WorldWideScience

Sample records for central west greenland

  1. Gyrfalcon diet in central west Greenland during the nestling period

    Science.gov (United States)

    Booms, Travis; Fuller, Mark R.

    2003-01-01

    We studied food habits of Gyrfalcons (Falco rusticolus) nesting in central west Greenland in 2000 and 2001 using three sources of data: time-lapse video (3 nests), prey remains (22 nests), and regurgitated pellets (19 nests). These sources provided different information describing the diet during the nesting period. Gyrfalcons relied heavily on Rock Ptarmigan (Lagopus mutus) and arctic hares (Lepus arcticus). Combined, these species contributed 79-91% of the total diet, depending on the data used. Passerines were the third most important group. Prey less common in the diet included waterfowl, arctic fox pups (Alopex lagopus), shorebirds, gulls, alcids, and falcons. All Rock Ptarmigan were adults, and all but one arctic hare were young of the year. Most passerines were fledglings. We observed two diet shifts, first from a preponderance of ptarmigan to hares in mid-June, and second to passerines in late June. The video-monitored Gyrfalcons consumed 94-110 kg of food per nest during the nestling period, higher than previously estimated. Using a combination of video, prey remains, and pellets was important to accurately document Gyrfalcon diet, and we strongly recommend using time-lapse video in future diet studies to identify biases in prey remains and pellet data.

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

    DEFF Research Database (Denmark)

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

    Spatial distribution of caribou (Rangifer tarandus groenlandicus) in West Greenland is a result of both short and long term changes in the Arctic landscape. To understand present distribution 40 satellite collars were deployed on 40 female caribou in the Akia-Maniitsoq herd, central West Greenland...... distribution and caribou in a realistic but manipulable “virtual world” of an IBM it is possible to examine the plausible effects of different environmental impacts on the population dynamics of caribou in West Greenland. The simulations will include introduction of mega-industry, roads, and transmission lines...

  3. A Comparison of Geoid Undulations for West Central Greenland

    Science.gov (United States)

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

    1997-01-01

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

  4. West Greenlandic Eskimo

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann; Fortescue, Michael David

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

  5. Spatial Variability in Surface Elevation Changes of Central-West Greenland Outlet Glaciers

    Science.gov (United States)

    Felikson, D.; Catania, G. A.; Kjaer, K. H.; Korsgaard, N. J.; Stearns, L. A.; Nash, J. D.; Shroyer, E.; Sutherland, D.; Walker, R. T.

    2014-12-01

    The mass balance of the Greenland ice sheet (GrIS) is, in part, governed by the dynamics of ocean-terminating glaciers. GRACE data reveal that along the central-west coast of the GrIS, overall ice loss has been accelerating since 2007. However, we do not know the physical processes controlling the loss here, and the changes observed are not uniform in this region; several glaciers have gone through periods of slow-down in the recent past. To address these uncertainties, we have performed ~30-year DEM differences of outlet glaciers in the region. Present-day DEMs have been created from WorldView-1 and -2 (WV) stereo imagery acquired in 2012 and 2013 using the AMES Stereo Pipeline. A 1985 DEM was created from a Greenland aerial photo survey. The DEM differences between the present-day WV DEMs and the 1985 aerial photo DEM show clearly that spatial variability in the surface elevation and terminus position changes of the glaciers in the region has been ongoing for the last ~30 years. We examine this variability in the context of ocean temperature and surface mass balance estimates to yield further insight into the external controls on these glaciers.

  6. Contamination of arctic Fjord sediments by Pb-Zn mining at Maarmorilik in central West Greenland

    DEFF Research Database (Denmark)

    Perner, Kerstin; Leipe, Thomas; Dellwig, O;

    2010-01-01

    This study focuses on heavy metal contamination of arctic sediments from a small Fjord system adjacent to the Pb-Zn "Black Angel" mine (West Greenland) to investigate the temporal and spatial development of contamination and to provide baseline levels before the mines re-opening in January 2009...... illustrate this transport and spatial distribution pattern of the contaminated material....

  7. Seismic architecture and evolution of the Disko Bay trough-mouth fan, central West Greenland margin

    Science.gov (United States)

    Hofmann, Julia C.; Knutz, Paul C.; Nielsen, Tove; Kuijpers, Antoon

    2016-09-01

    The present study is the first to document the large-scale glacigenic evolution of a West Greenland trough-mouth fan (TMF) system, i.e. the Disko Bay TMF, from onset of shelf-based glaciation to present. We have constrained the paleo-ice sheet configuration in the Disko Bay region and determine the controlling factors of ice-stream development using 2D- and 3D-seismic reflection data, seabed bathymetry and stratigraphic information from two exploration wells. This has revealed three stages of the Disko Bay TMF development. The early stage, probably of Pliocene-early Pleistocene age, marks the onset of a central depocentre located below the modern mid-shelf and constructed by sediment progradation delivered through at least two erosive pathways related to fast-flowing, grounded ice. At that time, ice-stream routing in the Disko Bay shelf region was strongly controlled by the pre-glacial topography and structural boundaries associated with fracture zones and deep-seated faults. During the middle evolutionary stage, the focus of deposition shifted from the mid-shelf to two elongate areas fringing the outer margin. The marginal depocentres were not only related to glacial processes but also alongslope deposition by contour currents, which may have developed as a consequence of basin subsidence surrounding the Davis Strait High and the Kangerluk Structure. The late stage of TMF development, presumably representing the late Pleistocene to Holocene, is characterized by the marginal depocentres becoming less significant and sediment aggradation occurring over wide parts of the mid-outer shelf, while features of subglacial erosion are generally absent. In contrast to the inferred fast-flowing ice streams of the early-middle evolutionary stages, this points to the existence of a rather thin and "lightly" grounded ice sheet, i.e. at the threshold of floatation. The "lightly" grounded ice sheet scenario, applying to the late Pleistocene interval of the Disko Bay TMF, was

  8. Permafrost degradation in West Greenland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2012-01-01

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

  9. Important Summer Concentrations of Seaducks in West Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.

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

  10. A new, detailed ice-age oxygen-18 record from the ice-sheet margin in central West Greenland

    Science.gov (United States)

    Reeh, Niels; Oerter, Hans; Letréguilly, Anne; Miller, Heinz; Hubberten, Hans-Wolfgang

    1991-10-01

    A new detailed oxygen-18 record measured on surface-ice samples from a West Greenland ice-margin location reveals the hitherto longest climatic record from the Greenland ice sheet, spanning the last c. 150,000 years. The new record implies that the Greenland deep ice-core records from Dye3 and Camp Century need to be re-interpreted. A comparison with the deuterium record from the Vostok deep ice core, Antarctica indicates that climate behaved differently in the northern and southern hemispheres during the last glacial/interglacial cycle, with major differences occurring in Emiliani isotopic stage 5.

  11. 10Be dating reveals early-middle Holocene age of the Drygalski Moraines in central West Greenland

    Science.gov (United States)

    Cronauer, Sandra L.; Briner, Jason P.; Kelley, Samuel E.; Zimmerman, Susan R. H.; Morlighem, Mathieu

    2016-09-01

    We reconstruct the history of the Greenland Ice Sheet margin on the Nuussuaq Peninsula in central West Greenland through the Holocene using lake sediment analysis and cosmogenic 10Be exposure dating of the prominent Drygalski Moraines. Erratics perched on bedrock outboard of the Drygalski Moraines constrain local deglaciation to ∼9.9 ± 0.6 ka (n = 2). Three Drygalski Moraine crests yield mean 10Be ages of 8.6 ± 0.4 ka (n = 2), 8.5 ± 0.2 ka (n = 3), and 7.6 ± 0.1 ka (n = 2) from outer to inner. Perched erratics between the inner two moraines average 7.8 ± 0.1 ka (n = 2) and are consistent with the moraine ages. Sediments from a proglacial lake with a catchment area extending an estimated 2 km beneath (inland of) the present ice sheet terminus constrain an ice sheet minimum extent from 5.4 ka to 0.6 ka. The moraine chronology paired with the lake sediment stratigraphy reveals that the ice margin likely remained within ∼2 km of its present position from ∼9.9 to 5.4 ka. This unexpected early Holocene stability, preceded by rapid ice retreat and followed by minimum ice extent between ∼5.4 and 0.6 ka, contrasts with many records of early Holocene warmth and the Northern Hemisphere summer insolation maximum. We suggest ice margin stability may instead be tied to adjacent ocean temperatures, which reached an optimum in the middle Holocene.

  12. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: 207Pb-206Pb dating of magnetite, monazite and allanite in the central and northern Nagssugtoqidian orogen, West Greenland

    Directory of Open Access Journals (Sweden)

    Frei, Robert

    2006-12-01

    Full Text Available Pb-isotopic data for magnetite from amphibolites in the Nagssugtoqidian orogen, central West Greenland, have been used to trace their source characteristics and the timing of metamorphism. Analyses of the magnetite define a Pb-Pb isochron age of 1726 ± 7 Ma. The magnetite is metamorphic in origin, and the 1726 Ma age is interpreted as a cooling age through the closing temperature of magnetite at ~600°C. Some of the amphibolites in this study come from the Naternaq supracrustal rocks in the northern Nagssugtoqidian orogen, which host the Naternaq sulphide deposit and may be part ofthe Nordre Strømfjord supracrustal suite, which was deposited at around 1950 Ma ago.Pb-isotopic signatures of magnetite from the Arfersiorfik quartz diorite in the central Nagssugtoqidian orogen are compatible with published whole-rock Pb-isotopic data from this suite; previous work has shown that it is a product of subduction-related calc-alkaline magmatism between 1920 and 1870 Ma. Intrusion of pegmatites occurred at around 1800 Ma in both the central and the northernparts of the orogen. Pegmatite ages have been determined by Pb stepwise leaching analyses of allanite and monazite, and source characteristics of Pb point to an origin of the pegmatites by melting of the surrounding late Archaean and Palaeoproterozoic country rocks. Hydrothermal activity took place after pegmatite emplacement and continued below the closure temperature of magnetite at 1800–1650 Ma. Because of the relatively inert and refractory nature of magnetite, Pb-isotopic measurements from this mineral may be of help to understand the metamorphic evolution of geologicallycomplex terrains.

  13. Mineral resources of the Precambrian shiled of central West Greenland (66 deg. to 70 deg. 15'N). Part 2. Mineral occurrences

    Energy Technology Data Exchange (ETDEWEB)

    Stendal, H.; Moeller Nielsen, B.; Secher, K.; Steenfelt, A.

    2004-07-01

    This report forms part of an assessment of the mineral resource potential of central West Greenland conducted by the Geological Survey of Denmark and Greenland 2000-2003. It presents the principles applied in classifying and describing 160 compiled mineral occurrences from the region as well as an evaluation of the mineral resource potential. The assessed region is underlain by an Archaean basement of tonalitic orthogneisses with intercalated supracrustal belts representing both continental and volcanic arc environments. The basement has been variably reworked during the Palaeoproterozoic Nagssugtoqidian collisional orogen and has been intruded by minor volumes of arc-related magmas in the core zone of the orogen. There are no mines in the region, and previous production has been limited to graphite. Many mineral showings have been recorded by commercial companies and the Survey during exploration since the 1960s, but none have so far become economically feasible. Most of the known occurrences are located in supracrustal belts and comprise banded ironformation, semi-massive to massive sulphides, together with syn- and epigenetic gold and copper. Pyrochlore and diamonds are found within a 0.6 Ga old carbonatite-kimberlite province and some pegmatites are rich in monazite. Based on the abundance, spatial distribution, size, grade, age and genesis of the mineral occurrences it is concluded that the following types of mineral occurrences have a potential for becoming economically feasible: 1) Syn- and epigenetic gold in Archaean supracrustal rocks. 2) Graphite in Palaeoproterozoic supracrustal rocks. 3) Speciality metals in carbonatite. 4) Diamonds in kimberlitic dykes. (au)

  14. Bowhead whale springtime song off West Greenland.

    Science.gov (United States)

    Stafford, Kathleen M; Moore, Sue E; Laidre, Kristin L; Heide-Jørgensen, M P

    2008-11-01

    Three songs were recorded from bowhead whales (Balaena mysticetus) in Disko Bay, West Greenland, during 59 h of recordings via sonobuoys deployed on seven days between 5 and 14 April 2007. Song elements were defined by units following the protocol of previous description of bowhead whale song. The two most prominent songs were loud, complex, and repeated in long bouts on multiple recording days while the third song was much simpler and recorded on only one day. Bowhead whale simple calls and faint song elements were also recorded using digital audio tape recorders and a dipping hydrophone deployed from the sea ice approximately 100-150 km southwest of Disko Bay on three separate days suggesting that song is also produced in the central portion of Baffin Bay in winter. Songs recorded in Disko Bay are from an area where approximately 85% of the whales have been determined to be adult females. Although it is not known which sex was singing, we speculate that, as in humpback whales (Megaptera novaeangliae), male bowhead whales may sing to mediate sexual competition or mate selection behaviors. This is the first detailed description of springtime songs for bowhead whales in the eastern Arctic. PMID:19045814

  15. Ice stream retreat following the LGM and onset of the west Greenland current in Uummannaq Trough, west Greenland

    Science.gov (United States)

    Sheldon, Christina; Jennings, Anne; Andrews, John T.; Ó Cofaigh, Colm; Hogan, Kelly; Dowdeswell, Julian A.; Seidenkrantz, Marit-Solveig

    2016-09-01

    The deglacial history and oceanography of Uummannaq Trough, central West Greenland continental shelf, was investigated using foraminiferal, sedimentological, and bathymetric records together with a radiocarbon chronology, providing a timeline for the retreat of glacial ice after the Last Glacial Maximum (LGM). To map ice stream retreat, data were collected from cores from the outer (JR175-VC45 and JR175-VC43) and inner (JR175-VC42) Uummannaq Trough. A large ice stream, fed by confluent glaciers draining the interior of the Greenland Ice Sheet, extended across the outer shelf during the LGM and was in retreat by 15.0 cal kyr BP. Foraminiferal data indicate that the 'warm' West Greenland Current (WGC) was established prior to 14.0 cal kyr BP, which is the hitherto earliest record of Atlantic Water found on the West Greenland shelf. For each of the cores, foraminifera indicate that ice sheet retreat was followed quickly by incursion of the WGC, suggesting that the warm water may have enhanced ice retreat. Prior to the Younger Dryas cold event, the radiocarbon chronology indicates that the ice sheet retreated to the mid-shelf, where it subsequently stabilised and formed a large grounding-zone wedge (GZW). After the Younger Dryas, around 11.5 cal kyr BP, the ice retreated rapidly from the GZW and into the fjords.

  16. Continental Collision Structures and Post-Orogenic Geological History of the Kangerlussuaq Area in the Southern Part of the Nagssugtoqidian Orogen, Central West Greenland

    Directory of Open Access Journals (Sweden)

    Jon Engström

    2014-12-01

    Full Text Available Deep-seated continental collision sutures, formed at a depth of more than 20 km, are exposed near Kangerlussuaq, close to the Greenland ice cap, on the southern margin of the Nagssugtoqidian orogen in Central West Greenland, thus offering a rare opportunity to study the tectonic deformation style of such an orogen. This paper adds new information on the tectonic history of the southern flank of the Nagssugtoqidian orogen. It focuses on (1 the results of a detailed structural investigation of lineament zones revealed from remote sensing of geophysical and topographic data and aerial photo interpretation, (2 detailed geological mapping at key locations and (3 a tectonic structural model describing the geological development of the area. The area has undergone several episodes of deformation, which have been compiled into an event succession that recognizes eight tectonic events overprinting each other: Two stages of folding (F1 and F2 have been identified along with one major episode of intrusion of the Kangâmiut mafic dyke swarm (2.05 Ga into the Archaean continent. These dyke intrusions are very important, since by examining the style of deformation for these intrusions it is possible to define the transition from the North Atlantic Craton in the south to the mobile belts in the Nagssugtoqidian orogen in the north. Five different types of pronounced lineaments and one less pronounced lineament post-dating the Kangâmiut dykes extending from ductile deformation shearing events to brittle deformation with extensive faulting. These lineaments cover both the collisional and post-collisional tectonic history of the area. The study focused on two types of lineaments: one semi-ductile type trending E–W with a dextral sense of shear and a second, a pronounced lineament outlining the Kangerlussuaq–Russell thrust fault. These two features are interpreted to be related to the Nagssugtoqidian orogeny, while the latter lineaments have a more brittle

  17. The lithospheric mantle below southern West Greenland

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  18. Contaminants in two West Greenland caribou populations.

    Science.gov (United States)

    Gamberg, Mary; Cuyler, Christine; Wang, Xiaowa

    2016-06-01

    Two caribou populations in West Greenland were sampled and the kidneys, liver and muscle analyzed for contaminants, including aluminum, arsenic, cadmium, copper, lead, mercury, selenium and zinc. Although close in proximity, the two populations are topographically separated by an ice cap, which creates different climates and vegetation types in each region. Contaminant levels reflected the differing diets of the two caribou populations. To the south in the wetter lichen-rich region, caribou had significantly more aluminum, arsenic, cadmium, lead, mercury, selenium and zinc, likely due to atmospheric deposition on lichens. To the north in the dry desert steppe where grasses predominate, caribou had higher levels of copper. Cows collected in late winter had significantly less hepatic copper, lead and mercury if pregnant, indicating placental transfer of these elements. Our results suggest that hepatic copper levels <200 μg g(-1) dry weight may result in copper depletion in pregnant cows and hepatic mercury concentrations above 0.5 μg g(-1) dry weight may negatively affect fertility in caribou cows. Hepatic mercury levels were negatively correlated with cow body weight, suggesting an adverse effect on body condition. Element concentrations found in tissues from these caribou are not considered to be of a health concern for those consuming this traditional food. PMID:26956180

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    document late-Holocene climate variability in West Greenland as inferred from a marine sediment record from the outer Disko Bay. Organic-walled dinoflagellate cysts and other palynomorphs were used to reconstruct environmental changes in the area through the last c. 1500 years at 30–40 years resolution....... Sea ice cover and primary productivity were identified as the two main factors driving dinoflagellate cyst community changes through time. Our data provide evidence for an opposite climate trend in West Greenland relative to the NE Atlantic region from c. AD 500 to 1050. For the same period, sea......Ribeiro, S., Moros, M., Ellegaard, M. & Kuijpers, A. 2012 (January): Climate variability in West Greenland during the past 1500 years: evidence from a high-resolution marine palynological record from Disko Bay. Boreas, Vol. 41, pp. 68–83. 10.1111/j.1502-3885.2011.00216.x. ISSN 0300-9483. Here we...

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

    OpenAIRE

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

    2006-01-01

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

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

    DEFF Research Database (Denmark)

    Larsen, Finn; Hammond, P.S.

    2004-01-01

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

  2. 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....

  3. Brief communication: Historical glacier length changes in West Greenland

    Directory of Open Access Journals (Sweden)

    P. W. Leclercq

    2012-08-01

    Full Text Available Past glacier fluctuations provide insight into glacier dynamics, climate change, and the contribution of glaciers to sea-level rise. Here, the length fluctuations since the 19th century of 18 local glaciers in West and South Greenland are presented, extending and updating the study by Weidick (1968. The studied glaciers all show an overall retreat with an average of 1.2 ± 0.2 km over the 20th century, indicating a general rise of the equilibrium line along the west coast of Greenland during the last century. The rate of retreat was largest in the first half of the 20th century.

  4. Brief communication "Historical glacier length changes in West Greenland"

    Directory of Open Access Journals (Sweden)

    P. W. Leclercq

    2012-11-01

    Full Text Available Past glacier fluctuations provide insight into glacier dynamics, climate change, and the contribution of glaciers to sea-level rise. Here, the length fluctuations since the 19th century of 18 local glaciers in West and South Greenland are presented, extending and updating the study by Weidick (1968. The studied glaciers all showed an overall retreat with an average of 1.2 ± 0.2 km over the 20th century, indicating a general rise of the equilibrium line along the west coast of Greenland during the last century. Furthermore, the average rate of retreat was largest in the first half of the 20th century.

  5. 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...

  6. Report on a Magnetotelluric Study in Kangerlussuaq, West Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

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

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

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    Christine Cuyler

    2007-04-01

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

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  9. Strategic environmental impact assessment of hydrocarbon activities in the Disko West area[Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Mosbech, A.; Boertmann, D.; Jespersen, Martin

    2007-05-15

    This publication is a strategic environmental impact assessment of activities related to exploration, development and exploitation of hydrocarbons in the sea of West Greenland between 67 deg. and 71 deg. N (= the Disko West Area). (au)

  10. Unusual features caused by lightning impact in West Greenland

    DEFF Research Database (Denmark)

    Appel, P.; Abrahamsen, N.; Rasmussen, T.

    2006-01-01

       Two lightning impacts are described from an area near the Inland Ice in West Greenland. The first lightning blasted an outcrop of metacherts. It subsequently split into two branches, which traversed rock outcrops and boulders, leaving behind two white almost straight lines, 30 m and 14 m long...... that a strong electric current indeed traversed the boulder. A few years later a second lightning impacted on a mountaintop close to the first impact. The second lightning left a trail on the rock surface covered by a thin layer of glass. The glass displays spectacular colours ranging from metallic blue, to red...

  11. Offshore Seabird Distributions during Summer and Autumn at West Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.

    This report presents the phenological and distributional results of seabird surveys carried out by ship in West Greenland waters. In 1977 observations were carried out from stationary platforms (oil exploration supply ships) and in the period 1992 to 2000 observations were carried out from sailing...... ships. The results from 1977 are presented as observations per 5-day periods and give an impression of the species temporal occurrence. The 1992-2000 results are presented as distribution maps. These show densities for more numerous and widespread species, and actual observations for the less numerous...

  12. Northern Shrimp (Pandalus borealis) Recruitment in West Greenland Waters

    DEFF Research Database (Denmark)

    Pedersen, S. A.; Storm, L. M.

    2002-01-01

    Lipid class and fatty acid compositions were determined in shrimp larvae (Pandalus borealis and P. montagui) collected along transects across banks on the West Greenland shelf in June 1999, May and July 2000. The lipid class contents were investigated as indices of larval shrimp lipid condition...... and food type. Fatty acid compositions were investigated for lipid biomarkers to establish trophic relationships between larval shrimp and potential prey. Phospholipids were the dominant lipid class in all six pelagic development stages of larval P. borealis and P. montagui, accounting for 80 to 92...

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

    DEFF Research Database (Denmark)

    Kraft, Helene Anja

    . 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......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...

  14. Estimating the future ice sheet hydropower potential in Paakitsoq, Ilulissat, West Greenland

    DEFF Research Database (Denmark)

    Ahlstrøm, Andreas P.; Mottram, R.H.; Nielsen, C.;

    2008-01-01

    Meltwater running off the Greenland ice sheet yield significant hydropower potentials in catchments bordering the ice sheet, especially in West and South Greenland. Hydropower has been chosen as the most desired source of energy by the Greenland Home Rule, but recent changes in the Greenland ice...... sheet has emphasized the risk of sudden changes in catchment supply. In this study, we present a thorough investigation of hydropower feasibility at the Paakitsoq basin, near Ilulissat in West Greenland. The catchment is completely dominated by the Greenland ice sheet which provides large quantities...... of meltwater during the summer season. However, geometrical changes in the ice sheet, for example due to a retreat or an advance of the ice sheet margin, could change the hydrological catchment within the ice sheet. Such a change would have a devastating economical impact as a hydropower plant is a significant...

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

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  16. 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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    DEFF Research Database (Denmark)

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

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

  19. Recurring dynamically induced thinning during 1985 to 2010 on Upernavik Isstrom, West Greenland

    NARCIS (Netherlands)

    Khan, Shfaqat Abbas; Kjaer, Kurt H.; Korsgaard, Niels J.; Wahr, John; Joughin, Ian R.; Timm, Lars H.; Bamber, Jonathan L.; van den Broeke, Michiel R.; Stearns, Leigh A.; Hamilton, Gordon S.; Csatho, Bea M.; Nielsen, Karina; Hurkmans, Ruud; Babonis, Greg

    2013-01-01

    Many glaciers along the southeast and northwest coasts of Greenland have accelerated, increasing the ice sheet's contribution to global sea-level rise. In this article, we map elevation changes on Upernavik Isstrom (UI), West Greenland, during 2003 to 2009 using high-resolution ice, cloud and land e

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

    DEFF Research Database (Denmark)

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

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

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

    Science.gov (United States)

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

    2013-04-01

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

  2. Holocene paleoceanography of Disko Bugt area, west Greenland

    Science.gov (United States)

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

    2014-05-01

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

  3. Soil Response to Aeolian Disturbance in West Greenland

    Science.gov (United States)

    Heindel, R. C.; Culler, L. E.; Chipman, J. W.; Virginia, R. A.

    2015-12-01

    Arctic soils are a critical ecological resource, yet are increasingly vulnerable to global change. In the Kangerlussuaq region of West Greenland, aeolian disturbance is the greatest threat to soil stability, with strong katabatic winds eroding vegetation and soil down to the underlying glacial till or bedrock. Little is known about what controls the distribution and rate of the aeolian erosion, which initially results in a state change from tundra to a deflated and nearly unvegetated ground. It is unclear if vegetation can eventually reestablish after erosion occurs, potentially aided by the biological soil crust (BSC) that develops within the eroded areas, or if this soil loss is an irreversible change in vegetation and soil carbon (C) and nitrogen (N) cycling. Our analysis of high-resolution satellite imagery shows that across the entire study region, deflated ground covers 22% of the terrestrial landscape. Aeolian erosion occurs more frequently closer to the Greenland Ice Sheet and on S-facing slopes. Using lichenometry, we estimate that erosional fronts move across the landscape at rates of 2.5 cm yr-1, leaving unproductive ground in their wake. The onset of widespread aeolian erosion occurred roughly 700-1000 years ago, pointing toward regional cooling and aridity as the drivers behind erosion. Finally, we consider whether the BSCs can improve soil quality enough to allow for full vegetation regrowth. Preliminary results show that while the BSCs fix atmospheric N and increase C storage, the rate of soil quality recovery is extremely slow. Understanding the thresholds between vegetated tundra and eroded ground is critical for predicting how the Kangerlussuaq landscape will respond to anticipated changes in climate and ice sheet dynamics.

  4. 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

    Radiometric ages for undated parts of the volcanic succession and intrusions in West Greenland were obtained by the 40Ar–39Ar incremental heating method. Acceptable crystallization ages were obtained for 27 samples. Combined with published results the new data provide a volcanic stratigraphy...... correlatable throughout the Nuussuaq Basin. The thick onshore volcanic pile consists of four widespread formations: 62.5–61 Ma picrites (Vaigat Formation), 61–60 Ma depleted basalts (Maligât Formation and the Hellefisk-1 well), 60–58 Ma less-depleted basalts (Svartenhuk Formation) and 56–54 Ma enriched basalts...... (Naqerloq Formation). Two local successions comprise 53.5 Ma alkali basalts (Erqua Formation) and 38.7 Ma transitional basalts (Talerua Member). A central volcano developed on Ubekendt Ejland, leading to the Sarqâta qáqâ gabbro-granophyre intrusion at 57–55 Ma. Pre-break-up volcanism took place further...

  5. Measurement campaign for wind power potential in west Greenland

    Science.gov (United States)

    Rønnow Jakobsen, Kasper

    2013-04-01

    Experiences and results from a wind resource exploring campaign 2003- in west Greenland. Like many other countries, Greenland is trying to reduce its dependency of fossil fuel by implementing renewable energy. The main challenge is that the people live on the coast in scattered settlements, without power infrastructure. Based on this a wind power potential project was established in 2002, funded by the Greenlandic government and the Technical University of Denmark. We present results and experiences of the campaign. 1 Field campaign There were only a few climate stations in or close to settlements and due to their positioning and instrumentation, they were not usable for wind resource estimation. To establish met stations in Arctic areas with complex topography, there are some challenges to face; mast positioning in complex terrain, severe weather conditions, instrumentation, data handling, installation and maintenance budget. The terrain in the ice free and populated part, mainly consists of mountains of different heights and shapes, separated by deep fjords going from the ice cap to the sea. With a generally low wind resource the focus was on the most exposed positions close to the settlements. Data from the nearest existing climate stations was studied for background estimations of predominant wind directions and extreme wind speeds, and based on that the first 10m masts were erected in 2003. 2 Instruments The first installations used standard NRG systems with low cost NRG instruments. For most of the sites this low cost setup did a good job, but there were some problems with the first design, including instrument and boom strains. In subsequent years, the systems were updated several times to be able to operate in the extreme conditions. Different types of instruments, data logger and boom systems were tested to get better data quality and reliability. Today 11 stations with heights ranging from 10-50m are installed and equipped according to the IEC standard

  6. Greenland

    Institute of Scientific and Technical Information of China (English)

    陈玮

    2002-01-01

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

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

    Science.gov (United States)

    Hofmann, Julia C.; Knutz, Paul C.

    2015-04-01

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

  8. Greenland

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Stendal, Henrik

    2006-12-01

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

  11. Assessment of Undiscovered Oil and Gas Resources of the West Greenland-East Canada Province, 2008

    Science.gov (United States)

    Schenk, Christopher J.; Bird, Kenneth J.; Brown, Philip J., II; Charpentier, Ronald R.; Gautier, Donald L.; Houseknecht, David W.; Klett, Timothy R.; Pawlewicz, Mark J.; Shah, Anjana; Tennyson, Marilyn E.

    2008-01-01

    The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the West Greenland?East Canada Province as part of the USGS Circum-Arctic Oil and Gas Resource Appraisal effort. The West Greenland?East Canada Province is essentially the offshore area between west Greenland and east Canada and includes Baffin Bay, Davis Strait, Lancaster Sound, and Nares Strait west of and including Kane Basin. The tectonic evolution of the West Greenland?East Canada Province led to the formation of several major structural domains that are the geologic basis for the five assessment units (AU) defined in this study. The five AUs encompass the entire province. Each AU was assessed in its entirety for undiscovered, technically recoverable (assuming absence of sea ice) oil and gas resources, but the assessment results reported here are only for those portions of each AU that are north of the Arctic Circle, as that latitude defines the area of the Circum-Arctic oil and gas assessment.

  12. Contemporary proglacial aeolian sediment transport in West Greenland

    Science.gov (United States)

    Bullard, J. E.; Austin, M. J.

    2007-12-01

    Glacial erosion processes produce significance quantities of fine sediments that are washed out from beneath glaciers by meltwater. When deposited on the glacier floodplain they dessicate and strong ice-driven winds can entrain and transport them across the landscape resulting in the formation of sand dunes and loess, and adding very fine particles (dust) to the atmosphere. Recent studies suggest that locally-generated dust can play an important role in regulating albedo and the melting rate of glaciers. Very few field process studies have examined the relationship between sediment-delivery to the proglacial floodplain by meltwater and the subsequent aeolian erosion and deposition of these fine sediments. This research reports the use of semi-isokinetic directional sediment samplers to make an initial assessment of the rates of transport of dust and sand in Sandflugtdalen, a valley adjacent to the West Greenland ice sheet. Vertical arrays (z(m) = 0.18, 0.43, 0.85, 1.4) of samplers were deployed in a down valley transect over a distance of 4 km. Trapped sediments were retrieved after intervals of 1 week and 9 weeks. The mass of sediment collected in the traps varied from 0.002-3.62 g cm2 wk-1. As expected, near surface traps collected more, and coarser, sediment than those deployed at 1.4 m height but the decrease in mass of sediment with height was highly variable. The array closest to the glacier trapped the greatest quantity of suspended sediment and the density of suspended sediment decreased with distance down valley. The flux of aeolian sediment comprises clays, silts and sand-sized particles. Areas of aeolian entrainment, transport and deposition are closely linked to the development and distribution of sediments on the proglacial floodplain which varies considerably in terms of surface roughness. At the east end of the valley, close to the ice sheet, aeolian sediment flux is controlled by sediment supply and topography rather than wind speed. Further down

  13. Rapid dynamic thinning on Upernavik Icestream, West Greenland

    DEFF Research Database (Denmark)

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

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

  14. Greenland

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet

    2015-01-01

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

  15. The effect of sea-ice loss on beluga whales (Delphinapterus leucas) in West Greenland

    DEFF Research Database (Denmark)

    Heide-Jørgensen, M.P.; Laidre, K.L.; Simon, Malene Juul;

    2009-01-01

    An aerial survey was conducted to estimate the abundance of belugas (Delphinapterus leucas) on their wintering ground in West Greenland in March-April 2006 and 2008. The survey was conducted as a double platform aerial line transect survey, and sampled approximately 17% of the total survey area o...

  16. Environmental factors affecting recruitment of northern shrimp (Pandalus borealis) in West Greenland waters

    DEFF Research Database (Denmark)

    Wieland, Kai; Siegstad, H.

    2012-01-01

    Survey estimates of biomass of Northern shrimp (Pandalus borealis) in West Greenland waters increased from about 178000 tons in 1998 to about 598000 tons in 2003. The increase in stock size was preceded by several consecutive years in which recruitment was substantially above average. Recruitment...

  17. Oil seepage onshore West Greenland: evidence of multiple source rocks and oil mixing

    Energy Technology Data Exchange (ETDEWEB)

    Bojesen-Koefoed, J.; Christiansen, F.G.; Nytoft, H.P.; Pedersen, A.K.

    1998-08-01

    Widespread oil seepage and staining are observed in lavas and hyaloclastites in the lower part of the volcanic succession on northwestern Disko and western Nuussuaq, central West Greenland. Chemical analyses suggest the existence of several petroleum systems in the underlying Cretaceous and Paleocene fluviodeltaic to marine sediments. Seepage and staining commonly occur within vesicular lava flow tops, and are often associated with mineral veins (mostly carbonates) in major fracture systems. Organic geochemical analyses suggest the existence of at least five distinct oil types: (1) a waxy oil, which on the basis of the presence of abundant angiosperm biological markers, is interpreted as generated from Paleocene mud-stones (the `Marraat type`); (2) a waxy oil, probably generated from coals and shales of the Cretaceous Atane formation (the `Kuugannguaq type`); (3) a low to moderately waxy oil containing 28,30-bisnorhopane, and abundant C{sub 27}-diasteranes and regular steranes (the `Itilli type`), possibly generated from presently unknown Cenomanian-Turonian marine modstones; (4) a low wax oil of marine, possibly lagoonal/saline lacustrine origin, containing ring-A methylated steranes and a previously unknown series of extended 28-norhopanes (the `Eqalulik type`); (5) a waxy oil with biological marker characteristics different from both the Kuugannguaq and Marraat oil types (the `Niaqornaarsuk type`), probably generated from Campanian mud-stones. The presence of widespread seepage and staining originating from several source rocks is encouraging for exploration in basins both on- and offshore western Greenland, where the existence of prolific source rocks has previously been the main exploration risk. (au) EFP-96. 34 refs.

  18. Lineament mapping and geological history of the Kangerlussuaq region, southern West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Klint, K.E.S.; Engstroem, J.; Parmenter, A.; Ruskeeniemi, T.; Claesson Liljedahl, L.; Lehtinen, A.; Collaboration: Ministry of Climate, Energy and Building. Geological Survey of Denmark and Greenland, Copenhagen (Denmark)

    2013-07-01

    How could future ice ages affect deep nuclear waste repositories in crystalline basement rocks? Deep repositories may be affected by a number of glacially induced processes including, but not limited to, (1) fault activation or re-activation and associated seismicity, (2) changing hydraulic and chemical groundwater dynamics and (3) enhanced erosion. Such processes are likely to affect not only man-made barriers in spent fuel repositories such as copper canisters and bentonite clay buffers, but also the rock masses that contain and isolate the repositories. In order to increase our understanding of this problem, an international study (the Greenland Analogue Project) was set up in 2008. The aim of the study was to use crystalline bedrock at the margin of the Inland Ice near Kangerlussuaq airport in West Greenland as an analogue for future nuclear fuel waste repositories affected by glaciation in Fennoscandia and Canada. Accordingly, a wide range of field surveys were conducted for the analogue project (Fig. 1). This paper describes a detailed structural investigation of lineament zones and the establishment of an event succession for fault and fracture zone evolution in central parts of the study area (Figs 1B, 2), as well as an interpretation of the distribution of fracture and fault zones with potentially increased permeability. Three deep holes were drilled in the study area, and instruments were installed in two of them for subsequent down-hole sampling and monitoring of groundwater to a depth of c. 600 m. The cores were used to compare the subsurface fracture patterns with those established on the basis of surface mapping. (Author)

  19. Rapid dynamic thinning on Upernavik Icestream, West Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

    . Here, we focus on Upernavik Icesteam, Northwest Greenland, and show that dynamic thinning on short timescales has been dominating the region at least twice between 1985 and 2010. We map changes on Upernavik Icesteram during 2003-2009 using high-resolution ICESat (Ice, Cloud and land Elevation Satellite......) laser altimetry data supplemented with altimeter surveys from NASA’s Airborne Topographic Mapper (ATM). To assess thinning prior to 2003, we analyze 1985 aerial photos and derived a 2x2 m grid digital elevation model (DEM)....

  20. Transfer of mercury in the marine food web of West Greenland.

    Science.gov (United States)

    Rigét, F; Møller, P; Dietz, R; Nielsen, T G; Asmund, G; Strand, J; Larsen, M M; Hobson, K A

    2007-08-01

    Total mercury (THg), methylmercury (MeHg) and stable isotopes of nitrogen (delta(15)N) and carbon (delta(13)C) were measured in three invertebrate, five fish, three seabird and three marine mammal species of central West Greenland to investigate trophic transfer of mercury in this Arctic marine food web. The food web magnification factor (FWMF) estimated as the slope of the regression between the natural logarithm of THg or MeHg concentrations (mg kg(-1) dw) and tissue delta(15)N ( per thousand) was estimated to 0.183 (SE = 0.052) for THg and 0.339 (SE = 0.075) for MeHg. The FWMFs were not only comparable with those reported for other Arctic marine food webs but also with quite different food webs such as freshwater lakes in the sub-Arctic, East Africa and Papua New Guinea. This suggests similar mechanisms of mercury assimilation and isotopic (delta(15)N) discrimination among a broad range of aquatic taxa and underlines the possibility of broad ecosystem comparisons using the combined contaminant and stable isotope approach. PMID:17671670

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  2. Legume Diversity Patterns in West Central Africa

    NARCIS (Netherlands)

    Estrella, de la M.; Mateo, M.A.; Wieringa, J.J.; Mackinder, B.; Munoz, J.

    2012-01-01

    Objectives - Species Distribution Models (SDMs) are used to produce predictions of potential Leguminosae diversity in West Central Africa. Those predictions are evaluated subsequently using expert opinion. The established methodology of combining all SDMs is refined to assess species diversity withi

  3. Abrupt Holocene climate change as an important factor for human migration in West Greenland

    OpenAIRE

    D’Andrea, William J.; Huang, Yongsong; Sherilyn C Fritz; Anderson, N. John

    2011-01-01

    West Greenland has had multiple episodes of human colonization and cultural transitions over the past 4,500 y. However, the explanations for these large-scale human migrations are varied, including climatic factors, resistance to adaptation, economic marginalization, mercantile exploration, and hostile neighborhood interactions. Evaluating the potential role of climate change is complicated by the lack of quantitative paleoclimate reconstructions near settlement areas and by the relative stab...

  4. Time trends of mercury in feathers of West Greenland birds of prey during 1851-2003

    DEFF Research Database (Denmark)

    Dietz, Rune; Riget, Frank Farsø; Boertmann, David;

    2006-01-01

    Temporal trends of mercury (Hg) in West Greenland gyrfalcons, peregrine falcons, and white-tailed eagles were determined over 150 years from 1851 to 2003. Hg was measured in the fifth primary feather. Results showed that Hg increased in the order gyrfalcon (lowest)intermediate......) account in the temporal trend analysis. Of eight time trend analyses (three species and three age groups of which one was missing), seven showed an increase in primary feather concentrations. Of these...

  5. Evidence of Quick-Clay Deposit at Kangerlussuaq, West Greenland

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Kirkelund, Gunvor Marie; Jørgensen, Anders Stuhr;

    2010-01-01

    , the riverbank was eroded approximately 40 m inland over the course of the jökulhlaup, which lasted approximately one day. It is the first time such a quick clay formation has been observed very near surface in inhabited areas in Greenland. If such deposits are found to be more widespread, it could be very...... problematic for the future infrastructural development in the region. Here we present the results of recent research, including a study of mineralogy of the quick clay using SEM and XRD. We also discuss the effect of climate warming on permafrost thaw in the area....... than the liquid limit. The formation has been stabilized by the presence of permafrost in the area, but the combination of erosional energy supplied by the river and the sensitive properties of the material have resulted in quick thaw, destabilization and erosion of the formation. As an effect...

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  7. Deglaciation of a major palaeo-ice stream in Disko Trough, West Greenland

    Science.gov (United States)

    Hogan, Kelly A.; Ó Cofaigh, Colm; Jennings, Anne E.; Dowdeswell, Julian A.; Hiemstra, John F.

    2016-09-01

    Recent work has confirmed that grounded ice reached the shelf break in central West Greenland during the Last Glacial Maximum (LGM). Here we use a combination of marine sediment-core data, including glacimarine lithofacies and IRD proxy records, and geomorphological and acoustic facies evidence to examine the nature of and controls on the retreat of a major outlet of the western sector of the Greenland Ice Sheet (GrIS) across the shelf. Retreat of this outlet, which contained the ancestral Jakobshavns Isbræ ice stream, from the outer shelf in Disko Trough was rapid and progressed predominantly through iceberg calving, however, minor pauses in retreat (tens of years) occurred on the middle shelf at a trough narrowing forming subtle grounding-zone wedges. By 12.1 cal kyr BP ice had retreated to a basalt escarpment and shallow banks on the inner continental shelf, where it was pinned and stabilised for at least 100 years. During this time the ice margin appears to have formed a calving bay over the trough and melting became an important mechanism of ice-mass loss. Fine-grained sediments (muds) were deposited alternately with IRD-rich sediments (diamictons) forming a characteristic deglacial lithofacies that may be related to seasonal climatic cycles. High influxes of subglacial meltwater, emanating from the nearby ice margins, deposited muddy sediments during the warmer summer months whereas winters were dominated by iceberg calving leading to the deposition of the diamictons. This is the first example of this glacimarine lithofacies from a continental-shelf setting and we suggest that the calving-bay configuration of the ice margin, plus the switching between calving and melting as ablation mechanisms, facilitated its deposition by channelling meltwater and icebergs through the inner trough. The occurrence of a major stillstand on the inner shelf in Disko Trough demonstrates that the ice-dynamical response to local topography was a crucial control on the behaviour

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

    OpenAIRE

    Mottram, R.; Nielsen, C.; Ahlstrøm, A. P.; Reeh, N.; Kristensen, Steen Savstrup; Christensen, Erik Lintz; Forsberg, René; Stenseng, Lars

    2009-01-01

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

  9. The Mantle Transition Zone in Central-Eastern Greenland

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    Schenk, Christopher J.

    2010-01-01

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

  11. Runoff simulations from the Greenland ice sheet at Kangerlussuaq from 2006-2007 to 2007/08. West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Mernild, Sebastian Haugard [Los Alamos National Laboratory; Hasholt, Bent [UNIV OF COPENHAGEN; Van Den Broeke, Michiel [UTRECHT UNIV; Liston, Glen [COLORADO STATE UNIV

    2009-01-01

    This study focuses on runoff from a large sector of the Greenland Ice Sheet (GrIS) - the Kangerlussuaq drainage area, West Greenland - for the runoff observation period 2006/07 to 2007/08. SnowModel, a state-of-the-art snow-evolution modeling system, was used to simulate winter accumulation and summer ablation processes, including runoff. Independent in situ end-of-winter snow depth and high-resolution runoff observations were used for validation of simulated accumulation and ablation processes. Runoff was modeled on both daily and hourly time steps, filling a data gap of runoff exiting part of the GrIS. Using hourly meteorological driving data instead of smoothed daily-averaged data produced more realistic meteorological conditions in relation to snow and melt threshold surface processes, and produced 6-17% higher annual cumulative runoff. The simulated runoff series yielded useful insights into the present conditions of inter-seasonal and inter-annual variability of Kangerlussuaq runoff, and provided an acceptable degree of agreement between simulated and observed runoff. The simulated spatial runoff distributions, in some areas of the GrIS terminus, were as high as 2,750 mm w.eq. of runoff for 2006/07, while only 900 mm w.eq was simulated for 2007/08. The simulated total runoff from Kangerlussuaq was 1.9 km{sup 3} for 2006/07 and 1.2 km{sup 3} for 2007/08, indicating a reduction of 35-40% caused by the climate conditions and changes in the GrIS freshwater storage. The reduction in runoff from 2006/07 to 2007/08 occurred simultaneously with the reduction in the overall pattern of satellite-derived GrIS surface melt from 2007 to 2008.

  12. Effect of freshwater from the West Greenland Current on the winter deep convection in the Labrador Sea

    Science.gov (United States)

    Kawasaki, T.; Hasumi, H.

    2014-03-01

    The effect of mesoscale eddies on the deep convection in the Labrador Sea is examined by using a realistically configured eddy-resolving ice-ocean model. The near-surface boundary current flowing into the Labrador Sea is realistically simulated, namely the West Greenland Current which carries upper/onshore fresh and lower/offshore warm water, and eddies separating from these boundary currents with cold/fresh water atop warm/salty water are also well reproduced. The modeled convection is confined to the southwestern Labrador Sea as observed, and its depth and width are reproduced better than in previous modeling studies. Although previous modeling studies demonstrated only the importance of eddy-induced heat transport in inhibition of deep convection over the central to northern Labrador Sea, our study found that the eddy-induced transport of near-surface fresh water also significantly contributes.

  13. Mass balance of the Amitsulôq ice cap, West Greenland

    DEFF Research Database (Denmark)

    Ahlstrøm, Andreas P.; Bøggild, Carl Egede; Olesen, Ole B.;

    2007-01-01

    We present detailed mass balance measurements from the Amitsulôq ice cap in West Greenland spanning from 1982 to 1990. The data includes summer and winter balances from 26 stake locations distributed over five transects covering the whole ice cap. The mass balance measurements are combined...... with a recent satellite-derived digital elevation model to calculate the specific balance, which is in turn compared to discharge data from the adjacent Tasersiaq basin. The correlation between specific summer balance and discharge is R2 = 0.93 indicating that the basin discharge is dominated by glacial...... meltwater, linking the hydropower potential of the basin closely to the fate of the adjoining Greenland ice-sheet margin....

  14. The influence of climatic and physiological performance on population dynamics of Mytilus edulis in West Greenland

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Blicher, Martin; Sejr, Mikael Kristian

    2014-01-01

    . Results show an overall decline in blue mussel abundance along the coast from south to north Greenland. Physiological adaptation and plasticity of blue mussels was found across latitudes spanning from the temperate to the High Arctic region. Combined our results indicate that low ocean temperature per se....... The blue mussel (Mytilus edulis) has recently expanded its northern distribution in Greenland and is considered to be a sensitive indicator of climate changes. Blue mussels could be a species that would respond to a warmer climate by increased abundance and growth rates in the Arctic. However, adequate...... data on current distribution and physiological performance of blue mussels in the Arctic is lacking, and knowledge of how “climate” in a broad sense specifically influence population dynamics of this species is unknown. Here, we present data on abundance, age and mortality of blue mussels in West...

  15. Recent North West Greenland climate variability documented by NEEM shallow ice cores

    Science.gov (United States)

    Masson-Delmotte, Valérie; Steen-Larsen, Hans-Christian; Popp, Trevor; Vinther, Bo; Oerter, Hans; Ortega, Pablo; White, Jim; Orsi, Anais; Falourd, Sonia; Minster, Benedicte; Jouzel, Jean; Landais, Amaelle; Risi, Camille; Werner, Martin; Swingedouw, Didier; Fettweis, Xavier; Gallée, Hubert; Sveinbjornsdottir, Arny; Gudlaugsdottir, Hera; Box, Jason

    2014-05-01

    Short water stable isotope records obtained from NEEM ice cores (North West Greenland) have been shown to be sensitive to NW Greenland temperature variations, and sea-ice extent in the Baffin Bay area (Steen-Larsen et al, JGR, 2011), with maximum snowfall deposition during summer, therefore providing information complementary to other Greenland ice core records. At the NEEM deep drilling camp, several snow pits and shallow ice cores have been retrieved and analysed at high resolution (seasonal to annual) for water stable isotopes using mass spectrometry and laser instruments in order to document recent climate variability, complementing and facilitating the interpretation of the long records obtained from the deep ice core which extends back to the last interglacial period (NEEM, Nature, 2013). The different pits and shallow ice core records allow to document the signal to noise ratio and to produce a robust stack back to 1750, and up to 2011. The stack record of annual mean d18O depicts a recent isotopic enrichment in parallel with the Greenland warming inferred from coastal weather stations, and shows that many features of decadal variations are in fact well captured by the low resolution profiles measured along the deep ice core data. Recent variations can therefore be compared to long-term trends and centennial variations of the last Holocene, documented at about 5 year resolution. For the past decades to centuries, the NEEM isotopic records are compared with estimations and simulations of local temperature for different seasons, results from NEEM borehole temperature inversions, d18O records from other Greenland ice cores, large scale modes of variability (NAO and AMO) and with simulations from atmospheric general circulation models equiped with water stable isotopes.

  16. Investigating a newly discovered firn aquifer on Disko Ice Cap, west Greenland: Insights from ground observations, remote sensing, and modeling

    Science.gov (United States)

    Trusel, L. D.; Das, S. B.; Smith, B.; Kuipers Munneke, P.; Evans, M. J.; Frey, K. E.; Osman, M.; York, A.

    2015-12-01

    Expanding and intensifying surface melt have accelerated contributions from Greenland to global sea level rise in recent decades. Yet, important questions remain regarding the evolution and eventual fate of this meltwater over time and space, a fact underscored by recent observations of expansive aquifers within the Greenland Ice Sheet firn. In April 2015 we observed liquid water retained at depth in an ice cap on Disko Island, central west Greenland. Two adjacent ~20 m firn/ice cores were collected before intercepting a layer saturated with liquid water as evident by water drainage from our cores. Borehole temperature profiling confirms increasing temperature with depth, revealing 0°C isothermal firn below ~10 m depth. Detailed physical stratigraphic analyses conducted on these cores allow us to assess firn properties and their small scale (1 m) and likely impermeable refrozen melt horizons exist above the inferred aquifer surface, raising questions about processes of aquifer formation. To discern the spatial character of the observed firn liquid water and melt stratigraphy, we utilize ground penetrating radar collected in 2014, as well as airborne radar data collected through NASA Operation IceBridge in 2012 and 12 days prior to our field observations in 2015. Glaciochemical analyses on our ice cores reveal preservation of an annual signal allowing derivation of net snow accumulation rates. Combined with surface mass balance modeled by RACMO2.3 and melt assessed via microwave remote sensing, we investigate the recently prevailing climatic and glaciological conditions on Disko. This work will provide new insights into mechanisms of firn aquifer formation and sustenance more broadly, as well as the representation of aquifers in existing radar observations and firn models.

  17. Identifying potential seasonal and historical drivers of marine-terminating glacier retreat in Disko and Uummannaq Bays, West Greenland

    Science.gov (United States)

    York, A.; Frey, K. E.; Das, S. B.

    2015-12-01

    The variability in outlet glacier termini positions is an important indicator of overall glacier health and the net effects of ice-ocean-atmosphere interactions. Glacier margins fluctuate on both seasonal and interannual time scales and satellite imagery provides a critical spatially- and temporally-extensive resource for monitoring glacier behavior. Outlet glaciers have generally been retreating globally over recent decades, but the magnitude of seasonal variation, overall retreat, and foremost drivers have proven unique to each glacier. The outlet glaciers in central West Greenland are generally experiencing the same regional atmospheric forcing, yet previous studies have shown varying magnitudes of retreat over the last forty years. In this study, we utilize Landsat imagery between the years 1985 and 2014 to digitize a time series of glacier front positions of 18 marine-terminating outlet glaciers in the Disko and Uummannaq Bay regions of West Greenland. We examine potential drivers of trends in outlet glacier retreat through satellite observations of adjacent sea ice concentrations and sea surface temperatures. Additionally, reanalysis data and long-term automatic weather station measurements are investigated to contextualize the role of atmospheric drivers at both a regional and local scale. Results indicate retreat of all glaciers in the region over the study period and no indication of a south to north trend in magnitude of retreat on either a seasonal or long-term scale. The 11 glaciers in Uummannaq Bay retreated between 25 m and 3.5 km, an average of 1.22 ± 1.20 km over the entire study period. The retreat of 7 glaciers in Disko Bay ranged from 181 m to 2.3 km, an average of 1.0 ± 0.78 km over the period. Although the mean terminus retreat rate between the two bays is comparable, there remains a wide range of total retreat amounts among the glaciers. We investigate the degree of seasonal variation in terminus position as an indicator of longer

  18. Regional variation of caesium-137 in minke whales ¤Balaenoptera acutorostrata¤ from West Greenland, the Northeast Atlantic and the North Sea

    DEFF Research Database (Denmark)

    Born, E.W.; Dahlgaard, H.; Riget, F.F.;

    2002-01-01

    Levels of radioactive caesium (Cs-137) were determined in minke whales (Balaenoptera acutorostrata) from West Greenland, the Northeast Atlantic region and the North Sea. The sample consisted of muscle tissue from 135 minke whales caught in 1998 in 7 different areas: West Greenland, n = 44; East G...

  19. Plant and Vegetation Dynamics on Disko Island, West Greenland : Snapshots Separated by Over 40 Years

    OpenAIRE

    Jantze, Elin; Callaghan, Terry; Christensen, Torben R.

    2011-01-01

    We report on a revisit in 2009 to sites where vegetation was recorded in 1967 and 1970 on Disko Island, West Greenland. Re-sampling of the same clones of the grass Phleum alpinum after 39 years showed complete stability in biometrics but dramatic earlier onset of various phenological stages that were not related to changes in population density. In a fell-field community, there was a net species loss, but in a herb-slope community, species losses balanced those that were gained. The type of s...

  20. Drainage of the ice-dammed Lake Tinninilik, West Greenland; implication on bedrock uplift

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Bjørk, Anders Anker;

    by Sarqardliup sermia in West Greenland, using air- and satellite-borne laser- and radar altimetry supplemented with Landsat imagery. We combine the observations with DEMs from aerial imagery to derive lake volume changes which we compare against GPS data used to monitor crustal uplift caused by mass loss close...... to the site.Our results suggest that the previous pattern of drainage every 10th year has changed to every ~7th year, likely a result of enhanced melting over the last decade in the region. Furthermore, the lake drainage, resulting in a c. 70 m elevation change of the lake level, can occur in less than two...

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

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas

    2006-01-01

    Permafrost delineation and thickness determination is of great importance in engineering related projects in arctic areas. In this paper, 2D geoelectrical measurements are applied and evaluated for permafrost mapping in an area in West Greenland. Multi-electrode resistivity profiles (MEP) have been...... of horizontal ice-lenses in the frozen clay deposits. It is concluded that where the resistivity method perform well for lateral permafrost mapping, great care should be taken in evaluating permafrost thickness based on 2D resistivity profiles alone. Additional information from boreholes or other geophysical...

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

    Science.gov (United States)

    Khan, S. A.; Kjaer, K. H.; Korsgaard, N. J.; Wahr, J. M.; Joughin, I. R.; Bamber, J. L.; Csatho, B. M.; van den Broeke, M. R.; Stearns, L. A.; Nielsen, K.; Babonis, G. S.; Hamilton, G. S.; Hurkmans, R. T.; Timm, L. H.

    2011-12-01

    Many glaciers along the southeast and northwest coast of Greenland have accelerated, increasing the ice sheet's contribution to global sea-level rise. Here, we map elevation changes on Upernavik Isstrøm (UI), West Greenland, during 2003-2009 using high-resolution Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data supplemented with altimeter surveys from NASA's Airborne Topographic Mapper (ATM) during 2002-2010. To assess thinning prior to 2002, we analyze aerial photographs from 1985. We document at least two distinct ice loss events characterized by rapid dynamic thinning, increased ice speed, and a retreat of the calving front. The most recent event coincides with the speedup of several glaciers along the northwest coast of Greenland in 2005, and with changes in the rate of mass loss observed using data from the Gravity Recovery and Climate Experiment (GRACE) satellite gravity mission. The first event of increased ice loss could have also taken place along the extended northwest coast. The total dynamic induced ice volume loss on the frontal portion of UI caused by the two events is 45.5 +/- 5.4 km3 (during 1985-2010), while the total melt induced ice volume loss during this same period is 7.4 +/- 1.3 km3.

  3. Recurring dynamically induced thinning during 1985 to 2010 on Upernavik Isstrøm, West Greenland

    Science.gov (United States)

    Khan, Shfaqat Abbas; KjæR, Kurt H.; Korsgaard, Niels J.; Wahr, John; Joughin, Ian R.; Timm, Lars H.; Bamber, Jonathan L.; Broeke, Michiel R.; Stearns, Leigh A.; Hamilton, Gordon S.; Csatho, Bea M.; Nielsen, Karina; Hurkmans, Ruud; Babonis, Greg

    2013-03-01

    Many glaciers along the southeast and northwest coasts of Greenland have accelerated, increasing the ice sheet's contribution to global sea-level rise. In this article, we map elevation changes on Upernavik Isstrøm (UI), West Greenland, during 2003to 2009 using high-resolution ice, cloud and land elevation satellite laser altimeter data supplemented with altimeter surveys from NASA's Airborne Topographic Mapper during 2002 to 2010. To assess thinning prior to 2002, we analyze aerial photographs from 1985. We document at least two distinct periods of dynamically induced ice loss during 1985 to 2010 characterized by a rapid retreat of the calving front, increased ice speed, and lowering of the ice surface. The first period occurred before 1991, whereas the latter occurred during 2005 to 2009. Analyses of air and sea-surface temperature suggest a combination of relatively warm air and ocean water as a potential trigger for the dynamically induced ice loss. We estimate a total catchment-wide ice-mass loss of UI caused by the two events of 72.3 ± 15.8 Gt during 1985 to 2010, whereas the total melt-induced ice-mass loss during this same period is 19.8 ± 2.8 Gt. Thus, 79% of the total ice-mass loss of the UI catchment was caused by ice dynamics, indicating the importance of including dynamically induced ice loss in the total mass change budget of the Greenland ice sheet.

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

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2014-01-01

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

  5. Centennial scale benthic foraminiferal record of late Holocene oceanographic variability in Disko Bugt, West Greenland

    Science.gov (United States)

    Perner, K.; Moros, M.; Lloyd, J. M.; Kuijpers, A.; Telford, R. J.; Harff, J.

    2011-09-01

    A new centennial scale benthic foraminiferal record of late Holocene climate variability and oceanographic changes off West Greenland (Disko Bugt) highlights substantial subsurface water mass changes (e.g. temperature and salinity) of the West Greenland Current (WGC) over the past 3.6 ka BP. Benthic foraminifera reveal a long-term late Holocene cooling trend, which may be attributed to increased advection of cold, low-salinity water masses derived from the East Greenland Current (EGC). Cooling becomes most pronounced from c. 1.7 ka BP onwards. At this point the calcareous Atlantic benthic foraminiferal fauna decrease significantly and is replaced by an agglutinated Arctic fauna. Superimposed on this cooling trend, centennial scale variability in the WGC reveals a marked cold phase at c. 2.5 ka BP, which may correspond to the 2.7 ka BP cooling-event recorded in marine and terrestrial archives elsewhere in the North Atlantic region. A warm phase recognized at c. 1.8 ka BP is likely to correspond to the 'Roman Warm Period' and represents the warmest bottom water conditions. During the time period of the 'Medieval Climate Anomaly' we observe only a slight warming of the WGC. A progressively more dominant cold water contribution from the EGC on the WGC is documented by the prominent rise in abundance of agglutinated Arctic water species from 0.9 ka BP onwards. This cooling event culminates at c. 0.3 ka BP and represents the coldest episode of the 'Little Ice Age'. Gradually increased influence of cold, low-salinity water masses derived from the EGC may be linked to enhanced advection of Polar and Arctic water by the EGC. These changes are possibly associated with a reported shift in the large-scale North Atlantic Oscillation atmospheric circulation pattern towards a more frequent negative North Atlantic Oscillation mode during the late Holocene.

  6. Environmental Oil Spill Sensitivity Atlas for the Northern West Greenland (72°-75° N) Coastal Zone

    DEFF Research Database (Denmark)

    Stjernholm, Michael; Boertmann, David; Mosbech, Anders;

    This oil spill sensitivity atlas covers the shoreline and the offshore areas of West Greenland between 72º N and 75º N. The coastal zone is divided into 118 shoreline segments and the offshore zone into 3 areas. A sensitivity index value is calculated for each segment/area, and each segment/area ...

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

    NARCIS (Netherlands)

    Dietz, R.; Riget, F.; Hobson, K.A.; Heide-Jorgensen, M.P.; Moller, P.; Cleemann, M.; Boer, de J.; Glasius, M.

    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 in the f

  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...

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  10. Helicopter-based Photography for use in SfM over the West Greenland Ablation Zone

    Science.gov (United States)

    Mote, T. L.; Tedesco, M.; Astuti, I.; Cotten, D.; Jordan, T.; Rennermalm, A. K.

    2015-12-01

    Results of low-elevation high-resolution aerial photography from a helicopter are reported for a supraglacial watershed in West Greenland. Data were collected at the end of July 2015 over a supraglacial watershed terminating in the Kangerlussuaq region of Greenland and following the Utrecht University K-Transect of meteorological stations. The aerial photography reported here were complementary observations used to support hyperspectral measurements of albedo, discussed in the Greenland Ice sheet hydrology session of this AGU Fall meeting. A compact digital camera was installed inside a pod mounted on the side of the helicopter together with gyroscopes and accelerometers that were used to estimate the relative orientation. Continuous video was collected on 19 and 21 July flights, and frames extracted from the videos are used to create a series of aerial photos. Individual geo-located aerial photos were also taken on a 24 July flight. We demonstrate that by maintaining a constant flight elevation and a near constant ground speed, a helicopter with a mounted camera can produce 3-D structure of the ablation zone of the ice sheet at unprecedented spatial resolution of the order of 5 - 10 cm. By setting the intervalometer on the camera to 2 seconds, the images obtained provide sufficient overlap (>60%) for digital image alignment, even at a flight elevation of ~170m. As a result, very accurate point matching between photographs can be achieved and an extremely dense RGB encoded point cloud can be extracted. Overlapping images provide a series of stereopairs that can be used to create point cloud data consisting of 3 position and 3 color variables, X, Y, Z, R, G, and B. This point cloud is then used to create orthophotos or large scale digital elevation models, thus accurately displaying ice structure. The geo-referenced images provide a ground spatial resolution of approximately 6 cm, permitting analysis of detailed features, such as cryoconite holes, evolving small

  11. 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

    Horizontal ice-core sites, where ancient ice is exposed at the glacier surface, offer unique opportunities for paleo-studies of trace components requiring large sample volumes. Following previous work at the Pakitsoq ice margin in West Greenland, we use a combination of geochemical parameters...... measured in the ice matrix (delta O-18(ice)) and air occlusions (delta O-18(atm), delta N-15 of N-2 and methane concentration) to date ice layers from specific climatic intervals. The data presented here expand our understanding of the stratigraphy and three-dimensional structure of ice layers outcropping...... 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...

  12. Effect of acidification on an Arctic phytoplankton community from Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Thoisen, Christina; Riisgaard, Karen; Lundholm, Nina;

    2015-01-01

    . Our findings show that coastal phytoplankton from Disko Bay is naturally exposed to pH fluctuations exceeding the experimental pH range used in most ocean acidification studies. We emphasize that studies on ocean acidification should include in situ pH before assumptions on the effect of acidification...... on marine organisms can be made. KEY WORDS: Ocean acidification · Coastal · Arctic phytoplankton · Growth rate · pH · CO2 · DIC......ABSTRACT: Long-term measurements (i.e. months) of in situ pH have not previously been reported from the Arctic; this study shows fluctuations between pH 7.5 and 8.3 during the spring bloom 2012 in a coastal area of Disko Bay, West Greenland. The effect of acidification on phytoplankton from...

  13. Twenty-one years of mass balance observations along the K-transect, West Greenland

    Directory of Open Access Journals (Sweden)

    R. S. W. van de Wal

    2012-08-01

    Full Text Available A 21-yr record is presented of surface mass balance measurements along the K-transect. The series covers the period 1990–2011. Data are available at eight sites along a transect over an altitude range of 380–1850 m at approximately 67° N in West Greenland. The surface mass balance gradient is on average 3.8 × 10−3 m w.e. m−1, and the mean equilibrium line altitude is 1553 m a.s.l. Only the lower three sites within 10 km of the margin up to an elevation of 700 m experience a significant increasing trend in the ablation over the entire period. Data are available at: doi:10.1594/PANGAEA.779181.

  14. Twenty-one years of mass balance observations along the K-transect, West Greenland

    Directory of Open Access Journals (Sweden)

    R. S. W. van de Wal

    2012-05-01

    Full Text Available A 21-yr record is presented of surface mass balance measurements along the K-transect. The series covers the period 1990–2011. Data are available at 8 sites along a transect over an altitude range of 390–1850 m at approximately 67° N in West Greenland. The surface mass balance gradient is on average 3.8 × 10−3 m w.e. m−1, and the mean equilibrium line altitude is 1553 m a.s.l. Only the lower 3 sites within 10 km of the margin experience a significant increasing trend in the ablation over the entire period. Data are available at: http://doi.pangaea.de/10.1594/PANGAEA.779181.

  15. Antler possession by west Greenland female caribou in relation to population characteristics

    Directory of Open Access Journals (Sweden)

    Henning Thing

    1986-06-01

    Full Text Available The frequency of antlerless adult female caribou (Rangifer tarandus groenlandicus was studied in four separate populations in west Greenland. Between the herds antlerlessness varied from 21% to 79%. An inverse relationship between winter range quality and percentage of unantlered cows is demonstrated. Relationship between calf percentage and maternal antler status was studied in one population and antlerless cows showed higher reproductive rate than antlered ones. In another population antlerless cows were almost absent outside the calving area. Calves of antlerless mothers were more susceptible to diseases and had significantly higher summer mortality than other calves, 42% and 27% respectively. The relative importance of factors influencing antler development under various environmental conditons are assessed and a close relationship between antlerlessness, physical condition, lactation, and length of period between calving and midsummer is discussed.

  16. Size and trends of the bowhead whale, beluga and narwhal stocks wintering off West Greenland

    Directory of Open Access Journals (Sweden)

    MP Heide-Jørgensen

    2014-01-01

    Full Text Available To assess the size and trends of the abundance of the bowhead whale (Balaena mysticetus, the beluga, or white whale (Delphinapterus leucas, and the narwhal (Monodon monoceros visual aerial surveys were conducted in West Greenland in March 1998 and 1999. An estimated 49 bowhead whales (95% CI: 13 to 188 were present at the surface in 1998. Data from land-based observations enabled correction for bowhead whales that were not available at the surface to be seen during the survey. By applying a rounded average of 80% (SE=3 for submergence an estimate of 246 bowhead whales (95% CI: 62 to 978 in 1998 was obtained. The 76 and 47 sightings of beluga pods in 1998 and 1999, respectively, had distributions similar to those of previous surveys with the highest concentration at the northern edge of the northern part of Store Hellefiskebanke. No belugas were seen in the southernmost area between Maniitsoq and Paamiut. The index estimate of the abundance of belugas comparable with previous surveys was 929 (95% CI: 563 to 1,533 in 1998 and 735 (95% CI: 436 to 1,239 in 1999. When analysing the sightings as a line-transect survey and correcting for whales that were either submerged or at the surface but missed by the observers an estimated 7,941 (95% CI: 3,650 to 17,278 belugas wintered in West Greenland in 1998-1999. The uncorrected estimate of narwhal abundance was 524 (95% CI: 214 to 1,284 and correcting for the same biases as for the belugas gives a total abundance of 2,861 (95% CI: 954 to 8,578 narwhals in 1998-1999.

  17. Recent changes in North West Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past temperature reconstructions

    Science.gov (United States)

    Masson-Delmotte, V.; Steen-Larsen, H. C.

    2014-12-01

    Stack records of accumulation, d18O and deuterium excess were produced from up to 4 shallow ice cores at NEEM (North-West Greenland), spanning 1724-2007 and updated to 2011 using pit water stable isotope data. Signal-to-noise ratio is high for d18O (1.3) and accumulation (1.2) but is low for deuterium excess (0.4). No long-term trend is observed in the accumulation record. By contrast, NEEM d18O shows multi-decadal increasing trends in the late 19th century and since the 1980s. Decadal d18O and accumulation variability is in phase with Atlantic Multi-decadal Oscillation indices, and enhanced at the beginning of the 19th century. Large-scale spatial coherency is detected between NEEM and other Greenland ice core and temperature records, strongest for North-West Greenland d18O and summer South-West coastal temperature instrumental records. The strength of correlations with the North Atlantic Oscillation is smaller than in central or south Greenland. The strongest positive d18O values are recorded at NEEM in 2010, followed by 1928, while maximum accumulation occurs in 1933. The coldest/driest decades are depicted at NEEM in 1815-1825 and 1836-1836. The spatial structure of these warm/ wet years and cold/dry decades is investigated using all available Greenland ice cores. During the period 1958-2011, the NEEM accumulation and d18O records are highly correlated with simulated precipitation, temperature and d18O from simulations performed with MAR, LMDZiso and ECHAM5iso atmospheric models, nudged to atmospheric reanalyses. Model-data agreement is better using ERA reanalyses than NCEP/NCAR and 20CR ones. Model performance is poor for deuterium excess. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the d18O-temperature relationship for the strong warming period in 1979-2007. The estimated slope of this relationship is 1.1±0.2‰ per °C, about twice larger than previously used to estimate last interglacial temperature

  18. East Asian origin of central Greenland last glacial dust: just one possible scenario?

    Science.gov (United States)

    Újvári, Gábor; Stevens, Thomas; Svensson, Anders; Klötzli, Urs Stephan; Manning, Christina; Németh, Tibor; Kovács, János

    2016-04-01

    Dust in Greenland ice cores is used to reconstruct the activity of dust emitting regions and atmospheric circulation for the last glacial period. However, the source dust material to Greenland over this period is the subject of considerable uncertainty. Here we use new clay mineral and Sr-Nd isotopic data from eleven loess samples collected around the Northern Hemisphere and compare the 87Sr/86Sr and 143Nd/144Nd isotopic signatures of fine (Greenland ice core dust data (GISP2, GRIP; [1]; [2]). Smectite contents and kaolinite/chlorite (K/C) ratios allow exclusion of continental US dust emitting regions as potential sources, because of the very high (>3.6) K/C ratios and extremely high (>~70%) smectite contents. At the same time, Sr-Nd isotopic compositions demonstrate that ice core dust isotopic compositions can be explained by East Asian (Chinese loess) and/or Central/East Central European dust contributions. Central/East Central European loess Sr-Nd isotopic compositions overlap most with ice core dust, while the Sr isotopic signature of Chinese loess is slightly more radiogenic. Nevertheless, an admixture of 90‒10 % from Chinese loess and circum-Pacific volcanic material would also account for the Sr‒Nd isotopic ratios of central Greenland LGM dust. At the same time, sourcing of ice core dust from Alaska, continental US and NE Siberia seems less likely based on Sr and Nd isotopic signatures. The data demonstrate that currently no unique source discrimination for Greenland dust is possible using both published and our new data [3]. Thus, there is a need to identify more diagnostic tracers. Based on initial Hf isotope analyses of fine separates of three loess samples (continental US, Central Europe, China), an apparent dependence of Hf isotopic signatures on the relative proportions of radiogenic clay minerals (primarily illite) was found, as these fine dust fractions are apparently zircon-free. The observed difference between major potential source regions in

  19. Understanding the Factors That Control Snow Albedo Over Central Greenland

    Science.gov (United States)

    Wright, P.; Bergin, M. H.; Dibb, J. E.; Domine, F.; Carmagnola, C.; Courville, Z.; Sokolik, I. N.; Lefer, B. L.

    2011-12-01

    Snow albedo plays a critical role in the energy balance of the Greenland Ice Sheet. In particular, the snow albedo influences the extent to which absorbing aerosols over Greenland (i.e. dust and black carbon) force climate. With this in mind the spectral snow albedo, physical snow properties, and snow chemistry were measured during May, June, and July 2011 at Summit, Greenland to investigate the variability in snow spectral albedo and its impact on aerosol direct radiative forcing. Optical and chemical properties of aerosol and aerosol optical depth were also measured as part of this study. Strellis et. al. will present a preliminary assessment of aerosol radiative forcing at Summit in summer 2011, in a separate presentation at this meeting. Spectral albedo was measured from 350-2500 nm with an ASD FieldSpec Pro spectroradiometer daily at four permanent sites and a moving fifth site where snow was sampled for characterization, as well as in more intensive diurnal and spatial surveys. Snow specific surface area (SSA), the ratio of snow crystal surface area to mass, was measured with a Dual Frequency Integrating Sphere (DUFISSS) at 1310 nm and 1550 nm, as well as with dyed and cast samples collected for stereology analysis. Snow stratigraphy, crystal size, and density were also measured on a daily basis, and snow samples will be analyzed for microstructural parameters determined from micro-CT imaging. Snow chemistry measurements include specific elements, major ions, and elemental and organic carbon. The time series of daily albedo measurements ranged from 0.88 to nearly 1.0 in visible wavelengths and from 0.42 to 0.65 in the near infrared. Changes as large as 0.1 were observed between consecutive daily measurements across the spectrum. Preliminary results show a strong correlation between variation in albedo and co-located measurements of snow specific surface area, specifically in the near infrared. By conducting our measurements near solar noon every day, and

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

    Directory of Open Access Journals (Sweden)

    Conelly, James N.

    2006-12-01

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

  1. Accumulation rates from central North Greenland during the past 700 year

    Science.gov (United States)

    Karlsson, Nanna B.; Eisen, Olaf; Nielsen, Lisbeth T.; Kipfstuhl, Sepp; Freitag, Johannes; Paden, John D.; Dahl-Jensen, Dorthe; Winter, Anna; Wilhelms, Frank

    2016-04-01

    A key variable when interpreting the evolution and mass loss from polar ice sheets is the input from the surface mass balance. While ice core records contain information on past accumulation rates, they always only provide information for a single location. Here, we present spatially distributed accumulation rates from central northern Greenland, specifically the area between the NEEM (North Greenland Eemian Drilling) and NGRIP (North Greenland Ice Core Project) ice core drill sites. The accumulation rates have been reconstructed using ice-penetrating radar, firn core measurements and inverse methods, and we are able to retrieve both spatial and temporal changes in the accumulation over an area spanning 300 km by 300 km. We investigate the stability of the accumulation pattern over the past several hundred years, and we address the question of how well the measured accumulation rates at the ice core sites capture the regional variations in accumulation. We find that while the accumulation rates at NEEM have been stable for the past 700 years, the NGRIP site has experienced fluctuations in accumulation rate. We interpret this as an indication of shifts in the dominating weather pattern over the ice divide in central North Greenland.

  2. Continuous monitoring of deep groundwater at the ice margin, Kangerlussuaq, West Greenland

    Science.gov (United States)

    Claesson Liljedahl, L.; Lehtinen, A. M.; Ruskeeniemi, T.; Engström, J.; Hansson, K.; Sundberg, J.; Henkemans, E.; Frape, S.; Johansson, S.; Acuna, J.

    2012-12-01

    The deep geologic repository (DGR) concept for the long-term management of used nuclear fuel involves the containment and isolation of used nuclear fuel at depths of approximately 500-1000 m below ground surface within a suitable geological formation for hundreds of thousands of years. A key objective of the used fuel DGR research programs of the Swedish, Finnish and Canadian nuclear waste management organizations (SKB, POSIVA and NWMO, respectively) is to further understanding of geosphere stability and long-term evolution. Future glaciation represents an intense external perturbation of a DGR situated in northern latitudes. To advance the understanding of processes associated with glaciation and their impact on the long-term performance of a DGR, the Greenland Analogue Project (GAP) was initiated by SKB, POSIVA and NWMO. The GAP was initiated in 2008 as a four-year field and modelling study utilizing the Greenland ice sheet and sub-surface conditions in West Greenland as an analogue for the conditions expected to prevail in Fennoscandia and Canada during future glacial cycles. One of the main aims of the GAP is to improve the understanding of how groundwater flow and water chemistry is influenced by an existing ice sheet and continuous permafrost. One way to study this is by monitoring deep drillholes. A 645 m deep drillhole (DH-GAP04) was drilled and instrumented in July 2011 at the ice-sheet margin in Kangerlussuaq, West Greenland to investigate the hydrogeochemical and hydrogeological conditions of a subglacial environment. Of particular interest is the recharge of glacial meltwater, and understanding to what depth it intrudes into the bedrock and whether it affects the chemistry and physico-chemical properties of the deep groundwater. DH-GAP04 is instrumented with a two-packer multi-sensor system, installed at a depth of 560 m, dividing the hole into three sections. The upper section extends from the base of permafrost (about 350 m) down to the upper packer

  3. The Subglacial Access and Fast Ice Research Experiment - SAFIRE - on Store Glacier, West Greenland

    Science.gov (United States)

    Christoffersen, P.; Hubbard, B. P.; Doyle, S. H.; Young, T. J.; Hofstede, C. M.; Bougamont, M. H.; Todd, J.; Toberg, N.; Nicholls, K. W.; Box, J.; Walter, J. I.; Hubbard, A.

    2015-12-01

    Marine-terminating outlet glaciers drain 90 percent of the Greenland Ice Sheet and are responsible for about half of the ice sheet's net annual mass loss, which currently raises global sea level by 1 mm per year. The basal controls on these fast-flowing glaciers are, however, poorly understood, with the implication that numerical ice sheet models needed to predict future dynamic ice loss from Greenland relies on uncertain and often untested basal parameterizations. The Subglacial Access and Fast Ice Research Experiment - SAFIRE - is addressing this paucity of observational constraints by drilling to the bed of Store Glacier, a fast-flowing outlet glacier terminating in Uummannaq Fjord, West Greenland. In 2014, we gained access to the bed in four boreholes drilled to depths of 603-616 m near the center of the glacier, 30 km inland from the calving terminus where ice flows at a rate of 700 m/year. A seismic survey showed the glacier bed to consist of water-saturated, soft sediment. The water level in all four boreholes nevertheless dropped rapidly to 80 m below the ice surface when the drill connected with a basal water system, indicating effective drainage over a sedimentary bed. We were able to install wired sensor strings at the bed (water pressure, temperature, electrical conductivity and turbidity) and within the glacier (temperature and tilt) in three boreholes. The sensors operated for up to 80+ days before cables stretched and ultimately snapped due to high internal strain. The data collected during this sensor deployment show ice as cold as -21 degrees Celcius; yet, temperature of water in the basal water system was persistently above the local freezing point. With diurnal variations detected in several sensor records, we hypothesise that surface water lubricates the ice flow while also warming basal ice. The fast basal motion of Store Glacier not only occurs by basal sliding, but from high rates of concentrated strain in the bottom third of the glacier

  4. Holocene glacial history of the west Greenland Ice Sheet inferred from cosmogenic exposure ages and threshold lakes

    DEFF Research Database (Denmark)

    Larsen, Nicolaj Krog; Kjaer, K. H.; Colding, Sune Oluf;

    2011-01-01

    In this study, we use a combination of 10Be exposure ages and threshold lakes to constrain the ice sheet history in Godthåbs- and Buksefjorden, west Greenland (63-64°N) during the Holocene. The 10Be cosmogenic exposure ages have been used to quantify both the ice retreat and thinning of the west....... Boulder samples from the highest peaks demonstrate that the ice was warm-based whereas bedrock samples often contain an inherited signal. These results may have implications for other studies in Greenland, which have inferred thin LGM ice based on 10Be ages of bedrock samples. The threshold lakes are used...... margin remained close to the present ice margin until around 7 cal. ka BP before it retreated behind the present extent during the Holocene Thermal Maximum (HTM). Here it remained until the Little Ice Age (LIA) where it readvanced to the present position around 0.5 cal. ka BP. Our results correspond...

  5. Arctic Outflow West Of Greenland: Nine Years Of Volume And Freshwater Transports From Observations In Davis Strait

    Science.gov (United States)

    Curry, B.; Lee, C.; Petrie, B.; Moritz, R. E.; Kwok, R.

    2014-12-01

    Recent Arctic changes suggest alterations in the export of freshwater from the Arctic to the North Atlantic, with conceivable impacts on the Atlantic Meridional Overturning circulation. Approximately 50% of the Arctic outflow exits west of Greenland, traveling through the Canadian Arctic Archipelago (CAA) and into Baffin Bay before crossing Davis Strait. The CAA outflow contributes over 50% of the net southward freshwater outflow through Davis Strait. The remainder is deeper outflow from Baffin Bay, flow from the West Greenland Current and runoff from West Greenland and CAA glaciers. Since September 2004, an observational program in Davis Strait has quantified volume and freshwater transport variability. The year-round program includes velocity, temperature and salinity measurements from 15 moorings spanning the full width (330 km) of the strait accompanied by autonomous Seagliders surveys (average profile separation = 4 km) and autumn ship-based hydrographic sections. Over the shallow Baffin Island and West Greenland shelves, moored instrumentation provides temperature and salinity measurements near the ice-ocean interface. From 2004-2013, the average net volume and liquid freshwater transports are -1.6 ± 0.2 Sv, -94 ± 7 mSv, respectively (salinity referenced to 34.8 and negative indicates southward transport); sea ice contributes an additional -10 ± 1 mSv. Over this period, volume and liquid freshwater transports show significant interannual variability and no clear trends, but a comparison with reanalyzed 1987-90 data indicate a roughly 40% decrease in net southward liquid volume transport and a corresponding an almost 30% decrease in freshwater transport. Connections between the Arctic are also captured, e.g., a unique yearlong Davis Strait freshening event starting September 2009 that was likely driven by an earlier freshening (January 2009 - April/May 2010) in the Canadian Arctic. The Davis Strait autumn 2009 salinity minimum was fresher (by about 0

  6. Raw material studies of West Central Serbia

    Directory of Open Access Journals (Sweden)

    Vera Bogosavljević Petrović

    2014-03-01

    Full Text Available This paper deals with raw material problems in the territory of West Central Serbia geologically determined as the Čačak-Kraljevo (or West Morava basin. Our research is presented through the most striking case studies, Lojanik, Vlaška Glava and Lazac.  The Lojanik hill is a silicified forest by origin. It has occasionally been in use from the earliest periods of prehistory until today as a source of black and ochre-coloured flint, opal and silicified wood. A detailed prospection, including the mapping of surface finds using square nets, was conducted during two research campaigns.The Vlaška Glava is an open-air Palaeolithic site at which artefacts made of white, ochre, red, brown and black chert, silicified magnesite, volcanic and metamorphic rocks were found. Our research of primary and secondary geological deposits in the vicinity of the site showed equivalent raw material. We also found an interesting primary deposit of high quality bluish grey flint with outcrop activities (Workshop 1.The Lazac shaft is a contemporary magnesite mine, recently abandoned because of the high percentage of silicon-dioxide. We determined the same raw material in collections found at nearby Neolithic sites. Certain similarities between the wooden support systems of ore exploration in the Middle Ages and modern times were established at the entrance of the shaft.Our research in the territory of the West Morava basin resulted in reconstruction of some links between geological deposits and settlements and also creation of a relevant base for future raw material studies.

  7. Modelling of subglacial hydrological development during a rapid lake drainage event, West Greenland

    Science.gov (United States)

    Dow, C. F.; Kulessa, B.; Pimentel, S.; Tsai, V. C.; Doyle, S. H.; Rutt, I. C.; Jones, G. A.; Booth, A. D.; Hubbard, A.

    2012-12-01

    We present results from a local-scale model of subglacial hydrological development during a rapid lake drainage event on the Russell Glacier catchment in West Greenland. Previous models applied to rapid lake drainage events include a turbulent radial model (Tsai and Rice, 2010) and a 1-D flowband model (Pimentel and Flowers, 2011). Both models have limitations for application to lake drainage events. For the former, the radial extent of water flow is restricted to several ice thicknesses and no provision is made for the development of basal channels. For the latter model, the input of water directly from the lake to the bed without modulation by englacial flow, together with the fact that lateral basal flux is neglected, causes unrealistic subglacial pressure levels. To resolve these limitations, we link the two models together, thus allowing both local radial flux and downstream development of a coupled efficient and distributed drainage system. Our model is constrained by inputs from fieldwork completed in summer 2010 at a rapid lake drainage site in the land-terminating region of West Greenland. Passive seismic records indicate the region of basal water injection. Reflection seismic amplitude vs. angle (AVA) surveys allow analysis of the basal material characteristics. Lake drainage rate and differential GPS vertical and horizontal motion records are used as constraints for our model outputs. Our preliminary results suggest that large basal channels do not necessarily form during the rapid drainage of supraglacial lakes. A lack of an efficient drainage system has an impact on the local ice dynamics and the treatment of lake drainage events in larger-scale dynamic models. References: Pimentel, S and Flowers, G. (2011). A numerical study of hydrologically driven glacier dynamics and subglacial flooding, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science, 467 (2126): doi: 10.1098/rspa.2010.0211. Tsai, V.C. and Rice, J.R. (2010). A

  8. Extreme variation in basal thermal conditions of the central Greenland Ice Sheet due to anomalous lithosphere structure

    Science.gov (United States)

    Rogozhina, Irina; Petrunin, Alexey; Vaughan, Alan P. M.; Kukkonen, Ilmo T.; Kaban, Mikhail K.; Koulakov, Ivan; Thomas, Maik

    2013-04-01

    At the Earth's surface, heat fluxes from the interior are generally insignificant when compared with fluxes from the sun and atmosphere; however, in areas permanently blanketed by ice these become very important. Modelling studies show that they are key to understanding the internal thermal structure of ice sheets and the distribution of melt water at their bases, information which is crucial for planning deep ice drilling campaigns and climate reconstructions. Unfortunately, the challenging conditions in ice-covered regions make measurement difficult in exactly the places where it is needed most. Until now, proxy methodologies have been considered best for determining geothermal heat flux (GHF) beneath ice sheets. Our method is to use a novel interdisciplinary approach, integrating a time-evolved climate-ice-lithosphere coupled model with a wide range of data such as direct ice-core measurements, past climate reconstructions and indirect estimates of the lithospheric thermal state. Here we show that the oldest (and thickest) part of the Greenland Ice Sheet (GIS) is strongly thermally influenced by both GHF increasing from west to east and glaciation-induced perturbations of the thermal structure of the upper crust. A pronounced lateral gradient in GHF across the Summit region of the GIS is due to anomalously thin lithosphere, which has only about 25 to 66% of the thickness typical for Archaean to early Proterozoic areas. Our findings suggest that the thermal basal conditions of the present-day central GIS are characterized by surprising rapid lateral variations in ice temperatures of up to 12°C along relatively small distances of 100 to 150 km. We reveal two areas of rapid basal melt in central Greenland, only one of which was previously predicted by ice-penetrating radar measurements and age-depth relations from internal layering (Fahnestock et al. [2001]). The endothermic phase transition associated with rapid basal ice melt is found to increase subglacial heat

  9. Mesozooplankton size data from the fjord branch Kapisigdlit located in the Godthaabsfjord system, West Greenland

    DEFF Research Database (Denmark)

    2013-01-01

    branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh......Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute...... for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord...

  10. Mesozooplankton abundance data from the fjord branch Kapisigdlit located in the Godthaabsfjord system, West Greenland, 2010

    DEFF Research Database (Denmark)

    2013-01-01

    branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh......Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute...... for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord...

  11. Photobiology of sea ice algae during initial spring growth in Kangerlussuaq, West Greenland

    DEFF Research Database (Denmark)

    Hawes, Ian; Lund-Hansen, Lars Chresten; Sorrell, Brian Keith;

    2012-01-01

    channels between laminar ice crystals in the lower 4–6 mm of the ice, with a several-fold spatial variation in inferred biomass on cm scales. The maximum quantum yield of photosynthesis, Fv/Fm, was initially low (~0.1), though this increased rapidly to ~0.5 by day 6. Day 6 also saw the onset of biomass......We undertook a series of measurements of photophysiological parameters of sea ice algae over 12 days of early spring growth in a West Greenland Fjord, by variable chlorophyll fluorescence imaging. Imaging of the ice–water interface showed the development of ice algae in 0.3–0.4 mm wide brine...... increase, the cessation of ice growth and the time at which brine had reached −2 °C. We interpret this as indicating that the establishment of stable brine channels at close to ambient salinity was required to trigger photosynthetically active populations. Maximum relative electron transport rate (r...

  12. The presence of thrust-block naled after a major surge event: Kuannersuit Glacier, West Greenland

    Science.gov (United States)

    Yde, Jacob C.; Knudsen, N. Tvis; Larsen, Nicolaj K.; Kronborg, Christian; Nielsen, Ole B.; Heinemeier, Jan; Olsen, Jesper

    Thrust-block naled in front of Kuannersuit Glacier, West Greenland, appears to have formed during the termination of a terrestrial surge event by a combination of enhanced winter runoff, rapid advance of the glacier terminus, and proglacial stress release by thrusting and stacking of naled blocks. This process is equivalent to the formation of thrust-block moraines. The thrust-block naled consists of at least seven thrust sheets, which are characterized by stratified ice with beds composed of a lower debris-rich lamina, an intermediate dispersed lamina and a top clean-ice lamina, and underlain by frozen outwash deposits. The thrust-block naled differs from basal stratified ice in the absence of internal deformation structures, a relatively low debris concentration, a clay-rich particle-size distribution and a preferential sorting of lighter minerals. The oxygen isotope composition of the thrust-block naled is indistinguishable from δ18O values from meteoric glacier ice and bulk meltwater, but different from basal stratified ice facies. The d-δD relationship indicates that thrust-block naled has been formed by freezing of successive thin layers of bulk waters with variable isotopic composition, whereas basal stratified ice has developed in a subglacial environment with regelation. This work shows that the association between proglacial naled and rapidly advancing glaciers may have significant consequences for the proglacial geomorphology and the interpretation of basal ice layers.

  13. Eimeria rangiferis (Protozoa: Eimeriidae reported from caribou in Ameralik, West Greenland

    Directory of Open Access Journals (Sweden)

    Karl Skírnisson

    2015-03-01

    Full Text Available In recent decades the native Barren-ground caribou (Rangifer tarandus groenlandicus south of the Godthaabs fjord (Nuup Kangerlua fjord in West Greenland have mixed with semi-domesticated Norwegian reindeer (R. t. tarandus imported in 1952 from Finnmark Norway and released onto the range of the Ameralik caribou population. Fecal samples from three calves of the Ameralik caribou population were examined for the presence of nematode eggs and eimerid oocysts. Two distinct nematode egg types were observed: the first, Nematodirella longissimespiculata, was found in all calves, while the second, a strongylid nematode, was detected in one calf. The coccidian eimerid Eimeria rangiferis was identified in all calves. This host-specific eimerid is found in Icelandic feral reindeer, which were also imported from Finnmark Norway. We suggest that Finnmark reindeer were the source of Eimeria rangiferis observed in Ameralik caribou today. There are three possible origins for the presence of N. longissimespiculata in Ameralik, 1 arrival with colonizing caribou from North America within the past 4000 years, 2 the 1952 introduction of semi-domesticated Norwegian reindeer, or 3 the current immigration of muskoxen.

  14. Biogeochemical data from terrestrial and aquatic ecosystems in a periglacial catchment, West Greenland

    Science.gov (United States)

    Lindborg, Tobias; Rydberg, Johan; Tröjbom, Mats; Berglund, Sten; Johansson, Emma; Löfgren, Anders; Saetre, Peter; Nordén, Sara; Sohlenius, Gustav; Andersson, Eva; Petrone, Johannes; Borgiel, Micke; Kautsky, Ulrik; Laudon, Hjalmar

    2016-09-01

    Global warming is expected to be most pronounced in the Arctic where permafrost thaw and release of old carbon may provide an important feedback mechanism to the climate system. To better understand and predict climate effects and feedbacks on the cycling of elements within and between ecosystems in northern latitude landscapes, a thorough understanding of the processes related to transport and cycling of elements is required. A fundamental requirement to reach a better process understanding is to have access to high-quality empirical data on chemical concentrations and biotic properties for a wide range of ecosystem domains and functional units (abiotic and biotic pools). The aim of this study is therefore to make one of the most extensive field data sets from a periglacial catchment readily available that can be used both to describe present-day periglacial processes and to improve predictions of the future. Here we present the sampling and analytical methods, field and laboratory equipment and the resulting biogeochemical data from a state-of-the-art whole-ecosystem investigation of the terrestrial and aquatic parts of a lake catchment in the Kangerlussuaq region, West Greenland. This data set allows for the calculation of whole-ecosystem mass balance budgets for a long list of elements, including carbon, nutrients and major and trace metals. The data set is freely available and can be downloaded from PANGAEA: doi:10.1594/PANGAEA.860961.

  15. Effect of acidification on an Arctic phytoplankton community from Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Thoisen, Christina; Riisgaard, Karen; Lundholm, Nina;

    2015-01-01

    show that coastal phytoplankton from Disko Bay is naturally exposed to pH fluctuations exceeding the experimental pH range used in most ocean acidification studies. We emphasize that studies on ocean acidification should include in situ pH before assumptions on the effect of acidification on marine......Long-term measurements (i.e. months) of in situ pH have not previously been reported from the Arctic; this study shows fluctuations between pH 7.5 and 8.3 during the spring bloom 2012 in a coastal area of Disko Bay, West Greenland. The effect of acidification on phytoplankton from this area was...... studied at both the community and species level in experimental pH treatments within (pH 8.0, 7.7 and 7.4) and outside (pH 7.1) in situ pH. The growth rate of the phytoplankton community decreased during the experimental acidification from 0.50 ± 0.01 d-1 (SD) at pH 8.0 to 0.22 ± 0.01 d-1 at pH 7...

  16. Three recent ice entrapments of Arctic cetaceans in West Greenland and the eastern Canadian High Arctic

    Directory of Open Access Journals (Sweden)

    MP Heide-Jørgensen

    2014-01-01

    Full Text Available Three ice entrapments of Monodontids have been reported in the western North Atlantic since 1993. Hunters in Disko Bay, West Greenland, discovered one in March 1994 that included about 150 narwhals (Monodon monoceros. The entrapment occurred during a sudden cold period which caused ice to form rapidly. The trapped whales were subject to hunting, but about 50 of the killed whales could not be retrieved in the ice. The whales were trapped in a small opening in the ice and because of that they would probably have succumbed even if not discovered by hunters. Two entrapments involving white whales or belugas (Delphinapterus leucas occurred in the eastern Canadian Arctic in May 1999; one in Lancaster Sound discovered by polar bear (Ursus maritimus researchers and one in Jones Sound discovered by hunters. The first included one bowhead whale (Balaena mysticetus and about 40 belugas that were being preyed upon by polar bears. The second involved at least 170 belugas, of which about 100 were killed by polar bears and 17 were taken by hunters. The entrapments in Disko Bay and Jones Sound both occurred in areas where entrapments have previously been reported, whereas the one in Lancaster Sound was in a new area.

  17. Meltwater flux and runoff modeling in the abalation area of jakobshavn Isbrae, West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Mernild, Sebastian Haugard [Los Alamos National Laboratory; Chylek, Petr [Los Alamos National Laboratory; Liston, Glen [COLORADO STATE UNIV.; Steffen, Konrad [UNIV OF COLORADO

    2009-01-01

    The temporal variability in surface snow and glacier melt flux and runoff were investigated for the ablation area of lakobshavn Isbrae, West Greenland. High-resolution meteorological observations both on and outside the Greenland Ice Sheet (GrIS) were used as model input. Realistic descriptions of snow accumulation, snow and glacier-ice melt, and runoff are essential to understand trends in ice sheet surface properties and processes. SnowModel, a physically based, spatially distributed meteorological and snow-evolution modeling system was used to simulate the temporal variability of lakobshavn Isbrre accumulation and ablation processes for 2000/01-2006/07. Winter snow-depth observations and MODIS satellite-derived summer melt observations were used for model validation of accumulation and ablation. Simulations agreed well with observed values. Simulated annual surface melt varied from as low as 3.83 x 10{sup 9} m{sup 3} (2001/02) to as high as 8.64 x 10{sup 9} m{sup 3} (2004/05). Modeled surface melt occurred at elevations reaching 1,870 m a.s.l. for 2004/05, while the equilibrium line altitude (ELA) fluctuated from 990 to 1,210 m a.s.l. during the simulation period. The SnowModel meltwater retention and refreezing routines considerably reduce the amount of meltwater available as ice sheet runoff; without these routines the lakobshavn surface runoff would be overestimated by an average of 80%. From September/October through May/June no runoff events were simulated. The modeled interannual runoff variability varied from 1.81 x 10{sup 9} m{sup 3} (2001/02) to 5.21 x 10{sup 9} m{sup 3} (2004/05), yielding a cumulative runoff at the Jakobshavn glacier terminus of {approx}2.25 m w.eq. to {approx}4.5 m w.eq., respectively. The average modeled lakobshavn runoff of {approx}3.4 km{sup 3} y{sup -1} was merged with previous estimates of Jakobshavn ice discharge to quantify the freshwater flux to Illulissat Icefiord. For both runoff and ice discharge the average trends are

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    Greenland is the most extreme of human habitats in regard to annual changes in natural light. From being very low, the rate of suicides in Greenland has increased during the past few decades to be among the highest in the world. Several studies have shown seasonality in suicides with spring or su...

  19. Estimating ice-melange properties with repeat UAV surveys over Store Glacier, West Greenland

    Science.gov (United States)

    Toberg, Nick; Ryan, Johnny; Christoffersen, Poul; Snooke, Neal; Todd, Joe; Hubbard, Alun

    2016-04-01

    In the past decade, tidewater outlet glaciers of the Greenland ice sheet (GrIS) have thinned and retreated when compared to the 1980s when the ice sheet was in a state of dynamic balance. With a growing amount of ice discharged into the sea by tidewater glaciers as well as more ice melting on the surface, the Greenland Ice Sheet has become the single largest cryospheric source of global sea level rise. Today, the ice sheet causes sea level rise of 1 mm per year, highlighting the need to understand the ice sheet's response to climate change. Atmospheric warming will inevitably continue to increase surface meltwater production, but the dynamic response, which includes hundreds of fast-flowing tidewater glaciers, is largely unknown. To develop new understanding of ice sheet dynamics, we investigated the mechanism whereby icebergs break off tidewater glaciers and form a proglacial ice melange. This melange is rigid in winter when sea ice and friction along the sidewalls of the fjord, or even at the sea floor, hold it together. The result is a resistive force, which reduces the rate of iceberg calving when the ice melange is rigid and is lost when the melange disappears in the summer. From early May to late July 2014, we launched unmanned aerial vehicles (UAVs) from a basecamp on a bluff overlooking the calving front of Store Glacier, a 5 km wide tidewater glacier flowing into Uummannaq Fjord in West Greenland. The Skywalker X8 UAVs had a wing-span of 2.1m and a payload containing a high resolution camera, an autopilot system and a GPS data logger. We generated almost 70,000 georeferenced images during 63 sorties over the glacier during a 10 week field season starting 13 May 2014. The images were used to construct orhorectified mosaics and digital elevation models of the proglacial melange with Photoscan structure-from-motion software. The imagery and the DEMs were analysed statistically to understand the spatial characteristics of the ice melange. By combining the

  20. Fatty Acid Composition of Muscle, Adipose Tissue and Liver from Muskoxen (Ovibos moschatus) Living in West Greenland.

    Science.gov (United States)

    Alves, Susana P; Raundrup, Katrine; Cabo, Ângelo; Bessa, Rui J B; Almeida, André M

    2015-01-01

    Information about lipid content and fatty acid (FA) composition of muskoxen (Ovibos moschatos) edible tissues is very limited in comparison to other meat sources. Thus, this work aims to present the first in-depth characterization of the FA profile of meat, subcutaneous adipose tissue and liver of muskoxen living in West Greenland. Furthermore, we aim to evaluate the effect of sex in the FA composition of these edible tissues. Samples from muscle (Longissimus dorsi), subcutaneous adipose tissue and liver were collected from female and male muskoxen, which were delivered at the butchery in Kangerlussuaq (West Greenland) during the winter hunting season. The lipid content of muscle, adipose tissue and liver averaged 284, 846 and 173 mg/g of dry tissue, respectively. This large lipid contents confirms that in late winter, when forage availability is scarce, muskoxen from West Greenland still have high fat reserves, demonstrating that they are well adapted to seasonal feed restriction. A detailed characterization of FA and dimethylacetal composition of muskoxen muscle, subcutaneous adipose tissue and liver showed that there are little differences on FA composition between sexes. Nevertheless, the 18:1cis-9 was the most abundant FA in muscle and adipose tissue, reaching 43% of total FA in muscle. The high content of 18:1cis-9 suggests that it can be selectively stored in muskoxen tissues. Regarding the nutritional composition of muskoxen edible tissues, they are not a good source of polyunsaturated FA; however, they may contribute to a higher fat intake. Information about the FA composition of muskoxen meat and liver is scarce, so this work can contribute to the characterization of the nutritional fat properties of muskoxen edible tissues and can be also useful to update food composition databases.

  1. Gravity changes in mid-west Greenland from GOCE gravity model and gradient data using ground and airborne gravity

    OpenAIRE

    Tscherning, Carl Christian; Herceg, Matija; Fredenslund Levinsen, Joanna

    2014-01-01

    GOCE TRF (terrestrial reference frame) vertical anomalous gradients (Tzz) from two periods have been used to determine gravity anomalies changes in mid-west Greenland, where a large mass-loss has been detected using GRACE (Fig. 1). As additional data were used the GOCE DIR-3 model and ground gravity at the coast on solid rock, where no mass loss is expected. The methods of Least-Squares Collocation (LSC) and the Reduced Point Mass (RPM) methods have been used, however only LSC included the gr...

  2. Gravity changes in mid-west Greenland from GOCE gravity model and gradient data using ground and airborne gravity

    DEFF Research Database (Denmark)

    Tscherning, Carl Christian; Herceg, Matija; Fredenslund Levinsen, Joanna

    GOCE TRF (terrestrial reference frame) vertical anomalous gradients (Tzz) from two periods have been used to determine gravity anomalies changes in mid-west Greenland, where a large mass-loss has been detected using GRACE (Fig. 1). As additional data were used the GOCE DIR-3 model and ground...... gravity at the coast on solid rock, where no mass loss is expected. The methods of Least-Squares Collocation (LSC) and the Reduced Point Mass (RPM) methods have been used, however only LSC included the ground data....

  3. Digital elevation model of Walker Lake, West-Central Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Walker Lake lies within a topographically closed basin in west-central Nevada and is the terminus of the Walker River. Accurately determining the bathymetry and...

  4. Herbicide concentrations in wetlands in west central Minnesota, 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Thirty emergent, seasonally to semi-permanently flooded wetlands in an intensively farmed area of west central Minnesota were sampled before and during the 1992...

  5. Solar forcing as an important trigger for West Greenland sea-ice variability over the last millennium

    Science.gov (United States)

    Sha, Longbin; Jiang, Hui; Seidenkrantz, Marit-Solveig; Muscheler, Raimund; Zhang, Xu; Knudsen, Mads Faurschou; Olsen, Jesper; Knudsen, Karen Luise; Zhang, Weiguo

    2016-01-01

    Arctic sea ice represents an important component of the climate system, and the present reduction of sea ice in the Arctic is of major concern. Despite its importance, little is known about past changes in sea-ice cover and the underlying forcing mechanisms. Here, we use diatom assemblages from a marine sediment core collected from the West Greenland shelf to reconstruct changes in sea-ice cover over the last millennium. The proxy-based reconstruction demonstrates a generally strong link between changes in sea-ice cover and solar variability during the last millennium. Weaker (or stronger) solar forcing may result in the increase (or decrease) in sea-ice cover west of Greenland. In addition, model simulations show that variations in solar activity not only affect local sea-ice formation, but also control the sea-ice transport from the Arctic Ocean through a sea-ice-ocean-atmosphere feedback mechanism. The role of solar forcing, however, appears to have been more ambiguous during an interval around AD 1500, after the transition from the Medieval Climate Anomaly to the Little Ice Age, likely to be driven by a range of factors.

  6. Variation and Distribution of Sediments in a Mixed Glacifluvial-Aeolian System in West Greenland

    Science.gov (United States)

    Austin, M. J.; Bullard, J. E.

    2007-12-01

    There is a clear association between the distribution of wind-blown sediments and the former extent of ice sheets and glaciers. Glacial erosion processes produce significant quantities of fine sediments that are washed out from beneath glaciers by meltwater. Once deposited and desiccated, aeolian processes may transport them across the landscape resulting in the formation of sand dunes and loess, and adding dust to the atmosphere. This research reports the use of digital imaging and laser sizing to obtain the grain size distribution and textural attributes of sand and dust in Sandflugtdalen, a valley adjacent to the West Greenland ice sheet. An initial assessment of the rates of sand and dust transport, made using semi-isokinetic directional sediment samplers, indicate that the flux of aeolian sediment comprises clays, silts and sand-sized particles. Digital imaging of the surficial sediment deposits provides a rapid means of sampling the large, spatially and temporally variable, proglacial valley. Sediments were initially photographed during June 2007 and then resampled after a 9-week interval. The grain size distribution and surface texture were computed using a calibrated autocorrelation method. It is estimated that individual particles may be resolved down to a size of 0.045 mm. The regions of aeolian entrainment, transport and deposition are directly linked to the development and distribution of sediments on the proglacial floodplain, which varies considerably in terms of surface roughness. On the floodplain close to the ice sheet, aeolian flux is controlled by sediment supply and lag formation and the total surface roughness is determined by the combination of grain-scale roughness and topography. Further down valley, recycling of sediments by aeolian and fluvial activity is significant and wind speed becomes an important controlling factor. Within the dunefields, surface roughness is principally determined by topography and vegetation. Close to the ice sheet

  7. Exploring controls on ice stream destabilisation during the LGM/Holocene transition in West Greenland

    Science.gov (United States)

    Roberts, D. H.; Lane, T. P.; Rea, B. R.; Ó Cofaigh, C.; Jamieson, S.; Vieli, A.

    2015-12-01

    Deglacial chronologies from West Greenland enable investigation of the role of climate and topography in controlling ice stream dynamics. The Uummannaq ice stream system (UIS) in particular has a comprehensive deglacial chronology which, when coupled with geometry, provides a framework for exploring controls on ice stream dynamics under changing climatic conditions. Here, we use a 2D numerical model to simulate grounding line-retreat behaviour and surface thinning in order explore the principal drivers of linear and non-linear ice stream behaviour during the end of the last glacial cycle. Deglaciation of the UIS began on the outer shelf at ~14.8 ka with ice retreat eastward to Ubekendt Ejland by ~12.4 ka. This initial retreat coincided with increasing air temperature, increasing solar radiation and sea-level rise. Awide, mid-shelf, trough also facilitated rapid retreat. The UIS then withdrew eastward ~ 100 km by ~11.4 ka - 10.8 ka as the northern and southern feeder zones unzipped. This coincided with increasing insolation and peak sea-level, but bathymetric over-deepening and fjord widening were also influential. Staircases of lateral moraines throughout the region point to step-wise thinning as ice retreated between 14.8 - 11.0 ka. By 8.7 ka the southern arm of the UIS had reached Store Gletscher and thereafter it retreated beyond the present day grounding line. This coincided with increased air/ocean temperatures and peak summer insolation. In contrast, the northern arm of the UIS stabilised until ~6.5 ka and became unresponsive to both atmospheric and ocean forcing due to topographic pinning. New research has adopted a 2D model approach to establish and quantify the relative importance of various mechanisms in governing UIS dynamics. These model results indicate that the non-linear retreat of the UIS is strongly influenced by vertical and lateral constrictions in the marine trough system which regulates grounding line stability. In turn, grounding line

  8. The Influence of Light Absorbing Aerosols on the Radiation Balance Over Central Greenland

    Science.gov (United States)

    Strellis, B.; Bergin, M. H.; Sokolik, I. N.; Dibb, J. E.; Sheridan, P. J.; Ogren, J. A.

    2011-12-01

    The Arctic region has proven to be more responsive to recent changes in climate than other parts of the Earth. A key component of the Arctic climate is the Greenland Ice Sheet, which has the potential to dramatically influence both sea level, depending on the amount of melting that occurs, and climate, through shifts in the regional radiation balance. Light absorbing aerosols from biomass burning, fossil fuel combustion, and dust sources can potentially have a significant impact on the radiation balance of the ice sheet, although at this time we lack the key measurements needed to accurately quantify aerosol forcing over the ice sheet. For this reason a field study was conducted at Summit, Greenland, from May-July of 2012. Our efforts included real-time measurements of aerosol physical and optical properties including size distribution, multi-wavelength scattering (σsp) and backscattering (σbsp) coefficients, and multi-wavelength absorption coefficient (σap), as well as measurements of wavelength dependent aerosol optical depth and spectral snow albedo. The measurements serve as inputs to a radiative transfer model to estimate the direct aerosol radiative forcing at both the surface and top of the atmosphere. Preliminary results indicate that the direct aerosol radiative forcing is often several Wm-2 and is at times greater than 10 Wm-2. The aerosol chemical composition (major ions, elements, and organic and elemental carbon compounds) was also determined through filter sampling and will be discussed in terms of the sources of light absorbing aerosols over central Greenland.

  9. Parasites as biological tags to track an ontogenetic shift in the feeding behaviour of Gadus morhua off West and East Greenland.

    Science.gov (United States)

    Münster, Julian; Klimpel, Sven; Fock, Heino O; MacKenzie, Ken; Kuhn, Thomas

    2015-07-01

    Parasites, being an integral part of every ecosystem and trophically transmitted along the food webs, can provide detailed insights into the structure of food webs and can close the information gap between short-term stomach content analyses and long-term fish otolith analyses. They are useful for tracking ontogenetic shifts in the host's diet, the occurrence of specific organisms or migratory behaviour of their hosts, even in inaccessible environments. In the present study, stomach content analyses and parasitological examinations were performed on 70 Atlantic cod Gadus morhua, one of the most important high-level predators of small fish in the North Atlantic, caught during one research vessel cruise from West and East Greenlandic waters. Analyses revealed significant differences in fish size with higher values for East Greenland (average total length (TL) of 50.5 cm) compared to West Greenland (average TL of 33.3 cm). Clear differences were also present in prey and parasite composition. Crustacea was the main food source for all fish (IRI = 10082.70), while the importance of teleosts increased with fish size. With a prevalence of 85 % in West Greenland and 100 % in East Greenland, Nematoda were the most abundant parasite group. The results indicate an ontogenetic shift in the diet, which are discussed in the context of the common distribution theory, stock dynamics and migratory behaviour.

  10. Hydrogeochemistry of Groundwater as Part of the Greenland Analogue Project in an Area of Continuous Permafrost Adjacent to the Greenland Ice Sheet, Kangerlussuaq, West Greenland

    Science.gov (United States)

    Henkemans, E.; Frape, S.; Ruskeeniemi, T.; Claesson-Liljedahl, L.; Lehtinen, A.; Annable, W. K.

    2011-12-01

    Studying groundwater in areas of continuous permafrost is often limited to studies of springs and open pingos (eg. Pollard et al. 1999 and Allen et al. 1976). Boreholes in such locations are expensive, risky and logistically challenging (eg. Stotler et al. 2011) resulting in a limited understanding of the interaction between continental scale ice sheets and groundwater. Continental ice sheet models are often coupled to groundwater flow systems; however, there is a lack of modern field data with which to compare the results of models and their treatment of groundwater flow systems under the influence of glaciation. The Greenland Analogue Project (GAP) aims to eliminate some of the uncertainties in modeling ice sheets by using the Greenland ice sheet as a modern analogue for past glaciations. Since 2009, 3 boreholes have been drilled, 2 of which contain sampling systems. DH-GAP01 is a 191 m deep borehole drilled at an angle into a talik and has been sampled and studied since 2009. DH-GAP04 is a 632 m deep, angled borehole that intersects the groundwater flow system directly beneath Isunguata Sermia and is producing preliminary groundwater samples. Additional information on groundwater in the Kangerlussuaq area comes from a spring located directly in front of the Leverett ice lobe. Geochemical and isotopic (δ18O, δ2H, δ37Cl, 87Sr/86Sr, and δ34S and δ18O of SO4) tools are used to interpret geochemical processes acting on groundwaters and provide insight into groundwater flow. Analyses of δ18O and δ2H in groundwaters from DH-GAP01 show the borehole waters fall along the Global Meteoric Water Line (GMWL). Evaporation is an important process affecting the δ18O-δ2H of surface waters in the region causing lakes to plot along a local evaporation line (Leng and Anderson, 2003). The waters from the Leverett spring plot to the right of the GMWL as possibly a mixture of groundwater and surface evaporated fluids. However, both the waters from DH-GAP01 and the Leverett

  11. Feeding ecology of capelin (Mallotus villosus Müller) in West Greenland waters

    DEFF Research Database (Denmark)

    Hedeholm, R.; Grønkjær, P.; Rysgaard, Søren

    2012-01-01

    Capelin (Mallotus villosus Müller) is a key pelagic mediator of energy from lower to higher trophic levels in arctic waters. This is also the case in Greenland waters, but little is known of its feeding behaviour in this region. By analysing stable nitrogen isotopes and stomach content of capelin...

  12. Air Temperatures Trends in the Jakobshavn Isbræ Region, West Greenland

    Science.gov (United States)

    Bayou, N.; Steffen, K.

    2012-12-01

    Since 1991, a network of Automated Weather Stations (AWS) has been monitoring the climate of the Greenland Ice Sheet (GIS) hourly. This study focuses on the trends in the climatology of the JAR3/Summit transept with an emphasis on the Swiss Camp records. Monthly and yearly averages as well as lapse rates and melt season length are explored

  13. 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...... contamination (isotopic composition (ca. 1% lower for 206Pb/204Pb and 0.1% higher for 87Sr/86Sr depending on the contaminant). Negative ¿Nb suggests a MORB affinity for the low-Ti magmas, however they are distinguished from.......g. depleted LREE) and are distinct from the high-Ti lavas that dominate the sequence. REE geochemistry implies derivation from a source more depleted than the typical MORB source, and suggests polybaric melting and contributions from both spinel and garnet facies mantle. The low-Ti basalts have Sr...

  14. A diatom-based sea-ice reconstruction of the last 5000 years in Vaigat Strait, Disko Bugt, West Greenland

    Science.gov (United States)

    Sha, Longbin; Jiang, Hui; Seidenkrantz, Marit-Solveig; Luise Knudsen, Karen; Olsen, Jesper; Kuijpers, Antoon; Liu, Yanguang

    2013-04-01

    Sea ice is a major component of the climate system, because it influences the planetary albedo and the exchanges of heat, moisture and gases between the ocean and the atmosphere. Thus, sea ice is a key parameter in atmospheric and ocean models assessing future climate change. However, observed reliable data on sea-ice cover, such as satellite data, are only available as far back as 30 years with the exception of records from ship logs, which are sporadic and irregular. To obtain longer time series of Arctic SIC, microfossils such as diatoms and dinoflagellate cysts are commonly used. We have developed a diatom-based sea-ice concentration (SIC) transfer function using 72 surface samples from west of Greenland and around Iceland, and through comparison with the associated modern SIC. Canonical correspondence analysis (CCA) on surface sediment diatoms and monthly average of SIC reveals that April SIC is the most important environmental factor controlling the distribution of diatoms in the area, and permits the development of a diatom-based SIC transfer function. The consistency between reconstructed SIC based on diatoms from West Greenland core GA306-BC4 and the instrumental and documentary data during the last ~75 years demonstrates that the diatom-based SIC reconstruction is reliable for studying the palaeoceanography off West Greenland. Based on the diatom record from a 446 cm long gravity core DA06-139G, collected from Vaigat Strait in Disko Bugt (water depth 384 m), the reconstructed April SIC varies between 40 and 70% with a mean value around 55% over the last 5000 years. Relatively warm conditions with strong influence of the IC are indicated for the early part of the record (~5000-3860 cal. yr BP), corresponding in time to the latest part of the Holocene Thermal Maximum. The April SIC oscillated around the mean value between 3860 and 1510 cal. yr BP and was above mean afterwards, particularly during the time interval 1510-1120 cal. yr BP and after 650 cal. yr

  15. Variations of the glacio-marine air mass front in West Greenland through water vapor isotopes

    Science.gov (United States)

    Kopec, B. G.; Lauder, A. M.; Posmentier, E. S.; Feng, X.

    2012-12-01

    While the isotopic distribution of precipitation has been widely used for research in hydrology, paleoclimatology, and ecology for decades, intensive isotopic studies of atmospheric water vapor has only recently been made possible by spectral-based technology. New instrumentation based on this technology opens up many opportunities to investigate short-term atmospheric dynamics involving the water cycle and moisture transport. We deployed a Los Gatos Water Vapor Isotope Analyzer (WVIA) at Kangerlussuaq, Greenland from July 21 to August 15, and measured the water vapor concentration and its isotopic ratios continuously at 10s intervals. A Danish Meteorological Institute site is located about 1 km from the site of the deployment, and meteorological data is collected at 30 min intervals. During the observation period, the vapor concentration of the ambient air ranges from 5608.4 to 11189.4 ppm; dD and d18O range from -254.5 to -177.7 ‰ and -34.2 to -23.2 ‰, respectively. The vapor content (dew point) and the isotopic ratios are both strongly controlled by the wind direction. The easterly winds are associated with dry, isotopically depleted air masses formed over the glacier, while westerly winds are associated with moist and isotopically enriched air masses from the marine/fjord surface. This region typically experiences katabatic winds off of the ice sheet to the east. However, during some afternoons, the wind shifts 180 degrees, blowing off the fjord to the west. This wind switch marks the onset of a sea breeze, and significant isotopic enrichment results. Enrichment in deuterium is up to 60 ‰ with a mean of 15‰, and oxygen-18 is enriched by 3‰ on average and up to 8 ‰. Other afternoons have no change in wind, and only small changes in humidity and vapor isotopic ratios. The humidity and isotopic variations suggest the local atmosphere circulation is dominated by relatively high-pressure systems above the cold glaciers and cool sea surface, and diurnal

  16. Pre-LGM ice dynamics of the Greenland Ice Sheet in Uummannaq Fjord West Greenland, revealed by blockfields, tors and till mantled surfaces

    Science.gov (United States)

    Rea, Brice; Roberts, David; Lane, Tim; Rhodés, Angel; Schnabel, Christoph

    2013-04-01

    The future response of the Greenland Ice Sheet has been the focus of much recent modelling work but in order to fully understand the dynamics of this ice mass it is also imperative that the past behaviour of the ice sheet is understood. Indeed it is only through successful hindcasts of past ice geometries and dynamics that confidence in predictions can be achieved. In most glaciated environments determining ice dynamics prior to the Last Glacial Maximum (LGM) and subsequent deglaciation are non-trivial. They rely on fortuitous preservation, more restricted ice cover at LGM than previously or protective cold based ice cover. Here results are presented from hypsometric surfaces in the Uummannaq Fjord region of West Greenland which can provide constrains on the dynamics of ice cover prior to and including the LGM. Uummanaq Fjord is a classic landscape of selective linear erosion containing deeply incised troughs juxtaposed with high elevation plateau where relief approaches 3 km in places. Excavations were made in a number of summit blockfields with samples collected. Results from a morphometric landscape analyses a presented, using both landscape hypsometry and an elevation-range slope-map approach to identify hypsometric surfaces. The hypsometric surfaces are divided into those which are now denuded and classified as regions of areal scour, those with a blockfield cover and areas which are still ice covered. A number of sites have been visited and excavations were made into blockfields. Data are presented indicating minimum depths, granulometry and mineralogy of blockfields which allowed a further subdivision into allochthonous and autochotonous blockfields. Samples were also collected for cosmogenic nuclide exposure analyses and indicate that blockfield boulders and tors exhibit ages extending significantly beyond the LGM. Based on equilibrium profile reconstructions of the LGM ice sheet (constrained by onshore and offshore geomorphology and cosmogenic and 14C ages

  17. Bathymetry data reveal glaciers vulnerable to ice-ocean interaction in Uummannaq and Vaigat glacial fjords, west Greenland

    Science.gov (United States)

    Rignot, E.; Fenty, I.; Xu, Y.; Cai, C.; Velicogna, I.; Cofaigh, C. Ó.; Dowdeswell, J. A.; Weinrebe, W.; Catania, G.; Duncan, D.

    2016-03-01

    Marine-terminating glaciers play a critical role in controlling Greenland's ice sheet mass balance. Their frontal margins interact vigorously with the ocean, but our understanding of this interaction is limited, in part, by a lack of bathymetry data. Here we present a multibeam echo sounding survey of 14 glacial fjords in the Uummannaq and Vaigat fjords, west Greenland, which extends from the continental shelf to the glacier fronts. The data reveal valleys with shallow sills, overdeepenings (>1300 m) from glacial erosion, and seafloor depths 100-1000 m deeper than in existing charts. Where fjords are deep enough, we detect the pervasive presence of warm, salty Atlantic Water (AW) (>2.5°C) with high melt potential, but we also find numerous glaciers grounded on shallow (<200 m) sills, standing in cold (<1°C) waters in otherwise deep fjords, i.e., with reduced melt potential. Bathymetric observations extending to the glacier fronts are critical to understand the glacier evolution.

  18. Longitudinal Inter-Comparison of Modeled and Measured West Greenland Ice Sheet Meltwater Runoff Losses (2004-2014)

    Science.gov (United States)

    Moustafa, S.; Rennermalm, A. K.; Tedesco, M.; Mote, T. L.; Koenig, L.; Smith, L. C.; Hagedorn, B.; Overeem, I.; Sletten, R. S.; Mikkelsen, A. B.; Hasholt, B.; Hall, D. K.

    2015-12-01

    Increased surface meltwater runoff, that exits the Greenland ice sheet (GrIS) margin via supra-, en-, and sub-glacial drainage networks into fjords, pro-glacial lakes and rivers, accounts for half or more of total mass loss. Despite its importance, modeled meltwater runoff fluxes are poorly constrained, primarily due to a lack of direct in situ observations. Here, we present the first ever longitudinal (north-south) inter-comparison of a multi-year dataset (2004-2014) of discharge for four drainage basins - Watson, Akuliarusiarsuup Kuua, Naujat Kuat, and North Rivers - along West Greenland. These in situ hydrologic measurements are compared with modeled runoff output from Modèle Atmosphérique Régional (MAR) regional climate model, and the performance of the model is examined. An analysis of the relationship between modeled and actual ice sheet runoff patterns is assessed, and provides insight into the model's ability to capture inter-annual and intra-annual variability, spatiotemporal patterns, and extreme melt events. This study's findings will inform future development and parameterization of ice sheet surface mass balance models.

  19. Research needs for lion conservation in West and Central Africa.

    Science.gov (United States)

    Bauer, Hans; De Iongh, Hans H; Princée, Frank P; Ngantou, Daniel

    2003-08-01

    The lion has historically probably been widespread at low densities in West and Central Africa, nowadays they are largely restricted to small isolated populations inside protected areas. The total number is probably between 1200 and 2700, the best possible guesstimate would be 1700. Mankind is the main cause for the suspected decline of lion populations, both inside and outside protected areas. Very little research has been done on West and Central African lions a few examples are summarized here. The international community is slowly becoming aware of threats to lions in the region and some initiatives for lion conservation have started.

  20. Environmental Oil Spill Sensitivity Atlas for the West Greenland (68°-72° N) Coastal Zone, 2nd revised edition

    DEFF Research Database (Denmark)

    Clausen, Daniel Spelling; Johansen, Kasper Lambert; Mosbech, Anders;

    This oil spill sensitivity atlas covers the shoreline and the offshore areas of West Greenland between 68º N and 72º N. The coastal zone is divided into 199 shoreline segments and the offshore zone into 8 areas. A sensitivity index value is calculated for each segment/area, and each segment....../area is subsequently ranked according to four degrees of sensitivity. Besides this general ranking a number of smaller areas are especially selected as they are of particular significance, they are especially vulnerable to oil spills and they have a size making oil spill response possible. The shoreline sensitivity....... Based on all the information, appropriate oil spill response methods have been assessed for each area....

  1. Spatial statistical analysis of contamination level of 241Am and 239Pu, Thule, North-West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Strodl Andersen, J. (JSA EnviroStat (Denmark))

    2011-10-15

    A spatial analysis of data on radioactive pollution on land at Thule, North-West Greenland is presented. The data comprises levels of 241Am and 239,240Pu on land. Maximum observed level of 241Am is 2.8x105 Bq m-2. Highest levels were observed near Narsaarsuk. This area was also sampled most intensively. In Groennedal the maximum observed level of 241Am is 1.9-104 Bq m-2. Prediction of the overall amount of 241Am and 239,240Pu is based on grid points within the range from the nearest measurement location. The overall amount is therefore highly dependent on the model. Under the optimal spatial model for Narsaarsuk, within the area of prediction, the predicted total amount of 241Am is 45 GBq and the predicted total amount of 239,240Pu is 270 GBq. (Author)

  2. Spatial statistical analysis of contamination level of 241Am and 239Pu, Thule, North-West Greenland

    DEFF Research Database (Denmark)

    Strodl Andersen, Jens

    A spatial analysis of data on radioactive pollution on land at Thule, North-West Greenland is presented. The data comprises levels of 241Am and 239,240Pu on land. Maximum observed level of 241Am is 2.8×105 Bq m-2. Highest levels were observed near Narsaarsuk. This area was also sampled most...... intensively. In Grønnedal the maximum observed level of 241Am is 1.9×104 Bq m-2. Prediction of the overall amount of 241Am and 239,240Pu is based on grid points within the range from the nearest measurement location. The overall amount is therefore highly dependent on the model. Under the optimal spatial...... model for Narsaarsuk, within the area of prediction, the predicted total amount of 241Am is 45 GBq and the predicted total amount of 239,240Pu is 270 GBq....

  3. Spatiotemporal distribution and composition of mixed stock fishery of Atlantic cod (Gadus morhua) in West Greenlandic waters based on retrospective genetic analysis

    DEFF Research Database (Denmark)

    Bonanomi, Sara; Therkildsen, Nina Overgaard; Hedeholm, Rasmus Berg;

    Historical samples of fish are a unique source of DNA to investigate the temporal dynamics of fish population structure and distribution over time. During the last century Atlantic cod (Gadus morhua) stocks have declined dramatically in Greenlandic Waters. Recent genetic investigations have...... in the contribution from the different spawning groups in population mixtures of cod in West Greenland Waters in response to climate variability and fisheries. Performing genetic assignment test, we found stable genetic composition of feeding aggregations over decades in some areas, whereas shifts in composition were...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  5. The Holocene sedimentary history of the Kangerlussuaq Fjord-valley fill, West Greenland

    DEFF Research Database (Denmark)

    Storms, Joep E.A.; de Winter, Ilja L.; Overeem, Irina;

    2012-01-01

    depositional phases. Phase I (>7000 yr BP) is represented by dominant glaciomarine deposition associated with a tide-water glacier system. As the Greenland Ice Sheet (GIS) continued to retreat it became land based. During phase II (7000-1500 yr BP) two separate depocenters formed. Keglen delta depocenter arose...... were formed at the delta front by hyperpycnal flows associated with jökulhlaup events. © 2012 Elsevier Ltd....

  6. Contaminants in the atmosphere. AMAP-Nuuk, West Greenland 2002-2004

    Energy Technology Data Exchange (ETDEWEB)

    Skov, H.; Bossi, S.; Waehlin, P. [and others

    2005-08-15

    This report presents the results of atmospheric monitoring in Nuuk, Greenland. A long series of heavy metals and persistent organic Pollutants (POPs) have been measured and model calculations have been carried out supporting the interpretation of the results. Financially, the Danish Environmental Protection Agency supported this work with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region and the work is part of the Danish contribution to Arctic Monitoring and Assessment Programme, AMAP. (au)

  7. Abrupt climate change in West Antarctica and Greenland during the last deglacial warming

    Science.gov (United States)

    Fudge, T. J.; Steig, E. J.; Brook, E.; Buizert, C.; Conway, H.; Ding, Q.; Markle, B. R.; McConnell, J. R.; Pedro, J. B.; Schoenemann, S. W.; Severinghaus, J. P.; Sigl, M.; Sowers, T. A.; Taylor, K.; Waddington, E. D.

    2013-12-01

    The WAIS Divide ice core is the first Southern Hemisphere record with precision similar to ice cores from Greenland. The annually resolved timescale and small gas-age ice-age difference allow the phasing of climate change in the two hemispheres to be compared with unprecedented precision. We focus on the three abrupt climate changes in Greenland during the deglacial transition and the corresponding changes at WAIS Divide. The onset of the Antarctic Cold Reversal (ACR) is clearly defined in the WAIS Divide record and lagged the Bolling-Allerod (BA) warming by 150×50 years. The phasing of the other two abrupt climate changes cannot be distinguished from synchronous with an uncertainty of ~200 years because the transitions from warming to cooling (or cooling to warming) are not distinct in the WAIS Divide record. The lead-lag relationships of no more than a couple centuries confirm the tight coupling between hemispheres during the deglaciation. The independent timescale of WAIS Divide confirms that meltwater Pulse 1a began near-coincident with the BA and ACR although the lack of direct synchronization between the annually dated ice-core imescales and the radiometrically dated coral timescale prevents the phasing from being known to better than a couple of centuries. A new observation from WAIS Divide is that accumulation increased ~40% between 12.0 and 11.6 ka, with the accumulation increase ending approximately coincident with the warming at the end of the Younger Dryas in Greenland. Other Antarctic ice cores lack timescales with sufficient resolution to identify such abrupt changes so it is unclear how much of Antarctica was affected by the increased accumulation rates. The inter-hemispheric relationships are often limited to a discussion of warming, but the WAIS Divide records suggests that the moisture transport may be another important constraint on the mechanisms that drive abrupt climate change.

  8. Structure and annual increase in a population of West Greenland caribou (Rangifer tarandus groenlandicus

    Directory of Open Access Journals (Sweden)

    Henning Thing

    1982-05-01

    Full Text Available During 1977-80 a large scale research program was carried out in West Greenland to study caribou ecology and population dynamics. Papers dealing with feeding ecology, range condition, calf mortality, and behaviour have been published elsewhere (Strandgaard 1980; Holt 1980; Clausen et al. 1980; Thing & Clausen 1980; Thing 1980; Roby 1980; Thing 1981; Roby & Thing 1982; Thing & Thing 1982. The present study deals with some dynamic parameters in the Sisimiut herd (Fig. 1, viz. group size, sex and age composition, calf/cow ratio, calf increment, and annual recruitment. Caribou in the Sisimiut region are mainly found in very small groups of one to five animals in most seasons. Aggregations of more than 50 animals are rarely seen except in the calving and summer seasons (Fig. 2. A distinct annual cycle is apparent in the mean group size with a steady increase from a mid winter minimum of 1.4 caribou/group towards a maximum of almost 25 caribou/group in the post-calving season (Fig. 3. The absence of important predators (especially wolves and the fact that winter food resources in the region have been depleted seem to reduce group size. Consequently, Sisimiut caribou are characterized year round by forming very small groups as compared to most other wild Rangifer populations. Caribou cows (females 2 years + make up approx. 50% of the herd, while bulls (males 2 years + average only 10% (Fig. 4. The number of bulls in the herd shows a significant decline caused by a selective hunting pressure as well as natural winter mortality (Fig. 5. The rut takes place in October during the fall migration from the inland ranges adjacent to the Inland Ice towards the coast line. The cows are apparently served mainly by 1 1/2 and 2 year old bulls. Despite scarcity of adequate food on the winter ranges there is a high calf production. This is probably explained by excellent forage conditions on the inland range prior to and during the calving season (May - June

  9. Coeval dust accumulation minima in Greenland and East Central Europe over 31-23 ka

    Science.gov (United States)

    Újvári, Gábor; Stevens, Thomas; Varga, György; Kovács, János; Molnár, Mihály

    2016-04-01

    As reflected in δ18O values in ice cores, the North Atlantic area experienced a series of abrupt, dramatic climatic fluctuations over the last glacial during which oceanic and atmospheric conditions alternated between full glacial (stadial) and relatively mild (interstadial) conditions [1,2]. Beyond the δ18O profiles, calcium ion concentration data (hereafter [Ca2+]) also exhibit particularly clear stadial/interstadial contrasts [3]. The Ca2+/dust concentration records are considered as a proxy for the amount of terrestrial dust reaching the ice sheet [4] and/or changing dust storm activity in the source areas around the Northern Hemisphere, mainly in East Asia [5,6]. The mode of the dust size distributions is thought to reflect transit times during transport, with larger modes indicating shorter transit times and transport routes, i.e. changed atmospheric circulation patterns [5]. However, based on clay mineralogy and Sr-Nd isotopic compositions of loess sediments Újvári, et al. [7] suggested that Central European dust cannot be excluded as a potential source of Greenland dust. As such, it is vital to analyze dust deposition in the key dust depocentres of Eastern Europe. As a record of Carpathian Basin dust source activity, we therefore studied loess sedimentation and grain size changes in the Dunaszekcsö loess sequence in Southern Hungary. For this record, we developed the highest resolution geochronological dataset for European loess based on 61 AMS 14C dates from molluscs and charcoal fragments. This allowed us to establish a uniquely high precision Bayesian age-depth model, with the mean 95% confidence ranges that vary between 119 and 798 yr. Sedimentation rates (SR) calculated from the age-depth model vary between 0.36-1.7 mm yr-1 and the estimated bulk dust mass accumulation rates (MAR) range from 551 to 2525 g m-2 yr-1. Both the SR and MAR display millennial/sub-millennial scale variations, visible uniquely due to the high precision dating, together

  10. Inuit health in Greenland

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  11. Nuuk, Greenland

    Science.gov (United States)

    2008-01-01

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

  12. The intertidal community in West Greenland: Large-scale patterns and small-scale variation on ecosystem dynamics along a climate gradient

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Blicher, Martin; Sejr, Mikael Kristian

    are largely unknown. The West Greenland coast is north - south orientated. This provides an ideal setting to study the impact of climate change on marine species population dynamics and distribution. We investigated the latitudinal changes in the rocky intertidal community along 18° latitudes (59-77°N......) in West Greenland. Using cleared quadrats we quantified patterns in abundance, biomass and species richness in the intertidal zone. We use this data to disentangle patterns in Arctic intertidal communities at different scales. We describe the effects of different environmental drivers and species...... interactions on distribution and dynamics of intertidal species. Our results indicate that changes in distribution and abundance of foundation species can have large effects on the ecosystem. We also show that the importance of small-scale variation may be of same magnitude as large- scale variation. Only...

  13. Changing surface-atmosphere energy exchange and refreezing capacity of the lower accumulation area, West Greenland

    DEFF Research Database (Denmark)

    Charalampidis, C.; Van As, D.; Box, J. E.;

    2015-01-01

    energy fluxes. The model reproduces the observed melt rates as well as the SMB for each season. A sensitivity analysis reveals that 71 % of the additional solar radiation in 2012 was used for melt, corresponding to 36 % (0.64 m) of the 2012 surface lowering. The remaining 64 % (1.14 m) of surface......We present 5 years (2009-2013) of automatic weather station measurements from the lower accumulation area (1840 m a.s.l.-above sea level) of the Greenland ice sheet in the Kangerlussuaq region. Here, the summers of 2010 and 2012 were both exceptionally warm, but only 2012 resulted in a strongly.......78), as meltwater was present at the ice sheet surface. Consequently, during the 2012 melt season, the ice sheet surface absorbed 28 % (213 MJ m-2) more solar radiation than the average of all other years. A surface energy balance model is used to evaluate the seasonal and interannual variability of all surface...

  14. Seasonal and interannual phytoplankton production in a sub-arctic tidewater outlet glacier fjord, west Greenland

    DEFF Research Database (Denmark)

    Juul-Pedersen, T.; Arendt, K.; Mortensen, J.;

    2015-01-01

    and hydrographic conditions during a 7 yr period. Total annual primary production during 2005 to 2012 was between 84.6 and 139.1 g C m−2 yr−1. Two phytoplankton blooms of similar magnitude reoccur in the fjord every year. A ‘classical’ spring bloom of up to 1743 mg C m−2 d−1 occurred in late April/early May...... in a water column almost fully mixed due to tidal forces at the fjord sill. After the spring bloom, primary production decreased in June, after which a summer bloom of up to 1383 mg C m−2 d−1 built up. This bloom coincided with the development of a pycnocline caused by substantial runoff from the Greenland...

  15. Atmospheric concentrations of organochlorine pesticides, polybrominated diphenyl ethers and polychloronaphthalenes in Nuuk, South-West Greenland

    DEFF Research Database (Denmark)

    Bossi, Rossana; Skov, Henrik; Vorkamp, Katrin;

    2008-01-01

    Atmospheric concentrations of organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDEs) and polychloronaphthalenes (PCNs) were measured for the first time in Nuuk, Greenland in 2004 and 2005. The annual mean concentrations af the measured OCs were: α-HCH 20.2 pg m-3, Υ-HCH (lindane) 5...... variation of PBDE concentrations was observed with maximum concentrations occurring in the summer months. The ∑PCNs concentrations ranged between 0.062 and 0.258 pg m-3 with an annual mean concentration of 0.161 ± 0.0004 pg m-3. The PCNs profile was dominated by the tetra-PCNs(74% of the annual mean......) and the penta-PCNs (18% of the annual mean). A seasonal trend for ∑PCNs was not observed. Atmospheric concentrations of the investigated compounds were correlated with temperature and anthropogenic CO in order to obtain information about their transport pattern. Positive correlations were found between CO...

  16. Rerouting of subglacial water flow between neighboring glaciers in West Greenland

    Science.gov (United States)

    Chu, Winnie; Creyts, Timothy T.; Bell, Robin E.

    2016-05-01

    Investigations of the Greenland ice sheet's subglacial hydrological system show that the connectivity of different regions of the system influences how the glacier velocity responds to variations in surface melting. Here we examine whether subglacial water flow paths can be rerouted beneath three outlet glaciers in the ablation zone of western Greenland. We use Lamont-Doherty and Center for Remote Sensing of Ice Sheets of University of Kansas (CReSIS) ice-penetrating radar data to create a new ice thickness map. We then use a simple subglacial water flow model to examine whether flow paths can be rerouted and identify the topographic conditions that are sensitive to subglacial rerouting. By varying water pressures within an observationally constrained range, we show that moderate changes in pressure can cause flow paths to reroute and exchange water from one subglacial catchment to another. Flow across subglacial overdeepenings is particularly sensitive to rerouting. These areas have low hydraulic gradients driving flow, so subtle water pressure variations have a strong influence on water flow direction. Based on correlations between water flow paths and ice velocity changes, we infer that water piracy between neighboring catchments can result in a different spatial pattern of hydrologically induced ice velocity speedup depending on the amount and timing of surface melt. The potential for subglacial water to reroute across different catchments suggests that multiple hydrographs from neighboring glaciers are likely necessary to accurately ascertain melt budgets from proglacial point measurements. The relationship between surface runoff, ice dynamics, and proglacial discharge can be altered by rerouting of subglacial water flow within and across outlet glaciers.

  17. Tidewater Dynamics at Store Glacier, West Greenland from Daily Repeat UAV Survey

    Science.gov (United States)

    Hubbard, A., II; Ryan, J.; Toberg, N.; Todd, J.; Christoffersen, P.; Snooke, N.; Box, J. E.

    2015-12-01

    A significant component of the Greenland ice sheet's mass wasteage to sea level rise is attributed to the acceleration and dynamic thinning at its tidewater margins. To improve understanding of the rapid mass loss processes occurring at large tidewater glaciers, we conducted a suite of daily repeat aerial surveys across the terminus of Store Glacier, a large outlet draining the western Greenland Ice Sheet, from May to July 2014 (https://www.youtube.com/watch?v=-y8kauAVAfE). A suite flock of Unmanned Aerial Vehicles (UAVs) were equipped with digital cameras, which, in combination with onboard GPS, enabled production of high spatial resolution orthophotos and digital elevation models (DEMs) using standard structure-from-motion techniques. These data provide insight into the short-term dynamics of Store Glacier surrounding the break-up of the sea-ice mélange that occurred between 4 and 7 June. Feature tracking of the orthophotos reveals that mean speed of the terminus is 16 - 18 md-1, which was independently verified against a high temporal resolution time-series derived from an expendable/telemetric GPS deployed at the terminus. Differencing the surface area of successive orthophotos enable quantification of daily calving rates, which significantly increase just after melange break-up. Likewise, by differencing bulk freeboard volume of icebergs through time we could also constrain the magnitude and variation of submarine melt. We calculate a mean submarine melt rate of 0.18 md-1 throughout the spring period with relatively little supraglacial runoff and no active meltwater plumes to stimulate fjord circulation and upwelling of deeper, warmer water masses. Finally, we relate calving rates to the zonation and depth of water-filled crevasses, which were prominent across parts of the terminus from June onwards.

  18. Modelling the dynamic response of Jakobshavn Isbræ, West Greenland, to calving rate perturbations

    Directory of Open Access Journals (Sweden)

    J. H. Bondzio

    2015-10-01

    Full Text Available Calving is a major means of ice discharge of the Antarctic and Greenland Ice Sheets. The breaking off of icebergs changes the ice front configuration of marine terminating glaciers, which affects the stress regime of their upstream areas. Recent observations show the close correlation between the ice front position and the behaviour of many outlet glaciers. However, modelling of a glacier subject to calving poses various challenges. No universal calving rate parametrisation is known, and tracking of a moving ice front and the related boundary conditions in two or three spatial dimensions is non-trivial. Here, we present the theoretical and technical framework for a Level-Set Method, an implicit boundary tracking scheme, which we implemented into the Ice Sheet System Model (ISSM. The scheme allows us to study the dynamic response of a drainage basin to user-defined front ablation rates. We apply the method in a suite of experiments to Jakobshavn Isbræ, a major marine terminating outlet glacier of the western Greenland Ice Sheet. The model robustly reproduces the high sensitivity of the glacier to frontal ablation in form of calving. We find that enhanced calving is able to trigger significant acceleration of the ice stream. Upstream acceleration is sustained through a combination of various feedback mechanisms. However, lateral stress and ice influx into the trough are able to stabilise the ice stream. This study contributes to the present discussion on causes and effects of the continued changes occurring at Jakobshavn Isbræ, and emphasises that the incorporation of seasonal calving and dynamic lateral effects is key for realistic model projections of future global sea level rise on centennial time scales.

  19. Climatic factors influencing triatomine occurrence in Central-West Brazil

    OpenAIRE

    Joyce Mendes Pereira; Paulo Silva de Almeida; Adair Vieira de Sousa; Aécio Moraes de Paula; Ricardo Bomfim Machado; Rodrigo Gurgel-Gonçalves

    2013-01-01

    We estimated the geographic distributions of triatomine species in Central-West Region of Brazil (CW) and analysed the climatic factors influencing their occurrence. A total of 3,396 records of 27 triatomine species were analysed. Using the maximum entropy method, ecological niche models were produced for eight species occurring in at least 20 municipalities based on 13 climatic variables and elevation. Triatoma sordida and Rhodnius neglectus were the species with the broadest geographic dist...

  20. CWRD: ICT in Education: Central and West Asia Executive

    OpenAIRE

    Asian Development Bank (ADB)

    2012-01-01

    This publication presents and analyzes the major conclusions of research conducted in Central and West Asia in 2006 through 2011 to ascertain the impact of information and communications technology (ICT) investments on education. It presents a critical overview of the effectiveness of ICT policies and strategies in basic education in Azerbaijan, Kazakhstan, the Kyrgyz Republic, Tajikistan, and Uzbekistan, with shorter studies on Afghanistan, Armenia, Georgia, and Pakistan. Among its many impo...

  1. 40 CFR 81.96 - West Central Florida Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false West Central Florida Intrastate Air... Air Quality Control Regions § 81.96 West Central Florida Intrastate Air Quality Control Region. The West Central Florida Intrastate Air Quality Control Region consists of the territorial area...

  2. Present conditions in Greenland and the Kangerlussuaq area

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-15

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

  3. Present conditions in Greenland and the Kangerlussuaq area

    International Nuclear Information System (INIS)

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

  4. Environmental Oil Spill Sensitivity Atlas for the West Greenland (68º-72º N) Coastal Zone

    DEFF Research Database (Denmark)

    Mosbech, A.; Boertmann, D.; Olsen, B. Ø.;

    This oil spill sensitivity atlas covers the shoreline and the offshore areas of West Greenlandbetween 68º N and 72º N. The coastal zone is divided into nearly 200 areas and the offshorezone into 8 areas. A sensitivity index value is calculated for each area, and each area issubsequently ranked ac...

  5. Modeling of ocean-induced ice melt rates of five west Greenland glaciers over the past two decades

    Science.gov (United States)

    Rignot, E.; Xu, Y.; Menemenlis, D.; Mouginot, J.; Scheuchl, B.; Li, X.; Morlighem, M.; Seroussi, H.; den Broeke, M. van; Fenty, I.; Cai, C.; An, L.; Fleurian, B. de

    2016-06-01

    High-resolution, three-dimensional simulations from the Massachusetts Institute of Technology general circulation model ocean model are used to calculate the subaqueous melt rate of the calving faces of Umiamako, Rinks, Kangerdlugssup, Store, and Kangilerngata glaciers, west Greenland, from 1992 to 2015. Model forcing is from monthly reconstructions of ocean state and ice sheet runoff. Results are analyzed in combination with observations of bathymetry, bed elevation, ice front retreat, and glacier speed. We calculate that subaqueous melt rates are 2-3 times larger in summer compared to winter and doubled in magnitude since the 1990s due to enhanced subglacial runoff and 1.6 ± 0.3°C warmer ocean temperature. Umiamako and Kangilerngata retreated rapidly in the 2000s when subaqueous melt rates exceeded the calving rates and ice front retreated to deeper bed elevation. In contrast, Store, Kangerdlugssup, and Rinks have remained stable because their subaqueous melt rates are 3-4 times lower than their calving rates, i.e., the glaciers are dominated by calving processes.

  6. Mesozooplankton biomass data from the Kapisigdlit an inner fjord branch of the Godthaabsfjord system, West Greenland, 2010

    DEFF Research Database (Denmark)

    2013-01-01

    branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh......Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute...... for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord...

  7. Multi-year elevation changes near the west margin of the Greenland ice sheet from satellite radar altimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lingle, C.S.; Brenner, A.C.; Zwally, H.J.; DiMarzio, J.P.

    1992-03-01

    Mean changes in the surface elevation near the west margin of the Greenland ice sheet are measured using Seasat altimetry and altimetry from the Geosat Exact Repeat Mission (ERM). The Seasat data extend from early July through early October 1978. The ERM data extend from winter 1986-87 through fall 1988. Both seasonal and multi-year changes are measured using altimetry referenced to GEM T2 orbits. The possible effects of orbit error are minimized by adjusting the orbits into a common ocean surface. Seasonal mean changes in the surface height are recognizable during the Geosat ERM. The multi-year measurements indicate the surface was lower by 0.4 +/- 0.4 m on average in late summer 1987 than in late summer 1978. The surface was lower by 0.2 +/- 0.5 m on average in late summer 1988 than in late summer 1978. As a control case, the computations are also carried out using altimetry referenced to orbits not adjusted into a common ocean surface.

  8. Multi-Year Elevation Changes Near the West Margin of the Greenland Ice Sheet from Satellite Radar Altimetry

    Science.gov (United States)

    Lingle, Craig S.; Brenner, Anita C.; Zwally, H. Jay; DiMarzio, John P.

    1991-01-01

    Mean changes in the surface elevation near the west margin of the Greenland ice sheet are measured using Seasat altimetry and altimetry from the Geosat Exact Repeat Mission (ERM). The Seasat data extend from early July through early October 1978. The ERM data extend from winter 1986-87 through fall 1988. Both seasonal and multi-year changes are measured using altimetry referenced to GEM T2 orbits. The possible effects of orbit error are minimized by adjusting the orbits into a common ocean surface. Seasonal mean changes in the surface height are recognizable during the Geosat ERM. The multi-year measurements indicate the surface was lower by 0.4 +/- 0.4 m on average in late summer 1987 than in late summer 1978. The surface was lower by 0.2 +/- 0.5 m on average in late summer 1988 than in late summer 1978. As a control case, the computations art also carried out using altimetry referenced to orbits not adjusted into a common ocean surface.

  9. Environmental oil spill sensitivity atlas for the West Greenland (68 deg.-72 deg. N) coastal zone, 2nd revised edition

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, D.; Johansen, Kasper L.; Mosbech, A.; Boertmann, D.; Wegeberg, S.

    2012-12-15

    This oil spill sensitivity atlas covers the shoreline and the offshore areas of West Greenland between 68 deg. N and 72 deg. N. The coastal zone is divided into 199 shoreline segments and the offshore zone into 8 areas. A sensitivity index value is calculated for each segment/area, and each segment/area is subsequently ranked according to four degrees of sensitivity. Besides this general ranking a number of smaller areas are especially selected as they are of particular significance, they are especially vulnerable to oil spills and they have a size making oil spill response possible. The shoreline sensitivity ranking are shown on 37 maps (in scale 1:250,000), which also show the different elements included and the selected areas. Coast types, logistics and proposed response methods along the coasts are shown on another 37 maps. The sensitivities of the offshore zones are depicted on 4 maps, one for each season. Based on all the information, appropriate oil spill response methods have been assessed for each area. (Author)

  10. Mineral nutrition and alimentary pools in muskoxen and caribou on the Angujaartorfiup Nunaa range in West Greenland

    Directory of Open Access Journals (Sweden)

    Hans Staaland

    1999-04-01

    Full Text Available Minerals (Na, K, Cl, Ca, P, Mg and crude protein concentrations as well as total contents were measured throughout the alimentary tract of muskoxen and caribou from Angujaatorfiup Nunaa range, Søndre Strømfjord area in West Greenland. The muskoxen had significantly higher K concentrations in the caecum and proximal colon than the caribou. Caribou collected during the summer season had the highest Mg concentrations throughout the alimentary tract. In both species water, Na, K and CI concentrations decreased through the distal part of the alimentary system whereas Ca, Mg, P and crude protein concentrations increased. The muskoxen had relatively larger mineral pools and total content in the omasum than the caribou, and the caribou relatively larger mineral pools (except K and CI and total content in the caecum. Higher concentrations of Mg in the alimentary tract of the caribou than the muskoxen during the summer could also indicate that the caribou feed more on herbs with high concentrations of Mg. The data does also indicate that both the caribou and the muskoxen are living in an area where high intakes of minerals from both vegetation and mineral licks are possible. Based on the present study the muskoxen is apparently a typical grazer whereas the caribou is more like a concentrate selector.

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

    Science.gov (United States)

    Pope, A.; Scambos, T. A.; Moussavi, M.; Tedesco, M.; Willis, M.; Shean, D.; Grigsby, S.

    2016-01-01

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

  12. Local and synoptic controls on rapid supraglacial lake drainage in West Greenland

    Science.gov (United States)

    Williamson, Andrew; Banwell, Alison; Arnold, Neil; Willis, Ian

    2016-04-01

    Many supraglacial lakes within the ablation zone of the Greenland Ice Sheet (GrIS) are known to drain rapidly (in scale factors, such as ice thickness, driving stresses, ice velocities and strain rates. A combination of the local water-volume threshold and one or more synoptic-scale factors may explain the overall patterns of rapid lake drainage, but this requires verification using targeted field- and remotely-based studies that cover large areas of the GrIS and span long timescales. Here, we investigate a range of potential controls on rapid supraglacial lake drainage in the land-terminating Paakitsoq region of the ice sheet, northeast of Jakobshavn Isbræ, for the 2014 melt season. We have analysed daily 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in order to calculate lake areas, depths and volumes, and have developed an automatic lake-tracking algorithm to determine the dates on which all rapid lake drainage events occur. For each rapidly draining lake, the water volumes immediately prior to drainage are compared with other local factors, notably lake-filling rate and ice thickness, and with a variety of synoptic-scale features, such as slope angles, driving stresses, surface velocities, surface strain rates and the incidence of nearby lake-drainage events. We present the outcomes of our statistical analysis to elicit the statistically significant controls on hydrofracture beneath supraglacial lakes.

  13. The mantle transition zone and the upper mantle in Central-Eastern Greenland

    Science.gov (United States)

    Anja Kraft, Helene; Thybo, Hans; Vinnik, Lev

    2016-04-01

    We present a receiver function (RF) study of the mantle transition zone (MTZ) and upper mantle in central-eastern Greenland. Our results are based on data from 18 temporary broad-band seismometers and 5 additional stations from the GLISN and GLATIS networks. The stations were operating in the region between Scoresby Sund and Summit (~ 70 ° N) with half of them installed on ice, the other half on bedrock. For our analysis we calculated low frequency PRF and SRF, which use the difference in travel times between converted and not converted phases at discontinuities. We see clear signals from P410s and P660s in most of our PRF and from S410p in the SRF. Their delay times suggest a surprisingly thin MTZ for most parts of the study area with up to 25 km of thinning compared to standard Earth models. The only exception is a small region in the centre of the study area, which shows times close to standard. It is mainly the delay time for P410s, that varies, while P660s is stable throughout our study area. This indicates, that the thinning of the MTZ is mainly due to topography on the 410-discontinuity. We furthermore observe an M-shaped signal for P410s at stations in the western part around Summit. A similar, complicated signal has been observed previously in different settings and is interpreted as a thin low velocity layer between 410 km and 520 km. In addition we jointly inverted the PRF and SRF for upper mantle velocities. These results show velocities slower than IASP91 for the entire study area. Both the low velocities in the upper mantle and the thinning of the MTZ are in contrary to simple models of old continental shields and might indicate a fairly recent heating event.

  14. Difference flow measurements under permafrost conditions in the Kangerlussuaq area, West Greenland

    Science.gov (United States)

    Lehtinen, A. M.; Rouhiainen, P.; Pöllänen, J.; Heikkinen, P.; Ruskeeniemi, T.; Claesson Liljedahl, L.

    2012-12-01

    To advance the understanding of the impact of glacial processes on the long-term performance of a deep geologic repository, the Greenland Analogue Project (GAP), a four-year field and modeling study of the Greenland ice sheet (2009-2012), was established collaboratively by the Swedish, Finnish and Canadian nuclear waste management organizations (SKB, POSIVA and NWMO, respectively). In order to study how groundwater flow and water chemistry is influenced by an existing ice sheet and continuous permafrost, a 645 m deep drillhole (DH-GAP04) was drilled, hydraulically tested using the Posiva Difference Flowmeter (PFL DIFF) method and instrumented at the ice margin in the Kangerlussuaq area in July 2011. PFL DIFF allows the quick and reliable characterization of flow-yielding fractures in bedrock. PFL DIFF measures the flow rate into or out of defined drillhole sections. The advantage that follows from measuring the flow rate in isolated sections is improved detection of incremental changes of flow along the drillhole. PFL DIFF can measure flows in the range 30 - 300 000 mLh-1. In addition, the PFL DIFF probe can be used to measure the electrical conductivity of both the drillhole water and fracture-specific water, the single point resistance (SPR) of the bedrock, the water pressure profile in a drillhole and the temperature of the drillhole water. Normally, PFL DIFF measurements in a new drillhole are conducted a week after the end of drilling in order to let the groundwater state recover in the drillhole. The PFL DIFF measurements were done in DH-GAP04 already three days after the drilling was completed. This measurement was the first PFL DIFF measurement ever conducted in an area of continuous permafrost and therefore, the measurement program was carefully designed. The length of the section in the flow logging measurements was 10 m and the interval spacing was two meters. Flow into the drillhole or from the drillhole into the bedrock was measured within the section

  15. Siderophile and chalcophile metal variations in Tertiary picrites and basalts from West Greenland with implications for the sulphide saturation history of continental flood basalt magmas

    Science.gov (United States)

    Keays, Reid R.; Lightfoot, Peter C.

    2007-04-01

    Sixty-five million year old continental flood basalts crop out on Qeqertarssuaq Island and the Nuussuaq Peninsula in West Greenland, and they include ˜1,000 m of picritic lavas and discrete 10- to 50-m-thick members of highly contaminated basalts. On Qeqertarssuaq, the lavas are allocated to the Vaîgat and Maligât Formations of which the former includes the Naujánguit member, which consists of picrites with 7-29 wt% MgO, 80-1,400 ppm Ni, 5.7-9.4 ppb Pt and 4.2-12.9 ppb Pd. The Naujánguit member contains two horizons of contaminated basalts, the Asûk and Kûgánguaq, which have elevated SiO2 (52-58 wt%) and low to moderate MgO (7.5-12.8 wt%). These lavas are broadly characterized by low Cu and Ni abundances (average, 40 ppm Ni and 45 ppm Cu) and very low Pt (0.16-0.63 ppb) and Pd (0.13-0.68 ppb) abundances, and in the case of the Asûk, they contain shale xenoliths and droplets of native iron and troilite. The contaminated basalts from Nuussuaq, the B0 to B4 members, are also usually Ni-, Cu-, and platinum-group elements (PGE)-depleted. The geochemical signatures (especially the ratios of incompatible trace elements such as Th/Nb) of all of the contaminated basalts from Qeqertarssuaq and some of those from Nuussuaq record what appears to be a chemical contribution from deltaic shales that lie immediately below the lavas. This suggests that the contamination of the magmas occurred during the migration of the magmas through plumbing systems developed in sedimentary rocks, and hence, at a high crustal level. Nickel, Cu, and PGE depletion together with geochemical signatures produced by crustal contamination are also a feature of Siberian Trap basalts from the Noril’sk region. These basalts belong to the 0- to 500-m thick, ˜5,000- to 10,000-km3 Nadezhdinsky Formation, which is centered in the Noril’sk Region. A major difference between Siberia and West Greenland is that PGE depletion in the Nadezhdinsky Formation samples with the lowest Cu and Ni contents is

  16. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  17. Overlap in diet and distribution of two goose species suggests potential for competition at a common moulting area in West Greenland

    DEFF Research Database (Denmark)

    Raundrup, Katrine; Levermann, Nette; Poulsen, Michael

    2012-01-01

    decreased over the last 15-20 years, while the Canada Goose, a species new to the area, has increased. This study explores the overlap in diet and space use of these species in Mudderbugten and Kvandalen, together with factors that could influence the degree of competition between the two species. Data......Inter-specific competition can occur where two or more species overlap in diet and/or spatial distribution. Such interactions might be most prevalent where a species invades areas previously occupied by another species. In West Greenland, the number of native Greenland White-fronted Geese has...... on activity budgets and spatial distribution were obtained from observations of behaviour, and diet selection was determined through analyses of plant epidermal fragments in faecal samples that were subsequently genotyped to goose species. No differences in diet or spatial distribution of the two species were...

  18. Tidal propagation off the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    in the Indian Ocean, Journal of Earth System Sciences, 116(3)(2007) 261-274. 12 Admiralty Tide Tables, (Published by the Hydrographer of the Navy, U.K.) 1996, Vol. 2. 13 Clarke, A.J. & Battisti, D.S., The effect of continental shelves on tides, Deep Sea... Journal of Geo-Marine Sciences Vol. 39(4), December 2010, pp. 485-488 Tidal propagation off the central west coast of India A S Unnikrishnan National Institute of Oceanography, Dona Paula, Goa 403004, India [E-mail: unni@nio.org] Received...

  19. Atmospheric concentrations of organochlorine pesticides, polybrominated diphenyl ethers and polychloronaphthalenes in Nuuk, South-West Greenland

    Science.gov (United States)

    Bossi, Rossana; Skov, Henrik; Vorkamp, Katrin; Christensen, Jesper; Rastogi, Suresh C.; Egeløv, Axel; Petersen, Dorthe

    Atmospheric concentrations of organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDEs) and polychloronaphthalenes (PCNs) were measured for the first time in Nuuk, Greenland in 2004 and 2005. The annual mean concentrations of the measured OCs were: α-HCH 20.2 pg m -3, γ-HCH (lindane) 5.1 pg m -3, endosulfan 4.8 pg m -3 and dieldrin 1.9 pg m -3. Concentrations of Σ-chlordanes, DDEs and heptachlor epoxide were generally similar and lower than those of α-HCH and γ-HCH. The concentrations of most chlorinated pesticides did not show any clear seasonal variation, with the exception of γ-HCH, which had maximum concentration in August in both years. The average annual mean for ΣPBDEs was 1.14 ± 0.81 pg m -3. The predominant congeners measured in Nuuk were BDE-47 and BDE-99 followed by BDE-100, -153 and -28, indicating the use of penta-BDE technical products as the main source. A clear seasonal variation of PBDE concentrations was observed with maximum concentrations occurring in the summer months. The ΣPCNs concentrations ranged between 0.062 and 0.258 pg m -3 with an annual mean concentration of 0.161 ± 0.004 pg m -3. The PCNs profile was dominated by the tetra-PCNs (74% of the annual mean) and the penta-PCNs (18% of the annual mean). A seasonal trend for ΣPCNs was not observed. Atmospheric concentrations of the investigated compounds were correlated with temperature and anthropogenic CO in order to obtain information about their transport pattern. Positive correlations were found between CO and chlordanes, p, p'-DDE and trifluralin, while a negative correlation was found for γ-HCH. A significant correlation with temperature variations was found for dieldrin, heptachlor epoxide, α-HCH, γ-HCH, BDE-47, BDE-99 and tetra-PCNs, which indicates that re-emission of these compounds from previously contaminated surfaces as an important factor for the observed variations in concentrations.

  20. 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

    records, dust concentrations do not affect the MS- concentrations in the ice, whereas the deposition of sulfate probably is enhanced by high dust concentrations in the atmosphere. The MS- signal has a higher potential of being a proxy record of DMS production changes in Greenlandic compared to Antarctic...

  1. 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.

  2. 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.

    Science.gov (United States)

    Aubail, Aurore; Dietz, Rune; Rigét, Frank; Simon-Bouhet, Benoît; Caurant, Florence

    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 ((13)C/(12)C) and nitrogen ((15)N/(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(15)N values were found to support the hypothesis of a diet shift over time. Furthermore, a decreasing temporal trend in delta(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.

  3. The plankton community on Sukkertop and Fylla Banks off West Greenland during a spring bloom and post-bloom period: Hydrography, phytoplankton and protozooplankton

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Reuss, N.

    2002-01-01

    The plankton community structure was investigated on Sukkertop and Fylla Banks off West Greenland during the spring bloom in May 2000 and the post-bloom period in June 1999. In May a small change in density, clearly illustrated by the profile of potential energy, was sufficient to support a spring...... bloom in the upper part of the water column. The spring bloom phytoplankton community displayed high biomass (92 +/- 45 mg C m(-3)) dominated by species of the genera Thalassiosira and Chaetoceros. The phytoplankton species composition, ongoing sedimentation and nutrient depletion indicated late spring...

  4. Growth, condition, and mortality of caribou (Rangifer tarandus groenlandicus in the Sisimiut Population, West Greenland

    Directory of Open Access Journals (Sweden)

    Vidar Holthe

    1984-05-01

    Full Text Available Growth and condition of the Sisimiut caribou was anlysed by means of mandible length, carcass weight, and back fat indices. Mandible lenght showed unchanged growth conditions since the late 1960s, and growth stops at 4 years of age. The Sisimiut caribou seems to be smaller than North American caribous, Greenlandic semi-domesticated reindeer and of same size or smaller than Scandinavian reindeer. Carcass weight showed similar results, however cow growth rate seems not to prolong sexual maturation. Back fat deposits were less than what is known from other reindeer and caribou populations. Sex and age distribution of mandibles from various materials and survival curves based on the same material shows — an uneven distribution between bulls and cows and a relatively large proportion of old cows in the bag from the last years, which seems to be caused by a light hunting pressure when the population peaked in the 1960s. Heavy natural mortality for animals born before or after a winter with unfavorable snow conditions was also showed.Vækst, kondition og dødelighed hos vildren (Rangifer tarandus groenlandicus i Sisimiut-bestanden, Vestgrønland.Abstract in Danish / Sammendrag: Vækst- og konditionsforhold for Sisimiut-vildrenbestanden i Vestgrønland er beskrevet ved hjæip af underkæbelængde, slagtevægt og rygfedt. Undersøgelsen af kæbelængde viste, at vækstforholdene havde været uforandret siden sidste halvdel af 1960-erne, at væksten standser ved 4-års alderen, samt at Sisimiut-vildrenen er mindre end de nordamerikanske caribou, Itinnera-tamrenen og på størrelse med eller mindre end skandinaviske rensdyr. Dette viste sig også ved sammenligninger af slagtevægt. Vægten af simlerne er dog ikke så ringe, at der kan iagttages nogen forsinkelse i kønsmodningen. Fedtreserverne ved indgangen til vinteren synes at være dårligere end i andre undersøgte rensdyrbestande. Køns- og aldersfordelingen blandt forskellige typer af indsamlet k

  5. High geothermal heat flow, Basal melt, and the origin of rapid ice flow in central Greenland.

    Science.gov (United States)

    Fahnestock, M; Abdalati, W; Joughin, I; Brozena, J; Gogineni, P

    2001-12-14

    Age-depth relations from internal layering reveal a large region of rapid basal melting in Greenland. Melt is localized at the onset of rapid ice flow in the large ice stream that drains north off the summit dome and other areas in the northeast quadrant of the ice sheet. Locally, high melt rates indicate geothermal fluxes 15 to 30 times continental background. The southern limit of melt coincides with magnetic anomalies and topography that suggest a volcanic origin. PMID:11743197

  6. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: Structural analysis of the northern Nagssugtoqidian orogen, West Greenland: an example of complex tectonic patterns in reworked high-grade metamorphic terrains

    Directory of Open Access Journals (Sweden)

    Mazur, Stanislaw

    2006-12-01

    Full Text Available Structural analysis of the deeply eroded northern flank of the Palaeoproterozoic Nagssugtoqidian orogen shows marked regional variations in both the orientation and type of fabrics, as is characteristic of Precambrian high-grade terrains subjected to polyphase deformation. Here we investigate the relationship between strain, metamorphic grade, and the resulting structural patterns. The study area south of Aasiaat in West Greenland consists of amphibolite- togranulite-gradeArchaean orthogneisses and relatively thin supracrustal units. The regional foliation displays a WSW–ENE to SW–NE strike associated with steep to moderate dips towards the WNW or SSE. Lineation trends are WSW–ENE and generally plunge gently towards the WSW. Mesoscopic fold hinges are usually colinear with the regional lineation. A systematic change in the plunge of lineations occurs across the south-western part of the study area. Towards the south, the lineation plunge progressively increases, despite the generally uniform strike of foliation. This southward increase of lineation pitch is typically associated with the transition from L > S or L = S shape fabrics in rocks characterised by a low pitch, to S > L or S fabrics in the zone of moderate to high pitch. The structural patterns point to subdivision of the study area into a southern domain mostly characterised by S or S > L shape fabrics and a moderate to high angle of lineation pitch, and a northern domain showing L > S or L = S fabrics and low angles of lineation pitch. This subdivision corresponds well with the map scale boundary between granulite facies rocks in the south and amphibolite facies rocks farther north. The observed structural pattern may be explained by two alternative tectonic models: (1 northward indentation of the previously cooled granulite block into the rheologically weaker amphibolite domain, and (2 strain partitioning within a mid-crustal transpression zone. In model 2 the northern domain

  7. Seasonal and regional variability in dissolved and particulate iron fluxes via glacial runoff along the West Greenland coast

    Science.gov (United States)

    Choquette, K.; Hagedorn, B.; Sletten, R. S.; Harrold, Z.; Liu, L.; Dieser, M.; Cameron, K. A.; Christner, B. C.; Junge, K.

    2012-12-01

    Subglacial weathering, due to biogeochemical and physical weathering processes, can affect the chemical evolution of subglacial waters and release dissolved and particulate iron via glacial runoff. Iron is a growth limiting nutrient and plays a critical role in the biogeochemical cycles of coastal and marine waters. More recently, dissolved and colloidal iron derived from subglacial sources have been considered an important contributor of Fe fluxes to the ocean; however, their dependency on lithology, grain size, and microbial activity is not well understood. This study characterizes the solute chemistry, in particular iron mineralogy and dissolved iron concentrations, released from beneath the Greenland Ice Sheet (GrIS), from two locations along the West Greenland coast, Thule (76°N, 68°W) and Kangerlussuaq (67°N, 50°W). We hypothesize that the subglacial lithology has a control on Fe fluxes from the GrIS to coastal and marine systems. The underlying bedrock in Thule is the Precambrian Dundas and Narssarssuk sedimentary formations which include sandstone, siltstone, and shale. The bedrock in Kangerlussuaq is dominated by Archean granodioritic gneiss and amphibolite within the Nagssugtoqidian Orogen. Supra and subglacial meltwater samples were collected directly in front of the Ice Sheet over an entire melt season in 2011 (North River, Thule) and 2012 (Akuliarusiarsuup Kuua River, Kangerlussuaq). In situ parameters such as temperature, pH, dissolved oxygen, and electrical conductivity were recorded in order to interpret meltwater chemistry. Dissolved Fe(II) and Fe(III) species were fixed immediately and analyzed within 24 hours after sampling in the field laboratory using a spectrophotometer and 10 cm cell. Total dissolved iron (FeT) of different size fractions (<0.22 and <0.05 μm) of iron were determined back in the home laboratory using reaction cell ICP MS. Preliminary results demonstrate that subglacial meltwater of North River has average Fe

  8. Climatic factors influencing triatomine occurrence in Central-West Brazil

    Directory of Open Access Journals (Sweden)

    Joyce Mendes Pereira

    2013-05-01

    Full Text Available We estimated the geographic distributions of triatomine species in Central-West Region of Brazil (CW and analysed the climatic factors influencing their occurrence. A total of 3,396 records of 27 triatomine species were analysed. Using the maximum entropy method, ecological niche models were produced for eight species occurring in at least 20 municipalities based on 13 climatic variables and elevation. Triatoma sordida and Rhodnius neglectus were the species with the broadest geographic distributions in CW Brazil. The Cerrado areas in the state of Goiás were found to be more suitable for the occurrence of synanthropic triatomines than the Amazon forest areas in the northern part of the state of Mato Grosso. The variable that best explains the evaluated models is temperature seasonality. The results indicate that almost the entire region presents climatic conditions that are appropriate for at least one triatomine species. Therefore, it is recommended that entomological surveillance be reinforced in CW Brazil.

  9. Multiresolution quantification of deciduousness in West Central African forests

    Directory of Open Access Journals (Sweden)

    G. Viennois

    2013-04-01

    Full Text Available The characterization of leaf phenology in tropical forests is of major importance and improves our understanding of earth-atmosphere-climate interactions. The availability of satellite optical data with a high temporal resolution has permitted the identification of unexpected phenological cycles, particularly over the Amazon region. A primary issue in these studies is the relationship between the optical reflectance of pixels of 1 km or more in size and ground information of limited spatial extent. In this paper, we demonstrate that optical data with high to very-high spatial resolution can help bridge this scale gap by providing snapshots of the canopy that allow discernment of the leaf-phenological stage of trees and the proportions of leaved crowns within the canopy. We also propose applications for broad-scale forest characterization and mapping in West Central Africa over an area of 141 000 km2. Eleven years of the Moderate Resolution Imaging Spectroradiometer (MODIS Enhanced Vegetation Index (EVI data were averaged over the wet and dry seasons to provide a dataset of optimal radiometric quality at a spatial resolution of 250 m. Sample areas covered at a very-high (GeoEye and high (SPOT-5 spatial resolution were used to identify forest types and to quantify the proportion of leaved trees in the canopy. The dry season EVI was positively correlated with the proportion of leaved trees in the canopy. This relationship allowed the conversion of EVI into canopy deciduousness at the regional level. On this basis, ecologically important forest types could be mapped, including young secondary, open Marantaceae, Gilbertiodendron dewevrei and swamp forests. We show that in west central African forests, a large share of the variability in canopy reflectance, as captured by the EVI, is due to variation in the proportion of leaved trees in the upper canopy, thereby opening new perspectives for biodiversity and carbon-cycle applications.

  10. Past sea-level data from Lakse Bugt, Disko Island, West Greenland from ground-penetrating radar data

    Science.gov (United States)

    Souza, Priscila E.; Nielsen, Lars; Kroon, Aart; Clemmensen, Lars B.

    2016-04-01

    Beach-ridge deposits have been used as sea-level indicators in numerous studies from temperate coastal regions. However, their present surface morphology in artic regions may not accurately correspond to past sea-level, because subsequent surface erosion, solifluction processes and/or later sediment deposition may have altered the surface significantly. The internal structure of these beach ridges, however, is often well-preserved and thus constitutes an important key to reconstruction of past sea levels as seen elsewhere. In the present study, high-resolution reflection GPR data and high-precision topographic data were collected at Lakse Bugt (Disko Island, West Greenland) using a shielded 250 MHz antennae system and a RTK-Trimble R8 DGPS, respectively. Three transects were collected across a sequence of fossil, raised beach ridge deposits, and two transects were obtained across modern beach deposits at the shoreline of the mesotidal regime. Along all radar profiles we observed downlap reflection points, which we interpret to represent the boundary between sediments deposited on the beachface and sediments deposited in the upper shoreface regime. Both the upper shoreface and the beachface deposits exhibit reflection patterns dipping in the seaward direction. The beachface deposits show the strongest dip. At or just below the downlap points strong diffractions are often observed indicating the presence of a layer containing stones. These stones are large enough to generate significant signal scattering. At the present day beach a sharp transition defined by the presence of large stones is observed near the low tide water level: cobbles characterize the seaside, while the land side is characterized by sand and gravel. Therefore, it seems reasonable to conclude that downlap points observed in the GPR data serve as indicators of past low-tide levels (at the time of deposition). The downlap points show a consistent offset with respect to present surface topography

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

    Science.gov (United States)

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

    2011-12-01

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

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

    Science.gov (United States)

    Komiya; Maruyama; Masuda; Nohda; Hayashi; Okamoto

    1999-09-01

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

  13. Serologic survey of West Nile virus in horses from Central-West, Northeast and Southeast Brazil

    Science.gov (United States)

    Silva, Jaqueline Raymondi; de Medeiros, Larissa Campos; dos Reis, Vinícius Pinho; Chávez, Juliana Helena; Munhoz, Thiago Demarchi; Borges, Gustavo Puia; Soares, Otavio Augusto Brioschi; de Campos, Carlos Henrique Coelho; Machado, Rosângela Zacarias; Baldani, Cristiane Divan; Silva, Maria Luana Cristiny Rodrigues; Faria, Joice Lara Maia; da Silva, Edson Elias; Figueiredo, Luiz Tadeu Moraes

    2013-01-01

    Since the emergence of West Nile virus (WNV) in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test. Our results showed that of 79 ELISA-positive horses, nine expressed WNV-specific neutralising antibodies. Eight of the infected horses were from the state of Mato Grosso do Sul and one was from the state of Paraíba. Our results provide additional evidence for the emergence of WNV in Brazil and for its circulation in multiple regions of the country. PMID:24037110

  14. Serologic survey of West Nile virus in horses from Central-West, Northeast and Southeast Brazil

    Directory of Open Access Journals (Sweden)

    Jaqueline Raymondi Silva

    2013-11-01

    Full Text Available Since the emergence of West Nile virus (WNV in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test. Our results showed that of 79 ELISA-positive horses, nine expressed WNV-specific neutralising antibodies. Eight of the infected horses were from the state of Mato Grosso do Sul and one was from the state of Paraíba. Our results provide additional evidence for the emergence of WNV in Brazil and for its circulation in multiple regions of the country.

  15. 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.

    OpenAIRE

    Aubail, Aurore; Dietz, Rune; Rigét, Frank; Simon-Bouhet, Benoit; Caurant, Florence

    2010-01-01

    International audience; 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 (13C/12C) and nitrogen (15N/14N) 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 t...

  16. Annual Patterns and Sources of Light-Absorbing Aerosols over Central Greenland

    Science.gov (United States)

    Hu, J.; Bergin, M. H.; Dibb, J. E.; Sheridan, P. J.; Ogren, J. A.

    2014-12-01

    The Arctic region has proven to be more responsive to recent changes in climate than other parts of the Earth. A key component of the Arctic climate is the Greenland ice sheet (GIS), which has the potential to dramatically influence sea level, depending on the amount of melting that occurs, as well as climate, through shifts in the regional radiation balance. Light-absorbing aerosols from biomass burning, fossil fuel combustion, and dust sources can potentially have a significant impact on the radiation balance of the GIS; however, in order to better understand their impact, it is important to first understand the annual trends of light-absorbing aerosols and their sources over the ice sheet. With this in mind, aerosol properties including the wavelength dependent aerosol light scattering and absorption coefficients have been continuously measured at Summit, Greenland since the spring of 2011. These measurements will be used to calculate the multi-wavelength single-scattering albedo (ω0) and absorption Ångström exponent, identify annual patterns of aerosols over the GIS and how they vary from year to year, detect events of high absorption, and determine the sources of the aerosols. Preliminary findings indicate that the aerosols have an absorption Ångström exponent of approximately 1, which is characteristic of black carbon (BC). Absorption and scattering coefficients are higher in the spring and summer (March-September) and consequently lower in the fall and winter (September-March). Absorption and single-scattering albedo are averaged over the sunlit months of April-August and are found to be highest and lowest, respectively, in the year of 2012, corresponding to the year of record melt extent over the GIS.

  17. The MajuagaaA Kimberlite Dike, Maniitsoq Regio, West Greenland: Constraints on an Mg-rich Silicocarbonatitic Melt Composition from Groundmass Mineralogy and Bulk Compositions

    DEFF Research Database (Denmark)

    Nielsen, Troels F. D.; Sand, Karina Krarup

    2008-01-01

    The Majuagaa kimberlite dike in the Maniitsoq region, southern West Greenland, is 564 Ma old, 2.5 km long, and up to 2 m wide. It is well exposed and very fresh, allowing detailed petrographic and chemical investigations. Little or no serpentinization is observed, and primary petrographic...... characteristics and grain morphologies are preserved. The dike is diamondiferous and carries xenoliths (up to 30 cm), megacrysts and macrocrysts characteristic of kimberlite. On the bases of the paragenesis and compositions of groundmass phlogopite, geikielite and Mg–Ti-enriched spinel, the dike is classified....... Most olivine (max. 37 wt.%) is found to be xenocrystic on the basis of Ni mass balance. The average bulk composition of the melt involved in the dike compares well with Group-1 kimberlite. Corrected for xenocrystic olivine and ilmenite, the melt has the composition of a silicocarbonatite and compares...

  18. Mapping of a Hydrological Ice Sheet Drainage Basin on the West Greenland Ice Sheet Margin from ERS-1/2 SAR Interferometry, Ice-Radar Measurement, and Modelling

    DEFF Research Database (Denmark)

    Ahlstrøm, Andreas P.; Bøggild, C.E.; Stenseng, L.;

    2002-01-01

    importance of the potential of the ice overburden pressure compared to the bedrock topography. The meltwater run-off for the basin delineations was modelled with an energy-balance model calibrated with observed ice-sheet ablation and compared to a 25 year time series of measured basin run-off. The standard......The hydrological ice-sheet basin draining into the Tasersiaq lake, West Greenland (66°13'N, 50°30'W), was delineated, First using standard digital elevation models (DEMs) for ice-sheet surface and bedrock, and subsequently using a new high-resolution dataset, with a surface DEM derived from repeat......-track interferometric synthetic aperture radar (SAR) and a bedrock topography derived from an airborne 60 MHz ice-penetrating radar. The extent of the delineation was calculated from a water-pressure potential as a function of the ice-sheet surface and bedrock elevations and a hydraulic factor κ describing the relative...

  19. Northern Shrimp (Pandalus borealis) Recruitment in West Greenland Waters. Part I. Distribution of Pandalus Shrimp Larvae in Relation to Hydrography and Plankton

    DEFF Research Database (Denmark)

    Pedersen, S. A.; Storm, L. M.; Simonsen, C. S.

    2002-01-01

    Plankton samples and oceanographic data were obtained during transect studies across fishing banks over the West Greenland shelf areas in June 1999, May, and July 2000. The hypothesis that larval shrimp are linked to the behaviour of hydrographic fronts was tested by determining whether larval...... shrimp abundance was linked to plankton distributions, species composition and primary productivity. We found six pelagic developmental stages (ZI–ZVI) in two species of Pandalus larvae. P. borealis was the most abundant species in all stages from ZII to ZVI. The smaller P. montagui larvae were slightly....... The two species showed minor differences in larval distribution across banks and between transects, indicating a wide larval dispersal and a relatively short hatching period. We found no relationship between indices of larval shrimp abundance and the T–S characteristics of water masses, chlorophyll...

  20. A combined DNA-microsatellite and isozyme analysis of the population structure of the harbour porpoise in Danish waters and west Greenland

    DEFF Research Database (Denmark)

    Andersen, L W; Holm, L E; Siegismund, Hans Redlef;

    1997-01-01

    . Three polymorphic microsatellites, 415/416, 417/418 and Igf-I (insulin-like growth factor I) were detected with nine, eight and 15 alleles, respectively, and from a former study two polymorphic isozymes, Mpi-1 and Pgm, with three and two alleles, respectively, were used in the analysis. Overall...... or nonrandom mating. The analysis of the genetical population structure showed that harbour porpoises from West Greenland, the North Sea and IDW were three geographically, genetically differentiated populations even though connected through some degree of gene flow. A tendency for females to be more stationary...... than males was suggested. Furthermore, the population structure suggested a closer relationship between IDW and the North Sea....

  1. Are seasonal calving dynamics forced by buttressing from ice mélange or undercutting by melting? Outcomes from full-Stokes simulations of Store Gletscher, West Greenland

    Directory of Open Access Journals (Sweden)

    J. Todd

    2014-07-01

    Full Text Available We use a full-Stokes 2-D model (Elmer/Ice to investigate the flow and calving dynamics of Store Gletscher, a fast flowing outlet glacier in West Greenland. Based on a new, subgrid-scale implementation of the crevasse depth calving criterion, we perform two sets of simulations; one to identify the primary forcing mechanisms and another to constrain future stability. We find that the mixture of icebergs and sea-ice, known as ice mélange or sikussak, is principally responsible for the observed seasonal advance of the ice front, whereas submarine melting plays a secondary role. Sensitivity analysis demonstrates that the glacier's calving dynamics are sensitive to seasonal perturbation, but are stable on interannual timescales due to the glacier's topographic setting. Our results shed light on the dynamics of calving glaciers while explaining why neighbouring glaciers do not necessarily respond synchronously to changes in atmospheric and oceanic forcing.

  2. A preliminary strategic environmental impact assessment of mineral and hydrocarbon activities on the Nuussuaq peninsula, West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Boertmann, D.; Asmund, G.; Glahder, C.; Tamstorf, M.

    2008-01-15

    There is an increasing interest for mineral and hydrocarbon exploration in Greenland and in both regards the Nuussuaq peninsula is in focus. This preliminary strategic environmental impact assessment describes the status of the biological knowledge from the area and designates potential conflicts between activities and the biological environment. Furthermore biological knowledge gaps are identified. These should be filled before specific environmental impacts assessments can be carried out and relevant studies to fill these data gaps are proposed. (au)

  3. [Production systems of Spondias purpurea (Anacardiaceae) in Central West Mexico].

    Science.gov (United States)

    Ramírez Hernández, Blanca C; Barrios Eulogio, Pimienta; Castellanos Ramos, Javier Z; Muñoz Urias, Alejandro; Palomino Hasbach, Guadalupe; Pimienta Barrios, Enrique

    2008-06-01

    Morphological, physical and chemical traits related with fruit quality characteristics of Spondias purpurea L. agroecosystems were studied in Central-West Mexico for wild and cultivated populations. Spondias purpurea regularly thrive in shallow, rocky infertile soils unsuitable for conventional crops. The weight, axial and radial length, pH, total soluble solids (SST), reducing sugars, proteins and mineral content in fruits were recorded. The mean fresh fruit weight was superior in the cultivated varieties (20 g) than in the wild (16 g). Similarly the highest values of pH, SST, reducing sugars and protein content (3.3, 12.15 degrees Brix, 0.38 g/100 g and 1.18 g/100 g, respectively) were observed in the cultivated plantations compared with wild populations (3.0, 8.31 degrees Brix, 0.24 g/100 g and 0.14 g/100 g, respectively). In cultivated plantations, productivity ranged from 0.15 ton ha(-1) to 5.0 ton ha(-1), and must be considered satisfactory, considering the low inputs of fertilizers and pesticides applied to orchards. The fruits of S. purpurea are similar in nutrimental content to more important commercial fruit species; it produces fresh fruits during the dry months of spring, when few fresh fruits are available in the local markets. In addition, S. purpurea is a source of water and food for domestic animals and wild fauna. These traits emphasize their agronomical and ecological importance for tropical and subtropical environments, where it can also be used in reforestation programs because it can grow in infertile rocky soils, and in agroecosystems inhabited by low income farmers that practice subsistence agriculture. In fact, the cultivation of Spondias has helped convert marginal lands into productive lands.

  4. Centrality of Event across Cultures. Emotionally Positive and Negative Events in Mexico, China, Greenland, and Denmark

    DEFF Research Database (Denmark)

    Zaragoza Scherman, Alejandra; Berntsen, Dorthe

    During their lifetime, people experience both emotionally positive and negative events. The Centrality of Event Scale (CES; Berntsen and Rubin, 2006; Berntsen, Rubin and Siegler, 2011) measures the extent to which an event is central to someone’s identity and life story. An event becomes central...... disorder (PTSD) and depression symptoms: Participants with higher PTSD and depression scores reported that a traumatic or negative event was highly central to their identity and life story; and 3) A significant number of positive event occurred during participants’ adolescence and early adulthood, while...... negative events increased as participants grew older....

  5. Melting at the base of the Greenland ice sheet explained by Iceland hotspot history

    Science.gov (United States)

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

    2016-05-01

    Ice-penetrating radar and ice core drilling have shown that large parts of the north-central Greenland ice sheet are melting from below. It has been argued that basal ice melt is due to the anomalously high geothermal flux that has also influenced the development of the longest ice stream in Greenland. Here we estimate the geothermal flux beneath the Greenland ice sheet and identify a 1,200-km-long and 400-km-wide geothermal anomaly beneath the thick ice cover. We suggest that this anomaly explains the observed melting of the ice sheet’s base, which drives the vigorous subglacial hydrology and controls the position of the head of the enigmatic 750-km-long northeastern Greenland ice stream. Our combined analysis of independent seismic, gravity and tectonic data implies that the geothermal anomaly, which crosses Greenland from west to east, was formed by Greenland’s passage over the Iceland mantle plume between roughly 80 and 35 million years ago. We conclude that the complexity of the present-day subglacial hydrology and dynamic features of the north-central Greenland ice sheet originated in tectonic events that pre-date the onset of glaciation in Greenland by many tens of millions of years.

  6. Mean Annual Precipitation in West-Central Nevada using the Precipitation-Zone Method

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains 1971-2000 mean annual precipitation estimates for west-central Nevada. This is a raster data set developed using the precipitation-zone...

  7. Benthic foraminifera as proxy for oxygen-depleted conditions off the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Mazumder, A.; Henriques, P.J.; Saraswat, R.

    In order to study the response of benthic foraminifera, especially the rectilinear bi- and tri-serial benthic foraminifera (RBF) to oxygen-depleted conditions from the Arabian Sea off central west coast of India, 103 surface sediment samples...

  8. Contribution from coastal laterites to the nearshore placers of central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A; Srinivas, K.

    The heavy mineral placers with variable concentrations of ilmenite and magnetite occur in the surface and in the sub-surface sediments of many bays along central west coast of India. These sediments are associated with pebbles of laterite...

  9. CRED 10 m Gridded multibeam bathymetry of Wake Island, West Central Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry shelf, bank and slope environments of Wake Island, West Central Pacific, under joint management of the United States Dept. of Interior and Air...

  10. CRED 60 m Gridded multibeam bathymetry of Wake Island, West Central Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry shelf, bank and slope environments of Wake Island, West Central Pacific, under joint management of the United States Dept. of Interior and Air...

  11. Herbicide Concentrations in Select Waterfowl Production Area Wetlands in West Central Minnesota, 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Twenty-eight emergent, seasonally to semipermanently flooded wetlands in an intensively farmed area of west central Minnesota were sampled before and during the...

  12. Food Habits of Black Ducks Wintering in West Central Tennessee: Annual report 1990-91

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study was conducted to describe the food habits of black ducks (Anas rubripes) wintering in west central Tennessee and to compare foods of black ducks and...

  13. Development of summer monsoon and onset of continuous rains over central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    A new interpretation of the start of summer monsoon along central west coast of India is presented in this paper. Many authors misinterpret onset of continuous rains as start of summer monsoon front, These two are different phenomena, continuous...

  14. CRED 1 meter resolution Reson 8101 multibeam backscatter data of Wake Island, West Central Pacific, 2007.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of Wake Island, West Central Pacific.These data provide coverage between 0 and 200m meters. The...

  15. Possible Greenland

    DEFF Research Database (Denmark)

    2012-01-01

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

  16. Business environment and enterprise behaviour in East Germany compared to West Germany and central Europe

    OpenAIRE

    Libor Krkoska; Katrin Robeck

    2007-01-01

    This paper examines institutional differences between the former East and West Germany and four central European transition countries (the Czech Republic, Hungary, Poland and the Slovak Republic). Using enterprise survey data we show that the quality of both formal and informal institutions in East Germany still differs from West Germany. In addition, central European transition countries are shown to have closed the gap in institutional quality with East Germany in many areas. We also show t...

  17. Heat sources for glacial ice melt in a West Greenland tidewater outlet glacier fjord: The role of subglacial freshwater discharge

    DEFF Research Database (Denmark)

    Bendtsen, Jørgen; Mortensen, John; Lennert, Kunuk;

    2015-01-01

    The melting of tidewater outlet glaciers from the Greenland Ice Sheet contributes significantly to global sea level rise. Accelerated mass loss is related to melt-processes in front of calving glaciers, yet the role of ocean heat transports is poorly understood. Here we present the first direct...... measurements from a subglacial plume in front of a calving tidewater outlet glacier. Surface salinity in the plume corresponded to a meltwater content of 7 %, which is indicative of significant entrainment of warm bottom water and, according to plume model calculations, significant ice melt. Energy balance...

  18. 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...

  19. Environmental radioactivity in Greenland in 1982

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-11-01

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

  1. Geographic distribution of phlebotomine sandfly species (Diptera: Psychodidae in Central-West Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Silva de Almeida

    2015-06-01

    Full Text Available This study updates the geographic distributions of phlebotomine species in Central-West Brazil and analyses the climatic factors associated with their occurrence. The data were obtained from the entomology services of the state departments of health in Central-West Brazil, scientific collections and a literature review of articles from 1962-2014. Ecological niche models were produced for sandfly species with more than 20 occurrences using the Maxent algorithm and eight climate variables. In all, 2,803 phlebotomine records for 127 species were analysed. Nyssomyia whitmani, Evandromyia lenti and Lutzomyia longipalpis were the species with the greatest number of records and were present in all the biomes in Central-West Brazil. The models, which were produced for 34 species, indicated that the Cerrado areas in the central and western regions of Central-West Brazil were climatically more suitable to sandflies. The variables with the greatest influence on the models were the temperature in the coldest months and the temperature seasonality. The results show that phlebotomine species in Central-West Brazil have different geographical distribution patterns and that climate conditions in essentially the entire region favour the occurrence of at least one Leishmania vector species, highlighting the need to maintain or intensify vector control and surveillance strategies.

  2. Geographic distribution of phlebotomine sandfly species (Diptera: Psychodidae) in Central-West Brazil

    Science.gov (United States)

    de Almeida, Paulo Silva; de Andrade, Andrey José; Sciamarelli, Alan; Raizer, Josué; Menegatti, Jaqueline Aparecida; Hermes, Sandra Cristina Negreli Moreira; de Carvalho, Maria do Socorro Laurentino; Gurgel-Gonçalves, Rodrigo

    2015-01-01

    This study updates the geographic distributions of phlebotomine species in Central-West Brazil and analyses the climatic factors associated with their occurrence. The data were obtained from the entomology services of the state departments of health in Central-West Brazil, scientific collections and a literature review of articles from 1962-2014. Ecological niche models were produced for sandfly species with more than 20 occurrences using the Maxent algorithm and eight climate variables. In all, 2,803 phlebotomine records for 127 species were analysed. Nyssomyia whitmani, Evandromyia lenti and Lutzomyia longipalpis were the species with the greatest number of records and were present in all the biomes in Central-West Brazil. The models, which were produced for 34 species, indicated that the Cerrado areas in the central and western regions of Central-West Brazil were climatically more suitable to sandflies. The variables with the greatest influence on the models were the temperature in the coldest months and the temperature seasonality. The results show that phlebotomine species in Central-West Brazil have different geographical distribution patterns and that climate conditions in essentially the entire region favour the occurrence of at least one Leishmania vector species, highlighting the need to maintain or intensify vector control and surveillance strategies. PMID:26018450

  3. The Subglacial Access and Fast Ice Research Experiment (SAFIRE): 2. High magnitude englacial strain detected with autonomous phase-sensitive FMCW radar on Store Glacier, West Greenland

    Science.gov (United States)

    Young, Tun Jan; Christoffersen, Poul; Nicholls, Keith; Bun Lok, Lai; Doyle, Samuel; Hubbard, Bryn; Stewart, Craig; Hofstede, Coen; Bougamont, Marion; Todd, Joseph; Brennan, Paul; Hubbard, Alun

    2016-04-01

    Fast-flowing outlet glaciers terminating in the sea drain 90% of the Greenland Ice Sheet. It is well-known that these glaciers flow rapidly due to fast basal motion, but its contributing processes and mechanisms are, however, poorly understood. In particular, there is a paucity of data to quantify the extent to which basal sliding and internal ice deformation by viscous creep contribute to the fast motion of Greenland outlet glaciers. To study these processes, we installed a network of global positioning system (GPS) receivers around an autonomous phase-sensitive radio-echo sounder (ApRES) capable of imaging internal reflectors and the glacier bed. The ApRES system, including antennas, were custom-designed to monitor and image ice sheets and ice shelves in monostatic and multiple-input multiple-output (MIMO) modes. Specifically, the system transmits a frequency-modulated continuous-wave (FMCW) that increases linearly from 200 to 400 MHz over a period of 1 second. We installed this system 30 km up-flow of the tidewater terminus of Store Glacier, which flows into Uummannaq Fjord in West Greenland, and data were recorded every hour from 06 May to 16 July 2014 and every 4 hours from 26 July to 11 December 2014. The same site was used to instrument 600 m deep boreholes drilled to the bed as part of the SAFIRE research programme. With range and reflector distances captured at high temporal (hourly) and spatial (millimetre) resolutions, we obtained a unique, 6-month-long time series of strain through the vertical ice column at the drill site where tilt was independently recorded in a borehole. Our results show variable, but persistently high vertical strain. In the upper three-fourths of the ice column, we have calculated strain rates on the order of a few percent per year, and the strain regime curiously shifts from vertical thinning in winter to vertical thickening at the onset of summer melt. In the basal ice layer we observed high-magnitude vertical strain rates on

  4. Bathymetry of Walker Lake, West-Central Nevada

    Science.gov (United States)

    Lopes, Thomas J.; Smith, J. LaRue

    2007-01-01

    Walker Lake lies within a topographically closed basin in west-central Nevada and is the terminus of the Walker River. Much of the streamflow in the Walker River is diverted for irrigation, which has contributed to a decline in lake-surface altitude of about 150 feet and an increase in dissolved solids from 2,500 to 16,000 milligrams per liter in Walker Lake since 1882. The increase in salinity threatens the fresh-water ecosystem and survival of the Lahontan cutthroat trout, a species listed as threatened under the Endangered Species Act. Accurately determining the bathymetry and relations between lake-surface altitude, surface area, and storage volume are part of a study to improve the water budget for Walker Lake. This report describes the updated bathymetry of Walker Lake, a comparison of results from this study and a study by Rush in 1970, and an estimate of the 1882 lake-surface altitude. Bathymetry was measured using a single-beam echosounder coupled to a differentially-corrected global positioning system. Lake depth was subtracted from the lake-surface altitude to calculate the altitude of the lake bottom. A Lidar (light detection and ranging) survey and high resolution aerial imagery were used to create digital elevation models around Walker Lake. The altitude of the lake bottom and digital elevation models were merged together to create a single map showing land-surface altitude contours delineating areas that are currently or that were submerged by Walker Lake. Surface area and storage volume for lake-surface altitudes of 3,851.5-4,120 feet were calculated with 3-D surface-analysis software. Walker Lake is oval shaped with a north-south trending long axis. On June 28, 2005, the lake-surface altitude was 3,935.6 feet, maximum depth was 86.3 feet, and the surface area was 32,190 acres. The minimum altitude of the lake bottom from discrete point depths is 3,849.3 feet near the center of Walker Lake. The lake bottom is remarkably smooth except for mounds near

  5. Gender Statistics in the Southern Caucasus and Central and West Asia: A Situational Analysis Promoting Gender-Inclusive Growth in Central and West Asian Developing Member Countries

    OpenAIRE

    Asian Development Bank (ADB)

    2012-01-01

    This report provides a baseline of the capacity of Asian Development Bank developing member countries to generate, analyze, disseminate, and use sex-disaggregated data. It introduces a framework on gender statistics and guides in assessing statistical systems in the Southern Caucasus (Armenia, Azerbaijan, Georgia), Central Asia (Kazakhstan, Kyrgyz Republic, Tajikistan, Turkmenistan, Uzbekistan), and West Asia (Afghanistan, Pakistan). It recommends ways to bridge the gaps in gender data collec...

  6. A ten-year record of supraglacial lake evolution and rapid drainage in West Greenland using an automated processing algorithm for multispectral imagery

    Directory of Open Access Journals (Sweden)

    B. F. Morriss

    2013-07-01

    Full Text Available The rapid drainage of supraglacial lakes introduces large pulses of meltwater to the subglacial environment and creates moulins, surface-to-bed conduits for future melt. Introduction of water to the subglacial system has been shown to affect ice flow, and modeling suggests that variability in water supply and delivery to the subsurface play an important role in the development of the subglacial hydrologic system and its ability to enhance or mitigate ice flow. We developed a fully automated method for tracking meltwater and rapid drainages in 78 large, perennial lakes along an outlet glacier flow band in West Greenland from 2002 to 2011 using ETM+ and MODIS imagery. Results indicate interannual variability in maximum coverage and spatial evolution of total lake area. We identify 238 rapid drainage events, occurring most often at low and middle elevations during periods of net filling or peak lake coverage. We observe a general progression of both lake filling and draining from lower to higher elevations but note that the timing of filling onset, peak coverage, and dissipation are also variable. While lake coverage is sensitive to air temperature, warm years exhibit greater variability in both coverage evolution and rapid drainage. Mid elevation drainages in 2011 coincide with large surface velocity increases at nearby GPS sites, though the relationships between iceshed-scale dynamics and meltwater input are still unclear.

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  8. Are seasonal calving dynamics forced by buttressing from ice mélange or undercutting by melting? Outcomes from full-Stokes simulations of Store Glacier, West Greenland

    Science.gov (United States)

    Todd, J.; Christoffersen, P.

    2014-12-01

    We use a full-Stokes 2-D model (Elmer/Ice) to investigate the flow and calving dynamics of Store Glacier, a fast-flowing outlet glacier in West Greenland. Based on a new, subgrid-scale implementation of the crevasse depth calving criterion, we perform two sets of simulations: one to identify the primary forcing mechanisms and another to constrain future stability. We find that the mixture of icebergs and sea ice, known as ice mélange or sikussak, is principally responsible for the observed seasonal advance of the ice front. On the other hand, the effect of submarine melting on the calving rate of Store Glacier appears to be limited. Sensitivity analysis demonstrates that the glacier's calving dynamics are sensitive to seasonal perturbation, but are stable on interannual timescales due to the strong topographic control on the flow regime. Our results shed light on the dynamics of calving glaciers and may help explain why neighbouring glaciers do not necessarily respond synchronously to changes in atmospheric and oceanic forcing.

  9. Pb isotopes as tracers of mining-related Pb in lichens, seaweed and mussels near a former Pb-Zn mine in West Greenland

    DEFF Research Database (Denmark)

    Søndergaard, Jens; Asmund, Gert; Johansen, Poul;

    2010-01-01

    Identification of mining-related contaminants is important in order to assess the spreading of contaminants from mining as well as for site remediation purposes. This study focuses on lead (Pb) contamination in biota near the abandoned ‘Black Angel Mine’ in West Greenland in the period 1988......–2008. Stable Pb isotope ratios and total Pb concentrations were determined in lichens, seaweed and mussels as well as in marine sediments. The results show that natural background Pb (207Pb/206Pb: 0.704–0.767) and Pb originating from the mine ore (207Pb/206Pb: 0.955) have distinct isotopic fingerprints. Total...... Pb in lichens, seaweed, and mussels was measured at values up to 633, 19 and 1536 mg kg-1 dry weight, respectively, and is shown to be a mixture of natural Pb and ore-Pb. This enables quantification of mining-related Pb and shows that application of Pb isotope data is a valuable tool for monitoring...

  10. Colonization history and clonal richness of asexual Daphnia in periglacial habitats of contrasting age in West Greenland.

    Science.gov (United States)

    Haileselasie, Tsegazeabe H; Mergeay, Joachim; Weider, Lawrence J; Jeppesen, Erik; De Meester, Luc

    2016-07-01

    Due to climate change, Arctic ice sheets are retreating. This leads to the formation of numerous new periglacial ponds and lakes, which are being colonized by planktonic organisms such as the water flea Daphnia. This system provides unique opportunities to test genotype colonization dynamics and the genetic assemblage of populations. Here, we studied clonal richness of the Daphnia pulex species complex in novel periglacial habitats created by glacial retreat in the Jakobshavn Isbrae area of western Greenland. Along a 10 km transect, we surveyed 73 periglacial habitats out of which 61 were colonized by Daphnia pulex. Hence, for our analysis, we used 21 ponds and 40 lakes in two clusters of habitats differing in age (estimated 150 years). We tested the expectation that genetic diversity would be low in recently formed (i.e. young), small habitats, but would increase with increasing age and size. We identified a total of 42 genetically distinct clones belonging to two obligately asexual species of the D. pulex species complex: D. middendorffiana and the much more abundant D. pulicaria. While regional clonal richness was high, most clones were rare: 16 clones were restricted to a single habitat and the five most widespread clones accounted for 68% of all individuals sampled. On average, 3·2 clones (range: 1-12) coexisted in a given pond or lake. There was no relationship between clonal richness and habitat size when we controlled for habitat age. Whereas clonal richness was statistically higher in the cluster of older habitats when compared with the cluster of younger ponds and lakes, most young habitats were colonized by multiple genotypes. Our data suggest that newly formed (periglacial) ponds and lakes are colonized within decades by multiple genotypes via multiple colonization events, even in the smallest of our study systems (4 m(2) ). PMID:27279332

  11. Origin and Role of Recycled Crust in Flood Basalt Magmatism: Case Study of the Central East Greenland Rifted Margin

    Science.gov (United States)

    Brown, E.; Lesher, C. E.

    2015-12-01

    Continental flood basalts (CFB) are extreme manifestations of mantle melting derived from chemically/isotopically heterogeneous mantle. Much of this heterogeneity comes from lithospheric material recycled into the convecting mantle by a range of mechanisms (e.g. subduction, delamination). The abundance and petrogenetic origins of these lithologies thus provide important constraints on the geodynamical origins of CFB magmatism, and the timescales of lithospheric recycling in the mantle. Basalt geochemistry has long been used to constrain the compositions and mean ages of recycled lithologies in the mantle. Typically, this work assumes the isotopic compositions of the basalts are the same as their mantle source(s). However, because basalts are mixtures of melts derived from different sources (having different fusibilities) generated over ranges of P and T, their isotopic compositions only indirectly represent the isotopic compositions of their mantle sources[1]. Thus, relating basalts compositions to mantle source compositions requires information about the melting process itself. To investigate the nature of lithologic source heterogeneity while accounting for the effects of melting during CFB magmatism, we utilize the REEBOX PRO forward melting model[2], which simulates adiabatic decompression melting in lithologically heterogeneous mantle. We apply the model to constrain the origins and abundance of mantle heterogeneity associated with Paleogene flood basalts erupted during the rift-to-drift transition of Pangea breakup along the Central East Greenland rifted margin of the North Atlantic igneous province. We show that these basalts were derived by melting of a hot, lithologically heterogeneous source containing depleted, subduction-modified lithospheric mantle, and recycled oceanic crust. The Paleozoic mean age we calculate for this recycled crust is consistent with an origin in the region's prior subduction history, and with estimates for the mean age of recycled

  12. Mineral dust variability in central West Antarctica associated with ozone depletion

    Directory of Open Access Journals (Sweden)

    M. Cataldo

    2013-02-01

    Full Text Available We present here data of mineral dust variability retrieved from an ice core of the central West Antarctic, spanning the last five decades. Main evidence provided by the geochemical analysis is that northerly air mass incursions to the coring site, tracked by insoluble dust microparticles, have declined over the past 50 yr. This result contrasts with dust records from ice cores reported to the coastal West Antarctic that show increases since mid-20th century. We attribute this difference to regional climatic changes due to the ozone depletion and its implications to westerly winds. We found that the diameters of insoluble microparticles in the central West Antarctica ice core are significantly correlated with cyclone depth (energy and wind intensity around Antarctica.

  13. Early Cretaceous decapod Crustacea from the Neuquén Basin, west-central Argentina

    NARCIS (Netherlands)

    Aguirre-Urreta, Maria Beatriz

    2003-01-01

    Marine deposits of the Neuquén Basin of west-central Argentina (southern South America) are richly fossiliferous; its Mesozoic invertebrate faunas, represented mostly by molluscs, have been extensively studied since the nineteenth century. However, Early Cretaceous decapod crustaceans are far less k

  14. Nematode species diversity as indicator of stressed benthic environment along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nanajkar, M.R.; Ingole, B.S.

    community as a tool for assessing the benthic environment. Total 32 meiofaunal samples were collected from the sub-tidal regions along the central west coast of India. Sediment samples were collected on board CRVSagar-Sukti (cruise no. SASU-60 and 105...

  15. Organised labour and neo-liberal economic and political reforms in West and Central Africa

    NARCIS (Netherlands)

    Konings, P.J.J.

    2003-01-01

    This article examines the impact of current neoliberal political reforms on trade union performance in West and Central Africa. To what extent have trade unions been involved in the political restructuring of the State? Has political liberalization constrained or enhanced their political influence a

  16. Tuna longline fishing around West and Central Pacific seamounts.

    Directory of Open Access Journals (Sweden)

    Telmo Morato

    Full Text Available BACKGROUND: Seamounts have been identified as aggregating locations for pelagic biodiversity including tuna; however the topography and prevailing oceanography differ between seamounts and not all are important for tuna. Although a relatively common feature in oceanic ecosystems, little information is available that identifies those that are biologically important. Improved knowledge offers opportunities for unique management of these areas, which may advance the sustainable management of oceanic resources. In this study, we evaluate the existence of an association between seamounts and tuna longline fisheries at the ocean basin scale, identify significant seamounts for tuna in the western and central Pacific Ocean, and quantify the seamount contribution to the tuna longline catch. METHODOLOGY/PRINCIPAL FINDINGS: We use data collected for the Western and Central Pacific Ocean for bigeye, yellowfin, and albacore tuna at the ocean basin scale. GLMs were applied to a coupled dataset of longline fisheries catch and effort, and seamount location information. The analyses show that seamounts may be associated with an annual longline combined catch of 35 thousand tonnes, with higher catch apparent for yellowfin, bigeye, and albacore tuna on 17%, 14%, and 14% of seamounts respectively. In contrast 14%, 18%, and 20% of seamounts had significantly lower catches for yellowfin, bigeye and albacore tuna respectively. Studying catch data in relation to seamount positions presents several challenges such as bias in location of seamounts, or lack of spatial resolution of fisheries data. Whilst we recognize these limitations the criteria used for detecting significant seamounts were conservative and the error in identification is likely to be low albeit unknown. CONCLUSIONS/SIGNIFICANCE: Seamounts throughout the study area were found to either enhance or reduce tuna catch. This indicates that management of seamounts is important Pacific-wide, but management

  17. Recent crustal deformation in west-central South America

    Science.gov (United States)

    Pritchard, Matthew Earl

    I use interferometric synthetic aperture radar (InSAR) to create maps of crustal deformation along the coast and within the volcanic arc of central South America. I image deformation associated with six subduction zone earthquakes, four volcanic centers, at least one shallow crustal earthquake, and several salt flats. In addition, I constrain the magnitude and location of post-seismic deformation from the aforementioned subduction zone earthquakes. I combine InSAR observations with data from the Global Positioning System (GPS) and teleseismic data to explore each source of deformation. I use the observations to constrain earthquake and volcanic processes of this subduction zone, including the plumbing system of the volcanoes and the decadal along strike variations in the subduction zone earthquake cycle. I created interferograms of over 900 volcanoes in the central Andes spanning 1992--2002, and found four areas of deformation. I constrained the temporal variability of the deformation, the depth of the sources of deformation assuming a variety of source geometries and crustal structures, and the possible cause of the deformation. I do not observe deformation associated with eruptions at several volcanoes, and I discuss the possible explanations for this lack of deformation. In addition, I constrain the amount of co-seismic and post-seismic slip on the subduction zone fault interface from the following earthquakes: 1995 Mw 8.1 Antofagasta, Chile; 1996 Mw 7.7 Nazca, Peru; 1998 Mw 7.1 Antofagasta, Chile; and 2001 Mw 8.4 Arequipa, Peru. In northern Chile, I compare the location and magnitude of co-seismic slip from 5 Mw > 7 earthquakes during the past 15 years with the post-seismic slip distribution. There is little post-seismic slip from the 1995 and 1996 earthquakes relative to the 2001 event and other recent subduction zone earthquakes.

  18. Evaluation of the use of common sculpin (Myoxocephalus scorpius) organ histology as bioindicator for element exposure in the fjord of the mining area Maarmorilik, West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Sonne, Christian, E-mail: csh@dmu.dk [Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde (Denmark); Bach, Lis; Søndergaard, Jens; Rigét, Frank F.; Dietz, Rune; Mosbech, Anders [Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde (Denmark); Leifsson, Pall S. [University of Copenhagen, Faculty of Health and Medical Sciences, Department of Veterinary Disease Biology, Bülowsvej 17, DK-1870 Frederiksberg (Denmark); Gustavson, Kim [Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde (Denmark)

    2014-08-15

    The former Black Angel lead–zinc mine in Maarmorilik, West Greenland, is a historic example of how mining activity may result in a significant impact on the surrounding fjord system in terms of elevated concentrations of especially lead (Pb) and zinc (Zn) in seawater, sediments and surrounding biota. In order to shed light on the present contamination and possible effects in the fjord we initiated a range of studies including a pilot study on gill and liver morphology of common sculpins (Myoxocephalus scorpius) around Maarmorilik. Sculpins were caught and sampled at five different stations known to represent a gradient of Pb concentrations. Fish livers from all specimens were analyzed for relevant elements in the area: Fe, Zn, As, Cu, Se, Cd, Pb, Ag, Hg, Co and Ni. Lead, As and Hg showed significant differences among the five stations. For 20% of the sculpins, Hg concentrations were in the range of lowest observed effect dose (LOED) of 0.1–0.5 μg/g ww for toxic threshold on reproduction and subclinical endpoints. Likewise LOEDs for tissue lesions, LOEDs for biochemistry, growth, survival and reproduction were exceeded for Cd (0.42–1.8 μg/g ww) and for As (11.6 μg/g ww) in 28% and 85% of the sculpins, respectively. Similar to this, the no observed effect dose (NOED) for biochemistry was exceeded for Pb (0.32 μg/g ww) and for growth, mortality and reproduction for Zn (60–68 μg/g ww) in 33% and 24% of the sculpins, respectively. For all sculpins, females were significantly larger than males and for five of the elements (Fe, Co, Ni, Cu, Se) females had higher concentrations. The chronic lesions observed in liver (mononuclear cell infiltrates, necrosis, vacuolar hepatocytes, portal fibrosis, bile duct hyperplasia, active melanomacrophage centers) and gills (fusion and edema of secondary lamellae, laminar telangiectasis, mononuclear cell infiltrates, blebs) were similar to those in the literature studies for both wild and laboratory exposed sculpins and

  19. Modelling atmospheric bulk deposition of Pb, Zn and Cd near a former Pb-Zn mine in West Greenland using transplanted Flavocetraria nivalis lichens.

    Science.gov (United States)

    Søndergaard, Jens; Bach, Lis; Asmund, Gert

    2013-03-01

    Atmospheric deposition of lead (Pb), zinc (Zn) and cadmium (Cd) was investigated near the former Black Angel Pb-Zn mine in Maarmorilik, West Greenland during 2010-2011. Thalli of the lichen Flavocetraria nivalis were transplanted from an uncontaminated site into sites near the mine and collected the following year. At 20 of the total 21 sites, concentrations of Pb, Zn and Cd were significantly elevated in lichens after 1 year of transplantation compared to initial concentrations. Elevated concentrations were observed within a distance of approx. 20 km from the mining area. Concentrations decreased with increasing distance from the mine and the relation was well described using a power function with a negative exponent (r(2)=0.90; 0.83 and 0.83 for Pb; Zn and Cd). To examine the relation between metal concentrations/uptake in lichen transplants and atmospheric bulk deposition, 10 Bergerhoff dust samplers were placed near lichen transplants and samplers and lichens were collected after a 7-weeks exposure period. A significant linear correlation was observed between metal concentrations in lichen transplants and atmospheric bulk metal deposition (r(2)=0.94; 0.88 and 0.89 for Pb; Zn and Cd). Combining the results and including an area distribution within a defined metal deposition area, the "annual" deposition of Pb, Zn and Cd as dust was estimated during the 2010-2011 snow-free period (∼5 months). The results reveal that 20 years after mine closure, 770 kg Pb, 3700 kg Zn and 24 kg Cd were still being deposited as dust per year (snow-free period only) within a distance of 20 km from the mine.

  20. Thin-layer effects in glaciological seismic amplitude-versus-angle (AVA analysis: implications for characterising a subglacial till unit, Russell Glacier, West Greenland

    Directory of Open Access Journals (Sweden)

    A. D. Booth

    2012-08-01

    Full Text Available Seismic amplitude-versus-angle (AVA methods are a powerful means of quantifying the physical properties of subglacial material, but serious interpretative errors can arise when AVA is measured over a thinly-layered substrate. A substrate layer with a thickness less than 1/4 of the seismic wavelength, λ, is considered "thin", and reflections from its bounding interfaces superpose and appear in seismic data as a single reflection event. AVA interpretation of subglacial till can be vulnerable to such thin-layer effects, since a lodged (non-deforming till can be overlain by a thin (metre-scale cap of dilatant (deforming till. We assess the potential for misinterpretation by simulating seismic data for a stratified subglacial till unit, with an upper dilatant layer between 0.1–5.0 m thick (λ / 120 to > λ / 4, with λ = 12 m. For dilatant layers less than λ / 6 thick, conventional AVA analysis yields acoustic impedance and Poisson's ratio that indicate contradictory water saturation. A thin-layer interpretation strategy is proposed, that accurately characterises the model properties of the till unit. The method is applied to example seismic AVA data from Russell Glacier, West Greenland, in which characteristics of thin-layer responses are evident. A subglacial till deposit is interpreted, having lodged till (acoustic impedance = 4.26±0.59 × 106 kg m−2 s−1 underlying a water-saturated dilatant till layer (thickness < 2 m, Poisson's ratio ~ 0.5. Since thin-layer considerations offer a greater degree of complexity in an AVA interpretation, and potentially avoid misinterpretations, they are a valuable aspect of quantitative seismic analysis, particularly for characterising till units.

  1. The seasonal cycle and interannual variability of surface energy balance and melt in the ablation zone of the west Greenland ice sheet

    Directory of Open Access Journals (Sweden)

    M. van den Broeke

    2011-03-01

    Full Text Available We present the seasonal cycle and interannual variability of the surface energy balance (SEB in the ablation zone of the west Greenland ice sheet, using seven years (September 2003–August 2010 of hourly observations from three automatic weather stations (AWS. The AWS are situated along the 67° N latitude circle at elevations of 490 m a.s.l. (S5, 1020 m a.s.l. (S6 and 1520 m a.s.l. (S9 at distances of 6, 38 and 88 km from the ice sheet margin. The hourly AWS data are fed into a model that calculates all SEB components and melt rate; the model allows for shortwave radiation penetration in ice and time-varying surface momentum roughness. Snow depth is prescribed from albedo and sonic height ranger observations. Modelled and observed surface temperatures for non-melting conditions agree very well, with RMSE's of 0.97–1.26 K. Modelled and observed ice melt rates at the two lowest sites also show very good agreement, both for total cumulative and 10-day cumulated amounts. Melt frequencies and melt rates at the AWS sites are discussed. Although absorbed shortwave radiation is the most important energy source for melt at all three sites, interannual melt variability at the lowest site is driven mainly by variability in the turbulent flux of sensible heat. This is explained by the quasi-constant summer albedo in the lower ablation zone, limiting the influence of the melt-albedo feedback, and the proximity of the snow free tundra, which heats up considerably in summer.

  2. Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past temperature reconstructions

    Science.gov (United States)

    Masson-Delmotte, V.; Steen-Larsen, H. C.; Ortega, P.; Swingedouw, D.; Popp, T.; Vinther, B. M.; Oerter, H.; Sveinbjornsdottir, A. E.; Gudlaugsdottir, H.; Box, J. E.; Falourd, S.; Fettweis, X.; Gallée, H.; Garnier, E.; Jouzel, J.; Landais, A.; Minster, B.; Paradis, N.; Orsi, A.; Risi, C.; Werner, M.; White, J. W. C.

    2015-01-01

    Combined records of snow accumulation rate, δ18O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (north-west Greenland), covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterize the isotope-temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ18O and accumulation variability is related to North Atlantic SST, and enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ18O shows multi-decadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ18O anomaly values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ18O (warmest), while the 11-year periods with the strongest depletion (coldest) are depicted at NEEM in 1815-1825 and 1836-1846, which are also the driest 11-year periods. The NEEM accumulation and δ18O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multi-decadal accumulation-temperature and δ18O-temperature relationships for the strong warming period in 1979-2007. The accumulation sensitivity to temperature is estimated at 11 ± 2% °C-1 and the δ18O-temperature slope at 1.1 ± 0.2‰ °C-1, about twice larger than previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core.

  3. Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past temperature reconstructions

    Directory of Open Access Journals (Sweden)

    V. Masson-Delmotte

    2015-01-01

    Full Text Available Combined records of snow accumulation rate, δ18O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (north-west Greenland, covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterize the isotope–temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ18O and accumulation variability is related to North Atlantic SST, and enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ18O shows multi-decadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ18O anomaly values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ18O (warmest, while the 11-year periods with the strongest depletion (coldest are depicted at NEEM in 1815–1825 and 1836–1846, which are also the driest 11-year periods. The NEEM accumulation and δ18O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multi-decadal accumulation–temperature and δ18O–temperature relationships for the strong warming period in 1979–2007. The accumulation sensitivity to temperature is estimated at 11 ± 2% °C−1 and the δ18O–temperature slope at 1.1 ± 0.2‰ °C−1, about twice larger than previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core.

  4. West Texas nursing education portal project: developing a regional centralized application system.

    Science.gov (United States)

    Allen, Patricia; Billings, Lynda; Cannon, Sharon; Majors, Jennifer; Sportsman, Susan; Ballesteros, Pauline A; Bezinque, Kim; Bolton, Cathy; Cottenoir, Marla; Edwards, Carmen; Louder, Justin; O'Neal, Cynthia; Morgan, Jackolyn; Reyes, Helen; Ross, Linda

    2011-01-01

    Because of the nursing shortage and a demand for maximum enrollment, a group of five baccalaureate and seven associate degree nursing programs in West Texas first met in 2007 to form the West Texas Nursing Education Consortium (WTNEC). To emphasize the importance of scale and distance, the West Texas region is larger than all of the northeastern states combined. The founding group agreed that the first mission of WTNEC should be to pool resources in order to increase admission and graduation rates for WTNEC schools. Two years later, this mission is being accomplished by the implementation of a plan designed to increase participating schools' admissions, retention, and graduation rates. A grant proposal was written and funded to develop a central regionalization of the application process for entry into WTNEC generic programs (associates degree in nursing and bachelor of science in nursing), with the goal of decreasing and possibly eliminating student vacancy rates in member schools and perhaps reducing the resources needed by each school for the admission process. The implemented centralized application system allowed prospective students to apply online to the centralized admission portal. Students maintained the freedom to choose the nursing program(s) they wanted to attend, but they were also made aware of possible openings in other participating schools. The admission portal also saved potential students time and money by submitting one centralized application, resulting in consolidation of the nursing school application process. Eleven of the 12 consortium schools participated in the centralized application system. PMID:21596353

  5. Distribution and drift of Atlantic cod ( Gadus morhua ) eggs and larvae in Greenland offshore waters

    DEFF Research Database (Denmark)

    Wieland, Kai; Hovgård, Holger

    2002-01-01

    recruitment of the West Greenland cod stock. It is also shown that cod eggs and larvae occasionally drift from Southwest Iceland across the Denmark Strait to the East Greenland shelf from where a subsequent transport and immigration of juveniles to West Greenland waters can occur. Larval transport across the...

  6. South Greenland

    DEFF Research Database (Denmark)

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

  7. 'Then give him to the crocodiles': violence, State formation, and cultural discontinuity in west central Zambia, 1600-2000

    OpenAIRE

    Binsbergen, van, W.M.J.

    2003-01-01

    The purpose of this chapter is to explore the extent to which violence can be said to underlie any form of Stae formation in precolonial Africa. This is done by examining the role of violence in State formation in west central Zambia from the 17th century onwards. The chapter shows that State formation in west central Zambia entailed the imposition upon local village communities of a more or less centralized sociopolitical structure, representing a departure from the social organization and i...

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

    Science.gov (United States)

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

    2015-04-01

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

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

    Science.gov (United States)

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

    2007-04-01

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

  10. Prevalence, microphysics, and radiative properties of diamond dust, fog, and blowing snow over the central Greenland Ice Sheet

    Science.gov (United States)

    Cox, C. J.; Noone, D. C.; O'Neill, M.; Walden, V. P.; Shupe, M.; Berkelhammer, M. B.; Miller, N.; Steffen, K.

    2014-12-01

    The surface mass balance of the Greenland ice sheet is modulated in part by clouds through their interactions with the hydrologic cycle and influence on the surface energy budget. Furthermore, precipitation and post-depositional processes influence the isotopic composition of the ice, which is used for paleoclimatic reconstructions. Despite these important roles, relatively little is known of the properties of clouds over Greenland. Therefore, detailed observations are needed to constrain the influence that clouds have on the ice sheet and to support climate and weather modeling. This work focuses on observations of surface-based clouds from Summit, Greenland (72N 38W 3200m), including supercooled liquid radiation fogs, diamond dust, and blowing snow. Co-located measurements from a variety of sensors are combined to report on the prevalence of these clouds, their microphysical and radiative properties, the influence they have on the isotopic ratio of surface accumulation, and the meteorological conditions under which they occur. Observations include in situ measurements from particle imaging and scattering probes as well as meteorology at 2m and 10m and remotely sensed observations made at the surface from a cloud radar, an infrared spectrometer, and a suite of broadband radiation sensors. The period of study is June 2012 through October 2013. Surface-based clouds (Nd > 1 cm-3) occur between 20% and 60% of the time, more often in winter and less in summer. Supercooled liquid is identified throughout the year and at temperatures as low as -40 C. These types of clouds exhibit a range of radiative, dynamic, and hydrologic interactions with the surface and therefore are sensitive to changes in aerosols, the presence of other cloud types, temperature, humidity, and near-surface stability.

  11. 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

    opening of the North Atlantic Ocean in the late Paleocene. Sea-floor spreading was accompanied by extrusion of Palaeogene (early Tertiary plateau basalts in both central West and central–southern East Greenland. During the Quaternary Greenland was almost completely covered by ice, and the present day Inland Ice is a relic from the Pleistocene ice ages. Vast amounts of glacially eroded detritus were deposited on the continental shelves around Greenland. Mineral exploitation in Greenland has so far encompassed cryolite, lead-zinc, gold, olivine and coal. Current prospecting activities in Greenland are concentrated on gold, base metals, platinum group elements, molybdenum, iron ore, diamonds and lead-zinc. Hydrocarbon potential is confined to the major Phanerozoic sedimentary basins, notably the large basins offshore North-East and West Greenland. While reserves of oil or gas have yet to be found, geophysical data com bined with discoveries of oil seeps onshore have revealed a considerable potential for offshore oil and gas.

  12. Legume Diversity Patterns in West Central Africa: Influence of Species Biology on Distribution Models

    OpenAIRE

    Manuel de la Estrella; Mateo, Rubén G.; Wieringa, Jan J.; Barbara Mackinder; Jesús Muñoz

    2012-01-01

    OBJECTIVES: Species Distribution Models (SDMs) are used to produce predictions of potential Leguminosae diversity in West Central Africa. Those predictions are evaluated subsequently using expert opinion. The established methodology of combining all SDMs is refined to assess species diversity within five defined vegetation types. Potential species diversity is thus predicted for each vegetation type respectively. The primary aim of the new methodology is to define, in more detail, areas of sp...

  13. Geochemical mapping using stream sediments in west-central Nigeria: Implications for environmental studies and mineral exploration in West Africa

    International Nuclear Information System (INIS)

    This paper provides an overview of regional geochemical mapping using stream sediments from central and south-western Nigeria. A total of 1569 stream sediment samples were collected and 54 major and trace elements determined by ICP-MS and Au, Pd and Pt by fire assay. Multivariate statistical techniques (e.g., correlation analysis and principal factor analysis) were used to explore the data, following appropriate data transformation, to understand the data structure, investigate underlying processes controlling spatial geochemical variability and identify element associations. Major geochemical variations are controlled by source geology and provenance, as well as chemical weathering and winnowing processes, more subtle variations are a result of land use and contamination from anthropogenic activity. This work has identified placer deposits of potential economic importance for Au, REE, Ta, Nb, U and Pt, as well as other primary metal deposits. Areas of higher As and Cr (>2 mg/kg and >70 mg/kg respectively) are associated with Mesozoic and younger coastal sediments in SW Nigeria. High stream sediment Zr concentrations (mean >0.2%), from proximal zircons derived from weathering of basement rocks, have important implications for sample preparation and subsequent analysis due to interferences. Associated heavy minerals enriched in high field strength elements, and notably rare earths, may also have important implications for understanding magmatic processes within the basement terrain of West Africa. This study provides important new background/baseline geochemical values for common geological domains in Nigeria (which extend across other parts of West Africa) for assessment of contamination from urban/industrial land use changes and mining activities. Regional stream sediment mapping is also able to provide important new information with applications across a number of sectors including agriculture, health, land use and planning.

  14. Evidence of climatic change during Holocene in the nearshore regions of Konkan (central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.; Guptha, M.V.S.

    In order to understand the paleoenvironmental setting of the nearshore area of the central west coast of India, three vibro-cores from the Kalbadevi Bay, from a depth range of 6-12 m were analysed for sedimentological, mineralogical...

  15. Distribution of knock-down resistance mutations in Anopheles gambiae molecular forms in west and west-central Africa

    Directory of Open Access Journals (Sweden)

    Caccone Adalgisa

    2008-04-01

    Full Text Available Abstract Background Knock-down resistance (kdr to DDT and pyrethroids in the major Afrotropical vector species, Anopheles gambiae sensu stricto, is associated with two alternative point mutations at amino acid position 1014 of the voltage-gated sodium channel gene, resulting in either a leucine-phenylalanine (L1014F, or a leucine-serine (L1014S substitution. In An. gambiae S-form populations, the former mutation appears to be widespread in west Africa and has been recently reported from Uganda, while the latter, originally recorded in Kenya, has been recently found in Gabon, Cameroon and Equatorial Guinea. In M-form populations surveyed to date, only the L1014F mutation has been found, although less widespread and at lower frequencies than in sympatric S-form populations. Methods Anopheles gambiae M- and S-form specimens from 19 sites from 11 west and west-central African countries were identified to molecular form and genotyped at the kdr locus either by Hot Oligonucleotide Ligation Assay (HOLA or allele-specific PCR (AS-PCR. Results The kdr genotype was determined for about 1,000 An. gambiae specimens. The L1014F allele was found at frequencies ranging from 6% to 100% in all S-form samples (N = 628, with the exception of two samples from Angola, where it was absent, and coexisted with the L1014S allele in samples from Cameroon, Gabon and north-western Angola. The L1014F allele was present in M-form samples (N = 354 from Benin, Nigeria, and Cameroon, where both M- and S-forms were sympatric. Conclusion The results represent the most comprehensive effort to analyse the overall distribution of the L1014F and L1014S mutations in An. gambiae molecular forms, and will serve as baseline data for resistance monitoring. The overall picture shows that the emergence and spread of kdr alleles in An. gambiae is a dynamic process and that there is marked intra- and inter-form heterogeneity in resistance allele frequencies. Further studies are needed to

  16. 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...... fail to model the Pb isotope systematics. Selective contamination during diffusional exchange, which can explain the complex Sr and Nd isotope compositions of the hybrid rocks (Blichert-Toft et al., 1992), cannot fully account for the variability of the Pb isotopic data using the identified crustal end......-members. The crustal anatectic end-member, although similar in Sr and Nd isotope composition, has a markedly different Pb isotopic composition than its source gneiss. The differences are consistent with preferential incorporation of radiogenic Pb from accessory phases such as metamict zircon or loosely-bound Pb from...

  17. Genetic Diversity of Porang Populations (Amorphophallus Muelleri Blume) In Central Java and West Java Based on LEAFY Second Intron Marker

    OpenAIRE

    Isna Arofatun Nikmah; Rodiyati Azrianingsih; Didik Wahyudi

    2016-01-01

    Porang (Amorphophallus muelleri Blume) is dispersed and grew well in Java island. This research aimed to determine the genetic diversity of porang populations in Central Java and West Java based on LEAFY second intron (nuclear genome encoding flower development). DNA samples of porang were from previous study, which were obtained from Central Java (Pamedaran, Grobogan, Wonogiri, Karangtengah) and West Java (Cisompet) as in-group. Amorphophallus variabilis from Pamedaran Brebes, Amorphophallus...

  18. A tectonically controlled basin-fill within the Valle del Cauca, West-Central Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Rine, J.M.; Keith, J.F. Jr.; Alfonso, C.A.; Ballesteros, I.; Laverde, F.; Sacks, P.E.; Secor, D.T. Jr. (Univ. of South Carolina, Columbia (United States)); Perez, V.E.; Bernal, I.; Cordoba, F.; Numpaque, L.E. (Ecopetrol, Bogota (Colombia))

    1993-02-01

    Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordillera Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

  19. Determination of Water Sensitivity Index in EstakoWest and Esan Central, Nigeria

    Directory of Open Access Journals (Sweden)

    Philipa O. Idogho

    2014-07-01

    Full Text Available As world population and industrial-agricultural outputs have increased, the use of water has accelerated. This development leads to extreme difficulty to provide sufficient safe drinking water in Etasko-West and Esan Central. Water sensitivity was measured in six major towns in Etasko-West and Esan Central. Water Measuring Indicators such as Water Poverty Index-Real Time (WPIr, Water Factor Value (WFV and Access-Demand Factor (γ were applied to generate water sensitivity iterations. The outputs of these iterations show that Irrua has the fairest water supply and distribution with WPIr, WFA and γ index value of 0.22; 0.77 and 0.76, while Auchi and Ewu experience acute water shortage with the following index values: WPIr-0.43, 0.39; WFV-0.06, 0.16; and γ-0.64, 0.6 respectively. Results of One-Sample Test and Paired Sample Statistics show that the proportion of monthly income spent on portable water is significant at 0.95 confidence interval in all towns, except Auchi. Comparative analysis indicates strong relationship (R 2=0.667 between the resources spent in procuring clean water and accessibility-demand ratio in the region. Private sector participation recorded highest investment value of 62% on water sector; government and corporate organization recorded 23% and 15% respectively. Since private sector determines the progresses of water sector, this accounts for the exorbitant tariff of 1, 500 N per m 3 in this region. It is deduced that the most significant problems faced with water accessibility-affordability are transportation, finance and power supply with computed constraint index value of 47%, 40% and 13% respectively. Finally, Etasko-West and Esan Central are highly waterstressed. Government, corporate organization and private investors need to establish technically-based measures to ensure perfect accessibility and affordability of this scarce utility.

  20. 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...

  1. Inuit dietary patterns in modern Greenland

    OpenAIRE

    Bjerregaard, Peter; Jeppesen, Charlotte

    2012-01-01

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

  2. Mortality of vertebrates in irrigation canals in an area of west-central Spain

    Directory of Open Access Journals (Sweden)

    P. Garcia

    2009-01-01

    Full Text Available Mortality patterns of vertebrates in irrigation canals have been poorly studied despite their potential impact on wildlife. Concrete irrigation canals in a cropland area in west-central Spain were monitored over 13 months to assess their impact on small fauna. A total of 134 vertebrates were found dead. Most were amphibians (86.46% or mammals (20.90%, though fishes, reptiles and a bird were also recorded. Mortality peaked in autumn months. Corrective measurements are needed to reduce this cause of non-natural mortality.

  3. An Economic Evaluation of Conservation Farming Practices for the Central West of NSW

    OpenAIRE

    Farrell, Terence C.

    2008-01-01

    Economic benefits that arise from conservation farming practices need to be assessed over several years to account for improvements in soil structure and nutrient levels. A gross margin model was used to assess benefits over the eight-year period 1999-2006 for 12 regions in the central west of NSW. The benefits from improved soil structure ranged from $39.85 to $114.26 per hectare (ha). A reduction in tractor power produced savings in the range of $6.74 to $40.98 per ha. The average net benef...

  4. Hydrologic and microclimate characterizations of Thornton’s Cave, West-Central Florida (USA)

    OpenAIRE

    Dorien K. McGee

    2012-01-01

    A cave’s environment is controlled by a suite of factors unique to the environments in which they formed, including, but not limited to, regional geologic and climate settings. These factors collectively owe to wide variations in cave biology, geomorphology and overall speleogenesis. This report combines local climate, hydrologic, and CO2 data collected over the course of a two-year study at Thornton’s Cave, a partially-flooded cave in the West-Central Florida karst belt, to characterize its ...

  5. Archaean fluid-assisted crustal cannibalism recorded by low δ18O and negative ɛHf(T) isotopic signatures of West Greenland granite zircon

    Science.gov (United States)

    Hiess, Joe; Bennett, Vickie C.; Nutman, Allen P.; Williams, Ian S.

    2011-06-01

    The role of fluids during Archaean intra-crustal magmatism has been investigated via integrated SHRIMP U-Pb, δ18O and LA-MC-ICPMS 176Hf isotopic zircon analysis. Six rock samples studied are all from the Nuuk region (southern West Greenland) including two ~3.69 Ga granitic and trondhjemitic gneisses, a 3.64 Ga granitic augen gneiss, a 2.82 Ga granodioritic Ikkattoq gneiss, a migmatite with late Neoarchaean neosome and a homogeneous granite of the 2.56 Ga Qôrqut Granite Complex (QGC). All zircon grains were thoroughly imaged to facilitate analysis of magmatic growth domains. Within the zircon analysed, there is no evidence for metamictization. Initial ɛHf zircon values ( n = 63) are largely sub-chondritic, indicating the granitic host magmas were generated by the remelting of older, un-radiogenic crustal components. Zircon from some granite samples displays more than one 207Pb/206Pb age, and correlated with 176Hf/177Hf compositions can trace multiple phases of remelting or recrystallization during the Archaean. Model ages calculated using Lu/Hf arrays for each sample indicate that the crustal parental rocks to the granites, granodiorites and trondhjemites segregated from a chondrite-like reservoir at an earlier time during the Archaean, corresponding to known formation periods of more primitive tonalite-trondhjemite-granodiorite (TTG) gneisses. Zircon from the ~3.69 Ga granite, the migmatite and QGC granite contains Eoarchaean cores with chondritic 176Hf/177Hf and mantle-like δ18O compositions. The age and geochemical signatures from these inherited components are identical to those of surrounding tonalitic gneisses, further suggesting genesis of these granites by remelting of broadly tonalitic protoliths. Zircon oxygen isotopic compositions ( n = 62) over nine age populations (six igneous and three inherited) have weighted mean or mean δ18O values ranging from 5.8 ± 0.6 to 3.7 ± 0.5‰. The 3.64 Ga granitic augen gneiss sample displays the highest δ18O with

  6. Sedimentary Record and Morphological Effects of a Landslide-Generated Tsunami in a Polar Region: The 2000 AD Tsunami in Vaigat Strait, West Greenland

    Science.gov (United States)

    Szczucinski, W.; Rosser, N. J.; Strzelecki, M. C.; Long, A. J.; Lawrence, T.; Buchwal, A.; Chague-Goff, C.; Woodroffe, S.

    2012-12-01

    To date, the effects of tsunami erosion and deposition have mainly been reported from tropical and temperate climatic zones yet tsunamis are also frequent in polar zones, particularly in fjord settings where they can be generated by landslides. Here we report the geological effects of a landslide-triggered tsunami that occurred on 21st November 2000 in Vaigat, northern Disko Bugt in west Greenland. To characterise the typical features of this tsunami we completed twelve detailed coastal transects in a range of depositional settings: cliff coasts, narrow to moderate width coastal plains, lagoons and a coastal lake. At each setting we completed a detailed map using a laser scanner and DGPS survey. The tsunami deposits were described from closely spaced trenches and, from the lake, by a series of sediment cores . At each setting we examined the sedimentological properties of the deposits, as well as their bulk geochemistry and diatom content. Selected specimens of arctic willow from inundated and non-inundated areas were collected to assess the impact of the event in their growth ring records. Samples of sediments beneath the AD 2000 deposit were studied for 137Cs to confirm the age of the tsunami and to assess the extent of erosion. Offshore sediment samples, modern beach and soils/sediments underlying the AD 2000 tsunami deposits were sampled to determine tsunami deposit sources. The observed tsunami run-up exceeded 20 m next to the tsunami trigger - a rock avalanche at Paatuut - and up to 10 m on the opposite coast of the fjord. The inland inundation distance ranged from several tens of meters to over 300 m. The wave was recorded as far as 180 km away from the source. The tsunami inundated the coast obliquely to the shoreline in all locations studied. The tsunami frequently caused erosion of existing beach ridges whilst erosional niches were formed inland. The tsunami deposits mainly comprise gravels and very coarse sand. They are over 30 cm thick close to the

  7. Evaluation of the use of common sculpin (Myoxocephalus scorpius) organ histology as bioindicator for element exposure in the fjord of the mining area Maarmorilik, West Greenland.

    Science.gov (United States)

    Sonne, Christian; Bach, Lis; Søndergaard, Jens; Rigét, Frank F; Dietz, Rune; Mosbech, Anders; Leifsson, Pall S; Gustavson, Kim

    2014-08-01

    The former Black Angel lead-zinc mine in Maarmorilik, West Greenland, is a historic example of how mining activity may result in a significant impact on the surrounding fjord system in terms of elevated concentrations of especially lead (Pb) and zinc (Zn) in seawater, sediments and surrounding biota. In order to shed light on the present contamination and possible effects in the fjord we initiated a range of studies including a pilot study on gill and liver morphology of common sculpins (Myoxocephalus scorpius) around Maarmorilik. Sculpins were caught and sampled at five different stations known to represent a gradient of Pb concentrations. Fish livers from all specimens were analyzed for relevant elements in the area: Fe, Zn, As, Cu, Se, Cd, Pb, Ag, Hg, Co and Ni. Lead, As and Hg showed significant differences among the five stations. For 20% of the sculpins, Hg concentrations were in the range of lowest observed effect dose (LOED) of 0.1-0.5 μg/g ww for toxic threshold on reproduction and subclinical endpoints. Likewise LOEDs for tissue lesions, LOEDs for biochemistry, growth, survival and reproduction were exceeded for Cd (0.42-1.8 μg/g ww) and for As (11.6 μg/g ww) in 28% and 85% of the sculpins, respectively. Similar to this, the no observed effect dose (NOED) for biochemistry was exceeded for Pb (0.32 μg/g ww) and for growth, mortality and reproduction for Zn (60-68 μg/g ww) in 33% and 24% of the sculpins, respectively. For all sculpins, females were significantly larger than males and for five of the elements (Fe, Co, Ni, Cu, Se) females had higher concentrations. The chronic lesions observed in liver (mononuclear cell infiltrates, necrosis, vacuolar hepatocytes, portal fibrosis, bile duct hyperplasia, active melanomacrophage centers) and gills (fusion and edema of secondary lamellae, laminar telangiectasis, mononuclear cell infiltrates, blebs) were similar to those in the literature studies for both wild and laboratory exposed sculpins and other fish

  8. Environmental interpretation of lithofacies and biofacies, lower Sierra Madre Limestone, west central Chiapas, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, D.K.T.

    1989-03-01

    The Jiquipilas section of the Cretaceous Sierra Madre Limestone, which encompasses the lower part of the formation, was measured northwest of the town of Ocozocuautla in west-central Chiapas, Mexico. The section is 2140 m thick and is characterized by six lithofacies interpreted to represent supratidal, intertidal platform, restricted inner shelf, open inner shelf, shoal, and open-marine middle shelf environments. Overall, the sequence is submergent, with minor emergent episodes. Based upon cluster analysis, three biofacies associations were established: offshore middle shelf, nearshore middle shelf, and inner shelf. The lower 2045 m of the section are dominated by the inner shelf association, while the upper 95 m are dominated by the offshore association. The nearshore middle-shelf association is a minor component throughout the section. Correlation with a measure section from a previous study resulted in a composite thickness for the Sierra Madre Limestone in west-central Chiapas of 3355 m. This figure is considerably greater than previously reported thicknesses for the formation. It indicates that sedimentation on the Yucatan carbonate platform during the middle Cretaceous may have approached sediment accumulation rates in modern sedimentary basins.

  9. Measuring bioavailable metals using diffusive gradients in thin films (DGT) and transplanted seaweed (Fucus vesiculosus), blue mussels (Mytilus edulis) and sea snails (Littorina saxatilis) suspended from monitoring buoys near a former lead-zinc mine in West Greenland.

    Science.gov (United States)

    Søndergaard, Jens; Bach, Lis; Gustavson, Kim

    2014-01-15

    Measuring loads of bioavailable metals is important for environmental assessment near mines and other industrial sources. In this study, a setup of monitoring buoys was tested to assess loads of bioavailable metals near a former Pb-Zn mine in West Greenland using transplanted seaweed, mussels and sea snails. In addition, passive DGT samplers were installed. After a 9-day deployment period, concentrations of especially Pb, Zn and Fe in the species were all markedly elevated at the monitoring sites closest to the mine. Lead concentrations in all three species and the DGT-Pb results showed a significant linear correlation. Zinc and Fe concentrations were less correlated indicating that the mechanisms for Zn and Fe accumulation in the three species are more complex. The results show that there is still a significant load of metals from the mine and that such buoys can be an adequate method to assess present loads of bioavailable metals.

  10. Tracing the origin of the east-west population admixture in the Altai region (Central Asia.

    Directory of Open Access Journals (Sweden)

    Mercedes González-Ruiz

    Full Text Available A recent discovery of Iron Age burials (Pazyryk culture in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia. Studies on ancient mitochondrial DNA of this region suggest that the Altai Mountains played the role of a geographical barrier between West and East Eurasian lineages until the beginning of the Iron Age. After the 7th century BC, coinciding with Scythian expansion across the Eurasian steppes, a gradual influx of East Eurasian sequences in Western steppes is detected. However, the underlying events behind the genetic admixture in Altai during the Iron Age are still unresolved: 1 whether it was a result of migratory events (eastward firstly, westward secondly, or 2 whether it was a result of a local demographic expansion in a 'contact zone' between European and East Asian people. In the present work, we analyzed the mitochondrial DNA lineages in human remains from Bronze and Iron Age burials of Mongolian Altai. Here we present support to the hypothesis that the gene pool of Iron Age inhabitants of Mongolian Altai was similar to that of western Iron Age Altaians (Russia and Kazakhstan. Thus, this people not only shared the same culture (Pazyryk, but also shared the same genetic east-west population admixture. In turn, Pazyryks appear to have a similar gene pool that current Altaians. Our results further show that Iron Age Altaians displayed mitochondrial lineages already present around Altai region before the Iron Age. This would provide support for a demographic expansion of local people of Altai instead of westward or eastward migratory events, as the demographic event behind the high population genetic admixture and diversity in Central Asia.

  11. Seasonal variability of the circulation system in a West Greenland tidewater outlet glacier fjord, Godthåbsfjord (64°N)

    DEFF Research Database (Denmark)

    Mortensen, John; Bendtsen, Jørgen; Lennert, Kunuk;

    2014-01-01

    Many tidewater outlet glacier fjords surround the coast of Greenland, and their dynamics and circulation are of great importance for understanding the heat transport toward glaciers from the ice sheet. Thus, fjord circulation is a critical aspect for assessing the threat of global sea level rise...... circulation phases are identified during the period, and they are related to exchange processes with coastal waters, tidal mixing, and melt processes on the Greenland Ice Sheet. During early summer, warm intermediate water is transported toward the glacier at an average velocity of about 7 cm s−1. In late...... summer, the average velocity decreases to 3 cm s−1 during a period with significant subglacial freshwater discharges. During this period, a large variability in current velocities is also observed. The associated average heat transport in an intermediate-depth range corresponds to 568 GW in early summer...

  12. Aponogeton pollen from the Cretaceous and Paleogene of North America and West Greenland: Implications for the origin and palaeobiogeography of the genus☆

    Science.gov (United States)

    Grímsson, Friðgeir; Zetter, Reinhard; Halbritter, Heidemarie; Grimm, Guido W.

    2014-01-01

    The fossil record of Aponogeton (Aponogetonaceae) is scarce and the few reported macrofossil findings are in need of taxonomic revision. Aponogeton pollen is highly diagnostic and when studied with light microscopy (LM) and scanning electron microscopy (SEM) it cannot be confused with any other pollen types. The fossil Aponogeton pollen described here represent the first reliable Cretaceous and Eocene records of this genus worldwide. Today, Aponogeton is confined to the tropics and subtropics of the Old World, but the new fossil records show that during the late Cretaceous and early Cenozoic it was thriving in North America and Greenland. The late Cretaceous pollen record provides important data for future phylogenetic and phylogeographic studies focusing on basal monocots, especially the Alismatales. The Eocene pollen morphotypes from North America and Greenland differ in morphology from each other and also from the older Late Cretaceous North American pollen morphotype, indicating evolutionary trends and diversification within the genus over that time period. The presence of Aponogeton in the fossil record of North America and Greenland calls for a reconsideration of all previous ideas about the biogeographic history of the family. PMID:24926107

  13. Population structure of clinical Pseudomonas aeruginosa from West and Central African countries.

    Directory of Open Access Journals (Sweden)

    Pascal Cholley

    Full Text Available Pseudomonas aeruginosa (PA has a non-clonal, epidemic population with a few widely distributed and frequently encountered sequence types (STs called 'high-risk clusters'. Clinical P. aeruginosa (clinPA has been studied in all inhabited continents excepted in Africa, where a very few isolates have been analyzed. Here, we characterized a collection of clinPA isolates from four countries of West and Central Africa.184 non-redundant isolates of clinPA from hospitals of Senegal, Ivory Coast, Nigeria, and Central African Republic were genotyped by MLST. We assessed their resistance level to antibiotics by agar diffusion and identified the extended-spectrum β-lactamases (ESBLs and metallo-β-lactamases (MBLs by sequencing. The population structure of the species was determined by a nucleotide-based analysis of the entire PA MLST database and further localized on the phylogenetic tree (i the sequence types (STs of the present collection, (ii the STs by continents, (iii ESBL- and MBL-producing STs from the MLST database.We found 80 distinct STs, of which 24 had no relationship with any known STs. 'High-risk' international clonal complexes (CC155, CC244, CC235 were frequently found in West and Central Africa. The five VIM-2-producing isolates belonged to CC233 and CC244. GES-1 and GES-9 enzymes were produced by one CC235 and one ST1469 isolate, respectively. We showed the spread of 'high-risk' international clonal complexes, often described as multidrug-resistant on other continents, with a fully susceptible phenotype. The MBL- and ESBL-producing STs were scattered throughout the phylogenetic tree and our data suggest a poor association between a continent and a specific phylogroup.ESBL- and MBL-encoding genes are borne by both successful international clonal complexes and distinct local STs in clinPA of West and Central Africa. Furthermore, our data suggest that the spread of a ST could be either due to its antibiotic resistance or to features

  14. Hydrologic reconnaissance of the southern Great Salt Lake Desert and summary of the hydrology of west-central Utah

    Science.gov (United States)

    Gates, Joseph S.; Kruer, Stacie A.

    1981-01-01

    This report is the last of 19 hydrologic reconnaissances of the basins in western Utah. The purposes of this series of studies are (1) to analyze available hydrologic data and describe the hydrologic system, (2) to evaluate existing and potential water-resources development, and (3) to identify additional studies that might be needed. Part 1 of this report gives an estimate of recharge and discharge, an estimate of the potential for water-resources development, and a statement on the quality of water in the southern Great Salt Lake Desert part of west-central Utah. Part 2 deals with the same aspects of west-central Utah as a whole. Part 2 also summarizes the evidence of interbasin ground-water flow in west-central Utah and presents a theory for the origin of the water discharged from Fish Springs.

  15. Norse Greenland

    DEFF Research Database (Denmark)

    Arneborg, Jette

    2015-01-01

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

  16. Geophysical Framework Investigations Influencing Ground-Water Resources in East-Central Nevada and West-Central Utah

    Science.gov (United States)

    Watt, Janet T.; Ponce, David A.

    2007-01-01

    A geophysical investigation was undertaken as part of an effort to characterize the geologic framework influencing ground-water resources in east-central Nevada and west-central Utah. New gravity data were combined with existing aeromagnetic, drill-hole, and geologic data to help determine basin geometry, infer structural features, estimate depth to pre-Cenozoic basement rocks, and further constrain the horizontal extents of exposed and buried plutons. In addition, a three-dimensional (3D) geologic model was constructed to help illustrate the often complex geometries of individual basins and aid in assessing the connectivity of adjacent basins. In general, the thirteen major valleys within the study area have axes oriented north-south and frequently contain one or more sub-basins. These basins are often asymmetric and typically reach depths of 2 km. Analysis of gravity data helped delineate geophysical lineaments and accommodation zones. Structural complexities may further compartmentalize ground-water flow within basins and the influence of tectonics on basin sedimentation further complicates their hydrologic properties. The horizontal extent of exposed and, in particular, buried plutons was estimated over the entire study area. The location and subsurface extents of these plutons will be very important for regional water resource assessments, as these features may act as either barriers or pathways for groundwater flow. A previously identified basement gravity low strikes NW within the study area and occurs within a highly extended terrane between the Butte and Confusion synclinoria. Evidence from geophysical, geologic, and seismic reflection data suggests relatively lower density plutonic rocks may extend to moderate crustal depths and rocks of similar composition may be the source of the entire basement gravity anomaly.

  17. Geologic map of the west-central Buffalo National River region, northern Arkansas

    Science.gov (United States)

    Hudson, Mark R.; Turner, Kenzie J.

    2014-01-01

    This map summarizes the geology of the west-central Buffalo National River region in the Ozark Plateaus region of northern Arkansas. Geologically, the region lies on the southern flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. Physiographically, the map area spans the Springfield Plateau, a topographic surface generally held up by Mississippian cherty limestone and the higher Boston Mountains to the south, held up by Pennsylvanian rocks. The Buffalo River flows eastward through the map area, enhancing bedrock erosion of an approximately 1,600-ft- (490-m-) thick sequence of Ordovician, Mississippian, and Pennsylvanian carbonate and clastic sedimentary rocks that have been mildly deformed by a series of faults and folds. Quaternary surficial units are present as alluvial deposits along major streams, including a series of terrace deposits from the Buffalo River, as well as colluvium and landslide deposits mantling bedrock on hillslopes.

  18. Antimicrobial susceptibility of environmental bovine mastitis pathogens in west central Iran.

    Science.gov (United States)

    Ebrahimi, Azizollah; Kheirabadi, K H Pirali; Nikookhah, Farzaneh

    2007-09-01

    The purpose of this study was to describe antimicrobial susceptibility of environmental mastitis pathogens isolated from dairy herds of Chahar Mahal province in west central Iran. Out of the 620 milk samples collected from the four districts, 180 were CMT (California mastitis test) positive that cultured and yield, 7 (3.88%) coagulase negative Staphylococci (CNS), 15 (8.33%) Streptococci other than agalactiae and 17 (9.44%) E. coli. CNS resistance to penicillin was 14.28% but for streptomycin, Oxytetracycline and Colistin, were 28.57%. Non agalactiae Streptococci resistance to Oxytetracycline and Kanamycin were 20 and 13.33%, respectively. E. coli resistance to penicillin, oxytetracycline, streptomycin, erythromycin and Colistin were 88.23, 82.35, 76.47, 76.47 and 52.94%, respectively. PMID:19090221

  19. Late Neogene slip transfer and extension within the curved Whisky Flat fault system central Walker Lane, west-central Nevada

    Science.gov (United States)

    Biholar, Alexander Kenneth Casian

    In Whisky Flat of west-central Nevada, northwest-striking faults in the Walker Lane curve to east-northeast orientations at the northern limits of the Mina deflection. This curve in strike results in the formation of ˜685 m deep depression bounded by north-south convex to the east range-front faults that at the apex of fault curvature are bisected at a high angle by a structural stepover. We use the vertical offset of a late Miocene erosional surface mapped in the highlands and inferred from gravity depth inversion in the basin to measure the magnitude of displacement on faults. A N65°W extensional axis determined through fault-slip inversion is used to constrain the direction in displacement models. Through the use of a forward rectilinear displacement model, we document that the complex array of faults is capable of developing with broadly contemporaneous displacements on all structures since the opening of the basin during the Pliocene.

  20. From Arctic greenhouse to icehouse: the Cenozoic development of the West Greenland-Baffin Bay margin and the case for scientific drilling

    Science.gov (United States)

    Knutz, Paul; Gregersen, Ulrik; Hopper, John R.; Dybkjær, Karen; Nøhr-Hansen, Henrik; Sheldon, Emma; Huuse, Mads

    2016-04-01

    The long-term evolution of glaciated margins plays an essential role in understanding the driving forces and interactions that determine the build-up and decay of ice sheets. The Greenland continental margin towards Baffin Bay is densely covered by industry seismic data and several exploration wells have been drilled, providing a regional stratigraphic framework for the sedimentary successions. This presentation provides an overview of the major depositional units and stratigraphy of the mid-late Cenozoic (since mid-Eocene), with examples demonstrating the different processes that have formed this margin. A sedimentary succession up to 3.5 km thick, of mid-Eocene to mid-Miocene age (mega-unit D), infills the pronounced ridge-basin structures of the rifted and tectonically inverted margin. The lower part of this interval, presumably late Eocene-Oligocene in age, is interpreted as basin-floor fan deposits, while the upper section, of early-middle Miocene age, is mainly marine mudstone. The basin infilling strata are overlain by a late Miocene-Pliocene succession consisting of two mega-units (B and C), with typical thicknesses of 0.5-1 km. The units are characterised by upslope-climbing sediment waves and along-slope trending sedimentary prisms reminiscent of giant contourite drifts. The borehole data associates the prism accumulations with a deep shelf environment influenced by strong marine currents and nearby fluvial sources. On the slope and in the deep basin of Baffin Bay the late Neogene succession is strongly influenced by mass wasting correlated with erosional scars updip. The uppermost seismic mega-unit (A) is dominated by aggradational wedges and prograding fan deposits displaying depocentres >3 km thick, formed at the terminus of palaeo-ice streams. Borehole information associates this interval with deposition of primarily diamict sediments and suggests a late Pliocene onset of major shelf based glaciations on the NW Greenland margin. The southwest margin

  1. The West Central Alberta Woodland Caribou Landscape Plan: Using a Modeling Approach to Develop Alternative Scenarios

    Directory of Open Access Journals (Sweden)

    Anne Hubbs

    2011-09-01

    Full Text Available Woodland caribou (Rangifer tarandus are classified as threatened in Alberta. In support of Canada's Species at Risk Act, a Recovery Plan for Woodland Caribou in Alberta was completed in 2004 which required local implementation plans to be completed within 5 areas of the province. The West Central Alberta Caribou Landscape Plan (WCCLP is the first of these to be initiated and it addresses the recovery strategies for 4 herds. Two aspatial computer models built on the STELLA© modelling platform (ISee Systems, 2007 were used to assist the planning team in evaluating cumulative effects and alternative scenarios for caribou conservation. The ALCES© (Forem Technologies 2008 modelling tool was used to forecast potential changes in the west central Alberta landscape over time. Yearly landscape condition outputs from ALCES© were then exported into a caribou-specific population model, REMUS© (Weclaw, 2004, that was used to project potential population responses by woodland caribou, other primary prey species [moose (Alces alces, elk (Cervus elaphus and deer (Odocoileus sp.] and wolves (Canis lupus (Weclaw & Hudson, 2004. Simulated habitat management strategies that resulted in the highest likelihood of caribou recovery included the maintenance of a high proportion of old forest, the aggregation of industrial footprints and the reclamation of historic seismic lines (although the latter took decades to provide real dividends. Sharing of industrial roads, protection of fragments of old-growth, and expanding an already aggressive fire control strategy in Alberta had little additional effect on caribou recovery. Simulated population management strategies that were successful all involved decades of intensive wolf control, either directly or indirectly through intensive primary prey control (with the exception of woodland caribou until old-growth forests recovered to densities that provided caribou habitat and decreased alternate prey of wolves. Although

  2. Physical activity in Greenland - a methodological perspective

    DEFF Research Database (Denmark)

    Dahl-Petersen, Inger

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

  3. Hydrological and meteorological investigations in a periglacial lake catchment near Kangerlussuaq, west Greenland – presentation of a new multi-parameter dataset

    Directory of Open Access Journals (Sweden)

    E. Johansson

    2014-12-01

    Full Text Available Few hydrological studies have been made in Greenland, other than on glacial hydrology associated with the ice sheet. Understanding permafrost hydrology and hydroclimatic change and variability, however, provides key information for understanding climate change effects and feedbacks in the Arctic landscape. This paper presents a new extensive and detailed hydrological and meteorological open access dataset, with high temporal resolution from a 1.56 km2 permafrost catchment with a lake underlain by a through talik close to the ice sheet in the Kangerlussuaq region, western Greenland. The paper describes the hydrological site investigations and utilized equipment, as well as the data collection and processing. The investigations were performed between 2010 and 2013. The high spatial resolution, within the investigated area, of the dataset makes it highly suitable for various detailed hydrological and ecological studies on catchment scale. The dataset is availble for all users via the PANGAEA database, http://doi.pangaea.de/10.1594/PANGAEA.836178. Please note this dataset is under review and recommended not to be used before the final version of the manuscript is accepted for publication.

  4. A TEX 86 lake record suggests simultaneous shifts in temperature in Central Europe and Greenland during the last deglaciation

    OpenAIRE

    Blaga, C. I.; Reichart, G.-J.; Lotter, A. F.; Anselmetti, F. S.; Sinninghe Damsté, J.S.

    2013-01-01

    High-resolution quantitative temperature records from continents covering glacial to interglacial transitions are scarce but important for understanding the climate system. We present the first decadal resolution record of continental temperatures in Central Europe during the last deglaciation (similar to 14,60010,600cal. yrB.P.) based on the organic geochemical palaeothermometer TEX86. The TEX86-inferred temperature record from Lake Lucerne (Vierwaldstattersee, Switzerland) reveals typical o...

  5. Intra- and Inter-Seasonal Supra-glacial Water Variability over the West Greenland Ice Sheet as Estimated from Combining High Resolution Satellite Optical Data and a Digital Elevation Model

    Science.gov (United States)

    Brown, M. G.; Tedesco, M.; Smith, L. C.; Rennermalm, A. K.; Yang, K.

    2015-12-01

    The supra-glacial hydrology of the Greenland Ice Sheet (GrIS) plays a crucial role on the surface energy and mass balance budgets of the ice sheet as a whole. The surface hydrology network variability of small streams in the ablation zone of Greenland is poorly understood both spatially and temporally. Using satellites that can spatially resolve the presence and associated properties of small streams, the scientific community is now able to be provided with accurate spatial and temporal analysis of surface hydrology on the ice sheet (that could not have been resolved with other sensors such as those on board MODIS or LANDSAT). In this study we report mapped supra-glacial water networks over a region of the West GrIS (approximately 164 km2) derived from high resolution multispectral satellite imagery from the Quickbird and WorldView - 2 satellites in tandem with a 2 meter stereographic SETSM DEM (digital elevation model). The branching complexity of the identified surface streams is computed from the available DEM as well as the intra- and inter seasonal changes observed in the hydrological system. The stream networks created during the melt season (at several different stages of melting) are compared and discussed as well as the networks mapped between consecutive years for proximate dates. Also, depth and volume estimations for the surface water features identified were extracted via band math algorithms, threshold classifications, and morphological operations. Our results indicate that the higher stream orders have the largest amount of stored surface water per km but the lower stream orders, specifically 1st order with widths of ~ 2 meters, hold more stored surface water overall. We also employ and compare runoff data from the numerical model MAR (Modèle Atmosphérique Régional) to the estimations found using imagery and the DEM.

  6. Investigating the intellectual origins of Euroland's macroeconomic policy regime: central banking institutions and traditions in West Germany after the war

    OpenAIRE

    Bibow, Jörg

    2004-01-01

    This paper investigates the (re-) establishment of central banking in West Germany after 1945 and the history of the Bundesbank Act of 1957. The main focus is on the early emphasis on the ‘independence’ of the central bank, which, together with a ‘stability-orientation’ in monetary policy, proved a lasting German peculiarity. The paper inquires whether contemporary German economic thought may have provided a theoretical case for this peculiar tradition and scrutinizes the political calculus t...

  7. Evidence for selection at HIV host susceptibility genes in a West Central African human population

    Directory of Open Access Journals (Sweden)

    Zhao Kai

    2012-12-01

    Full Text Available Abstract Background HIV-1 derives from multiple independent transfers of simian immunodeficiency virus (SIV strains from chimpanzees to human populations. We hypothesized that human populations in west central Africa may have been exposed to SIV prior to the pandemic, and that previous outbreaks may have selected for genetic resistance to immunodeficiency viruses. To test this hypothesis, we examined the genomes of Biaka Western Pygmies, who historically resided in communities within the geographic range of the central African chimpanzee subspecies (Pan troglodytes troglodytes that carries strains of SIV ancestral to HIV-1. Results SNP genotypes of the Biaka were compared to those of African human populations who historically resided outside the range of P. t. troglodytes, including the Mbuti Eastern Pygmies. Genomic regions showing signatures of selection were compared to the genomic locations of genes reported to be associated with HIV infection or pathogenesis. In the Biaka, a strong signal of selection was detected at CUL5, which codes for a component of the vif-mediated APOBEC3 degradation pathway. A CUL5 allele protective against AIDS progression was fixed in the Biaka. A signal of selection was detected at TRIM5, which codes for an HIV post-entry restriction factor. A protective mis-sense mutation in TRIM5 had the highest frequency in Biaka compared to other African populations, as did a protective allele for APOBEC3G, which codes for an anti-HIV-1 restriction factor. Alleles protective against HIV-1 for APOBEC3H, CXCR6 and HLA-C were at higher frequencies in the Biaka than in the Mbuti. Biaka genomes showed a strong signal of selection at TSG101, an inhibitor of HIV-1 viral budding. Conclusions We found protective alleles or evidence for selection in the Biaka at a number of genes associated with HIV-1 infection or progression. Pygmies have also been reported to carry genotypes protective against HIV-1 for the genes CCR5 and CCL3L1. Our

  8. Origin of amphibole-rich beach sands from Tila-Mati, Karwar, central-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Iyer, S.D.

    The pocket beach at Tila-Mati, Karwar, central west coast of India, is characterised by the occurrence of amphibole-rich (chiefly tremolite-actinolite) coarse sand in the zone of minimal impact of waves and currents. In the total sediment, grain...

  9. 78 FR 54394 - Determination of Attainment for the West Central Pinal Nonattainment Area for the 2006 Fine...

    Science.gov (United States)

    2013-09-04

    ... 2006 Fine Particle Standard; Arizona; Determination Regarding Applicability of Clean Air Act...-hour fine particle (PM 2.5 ) National Ambient Air Quality Standard (NAAQS). This determination is based... Action On July 12, 2013 (78 FR 41901), EPA proposed to determine that the West Central...

  10. REGIONAL EMISSIONS OF NITRIC OXIDE (NO) AND CARBON DIOXIDE (CO2) IN AGROECOSYSTEMS IN CENTRAL WEST REGION, BRAZIL.

    Science.gov (United States)

    The Central West Region in Brazil has been the focus of intense agricultural expansion since the 1970s and, nowadays, a large area of native cerrado has been converted to agricultural use. The expansion was accompanied by intensive use of fertilizer, irrigation and management pra...

  11. Tendencies of mortality by prostate cancer in the states of the Central-West Region of Brazil, 1980-2011.

    Science.gov (United States)

    da Silva, João Francisco Santos; Mattos, Inês Echenique; Aydos, Ricardo Dutra

    2014-01-01

    This study aimed at analyzing the pattern of prostate cancer mortality in the Central-West Region, in the period 1980 - 2011. The quadrennial and annual mortality rates, age-standardized by the world population, were calculated. Polynomial regression models were estimated to analyze trends of mortality in Brazilian regions and in the states of the Central-West Region. Throughout Brazil there was an increase in the magnitude of mortality rates during the study's period. In the Central-West Region, mortality rates from prostate cancer increased from 7.65/100,000 in the period 1980 - 1983, to 14.36/100,000 in the last four years, exceeding the national average. For Mato Grosso do Sul, an increased trend, although not constant, was observed for prostate mortality rates, while those rates showed stability for Mato Grosso and presented a constant trend of increment for Goiás along the studied period. There was a statistically significant negative correlation between mortality rates from prostate cancer and the proportional mortality from ill-defined causes of death in the three states, but no correlations were observed between these rates and the ratios of Prostate Specific Antigen (PSA) tests realized. Difficulties in the access to the health services network, better quality of death records with reduction of ill-defined causes and increased use of PSA may have contributed to the mortality pattern observed in the Central-West Region. Further studies are needed to investigate these relationships in order, to better understand the patterns of mortality from this cancer in the Central-West population.

  12. Numerical simulation of the groundwater-flow system of the Kitsap Peninsula, west-central Washington

    Science.gov (United States)

    Frans, Lonna M.; Olsen, Theresa D.

    2016-05-05

    A groundwater-flow model was developed to improve understanding of water resources on the Kitsap Peninsula. The Kitsap Peninsula is in the Puget Sound lowland of west-central Washington, is bounded by Puget Sound on the east and by Hood Canal on the west, and covers an area of about 575 square miles. The peninsula encompasses all of Kitsap County, Mason County north of Hood Canal, and part of Pierce County west of Puget Sound. The peninsula is surrounded by saltwater, and the hydrologic setting is similar to that of an island. The study area is underlain by a thick sequence of unconsolidated glacial and interglacial deposits that overlie sedimentary and volcanic bedrock units that crop out in the central part of the study area. Twelve hydrogeologic units consisting of aquifers, confining units, and an underlying bedrock unit form the basis of the groundwater-flow model.Groundwater flow on the Kitsap Peninsula was simulated using the groundwater-flow model, MODFLOW‑NWT. The finite difference model grid comprises 536 rows, 362 columns, and 14 layers. Each model cell has a horizontal dimension of 500 by 500 feet, and the model contains a total of 1,227,772 active cells. Groundwater flow was simulated for transient conditions. Transient conditions were simulated for January 1985–December 2012 using annual stress periods for 1985–2004 and monthly stress periods for 2005–2012. During model calibration, variables were adjusted within probable ranges to minimize differences between measured and simulated groundwater levels and stream baseflows. As calibrated to transient conditions, the model has a standard deviation for heads and flows of 47.04 feet and 2.46 cubic feet per second, respectively.Simulated inflow to the model area for the 2005–2012 period from precipitation and secondary recharge was 585,323 acre-feet per year (acre-ft/yr) (93 percent of total simulated inflow ignoring changes in storage), and simulated inflow from stream and lake leakage was 43

  13. Paleobiogeographic affinities of emsian (late early devonian) gastropods from farewell terrane (west-central Alaska)

    Science.gov (United States)

    Fryda, J.; Blodgett, R.B.

    2008-01-01

    The vast majority of Emsian gastropods from Limestone Mountain, Medfra B-4 quadrangle, west-central Alaska (Farewell terrane) belong to species with lecithotrophic larval strategy. The present data show that there is no significant difference in the paleobiogeo-graphic distribution of Emsian gastropod genera with lecithotrophic and planktotrophic larval strategies. Numerical analysis of the faunal affinities of the Emsian gastropod fauna from the Farewell terrane reveals that this terrane has much stronger faunal connections to regions like Variscan Europe, eastern Australia, and the Alexander terrane of southeast Alaska than to cratonic North America (Laurentia). The Canadian Arctic Islands is the only region of cratonic North America (Laurentia) that shows significant faunal affinities to the Emsian gastropod faunas of the Farewell terrane. The analysis also indicates a close faunal link between the Farewell and Alexander terranes. Published paleontological and geological data suggest that the Farewell and Alexander terranes represents tectonic entities that have been rifted away from the Siberia, Baltica, or the paleo-Pacific margin of Australia. The results of the present numerical analysis are not in conflict with any of these possibilities. However, the principle of spatial continuity of the wandering path prefers Siberia as the most probable "parental" paleocontinent for the derivation of both the Farewell and Alexander terranes. ?? 2008 The Geological Society of America.

  14. Radiation-hazardous objects at the west and central Kazakstan territory

    International Nuclear Information System (INIS)

    In 1965-1987, there were conducted 39 industrial underground explosions in the territory of Kazakhstan Republic, in particular in its west and central region (explosions conducted at Semipalatinsk test site, East-Kazakhstan oblates are not included). These explosions were conducted in terms of the Program 7 Peaceful nuclear explosions for industrial purposes with the purpose of test-industrial investigation conducting for testing a technology for formation of cavities in rock salt in order to be used as multipurpose large volume storage. Energy from underground nuclear explosions was used for peaceful technological purposes, in particular, in the territories of hydrocarbon raw materials mining and industrial developing. It is obvious, that residual radioactivity, even if it is very small, is a factor, that hampers to use nuclear explosions for this purpose. The major problems are the following: safety measures, which are necessary for implementation of the projects on nuclear explosion usage in peaceful purposes, admissible level of environment pollution in whole and possible consequences. All necessary measures must be taken to ensure safety in the regions, where explosions were conducted, including all the least probable accidents (for instance, breach during camuflet explosions). To make sure, that existing admissible standards will not be exceeded, it is necessary to know the level of environment radiation contamination and to forecast probable contamination caused by explosions

  15. Astrovirus infection in children living in the Central West region of Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Alessandro Tôgo Santos

    2007-03-01

    Full Text Available This study presents data regarding the circulation of astrovirus in Goiânia-GO and Brasília-DF. These viruses were detected in fecal samples from hospitalized children up to five years old with and without acute gastroenteritis. A total of 1244 fecal samples were collected in two periods, 1994 to 1996 (Brasília and 1998 to 2002 (Goiânia and Brasília, and were analyzed for viral RNA using the reverse transcription-polymerase chain reaction (RT-PCR. Positivity rates of 4.3 and 0.5% for astrovirus were observed in children with acute gastroenteritis and those without gastroenteritis, respectively. Among children with gastroenteritis no statistically significant difference was seen with regards to viral positivity rates in relation to gender and age. However, a higher incidence rate was observed for children from Brasília aged 36 months or more. Overall, astroviruses occurred predominantly from September to March in the two cities, suggesting a seasonal pattern for these viruses which coincides with the highest relative air humidity period. The results of this study highlight the importance of astrovirus as an etiologic agent of acute gastroenteritis in children of the Central West region of Brazil.

  16. New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.

    Science.gov (United States)

    Mondol, Samrat; Moltke, Ida; Hart, John; Keigwin, Michael; Brown, Lisa; Stephens, Matthew; Wasser, Samuel K

    2015-12-01

    The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification. PMID:26577954

  17. Land use patterns and the risk of West Nile virus transmission in central Illinois.

    Science.gov (United States)

    Gardner, Allison M; Lampman, Richard L; Muturi, Ephantus J

    2014-05-01

    Understanding how human land use patterns influence mosquito ecology and the risk of mosquito-borne pathogens is critical for the development of disease management strategies. We examined how different environments influenced mosquito species composition, abundance, and West Nile virus (WNV) infection rates in central Illinois. Using a combination of gravid traps and CDC light traps, adult mosquitoes were collected every other week from June 24 to September 16, 2012, in four major land use categories-row crops, prairies, forest fragments, and residential neighborhoods. The mosquitoes were identified to species morphologically, and pools of pure and mixed Culex mosquitoes (primarily Culex pipiens and Culex restuans) were tested for WNV-RNA by qRT-PCR. Mosquito species diversity was significantly higher in forest habitats compared to residential, agricultural, and prairie land use categories. All the four landscape types were equally important habitats for WNV vectors Cx. pipiens and Cx. restuans, contrary to previous findings that these species principally inhabit the residential areas. WNV-infected mosquito pools were observed in all land use types, and the infection rates overlapped among land use categories. Although our findings support the importance of residential habitats for WNV transmission to humans, they also establish that prairie, row crops, and wood lots are potentially important refuges for enzootic transmission. This is particularly important in urban ecosystems where these land use categories are small, interspersed fragments serving as potential refuge sites during periods of low rainfall. PMID:24746038

  18. Reproductive biology of yellowfin tuna T. albacares in the west-central Indian Ocean

    Science.gov (United States)

    Zhu, Guoping; Xu, Liuxiong; Zhou, Yingqi; Song, Liming

    2008-08-01

    Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese longliners during 2003, 2004 and 2005, which is a part of Chinese Tuna Fishery Scientific Observer Program (CTFSOP). The reproductive biology has been investigated. A total of 1 023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59, and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is estimated at 113.77 cm for female and 120.20 cm for male, whereas maturation rate is 0.066 cm-1 for female and 0.091 cm-1 for male. Sex ratio by length class indicates that the proportion of male is higher than female’s along with size increasing; for instance, in the group of the body length longer than 145 cm, some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically, yellowfin tuna has a significant seasonal reproduction.

  19. Climate Change in Central and West Asia. Routes to a More Secure, Low-Carbon Future

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-11-15

    ADB's Central and West Asian countries are Afghanistan, Armenia, Azerbaijan, Georgia, Kazakhstan, the Kyrgyz Republic, Pakistan, Tajikistan, Turkmenistan, and Uzbekistan. Geoclimatic and environmental factors make this region highly vulnerable to the risks and hazards of climate change. For example, accelerated glacial melt has serious implications for agriculture, water supply, and energy generation - problems exacerbated by overexploitation of natural resources. Countries may find it difficult to shift to low-carbon growth, since many have abundant fossil fuel and tend to use energy inefficiently. ADB is responding to these climate hazards and low-carbon pathways with a comprehensive strategy that strengthens policies, governance, and capacity support; expands the use of clean and renewable energy; encourages sustainable transport and urban development; promotes development that will be more resilient to climate change, especially in water-dependent sectors; and manages land use and forests for carbon sequestration. ADB's support is helping its developing member countries face the challenges of climate change and, with partners, is providing innovative solutions, while continuing to work to reduce poverty.

  20. Quaternary Geology and Geomorphology of Terna River Basin in West Central India

    Directory of Open Access Journals (Sweden)

    Mohammad Babar

    2012-12-01

    Full Text Available This paper presents the morphostratigraphy, lithostratigraphy and sedimentary structures of Terna River basin in the Deccan Basaltic Province (DBP of West Central India. These Quaternary deposits have been divided into three informal formations (i dark grey silt formation – Late Holocene, (ii Light grey silt formations – Early Holocene, (iii Dark grayish brown silt formation – Late Pleistocene with the older Quaternary Alluvial deposits of Upper Pleistocene age. The fine clay and silt formations in the lower reaches reflect that the streams are of low gradient and more sinuous. The river shows evidences of channel movement by avulsion, largely controlled by lineaments. Palaeo-levees, in the form 4–5 m high ridges exist along the Terna River floodplain, specifically in the Ter, Killari, Sastur, Dhuta and Makni villages. Several lineaments occur along NE-SW, NW-SE, E-W and WNW-ESE directions, which control the basement structure in the study area. The values of the Topographic Sinuosity Index (TSI indicate rejuvenation of the area leading to the dominance of topography on the sinuosity of the river channels. The break in slope in the long profile is also indication of the Quaternary tectonic uplift of the area. Radiocarbon dating of some charcoal fragments collected from folded beddings indicates that paleoseismic activity might have taken place along the basin between AD 120 and AD 1671.

  1. Traits associated with winter wheat grain yield in Central and West Asia

    Institute of Scientific and Technical Information of China (English)

    Marta Silva Lopes; Didem Saglam; Mutlu Ozdogan; Matthew Reynolds

    2014-01-01

    Improved adaptation of winter wheat (Triticum aestivum L.) to drought and heat may be influenced by days to heading, plant height, biomass, canopy temperature (CT) at grain fil ing, and rate of senescence. This study shows that, under supplemental irrigation or rainfed conditions, days to heading and plant height together explain up to 68%of grain yield (GY) variation, and these associations were further confirmed in several locations across West and Central Asia. Days to heading can be slightly reduced below that of check line Karahan to further improve GY while avoiding the effect of late frosts. Plant height has been decreased in recent germplasm, but further reductions below that of check line Karahan could stil improve GY in a wide range of environ-ments. However, in Iranian sites, tal er genotypes showed better adaptation with higher biomass and increased reserves for grain fil ing. Canopy temperature and rate senescence were not associated with GY. A normalized difference vegetation index, used to estimate biomass (Feekes stages 4-5), had intermediate heritability across environments and correlated positively with GY under low plant density and should be explored further as a tool for early selection.

  2. New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.

    Science.gov (United States)

    Mondol, Samrat; Moltke, Ida; Hart, John; Keigwin, Michael; Brown, Lisa; Stephens, Matthew; Wasser, Samuel K

    2015-12-01

    The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification.

  3. Assessment of processes affecting low-flow water quality of Cedar Creek, west-central Illinois

    Science.gov (United States)

    Schmidt, Arthur R.; Freeman, W.O.; McFarlane, R.D.

    1989-01-01

    Water quality and the processes that affect dissolved oxygen, nutrient (nitrogen and phosphorus species), and algal concentrations were evaluated for a 23.8-mile reach of Cedar Creek near Galesburg, west-central Illinois, during periods of warm-weather, low-flow conditions. Water quality samples were collected and stream conditions were measured over a diel (24 hour) period on three occasions during July and August 1985. Analysis of data from the diel-sampling periods indicates that concentrations of iron, copper, manganese, phenols, and total dissolved-solids exceeded Illinois ' general-use water quality standards in some locations. Dissolved-oxygen concentrations were less than the State minimum standard throughout much of the study reach. These data were used to calibrate and verify a one-dimensional, steady-state, water quality model. The computer model was used to assess the relative effects on low-flow water quality of processes such as algal photosynthesis and respiration, ammonia oxidation, biochemical oxygen demand, sediment oxygen demand, and stream reaeration. Results from model simulations and sensitivity analysis indicate that sediment oxygen demand is the principal cause of low dissolved-oxygen concentrations in the creek. (USGS)

  4. Reproductive Biology of Yeilowfin Tuna T. albacares in the West-Central Indian Ocean

    Institute of Scientific and Technical Information of China (English)

    ZHU Guoping; XU Liuxiong; ZHOU Yingqi; SONG Liming

    2008-01-01

    Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese Iongliners during 2003, 2004 and 2005, which is a part of Chinese Tuna Fishery Scientific Observer Program (CTFSOP). The reproductive biology has been investigated. A total of 1023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59, and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is esti- mated at 113.77 cm for female and 120.20 cm for male, whereas maturation rate is 0.066 cm-1 for female and 0.091 cm-1 for male. Sex ratio by length class indicates that the proportion of male is higher than female's along with size increasing; for instance, in the group of the body length longer than 145 cm, some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically, yellowfin tuna has a significant seasonal reproduction.

  5. Adventure Learning @ Greenland

    Science.gov (United States)

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

    2013-12-01

    Summit (ICECAPS) project (Shupe et al. 2012; http://www.esrl.noaa.gov/psd/arctic/observatories/summit/). ICECAPS is an atmospheric observatory focused on obtaining high temporal resolution measurements of clouds from ground-based remote sensors including radar, lidar, infrared spectra and others. ICECAPS also launches radiosondes twice daily. This large suite of complementary observations are providing an important baseline understanding of cloud and atmospheric conditions over the central Greenland ice sheet and are supporting Arctic climate research on cloud processes and climate model validation. ICECAPS measures parameters that are associated with those identified in student misconceptions, for example, different types of atmospheric radiation, the effect of greenhouse gases, and climate versus weather (see also Haller et al., 2011). Thus, ICECAPS research and the AL@GL project combined to create a learning environment and educational activities that sought to increase climate literacy in high school students as well as communicate important atmospheric research to a broader audience.

  6. Success and failure of reindeer herding in Greenland

    Directory of Open Access Journals (Sweden)

    Christine Cuyler

    1999-04-01

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

  7. Variable influx of West Greenland Current water into the Labrador Current through the last 8000 years, based on a multiproxy study from Trinity Bay, NE Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Frandsen, Paul;

    2015-01-01

    This multi-proxy study of marine sediment gravity core AI07-06G from Trinity Bay, Newfoundland, recorded changes in the strength of the Labrador Current (LC) during the Holocene. From ca. 8-5 cal kyr BP, Trinity Bay's seafloor was influenced by cooled Atlantic water derived from the West Greenlan...

  8. Surface-water radon-222 distribution along the west-central Florida shelf

    Science.gov (United States)

    Smith, C.G.; Robbins, L.L.

    2012-01-01

    In February 2009 and August 2009, the spatial distribution of radon-222 in surface water was mapped along the west-central Florida shelf as collaboration between the Response of Florida Shelf Ecosystems to Climate Change project and a U.S. Geological Survey Mendenhall Research Fellowship project. This report summarizes the surface distribution of radon-222 from two cruises and evaluates potential physical controls on radon-222 fluxes. Radon-222 is an inert gas produced overwhelmingly in sediment and has a short half-life of 3.8 days; activities in surface water ranged between 30 and 170 becquerels per cubic meter. Overall, radon-222 activities were enriched in nearshore surface waters relative to offshore waters. Dilution in offshore waters is expected to be the cause of the low offshore activities. While thermal stratification of the water column during the August survey may explain higher radon-222 activities relative to the February survey, radon-222 activity and integrated surface-water inventories decreased exponentially from the shoreline during both cruises. By estimating radon-222 evasion by wind from nearby buoy data and accounting for internal production from dissolved radium-226, its radiogenic long-lived parent, a simple one-dimensional model was implemented to determine the role that offshore mixing, benthic influx, and decay have on the distribution of excess radon-222 inventories along the west Florida shelf. For multiple statistically based boundary condition scenarios (first quartile, median, third quartile, and maximum radon-222 inshore of 5 kilometers), the cross-shelf mixing rates and average nearshore submarine groundwater discharge (SGD) rates varied from 100.38 to 10-3.4 square kilometers per day and 0.00 to 1.70 centimeters per day, respectively. This dataset and modeling provide the first attempt to assess cross-shelf mixing and SGD on such a large spatial scale. Such estimates help scale up SGD rates that are often made at 1- to 10-meter

  9. Weather Test Reference Year of Greenland

    DEFF Research Database (Denmark)

    Kragh, Jesper; Pedersen, Frank; Svendsen, Svend

    2005-01-01

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

  10. The Choice Between External and Domestic Debt in Financing Budget Deficits; The Case of Central and West African Countries

    OpenAIRE

    Philippe Beaugrand; Montfort Mlachila; Boileau Loko

    2002-01-01

    The paper reviews the principles and practical considerations involved in the choice between foreign and domestic financing of fiscal deficits, and derives a series of recommendations broadly applicable to Central and West African countries. The paper develops a simple analytical framework and shows that highly concessional external debt is usually a superior choice to domestic debt in terms of financial costs and risks, even in the face of a probable devaluation. The paper stresses the impor...

  11. Historic impact of watershed change and sedimentation to reefs along west-central Guam

    Science.gov (United States)

    Prouty, Nancy G.; Storlazzi, Curt D.; McCutcheon, Amanda L.; Jenson, John W.

    2014-09-01

    Using coral growth parameters (extension, density, calcification rates, and luminescence) and geochemical measurements (barium to calcium rations; Ba/Ca) from coral cores collected in west-central Guam, we provide a historic perspective on sediment input to coral reefs adjacent to the Piti-Asan watershed. The months of August through December are dominated by increased coral Ba/Ca values, corresponding to the rainy season. With river water enriched in barium related to nearshore seawater, coral Ba/Ca ratios are presented as a proxy for input of fine-grained terrigenous sediment to the nearshore environment. The century-long Ba/Ca coral record indicates that the Asan fore reef is within the zone of impact from discharged sediments transported from the Piti-Asan watershed and has experienced increased terrestrial sedimentation since the 1940s. This abrupt shift in sedimentation occurred at the same time as both the sudden denudation of the landscape by military ordinance and the immediate subsequent development of the Asan area through the end of the war, from 1944 through 1945. In response to rapid input of sediment, as determined from coral Ba/Ca values, coral growth rates were reduced for almost two decades, while calcification rates recovered much more quickly. Furthermore, coral luminescence is decoupled from the Ba/Ca record, which is consistent with degradation of soil organic matter through disturbance by forest fires, suggesting a potential index of fire history and degradation of soil organic matter. These patterns were not seen in the cores from nearby reefs associated with watersheds that have not undergone the same degree of landscape denudation. Taken together, these records provide a valuable tool for understanding the compounding effects of land-use change on coral reef health.

  12. Historic impact of watershed change and sedimentation to reefs along west-central Guam

    Science.gov (United States)

    Prouty, Nancy G.; Storlazzi, Curt D.; McCutcheon, Amanda L.; Jenson, John W.

    2014-01-01

    Using coral growth parameters (extension, density, calcification rates, and luminescence) and geochemical measurements (barium to calcium rations; Ba/Ca) from coral cores collected in west-central Guam, we provide a historic perspective on sediment input to coral reefs adjacent to the Piti-Asan watershed. The months of August through December are dominated by increased coral Ba/Ca values, corresponding to the rainy season. With river water enriched in barium related to nearshore seawater, coral Ba/Ca ratios are presented as a proxy for input of fine-grained terrigenous sediment to the nearshore environment. The century-long Ba/Ca coral record indicates that the Asan fore reef is within the zone of impact from discharged sediments transported from the Piti-Asan watershed and has experienced increased terrestrial sedimentation since the 1940s. This abrupt shift in sedimentation occurred at the same time as both the sudden denudation of the landscape by military ordinance and the immediate subsequent development of the Asan area through the end of the war, from 1944 through 1945. In response to rapid input of sediment, as determined from coral Ba/Ca values, coral growth rates were reduced for almost two decades, while calcification rates recovered much more quickly. Furthermore, coral luminescence is decoupled from the Ba/Ca record, which is consistent with degradation of soil organic matter through disturbance by forest fires, suggesting a potential index of fire history and degradation of soil organic matter. These patterns were not seen in the cores from nearby reefs associated with watersheds that have not undergone the same degree of landscape denudation. Taken together, these records provide a valuable tool for understanding the compounding effects of land-use change on coral reef health.

  13. Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past-temperature reconstructions

    Science.gov (United States)

    Masson-Delmotte, V.; Steen-Larsen, H. C.; Ortega, P.; Swingedouw, D.; Popp, T.; Vinther, B. M.; Oerter, H.; Sveinbjornsdottir, A. E.; Gudlaugsdottir, H.; Box, J. E.; Falourd, S.; Fettweis, X.; Gallée, H.; Garnier, E.; Gkinis, V.; Jouzel, J.; Landais, A.; Minster, B.; Paradis, N.; Orsi, A.; Risi, C.; Werner, M.; White, J. W. C.

    2015-08-01

    Combined records of snow accumulation rate, δ18O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (North Greenland Eemian Ice Drilling), covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterise the isotope-temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ18O and accumulation variability is related to North Atlantic sea surface temperature and is enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ18O shows multidecadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ18O values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ18O (warmest), while the 11-year periods with the strongest depletion (coldest) are depicted at NEEM in 1815-1825 and 1836-1846, which are also the driest 11-year periods. The NEEM accumulation and δ18O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multidecadal accumulation-temperature and δ18O-temperature relationships for the strong warming period in 1979-2007. The accumulation sensitivity to temperature is estimated at 11 ± 2 % °C-1 and the δ18O-temperature slope at 1.1 ± 0.2 ‰ °C-1, about twice as large as previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core.

  14. Persistent organic pollutants and methoxylated polybrominated diphenyl ethers in different tissues of white-tailed eagles (Haliaeetus albicilla) from West Greenland

    DEFF Research Database (Denmark)

    Jaspers, V L B; Sonne, C; Soler-Rodriguez, F;

    2013-01-01

    We investigated polychlorinated biphenyls (PCBs), organochlorine pesticides (e.g. dichlorodiphenyltrichloroethane (DDT)), polybrominated diphenyl ethers (PBDEs) and methoxylated PBDEs (MeO-PBDEs), in six matrices (muscle, liver, kidney, adipose, blood, preen oil) of 17 white-tailed eagles from West...... > 5 years) displayed PCB levels up to 1500 μg/g lw in liver, which is the highest concentration ever reported in Arctic wildlife. Muscle generally contained the highest median levels, while adipose tissue displayed the lowest median levels on a lipid basis. No significant differences were found among...... tissues for MeO-PBDEs. Remarkably, we found distinct correlations (0.62 ≤ r ≤ 0.98;...

  15. Backscatter Mapping of the West Florida Shelf (Central Region), Gulf of Mexico (NODC Accession 0001410)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format data generated from the 2001 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and...

  16. Bathymetry Mapping of the West Florida Shelf (Central Region), Gulf of Mexico (NODC Accession 0001410)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format data generated from the 2001 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and...

  17. Spatial distribution of the nematodes in the subtidal community of the Central West Coast of India with emphasis on Tershellingia longicaudata (Nematoda: Linhomoeidae)

    Digital Repository Service at National Institute of Oceanography (India)

    Nanajkar, M.; Ingole, B.S.; Chatterjee, T.

    , possibly due to lack of expertise. Meiofauna was investigated with emphasis on nematodes, which were the most dominant group and one species - Terschellingia longicaudata (De Man, 1907) - along the central west coast of India, stretching between Ratnagiri...

  18. Overwintering of Uranotaenia Unguiculata Adult Females in Central Europe: A Possible Way of Persistence of the Putative New Lineage of West Nile Virus?

    Science.gov (United States)

    Rudolf, Ivo; Šebesta, Oldřich; Straková, Petra; Betášová, Lenka; Blažejová, Hana; VEnclíková, Kristýna; Seidel, Bernhard; Tóth, Sandor; Hubálek, Zdeněk; Schaffner, Francis

    2015-12-01

    We report the overwintering of Uranotaenia unguiculata adult females in Central Europe (Czech Republic, Hungary, Austria). This finding suggests a potential mode of winter persistence of putative novel lineage of West Nile virus in the temperate regions of Europe.

  19. Zooplankton variability and copepod assemblage in the coastal and estuarine waters of Goa along the central-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Ramaiah, Neelam; Padmavati, G.

    Seasonal variations in zooplankton distribution and community structure of copepod species in coastal and estuarine waters of Goa along the central-west coast of India are compared in relation to water temperature, salinity and dissoved oxygen...

  20. Avoidable deaths in Greenland 1968-1985

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Juel, K

    1990-01-01

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

  1. Near shore waves, long-shore currents and sediment transport along micro-tidal beaches, central west coast of India

    Institute of Scientific and Technical Information of China (English)

    Sajiv Philip CHEMPALAYIL; V Sanil KUMAR; G Udhaba DORA; Glejin JOHNSON

    2014-01-01

    Coastlines are undergoing constant geomorphologic changes with respect to the incident wave climate. Based on waves measured at 9 m water depth, simulation of near shore wave transformation is done using REFDIF-1 numerical model and the near shore breaker parameters are estimated at two micro-tidal beaches along central west coast of India. Model results are validated with measured values. From the breaker parameters, long-shore current and long-shore sediment transport rates (LSTR) are computed by using semi-empirical equations. Estimated long-shore current and LSTR are showing dramatic variations with respect to seasons. Predominant direction of LSTR is observed towards north since the approach waves are from south-west direction during pre-monsoon and post monsoon. During monsoon season, waves are from west south-west and resulted in southerly transport. The estimated annual net and gross LSTR by Cambridge Environmental Research Consultants (CERC) at two locations are in the same order whereas LSTR estimated by Walton & Bruno and Kamphuis equations are showing different estimations because of difference in surf-zone width and foreshore slope between the two locations. For micro-tidal beaches with length less than 6 km, Kamphuis equation is giving agreeable estimation of LSTR. Sensitivity analysis of LSTR estimate shows that coastal inclination is the prominent factor in determining LSTR than incident wave angle.

  2. Standardising Visual Control Devices for Tsetse Flies: Central and West African Species Glossina palpalis palpalis

    Science.gov (United States)

    Kaba, Dramane; Zacarie, Tusevo; M'Pondi, Alexis Makumyaviri; Njiokou, Flobert; Bosson-Vanga, Henriette; Kröber, Thomas; McMullin, Andrew; Mihok, Steve; Guerin, Patrick M.

    2014-01-01

    Background Glossina palpalis palpalis (G. p. palpalis) is one of the principal vectors of sleeping sickness and nagana in Africa with a geographical range stretching from Liberia in West Africa to Angola in Central Africa. It inhabits tropical rain forest but has also adapted to urban settlements. We set out to standardize a long-lasting, practical and cost-effective visually attractive device that would induce the strongest landing response by G. p. palpalis for future use as an insecticide-impregnated tool in area-wide population suppression of this fly across its range. Methodology/Principal Findings Trials were conducted in wet and dry seasons in the Ivory Coast, Cameroon, the Democratic Republic of Congo and Angola to measure the performance of traps (biconical, monoconical and pyramidal) and targets of different sizes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used as a practical enumerator at these remote locations to compare landing efficiencies of devices. Independent of season and country, both phthalogen blue-black and blue-black-blue 1 m2 targets covered with adhesive film proved to be as good as traps in phthalogen blue or turquoise blue for capturing G. p. palpalis. Trap efficiency varied (8–51%). There was no difference between the performance of blue-black and blue-black-blue 1 m2 targets. Baiting with chemicals augmented the overall performance of targets relative to traps. Landings on smaller phthalogen blue-black 0.25 m2 square targets were not significantly different from either 1 m2 blue-black-blue or blue-black square targets. Three times more flies were captured per unit area on the smaller device. Conclusions/Significance Blue-black 0.25 m2 cloth targets show promise as simple cost effective devices for management of G. p. palpalis as they can be used for both control when impregnated with insecticide and for population sampling when

  3. Ordovician Intrusive-related Gold-Copper Mineralization in West-Central New South Wales, Australia

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Three major types of Ordovician intrusive-related gold-copper deposits are recognized in central-west New South Wales,, Australia: porphyry, skam and high sulphidation epithermal deposits.These deposits are mainly distributed within two Ordovician volcano-intrusive belts of the Lachlan Fold Be1t: the Orange-Wellington Belt and the Parkes-Narromine Belt. Available isotopic age data suggest that mineralization of the three types of deposits is essentially coeval with the Ordovician intrusive rocks (480-430 Ma). Porphyry gold-copper deposits can be further divided into two groups. The first group is associated with monzoniteshowing shoshonitic features represented by Cadia and Goonumbla. The second group is associated with diorite and dacite, including the Copper Hill and Cargo gold-copper deposits. Gold skarn is associated with Late Ordovician (430-439 Ma) monzonitic intrusive complexes in the Junction Reefs area (Sheahan-Grants, Frenchmans, and Cornishmens), Endeavour 6, 7 and 44, Big and Little Cadia. The epithermal gold deposits with high sulphidation including Gidginbung (Temora) and Peak Hill mainly occur within Ordovician andesite and volcaniclastic rocks, and are associated with advanced argillic alteration. Available isotopic age data indicate that both alteration and mineralization of the porphyry, skam and epithermal gold-copper deposits are broadly coeval with the Late Ordovician hoshonitic mangmatism, which is thought to result from the melting of sub-continental lithosphere caused by Palaeozoic subduction events. The Ordovician intrusive-related gold-copper deposits are restricted to two longitudinal parallel volcano-intrusive belts, rarely extending outside them. Diagonal intra-belt trends of mineralization are common, particularly at the intersections of longitudinal and transverse (oblique) fault/fracture zones basedon the authors'review of available geological data. The locations of these gold-copper deposits are obviously influenced by transverse

  4. Detrital zircon evidence for progressive underthrusting in Franciscan metagraywackes, west-central California

    Science.gov (United States)

    Snow, C.A.; Wakabayashi, J.; Ernst, W.G.; Wooden, J.L.

    2010-01-01

    central Coast Ranges is a classic accretionary prism, where younger, structurally lower allochthons are exposed on the west, and older, structurally higher allochthons occur to the east, in the heavily studied San Francisco Bay area. ?? 2009 Geological Society of America.

  5. Standardising visual control devices for tsetse flies: Central and West African species Glossina palpalis palpalis.

    Directory of Open Access Journals (Sweden)

    Dramane Kaba

    Full Text Available BACKGROUND: Glossina palpalis palpalis (G. p. palpalis is one of the principal vectors of sleeping sickness and nagana in Africa with a geographical range stretching from Liberia in West Africa to Angola in Central Africa. It inhabits tropical rain forest but has also adapted to urban settlements. We set out to standardize a long-lasting, practical and cost-effective visually attractive device that would induce the strongest landing response by G. p. palpalis for future use as an insecticide-impregnated tool in area-wide population suppression of this fly across its range. METHODOLOGY/PRINCIPAL FINDINGS: Trials were conducted in wet and dry seasons in the Ivory Coast, Cameroon, the Democratic Republic of Congo and Angola to measure the performance of traps (biconical, monoconical and pyramidal and targets of different sizes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used as a practical enumerator at these remote locations to compare landing efficiencies of devices. Independent of season and country, both phthalogen blue-black and blue-black-blue 1 m(2 targets covered with adhesive film proved to be as good as traps in phthalogen blue or turquoise blue for capturing G. p. palpalis. Trap efficiency varied (8-51%. There was no difference between the performance of blue-black and blue-black-blue 1 m(2 targets. Baiting with chemicals augmented the overall performance of targets relative to traps. Landings on smaller phthalogen blue-black 0.25 m(2 square targets were not significantly different from either 1 m(2 blue-black-blue or blue-black square targets. Three times more flies were captured per unit area on the smaller device. CONCLUSIONS/SIGNIFICANCE: Blue-black 0.25 m(2 cloth targets show promise as simple cost effective devices for management of G. p. palpalis as they can be used for both control when impregnated with insecticide and for

  6. Environmental history of mangrove vegetation in Pacific west-central Mexico during the last 1300 years

    Directory of Open Access Journals (Sweden)

    Blanca Lorena Figueroa-Rangel

    2016-08-01

    Full Text Available AbstractMangroves are a highly threatened ecosystem due to climate change and human activity, which increases coastal vulnerability. Knowledge about the ecological dynamics of mangroves on a centennial timescale can reveal the different responses in vegetation, which is useful for implementing basic actions for mangrove restoration, conservation and management. A mangrove ecosystem in the Cuyutlán Lagoon area along the Pacific coast of west-central Mexico is significantly altered as a result of industrialization, salt extraction, and road construction. The long-term dynamics of the mangrove ecosystem has also been controlled by Holocene climatic variability. This study reconstructs the environmental history of mangrove vegetation around the Cuyutlán Lagoon during the last ~1300 years in response to periods of human activity and climate change. The reconstruction was performed using paleoecological techniques in sediment cores that include the use of fossil pollen as a proxy for vegetation and magnetic susceptibility and geochemical data (determined by loss-on-ignition and X-ray fluorescence as a proxy for past environmental changes. The chronology was determined using 14C dating and the age-depth model was constructed by linear interpolation. Redundancy analysis and non-metric multidimensional scaling (NMDS were used to discern patterns of distribution of the different proxies. Results revealed that the mangrove pollen assemblage of the Cuyutlán Lagoon was dominated by the arboreal taxa Rhizophora mangle, Euphorbiaceae, Moraceae and Pinaceae, herbaceous taxa like Poaceae, Chenopodiaceae/Amaranthaceae, and aquatics such as Typhaceae and Cyperaceae. NMDS showed a clear separation between two events of human activity—the Spanish Occupation of Colima (~AD 1523-1524 and the opening of the Manzanillo port (~AD 1824-1825. Climate change events such as the Medieval Climate Anomaly (MCA (~AD 800-1200 and the Little Ice Age (LIA (~AD 1350-1850 were

  7. Popular music from Greenland

    DEFF Research Database (Denmark)

    Otte, Andreas Roed

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

  8. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

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

  9. Genetic evidence of enzootic leishmaniasis in a stray canine and Texas mouse from sites in west and central Texas

    Science.gov (United States)

    Kipp, Evan J; Mariscal, Jacqueline; Armijos, Rodrigo X; Weigel, Margaret; Waldrup, Kenneth

    2016-01-01

    We detected Leishmania mexicana in skin biopsies taken from a stray canine (Canis familiaris) and Texas mouse (Peromyscus attwateri) at two ecologically disparate sites in west and central Texas using polymerase chain reaction (PCR). A single PCR-positive dog was identified from a sample of 96 stray canines and was collected in a peri-urban area in El Paso County, Texas. The PCR-positive P. attwateri was trapped at a wildlife reserve in Mason County, Texas, from a convenience sample of 20 sylvatic mammals of different species. To our knowledge, this represents the first description of L. mexicana in west Texas and extends the known geographic range of the parasite to an area that includes the arid Chihuahuan Desert. Our finding of L. mexicana in P. attwateri represents a new host record and is the first description of the parasite in a wild peromyscid rodent in the United States. PMID:27759765

  10. The Jurassic of Denmark and Greenland: Sedimentology and sequence stratigraphy of the Bryne and Lulu Formations, Middle Jurassic, northern Danish Central Graben

    Directory of Open Access Journals (Sweden)

    Andsbjerg, Jan

    2003-10-01

    Full Text Available The Middle Jurassic Bryne and Lulu Formations of the Søgne Basin (northern part of the Danish Central Graben consist of fluvially-dominated coastal plain deposits, overlain by interfingering shoreface and back-barrier deposits. Laterally continuous, mainly fining-upwards fluvial channel sandstones that locally show evidence for tidal influence dominate the alluvial/coastal plain deposits of the lower Bryne Formation. The sandstones are separated by units of fine-grained floodplain sediments that show a fining-upwards - coarsening-upwards pattern and locally grade into lacustrine mudstones. A regional unconformity that separates the lower Bryne Formation from the mainly estuarine upper Bryne Formation is defined by the strongly erosional base of a succession of stacked channel sandstones, interpreted as the fill of a system of incised valleys. Most of the stacked channel sandstones show abundant mud laminae and flasers, and rare herringbone structures, suggesting that they were deposited in a tidal environment, probably an estuary. Several tens of metres of the lower Bryne Formation may have been removed by erosion at this unconformity. The estuarine channel sandstone succession is capped by coal beds that attain a thickness of several metres in the western part of the Søgne Basin, but are thin and poorly developed in the central part of the basin. Above the coal beds, the Lulu Formation is dominated by various types of tidally influenced paralic deposits in the western part of the basin and by coarsening-upwards shoreface and beach deposits in central parts. Westwards-thickening wedges of paralic deposits interfinger with eastwards-thickening wedges of shallow marine deposits. The Middle Jurassic succession is subdivided into nine sequences. In the lower Bryne Formation, sequence boundaries are situated at the base of laterally continuous fluvial channel sandstones whereas maximum flooding surfaces are placed in laterally extensive floodplain

  11. Geologic Map of the Denver West 30' x 60' Quadrangle, North-Central Colorado

    Science.gov (United States)

    Kellogg, Karl S.; Shroba, Ralph R.; Bryant, Bruce; Premo, Wayne R.

    2008-01-01

    The Denver West quadrangle extends east-west across the entire axis of the Front Range, one of numerous uplifts in the Rocky Mountain region in which Precambrian rocks are exposed. The history of the basement rocks in the Denver West quadrangle is as old as 1,790 Ma. Along the east side of the range, a sequence of sedimentary rocks as old as Pennsylvanian, but dominated by Cretaceous-age rocks, overlies these ancient basement rocks and was upturned and locally faulted during Laramide (Late Cretaceous to early Tertiary) uplift of the range. The increasingly coarser grained sediments up section in rocks of latest Cretaceous to early Tertiary age record in remarkable detail this Laramide period of mountain building. On the west side of the range, a major Laramide fault (Williams Range thrust) places Precambrian rocks over Cretaceous sedimentary rocks. The geologic history of the quadrangle, therefore, can be divided into four major periods: (1) Proterozoic history, (2) Pennsylvanian to pre-Laramide, Late Cretaceous history, (3) Late Cretaceous to early Tertiary Laramide mountain building, and (4) post-Laramide history. In particular, the Quaternary history of the Denver West quadrangle is described in detail, based largely on extensive new mapping.

  12. Geochronology of the Birim Supergroup of the West African craton in the Wa-Bolé region of west-central Ghana: Implications for the stratigraphic framework

    Science.gov (United States)

    de Kock, G. S.; Armstrong, R. A.; Siegfried, H. P.; Thomas, E.

    2011-01-01

    The Birim rocks of the West African craton comprise belts of greenschist- to amphibolite-grade gneiss and schist, and subparallel basins of greenschist-grade phyllite of volcaniclastic and epiclastic origin, which were intruded by igneous rocks. The granitoids intruded between 2213 and 2060 Ma and overlap with the volcaniclastic units dated between 2211 and 2064 Ma. The simultaneous occurrence of the magmatic events and irregular distribution of the rock ages hamper the formulation of a stratigraphic succession. SHRIMP spot analyses were done on older cores, crystals and rims from 23 rocks from the Bolé-Wa region in west-central Ghana. The crystallization ages range from 2195 to 2118 Ma, the inherited ages from 2876 to 2130 Ma, and metamorphic ages from 2114 to 2090 Ma. Aided by metamorphic, structural and chemical studies an older geotectonic cycle (2195-2150 Ma), containing the Dole and Guropie Suite and Bolé Group, was established. These units were subjected to several orthogonal and shear deformation events. These events were followed by the contemporaneous Sawla calc-alkaline monzonitic plutonism (2132-2126 Ma) and deposition of the epiclastic Maluwe Group (2137-2125 Ma) of calc-alkaline felsic to tholeiitic volcanic origin. Deformation of the basin beds was succeeded by the intrusion of the Tanina Suite granitoids of 2122-2120 Ma, which, themselves, were deformed prior to 2119 Ma. At 2118 Ma syenite and gabbro intruded along conjugate extension fractures. The gabbro and syenite of the Wakawaka Suite were only affected by three events of brittle strike-slip faulting. The first had significant displacement along NNE- to NE-directed shear zones, while the latter only formed conjugate joint systems with limited transport. Palaeo- to Neoarchaean cores, the oldest yet reported in the Baoulé Mossi domain, are restricted to the gneissic Dole Suite biotite granites. The presence of Dole-, Guropie-, Sawla-, and Tanina-aged older cores and grains in younger rocks

  13. 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

    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...

  14. Considerations concerning the evolution of the forest area in the west side of The Central Moldavian Tableland

    Directory of Open Access Journals (Sweden)

    Vasile BUDUI

    2010-03-01

    Full Text Available The areal evolution of the forests from the west side ofThe Central Moldavian Tableland was influenced by some historical events that encouraged deforestations. The reducing process rate of the forests surfaces increased at beginning with the XVI century to XIX century, them this process decreased very much. This paper presents some definitely stages in forests areal evolution, reconstitute from maps and satellite images, in completion with terrain observations made in last years.

  15. Dutch Disease in the Post-Soviet Countries of Central and South-West Asia: How Contagious is it?

    OpenAIRE

    Egert, Balazs

    2013-01-01

    This study seeks to determine the extent to which the former communist states of Central and South-West Asia are “infected” by the Dutch Disease. We take a detailed look at the functioning of the transmission mechanism of the Dutch Disease, i.e. the chains that run from commodity prices to real output in manufacturing. We complement this with two econometric exercises. First, we estimate nominal and real exchange rate models to see whether commodity prices are correlated with the exchange rat...

  16. Revisiting Emplacement Depths of the Fine Gold Intrusive Suite, West-Central Sierra Nevada

    Science.gov (United States)

    Head, D.; Lackey, J.

    2013-12-01

    The Fine Gold Intrusive Suite (FGIS) is a large intrusive complex in the west central portion of the Sierra Nevada Batholith. Portions of the Sierra Nevada Batholith have been well studied for plutonic pressure and crystallization histories (e.g., Ague and Brimhall, 1988, GSAB), whereas the regional depth of emplacement of the FGIS is not well characterized, and in previous work pressure estimates were not corrected for crystallization temperatures. An accurate sense of barometric gradient in the FGIS is important to evaluate the roles of pre-batholithic structural breaks in controlling magma emplacement levels, and also to reconstruct erosional levels within the Sierra Nevada as a whole. In this study, samples from the FGIS, all from the Bass Lake Tonalite, were petrographically characterized to identify those samples that contain mineral assemblage and crystallization textures appropriate for application of the Aluminum-in-Hornblende barometer of Hammarstrom and Zen (1986) re-calibrated by Anderson and Smith (1995). Analysis of these samples and use of the barometer results in both pressure and temperature of crystallization. FGIS amphiboles are typical magnesio-hornblende on average: K0.2Na0.1Ca1.8[Mg2.4(Al,Fe3+)(0.2-0.6)]Si6.7Ti0.1Al1.3O22(OH)2. Plagioclase compositional ranges are Ab(54-69)An(30-45)Or(0-1). Bass Lake Tonalite data of Ague and Brimhall (1988) were re-calculated for typical plagioclase composition in the Bass Lake Tonalite (Ab62An37Or1), yielding slightly higher crystallization pressures (3.3 to 5.8 kbar) than the original range (2.4 to 4.5 kbar). New FGIS crystallization pressures of 2.6 to 3.5 kbar match the recalculated data well, thus providing larger coverage for estimates of emplacement depth. Apparent temperatures from adjacent amphibole and plagioclase rims were found to be 691 to 767°C. When all barometric data are considered together, and uncertainties of the calibration are factored in, we find that FGIS crystallization pressures

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

    Science.gov (United States)

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

    2016-01-01

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

  18. Health expectancy in Greenland

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    assessed based on data from reproductive organs and was estimated to be 8–9 years for females and 12–20 years for males. Pregnancy rates for East and West Greenland were estimated to be 0.38–0.42 and 0.38, respectively. Maximum life span expectancy was found to be approximately 100 years. A population......Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007...

  20. High-resolution analysis of Y-chromosomal polymorphisms reveals signatures of population movements from Central Asia and West Asia into India

    Indian Academy of Sciences (India)

    Namita Mukherjee; Almut Nebel; Ariella Oppenheim; Partha P. Majumder

    2001-12-01

    Linguistic evidence suggests that West Asia and Central Asia have been the two major geographical sources of genes in the contemporary Indian gene pool. To test the nature and extent of similarities in the gene pools of these regions we have collected DNA samples from four ethnic populations of northern India, and have screened these samples for a set of 18 Y-chromosome polymorphic markers (12 unique event polymorphisms and six short tandem repeats). These data from Indian populations have been analysed in conjunction with published data from several West Asian and Central Asian populations. Our analyses have revealed traces of population movement from Central Asia and West Asia into India. Two haplogroups, HG-3 and HG-9, which are known to have arisen in the Central Asian region, are found in reasonably high frequencies (41.7% and 14.3% respectively) in the study populations. The ages estimated for these two haplogroups are less in the Indian populations than those estimated from data on Middle Eastern populations. A neighbour-joining tree based on Y-haplogroup frequencies shows that the North Indians are genetically placed between the West Asian and Central Asian populations. This is consistent with gene flow from West Asia and Central Asia into India.

  1. Retrospective seasonal prediction of summer monsoon rainfall over West Central and Peninsular India in the past 142 years

    Science.gov (United States)

    Li, Juan; Wang, Bin; Yang, Young-Min

    2016-06-01

    Prediction of Indian summer (June-September) rainfall on regional scales remains an open issue. The operational predictions of West Central Indian summer rainfall (WCI-R) and Peninsular Indian summer rainfall (PI-R) made by the Indian Meteorological Department (IMD) had no skills during 2004-2012. This motivates the present study aiming at better understanding the predictability sources and physical processes governing summer rainfall variability over these two regions. Analysis of 133 year data reveal that although the lower boundary forcing that associated with enhanced WCI-R and PI-R featured a similar developing La-Nina and "east high west low" sea-level pressure (SLP) dipole pattern across the Indo-Pacific, the anomalous high sea surface temperature (SST) over the northern Indian Ocean and weak low pressure over northern Asia tended to enhance PI-R but reduce WCI-R. Based on our understanding of physical linkages with the predictands, we selected four and two causative predictors for predictions of the WCI-R and PI-R, respectively. The intensified summer WCI-R is preceded by (a) Indian Ocean zonal dipole-like SST tendency (west-warming and east-cooling), (b) tropical Pacific zonal dipole SST tendency (west-warming and east-cooling), (c) central Pacific meridional dipole SST tendency (north-cooling and south-warming), and (d) decreasing SLP tendency over northern Asia in the previous season. The enhanced PI-R was lead by the central-eastern Pacific cooling and 2-m temperature cooling tendency east of Lake Balkhash in the previous seasons. These causative processes linking the predictors and WCI-R and PI-R are supported by ensemble numerical experiments using a coupled climate model. For the period of 1871-2012, the physics-based empirical (P-E) prediction models built on these predictors result in cross-validated forecast temporal correlation coefficient skills of 0.55 and 0.47 for WCI-R and PI-R, respectively. The independent forecast skill is significantly

  2. Changes in Intense Precipitation Events in West Africa and the central U.S. under Global Warming

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Kerry H. [Univ. of Texas, Austin, TX (United States); Vizy, Edward [Univ. of Texas, Austin, TX (United States)

    2016-02-08

    The purpose of the proposed project is to improve our understanding of the physical processes and large-scale connectivity of changes in intense precipitation events (high rainfall rates) under global warming in West Africa and the central U.S., including relationships with low-frequency modes of variability. This is in response to the requested subject area #2 “simulation of climate extremes under a changing climate … to better quantify the frequency, duration, and intensity of extreme events under climate change and elucidate the role of low frequency climate variability in modulating extremes.” We will use a regional climate model and emphasize an understanding of the physical processes that lead to an intensification of rainfall. The project objectives are as follows: 1. Understand the processes responsible for simulated changes in warm-season rainfall intensity and frequency over West Africa and the Central U.S. associated with greenhouse gas-induced global warming 2. Understand the relationship between changes in warm-season rainfall intensity and frequency, which generally occur on regional space scales, and the larger-scale global warming signal by considering modifications of low-frequency modes of variability. 3. Relate changes simulated on regional space scales to global-scale theories of how and why atmospheric moisture levels and rainfall should change as climate warms.

  3. Analysis of variables affecting unemployment rate and detecting for cluster in West Java, Central Java, and East Java in 2012

    Science.gov (United States)

    Samuel, Putra A.; Widyaningsih, Yekti; Lestari, Dian

    2016-02-01

    The objective of this study is modeling the Unemployment Rate (UR) in West Java, Central Java, and East Java, with rate of disease, infant mortality rate, educational level, population size, proportion of married people, and GDRP as the explanatory variables. Spatial factors are also considered in the modeling since the closer the distance, the higher the correlation. This study uses the secondary data from BPS (Badan Pusat Statistik). The data will be analyzed using Moran I test, to obtain the information about spatial dependence, and using Spatial Autoregressive modeling to obtain the information, which variables are significant affecting UR and how great the influence of the spatial factors. The result is, variables proportion of married people, rate of disease, and population size are related significantly to UR. In all three regions, the Hotspot of unemployed will also be detected districts/cities using Spatial Scan Statistics Method. The results are 22 districts/cities as a regional group with the highest unemployed (Most likely cluster) in the study area; 2 districts/cities as a regional group with the highest unemployed in West Java; 1 district/city as a regional groups with the highest unemployed in Central Java; 15 districts/cities as a regional group with the highest unemployed in East Java.

  4. Factors associated with the occurrence of Triatoma sordida (Hemiptera: Reduviidae in rural localities of Central-West Brazil

    Directory of Open Access Journals (Sweden)

    Juliana Chedid Nogared Rossi

    2015-04-01

    Full Text Available This study estimates the factors of artificial environments (houses and peridomestic areas associated with Triatoma sordida occurrence. Manual searches for triatomines were performed in 136 domiciliary units (DUs in two rural localities of Central-West Brazil. For each DU, 32 structural, 23 biotic and 28 management variables were obtained. Multiple logistic regression analysis was performed in order to identify statistically significant variables associated with occurrence of T. sordida in the study areas. A total of 1,057 specimens (99% in peridomiciles, mainly chicken coops of T. sordida were collected from 63 DUs (infestation: 47%; density: ~8 specimens/DU; crowding: ~17 specimens/infested DU; colonisation: 81%. Only six (0.6% out of 945 specimens examined were infected with Trypanosoma cruzi. The final adjusted logistic regression model indicated that the probability of T. sordida occurrence was higher in DU with wooden chicken coops, presence of > 30 animals in wooden corrals, presence of wood piles and presence of food storeroom. The results show the persistence of T. sordida in peridomestic habitats in rural localities of Central-West Brazil. However, the observed low intradomestic colonisation and minimal triatomine infection rates indicate that T. sordida has low potential to sustain high rates of T. cruzi transmission to residents of these localities.

  5. Yield gaps and potential agricultural growth in West and Central Africa:

    OpenAIRE

    Nin-Pratt, Alejandro; Johnson, Michael; Magalhaes, Eduardo; You, Liangzhi; DIAO, Xinshen; Chamberlin, Jordan

    2011-01-01

    The authors identify a set of development priorities for agriculture that cut across West Africa at both the country and regional levels to achieve economywide growth goals in the region. To do this we adopt a modeling and analytical framework that involves the integration of spatial analysis to identify yield gaps determining the growth potential of different agricultural activities for areas with similar conditions and an economywide multimarket model to simulate ex ante the economic effect...

  6. Vegetation, Fire and Climate Over the Last 2000 Yrs in Central West Patagonia (45°S)

    Science.gov (United States)

    Villa-Martinez, R. P.; Simi, E. I.; Moreno, P. I.

    2014-12-01

    We report high-resolution pollen and charcoal records from lake sediments obtained from Lago Mellizas and Lago Churrasco to reconstruct the history of vegetation, fire and past variations of the southern westerly winds (SWW) over the last 2000 years. Both sites are located near to the climate-modulated forest-steppe ecotone in central west Patagonia. In this region the SWW are the only source of precipitation and is ideal for reconstructing past changes in atmospheric circulation. This is facilitated by the marked west-east precipitation gradient across the Patagonian Andes that induces a zonation of the regional vegetation which can be used for inferring past changes in precipitation regimes based on fossil pollen records. Furthermore, the Chilean-European colonization process in central west Patagonia started early in the 20th century, allowing characterization of natural vegetation and climate variability in the absence of human disturbance until the end of the 19th century. The pollen records shows dominance of Nothofagus deciduous forests with minor fluctuations and low herb and aquatics abundances, which suggest humid climate conditions. We detect a major change in the pollen stratigraphy at 200 cal yr BP, when started a sustained decreasing trend in Nothofagus, along with increases of Poaceae and aquatics plants (Cyperaceae, Myriophyllum). We interpret these changes as a forest opening and centripetal expansion of littoral environments toward the lake center driven by lake-level lowering in response to lowered precipitation brought by the SWW. Pinus, Rumex, Plantago, which indicate human perturbation, increase in 1900 AD. Macroscopic charcoal increases at 1750, 1400, 850-700, 500, and 200 cal yr BP, suggesting local fires, followed by sharp increases during the last 100 years. We interpret the pre-20th century charcoal peaks as dry intervals with lowered SWW influence. Acknowledgement: Fondecyt 1121141, Fondap 15110009, and ICM grants P02-51 and NC120066.

  7. Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada

    Science.gov (United States)

    Lopes, Thomas J.; Allander, Kip K.

    2009-01-01

    The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. Between 1882 and 2008, agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-ft. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes the hydrologic setting of the Walker River basin and a conceptual hydrologic model of the relations among streams, groundwater, and Walker Lake with emphasis on the lower Walker River basin from Wabuska to Hawthorne, Nevada. The Walker River basin is about 3,950 square miles and straddles the California-Nevada border. Most streamflow originates as snowmelt in the Sierra Nevada. Spring runoff from the Sierra Nevada typically reaches its peak during late May to early June with as much as 2,800 cubic feet per second in the Walker River near Wabuska. Typically, 3 to 4 consecutive years of below average streamflow are followed by 1 or 2 years of average or above average streamflow. Mountain ranges are comprised of consolidated rocks with low hydraulic conductivities, but consolidated rocks transmit water where fractured. Unconsolidated sediments include fluvial deposits along the active channel of the Walker River, valley floors, alluvial slopes, and a playa. Sand and gravel deposited by the Walker River likely are discontinuous strata throughout the valley floor. Thick clay strata likely were deposited in Pleistocene Lake Lahontan and are horizontally continuous, except where strata have been eroded by the Walker River. At Walker Lake, sediments mostly are clay interbedded with alluvial slope, fluvial, and deltaic deposits along the lake margins. Coarse sediments form a multilayered, confined-aquifer system that could extend several miles from the shoreline

  8. The Greenland Telescope

    Science.gov (United States)

    Grimes, Paul; Blundell, Raymond

    2012-09-01

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

  9. First Younger Dryas moraines in Greenland

    Science.gov (United States)

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

    2016-04-01

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

  10. Diachronous retreat of the Greenland ice sheet during the last deglaciation

    Science.gov (United States)

    Sinclair, G.; Carlson, A. E.; Mix, A. C.; Lecavalier, B. S.; Milne, G.; Mathias, A.; Buizert, C.; DeConto, R.

    2016-08-01

    The last deglaciation is the most recent interval of large-scale climate change that drove the Greenland ice sheet from continental shelf to within its present extent. Here, we use a database of 645 published 10Be ages from Greenland to document the spatial and temporal patterns of retreat of the Greenland ice sheet during the last deglaciation. Following initial retreat of its marine margins, most land-based deglaciation occurred in Greenland following the end of the Younger Dryas cold period (12.9-11.7 ka). However, deglaciation in east Greenland peaked significantly earlier (13.0-11.5 ka) than that in south Greenland (11.0-10 ka) or west Greenland (10.5-7.0 ka). The terrestrial deglaciation of east and south Greenland coincide with adjacent ocean warming. 14C ages and a recent ice-sheet model reconstruction do not capture this progression of terrestrial deglacial ages from east to west Greenland, showing deglaciation occurring later than observed in 10Be ages. This model-data misfit likely reflects the absence of realistic ice-ocean interactions. We suggest that oceanic changes may have played an important role in driving the spatial-temporal ice-retreat pattern evident in the 10Be data.

  11. Explosive spread of a neuroinvasive lineage 2 West Nile virus in Central Europe, 2008/2009.

    Science.gov (United States)

    Bakonyi, Tamás; Ferenczi, Emőke; Erdélyi, Károly; Kutasi, Orsolya; Csörgő, Tibor; Seidel, Bernhard; Weissenböck, Herbert; Brugger, Katharina; Bán, Enikő; Nowotny, Norbert

    2013-07-26

    For the first time outside sub-Saharan Africa, a lineage 2 West Nile virus (WNV) emerged in Hungary in 2004. It caused sporadic cases of encephalitis in goshawks (Accipiter gentilis), other predatory birds, and in mammals. As a consequence, a surveillance program was initiated in Hungary and in Austria, which included virological, molecular, serological and epidemiological investigations in human beings, birds, horses, and mosquitoes. The virus strain became endemic to Hungary, however only sporadic cases of infections were observed between 2004 and 2007. Unexpectedly, explosive spread of the virus was noted in 2008, when neuroinvasive West Nile disease (WND) was diagnosed all over Hungary in dead goshawks and other birds of prey (n=25), in horses (n=12), and humans (n=22). At the same time this virus also spread to the eastern part of Austria, where it was detected in dead wild birds (n=8). In 2009, recurrent WND outbreaks were observed in Hungary and Austria, in wild birds, horses, and humans in the same areas. Virus isolates of both years exhibited closest genetic relationship to the lineage 2 WNV strain which emerged in 2004. As we know today, the explosive spread of the lineage 2 WNV in 2008 described here remained not restricted to Hungary and Austria, but this virus dispersed further to the south to various Balkan states and reached northern Greece, where it caused the devastating neuroinvasive WND outbreak in humans in 2010.

  12. Explosive spread of a neuroinvasive lineage 2 West Nile virus in Central Europe, 2008/2009.

    Science.gov (United States)

    Bakonyi, Tamás; Ferenczi, Emőke; Erdélyi, Károly; Kutasi, Orsolya; Csörgő, Tibor; Seidel, Bernhard; Weissenböck, Herbert; Brugger, Katharina; Bán, Enikő; Nowotny, Norbert

    2013-07-26

    For the first time outside sub-Saharan Africa, a lineage 2 West Nile virus (WNV) emerged in Hungary in 2004. It caused sporadic cases of encephalitis in goshawks (Accipiter gentilis), other predatory birds, and in mammals. As a consequence, a surveillance program was initiated in Hungary and in Austria, which included virological, molecular, serological and epidemiological investigations in human beings, birds, horses, and mosquitoes. The virus strain became endemic to Hungary, however only sporadic cases of infections were observed between 2004 and 2007. Unexpectedly, explosive spread of the virus was noted in 2008, when neuroinvasive West Nile disease (WND) was diagnosed all over Hungary in dead goshawks and other birds of prey (n=25), in horses (n=12), and humans (n=22). At the same time this virus also spread to the eastern part of Austria, where it was detected in dead wild birds (n=8). In 2009, recurrent WND outbreaks were observed in Hungary and Austria, in wild birds, horses, and humans in the same areas. Virus isolates of both years exhibited closest genetic relationship to the lineage 2 WNV strain which emerged in 2004. As we know today, the explosive spread of the lineage 2 WNV in 2008 described here remained not restricted to Hungary and Austria, but this virus dispersed further to the south to various Balkan states and reached northern Greece, where it caused the devastating neuroinvasive WND outbreak in humans in 2010. PMID:23570864

  13. 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...

  14. Cool or hot Greenland?

    DEFF Research Database (Denmark)

    Ren, Carina Bregnholm

    2016-01-01

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

  15. Petrogenesis of Early-Permian sanukitoids from West Junggar, Northwest China: Implications for Late Paleozoic crustal growth in Central Asia

    Science.gov (United States)

    Yin, Jiyuan; Chen, Wen; Xiao, Wenjiao; Yuan, Chao; Sun, Min; Tang, Gongjian; Yu, Shun; Long, Xiaoping; Cai, Keda; Geng, Hongyan; Zhang, Yan; Liu, Xinyu

    2015-11-01

    Sanukitoids and their equivalents are rare subduction-related rock types that have been found in modern arc settings and in Late Archean sequences. The investigation of sanukitoids is of particular importance to a better understanding of crust-forming processes and continental growth. In this paper we report zircon U-Pb and Ar-Ar ages and major element, trace element, and Sr-Nd-Hf isotope data for the Bieluagaxi dioritic pluton and dikes from the southern part of the West Junggar, NW China. These rocks formed in the Early Permian and show a remarkable geochemical affinity with Cenozoic sanukitoids of the Setouchi Volcanic Belt of SW Japan with high Mg# (48-73) values, Cr (54-539 ppm), Ni (21-197 ppm) contents and Th/La (0.15-0.37) ratios and low Sr/Y ratios (16-27) and Sr (263-442 ppm) contents. They may be generated by the partial melting of subducting sediments, and subsequent melt-mantle interaction. Additionally, the sanukitoids are also widespread in the Karamay-Baogutu area of West Junggar accompanied by high Sr (average 713 ppm) contents and Sr/Y (50-130) ratios, and low Y (6.9-12.6 ppm) contents. The difference in petrochemical characteristics between the Baogutu-Karamay and Bieluagaxi sanukitoids can be explained by the difference in depth of initial melting, origin composition and fractional crystallization. The Baogutu-Karamay sanukitoids were probably formed under eclogitic conditions, while the Bieluagaxi sanukitoids were at a shallower depth. Moreover, the compositional similarity between continental-crust forming rocks and the Bieluagaxi sanukitoids suggests that the sanukitoids genesis could be closely related to the process of continental crust formation. The Late Carboniferous-Early Permian sanukitoids in the West Junggar may be an indicator of anomalous thermal activity. Ridge subduction may play a crucial role in the evolution and growth of the continental crust in Central Asia.

  16. 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....

  17. The Greenland Ramsar Sites

    DEFF Research Database (Denmark)

    Egevang, C.; Boertmann, D.

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

  18. Interaction of Rahaliya-Ekhedhur groundwater with the aquifer rock, West Razzaza Lake, Central Iraq

    Science.gov (United States)

    Al-Dabbas, Moutaz A.

    2016-09-01

    The groundwater of Dammam aquifer in Rahaliya-Ekhedhur area, West Razzaza, Iraq, was studied to identify the main hydrogeochemical processes and the groundwater-rock interaction. The results indicated that Na+ and SO4 2- are the dominant ions in the groundwater. The average contribution of cations in the aquifer is Na+ + K+ (24.7 %), Ca2+ (13.9 %), and Mg2+ (11.4 %), while anions contribution is SO4 2- (23.0 %), Cl- (20.7 %), and HCO3 - (6.3 %). The groundwater characterized by neutral to slightly alkaline hard water, excessively mineralized, and slightly brackish water type. Rock-water interaction processes are identified to include dissolution of carbonates, sulfates, halite, and clay minerals, leaching, and cation exchanges, with little impact of evaporation.

  19. Hydrogeology of the Hanford Site Central Plateau – A Status Report for the 200 West Area

    Energy Technology Data Exchange (ETDEWEB)

    Last, George V.; Thorne, Paul D.; Horner, Jacob A.; Parker, Kyle R.; Bjornstad, Bruce N.; Mackley, Rob D.; Lanigan, David C.; Williams, Bruce A.

    2009-08-27

    The Remediation Decisions Support (RDS) function of the Soil and Groundwater Remediation Project (managed by CH2M HILL Plateau Remediation Company [CHPRC]) is responsible for facilitating the development of consistent data, parameters, and conceptual models to resolve technical issues and support efforts to estimate contaminant migration and impacts (i.e., the assessment process). In particular, the RDS function is working to update electronic data sources and conceptual models of the geologic framework and associated hydraulic and geochemical parameters to facilitate traceability, transparency, defensibility, and consistency in support of environmental assessments. This report summarizes the efforts conducted by Pacific Northwest National Laboratory (PNNL) scientists in fiscal year 2008 (FY08) that focused primarily on the 200 West Area, as well as a secondary effort initiated on the 200 East Area.

  20. An integrtated approach to the use of Landsat TM data for gold exploration in west central Nevada

    Science.gov (United States)

    Mouat, D. A.; Myers, J. S.; Miller, N. L.

    1987-01-01

    This paper represents an integration of several Landsat TM image processing techniques with other data to discriminate the lithologies and associated areas of hydrothermal alteration in the vicinity of the Paradise Peak gold mine in west central Nevada. A microprocessor-based image processing system and an IDIMS system were used to analyze data from a 512 X 512 window of a Landsat-5 TM scene collected on June 30, 1984. Image processing techniques included simple band composites, band ratio composites, principal components composites, and baseline-based composites. These techniques were chosen based on their ability to discriminate the spectral characteristics of the products of hydrothermal alteration as well as of the associated regional lithologies. The simple band composite, ratio composite, two principal components composites, and the baseline-based composites separately can define the principal areas of alteration. Combined, they provide a very powerful exploration tool.

  1. Policies to improve the local impact from hydrocarbon extraction: Observations on West Africa and possible lessons for Central Asia

    International Nuclear Information System (INIS)

    The paper offers specific inputs to the debate on local content promotion in the oil industries of West Africa and Central Asia. To this end, we document the international experience with local content promotion to derive best practices in the field. We then use a case study approach to devise a simple analytical framework for rationalizing the selection of viable sectors for local content promotion, in an attempt to make operational one of the best practice principles (efficiency) developed before. By proposing specific rules regarding the acceptability of a project, the analysis seeks to add rigor and address distortions on localization outcomes from rent-seeking. The emphasis is not on supporting efforts to 'pick winners' and subsidize them through a range of by and large discredited instruments. Rather, the paper focuses on the specific public inputs the government would have to provide to support an otherwise market-driven process

  2. Future energy consumption and emissions in East-, Central- and West-China: Insights from soft-linking two global models

    DEFF Research Database (Denmark)

    Dai, Hancheng; Mischke, Peggy

    2014-01-01

    China's role in the global economy and energy markets is expanding, however many uncertainties with regards to the country's future energy consumption and emissions remain. Large regional disparities between China's provinces exist. Scenario analysis for different sub-regions of China will be...... useful for an improved understanding of China's potential future development and associated global impacts. This study soft-links a global dynamic CGE model and a global technology-rich energy system model. Both models are expanded to include East-, Central-, and West-China. This study shows that soft......-linking affects the China-specific reference scenario results in the CGE model considerably. Energy consumption and emissions are decreasing in China until 2050 while regional differences within China remain high....

  3. Thanetian transgressive-regressive sequences based on foraminiferal paleobathymetry at Gebel Matulla, west-central Sinai, Egypt

    Science.gov (United States)

    Farouk, Sherif; Elamri, Zaineb; El-Sorogy, Abdelbaset

    2016-09-01

    Qualitative and quantitative analysis of Thanetian foraminiferal assemblages at Gebel Matulla in west-central Sinai has been carried out. Three benthic foraminiferal assemblages are recorded from shallowest to deepest as Cibicidoides pseudoacutus, Angulogavelinella avnimelechi, Gavelinella danica witch evidences of fluctuations from middle neritic to upper bathyal environments. Changes in the foraminiferal population enabled us to classify the Thanetian succession into two fourth order transgressive-regressive (T-R) sequences. Three sequence boundaries are identified, at the Selandian/Thanetian (S/T) boundary, within the Thanetian succession, and the Paleocene/Eocene (P/E) boundary. It occurs at the top part of the maximum regression associated with major discontinuities and changes in depositional regimes as well as vertical facies changes. Broad correlation with eustatic records based upon integrated microplanktonic biostratigraphy suggests that the fluctuations of foraminiferal population were controlled by global sea-level changes.

  4. Kyllinga cataphyllata (Cyperaceae), a new species from the highlands of West and Central Africa

    NARCIS (Netherlands)

    Huygh, W.; Schouppe, D.; Larridon, I.; Simpson, D.A.; Goetghebeur, P.

    2010-01-01

    Kyllinga cataphyllata, a new species of Cyperaceae from the highlands of Western and Central Africa, is described and illustrated. This new species is easy recognized by the ascending rhizome densely covered by large cataphylls. The head-like inflorescence consisting of a single spike with spikelets

  5. Use of clay from kangerlussuaq in the Greenlandic construction industry

    DEFF Research Database (Denmark)

    Belmonte, Louise Josefine; Villumsen, Arne; Ottosen, Lisbeth M.;

    2010-01-01

    Clay material from Kangerlussuaq in West Greenland was characterised and its possible use for the production of bricks, expanded clay products and inert filler material was investigated. It was generally found that it was possible to use the clay in all of the above mentioned materials, although,...

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

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  8. Resilience and Renewable Energy Planning in Greenland

    DEFF Research Database (Denmark)

    Carruth, Susan

    2014-01-01

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

  9. 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...

  10. Mercury in the snow and firn at Summit Station, Central Greenland, and implications for the study of past atmospheric mercury levels

    Directory of Open Access Journals (Sweden)

    X. Faïn

    2008-07-01

    Full Text Available Gaseous Elemental Mercury (Hg° or GEM was investigated at Summit Station, Greenland, in the interstitial air extracted from the perennial snowpack (firn at depths ranging from the surface to 30 m, during summer 2005 and spring 2006. Photolytic production and destruction of Hg° were observed close to the snow surface during summer 2005 and spring 2006, and we observed dark oxidation of GEM up to 270 cm depth in June 2006. Photochemical transformation of gaseous elemental mercury resulted in diel variations in the concentrations of this gas in the near-surface interstitial air, but destruction of Hg° was predominant in June, and production was the main process in July. This seasonal evolution of the chemical mechanisms involving gaseous elemental mercury produces a signal that propagates downward through the firn air, but is unobservably small below 15 m in depth. As a consequence, multi-annual averaged records of GEM concentration should be well preserved in deep firn air at depths below 15 m, and available for the reconstruction of the past atmospheric history of GEM over the last decades.

  11. Future markers of the West Greenlandic

    DEFF Research Database (Denmark)

    Trondhjem, Naja Blytmann

    2010-01-01

    , and it is used when none of the others can be used. It seems that some of the tense suffixes i.e. past (-sima, perfective, perfect, preterite) and future (-ler, begin, be about to, near future) originally had a more or less concrete aspectual meanings and have developed into more abstract tense meanings...

  12. Swath-bathymetric Mapping of Glacial Landforms in the Central Pine Island Trough, West Antarctica

    Science.gov (United States)

    Jakobsson, M.; Anderson, J. B.; Nitsche, F. O.; Gyllencreutz, R.; Kirshner, A. E.; Kirchner, N.; O'regan, M. A.; Mohammad, R.; Eriksson, B.

    2011-12-01

    The Pine Island Glacier drains the West Antarctic Ice Sheet into the Amundsen Sea. During the Last Glacial Maximum (LGM), the Pine Island Glacier extended nearly 500 km from its present location, across the continental shelf to the shelf break. The Oden-Southern-Ocean 2009/2010 (OSO0910) expedition with Swedish icebreaker Oden carried out swath-bathymetric mapping and chirp sonar profiling of the mid-shelf section of Pine Island Trough. Since the bay was virtually ice free during the 2010 austral summer, the swath-bathymetric mapping could be conducted as a systematic survey which covered a coherent area of 4,140 km^2 of the mid-shelf glacial trough. The swath-bathymetric mapping and chirp sonar profiling were carried out with Oden's hull-mounted Kongsberg 12 kHz EM122 1°x1° multibeam echo sounder and integrated SBP 120 3°x3° chirp sonar. From these data we present new insights into to the glacial dynamics during the deglaciation of the mid-continental shelf since LGM. The landforms imaged in Pine Island Trough indicate stepwise retreat of the Pine Island Ice Stream punctuated by periods of grounding line stability and a minor advance followed by episodes of rapid retreat. Notably, directions of mapped mega scale lineations clearly show that the Pine Island Ice Stream changed its flow path during the advance. This advance followed a massive ice shelf break-up and grounding line retreat inferred from mapped corrugation ridges and iceberg plow ridges previously reported by Jakobsson et al., (2011). The periods of grounding line stability during the deglaciation are marked by sediment accumulations in the form of grounding zone wedges. Some of these wedges are here mapped to their full extents and in sufficient detail to characterize spatial dimensions and to estimate the volume of deposited sediment. Considering a range of sediment flux rates from the paleo-Pine Island Ice Stream we estimate that the largest and most clearly defined grounding zone wedge located

  13. 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.

  14. An assessment of the occupational and environmental health needs in seven Southeastern European and West-Central Asian countries.

    Science.gov (United States)

    Coman, Alexandru; Cherecheş, Răzvan M; Ungureanu, Marius I; Marton-Vasarhelyi, Emanuela O; Valentine, Marissa A; Sabo-Attwood, Tara; Gray, Gregory C

    2015-12-01

    Eastern European and Central Asian countries are undergoing rapid socioeconomic and political reforms. Many old industrial facilities are either abandoned, or use outdated technologies that severely impact the environment. Emerging industries have less regulation than in developed countries and environmental and occupational problems seem to be increasing. Under a US National Institutes of Health pilot grant, we developed an interdisciplinary One Health research network in Southeastern Europe and West-Central Asia to identify environmental and occupational problems. From 2012 to 2014, this GeoHealth Hub engaged 11 academic centers and 16 public health institutions in eight different countries: Albania, Armenia, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Romania, and the United States with a goal of strengthening environmental and occupational research and training capacities. Employing face-to-face interviews and large group meetings, we conducted an evidenced-based needs and opportunities assessment focused on aquatic health, food safety, and zoonotic diseases. Comprehensive reviews of the published literature yielded priority research areas for each of the seven GeoHealth Hub countries including heavy metal and pesticide contamination, tick-borne diseases, rabies, brucellosis, and inadequate public health surveillance.

  15. Preliminary investigation of haemoglobin polymorphism and association with morphometric traits in West African Dwarf goats in north central Nigeria

    Directory of Open Access Journals (Sweden)

    Abdulmojeed Yakubu

    2014-03-01

    Full Text Available The aim of this study was to characterize the genetic pool of the West African Dwarf (WAD goats using haemoglobin (Hb polymorphism, as well as the association of some morphological traits with the Hb variants. Blood samples were collected from a total of 104 mature goats of both sexes belonging to the WAD breed in north central Nigeria. The red cell lysates were subjected to cellulose acetate electrophoresis and specific staining procedure to reveal the band patterns of haemoglobin. Three co-dominant alleles, causing the presence of three genotypes (AA, AB and AC were detected among individual goats. The frequencies of the A, B and C alleles were 0.69, 0.30 and 0.01, respectively. The corresponding genotype frequencies for AA, AB and AC in the goat population were 0.37, 0.61 and 0.02, respectively. The discrepancy between the observed and the expected genotype number was significant (P0.05 by Hb variants. There is a need for further study encompassing more number of goats covering larger areas, use of DNA markers and their relationship with economic traits as well as performance study for detailed understanding of breed characteristics, conservation and genetic improvement of WAD goats in north central Nigeria.

  16. Neotropical River Otter Micro-Habitat Preference In West-Central Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Carrillo-Rubio E.

    2004-07-01

    Full Text Available We characterised habitat selected by the Neotropical otter (Lontra longicaudis in the Río San Pedro, located in the central portion of the State of Chihuahua in Northern Mexico. We monitored a 30 km stretch of the river for over two years and compared micro-site habitat characteristics at 21 used and 25 random sites. Characteristics of habitat preferred by the otter included pools that averaged >0.8 m deep, >14.6 m wide, >64% under-story vegetation cover, and rock talus/vegetation cover within 4.8 m.

  17. Multibeam Data and Socio-Economic Issues in West-Central San Francisco Bay, California

    Science.gov (United States)

    Chin, John L.; Carlson, Paul R.; Wong, Florence L.; Cacchione, David A.

    1998-01-01

    San Francisco Bay is the largest estuary on the conterminous U.S. Pacific Coast and is one of the world's largest natural harbors. It is a biologically productive and diverse environment. San Francisco Bay has a maritime economy that annually generates over $7.5 billion, handles 50 million tons of cargo, and involves thousands of jobs. Recent investigations by the USGS in this estuary help address both socio-economic and scientific issues: *Trimming pinnacles may prevent a calamitous oil spill. *Can San Francisco Bay accept more dredge spoil? *Bay floor biological habitats are quite varied. *How thick and how variable is the sediment fill in central San Francisco Bay?

  18. Spatial and temporal distribution of foraminifera in sediments off the central west coast of India and use of their test morphologies for the reconstruction of paleomonsoonal precipitation

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Khare, N.

    From the shallow region off the central west coast of India, 21 samples of surface sediments (ranging in depth from 22 to 52 m) along with two sediment cores of 4.80 m and 4.00 m (surface/subsurface) have been analyzed for foraminiferal composition...

  19. Spatio-Temporal Identification of Areas Suitable for West Nile Disease in the Mediterranean Basin and Central Europe.

    Directory of Open Access Journals (Sweden)

    Annamaria Conte

    Full Text Available West Nile virus (WNV is a mosquito-transmitted Flavivirus belonging to the Japanese encephalitis antigenic complex of the Flaviviridae family. Its spread in the Mediterranean basin and the Balkans poses a significant risk to human health and forces public health officials to constantly monitor the virus transmission to ensure prompt application of preventive measures. In this context, predictive tools indicating the areas and periods at major risk of WNV transmission are of paramount importance. Spatial analysis approaches, which use environmental and climatic variables to find suitable habitats for WNV spread, can enhance predictive techniques. Using the Mahalanobis Distance statistic, areas ecologically most suitable for sustaining WNV transmission were identified in the Mediterranean basin and Central Europe. About 270 human and equine clinical cases notified in Italy, Greece, Portugal, Morocco, and Tunisia, between 2008 and 2012, have been considered. The environmental variables included in the model were altitude, slope, night time Land Surface Temperature, Normalized Difference Vegetation Index, Enhanced Vegetation Index, and daily temperature range. Seasonality of mosquito population has been modelled and included in the analyses to produce monthly maps of suitable areas for West Nile Disease. Between May and July, the most suitable areas are located in Tunisia, Libya, Egypt, and North Cyprus. Summer/Autumn months, particularly between August and October, characterize the suitability in Italy, France, Spain, the Balkan countries, Morocco, North Tunisia, the Mediterranean coast of Africa, and the Middle East. The persistence of suitable conditions in December is confined to the coastal areas of Morocco, Tunisia, Libya, Egypt, and Israel.

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

    Science.gov (United States)

    Bennike, Ole

    2008-01-01

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

  1. Driving forces in the Greenlandic urbanization

    DEFF Research Database (Denmark)

    Hendriksen, Kåre

    2014-01-01

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

  2. Strategic environmental impact assessment of hydrocarbon activities in the Disko West area

    International Nuclear Information System (INIS)

    This publication is a strategic environmental impact assessment of activities related to exploration, development and exploitation of hydrocarbons in the sea of West Greenland between 67 deg. and 71 deg. N (the Disko West Area). (au)

  3. 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.

  4. Greenland climate change

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  5. Ionospheric travelling convection vortices observed by the Greenland magnetometer chain

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Stolle, Claudia; Friis-Christensen, Eigil;

    2013-01-01

    The Greenland magnetometer array continuously provides geomagnetic variometer data since the early eighties. With the polar cusp passing over it almost every day, the array is suitable to detect ionospheric traveling convection vortices (TCVs), which were rst detected by Friis-Christensen et al...... are discussed. Specifically, three years of magnetometer data, from 1986 to 1988, collected at seven stations at the West coast of Greenland are analysed and TCV events are identied and isolated. The events are classied with respect to their intensity, duration and time of occurrence and they are correlated...

  6. Terrestrial lichen response to partial cutting in lodgepole pine forests on caribou winter range in west-central British Columbia

    Directory of Open Access Journals (Sweden)

    Michaela J. Waterhouse

    2011-09-01

    Full Text Available In west-central British Columbia, terrestrial lichens located in older, lodgepole pine (Pinus contorta forests are important winter forage for woodland caribou (Rangifer tarandus caribou. Clearcut harvesting effectively removes winter forage habitat for decades, so management approaches based on partial cutting were designed to maintain continuous lichen-bearing habitat for caribou. This study tested a group selection system, based on removal of 33% of the forest every 80 years in small openings (15 m diameter, and two irregular shelterwood treatments (whole-tree and stem-only harvesting methods where 50% of the stand area is cut every 70 years in 20 to 30 m diameter openings. The abundance of common terrestrial lichens among the partial cutting and no-harvest treatments was compared across five replicate blocks, pre-harvest (1995 and post-harvest (1998, 2000 and 2004. The initial loss of preferred forage lichens (Cladonia, Cladina, Cetraria and Stereocaulon was similar among harvesting treatments, but there was greater reduction in these lichens in the openings than in the residual forest. After eight years, forage lichens in the group selection treatment recovered to pre-harvest amounts, while lichen in the shelterwood treatments steadily increased from 49 to 57% in 1998 to about 70% of pre-harvest amounts in 2004. Although not part of the randomized block design, there was substantially less lichen in three adjacent clearcut blocks than in the partial cuts. Regression analysis pre- and post-harvest indicated that increased cover of trees, shrubs, herbs, woody debris and logging slash corresponded with decreased forage lichen abundance. In the short-term, forestry activities that minimize inputs of woody debris, control herb and shrub development, and moderate the changes in light and temperatures associated with canopy removal will lessen the impact on lichen. Implementation of stand level prescriptions is only one aspect of caribou habitat

  7. Pertussis in the central-west region of Brazil: one decade study

    Directory of Open Access Journals (Sweden)

    Angelita Fernandes Druzian

    2014-04-01

    Full Text Available In many parts of the world, numerous outbreaks of pertussis have been described despite high vaccination coverage. In this article we report the epidemiological characteristics of pertussis in Brazil using a Surveillance Worksheet. Secondary data of pertussis case investigations reported from January 1999 to December 2008 recorded in the Information System for Notifiable Diseases (SINAN and the Central Laboratory for Public Health (LACEN-MS were utilized. The total of 561 suspected cases were reported and 238 (42.4% of these were confirmed, mainly in children under six months (61.8% and with incomplete immunization (56.3%. Two outbreaks were detected. Mortality rate ranged from 2.56% to 11.11%. The occurrence of outbreaks and the poor performance of cultures for confirming diagnosis are problems which need to be addressed. High vaccination coverage is certainly a good strategy to reduce the number of cases and to reduce the impact of the disease in children younger than six months.

  8. Deep Crustal Earthquakes and Repeating Earthquakes in the West-Central Sierra Nevada, Western USA

    Science.gov (United States)

    Hurd, O.; Frassetto, A.; Zandt, G.; Gilbert, H.; Jones, C.; Owens, T. J.

    2006-12-01

    The Sierra Nevada EarthScope Project (SNEP) is a multiple institution, collaborative research project focused on investigating the structure and evolution of the Sierra Nevada batholith in eastern California. The first phase of the project (summer 2005-summer 2006) saw the deployment of over forty (40) broadband seismometers spanning the central Sierra Nevada from Fresno, California to just south of the Lake Tahoe region. These seismic stations recorded many small, local earthquakes in both the western foothills and high Sierra Nevada that were mostly located from 20 to 120 km north of Fresno and were not present in other regional catalogs. Seismicity in this region is notable because it occurs in the interior of a plate away from major known faults. Ninety (90) events were picked on as many as 20 SNEP stations and located. These events occurred from late May 2005 to late January 2006 at a rate of ~10 per month and were located between 10 and 35 km depth. Many of the events fall within two distinct clusters beneath the array. The first cluster contains ~45 events and is located 30-70 km east of Merced, California and 30-90 km north of Fresno, California. The second represents ~30 events and is centered about the southern Yosemite National Park region. Average depth of the events in the first cluster is ~27 km compared to ~16 km for the events in the second. Past studies have found that events from similar locations in the western Sierra Nevada foothills exhibited ML magnitudes from 0 to 3.2 and had focal mechanisms displaying strike-slip faulting combined with normal and reverse components (Wong and Savage, 1983, BSSA). Direct comparison between waveforms of picked events occurring in small clusters (2-5 events) found that some events had nearly identical waveforms. This suggests similar rupture locations and characteristics despite the events having occurred a couple days to several weeks apart.

  9. Transitive Business Model of Management in Central Europe – Torn between East and West

    Directory of Open Access Journals (Sweden)

    Artur K. MODLIŃSKI

    2013-06-01

    Full Text Available The objective of the article is to present the internal and external model of management and how it is connected to the political system and national culture among the Visegrad countries.  The  paper  presents  several  examples  of  transitive models of management. It aims to indicate which advantages and disadvantages can be  identified  in  the  transitive  groups,  how  they  can  influences  the  international investment potential and image of the company. Qualitative research on asample of Polish, German and Ukrainian companies combined with secondary data. Polish business culture can be regarded as transitive –the influence of two bordering civilization (Western and Orthodox is noticeable. This phenomenon has shaped the business values and it is still present in the international context. The  transitive  business  model  of  management allows  to  predict  and  avoid  the  problems  occurring  in  the  internal  and  external relationships  in  the  companies  from  Central  Europe  who  are  involved  into international projects. The  paper  enables  the  clarification  of  the  transitive management  culture;  the  juxtaposition  of  differences  and  similarities  and  their impacts  of  the  internal  and  external  business  relationships;  the  explicitness  of dichotomy and its influence on international business image of Visegrad countries.

  10. Hydrogeology and ground-water flow in the Edwards-Trinity aquifer-system, west-central, Texas

    Science.gov (United States)

    Kuniansky, E.L.; Ardis, A.F.

    1997-01-01

    Two finite-element ground-water flow models were developed for the Edwards–Trinity aquifer system, west-central Texas, to gain a better understanding of the flow system; one ground-water flow model was developed at a large scale to simulate the regional system and contiguous, hydraulically connected units, and one model was constructed at a smaller more detailed scale to simulate the most active areas of the system. The study area is divided into four geographic subareas: the Trans-Pecos (9,750 square miles), the Edwards Plateau (23,750 square miles), the Hill Country (5,500 square miles), and the Balcones fault zone (3,000 square miles). The major aquifers within the study area are the Edwards–Trinity aquifer underlying the Trans-Pecos and Edwards Plateau, the Trinity aquifer underlying the Hill Country, and the Edwards aquifer in the Balcones fault zone. Hydraulically connected aquifers include the High Plains aquifer north of the Edwards Plateau, and the Cenozoic Pecos alluvium aquifer adjacent to both the Trans-Pecos and the Edwards Plateau along the Pecos River. Minor contiguous aquifers include the Dockum, Ellenburger– San Saba, Marble Falls, Hickory, and Lipan, which is adjacent to the Colorado River in Tom Green and Concho Counties, Texas.

  11. Digital model of predevelopment flow in the Tertiary limestone (Floridan) aquifer system in West-Central Florida

    Science.gov (United States)

    Ryder, Paul D.

    1982-01-01

    A computer model was calibrated to approximate predevelopment flow conditions in a multilayered aquifer system in 10,600 square miles in west-central Floria. The lowermost aquifer, called the Floridan aquifer, is confined in most of the study area and consists of carbonate rocks ranging up to 1,300 feet thick. The Floridan aquifer is the chief source for large withdrawals and natural springflow in the study area. Daily springflows within the study area have averaged about 2.4 billion gallons. The secondary artesian and the surficial aquifers are much less permeable than the Floridan aquifer. Where they are present and have heads higher than those in the Floridan aquifer, they provide recharge to the Floridan. Initial estimates of recharge to the Floridan aquifer were from water-balance calculations for surface-water basins; initial estimates of transmissivity were from aquifer tests and flow-net analyses. The model was calibrated for the predevelopment era, wherein steady-state flow conditions were assumed. Calibrated transmissivities for the Floridan aquifer range from less than 15,000 to several million feet squared per day. Recharge to the system was about 3,700 cubic feet per second. About 90% was discharged as springflow, and 10% was upward leakage. (USGS)

  12. Municipal solid-waste disposal and ground-water quality in a coastal environment, west-central Florida

    Science.gov (United States)

    Fernandez, Mario

    1983-01-01

    Solid waste is defined along with various methods of disposal and the hydrogeologic factors to be considered when locating land-fills is presented. Types of solid waste, composition, and sources are identified. Generation of municipal solid waste in Florida has been estimated at 4.5 pounds per day per person or about 7.8 million tons per year. Leachate is generated when precipitation and ground water percolate through the waste. Gases, mainly carbon dioxide and methane, are also produced. Leachate generally contains high concentrations of dissolved organic and inorganic matter. The two typical hydrogeologic conditions in west-central Florida are (1) permeable sand overlying clay and limestone and (2) permeable sand overlying limestone. These conditions are discussed in relation to leachate migration. Factors in landfill site selection are presented and discussed, followed by a discussion on monitoring landfills. Monitoring of landfills includes the drilling of test holes, measuring physical properties of the corings, installation of monitoring wells, and water-quality monitoring. (USGS)

  13. A digital model for planning water management at Benton Lake National Wildlife Refuge, west-central Montana

    Science.gov (United States)

    Nimick, David A.; McCarthy, Peter M.; Fields, Vanessa

    2011-01-01

    Benton Lake National Wildlife Refuge is an important area for waterfowl production and migratory stopover in west-central Montana. Eight wetland units covering about 5,600 acres are the essential features of the refuge. Water availability for the wetland units can be uncertain owing to the large natural variations in precipitation and runoff and the high cost of pumping supplemental water. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, has developed a digital model for planning water management. The model can simulate strategies for water transfers among the eight wetland units and account for variability in runoff and pumped water. This report describes this digital model, which uses a water-accounting spreadsheet to track inputs and outputs to each of the wetland units of Benton Lake National Wildlife Refuge. Inputs to the model include (1) monthly values for precipitation, pumped water, runoff, and evaporation; (2) water-level/capacity data for each wetland unit; and (3) the pan-evaporation coefficient. Outputs include monthly water volume and flooded surface area for each unit for as many as 5 consecutive years. The digital model was calibrated by comparing simulated and historical measured water volumes for specific test years.

  14. Chemical composition of red, brown and green macroalgae from Buarcos bay in Central West Coast of Portugal.

    Science.gov (United States)

    Rodrigues, Dina; Freitas, Ana C; Pereira, Leonel; Rocha-Santos, Teresa A P; Vasconcelos, Marta W; Roriz, Mariana; Rodríguez-Alcalá, Luís M; Gomes, Ana M P; Duarte, Armando C

    2015-09-15

    Six representative edible seaweeds from the Central West Portuguese Coast, including the less studied Osmundea pinnatifida, were harvested from Buarcos bay, Portugal and their chemical characterization determined. Protein content, total sugar and fat contents ranged between 14.4% and 23.8%, 32.4% and 49.3% and 0.6-3.6%. Highest total phenolic content was observed in Codium tomentosum followed by Sargassum muticum and O. pinnatifida. Fatty acid (FA) composition covered the branched chain C13ai to C22:5 n3 with variable content in n6 and n3 FA; low n6:n3 ratios were observed in O. pinnatifida, Grateloupia turuturu and C. tomentosum. Some seaweed species may be seen as good sources of Ca, K, Mg and Fe, corroborating their good nutritional value. According to FTIR-ATR spectra, G. turuturu was associated with carrageenan seaweed producers whereas Gracilaria gracilis and O. pinnatifida were mostly agar producers. In the brown algae, S. muticum and Saccorhiza polyschides, alginates and fucoidans were the main polysaccharides found. PMID:25863629

  15. Analysis of ambient air quality trends at selected West Central Airshed Society stations : Tomahawk and Carrot Creek

    International Nuclear Information System (INIS)

    Ambient air trends were evaluated using data collected over a 10 year period from two West Central Airshed Society monitoring stations in rural Alberta. The pollutants studied included ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter (PM2.5). Two approaches were used to evaluate the trends. The first approach used various percentiles of hourly concentration distributions from each year, while the second approach used frequencies of the number of hours in which various benchmark concentrations were exceeded each year. These statistics were assumed to be linear over the period of study. Hypothesis tests were conducted on the best-fit lines to check whether slope of the lines was zero in order to indicate change. Results from both approaches were found to be in good agreement. At the Tomahawk Station, no statistically dominant change was detected in air quality with respect to O3 and PM2.5. However, SO2 and NO2 showed statistically significant decreasing trends. At the Carrot Creek Station, a pronounced decreasing trend in SO2 was observed, but there was no change in O3 and NO2. The decreasing trends observed with SO2 at both stations is consistent with the province's efforts to reduced natural gas flaring and venting. It was cautioned that since the period of study over which trends were examined was short, the changes or lack of changes observed do not necessarily indicate long term trends

  16. The west-central Florida inner shelf and coastal system: A geologic conceptual overview and introduction to the special issue

    Science.gov (United States)

    Hine, A.C.; Brooks, G.R.; Davis, R.A.; Duncan, D.S.; Locker, S.D.; Twichell, D.C.; Gelfenbaum, G.

    2003-01-01

    This paper provides an overview for this special publication on the geologic framework of the inner shelf and coastal zone of west-central Florida. This is a significant geologic setting in that it lies at the center of an ancient carbonate platform facing an enormous ramp that has exerted large-scale control on coastal geomorphology, the availability of sediments, and the level of wave energy. In order to understand the Holocene geologic history of this depositional system, a regional study defined by natural boundaries (north end of a barrier island to the apex of a headland) was undertaken by a group of government and university coastal geologists using a wide variety of laboratory and field techniques. It is the purpose of this introductory paper to define the character of this coastal/inner shelf system, provide a historical geologic perspective and background of environmental information, define the overall database, present the collective objectives of this regional study, and very briefly present the main aspects of each contribution. Specific conclusions are presented at the end of each paper composing this volume. ?? 2003 Elsevier B.V. All rights reserved.

  17. Mid to late Holocene strengthening of the East Greenland Current linked to warm subsurface Atlantic water

    Science.gov (United States)

    Perner, Kerstin; Moros, Matthias; Lloyd, Jeremy M.; Jansen, Eystein; Stein, Rüdiger

    2015-12-01

    The relatively fresh and cold East Greenland Current (EGC) connects the Arctic with the subpolar North Atlantic Ocean. Its strength and influence on the freshwater balance in the North Atlantic affects both the Subpolar Gyre dynamics and deep convection in the Labrador Sea. Enhanced freshwater and sea-ice expansion in the subpolar North Atlantic is suggested to modify the northward heat transport within the North Atlantic Current. High-resolution palaeoceanographic reconstructions, based on planktic and benthic foraminifera assemblage data, from the central East Greenland shelf (Foster Bugt) reveal distinct centennial to millennial-scale oceanographic variability that relates to climatic changes during the mid to late Holocene (the last c. 6.3 ka BP). Our data highlight intervals of cooling and freshening of the polar surface EGC waters that accompany warming in the subsurface Atlantic waters, which are a combination of chilled Atlantic Intermediate Water (AIW) from the Arctic Ocean and of the Return Atlantic Current (RAC) from the West Spitsbergen Current (WSC). Mid Holocene thermal optimum conditions prevailed until c. 4.5 ka BP. A thin/absent surface Polar Water layer, low drift/sea-ice occurrence and strong contribution of recirculating warm Atlantic waters at the subsurface, suggest a relatively weak EGC during this period. Subsequently, between 1.4 and 4.5 ka BP, the water column became well stratified as the surface Polar Water layer thickened and cooled, indicating a strong EGC. This EGC strengthening parallelled enhanced subsurface chilled AIW contribution from the Arctic Ocean after c. 4.5 ka BP, which culminated from 1.4 to 2.3 ka BP. This coincides with warming identified in earlier work of the North Atlantic Current, the Irminger Current, and the West Greenland Current. We link the enhanced contribution of chilled Atlantic Water during this period to the time of the 'Roman Warm Period'. The observed warming offshore East Greenland, centred at c. 1.8 ka

  18. 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...

  19. 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...

  20. Commentary: Future Greenland 2015

    DEFF Research Database (Denmark)

    Bjørst, Lill Rastad

    2015-01-01

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

  1. APISSEQ Sisimiut – Greenland

    DEFF Research Database (Denmark)

    Kotol, Martin

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

  2. Spatiotemporal distribution of rabies in Arctic foxes in Greenland

    DEFF Research Database (Denmark)

    Raundrup, Katrine; Moshøj, Charlotte; Wennerberg, Sanne E.;

    2015-01-01

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

  3. Shifting shoals and shattered rocks : How man has transformed the floor of west-central San Francisco Bay

    Science.gov (United States)

    Chin, John L.; Wong, Florence L.; Carlson, Paul R.

    2004-01-01

    subembayments--north bay (San Pablo and Suisun Bays), central bay, and south bay--each characterized by a central area of open water surrounded by intertidal mudflats and marshes. Central bay includes Alcatraz and Angel Islands and also a number of submerged bedrock knobs that protrude through the sediment of the bay floor and rise to within about 40 feet (12 m) of the water surface. The most prominent of these are Harding, Shag, Arch, and Blossom Rocks. These rocks have been lowered by blasting several times in the past, but they remain a potential hazard to shipping because newer cargo vessels are designed with increasingly deeper drafts. Central bay's location adjacent to two major population and commerce centers, San Francisco and Oakland, subjects it to greater human influences than less developed parts of the estuary. The western part of central San Francisco Bay is adjacent to the Golden Gate, the estuary's outlet to the Pacific Ocean. The changing submarine topography of the west-central bay, as well as its geology, form the main focus of this book.

  4. Geohydrology, Geochemistry, and Ground-Water Simulation-Optimization of the Central and West Coast Basins, Los Angeles County, California

    Science.gov (United States)

    Reichard, Eric G.; Land, Michael; Crawford, Steven M.; Johnson, Tyler D.; Everett, Rhett; Kulshan, Trayle V.; Ponti, Daniel J.; Halford, Keith L.; Johnson, Theodore A.; Paybins, Katherine S.; Nishikawa, Tracy

    2003-01-01

    Historical ground-water development of the Central and West Coast Basins in Los Angeles County, California through the first half of the 20th century caused large water-level declines and induced seawater intrusion. Because of this, the basins were adjudicated and numerous ground-water management activities were implemented, including increased water spreading, construction of injection barriers, increased delivery of imported water, and increased use of reclaimed water. In order to improve the scientific basis for these water management activities, an extensive data collection program was undertaken, geohydrological and geochemical analyses were conducted, and ground-water flow simulation and optimization models were developed. In this project, extensive hydraulic, geologic, and chemical data were collected from new multiple-well monitoring sites. On the basis of these data and data compiled and collected from existing wells, the regional geohydrologic framework was characterized. For the purposes of modeling, the three-dimensional aquifer system was divided into four aquifer systems?the Recent, Lakewood, Upper San Pedro, and Lower San Pedro aquifer systems. Most pumpage in the two basins is from the Upper San Pedro aquifer system. Assessment of the three-dimensional geochemical data provides insight into the sources of recharge and the movement and age of ground water in the study area. Major-ion data indicate the chemical character of water containing less than 500 mg/L dissolved solids generally grades from calcium-bicarbonate/sulfate to sodium bicarbonate. Sodium-chloride water, high in dissolved solids, is present in wells near the coast. Stable isotopes of oxygen and hydrogen provide information on sources of recharge to the basin, including imported water and water originating in the San Fernando Valley, San Gabriel Valley, and the coastal plain and surrounding hills. Tritium and carbon-14 data provide information on relative ground-water ages. Water with

  5. A TEX86 lake record suggests simultaneous shifts in temperature in Central Europe and Greenland during the last deglaciation

    OpenAIRE

    Blaga, C. I.; G. J. Reichart; Lotter, A. F.; Anselmetti, F. S.; Sinninghe Damsté, J.S.

    2013-01-01

    High-resolution quantitative temperature records from continents covering glacial to interglacial transitions are scarce but important for understanding the climate system. We present the first decadal resolution record of continental temperatures in Central Europe during the last deglaciation (similar to 14,60010,600cal. yrB.P.) based on the organic geochemical palaeothermometer TEX86. The TEX86-inferred temperature record from Lake Lucerne (Vierwaldstattersee, Switzerland) reveals typical o...

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

    DEFF Research Database (Denmark)

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

    2006-01-01

    Thickness of eggshell fragments and whole eggs from the Peregrine Falcon Falco peregrinus collected in South and West Greenland between 1972 and 2003 was measured and compared to shell thickness of pre-DDT eggs, also collected in Greenland. Linear regression yields a significant increase...... in the average thickness of eggshells over the period of 0.19% per year, corresponding to a change in eggshell thinning from 13.9% in 1972 to 7.8% in 2003. Backwards extrapolation of the data, suggests that the Greenlandic Peregrine population probably was never critically affected by DDT-induced eggshell...

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

    DEFF Research Database (Denmark)

    Kapel, C. M O; Nansen, P.

    1996-01-01

    of Greenland. In general, the composition of the helminth fauna of arctic foxes in Greenland showed distinct differences geographically. Thus, the diversity of helminth species in foxes caught in the northern districts of Greenland seems lower than in the southern districts; only nematode species with direct...... life cycles were represented equally in all parts of the country. The diversity of the surrounding fauna, and thereby the food items available for the foxes, seems to determine the spectrum of helminth species. Helminths requiring rodents as intermediate hosts were absent on the west coast, even...

  8. The predominance of Human Immunodeficiency Virus type 1 (HIV-1 circulating recombinant form 02 (CRF02_AG in West Central Africa may be related to its replicative fitness

    Directory of Open Access Journals (Sweden)

    Butel Christelle

    2006-07-01

    Full Text Available Abstract Background CRF02_AG is the predominant HIV strain circulating in West and West Central Africa. The aim of this study was to test whether this predominance is associated with a higher in vitro replicative fitness relative to parental subtype A and G viruses. Primary HIV-1 isolates (10 CRF02_AG, 5 subtype A and 5 subtype G were obtained from a well-described Cameroonian cohort. Growth competition experiments were carried out at equal multiplicity of infection in activated T cells and monocyte-derived dendritic cells (MO-DC in parallel. Results Dual infection/competition experiments in activated T cells clearly indicated that CRF02_AG isolates had a significant replication advantage over the subtype A and subtype G viruses. The higher fitness of CRF02_AG was evident for isolates from patients with CD4+ T cell counts >200 cells/μL (non-AIDS or CD4+ T cell counts Conclusion We observed a higher ex vivo replicative fitness of CRF02_AG isolates compared to subtype A and G viruses from the same geographic region and showed that this was independent of the co-receptor tropism and irrespective of high or low CD4+ T cell count. This advantage in replicative fitness may contribute to the dominant spread of CRF02_AG over A and G subtypes in West and West Central Africa.

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

    Directory of Open Access Journals (Sweden)

    T. Hughes

    2014-04-01

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

  10. 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.

  11. Au-Sn-W-Cu-Mineralization in the Astaneh-Sarband Area, West Central Iran : including a comparison of the ores with ancient bronze artifacts from Western Asia

    OpenAIRE

    Nezafati, Nima

    2006-01-01

    The present study deals with two primary aims; (1) geological, mineralogical, and geochemical investigations of the Deh Hosein, Astaneh, and Nezam Abad mineralizations in the Astaneh-Sarband area, west central Iran, with the aim to understand the characteristics of the occurrences and their conditions of formation, and (2) geochemical investigations on ancient bronze artifacts from Iran and Western Asia in order to compare their characteristics with the high-tin copper ore of Deh Hosein and e...

  12. On the Annual Cycle of Central South-West Asia precipitation in GCMs: an Analysis of AMIP Simulation Results

    Science.gov (United States)

    Malik, K. M.; Taylor, P.; Szeto, K.

    2009-12-01

    This study evaluates simulations of precipitation patterns over the Central South-West Asia region (25-40N and 45-75E) by using results from the Atmospheric Model Inter-comparison Project (AMIP). Annual and monthly spatial precipitation fields produced by a subset of 13 currently available AMIP model experiments are evaluated for the region and compared with GPCC (Global Precipitation Climatology Centre) monthly precipitation data for the period of 1979-2001. GPCC precipitation data are available with 0.5 degree resolution and correlate with observational precipitation data with a correlation factor of 0.953. The models show large variations in their ability to capture the seasonal precipitation, although spatial correlations indicate that some of the models simulate the pattern of GPCC precipitation fields fairly well. Some models cannot capture the convective precipitation in the region that occurs during spring (March-April) and fall (Sept-Oct). Relative to the GPCC data most of the models predicted well in winter whereas some models cannot adequately capture the summer (monsoon) precipitation which enters the domain from east. On the spatial scales of the selected region, there is little consistent evidence that points to any specific feature as an indicator of model performance. None of the obvious candidates such as horizontal resolution, convective closure schemes, or land surface schemes are reliable discriminators of a models ability to simulate precipitation accurately. Horizontal resolution effects are apparent in the inter-mountain region, where high resolution models do better that low resolution models. However, there is not enough evidence to produce reliable simulation on this basis. Correlation coefficients of observed precipitation with model output can be improved by using ensemble averaged precipitation from several models.

  13. Radionuclide migration pathways analysis for the Oak Ridge Central Waste Disposal Facility on the West Chestnut Ridge site

    International Nuclear Information System (INIS)

    A dose-to-man pathways analysis is performed for disposal of low-level radioactive waste at the Central Waste Disposal Facility on the West Chestnut Ridge Site. Both shallow land burial (trench) and aboveground (tumulus) disposal methods are considered. The waste volumes, characteristics, and radionuclide concentrations are those of waste streams anticipated from the Oak Ridge National Laboratory, the Y-12 Plant, and the Oak Ridge Gaseous Diffusion Plant. The site capacity for the waste streams is determined on the basis of the pathways analysis. The exposure pathways examined include (1) migration and transport of leachate from the waste disposal units to the Clinch River (via the groundwater medium for trench disposal and Ish Creek for tumulus disposal) and (2) those potentially associated with inadvertent intrusion following a 100-year period of institutional control: an individual resides on the site, inhales suspended particles of contaminated dust, ingests vegetables grown on the plot, consumes contaminated water from either an on-site well or from a nearby surface stream, and receives direct exposure from the contaminated soil. It is found that either disposal method would provide effective containment and isolation for the anticipated waste inventory. However, the proposed trench disposal method would provide more effective containment than tumuli because of sorption of some radionuclides in the soil. Persons outside the site boundary would receive radiation doses well below regulatory limits if they were to ingest water from the Clinch River. An inadvertent intruder could receive doses that approach regulatory limits; however, the likelihood of such intrusions and subsequent exposures is remote. 33 references, 31 figures, 28 tables

  14. Cave bats of the central west coast and southern section of the Northwest Panay Peninsula, Panay Island, the Philippines

    Directory of Open Access Journals (Sweden)

    A. Mould

    2012-09-01

    Full Text Available Bats (order Chiroptera form a large proportion of the species-rich mammalian fauna of the Philippines, and while the threats posed to these animals are well documented, for many species there is currently insufficient data to enable even a basic assessment of their conservation status. This is true for Panay Island, located in the Western Visayas region of the archipelago, where the need for surveying remaining suitable bat habitat has been identified as a priority. Between 5 April and 9 May 2011 a survey of 21 caves was undertaken on Panay, along the central section of the west coast of the island and within the southern section of the Northwest Panay Peninsula. Survey methods included visual observations, emergence counts and the recording of echolocation calls. Of the caves surveyed, 19 were found to support bats or show signs of their use, and at least 12 different species were observed. Three large maternity colonies of the Common Rousette Rousettus amplexicaudatus and two of the Dusky Roundleaf Bat Hipposideros ater were noted as having particular significance in terms of their conservation value for local populations. Potential maternity colonies of Asian Lesser False Vampire Megaderma spasma, Black-bearded Tomb Bat Taphozous melanopogon and Diadem Roundleaf Bat Hipposideros diadema were also observed but not confirmed. M. spasma was the most frequently encountered species, occurring in small numbers at five different caves. Other species/genera encountered in small numbers were the Arcuate Horseshoe Bat Rhinolophus arcuatus, Common Short-nosed Fruit Bat Cynopterus brachyotis, Philippine Sheath-tailed Bat Emballonura alecto, Yellow-faced Horseshoe Bat Rhinolophus virgo, Bent-wing (Miniopterus and Myotis bat species, and at least one other Horseshoe (Rhinolophus bat species. Ten of the caves were confirmed to support multiple bat species. An indication of current threats and recommendations for further survey and management priorities are

  15. Model equations for Calculating Rn-gas Concentrations in Air of Uranium Exploratory Tunnels, Allouga, West-Central Sinai , Egypt

    International Nuclear Information System (INIS)

    Gabal Allouga area is located some 40 km due east from Abu Zenima town on the east coast of the Gulf of Suez, West-Central Sinai, Egypt. A network of exploratory tunnels totaling 670m in length and approximately 2x2 m in cross section, were excavated within a paleosol clayey bed. They host (Fe, Mn)-, Cu-, and U-mineralizations. Portions of the tunnels are naturally ventilated and others portions are non-ventilated and show ground water seepage through fractures. Model equations were developed for calculating the Rn-gas concentrations in the air of the tunnels under dry conditions where Rn-gas transport is mainly by air flow through porous media as well as for wet conditions where Rn-gas transport is mainly by ground water flow into the tunnels. Under dry conditions the model calculated Rn-gas concentrations(15.2-60.6 PCi/1) are consistent with measured values by active techniques (3.26-22.85 pCi/1) and by SSNTD techniques (19-69.1 pCi/1) when the Rn-emanation coefficient (alpha= 0.05-0.2), the emanating rock thickness (X=10 cm) and U-concentration averages 30 ppm. Under wet and non-ventilated conditions the model calculated Rn-gas concentrations (159-1248 pCi/1) are consistent with the measured values by active techniques (231-1348 pCi/1) and by SSNTD techniques (144-999pCi/1), when the Rn-emanation coefficient (alpha=0.1-0.25), the ground water flow (F=0.04-0.10 ml/s-1cm-2) and U-concertrations (100-250ppm)

  16. Prevalence and risk factors of obesity and hypertension among students at a central university in the West Bank

    Directory of Open Access Journals (Sweden)

    Yasin I. Tayem

    2012-10-01

    Full Text Available Objectives : We aimed to determine the prevalence and correlates of obesity and hypertension (HTN among students at a central university in the West Bank. Materials and methods : This cross-sectional study targeted a cohort of 553 students (59.5% males, 40.5% females aged 17–26 years (median = 21 from Al-Quds University. Body mass index (BMI and blood pressure (BP were measured. Participants completed a questionnaire on physical activity, sedentary behavior, dietary factors, smoking and family history of obesity, HTN, and coronary artery disease. The magnitude of correlation was assessed by Spearman's rho (r s and Chi-square tests. Results : The prevalence of overweight was 25% (31.1% males, 15.6% females and obesity 7.2% (9.4% males, 4% females. Obesity and overweight were associated with family history of obesity in both genders (p<0.001 and physical activity in males (r s= − 0.162, p<0.005. No correlation was demonstrated between participants’ BMI and sedentary lifestyle or consumption of fast food. Pre-HTN was detected in 27.1% (38% males, 11.2% females and HTN in 2.2% (3.3% males, 0.4% females. Pre-HTN and HTN were associated with obesity (r s=0.252, p<0.001 and smoking (p<0.05. No relationship was detected between students’ BP and sedentary behavior, family history of HTN/CAD, or consumption of fast food. The prevalence of increased BMI and BP among males was significantly higher than females (p<0.001. Conclusions : We detected a high prevalence of elevated BP and excess weight gain among students at Al-Quds University. An interventional program is urgently needed to control these cardiovascular risk factors in this community.

  17. Use of radioactive fallout cesium-137 to estimate soil erosion on three farms in west central Ohio

    International Nuclear Information System (INIS)

    Assessment of the impact of soil erosion on productivity and environment quality requires comprehensive and credible estimates of erosion. Measuring concentration of 137Cs fallout is a relatively simple and rapid technique for determining long-term mean annual rates of soil erosion and deposition. The purpose of this study was to evaluate the potential of the 137Cs activity-soil depth relationship in estimating soil erosion from arable land in west central Ohio. Thus, soil samples obtained from three to four genetic horizons of four erosion phases at three farms in Clark Co., Ohio, (hereafter called Sites A, B, and C) were analyzed for 137Cs activity. Relationships between 137Cs activity and soil depth at undisturbed reference sites were used to calculate the depth of soil eroded and mean annual erosion rates. Cumulative 137Cs activities ranged from 6.8 mBq g-1 for the severely eroded phase at Site C to 16.6 mBq g-1 for the deposition phase at Site A. These activities corresponded to soil erosion rates of 125.9 Mg ha-1 y-1 for severe to 26.6 Mg ha-1 y-1 for deposition phases. A general trend of increasing soil erosion (by 24 to 85%) from slightly to severely eroded phases was observed although the data were highly variable. Estimated soil erosion rates depended on the regression model used and were more than an order of magnitude higher than those determined using the Revised Universal Soil Loss Equation. Sampling rigorously at small depth increments by means of a core sampler, careful selection of reference sites, and calibration or validation of this technique with other models can improve estimation of soil erosion using 137Cs. The 137Cs technique is, however, limited to local scale estimates of erosion because the empirical models are site specific

  18. Tectonic stratigraphy near a metamorphic core complex: Lessons from the Castaneda-signal area of west-central Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Lucchitta, I. (Geological Survey, Flagstaff, AZ (United States)); Suneson, N.H. (Oklahoma Geological Survey, Norman, OK (United States))

    1993-04-01

    A sequence of latest Oligocene through Quaternary sedimentary and volcanic rocks, when analyzed tectonically and combined with lithologically distinctive source terranes, clarifies the character and timing of Neogene extension just north of the Buckskin-Rawhide metamorphic core complex (BRMCC) in west-central Arizona. The oldest strata (basal arkose of Lucchitta and Suneson) reflect regional stability and a southwesterly paleoslope. In latest Oligocene time, this drainage was ponded by an upwarp (now exposed as the BRMCC) rising to the southwest. The resulting lake beds contain a thin 26.6 MA airfall tuff that marks the beginning of volcanic activity in the region. A widespread breccia records the progressive unroofing of the still-rising CC. Mantle-driven crustal heating probably caused the upwarp and allowed the eruption of voluminous mantle-derived basalt and basaltic andesite about 19 MA (early basalts, Artillery Basalt). The overlying syntectonic conglomerate (arkose of Keenan Camp) was deposited during a period of extreme extension, low-angle detachment faulting, and block rotation, typical of highly extended terranes. The conglomerate is interlayered with widespread silicic volcanic rocks (15--10 MA) derived from the lower crust and large gravity-glide sheets lithologically identical to the breccia and similarly derived from the CC to the south. Unconformably overlying the conglomerate are locally derived fanglomerate and 13--8.5 MA (mesa-forming) basalt that accumulated in present-day basins of classic basin-range type. Untilted and nearly unfaulted 7.7--5.4 MA mantle-derived megacryst-bearing basalt marks the cessation of tectonic activity.

  19. Increasing Use of Postpartum Family Planning and the Postpartum IUD: Early Experiences in West and Central Africa.

    Science.gov (United States)

    Pleah, Tsigue; Hyjazi, Yolande; Austin, Suzanne; Diallo, Abdoulaye; Dao, Blami; Waxman, Rachel; Karna, Priya

    2016-08-11

    A global resurgence of interest in the intrauterine device (IUD) as an effective long-acting reversible contraceptive and in improving access to a wide range of contraceptive methods, as well as an emphasis on encouraging women to give birth in health care facilities, has led programs to introduce postpartum IUD (PPIUD) services into postpartum family planning (PPFP) programs. We describe strategic, organizational, and technical elements that contributed to early successes of a regional initiative in West and Central Africa to train antenatal, maternity, and postnatal care providers in PPFP counseling for the full range of available methods and in PPIUD service delivery. In November 2013, the initiative provided competency-based training in Guinea for providers from the main public teaching hospital in 5 selected countries (Benin, Chad, Côte d'Ivoire, Niger, and Senegal) with no prior PPFP counseling or PPIUD capacity. The training was followed by a transfer-of-learning visit and monitoring to support the trained providers. One additional country, Togo, replicated the initiative's model in 2014. Although nascent, this initiative has introduced high-quality PPFP and PPIUD services to the region, where less than 1% of married women of reproductive age use the IUD. In total, 21 providers were trained in PPFP counseling, 18 of whom were also trained in PPIUD insertion. From 2014 to 2015, more than 15,000 women were counseled about PPFP, and 2,269 women chose and received the PPIUD in Benin, Côte d'Ivoire, Niger, Senegal, and Togo. (Introduction of PPIUD services in Chad has been delayed.) South-South collaboration has been central to the initiative's accomplishments: Guinea's clinical centers of excellence and qualified trainers provided a culturally resonant example of a PPFP/PPIUD program, and trainings are creating a network of regional trainers to facilitate expansion. Two of the selected countries (Benin and Niger) have expanded their PPFP/PPUID training

  20. Increasing Use of Postpartum Family Planning and the Postpartum IUD: Early Experiences in West and Central Africa

    Science.gov (United States)

    Pleah, Tsigue; Hyjazi, Yolande; Austin, Suzanne; Diallo, Abdoulaye; Dao, Blami; Waxman, Rachel; Karna, Priya

    2016-01-01

    ABSTRACT A global resurgence of interest in the intrauterine device (IUD) as an effective long-acting reversible contraceptive and in improving access to a wide range of contraceptive methods, as well as an emphasis on encouraging women to give birth in health care facilities, has led programs to introduce postpartum IUD (PPIUD) services into postpartum family planning (PPFP) programs. We describe strategic, organizational, and technical elements that contributed to early successes of a regional initiative in West and Central Africa to train antenatal, maternity, and postnatal care providers in PPFP counseling for the full range of available methods and in PPIUD service delivery. In November 2013, the initiative provided competency-based training in Guinea for providers from the main public teaching hospital in 5 selected countries (Benin, Chad, Côte d’Ivoire, Niger, and Senegal) with no prior PPFP counseling or PPIUD capacity. The training was followed by a transfer-of-learning visit and monitoring to support the trained providers. One additional country, Togo, replicated the initiative’s model in 2014. Although nascent, this initiative has introduced high-quality PPFP and PPIUD services to the region, where less than 1% of married women of reproductive age use the IUD. In total, 21 providers were trained in PPFP counseling, 18 of whom were also trained in PPIUD insertion. From 2014 to 2015, more than 15,000 women were counseled about PPFP, and 2,269 women chose and received the PPIUD in Benin, Côte d’Ivoire, Niger, Senegal, and Togo. (Introduction of PPIUD services in Chad has been delayed.) South–South collaboration has been central to the initiative’s accomplishments: Guinea’s clinical centers of excellence and qualified trainers provided a culturally resonant example of a PPFP/PPIUD program, and trainings are creating a network of regional trainers to facilitate expansion. Two of the selected countries (Benin and Niger) have expanded their PPFP

  1. Crustal structure beneath Eastern Greenland

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  2. Hydrogeologic framework and occurrence, movement, and chemical characterization of groundwater in Dixie Valley, west-central Nevada

    Science.gov (United States)

    Huntington, Jena M.; Garcia, C. Amanda; Rosen, Michael R.

    2014-01-01

    Dixie Valley, a primarily undeveloped basin in west-central Nevada, is being considered for groundwater exportation. Proposed pumping would occur from the basin-fill aquifer. In response to proposed exportation, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and Churchill County, conducted a study to improve the understanding of groundwater resources in Dixie Valley. The objective of this report is to characterize the hydrogeologic framework, the occurrence and movement of groundwater, the general water quality of the basin-fill aquifer, and the potential mixing between basin-fill and geothermal aquifers in Dixie Valley. Various types of geologic, hydrologic, and geochemical data were compiled from previous studies and collected in support of this study. Hydrogeologic units in Dixie Valley were defined to characterize rocks and sediments with similar lithologies and hydraulic properties influencing groundwater flow. Hydraulic properties of the basin-fill deposits were characterized by transmissivity estimated from aquifer tests and specific-capacity tests. Groundwater-level measurements and hydrogeologic-unit data were combined to create a potentiometric surface map and to characterize groundwater occurrence and movement. Subsurface inflow from adjacent valleys into Dixie Valley through the basin-fill aquifer was evaluated using hydraulic gradients and Darcy flux computations. The chemical signature and groundwater quality of the Dixie Valley basin-fill aquifer, and potential mixing between basin-fill and geothermal aquifers, were evaluated using chemical data collected from wells and springs during the current study and from previous investigations. Dixie Valley is the terminus of the Dixie Valley flow system, which includes Pleasant, Jersey, Fairview, Stingaree, Cowkick, and Eastgate Valleys. The freshwater aquifer in the study area is composed of unconsolidated basin-fill deposits of Quaternary age. The basin-fill hydrogeologic unit

  3. Uncovering the genetic history of the present-day Greenlandic population.

    Science.gov (United States)

    Moltke, Ida; Fumagalli, Matteo; Korneliussen, Thorfinn S; Crawford, Jacob E; Bjerregaard, Peter; Jørgensen, Marit E; Grarup, Niels; Gulløv, Hans Christian; Linneberg, Allan; Pedersen, Oluf; Hansen, Torben; Nielsen, Rasmus; Albrechtsen, Anders

    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 ∼200,000 SNPs from more than 10% of the adult Greenlandic population (n = 4,674). We found that recent gene flow from Europe has had a substantial impact on the population: more than 80% of the Greenlanders have some European ancestry (on average ∼25% of their genome). However, we also found that the amount of recent European gene flow varies across Greenland and is far smaller in the more historically isolated areas in the north and east and in the small villages in the south. Furthermore, we found that there is substantial population structure in the Inuit genetic component of the Greenlanders and that individuals from the east, west, and north can be distinguished from each other. Moreover, the genetic differences in the Inuit ancestry are consistent with a single colonization wave of the island from north to west to south to east. Although it has been speculated that there has been historical admixture 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 lived in Greenland before the Inuit.

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

    Directory of Open Access Journals (Sweden)

    P. Martinerie

    2012-10-01

    Full Text Available Air and water stable isotope measurements from three Greenland deep ice cores (GISP2, NGRIP and NEEM are investigated over a series of Dansgaard-Oeschger events (DO 8-9-10 which are representative of glacial millennial scale variability. Combined with firn modeling, air isotope data allow to quantify abrupt temperature increases for each drill site. Our data show that the magnitude of stadial-interstadial temperature increase is up to 3 °C larger in Central and North Greenland than in North West Greenland. The temporal water isotope (δ18O – temperature relationship varies between 0.3 and 0.6 ± 0.08‰ °C−1 and is systematically larger at NEEM, possibly due to limited changes in precipitation seasonality compared to GISP2 or NGRIP. The gas age-ice age difference of warming events represented in water and air isotopes can only be modeled when assuming a 26% (NGRIP to 34% (NEEM lower accumulation than derived from a Dansgaard-Johnsen ice flow model.

  5. Vegetation of the Angmagssalik District Southeast Greenland. I. Littoral vegetation

    NARCIS (Netherlands)

    Molenaar, de J.G.

    1974-01-01

    The present study deals with a part of the results of observations made during expeditions in 1968 and 1969 to the Angmagssalik District, the central and largest deglaciated area on the Southeast coast of Greenland; which journeys were preceded by a reconaissance in 1966. The Angmagssalik District i

  6. Trends and Bioclimatic Assessment of Extreme Indices: Emerging Insights for Rainfall Derivative Crop Microinsurance in Central-West Nigeria

    Science.gov (United States)

    Awolala, D. O.

    2015-12-01

    Scientific predictions have forecasted increasing economic losses by which farming households will be forced to consider new adaptation pathways to close the food gap and be income secure. Pro-poor adaptation planning decisions therefore must rely on location-specific details from systematic assessment of extreme climate indices to provide template for most suitable financial adaptation instruments. This paper examined critical loss point to water stress in maize production and risk-averse behaviour to extreme local climate in Central West Nigeria. Trends of extreme indices and bio-climatic assessment based on RClimDex for numerical weather predictions were carried out using a 3-decade time series daily observational climate data of the sub-humid region. The study reveals that the flowering and seed formation stage was identified as the most critical loss point when seed formation is a function of per unit soil water available for uptake. The sub-humid has a bi-modal rainfall pattern but faces longer dry spell with a fast disappearing mild climate measured by budyko evaporation of 80.1%. Radiation index of dryness of 1.394 confirms the region is rapidly becoming drier at an evaporation rate of 949 mm/year and rainfall deficit of 366 mm/year. Net primary production from rainfall is fast declining by 1634 g(DM)/m2/year. These conditions influenced by monthly rainfall uncertainties are associated with losses of standing crops because farmers are uncertain of rainfall probability distribution especially during most important vegetative stage. In a simulated warmer climate, an absolute dryness of months was observed compared with 4 dry months in a normal climate which explains triggers of food deficits and income losses. Positive coefficients of tropical nights (TR20), warm nights (TN90P) and warm days (TX90P), and the negative coefficient of cold days (TX10P) with time are significant at P<0.05. The increasing gradient of warm spell indicator (WSDI), the decreasing

  7. Atuarfitsialak: Greenland's Cultural Compatible Reform

    Science.gov (United States)

    Wyatt, Tasha R.

    2012-01-01

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

  8. Abundance and energy requirements of eiders (Somateria spp.) suggest high predation pressure on macrobenthic fauna in a key wintering habitat in SW Greenland

    DEFF Research Database (Denmark)

    Blicher, Martin Emil; Rasmussen, Lars Maltha; Sejr, Mikael Kristian;

    2011-01-01

    The number of common eiders (Somateria mollissima borealis) in west Greenland declined dramatically during the twentieth century, supposedly because of human activities. However, their sensitivity to alternative drivers of variation, such as climate conditions, diseases or food availability...

  9. Conceptualizing and contextualizing food insecurity among Greenlandic children

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  10. Greenland temperature response to climate forcing during the last deglaciation.

    Science.gov (United States)

    Buizert, Christo; Gkinis, Vasileios; Severinghaus, Jeffrey P; He, Feng; Lecavalier, Benoit S; Kindler, Philippe; Leuenberger, Markus; Carlson, Anders E; Vinther, Bo; Masson-Delmotte, Valérie; White, James W C; Liu, Zhengyu; Otto-Bliesner, Bette; Brook, Edward J

    2014-09-01

    Greenland ice core water isotopic composition (δ(18)O) provides detailed evidence for abrupt climate changes but is by itself insufficient for quantitative reconstruction of past temperatures and their spatial patterns. We investigate Greenland temperature evolution during the last deglaciation using independent reconstructions from three ice cores and simulations with a coupled ocean-atmosphere climate model. Contrary to the traditional δ(18)O interpretation, the Younger Dryas period was 4.5° ± 2°C warmer than the Oldest Dryas, due to increased carbon dioxide forcing and summer insolation. The magnitude of abrupt temperature changes is larger in central Greenland (9° to 14°C) than in the northwest (5° to 9°C), fingerprinting a North Atlantic origin. Simulated changes in temperature seasonality closely track changes in the Atlantic overturning strength and support the hypothesis that abrupt climate change is mostly a winter phenomenon.

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

    Directory of Open Access Journals (Sweden)

    Ane-Kersti Skaarup Knudsen

    2015-11-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  14. 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.

  15. 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.

  16. Instrument for Analysis of Greenland's Glacier Mills

    Science.gov (United States)

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

    2010-01-01

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

  17. Description of the physical environment an coal-mining history of West-Central Indiana, with emphasis on six small watersheds

    Science.gov (United States)

    Martin, Jeffrey D.; Crawford, Charles G.; Duwelius, Richard F.; Renn, Danny E.

    1990-01-01

    This report describes the physical and human environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds selected for study of the hydrologic effects of surface coal mining. The report summarizes information on the geology, geomorphology, soils, climate, hydrology, water use, land use, population, and coal-mining history of Clay, Owen, Sullivan, and Vigo Counties in Indiana. Site-specific information is given on the morphology, geology, soils, land use, coal-mining history, and hydrologic instrumentation of the six watersheds, which are each less than 3 square miles in area.

  18. Changes in erosional and depositional processes with time and management of Goa Coast, central west coast of India

    Science.gov (United States)

    Nayak, Ganapati; D'Souza, Joseph

    2010-05-01

    Coastal and estuarine environments, world over are facing immense impact due to both natural and anthropogenic processes. The natural processes include climatic changes, rise in sea level, cyclone, flood, tsunamis, coastal erosion, salinity ingress and siltation. Likewise, anthropogenic pressures include population expansion, ocean traffic, dredging, resource exploitation, pollution, unplanned urbanization and intensive industrialization. Due to these impacts the fragile coastal ecosystem and its entities, like sub ecosystems, resources, morphological units are undergoing unprecedented degradation, rendering these coastal regions vulnerable, impinging risk to human population, livestock, properties, as also, devastation of resourceful lands. This accelerates economic fatalities and irreversible obliteration to the ecosystems. Evidences on the global concern towards this issue have been well established. The countries world over, including India, pledged consensus towards the protection of the fragile coastal ecosystems through UNCED, Agenda-21. India, on 19th February 1991, has designated specified corridors along the landward side of the coastline as "Coastal Regulatory Zones" (CRZ), through appropriate policy and law. In context with the CRZ notification, scientific database at local and site-specific areas, developed. Synergy of ecosystems, landscape and resources with demographic, tourism data, vis-à-vis, economic corridors/sectors aided the paradigms and criterion for local and site specific prescriptions for Goa Coast. The Goa coast is a part of central west coast of India and is characterized by pocket beaches flanked by rocky cliffs, estuaries, bays, and at some places mangroves. Beaches in southern Goa are long and linear in nature with sand dunes. The Mandovi and Zuari estuarine system in Goa is the largest in this part of the coast. Mud flats, swampy marshes and wetlands are found mainly along estuaries and creeks. The beaches of Goa are stable beaches

  19. Greenland Telescope (GLT Project

    Directory of Open Access Journals (Sweden)

    Nakamura M.

    2013-12-01

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

  20. Vestiges of an Ordovician west-vergent thin-skinned Ocloyic thrust belt in the Argentine Precordillera, southern Central Andes

    Science.gov (United States)

    Thomas, William A.; Astini, Ricardo A.

    2007-08-01

    Collision of the down-going, Laurentia-derived Argentine Precordillera terrane with the Gondwanan margin drove the Ordovician Ocloyic orogeny, including subduction volcanism, metamorphism, and top-to-west shearing east of the Precordillera. In the Precordillera, above passive-margin carbonates (Lower Ordovician San Juan Limestone and older carbonates), a Middle to Upper Ordovician westward-prograding synorogenic clastic wedge of black shale (Gualcamayo Shale) and coarser clastic sediment (Las Vacas Conglomerate and Trapiche Formation) fills a peripheral foreland basin. New research has identified vestiges of a west-directed thin-skinned Ocloyic foreland thrust belt that has been fragmented by east-directed Andean thrusting. The El Corral thrust sheet, with hanging-wall detachment in the San Juan Limestone, extends over a west-directed footwall frontal ramp and extensive flat to low-angle footwall cutoff in the Gualcamayo and Las Vacas formations. Las Vacas conglomerates in the footwall include olistoliths (10-m scale) exclusively of San Juan Limestone and Gualcamayo Shale; the beds in some olistoliths are folded. The advancing El Corral thrust sheet successively supplied and overrode the stratigraphically restricted olistoliths. In the El Corral footwall, tight west-vergent folds and faults within an anticlinorium in the San Juan Limestone and Gualcamayo Shale suggest a deeper (unexposed) thrust fault, the Los Celestitos fault. West of the anticlinorium, easterly dip (restored to remove Andean deformation) beneath an angular unconformity between Las Vacas and Trapiche beds is consistent geometrically with the trailing limb of a west-vergent fault-propagation anticline in the hanging wall of the subsurface Los Celestitos fault. The same angular unconformity truncates the El Corral fault and hanging-wall strata. In the Trapiche Formation, contrasting sedimentary facies from sandy turbidites westward to limestone-clast megabeds and olistoliths suggest another frontal

  1. An eddy covariance derived annual carbon budget for an arctic terrestrial ecosystem (Disko, Greenland)

    Science.gov (United States)

    McConnell, Alistair; Lund, Magnus; Friborg, Thomas

    2016-04-01

    Ecosystems with underlying permafrost cover nearly 25% of the ice-free land area in the northern hemisphere and store almost half of the global soil carbon. Future climate changes are predicted to have the most pronounced effect in northern latitudes. These Arctic ecosystems are therefore subject to dramatic changes following thawing of permafrost, glacial retreat, and coastal erosion. The most dramatic effect of permafrost thawing is the accelerated decomposition and potential mobilization of organic matter stored in the permafrost. This will impact global climate through the mobilization of carbon and nitrogen accompanied by release of greenhouses gases, including carbon dioxide. This study presents the initial findings and first full annual carbon (CO2) budget, derived from eddy covariance measurements, for an Arctic landscape in West Greenland. The study site, a terrestrial Arctic maritime climate, is located at Østerlien, near Qeqertarsuaq, on the southern coast of Disko Island in central West Greenland (69° 15' N, 53° 34' W) within the transition zone from continuous to discontinuous permafrost. The mean annual air temperature is -5 C and the annual precipitation as rain is 150-200 mm. Arctic ecosystem feedback mechanisms and processes interact on micro, local and regional scales. This is further complicated by several potential feedback mechanisms likely to occur in permafrost-affected ecosystems, involving the interactions of microorganisms, vegetation and soil. The eddy covariance method allows us to interrogate the processes and drivers of land-atmosphere carbon exchange at extremely high temporary frequency (10 Hz), providing landscape-scale measurements of CO2, H2O and heat fluxes for the site, which are processed to derive daily, monthly and now, annual carbon fluxes. We discuss the scientific methodology, challenges, and analysis, as well as the practical and logistic challenges of working in the Arctic, and present an annual carbon budget

  2. Seabird Colonies in Western Greenland

    DEFF Research Database (Denmark)

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

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

  3. Sensitivity of Greenland Ice Sheet surface mass balance to surface albedo parameterization: a study with a regional climate model

    OpenAIRE

    Angelen, J. H.; Lenaerts, J. T. M.; S. Lhermitte; X. Fettweis; P. Kuipers Munneke; M. R. van den Broeke; van Meijgaard, E.

    2012-01-01

    We present a sensitivity study of the surface mass balance (SMB) of the Greenland Ice Sheet, as modeled using a regional atmospheric climate model, to various parameter settings in the albedo scheme. The snow albedo scheme uses grain size as a prognostic variable and further depends on cloud cover, solar zenith angle and black carbon concentration. For the control experiment the overestimation of absorbed shortwave radiation (+6%) at the K-transect (west Greenland) for the period 2004–2009 is...

  4. The NEEM Stable Water Isotope Profile - new evidence of past Greenland Ice Sheet responses to Climate Change

    Science.gov (United States)

    Vinther, Bo; Neem Isotope Consortium, The

    2013-04-01

    Deep ice cores from the Greenland ice sheet are providing an ever expanding set of records of past Greenland climatic conditions throughout the last glacial-interglacial cycle. Stable water isotope records from the ice cores have been influenced both by changing climatic conditions and by any elevation change that has happened at the ice core drill site. The new NEEM ice core drilled in NW Greenland is located on an ice divide connected to the very summit of the Greenland ice sheet. In fact four ice cores have now been drilled on this divide: GRIP (at the summit), NGRIP some 300km north of GRIP, NEEM some 350km north-west of NGRIP and Camp Century some 250 km west of NEEM. All four ice cores contain both the entire Holocene and most of the glacial period undisturbed. The new NEEM δ18O record therefore completes a four core transect along this ice divide. The four δ18O records from the cores all span more than 100,000 years. From an inter-comparison of these records a picture emerges of a dynamic Greenland ice sheet shrinking and expanding in direct response to changing climatic conditions. Indeed the glacial Greenland ice sheet must have covered vast areas that are now ice free, expanding far out on the continental shelf and forming an ice ridge all the way to the Canadian high arctic. During both the transition period and the early Holocene, the Greenland ice sheet retreated dramatically.

  5. Setting the scene in Nuuk: Introducing the cast of characters in Greenlandic foreign policy narratives

    DEFF Research Database (Denmark)

    Jacobsen, Marc; Gad, Ulrik Pram

    2016-01-01

    cultural traditions with envisioned future independence. Hence, the chapter introduces the central members of the cast of characters in the most important narratives, which Greenland is telling about its place in the world. The analysis shows how narratives about indigenous identity combines...... international politics and foreign policy as driven by narratively structured discourses constructing nation state identities in relation to Others....... policy strategy; “It is important that the interest in the Arctic and Greenland is converted into concrete opportunities for the Greenlandic people and its development as a nation” (2011:3). This chapter investigates how Greenland’s foreign policy supports the national self-image in combining indigenous...

  6. Ancient Maya Regional Settlement and Inter-Site Analysis: The 2013 West-Central Belize LiDAR Survey

    Directory of Open Access Journals (Sweden)

    Arlen F. Chase

    2014-09-01

    Full Text Available During April and May 2013, a total of 1057 km2 of LiDAR was flown by NCALM for a consortium of archaeologists working in West-central Belize, making this the largest surveyed area within the Mayan lowlands. Encompassing the Belize Valley and the Vaca Plateau, West-central Belize is one of the most actively researched parts of the Maya lowlands; however, until this effort, no comprehensive survey connecting all settlement had been conducted. Archaeological projects have investigated at least 18 different sites within this region. Thus, a large body of archaeological research provides both the temporal and spatial parameters for the varied ancient Maya centers that once occupied this area; importantly, these data can be used to help interpret the collected LiDAR data. The goal of the 2013 LiDAR campaign was to gain information on the distribution of ancient Maya settlement and sites on the landscape and, particularly, to determine how the landscape was used between known centers. The data that were acquired through the 2013 LiDAR campaign have significance for interpreting both the composition and limits of ancient Maya political units. This paper presents the initial results of these new data and suggests a developmental model for ancient Maya polities.

  7. Description of the physical environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds

    International Nuclear Information System (INIS)

    West-central Indiana is underlain by coal-bearing Pennsylvanian rocks. Nearly all of the area has been glaciated at least once and is characterized by wide flood plains and broad, flat uplands. The most productive aquifers are confined or unconfined outwash aquifers located along the major rivers. Bedrock aquifers are regionally insignificant but are the sole source of groundwater for areas that lack outwash, alluvium, or sand and gravel lenses in till. Indiana has > 17 billion short tons of recoverable coal reserves; about 11% can be mined by surface methods. More than 50,000 acres in west-central Indiana were disturbed by surface coal mining from 1941 through 1980. Ridges of mine spoil have been graded to a gently rolling topography. Soils are well drained and consist of 6 to 12 inches of silt-loam topsoil that was stockpiled and then replaced over shale and sandstone fragments of the graded mine spoil. Grasses and legumes form the vegetative cover in each watershed. Pond Creek and the unnamed tributary to Big Branch are streams that drain mined and unreclaimed watersheds. Approximately one-half of the Pond Creek watershed is unmined,agricultural land. Soils are very well drained shaly silty loams that have formed on steeply sloping spoil banks. Both watersheds contain numerous impoundments of water and have enclosed areas that do not contribute surface runoff to streamflow. The ridges of mine spoil are covered with pine trees, but much of the soil surface is devoid of vegetation

  8. The landscape configuration of zoonotic transmission of Ebola virus disease in West and Central Africa: interaction between population density and vegetation cover

    Directory of Open Access Journals (Sweden)

    Michael G. Walsh

    2015-01-01

    Full Text Available Ebola virus disease (EVD is an emerging infectious disease of zoonotic origin that has been responsible for high mortality and significant social disruption in West and Central Africa. Zoonotic transmission of EVD requires contact between susceptible human hosts and the reservoir species for Ebolaviruses, which are believed to be fruit bats. Nevertheless, features of the landscape that may facilitate such points of contact have not yet been adequately identified. Nor have spatial dependencies between zoonotic EVD transmission and landscape structures been delineated. This investigation sought to describe the spatial relationship between zoonotic EVD transmission events, or spillovers, and population density and vegetation cover. An inhomogeneous Poisson process model was fitted to all precisely geolocated zoonotic transmissions of EVD in West and Central Africa. Population density was strongly associated with spillover; however, there was significant interaction between population density and green vegetation cover. In areas of very low population density, increasing vegetation cover was associated with a decrease in risk of zoonotic transmission, but as population density increased in a given area, increasing vegetation cover was associated with increased risk of zoonotic transmission. This study showed that the spatial dependencies of Ebolavirus spillover were associated with the distribution of population density and vegetation cover in the landscape, even after controlling for climate and altitude. While this is an observational study, and thus precludes direct causal inference, the findings do highlight areas that may be at risk for zoonotic EVD transmission based on the spatial configuration of important features of the landscape.

  9. Enhancement of volcanism and geothermal heat flux by ice-age cycling: A stress modeling study of Greenland

    Science.gov (United States)

    Stevens, Nathan T.; Parizek, Byron R.; Alley, Richard B.

    2016-08-01

    Ice-age cycling of the Greenland ice sheet likely contributed to locally elevated subglacial geothermal heat fluxes (GHFs), based on recent thermal modeling. Borehole and geophysical data indicate higher GHF in some areas than suggested by current knowledge of underlying geology, particularly at the head of the Northeast Greenland Ice Stream. Changes in lithospheric loading during ice-sheet growth and decay cycles produce large and geologically rapid changes in the effective stress state beneath and near the ice sheet. Oscillations in melt fraction from cyclic loading through multiple ice-age cycles will enhance upward magma migration through the nonlinear increase of melt migration velocity with melt fraction. We simulate periodic ice-sheet loading scenarios along an east-west transect across central Greenland on an Elastic Lithosphere, Relaxed Asthenosphere Earth model. Under likely parameter ranges, deviatoric stresses in the elastic lithosphere across widespread regions are sufficiently high to meaningfully enhance dike emplacement and also allow vug-wave propagation in some scenarios. Stress patterns migrate laterally in response to ice-sheet dynamics, favoring multistage magma ascent. If melt occurs at depth, our modeling suggests that ice-age cycling could help it migrate upward to shallow depth or erupt, contributing to the high observed GHF. Furthermore, shallow magma emplacement might feed hydrothermal systems exploiting enhanced faulting or fracturing from ice-age cycling, adding to elevated GHF. The preglacial passage of the Iceland-Jan Mayen hot spot could have sourced such magmas. Direct observations of these lithospheric processes needed to further constrain our models are limited, highlighting the value of more targeted geophysical studies informing future modeling.

  10. Why is Transparency Greenland Necessary?

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2012-01-01

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

  11. Wastewater Treatment in Greenland

    DEFF Research Database (Denmark)

    Gunnarsdottir, Ragnhildur

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

  12. (CH4)-C-14 Measurements in Greenland Ice: Investigating Last Glacial Termination CH4 Sources

    DEFF Research Database (Denmark)

    Petrenko, V. V.; Smith, A. M.; Brook, E. J.;

    2009-01-01

    contributions to this increase. We present measurements of (CH4)-C-14 in glacial ice, targeting this transition, performed by using ice samples obtained from an ablation site in west Greenland. Measured (CH4)-C-14 values were higher than predicted under any scenario. Sample (CH4)-C-14 appears to be elevated by...

  13. Investigating the past and recent δ18O-accumulation relationship seen in Greenland ice cores

    OpenAIRE

    Buchardt, S. L.; Clausen, H. B.; Vinther, B. M.; Dahl-Jensen, D.

    2012-01-01

    Decadal means of δ18O and accumulation rates from 52 ice core locations in Greenland are presented. The accumulation rates are derived from annual layers determined in the δ18O curve. Investigation of the δ18O-accumulation relationship across the ice divide reveals a significant Foehn effect with anticorrelation of δ18O and accumulation rate on the lee side of the divide in Southern Greenland, while no effect is seen in Central Greenl...

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

    DEFF Research Database (Denmark)

    Laubjerg, Merete; Petersson, Birgit

    2010-01-01

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

  15. 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...... indicates that 'hot particles' hold considerably more plutonium than previously anticipated and that the Bylot Sound sediments may account for the major part of the un-recovered plutonium after the accident, i.e. approximately 3 kg. (C) 2004 Elsevier B.V. All rights reserved....

  16. On the origin of multi-decadal to centennial Greenland temperature anomalies over the past 800 yr

    Directory of Open Access Journals (Sweden)

    T. Kobashi

    2012-11-01

    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 associated with accelerating sea level rise. However, the causes of multi-decadal-to-centennial temperature changes in Greenland are not well understood, largely owing to short observational records. To examine the causes of the Greenland temperature variability, we calculated the Greenland temperature anomalies (GTA(G-NH over the past 800 yr by subtracting the standardised NH temperature from the standardised Greenland temperature. It 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 explains 31–35% of the variation of Greenland temperature in the multi-decadal-to-centennial time scale over the past 800 yr. Another orthogonal component of the Greenland and NH temperatures, GTP(G+NH (Greenland temperature plus = standardized Greenland temperature + standardized NH temperature exhibited the multi-decadal variations that were likely induced by large volcanic eruptions, increasing greenhouse gasses, and internal variation of climate. We found that the GTA(G-NH has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by North Atlantic Oscillation/Arctic Oscillation (NAO/AO. Climate modelling indicates that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC and to associated changes in northward oceanic heat transport.

  17. The Implementation of Performance Management in European Central Governments: More a North-South than an East-West Divide

    OpenAIRE

    Hammerschmid Gerhard; Löffler Lorenz

    2015-01-01

    This article presents the first country-comparative evidence on the importance and use of performance management in European central governments, based on an executive survey conducted in 17 countries. The data confirm that performance management has made its way into European central governments and continues to constitute a major reform trend. At the organizational level of ministries and agencies we find a consistently strong use of strategic planning, performance appraisal and management ...

  18. Miocene uplift of the NE Greenland margin linked to plate tectonics: Seismic evidence from the Greenland Fracture Zone, NE Atlantic.

    Science.gov (United States)

    Døssing, Arne; Japsen, Peter; Watts, Anthony; Nielsen, Tove; Jokat, Wilfried; Thybo, Hans

    2016-04-01

    Tectonic models predict that, following breakup, rift margins undergo only decaying thermal subsidence during their post-rift evolution. However, post-breakup stratigraphy beneath the NE Atlantic shelves shows evidence of regional-scale unconformities, commonly cited as outer margin responses to inner margin episodic uplift, including the formation of coastal mountains. The origin of these events remains enigmatic. We present a seismic reflection study from the Greenland Fracture Zone - East Greenland Ridge (GFZ-EGR) and the NE Greenland shelf. We document a regional intra-Miocene seismic unconformity (IMU), which marks the termination of syn-rift deposition in the deep-sea basins and onset of: (i) thermo-mechanical coupling across the GFZ, (ii) basin compression, and (iii) contourite deposition, north of the EGR. The onset of coupling across the GFZ is constrained by results of 2-D flexural backstripping. We explain the thermo-mechanical coupling and the deposition of contourites by the formation of a continuous plate boundary along the Mohns and Knipovich ridges, leading to an accelerated widening of the Fram Strait. We demonstrate that the IMU event is linked to onset of uplift and massive shelf-progradation on the NE Greenland margin. Given an estimated middle-to-late Miocene (~15-10 Ma) age of the IMU, we speculate that the event is synchronous with uplift of the East and West Greenland margins. The correlation between margin uplift and plate-motion changes further indicates that the uplift was triggered by plate tectonic forces, induced perhaps by a change in the Iceland plume (a hot pulse) and/or by changes in intra-plate stresses related to global tectonics.

  19. Post-colonial identity in Greenland?

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2009-01-01

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

  20. Problems concerning musk oxen in Greenland

    Data.gov (United States)

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

  1. 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....

  2. The Greenland ice sheet margin as a source of paleo-environmental data

    International Nuclear Information System (INIS)

    Oxygen-18 records measured on surface ice samples from Greenland ice sheet margins show that ice of pre-Holocene age is present at many locations along the ice margin. Several records have been obtained from West, North, and Northeast Greenland. At all locations where pre-Holocene ice is found, it constitutes a band running parallel to the ice edge. However, the width of the band varies greatly from one location to another, ranging between 30 m and 1,500 m. So far, the most detailed oxygen-18 record has been obtained from a West Greenland ice margin location. It spans the last glacial (the Wisconsinan), the last inter-glacial (Sangamon, Eem), and part of the previous glacial (the Illinoian). A correlation with the oxygen-18 records from the Greenland deep ice cores from Camp Century and Dye-3 indicates that neither of these records reach back to the previous glacial, probably due to substantial thinning and retreat of the ice sheet in North and South Greenland in the Eemian inter-glacial. The oxygen-18 record has been translated into a Greenland temperature record covering the past 150,000 years. The isotopic temperatures indicate large temperature variations in marine isotopic stage 5, with a climate warmer than at present not only in sub-stage 5c, but also in sub-stage 5c and in a short period of sub-stage 5a. The ice margin studies indicate that Greenland ice sheet margins have a large potential as sources of paleo-environmental information. Large volumes of ice can easily be mined e.g. for Carbon-14 dating and other measurements that require large amounts of ice. Therefore, ice margin studies are an important supplement to deep drilling programs in the interior regions of the ice sheet

  3. The Satah Mountain and Baldface Mountain volcanic fields: Pleistocene hot spot volcanism in the Anahim Volcanic Belt, west-central British Columbia, Canada

    Science.gov (United States)

    Kuehn, Christian; Guest, Bernard; Russell, James K.; Benowitz, Jeff A.

    2015-03-01

    The Satah Mountain and Baldface Mountain volcanic fields (SMVF, BMVF) comprise more than three dozen small volcanic centers and erosional remnants thereof. These fields are located in the Chilcotin Highland of west-central British Columbia, Canada, and are spatially associated with the Anahim Volcanic Belt (AVB), a linear feature of alkaline to peralkaline plutonic and volcanic centers of Miocene to Holocene ages. The AVB has been postulated to be the track of a hot spot passing beneath the westward moving Cordilleran lithosphere. We test the AVB hot spot model by applying whole-rock 40Ar/39Ar geochronology ( n = 24) and geochemistry. Whole-rock chemical compositions of volcanic rock samples ( n = 59) from these two fields suggest a strong geochemical affinity with the nearby Itcha Range shield volcano; however, SMVF and BMVF centers are mostly small in volume (interaction of the potential hot spot with (pre)existing fracture systems in vicinity of the Itcha Range.

  4. The Implementation of Performance Management in European Central Governments: More a North-South than an East-West Divide

    Directory of Open Access Journals (Sweden)

    Hammerschmid Gerhard

    2015-12-01

    Full Text Available This article presents the first country-comparative evidence on the importance and use of performance management in European central governments, based on an executive survey conducted in 17 countries. The data confirm that performance management has made its way into European central governments and continues to constitute a major reform trend. At the organizational level of ministries and agencies we find a consistently strong use of strategic planning, performance appraisal and management objectives, along with only a partial institutionalization of a performance-management logic. Scepticism towards measurement and the difficulty of acting upon performance information are persistent challenges. We also find that performance-management implementation is significantly stronger in agencies and larger organizations, and that it varies strongly between different countries. Implementation is substantially higher in Scandinavian countries and Anglo-Saxon countries than in Continental and Southern European countries, with a rather varied pattern for Central and Eastern European countries. The findings thereby confirm the need for a more context-sensitive understanding of performance management, along with the need for more extensive research and evidence to further develop this cross-comparative European perspective.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  6. 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).

  7. Ecological Forecasting of West Nile Virus Outbreaks in a High-Risk Area of the North-Central United States

    Science.gov (United States)

    Wimberly, M. C.; Merkord, C. L.; Kightlinger, L.; Vincent, G.; Hildreth, M. B.

    2015-12-01

    West Nile virus (WNV) is the most widespread and important mosquito-borne pathogen in North America. Since its emergence in the western hemisphere in 1999, human WNV disease has continued to exhibit recurrent outbreaks. Perplexingly, the incidence of this tropical disease has been highest in the cold-temperate climates of the Northern Great Plains (NGP). The spatial and temporal distributions of the vector mosquitoes and bird hosts, and consequently the risk of disease in humans, are strongly influenced by temperature, precipitation, vegetation, soils, and land use. We have utilized satellite remote sensing to map these environmental factors through time and develop models of disease risk. Outbreak years in South Dakota were preceded by warm winters, and WNV cases were most likely to occur during the hottest weeks of summer. Hot spots of persistent WNV transmission within the state were associated with rural land cover as well as patterns of physiography and climate. These models are currently being integrated into the South Dakota Mosquito Early Warning system (SDMIS), an automated WNV outbreak detection system that integrates remotely-sensed environmental indicators with vector abundance and infection data from a statewide mosquito surveillance network. The major goal of this effort is to leverage global environmental monitoring datasets to provide up-to-date, locally relevant information that can improve the effectiveness of mosquito control and disease prevention activities. This system was implemented for the first time during the summer of 2015. We will review the outcomes of this implementation, including the underlying influences of temperature on WNV risk, a preliminary statewide WNV risk map, and dynamic risk predictions made during the 2015 WNV season. Lessons learned as well as plans for future years will be discussed.

  8. Geological Studies of the Salmon River Suture Zone and Adjoining Areas, West-Central Idaho and Eastern Oregon

    Science.gov (United States)

    Kuntz, Mel A.; Snee, Lawrence W.

    2007-01-01

    The papers in this volume describe petrologic, structural, and geochemical studies related to geographic areas adjacent to and including the Salmon River suture zone. We therefore start this volume by defining and giving a general description of that suture zone. The western margin of the North American continent was the setting for complex terrane accretion and large-scale terrane translation during Late Cretaceous and Eocene time. In western Idaho, the boundary that separates the Paleozoic-Mesozoic accreted oceanic, island-arc rocks on the west from Precambrian continental metamorphic and sedimentary rocks on the east is called the Salmon River suture zone (SRSZ). Readers will note that the term 'Salmon River suture zone' is used in the title of this volume and in the text of several of the papers and the term 'western Idaho suture zone' is used in several other papers in this volume. Both terms refer to the same geologic feature and reflect historical usage and custom; thus no attempt has been made by the editors to impose or demand a single term by the various authors of this volume. The suture zone is marked by strong lithologic and chemical differences. Rocks adjacent to the suture zone are characterized by high-grade metamorphism and much structural deformation. In addition, the zone was the locus of emplacement of plutons ranging in composition from tonalite to monzogranite during and after the final stages of accretion of the oceanic terrane to the North American continent. The contents of this paper consists of seven chapters.

  9. Characterization of Potential Plant Growth Promoting Rhizobacteria Isolated from Maize (Zea mays L. in Central and Northern Benin (West Africa

    Directory of Open Access Journals (Sweden)

    Nadège A. Agbodjato

    2015-01-01

    Full Text Available Our study aims to characterize Plant Growth Promoting Rhizobacteria (PGPR isolated from maize roots in five agroecological zones of central and northern Benin. Sixty samples were collected at the rate of four samples per village and three villages per agroecological zone. Rhizobacteria strains were isolated from these samples and biochemically characterized. These strains were analyzed for some of their PGPR traits like ammonia production and hydrogen cyanide following conventional methods. Microbiological investigation of these samples has shown that maize rhizospheres in central and northern Benin contain a high diversity of microorganisms. A total of nine species of maize Plant Growth Promoting Rhizobacteria were identified. Those PGPR include five Bacillus species (B. polymyxa, B. pantothenticus, B. anthracis, B. thuringiensis, and B. circulans, three Pseudomonas species (P. cichorii, P. putida, and P. syringae, and Serratia marcescens. The microbial diversity does not depend on the soil types. The microbial density, generally high, varies according to both soil types and agroecological zones. All Serratia strains (100% have produced ammonia, whereas 80% of Bacillus and 77.77% of Pseudomonas produced this metabolite. The hydrogen cyanide was produced by all isolates (100% independent of their genus. These results suggest the possibility to use these rhizobacteria as biological fertilizers to increase maize production.

  10. The Braconidae (Hymenoptera) of Greenland

    NARCIS (Netherlands)

    Achterberg, van C.

    2006-01-01

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

  11. The Pedagogical Situation in Greenland.

    Science.gov (United States)

    Gunther, Bent

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

  12. Health and society in Greenland

    OpenAIRE

    Kjeldsen, Anne B,

    2005-01-01

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

  13. 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

    During the early 2000s the Greenland Ice Sheet experienced the largest ice-mass loss of the instrumental record(1), largely as a result of the acceleration, thinning and retreat of large outlet glaciers in West and southeast Greenland(2-5). The quasi-simultaneous change in the glaciers suggests...... 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...... Helheim Glacier terminates. Specifically, we use the annual deposition of sand grains as a proxy for iceberg discharge. Our record reveals large fluctuations in calving rates, but the present high rate was reproduced only in the 1930s. A comparison with climate indices indicates that high calving activity...

  14. The research station "Vaskiny Dachi", Central Yamal, West Siberia, Russia – a review of 25 years of permafrost studies

    Directory of Open Access Journals (Sweden)

    Marina O. Leibman

    2015-03-01

    Full Text Available The research station "Vaskiny Dachi" on the Yamal Peninsula was established in 1988. Activities aimed at monitoring of permafrost and related environmental features under a relatively low level of nature disturbances caused by gas field development. Cryogenic processes that may affect the environment and their structures have been of primary interest. Landslides are the most common cryogenic processes in Central Yamal in general and also in the proximity of the station. Field surveys of numerous landslides, analysis of their dependence on climatic parameters and their fluctuations resulted in novel classification of cryogenic landslides based on mechanisms of their development. Dating by radiocarbon and dendrochronology allows the separation of cycles of landslide activation. Cryogenic landslides control the development of other processes, such as thermal erosion, river channel erosion and thermokarst. It also affects topography, vegetation pattern, geochemistry of vegetation, ground water and soils. As a result, permafrost parameters, specifically active layer depth and ground temperature, moisture and ice content in the active layer, depend indirectly on landsliding. Monitoring within the framework of the main programs of the International Permafrost Association, such as Circumarctic Active Layer Monitoring (CALM, since 1993 and Thermal State of Permafrost (TSP, since 2011, play an important role among the research activities. From the collected data one can conclude that ground temperature increased on average by about 1 °C since the 1990s. At the same time, active layer fluctuations do not exactly follow the air temperature changes. Spatial changes in ground temperature are controlled by the redistribution of snow which is resulting from strong winds characteristic for tundra environments and the highly dissected relief of Central Yamal. Temporal variations rather depend on air temperature fluctuations but the rate differs in various

  15. Significance of zircon U-Pb ages from the Pescadero felsite, west-central California coast ranges

    Science.gov (United States)

    McLaughlin, Robert J.; Moore, Diane E.; ,; Martens, UWE C.; Clark, J.C.

    2011-01-01

    Weathered felsite is associated with the late Campanian–Maastrichtian Pigeon Point Formation near Pescadero, California. Poorly exposed, its age and correlation are uncertain. Is it part of the Pigeon Point section west of the San Gregorio–Hosgri fault? Does it rest on Nacimiento block basement? Is it dextrally offset from the Oligocene Cambria Felsite, ∼185 km to the southeast? Why is a calc-alkaline hypabyssal igneous rock intrusive into the outboard accretionary prism? To address these questions, we analyzed 43 oscillatory-zoned zircon crystals from three incipiently recrystallized pumpellyite ± prehnite ± laumontite-bearing Pescadero felsite samples by sensitive high-resolution ion microprobe–reverse geometry (SHRIMP-RG) and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) techniques. Thirty-three zircons gave late Mesozoic U-Pb ages, with single-grain values ranging from 81 to 167 Ma; ten have pre-Mesozoic, chiefly Proterozoic ages. A group of the four youngest Pescadero zircons yielded an apparent maximum igneous age of ca. 86–90 Ma. Reflecting broad age scatter and presence of partly digested sandstone inclusions, we interpret the rest of the zircons (perhaps all) as xenocrysts. Twenty-three zircons were separated and analyzed from two samples of the similar Cambria Felsite, yielding a unimodal 27 Ma U-Pb age. Clearly, the origin of the Upper Oligocene Cambria Felsite is different from that of the Upper Cretaceous Pescadero felsite; these rocks are not correlated, and do not constrain displacement along the San Gregorio–Hosgri fault. Peak ages differ slightly, but relative probability curves for Mesozoic and pre-Mesozoic Pescadero zircons compare well, for example, with abundant U-Pb age data for detrital zircons from Franciscan metaclastic strata ∼100 km to the east in the Diablo Range–San Francisco Bay area, San Joaquin Great Valley Group turbidites, Upper Cretaceous Nacimiento block Franciscan strata, and Upper

  16. The East Greenland rifted volcanic margin

    Directory of Open Access Journals (Sweden)

    C. Kent Brooks

    2011-12-01

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

  17. Description of the physical environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds

    Science.gov (United States)

    Martin, J.D.; Crawford, Charles G.; Duwelius, R.F.; Renn, D.E.

    1987-01-01

    Information on the geology, geomorphology, soils, climate, hydrology, water use, land use, population, and coal mining history of Clay, Owen, Sullivan, and Vigo Counties in Indiana is summarized. Site-specific information is given on the morphology , geology, soils, land use, coal mining history, and hydrologic instrumentation of the six watersheds which are each less than 3 sq mi in area. The Wabash, White, and Eel Rivers are the major drainages in west-central Indiana. Average annual precipitation is about 39.5 in/yr and average annual runoff is about 13 in/yr. The most productive aquifers are confined or unconfined outwash aquifers located along the major rivers. Bedrock aquifers are regionally insignificant but are the sole source of groundwater for areas that lack outwash, alluvium, or sand and gravel lenses in till. Indiana has more than 17 billion short tons of recoverable coal reserves; about 11% can be mined by surface methods. Almost half of Indiana 's surface reserves are in Clay, Owen, Sullivan, and Vigo Counties. More than 50,000 acres in west-central Indiana have been disturbed by surface coal mining from 1941 through 1980. Big Slough and Hooker Creek are streams that drain unmined, agricultural watersheds. Row-crop corn and soybeans are the principal crops. Soils are moderately well drained silt loams, and the watersheds well developed dendritic drainage systems. Unnamed tributaries drain mined and reclaimed watersheds. Ridges of mine spoil have been graded to a gently rolling topography. Soils are well drained and consist of 6 to 12 inches of silt-loam topsoil that was stockpiled and then replaced over shale and sandstone fragments of the graded mine spoil. Grasses and legumes form the vegetative cover in each watershed. Pond Creek and an unnamed tributary to Big Branch are streams that drain mined and unreclaimed watersheds. Soils are very well drained shaly silty loams that have formed on steeply sloping banks. Both watersheds contain numerous

  18. Natural contamination with arsenic and other trace elements in groundwater of the Central-West region of Chaco, Argentina.

    Science.gov (United States)

    Blanes, Patricia S; Buchhamer, Edgar E; Giménez, María C

    2011-01-01

    This study covered the central agricultural region of the Chaco province, which lacks a permanent river networks. However, during the rainy period there is localized groundwater recharge. About 84 groundwater samples were taken during the period April-December 2007. These groundwater samples were collected from two different depths: 62 samples from shallow wells (4 to 20 m) and 24 samples from deep wells (20 to 100 m). Chemical variables were determined: pH, specific conductance, total dissolved solid, hardness, alkalinity, HCO(3)-, CO(3)(2-), SO(4)(2-), Cl-, NO(3)-, NO(2) -, NH(4)+, F-, As((tot)), Na+, K+, Ca2+, Mg2+, Fe, Cu, Ni, Pb and Zn. The chemical composition of groundwater in the study area is dominantly sodium bicarbonate and sodium chloride bicarbonate, comprising more than 60% (52/86) of shallow and deep groundwater samples. Of the 86 analyzed groundwater samples, 88% exceeded the WHO (World Health Organization) and CAA (Código Alimentario Argentino) standards (10 μg/L) for As (arsenic) and 9% exceeded the WHO standard (1.5 mg/L) for F(-).Groundwater highly contaminated with As (max. 1,073 μg/L) and F- (max. 4.2 mg/L) was found in shallow aquifer. The contaminated groundwater is characterized by high pH (max. 8.9), alkalinity (max. HCO(3)- 1,932 mg/L), SO(4)(2-) (max. 11,862 mg/L), Na(+) (max. 3,158 mg/L), Cl(-) (max. 10,493 mg/L) and electric conductivity greater than 33.3 μS/cm. Other associated elements (Ni, Pb, Cu and Zn) are present in low concentrations, except for Fe that in 32% of samples exceeded the guideline value of 0.3 mg/L suggested by the CAA.

  19. Geochemical information for the West Chestnut Ridge Central Waste Disposal Facility for low-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, F.G.; Kelmers, A.D.

    1984-06-01

    Geochemical support activities for the Central Waste Disposal Facility (CWDF) project included characterization of site materials, as well as measurement of radionuclide sorption and desorption isotherms and apparent concentration limit values under site-relevant laboratory test conditions. The radionuclide sorption and solubility information is needed as input data for the pathways analysis calculations to model expected radioactivity releases from emplaced waste to the accessible environment under various release scenarios. Batch contact methodology was used to construct sorption and desorption isotherms for a number of radionuclides likely to be present in waste to be disposed of at the site. The sorption rates for uranium and europium were rapid (> 99.8% of the total radionuclide present was adsorbed in approx. 30 min). With a constant-pH isotherm technique, uranium, strontium, cesium, and curium exhibited maximum Rs values of 4800 to > 30,000 L/kg throughout the pH range 5 to 7. Sorption ratios were generally lower at higher or lower pH levels. Retardation factors for uranium, strontium, and cesium, explored by column chromatographic tests, were consistent with the high sorption ratios measured in batch tests for these radionuclides. The addition of as little as 0.01 M organic reagent capable of forming strong soluble complexes with metals (e.g., ethylenediaminetetraacetic acid (EDTA) or citric acid) was found to reduce the sorption ratio for uranium by as much as two orders of magnitude. Substitution of an actual low-level waste site trench water for groundwater in these tests was found to give a similar reduction in the sorption ratio.

  20. Geochemical information for the West Chestnut Ridge Central Waste Disposal Facility for low-level radioactive waste

    International Nuclear Information System (INIS)

    Geochemical support activities for the Central Waste Disposal Facility (CWDF) project included characterization of site materials, as well as measurement of radionuclide sorption and desorption isotherms and apparent concentration limit values under site-relevant laboratory test conditions. The radionuclide sorption and solubility information is needed as input data for the pathways analysis calculations to model expected radioactivity releases from emplaced waste to the accessible environment under various release scenarios. Batch contact methodology was used to construct sorption and desorption isotherms for a number of radionuclides likely to be present in waste to be disposed of at the site. The sorption rates for uranium and europium were rapid (> 99.8% of the total radionuclide present was adsorbed in approx. 30 min). With a constant-pH isotherm technique, uranium, strontium, cesium, and curium exhibited maximum Rs values of 4800 to > 30,000 L/kg throughout the pH range 5 to 7. Sorption ratios were generally lower at higher or lower pH levels. Retardation factors for uranium, strontium, and cesium, explored by column chromatographic tests, were consistent with the high sorption ratios measured in batch tests for these radionuclides. The addition of as little as 0.01 M organic reagent capable of forming strong soluble complexes with metals [e.g., ethylenediaminetetraacetic acid (EDTA) or citric acid] was found to reduce the sorption ratio for uranium by as much as two orders of magnitude. Substitution of an actual low-level waste site trench water for groundwater in these tests was found to give a similar reduction in the sorption ratio

  1. 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)

  2. Constraining ice mass loss from Jakobshavn Isbræ (Greenland) using InSAR-measured crustal uplift

    DEFF Research Database (Denmark)

    Liu, Lin; Wahr, John; Howat, Ian;

    2012-01-01

    Jakobshavn Isbræ in west Greenland has been undergoing dramatic thinning since 1997. Applying the interferometric synthetic aperture radar (InSAR) technique to Radarsat-1 SAR data, we measure crustal uplift near Jakobshavn Isbræ caused by recent ice mass loss. The crustal uplift is predominantly ...

  3. 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

    of fine (silty) sediments related to strong melt-water discharge from the Inland Ice. The benthic foraminiferal fauna demonstrates the presence of well-ventilated, saline bottom water originating from inflow of subsurface West Greenland Current water of Atlantic (Irminger Sea) origin. The hydrographic...

  4. The Jan Mayen whaling industry - Its exploitation of the Greenland right whale and its impact on the marine ecosystem

    NARCIS (Netherlands)

    Hacquebord, L; Skreslet, S

    2004-01-01

    After a relatively late discovery of the island, Dutch whalers used Jan Mayen as a base for their whaling industry. They built stations on the west coast of the island where they rendered whale oil from the blubber of the Greenland right whales. Altogether the whalers stayed for twenty-two years on

  5. The South Greenland uranium exploration programme

    International Nuclear Information System (INIS)

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

  6. A New Species of Farranula (Copepoda: Cyclopoida: Corycaeidae from the West Central Pacific, with a Key to Species of the Genus

    Directory of Open Access Journals (Sweden)

    Wi, Jin Hee

    2015-01-01

    Full Text Available A new species of the genus Farranula Wilson, 1942 (Cyclopoida, Corycaeidae is described based on both sexes collected off Chuuk Island in Micronesia (West Central Pacific. The new species F. dahlae differs from its close congener F. gibbula (Giesbrecht, 1891 in the following combination of characters in both sexes: body length is longer, length to width ratio of caudal rami is larger, basal element of maxilliped is distinctly longer, and terminal spine to distal segment ratio of P4 is smaller; while in females, lateral margins of fourth pedigerous somite are extended to mid-region of second urosomal somite, maximum width of the second urosomal somite is located at middle region in dorsal and lateral views, and length ratio of caudal seta III to seta V is much larger; and in males, sharply contracted portion of second somite is located at two-thirds distance from anterior margin. Some additional morphological details of F. gibbula are given and a key to species of the genus Farranula is provided.

  7. Clutch and egg allometry of the turtle Mauremys leprosa (Chelonia: Geoemydidae) from a polluted peri-urban river in west-central Morocco

    Science.gov (United States)

    Naimi, Mohamed; Znari, Mohammed; Lovich, Jeffrey E.; Feddadi, Youssef; Baamrane, Moulay Abdeljalil Ait

    2012-01-01

    We examined the relationships of clutch size (CS) and egg size to female body size (straight-line carapace length, CL) in a population of the turtle Mauremys leprosa from a polluted segment of oued (river) Tensift in arid west-central Morocco. Twenty-eight adult females were collected in May–July, 2009 and all were gravid. Each was weighed, measured, humanely euthanized and then dissected. Oviductal shelled eggs were removed, weighed (egg mass, EM) and measured for length (EL) and width (EW). Clutch mass (CM) was the sum of EM for a clutch. Pelvic aperture width (PAW) was measured at the widest point between the ilia bones through which eggs must pass at oviposition. The smallest gravid female had a CL of 124.0 mm. Mean CS was relatively large (9.7±2.0 eggs, range: 3–13) and may reflect high productivity associated with polluted (eutrophic) waters. Regression analyses were conducted using log-transformed data. CM increased isometrically with maternal body size. CS, EW and EM were all significantly hypoallometric in their relationship with CL. EL did not change significantly with increases in CL. EW increased at a hypoallometric rate with increasing CL but was unconstrained by PAW since the widest egg was smaller than the narrowest PAW measurement when excluding the three smallest females. Smaller females may have EW constrained by PAW. As females increase in size they increase both clutch size and egg width in contradiction to predictions of optimal egg size theory.

  8. Assessing the length of the post-disturbance recovery period for woodland caribou habitat after fire and logging in west-central Manitoba

    Directory of Open Access Journals (Sweden)

    Juha M. Metsaranta

    2007-04-01

    Full Text Available This study examined the habitat characteristics of areas used by woodland caribou and areas disturbed by fire or logging in the Naosap caribou range in west-central Manitoba. The population inhabiting this area is currently considered to be of high conservation concern. The purpose was to determine how long after disturbance forests again resembled caribou habitat and whether there were differences in the recovery period between fire disturbed and logged areas. Sample transects were located in areas used by caribou and areas disturbed by fire or logging. Previously, it was shown that variables positively associated with habitat suitability in this region were species composition (presence of black spruce, an index of arboreal lichen abundance and tree size, while variables negatively associated with habitat suitability were deadfall abundance and species composition (presence of trembling aspen. It was hypothesized that if disturbed sites had become suitable caribou habitat, then they should be statistically indistinguishable from sites used by caribou based on these variables. Using cluster analysis, it was found that 2 statistical clusters showed the highest level of agreement with sampling clusters, with 88% of plots used by caribou classified into one cluster, and 74% of disturbed plots classified into the other. Although a small proportion (12% of disturbed plots resembled used plots, 30 years (the age of the oldest disturbed plot was not enough time, in general, for forest to return to conditions resembling caribou habitat in this region.

  9. Bathymetric preference of four major genera of rectilinear benthic foraminifera within oxygen minimum zone in Arabian Sea off central west coast of India

    Indian Academy of Sciences (India)

    Abhijit Mazumder; Rajiv Nigam

    2014-04-01

    Fifty two surface sediment samples collected from the region off Goa, central west coast of India from water depths of 15–3300 m were analyzed with special emphasis on foraminiferal content. Rectilinear benthic foraminiferal morphogroup shows a high relative abundance within Oxygen Minimum Zone (OMZ), both shallow marine (50–60 m water depth) and intermediate to deep water (150–1500 m water depth). We gave special emphasis on four rectilinear foraminiferal genera, namely Fursenkoina, Bolivina, Bulimina and Uvigerina to observe their individual distribution among OMZ. We found genus Fursenkoina predominates at the shallow water OMZ, within the water depth zone of 50–60 m. Within 150–1500 m water depth, which is considered as intermediate to deep water OMZ in this region, genus Uvigerina shows its highest abundance above 1000 m water depth, whereas genus Bulimina shows its affinity with deeper water environment (< 1000 m water depth). Genus Bolivina does not show any such depth preference, except its higher abundance in only intermediate to deep water OMZ. This depth differentiation among four rectilinear benthic foraminiferal genera presents the basic data for palaeoclimatic study based on the extent and intensity of OMZ along with the palaeobathymetry study.

  10. Adsorption Kinetics of CO2, CH4, and their Equimolar Mixture on Coal from the Black Warrior Basin, West-Central Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Naney, Michael {Mike} T [ORNL; Blencoe, James {Jim} G [ORNL; Cole, David R [ORNL; Pashin, Jack C. [Geological Survey of Alabama; Carroll, Richard E. [Geological Survey of Alabama

    2009-01-01

    Laboratory experiments were conducted to investigate the adsorption kinetic behavior of pure and mixed gases (CO2, CH4, approximately equimolar CO2 + CH4 mixtures, and He) on a coal sample obtained from the Black Warrior Basin at the Littleton Mine (Twin Pine Coal Company), Jefferson County, west-central Alabama. The sample was from the Mary Lee coal zone of the Pottsville Formation (Lower Pennsylvanian). Experiments with three size fractions (45-150 m, 1-2 mm, and 5-10 mm) of crushed coal were performed at 40 C and 35 C over a pressure range of 1.4 6.9 MPa to simulate coalbed methane reservoir conditions in the Black Warrior Basin and provide data relevant for enhanced coalbed methane recovery operations. The following key observations were made: (1) CO2 adsorption on both dry and water-saturated coal is much more rapid than CH4 adsorption; (2) water saturation decreases the rates of CO2 and CH4 adsorption on coal surfaces, but it appears to have minimal effects on the final magnitude of CO2 or CH4 adsorption if the coal is not previously exposed to CO2; (3) retention of adsorbed CO2 on coal surfaces is significant even with extreme pressure cycling; and (4) adsorption is significantly faster for the 45-150 m size fraction compared to the two coarser fractions.

  11. Arsenic and Mercury Levels in Earthenware Clays in Otsew in Gomoa West District of Central Region of Ghana using Instrumental Neutron Activation Analysis

    Directory of Open Access Journals (Sweden)

    B.V. Samlafo

    2011-08-01

    Full Text Available This study was conducted to investigate the occurrence and extent of potentially toxic heavy metals, As and Hg in earthenware clay deposits at Otsew in the Gomoa West District of the Central Region of Ghana using the Instrumental Neutron Activation Analysis (INAA technique. Arsenic concentrations in the clay ranged from 1.55±0.23 to 18.47±2.60 μg/g at S6 and S10 respectively with a mean of 9.48 μg/g. Arsenic was not detected in sample S3. Mercury concentration in the clay ranged from 0.030±0.005 to 0.31±0.01 μg/g in S2 and S3 respectively, with a mean of 0.14 μg/g. Mercury was however, not detected in S10. The precision and accuracy of the analytical technique (INAA were assessed by simultaneous activation of reference material IAEA soil-7. The values obtained compared favourably well with the recommended values as Spearman’s correlation coefficient was +0.99. The experimental samples were within ±5% of the recommended values. The measurement precision specified by the relative standard deviation was within ±4%.

  12. Digital geologic map and Landsat image map of parts of Loralai, Sibi, Quetta, and Khuzar Divisions, Balochistan Province, west-central Pakistan

    Science.gov (United States)

    Maldonado, Florian; Menga, Jan Mohammad; Khan, Shabid Hasan; Thomas, Jean-Claude

    2011-01-01

    This generalized digital geologic map of west-central Pakistan is a product of the Balochistan Coal-Basin Synthesis Study, which was part of a cooperative program of the Geological Survey of Pakistan and the United States Geological Survey. The original nondigital map was published by Maldonado and others (1998). Funding was provided by the Government of Pakistan and the United States Agency for International Development. The sources of geologic map data are primarily 1:253,440-scale geologic maps obtained from Hunting Survey Corporation (1961) and the geologic map of the Muslim Bagh Ophiolite Complex and Bagh Complex area. The geology was modified based on reconnaissance field work and photo interpretation of 1:250,000-scale Landsat Thematic Mapper photo image. The descriptions and thicknesses of map units were based on published and unpublished reports and converted to U.S. Geological Survey format. In the nomenclature of the Geological Survey of Pakistan, there is both an Urak Group and an Urak Formation.

  13. A synthesis and review of geomorphic surfaces of the boundary zone Mt. Taylor to Lucero uplift area, West-Central New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Wells, S.G. [NEOTEC, Inc., Albuquerque, NM (United States)

    1989-01-01

    The Mt. Taylor volcanic field and Lucero uplift of west-central New Mexico occur in a transitional-boundary zone between the tectonically active Basin-and Range province (Rio Grande rift) and the less tectonically active Colorado plateau. The general geomorphology and Cenozoic erosional history has been discussed primarily in terms of a qualitative, descriptive context and without the knowledge of lithospheric processes. The first discussion of geomorphic surfaces suggested that the erosional surface underlying the Mt. Taylor volcanic rocks is correlative with the Ortiz surface of the Rio Grande rift. In 1978 a study supported this hypothesis with K-Ar dates on volcanic rocks within each physiographic province. The correlation of this surface was a first step In the regional analysis of the boundary zone; however, little work has been done to verify this correlation with numerical age dates and quantitatively reconstruct the surface for neotectonic purposes. Those geomorphic surfaces inset below and younger than the ``Ortiz`` surface have been studied. This report provides a summary of this data as well as unpublished data and a conceptual framework for future studies related to the LANL ISR project.

  14. Hepatitis C as a risk factor for diabetes type 2: lack of evidence in a hospital in central-west Brazil

    Directory of Open Access Journals (Sweden)

    Luce Marina Freires Corrêa da Costa

    2008-02-01

    Full Text Available In order to assess the importance of HCV infection as a possible risk factor for type 2 diabetes mellitus, a case-control study was conducted, comparing the prevalence of HCV infection among diabetic and non-diabetic patients. Diabetic outpatients attending to a University Hospital in Central-West Brazil were evaluated between April and October 2005. A control group composed by patients from the same institution was matched by gender and age. Candidates to control group were included only if fasting glucose measures were under 100 mg/dL. Diabetics and controls had blood samples taken in order to test for antibodies against HCV (anti-HCV by enzyme-immunoassay. Polymerase chain reaction and immunoblot were performed to confirm the anti-HCV status. Each group included 206 participants. Despite of the groups were in general comparable. The diabetics had a greater body mass average and smaller family income. The prevalence of confirmed anti-HCV in the diabetic group was of 1.4%, which was similar to the controls (1%. Finding statistical difference may have been hampered by the low frequency of HCV infection in both groups. It was not possible to demonstrate a role of HCV as an etiologic factor in type 2 diabetes, since HCV infected patients represented a small portion of the overall diabetes cases. This finding does not allow to recommend regular screening for HCV infection in type 2 diabetics in this region.

  15. Genetics, Morphology, Advertisement Calls, and Historical Records Distinguish Six New Polyploid Species of African Clawed Frog (Xenopus, Pipidae from West and Central Africa.

    Directory of Open Access Journals (Sweden)

    Ben J Evans

    Full Text Available African clawed frogs, genus Xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. Here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-Saharan Africa, including four tetraploids and two dodecaploids. We provide information on molecular variation, morphology, karyotypes, vocalizations, and estimated geographic ranges, which support the distinctiveness of these new species. We resurrect Xenopus calcaratus from synonymy of Xenopus tropicalis and refer populations from Bioko Island and coastal Cameroon (near Mt. Cameroon to this species. To facilitate comparisons to the new species, we also provide comments on the type specimens, morphology, and distributions of X. epitropicalis, X. tropicalis, and X. fraseri. This includes significantly restricted application of the names X. fraseri and X. epitropicalis, the first of which we argue is known definitively only from type specimens and possibly one other specimen. Inferring the evolutionary histories of these new species allows refinement of species groups within Xenopus and leads to our recognition of two subgenera (Xenopus and Silurana and three species groups within the subgenus Xenopus (amieti, laevis, and muelleri species groups.

  16. Adsorption kinetics of CO2, CH4, and their equimolar mixture on coal from the Black Warrior Basin, West-Central Alabama

    Science.gov (United States)

    Gruszkiewicz, M.S.; Naney, M.T.; Blencoe, J.G.; Cole, D.R.; Pashin, J.C.; Carroll, R.E.

    2009-01-01

    Laboratory experiments were conducted to investigate the adsorption kinetic behavior of pure and mixed gases (CO2, CH4, approximately equimolar CO2 + CH4 mixtures, and He) on a coal sample obtained from the Black Warrior Basin at the Littleton Mine (Twin Pine Coal Company), Jefferson County, west-central Alabama. The sample was from the Mary Lee coal zone of the Pottsville Formation (Lower Pennsylvanian). Experiments with three size fractions (45-150????m, 1-2??mm, and 5-10??mm) of crushed coal were performed at 40????C and 35????C over a pressure range of 1.4-6.9??MPa to simulate coalbed methane reservoir conditions in the Black Warrior Basin and provide data relevant for enhanced coalbed methane recovery operations. The following key observations were made: (1) CO2 adsorption on both dry and water-saturated coal is much more rapid than CH4 adsorption; (2) water saturation decreases the rates of CO2 and CH4 adsorption on coal surfaces, but it appears to have minimal effects on the final magnitude of CO2 or CH4 adsorption if the coal is not previously exposed to CO2; (3) retention of adsorbed CO2 on coal surfaces is significant even with extreme pressure cycling; and (4) adsorption is significantly faster for the 45-150????m size fraction compared to the two coarser fractions. ?? 2008 Elsevier B.V.

  17. Periodic anoxic shelf in the Early-Middle Ordovician transition: ichnosedimentologic evidence from west-central Utah, USA

    Institute of Scientific and Technical Information of China (English)

    GONG; Yiming

    2001-01-01

    stratigraphic sections for western Utah, Utah Geological and Mineralogical Survey Bulletin, 1951, 39: 1-99.[11]Hintze, L. F.. Lower and Middle Ordovician stratigraphic sections in the Ibex area, Millard county, Utah., Brigham Young University Geology Studies, 1973, 20(4): 3-36.[12]Droser, M. L., Bottjer. D. J., Trends and patterns of Phanerozoic ichnofabrics, Annu. Rev. Earth Planet. Sci., 1993, 21: 205-225.[13]Bromley, R. G., Ekdale, A. A., Composite ichnofabrics and tiering of burrows, Geological Magazine, 1986, 123 (1): 59- 65.[14]Goldring, R., Organisms and the substrate: response and effect, in Marine Palaeoenvironmental Analysis from Fossils (eds.Bosence. D. W. J., Allison, P. A.), Geological Society Special Publication, London, 1995, 83:151-180.[15]Bromley, R. G., Ekdale, A. A., Chondrites: a trace fossil indicator of anoxia in sediments, Science, 1984, 224: 872-874.[16]Ekdale, A. A., Bromley, R. G., Analysis of composite ichnofabrics: an example in uppermost Cretaceous chalk of Denmark, Palaios, 1991, 6: 232-249.[17]Ekdale. A. A.. Mason, T. R.. Characteristic trace fossil associations in oxygen-poor sedimentary environments, Geology, 1988. 16: 720-723.[18]Savrda, C. E., Trace fossils and bethic oxygenation, in Trace Fossils (eds. Maples, C. G., West, R. R.), Knoxville: Paleontological Society, Short Courses in Paleontology, 1992, 5: 172- 196.[19]Gong, Y. M., Li, B. H., Wang, Ch. Y. et al., Orbital cyclostratigraphy of the Devonian Frasnian-Famennian transition in South China, Palaeogeography, Palaeoclimatology, Palaeoecology, 2001, 168(3-4): 237-248.[20]Hallam, A., Wignall, P. B., Mass extinctions and their aftermath, Oxford: Oxford University Press, 1997, 1-320.[21]Savrda, C. E., Bottjer, D. J., Trace fossil model for reconstruction of paleo-oxygenation in bottom waters, Geology, 1986,14: 3--6.[22]Savrda, C. E., Bottjer, D, J., Oxygen-related biofacies in marine strata: overview and update, in Modem and Ancient

  18. Joint Science Education Project: Learning about polar science in Greenland

    Science.gov (United States)

    Foshee Reed, Lynn

    2014-05-01

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

  19. Metazooplankton community structure, feeding rate estimates, and hydrography in a meltwater-influenced Greenlandic fjord

    OpenAIRE

    Tang, K.W.; Nielsen, Torkel Gissel; Munk, Peter; Mortensen, J.; Møller, E.F.; Arendt, K.E.; Tönnesson, K.; Juul-Pedersen, T

    2011-01-01

    In order to assess the potential responses of Greenland’s coastal ecosystems to future climate change, we studied the hydrography and distribution of metazooplankton, along a transect from the slope waters beyond Fyllas Banke to the inner part of Godthåbsfjord, West Greenland, in July and August 2008, and estimated feeding rates for some of the larger species groups. Within the 4 regional domains that were covered in the study (continental slope, continental shelf, outer sill region, and main...

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

    OpenAIRE

    Pedersen, Ivalu Søvndahl

    2009-01-01

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