years. To further increase spirometry performance, it is recommended to explore possible barriers in health

  17. Ice flow Modelling of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Tangaa

    Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others. In t...... a steady state with respect to the reference climate at the end of the simulation and that the mass balance of the ice sheet at this time was more sensitive to recent climate fluctuations than the temperature forcing in the early or mid-Holocene.......Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others....... In this PhD project, the use of ice flow models for the interpretation of the age-structure of the Greenland ice sheet, i.e. the depth within the ice, at which ice deposited at given times are found at present day. Two different observational data sets of this archive were investigated. Further, paleo...

  18. Clouds enhance Greenland ice sheet mass loss

    Science.gov (United States)

    Van Tricht, Kristof; Gorodetskaya, Irina V.; L'Ecuyer, Tristan; Lenaerts, Jan T. M.; Lhermitte, Stef; Noel, Brice; Turner, David D.; van den Broeke, Michiel R.; van Lipzig, Nicole P. M.

    2015-04-01

    Clouds have a profound influence on both the Arctic and global climate, while they still represent one of the key uncertainties in climate models, limiting the fidelity of future climate projections. The potentially important role of thin liquid-containing clouds over Greenland in enhancing ice sheet melt has recently gained interest, yet current research is spatially and temporally limited, focusing on particular events, and their large scale impact on the surface mass balance remains unknown. We used a combination of satellite remote sensing (CloudSat - CALIPSO), ground-based observations and climate model (RACMO) data to show that liquid-containing clouds warm the Greenland ice sheet 94% of the time. High surface reflectivity (albedo) for shortwave radiation reduces the cloud shortwave cooling effect on the absorbed fluxes, while not influencing the absorption of longwave radiation. Cloud warming over the ice sheet therefore dominates year-round. Only when albedo values drop below ~0.6 in the coastal areas during summer, the cooling effect starts to overcome the warming effect. The year-round excess of energy due to the presence of liquid-containing clouds has an extensive influence on the mass balance of the ice sheet. Simulations using the SNOWPACK snow model showed not only a strong influence of these liquid-containing clouds on melt increase, but also on the increased sublimation mass loss. Simulations with the Community Earth System Climate Model for the end of the 21st century (2080-2099) show that Greenland clouds contain more liquid water path and less ice water path. This implies that cloud radiative forcing will be further enhanced in the future. Our results therefore urge the need for improving cloud microphysics in climate models, to improve future projections of ice sheet mass balance and global sea level rise.

  19. Homicide in Greenland 1985-2010.

    Science.gov (United States)

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

    2016-03-01

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

  20. 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