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Sample records for alaska greenland turbot

  1. 78 FR 54591 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-05

    ... Economic Zone Off Alaska; Greenland Turbot in the Bering Sea and Aleutian Islands Management Area AGENCY... Greenland turbot in the Bering Sea subarea of the Bering Sea and Aleutian Islands Management Area (BSAI). This action is necessary to fully use the 2013 initial total allowable catch (ITAC) of Greenland...

  2. 78 FR 24362 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... for Greenland turbot in the Aleutian Islands subarea of the Bering Sea and Aleutian Islands...

  3. 78 FR 24361 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... Management Area AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... for Greenland turbot in the Bering Sea subarea of the Bering Sea and Aleutian Islands management area (BSAI). This action is necessary to prevent exceeding the 2013 Greenland turbot initial total...

  4. 75 FR 38430 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... current available data and finds that the ITAC for Greenland turbot in the Aleutian Islands subarea needs... most recent fisheries data in a timely fashion and would delay the apportionment of the non-specified... and processors. NMFS was unable to publish a notice providing time for public comment because the...

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

    PubMed

    Peterson, Megan J; Mueter, Franz; Criddle, Keith; Haynie, Alan C

    2014-01-01

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

  6. Ocean-Glacier Interactions in Alaska and Comparison to Greenland

    NASA Astrophysics Data System (ADS)

    Motyka, R. J.; Truffer, M.

    2011-12-01

    Meltwater from Alaska's coastal glaciers and icefields accounts for nearly half of the total freshwater discharged into the Gulf of Alaska (GOA), with 10% coming from glacier volume loss associated with rapid thinning and retreat of glaciers (Neal et al, 2010). This glacier freshwater discharge contributes to maintaining the Alaska Coastal Current (ACC), which eventually reaches the Arctic Ocean (Royer and Grosch, 2006), thereby linking changes of glaciers along the coast of Alaska to the whole Arctic system. Water column temperatures on the shelf of northern GOA, monitored at buoy GAK1 near Seward, have increased by about 1 deg C since 1970 throughout the 250 m depth and vertical density stratification has also increased. Roughly half of the glacier contribution to ACC is derived from the ~ 50 tidewater glaciers (TWG) that drain from Alaska's coastal mountains into the Gulf of Alaska (GOA). Fjord systems link these TWGs to the GOA, with fjord circulation patterns driven in part by buoyancy-driven convection of subglacial freshwater discharge at the head of the fjord. Neoglacial shallow sills (< 50 m deep) modulate the influx of warm ocean waters (up to 10 deg C) into these fjords. Convection of these warm waters melts icebergs and submerged faces of TWGs. The study of interactions between glaciers, fjords, and the ocean in coastal Alaska has had a long but very sporadic history. We examine this record starting with the "TWG cycle" hypothesis. We next examine recent hydrographic data from several different TWG fjords, representative of advancing and retreating TWGs (Columbia, Yahtse, Hubbard, and LeConte Glaciers), evaluate similarities and differences, and estimate the relative contributions of submarine glacier melting and subglacial discharge to fjord circulation. Circulation of warm ocean waters in fjords has also been hypothesized to play an important role in destabilizing and modulating glacier discharge from outlet glaciers in Greenland. We therefore compare

  7. Native Language Dictionaries and Grammars of Alaska, Northern Canada, and Greenland.

    ERIC Educational Resources Information Center

    Goniwiecha, Mark C.; Hales, David A.

    1988-01-01

    Describes recent political and social activities aimed at preserving the culture of Native Americans in Alaska, Northern Canada, and Greenland. An annotated bibliography of sources for the Eskimo Aleut, Tsimshian, Haida, Athabascan (Athapascan), Eyak and Tlingit languages is provided. (CLB)

  8. Correlation of the Cretaceous formations of Greenland and Alaska

    USGS Publications Warehouse

    Imlay, Ralph Willard; Reeside, John B.

    1953-01-01

    This is Number 10d of a series of correlation charts prepared for the Committee on Stratigraphy of the National Research Council. It has been sponsored by the U.S. Geological Survey and has required about seven months' time of both authors gathering and compiling data and evaluating fossil evidence. As the two regions dealt with in the chart are widely separated, the lists of references are also given separately. The annotations dealing with Greenland are based entirely on published information. The annotations dealing with Alaska are based on a re-examination of nearly all the Cretaceous fossils from Alaska are based on a re-examination of nearly all the Cretaceous fossils from Alaska in the collections of the Geological Survey. This has resulted in many concepts not hitherto published and in some concepts that are completely at variance with those that have been published. Naturally for large areas undergoing active exploration, such as Alaska, a correlation chart is out of date in many particulars as soon as published. Nevertheless it is valuable to the field man whose activities are confined to small areas but who must interpret much of his data in terms of surrounding areas that he has not seen. It is valuable to the student and to the general geologist because it organizes scattered information in a manner that can be applied in their field problems, makes quite unnecessary the memorization of stratigraphic correlations are based on observation and reasoning and not on a vast memory. It is probably of greatest value to the specialist who makes the chart because he discovers what areas and problems are most in need of research and can thereby direct his efforts and those of his associates in a manner that will yield the greatest results.

  9. Cross-Cultural Education and the Economic Situation: The Greenland and Alaska Cases.

    ERIC Educational Resources Information Center

    Rogers, George W.

    The paper examines the economic situations in Greenland and Alaska. Similar in many ways, the 2 countries represent opposite policy poles from a cultural standpoint. The basic economic problem is one of severe regional imbalance when compared with the rest of the nation. For both, government policy has tried to raise income and consumption to a…

  10. Movements of a polar bear from northern Alaska to northern Greenland

    USGS Publications Warehouse

    Durner, George M.; Amstrup, Steven C.

    1995-01-01

    Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and came within 2 degrees of the North Pole. During the first year following her capture, she traveled 5256 km. Evidence to suggest her use of maternity dens in northern Alaska and in northern Greenland demonstrates the potential for genetic exchange between two widely separate populations of polar bears. The long life spans of polar bears and the rarity of their long-range movements means the significance of interpopulation movement can be assessed after long-term monitoring of individuals.

  11. Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends

    NASA Astrophysics Data System (ADS)

    Harig, Christopher; Simons, Frederik J.

    2016-04-01

    Over the past several decades mountain glaciers and ice caps have been significant contributors to sea level rise. Here we estimate the ice mass changes in the Canadian Archipelago, the Gulf of Alaska, and Greenland since 2003 by analyzing time-varying gravimetry data from the Gravity Recovery and Climate Experiment. Prior to 2013, interannual ice mass variability in the Gulf of Alaska and in regions around Greenland remains within the average estimated over the whole data span. Beginning in summer 2013, ice mass in regions around Greenland departs positively from its long-term trend. Over Greenland this anomaly reached almost 500 Gt through the end of 2014. Overall, long-term ice mass loss from Greenland and the Canadian Archipelago continues to accelerate, while losses around the Gulf of Alaska region continue but remain steady with no significant acceleration.

  12. Methane seeps along boundaries of receding glaciers in Alaska and Greenland

    NASA Astrophysics Data System (ADS)

    Walter Anthony, K. M.; Anthony, P. M.; Grosse, G.; Chanton, J.

    2012-12-01

    Glaciers, ice sheets, and permafrost form a 'cryosphere cap' that traps methane formed in the subsurface, restricting its flow to the Earth's surface and atmosphere. Despite model predictions that glacier melt and degradation of permafrost open conduits for methane's escape, there has been a paucity of field evidence for 'subcap' methane seepage to the atmosphere as a direct result of cryosphere disintegration in the terrestrial Arctic. Here, we document for the first time the release of sub-cryosphere methane to lakes, rivers, shallow marine fjords and the atmosphere from abundant gas seeps concentrated along boundaries of receding glaciers and permafrost thaw in Alaska and Greenland. Through aerial and ground surveys of 6,700 lakes and fjords in Alaska we mapped >150,000 gas seeps identified as bubbling-induced open holes in seasonal ice. Using gas flow rates, stable isotopes, and radiocarbon dating, we distinguished recent ecological methane from subcap, geologic methane. Subcap seeps had anomalously high bubbling rates, 14C-depletion, and stable isotope values matching microbial sources associated with sedimentary deposits and coal beds as well as thermogenic methane accumulations in Alaska. Since differential ice loading can overpressurize fluid reservoirs and cause sediment fracturing beneath ice sheets, and since the loss of glacial ice reduces normal stress on ground, opens joints, and activates faults and fissures, thereby increasing permeability of the crust to fluid flow, we hypothesized that in the previously glaciated region of Southcentral Alaska, where glacial wastage continues presently, subcap seeps should be disproportionately associated with neotectonic faults. Geospatial analysis confirmed that subcap seep sites were associated with faults within a 7 km belt from the modern glacial extent. The majority of seeps were located in areas affected by seismicity from isostatic rebound associated with deglaciation following the Little Ice Age (LIA; ca

  13. 76 FR 71269 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-17

    ... Federal Building: Address written comments to Glenn Merrill, Assistant Regional Administrator, Sustainable... written comments to Glenn Merrill, Assistant Regional Administrator, Sustainable Fisheries Division...: Address written comments to Glenn Merrill, Assistant Regional Administrator, Sustainable...

  14. 78 FR 76245 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... the fishery. The Assistant Administrator for Fisheries, NOAA (AA), finds good cause to waive the..., 2013. The AA also finds good cause to waive the 30-day delay in the effective date of this action...

  15. Comparison of UV irradiance measurements at Summit, Greenland; Barrow, Alaska; and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Bernhard, G.; Booth, C. R.; Ehramjian, J. C.

    2008-08-01

    An SUV-150B spectroradiometer for measuring solar ultraviolet (UV) irradiance was installed at Summit, Greenland, in August 2004. Here we compare the initial data from this new location with similar measurements from Barrow, Alaska, and South Pole. Measurements of irradiance at 345 nm performed at equivalent solar zenith angles (SZAs) are almost identical at Summit and South Pole. The good agreement can be explained with the similar location of the two sites on high-altitude ice caps with high surface albedo. Clouds attenuate irradiance at 345 nm at both sites by less than 6% on average, but can reduce irradiance at Barrow by more than 75%. Clear-sky measurements at Barrow are smaller than at Summit by 14% in spring and 36% in summer, mostly due to differences in surface albedo and altitude. Comparisons with model calculations indicate that aerosols can reduce clear-sky irradiance at Summit by 4 6%; aerosol influence is largest in April. Differences in total ozone at the three sites have a large influence on the UV Index. At South Pole, the UV Index is on average 20 80% larger during the ozone hole period than between January and March. At Summit, total ozone peaks in April and UV Indices in spring are on average 10 25% smaller than in the summer. Maximum UV Indices ever observed at Summit, Barrow, and South Pole are 6.7, 5.0, and 4.0, respectively. The larger value at Summit is due to the site's lower latitude. For comparable SZAs, average UV Indices measured during October and November at South Pole are 1.9 2.4 times larger than measurements during March and April at Summit. Average UV Indices at Summit are over 50% greater than at Barrow because of the larger cloud influence at Barrow.

  16. Comparison of UV climates at Summit, Greenland; Barrow, Alaska and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Bernhard, G.; Booth, C. R.; Ehramjian, J. C.

    2008-03-01

    An SUV-150B spectroradiometer for measuring solar ultraviolet (UV) irradiance was installed at Summit, Greenland, in August 2004. Here we compare the initial data from this new location with similar measurements from Barrow, Alaska and South Pole. Measurements of irradiance at 345 nm performed at equivalent solar zenith angles (SZAs) are almost identical at Summit and South Pole. The good agreement can be explained with the similar location of the two sites on high-altitude ice caps with high surface albedo. Clouds have little impact at both sites, but can reduce irradiance at Barrow by more than 75%. Clear-sky measurements at Barrow are smaller than at Summit by 14% in spring and 36% in summer, mostly due to differences in surface albedo and altitude. Comparisons with model calculations indicate that aerosols can reduce clear-sky irradiance at 345 nm by 4-6%; aerosol influence is largest in April. Differences in total ozone at the three sites have a large influence on the UV Index. At South Pole, the UV Index is on average 20-80% larger during the ozone hole period than between January and March. At Summit, total ozone peaks in April and UV Indices in spring are on average 10-25% smaller than in the summer. Maximum UV Indices ever observed at Summit and South Pole are 6.7 and 4.0, respectively. The larger value at Summit is due to the site's lower latitude. For comparable SZAs, average UV Indices measured during October and November at South Pole are 1.9-2.4 times larger than measurements during March and April at Summit. Average UV Indices at Summit are over 50% greater than at Barrow because of the larger cloud influence at Barrow.

  17. Antarctica, Greenland and Gulf of Alaska Land-Ice Evolution from an Iterated GRACE Global Mascon Solution

    NASA Technical Reports Server (NTRS)

    Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.

    2013-01-01

    We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.

  18. Antarctica, Greenland and Gulf of Alaska Land-ice Evolution from an Iterated GRACE Global Mascon Solution

    NASA Technical Reports Server (NTRS)

    Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.

    2013-01-01

    We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.

  19. Overseas trip report, CV 990 underflight mission. [Norwegian Sea, Greenland ice sheet, and Alaska

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Crawford, J.; Hardis, L.

    1980-01-01

    The scanning microwave radiometer-7 simulator, the ocean temperature scanner, and an imaging scatterometer/altimeter operating at 14 GHz were carried onboard the NASA CV-990 over open oceans, sea ice, and continental ice sheets to gather surface truth information. Data flights were conducted over the Norwegian Sea to map the ocean polar front south and west of Bear Island and to transect several Nimbus-7 footprints in a rectangular pattern parallel to the northern shoreline of Norway. Additional flights were conducted to obtain correlative data on the cryosphere parameters and characteristics of the Greenland ice sheet, and study the frozen lakes near Barrow. The weather conditions and flight path way points for each of the nineteen flights are presented in tables and maps.

  20. Flame retardants and legacy contaminants in polar bears from Alaska, Canada, East Greenland and Svalbard, 2005-2008.

    PubMed

    McKinney, Melissa A; Letcher, Robert J; Aars, Jon; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; Gabrielsen, Geir W; Peacock, Elizabeth; Sonne, Christian

    2011-02-01

    Flame retardants and legacy contaminants were analyzed in adipose tissue from 11 circumpolar polar bear (Ursus maritimus) subpopulations in 2005-2008 spanning Alaska east to Svalbard. Although 37 polybrominated diphenyl ethers (PBDEs), total-(α)-hexabromocyclododecane (HBCD), 2 polybrominated biphenyls (PBBs), pentabromotoluene, pentabromoethylbenzene, hexabromobenzene, 1,2-bis(2,4,6-tribromophenoxy(ethane) and decabromodiphenyl ethane were screened, only 4 PBDEs, total-(α-)HBCD and BB153 were consistently found. Geometric mean ΣPBDE (4.6-78.4 ng/g lipid weight (lw)) and BB153 (2.5-81.1 ng/g lw) levels were highest in East Greenland (43.2 and 39.2 ng/g lipid weight (lw), respectively), Svalbard (44.4 and 20.9 ng/g lw) and western (38.6 and 30.1 ng/g lw) and southern Hudson Bay (78.4 and 81.1 ng/g lw). Total-(α)-HBCD levels (<0.3-41.1 ng/g lw) were lower than ΣPBDE levels in all subpopulations except in Svalbard, consistent with greater European HBCD use versus North American pentaBDE product use. ΣPCB levels were high relative to flame retardants as well as other legacy contaminants and increased from west to east (1797-10,537 ng/g lw). ΣCHL levels were highest among legacy organochlorine pesticides and relatively spatially uniform (765-3477 ng/g lw). ΣDDT levels were relatively low and spatially variable (31.5-206 ng/g lw). However, elevated proportions of p,p'-DDT to ΣDDT in Alaska and Beaufort Sea relative to other subpopulations suggested fresh inputs from vector control use in Asia and/or Africa. Comparing earlier circumpolar polar bear studies, ΣPBDE, total-(α)-HBCD, p,p'-DDE and ΣCHL levels consistently declined, whereas levels of other legacy contaminants did not. International regulations have clearly been effective in reducing levels of several legacy contaminants in polar bears relative to historical levels. However, slow or stalling declines of certain historic pollutants like PCBs and a complex mixture of "new" chemicals continue to be of

  1. Tradition and transition: parasitic zoonoses of people and animals in Alaska, northern Canada, and Greenland.

    PubMed

    Jenkins, Emily J; Castrodale, Louisa J; de Rosemond, Simone J C; Dixon, Brent R; Elmore, Stacey A; Gesy, Karen M; Hoberg, Eric P; Polley, Lydden; Schurer, Janna M; Simard, Manon; Thompson, R C Andrew

    2013-01-01

    Zoonotic parasites are important causes of endemic and emerging human disease in northern North America and Greenland (the North), where prevalence of some parasites is higher than in the general North American population. The North today is in transition, facing increased resource extraction, globalisation of trade and travel, and rapid and accelerating environmental change. This comprehensive review addresses the diversity, distribution, ecology, epidemiology, and significance of nine zoonotic parasites in animal and human populations in the North. Based on a qualitative risk assessment with criteria heavily weighted for human health, these zoonotic parasites are ranked, in the order of decreasing importance, as follows: Echinococcus multilocularis, Toxoplasma gondii, Trichinella and Giardia, Echinococcus granulosus/canadensis and Cryptosporidium, Toxocara, anisakid nematodes, and diphyllobothriid cestodes. Recent and future trends in the importance of these parasites for human health in the North are explored. For example, the incidence of human exposure to endemic helminth zoonoses (e.g. Diphyllobothrium, Trichinella, and Echinococcus) appears to be declining, while water-borne protozoans such as Giardia, Cryptosporidium, and Toxoplasma may be emerging causes of human disease in a warming North. Parasites that undergo temperature-dependent development in the environment (such as Toxoplasma, ascarid and anisakid nematodes, and diphyllobothriid cestodes) will likely undergo accelerated development in endemic areas and temperate-adapted strains/species will move north, resulting in faunal shifts. Food-borne pathogens (e.g. Trichinella, Toxoplasma, anisakid nematodes, and diphyllobothriid cestodes) may be increasingly important as animal products are exported from the North and tourists, workers, and domestic animals enter the North. Finally, key needs are identified to better assess and mitigate risks associated with zoonotic parasites, including enhanced

  2. Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland.

    PubMed

    Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; Fisk, Aaron T; Peacock, Elizabeth; Sonne, Christian

    2011-08-01

    Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg(2+)-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements.

  3. Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland

    USGS Publications Warehouse

    Routti, H.; Letcher, R.J.; Born, E.W.; Branigan, M.; Dietz, R.; Evans, T.J.; Fisk, A.T.; Peacock, E.; Sonne, C.

    2011-01-01

    Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg 2+-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements. ?? 2011 The Royal Society of Chemistry.

  4. Alaska

    SciTech Connect

    Jones, B.C.; Sears, D.W.

    1981-10-01

    Twenty-five exploratory wells were drilled in Alaska in 1980. Five oil or gas discovery wells were drilled on the North Slope. One hundred and seventeen development and service wells were drilled and completed, primarily in the Prudhoe Bay and Kuparuk River fields on the North Slope. Geologic-geophysical field activity consisted of 115.74 crew months, an increase of almost 50% compared to 1979. These increases affected most of the major basins of the state as industry stepped up preparations for future lease sales. Federal acreage under lease increased slightly, while state lease acreage showed a slight decline. The year's oil production showed a increase of 16%, while gas production was down slightly. The federal land freeze in Alaska showed signs of thawing, as the US Department of Interior asked industry to identify areas of interest onshore for possible future leasing. National Petroleum Reserve in Alaska was opened to private exploration, and petroleum potential of the Arctic Wildlife Refuge will be studied. One outer continental shelf lease sale was held in the eastern Gulf of Alaska, and a series of state and federal lease sales were announced for the next 5 years. 5 figures, 5 tables.

  5. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Though it's not quite spring, waters in the Gulf of Alaska (right) appear to be blooming with plant life in this true-color MODIS image from March 4, 2002. East of the Alaska Peninsula (bottom center), blue-green swirls surround Kodiak Island. These colors are the result of light reflecting off chlorophyll and other pigments in tiny marine plants called phytoplankton. The bloom extends southward and clear dividing line can be seen west to east, where the bloom disappears over the deeper waters of the Aleutian Trench. North in Cook Inlet, large amounts of red clay sediment are turning the water brown. To the east, more colorful swirls stretch out from Prince William Sound, and may be a mixture of clay sediment from the Copper River and phytoplankton. Arcing across the top left of the image, the snow-covered Brooks Range towers over Alaska's North Slope. Frozen rivers trace white ribbons across the winter landscape. The mighty Yukon River traverses the entire state, beginning at the right edge of the image (a little way down from the top) running all the way over to the Bering Sea, still locked in ice. In the high-resolution image, the circular, snow-filled calderas of two volcanoes are apparent along the Alaska Peninsula. In Bristol Bay (to the west of the Peninsula) and in a couple of the semi-clear areas in the Bering Sea, it appears that there may be an ice algae bloom along the sharp ice edge (see high resolution image for better details). Ground-based observations from the area have revealed that an under-ice bloom often starts as early as February in this region and then seeds the more typical spring bloom later in the season.

  6. Colour preferences of juvenile turbot (Scophthalmus maximus).

    PubMed

    Li, Xian; Chi, Liang; Tian, Huiqin; Meng, Lingjie; Zheng, Jimeng; Gao, Xiaolong; Liu, Ying

    2016-03-15

    The background colour of aquaculture tanks is normally chosen based on practical experience and/or observations of fish behaviour and the growth rates achieved. However, some farmed species, including turbot, are sentient and can show a preference for a particular environment. In the current study, a self-referent colour preference device was developed and the self-referent colour preference of farmed fish investigated. In experiment 1, the background colour preference of juvenile turbot cultured under a grey background for >3months post-incubation was evaluated. Based on these results, in experiment 2, juvenile turbot were adapted to blue, pink, white, or black backgrounds for 50days and their preferences established. Meanwhile, the growth rates, feed intake, and metabolic rates (including oxygen consumption rate, and ammonia excretion rate) of the turbot were evaluated. The results showed that turbot farmed under a grey background, or after long-term white, blue, pink and black colour adaptation, always displayed a preference for a white background and a dislike for black, red, or brown backgrounds, although their body colour was greyish. Long-term adaptation influenced the frequency of juveniles selecting white, black, pink or blue backgrounds. They showed the highest growth rate, feed intake, and metabolic rates under blue and white backgrounds, and the lowest under a black background in accordance with their preferences shown in experiment 1. Although it is unclear how turbot determine their self-referent colour preferences over such a short period of time, these results indicate that dark colours are unsuitable for the aquaculture of turbot culture in terms of the welfare of the fish.

  7. Reassortant betanodavirus infection in turbot (Scophthalmus maximus).

    PubMed

    Souto, S; Olveira, J G; Dopazo, C P; Bandín, I

    2016-11-01

    In this study, the susceptibility of turbot juveniles to two betanodavirus strains was assessed, a RGNNV/SJNNV reassortant (Ss160.03) and a SJNNV strain. The reassortant isolate exhibits a slightly modified SJNNV CP, with two amino acid substitutions in the C-terminal domain (positions 247 and 270). To analyse the role of these residues as virulence and host determinants in turbot, three recombinant strains (rSs160.03247 , rSs160.03270 , rSs160.03247+270 ) harbouring site-specific mutations in the CP sequence were also tested in experimental trials. Moderate mortalities (up to 50%) were recorded at 18 °C in the fish challenged with the Ss160.03 strain, whereas low mortalities (17%) were observed in the group challenged with the SJNNV strain. A slight decrease (around 10%) was observed in the mortalities caused by the mutants rSs160.03247 and rSs160.03270 , whilst the mutation of both positions reduced mortality by more than half of that observed in fish challenged with the wild strain. These results are confirmed by the replication in brain tissues, because whereas the wild strain was detected from 5 to 30 dpi and reached the highest viral load, the recombinant virus harbouring both mutations was not detected in the brain until 20 dpi and with a moderate viral load.

  8. Gravity anomaly at a Pleistocene lake bed in NW Alaska interpreted by analogy with Greenland's Lake Taserssauq and its floating ice tongue

    USGS Publications Warehouse

    Barnes, D.F.

    1987-01-01

    A possible example of a very deep glacial excavation is provided by a distinctive gravity low located at the front of a valley glacier that once flowed into glacial Lake Aniuk (formerly Lake Noatak) in the western Brooks Range. Geologic and geophysical data suggest that sediments or ice filling a glacially excavated valley are the most probable cause of the 30-50 mGal anomaly. Reasonable choices of geometric models and density contrasts indicate that the former excavation is now filled with a buried-ice thickness of 700 m or sediment thicknesses greater than 1 km. No direct evidence of efficient excavation was observed in Greenland, but efficient glacial erosion behind a floating polar ice tongue could explain the excavation that caused the Alaskan gravity anomaly. -from Author

  9. Post-release survival and feeding in reared turbot

    NASA Astrophysics Data System (ADS)

    Sparrevohn, Claus R.; Støttrup, Josianne G.

    2007-02-01

    As part of the Danish restocking program, an experiment was carried out with four groups of turbot Psetta maxima released on two different occasions at the same location in Århus Bay, Denmark. One objective was to analyse the duration of post-release mortality and the magnitude of this mortality. In 2003 a group called Large turbot (17.1 cm total length (L T)) and a group called Intermediate (L T = 11.8 cm) were released, and in 2004 two similar-sized groups called Naive and Conditioned (L T = 9.8 cm) were released. The Conditioned differed from the Naive turbot by being transferred to enclosures at the release location six days prior to the actual release. This experiment was performed to investigate whether such a conditioning period had a positive effect on the survival and hence the success of the stocking. All the groups released were monitored daily until day 8, using a juvenile flatfish-trawl to recapture the fish. The catches were analyzed on the basis of a normal distribution approximation method, founded in diffusion theory, from which daily abundance of the released fish and hence post-release mortality could be estimated. The group of Large turbot suffered negligible post-release mortality, but for the Conditioned, Naive and Intermediate groups the loss varied between 34 and 66% d - 1 . The mortality for the Conditioned group was found to be half that of the Naive turbot released simultaneously. The period of high post-release mortality was estimated to be restricted to three days after release. The only active predators observed in the area were birds. Besides estimating mortality the diffusion model provides an estimate on the catchability of the released turbot when fished with a juvenile flatfish-trawl. Catchabilities varied between 38 and 52% for all releases except for the 17 cm sized turbot released, where catchability was only 12%. The feeding performance of the released fish was also analysed and compared with that of wild fish caught at the

  10. Nuuk, Greenland

    NASA Technical Reports Server (NTRS)

    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.

  11. Biogeochemical Indicators in High- and Low-Arctic Marine and Terrestrial Avian Community Changes: Comparative Isotopic (13C, 15N, and 34S) Studies in Alaska and Greenland

    NASA Astrophysics Data System (ADS)

    Causey, D.; Bargmann, N. A.; Burnham, K. K.; Burnham, J. L.; Padula, V. M.; Johnson, J. A.; Welker, J. M.

    2011-12-01

    Understanding the complex dynamics of environmental change in northern latitudes is of paramount importance today, given documented rapid shifts in sea ice, plant phenology, temperatures, deglaciation, and habitat fidelity. This knowledge is particularly critical for Arctic avian communities, which are integral components by which biological teleconnections are maintained between the mid and northern latitudes. Furthermore, Arctic birds are fundamental to Native subsistence lifestyles and a focus for conservation activities. Avian communities of marine and terrestrial Arctic environments represent a broad spectrum of trophic levels, from herbivores (eg., geese Chen spp.), planktivores (eg., auklets Aethia spp.), and insectivores (eg., passerines: Wheatears Oenanthe spp., Longspurs Calcarius spp.), to predators of marine invertebrates (eg., eiders Somateria spp.), nearshore and offshore fish (eg., cormorants Phalacrocorax spp, puffins Fratercula spp.), even other bird species (eg., gulls Larus spp., falcons Peregrinus spp.). This diversity of trophic interconnections is an integral factor in the dynamics of Arctic ecosystem ecology, and they are key indicators for the strength and trajectories of change. We are especially interested in their feeding ecology, using stable isotope-diet relations to examine historical diets and to predict future feeding ecology by this range of species. Since 2009, we have been studying the foodweb ecology using stable isotopes (δ13C, δ15N, δ34S) of contemporaneous coastal and marine bird communities in High Arctic (Northwest Greenland) and Low Arctic (western Aleutian Islands, AK). We are quantifying the isotopic values of blood, organ tissues, and feathers, and have carried out comparisons between native and lipid-extracted samples. Although geographically distant, these communities comprise similar taxonomic and ecological congeners, including several species common to both (eg., Common Eider, Black-legged Kittiwake, Northern

  12. A Microsatellite Genetic Map of the Turbot (Scophthalmus maximus)

    PubMed Central

    Bouza, Carmen; Hermida, Miguel; Pardo, Belén G.; Fernández, Carlos; Fortes, Gloria G.; Castro, Jaime; Sánchez, Laura; Presa, Pablo; Pérez, Montse; Sanjuán, Andrés; de Carlos, Alejandro; Álvarez-Dios, José Antonio; Ezcurra, Susana; Cal, Rosa M.; Piferrer, Francesc; Martínez, Paulino

    2007-01-01

    A consensus microsatellite-based linkage map of the turbot (Scophthalmus maximus) was constructed from two unrelated families. The mapping panel was derived from a gynogenetic family of 96 haploid embryos and a biparental diploid family of 85 full-sib progeny with known linkage phase. A total of 242 microsatellites were mapped in 26 linkage groups, six markers remaining unlinked. The consensus map length was 1343.2 cM, with an average distance between markers of 6.5 ± 0.5 cM. Similar length of female and male maps was evidenced. However, the mean recombination at common intervals throughout the genome revealed significant differences between sexes, ∼1.6 times higher in the female than in the male. The comparison of turbot microsatellite flanking sequences against the Tetraodon nigroviridis genome revealed 55 significant matches, with a mean length of 102 bp and high sequence similarity (81–100%). The comparative mapping revealed significant syntenic regions among fish species. This study represents the first linkage map in the turbot, one of the most important flatfish in European aquaculture. This map will be suitable for QTL identification of productive traits in this species and for further evolutionary studies in fish and vertebrate species. PMID:18073440

  13. Effects of bacteria on the growth of an amoeba infecting the gills of turbot.

    PubMed

    Paniagua, E; Paramá, A; Iglesias, R; Sanmartín, M L; Leiro, J

    2001-05-04

    We analysed the influence of various bacteria on the in vitro growth of trophozoites of a Platyamoeba strain isolated from diseased gill tissues of cultured turbot. Little or no growth was shown by amoebae cultured in the presence of (1) the turbot-pathogenic bacteria Vibrio anguillarum, Aeromonas salmonicida or Streptococcus sp., (2) Pasteurella piscicida or Vibrio vulnificus (pathogenic for some fishes but not turbot), or (3) the non-pathogenic 'environmental' bacteria Vibrio campbelli, Vibrio fluvialis or Pseudomonas dondorofii. The only bacteria which were successfully utilized as food sources were Aeromonas hydrophila (pathogenic for some fishes but not turbot) and the non-pathogens Vibrio natriegens, Pseudomonas nautica and Escherichia coli. These results suggest that the colonization of the gills of cultured turbot by the epizoic amoeba Platyamoeba may be an indicator of faecal contamination.

  14. Turbot (Scophthalmus maximus) vs. VHSV (Viral Hemorrhagic Septicemia Virus): A Review.

    PubMed

    Pereiro, Patricia; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Turbot (Scophthalmus maximus) is a very valuable fish species both in Europe and China. The culture of this flatfish is well-established but several bacteria, viruses, and parasites can produce mortality or morbidity episodes in turbot farms. Viral Hemorrhagic Septicemia Virus (VHSV) is one of the most threatening pathogens affecting turbot, because neither vaccines nor treatments are commercially available. Although the mortality in the turbot farms is relatively low, when this virus is detected all the stock have to be destroyed. The main goals that need to be improved in order to reduce the incidence of this disease is to know what are the strategies or molecules the host use to fight the virus and, in consequence, try to potentiate this response using different ways. Certain molecules can be selected as potential antiviral treatments because of their high protective effect against VHSV. On the other hand, the use of resistance markers for selective breeding is one of the most attractive approaches. This review englobes all the investigation concerning the immune interaction between turbot and VHSV, which until the last years was very scarce, and the knowledge about VHSV-resistance markers in turbot. Nowadays, the availability of abundant transcriptomic information and the recent sequencing of the turbot genome open the door to a more exhaustive and profuse investigation in these areas.

  15. Development of an inactivated iridovirus vaccine against turbot viral reddish body syndrome

    NASA Astrophysics Data System (ADS)

    Fan, Tingjun; Hu, Xiuzhong; Wang, Liyan; Geng, Xiaofen; Jiang, Guojian; Yang, Xiuxia; Yu, Miaomiao

    2012-03-01

    Turbot ( Scophthalmus maximus L.) reddish body iridovirus (TRBIV) was propagated in turbot fin cells (TF cells) and inactivated as the TRBIV vaccine with its protection efficiency evaluated in this study. TF cells were cultured in 10% bovine calf serum (BCS)-containing MEM medium (pH7.0) at 22°C, in which TRBIV propagated to a titer as high as 105.6 TCID50 mL-1. The TRBIV was inactivated with 0.1% formalin and formulated with 0.5% aluminum hydroxide. The inactivated vaccine caused neither cytopathogenic effect (CPE) on TF cells nor pathogenic effect on turbots. After being administered with the vaccine twice via muscle injection, the turbot developed high-tittered TRBIV neutralizing antibodies in a dose-dependent manner. The vaccine protected the turbot from dying with an immunoprotection rate of 83.3% as was determined via subcutaneous vaccination in the laboratory and 90.5% via bath vaccination in turbot farms, respectively. The inactivated vaccine was very immunogenic, efficiently preventing turbot from death. It holds the potential of being applied in aquaculture.

  16. Turbot (Scophthalmus maximus) vs. VHSV (Viral Hemorrhagic Septicemia Virus): A Review

    PubMed Central

    Pereiro, Patricia; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Turbot (Scophthalmus maximus) is a very valuable fish species both in Europe and China. The culture of this flatfish is well-established but several bacteria, viruses, and parasites can produce mortality or morbidity episodes in turbot farms. Viral Hemorrhagic Septicemia Virus (VHSV) is one of the most threatening pathogens affecting turbot, because neither vaccines nor treatments are commercially available. Although the mortality in the turbot farms is relatively low, when this virus is detected all the stock have to be destroyed. The main goals that need to be improved in order to reduce the incidence of this disease is to know what are the strategies or molecules the host use to fight the virus and, in consequence, try to potentiate this response using different ways. Certain molecules can be selected as potential antiviral treatments because of their high protective effect against VHSV. On the other hand, the use of resistance markers for selective breeding is one of the most attractive approaches. This review englobes all the investigation concerning the immune interaction between turbot and VHSV, which until the last years was very scarce, and the knowledge about VHSV-resistance markers in turbot. Nowadays, the availability of abundant transcriptomic information and the recent sequencing of the turbot genome open the door to a more exhaustive and profuse investigation in these areas. PMID:27303308

  17. Dietary protein requirement of juvenile turbot ( Scophthalmus maximus Linnaeus)

    NASA Astrophysics Data System (ADS)

    Liu, Xingwang; Mai, Kangsen; Liufu, Zhiguo; Ai, Qinghui

    2015-04-01

    The dietary protein requirement of juvenile turbot (initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with fish meal as protein source, which contained different concentrations of protein (47.2%, 51.0%, 54.6%, 59.3% and 63.6% of dry diet). Three groups of fish with 18 individuals in each, were cultured in 300-L tanks and fed twice a day for 8 weeks. During culture, temperature was controlled between 15.0 and 18.0°C, salinity was controlled between 28.5 and 32.0, acidity was controlled between pH7.8 and pH8.5, and ammonia nitrogen was maintained below 0.03 mg L-1 and dissolved oxygen was maintained about 7 mg L-1. Results showed that the growth of fish was significantly affected by dietary protein content ( P < 0.05). Specific growth rate ( SGR) of turbot increased when dietary protein content varied between 47.2% and 51.0% ( P < 0.05), and then kept stable when dietary protein content was higher than 51.0%. Fish which were fed the diet containing 63.6% protein showed the highest SGR while those fed the diet containing 59.3% protein showed the highest feed efficiency rate. No significant difference of feed intake and protein efficiency ratio was found among experimental diets ( P > 0.05). Broken-line regression analysis of SGR showed that the optimal dietary protein requirement of turbot was about 57.0%.

  18. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life

    PubMed Central

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A.; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G.; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-01-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  19. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot.

  20. The Greenland Ice Mapping Project

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  1. Effects of Enteromyxum scophthalmi experimental infection on the neuroendocrine system of turbot, Scophthalmus maximus (L.).

    PubMed

    Losada, A P; Bermúdez, R; Faílde, L D; Di Giancamillo, A; Domeneghini, C; Quiroga, M I

    2014-10-01

    Enteromyxum scophthalmi is an intestinal myxosporean parasite responsible for serious outbreaks in turbot Scophthalmus maximus (L.) culture, in North-western Spain. The disease affects the digestive tract, provokes severe catarrhal enteritis, emaciation and high rates of mortality. The digestive parasitization triggers a response with the coordinate participation of immune and neuroendocrine systems through the action of peptides released by enteroendocrine cells and present in nervous elements, acting as neuro-immune modulators. The present study was designed to assess the response of the turbot neuroendocrine system against E. scophthalmi infection. Immunohistochemical tests were applied to sections of the gastrointestinal tract of uninfected and E. scophthalmi-infected turbot to characterize the presence of bombesin (BOM), glucagon (GLUC), somatostatin (SOM), leu-enkephalin (LEU) and met-enkephalin (MET). The occurrence of E. scophthalmi in the turbot gastrointestinal tract increased the number of enteroendocrine cells immunoreactive to SOM, LEU and MET. On the other hand, BOM and GLUC immunoreactive cells were less numerous in the gastrointestinal tract of the parasitized turbot. Scarce immunoreactivity to BOM, GLUC and SOM was observed in nerve fibres and neurons of the myenteric plexus of control and infected fish. The results indicate that E. scophthalmi infection in turbot induced changes in the neuroendocrine system, with the diminution of the anorexigenic peptides BOM and GLUC; the increase of enkephalins, related to pro-inflammatory processes; and the increase of SOM, which may cause inhibitory effects on the immune response, constituting a compensatory mechanism to the exacerbated response observed in E. scophthalmi-infected turbot.

  2. Fine Mapping and Evolution of the Major Sex Determining Region in Turbot (Scophthalmus maximus)

    PubMed Central

    Taboada, Xoana; Hermida, Miguel; Pardo, Belén G.; Vera, Manuel; Piferrer, Francesc; Viñas, Ana; Bouza, Carmen; Martínez, Paulino

    2014-01-01

    Fish sex determination (SD) systems are varied, suggesting evolutionary changes including either multiple evolution origins of genetic SD from nongenetic systems (such as environmental SD) and/or turnover events replacing one genetic system by another. When genetic SD is found, cytological differentiation between the two members of the sex chromosome pair is often minor or undetectable. The turbot (Scophthalmus maximus), a valuable commercial flatfish, has a ZZ/ZW system and a major SD region on linkage group 5 (LG5), but there are also other minor genetic and environmental influences. We here report refined mapping of the turbot SD region, supported by comparative mapping with model fish species, to identify the turbot master SD gene. Six genes were located to the SD region, two of them associated with gonad development (sox2 and dnajc19). All showed a high association with sex within families (P = 0), but not at the population level, so they are probably partially sex-linked genes, but not SD gene itself. Analysis of crossovers in LG5 using two families confirmed a ZZ/ZW system in turbot and suggested a revised map position for the master gene. Genetic diversity and differentiation for 25 LG5 genetic markers showed no differences between males and females sampled from a wild population, suggesting a recent origin of the SD region in turbot. We also analyzed associations with markers of the most relevant sex-related linkage groups in brill (S. rhombus), a closely related species to turbot; the data suggest that an ancient XX/XY system in brill changed to a ZZ/ZW mechanism in turbot. PMID:25106948

  3. Population ecology of turbot and brill: What can we learn from two rare flatfish species?

    NASA Astrophysics Data System (ADS)

    van der Hammen, Tessa; Poos, Jan Jaap; van Overzee, Harriët M. J.; Heessen, Henk J. L.; Magnusson, Arni; Rijnsdorp, Adriaan D.

    2013-11-01

    Turbot and brill are widely distributed in the Northeast Atlantic but occur at low abundance. They are ecologically very similar and closely related. The low abundance and the similarities make them particularly interesting to study the population dynamics because it raises the questions how the populations can sustain themselves at low abundances and how turbot and brill avoid strong interspecific competition. Knowledge of both species is hampered by lack of analysed data. The main objective of this study is therefore to increase the knowledge of turbot and brill and in particular to compare the two species in order to address the above questions. Based on biological samples collected in the North Sea, we calculated seasonal von Bertalanffy growth parameters, maturity ogives, monthly gonado-somatic indices (GSI) and condition factors (Fulton's K) and indices of inter- and intraspecific mean crowding and compared the results for turbot and brill. The main differences between the two species were found in their spawning period, with brill having a more protracted spawning period. Brill also showed an earlier peak in their GSI values, suggesting an earlier start of their spawning period. The mean crowding showed that interspecific competition was lower than intraspecific competition. The exploitation pattern was also studied. Turbot and brill are exploited as a bycatch species in the mixed demersal fishery. We found that productivity is highest in areas where the maximum temperature is close to the optimal temperature for growth (16-18 °C) and landings decrease where salinity falls below ~ 5 psu (turbot) and ~ 15 psu (brill). Recent fishing mortality rates of North Sea turbot are around 0.5-0.7, but there is no indication that recruitment is impaired at low levels of spawning stock biomass. We conclude that although both species have similar ecological characteristics, differences may reduce inter-specific competition.

  4. Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

    2013-11-01

    In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

  5. Expressed sequence tags (ESTs) from immune tissues of turbot (Scophthalmus maximus) challenged with pathogens

    PubMed Central

    Pardo, Belén G; Fernández, Carlos; Millán, Adrián; Bouza, Carmen; Vázquez-López, Araceli; Vera, Manuel; Alvarez-Dios, José A; Calaza, Manuel; Gómez-Tato, Antonio; Vázquez, María; Cabaleiro, Santiago; Magariños, Beatriz; Lemos, Manuel L; Leiro, José M; Martínez, Paulino

    2008-01-01

    Background The turbot (Scophthalmus maximus; Scophthalmidae; Pleuronectiformes) is a flatfish species of great relevance for marine aquaculture in Europe. In contrast to other cultured flatfish, very few genomic resources are available in this species. Aeromonas salmonicida and Philasterides dicentrarchi are two pathogens that affect turbot culture causing serious economic losses to the turbot industry. Little is known about the molecular mechanisms for disease resistance and host-pathogen interactions in this species. In this work, thousands of ESTs for functional genomic studies and potential markers linked to ESTs for mapping (microsatellites and single nucleotide polymorphisms (SNPs)) are provided. This information enabled us to obtain a preliminary view of regulated genes in response to these pathogens and it constitutes the basis for subsequent and more accurate microarray analysis. Results A total of 12584 cDNAs partially sequenced from three different cDNA libraries of turbot (Scophthalmus maximus) infected with Aeromonas salmonicida, Philasterides dicentrarchi and from healthy fish were analyzed. Three immune-relevant tissues (liver, spleen and head kidney) were sampled at several time points in the infection process for library construction. The sequences were processed into 9256 high-quality sequences, which constituted the source for the turbot EST database. Clustering and assembly of these sequences, revealed 3482 different putative transcripts, 1073 contigs and 2409 singletons. BLAST searches with public databases detected significant similarity (e-value ≤ 1e-5) in 1766 (50.7%) sequences and 816 of them (23.4%) could be functionally annotated. Two hundred three of these genes (24.9%), encoding for defence/immune-related proteins, were mostly identified for the first time in turbot. Some ESTs showed significant differences in the number of transcripts when comparing the three libraries, suggesting regulation in response to these pathogens. A total of

  6. Differentiation of farmed and wild turbot (Psetta maxima): proximate chemical composition, fatty acid profile, trace minerals and antimicrobial resistance of contaminant bacteria.

    PubMed

    Martínez, B; Miranda, J M; Nebot, C; Rodriguez, J L; Cepeda, A; Franco, C M

    2010-10-01

    The proximate, cholesterol, fatty acid and trace mineral compositions in the flesh of farmed and wild turbot (Psetta maxima) were evaluated. Additionally, the potential influence of the use of antimicrobial agents in the bacteria carried by farmed turbot was investigated. For this purpose, a total of 144 Pseudomonas spp. and 127 Aeromonas spp. were isolated and tested for their susceptibility to 12 antimicrobials by a disk diffusion method. Farmed turbot contained higher fat, cholesterol and calories as well as lower moisture content than its wild counterpart. The fatty acid profile of farmed turbot included higher levels of myristic, pentadecanoic, palmitoleic, gadoleic, cetoleic, linoleic, linolenic, stearidonic, eicosadienoic and eicosapentaenoic acids, and lower levels of stearic, arachidonic, docosapentaenoic and docosahexaenoic acids than its wild counterpart. The proportions of polyunsaturated fatty acids and n-3/n-6 ratios were higher in wild turbot than in farmed turbot. With respect to trace minerals, no toxic levels were found, and higher amounts of Cd, Co, Cu, Fe, Mn, Pb and Zn, as well as lower amounts of Cr, were found in farmed turbot relative to wild turbot. The antimicrobial resistance of Pseudomonas spp. and Aeromonas spp. were quite similar, with only the trimethoprim-sulfamethoxazole resistance of Aeromonas spp. isolated from farmed turbot being higher than those isolated from wild turbot. In the case of ampicillin, Pseudomonas spp. isolated from wild turbot showed higher resistance levels than those of their counterparts isolated from farmed turbot. In conclusion, the nutritional parameters of wild turbot are more adequate with respect to nutritional recommendations, while no differences were observed in food safety derived from trace mineral concentrations or the antimicrobial resistance of bacteria isolated from wild and farmed turbot.

  7. Chemokine receptor CXCR3 in turbot (Scophthalmus maximus): cloning, characterization and its responses to lipopolysaccharide.

    PubMed

    Chen, Yadong; Zhou, Shuhong; Jiang, Zhiqiang; Wang, Xiuli; Liu, Yang

    2016-04-01

    Chemokine (C-X-C motif) receptor 3, a member of the G protein-coupled receptors superfamily, regulates the responses of many immune responses. In this experiment, we cloned and characterized the cDNA of CXCR3 in Scophthalmus maximus (turbot). A 5'-UTR of 216-bp, a 259-bp 3'-UTR with a poly (A) tail and a 1089-bp CDS encoding 362 amino acids form the cDNA of CXCR3, which is 1564-bp long. Phylogenetic analyses indicated that turbot CXCR3 shared a high similarity with other CXCR3s and shared more similarity with CXCR5 than the other subfamilies of chemokines. The CXCR3 protein in turbot showed the highest similarity with the CXCR3b from rainbow trout (44.5%), which indicated that this CXCR3 gene/protein may be a CXCR3b isoform. Quantitative real-time PCR analysis showed that CXCR3 transcripts were constitutively expressed in all the tissues of the non-injected turbot used in this study, with the highest expression occurring in blood. Several immune-related tissues of fish, such as the spleen, head kidney, liver and blood, tissues, which were abundant of lymphocyte, were investigated in this study. CXCR3 gene was expressed at the highest level in blood than the other tested tissues. The injection experiment suggested that the CXCR3 expression level after LPS injection was significantly up-regulated in all immune-related tissues in turbot. These results improve our understanding of the functions of CXCR3 in the turbot immune response.

  8. Greenland Ice Flow

    NASA Video Gallery

    Greenland looks like a big pile of snow seen from space using a regular camera. But satellite radar interferometry helps us detect the motion of ice beneath the snow. Ice starts flowing from the fl...

  9. Entering uncharted waters: Long-term dynamics of two data limited fish species, turbot and brill, in the North Sea

    NASA Astrophysics Data System (ADS)

    Kerby, Tina K.; Cheung, William W. L.; van Oosterhout, Cock; Engelhard, Georg H.

    2013-11-01

    In the North Sea, turbot (Scophthalmus maximus) and brill (Scophthalmus rhombus) represent highly valuable species in commercial fisheries. Still, available data for both species are limited, making stock assessment difficult. Long-term fisheries data have the potential to improve the understanding of stock dynamics such as long-term distribution changes or development in species' abundances. Historical British otter trawler lpue (landings-per-unit-effort) data from 1923 to 2009, and at the spatial scale of ICES rectangles, revealed that the distribution patterns of turbot and brill were different for most of the 20th century and only became similar in the recent decade. Further, between the 1920s and 1960s, turbot was commonly caught in the northern North Sea and in particular on Turbot Bank, at that time a turbot hotspot off the east coast of Scotland. Within a short time period turbot nearly disappeared from this region. Brill, in contrast, revealed a stable distribution in the southern and central North Sea with a slow expansion into the central North Sea. We used survey cpue (catch-per-unit-effort) from the International Bottom Trawl Survey (IBTS; 1970-2009) and the Beam Trawl Survey (BTS; 1985-2009), as well as British otter trawler lpue, as proxies for the abundance of adult turbot and brill. Commercial lpue suggested for brill and turbot a long-term decrease in abundance. IBTS cpue suggested an increase in abundance for turbot, but this was not confirmed by the BTS. For brill, both surveys did not show a clear trend.

  10. Flying Low over Southeast Greenland

    NASA Video Gallery

    Few of us ever get to see Greenland's glaciers from 500 meters above the ice. But in this video — recorded on April 9,2013 in southeast Greenland using a cockpit camera installed and operated by ...

  11. Genomic Sequencing of Ranaviruses Isolated from Turbot (Scophthalmus maximus) and Atlantic Cod (Gadus morhua)

    PubMed Central

    Steckler, Natalie K.; Olesen, Niels J.; Waltzek, Thomas B.

    2016-01-01

    Ranaviruses have been isolated from Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus) in Denmark. Phylogenomic analyses revealed that these two ranaviruses are nearly identical and form a distinct clade at the base of the ranavirus tree branching off near other fish ranaviruses. PMID:27979944

  12. Morphological, immunohistochemical and ultrastructural characterization of the skin of turbot (Psetta maxima L.).

    PubMed

    Faílde, L D; Bermúdez, R; Vigliano, F; Coscelli, G A; Quiroga, M I

    2014-10-01

    This study was undertaken to identify the normal morphologic, immunohistochemical and ultrastructural features of skin of the turbot (Psetta maxima L.). In the turbot skin, three morphologically distinct layers were identified: epidermis, dermis and hypodermis. The epidermis was non-keratinizing, stratified squamous epithelium that varies in thickness from 5 to 14 cells and 60 to 100μm in size. Goblet cells were seen randomly distributed between malpighian cells in the epidermal layer. These mucous cells were mainly located in the upper third of the epidermis and displayed a spherical to elongated morphology. Dermis was divided in two well-differentiated layers, the superficial stratum laxum and the deeper stratum compactum. Hypodermis was a loose layer mainly composed by adipocytes but we could observe variable amounts of fibroblast, collagen and blood vessels. In turbot two pigmentary layers could be identified: the pigmentary layer of dermis was located between basement membrane and dermis and the pigmentary layer of hypodermis immediately above the muscular layer. Three different types of chromatophores were present: melanophores, iridophores and xanthophores. The main differences observed between groups of fish with different colouration were in the amount of melanophores and xanthophores. The purpose of this article is to provide an overview of normal cutaneous biology prior to consideration of specific cutaneous alterations and diseases in turbot.

  13. Pharmacokinetics and acetylation of sulfamethoxazole in turbot Scophthalmus maximus after intravascular administration

    NASA Astrophysics Data System (ADS)

    Chang, Zhiqiang; Liu, Fei; Lian, Chun'ang; Zhai, Qianqian; Li, Jian

    2016-07-01

    The pharmacokinetic profiles and sulfamethoxazole (SMX) acetylation process in turbot reared at 18°C were investigated. Either SMX (parent drug) or its acetylized metabolite, N4-acetylsulfamethoxazole (AcSMX), was administered intravascularly to turbot at a dosage of 50 mg/kg BW. Serum concentrations of the parent drug and its metabolite were both measured by HPLC, and the changes in concentration over time were analyzed in two- and non-compartment models because SMX treatment produced multiple peaks. The results demonstrated that the elimination half-life of the parent drugs, SMX and AcSMX, were 159.2 and 5.9 h, respectively. The apparent volume of distribution was 0.2 and 0.8 L/kg, and the clearance was 0.038 and 0.222 L/(h·kg), for SMX and AcSMX, respectively. SMX acetylation in turbot was 2.8%, and the deacetylation of AcSMX was 0.2%. These findings may be useful in optimizing SMX dosage regimens in turbot aquaculture.

  14. Enhancing the culturability of bacteria from the gastrointestinal tract of farmed adult turbot Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Xing, Mengxin; Hou, Zhanhui; Qu, Yanmei; Liu, Bin

    2014-03-01

    Eighteen agar media were tested for the culture of gut-associated bacteria from farmed adult turbot ( Scophthalmus maximus), including 16 agar media with or without 1% gastrointestinal (GI) supernatant, or with 2% or 4% GI supernatant. A total of 1 711 colonies were analyzed and 24 operational taxonomic units (OTUs) were identified. The greatest bacterial diversity was isolated on Zobell 2216E/Zobell 2216E+ agar media, whereas MRS/MRS+ agar media produced a low diversity of colonies. Agar media with GI supernatant (1%, 2%, or 4%) showed increased diversity and yielded different profiles of OTUs from the corresponding original media, suggesting that GI supernatant provides substances that enhance the culture efficiency of bacteria from the turbot GI tract. The large majority of the colonies (82%) were γ-Proteobacteria, whereas 15.6% and 2.4% of colonies were Firmicutes and Actinobacteria, respectively. At the genus level, 49.4% of all colonies were assigned to Vibrio. Other potential pathogens, including Pseudomonas, Photobacterium, and Enterobacter, and potential probiotics, including Bacillus, Paenibacillus, and Pseudomonas, were also isolated on agar media. Most cultured bacteria belonged to species that were first described in the turbot GI tract. The impact of these species on turbot physiology and health should be investigated further.

  15. UNIT, ALASKA.

    ERIC Educational Resources Information Center

    Louisiana Arts and Science Center, Baton Rouge.

    THE UNIT DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY OF ALASKA. THE UNIT IS PRESENTED IN OUTLINE FORM. THE FIRST SECTION DEALS PRINCIPALLY WITH THE PHYSICAL GEOGRAPHY OF ALASKA. DISCUSSED ARE (1) THE SIZE, (2) THE MAJOR LAND REGIONS, (3) THE MOUNTAINS, VOLCANOES, GLACIERS, AND RIVERS, (4) THE NATURAL RESOURCES, AND (5) THE CLIMATE. THE…

  16. Molecular characterization and quantification of estrogen receptors in turbot (Scophthalmus maximus).

    PubMed

    Hu, Peng; Meng, Zhen; Jia, Yudong

    2017-01-10

    Estrogens regulate various reproductive processes via estrogen receptor (ER)-mediated signaling pathway in vertebrates. In this study, full-length sequences coding for ERα, ERβ1 and ERβ2 were isolated from female turbot (Scophthalmus maximus) by homology cloning and a strategy based on rapid amplification of cDNA end-polymerase chain reaction (RACE-PCR). The nucleotide and amino acid sequences of turbot ERs showed high homologies with the corresponding sequences of other fish species and significant homology with the Japanese flounder (Paralichthys olivaceus) and the European sea bass (Dicentrarchus labrax). Turbot ERs contained six typical nuclear receptor-characteristic domains and exhibited high evolutionary conservation in the functional domains. Quantitative real-time polymerase chain reaction analysis revealed that the erα and erβ (β1, β2) mRNAs were abundant in the liver and ovary, respectively. Furthermore, hepatic mRNA levels of erα and vitellogenin (vtg) were found increased gradually from pre-vitellogenesis to late-vitellogenesis stages, with the highest values observed at the late-vitellogenesis stage, and then decreased from migratory-nucleus to atresia stages. However, mRNA levels of erα in the ovary remained unchanged during ovarian development. Hepatosomatic index, gonadosomatic index, serum estradiol-17β and the mRNA levels of erβ1 and erβ2 in the ovary manifested results similar to the expression of erα mRNAs in the liver. These findings indicated that ERα is mainly involved in hepatic vitellogenesis, and ERβs may play crucial roles to regulate ovarian development in turbot. Overall, this study improves understanding of the physiological functions of turbot ERs, which will be valuable for fish reproduction and broodstock management.

  17. Glaciers of Greenland

    USGS Publications Warehouse

    Williams, Richard S.; Ferrigno, Jane G.

    1995-01-01

    Landsat imagery, combined with aerial photography, sketch maps, and diagrams, is used as the basis for a description of the geography, climatology, and glaciology, including mass balance, variation, and hazards, of the Greenland ice sheet and local ice caps and glaciers. The Greenland ice sheet, with an estimated area of 1,736,095+/-100 km2 and volume of 2,600,000 km3, is the second largest glacier on the planet and the largest relict of the Ice Age in the Northern Hemisphere. Greenland also has 48,599+/-100 km2 of local ice caps and other types of glaciers in coastal areas and islands beyond the margin of the ice sheet.

  18. Signal transducer and activator of transcription 3 (STAT3) homologue in turbot (Scophthalmus maximus): molecular characterization and expression analysis.

    PubMed

    Wang, Na; Yang, Chang-Geng; Sun, Zhong-Zhi; Wang, Xian-Li; Chen, Song-Lin

    2011-01-01

    Signal transducer and activator of transcription 3 (STAT3) acts as an important mediator in multiple biological processes induced by different cytokines. So far, little information is available in fish STAT3. In this study, turbot (Scophthalmus maximus) STAT3 gene was cloned and characterized for the first time. The turbot STAT3 full-length cDNA consists of 2355 nucleotides encoding a polypeptide of 784 amino acids with four conserved domains including STAT_int, STAT_alpha, STAT_bind and SH2 domain. The phylogenetic tree showed that turbot STAT3 shared the closest relationship with mandarin fish (Siniperca chuatsi) STAT3. The autoactivation experiment in yeast proved that turbot STAT3 was a strong transcription factor. The quantitative RT-PCR experiment indicated that Stat3 mRNA was expressed in widespread tissues with the highest expression levels in the liver. And the further expression patterns analysis revealed that turbot Stat3 expression levels were increased in liver, spleen, kidney of fish infected with Vibrio anguillarum and liver of fish infected with LCDV. Meantime, hepcidin, one of STAT3 target gene, was also up-regulated in liver of fish infected with two pathogens. These results suggested that turbot Stat3 may involved in the immune defense process as a transcription factor.

  19. Regional Observations of Alaska Glacier Dynamics

    NASA Astrophysics Data System (ADS)

    Burgess, E. W.; Forster, R. R.; Hall, D. K.

    2010-12-01

    Alaska glaciers contribute more to sea level rise than any other glacierized mountain region in the world. Alaska is loosing ~84 Gt of ice annually, which accounts for ~0.23 mm/yr of SLR (Luthcke et al., 2008). Complex glacier flow dynamics, frequently related to tidewater environments, is the primary cause of such rapid mass loss (Larsen et al., 2007). Indirect observations indicate these complex flow dynamics occur on many glaciers throughout Alaska, but no comprehensive velocity measurements exist. We are working to measure glacier surface velocities throughout Alaska using synthetic aperture radar (SAR) offset tracking. This work focuses on the Seward/Malaspina, Bering, Columbia, Kaskawulsh, and Hubbard Glaciers and uses a MODIS land surface temperature "melt-day" product (Hall et al., 2006, 2008) to identify potential links between velocity variability and summertime temperature fluctuations. Hall, D., R. Williams Jr., K. Casey, N. DiGirolamo, and Z. Wan (2006), Satellite-derived, melt-season surface temperature of the Greenland Ice Sheet (2000-2005) and its relationship to mass balance, Geophysical Research Letters, 33(11). Hall, D., J. Box, K. Casey, S. Hook, C. Shuman, and K. Steffen (2008), Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over Greenland, Remote Sensing of Environment, 112(10), 3739-3749. Larsen, C. F., R. J. Motyka, A. A. Arendt, K. A. Echelmeyer, and P. E. Geissler (2007), Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise, J. Geophys. Res. Luthcke, S., A. Arendt, D. Rowlands, J. McCarthy, and C. Larsen (2008), Recent glacier mass changes in the Gulf of Alaska region from GRACE mascon solutions, Journal of Glaciology, 54(188), 767-777.

  20. The Wegener Memorial Expedition to the Greenland Caledonides

    NASA Astrophysics Data System (ADS)

    Stüwe, Kurt; Piller, Werner

    2014-05-01

    2012 marked the 100 anniversary of the publication of Alfred Wegeners book: 'Die Entstehung der Kontinente' - which is often hailed as the discovery of continental drift theory in the advent of plate tectonics. Wegener was later appointed as professor for geophysics at the University of Graz in Austria - in part for this discovery. He held this position until his death in Greenland in 1930. In honor of the hundredth anniversary of the 1912 milestone publication, the University of Graz in Austria stages an expedition to Greenland in the spirit of Alfred Wegener, supported by the Austrian Academy of Sciences. The expedition aims predominantly to unravel secrets of the Caledonides of Northeastern Greenland using an extensive sampling program to some of the least explored corners of the orogenic belt. Particular emphasis will be placed on the Hager Bjerg allochthon and its relationship to the hanging wall and footwall units. The expedition will use the unparalleled flexibility of small aircraft that will be piloted by experienced Alaskan bush pilots and brought to Greenland from Alaska for this purpose.

  1. Accumulation of polychlorinated biphenyls in turbot (Scophthalmus maximus) from seawater sediments and food

    NASA Astrophysics Data System (ADS)

    Courtney, W. A. M.; Langston, W. J.

    1980-03-01

    Juvenile turbot, Scophthalmus maximus (L.), were exposed to 0.58 µg 1-1 Aroclor 1254 in seawater, to sediments containing 100, 60 and 1 ppm or fed with cockle containing 20 ppm PCB (polychlorinated biphenyls). Concentration factors for liver and muscle were 104 and 103, respectively, for uptake of PCB from seawater. Contamination of muscle was similar to that of sediments containing 1 and 60 ppm PCB to which turbot were exposed, but less than the 20 ppm in their experimental diet. Contamination of flatfish in the North Sea area is compared with the levels of PCB in the flounder, Platichthys flesus (L.), in the River Thames and predictable values for uptake of PCB from different pathways discussed.

  2. Transcriptome profiles associated to VHSV infection or DNA vaccination in turbot (Scophthalmus maximus).

    PubMed

    Pereiro, Patricia; Dios, Sonia; Boltaña, Sebastián; Coll, Julio; Estepa, Amparo; Mackenzie, Simon; Novoa, Beatriz; Figueras, Antonio

    2014-01-01

    DNA vaccines encoding the viral G glycoprotein show the most successful protection capability against fish rhabdoviruses. Nowadays, the molecular mechanisms underlying the protective response remain still poorly understood. With the aim of shedding light on the protection conferred by the DNA vaccines based in the G glycoprotein of viral haemorrhagic septicaemia virus (VHSV) in turbot (Scophthalmus maximus) we have used a specific microarray highly enriched in antiviral sequences to carry out the transcriptomic study associated to VHSV DNA vaccination/infection. The differential gene expression pattern in response to empty plasmid (pMCV1.4) and DNA vaccine (pMCV1.4-G860) intramuscular administration with regard to non-stimulated turbot was analyzed in head kidney at 8, 24 and 72 hours post-vaccination. Moreover, the effect of VHSV infection one month after immunization was also analyzed in vaccinated and non-vaccinated fish at the same time points. Genes implicated in the Toll-like receptor signalling pathway, IFN inducible/regulatory proteins, numerous sequences implicated in apoptosis and cytotoxic pathways, MHC class I antigens, as well as complement and coagulation cascades among others were analyzed in the different experimental groups. Fish receiving the pMCV1.4-G860 vaccine showed transcriptomic patterns very different to the ones observed in pMCV1.4-injected turbot after 72 h. On the other hand, VHSV challenge in vaccinated and non-vaccinated turbot induced a highly different response at the transcriptome level, indicating a very relevant role of the acquired immunity in vaccinated fish able to alter the typical innate immune response profile observed in non-vaccinated individuals. This exhaustive transcriptome study will serve as a complete overview for a better understanding of the crosstalk between the innate and adaptive immune response in fish after viral infection/vaccination. Moreover, it provides interesting clues about molecules with a potential

  3. Effects of stocking density on antioxidant status, metabolism and immune response in juvenile turbot (Scophthalmus maximus).

    PubMed

    Liu, Baoliang; Jia, Rui; Han, Cen; Huang, Bin; Lei, Ji-Lin

    2016-12-01

    This study was designed to evaluate the physiological and immune responses of juvenile turbot to stocking density. Turbot (average weight 185.4g) were reared for 120days in a land based recirculating aquaculture system (RAS) under three stocking densities: low density (LD, ~9.3-26.1kg/m(2), initial to final density), medium density (MD, ~13.6-38.2kg/m(2)) and high density (HD, ~19.1-52.3kg/m(2)). Fish were sampled at days 0, 40, 80 and 120 to obtain growth parameters and liver tissues. No significant difference was detected in growth, biochemical parameters and gene expression among the three densities until at the final sampling (day 120). At the end of this trial, fish reared in HD group showed lower specific growth rate (SGR) and mean weight than those reared in LD and MD groups. Similarly, oxidative stress and metabolism analyses represented that antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione (GSH)) and metabolic enzymes (glycerol-3-phosphate dehydrogenase (G3PDH) and glucose-6-phosphate dehydrogenase (G6PDH)) clearly reduced in the liver of turbot reared in HD group. The gene expression data showed that glutathione S-transferase (GST), cytochrome P450 1A (CYP1A), heat shock protein 70 (HSP 70) and metallothionein (MT) mRNA levels were significantly up-regulated, and lysozyme (LYS) and hepcidin (HAMP) mRNA levels were significantly down-regulated in HD group on day 120. Overall, our results indicate that overly high stocking density might block the activities of metabolic and antioxidant enzymes, and cause physiological stress and immunosuppression in turbot.

  4. Immunohistochemical detection and gene expression of TNFα in turbot (Scophthalmus maximus) enteromyxosis.

    PubMed

    Ronza, Paolo; Bermúdez, Roberto; Losada, Ana Paula; Sitjà-Bobadilla, Ariadna; Pardo, Belén G; Quiroga, María Isabel

    2015-11-01

    Enteromyxum scophthalmi (Myxozoa) constitutes one of the most devastating pathogens for turbot (Scophthalmus maximus, L.) aquaculture. This parasite causes a severe intestinal parasitosis that leads to a cachectic syndrome with high morbidity and mortality rates for which no therapeutic options are available. Presence of inflammatory infiltrates, increased apoptotic rates and epithelial detaching have been described at intestinal level, as well as leukocyte depletion in lymphohaematopoietic organs. Previous investigations on enteromyxosis in turbot showed the high susceptibility of this species to the parasite and reported the existence of a dysregulated immune response against the parasite. The pleiotropic cytokine tumour necrosis factor alpha (TNFα) plays a major role in immune response and is involved in a wide range of biological activities. In teleost, the gene expression of this cytokine has been found regulated under several pathological conditions. Teleost TNFα shows some analogous functions with its mammalian counterparts, but the extent of its activities is still poorly understood. Cytokines are generally considered as a double-edge sword and TNFα has been implicated in the pathogenesis of different inflammatory diseases as well as in wasting syndromes described in mammals. The aim of this work was to analyse the expression of TNFα during enteromyxosis with molecular (Q-PCR) and morphological (immunohistochemistry) tools. Kidney, spleen and pyloric caeca from turbot with moderate and severe infections were analysed and compared to healthy naïve fish. TNFα expression was increased in both spleen and kidney in the earlier stages of the disease, whereas in severely infected fish, the expression decreased, especially in kidney. At the intestinal level, an increase in the number of TNFα-positive cells was noticed, which was proportional to the infiltration of inflammatory cells. The results demonstrate the involvement of TNFα in the immune response to

  5. Identification of the Major Sex-Determining Region of Turbot (Scophthalmus maximus)

    PubMed Central

    Martínez, Paulino; Bouza, Carmen; Hermida, Miguel; Fernández, Jesús; Toro, Miguel Angel; Vera, Manuel; Pardo, Belén; Millán, Adrián; Fernández, Carlos; Vilas, Román; Viñas, Ana; Sánchez, Laura; Felip, Alicia; Piferrer, Francesc; Ferreiro, Isabel; Cabaleiro, Santiago

    2009-01-01

    Sex determination in fish is a labile character in evolutionary terms. The sex-determining (SD) master gene can differ even between closely related fish species. This group is an interesting model for studying the evolution of the SD region and the gonadal differentiation pathway. The turbot (Scophthalmus maximus) is a flatfish of great commercial value, where a strong sexual dimorphism exists for growth rate. Following a QTL and marker association approach in five families and a natural population, we identified the main SD region of turbot at the proximal end of linkage group (LG) 5, close to the SmaUSC-E30 marker. The refined map of this region suggested that this marker would be 2.6 cM and 1.4 Mb from the putative SD gene. This region appeared mostly undifferentiated between males and females, and no relevant recombination frequency differences were detected between sexes. Comparative genomics of LG5 marker sequences against five model species showed no similarity of this chromosome to the sex chromosomes of medaka, stickleback, and fugu, but suggested a similarity to a sex-associated QTL from Oreochromis spp. The segregation analysis of the closest markers to the SD region demonstrated a ZW/ZZ model of sex determination in turbot. A small proportion of families did not fit perfectly with this model, which suggests that other minor genetic and/or environmental factors are involved in sex determination in this species. PMID:19786621

  6. Combined antiparasitic and anti-inflammatory effects of the natural polyphenol curcumin on turbot scuticociliatosis.

    PubMed

    Mallo, N; DeFelipe, A P; Folgueira, I; Sueiro, R A; Lamas, J; Leiro, J M

    2017-02-01

    The histiophagous scuticociliate Philasterides dicentrarchi is the aetiological agent of scuticociliatosis, a parasitic disease of farmed turbot. Curcumin, a polyphenol from Curcuma longa (turmeric), is known to have antioxidant and anti-inflammatory properties. We investigated the in vitro effects of curcumin on the growth of P. dicentrarchi and on the production of pro-inflammatory cytokines in turbot leucocytes activated by parasite cysteine proteases. At 100 μm, curcumin had a cytotoxic effect and completely inhibited the growth of the parasite. At 50 μm, curcumin inhibited the protease activity of the parasite and expression of genes encoding two virulence-associated proteases: leishmanolysin-like peptidase and cathepsin L-like. At concentrations between 25 and 50 μm, curcumin inhibited the expression of S-adenosyl-L-homocysteine hydrolase, an enzyme involved in the biosynthesis of the amino acids methionine and cysteine. At 100 μm, curcumin inhibited the expression of the cytokines tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) produced in turbot leucocytes activated by parasite proteases. Results show that curcumin has a dual effect on scuticociliatosis: an antiparasitic effect on the catabolism and anabolism of ciliate proteins, and an anti-inflammatory effect that inhibits the production of proinflammatory cytokines in the host. The present findings suggest the potential usefulness of this polyphenol in treating scuticociliatosis.

  7. Genotypic diversity of Vibrio isolates associated with turbot (Scophthalmus maximus) culture.

    PubMed

    Montes, Mercedes; Farto, Rosa; Pérez, María J; Armada, Susana P; Nieto, Teresa P

    2006-06-01

    One hundred environmental strains of Vibrio isolated from seawater and skin of healthy turbot in an aquaculture system were analyzed. Chromosomal DNA was digested with HindIII and MluI, and hybridized using a digoxigenin-labeled probe complementary to 16S and 23S rRNA of Escherichia coli. Nineteen riboclusters were defined by ribotyping analysis at a value of SD> or = 70%, using the Dice coefficient (S(D)) and UPGMA. The phylogenetic position of each ribocluster was achieved by 16S rRNA gene sequencing of representative isolates. Both techniques were necessary and useful for identifying the isolates. V. parahaemolyticus, V. scophthalmi, V. splendidus-V. lentus related group, V. halioticoli, V. fischeri and V. ichthyoenteri were identified and clustered separately. Their ribocluster diversity was studied. Throughout the year, ribotypic profiles of corresponding strains isolated from both seawater and turbot skin appeared, indicating that environmental strains can easily colonize turbot. No correspondence between riboclusters and the season of isolation was found. Some ribotypes had been found in previous studies, demonstrating that ribotyping is a useful tool for monitoring environmental isolates and to finding strains that can colonize aquatic organisms and are able to produce outbreaks. The ribotype schemes defined here can be used as a ribotype database of environmental isolates of these species.

  8. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    PubMed Central

    Manthey-Karl, Monika; Lehmann, Ines; Ostermeyer, Ute; Schröder, Ute

    2016-01-01

    To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus) and barramundi (Lates calcarifer) and of farmed pangasius (Pangasianodon hypophthalmus). The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1) were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable. PMID:28231154

  9. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi.

    PubMed

    Manthey-Karl, Monika; Lehmann, Ines; Ostermeyer, Ute; Schröder, Ute

    2016-08-30

    To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus) and barramundi (Lates calcarifer) and of farmed pangasius (Pangasianodon hypophthalmus). The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg(-1)) were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable.

  10. Endocrine alteration and other biochemical responses in juvenile turbot exposed to the Prestige fuel oil.

    PubMed

    Martin-Skilton, Rebeca; Saborido-Rey, Fran; Porte, Cinta

    2008-10-01

    Juvenile turbot (Scophthalmus maximus) were exposed to different concentrations of the Prestige fuel oil through the diet. The effects on hepatic biotransformation enzymes, namely, 7-ethoxyresorufin O-deethylase (EROD), catalase, and phase II activities - UDP-glucuronosyltransferases (UGT) and cytosolic sulfotransferases (SULT) -, were monitored after 42-day exposure. Additionally, potential alterations on the endocrine system of juvenile turbot were assessed by measuring circulating levels of testosterone and 17beta-estradiol in plasma, together with gonadal P450 aromatase activity and the glucuronidation of testosterone by liver microsomal fractions. Fluorescent aromatic compounds (FACs) in bile were determined as an indicator of exposure to polycyclic aromatic hydrocarbons (PAHs). EROD activity increased in a dose dependent manner, and a positive correlation between levels of FACs in bile and EROD activity was observed. A significant increase in UGT activity was observed in fish exposed to medium and high fuel doses, whereas SULT cytosolic activity was not responsive to exposure. Exposure to the Prestige fuel oil sharply reduced circulating levels of testosterone in plasma. The obtained results suggest the ability of the Prestige fuel oil to alter hepatic biotransformation enzymes and to disrupt endogenous hormone levels in juvenile turbot, with unknown consequences in terms of sexual differentiation and reproduction.

  11. Protection and antibody response induced by intramuscular DNA vaccine encoding for viral haemorrhagic septicaemia virus (VHSV) G glycoprotein in turbot (Scophthalmus maximus).

    PubMed

    Pereiro, P; Martinez-Lopez, A; Falco, A; Dios, S; Figueras, A; Coll, J M; Novoa, B; Estepa, A

    2012-06-01

    Turbot (Scophthalmus maximus) is a high-value farmed marine flatfish with growing demand and production levels in Europe susceptible to turbot-specific viral haemorrhagic septicaemia virus (VHSV) strains. To evaluate the possibility of controlling the outbreaks of this infectious disease by means of DNA vaccination, the gpG of a VHSV isolated from farmed turbot (VHSV(860)) was cloned into an expression plasmid containing the human cytomegalovirus (CMV) promoter (pMCV1.4-G(860)). In our experimental conditions, DNA immunised turbots were more than 85% protected against VHSV(860) lethal challenge and showed both VHSV-gpG specific and neutralizing antibodies. To our knowledge this is the first report showing the efficacy of turbot genetic immunisation against a VHSV. Work is in progress to determine the contribution of innate and adaptive immunity to the protective response elicited by the immunization.

  12. Immunohistochemical study on the neuroendocrine system of the digestive tract of turbot, Scophthalmus maximus (L.), infected by Enteromyxum scophthalmi (Myxozoa).

    PubMed

    Bermúdez, R; Vigliano, F; Quiroga, M I; Nieto, J M; Bosi, G; Domeneghini, C

    2007-03-01

    In recent years a new parasite, causing severe losses, has been detected in farmed turbot, Scophthalmus maximus (L.), in Northwestern Spain. Dead fish showed emaciation and cachexia caused by severe necrotizing enteritis, which affected all areas of the digestive tract. The parasite was classified as a myxosporean and named Enteromyxum scophthalmi. This study was designed to assess the response of the turbot neuroendocrine system against E. scophthalmi infection. Immunohistochemical tests were applied to sections of the gastrointestinal tract of uninfected and E. scophthalmi-infected turbot, and the presence of cholecystokinin (CCK-8), serotonin (5-HT), substance P (SP), calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP) were documented. A higher abundance of both endocrine epithelial cells (ECs) and nerve cell bodies and fibres for CCK-8, 5-HT and SP were recorded in the gastrointestinal tract of infected turbot, whereas VIP-like substance decreased. The results indicate that E. scophthalmi infection in turbot induced changes in the neuroendocrine system, which may cause alterations in gut motility, electrolyte and fluid secretion, and vascular and immune functions.

  13. Effects of waterborne Fe(II) on juvenile turbot Scophthalmus maximus: analysis of respiratory rate, hematology and gill histology

    NASA Astrophysics Data System (ADS)

    Wu, Zhihao; You, Feng; Liu, Hongjun; Liu, Mengxia; Li, Jun; Zhang, Peijun

    2012-03-01

    The concentration of Fe(II) is high in some groundwater supplies used in turbot culture, and the toxicity of waterborne Fe(II) is unknown. We investigated the stress responses of juvenile turbot, Scophthalmus maximus, exposed to Fe(II) of different concentrations (0.01, 0.05, 0.1, 0.5, 1, and 2 mg/L) for 1, 7, 14, and 28 d, under the same ambient conditions of other parameters. Changes in respiratory rate, hematological parameters, and gill structure were determined. The results show that waterborne Fe(II) did not cause severe hematological perturbation to turbot. A low-medium Fe(II) concentration (lower than 0.1 mg/L) could boost the respiratory rate, and caused no or very limited damage to fish. A high Fe(II) concentration (0.1 mg/L or higher), however, caused gill damage, such as vacuoles in branchial lamellae, epithelial necrosis, and hypertrophy of epithelial cells, and even death after extended exposure time. Therefore, excess waterborne Fe(II) and long-term exposure to Fe(II) could be responsible for poor growth and high mortality of turbot in culture. The concentration of waterborne Fe(II) in turbot culture should be kept below 0.1 mg/L.

  14. QTL detection for Aeromonas salmonicida resistance related traits in turbot (Scophthalmus maximus)

    PubMed Central

    2011-01-01

    Background Interactions between fish and pathogens, that may be harmless under natural conditions, often result in serious diseases in aquaculture systems. This is especially important due to the fact that the strains used in aquaculture are derived from wild strains that may not have had enough time to adapt to new disease pressures. The turbot is one of the most promising European aquaculture species. Furunculosis, caused by the bacterium Aeromonas salmonicida, produces important losses to turbot industry. An appealing solution is to achieve more robust broodstock, which can prevent or diminish the devastating effects of epizooties. Genomics strategies have been developed in turbot to look for candidate genes for resistance to furunculosis and a genetic map with appropriate density to screen for genomic associations has been also constructed. In the present study, a genome scan for QTL affecting resistance and survival to A. salmonicida in four turbot families was carried out. The objectives were to identify consistent QTL using different statistical approaches (linear regression and maximum likelihood) and to locate the tightest associated markers for their application in genetic breeding strategies. Results Significant QTL for resistance were identified by the linear regression method in three linkage groups (LGs 4, 6 and 9) and for survival in two LGs (6 and 9). The maximum likelihood methodology identified QTL in three LGs (5, 6 and 9) for both traits. Significant association between disease traits and genotypes was detected for several markers, some of them explaining up to 17% of the phenotypic variance. We also identified candidate genes located in the detected QTL using data from previously mapped markers. Conclusions Several regions controlling resistance to A. salmonicida in turbot have been detected. The observed concordance between different statistical methods at particular linkage groups gives consistency to our results. The detected associated

  15. Eastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this SeaWiFS image of eastern Alaska, the Aleutian Islands, Kodiak Island, Yukon and Tanana rivers are clearly visible. Also visible, but slightly hidden beneath the clouds, is a bloom in Bristol Bay. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  16. Adventure Learning @ Greenland

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  17. High-Throughput Sequence Analysis of Turbot (Scophthalmus maximus) Transcriptome Using 454-Pyrosequencing for the Discovery of Antiviral Immune Genes

    PubMed Central

    Pereiro, Patricia; Balseiro, Pablo; Romero, Alejandro; Dios, Sonia; Forn-Cuni, Gabriel; Fuste, Berta; Planas, Josep V.; Beltran, Sergi; Novoa, Beatriz; Figueras, Antonio

    2012-01-01

    Background Turbot (Scophthalmus maximus L.) is an important aquacultural resource both in Europe and Asia. However, there is little information on gene sequences available in public databases. Currently, one of the main problems affecting the culture of this flatfish is mortality due to several pathogens, especially viral diseases which are not treatable. In order to identify new genes involved in immune defense, we conducted 454-pyrosequencing of the turbot transcriptome after different immune stimulations. Methodology/Principal Findings Turbot were injected with viral stimuli to increase the expression level of immune-related genes. High-throughput deep sequencing using 454-pyrosequencing technology yielded 915,256 high-quality reads. These sequences were assembled into 55,404 contigs that were subjected to annotation steps. Intriguingly, 55.16% of the deduced protein was not significantly similar to any sequences in the databases used for the annotation and only 0.85% of the BLASTx top-hits matched S. maximus protein sequences. This relatively low level of annotation is possibly due to the limited information for this specie and other flatfish in the database. These results suggest the identification of a large number of new genes in turbot and in fish in general. A more detailed analysis showed the presence of putative members of several innate and specific immune pathways. Conclusions/Significance To our knowledge, this study is the first transcriptome analysis using 454-pyrosequencing for turbot. Previously, there were only 12,471 EST and less of 1,500 nucleotide sequences for S. maximus in NCBI database. Our results provide a rich source of data (55,404 contigs and 181,845 singletons) for discovering and identifying new genes, which will serve as a basis for microarray construction, gene expression characterization and for identification of genetic markers to be used in several applications. Immune stimulation in turbot was very effective, obtaining an

  18. Greenland's Biggest Losers

    NASA Astrophysics Data System (ADS)

    Box, J. E.; Hubbard, A.; Howat, I. M.; Csatho, B. M.; Decker, D. T.; Bates, R.; Tulaczyk, S. M.

    2010-12-01

    On 4 August, 2010, 275 square km of the front of the floating Petermann Glacier, far northwest Greenland, broke away. The glacier effectively retreated 15 km. Petermann has retreated 21 km since year 2000. Consulting available imagery, publications, and maps spanning the past century, we conclude that this is a retreat to a minimum extent in the observational record. This glacier is not the only ice are loser in Greenland. GRACE observations verify the concern of increased mass budget deficit. Retreat is ongoing at the 110 km wide Humboldt glacier and at the 23 km wide Zachariae ice stream. Humboldt, Zachariae, and Petermann (16 km wide) are among a handful of large marine-terminating outlets that have bedrock trenches that lead inland below sea level to the thick, interior reservoir of the ice sheet. Sleeping giants are awakening. Our area change survey of the 35 widest Greenland outlets indicates an annual marine-terminating glacier area loss rate in excess of 130 sq km per year. Here, we evaluate in this context the mechanisms for marine-terminating glacier retreat, dynamical responses to calving, and the apparent climate forcings. The work thus consults a suite of data sets, including: long-term meteorological station records; satellite-derived sea and land surface temperatures; satellite-derived sea ice extent; regional climate model output; oceanographic casts; time lapse cameras, surface elevation change, and tidal records. Cumulative area change at Greenland’s glacier top 5 “losers”. 2010 areas are measured ~1 month prior to the end of summer melt when the survey usually is made . We do not expect 2010 area changes to be much different using the future data. If anything, we expect the losses to be larger. Click here for a full resolution graphic.

  19. Greenland Glacier Albedo Variability

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The program for Arctic Regional Climate Assessment (PARCA) is a NASA-funded project with the prime goal of addressing the mass balance of the Greenland ice sheet. Since the formal initiation of the program in 1995, there has been a significant improvement in the estimates of the mass balance of the ice sheet. Results from this program reveal that the high-elevation regions of the ice sheet are approximately in balance, but the margins are thinning. Laser surveys reveal significant thinning along 70 percent of the ice sheet periphery below 2000 m elevations, and in at least one outlet glacier, Kangerdlugssuaq in southeast Greenland, thinning has been as much as 10 m/yr. This study examines the albedo variability in four outlet glaciers to help separate out the relative contributions of surface melting versus ice dynamics to the recent mass balance changes. Analysis of AVHRR Polar Pathfinder albedo shows that at the Petermann and Jakobshavn glaciers, there has been a negative trend in albedo at the glacier terminus from 1981 to 2000, whereas the Stor+strommen and Kangerdlugssuaq glaciers show slightly positive trends in albedo. These findings are consistent with recent observations of melt extent from passive microwave data which show more melt on the western side of Greenland and slightly less on the eastern side. Significance of albedo trends will depend on where and when the albedo changes occur. Since the majority of surface melt occurs in the shallow sloping western margin of the ice sheet where the shortwave radiation dominates the energy balance in summer (e.g. Jakobshavn region) this region will be more sensitive to changes in albedo than in regions where this is not the case. Near the Jakobshavn glacier, even larger changes in albedo have been observed, with decreases as much as 20 percent per decade.

  20. mtDNA Variation among Greenland Eskimos: The Edge of theBeringian Expansion

    PubMed Central

    Saillard, Juliette; Forster, Peter; Lynnerup, Niels; Bandelt, Hans-Jürgen; Nørby, Søren

    2000-01-01

    The Eskimo-Aleut language phylum is distributed from coastal Siberia across Alaska and Canada to Greenland and is well distinguished from the neighboring Na Dene languages. Genetically, however, the distinction between Na Dene and Eskimo-Aleut speakers is less clear. In order to improve the genetic characterization of Eskimos in general and Greenlanders in particular, we have sequenced hypervariable segment I (HVS-I) of the mitochondrial DNA (mtDNA) control region and typed relevant RFLP sites in the mtDNA of 82 Eskimos from Greenland. A comparison of our data with published sequences demonstrates major mtDNA types shared between Na Dene and Eskimo, indicating a common Beringian history within the Holocene. We further confirm the presence of an Eskimo-specific mtDNA subgroup characterized by nucleotide position 16265G within mtDNA group A2. This subgroup is found in all Eskimo groups analyzed so far and is estimated to have originated <3,000 years ago. A founder analysis of all Eskimo and Chukchi A2 types indicates that the Siberian and Greenland ancestral mtDNA pools separated around the time when the Neo-Eskimo culture emerged. The Greenland mtDNA types are a subset of the Alaskan mtDNA variation: they lack the groups D2 and D3 found in Siberia and Alaska and are exclusively A2 but at the same time lack the A2 root type. The data are in agreement with the view that the present Greenland Eskimos essentially descend from Alaskan Neo-Eskimos. European mtDNA types are absent in our Eskimo sample. PMID:10924403

  1. Molecular cloning, subcelluar location and expression profile of signal transducer and activator of transcription 2 (STAT2) from turbot, Scophthalmus maximus.

    PubMed

    Wang, Na; Wang, Xian-Li; Yang, Chang-Geng; Chen, Song-Lin

    2013-10-01

    Signal transducer and activator of transcription 2 (STAT2) is an important molecule involved in the type I interferon signalling pathway. To date, little STAT2 homologue is available in fish except Atlantic salmon and goldfish. In this paper, STAT2 was firstly cloned and characterized from turbot, a marine flatfish with high economic value. Briefly, turbot STAT2 cDNA is 3206 bp in length encoding a predicted protein of 793 amino acids. The phylogenetic tree shows that turbot STAT2 protein shared the closest relationship with Atlantic salmon. Analysis of subcellular distribution indicates that STAT2 is mainly present in the cytoplasm of TK cells. Stat2 mRNA is constitutively expressed in widespread tissues and induced by several folds in turbot tissues and TK cells after stimulation with Vibrio anguillarum and lymphocystis disease virus (LCDV). Unlike the higher vertebrate STAT2, turbot STAT2 nuclear export signal (NES) exists not in the C-terminal 79 amino acids but in N-terminal 137-312 amino acids (STAT_alpha domain). The nuclear translocation of turbot STAT2 after Poly(I:C) treatment proved its transcription activity in TK cells. All these results suggested that STAT2 may be involved in the immune response in turbot as a transcription factor.

  2. Greenland Sea observations

    SciTech Connect

    Gudmandsen, P.; Mortensen, H.B.; Pedersen, L.T.; Skriver, H.; Minnett, P.

    1992-12-31

    ERS-1 SAR data have been acquired over the Greenland Sea and Fram Strait during two periods, the Ice Phase of three-day repeat cycle from January to March 1992 and a one-month period in the 35-day repeat cycle from 16 July to 15 August 1992. Most data became available by way of the Broadband Data Dissemination System, i.e. with a spatial resolution of about 100 m. With these data various algorithms have been tested to derive sea ice parameters such as ice extent, ice concentration and ice displacement. In the latter period data were collected to support the activities of a research vessel in the area mainly related to the large polynyas that form east and north of Greenland. The formation of polynyas could clearly be outlined but also other phenomena were observed related to the influence of wind streets and gravity waves associated with the atmospheric boundary layer. The data will have to be studied further including full-resolution data to substantiate the conclusions arrived at.

  3. Annual and spatial variation in the abundance length and condition of juvenile turbot ( Psetta maxima L.) on nursery grounds on the west coast of Ireland: 2000-2007

    NASA Astrophysics Data System (ADS)

    Haynes, Paula S.; Brophy, Deirdre; McGrath, David; O'Callaghan, Roisin; Comerford, Stephen; Casburn, Paul

    2010-11-01

    Turbot ( Psetta maxima Linnaeus) is a high value commercially exploited marine flatfish which occurs in European waters, from the Northeast Atlantic to the Arctic Circle, the Baltic and Mediterranean Sea. In Ireland, turbot are the most valuable commercial non-quota species. Very little is known about their population dynamics in the wild, in particular during the sandy beach nursery phase of the life history. In 2000, a survey was established to assess flatfish species on nursery grounds on the west coast of Ireland. Eleven sandy beaches were assessed for 0+ turbot by beach seining, over an eight year period (2000-2007) during the months of August and September. The objective of the study was to estimate juvenile turbot abundance and size structure to determine if any spatial and annual trends existed. Large scale variability in the recruitment of fish to nursery grounds may be indicative of fluctuations in the adult stock. Turbot were found to recruit to five beaches consistently over the eight year period. Temporal and spatial variability in the relative abundance and length of turbot was discerned, with no apparent overall trend. However, certain nursery grounds were shown in most of the years examined to support higher abundances of turbot in comparison to other areas over the eight year period. Turbot abundances on nursery grounds were significantly correlated with mean spring sea temperatures during the pelagic stage. The condition of turbot did not significantly differ on an annual or spatial scale. Mean densities of 0+ turbot along the Irish coast were found to be similar and at times higher than other areas in Europe, ranging from 0.1 (± 0.3) individuals 1000 m - 2 to 18.5 (± 6.9) individuals 1000 m - 2 . Mean turbot total length on beaches ranged from 3.8 cm (± 0.6) to 6.6 cm (± 4.3). The observed spatial and temporal variability in abundance and length highlights the need for long-term studies when assessing juvenile flatfish populations. Results

  4. Trophic transfer and effects of DDT in male hornyhead turbot (Pleuronichthys verticalis) from Palos Verdes Superfund site, CA (USA) and comparisons to field monitoring.

    PubMed

    Crago, Jordan; Xu, Elvis Genbo; Kupsco, Allison; Jia, Fang; Mehinto, Alvine C; Lao, Wenjian; Maruya, Keith A; Gan, Jay; Schlenk, Daniel

    2016-06-01

    High concentrations of DDT and metabolites (ΣDDT) have been detected in sediment and the demersal flatfish hornyhead turbot (Pleuronichtys verticalis) collected from Palos Verdes (PV), California, USA, a site contaminated with over 100 metric tons of DDT throughout 1960s-70s. This study was conducted to assess the transfer of ΣDDT from PV-sediment into polychaetes (Neanthes arenaceodentata) and hornyhead turbot, and to investigate if the responses in turbots from two different laboratory exposures mimic those in turbots caught in PV (PV-turbot). Turbot fed PV-sediment-contaminated polychaete for 7 days had liver concentrations of ΣDDT similar to PV-turbot. After 28 days, ΣDDT also accumulated in livers of turbot gavaged with a ΣDDT mixture. In vitro cell bioassays indicated significant increases of 17β-estradiol equivalents (EEQ) in turbot bile extracts as compared to the control in the 7-day study. These responses corresponded to those measured in PV-fish. Glucocorticoid receptor (GR), anti-androgen receptor (anti-AR), estrogen receptor (ER) or aryl hydrocarbon receptor (AhR) activities were also observed in extracts of PV-sediment, and PV-sediment-exposed worm. Anti-AR, AhR and GR activities were significantly higher in PV-sediment than reference sediment (San Diego, SD). Higher transcripts of hepatic VTG, ERα and ERβ were found in PV-turbot than SD-turbot, but were unaltered in fish exposed to sediment-contaminated worms for the 7-day study. In contrast, liver extracts from the 28-day treatment of ΣDDT showed lower EEQ but similar hepatic VTG and ERβ transcripts relative to those of PV-turbot. These data indicated that trophic transfer of sediment-associated DDT in 7-day exposures corresponded to field measurements of DDT residues and in vitro ER bioactivities, but failed to mimic in vivo biological effects observed in field fish. In contrast, treatment with ΣDDT alone for 28 days mimicked in vivo biological effects of DDTs in PV fish, but did not

  5. Alaska Resource Data File, Noatak Quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.; Dumoulin, Julie A.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Noatak 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  6. Variation in the immunoglobulin levels in turbot ( Scophthalmus maximus) after vaccination with Streptococcus iniae

    NASA Astrophysics Data System (ADS)

    Zhan, Wenbin; Liu, Hongming; Xing, Jing; Sheng, Xiuzhen; Tang, Xiaoqian

    2009-09-01

    A pathogenic bacterium (S636), identified as Streptococcus iniae, was isolated from turbot ( Scophthalmus maximus) in 2005. We immunized turbot with formalin-killed S. iniae four times (on days 1, 14, 21, and 28) by intraperitoneal inoculation. After each vaccination, we obtained serum samples and isolated the lymphocytes from the peripheral blood, spleen, pronephros, and mesonephros. We measured surface Ig-positive (sIg+) lymphocytes and serum antibody levels from these organs using flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively, using monoclonal antibodies against turbot immunoglobulin. We confirmed that the antibody reacted with both the surface and plasma Ig by confocal laser scanning microscopy and electron microscopy. The percentage of sIg+ in the lymphocytes increased following each successive vaccination. The mean percentage increased from 31.96% (control) to 37.49%, 38.36%, 42.9%, and 51.63% in the peripheral blood; from 27.09% to 36.63%, 36.81%, 39.28%, and 46.0% in the spleen; from 22.2% to 28.99%, 29.21%, 32.83%, and 41.58% in pronephros; and from 18.12% to 22.17%, 22.45%, 25.69%, and 31.68% in the mesonephros. The ELISA results were consistent with these results. Both the total and specific antibody levels increased with each vaccination. The mean OD value of the specific antibody assay increased from 0.094, to 0.269, 0.283, 0.333, and 0.421; for total antibody the mean OD value increased from 0.133, to 0.292, 0.323, 0.413, and 0.527.

  7. Comprehensive transcriptomic analysis of the process of gonadal sex differentiation in the turbot (Scophthalmus maximus).

    PubMed

    Ribas, L; Robledo, D; Gómez-Tato, A; Viñas, A; Martínez, P; Piferrer, F

    2016-02-15

    The turbot is a flatfish with a ZW/ZZ sex determination system but with a still unknown sex determining gene(s), and with a marked sexual growth dimorphism in favor of females. To better understand sexual development in turbot we sampled young turbot encompassing the whole process of gonadal differentiation and conducted a comprehensive transcriptomic study on its sex differentiation using a validated custom oligomicroarray. Also, the expression profiles of 18 canonical reproduction-related genes were studied along gonad development. The expression levels of gonadal aromatase cyp19a1a alone at three months of age allowed the accurate and early identification of sex before the first signs of histological differentiation. A total of 56 differentially expressed genes (DEG) that had not previously been related to sex differentiation in fish were identified within the first three months of age, of which 44 were associated with ovarian differentiation (e.g., cd98, gpd1 and cry2), and 12 with testicular differentiation (e.g., ace, capn8 and nxph1). To identify putative sex determining genes, ∼4.000 DEG in juvenile gonads were mapped and their positions compared with that of previously identified sex- and growth-related quantitative trait loci (QTL). Although no genes mapped to the previously identified sex-related QTLs, two genes (foxl2 and 17βhsd) of the canonical reproduction-related genes mapped to growth-QTLs in linkage group (LG) 15 and LG6, respectively, suggesting that these genes are related to the growth dimorphism in this species.

  8. Effect of stocking density on performances of juvenile turbot ( Scophthalmus maximus) in recirculating aquaculture systems

    NASA Astrophysics Data System (ADS)

    Li, Xian; Liu, Ying; Blancheton, Jean-Paul

    2013-05-01

    Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2) for 10 weeks in RAS at 23±1°C. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

  9. Transcriptome Profiles Associated to VHSV Infection or DNA Vaccination in Turbot (Scophthalmus maximus)

    PubMed Central

    Pereiro, Patricia; Dios, Sonia; Boltaña, Sebastián; Coll, Julio; Estepa, Amparo; Mackenzie, Simon; Novoa, Beatriz; Figueras, Antonio

    2014-01-01

    DNA vaccines encoding the viral G glycoprotein show the most successful protection capability against fish rhabdoviruses. Nowadays, the molecular mechanisms underlying the protective response remain still poorly understood. With the aim of shedding light on the protection conferred by the DNA vaccines based in the G glycoprotein of viral haemorrhagic septicaemia virus (VHSV) in turbot (Scophthalmus maximus) we have used a specific microarray highly enriched in antiviral sequences to carry out the transcriptomic study associated to VHSV DNA vaccination/infection. The differential gene expression pattern in response to empty plasmid (pMCV1.4) and DNA vaccine (pMCV1.4-G860) intramuscular administration with regard to non-stimulated turbot was analyzed in head kidney at 8, 24 and 72 hours post-vaccination. Moreover, the effect of VHSV infection one month after immunization was also analyzed in vaccinated and non-vaccinated fish at the same time points. Genes implicated in the Toll-like receptor signalling pathway, IFN inducible/regulatory proteins, numerous sequences implicated in apoptosis and cytotoxic pathways, MHC class I antigens, as well as complement and coagulation cascades among others were analyzed in the different experimental groups. Fish receiving the pMCV1.4-G860 vaccine showed transcriptomic patterns very different to the ones observed in pMCV1.4-injected turbot after 72 h. On the other hand, VHSV challenge in vaccinated and non-vaccinated turbot induced a highly different response at the transcriptome level, indicating a very relevant role of the acquired immunity in vaccinated fish able to alter the typical innate immune response profile observed in non-vaccinated individuals. This exhaustive transcriptome study will serve as a complete overview for a better understanding of the crosstalk between the innate and adaptive immune response in fish after viral infection/vaccination. Moreover, it provides interesting clues about molecules with a potential

  10. Modelling Greenland Outlet Glaciers

    NASA Technical Reports Server (NTRS)

    vanderVeen, Cornelis; Abdalati, Waleed (Technical Monitor)

    2001-01-01

    The objective of this project was to develop simple yet realistic models of Greenland outlet glaciers to better understand ongoing changes and to identify possible causes for these changes. Several approaches can be taken to evaluate the interaction between climate forcing and ice dynamics, and the consequent ice-sheet response, which may involve changes in flow style. To evaluate the icesheet response to mass-balance forcing, Van der Veen (Journal of Geophysical Research, in press) makes the assumption that this response can be considered a perturbation on the reference state and may be evaluated separately from how this reference state evolves over time. Mass-balance forcing has an immediate effect on the ice sheet. Initially, the rate of thickness change as compared to the reference state equals the perturbation in snowfall or ablation. If the forcing persists, the ice sheet responds dynamically, adjusting the rate at which ice is evacuated from the interior to the margins, to achieve a new equilibrium. For large ice sheets, this dynamic adjustment may last for thousands of years, with the magnitude of change decreasing steadily over time as a new equilibrium is approached. This response can be described using kinematic wave theory. This theory, modified to pertain to Greenland drainage basins, was used to evaluate possible ice-sheet responses to perturbations in surface mass balance. The reference state is defined based on measurements along the central flowline of Petermann Glacier in north-west Greenland, and perturbations on this state considered. The advantage of this approach is that the particulars of the dynamical flow regime need not be explicitly known but are incorporated through the parameterization of the reference ice flux or longitudinal velocity profile. The results of the kinematic wave model indicate that significant rates of thickness change can occur immediately after the prescribed change in surface mass balance but adjustments in flow

  11. Draft Genome Sequence of Edwardsiellapiscicida Strain ACC35.1 Isolated from Diseased Turbot (Scophthalmus maximus) in Europe.

    PubMed

    Buján, Noemí; Toranzo, Alicia E; Magariños, Beatriz

    2017-02-16

    Edwardsiella piscicida is a bacterial fish pathogen with a high degree of virulence. The strain ACC35.1 was isolated from diseased turbot in Europe. The draft genome sequence comprises 3.84 Mb with a G+C content of 59.8% and >3,450 protein-coding genes.

  12. Draft Genome Sequence of Edwardsiella piscicida Strain ACC35.1 Isolated from Diseased Turbot (Scophthalmus maximus) in Europe

    PubMed Central

    Toranzo, Alicia E.; Magariños, Beatriz

    2017-01-01

    ABSTRACT   Edwardsiella piscicida is a bacterial fish pathogen with a high degree of virulence. The strain ACC35.1 was isolated from diseased turbot in Europe. The draft genome sequence comprises 3.84 Mb with a G+C content of 59.8% and >3,450 protein-coding genes. PMID:28209828

  13. Authentication of farmed and wild turbot (Psetta maxima) by fatty acid and isotopic analyses combined with chemometrics.

    PubMed

    Busetto, Maria L; Moretti, Vittorio M; Moreno-Rojas, Jose M; Caprino, Fabio; Giani, Ivan; Malandra, Renato; Bellagamba, Federica; Guillou, Claude

    2008-04-23

    Fatty acid composition and stable isotope ratios of carbon (delta(13)C) and nitrogen (delta(15)N) were determined in muscle tissue of turbot (Psetta maxima). The multivariate analysis of the data was performed to evaluate their utility in discriminating wild and farmed fish. Wild (n=30) and farmed (n=30) turbot of different geographical origins (Denmark, The Netherlands, and Spain) were sampled from March 2006 to February 2007. The application of linear discriminant analysis (LDA) and soft independent modeling of class analogy (SIMCA) to analytical data demonstrated the combination of fatty acids and isotopic measurements to be a promising method to discriminate between wild and farmed fish and between wild fish of different geographical origin. In particular, IRMS (Isotope Ratio Mass Spectrometry) alone did not permit us to separate completely farmed from wild samples, resulting in some overlaps between Danish wild and Spanish farmed turbot. On the other hand, fatty acids alone differentiated between farmed and wild samples by 18:2n-6 but were not able to distinguish between the two groups of wild turbot. When applying LDA isotope ratios, 18:2n-6, 18:3n-3, and 20:4n-6 fatty acids were decisive to distinguish farmed from wild turbot of different geographical origin, while delta(15)N, 18:2n-6, and 20:1n-11 were chosen to classify wild samples from different fishing zones. In both cases, 18:2n-6 and delta(15)N were determinant for classification purposes. We would like to emphasize that IRMS produces rapid results and could be the most promising technique to distinguish wild fish of different origin. Similarly, fatty acid composition could be used to easily distinguish farmed from wild samples.

  14. Identification and characterization of pathogen to bacterial septicaemia in cultured turbot, Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Qin, Guomin; Zhang, Xiaojun; Chen, Cuizhen; Fang, Hai; Zhan, Wenbin

    2007-10-01

    Bacteria-infected turbots Scophthalmus maximus with septicaemia were examined between 2001 and 2004 in aspects of the conditions of disease occurrence, clinical syndromes and pathological changes. The phenotypic information of pathogenic bacteria was studied, including morphology, physiological and biochemical characteristics, and the mol% G+C of the DNA. In addition, representative strains (S010623-1, LH031120-1) were selected for molecular identification by partial 16S rRNA gene sequencing. The results show that the isolates (LH031120-1 to LH031120-6, HT040308-1 to HT040308-6, HT040620-1 to HT040620-6) from three farms were identified as Edwardsiella tarda. The isolates (S010610-1 to S010610-10, S010623-1 to S010623-20) from one farm were identified as Listonella anguillarum. We conducted studies on the pathogenicity of isolates by artificial infection, and revealed all infected groups in morbidity and mortality. The septicaemia infected turbot showed a syndrome similar to that of the naturally infected fish. Antibiotic sensitivity showed that of 37 antimicrobial agents, E. tarda was sensitive to 27 agents, and L. anguillarum was sensitive to 21 agents.

  15. Cloning, expression and characterization of translationally controlled tumor protein (TCTP) gene from flatfish turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Guo, Huarong; Zhang, Shicui; Yin, Licheng; Guo, Bin; Wang, Shaojie

    2008-05-01

    A full-length cDNA encoding translationally controlled tumor protein of marine flatfish turbot ( Scophthalmus maximus), SmTCTP, was isolated with rapid amplification of cDNA Ends (RACE). SmTCTP consisted of a 5' untranslated region (UTR) of 84 bp, a 3' UTR of 451 bp and an open reading frame (ORF) of 513 bp, encoding a protein of 170 amino acid residues, which contained two signature sequences of TCTP family. The 5'UTR of SmTCTP started with a 5'-terminal oligopyrimidine tract (5'-TOP), a typical feature for translationally controlled mRNAs. The deduced amino acid sequence of SmTCTP was similar to the other known vertebrate TCTPs in a range of 58.8% to 64.1%. The length of fish TCTPs was diverse among species, e.g., TCP of turbot and sea perch ( Lateolabrax japonicus) is 170 aa in length, while that of zebrafish ( Danio rerio) and rohu ( Labeo rohita) is 171 aa in length. Northern blot analysis revealed that SmTCTP has only one type of mRNA. Its expression level in albino skin was slightly higher than that in normal skin. We constructed the pET30a- SmTCTP expression plasmid. The recombinant protein of His-tag SmTCTP was over-expressed in E. coli, purified and identified with peptide mass fingerprinting. These results may pave the way of further investigation of the biological function of TCTP in fish.

  16. Chronic rapamycin treatment on the nutrient utilization and metabolism of juvenile turbot (Psetta maxima)

    PubMed Central

    Wang, Qingchao; He, Gen; Mai, Kangsen; Xu, Wei; Zhou, Huihui; Wang, Xuan; Mei, Lin

    2016-01-01

    High dietary protein inclusion is necessary in fish feeds and also represents a major cost in the aquaculture industry, which demands improved dietary conversion into body proteins in fish. In mammals, the target of rapamycin (TOR) is a key nutritionally responsive molecule governing postprandial anabolism. However, its physiological significance in teleosts has not been fully examined. In the present study, we examined the nutritional physiology of turbot after chronic rapamycin inhibition. Our results showed that a 6-week inhibition of TOR using dietary rapamycin inclusion (30 mg/kg diet) reduced growth performance and feed utilization. The rapamycin treatment inhibited TOR signaling and reduced expression of key enzymes in glycolysis, lipogenesis, cholesterol biosynthesis, while increasing the expression of enzymes involved in gluconeogenesis. Furthermore, rapamycin treatment increased intestinal goblet cell number in turbot, while the expressions of Notch and Hes1 were down regulated. It was possible that stimulated goblet cell differentiation by rapamycin was mediated through Notch-Hes1 pathway. Therefore, our results demonstrate the important role of TOR signaling in fish nutritional physiology. PMID:27305975

  17. Effect of dietary vitamin E on the sperm quality of turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Xu, Houguo; Huang, Lina; Liang, Mengqing; Zheng, Keke; Wang, Xinxing

    2015-08-01

    A 3-month feeding experiment was conducted in an in-door seawater system to investigate the effect of dietary vitamin E (Ve) on the sperm quality of turbot ( Scophthalmus maximus). D-α-tocopherol acetate was supplemented to the basal (control) diet (65.14 mg kg-1 Ve) to obtain low and high levels of dietary Ve (244.60 mg kg-1, LVe; 721.60 mg kg-1, HVe). Compared with the control, sperm concentration was significantly increased in Ve-supplemented groups (LVe and HVe); while relative sperm volume and testis-somatic index were significantly increased in group HVe only. Sperm motility duration was significantly longer in group HVe than in the control, but no significant difference was observed in percent motility among groups. Sperm size, the uniformity of mitochondrial size, and the integrity of mitochondria cristae and plasma membrane were improved by dietary Ve, especially in HVe. The content of Ve in testis and liver as well as polyunsaturated fatty acids in sperm increased with dietary Ve. These results suggested that dietary Ve, especially at the high level (721.60 mg kg-1), significantly improved sperm concentration and motility duration and maintained normal sperm morphology of turbot.

  18. Zinc, cadmium, mercury and selenium in polar bears (Ursus maritimus) from Central East Greenland

    SciTech Connect

    Dietz, R.; Born, E.W.; Agger, C.T.; Nielsen, C.O.

    1995-02-01

    Muscle, liver, and kidney tissues from 38 polar bears (Ursus maritimus) caught in the Scoresby Sound area, Central East Greenland, were analysed for zinc, cadmium, mercury and selenium. In general, cadmium concentrations were low in muscle, liver and kidney tissue. This finding can be explained by low cadmium levels in the blubber of ringed seals. The concentration of mercury in muscle tissue was low, whereas concentrations in liver and kidney tissue were relatively high. Mercury and cadmium were positively correlated with age in liver and kidney. Zinc was positively correlated with in kidney, and selenium was correlated with age in liver. Contrary to other marine mammals, polar bears had higher mercury levels in the kidneys than in the liver. In all three tissues polar bears had significantly lower cadmium levels than ringed seals from the same area. Mercury levels were significantly lower in the muscle tissue of polar bears than in ringed seals, where-as levels in the liver and kidney were significantly higher. The previous geographic trend for cadmium and mercury found in Canadian polar bears could be extended to cover East Greenland as well. Hence cadmium levels were higher in Greenland than in Canada, while the opposite was the case for mercury. Greenland polar bears had higher mercury and cadmium contents in livers and kidneys than polar bears from Svalbard. The mercury levels in muscle and liver tissue from polar bears from East Greenland were twice as high as found in bears from western Alaska, but half the levels found in northern Alaska. Cadmium and zinc were partially correlated in kidney tissue, and this was found for mercury and selenium as well. Cadmium and zinc showed molar ratios close to unity with the highest concentrations occurring in kidney tissue, while the levels of zinc exceeded cadmium in muscle and liver tissue by up to several decades. Mercury and selenium showed molar ratios close to unity in liver and kidneys. 56 refs., 5 figs., 6 tabs.

  19. 75 FR 76372 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands; Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ...,107,000 996,300 110,700 2012 BS 1,220,000 1,110,000 1,105,000 994,500 110,500 AI 39,100 32,200 19,000... Sablefish \\5\\ BS 2,970 2,500 2,500 1,063 94 AI 2,200 1,860 1,860 434 38 Atka mackerel BSAI 76,200 65,000 65...,000 90,000 80,370 9,630 Greenland turbot BSAI 6,860 5,370 5,370 4,565 n/a BS 3,700 3,700 3,145 396...

  20. Oxidants and anti-oxidants in turbot seminal plasma and their effects on sperm quality

    NASA Astrophysics Data System (ADS)

    Han, Mingming; Ding, Fuhong; Meng, Zhen; Lei, Jilin

    2015-08-01

    In this research, the concentration and activity of oxidants and anti-oxidants in turbot semen, and their effects on sperm quality were studied. The results showed that superoxide dismutase (SOD), catalase, glutathione reductase (GR), uric acid, vitamin E (VE) and vitamin C (VC) were more abundant in seminal plasma than in spermatozoa. The variation for each of them was specific. In seminal plasma, the activity of SOD and GR increased from November 15, November 30 to December 15, and then decreased on December 30. The concentrations of both VC and uric acid decreased during the first 3 sampling times and increased on December 30. The oxidants in seminal plasma accumulated to the highest on December 30. Lactic acid (LA) and ATP levels decreased to the lowest on December 30. The correlation analysis showed that GR had the significant positive relevance to sperm motility and VSL/VCL, while ·OH had negative relevance to them.

  1. Effects of contaminated sediment from Cork Harbour, Ireland on the cytochrome P450 system of turbot.

    PubMed

    Kilemade, M; Hartl, M G J; O'Halloran, J; O'Brien, N M; Sheehan, D; Mothersill, C; van Pelt, F N A M

    2009-03-01

    Hatchery-reared juvenile turbot (Scophthalmus maximus L.) were exposed for 3 weeks, under laboratory conditions, to inter-tidal sediments collected from polluted sites in Cork Harbour (Whitegate and Agahda) and a reference site at Ballymacoda Co., Cork, Ireland. The potential of the sediment exposure to induce cytochrome P450 activities and CYP1A1 in the fish was assessed. Chemical analysis revealed that the sediments originating from the reference and harbour sites were contaminated principally with PAHs-the harbour sites having double the levels of those at the reference site. Following 3 weeks exposure to the sediments western blotting demonstrated a strong immunogenic response for CYP1A1 in the liver, but not for gill or intestine. P450 activities were generally significantly higher than those exposed to reference site sediment. Liver was the most responsive tissue with significantly greater P450 activities compared with gill and intestinal tissues.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  3. Alaska's Children, 1997.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1997-01-01

    These four issues of the "Alaska's Children" provide information on the activities of the Alaska Head Start State Collaboration Project and other Head Start activities. Legal and policy changes affecting the education of young children in Alaska are also discussed. The Spring 1997 issue includes articles on brain development and the…

  4. Alaska's Economy: What's Ahead?

    ERIC Educational Resources Information Center

    Alaska Review of Social and Economic Conditions, 1987

    1987-01-01

    This review describes Alaska's economic boom of the early 1980s, the current recession, and economic projections for the 1990s. Alaska's economy is largely influenced by oil prices, since petroleum revenues make up 80% of the state government's unrestricted general fund revenues. Expansive state spending was responsible for most of Alaska's…

  5. Alaska Natives & the Land.

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Pursuant to the Native land claims within Alaska, this compilation of background data and interpretive materials relevant to a fair resolution of the Alaska Native problem seeks to record data and information on the Native peoples; the land and resources of Alaska and their uses by the people in the past and present; land ownership; and future…

  6. Microarray analysis of the inflammatory and immune responses in head kidney turbot leucocytes treated with resveratrol.

    PubMed

    Domínguez, Berta; Pardo, Belén G; Noia, Manuel; Millán, Adrián; Gómez-Tato, Antonio; Martínez, Paulino; Leiro, José; Lamas, Jesús

    2013-03-01

    A DNA oligo-microarray enriched in genes and involved in inflammatory and immune responses was used to evaluate the effects of resveratrol on gene expression in turbot head kidney leucocytes. Leucocytes were cultured for 3, 6 and 24 h, in the presence or absence of resveratrol, or were stimulated with the membrane fraction of the parasite Philasterides dicentrarchi or with the membrane plus resveratrol. Gene expression changed considerably in control cells, and several of the regulated genes were related to inflammatory and immune responses and to the cytoskeleton. Similar changes in gene expression occurred in control cells and in cells stimulated with P. dicentrarchi membrane fraction. Treatment with resveratrol induced changes in the expression (mostly down-regulation) of several genes involved in immune responses and inflammation. Thus, the down-regulation of the transcription factor PU.1, pentraxin-multidomain protein, heme oxygenase 1, S100 calcium-binding protein A-16 (S100A16) and the signal transducer and activator of transcription 4 was observed after all three incubation times. The down-regulation of the suppressor of cytokine signalling 3a, LPS-induced tumour necrosis alpha, hepcidin, metallothionein, TLR8 and the calcium dependent lectin A was observed after 3 and 6 h. Resveratrol also decreased the expression of CCL20, IL-8, apolipoprotein E and glutathione S-transferase after incubation for 6 and 24 h, and of TNF-α after incubation for 3 and 24 h. Resveratrol also induced strong regulation of several cytoskeleton-related genes. The use of the turbot oligo-microarray enabled us to discover genes whose expression was not previously suspected of being modulated by this polyphenol.

  7. The physiological performance and immune response of juvenile turbot (Scophthalmus maximus) to nitrite exposure.

    PubMed

    Jia, Rui; Liu, Bao-Liang; Han, Cen; Huang, Bin; Lei, Ji-Lin

    2016-01-01

    Nitrite (NO(2-)) is the most common toxic nitrogenous compound in aquatic environment. The aim of the present study was to investigate the effects of nitrite physiological performance and immune response of turbot. Fish were exposed to 0, 0.02, 0.08, 0.4 and 0.8 mM nitrite for 96 h. After 0, 24, 48 and 96 h of exposure, blood were collected to measure the levels of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), alkaline phosphatase (ALP), total protein (TP), albumin (Alb), complement C3 (C3), complement C4 (C4), immunoglobulin M (IgM) and lysozyme (LYS); gill samples were taken to analyze mRNA levels of LYS, heat shock protein 70 (HSP 70), heat shock protein 90 (HSP 90), metallothionein (MT), toll-like receptor 3 (TLR-3), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and insulin-like growth factor I (IGF-I). The results showed that nitrite (0.4 and/or 0.8mM) significantly increased the levels of GPT, GOT, ALP, C3 and C4, reduced the levels of IgM and LYS, up-regulated the gene expressions of HSP 70, HSP 90, MT, TLR-3, TNF-α and IL-1β, and down-regulated the gene expressions of LYS and IGF-1 after 48 and 96 h of exposure. Based on the results, it can be concluded that high level nitrite exposure results in dysfunction of the blood physiology and immunity in turbot. Further, this study will be helpful to understand the mechanism of aquatic toxicology induced by nitrite in marine fish.

  8. Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

    PubMed

    Møller, Lone Nukâraq; Petersen, Eskild; Kapel, Christian M O; Melbye, Mads; Koch, Anders

    2005-09-05

    The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

  9. Dietary uptake of polybrominated diphenyl ethers (PBDEs), occurrence and profiles, in aquacultured turbots (Psetta maxima) from Galicia, Spain.

    PubMed

    Blanco, Sonia Lucía; Martínez, Aníbal; Porro, Corina; Vieites, Juan M

    2011-10-01

    Polybromodiphenyl ethers (PBDEs) are one of the many toxic chemicals present in the environment and in the food we eat every day, being fish one of the main sources of persistent organic pollutants in our diet; like other lipid-related contaminants, they are of concern since they can bioaccumulate and biomagnify through the trophic chain. We published a study focused on the dietary uptake of dioxins and furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) in a set of samples of Spanish farmed turbot (Blanco et al., 2007). In the present paper, we extend the study to PBDEs to provide more information about the uptake and transfer from feed to fish of halogenated contaminants. PBDEs in the feeds (2.35-4.76 ng g(-1)) were reflected in turbot fillets (0.54-2.05 ng g(-1)): predominant congeners were tetra-BDE 47, penta-BDEs 99 and 100. It is remarkable that tetra-BDE 49, accounting for only 2% in the feed, contributed to 15% of total PBDEs in turbot fillets. Dietary net accumulation values, 30-45%, showed that tri-, tetra-, penta- and hexa-BDEs were as efficiently transferred into turbot as dl-PCBs and tetra- and penta-chlorinated PCDD/Fs. Lipid-normalized biomagnification factors relating concentration in fish and in feed, BMFs>1 were obtained, except for BDE 209. BDE 49 accumulation, 90%, was possibly contributed by metabolism of higher brominated BDEs. Implication in aquaculture management is a need for uncontaminated fish feed to offer safe products.

  10. RNA-seq analysis of early enteromyxosis in turbot (Scophthalmus maximus): new insights into parasite invasion and immune evasion strategies.

    PubMed

    Ronza, Paolo; Robledo, Diego; Bermúdez, Roberto; Losada, Ana Paula; Pardo, Belén G; Sitjà-Bobadilla, Ariadna; Quiroga, María Isabel; Martínez, Paulino

    2016-07-01

    Enteromyxum scophthalmi, an intestinal myxozoan parasite, is the causative agent of a threatening disease for turbot (Scophthalmus maximus, L.) aquaculture. The colonisation of the digestive tract by this parasite leads to a cachectic syndrome associated with high morbidity and mortality rates. This myxosporidiosis has a long pre-patent period and the first detectable clinical and histopathological changes are subtle. The pathogenic mechanisms acting in the early stages of infection are still far from being fully understood. Further information on the host-parasite interaction is needed to assist in finding efficient preventive and therapeutic measures. Here, a RNA-seq-based transcriptome analysis of head kidney, spleen and pyloric caeca from experimentally-infected and control turbot was performed. Only infected fish with early signs of infection, determined by histopathology and immunohistochemical detection of E. scophthalmi, were selected. The RNA-seq analysis revealed, as expected, less intense transcriptomic changes than those previously found during later stages of the disease. Several genes involved in IFN-related pathways were up-regulated in the three organs, suggesting that the IFN-mediated immune response plays a main role in this phase of the disease. Interestingly, an opposite expression pattern had been found in a previous study on severely infected turbot. In addition, possible strategies for immune system evasion were suggested by the down-regulation of different genes encoding complement components and acute phase proteins. At the site of infection (pyloric caeca), modulation of genes related to different structural proteins was detected and the expression profile indicated the inhibition of cell proliferation and differentiation. These transcriptomic changes provide indications regarding the mechanisms of parasite attachment to and invasion of the host. The current results contribute to a better knowledge of the events that characterise the early

  11. Involvement of Acylated Homoserine Lactones (AHLs) of Aeromonas sobria in Spoilage of Refrigerated Turbot (Scophthalmus maximus L.)

    PubMed Central

    Li, Tingting; Cui, Fangchao; Bai, Fengling; Zhao, Guohua; Li, Jianrong

    2016-01-01

    One quorum sensing strain was isolated from spoiled turbot. The species was determined by 16S rRNA gene analysis and classical tests, named Aeromonas sobria AS7. Quorum-sensing (QS) signals (N-acyl homoserine lactones (AHLs)) were detected by report strains and their structures were further determined by GC-MS. The activity changes of AHLs on strain growth stage as well as the influence of different culture conditions on secretion activity of AHLs were studied by the punch method. The result indicated that strain AS7 could induce report strains to produce typical phenotypic response. N-butanoyl-dl-homoserine lactone (C4–HSL), N-hexanoyl-dl-homoserine lactone (C6–HSL), N-octanoyl-dl-homoserine lactone (C8–HSL), N-decanoyl-dl-homoserine lactone (C10–HSL), N-dodecanoyl-dl-homoserine lactone (C12–HSL) could be detected. The activities of AHLs were density-dependent and the max secretion level was at pH 8, sucrose culture, 1% NaCl and 32 h, respectively. The production of siderophore in strain AS7 was regulated by exogenous C8–HSL, rather than C6–HSL. Exogenous C4–HSL and C8–HSL accelerated the growth rate and population density of AS7 in turbot samples under refrigerated storage. However, according to the total viable counts and total volatile basic nitrogen (TVB-N) values of the fish samples, exogenous C6–HSL did not cause spoilage of the turbot fillets. In conclusion, our results suggested that QS was involved in the spoilage of refrigerated turbot. PMID:27420072

  12. Inter-species transmission of viral hemorrhagic septicemia virus (VHSV) from turbot (Scophthalmus maximus) to rainbow trout (Onchorhynchus mykiss).

    PubMed

    Schönherz, Anna A; Lorenzen, Niels; Einer-Jensen, Katja

    2013-04-01

    Successful viral infection is a complex mechanism, involving many host-pathogen interactions that developed during coevolution of host and pathogen, and often result in host-species specificity. Nevertheless, many viruses are able to infect several host species and sporadically cross species barriers. The viral hemorrhagic septicemia virus (VHSV), a rhabdovirus with high economic impact on the aquaculture industry, has developed an exceptionally wide host range across marine and freshwater environments. Transmission of VHSV between host species therefore represents a potential risk for aquaculture, which currently is not addressed in biosecurity managements. The objective of this study was to investigate the inter-species transmission potential of VHSV and evaluate whether infected marine wild fish pose a potential risk on marine cultured rainbow trout. A cohabitation infection trial with turbot as donor and rainbow trout as recipient host species was conducted. Turbot were intraperitoneally injected with either a marine-adapted (MA) or a trout-adapted (TA) VHSV isolate and subsequently grouped with naïve rainbow trout. Both VHSV isolates were able to replicate and cause mortality in turbot, while only the TA isolate was able to cross the species barrier and infect rainbow trout with fatal outcome. The results demonstrate that a marine fish species can function as reservoir and transmitter of TA VHSV isolates.

  13. Exploitation of a turbot (Scophthalmus maximus L.) immune-related expressed sequence tag (EST) database for microsatellite screening and validation.

    PubMed

    Navajas-Pérez, R; Robles, F; Molina-Luzón, M J; De La Herrán, R; Alvarez-Dios, J A; Pardo, B G; Vera, M; Bouza, C; Martínez, P

    2012-07-01

    In this study, we identified and characterized 160 microsatellite loci from an expressed sequence tag (EST) database generated from immune-related organs of turbot (Scophthalmus maximus). A final set of 83 new polymorphic microsatellites were validated after the analysis of 40 individuals of Atlantic origin including both wild and farmed individuals. The allele number and the expected heterozygosity ranged from 2 to 18 and from 0.021 to 0.951, respectively. Evidences of null alleles at moderate-high frequencies were detected at six loci using population data. None of the analysed loci showed deviations from Mendelian segregation after the analysis of five full-sib families including approximately 92 individuals/family. The markers are used to consolidate the turbot genetic map, and because they are mostly EST-derived, they will be very useful for comparative genomic studies within flatfishes and with model fish species. Using an in silico approach, we detected significant homologies of microsatellite sequences with the EST databases of the flatfish species with highest genomic resources (Senegalese sole, Atlantic halibut, bastard halibut) in 31% of these turbot markers. The conservation of these microsatellites within Pleuronectiformes will pave the way for anchoring genetic maps of different species and identifying genomic regions related to productive traits.

  14. A novel hepcidin-like in turbot (Scophthalmus maximus L.) highly expressed after pathogen challenge but not after iron overload.

    PubMed

    Pereiro, P; Figueras, A; Novoa, B

    2012-05-01

    Hepcidins are antimicrobial peptides with an important role in the host innate immunity. Moreover, it has been reported that mammalian hepcidins present a dual-function being a key regulator in the iron homeostasis. Here, we describe the coding sequence of a novel hepcidin-like peptide in turbot, Scophthalmus maximus. This molecule presents several differences with regard to the previously characterized hepcidin in this flatfish species and it has not the hypothetical iron regulatory sequence Q-S/I-H-L/I-S/A-L in the N-terminal region. Therefore we propose the existence of at least two types of hepcidin in turbot. Moreover, results revealed a higher variability in the mRNA sequences of the novel hepcidin compared with the other form. Constitutive expression of turbot hepcidins (Hepcidin-1 and Hepcidin-2) was analyzed in several tissues and as expected, both molecules were highly represented in liver. On the other hand, the effect of three different stimuli (bacterial or viral infection and iron overloading) in the level of hepcidin mRNA was also examined and a differential response to pathogens and iron was observed. Whereas both hepcidins were affected by pathogen challenge, only Hepcidin-1 was up-regulated after iron overloading. Therefore, this and other evidences suggest that these peptides could be involved in different functions covering the dual role of mammalian hepcidins.

  15. Bioremediation of bacteria pollution using the marine sponge Hymeniacidon perlevis in the intensive mariculture water system of turbot Scophthalmus maximus.

    PubMed

    Zhang, Xichang; Zhang, Wei; Xue, Lingyun; Zhang, Bi; Jin, Meifang; Fu, Wantao

    2010-01-01

    Sessile filter-feeding marine sponges (Porifera) have been reported to possess high efficiency in removing bacteria pollution from natural or aquaculture seawater. However, no investigation has been carried out thus far in a true mariculture farm water system. Therefore this study sought to investigate the ability of the marine sponge Hymeniacidon perlevis to bioremediate the bacteria pollution in the intensive aquaculture water system of turbot Scophthalmus maximus. Sponge specimens were hung in fish culture effluent at different temperature to investigate the optimal temperature condition for bacteria removal by H. perlevis. Turbots S. maximus were co-cultured with sponge H. perlevis in 1.5 m(3) of water system at 15-18 degrees C for 6 weeks to control the growth of bacteria. It was found that H. perlevis was able to remove pathogenic bacteria efficiently at 10-20 degrees C, with a maximal removal of 71.4-78.8% of fecal coliform, 73.9-98.7% of pathogenic vibrio, and 75.0-83.7% of total culturable bacteria from fish-culture effluent at 15 degrees C; H. perlevis continuously showed good bioremediation of bacteria pollution in the S. maximus culture water system, achieving removal of 60.0-90.2% of fecal coliform, 37.6-81.6% of pathogenic vibrio, and 45.1-83.9% of total culturable bacteria. The results demonstrate that H. perlevis is an effective bioremediator of bacteria pollution in the turbot S. maximus culture farm water system.

  16. Integrative Transcriptome, Genome and Quantitative Trait Loci Resources Identify Single Nucleotide Polymorphisms in Candidate Genes for Growth Traits in Turbot.

    PubMed

    Robledo, Diego; Fernández, Carlos; Hermida, Miguel; Sciara, Andrés; Álvarez-Dios, José Antonio; Cabaleiro, Santiago; Caamaño, Rubén; Martínez, Paulino; Bouza, Carmen

    2016-02-17

    Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotide polymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species.

  17. Involvement of VAMP-2 in exocytosis of IL-1{beta} in turbot (Scophthalmus maximus) leukocytes after Vibrio anguillarum infection

    SciTech Connect

    Chai Yingmei; Huang Xiaohang . E-mail: xiaohanghuang@yahoo.ca; Cong Bailin; Liu Shenghao; Chen Kui; Li Guangyou; Gaisano, Herbert Y.

    2006-04-07

    Vibrio anguillarum is a major pathogen threatening the fish aquaculture in China. Infection of cultivated turbot (Scophthalmus maximus) with V. anguillarum induced rapid synthesis and secretion of IL-1{beta}, which initiates the innate immune response. SNARE proteins are known to regulate vesicular trafficking and fusion in all eukaryotes. Here, we determined whether SNARE proteins, specifically vesicle-associated membrane protein-2 (VAMP-2), are involved in regulated exocytosis of IL-1{beta} of leukocytes in marine fish. We show that VAMP-2 is present in turbot blood leukocytes, with nucleotide sequence identity of 88.2% and 93.0% to those of zebra fish and sea bass, respectively. After Vibrio infection, turbot leukocyte VAMP-2 was increased at the levels of transcription and translation in a temporal pattern coinciding with leukocyte IL-1{beta} secretion. Confocal microscopy localized VAMP-2 to vesicle structures in leukocytes. Taken together, our results suggest that VAMP-2 is involved in regulated exocytosis of cytokines in immunocytes in fish.

  18. Integrative Transcriptome, Genome and Quantitative Trait Loci Resources Identify Single Nucleotide Polymorphisms in Candidate Genes for Growth Traits in Turbot

    PubMed Central

    Robledo, Diego; Fernández, Carlos; Hermida, Miguel; Sciara, Andrés; Álvarez-Dios, José Antonio; Cabaleiro, Santiago; Caamaño, Rubén; Martínez, Paulino; Bouza, Carmen

    2016-01-01

    Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotide polymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species. PMID:26901189

  19. In vitro and in vivo evaluation of lactic acid bacteria of aquatic origin as probiotics for turbot (Scophthalmus maximus L.) farming.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Magadán, Susana; Hernández, Pablo E; Herranz, Carmen; Santos, Ysabel; Cintas, Luis M

    2014-12-01

    Turbot (Scophthalmus maximus L.) is an important commercial marine flatfish. Its production may be affected by bacterial diseases that cause severe economical losses, mainly tenacibaculosis and vibriosis, provoked by Tenacibaculum maritimum and Vibrio splendidus, respectively. An alternative or complementary strategy to chemotherapy and vaccination for the control of these diseases is the use of probiotics. In this work, we report the in vitro and in vivo potential of eight lactic acid bacteria (LAB), previously isolated from fish, seafood and fish products intended for human consumption, as turbot probiotics. Seven out of the eight LAB exerted direct antimicrobial activity against, at least, four strains of T. maritimum and V. splendidus. All LAB survived in seawater at 18 °C for 7 days, and withstood exposure to pH 3.0 and 10% (v/v) turbot bile; however, they differed in cell surface hydrophobicity (8.2-21.7%) and in their ability to adhere to turbot skin (1.2-21.7%) and intestinal (0.7-2.1%) mucus. Most of the tested strains inhibited the binding of turbot pathogens to the mucus. Leuconostoc mesenteroides subsp. cremoris SMM69 and Weissella cibaria P71 were selected based on their strong antimicrobial activity against T. maritimum and V. splendidus, good probiotic properties, and different adhesion ability to skin mucus and capacity to inhibit the adhesion of turbot pathogens to mucus. These two LAB strains were harmless when administered by bath to turbot larvae and juveniles; moreover, real-time PCR on the transcription levels of the immunity-related genes encoding IL-1β, TNF-α, lysozyme, C3, MHC-Iα and MHC-IIα in five organs (head-kidney, spleen, liver, intestine and skin) revealed the ability of these LAB to stimulate their expression in turbot juveniles, especially the non-specific immunity associated genes in mucosal tissues. Based on our results, Lc. cremoris SMM69 and W. cibaria P71 may be considered as suitable probiotic candidates for turbot

  20. Molecular Analysis of Endocrine Disruption in Hornyhead Turbot at Wastewater Outfalls in Southern California Using a Second Generation Multi-Species Microarray

    PubMed Central

    Baker, Michael E.; Vidal-Dorsch, Doris E.; Ribecco, Cataldo; Sprague, L. James; Angert, Mila; Lekmine, Narimene; Ludka, Colleen; Martella, Andrea; Ricciardelli, Eugenia; Bay, Steven M.; Gully, Joseph R.; Kelley, Kevin M.; Schlenk, Daniel; Carnevali, Oliana; Šášik, Roman; Hardiman, Gary

    2013-01-01

    Sentinel fish hornyhead turbot (Pleuronichthysverticalis) captured near wastewater outfalls are used for monitoring exposure to industrial and agricultural chemicals of ~ 20 million people living in coastal Southern California. Although analyses of hormones in blood and organ morphology and histology are useful for assessing contaminant exposure, there is a need for quantitative and sensitive molecular measurements, since contaminants of emerging concern are known to produce subtle effects. We developed a second generation multi-species microarray with expanded content and sensitivity to investigate endocrine disruption in turbot captured near wastewater outfalls in San Diego, Orange County and Los Angeles California. Analysis of expression of genes involved in hormone [e.g., estrogen, androgen, thyroid] responses and xenobiotic metabolism in turbot livers was correlated with a series of phenotypic end points. Molecular analyses of turbot livers uncovered altered expression of vitellogenin and zona pellucida protein, indicating exposure to one or more estrogenic chemicals, as well as, alterations in cytochrome P450 (CYP) 1A, CYP3A and glutathione S-transferase-α indicating induction of the detoxification response. Molecular responses indicative of exposure to endocrine disruptors were observed in field-caught hornyhead turbot captured in Southern California demonstrating the utility of molecular methods for monitoring environmental chemicals in wastewater outfalls. Moreover, this approach can be adapted to monitor other sites for contaminants of emerging concern in other fish species for which there are few available gene sequences. PMID:24086568

  1. Quorum Sensing Involved in the Spoilage Process of the Skin and Flesh of Vacuum-Packaged Farmed Turbot (Scophthalmus maximus) Stored at 4 °C.

    PubMed

    Zhang, Caili; Zhu, Suqin; Wu, Haohao; Jatt, Abdul-Nabi; Pan, Yurong; Zeng, Mingyong

    2016-10-03

    Fish skin has both positive and negative effects on the shelf-life of the fish. This study aimed to investigate the spoilage process of the skin and flesh of refrigerated farmed turbot (Scophthalmus maximus) with vacuum packaging. Microbial community changes were analyzed by combining culture-dependent and culture-independent methods. The results indicated that the shelf-life of vacuum-packaged refrigerated turbot was 16 d; skin mucus was the interference factor of turbot quality. The culture-dependent analysis demonstrated that the total viable counts and the population of H2 S-producing bacteria, Pseudomonas spp., Enterobacteriaceae spp., and lactic acid bacteria in skin had a range of 0.45 to 1.40 log (CFU/g) higher than the microbial numbers in flesh after 16 d in storage. 16S high throughout sequencing results demonstrated that the compositions of spoilage microbes were similar in skin and flesh. Shewanella spp., followed by Carnobacterium spp., was the dominant spoilage organism at day 16. Quorum sensing (QS) signaling activity increased during the storage. Exogenous N-butanoyl-L-homoserinelactone(C4-HSL) and N-hexanoyl-Lhomoserine lactone (C6-HSL) significantly accelerated the spoilage process of refrigerated turbot, while the addition of 4, 5-Dihydroxypentane-2, 3-dione (DPD) prolonged the lag phase duration. Therefore, QS may be involved in the spoilage process of refrigerated turbot.

  2. Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus)

    PubMed Central

    Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

    2015-01-01

    The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot. PMID:26556346

  3. Selenium status in Greenland Inuit.

    PubMed

    Hansen, Jens C; Deutch, Bente; Pedersen, Henning Sloth

    2004-09-20

    In Greenland, the human intake of selenium has always been relatively high and is closely connected to intake of the traditional food of marine origin. Analyses of historic and present day human and animal hair samples have indicated that the selenium level in the marine environment has been constant over time, while the levels in humans have declined corresponding to a decrease in intake of traditional food. The Inuit population in Greenland is in dietary transition where western-style food will increasingly dominate. As a consequence, the ample supply of selenium may not be sustained in the future. We report here the selenium status in three Greenlandic population groups, Ittoqqortoormiit and Tasiilaq on the east coast and Uummannaq on the west coast. Mean whole blood concentrations ranged from 178 microg/l in Tasiilaq men to 488 microg/l in Uummannaq men. Plasma concentrations ranged from 79 microg/l in Tasiilaq women to 113 microg/l in Uummannaq men. With increasing Se concentrations in whole blood, the plasma concentrations increased but tended to stabilise a level approximately 140 microg/l. Selenium blood levels were highly significantly correlated with long chain marine fatty acids. Dietary survey and food composition data from the west coast showed that whale skin, muktuk, is the main source of Se followed by birds, seal meat and organs, and fish. Terrestrial animals contributed only insignificantly to the selenium intake. In West Greenland, daily Se intake (235 microg/day) was estimated by dietary survey; it corresponded well with a calculated intake (220 microg/day) based on the mean blood concentration.

  4. Alaska Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Murray, Tom; Read, Cyrus

    2008-01-01

    Steam plume from the 2006 eruption of Augustine volcano in Cook Inlet, Alaska. Explosive ash-producing eruptions from Alaska's 40+ historically active volcanoes pose hazards to aviation, including commercial aircraft flying the busy North Pacific routes between North America and Asia. The Alaska Volcano Observatory (AVO) monitors these volcanoes to provide forecasts of eruptive activity. AVO is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Augustine volcano and AVO at http://www.avo.alaska.edu.

  5. Food and feeding habits of juvenile flounder Platichthys flesus (L.), abd turbot Scophthalmus maximus L. in the åland archipelago, northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Aarnio, Katri; Bonsdorff, Erik; Rosenback, Nina

    1996-12-01

    The food choice of juvenile flounder ( Platichthys flesus) and turbot ( Scophthalmus maximus) was studied in the northern Baltic Sea during the years 1988, 1989, 1994 and 1995. The diet included organisms from 30 species/taxa in flounder (n = 306) and 10 species/taxa in turbot (n = 41). Flounder ⩽ 45 mm mainly consumed meiofauna (dominating taxon: Harpacticoida, Copepoda) and larger fish (46-101 mm) consumed macrofauna (dominating taxa: Oligochaeta, Amphipoda and Chironomidae). In terms of biomass, macrofauna dominated for all sizes of flounders, and meiofauna was important only for the smallest fish. A strong seasonal variation could be detected in the diet. In spring, macrofauna dominated for all size classes of fish (only fish > 30 mm were caught in spring), while in summer and autumn meiofauna dominated the diets for fish ⩽ 45 mm in size. Juvenile turbot (22-88 mm) consumed macrofauna and small fish. Turbot ⩽ 30 mm consumed mainly amphipods, while > 30 mm turbot consumed mysid shrimps, amphipods and fish. The ontogenetic shift from meio- to macrofauna-sized prey in flounders occurs at a larger fish size in the northern Baltic Sea than reported in other areas, possibly depending on the increased relative importance of meiofauna in the northern Baltic. The seasonal variation in the diet could be due to seasonally changing abundances in the zoobenthos, or for the small fish (1-group, spring), to switching from meio- to macrofauna in order to optimize their energy gain. The 0-group flounders consumed meiofauna for a long period, possibly due to a learning-process or simply due to easy availability of meiofauna. Turbot has a much larger mouth gap than flounders, thus allowing them to consume macrofauna from the beginning of their benthic life.

  6. Immunological responses of turbot (Psetta maxima) to nodavirus infection or polyriboinosinic polyribocytidylic acid (pIC) stimulation, using expressed sequence tags (ESTs) analysis and cDNA microarrays.

    PubMed

    Park, Kyoung C; Osborne, Jane A; Montes, Ariana; Dios, Sonia; Nerland, Audun H; Novoa, Beatriz; Figueras, Antonio; Brown, Laura L; Johnson, Stewart C

    2009-01-01

    To investigate the immunological responses of turbot to nodavirus infection or pIC stimulation, we constructed cDNA libraries from liver, kidney and gill tissues of nodavirus-infected fish and examined the differential gene expression within turbot kidney in response to nodavirus infection or pIC stimulation using a turbot cDNA microarray. Turbot were experimentally infected with nodavirus and samples of each tissue were collected at selected time points post-infection. Using equal amount of total RNA at each sampling time, we made three tissue-specific cDNA libraries. After sequencing 3230 clones we obtained 3173 (98.2%) high quality sequences from our liver, kidney and gill libraries. Of these 2568 (80.9%) were identified as known genes and 605 (19.1%) as unknown genes. A total of 768 unique genes were identified. The two largest groups resulting from the classification of ESTs according to function were the cell/organism defense genes (71 uni-genes) and apoptosis-related process (23 uni-genes). Using these clones, a 1920 element cDNA microarray was constructed and used to investigate the differential gene expression within turbot in response to experimental nodavirus infection or pIC stimulation. Kidney tissue was collected at selected times post-infection (HPI) or stimulation (HPS), and total RNA was isolated for microarray analysis. Of the 1920 genes studied on the microarray, we identified a total of 121 differentially expressed genes in the kidney: 94 genes from nodavirus-infected animals and 79 genes from those stimulated with pIC. Within the nodavirus-infected fish we observed the highest number of differentially expressed genes at 24 HPI. Our results indicate that certain genes in turbot have important roles in immune responses to nodavirus infection and dsRNA stimulation.

  7. An Expressed Sequence Tag (EST)-enriched genetic map of turbot (Scophthalmus maximus): a useful framework for comparative genomics across model and farmed teleosts

    PubMed Central

    2012-01-01

    Background The turbot (Scophthalmus maximus) is a relevant species in European aquaculture. The small turbot genome provides a source for genomics strategies to use in order to understand the genetic basis of productive traits, particularly those related to sex, growth and pathogen resistance. Genetic maps represent essential genomic screening tools allowing to localize quantitative trait loci (QTL) and to identify candidate genes through comparative mapping. This information is the backbone to develop marker-assisted selection (MAS) programs in aquaculture. Expressed sequenced tag (EST) resources have largely increased in turbot, thus supplying numerous type I markers suitable for extending the previous linkage map, which was mostly based on anonymous loci. The aim of this study was to construct a higher-resolution turbot genetic map using EST-linked markers, which will turn out to be useful for comparative mapping studies. Results A consensus gene-enriched genetic map of the turbot was constructed using 463 SNP and microsatellite markers in nine reference families. This map contains 438 markers, 180 EST-linked, clustered at 24 linkage groups. Linkage and comparative genomics evidences suggested additional linkage group fusions toward the consolidation of turbot map according to karyotype information. The linkage map showed a total length of 1402.7 cM with low average intermarker distance (3.7 cM; ~2 Mb). A global 1.6:1 female-to-male recombination frequency (RF) ratio was observed, although largely variable among linkage groups and chromosome regions. Comparative sequence analysis revealed large macrosyntenic patterns against model teleost genomes, significant hits decreasing from stickleback (54%) to zebrafish (20%). Comparative mapping supported particular chromosome rearrangements within Acanthopterygii and aided to assign unallocated markers to specific turbot linkage groups. Conclusions The new gene-enriched high-resolution turbot map represents a

  8. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  9. A genome scan for candidate genes involved in the adaptation of turbot (Scophthalmus maximus).

    PubMed

    Vilas, Román; Vandamme, Sara G; Vera, Manuel; Bouza, Carmen; Maes, Gregory E; Volckaert, Filip A M; Martínez, Paulino

    2015-10-01

    Partitioning phenotypic variance in genotypic and environmental variance may benefit from the population genomic assignment of genes putatively involved in adaptation. We analyzed a total of 256 markers (120 microsatellites and 136 Single Nucleotide Polymorphisms - SNPs), several of them associated to Quantitative Trait Loci (QTL) for growth and resistance to pathologies, with the aim to identify potential adaptive variation in turbot Scophthalmus maximus L. The study area in the Northeastern Atlantic Ocean, from Iberian Peninsula to the Baltic Sea, involves a gradual change in temperature and an abrupt change in salinity conditions. We detected 27 candidate loci putatively under selection. At least four of the five SNPs identified as outliers are located within genes coding for ribosomal proteins or directly related with the production of cellular proteins. One of the detected outliers, previously identified as part of a QTL for growth, is a microsatellite linked to a gene coding for a growth factor receptor. A similar set of outliers was detected when natural populations were compared with a sample subjected to strong artificial selection for growth along four generations. The observed association between FST outliers and growth-related QTL supports the hypothesis of changes in growth as an adaptation to differences in temperature and salinity conditions. However, further work is needed to confirm this hypothesis.

  10. [Visualization of the chilling storage time for turbot flesh based on hyperspectral imaging technique].

    PubMed

    Zhu, Feng-Le; Zhang, Hai-Liang; Shao, Yong-Ni; He, Yong

    2014-07-01

    This study proposed a new method using visible and near infrared (Vis/NIR) hyperspectral imaging for the detection and visualization of the chilling storage time for turbot flesh rapid and nondestructively. A total of 160 fish samples with 8 different storage days were collected for hyperspectral image scanning, and mean spectra were extracted from the region of interest (ROD inside each image. Partial least squares regression (PLSR) was applied as calibration method to correlate the spectral data and storage time for the 120 samples in calibration set. Then the PLSR model was used to predict the storage time for the 40 prediction samples, which achieved accurate results with determination coefficient (R2) of 0.966 2 and root mean square error of prediction (RMSEP) of 0.679 9 d. Finally, the storage time of each pixel in the hyperspectral images for all prediction samples was predicted and displayed in different colors for visualization based on pseudo-color images with the aid of an IDL program. The results indicated that hyperspectral imaging technique combined with chemometrics and image processing allows the determination and visualization of the chilling storage time for fish, displaying fish freshness status and distribution vividly and laying a foundation for the automatic processing of aquatic products.

  11. Cloning and early expression pattern of two melatonin biosynthesis enzymes in the turbot (Scophthalmus maximus).

    PubMed

    Vuilleumier, Robin; Boeuf, Gilles; Fuentes, Michael; Gehring, Walter J; Falcón, Jack

    2007-05-01

    Melatonin biosynthesis from serotonin involves the sequential activation of the arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole-O-methyltransferase (HIOMT). Photoperiod synchronizes a daily rhythm in pineal and retinal melatonin secretion through controlling AANAT activity. Teleost fish possess two Aanat, one expressed in the retina (AANAT1) and the other expressed in the pineal gland (AANAT2). We report here the full-length cloning of Aanat1, Aanat2, SmHiomt and Otx5 (orthodenticle homeobox homolog 5) in the turbot (Scophthalmus maximus, Sm), a flatfish belonging to an evolutionary recent group of Teleost. The temporal expression pattern of the genes investigated is consistent with the idea that OTX5 is needed for photoreceptor specification, and that the pineal gland differentiates before the retina. SmAanat2 expression remained pineal specific during the period of time investigated, whereas SmOtx5 and SmHiomt expressions were seen in both the retina and pineal gland. Our results do not support the existence of a second SmHiomt, as is the case for SmAanat. Neither SmAanat2 nor SmHiomt mRNAs displayed cyclic accumulation in the pineal organ of embryos and larvae maintained under a light-dark cycle from fertilization onward. This is in marked contrast with the situation observed with zebrafish Aanat2, indicating that the molecular mechanisms controlling the development of the pineal melatonin system have been modified during the evolution of Teleost.

  12. Branchial structure and hydromineral equilibrium in juvenile turbot (Scophthalmus maximus) exposed to heavy fuel oil.

    PubMed

    Goanvec, Christelle; Poirier, Elisabeth; Le-Floch, Stéphane; Theron, Michaël

    2011-09-01

    This study is an attempt to go further in the comprehension of the effects of heavy fuel oil in the context of an accidental oil spill at sea. It focuses on the link between morphological and functional impacts of realistic doses of the dissolved fraction of a heavy fuel oil on fish gills. Juvenile turbot, Scophthalmus maximus were exposed to the dissolved fraction of a heavy fuel oil for 5 days and then placed 30 days in clean sea water for recovery. During the contamination period, the concentration of the 16 US EPA priority poly-aromatic hydrocarbons showed small variations around a mean value of 321.0 ± 9.1 ng l⁻¹ (mean ± SEM). The contamination induced a 64% increase in hepatic cytochrome P 450 1A (Western blot analysis). Osmolality, [Na⁺] and [Cl⁻] rapidly and significantly increased (by 14, 23 and 28% respectively) and slowly decreased to normal levels during the recovery period. At the same time, branchial histology showed decreases in the number of mucocytes (by 30%) and of chloride cells (by 95%) in the interlamellar epithelium. Therefore, it is suggested that the osmotic imbalance observed after the 5 days of exposure to the dissolved fraction of the heavy fuel oil is the consequence of the structural alteration of the gills i.e, the strong reduction of ionocyte numbers.

  13. Induction of apoptosis in a carp leucocyte cell line infected with turbot (Scophthalmus maximus L.) rhabdovirus.

    PubMed

    Du, Changsheng; Zhang, Qiya; Li, Chunliang; Miao, Dali; Gui, Jianfang

    2004-05-01

    A rhabdovirus was observed from the diseased turbot (Scophthalmus maximus L.) with lethal syndrome. In this study, a carp leucocyte (CLC) cell line was used to investigate the infection process and cell death mechanism occurring during the virus infection. Strong cytopathogenic effect (CPE) and the morphological changes, such as extreme chromatin condensation, nucleus fragmentation, and apoptotic body formation, were observed under fluorescence microscopy after DAPI staining in the infected CLC cells. Transmission electron microscopy analysis showed cell shrinkage, plasma membrane blebbing, cytoplasm vacuolization, chromatin condensation, nuclear breakdown and formation of discrete apoptotic bodies. The bullet-shaped nucleocapsids were measured and ranged in size from 110 to 150 nm in length and 40 to 60 nm in diameter. And therefore the virus is called Scophthalmus maximus rhabdovirus (SMRV). Agarose gel electrophoresis analysis of the DNA extracted from infected cells showed typical DNA ladder in the course of SMRV infection. Flow cytometry analysis of SMRV infected CLC cells detected apoptotic peak in the virus infected CLC cells. Virus titre analysis and electron microscopic observation revealed that the virus replication fastigium was earlier than that of the apoptosis occurrence. No apoptosis was observed in the CLC infected with UV-inactivated SMRV. All these supported that SMRV infected CLC cells undergo apoptosis and the virus replication is necessary for apoptosis induction of CLC cells.

  14. Turbot (Scophthalmus maximus) hepcidin-1 and hepcidin-2 possess antimicrobial activity and promote resistance against bacterial and viral infection.

    PubMed

    Zhang, Jian; Yu, Lan-Ping; Li, Mo-Fei; Sun, Li

    2014-05-01

    Hepcidin is an antimicrobial peptide and a regulator of iron homeostasis. In turbot (Scophthalmus maximus), two types of hepcidins have been identified, which share approximately 50% sequence identity. In this study, we examined the antimicrobial potentials of the two hepcidins in the form of synthesized peptides, SmHep1P and SmHep2P. We found that SmHep1P and SmHep2P exhibited apparent bactericidal activities against both Gram-positive and Gram-negative bacteria in a dose-dependent manner. The bactericidal effect of SmHep1P was stronger against Gram-positive bacteria, while the bactericidal effect of SmHep2P was stronger against Gram-negative bacteria. Fluorescence and electron microscopy showed that both peptides were able to bind to the target bacterial cells and alter the surface structure of the cells. In vitro studies showed that SmHep1P and SmHep2P reduced bacterial invasion into cultured fish cells. In vivo studies showed that turbot administered with SmHep1P and SmHep2P exhibited significantly enhanced resistance against bacterial and viral infection. In both in vivo and in vitro studies, the antimicrobial activities of SmHep2P were in most cases significantly stronger than those of SmHep1P. Together these results indicate that the two hepcidins of turbot most likely possess antimicrobial properties and play a role in the innate immune defense against bacterial and viral pathogens.

  15. Effects of dietary stachyose on growth performance, digestive enzyme activities and intestinal morphology of juvenile turbot ( Scophthalmus maximus L)

    NASA Astrophysics Data System (ADS)

    Hu, Haibin; Zhang, Yanjiao; Mai, Kangsen; Ai, Qinghui; Xu, Wei; Zhang, Wenbing; Li, Yanxian; Liu, Jintao

    2015-10-01

    A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot ( Scophthalmus maximus L). Five isonitrogenous (49.58% crude protein) and isolipidic (10.50% crude lipid) diets were formulated to contain 0 (Control), 0.625% (S-0.625), 1.25% (S-1.25), 2.5% (S-2.5) and 5% (S-5) stachyose, respectively. With the increase of stachyose level, the growth performance and feed utilization of turbot, such as the specific growth rate, final mean body weight, weight gain rate and feed efficiency, increased significantly ( P< 0.05) and then stabilized. The feed intake of fish fed S-5 was significantly higher ( P< 0.05) than that of fish in other groups. The activities of trypsin, intestinal caseinolytic, stomach and intestinal amylase were significantly influenced by stachyose ( P<0.05). The highest values of trypsin and intestinal caseinolytic activities were observed in group S-1.25, while the highest activity of stomach amylase and the lowest activity of intestine amylase were observed in group S-5. No lesion or damage was found on the distal intestine structures of fish from all treatments, while the height of simple folds in the distal intestine was significantly increased ( P< 0.05) when 1.25% or 2.5% stachyose was added in the diets. These results indicated that moderate level of stachyose (1.25%) improves the growth performance, feed utilization, digestive enzyme activities and the distal intestine structures of juvenile turbot.

  16. Effects of dietary carbohydrate-to-lipid ratio on the growth performance and feed utilization of juvenile turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Miao, Shuyan; Nie, Qin; Miao, Huijun; Zhang, Wenbing; Mai, Kangsen

    2016-08-01

    A 9-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid ratio (CHO:LIP) on the growth performance and feed utilization of juvenile turbot Scophthalmus maximus (initial body weight 8.75 g ± 0.04 g). Four isonitrogenous and isoenergetic low protein level (39%) diets were formulated with increasing ratios of dietary carbohydrate to lipid (2:18, 6:18, 18:12 and 28:6). A high protein level (50%) diet with the 2:12 ratio of carbohydrate to lipid was used as the control. Results showed that the survival rate, contents of moisture, crude protein and ash in muscle were not significantly affected by dietary treatments. With the dietary CHO:LIP ratio increased from 2:18 to 18:12, weight gain rate significantly increased ( P < 0.05). Higher dietary CHO:LIP ratio (28:6) resulted in the significantly decreased weight gain rate ( P < 0.05). Meanwhile, this treatment also resulted in the highest daily feed intake and liver glycogen content, as well as the lowest feed efficiency ( P < 0.05). Muscle glycogen content in fish fed the diet with 2:12 or 2:18 CHO:LIP ratio was significantly lower than those fed with the other three diets ( P < 0.05). The present results confirmed that the juvenile turbot can utilize carbohydrate. Furthermore, the appropriate ratio of dietary carbohydrate to lipid was important to the growth and feed utilization of turbot. The proper CHO:LIP ratio based on the growth performance in the present study was determined to be 18:12 when the dietary protein level was 39%.

  17. Alaska geothermal bibliography

    SciTech Connect

    Liss, S.A.; Motyka, R.J.; Nye, C.J.

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  18. Renewable Energy in Alaska

    SciTech Connect

    Not Available

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  19. Pharmacokinetics and tissue behavior of enrofloxacin and its metabolite ciprofloxacin in turbot Scophthalmus maximus at two water temperatures

    NASA Astrophysics Data System (ADS)

    Liang, Junping; Li, Jian; Zhao, Fazhen; Liu, Ping; Chang, Zhiqiang

    2012-07-01

    Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fish infections. However, studies concerning the pharmacokinetics of enrofloxacin in turbot are limited. In this study, the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin, were investigated in the turbot following intravenous and oral administration at 10 mg enrofloxacin/kg body weight, at 16°C and 10°C water temperatures. The concentrations of enrofloxacin and ciprofloxacin in the main tissues (plasma, muscle, liver and kidney) were detected by HPLC. The results show that the plasma concentration-time data for enrofloxacin were best described as a two-compartment open model after intravenous and oral administration. Three pharmacokinetic equations were established between the concentrations and temperatures. The kinetic profile of enrofloxacin was temperature dependent. The absorption half-life of enrofloxacin was 1.99 h and 2.17 h after oral administration, whereas the elimination half-life of the drug was 98.63 h and 136.59 h at 16°C and 10°C, respectively. The peak concentration of enrofloxacin in plasma and tissues was higher at 16°C than that at 10°C, and the peak plasma concentration time in the liver was the shortest at both temperatures among those of other tissues. The plasma C max /MIC ratio varied between 11.08 and 5 540.00 at 16°C; and between 7.92 and 3 960.00 at 10°C. The AUC/MIC ratio was 467.82-280 690.00 at 16°C, and 359.48-215 690.00 at 10°C. These ratios indicate that it is possible to obtain therapeutic efficacy. Very low levels of ciprofloxacin were detected. The AUC ratios of ciprofloxacin and enrofloxacin in plasma suggest that plasma ciprofloxacin might play a minor role in enrofloxacin treatment for turbot.

  20. The Greenland gravitational constant experiment.

    NASA Astrophysics Data System (ADS)

    Zumberge, M. A.; Ander, M. E.; Lautzenhiser, T. V.; Parker, R. L.; Aiken, C. L. V.; Gorman, M. R.; Nieto, M. M.; Cooper, A. P. R.; Ferguson, J. F.; Fisher, E.; Greer, J.; Hammer, P.; Hansen, B. L.; McMechan, G. A.; Sasagawa, G. S.; Sidles, C.; Stevenson, J. M.; Wirtz, J.

    1990-09-01

    An Airy-type geophysical experiment was conducted in a 2-km-deep hole in the Greenland ice cap at depths between 213 m and 1673 m to test for possible violations of Newton's inverse square law. Gravity measurements were made at eight depths in 183-m intervals with a LaCoste & Romberg borehole gravity meter. An anomalous variation in gravity totaling 3.87 mGal (3.87x10-5m/s2) in the depth interval of 1460 m was observed. This may be attributed either to a breakdown of Newtonian gravity or to unexpected density variations in the rock below the ice.

  1. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland

    PubMed Central

    Hanke, Dennis; Freuling, Conrad M.; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R.; Bøtner, Anette; Mettenleiter, Thomas C.; Beer, Martin; Rasmussen, Thomas B.; Müller, Thomas F.; Höper, Dirk

    2016-01-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1–4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I – 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure

  2. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

    PubMed

    Hanke, Dennis; Freuling, Conrad M; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R; Bøtner, Anette; Mettenleiter, Thomas C; Beer, Martin; Rasmussen, Thomas B; Müller, Thomas F; Höper, Dirk

    2016-07-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in

  3. Alaska Problem Resource Manual: Alaska Future Problem Solving Program. Alaska Problem 1985-86.

    ERIC Educational Resources Information Center

    Gorsuch, Marjorie, Ed.

    "Alaska's Image in the Lower 48," is the theme selected by a Blue Ribbon panel of state and national leaders who felt that it was important for students to explore the relationship between Alaska's outside image and the effect of that image on the federal programs/policies that impact Alaska. An overview of Alaska is presented first in…

  4. Transcriptional responses of cancer-related genes in turbot Scophthalmus maximus and mussels Mytilus edulis exposed to heavy fuel oil no. 6 and styrene.

    PubMed

    Ruiz, Pamela; Orbea, Amaia; Rotchell, Jeanette M; Cajaraville, Miren P

    2012-04-01

    Recent spills in European waters have released polycyclic aromatic hydrocarbons, important components of heavy fuel oil, and the hydrocarbon styrene. Heavy fuel oil and styrene are classified as potentially genotoxic and carcinogenic. Here we investigate transcription of genes involved in cancer development in the liver of juvenile turbots and in the digestive gland of mussels exposed to heavy fuel oil and to styrene and after a recovery period. In turbot, oil produced a significant up-regulation of p53 and gadd45α after 14 days exposure. cyclin G1 was up-regulated after 7 days treatment with styrene. In mussels, ras was down-regulated in both treatments after the recovery periods. No mutations in ras hotspots were detected in exposed mussels. gadd45α was up-regulated after the recovery period of the styrene experiment. Overall, transcriptional responses differed in mussels compared to turbot. Turbot responded to hydrocarbon exposure by triggering cell cycle arrest (p53) and DNA repair (gadd45α).

  5. A combined strategy involving Sanger and 454 pyrosequencing increases genomic resources to aid in the management of reproduction, disease control and genetic selection in the turbot (Scophthalmus maximus)

    PubMed Central

    2013-01-01

    Background Genomic resources for plant and animal species that are under exploitation primarily for human consumption are increasingly important, among other things, for understanding physiological processes and for establishing adequate genetic selection programs. Current available techniques for high-throughput sequencing have been implemented in a number of species, including fish, to obtain a proper description of the transcriptome. The objective of this study was to generate a comprehensive transcriptomic database in turbot, a highly priced farmed fish species in Europe, with potential expansion to other areas of the world, for which there are unsolved production bottlenecks, to understand better reproductive- and immune-related functions. This information is essential to implement marker assisted selection programs useful for the turbot industry. Results Expressed sequence tags were generated by Sanger sequencing of cDNA libraries from different immune-related tissues after several parasitic challenges. The resulting database (“Turbot 2 database”) was enlarged with sequences generated from a 454 sequencing run of brain-hypophysis-gonadal axis-derived RNA obtained from turbot at different development stages. The assembly of Sanger and 454 sequences generated 52,427 consensus sequences (“Turbot 3 database”), of which 23,661 were successfully annotated. A total of 1,410 sequences were confirmed to be related to reproduction and key genes involved in sex differentiation and maturation were identified for the first time in turbot (AR, AMH, SRY-related genes, CYP19A, ZPGs, STAR FSHR, etc.). Similarly, 2,241 sequences were related to the immune system and several novel key immune genes were identified (BCL, TRAF, NCK, CD28 and TOLLIP, among others). The number of genes of many relevant reproduction- and immune-related pathways present in the database was 50–90% of the total gene count of each pathway. In addition, 1,237 microsatellites and 7,362 single

  6. Libraries in Alaska: MedlinePlus

    MedlinePlus

    ... this page: https://medlineplus.gov/libraries/alaska.html Libraries in Alaska To use the sharing features on ... JavaScript. Anchorage University of Alaska Anchorage Alaska Medical Library 3211 Providence Drive Anchorage, AK 99508-8176 907- ...

  7. Southwest coast of Greenland and Davis Strait

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image was taken by MODIS as it passed over the southwest coast of Greenland (right) and the Davis Strait (center and left). The Davis Strait connects Baffin Bay to the north and the Labrador Sea to the south, and separates Greenland from Baffin Island, Canada. The Davis Strait is part of the Northwest Passage, a navigable seaway connecting the Atlantic Ocean and the Pacific Ocean. The image shows the prevailing currents in the area, with the warm water of a branch of the North Atlantic Drift flowing northward along the Greenland coast, and the cold, iceberg-filled Labrador Current flowing southward along the Baffin Island coast.

  8. UAFSmoke Modeling in Alaska

    NASA Astrophysics Data System (ADS)

    Stuefer, M.; Grell, G.; Freitas, S.; Newby, G.

    2008-12-01

    Alaska wildfires have strong impact on air pollution on regional Arctic, Sub-Arctic and even hemispheric scales. In response to a high number of wildfires in Alaska, emphasis has been placed on developing a forecast system for wildfire smoke dispersion in Alaska. We have developed a University of Alaska Fairbanks WRF/Chem smoke (UAFSmoke) dispersion system, which has been adapted and initialized with source data suitable for Alaska. UAFSmoke system modules include detection of wildfire location and area using Alaska Fire Service information and satellite remote sensing data from the MODIS instrument. The fire emissions are derived from above ground biomass fuel load data in one-kilometer resolution. WRF/Chem Version 3 with online chemistry and online plume dynamics represents the core of the UAFSmoke system. Besides wildfire emissions and NOAA's Global Forecast System meteorology, WRF/Chem initial and boundary conditions are updated with anthropogenic and sea salt emission data from the Georgia Institute of Technology-Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) Model. System runs are performed at the Arctic Region Supercomputing Center's Sun Opteron cluster "Midnight". During the 2008 fire season once daily UAFSmoke runs were presented at a dedicated webpage at http://smoke.arsc.edu. We present examples from these routine runs and from the extreme 2004 Alaska wildfire season.

  9. Selection of normalization factors for quantitative real time RT-PCR studies in Japanese flounder (Paralichthys olivaceus) and turbot (Scophthalmus maximus) under conditions of viral infection.

    PubMed

    Zhang, Jian; Hu, Yong-hua; Sun, Bo-guang; Xiao, Zhi-zhong; Sun, Li

    2013-04-15

    Disease outbreaks caused by iridoviruses are known to affect farmed flounder (Paralichthys olivaceus) and turbot (Scophthalmus maximus). To facilitate quantitative real time RT-PCR (qRT-PCR) analysis of gene expression in flounder and turbot during viral infection, we in this study examined the potentials of 9 housekeeping genes of flounder and turbot as internal references for qRT-PCR under conditions of experimental infection with megalocytivirus, a member of the Iridoviridae family. The mRNA levels of the 9 housekeeping genes in the brain, gill, heart, intestine, kidney, liver, muscle, and spleen of flounder and turbot were determined by qRT-PCR at 24h and 72h post-viral infection, and the expression stabilities of the genes were determined with geNorm and NormFinder algorithms. The results showed that (i) viral infection induced significant changes in the mRNA levels of the all the examined genes in a manner that was dependent on both tissue type and infection stage; (ii) for a given time point of infection, stability predictions made by the two algorisms were highly consistent for most tissues; (iii) the optimum reference genes differed at different infection time points at least in some tissues; (iv) at both examined time points, no common reference genes were identified across all tissue types. These results indicate that when studying gene expression in flounder and turbot in relation to viral infection, different internal references may have to be used not only for different tissues but also for different infection stages.

  10. High-Density Genetic Linkage Mapping in Turbot (Scophthalmus maximus L.) Based on SNP Markers and Major Sex- and Growth-Related Regions Detection

    PubMed Central

    Wang, Weiji; Hu, Yulong; Ma, Yu; Xu, Liyong; Guan, Jiantao; Kong, Jie

    2015-01-01

    This paper describes the development of a high density consensus genetic linkage map of a turbot (Scophthalmus maximus L.) family composed of 149 mapping individuals using Single Nucleotide Polymorphisms (SNP) developed using the restriction-site associated DNA (RAD) sequencing technique with the restriction enzyme, PstI. A total of 6,647 SNPs were assigned to 22 linkage groups, which is equal to the number of chromosome pairs in turbot. For the first time, the average marker interval reached 0.3958 cM, which is equal to approximately 0.1203 Mb of the turbot genome. The observed 99.34% genome coverage indicates that the linkage map was genome-wide. A total of 220 Quantitative Traits Locus (QTLs) associated with two body length traits, two body weight traits in different growth periods and sex determination were detected with an LOD > 5.0 in 12 linkage groups (LGs), which explained the corresponding phenotypic variance (R2), ranging from 14.4–100%. Among them, 175 overlapped with linked SNPs, and the remaining 45 were located in regions between contiguous SNPs. According to the QTLs related to growth trait distribution and the changing of LGs during different growth periods, the growth traits are likely controlled by multi-SNPs distributed on several LGs; the effect of these SNPs changed during different growth periods. Most sex-related QTLs were detected at LG 21 with a linkage span of 70.882 cM. Additionally, a small number of QTLs with high feasibility and a narrow R2 distribution were also observed on LG7 and LG14, suggesting that multi LGs or chromosomes might be involved in sex determination. High homology was recorded between LG21 in Cynoglossus semilaevis and turbot. This high-saturated turbot RAD-Seq linkage map is undoubtedly a promising platform for marker assisted selection (MAS) and flatfish genomics research. PMID:25775256

  11. Isolation and characterization of 45 Polymorphie microsatellite loci of turbot ( Scophthalmus maximus) and cross-species amplification

    NASA Astrophysics Data System (ADS)

    Hou, Shiying; Ma, Aijun; Wang, Xin'an; Huang, Zhihui; Xue, Baogui; Yang, Zhi; Qu, Jiangbo

    2011-03-01

    Turbot ( Scophthalmus maximus) is a flatfish species commercially important for aquaculture. In this study, we generated a microsatellite-enriched genomic DNA library for Scophthalmus maximus, and then isolated and characterized 45 microsatellite loci by genotyping 30 individuals. The observed number of alleles ranged from 2 to 19 with an average of 6.24, while the effective number of alleles ranged from 1.30 to 11.11 with an average of 3.66. The expected heterozygosities varied from 0.235 to 0.925 4 and Polymorphie information content ranged from 0.2044 to 0.903 3, with an average of 0.622. Twelve loci deviated significantly from Hardy-Weinberg equilibrium, and no significant linkage disequilibrium was observed between any pair of loci after Bonferroni correction. In cross-species amplification, five flatfish species ( Paralichthys lethostigma, Verasper moseri, platichthys stellatus, Hippoglossoides dubius and Cynoglossus semilaevis) showed at least one Polymorphie locus. These Polymorphie microsatellite loci should prove useful for Population analysis of turbot and other related species.

  12. Vaccine-induced modulation of gene expression in turbot peritoneal cells. A microarray approach.

    PubMed

    Fontenla, Francisco; Blanco-Abad, Verónica; Pardo, Belén G; Folgueira, Iria; Noia, Manuel; Gómez-Tato, Antonio; Martínez, Paulino; Leiro, José M; Lamas, Jesús

    2016-07-01

    We used a microarray approach to examine changes in gene expression in turbot peritoneal cells after injection of the fish with vaccines containing the ciliate parasite Philasterides dicentrarchi as antigen and one of the following adjuvants: chitosan-PVMMA microspheres, Freund́s complete adjuvant, aluminium hydroxide gel or Matrix-Q (Isconova, Sweden). We identified 374 genes that were differentially expressed in all groups of fish. Forty-two genes related to tight junctions and focal adhesions and/or actin cytoskeleton were differentially expressed in free peritoneal cells. The profound changes in gene expression related to cell adherence and cytoskeleton may be associated with cell migration and also with the formation of cell-vaccine masses and their attachment to the peritoneal wall. Thirty-five genes related to apoptosis were differentially expressed. Although most of the proteins coded by these genes have a proapoptotic effect, others are antiapoptotic, indicating that both types of signals occur in peritoneal leukocytes of vaccinated fish. Interestingly, many of the genes related to lymphocytes and lymphocyte activity were downregulated in the groups injected with vaccine. We also observed decreased expression of genes related to antigen presentation, suggesting that macrophages (which were abundant in the peritoneal cavity after vaccination) did not express these during the early inflammatory response in the peritoneal cavity. Finally, several genes that participate in the inflammatory response were differentially expressed, and most participated in resolution of inflammation, indicating that an M2 macrophage response is generated in the peritoneal cavity of fish one day post vaccination.

  13. Effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus).

    PubMed

    Jia, Rui; Han, Cen; Lei, Ji-Lin; Liu, Bao-Liang; Huang, Bin; Huo, Huan-Huan; Yin, Shu-Ting

    2015-12-01

    Nitrite (NO2(-)) is commonly present as contaminant in aquatic environment and toxic to aquatic organisms. In the present study, we investigated the effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus). Fish were exposed to various concentrations of nitrite (0, 0.02, 0.08, 0.4 and 0.8mM) for 96 h. Fish blood and gills were collected to assay haematological parameters, oxidative stress and expression of genes after 0, 24, 48 and 96 h of exposure. In blood, the data showed that the levels of methemoglobin (MetHb), triglyceride (TG), potassium (K(+)), cortisol, heat shock protein 70 (HSP70) and glucose significantly increased in treatments with higher concentrations of nitrite (0.4 and/or 0.8mM) after 48 and 96 h, while the levels of haemoglobin (Hb) and sodium (Na(+)) significantly decreased in these treatments. In gills, nitrite (0.4 and/or 0.8mM) apparently reduced the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH), increased the formation of malondialdehyde (MDA), up-regulated the mRNA levels of c-jun amino-terminal kinase (JUK1), p53, caspase-3, caspase-7 and caspase-9 after 48 and 96 h of exposure. The results suggested caspase-dependent and JUK signaling pathways played important roles in nitrite-induced apoptosis in fish. Further, this study provides new insights into how nitrite affects the physiological responses and apoptosis in a marine fish.

  14. Inflammatory responses and side effects generated by several adjuvant-containing vaccines in turbot.

    PubMed

    Noia, M; Domínguez, B; Leiro, J; Blanco-Méndez, J; Luzardo-Álvarez, A; Lamas, J

    2014-05-01

    Several of the adjuvants used in fish vaccines cause adhesions in internal organs when they are injected intraperitoneally. We describe the damage caused by vaccines containing different adjuvants in the turbot Scophthalmus maximus and show that internal adhesions can be greatly reduced by injecting the fish in a specific way. Injection of fish with the needle directed towards the anterior part of the peritoneal cavity induced formation of a single cell-vaccine mass (CVM) that became attached to the parietal peritoneum. However, injection of the fish with the needle pointing in the opposite direction generated many small CVM that became attached to the visceral and parietal peritoneum and in some cases caused internal adhesions. We describe the structural and cellular changes in the adjuvant-induced CVMs. The CVMs mainly comprised neutrophils and macrophages, although most of the former underwent apoptosis, which was particularly evident from day 3 post-injection. The apoptotic cells were phagocytosed by macrophages, which were the dominant cell type from the first days onwards. All of the vaccines induced angiogenesis in the area of contact between the CVM and the mesothelium. Vaccines containing oil-based adjuvants or microspheres induced the formation of granulomas in the CVM; however, no granulomas were observed in the CVM induced by vaccines containing aluminium hydroxide or Matrix-Q(®) as adjuvants. All of the vaccines induced strong migration of cells to the peritoneal cavity. Although some of these cells remained unattached in the peritoneal cavity, most of them formed part of the CVM. We also observed migration of the cells from the peritoneal cavity to lymphoid organs, indicating bidirectional traffic of cells between the inflamed areas and these organs.

  15. Low temperature stress on the hematological parameters and HSP gene expression in the turbot Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Ji, Liqin; Jiang, Keyong; Liu, Mei; Wang, Baojie; Han, Longjiang; Zhang, Mingming; Wang, Lei

    2016-05-01

    To study the effect of low temperature stress on hematological parameters and HSP gene expression in the turbot ( Scophthalmus maximus), water temperature was lowered rapidly from 18 to 1°C. During the cooling process, three individuals were removed from culture tanks at 18, 13, 8, 5, 3, and 1°C. Blood samples and tissues were taken from each individual, hematological indices and HSP gene expression in tissues were measured. The red blood cell count, white blood cell count, and hemoglobin concentration decreased significantly ( P < 0.05) as temperature decreased. Enzyme activities of plasma alanine transaminase and creatine kinase increased as temperature decreased, whereas aspartic transaminase and γ-glutamyl transpeptidase activities displayed no obvious changes above 1°C and lactate dehydrogenase activity increased first and then decreased. Blood urea nitrogen and uric acid levels were highest at 8°C, and creatinine concentration was highest at 3°C. The concentrations of plasma cortisol, cholesterol, and triglyceride all increased significantly ( P < 0.05) as temperature decreased. The serum glucose concentration increased first and then decreased to the initial level. The HSP70 mRNA expression showed various patterns in different tissues, whereas HSP90 mRNA expression showed the same tendency in all tissues. Overall, these results indicate that temperature decreases in the range of 8 to 5°C may induce a stress response in S. maximus and that temperature should be kept above 8°C in the aquaculture setting to avoid damage to the fish.

  16. Alaska marine ice atlas

    SciTech Connect

    LaBelle, J.C.; Wise, J.L.; Voelker, R.P.; Schulze, R.H.; Wohl, G.M.

    1982-01-01

    A comprehensive Atlas of Alaska marine ice is presented. It includes information on pack and landfast sea ice and calving tidewater glacier ice. It also gives information on ice and related environmental conditions collected over several years time and indicates the normal and extreme conditions that might be expected in Alaska coastal waters. Much of the information on ice conditions in Alaska coastal waters has emanated from research activities in outer continental shelf regions under assessment for oil and gas exploration and development potential. (DMC)

  17. Alaska geology revealed

    USGS Publications Warehouse

    Wilson, Frederic H.; Labay, Keith A.

    2016-11-09

    This map shows the generalized geology of Alaska, which helps us to understand where potential mineral deposits and energy resources might be found, define ecosystems, and ultimately, teach us about the earth history of the State. Rock units are grouped in very broad categories on the basis of age and general rock type. A much more detailed and fully referenced presentation of the geology of Alaska is available in the Geologic Map of Alaska (http://dx.doi.org/10.3133/sim3340). This product represents the simplification of thousands of individual rock units into just 39 broad groups. Even with this generalization, the sheer complexity of Alaskan geology remains evident.

  18. Alaska telemedicine: growth through collaboration.

    PubMed

    Patricoski, Chris

    2004-12-01

    The last thirty years have brought the introduction and expansion of telecommunications to rural and remote Alaska. The intellectual and financial investment of earlier projects, the more recent AFHCAN Project and the Universal Service Administrative Company Rural Health Care Division (RHCD) has sparked a new era in telemedicine and telecommunication across Alaska. This spark has been flamed by the dedication and collaboration of leaders at he highest levels of organizations such as: AFHCAN member organizations, AFHCAN Office, Alaska Clinical Engineering Services, Alaska Federal Health Care Partnership, Alaska Federal Health Care Partnership Office, Alaska Native health Board, Alaska Native Tribal health Consortium, Alaska Telehealth Advisory Council, AT&T Alascom, GCI Inc., Health care providers throughout the state of Alaska, Indian Health Service, U.S. Department of Health and Human Services, Office of U.S. Senator Ted Steens, State of Alaska, U.S. Department of Homeland Security--United States Coast Guard, United States Department of Agriculture, United States Department of Defense--Air Force and Army, United States Department of Veterans Affairs, University of Alaska, and University of Alaska Anchorage. Alaska now has one of the largest telemedicine programs in the world. As Alaska moves system now in place become self-sustaining, and 2) collaborating with all stakeholders in promoting the growth of an integrated, state-wide telemedicine network.

  19. Alaska Resource Data File, Nabesna quadrangle, Alaska

    USGS Publications Warehouse

    Hudson, Travis L.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  20. Alaska Resource Data File, Wiseman quadrangle, Alaska

    USGS Publications Warehouse

    Britton, Joe M.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  1. Alaska Resource Data File, Juneau quadrangle, Alaska

    USGS Publications Warehouse

    Barnett, John C.; Miller, Lance D.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  2. Rich Rogers Flying Over Greenland Icecap

    NASA Video Gallery

    Ihis is a view from the NASA P3 aircraft cockpit as it flies 1000 feet over the Greenland icecap during Operation Icebridge mission, which flies each March-May. The end of video shows an ice camp w...

  3. Alaska: A frontier divided

    SciTech Connect

    O'Dell, R. )

    1986-09-01

    The superlatives surrounding Alaska are legion. Within the borders of the 49th US state are some of the world's greatest concentrations of waterfowl, bald eagles, fur seals, walrus, sea lions, otters, and the famous Kodiak brown bear. Alaska features the highest peak of North America, the 20,320-foot Mount McKinley, and the longest archipelago of small islands, the Aleutians. The state holds the greatest percentage of protected wilderness per capita in the world. The expanse of some Alaskan glaciers dwarfs entire countries. Like the periodic advance and retreat of its glaciers, Alaska appears with some regularity on the national US agenda. It last achieved prominence when President Jimmy Carter signed the Alaska National Interest Lands Conservation Act in 1980. Since then the conflict between environmental protection and economic development has been played out throughout the state, and Congress is expected to turn to Alaskan issues again in its next sessions.

  4. Hawkweed Control in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several hawkweed species from Europe have escaped ornamental planting and have colonized roadsides and grasslands in south central and southeast Alaska. These plants form near monotypic stands, reducing plant diversity and decreasing pasture productivity. A replicated greenhouse study was conducted ...

  5. Greenland's Coast in Holiday Colors

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Vibrant reds, emerald greens, brilliant whites, and pastel blues adorn this view of the area surrounding the Jakobshavn Glacier on the western coast of Greenland. The image is a false-color (near-infrared, green, blue) view acquired by the Multi-angle Imaging SpectroRadiometer's nadir camera. The brightness of vegetation in the near-infrared contributes to the reddish hues; glacial silt gives rise to the green color of the water; and blue-colored melt ponds are visible in the bright white ice. A scattering of small icebergs in Disco Bay adds a touch of glittery sparkle to the scene.

    The large island in the upper left is called Qeqertarsuaq. To the east of this island, and just above image center, is the outlet of the fast-flowing Jakobshavn (or Ilulissat) glacier. Jakobshavn is considered to have the highest iceberg production of all Greenland glaciers and is a major drainage outlet for a large portion of the western side of the ice sheet. Icebergs released from the glacier drift slowly with the ocean currents and pose hazards for shipping along the coast.

    The Multi-angle Imaging SpectroRadiometer views the daylit Earth continuously and the entire globe between 82 degrees north and 82 degrees south latitude is observed every 9 days. These data products were generated from a portion of the imagery acquired on June 18, 2003 during Terra orbit 18615. The image cover an area of about 254 kilometers x 210 kilometers, and use data from blocks 34 to 35 within World Reference System-2 path 10.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  6. The Greenland gravitational constant experiment

    NASA Astrophysics Data System (ADS)

    Ander, Mark E.; Parker, Robert L.; Aiken, Carlos L. V.; Gorman, Michael R.; Nieto, Michael Martin; Cooper, A. Paul R.; Ferguson, John F.; Fisher, Elizabeth; Greer, James; Hammer, Phil; Hansen, B. Lyle; McMechan, George A.; Sasagawa, Glenn S.; Sidles, Cyndi; Stevenson, J. Mark; Wirtz, Jim

    1990-09-01

    An Airy-type geophysical experiment was conducted in a 2-km-deep hole in the Greenland ice cap at depths between 213 m and 1673 m to test for possible violations of Newton's inverse square law. The experiment was done at Dye 3, the location of a Distant Early Warming Line radar dome and the site of the deepest of the Greenland Ice-Sheet Program (GISP) drill holes. Gravity measurements were made at eight depths in 183-m intervals with a LaCoste & Romberg borehole gravity meter. Prior to the experiment the borehole, gravity meter was calibrated with an absolute gravity meter, and the wireline depth-finding system used in the borehole logging was calibrated in a vertical mine-shaft against a laser geodimeter. The density of the ice in the region was calculated from measurements taken from ice cores obtained from earlier drilling observations. Ice penetrating radar was employed in order to correct the gravity data for the topography of the ice-rock interface. Surface gravity observations were made to assess the extent to which density variations in the sub-ice rock could affect the vertical gravity gradient. The locations of the gravity observation points were determined with a combination of GPS recording, first-order leveling, and EDM surveying. An anomalous variation in gravity totaling 3.87 mGal (3.87×10-5 m/s2) in a depth interval of 1460 m was observed. This may be attributed either to a breakdown of Newtonian gravity or to unexpected density variations in the rock below the ice.

  7. Alaska Resource Data File, Point Lay quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Point Lay 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  8. Alaska looks HOT!

    SciTech Connect

    Belcher, J.

    1997-07-01

    Production in Alaska has been sluggish in recent years, with activity in the Prudhoe Bay region in the North Slope on a steady decline. Alaska North Slope (ANS) production topped out in 1988 at 2.037 MMbo/d, with 1.6 MMbo/d from Prudhoe Bay. This year operators expect to produce 788 Mbo/d from Prudhoe Bay, falling to 739 Mbo/d next year. ANS production as a whole should reach 1.3 MMbo/d this year, sliding to 1.29 MMbo/d in 1998. These declining numbers had industry officials and politicians talking about the early death of the Trans-Alaskan Pipeline System-the vital link between ANS crude and markets. But enhanced drilling technology coupled with a vastly improved relationship between the state government and industry have made development in Alaska more economical and attractive. Alaska`s Democratic Gov. Tommy Knowles is fond of telling industry {open_quotes}we`re open for business.{close_quotes} New discoveries on the North Slope and in the Cook Inlet are bringing a renewed sense of optimism to the Alaska exploration and production industry. Attempts by Congress to lift a moratorium on exploration and production activity in the Arctic National Wildlife Refuge (ANWR) have been thwarted thus far, but momentum appears to be with proponents of ANWR drilling.

  9. Crustal Structure in Central-Eastern Greenland

    NASA Astrophysics Data System (ADS)

    Shulgin, A.; Thybo, H.

    2013-12-01

    We present the seismic structure in the interior of Greenland based on the first measurements by the seismic refraction/wide angle reflection method. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where the crustal structure is affected by oceanic break-up and may not be representative of the interior of the island. Acquisition of geophysical data onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The EW-trending profile extends 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the centre of the ice cap. The planned extension of the profile by use of OBSs and air gun shooting in Scoresbysund Fjord to the east coast of Greenland was unfortunately cancelled, because navigation was prevented by ice drift. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 100 kg at 35-85 m depth in individual boreholes. Two-dimensional velocity model based on forward ray tracing and tomography modelling shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western part to 40 km in the eastern part of the profile. Earlier studies show that crustal thickness further decreases eastward to ca. 30 km below the fjord system, but details of the changes are unknown. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the TopoGreenland profile may indicate past collision tectonics or may be related or to the passage of the Iceland mantle plume. The origin of the pronounced circum-Atlantic mountain ranges in Norway and eastern Greenland, which have

  10. Responses of conventional and molecular biomarkers in turbot Scophthalmus maximus exposed to heavy fuel oil no. 6 and styrene.

    PubMed

    Ruiz, Pamela; Ortiz-Zarragoitia, Maren; Orbea, Amaia; Theron, Michael; Le Floch, Stéphane; Cajaraville, Miren P

    2012-07-15

    Several accidental spills in European coastal areas have resulted in the release of different toxic compounds into the marine environment, such as heavy fuel oil type no. 6 in the "Erika" and "Prestige" oil spills and the highly toxic styrene after the loss of the "Ievoli Sun". There is a clear need to develop tools that might allow assessing the biological impact of these accidental spills on aquatic organisms. The aim of the present study was to determine the short-term effects and recovery after exposure of juvenile fish (Scophthalmus maximus) to heavy fuel oil no. 6 and styrene by using a battery of molecular, cell and tissue level biomarkers. Turbots were exposed to styrene for 7 days and to the diluted soluble fraction of the oil (10%) for 14 days, and then allowed to recover in clean seawater for the same time periods. cyp1a1 transcript was overexpressed in turbots after 3 and 14 days of exposure to heavy fuel oil, whereas ahr transcription was not modulated after heavy fuel oil and styrene exposure. pparα transcription level was significantly up-regulated after 3 days of treatment with styrene. Liver activity of peroxisomal acyl-CoA oxidase (AOX) was significantly induced after 14 days of oil exposure, but it was not affected by styrene. Hepatocyte lysosomal membrane stability (LMS) was significantly reduced after exposure to both treatments, indicating that the tested compounds significantly impaired fish health. Both AOX and LMS values returned to control levels after the recovery period. No differences in gamete development were observed between fuel- or styrene- exposed fish and control fish, and vitellogenin plasma levels were low, suggesting no xenoestrogenic effects of fuel oil or styrene. While styrene did not cause any increase in the prevalence of liver histopathological alterations, prevalence of extensive cell vacuolization increased after exposure to heavy fuel oil for 14 days. In conclusion, the suite of selected biomarkers proved to be

  11. Alaska Resource Data File: Chignik quadrangle, Alaska

    USGS Publications Warehouse

    Pilcher, Steven H.

    2000-01-01

    Descriptions of the mineral occurrences can be found in the report. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska. There is a website from which you can obtain the data for this report in text and Filemaker Pro formats

  12. Earthshots: Satellite images of environmental change – Petermann Glacier, Greenland

    USGS Publications Warehouse

    Adamson, Thomas

    2016-01-01

    This calving is normal, but it’s worth watching Petermann and other Greenland glaciers closely. Petermann is one of the major marine-terminating glaciers of Greenland. Ice loss from the Greenland Ice Sheet has increased recently. An article in Nature concluded that climate change may cause Petermann and other Greenland glaciers to contribute to sea level rise. Landsat helps glaciologists keep a close eye on this remote but significant glacier.

  13. Clouds enhance Greenland ice sheet meltwater runoff.

    PubMed

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

    2016-01-12

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

  14. Clouds enhance Greenland ice sheet meltwater runoff

    PubMed Central

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

    2016-01-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise. PMID:26756470

  15. Clouds enhance Greenland ice sheet meltwater runoff

    NASA Astrophysics Data System (ADS)

    Van Tricht, Kristof; Lhermitte, Stef; Lenaerts, Jan T. M.; Gorodetskaya, Irina V.; L'Ecuyer, Tristan S.; Noël, Brice; van den Broeke, Michiel R.; Turner, David D.; van Lipzig, Nicole P. M.

    2016-04-01

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

  16. Pharmacokinetic model of florfenicol in turbot (Scophthalmus maximus): establishment of optimal dosage and administration in medicated feed.

    PubMed

    de Ocenda, V-R; Almeida-Prieto, S; Luzardo-Álvarez, A; Barja, J L; Otero-Espinar, F J; Blanco-Méndez, J

    2017-03-01

    The pharmacokinetics of florfenicol (FF) in turbot (Scophthalmus maximus) was studied after single intravenous (10 mg kg(-1) ) and oral (100 mg kg(-1) ) administration. The plasma concentration-time data of florfenicol were described by an open one-compartment model. The elimination half-life (t1/2 ) was estimated to be 21.0 h, and the total body clearance, Cl, was determined as 0.028 L kg h(-1) . The apparent volume distribution (Vd ) was calculated to be 0.86 L kg(-1) and the mean residence time (MRTiv ) was 30.2 h. Following oral administration, the maximum plasma concentration (Cmax ) of 55.4 μg mL(-1) was reached at 12 h (Tmax ). The absorption constant (ka ) was 0.158 h(-1) . The bioavailability was estimated to be 57.1%. The low bioavailability observed at higher doses was explained by the saturation of the mechanisms of absorption. The drug absorption process was limited by its inherent low solubility, which limited the amount of available FF absorbed in the gastrointestinal tract. Based on the pharmacokinetic data, an optimal dosing schedule for FF administration is hereby provided. Based on the minimum inhibitory concentration found for susceptible strains of Aeromonas salmonicida, oral FF administration of first, an initial dose of 30 mg FF kg(-1) , followed by 6 maintenance doses at 18 mg kg(-1) /daily could be effective against furunculosis in turbot.

  17. Airborne Laser Mapping of Greenland

    SciTech Connect

    Krabill, W.B.; Thomas, R.H.; Martin, C.F.; Sonntag, J.G.

    1996-10-01

    The Polar ice sheets contain enough water to raise Earth`s sea level by some 70 m. It is not clear whether changes in these ice sheets are contributing to the current rise. Ice sheet mass balance estimates can be obtained by monitoring the topography of selected Polar regions. The Arctic Ice Mapping (AIM) Project is a continuing program designed to provide a record of the absolute height of representative Arctic ice sheets. Using the Global Positioning System (GPS), aircraft flight lines may be duplicated with sufficient tolerance to provide repeated laser elevation measurements from one year to another. The raw GPS measurements are re-processed post-mission to provide sub-10 cm trajectories for each aircraft flight. This program began in 1991 with a proof-of-concept mission to Greenland. The data from this mission demonstrates 20 cm repeatability, principally due to the limited GPS constellation available. Refinements in all phases of the program (software, law and GPS hardware, and a complete GPS constellation) have yielded 10 cm repeatability in data from subsequent years, which includes probable geophysical change in the surface due to storm events and wind drift. 5 refs., 5 figs., 2 tabs.

  18. Accretion of southern Alaska

    USGS Publications Warehouse

    Hillhouse, J.W.

    1987-01-01

    Paleomagnetic data from southern Alaska indicate that the Wrangellia and Peninsular terranes collided with central Alaska probably by 65 Ma ago and certainly no later than 55 Ma ago. The accretion of these terranes to the mainland was followed by the arrival of the Ghost Rocks volcanic assemblage at the southern margin of Kodiak Island. Poleward movement of these terranes can be explained by rapid motion of the Kula oceanic plate, mainly from 85 to 43 Ma ago, according to recent reconstructions derived from the hot-spot reference frame. After accretion, much of southwestern Alaska underwent a counterclockwise rotation of about 50 ?? as indicated by paleomagnetic poles from volcanic rocks of Late Cretaceous and Early Tertiary age. Compression between North America and Asia during opening of the North Atlantic (68-44 Ma ago) may account for the rotation. ?? 1987.

  19. Genotoxicity of field-collected inter-tidal sediments from Cork Harbor, Ireland, to juvenile turbot (Scophthalmus maximus L.) as measured by the Comet assay.

    PubMed

    Kilemade, M F; Hartl, M G J; Sheehan, D; Mothersill, C; Van Pelt, F N A M; O'Halloran, J; O'Brien, N M

    2004-01-01

    The alkaline single cell gel electrophoresis (SCGE) or Comet assay was employed to test the potential of surficial sediment collected from Cork Harbor, Ireland, to induce DNA damage in turbot (Scophthalmus maximus L.) in a laboratory exposure experiment. Turbot were exposed for 21 days to field-collected sediment from Cork Harbor and from a relatively clean reference site at Ballymacoda and sampled at 0, 7, 14, and 21 days. As a positive control for the sediment exposure experiment, a subsample of the turbot was exposed to cadmium chloride-spiked seawater. DNA damage analysis was performed on epidermal, gill, spleen, liver, and whole blood cell preparations. Liver, gill, and blood were the most sensitive tissues while a lower level of damage was detected in the epidermis and spleen. The blood was determined to be a suitable predictor of DNA damage in the whole organism. Chemical analysis of the sediment indicated that polycyclic aromatic hydrocarbons formed the bulk of the contaminants, with the harbor sites having almost double the levels of those from the reference site. The data indicated that turbot exposed to sediments from Cork Harbor elicited a significant increase in DNA damage in comparison with those exposed to sediment from the reference site and that exposure to the contaminated sediments caused a multi-organ genotoxic response. Results from the study indicate a relationship between the presence of genotoxicants in sediment and DNA damage. This finding was encouraging with regard to the potential use of the Comet assay as part of a marine biomonitoring strategy.

  20. Expression analysis of the insulin-like growth factors I and II during embryonic and early larval development of turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Wen, Haishen; Qi, Qian; Hu, Jian; Si, Yufeng; He, Feng; Li, Jifang

    2015-04-01

    The insulin-like growth factors I and II (IGF-I and IGF-II) are important proteins involved in fish growth and development. Here, we report the isolation of IGF-II and expression analysis of IGFs in turbot Scophthalmus maximus, aiming to clarify their function in embryonic and larval development of fish. The deduced IGF-II gene is 808 bp in full length, which encodes a protein of 219 amino acids and is 93% similar with that of Paralichthys olicaceus in amino acid sequence. The tissue abundance and the expression pattern of IGFs in a turbot at early development stages were investigated via reverse transcription-polymer chain reaction. Result showed that the IGF-I and IGF-II genes were widely expressed in tissues of S. maximus. IGF-I was detected in all tissues except intestines with the highest level in liver, while IGF-II transcript presented in all tissues except muscle. At the stages of embryonic and larval development, the mRNA levels of IGFs sharply increased from the stage of unfertilized egg to post larva, followed by a decrease with larval development. However, there was an increase in IGF-I at the embryonic stage and IGF-II at the gastrula stage, respectively. These results suggested that IGFs play important roles in cell growth and division of the turbot. Our study provides reference data for further investigation of growth regulation in turbot, which can guarantee better understanding of the physiological role that IGFs play in fish.

  1. Skerrylike mirages and the discovery of greenland.

    PubMed

    Lehn, W H

    2000-07-20

    The Norse discovery of Greenland is associated with the sighting of low barren islands called Gunnbjörn's Skerries, which have never been satisfactorily identified. Here the historical references that connect the skerries to Greenland are reviewed. A mirage of the Greenland coast, arising specifically from optical ducting under a sharp temperature inversion, is used to explain the vision of skerries seen by the Norse mariners. Images from both ducting and uniform inversions are calculated. Under the assumption of a clean Rayleigh atmosphere, sufficient visibility remains to see the skerry image at a distance of 220 km. There is significant circumstantial evidence to indicate that the Norse were familiar with the skerrylike mirage and that they used it to discover new lands.

  2. Measurements of Glacial Isostatic Adjustment in Greenland

    NASA Astrophysics Data System (ADS)

    Khan, Shfaqat Abbas; Bamber, Jonathan; Bevis, Michael; Wahr, John; van dam, Tonie; Wouters, Bert; Willis, Michael

    2015-04-01

    The Greenland GPS network (GNET) was constructed to provide a new means to assess viscoelastic and elastic adjustments driven by past and present-day changes in ice mass. Here we assess existing glacial isostatic adjustments (GIA) models by analysing 1995-present data from 61 continuous GPS receivers located along the edge of the Greenland ice sheet. Since GPS receivers measure both the GIA and elastic signal, we isolate the GIA signal, by removing the elastic adjustments of the crust due to present-day mass loss using high-resolution ice surface elevation change grids derived from satellite and airborne altimetry measurements (ERS1/2, ICESat, ATM, ENVISAT, and CryoSat-2). In general, our observed GIA rates contradict models, suggesting GIA models and hence their ice load history for Greenland are not well constrained.

  3. Fatal outbreak of botulism in Greenland.

    PubMed

    Hammer, Tóra Hedinsdottir; Jespersen, Sanne; Kanstrup, Jakob; Ballegaard, Vibe Cecilie; Kjerulf, Anne; Gelvan, Allan

    2015-03-01

    Botulism commonly occurs when the anaerobic, gram-positive bacterium Clostridium botulinum, under suitable conditions, produces botulinum neurotoxins. Named A-F, these toxins are the immediate causative agent of the clinical symptoms of symmetrical, descending neurological deficits, including respiratory muscle paralysis. We present five cases of foodborne botulism occurring in Greenland, two with fatal outcome, caused by ingestion of tradionally preserved eider fowl. In the cases of the survivors, antitoxin and supportive care, including mechanical ventilation, were administered. In these cases recovery was complete. Microbiological assays, including toxin neutralization bioassay, demonstrated the presence of neurotoxin E in two survivors. The third survivor was shown by PCR to have the BoNT type E gene in faeces. This is the first report of cases of fatal botulism in Greenland. It underscores the importance of prompt coordinated case management effort in a geographically isolated area such as Greenland.

  4. 2012 Alaska Performance Scholarship Outcomes Report

    ERIC Educational Resources Information Center

    Rae, Brian

    2012-01-01

    As set forth in Alaska Statute 14.43.840, Alaska's Departments of Education & Early Development (EED) and Labor and Workforce Development (DOLWD), the University of Alaska (UA), and the Alaska Commission on Postsecondary Education (ACPE) present this first annual report on the Alaska Performance Scholarship to the public, the Governor, and the…

  5. Late Holocene expansion of Istorvet ice cap, Liverpool Land, east Greenland

    NASA Astrophysics Data System (ADS)

    Lowell, Thomas V.; Hall, Brenda L.; Kelly, Meredith A.; Bennike, Ole; Lusas, Amanda R.; Honsaker, William; Smith, Colby A.; Levy, Laura B.; Travis, Scott; Denton, George H.

    2013-03-01

    The Greenland Ice Sheet is undergoing dynamic changes that will have global implications if they continue into the future. In this regard, an understanding of how the ice sheet responded to past climate changes affords a baseline for anticipating future behavior. Small, independent ice caps adjacent to the Greenland Ice Sheet (hereinafter called "local ice caps") are sensitive indicators of the response of Greenland ice-marginal zones to climate change. Therefore, we reconstructed late Holocene ice-marginal fluctuations of the local Istorvet ice cap in east Greenland, using radiocarbon dates of subfossil plants, 10Be dates of surface boulders, and analyses of sediment cores from both threshold and control lakes. During the last termination, the Istorvet ice cap had retreated close to its maximum Holocene position by ˜11,730 cal yr BP. Radiocarbon dates of subfossil plants exposed by recent recession of the ice margin indicate that the Istorvet cap was smaller than at present from AD 200 to AD 1025. Sediments from a threshold lake show no glacial input until the ice cap advanced to within 365 m of its Holocene maximum position by ˜AD 1150. Thereafter the ice cap remained at or close to this position until at least AD 1660. The timing of this, the most extensive of the Holocene, expansion is similar to that recorded at some glaciers in the Alps and in southern Alaska. However, in contrast to these other regions, the expansion in east Greenland at AD 1150 appears to have been very close to, if not at, a maximum Holocene value. Comparison of the Istorvet ice-cap fluctuations with Holocene glacier extents in Southern Hemisphere middle-to-high latitude locations on the Antarctic Peninsula and in the Andes and the Southern Alps suggests an out-of-phase relationship. If correct, this pattern supports the hypothesis that a bipolar see-saw of oceanic and/or atmospheric circulation during the Holocene produced asynchronous glacier response at some localities in the two

  6. USGS Alaska State Mosaic

    USGS Publications Warehouse

    ,

    2008-01-01

    The Alaska State Mosaic consists of portions of scenes from the Multi-Resolution Land Characteristics 2001 (MRLC 2001) collection. The 172 selected scenes have been geometrically and radiometrically aligned to produce a seamless, relatively cloud-free image of the State. The scenes were acquired between July 1999 and September 2002, resampled to 120-meter pixels, and cropped to the State boundary. They were reprojected into a standard Alaska Albers projection with the U.S. National Elevation Dataset (NED) used to correct for relief.

  7. Late Pliocene deglaciation of Southern Greenland

    NASA Astrophysics Data System (ADS)

    Walczak, M. H.; Carlson, A. E.; Stoner, J. S.; Hatfield, R. G.; Wolhowe, M. D.; Mathias, A.

    2015-12-01

    Predicting the response of the remaining Antarctic and Greenland ice sheets to increasing atmospheric greenhouse gas concentrations is an important goal of climate science. The late Pliocene (3.3-3.0 Ma; formerly the middle Pliocene) may offer a natural quasi-analogue to climate in the upcoming centuries: CO2 levels were ~400 PPM, global surface temperatures were 2-3 degrees higher, and sea level was likely at least 6 m higher than today. Yet little is currently known about the history of the pre-Quaternary Greenland ice sheet. IODP Expedition 303 site U1307 at 2575 m depth on the Eirik Ridge extends back to 3.4 Ma, capturing the late-Pliocene warm period adjacent to the southern Greenland ice sheet. Ice-rafted debris records, interpreted on a paleomagnetic reversal age model, suggest roughly 40 ka cyclicity of between ~5% and ~40% sand. Between ~3.3 and 3.2 Ma there is a significant change in lithology characterized by an abrupt reduction in magnetic susceptibility, during which time the sand fraction remains below 10%. Assuming a magnetite mineralogy, hysteresis ratios support a much finer magnetic assemblage of unique provenance in this interval; Mrs/Ms values of the silt fraction range from ~0.2-0.25, compared to ~0.1 in the sediments above and below. The origin this material will be discussed, although this observation is unambiguously consistent with the disappearance of silt transported from the southern Greenland ice sheet. The lack of Greenlandic source material observed in this interval is unique in the last 3.4 Ma at this location, and may indicate full deglaciation of southern Greenland in the late Pliocene.

  8. Towards Greenland Glaciation: cumulative or abrupt transition?

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  9. Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Lluch, Nuria; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Magadán, Susana

    2015-05-01

    In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening.

  10. Paleoclimate. Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming.

    PubMed

    Praetorius, Summer K; Mix, Alan C

    2014-07-25

    Some proposed mechanisms for transmission of major climate change events between the North Pacific and North Atlantic predict opposing patterns of variations; others suggest synchronization. Resolving this conflict has implications for regulation of poleward heat transport and global climate change. New multidecadal-resolution foraminiferal oxygen isotope records from the Gulf of Alaska (GOA) reveal sudden shifts between intervals of synchroneity and asynchroneity with the North Greenland Ice Core Project (NGRIP) δ(18)O record over the past 18,000 years. Synchronization of these regions occurred 15,500 to 11,000 years ago, just prior to and throughout the most abrupt climate transitions of the last 20,000 years, suggesting that dynamic coupling of North Pacific and North Atlantic climates may lead to critical transitions in Earth's climate system.

  11. Quaternary vertebrates from Greenland: A review

    NASA Astrophysics Data System (ADS)

    Bennike, Ole

    Remains of fishes, birds and mammals are rarely reported from Quaternary deposits in Greenland. The oldest remains come from Late Pliocene and Early Pleistocene deposits and comprise Atlantic cod, hare, rabbit and ringed seal. Interglacial and interstadial deposits have yielded remains of cod, little auk, collared lemming, ringed seal, reindeer and bowhead whale. Early and Mid-Holocene finds include capelin, polar cod, red fish, sculpin, three-spined stickleback, Lapland longspur, Arctic hare, collared lemming, wolf, walrus, ringed seal, reindeer and bowhead whale. It is considered unlikely that vertebrates could survive in Greenland during the peak of the last glaciation, but many species had probably already immigrated in the Early Holocene.

  12. First Younger Dryas moraines in Greenland

    NASA Astrophysics Data System (ADS)

    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

  13. Alaska's Cold Desert.

    ERIC Educational Resources Information Center

    Brune, Jeff; And Others

    1996-01-01

    Explores the unique features of Alaska's Arctic ecosystem, with a focus on the special adaptations of plants and animals that enable them to survive in a stressful climate. Reviews the challenges facing public and private land managers who seek to conserve this ecosystem while accommodating growing demands for development. Includes classroom…

  14. Alaska Mathematics Standards

    ERIC Educational Resources Information Center

    Alaska Department of Education & Early Development, 2012

    2012-01-01

    High academic standards are an important first step in ensuring that all Alaska's students have the tools they need for success. These standards reflect the collaborative work of Alaskan educators and national experts from the nonprofit National Center for the Improvement of Educational Assessment. Further, they are informed by public comments.…

  15. Alaska Glaciers and Rivers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image on October 7, 2007, showing the Alaska Mountains of south-central Alaska already coated with snow. Purple shadows hang in the lee of the peaks, giving the snow-clad land a crumpled appearance. White gives way to brown on the right side of the image where the mountains yield to the lower-elevation Susitna River Valley. The river itself cuts a silver, winding path through deep green forests and brown wetlands and tundra. Extending from the river valley, are smaller rivers that originated in the Alaska Mountains. The source of these rivers is evident in the image. Smooth white tongues of ice extend into the river valleys, the remnants of the glaciers that carved the valleys into the land. Most of the water flowing into the Gulf of Alaska from the Susitna River comes from these mountain glaciers. Glacier melt also feeds glacier lakes, only one of which is large enough to be visible in this image. Immediately left of the Kahiltna River, the aquamarine waters of Chelatna Lake stand out starkly against the brown and white landscape.

  16. Venetie, Alaska energy assessment.

    SciTech Connect

    Jensen, Richard Pearson; Baca, Michael J.; Schenkman, Benjamin L.; Brainard, James Robert

    2013-07-01

    This report summarizes the Energy Assessment performed for Venetie, Alaska using the principals of an Energy Surety Microgrid (ESM) The report covers a brief overview of the principals of ESM, a site characterization of Venetie, a review of the consequence modeling, some preliminary recommendations, and a basic cost analysis.

  17. Alaska's Logging Camp School.

    ERIC Educational Resources Information Center

    Millward, Robert E.

    1999-01-01

    A visit to Ketchikan, Alaska, reveals a floating, one-teacher logging-camp school that uses multiage grouping and interdisciplinary teaching. There are 10 students. The school gym and playground, bunkhouse, fuel tanks, mess hall, and students' homes bob up and down and are often moved to other sites. (MLH)

  18. Seismology Outreach in Alaska

    NASA Astrophysics Data System (ADS)

    Gardine, L.; Tape, C.; West, M. E.

    2014-12-01

    Despite residing in a state with 75% of North American earthquakes and three of the top 15 ever recorded, most Alaskans have limited knowledge about the science of earthquakes. To many, earthquakes are just part of everyday life, and to others, they are barely noticed until a large event happens, and often ignored even then. Alaskans are rugged, resilient people with both strong independence and tight community bonds. Rural villages in Alaska, most of which are inaccessible by road, are underrepresented in outreach efforts. Their remote locations and difficulty of access make outreach fiscally challenging. Teacher retention and small student bodies limit exposure to science and hinder student success in college. The arrival of EarthScope's Transportable Array, the 50th anniversary of the Great Alaska Earthquake, targeted projects with large outreach components, and increased community interest in earthquake knowledge have provided opportunities to spread information across Alaska. We have found that performing hands-on demonstrations, identifying seismological relevance toward career opportunities in Alaska (such as natural resource exploration), and engaging residents through place-based experience have increased the public's interest and awareness of our active home.

  19. Arctic cyclone water vapor isotopes support past sea ice retreat recorded in Greenland ice.

    PubMed

    Klein, Eric S; Cherry, J E; Young, J; Noone, D; Leffler, A J; Welker, J M

    2015-05-29

    Rapid Arctic warming is associated with important water cycle changes: sea ice loss, increasing atmospheric humidity, permafrost thaw, and water-induced ecosystem changes. Understanding these complex modern processes is critical to interpreting past hydrologic changes preserved in paleoclimate records and predicting future Arctic changes. Cyclones are a prevalent Arctic feature and water vapor isotope ratios during these events provide insights into modern hydrologic processes that help explain past changes to the Arctic water cycle. Here we present continuous measurements of water vapor isotope ratios (δ(18)O, δ(2)H, d-excess) in Arctic Alaska from a 2013 cyclone. This cyclone resulted in a sharp d-excess decrease and disproportional δ(18)O enrichment, indicative of a higher humidity open Arctic Ocean water vapor source. Past transitions to warmer climates inferred from Greenland ice core records also reveal sharp decreases in d-excess, hypothesized to represent reduced sea ice extent and an increase in oceanic moisture source to Greenland Ice Sheet precipitation. Thus, measurements of water vapor isotope ratios during an Arctic cyclone provide a critical processed-based explanation, and the first direct confirmation, of relationships previously assumed to govern water isotope ratios during sea ice retreat and increased input of northern ocean moisture into the Arctic water cycle.

  20. Discharge of debris from ice at the margin of the Greenland ice sheet

    USGS Publications Warehouse

    Knight, P.G.; Waller, R.I.; Patterson, C.J.; Jones, A.P.; Robinson, Z.P.

    2002-01-01

    Sediment production at a terrestrial section of the ice-sheet margin in West Greenland is dominated by debris released through the basal ice layer. The debris flux through the basal ice at the margin is estimated to be 12-45 m3 m-1 a-1. This is three orders of magnitude higher than that previously reported for East Antarctica, an order of magnitude higher than sites reported from in Norway, Iceland and Switzerland, but an order of magnitude lower than values previously reported from tidewater glaciers in Alaska and other high-rate environments such as surging glaciers. At our site, only negligible amounts of debris are released through englacial, supraglacial or subglacial sediment transfer. Glacio-fluvial sediment production is highly localized, and long sections of the ice-sheet margin receive no sediment from glaciofluvial sources. These findings differ from those of studies at more temperate glacial settings where glaciofluvial routes are dominant and basal ice contributes only a minor percentage of the debris released at the margin. These data on debris flux through the terrestrial margin of an outlet glacier contribute to our limited knowledge of debris production from the Greenland ice sheet.

  1. Arctic cyclone water vapor isotopes support past sea ice retreat recorded in Greenland ice

    PubMed Central

    Klein, Eric S.; Cherry, J. E.; Young, J.; Noone, D.; Leffler, A. J.; Welker, J. M.

    2015-01-01

    Rapid Arctic warming is associated with important water cycle changes: sea ice loss, increasing atmospheric humidity, permafrost thaw, and water-induced ecosystem changes. Understanding these complex modern processes is critical to interpreting past hydrologic changes preserved in paleoclimate records and predicting future Arctic changes. Cyclones are a prevalent Arctic feature and water vapor isotope ratios during these events provide insights into modern hydrologic processes that help explain past changes to the Arctic water cycle. Here we present continuous measurements of water vapor isotope ratios (δ18O, δ2H, d-excess) in Arctic Alaska from a 2013 cyclone. This cyclone resulted in a sharp d-excess decrease and disproportional δ18O enrichment, indicative of a higher humidity open Arctic Ocean water vapor source. Past transitions to warmer climates inferred from Greenland ice core records also reveal sharp decreases in d-excess, hypothesized to represent reduced sea ice extent and an increase in oceanic moisture source to Greenland Ice Sheet precipitation. Thus, measurements of water vapor isotope ratios during an Arctic cyclone provide a critical processed-based explanation, and the first direct confirmation, of relationships previously assumed to govern water isotope ratios during sea ice retreat and increased input of northern ocean moisture into the Arctic water cycle. PMID:26023728

  2. Drivers of River Water Temperature Space-time Variability in Northeast Greenland

    NASA Astrophysics Data System (ADS)

    Hannah, D. M.; Docherty, C.; Milner, A.

    2015-12-01

    Water temperature plays an important role in stream ecosystem functioning; however, water temperature dynamics in high Arctic environments have received relatively little attention. Given that global climate is predicted to change most at high latitudes, it is vital we broaden our knowledge of space-time variability in Arctic river temperature to understand controlling processes and potential consequences of climate change. To address this gap, our research aims: (1) to characterise seasonal and diel patterns of variability over three summer and two winter seasons with contrasting hydrometeorological conditions, (2) to unravel the key drivers influencing thermal regimes and (3) to place these results in the context of other snow/ glacier-melt dominated environments. Fieldwork was undertaken in July-September 2013, 2014 and 2015 close to the Zackenberg Research Station in Northeast Greenland - an area of continuous permafrost with a mean July air temperature of 6 °C. Five streams were chosen that drain different water source contributions (glacier melt, snow melt, groundwater). Data were collected at 30 minute intervals using micro-dataloggers. Air temperature data were collected within 7km by the Greenland Survey. Weather conditions were highly variable between field campaigns, with 2013 experiencing below average, and 2014 and 2015 above average, snowfall. Summer water temperatures appear to be high in comparison to some Arctic streams in Alaska and in Svalbard. Winter snowfall extent decreases stream water temperature; and water temperature increases with atmospheric exposure time (distance from source) - illustrating the intertwined controls of water and heat fluxes. These Greenland streams are most strongly influenced by snowmelt, but groundwater contributions could increase with a changing climate due to increased active layer thickness, which may result in increased river temperature with implications for aquatic biodiversity and ecosystem functioning.

  3. Influence of light and feeding conditions on swimming activity rhythms of larval and juvenile turbot. Scophthalmus maximus L.: An experimental study

    NASA Astrophysics Data System (ADS)

    Champalbert, Gisèle; Le Direach-Boursier, Laurence

    1998-12-01

    Turbot larvae are transported towards coastal nursery areas and live in very shallow waters. Food availability is assumed to be an important factor that retains them in such areas. To study the effects of a biotic factor (food) and an abiotic factor (light) that strongly influence behavioural mechanisms, experiments were carried out on laboratory-reared animals: larvae (1 cm), post-larvae (1.2 to 2.5 cm) and early juveniles (6 to 7 cm). Three kinds of apparatus and methods were used to record variations in swimming activity: (1) a phototaxis device to study orientation reactions in horizontal tanks; (2) actographs with infrared photoelectric barriers fitted around vertical cylindrical tanks; and (3) video cameras and cylindrical tanks. Observations were performed in total darkness and under dark-light regimes. Different types and quantities of food were provided to the fish. Larvae and juveniles of turbot exhibited a positive phototaxis from 1 to 1000 μW cm -2. At intensities lower than or equal to 0.1 μW cm -2, they did not exhibit clear reactions toward or away from the light. Turbot larvae and juveniles kept in total darkness did not show a clear rhythm of activity. Under natural illumination as well as in artificial LD conditions of similar periodicity, larvae swam by day and night. Live food ( Artemia nauplii or juvenile mysids) induced an immediate increase in activity or the maintenance of a high level of activity, which decreased over the following days. Recently metamorphosed turbot kept under LD conditions exhibited a clear rhythm with a nocturnal maximum. Food given at night did not induce swimming changes as long as food density remained low. At higher prey concentrations, increased activity during feeding was followed by reduced activity for more than 24 hours. A similar response pattern was noted when active food was given in large quantities during the day: juveniles displayed an immediate increase in activity, which subsequently decreased. Regular

  4. Characterization of household waste in Greenland

    SciTech Connect

    Eisted, Rasmus; Christensen, Thomas H.

    2011-07-15

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

  5. Characterization of household waste in Greenland.

    PubMed

    Eisted, Rasmus; Christensen, Thomas H

    2011-07-01

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

  6. Greenland's pronounced glacier retreat not irreversible

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-02-01

    In recent decades, the combined forces of climate warming and short-term variability have forced the massive glaciers that blanket Greenland into retreat, with some scientists worrying that deglaciation could become irreversible. The short history of detailed glacier observations, however, makes pinning the ice loss to either short-term dynamics or long-term change difficult. Research by Young et al. detailing the effects of two bouts of sudden and temporary cooling during an otherwise warm phase in Greenland's climate history could help answer that question by showing just how heavy a hand short-term variability can have in dictating glacier dynamics. Along the western edge of Greenland the massive Jakobshavn Isbræ glacier reaches out to the coast, its outflow dropping icebergs into Baffin Bay during the summer months. Flanking the glacier's tongue are the Tasiussaq and Marrait moraines—piles of rock marking the glacier's former extent. Researchers suspected the moraines were tied to two periods of abrupt cooling that hit Greenland 9300 and 8200 years ago, and that association was reinforced by the authors' radiocarbon and beryllium isotope analyses of the area surrounding the moraines. Beryllium-10 forms when cosmic radiation travels through the atmosphere and strikes the Earth's surface, with surface rock concentrations indicating how long it has been ice-free.

  7. Climate science: The history of Greenland's ice

    NASA Astrophysics Data System (ADS)

    Blard, Pierre-Henri; Leduc, Guillaume; Glasser, Neil

    2016-12-01

    Global sea levels would rise by several metres if the Greenland Ice Sheet melted completely. Two studies have examined its past behaviour in an effort to evaluate its vulnerability in a warming world -- and have come to seemingly conflicting conclusions. Two geochemists and a glaciologist discuss the issues. See Letters p.252 & p.256

  8. Greenland Ice Sheet retreat during the Eemian

    NASA Astrophysics Data System (ADS)

    van de Berg, W. J.; Helsen, M. M.; van de Wal, R. S. W.; van den Broeke, M. R.; Oerlemans, J.

    2012-04-01

    We present a new estimate of the evolution of the Greenland Ice Sheet through the Eemian (130 till 115 ky BP). This estimate is determined using the 3D 'shallow' ice sheet model ANICE and the regional climate model RACMO2/GR. The two models are time-slice coupled with an interval of 1500 years. 3D interpolated surface mass balance fields from RACMO2/GR force ANICE. Eemian and post-Eemian climate from the GCM ECHO-G drives RACMO2/GR on its lateral boundaries. These boundaries are gradually adjusted from maximum Eemian conditions to post-Eemian inception conditions, following the orbital parameters and Greenhouse gas concentrations derived from ice cores. The simulation shows a steady mass loss till the insolation conditions decline and the summer climate cools, with a typical rate of mass loss equivalent to 5 cm sea level rise per century for most of the time. Once summer start to cool the Greenland ice sheet recovers fast. The maximum ice loss is about 2 m eustatic sea level compared to present day volume and originates predominantly from southwest Greenland. Our results align with paleo-observations of Eemian ice sheet existence in South Greenland. Strong summer radiation also induces ice retreat in northern Greenland. Moreover, it agrees with preceding studies that the Greenland ice sheet had only a limited contribution to the Eemian sea level high stand. A finding of this novel approach is the impact of topographic pinpoints on the ice sheet evolution. Subglacial topography, like at 52° W 72° N (near Uummannaq), cause promontories in the ice sheet that enhances snowfall. Locations with high snowfall react less on warming than dry locations, because more melt is needed before all snow is removed, and the more efficient ice melt starts. The reduced ice depth also buttresses inland ice, limiting the ice sheet response to enhanced ablation. As a result, this topographical feature becomes the northern limit of significant ice sheet retreat, and shields the north

  9. The multifaceted West Greenland passive margin

    NASA Astrophysics Data System (ADS)

    Breuer, Sonja; Damm, Volkmar; Block, Martin; Schreckenberger, Bernd; Heyde, Ingo; Nelson, Catherine; Kouwe, Wim

    2013-04-01

    The Baffin Bay located between Greenland and Canada, is the northward extension of the Labrador Sea. The Davis Strait High separates these two marine basins. The evolution of these basins is closely linked, and is as well affiliated to the opening of the North Atlantic Ocean. The opening history started in the Cretaceous with the formation of several terrestrial rift basins with a block-faulted, metamorphic Precambrian basement. The further opening of the Baffin Bay coincides with the volcanic activity (60.9-52.5 Ma) along the West Greenland margin (Storey et al., 1998). The subsequent seafloor spreading in the Baffin Bay is linked to the Labrador Sea by the Ungava Fault Zone (UFZ), which is the most prominent transform fault in this region. Two main problems are still unsolved: 1) There are clear indications for normal seafloor spreading in the Baffin Bay like the seaward dipping reflectors (SDRs) on the Canadian side (Skaarup et al., 2006) and on the Greenland side based on our data. On the other hand, associated magnetic spreading anomalies are not yet discovered in the Baffin Bay or are not formed. These findings may either point to slow or ultraslow spreading or underlying strongly extended continental crust and/or serpentinised mantle. 2) The Greenlandic margin is much wider than the Canadian. In addition, a breakup unconformity can only be traced on the Greenland side and is not reported for the Canadian side. Which process causes this asymmetric margin and differences in shelf width? Is it a result of asymmetric spreading or connected to volcanic activity during breakup processes? In summer 2008, a marine geoscientific expedition (MSM09/03) was conducted with the research vessel "Maria S. Merian" in the Davis Strait and southern Baffin Bay. Approximately 1800 km of multichannel reflection seismic data were acquired. To supplement the database, a subsequent marine geoscientific expedition ARK-XXV/3 with RV POLARSTERN in summer 2010 was conducted. In our

  10. Host and environmental risk factors associated with Cryptosporidium scophthalmi (Apicomplexa) infection in cultured turbot, Psetta maxima (L.) (Pisces, Teleostei).

    PubMed

    Alvarez-Pellitero, Pilar; Perez, Andrés; Quiroga, M Isabel; Redondo, M José; Vázquez, Sonia; Riaza, Ana; Palenzuela, Oswaldo; Sitjà-Bobadilla, Ariadna; Nieto, José M

    2009-11-12

    An epidemiological cohort study of Cryptosporidium scophthalmi in cultured turbot Psetta maxima L. of Northwestern Spain was conducted along a four-year period. Four different ongrowing cohorts were monitored monthly from introduction into the ongrowing tanks (10-50 g) until reaching market size (400-1400 g). The association of host and environmental factors with five categories of parasite abundance was assessed using a multivariable regression framework. Epidemiological factors assessed here were water temperature, weight, length, month of collection, season, age, origin, condition factor, water filtration, and status to the myxozoan Enteromyxum scophthalmi infection. E. scophthalmi was included into the analysis because it targets the same organ than C. scophthalmi and it was prevalent in the studied population. The multivariable analysis demonstrated the statistically significant association between several factors and parasite abundance. C. scophthalmi abundance was associated (P<0.05) with age, condition factor, season, and status to E. scophthalmi infection. Young animals, with poor condition factor, during spring or summer, and not infected with the myxozoan were most likely to be highly infected by C. scophthalmi. Inclusion of these four variables significantly (P<0.05) improved the model, compared to the model that did not include any of these epidemiological factors. Increasing levels of C. scophthalmi abundance were associated (P<0.01) with higher severity of C. scophthalmi-compatible lesions. The frequency of distribution of C. scophthalmi abundance was clearly right-skewed and fitted a negative binomial distribution, whereas the intensity of infection fitted a Poisson distribution. The quantification of the variance-to-mean ratio stratified by age demonstrated overdispersion for 8-16 months old fish, although this bivariate association is likely affected by several other factors, as suggested by the results of the multivariable analysis. The negative

  11. Recent Changes in Arctic Glaciers, Ice Caps, and the Greenland Ice Sheet: Cold Facts About Warm Ice

    NASA Astrophysics Data System (ADS)

    Abdalati, W.

    2005-12-01

    One of the major manifestations of Arctic change can be observed in the state of balance of Arctic glaciers and ice caps and the Greenland ice sheet. These ice masses are estimated to contain nearly 3 million cubic kilometers of ice, which is more than six times greater than all the water stored in the Earth's lakes, rivers, and snow combined and is the equivalent of over 7 meters of sea level. Most of these ice masses have been shrinking in recent in years, but their mass balance is highly variable on a wide range of spatial and temporal scales. On the Greenland ice sheet most of the coastal regions have thinned substantially as melt has increased and some of its outlet glaciers have accelerated. Near the equilibrium line in West Greenland, we have seen evidence of summer acceleration that is linked to surface meltwater production, suggesting a relatively rapid response mechanism of the ice sheet change to a warming climate. At the same time, however, the vast interior regions of the Greenland ice sheet have shown little change or slight growth, as accumulation in these areas may have increased. Throughout much of the rest of the Arctic, many glaciers and ice caps have been shrinking in the past few decades, and in Canada and Alaska, the rate of ice loss seems to have accelerated during the late 1990s. These recent observations offer only a snapshot in time of the long-term behavior, but they are providing crucial information about the current state of ice mass balance and the mechanisms that control it in one of the most climatically sensitive regions on Earth. As we continue to learn more through a combination of remote sensing observations, in situ measurements and improved modeling capabilities, it is important that we coordinate and integrate these approaches effectively in order to predict future changes and their impact on sea level, freshwater discharge, and ocean circulation.

  12. Coal resources of Alaska

    SciTech Connect

    Sanders, R.B.

    1982-01-01

    In the late 1800s, whaling ships carried Alaskan coal, and it was used to thaw ground for placer gold mining. Unfortunate and costly political maneuvers in the early 1900s delayed coal removal, but the Alaska Railroad and then World War II provided incentives for opening mines. Today, 33 million acres (about 9% of the state) is classified as prospectively valuable for coal, much of it under federal title. Although the state's geology is poorly known, potential for discovery of new fields exists. The US Geological Survey estimates are outdated, although still officially used. The total Alaska onshore coal resource is estimated to be 216 to 4216 billion tons of which 141 billion tons are identified resources; an additional 1430 billion tons are believed to lie beneath Cook Inlet. Transportation over mountain ranges and wetlands is the biggest hurdle for removal. Known coal sources and types are described and mapped. 1 figure.

  13. Seabirds in Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Piatt, John F.

    1995-01-01

    Techniques for monitoring seabird populations vary according to habitat types and the breeding behavior of individual species (Hatch and Hatch 1978, 1989; Byrd et al. 1983). An affordable monitoring program can include but a few of the 1,300 seabird colonies identified in Alaska, and since the mid-1970's, monitoring effotrts have emphasized a small selection of surface-feeding and diving species, primarily kittiwakes (Rissa spp.) and murres (Uria spp.). Little or no information on trends is available for other seabirds (Hatch 1993a). The existing monitoring program occurs largely on sites within the Alaska Maritime National Wildlife Refuge, which was established primarily for the conservation of marine birds. Data are collected by refuge staff, other state and federal agencies, private organizations, university faculty, and students.

  14. Rapid wastage of Alaska glaciers and their contribution to rising sea level.

    PubMed

    Arendt, Anthony A; Echelmeyer, Keith A; Harrison, William D; Lingle, Craig S; Valentine, Virginia B

    2002-07-19

    We have used airborne laser altimetry to estimate volume changes of 67 glaciers in Alaska from the mid-1950s to the mid-1990s. The average rate of thickness change of these glaciers was -0.52 m/year. Extrapolation to all glaciers in Alaska yields an estimated total annual volume change of -52 +/- 15 km3/year (water equivalent), equivalent to a rise in sea level (SLE) of 0.14 +/- 0.04 mm/year. Repeat measurements of 28 glaciers from the mid-1990s to 2000-2001 suggest an increased average rate of thinning, -1.8 m/year. This leads to an extrapolated annual volume loss from Alaska glaciers equal to -96 +/- 35 km3/year, or 0.27 +/- 0.10 mm/year SLE, during the past decade. These recent losses are nearly double the estimated annual loss from the entire Greenland Ice Sheet during the same time period and are much higher than previously published loss estimates for Alaska glaciers. They form the largest glaciological contribution to rising sea level yet measured.

  15. Geologic map of Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Hults, Chad P.; Mull, Charles G.; Karl, Susan M.

    2015-12-31

    This Alaska compilation is unique in that it is integrated with a rich database of information provided in the spatial datasets and standalone attribute databases. Within the spatial files every line and polygon is attributed to its original source; the references to these sources are contained in related tables, as well as in stand-alone tables. Additional attributes include typical lithology, geologic setting, and age range for the map units. Also included are tables of radiometric ages.

  16. Greenland Ice Sheet Today: A daily look at surface melt of the Greenland ice sheet

    NASA Astrophysics Data System (ADS)

    Leslie, S. R.; Gergely, K. L.; Beitler, J.; Scambos, T. A.; Stroeve, J. C.

    2013-12-01

    An increase in the surface melt of the Greenland ice sheet in recent decades signals the waning of the ice sheet in a changing climate. The unprecedented intense surface melt of the ice sheet in 2012 prompted NASA and NSIDC to launch Greenland Ice Sheet Today, a Web site that offers daily updated satellite data and periodic scientific analysis on surface melting of the Greenland ice sheet. Near-real-time melt data are derived from an algorithm that estimates melt and is applied to DMSP SSMIS brightness temperatures gridded to a 25km EASE-Grid. These data are then used to generate a daily melt image, a cumulative melt days image, and a daily melt graph. Contextual background information on ice sheets as well as scientific discussions about the status of the Greenland ice sheet are posted periodically. Greenland Ice Sheet Today serves to keep a wide range of user communities informed about a crucial part of the Earth's cryosphere and here we examine the development of and reactions to the Web site.

  17. A moderate resolution inventory of small glaciers and ice caps surrounding Greenland and the Antarctic peninsula

    NASA Astrophysics Data System (ADS)

    Chen, C.; Box, J. E.; Hock, R. M.; Cogley, J. G.

    2011-12-01

    Current estimates of global Mountain Glacier and Ice Caps (MG&IC) mass changes are subject to large uncertainties due to incomplete inventories and uncertainties in land surface classification. This presentation features mitigative efforts through the creation of a MODIS dependent land ice classification system and its application for glacier inventory. Estimates of total area of mountain glaciers [IPCC, 2007] and ice caps (including those in Greenland and Antarctica) vary 15%, that is, 680 - 785 10e3 sq. km. To date only an estimated 40% of glaciers (by area) is inventoried in the World Glacier Inventory (WGI) and made available through the World Glacier Monitoring System (WGMS) and the National Snow and Ice Data Center [NSIDC, 1999]. Cogley [2009] recently compiled a more complete version of WGI, called WGI-XF, containing records for just over 131,000 glaciers, covering approximately half of the estimated global MG&IC area. The glaciers isolated from the conterminous Antarctic and Greenland ice sheets remain incompletely inventoried in WGI-XF but have been estimated to contribute 35% to the MG&IC sea-level equivalent during 1961-2004 [Hock et al., 2009]. Together with Arctic Canada and Alaska these regions alone make up almost 90% of the area that is missing in the global WGI-XF inventory. Global mass balance projections tend to exclude ice masses in Greenland and Antarctica due to the paucity of data with respect to basic inventory base data such as area, number of glaciers or size distributions. We address the need for an accurate Greenland and Antarctic peninsula land surface classification with a novel glacier surface classification and inventory based on NASA Moderate Resolution Imaging Spectroradiometer (MODIS) data gridded at 250 m pixel resolution. The presentation includes a sensitivity analysis for surface mass balance as it depends on the land surface classification. Works Cited +Cogley, J. G. (2009), A more complete version of the World Glacier

  18. Building sustained partnerships in Greenland through shared science

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  19. Satellite Gravity Measurements Confirm Accelerated Melting of Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Chen, J. L.; Wilson, C. R.; Tapley, B. D.

    2006-09-01

    Using time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, we estimate ice mass changes over Greenland during the period April 2002 to November 2005. After correcting for the effects of spatial filtering and limited resolution of GRACE data, the estimated total ice melting rate over Greenland is -239 +/- 23 cubic kilometers per year, mostly from East Greenland. This estimate agrees remarkably well with a recent assessment of -224 +/- 41 cubic kilometers per year, based on satellite radar interferometry data. GRACE estimates in southeast Greenland suggest accelerated melting since the summer of 2004, consistent with the latest remote sensing measurements.

  20. 2013 Alaska Performance Scholarship Outcomes Report

    ERIC Educational Resources Information Center

    Rae, Brian

    2013-01-01

    In accordance with Alaska statute the departments of Education & Early Development (EED) and Labor and Workforce Development (DOLWD), the University of Alaska (UA), and the Alaska Commission on Postsecondary Education (ACPE) present this second annual report on the Alaska Performance Scholarship (APS). Among the highlights: (1) In the public…

  1. Postprandial nutrient-sensing and metabolic responses after partial dietary fishmeal replacement by soyabean meal in turbot (Scophthalmus maximus L.).

    PubMed

    Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

    2016-02-14

    In this study, we chose a carnivorous fish, turbot (Scophthalmus maximus L.), to examine its nutrient-sensing and metabolic responses after ingestion of diets with fishmeal (FM), or 45% of FM replaced by soyabean meal (34·6% dry diet) balanced with or without essential amino acids (EAA) to match the amino acid profile of FM diet for 30 d. After a 1-month feeding trial, fish growth, feed efficiency and nutrient retention were markedly reduced by soyabean meal-incorporated (SMI) diets. Compared with the FM diet, SMI led to a reduction of postprandial influx of free amino acids, hypoactivated target of rapamycin signalling and a hyperactivated amino acid response pathway after refeeding, a status associated with reduced protein synthesis, impaired postprandial glycolysis and lipogenesis. These differential effects were not ameliorated by matching an EAA profile of soyabean meal to that of the FM diet through dietary amino acid supplementation. Therefore, this study demonstrated that the FM diet and SMI diets led to distinct nutrient-sensing responses, which in turn modulated metabolism and determined the utilisation efficiency of diets. Our results provide a new molecular explanation for the role of nutrient sensing in the inferior performance of aquafeeds in which FM is replaced by soyabean meal.

  2. Protein carbonylation during electron beam irradiation may be responsible for changes in IgE binding to turbot parvalbumin.

    PubMed

    Li, Zhenxing; Lu, Zongchao; Khan, Muhammad Naseem; Lin, Hong; Zhang, Limin

    2014-07-01

    The present study aimed to investigate the relationship between protein carbonylation and changes of the IgE reactivity of turbot parvalbumin (PV) following electron beam (EB) irradiation. The concentration of protein carbonyls, specific IgE binding, and IgE binding inhibition between irradiated and oxidized PV were assessed. Irradiation resulted in a 3-fold enhancement in the protein carbonyl content. In purified PV irradiated with a 10-kGy dose, specific IgE binding was reduced by 91.2±6.2%. When raw PV was treated with reactive oxygen species (ROS), the protein carbonyl content increased 17.6-fold, with the specific IgE binding being reduced by 87.9±6.5% at an ROS concentration of 10 nmol/mL. The IgE binding inhibition between irradiated and oxidized PV was investigated using an inhibition ELISA. Results showed that oxidized PV can inhibit the binding between irradiated PV and specific IgE with an IC50 of 8.2-58 ng according to different doses of irradiation. These findings suggest that EB irradiation reduces specific IgE binding, probably by the induction of protein carbonylation.

  3. Rural Alaska Mentoring Project (RAMP)

    ERIC Educational Resources Information Center

    Cash, Terry

    2011-01-01

    For over two years the National Dropout Prevention Center (NDPC) at Clemson University has been supporting the Lower Kuskokwim School District (LKSD) in NW Alaska with their efforts to reduce high school dropout in 23 remote Yup'ik Eskimo villages. The Rural Alaska Mentoring Project (RAMP) provides school-based E-mentoring services to 164…

  4. Alaska provides icy training ground

    SciTech Connect

    Rintoul, B.

    1983-04-01

    Offshore oil drilling platforms and oil exploration off the coast of Alaska are discussed. Sohio is investigating the feasibility of platform supporters from shore such as icebreakers and air-cushion vehicles. At Prudhoe Bay Arco is embarking on the first tertiary oil recovery project to take place on Alaska's North Slope.

  5. Alaska High Altitude Photography Program

    NASA Technical Reports Server (NTRS)

    Petersen, Earl V.; Knutson, Martin A.; Ekstrand, Robert E.

    1986-01-01

    In 1978, the Alaska High Altitude Photography Program was initiated to obtain simultaneous black and white and color IR aerial photography of Alaska. Dual RC-10 and Zeiss camera systems were used for this program on NASA's U-2 and WB-57F, respectively. Data collection, handling, and distribution are discussed as well as general applications and the current status.

  6. Holocene deceleration of the Greenland Ice Sheet.

    PubMed

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

    2016-02-05

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

  7. Holocene deceleration of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  8. Complex Greenland outlet glacier flow captured

    PubMed Central

    Aschwanden, Andy; Fahnestock, Mark A.; Truffer, Martin

    2016-01-01

    The Greenland Ice Sheet is losing mass at an accelerating rate due to increased surface melt and flow acceleration in outlet glaciers. Quantifying future dynamic contributions to sea level requires accurate portrayal of outlet glaciers in ice sheet simulations, but to date poor knowledge of subglacial topography and limited model resolution have prevented reproduction of complex spatial patterns of outlet flow. Here we combine a high-resolution ice-sheet model coupled to uniformly applied models of subglacial hydrology and basal sliding, and a new subglacial topography data set to simulate the flow of the Greenland Ice Sheet. Flow patterns of many outlet glaciers are well captured, illustrating fundamental commonalities in outlet glacier flow and highlighting the importance of efforts to map subglacial topography. Success in reproducing present day flow patterns shows the potential for prognostic modelling of ice sheets without the need for spatially varying parameters with uncertain time evolution. PMID:26830316

  9. Secret Science: Exploring Cold War Greenland

    NASA Astrophysics Data System (ADS)

    Harper, K.

    2013-12-01

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

  10. Measured and modelled absolute gravity in Greenland

    NASA Astrophysics Data System (ADS)

    Nielsen, E.; Forsberg, R.; Strykowski, G.

    2012-12-01

    Present day changes in the ice volume in glaciated areas like Greenland will change the load on the Earth and to this change the lithosphere will respond elastically. The Earth also responds to changes in the ice volume over a millennial time scale. This response is due to the viscous properties of the mantle and is known as Glaical Isostatic Adjustment (GIA). Both signals are present in GPS and absolute gravity (AG) measurements and they will give an uncertainty in mass balance estimates calculated from these data types. It is possible to separate the two signals if both gravity and Global Positioning System (GPS) time series are available. DTU Space acquired an A10 absolute gravimeter in 2008. One purpose of this instrument is to establish AG time series in Greenland and the first measurements were conducted in 2009. Since then are 18 different Greenland GPS Network (GNET) stations visited and six of these are visited more then once. The gravity signal consists of three signals; the elastic signal, the viscous signal and the direct attraction from the ice masses. All of these signals can be modelled using various techniques. The viscous signal is modelled by solving the Sea Level Equation with an appropriate ice history and Earth model. The free code SELEN is used for this. The elastic signal is modelled as a convolution of the elastic Greens function for gravity and a model of present day ice mass changes. The direct attraction is the same as the Newtonian attraction and is calculated as this. Here we will present the preliminary results of the AG measurements in Greenland. We will also present modelled estimates of the direct attraction, the elastic and the viscous signals.

  11. Greenland Meltwater and Arctic Circulation Regimes

    NASA Astrophysics Data System (ADS)

    Dukhovskoy, D. S.; Proshutinsky, A. Y.; Timmermans, M. L.; Myers, P. G.; Platov, G.

    2015-12-01

    Between 1948 and 1996, wind-driven components of ice drift and surface ocean currents experienced a well-pronounced decadal variability alternating between anticyclonic and cyclonic circulation regimes. During cyclonic regimes, low sea level atmospheric pressure dominated over the Arctic Ocean driving sea ice and the upper ocean clockwise; the Arctic atmosphere was relatively warm and humid and freshwater flux from the Arctic Ocean toward the sub-Arctic seas was intensified. During anticylonic circulation regimes, high sea level pressure dominated over the Arctic driving sea ice and ocean counter-clockwise; the atmosphere was cold and dry and the freshwater flux from the Arctic to the sub-Arctic seas was reduced. Since 1997, however, the Arctic system has been dominated by an anticyclonic circulation regime with a set of environmental parameters that are atypical for these regimes. Of essential importance is to discern the causes and consequences of the apparent break-down in the natural decadal variability of the Arctic climate system, and specifically: Why has the well-pronounced decadal variability observed in the 20th century been replaced by relatively weak interannual changes under anticyclonic circulation regime conditions in the 21st century? We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from Greenland impact environmental conditions and interrupt their decadal variability. In order to test this hypothesis, numerical experiments with several FAMOS (Forum for Arctic Modeling & Observational Synthesis) ice-ocean coupled models have been conducted. In these experiments, Greenland melt freshwater is tracked by passive tracers being constantly released along the Greenland coast. Propagation pathways and time scales of Greenland meltwater within the sub-Arctic seas are discussed.

  12. Generating synthetic fjord bathymetry for coastal Greenland

    NASA Astrophysics Data System (ADS)

    Williams, Christopher N.; Cornford, Stephen L.; Jordan, Thomas M.; Dowdeswell, Julian A.; Siegert, Martin J.; Clark, Christopher D.; Swift, Darrel A.; Sole, Andrew; Fenty, Ian; Bamber, Jonathan L.

    2017-02-01

    Bed topography is a critical boundary for the numerical modelling of ice sheets and ice-ocean interactions. A persistent issue with existing topography products for the bed of the Greenland Ice Sheet and surrounding sea floor is the poor representation of coastal bathymetry, especially in regions of floating ice and near the grounding line. Sparse data coverage, and the resultant coarse resolution at the ice-ocean boundary, poses issues in our ability to model ice flow advance and retreat from the present position. In addition, as fjord bathymetry is known to exert strong control on ocean circulation and ice-ocean forcing, the lack of bed data leads to an inability to model these processes adequately. Since the release of the last complete Greenland bed topography-bathymetry product, new observational bathymetry data have become available. These data can be used to constrain bathymetry, but many fjords remain completely unsampled and therefore poorly resolved. Here, as part of the development of the next generation of Greenland bed topography products, we present a new method for constraining the bathymetry of fjord systems in regions where data coverage is sparse. For these cases, we generate synthetic fjord geometries using a method conditioned by surveys of terrestrial glacial valleys as well as existing sinuous feature interpolation schemes. Our approach enables the capture of the general bathymetry profile of a fjord in north-west Greenland close to Cape York, when compared to observational data. We validate our synthetic approach by demonstrating reduced overestimation of depths compared to past attempts to constrain fjord bathymetry. We also present an analysis of the spectral characteristics of fjord centrelines using recently acquired bathymetric observations, demonstrating how a stochastic model of fjord bathymetry could be parameterised and used to create different realisations.

  13. GeoFORCE Alaska, A Successful Summer Exploring Alaska's Geology

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2012-12-01

    Thirty years old this summer, RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. This summer, in collaboration with the University of Texas Austin, the Rural Alaska Honors Institute launched a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science to entice kids to get excited about dinosaurs, volcanoes and earthquakes, and includes physics, chemistry, math, biology and other sciences. Students were recruited from the Alaska's Arctic North Slope schools, in 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The culmination is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks and Anchorage, Arizona, Oregon and the Appalachians. All trips focus on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska was begun by the University of Alaska Fairbanks in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska is managed by UAF's long-standing Rural Alaska Honors Institute, that has been successfully providing intense STEM educational opportunities for Alaskan high school students for over 30 years. The program will add a new cohort of 9th graders each year for the next four years. By the summer of 2015, GeoFORCE Alaska is targeting a capacity of 160 students in grades 9th through 12th. Join us to find out more about this exciting new initiative, which is enticing young Alaska Native

  14. Holocene thinning of the Greenland ice sheet.

    PubMed

    Vinther, B M; Buchardt, S L; Clausen, H B; Dahl-Jensen, D; Johnsen, S J; Fisher, D A; Koerner, R M; Raynaud, D; Lipenkov, V; Andersen, K K; Blunier, T; Rasmussen, S O; Steffensen, J P; Svensson, A M

    2009-09-17

    On entering an era of global warming, the stability of the Greenland ice sheet (GIS) is an important concern, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins. Studying the response of the GIS to past climatic change may help to advance our understanding of GIS dynamics. The previous interpretation of evidence from stable isotopes (delta(18)O) in water from GIS ice cores was that Holocene climate variability on the GIS differed spatially and that a consistent Holocene climate optimum-the unusually warm period from about 9,000 to 6,000 years ago found in many northern-latitude palaeoclimate records-did not exist. Here we extract both the Greenland Holocene temperature history and the evolution of GIS surface elevation at four GIS locations. We achieve this by comparing delta(18)O from GIS ice cores with delta(18)O from ice cores from small marginal icecaps. Contrary to the earlier interpretation of delta(18)O evidence from ice cores, our new temperature history reveals a pronounced Holocene climatic optimum in Greenland coinciding with maximum thinning near the GIS margins. Our delta(18)O-based results are corroborated by the air content of ice cores, a proxy for surface elevation. State-of-the-art ice sheet models are generally found to be underestimating the extent and changes in GIS elevation and area; our findings may help to improve the ability of models to reproduce the GIS response to Holocene climate.

  15. Hepatic gene transcription profiles in turbot (Scophthalmus maximus) experimentally exposed to heavy fuel oil nº 6 and to styrene.

    PubMed

    Diaz de Cerio, Oihane; Bilbao, Eider; Ruiz, Pamela; Pardo, Belén G; Martínez, Paulino; Cajaraville, Miren P; Cancio, Ibon

    2017-02-01

    Oil and chemical spills in the marine environment, although sporadic, are highly dangerous to biota inhabiting coastal and estuarine areas. Effects of spilled compounds in exposed organisms occur at different biological organization levels: from molecular, cellular or tissue levels to the physiological one. The present study aims to determine the specific hepatic gene transcription profiles observed in turbot juveniles under exposure to fuel oil n °6 and styrene vs controls using an immune enriched turbot (Scophthalmus maximus) oligo-microarray containing 2716 specific gene probes. After 3 days of exposure, fuel oil specifically induced aryl hydrocarbon receptor mediated transcriptional response through up-regulation of genes, such as ahrr and cyp1a1. More gene transcripts were regulated after 14 days of exposure involved in ribosomal biosynthesis, immune modulation, and oxidative response among the most significantly regulated functional pathways. On the contrary, gene transcription alterations caused by styrene did not highlight any significantly regulated molecular or metabolic pathway. This was also previously reported at cell and tissue level where no apparent responses were distinguishable. For the fuel oil experiment, obtained specific gene profiles could be related to changes in cell-tissue organization in the same individuals, such as increased hepatocyte vacuolization, decrease in melano-macrophage centers and the regulation of leukocyte numbers. In conclusion, the mode of action reflected by gene transcription profiles analyzed hereby in turbot livers could be linked with the responses previously reported at higher biological organization levels. Molecular alterations described hereby could be preceding observed alterations at cell and tissue levels.

  16. Cloning and sequence analysis of a full-length cDNA of SmPP1cb encoding turbot protein phosphatase 1 beta catalytic subunit

    NASA Astrophysics Data System (ADS)

    Qi, Fei; Guo, Huarong; Wang, Jian

    2008-02-01

    Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 (PP1) is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase 1(PP1cb), was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPP1cb, by the rapid amplification of cDNA ends (RACE) technique. The cDNA sequence of SmPP1cb we obtained contains a 984 bp open reading frame (ORF), flanked by a complete 39 bp 5' untranslated region and 462 bp 3' untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B (PP2B). And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPP1cb is extremely conserved in both amino acid and nucleotide acid levels compared with the PP1cb of other vertebrates and invertebrates, and its Kozak motif contained in the 5'UTR around ATG start codon is GXXAXXGXX ATGG, which is different from mammalian in two positions A-6 and G-3, indicating the possibility of different initiation of translation in turbot, and also the 3'UTR of SmPP1cb is highly diverse in the sequence similarity and length compared with other animals, especially zebrafish. The cloning and sequencing of SmPP1cb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.

  17. Continuous Monitoring of Greenland Outlet Glaciers Using an Autonomous Terrestrial LiDAR Scanning System: Design, Development and Testing at Helheim Glacier

    NASA Astrophysics Data System (ADS)

    LeWinter, A. L.; Finnegan, D. C.; Hamilton, G. S.; Stearns, L. A.; Gadomski, P. J.

    2014-12-01

    Greenland's fast-flowing tidewater outlet glaciers play a critical role in modulating the ice sheet's contribution to sea level rise. Increasing evidence points to the importance of ocean forcing at the marine margins as a control on outlet glacier behavior, but a process-based understanding of glacier-ocean interactions remains elusive in part because our current capabilities for observing and quantifying system behavior at the appropriate spatial and temporal scales are limited. A recent international workshop on Greenland's marine terminating glaciers (US CLIVAR, Beverly, MA, June 2013) recommended the establishment of a comprehensive monitoring network covering Greenland's largest outlet glacier-fjord systems to collect long-term time series of critical in situ glaciological, oceanographic and atmospheric parameters needed to understand evolving relationships between different climate forcings and glacier flow. Given the remote locations and harsh environments of Greenland's glacial fjords, the development of robust autonomous instrumentation is a key step in making the observing networks a reality. This presentation discusses the design and development of a fully-autonomous ground-based Light Detection and Ranging (LiDAR) system for monitoring outlet glacier behavior. Initial deployment of the system is planned for spring 2015 at Helheim Glacier in southeast Greenland. The instrument will acquire multi-dimensional point-cloud measurements of the mélange, terminus, and lower-reaches of the glacier. The heart of the system is a long-range, 1064 nm wavelength Terrestrial Laser Scanner (TLS) that we have previously used in campaign-style surveys at Helheim Glacier and at Hubbard Glacier in Alaska. We draw on this experience to design and fabricate the power and enclosure components of the new system, and use previously acquired data from the instrument, collected August 2013 and July 2014 at Helheim, to optimize our data collection strategy and design the data

  18. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary sedimentary and volcanic rocks and Quaternary deposits.

  19. Comparison of the bioaccumulation from seawater and depuration of heavy metals and radionuclides in the spotted dogfish Scyliorhinus canicula (Chondrichthys) and the turbot Psetta maxima (Actinopterygii: Teleostei).

    PubMed

    Jeffree, Ross A; Warnau, Michel; Teyssié, Jean-Louis; Markich, Scott J

    2006-09-15

    The bioaccumulation of selected heavy metals and radionuclides ((241)Am, (109)Cd, (57)Co, (51)Cr, (134)Cs, (54)Mn and (65)Zn) from seawater was experimentally compared in the Chondrichthyan Scyliorhinus canicula (spotted dogfish) and the Actinopterygian Teleost Psetta maxima (turbot), of comparable size, age and benthic feeding habits. The speciation of these elements in seawater (salinity 38 per thousand, pH 8.1, temperature 16.5 degrees C) was also calculated to determine their potential bioavailability. The uptake rates, measured over 14 days, varied greatly among isotopes and between species. Concentration factors (CFs) in P. maxima varied 5-fold between ca. 0.2 for (51)Cr and 2.5 for (65)Zn and (134)Cs, whereas in S. canicula they varied by a much greater factor of 350, with CFs for (51)Cr and (241)Am ranging from ca. 0.4 to 140, respectively. With the exception of (134)Cs, all radiotracers were accumulated at a faster rate in S. canicula than in P. maxima, particularly for (241)Am and (65)Zn where the CFs attained during the uptake phase were, two and one order of magnitude greater in S. canicula, respectively. In contrast, (134)Cs reached a CF of about 2.5 in P. maxima, which was 5-fold greater than in S. canicula. Patterns of loss from the experimental depuration phase over 29 days showed greater similarities between species, compared to the uptake phase that highlighted the greater differences between elements. The distributions of these seven radioisotopes among six body components indicated that between the two species the skin of the dogfish displayed a greater bioaccumulation potential, particularly for (241)Am, (57)Co and (65)Zn. However (65)Zn was also distinctive from (241)Am and (57)Co in its pattern of bioaccumulation in dogfish, with its other body components attaining concentrations of (65)Zn that were comparable to the levels found in its skin. The heightened uptake of (134)Cs in turbot was characterised by a more even percentage distribution

  20. Uncertainty of GIA models across the Greenland

    NASA Astrophysics Data System (ADS)

    Ruggieri, Gabriella

    2013-04-01

    In the last years various remote sensing techniques have been employed to estimate the current mass balance of the Greenland ice sheet (GIS). In this regards GRACE, laser and radar altimetry observations, employed to constrain the mass balance, consider the glacial isostatic adjustment (GIA) a source of noise. Several GIA models have been elaborated for the Greenland but they differ from each other for mantle viscosity profile and for time history of ice melting. In this work we use the well know ICE-5G (VM2) ice model by Peltier (2004) and two others alternative scenarios of ice melting, ANU05 by Lambeck et al. (1998) and the new regional ice model HUY2 by Simpson et al. (2009) in order to asses the amplitude of the uncertainty related to the GIA predictions. In particular we focus on rates of vertical displacement field, sea surface variations and sea-level change at regional scale. The GIA predictions are estimated using an improved version of SELEN code that solve the sea-level equation for a spherical self-gravitating, incompressible and viscoelastic Earth structure. GIA uncertainty shows a highly variable geographic distribution across the Greenland. Considering the spatial pattern of the GIA predictions related to the three ice models, the western sector of the Greenland Ice Sheets (GrIS) between Thule and Upernavik and around the area of Paamiut, show good agreement while the northeast portion of the Greenland is characterized by a large discrepancy of the GIA predictions inferred by the ice models tested in this work. These differences are ultimately the consequence of the different sets of global relative sea level data and modern geodetic observations used by the authors to constrain the model parameters. Finally GPS Network project (GNET), recently installed around the periphery of the GrIS, are used as a tool to discuss the discrepancies among the GIA models. Comparing the geodetic analysis recently available, appears that among the GPS sites the

  1. Towards Greenland Glaciation: Cumulative or Abrupt Transition?

    NASA Astrophysics Data System (ADS)

    Tan, N.; Ramstein, G.; Contoux, C.; Ladant, J. B.; Dumas, C.; Donnadieu, Y.

    2014-12-01

    The insolation evolution [Laskar 2004] from 4 to 2.5 Ma depicts a series of three summer solstice insolation minima between 2.7 and 2.6 Ma, but there are other more important summer solstice minima notably around 3.82 and 3.05 Ma. On such a time span of more than 1 Ma, data shows that there are variations in the evolution of atmospheric CO2 concentration with a local maximum around 3 Ma [Seki et al.2010; Bartoli et al. 2011], before a decrease between 3 and 2.6 Ma. The latter, suggesting an abrupt ice sheet inception around 2.7 Ma, has been shown to be a major culprit for the full Greenland Glaciation [Lunt et al. 2008]. However, a recent study [Contoux et al. 2014, in review] suggests that a lowering of CO2 is not sufficient to initiate a glaciation on Greenland and must be combined to low summer insolation, with surviving ice during insolation maximum, suggesting a cumulative process in the first place, which could further lead to full glaciation at 2.7 Ma. Through a new tri-dimensional interpolation method implemented within the asynchronous coupling between an atmosphere ocean general circulation model (IPSL-CM5A) and an ice sheet model (GRISLI), we investigate the transient evolution of Greenland ice sheet during the Pliocene to diagnose whether the ice sheet inception is an abrupt event or rather a cumulative process, involving waxing and waning of the ice sheet during several orbital cycles. ReferencesBartoli, G., Hönisch, B., & Zeebe, R. E. (2011). Atmospheric CO2 decline during the Pliocene intensification of Northern Hemisphere glaciations. Paleoceanography, 26(4). Contoux C, Dumas C, Ramstein G, Jost A, Dolan A. M. (2014) Modelling Greenland Ice sheet inception and sustainability during the late Pliocene. (in review for Earth and Planetary Science Letters.).Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., & Levrard, B. (2004). A long-term numerical solution for the insolation quantities of the Earth. Astronomy & Astrophysics, 428

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Metamorphic facies map of Alaska

    SciTech Connect

    Dusel-Bacon, C.; O-Rourke, E.F.; Reading, K.E.; Fitch, M.R.; Klute, M.A.

    1985-04-01

    A metamorphic-facies of Alaska has been compiled, following the facies-determination scheme of the Working Group for the Cartography of the Metamorphic Belts of the World. Regionally metamorphosed rocks are divided into facies series where P/T gradients are known and into facies groups where only T is known. Metamorphic rock units also are defined by known or bracketed age(s) of metamorphism. Five regional maps have been prepared at a scale of 1:1,000,000; these maps will provide the basis for a final colored version of the map at a scale of 1:2,500,000. The maps are being prepared by the US Geological Survey in cooperation with the Alaska Division of Geological and Geophysical Surveys. Precambrian metamorphism has been documented on the Seward Peninsula, in the Baird Mountains and the northeastern Kuskokwim Mountains, and in southwestern Alaska. Pre-Ordovician metamorphism affected the rocks in central Alaska and on southern Prince of Wales Island. Mid-Paleozoic metamorphism probably affected the rocks in east-central Alaska. Most of the metamorphic belts in Alaska developed during Mesozoic or early Tertiary time in conjuction with accretion of many terranes. Examples are Jurassic metamorphism in east-central Alaska, Early Cretaceous metamorphism in the southern Brooks Range and along the rim of the Yukon-Kovyukuk basin, and late Cretaceous to early Tertiary metamorphism in the central Alaska Range. Regional thermal metamorphism was associated with multiple episodes of Cretaceous plutonism in southeastern Alaska and with early Tertiary plutonism in the Chugach Mountains. Where possible, metamorphism is related to tectonism. Meeting participants are encouraged to comment on the present version of the metamorphic facies map.

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

    NASA Astrophysics Data System (ADS)

    Citterio, M.; Ahlstrøm, A. P.

    2013-03-01

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

  5. Development and Validation of Single Nucleotide Polymorphisms (SNPs) Markers from Two Transcriptome 454-Runs of Turbot (Scophthalmus maximus) Using High-Throughput Genotyping.

    PubMed

    Vera, Manuel; Alvarez-Dios, Jose-Antonio; Fernandez, Carlos; Bouza, Carmen; Vilas, Roman; Martinez, Paulino

    2013-03-12

    The turbot (Scophthalmus maximus) is a commercially valuable flatfish and one of the most promising aquaculture species in Europe. Two transcriptome 454-pyrosequencing runs were used in order to detect Single Nucleotide Polymorphisms (SNPs) in genes related to immune response and gonad differentiation. A total of 866 true SNPs were detected in 140 different contigs representing 262,093 bp as a whole. Only one true SNP was analyzed in each contig. One hundred and thirteen SNPs out of the 140 analyzed were feasible (genotyped), while Ш were polymorphic in a wild population. Transition/transversion ratio (1.354) was similar to that observed in other fish studies. Unbiased gene diversity (He) estimates ranged from 0.060 to 0.510 (mean = 0.351), minimum allele frequency (MAF) from 0.030 to 0.500 (mean = 0.259) and all loci were in Hardy-Weinberg equilibrium after Bonferroni correction. A large number of SNPs (49) were located in the coding region, 33 representing synonymous and 16 non-synonymous changes. Most SNP-containing genes were related to immune response and gonad differentiation processes, and could be candidates for functional changes leading to phenotypic changes. These markers will be useful for population screening to look for adaptive variation in wild and domestic turbot.

  6. Development and Validation of Single Nucleotide Polymorphisms (SNPs) Markers from Two Transcriptome 454-Runs of Turbot (Scophthalmus maximus) Using High-Throughput Genotyping

    PubMed Central

    Vera, Manuel; Alvarez-Dios, Jose-Antonio; Fernandez, Carlos; Bouza, Carmen; Vilas, Roman; Martinez, Paulino

    2013-01-01

    The turbot (Scophthalmus maximus) is a commercially valuable flatfish and one of the most promising aquaculture species in Europe. Two transcriptome 454-pyrosequencing runs were used in order to detect Single Nucleotide Polymorphisms (SNPs) in genes related to immune response and gonad differentiation. A total of 866 true SNPs were detected in 140 different contigs representing 262,093 bp as a whole. Only one true SNP was analyzed in each contig. One hundred and thirteen SNPs out of the 140 analyzed were feasible (genotyped), while III were polymorphic in a wild population. Transition/transversion ratio (1.354) was similar to that observed in other fish studies. Unbiased gene diversity (He) estimates ranged from 0.060 to 0.510 (mean = 0.351), minimum allele frequency (MAF) from 0.030 to 0.500 (mean = 0.259) and all loci were in Hardy-Weinberg equilibrium after Bonferroni correction. A large number of SNPs (49) were located in the coding region, 33 representing synonymous and 16 non-synonymous changes. Most SNP-containing genes were related to immune response and gonad differentiation processes, and could be candidates for functional changes leading to phenotypic changes. These markers will be useful for population screening to look for adaptive variation in wild and domestic turbot. PMID:23481633

  7. Effects of temperature, pH and NaCl on protease activity in digestive tract of young turbot, Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Chen, Muyan; Zhang, Xiumei; Gao, Tianxiang; Chen, Chao

    2006-09-01

    The protease activity in digestive tract of young turbot Scophthalmus maximum was studied, and the optimal pH, temperature and NaCl concentration were determined for different portions of the fish's internal organs. The optimal activity in the fish's stomach was at pH of 2.2, while that in the intestinal extracts was within the alkaline range from 9.5 to 10.0. In hepatopancreas, the optimal pH was in low alkalinity at 8.5. The optimal reaction temperature was above 40°C in stomach, intestine and hepatopancreas. With increasing temperature, the pH value increased in stomach, while in the intestine, an opposite tendency was observed due to combined effect of pH and temperature. NaCl concentration showed inhibitory impact on protein digestion in hepatopancreas. The main protease for protein digestion in turbot seemed to be pepsin. Moreover, the maximum protease activity in different segments of intestine existed in the hindgut.

  8. Expression pattern of peptide and amino acid genes in digestive tract of transporter juvenile turbot ( Scophthalmus maximus L.)

    NASA Astrophysics Data System (ADS)

    Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

    2016-04-01

    Turbot ( Scophthalmus maximus L.), a carnivorous fish species with high dietary protein requirement, was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach, pyloric caeca, rectum, and three equal parts of the remainder of the intestine. The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns. Peptide transporter 1 (PepT1) was rich in proximal intestine while peptide transporter 2 (PepT2) was abundant in distal intestine. A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B0-type amino acid transporter 1 (B0AT1), L-type amino acid transporter 2 (LAT2), T-type amino acid transporter 1 (TAT1), proton-coupled amino acid transporter 1 (PAT1), y+L-type amino acid transporter 1 (y+LAT1), and cationic amino acid transporter 2 (CAT2) while ASC amino acid transporter 2 (ASCT2), sodium-coupled neutral amino acid transporter 2 (SNAT2), and y+L-type amino acid transporter 2 (y+LAT2) abundantly expressed in stomach. In addition, system b0,+ transporters (rBAT and b0,+AT) existed richly in distal intestine. These findings comprehensively characterized the distribution of solute carrier family proteins, which revealed the relative importance of peptide and amino acid absorption through luminal membrane. Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract.

  9. Alaska Interagency Ecosystem Health Work Group

    USGS Publications Warehouse

    Shasby, Mark

    2009-01-01

    The Alaska Interagency Ecosystem Health Work Group is a community of practice that recognizes the interconnections between the health of ecosystems, wildlife, and humans and meets to facilitate the exchange of ideas, data, and research opportunities. Membership includes the Alaska Native Tribal Health Consortium, U.S. Geological Survey, Alaska Department of Environmental Conservation, Alaska Department of Health and Social Services, Centers for Disease Control and Prevention, U.S. Fish and Wildlife Service, Alaska Sea Life Center, U.S. Environmental Protection Agency, and Alaska Department of Fish and Game.

  10. Growth of Greenland ice sheet - Measurement

    NASA Technical Reports Server (NTRS)

    Zwally, H. Jay; Bindschadler, Robert A.; Marsh, James G.; Brenner, Anita C.; Major, Judy A.

    1989-01-01

    Measurements of ice-sheet elevation change by satellite altimetry show that the Greenland surface elevation south of 72 deg north latitude is increasing. The vertical velocity of the surface is 0.20 + or - 0.06 meters/year from measured changes in surface elevations at 5906 intersections between Geosat paths in 1985 and Seasat in 1978, and 0.28 + or - 0.02 meters/year from 256,694 intersections of Geosat paths during a 548-day period of 1985 to 1986.

  11. North Greenland's Ice Shelves and Ocean Warming

    NASA Astrophysics Data System (ADS)

    Muenchow, A.; Schauer, U.; Padman, L.; Melling, H.; Fricker, H. A.

    2014-12-01

    Rapid disintegration of ice shelves (the floating extensions of marine-terminating glaciers) can lead to increasing ice discharge, thinning upstream ice sheets, rising sea level. Pine Island Glacier, Antarctica, and Jacobshavn Isbrae, Greenland, provide prominent examples of these processes which evolve at decadal time scales. We here focus on three glacier systems north of 78 N in Greenland, each of which discharges more than 10 Gt per year of ice and had an extensive ice shelf a decade ago; Petermann Gletscher (PG), Niogshalvfjerdsfjorden (79N), and Zachariae Isstrom (ZI). We summarize and discuss direct observations of ocean and glacier properties for these systems as they have evolved in the northwest (PG) and northeast (79N and ZI) of Greenland over the last two decades. We use a combination of modern and historical snapshots of ocean temperature and salinity (PG, 79N, ZI), moored observations in Nares Strait (PG), and snapshots of temperature and velocity fields on the broad continental shelf off northeast Greenland (79N, ZI) collected between 1993 and 2014. Ocean warming adjacent to PG has been small relative to the ocean warming adjacent to 79N and ZI; however, ZI lost its entire ice shelf during the last decade while 79N, less than 70 km to the north of ZI, remained stable. In contrast, PG has thinned by about 10 m/y just prior to shedding two ice islands representing almost half its ice shelf area or a fifth by volume. At PG advective ice flux divergence explains about half of the dominantly basal melting while response to non-steady external forcing explains the other half. The observations at PG,79N, and ZI suggest that remotely sensed ambient surface ocean temperatures are poor proxies to explain ice shelf thinning and retreat. We posit that local dynamics of the subsurface ocean heat flux matters most. Ocean heat must first be delivered over the sill into the fjord and then within the ice shelf cavity to the base of the shelf near the grounding line

  12. The recent warming trend in North Greenland

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  13. Towards Introducing a Geocoding Information System for Greenland

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

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

  14. An Alaska Soil Carbon Database

    NASA Astrophysics Data System (ADS)

    Johnson, Kristofer; Harden, Jennifer

    2009-05-01

    Database Collaborator's Meeting; Fairbanks, Alaska, 4 March 2009; Soil carbon pools in northern high-latitude regions and their response to climate changes are highly uncertain, and collaboration is required from field scientists and modelers to establish baseline data for carbon cycle studies. The Global Change Program at the U.S. Geological Survey has funded a 2-year effort to establish a soil carbon network and database for Alaska based on collaborations from numerous institutions. To initiate a community effort, a workshop for the development of an Alaska soil carbon database was held at the University of Alaska Fairbanks. The database will be a resource for spatial and biogeochemical models of Alaska ecosystems and will serve as a prototype for a nationwide community project: the National Soil Carbon Network (http://www.soilcarb.net). Studies will benefit from the combination of multiple academic and government data sets. This collaborative effort is expected to identify data gaps and uncertainties more comprehensively. Future applications of information contained in the database will identify specific vulnerabilities of soil carbon in Alaska to climate change, disturbance, and vegetation change.

  15. Operation IceBridge Alaska

    NASA Astrophysics Data System (ADS)

    Larsen, C.

    2015-12-01

    The University of Alaska Fairbanks (UAF) has flown LiDAR missions for Operation IceBridge in Alaska each year since 2009, expanding upon UAF's airborne laser altimetry program which started in 1994. These observations show that Alaska's regional mass balance is -75+11/-16 Gt yr-1 (1994-2013) (Larsen et al., 2015). A surprising result is that the rate of surface mass loss observed on non-tidewater glaciers in Alaska is extremely high. At these rates, Alaska contributes ~1 mm to global sea level rise every 5 years. Given the present lack of adequate satellite resources, Operation IceBridge airborne surveys by UAF are the most effective and efficient method to monitor this region's impact on global sea level rise. Ice depth measurements using radar sounding have been part of these airborne surveys since 2012. Many of Alaska's tidewater glaciers are bedded significantly below sea level. The depth and extent of glacier beds below sea level are critical factors in the dynamics of tidewater retreat. Improved radar processing tools are being used to predict clutter using forward simulation. This is essential to properly sort out true bed returns, which are often masked or obscured by valley wall returns. This presentation will provide an overview of the program, highlighting recent findings and observations from the most recent campaigns, and focusing on techniques used for the extrapolation of surface elevation changes to regional mass balances.

  16. Alaska's Children, 1998. Alaska Head Start State Collaboration Project, Quarterly Report.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1998-01-01

    This document consists of four issues of the quarterly report "Alaska's Children," which provides information on the Alaska Head Start State Collaboration Project and updates on Head Start activities in Alaska. Regular features in the issues include a calendar of conferences and meetings, a status report on Alaska's children, reports…

  17. 77 FR 58731 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2013... Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the... and Wildlife Service (Service or we) proposes migratory bird subsistence harvest regulations in...

  18. Distribution of Alexandrium fundyense (Dinophyceae) cysts in Greenland and Iceland, with an emphasis on viability and growth in the Arctic

    PubMed Central

    Richlen, Mindy L.; Zielinski, Oliver; Holinde, Lars; Tillmann, Urban; Cembella, Allan; Lyu, Yihua; Anderson, Donald M.

    2016-01-01

    The bloom-forming dinoflagellate Alexandrium fundyense has been extensively studied due its toxin-producing capabilities and consequent impacts to human health and economies. This study investigated the prevalence of resting cysts of A. fundyense in western Greenland and Iceland to assess the historical presence and magnitude of bloom populations in the region, and to characterize environmental conditions during summer, when bloom development may occur. Analysis of sediments collected from these locations showed that Alexandrium cysts were present at low to moderate densities in most areas surveyed, with highest densities observed in western Iceland. Additionally, laboratory experiments were conducted on clonal cultures established from isolated cysts or vegetative cells from Greenland, Iceland, and the Chukchi Sea (near Alaska) to examine the effects of photoperiod interval and irradiance levels on growth. Growth rates in response to the experimental treatments varied among isolates, but were generally highest under conditions that included both the shortest photoperiod interval (16h:8h light:dark) and higher irradiance levels (~146–366 μmol photons m−2 s−1), followed by growth under an extended photoperiod interval and low irradiance level (~37 μmol photons m−2 s−1). Based on field and laboratory data, we hypothesize that blooms in Greenland are primarily derived from advected Alexandrium populations, as low bottom temperatures and limited light availability would likely preclude in situ bloom development. In contrast, the bays and fjords in Iceland may provide more favorable habitat for germling cell survival and growth, and therefore may support indigenous, self-seeding blooms. PMID:27721528

  19. Low Frequency Radio Research at Thule, Greenland.

    DTIC Science & Technology

    1998-01-01

    the period January-March 1997, we participated in two Alaska campaigns involv- ing ionospheric heating by the HIPAS and HAARP transmitters, during...Given a strong auroral electrojet in the ionosphere that can be reached by the HAARP HF transmissions, we have little doubt that ELF signals can be...Contract Manager EDWARD J. WEBER, Chief Ionospheric Hazards Branch o^e DAVID A. HARDY, Acting Chief Battlespace Environment Division This

  20. Alaska Athabascan stellar astronomy

    NASA Astrophysics Data System (ADS)

    Cannon, Christopher M.

    2014-01-01

    Stellar astronomy is a fundamental component of Alaska Athabascan cultures that facilitates time-reckoning, navigation, weather forecasting, and cosmology. Evidence from the linguistic record suggests that a group of stars corresponding to the Big Dipper is the only widely attested constellation across the Northern Athabascan languages. However, instruction from expert Athabascan consultants shows that the correlation of these names with the Big Dipper is only partial. In Alaska Gwich'in, Ahtna, and Upper Tanana languages the Big Dipper is identified as one part of a much larger circumpolar humanoid constellation that spans more than 133 degrees across the sky. The Big Dipper is identified as a tail, while the other remaining asterisms within the humanoid constellation are named using other body part terms. The concept of a whole-sky humanoid constellation provides a single unifying system for mapping the night sky, and the reliance on body-part metaphors renders the system highly mnemonic. By recognizing one part of the constellation the stargazer is immediately able to identify the remaining parts based on an existing mental map of the human body. The circumpolar position of a whole-sky constellation yields a highly functional system that facilitates both navigation and time-reckoning in the subarctic. Northern Athabascan astronomy is not only much richer than previously described; it also provides evidence for a completely novel and previously undocumented way of conceptualizing the sky---one that is unique to the subarctic and uniquely adapted to northern cultures. The concept of a large humanoid constellation may be widespread across the entire subarctic and have great antiquity. In addition, the use of cognate body part terms describing asterisms within humanoid constellations is similarly found in Navajo, suggesting a common ancestor from which Northern and Southern Athabascan stellar naming strategies derived.

  1. Station Climatic Summaries, North America. Volume 2. Alaska, Canada and Greenland

    DTIC Science & Technology

    1993-02-01

    mupracs or CA WIND am198 "mU opAN mom 70A I Wf OM -DATA AVRILNU.wi VIRD 133 G10 ...HOURS * I U I * * B * * B * 8. % FREt OF CIG/VIS < 100/0.25 MI: JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN 00-02 [ST 0 * B B I • B * • * I

  2. Robots could assist scientists working in Greenland

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-07-01

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

  3. Toxaphene in the aquatic environment of Greenland.

    PubMed

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

    2015-05-01

    The octa- and nonachlorinated bornanes (toxaphene) CHBs 26, 40, 41, 44, 50 and 62 were analysed in Arctic char (Salvelinus alpinus), shorthorn sculpin (Myoxocephalus scorpius), ringed seal (Pusa hispida) and black guillemot eggs (Cepphus grylle) from Greenland. Despite their high trophic level, ringed seals had the lowest concentrations of these species, with a Σ6Toxaphene median concentration of 13-20 ng/g lipid weight (lw), suggesting metabolisation. The congener composition also suggests transformation of nona- to octachlorinated congeners. Black guillemot eggs had the highest concentrations (Σ6Toxaphene median concentration of 971 ng/g lw). Although concentrations were higher in East than in West Greenland differences were smaller than for other persistent organic pollutants. In a circumpolar context, toxaphene had the highest concentrations in the Canadian Arctic. Time trend analyses showed significant decreases for black guillemot eggs and juvenile ringed seals, with annual rates of -5 to -7% for Σ6Toxaphene. The decreases were generally steepest for CHBs 40, 41 and 44.

  4. Instrument for Analysis of Greenland's Glacier Mills

    NASA Technical Reports Server (NTRS)

    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.

  5. Buoyant Currents West and East of Greenland

    NASA Astrophysics Data System (ADS)

    Aksenov, Y.; Bacon, S.; Nurser, G.; Coward, A.

    2014-12-01

    Low salinity buoyant polar waters exit the Arctic Ocean into the Nordic Seas and the North Atlantic, affecting deep convection in the Nordic and Labrador Seas with potential impacts on the meridional overturning circulation. The pathways of the polar water in Davis Strait, Fram Strait and then to the south are well documented by observations and model simulations. In contrast, measurements upstream of Fram Strait are too sparse to allow us to explain what causes the outflows to exit either west or east of Greenland or to attribute the variability in the Arctic outflows to atmospheric or oceanic mechanisms. Two high-resolution global ocean general circulation models (OGCM), NEMO-ORCA025, of ~12 km resolution, and NEMO-ORCA12, of ~4 km resolution, have been used to examine the dynamics and seasonal variability of the outflow west and east of Greenland. Montgomery potential analysis is used to investigate the dynamics of the currents in the area. The model results suggest wind as a driving mechanism for the seasonal variability of the ocean circulation in the area.

  6. Pathways of Petermann Glacier meltwater, Greenland

    NASA Astrophysics Data System (ADS)

    Heuzé, Céline; Wåhlin, Anna; Johnson, Helen; Münchow, Andreas

    2016-04-01

    Radar and satellite observations suggest that the floating ice shelf of Petermann Glacier loses up to 80% of its mass through basal melting, caused by the intrusion of warm Atlantic Water into the fjord and under the ice shelf. The fate of Petermann's glacial meltwater is still largely unknown. It is investigated here, using hydrographic observations collected during a research cruise on board I/B Oden in August 2015. Two methods are used to detect the meltwater from Petermann: a mathematical one that provides the concentration of ice shelf meltwater, and a geometrical one to distinguish the meltwater from Petermann and the meltwater from other ice shelves. The meltwater from Petermann mostly circulates on the north side of the fjord. At the sill, 0.5 mSv of meltwater leave the fjord, mostly on the northeastern side between 100 and 350 m depth, but also in the central channel, albeit with a lesser concentration. Meltwater from Petermann is found in all the casts in Hall Basin, notably north of the sill by Greenland coast. The geometrical method reveals that the casts closest to the Canadian side mostly contain meltwater from other, unidentified glaciers. As Atlantic Water warms up, it is key to monitor Greenland melting glaciers and track their meltwater to properly assess their impact on the ocean circulation and sea level rise.

  7. Central Greenland Holocene Deuterium Excess Variability

    NASA Astrophysics Data System (ADS)

    Masson-Delmotte, V.; Jouzel, J.; Falourd, S.; Cattani, O.; Dahl-Jensen, D.; Johnsen, S.; Sveinbjornsdottir, A. E.; White, J. W. C.

    Water stable isotopes (oxygen 18 and deuterium) have been measured along the Holocene part of two deep ice cores from central Greenland, GRIP and North GRIP. Theoretical studies have shown that the second-order isotopic parameter, the deu- terium excess (d=dD-8d18O), is an indicator of climatic changes at the oceanic mois- ture source reflecting at least partly changes in sea-surface-temperature. The two deu- terium excess records from GRIP and North GRIP show a long term increasing trend already observed in Antarctic deep ice cores and related to changes in the Earth's obliquity during the Holocene : an decreased obliquity is associated with a larger low to high latitude annual mean insolation gradient, warmer tropics, colder poles, and a more intense atmospheric transport from the tropics to the poles, resulting in a higher moisture source temperature and higher deuterium excess values. Superimposed onto this long term trend, central Greenland deuterium excess records also exhibit small abrupt events (8.2 ka BP and 4.5 ka BP) and a high frequency variability.

  8. Greenland Ice Core: Geophysics, Geochemistry, and the Environment

    NASA Astrophysics Data System (ADS)

    Langway, C. C., Jr.; Oeschger, H.; Dansgaard, W.

    The Greenland Ice Sheet Program (GISP) is already recognized as a major achievement in glaciology. GISP support came from the Swiss National Science Foundation, the Danish Commission for Scientific Research in Greenland and the United States National Science Foundation. And with the spirit, drive, and ability of Hans Oeschger, Willi Dansgaard and Chester Langway, GISP was planned, undertaken and successfully concluded. The results presented here demonstrate the significance of the climatic record stored in ice sheets and reemphasizes the need for additional deep ice cores from Greenland and Antarctica.

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

    NASA Technical Reports Server (NTRS)

    Koenig, Lora

    2009-01-01

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

  10. Comparison of magnetic activity in Greenland and Nordic countries

    NASA Astrophysics Data System (ADS)

    Peitso, P.; Tanskanen, E. I.; Stolle, C.; Berthou Lauritsen, N.; Matzka, J.

    2014-04-01

    We will examine geomagnetic activity from Greenland and IMAGE magnetic observations. Geomagnetic activity maps for the Greenland and IMAGE magnetic field measurements will be produced. The maps will be produced separately for the different months where the seasonal variation will be examined. We will compare geomagnetic conditions during winter and summer separately to examine in detail the differences and similarities. The Greenland magnetic field measurements will be used to estimate the geomagnetic field variation between Svalbard and northernmost tip of Norway, where we lack magnetic measurements due to the Arctic Ocean.

  11. SIMPL/AVIRIS-NG Greenland 2015: Flight Report

    NASA Technical Reports Server (NTRS)

    Brunt, Kelly M.; Neumann, Thomas A.; Markus, Thorsten

    2015-01-01

    In August 2015, NASA conducted a two-­aircraft, coordinated campaign based out of Thule Air Base, Greenland, in support of Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) algorithm development. The survey targeted the Greenland Ice Sheet and sea ice in the Arctic Ocean during the summer melt season. The survey was conducted with a photon-counting laser altimeter in one aircraft and an imaging spectrometer in the second aircraft. Ultimately, the mission, SIMPL/AVIRIS-NG Greenland 2015, conducted nine coordinated science flights, for a total of 37 flight hours over the ice sheet and sea ice.

  12. Physical Properties of the Ice Cover of the Greenland Sea.

    DTIC Science & Technology

    1982-11-01

    DA-A13 i PHYSICAL PROPERTIES OF THE ICE COVER OF THE GREENLAND 1/1 I SEAMU COLD REGIONS RESEARCH AND ENGINEERING LAB USI FE HANOVER NH N F REEKS NOV...I PERIOD COVERED PHYSICAL PROPERTIES OF THE ICE COVER OF THE GREENLAND SEA S. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(e) S. CONTRACT OR GRANT NUMBER...NOTES 19. KEY WORDS (Continue on revere aide if neceaary and identify by block number) Greenland Ice Ice properties Sea ice SABSTRACT (Vntmm em reverse

  13. Greenland Ice Sheet Program. 1979. Phase 1. Casing Operation.

    DTIC Science & Technology

    1980-06-01

    A-l0-1119 699 COLD. REGIONS RESEARCH AND ENGINEERING LAS HANOVER NH F/6 8/12 GREENLAND ICE SHEET PROGRAM. 1979. PHASE 1. CASING OPERATION. (U) JNAB J...Thermal drills Drills Glac iology Greenland 124 AnRACr (cimEaeu m reverse ssNnouiesaw ad Middfr by block nmber) )A modified CHREL thermal drill was used at...DYE-3 in Greenland to drill a 8.T5-in.-diamneter hole 251 ft deep for the installation of a steel casing. This activity was accomplished by a drill

  14. Alaska GeoFORCE, A New Geologic Adventure in Alaska

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2011-12-01

    RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. A program of rigorous academic activity combines with social, cultural, and recreational activities. Students are purposely stretched beyond their comfort levels academically and socially to prepare for the big step from home or village to a large culturally western urban campus. This summer RAHI is launching a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science as the hook because most kids get excited about dinosaurs, volcanoes and earthquakes, but it includes physics, chemistry, math, biology and other sciences. Students will be recruited, initially from the Arctic North Slope schools, in the 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The carrot on the end of the stick is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks, Arizona, Oregon and the Appalachians. All trips are focused on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska is being launched by UAF in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska will be managed by UAF's long-standing Rural Alaska Honors Insitute (RAHI) that has been successfully providing intense STEM educational opportunities for Alaskan high school students for almost 30 years. The Texas program, with adjustments for differences in culture and environment, will be

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

    NASA Astrophysics Data System (ADS)

    Shulgin, Alexey; Thybo, Hans

    2014-05-01

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

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

    NASA Technical Reports Server (NTRS)

    Steffen, Konrad; Box, Jason

    2003-01-01

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

  17. 50 CFR 17.5 - Alaska natives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... resides in Alaska; or (2) Any non-native permanent resident of an Alaskan native village who is primarily... pursuant to paragraph (a) of this section may be sold in native villages or towns in Alaska for native consumption within native villages and towns in Alaska. (c) Non-edible by-products of endangered or...

  18. Alaska Women's Commission Regional Conferences 1986.

    ERIC Educational Resources Information Center

    Callahan, Christine

    This booklet describes the work of the Alaska Women's Commission, a state agency dedicated to the achievement of equal legal, economic, social, and political status for women in Alaska. Since its inception, the Alaska Women's Commission has provided funding for regional women's conferences in rural parts of the state. The document describes four…

  19. 75 FR 45649 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... to the Alaska Native Claims Settlement Act. The lands are in the vicinity of Holy Cross, Alaska, and... Bureau of Land Management Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice of decision approving lands for conveyance. SUMMARY: As required by 43 CFR...

  20. Alaska Performance Scholarship Outcome Report 2015

    ERIC Educational Resources Information Center

    Rae, Brian

    2015-01-01

    The Alaska Performance Scholarship was established in state law in 2011 and first offered to Alaska high school graduates beginning with the class of 2011. Described as "an invitation to excellence" to Alaska's high school students, its goal was to inspire students to push themselves academically in areas that correlate to success in…

  1. Trends in Alaska's People and Economy.

    ERIC Educational Resources Information Center

    Leask, Linda; Killorin, Mary; Martin, Stephanie

    This booklet provides data on Alaska's population, economy, health, education, government, and natural resources, including specific information on Alaska Natives. Since 1960, Alaska's population has tripled and become more diverse, more stable, older, less likely to be male or married, and more concentrated. About 69 percent of the population…

  2. Palatability of water-soluble extracts of protein sources and replacement of fishmeal by a selected mixture of protein sources for juvenile turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Dong, Chun; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei

    2016-06-01

    Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source (single extract pellets) and the mixture of these extracts with different proportions (blended extract pellets) in juvenile turbot ( Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52 (wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio (the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous (52% crude protein) and isocaloric (20 kJ g-1 gross energy) diets were formulated by replacing 0 (control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an

  3. Skeletal development and abnormalities of the vertebral column and of the fins in hatchery-reared turbot Scophthalmus maximus.

    PubMed

    Tong, X H; Liu, Q H; Xu, S H; Ma, D Y; Xiao, Z Z; Xiao, Y S; Li, J

    2012-03-01

    To describe the skeletal development and abnormalities in turbot Scophthalmus maximus, samples were collected every day from hatching to 60 days after hatching (DAH). A whole-mount cartilage and bone-staining technique was used. Vertebral ontogeny started with the formation of anterior haemal arches at 5·1 mm standard length (L(S) ) c. 11 DAH, and was completed by the full attainment of parapophyses at 16·9 mm L(S) c. 31 DAH. Vertebral centra started to develop at 6·3 mm L(S) c. 16 DAH and ossification in all centra was visible at 11·0 mm L(S) c. 25 DAH. The caudal fin appeared at 5·1 mm L(S) c. 11 DAH and ossification was visible at 20·6 mm L(S) c. 37 DAH. The onset of dorsal and anal fin elements appeared at 5·8 mm L(S) c. 15 DAH and 6·3 mm L(S) c. 16 DAH, respectively. Ossifications of both dorsal fin and anal fin were visible at 20·6 mm L(S) c. 37 DAH. The pectorals were the only fins present before first feeding, their ossifications were completed at 23·5 mm L(S) c. 48 DAH. Pelvic fins began forming at 7·2 mm L(S) c. 19 DAH and calcification of the whole structure was visible at 19·8 mm L(S) c. 36 DAH. In the present study, 24 types of skeletal abnormalities were observed. About 51% of individuals presented skeletal abnormalities, and the highest occurrence was found in the haemal region of the vertebral column. As for each developmental stage, the most common abnormalities were in the dorsal fin during early metamorphic period (stage 2), vertebral fusion during climax metamorphosis (stage 3) and caudal fin abnormality during both late-metamorphic period (stage 4) and post-metamorphic period (stage 5). Such research will be useful for early detection of skeletal malformations during different growth periods of reared S. maximus.

  4. Modelling spoilage of fresh turbot and evaluation of a time-temperature integrator (TTI) label under fluctuating temperature.

    PubMed

    Nuin, Maider; Alfaro, Begoña; Cruz, Ziortza; Argarate, Nerea; George, Susie; Le Marc, Yvan; Olley, June; Pin, Carmen

    2008-10-31

    Kinetic models were developed to predict the microbial spoilage and the sensory quality of fresh fish and to evaluate the efficiency of a commercial time-temperature integrator (TTI) label, Fresh Check(R), to monitor shelf life. Farmed turbot (Psetta maxima) samples were packaged in PVC film and stored at 0, 5, 10 and 15 degrees C. Microbial growth and sensory attributes were monitored at regular time intervals. The response of the Fresh Check device was measured at the same temperatures during the storage period. The sensory perception was quantified according to a global sensory indicator obtained by principal component analysis as well as to the Quality Index Method, QIM, as described by Rahman and Olley [Rahman, H.A., Olley, J., 1984. Assessment of sensory techniques for quality assessment of Australian fish. CSIRO Tasmanian Regional Laboratory. Occasional paper n. 8. Available from the Australian Maritime College library. Newnham. Tasmania]. Both methods were found equally valid to monitor the loss of sensory quality. The maximum specific growth rate of spoilage bacteria, the rate of change of the sensory indicators and the rate of change of the colour measurements of the TTI label were modelled as a function of temperature. The temperature had a similar effect on the bacteria, sensory and Fresh Check kinetics. At the time of sensory rejection, the bacterial load was ca. 10(5)-10(6) cfu/g. The end of shelf life indicated by the Fresh Check label was close to the sensory rejection time. The performance of the models was validated under fluctuating temperature conditions by comparing the predicted and measured values for all microbial, sensory and TTI responses. The models have been implemented in a Visual Basic add-in for Excel called "Fish Shelf Life Prediction (FSLP)". This program predicts sensory acceptability and growth of spoilage bacteria in fish and the response of the TTI at constant and fluctuating temperature conditions. The program is freely

  5. The first glacier inventory for entire Greenland

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  6. Malaspina Glacier, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite covers an area of 55 by 40 kilometers (34 by 25 miles) over the southwest part of the Malaspina Glacier and Icy Bay in Alaska. The composite of infrared and visible bands results in the snow and ice appearing light blue, dense vegetation is yellow-orange and green, and less vegetated, gravelly areas are in orange. According to Dr. Dennis Trabant (U.S. Geological Survey, Fairbanks, Alaska), the Malaspina Glacier is thinning. Its terminal moraine protects it from contact with the open ocean; without the moraine, or if sea level rises sufficiently to reconnect the glacier with the ocean, the glacier would start calving and retreat significantly. ASTER data are being used to help monitor the size and movement of some 15,000 tidal and piedmont glaciers in Alaska. Evidence derived from ASTER and many other satellite and ground-based measurements suggests that only a few dozen Alaskan glaciers are advancing. The overwhelming majority of them are retreating.

    This ASTER image was acquired on June 8, 2001. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next six years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, along-term research and

  7. Mapping Greenland's mass loss in space and time.

    PubMed

    Harig, Christopher; Simons, Frederik J

    2012-12-04

    The melting of polar ice sheets is a major contributor to global sea-level rise. Early estimates of the mass lost from the Greenland ice cap, based on satellite gravity data collected by the Gravity Recovery and Climate Experiment, have widely varied. Although the continentally and decadally averaged estimated trends have now more or less converged, to this date, there has been little clarity on the detailed spatial distribution of Greenland's mass loss and how the geographical pattern has varied on relatively shorter time scales. Here, we present a spatially and temporally resolved estimation of the ice mass change over Greenland between April of 2002 and August of 2011. Although the total mass loss trend has remained linear, actively changing areas of mass loss were concentrated on the southeastern and northwestern coasts, with ice mass in the center of Greenland steadily increasing over the decade.

  8. Permian of Norwegian-Greenland sea margins: future exploration target

    SciTech Connect

    Surlyk, F.; Hurst, J.M.; Piasecki, S.; Rolle, F.; Stemmerik, L.; Thomsen, E.; Wrang, P.

    1984-09-01

    Oil and gas exploration in the northern North Sea and the southern Norwegian shelf has mainy been concentrated on Jurassic and younger reservoirs with Late Jurassic black shale source rocks. New onshore investigations in Jameson Land, central East Greenland, suggest that the Permian of the Norwegian-Greenland Sea margins contains relatively thick sequences of potential oil source rocks interbedded with carbonate reefs. The East Greenland, Upper Permian marine basin is exposed over a length of 400 km (250 mi) from Jameson Land in the south to Wollaston Forland in the north, parallel with the continental margin. The Upper Permian black shale is relatively thick, widely distributed, has a high organic carbon content, and a favorable kerogen type. Consequently, the possibilities for a Permian play in the northern part of the Norwegian shelf and along parts of the Norwegian-Greenland Sea margins are worth evaluating.

  9. Greenland Expeditions by Alfred Wegener - A photographic window to past

    NASA Astrophysics Data System (ADS)

    Leitner, M.; Tschürtz, S.; Kirchengast, G.; Kranzelbinder, H.; Prügger, B.; Krause, R. A.; Kalliokoski, M.; Thórhallsdóttir, E.

    2012-04-01

    On several expeditions to Greenland, Alfred Wegener (1880-1930) took pictures on glass plates from landscapes and glaciers, the expedition equipment, the people and animals taking part on the expeditions as well as physical phenomena as dust storm, clouds or spherical light phenomena. Chronologically the plates show the Danmark Expedition 1906-1908, the crossing of Greenland expedition with stop in Iceland 1912-1913, and the German Greenland Expedition 1929-1930. Until the tragic end of the expedition in 1930, Wegener was professor at the University of Graz, and such a stock of about 300 glass plates stayed there. The aim of our work is to digitize all plates for further studies. We present a first selection of Wegener's Greenland expedition pictures. For those made at Iceland in 1912 we will present a comparison of the past with pictures from the same viewing point made in 2011.

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  11. Late Pleistocene and Holocene tephrostratigraphy of interior Alaska and Yukon: Key beds and chronologies over the past 30,000 years

    NASA Astrophysics Data System (ADS)

    Davies, Lauren J.; Jensen, Britta J. L.; Froese, Duane G.; Wallace, Kristi L.

    2016-08-01

    The Aleutian Arc-Alaska Peninsula and Wrangell volcanic field are the main source areas for tephra deposits found across Alaska and northern Canada, and increasingly, tephra from these eruptions have been found further afield in North America, Greenland, and Europe. However, there have been no broad scale reviews of the Late Pleistocene and Holocene tephrostratigraphy for this region since the 1980s, and this lack of data is hindering progress in identifying these tephra both locally and regionally. To address this gap and the variable quality of associated geochemical and chronological data, we undertake a detailed review of the latest Pleistocene to Holocene tephra found in interior Alaska and Yukon. This paper discusses nineteen tephra that have distributions beyond southwest Alaska and that have the potential to become, or already are, important regional markers. This includes three 'modern' events from the 20th century, ten with limited data availability but potentially broad distributions, and six that are widely reported in interior Alaska and Yukon. Each tephra is assessed in terms of chronology, geochemistry and distribution, with new Bayesian age estimates and geochemical data when possible. This includes new major-element geochemical data for Crater Peak 1992, Redoubt 1989-90, and two andesitic tephra from St Michael Island (Tephra D), as well as revised age estimates for Dawson tephra, Oshetna, Hayes set H, Aniakchak CFE II, and the White River Ashes, northern and eastern lobes.

  12. Changes in the velocity structure of the Greenland Ice Sheet.

    PubMed

    Rignot, Eric; Kanagaratnam, Pannir

    2006-02-17

    Using satellite radar interferometry observations of Greenland, we detected widespread glacier acceleration below 66 degrees north between 1996 and 2000, which rapidly expanded to 70 degrees north in 2005. Accelerated ice discharge in the west and particularly in the east doubled the ice sheet mass deficit in the last decade from 90 to 220 cubic kilometers per year. As more glaciers accelerate farther north, the contribution of Greenland to sea-level rise will continue to increase.

  13. Climate Change and Baleen Whale Trophic Cascades in Greenland

    DTIC Science & Technology

    2008-01-01

    species in West Greenland. We use a multidisciplinary approach by combining observations of foraging ecology and phenology collected by satellite and...feeding in each site and the phenology of the use of the focal areas. These data are related to long-term physical and biological monitoring program...in Nuuk Fjord and on the coast of West Greenland, where long-term fishery data are collected to quantify seasonal and inter-annual variations in the

  14. Alaska Energy Inventory Project: Consolidating Alaska's Energy Resources

    NASA Astrophysics Data System (ADS)

    Papp, K.; Clough, J.; Swenson, R.; Crimp, P.; Hanson, D.; Parker, P.

    2007-12-01

    Alaska has considerable energy resources distributed throughout the state including conventional oil, gas, and coal, and unconventional coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass. While much of the known large oil and gas resources are concentrated on the North Slope and in the Cook Inlet regions, the other potential sources of energy are dispersed across a varied landscape from frozen tundra to coastal settings. Despite the presence of these potential energy sources, rural Alaska is mostly dependent upon diesel fuel for both electrical power generation and space heating needs. At considerable cost, large quantities of diesel fuel are transported to more than 150 roadless communities by barge or airplane and stored in large bulk fuel tank farms for winter months when electricity and heat are at peak demands. Recent increases in the price of oil have severely impacted the price of energy throughout Alaska, and especially hard hit are rural communities and remote mines that are off the road system and isolated from integrated electrical power grids. Even though the state has significant conventional gas resources in restricted areas, few communities are located near enough to these resources to directly use natural gas to meet their energy needs. To address this problem, the Alaska Energy Inventory project will (1) inventory and compile all available Alaska energy resource data suitable for electrical power generation and space heating needs including natural gas, coal, coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass and (2) identify locations or regions where the most economic energy resource or combination of energy resources can be developed to meet local needs. This data will be accessible through a user-friendly web-based interactive map, based on the Alaska Department of Natural Resources, Land Records Information Section's (LRIS) Alaska Mapper, Google Earth, and Terrago Technologies' Geo

  15. Distinct patterns of seasonal Greenland glacier velocity.

    PubMed

    Moon, Twila; Joughin, Ian; Smith, Ben; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Usher, Mika

    2014-10-28

    Predicting Greenland Ice Sheet mass loss due to ice dynamics requires a complete understanding of spatiotemporal velocity fluctuations and related control mechanisms. We present a 5 year record of seasonal velocity measurements for 55 marine-terminating glaciers distributed around the ice sheet margin, along with ice-front position and runoff data sets for each glacier. Among glaciers with substantial speed variations, we find three distinct seasonal velocity patterns. One pattern indicates relatively high glacier sensitivity to ice-front position. The other two patterns are more prevalent and appear to be meltwater controlled. These patterns reveal differences in which some subglacial systems likely transition seasonally from inefficient, distributed hydrologic networks to efficient, channelized drainage, while others do not. The difference may be determined by meltwater availability, which in some regions may be influenced by perennial firn aquifers. Our results highlight the need to understand subglacial meltwater availability on an ice sheet-wide scale to predict future dynamic changes.

  16. Growth of Greenland ice sheet - Interpretation

    NASA Technical Reports Server (NTRS)

    Zwally, H. Jay

    1989-01-01

    An observed 0.23 m/year thickening of the Greenland ice sheet indicates a 25 percent to 45 percent excess ice accumulation over the amount required to balance the outward ice flow. The implied global sea-level depletion is 0.2 to 0.4 mm/year, depending on whether the thickening is only recent (5 to 10 years) or longer term (less than 100 years). If there is a similar imbalance in the northern 60 percent of the ice-sheet area, the depletion is 0.35 to 0.7 mm/year. Increasing ice thickness suggests that the precipitation is higher than the long-term average; higher precipitation may be a characteristic of warmer climates in polar regions.

  17. Analysis of recent glacial earthquakes in Greenland

    NASA Astrophysics Data System (ADS)

    Olsen, K.; Nettles, M.

    2015-12-01

    Large calving events at Greenland's outlet glaciers produce teleseismically detectable glacial earthquakes. These events are observed in the seismic record for the past 22 years, but the complete catalog of glacial earthquakes still numbers only ~300. The annual occurrence of these long-period events has increased over time, which makes recent years especially valuable in expanding the global dataset. Glacial earthquakes from 1993- 2010 have been analyzed systematically (Tsai and Ekström, 2007; Veitch and Nettles, 2012). Here, we analyze more recent events using the same centroid—single-force (CSF) approach as previous authors, focusing initially on data from 2013. In addition, we perform a focused study of selected events from 2009-2010 to assess the reliability of the force azimuths obtained from such inversions. Recent spatial and temporal patterns of glacial earthquakes in Greenland differ from those in previous years. In 2013, three times as many events occurred on the west coast as on the east, and these events originated predominantly from two glaciers: Jakobshavn Glacier on the west coast and Helheim Glacier on the east. Kangerdlugssuaq Glacier, on the east coast, produced no glacial earthquakes in 2013, though it produced many events in earlier years. Previous CSF results for glacial earthquakes show force azimuths perpendicular to the glacier front during a calving event, with force plunges near horizontal. However, some azimuths indicate forces initially oriented upglacier, while others are oriented downglacier (seaward). We perform a set of experiments on events from 2009 and 2010 and find two acceptable solutions for each glacial earthquake, oriented 180° apart with plunges of opposite sign and centroid times differing by approximately one half of the assumed duration of the earthquake time function. These results suggest the need for a more complex time function to model glacial earthquakes more accurately.

  18. The Alaska SAR processor

    NASA Technical Reports Server (NTRS)

    Carande, R. E.; Charny, B.

    1988-01-01

    The Alaska SAR processor was designed to process over 200 100 km x 100 km (Seasat like) frames per day from the raw SAR data, at a ground resolution of 30 m x 30 m from ERS-1, J-ERS-1, and Radarsat. The near real time processor is a set of custom hardware modules operating in a pipelined architecture, controlled by a general purpose computer. Input to the processor is provided from a high density digital cassette recording of the raw data stream as received by the ground station. A two pass processing is performed. During the first pass clutter-lock and auto-focus measurements are made. The second pass uses the results to accomplish final image formation which is recorded on a high density digital cassette. The processing algorithm uses fast correlation techniques for range and azimuth compression. Radiometric compensation, interpolation and deskewing is also performed by the processor. The standard product of the ASP is a high resolution four-look image, with a low resolution (100 to 200 m) many look image provided simultaneously.

  19. Alaska Pipeline Insulation

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Crude oil moving through the 800-mile Trans-Alaska Pipeline must be kept at a relatively high temperature, about 180 degrees Fahrenheit, to maintain the fluidity of the oil. In Arctic weather, that demands highly effective insulation. General Electric Co.'s Space Division, Valley Forge, Pennsylvania, provided it with a spinoff product called Therm-O-Trol. Shown being installed on the pipeline, Therm-O-Trol is a metal-bonded polyurethane foam especially formulated for Arctic insulation. A second GE spinoff product, Therm-O-Case, solved a related problem involved in bringing hot crude oil from 2,000-foot-deep wells to the surface without transferring oil heat to the surrounding permafrost soil; heat transfer could melt the frozen terrain and cause dislocations that might destroy expensive well casings. Therm-O-Case is a double-walled oil well casing with multi-layered insulation which provides an effective barrier to heat transfer. Therm-O-Trol and Therm-O-Case are members of a family of insulating products which stemmed from technology developed by GE Space Division in heat transferlthermal control work on Gemini, Apollo and other NASA programs.

  20. Alexander Archipelago, Southeastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    West of British Columbia, Canada, and south of the Yukon Territory, the southeastern coastline of Alaska trails off into the islands of the Alexander Archipelago. The area is rugged and contains many long, U-shaped, glaciated valleys, many of which terminate at tidewater. The Alexander Archipelago is home to Glacier Bay National Park. The large bay that has two forks on its northern end is Glacier Bay itself. The eastern fork is Muir inlet, into which runs the Muir glacier, named for the famous Scottish-born naturalist John Muir. Glacier Bay opens up into the Icy Strait. The large, solid white area to the west is Brady Icefield, which terminates at the southern end in Brady's Glacier. To locate more interesting features from Glacier Bay National Park, take a look at the park service map. As recently as two hundred years ago, a massive ice field extended into Icy Strait and filled the Glacier Bay. Since that time, the area has experienced rapid deglaciation, with many large glaciers retreating 40, 60, even 80 km. While temperatures have increased in the region, it is still unclear whether the rapid recession is part of the natural cycle of tidewater glaciers or is an indicator of longer-term climate change. For more on Glacier Bay and climate change, read an online paper by Dr. Dorothy Hall, a MODIS Associate Science Team Member. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  1. The first characterization of two type I interferons in turbot (Scophthalmus maximus) reveals their differential role, expression pattern and gene induction.

    PubMed

    Pereiro, P; Costa, M M; Díaz-Rosales, P; Dios, S; Figueras, A; Novoa, B

    2014-08-01

    Type I interferons (IFNs) are considered the main cytokines directing the antiviral immune response in vertebrates. These molecules are able to induce the transcription of interferon-stimulated genes (ISGs) which, using different blocking mechanisms, reduce the viral proliferation in the host. In addition, a contradictory role of these IFNs in the protection against bacterial challenges using murine models has been observed, increasing the survival or having a detrimental effect depending on the bacteria species. In teleosts, a variable number of type I IFNs has been described with different expression patterns, protective capabilities or gene induction profiles even for the different IFNs belonging to the same species. In this work, two type I IFNs (ifn1 and ifn2) have been characterized for the first time in turbot (Scophthalmus maximus), showing different properties. Whereas Ifn1 reflected a clear antiviral activity (over-expression of ISGs and protection against viral haemorrhagic septicaemia virus), Ifn2 was not able to induce this response, although both transcripts were up-regulated after viral challenge. On the other hand, turbot IFNs did not show any protective effect against the bacteria Aeromonas salmonicida, although they were induced after bacterial challenge. Both IFNs induced the expression of several immune genes, but the effect of Ifn2 was mainly limited to the site of administration (intramuscular injection). Interestingly, Ifn2 but not Ifn1 induced an increase in the expression level of interleukin-1 beta (il1b). Therefore, the role of Ifn2 could be more related with the immune regulation, being involved mainly in the inflammation process.

  2. Trace element concentrations in livers of polar bears from two populations in Northern and Western Alaska.

    PubMed

    Kannan, Kurunthachalam; Agusa, Tetsuro; Evans, Thomas J; Tanabe, Shinsuke

    2007-10-01

    Concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of polar bears (Ursus maritimus) collected from Northern and Western Alaska from 1993 to 2002 to examine differences in the profiles of trace metals between the Beaufort Sea (Northern Alaska) and the Chukchi Sea (Western Alaska) subpopulations in Alaska. Among the trace elements analyzed, concentrations of Cu (50-290 microg/g, dry wt) in polar bear livers were in the higher range of values that have been reported for marine mammals. Concentrations of Hg in polar bears varied widely, from 3.5 to 99 microg/g dry wt, and the mean concentrations in polar bears were comparable to concentrations reported previously for several other species of marine mammals. Mean concentrations of Pb and Cd were 0.67 and 1.0 microg/g dry wt, respectively; these concentrations were lower than levels reported elsewhere for polar bears from Greenland and Canada. Age- and gender-related variations in the concentrations of trace elements in our polar bears were minimal. Concentrations of Hg decreased slowly in samples collected during 1993-2002, whereas Cd and Pb concentrations were found to be stable or slowly increasing, in the livers of Alaskan polar bears. Concentrations of Ag, Bi, Ba, Cu, and Sn were significantly higher in the Chukchi Sea subpopulation than in the Beaufort Sea subpopulation. Concentrations of Hg were significantly higher in the Beaufort Sea subpopulation than in the Chukchi Sea subpopulation. Differences in the profiles and concentrations of Hg, Ag, Bi, Ba, Cu, and Sn suggest that the sources of exposure to these trace elements between Western and Northern Alaskan polar bears are different, in agreement with findings reported earlier for several organic contaminants.

  3. Alaska volcanoes guidebook for teachers

    USGS Publications Warehouse

    Adleman, Jennifer N.

    2011-01-01

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

  4. The United States National Climate Assessment - Alaska Technical Regional Report

    USGS Publications Warehouse

    Markon, Carl J.; Trainor, Sarah F.; Chapin, F. Stuart; Markon, Carl J.; Trainor, Sarah F.; Chapin, F. Stuart

    2012-01-01

    , because cold sea water absorbs CO2 more rapidly than warm water, and a decrease in sea ice extent has allowed increased sea surface exposure and more uptake of CO2 into these northern waters. Ocean acidification will likely affect the ability of organisms to produce and maintain shell material, such as aragonite or calcite (calcium carbonate minerals structured from carbonate ions), required by many shelled organism, from mollusks to corals to microscopic organisms at the base of the food chain. Direct biological effects in Alaska further along the food chain have yet to be studied and may vary among organisms. Some of the potentially most significant changes to Alaska that could result from a changing climate are the effects on the terrestrial cryosphere - particularly glaciers and permafrost. Alaskan glaciers are changing at a rapid rate, the primary driver appearing to be temperature. Statewide, glaciers lost 13 cubic miles of ice annually from the 1950s to the 1990s, and that rate doubled in the 2000s. However, like temperature and precipitation, glacier ice loss is not spatially uniform; most glaciers are losing mass, yet some are growing (for example Hubbard Glacier in southeast Alaska). Alaska glaciers with the most rapid loss are those terminating in sea water or lakes. With this increasing rate of melt, the contribution of surplus fresh water entering into the oceans from Alaska's glaciers, as well as those in neighboring British Columbia, Canada, is approximately 20 percent of that contributed by the Greenland Ice Sheet. Permafrost degradation (that is, the thawing of ice-rich soils) is currently (2012) impacting infrastructure and surface-water availability in areas of both discontinuous and continuous ground ice. Over most of the State, the permafrost is warming, with increasing temperatures broadly consistent with increasing air temperatures. On the Arctic coastal plain of Alaska, permafrost temperatures showed some cooling in the 1950s and 1960s but have

  5. Alaska Resource Data File, Talkeetna Mountains quadrangle, Alaska

    USGS Publications Warehouse

    Rogers, Robert K.; Schmidt, Jeanine M.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  6. Alaska Resource Data File, McCarthy quadrangle, Alaska

    USGS Publications Warehouse

    Hudson, Travis L.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

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

    PubMed

    Dahlgaard, Henning; Eriksson, Mats; Nielsen, Sven P; Joensen, Hans Pauli

    2004-09-20

    Levels of radioactive contaminants in various Greenland environments have been assessed during 1999-2001. The source of 137Cs, 90Sr and (239,240)Pu in terrestrial and fresh water environments is mainly global fallout. In addition, the Chernobyl accident gave a small contribution of 137Cs. Reindeer and lamb contain the largest observed 137Cs concentrations in the terrestrial environment--up to 80 Bq kg(-1) fresh weight have been observed in reindeer. Due to special environmental conditions, 137Cs is transferred to landlocked Arctic char with extremely high efficiency in South Greenland leading to concentrations up to 100 Bq kg(-1) fresh weight. In these cases very long ecological half-lives are seen. Concentrations of 99Tc, 137Cs and 90Sr in seawater and in marine biota decrease in the order North-East Greenland and the coastal East Greenland current > South-West Greenland > Central West Greenland and North-West Greenland > Irmiger Sea-Faroe Islands. The general large-scale oceanic circulation combined with European coastal discharges and previous contamination of the Arctic Ocean causes this. As the same tendency is seen for the persistent organic pollutants (POPs) DDT and PCB in marine biota, it is suggested that long-distance oceanic transport by coastal currents is a significant pathway also for POPs in the Greenland marine environment. The peak 99Tc discharge from Sellafield 1994-1995 has only been slightly visible in the present survey year 2000. 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

  8. Role of Greenland meltwater in the changing Arctic

    NASA Astrophysics Data System (ADS)

    Dukhovskoy, Dmitry; Proshutinsky, Andrey; Timmermans, Mary-Louise; Myers, Paul; Platov, Gennady; Bamber, Jonathan; Curry, Beth; Somavilla, Raquel

    2016-04-01

    Observational data show that the Arctic ocean-ice-atmosphere system has been changing over the last two decades. Arctic change is manifest in the atypical behavior of the climate indices in the 21st century. Before the 2000s, these indices characterized the quasi-decadal variability of the Arctic climate related to different circulation regimes. Between 1948 and 1996, the Arctic atmospheric circulation alternated between anticyclonic circulation regimes and cyclonic circulation regimes with a period of 10-15 years. Since 1997, however, the Arctic has been dominated by an anticyclonic regime. Previous studies indicate that in the 20th century, freshwater and heat exchange between the Arctic Ocean and the sub-Arctic seas were self-regulated and their interactions were realized via quasi-decadal climate oscillations. What physical processes in the Arctic Ocean - sub-Arctic ocean-ice-atmosphere system are responsible for the observed changes in Arctic climate variability? The presented work is motivated by our hypothesis that in the 21st century, these quasi-decadal oscillations have been interrupted as a result of an additional freshwater source associated with Greenland Ice Sheet melt. Accelerating since the early 1990s, the Greenland Ice Sheet mass loss exerts a significant impact on thermohaline processes in the sub-Arctic seas. Surplus Greenland freshwater, the amount of which is about a third of the freshwater volume fluxed into the region during the 1970s Great Salinity Anomaly event, can spread and accumulate in the sub-Arctic seas influencing convective processes there. It is not clear, however, whether Greenland freshwater can propagate into the interior convective regions in the Labrador Sea and the Nordic Seas. In order to investigate the fate and pathways of Greenland freshwater in the sub-Arctic seas and to determine how and at what rate Greenland freshwater propagates into the convective regions, several numerical experiments using a passive tracer to

  9. Instrumentation for single-dish observations with The Greenland Telescope

    NASA Astrophysics Data System (ADS)

    Grimes, Paul K.; Asada, K.; Blundell, R.; Burgos, R.; Chang, H.-H.; Chen, M. T.; Goldie, D.; Groppi, C.; Han, C. C.; Ho, P. T. P.; Huang, Y. D.; Inoue, M.; Kubo, D.; Koch, P.; Leech, J.; de Lera Acedo, E.; Martin-Cocher, P.; Nishioka, H.; Nakamura, M.; Matsushita, S.; Paine, S. N.; Patel, N.; Raffin, P.; Snow, W.; Sridharan, T. K.; Srinivasan, R.; Thomas, C. N.; Tong, E.; Wang, M.-J.; Wheeler, C.; Withington, S.; Yassin, G.; Zeng, L.-Z.

    2014-07-01

    The Greenland Telescope project will deploy and operate a 12m sub-millimeter telescope at the highest point of the Greenland i e sheet. The Greenland Telescope project is a joint venture between the Smithsonian As- trophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). In this paper we discuss the concepts, specifications, and science goals of the instruments being developed for single-dish observations with the Greenland Telescope, and the coupling optics required to couple both them and the mm-VLBI receivers to antenna. The project will outfit the ALMA North America prototype antenna for Arctic operations and deploy it to Summit Station,1 a NSF operated Arctic station at 3,100m above MSL on the Greenland I e Sheet. This site is exceptionally dry, and promises to be an excellent site for sub-millimeter astronomical observations. The main science goal of the Greenland Telescope is to carry out millimeter VLBI observations alongside other telescopes in Europe and the Americas, with the aim of resolving the event horizon of the super-massive black hole at the enter of M87. The Greenland Telescope will also be outfitted for single-dish observations from the millimeter-wave to Tera-hertz bands. In this paper we will discuss the proposed instruments that are currently in development for the Greenland Telescope - 350 GHz and 650 GHz heterodyne array receivers; 1.4 THz HEB array receivers and a W-band bolometric spectrometer. SAO is leading the development of two heterodyne array instruments for the Greenland Telescope, a 48- pixel, 325-375 GHz SIS array receiver, and a 4 pixel, 1.4 THz HEB array receiver. A key science goal for these instruments is the mapping of ortho and para H2D+ in old protostellar ores, as well as general mapping of CO and other transitions in molecular louds. An 8-pixel prototype module for the 350 GHz array is currently being built for laboratory and operational testing on the Greenland Telescope

  10. Teshekpuk Lake, Alaska

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This ASTER image of Teshekpuk Lake on Alaska's North Slope, within the National Petroleum Reserve, was acquired on August 15, 2000. It covers an area of 58.7 x 89.9 km, and is centered near 70.4 degrees north latitude, 153 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    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.

    Size: 58.7 by 89.9 kilometers (36.4 by 55.7 miles) Location: 70.4 degrees North latitude, 153 degrees West longitude Orientation: North at top Image Data: ASTER Bands 3, 2, and 1 Original Data Resolution: ASTER 30 meters (98.4 feet) Dates Acquired: August 15, 2000

  11. Dental caries in rural Alaska Native children--Alaska, 2008.

    PubMed

    2011-09-23

    In April 2008, the Arctic Investigations Program (AIP) of CDC was informed by the Alaska Department of Health and Social Services (DHSS) of a large number of Alaska Native (AN) children living in a remote region of Alaska who required full mouth dental rehabilitations (FMDRs), including extractions and/or restorations of multiple carious teeth performed under general anesthesia. In this remote region, approximately 400 FMDRs were performed in AN children aged <6 years in 2007; the region has approximately 600 births per year. Dental caries can cause pain, which can affect children's normal growth and development. AIP and Alaska DHSS conducted an investigation of dental caries and associated risk factors among children in the remote region. A convenience sample of children aged 4-15 years in five villages (two with fluoridated water and three without) was examined to estimate dental caries prevalence and severity. Risk factor information was obtained by interviewing parents. Among children aged 4-5 years and 12-15 years who were evaluated, 87% and 91%, respectively, had dental caries, compared with 35% and 51% of U.S. children in those age groups. Among children from the Alaska villages, those aged 4-5 years had a mean of 7.3 dental caries, and those aged 12-15 years had a mean of 5.0, compared with 1.6 and 1.8 dental caries in same-aged U.S. children. Of the multiple factors assessed, lack of water fluoridation and soda pop consumption were significantly associated with dental caries severity. Collaborations between tribal, state, and federal agencies to provide effective preventive interventions, such as water fluoridation of villages with suitable water systems and provision of fluoride varnishes, should be encouraged.

  12. Early Tertiary marine fossils from northern Alaska: implications for Arctic Ocean paleogeography and faunal evolution.

    USGS Publications Warehouse

    Marincovich, L.; Brouwers, E.M.; Carter, L.D.

    1985-01-01

    Marine mollusks and ostracodes indicate a post-Danian Paleocene to early Eocene (Thanetian to Ypresian) age for a fauna from the Prince Creek Formation at Ocean Point, northern Alaska, that also contains genera characteristic of the Cretaceous and Neogene-Quaternary. The life-assocation of heterochronous taxa at Ocean Point resulted from an unusual paleogeographic setting, the nearly complete isolation of the Arctic Ocean from about the end of the Cretaceous until sometime in the Eocene, in which relict Cretaceous taxa survived into Tertiary time while endemic taxa evolved in situ; these later migrated to the northern mid- latitudes. Paleobiogeographic affinities of the Ocean Point assocation with mild temperate faunas of the London Basin (England), Denmark, and northern Germany indicate that a shallow, intermittent Paleocene seaway extended through the Norwegian-Greenland Sea to the North Sea Basin. Early Tertiary Arctic Ocean paleogeography deduced from faunal evidence agrees with that inferred from plate-tectonic reconstructions.-Authors

  13. How warm was Greenland during the last interglacial period?

    NASA Astrophysics Data System (ADS)

    Landais, Amaelle; Masson-Delmotte, Valérie; Capron, Emilie; Langebroek, Petra M.; Bakker, Pepijn; Stone, Emma J.; Merz, Niklaus; Raible, Christoph C.; Fischer, Hubertus; Orsi, Anaïs; Prié, Frédéric; Vinther, Bo; Dahl-Jensen, Dorthe

    2016-09-01

    The last interglacial period (LIG, ˜ 129-116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 °C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning, suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Greenland surface warming using ice core air isotopic composition (δ15N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 °C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 °C warming initially determined from NEEM water isotopes but at the upper end of the preindustrial period to LIG temperature difference of +5.2 ± 2.3 °C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 °C) are produced in response to prescribed changes in sea ice extent and ice sheet topography.

  14. Adventures in the Alaska Economy.

    ERIC Educational Resources Information Center

    Jackstadt, Steve; Huskey, Lee

    This publication was developed to increase students' understanding of basic economic concepts and the historical development of Alaska's economy. Comics depict major historical events as they occurred, but specific characters are fictionalized. Each of nine episodes is accompanied by several pages of explanatory text, which enlarges on the episode…

  15. Survey of Alaska Information Systems.

    ERIC Educational Resources Information Center

    Allen, Anda; Sokolov, Barbara J.

    This survey by the Arctic Environmental Information and Data Center at the University of Alaska identifies and describes information and data collections within Alaskan libraries and agency offices which pertain to fish and wildlife or their habitat. Included in the survey are descriptions of the location, characteristics, and availability of…

  16. Alaska and Bering Sea Bloom

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Alaska was relatively clear as was part of the Bering Sea where the aquamarine bloom is still visible in this SeaWiFS image. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  17. Licensed Optometrists in Alaska 1973.

    ERIC Educational Resources Information Center

    Health Resources Administration (DHEW/PHS), Bethesda, MD. Div. of Manpower Intelligence.

    This report presents preliminary findings from a mail survey of all optometrists licensed to practice in the State of Alaska. The survey was conducted in 1973 by the International Association of Boards of Examiners in Optometry as part of a national endeavor to collect data on all optometrists in the United States. Since there was a 100 percent…

  18. Legal Guide for Alaska Youth.

    ERIC Educational Resources Information Center

    Nesbitt, Buell, Ed.; And Others

    This legal guide, developed by the Alaska Congress of Parents and Teachers, is intended for young citizens and parents to advise youth of their civil rights and explain what constitutes a criminal offense. The aim is to objectively state the law in understandable terms. The book is arranged in four sections. Section one explains the legal rights…

  19. Tuberculosis among Children in Alaska.

    ERIC Educational Resources Information Center

    Gessner, Bradford D.

    1997-01-01

    The incidence of tuberculosis among Alaskan children under 15 was more than twice the national rate, with Alaska Native children showing a much higher incidence. Children with household exposure to adults with active tuberculosis had a high risk of infection. About 22 percent of pediatric tuberculosis cases were identified through school…

  20. Antidote: Civic Responsibility. Alaska Law.

    ERIC Educational Resources Information Center

    Phi Alpha Delta Law Fraternity International, Washington, DC.

    Designed for middle school through high school students, this unit contains eight lesson plans that focus on Alaska state law. The state lessons correspond to lessons in the volume, "Antidote: Civic Responsibility. Drug Avoidance Lessons for Middle School & High School Students." Developed to be presented by educators, law student,…

  1. Minority Women's Health: American Indians/Alaska Natives

    MedlinePlus

    ... Minority Women's Health > American Indians/Alaska Natives Minority Women's Health American Indians/Alaska Natives Related information How ... conditions common in American Indian and Alaska Native women Accidents Alcoholism and drug abuse Breast cancer Cancer ...

  2. Chronic Liver Disease and American Indians/Alaska Natives

    MedlinePlus

    ... American Indian/Alaska Native > Chronic Liver Disease Chronic Liver Disease and American Indians/Alaska Natives Among American Indians and Alaska Natives, chronic liver disease is a leading cause of death. While ...

  3. Stroke Mortality Among Alaska Native People

    PubMed Central

    Horner, Ronnie D.; Day, Gretchen M.; Lanier, Anne P.; Provost, Ellen M.; Hamel, Rebecca D.

    2009-01-01

    Objectives. We aimed to describe the epidemiology of stroke among Alaska Natives, which is essential for designing effective stroke prevention and intervention efforts for this population. Methods. We conducted an analysis of death certificate data for the state of Alaska for the period 1984 to 2003, comparing age-standardized stroke mortality rates among Alaska Natives residing in Alaska vs US Whites by age category, gender, stroke type, and time. Results. Compared with US Whites, Alaska Natives had significantly elevated stroke mortality from 1994 to 2003 but not from 1984 to 1993. Alaska Native women of all age groups and Alaska Native men younger than 45 years of age had the highest risk, although the rates for those younger than 65 years were statistically imprecise. Over the 20-year study period, the stroke mortality rate was stable for Alaska Natives but declined for US Whites. Conclusions. Stroke mortality is higher among Alaska Natives, especially women, than among US Whites. Over the past 20 years, there has not been a significant decline in stroke mortality among Alaska Natives. PMID:19762671

  4. Sampson v. state of Alaska: in the Supreme Court of the state of Alaska.

    PubMed

    Bostrom, B A

    2001-01-01

    HELD: The Alaska Constitution's guarantees of privacy and liberty do not afford terminally ill persons the right to a physician's assistance in committing suicide and Alaska's statute prohibiting suicide assistance does not violate their right of equal protection.

  5. Effect of microorganism on Greenland ice sheet surface temperature change

    NASA Astrophysics Data System (ADS)

    Shimada, R.; Takeuchi, N.; Aoki, T.

    2012-12-01

    Greenland ice sheet holds approximately 10% of the fresh water on earth. If it melts all, sea level rises about 7.2meter. It is reported that mass of Greenland ice sheet is decreasing with temperature rising of climate change. Melting of the coastal area is particularly noticeable. It is established that 4 to 23% of the sea level rising from 1993 to 2005 is caused by the melting of Greenland ice sheet. In 2010, amount of melting per year became the largest than the past. However many climate models aren't able to simulate the recent melting of snow and ice in the Arctic including Greenland. One of the possible causes is albedo reduction of snow and ice surface by light absorbing snow impurities such as black carbon and dust and by glacial microorganisms. But there are few researches for effect of glacial microorganism in wide area. So it is important to clarify the impact of glacial microorganisms in wide area. The purpose of this study is to clarify the effect of microorganism on Greenland ice sheet surface temperature change using satellite images of visible, near infrared and thermal infrared wavelength range and observation carried out in northwestern Greenland. We use MODIS Land Surface Temperature Product as ice sheet surface temperature. It estimates land surface temperature based on split window method using thermal infrared bands. MODIS data is bound to cover the whole of Greenland, and calculated the ratio of the temperature change per year. Analysis period is from December 2002 to November 2010. Results of calculating Greenland ice sheet surface temperature change using the MODIS data, our analysis shows that it is upward trend in the whole region. We find a striking upward trend in northern and western part of Greenland. The rate is 0.33±0.03 degree Celsius per a year from 47.5°W to 49°W. While in the coastal area from 49°W to 50.7°W, the rate is 0.26±0.06 degree Celsius per a year. This large upward trend area is the same area as dark region

  6. Resolving bathymetry from airborne gravity along Greenland fjords

    NASA Astrophysics Data System (ADS)

    Boghosian, Alexandra; Tinto, Kirsty; Cochran, James R.; Porter, David; Elieff, Stefan; Burton, Bethany L.; Bell, Robin E.

    2015-12-01

    Recent glacier mass loss in Greenland has been attributed to encroaching warming waters, but knowledge of fjord bathymetry is required to investigate this mechanism. The bathymetry in many Greenland fjords is unmapped and difficult to measure. From 2010 to 2012, National Aeronautics and Space Administration's Operation IceBridge collected a unique set of airborne gravity, magnetic, radar, and lidar data along the major outlet glaciers and fjords in Greenland. We applied a consistent technique using the IceBridge gravity data to create 90 bathymetric profiles along 54 Greenland fjords. We also used this technique to recover subice topography where warm or crevassed ice prevents the radar system from imaging the bed. Here we discuss our methodology, basic assumptions and error analysis. We present the new bathymetry data and discuss observations in six major regions of Greenland covered by IceBridge. The gravity models provide a total of 1950 line kilometers of bathymetry, 875 line kilometers of subice topography, and 12 new grounding line depths.

  7. Resolving bathymetry from airborne gravity along Greenland fjords

    USGS Publications Warehouse

    Boghosian, Alexandra; Tinto, Kirsty; Cochran, James R.; Porter, David; Elieff, Stefan; Burton, Bethany; Bell, Robin E.

    2015-01-01

    Recent glacier mass loss in Greenland has been attributed to encroaching warming waters, but knowledge of fjord bathymetry is required to investigate this mechanism. The bathymetry in many Greenland fjords is unmapped and difficult to measure. From 2010 to 2012, National Aeronautics and Space Administration's Operation IceBridge collected a unique set of airborne gravity, magnetic, radar, and lidar data along the major outlet glaciers and fjords in Greenland. We applied a consistent technique using the IceBridge gravity data to create 90 bathymetric profiles along 54 Greenland fjords. We also used this technique to recover subice topography where warm or crevassed ice prevents the radar system from imaging the bed. Here we discuss our methodology, basic assumptions and error analysis. We present the new bathymetry data and discuss observations in six major regions of Greenland covered by IceBridge. The gravity models provide a total of 1950 line kilometers of bathymetry, 875 line kilometers of subice topography, and 12 new grounding line depths.

  8. How warm was Greenland during the last interglacial period?

    NASA Astrophysics Data System (ADS)

    Landais, Amaelle; Masson-Delmotte, Valérie; Capron, Emilie; Langenbroeck, Petra; Bakker, Pepijn; Stone, Emma; Fischer, Hubertus; Vinther, Bo; Dahl-Jensen, Dorthe

    2016-04-01

    The last interglacial period (LIG, ~129-116 thousand years ago) provides the most recent evidence for the response of Greenland and Antarctic ice sheets to polar warming above pre-industrial level, and a valuable test bed for ice sheet models. Key constraints on past changes in both ice sheet topography and surface temperature are derived from Greenland ice cores. The large warming estimated from the recent NEEM ice core drilled in northwest Greenland (8 ±4°C above pre-industrial) together with the evidence for limited local ice thinning have led to the "NEEM paradox", suggesting more stability of the ice sheet than simulated by ice flow models in response to such large warming. Here, we provide a new assessment of the LIG warming using ice core air isotopic composition (d15N) together with available relationships for Greenland between accumulation rate and temperature. The temperature at the upstream NEEM deposition site is estimated to be between -20°C to -24°C which is consistent with the 8±4°C warming relative to pre-industrial previously determined from water isotopic records measured on the NEEM ice, although we feel the lower end of this range to be more likely. Moreover, we show that under such warm temperature, melting of snow probably led to a significant firn shrinking by 15 m. We show that confirmation of this high temperature range for the LIG in Greenland is difficult to reconcile with climate modeling experiments

  9. Exploring Greenland: science and technology in Cold War settings.

    PubMed

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

    2010-01-01

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

  10. Fisheries Education in Alaska. Conference Report. Alaska Sea Grant Report 82-4.

    ERIC Educational Resources Information Center

    Smoker, William W., Ed.

    This conference was an attempt to have the fishing industry join the state of Alaska in building fisheries education programs. Topics addressed in papers presented at the conference include: (1) fisheries as a part of life in Alaska, addressing participation of Alaska natives in commercial fisheries and national efforts; (2) the international…

  11. Selected 1970 Census Data for Alaska Communities. Part 2 - Northwest Alaska.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Community and Regional Affairs, Juneau. Div. of Community Planning.

    As 1 of 6 regional reports supplying statistical information on Alaska's incorporated and unincorporated communities (those of 25 or more people), this report on Northwest Alaska presents data derived from the 1970 U.S. Census first-count microfilm. Organized via the 3 Northwest Alaska census division, data are presented for the 32 communities of…

  12. 78 FR 53137 - Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., Conoco... Pipeline Proceedings, 18 CFR 343.2 (2013), Flint Hills Resources Alaska, LLC (FHR or Complainant) filed...

  13. 76 FR 68263 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Department of the Interior Fish and Wildlife Service 50 CFR Part 92 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2012 Season; Proposed Rule #0;#0...-1231-9BPP-L2] RIN 1018-AX55 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations...

  14. 78 FR 11988 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AY70 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2013 Season AGENCY: Fish and Wildlife Service... migratory bird subsistence harvest regulations in Alaska for the 2013 season. These regulations enable...

  15. 77 FR 17353 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AX55 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2012 Season AGENCY: Fish and Wildlife Service... migratory bird subsistence harvest regulations in Alaska for the 2012 season. These regulations will...

  16. 76 FR 303 - Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... AGENCY 40 CFR Parts 239 and 258 Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit... proposes to approve Alaska's modification of its approved Municipal Solid Waste Landfill (MSWLF) permit... Domenic Calabro, Office of Air, Waste, and Toxics, U.S. EPA, Region 10, 1200 Sixth Avenue, Suite...

  17. Modeling deep convection in the Greenland Sea

    NASA Technical Reports Server (NTRS)

    Hakkinen, S.; Mellor, G. L.; Kantha, L. H.

    1992-01-01

    The development of deep convective events in the high-latitude ocean is studied using a three-dimensional, coupled ice-ocean model. Oceanic mixing is described according to the level 2.5 turbulence closure scheme in which convection occurs in a continuous way, i.e., convective adjustment is not invoked. The model is forced by strong winds and surface cooling. Strong upwelling at the multilyear ice edge and consequent entrainment of warm Atlantic waters into the mixed layer is produced by winds parallel to the ice edge. Concomitant cooling drives deep convection and produces chimneylike structures. Inclusion of a barotropic mean flow over topography to the model provides important preconditioning and selects the location of deep convection. The most efficient preconditioning occurs at locations where the flow ascends a slope. In a stratified environment similar to the Greenland Sea with a 12 m/s wind the model simulations show that localized deep convection takes place after about 10 days to depths of 1000 m.

  18. Greenland ice sheet mass balance: a review.

    PubMed

    Khan, Shfaqat A; Aschwanden, Andy; Bjørk, Anders A; Wahr, John; Kjeldsen, Kristian K; Kjær, Kurt H

    2015-04-01

    Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance and to ice discharge, which are forced by internal or external (atmospheric/oceanic/basal) fluctuations. Regardless of the measurement method, observations over the last two decades show an increase in ice loss rate, associated with speeding up of glaciers and enhanced melting. However, both ice discharge and melt-induced mass losses exhibit rapid short-term fluctuations that, when extrapolated into the future, could yield erroneous long-term trends. In this paper we review the GrIS mass loss over more than a century by combining satellite altimetry, airborne altimetry, interferometry, aerial photographs and gravimetry data sets together with modelling studies. We revisit the mass loss of different sectors and show that they manifest quite different sensitivities to atmospheric and oceanic forcing. In addition, we discuss recent progress in constructing coupled ice-ocean-atmosphere models required to project realistic future sea-level changes.

  19. Force balance along Isunnguata Sermia, west Greenland

    NASA Astrophysics Data System (ADS)

    Meierbachtol, Toby; Harper, Joel; Johnson, Jesse

    2016-09-01

    Ice flows when gravity acts on gradients in surface elevation, producing driving stresses. In the Isunnguata Sermia and Russel Glacier catchments of western Greenland, a 50% decline in driving stress along a flow line is juxtaposed with increasing surface flow speed. Here, these circumstances are investigated using modern observational data sources and an analysis of the balance of forces. Stress gradients in the ice mass and basal drag which resist the local driving stress are computed in order to investigate the underlying processes influencing the velocity and stress regimes. Our results show that the largest resistive stress gradients along the flowline result from increasing surface velocity. However, the longitudinal coupling stresses fail to exceed 15 kPa, or 20% of the local driving stress. Consequently, computed basal drag declines in proportion to the driving stress. In the absence of significant resistive stress gradients, other mechanisms are therefore necessary to explain the observed velocity increase despite declining driving stress. In the study area, the observed velocity - driving stress feature occurs at the long-term mean position of the equilibrium line of surface mass balance. We hypothesize that this position approximates the inland limit where surface meltwater penetrates the bed, and that the increased surface velocity reflects enhanced basal motion associated with seasonal meltwater perturbations.

  20. Distinct patterns of seasonal Greenland glacier velocity

    PubMed Central

    Moon, Twila; Joughin, Ian; Smith, Ben; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Usher, Mika

    2014-01-01

    Predicting Greenland Ice Sheet mass loss due to ice dynamics requires a complete understanding of spatiotemporal velocity fluctuations and related control mechanisms. We present a 5 year record of seasonal velocity measurements for 55 marine-terminating glaciers distributed around the ice sheet margin, along with ice-front position and runoff data sets for each glacier. Among glaciers with substantial speed variations, we find three distinct seasonal velocity patterns. One pattern indicates relatively high glacier sensitivity to ice-front position. The other two patterns are more prevalent and appear to be meltwater controlled. These patterns reveal differences in which some subglacial systems likely transition seasonally from inefficient, distributed hydrologic networks to efficient, channelized drainage, while others do not. The difference may be determined by meltwater availability, which in some regions may be influenced by perennial firn aquifers. Our results highlight the need to understand subglacial meltwater availability on an ice sheet-wide scale to predict future dynamic changes. Key Points First multi-region seasonal velocity measurements show regional differences Seasonal velocity fluctuations on most glaciers appear meltwater controlled Seasonal development of efficient subglacial drainage geographically divided PMID:25821275

  1. Forestry timber typing. Tanana demonstration project, Alaska ASVT. [Alaska

    NASA Technical Reports Server (NTRS)

    Morrissey, L. A.; Ambrosia, V. G.

    1982-01-01

    The feasibility of using LANDSAT digital data in conjunction with topographic data to delineate commercial forests by stand size and crown closure in the Tanana River basin of Alaska was tested. A modified clustering approach using two LANDSAT dates to generate an initial forest type classification was then refined with topographic data. To further demonstrate the ability of remotely sensed data in a fire protection planning framework, the timber type data were subsequently integrated with terrain information to generate a fire hazard map of the study area. This map provides valuable assistance in initial attack planning, determining equipment accessibility, and fire growth modeling. The resulting data sets were incorporated into the Alaska Department of Natural Resources geographic information system for subsequent utilization.

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

    PubMed

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

    2000-07-21

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

  3. Subglacial lake drainage detected beneath the Greenland ice sheet

    PubMed Central

    Palmer, Steven; McMillan, Malcolm; Morlighem, Mathieu

    2015-01-01

    The contribution of the Greenland ice sheet to sea-level rise has accelerated in recent decades. Subglacial lake drainage events can induce an ice sheet dynamic response—a process that has been observed in Antarctica, but not yet in Greenland, where the presence of subglacial lakes has only recently been discovered. Here we investigate the water flow paths from a subglacial lake, which drained beneath the Greenland ice sheet in 2011. Our observations suggest that the lake was fed by surface meltwater flowing down a nearby moulin, and that the draining water reached the ice margin via a subglacial tunnel. Interferometric synthetic aperture radar-derived measurements of ice surface motion acquired in 1995 suggest that a similar event may have occurred 16 years earlier, and we propose that, as the climate warms, increasing volumes of surface meltwater routed to the bed will cause such events to become more common in the future. PMID:26450175

  4. Subglacial lake drainage detected beneath the Greenland ice sheet.

    PubMed

    Palmer, Steven; McMillan, Malcolm; Morlighem, Mathieu

    2015-10-09

    The contribution of the Greenland ice sheet to sea-level rise has accelerated in recent decades. Subglacial lake drainage events can induce an ice sheet dynamic response--a process that has been observed in Antarctica, but not yet in Greenland, where the presence of subglacial lakes has only recently been discovered. Here we investigate the water flow paths from a subglacial lake, which drained beneath the Greenland ice sheet in 2011. Our observations suggest that the lake was fed by surface meltwater flowing down a nearby moulin, and that the draining water reached the ice margin via a subglacial tunnel. Interferometric synthetic aperture radar-derived measurements of ice surface motion acquired in 1995 suggest that a similar event may have occurred 16 years earlier, and we propose that, as the climate warms, increasing volumes of surface meltwater routed to the bed will cause such events to become more common in the future.

  5. Greenland temperature response to climate forcing during the last deglaciation.

    PubMed

    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

    2014-09-05

    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.

  6. Deformation Studies of NEEM, Greenland Basal Folded Ice

    NASA Astrophysics Data System (ADS)

    Keegan, K.; Dahl-Jensen, D.; Montagnat, M.; Weikusat, I.

    2015-12-01

    Deep Greenland ice cores and airborne radio echo sounding (RES) images have recently revealed that basal ice flow of the Greenland Ice Sheet is very unstable. In many locations, a basal layer of disturbed ice is observed. At the NEEM, Greenland site this folding occurs at the boundary between the Eemian and glacial ice regimes, indicating that differences in physical properties of the ice play a role in the disturbance. Past work in metallurgy and ice suggests that impurity content controls grain evolution and therefore deformation. We hypothesize that the differences in ice flow seen deep in the NEEM ice core are controlled by differences in the impurity content of the ice layers. Here we present results of fabric, grain size, impurity content, and deformation studies from samples above and below this unstable boundary in the ice sheet.

  7. Sparteine oxidation polymorphism in Greenlanders living in Denmark.

    PubMed Central

    Brøsen, K

    1986-01-01

    Sparteine oxidation appeared to be polymorphic in 185 healthy Greenlanders living in Denmark. Six subjects (3.2%) were phenotyped as poor metabolizers (PM) and 179 subjects as extensive metabolizers (EM). The metabolic ratio (MR) between sparteine and 2- + 5-dehydrosparteine in a 12 h urine sample ranged from 0.06-3.12 in EM and from 30-480 in PM. The excretion of dehydrosparteines accounted for less than 2.2% of the dose in PM and ranged from 5.6%-63% in EM. The urinary recovery (% of dose) of sparteine, 2-dehydrosparteine and total sparteine + dehydrosparteines was lower in Greenlander EM than in Danish EM (Brøsen et al., 1985). Incomplete urine collection in a substantial proportion of the Greenlanders could explain these discrepancies. PMID:3768256

  8. Greenland ice mass balance estimation from GRACE: a reexamination

    NASA Astrophysics Data System (ADS)

    Jensen, L.; Eicker, A.; Kusche, J.

    2011-12-01

    In recent years there have been several studies using GRACE satellite data to investigate the melting of the Greenland ice sheet. The results of the different investigations vary considerably. In this study, monthly GRACE solutions calculated by the Institute of Geodesy and Geoinformation of the University Bonn (ITG-GRACE2010 solutions) are evaluated to obtain a new estimate for the mass balance of the Greenland ice sheet including the corresponding error estimate. One of the major issues when dealing with the mass variations in Greenland is the leakage problem. In the contribution at hand, leakage-in effects caused by external mass variations are adressed by estimating a regional adjustment of the applied ocean model. The approach assumes time-invariant spatial patterns of ocean mass variations to be correctly reproduced in the circulation model but their time-variable amplitudes to be improvable. New amplitudes are determined by comparison to the GRACE observations in a least-squares estimation process. Leakage-out can be compensated for by rescaling the ice mass changes with a constant factor. In addition to a simple technique, a more complex approach developed by Baur et al. (2009) is applied in this investigation to obtain the rescaling factor. Besides mass variations in the area of Greenland also mass variations in an extended area around Greenland are taken into account in this procedure. A further important aspect is the problem of signal separation, especially separating the ice mass variations from mass trends caused by glacial isostatic adjustment (GIA). A comparison of different GIA models shows why this is one of the major sources of uncertainty when trying to determine the Greenland ice mass balance. The possibility to improve GIA modelling using geodetic data is therefore another aspect which will be discussed on the poster. The results of the new ice mass balance estimate from GRACE will be compared to the results obtained from alternative

  9. Evolution of the elevated passive margin of northwest Greenland

    NASA Astrophysics Data System (ADS)

    Spiegel, Cornelia; Reiter, Wolfgang; Lisker, Frank; Damm, Volkmar

    2015-04-01

    The geomorphic evolution of high-standing passive continental margins is still controversially discussed. This is particularly true for the elevated margins of Greenland. They have alternatively been explained by resulting from prolonged very slow erosion following Paleozoic orogeny, resulting from rifting and opening of ocean basins adjacent to the Greenland continental margins, or as young geomorphic features only formed during the Cenozoic. This study focuses on the northwestern margin of Greenland, north of the Melville Bugt at the northern end of Baffin Bay, using a combination of apatite fission track and (U-Th-Sm)/He thermochronology. Opening and formation of oceanic crust of Baffin Bay took place during the Late Cretaceous. The study area is also situated at the southern termination of the postulated Wegener Fault, a controversially discussed large-scale strike-slip fault system supposedly active during the Paleogene, which has been described as one of the last problems of global plate tectonic reconstructions. Our data show that several normal faults dissecting the northwest Greenland margin were active during or after the Cretaceous, presumably related to extension associated with the opening of Baffin Bay. Also, our data show a clear - although not very pronounced - cooling signal at the end of the Cretaceous, which we interpret as reflecting initial formation of an elevated margin during and after continental breakup. Margin formation was followed by subsidence, with maximum burial at c. 30 Ma, again followed by a period of relatively rapid exhumation associated with net denudation of 2 - 3 km. This post-30 Ma denudation period may be related to tectonic activity associated with ongoing northward movement of Greenland, or to climatic changes such as early glaciation of the Arctic realm. In any case, our data imply that the present morphologic expression of the northwest Greenland margin results from young Cenozoic processes unrelated to earlier

  10. Leakage of the Greenland Ice Sheet through accelerated ice flow

    NASA Astrophysics Data System (ADS)

    Rignot, E.

    2005-12-01

    A map of coastal velocities of the Greenland ice sheet was produced from Radarsat-1 acquired during the background mission of 2000 and combined with radio echo sounding data to estimate the ice discharge from the ice sheet. On individual glaciers, ice discharge was compared with snow input from the interior and melt above the flux gate to determine the glacier mass balance. Time series of velocities on several glaciers at different latitudes reveal seasonal fluctuations of only 7-8 percent so that winter velocities are only 2 percent less than the yearly mean. The results show the northern Greenland glaciers to be close to balance yet losing mass. No change in ice flow is detected on Petermann, 79north and Zachariae Isstrom in 2000-2004. East Greenland glaciers are in balance and flowing steadily north of Kangerdlussuaq, but Kangerdlussuaq, Helheim and all the southeastern glaciers are thinning dramatically. All these glaciers accelerated, Kangerdlussuaq in 2000, Helheim prior to 2004, and southeast Greenland glaciers accelerated 10 to 50 percent in 2000-2004. Glacier acceleration is generally brutal, probably once the glacier reached a threshold, and sustained. In the northwest, most glaciers are largely out of balance. Jakobshavn accelerated significantly in 2002, and glaciers in its immediate vicinity accelerated more than 50 percent in 2000-2004. Less is known about southwest Greenland glaciers due to a lack of ice thickness data but the glaciers have accelerated there as well and are likely to be strongly out of balance despite thickening of the interior. Overall, I estimate the mass balance of the Greenland ice sheet to be about -80 +/-10 cubic km of ice per year in 2000 and -110 +/-15 cubic km of ice per year in 2004, i.e. more negative than based on partial altimetry surveys of the outlet glaciers. As climate continues to warm, more glaciers will accelerate, and the mass balance will become increasingly negative, regardless of the evolution of the ice sheet

  11. Vanadium and Other Elements in Greenland Ice Cores

    DTIC Science & Technology

    1976-07-01

    Photograph by C’.C. Langway , Jr.) :1 CRREL Report 76-24 Vanadium and other elements in Greenland ice cores M.M. Herron, C.C. Langway , Jr., H.V. Weiss...Chemistry, San Diego State University; by Dr. C.C. Langway , Jr., Chairman of the Department of Geological Sciences, State University of New. York at Buffalo...the use of such commercial products. ij! 𔃼y\\ .j =3 VANADIUM AND OTHER ELEMENTS IN GREENLAND ICE CORES M.M. Herron;C.C. Langway , Jr., H.V.,Weiss, J

  12. Control and monitoring software for the Greenland Telescope

    NASA Astrophysics Data System (ADS)

    Patel, Nimesh A.; Nishioka, Hiroaki; Huang, Chih-Wei Locutus

    2016-08-01

    The Greenland Telescope (GLT) is a 12m diameter antenna that is being developed from the ALMA North America prototype antenna, for VLBI observations and single-dish science approaching THz, at the Summit station in Greenland. The GLT is a collaboration between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics. We describe the control and monitoring software that is being developed for GLT. The present version of the software is ready for the initial tests of the antenna at Thule, including optical and radio pointing calibration, holography, and VLBI observations at 230 GHz.

  13. Surface Drifters Track the Fate of Greenland Ice Sheet Meltwater

    NASA Astrophysics Data System (ADS)

    Hauri, Claudine; Truffer, Martin; Winsor, Peter; Lennert, Kunuk

    2014-07-01

    Understanding the fate and influence of glacial meltwater in heavily ice-covered fjord systems has proven difficult because previous measurement platforms were con­strained to deeper water to keep instrumentation safe from drifting icebergs. Now, using novel, satellite-tracked devices that can with­ stand multiple collisions with ice blocks (see Figure 1) without incurring much damage, scientists have obtained new and detailed data about the role of Greenland Ice Sheet meltwater and its trajectories through God­thåbsfjord in western Greenland.

  14. Smoking as a determinant of high organochlorine levels in Greenland.

    PubMed

    Deutch, Bente; Pedersen, Henning Sloth; Jørgensen, Eva C Bonefeld; Hansen, Jens C

    2003-01-01

    The authors investigated the accumulation of organochlorines among smoking and nonsmoking Inuit hunters (n = 48) in Uummanaq, Greenland, a population with high dietary exposure to persistent organic pollutants (POPs). Human plasma organochlorine levels were positively correlated with age, marine diet, and smoking or plasma cotinine in multiple linear-regression models (p < 0.001). Body mass index was inversely correlated with organochlorine accumulation, independent of smoking status. These findings confirm that the source of POPs among the Inuit in Greenland is diet, but smoking is an important determinant of POP bioaccumulation. Smoking cessation may provide a means to lower the body burden of POPs.

  15. North and northeast Greenland ice discharge from satellite radar interferometry

    SciTech Connect

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

    1997-05-09

    Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier front, because basal melting is extensive at the underside of the floating glacier sections. The results suggest that the north and northeast parts of the Greenland ice sheet may be thinning and contributing positively to sea-level rise. 24 refs., 3 figs., 1 tab.

  16. Operation of a Radar Altimeter over the Greenland Ice Sheet

    NASA Technical Reports Server (NTRS)

    Grund, Matthew D.

    1996-01-01

    This thesis presents documentation for the Advanced Application Flight Experiment (AAFE) pulse compression radar altimeter and its role in the NASA Multisensor Airborne Altimetry Experiment over Greenland in 1993. The AAFE Altimeter is a Ku-band microwave radar which has demonstrated 14 centimeter range precision in operation over arctic ice. Recent repairs and improvements were required to make the Greenland missions possible. Transmitter, receiver and software modifications, as well as the integration of a GPS receiver are thoroughly documented. Procedures for installation, and operation of the radar are described. Finally, suggestions are made for further system improvements.

  17. Unified Ecoregions of Alaska: 2001

    USGS Publications Warehouse

    Nowacki, Gregory J.; Spencer, Page; Fleming, Michael; Brock, Terry; Jorgenson, Torre

    2003-01-01

    Major ecosystems have been mapped and described for the State of Alaska and nearby areas. Ecoregion units are based on newly available datasets and field experience of ecologists, biologists, geologists and regional experts. Recently derived datasets for Alaska included climate parameters, vegetation, surficial geology and topography. Additional datasets incorporated in the mapping process were lithology, soils, permafrost, hydrography, fire regime and glaciation. Thirty two units are mapped using a combination of the approaches of Bailey (hierarchial), and Omernick (integrated). The ecoregions are grouped into two higher levels using a 'tri-archy' based on climate parameters, vegetation response and disturbance processes. The ecoregions are described with text, photos and tables on the published map.

  18. USGS releases Alaska oil assessment

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    With the U.S. Congress gearing up for a House-Senate conference committee battle about whether to open the Alaska National Wildlife Refuge (ANWR) for oil drilling, a new assessment of the amount of oil in the federal portion of the U.S. National Petroleum Reserve in Alaska (NRPA) is influencing the debate.The U.S. Geological Survey has found that the NPRA holds "significantly greater" petroleum resources than had been estimated previously This finding was disclosed in a 16 May report. The assessment estimated that technically recoverable oil on NPRA federal lands are between 5.9 and 13.2 billion barrels of oil; a 1980 assessment estimated between 0.3 and 5.4 billion barrels.

  19. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    USGS Publications Warehouse

    Thoms, Evan E.; Haeussler, Peter J.; Anderson, Rebecca D.; McGimsey, Robert G.

    2014-01-01

    On March 27, 1964, at 5:36 p.m., a magnitude 9.2 earthquake, the largest recorded earthquake in U.S. history, struck southcentral Alaska (fig. 1). The Great Alaska Earthquake (also known as the Good Friday Earthquake) occurred at a pivotal time in the history of earth science, and helped lead to the acceptance of plate tectonic theory (Cox, 1973; Brocher and others, 2014). All large subduction zone earthquakes are understood through insights learned from the 1964 event, and observations and interpretations of the earthquake have influenced the design of infrastructure and seismic monitoring systems now in place. The earthquake caused extensive damage across the State, and triggered local tsunamis that devastated the Alaskan towns of Whittier, Valdez, and Seward. In Anchorage, the main cause of damage was ground shaking, which lasted approximately 4.5 minutes. Many buildings could not withstand this motion and were damaged or collapsed even though their foundations remained intact. More significantly, ground shaking triggered a number of landslides along coastal and drainage valley bluffs underlain by the Bootlegger Cove Formation, a composite of facies containing variably mixed gravel, sand, silt, and clay which were deposited over much of upper Cook Inlet during the Late Pleistocene (Ulery and others, 1983). Cyclic (or strain) softening of the more sensitive clay facies caused overlying blocks of soil to slide sideways along surfaces dipping by only a few degrees. This guide is the document version of an interactive web map that was created as part of the commemoration events for the 50th anniversary of the 1964 Great Alaska Earthquake. It is accessible at the U.S. Geological Survey (USGS) Alaska Science Center website: http://alaska.usgs.gov/announcements/news/1964Earthquake/. The website features a map display with suggested tour stops in Anchorage, historical photographs taken shortly after the earthquake, repeat photography of selected sites, scanned documents

  20. Late glacial and Holocene history of the Greenland Ice Sheet margin, Nunatarssuaq, Northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Farnsworth, L. B.; Kelly, M. A.; Axford, Y.; Bromley, G. R.; Osterberg, E. C.; Howley, J. A.; Zimmerman, S. R. H.; Jackson, M. S.; Lasher, G. E.; McFarlin, J. M.

    2015-12-01

    Defining the late glacial and Holocene fluctuations of the Greenland Ice Sheet (GrIS) margin, particularly during periods that were as warm or warmer than present, provides a longer-term perspective on present ice margin fluctuations and informs how the GrIS may respond to future climate conditions. We focus on mapping and dating past GrIS extents in the Nunatarssuaq region of northwestern Greenland. During the summer of 2014, we conducted geomorphic mapping and collected rock samples for 10Be surface exposure dating as well as subfossil plant samples for 14C dating. We also obtained sediment cores from an ice-proximal lake. Preliminary 10Be ages of boulders deposited during deglaciation of the GrIS subsequent to the Last Glacial Maximum range from ~30-15 ka. The apparently older ages of some samples indicate the presence of 10Be inherited from prior periods of exposure. These ages suggest deglaciation occurred by ~15 ka however further data are needed to test this hypothesis. Subfossil plants exposed at the GrIS margin on shear planes date to ~ 4.6-4.8 cal. ka BP and indicate less extensive ice during middle Holocene time. Additional radiocarbon ages from in situ subfossil plants on a nunatak date to ~3.1 cal. ka BP. Geomorphic mapping of glacial landforms near Nordsø, a large proglacial lake, including grounding lines, moraines, paleo-shorelines, and deltas, indicate the existence of a higher lake level that resulted from a more extensive GrIS margin likely during Holocene time. A fresh drift limit, characterized by unweathered, lichen-free clasts approximately 30-50 m distal to the modern GrIS margin, is estimated to be late Holocene in age. 10Be dating of samples from these geomorphic features is in progress. Radiocarbon ages of subfossil plants exposed by recent retreat of the GrIS margin suggest that the GrIS was at or behind its present location at AD ~1650-1800 and ~1816-1889. Results thus far indicate that the GrIS margin in northwestern Greenland

  1. A new bed elevation dataset for Greenland

    NASA Astrophysics Data System (ADS)

    Griggs, J. A.; Bamber, J. L.; Hurkmans, R. T. W. L.; Dowdesewell, J. A.; Gogineni, S. P.; Howat, I.; Mouginot, J.; Paden, J.; Palmer, S.; Rignot, E.; Steinhage, D.

    2012-11-01

    We present a new bed elevation dataset for Greenland derived from a combination of multiple airborne ice thickness surveys undertaken between the 1970s and 2011. Around 344 000 line kilometres of airborne data were used, with the majority of this having been collected since the year 2000, when the last comprehensive compilation was undertaken. The airborne data were combined with satellite-derived elevations for non glaciated terrain to produce a consistent bed digital elevation model (DEM) over the entire island including across the glaciated/ice free boundary. The DEM was extended to the continental margin with the aid of bathymetric data, primarily from a compilation for the Arctic. Ice shelf thickness was determined where a floating tongue exists, in particular in the north. The across-track spacing between flight lines warranted interpolation at 1 km postings near the ice sheet margin and 2.5 km in the interior. Grids of ice surface elevation, error estimates for the DEM, ice thickness and data sampling density were also produced alongside a mask of land/ocean/grounded ice/floating ice. Errors in bed elevation range from a minimum of ±6 m to about ±200 m, as a function of distance from an observation and local topographic variability. A comparison with the compilation published in 2001 highlights the improvement in resolution afforded by the new data sets, particularly along the ice sheet margin, where ice velocity is highest and changes most marked. We use the new bed and surface DEMs to calculate the hydraulic potential for subglacial flow and present the large scale pattern of water routing. We estimate that the volume of ice included in our land/ice mask would raise eustatic sea level by 7.36 m, excluding any solid earth effects that would take place during ice sheet decay.

  2. A new bed elevation dataset for Greenland

    NASA Astrophysics Data System (ADS)

    Bamber, J. L.; Griggs, J. A.; Hurkmans, R. T. W. L.; Dowdeswell, J. A.; Gogineni, S. P.; Howat, I.; Mouginot, J.; Paden, J.; Palmer, S.; Rignot, E.; Steinhage, D.

    2013-03-01

    We present a new bed elevation dataset for Greenland derived from a combination of multiple airborne ice thickness surveys undertaken between the 1970s and 2012. Around 420 000 line kilometres of airborne data were used, with roughly 70% of this having been collected since the year 2000, when the last comprehensive compilation was undertaken. The airborne data were combined with satellite-derived elevations for non-glaciated terrain to produce a consistent bed digital elevation model (DEM) over the entire island including across the glaciated-ice free boundary. The DEM was extended to the continental margin with the aid of bathymetric data, primarily from a compilation for the Arctic. Ice thickness was determined where an ice shelf exists from a combination of surface elevation and radar soundings. The across-track spacing between flight lines warranted interpolation at 1 km postings for significant sectors of the ice sheet. Grids of ice surface elevation, error estimates for the DEM, ice thickness and data sampling density were also produced alongside a mask of land/ocean/grounded ice/floating ice. Errors in bed elevation range from a minimum of ±10 m to about ±300 m, as a function of distance from an observation and local topographic variability. A comparison with the compilation published in 2001 highlights the improvement in resolution afforded by the new datasets, particularly along the ice sheet margin, where ice velocity is highest and changes in ice dynamics most marked. We estimate that the volume of ice included in our land-ice mask would raise mean sea level by 7.36 m, excluding any solid earth effects that would take place during ice sheet decay.

  3. Alaska Natives and Alaska Higher Education, 1960-1972: A Descriptive Study. Alaska Native Human Resources Development Program, Publication 1.

    ERIC Educational Resources Information Center

    Jacquot, Louis F.

    Utilizing data derived from numerous sources (institutions, Alaska Native organizations, Federal and State agencies, conferences, etc.), this descriptive study is divided into 6 chapters which trace the evolution of and the necessity for Alaska Native higher education. Following a detailed introduction, Chapter 2 describes the physical and…

  4. ORTHOPHOTOQUAD MAPPING PROGRAM FOR ALASKA.

    USGS Publications Warehouse

    Plasker, James R.

    1985-01-01

    The U. S. Geological Survey (USGS) is the lead civilian mapping agency in the United States and is responsible for creating and maintaining numerous map series. In Alaska the standard topographic map series is at a scale of 1:63,360, and maps at that scale have been available from the USGS since the late 1940's. In 1981 USGS initiated production of orthophotoquads of Alaska, also at a scale of 1:63,360 to be compatible with the topographic map series. An orthophotoquad (OQ) is prepared from a rectified or differentially rectified and scaled black-and-white photographic image published in quadrangle format. The current status of the Alaska OQ program is summarized and sample OQ's are illustrated. Engineering applications of orthophotoquads are discussed, with an emphasis on their use in the on-shore and near-shore areas. A combination of orthophoto imagery and topographic line maps is described as a planning and engineering tool. Sources of map separates and orthophotoquads are provided.

  5. Exposure of juvenile turbot (Scophthalmus maximus) to silver nanoparticles and 17α-ethinylestradiol mixtures: Implications for contaminant uptake and plasma steroid hormone levels.

    PubMed

    Farkas, Julia; Salaberria, Iurgi; Styrishave, Bjarne; Staňková, Radka; Ciesielski, Tomasz M; Olsen, Anders J; Posch, Wilfried; Flaten, Trond P; Krøkje, Åse; Salvenmoser, Willi; Jenssen, Bjørn M

    2017-01-01

    Combined exposure to engineered nanoparticles (ENPs) and anthropogenic contaminants can lead to changes in bioavailability, uptake and thus effects of both groups of contaminants. In this study we investigated effects of single and combined exposures of silver (Ag) nanoparticles (AgNPs) and the synthetic hormone 17α-ethinylestradiol (EE2) on tissue uptake of both contaminants in juvenile turbot (Scophthalmus maximus). Silver uptake and tissue distribution (gills, liver, kidney, stomach, muscle and bile) were analyzed following a 14-day, 2-h daily pulsed exposure to AgNPs (2 μg L(-1) and 200 μg L(-1)), Ag(+) (50 μg L(-1)), EE2 (50 ng L(-1)) and AgNP + EE2 (2 or 200 μg L(-1)+50 ng L(-1)). Effects of the exposures on plasma vitellogenin (Vtg) levels, EE2 and steroid hormone concentrations were investigated. The AgNP and AgNP + EE2 exposures resulted in similar Ag concentrations in the tissues, indicating that combined exposure did not influence Ag uptake in tissues. The highest Ag concentrations were found in gills. For the Ag(+) exposed fish, the highest Ag concentrations were measured in the liver. Our results show dissolution processes of AgNPs in seawater, indicating that the tissue concentrations of Ag may partly originate from ionic release. Plasma EE2 concentrations and Vtg induction were similar in fish exposed to the single contaminants and the mixed contaminants, indicating that the presence of AgNPs did not significantly alter EE2 uptake. Similarly, concentrations of most steroid hormones were not significantly altered due to exposures to the combined contaminants versus the single compound exposures. However, high concentrations of AgNPs in combination with EE2 caused a drop of estrone (E1) (female fish) and androstenedione (AN) (male and female fish) levels in plasma below quantification limits. Our results indicate that the interactive effects between AgNPs and EE2 are limited, with only high concentrations of AgNPs triggering

  6. Transcriptome Analysis for Identification of Genes Related to Gonad Differentiation, Growth, Immune Response and Marker Discovery in The Turbot (Scophthalmus maximus)

    PubMed Central

    Ma, Deyou; Ma, Aijun; Huang, Zhihui; Wang, Guangning; Wang, Ting; Xia, Dandan; Ma, Benhe

    2016-01-01

    Background Turbot Scophthalmus maximus is an economically important species extensively aquacultured in China. The genetic selection program is necessary and urgent for the sustainable development of this industry, requiring more and more genome background knowledge. Transcriptome sequencing is an excellent alternative way to identify transcripts involved in specific biological processes and exploit a considerable quantity of molecular makers when no genome sequences are available. In this study, a comprehensive transcript dataset for major tissues of S. maximus was produced on basis of an Illumina platform. Results Total RNA was isolated from liver, spleen, kidney, cerebrum, gonad (testis and ovary) and muscle. Equal quantities of RNA from each type of tissues were pooled to construct two cDNA libraries (male and female). Using the Illumina paired-end sequencing technology, nearly 44.22 million clean reads in length of 100 bp were generated and then assembled into 106,643 contigs, of which 71,107 were named unigenes with an average length of 892 bp after the elimination of redundancies. Of these, 24,052 unigenes (33.83% of the total) were successfully annotated. GO, KEGG pathway mapping and COG analysis were performed to predict potential genes and their functions. Based on our sequence analysis and published documents, many candidate genes with fundamental roles in sex determination and gonad differentiation (dmrt1), growth (ghrh, myf5, prl/prlr) and immune response (TLR1/TLR21/TLR22, IL-15/IL-34), were identified for the first time in this species. In addition, a large number of credible genetic markers, including 21,192 SSRs and 8,642 SNPs, were identified in the present dataset. Conclusion This informative transcriptome provides valuable new data to increase genomic resources of Scophthalmus maximus. The future studies of corresponding gene functions will be very useful for the management of reproduction, growth and disease control in turbot aquaculture

  7. Want To Work in Alaska's Schools? A Guide for Educators.

    ERIC Educational Resources Information Center

    LaBerge, MaryEllen

    This manual offers practical advice to educators on conducting a job search and obtaining a position in Alaska. Alaska Teacher Placement (University of Alaska Fairbanks) is a statewide clearinghouse for the placement of educators. Although Alaska's certification requirements are similar to those of other states, school administrators are also…

  8. 40 CFR 81.402 - Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Alaska. 81.402 Section 81.402 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF... Visibility Is an Important Value § 81.402 Alaska. Area name Acreage Public Law establishing Federal...

  9. 43 CFR 9239.3 - Grazing, Alaska.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Grazing, Alaska. 9239.3 Section 9239.3..., DEPARTMENT OF THE INTERIOR TECHNICAL SERVICES (9000) TRESPASS Kinds of Trespass § 9239.3 Grazing, Alaska. (a) Reindeer. (1) Any use of the Federal lands for reindeer grazing purposes, unless authorized by a...

  10. Alaska School District Cost Study Update

    ERIC Educational Resources Information Center

    Tuck, Bradford H.; Berman, Matthew; Hill, Alexandra

    2005-01-01

    The Legislative Budget and Audit Committee of the Alaska Legislature has asked The Institute of Social and Economic Research (ISER) at the University of Alaska Anchorage to make certain changes and adjustments to the Geographic Cost of Education Index (GCEI) that the American Institutes for Research (AIR) constructed and reported on in Alaska…

  11. Some Books about Alaska Received in 1990.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Div. of State Libraries.

    This annual bibliography of Alaska- and Arctic-related publications received by the Alaska Division of State Libraries is divided into three categories. There are 26 titles in the "Juvenile Fiction" section, 122 in the "Adult Non-Fiction" section, and 19 in the "Adult Fiction" section. Government publications are…

  12. 75 FR 9427 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ..., Limited. The lands are in the vicinity of Holy Cross and Huslia, Alaska, and are located in: Kateel River... Bureau of Land Management [AA-8103-63, AA-8103-65, F-21902-06, F-21903-54, F-21903-55, F-21903- 56; LLAK-96400-L14100000-KC0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management,...

  13. Alaska Performance Scholarship Outcome Report 2016

    ERIC Educational Resources Information Center

    Rae, Brian

    2016-01-01

    Five years ago Alaska's high school graduating class of 2011 became the first with the opportunity to accept the state's "invitation to excellence," the Alaska Performance Scholarship (APS), to pursue their postsecondary studies. Eligible graduates could receive up to $4,755 per year for up to four years to study at a participating…

  14. Viewpoints: Reflections on the Principalship in Alaska.

    ERIC Educational Resources Information Center

    Hagstrom, David A., Ed.

    In this collection, 32 Alaskan principals, retired principals, assistant principals, and principals-to-be share their experiences as administrators and reflect on their feelings about the nature of the work and about schooling issues in Alaska. Nine of the writings were selected from "Totem Tales," the newsletter of Alaska's Association…

  15. Alaska Native Parkinson’s Disease Registry

    DTIC Science & Technology

    2011-06-01

    Investigator Parkinsonism (PS) is a syndrome characterized by tremor , rigidity, slowness of movement, and problems with walking and balance...2. Developing an identification protocol. The primary source of parkinsonism cases will be the Indian Health Service (IHS) provider database, called...of parkinsonism among Alaska Natives. Status: Complete 3. Developing a secure Alaska Native parkinsonism registry database. Status: The database

  16. Distance Learning in Alaska's Rural Schools.

    ERIC Educational Resources Information Center

    Bramble, William J.

    1986-01-01

    The distance education and instructional technology projects that have been undertaken in Alaska over the last decade are detailed in this paper. The basic services offered by the "Learn Alaska Network" are described in relation to three user groups: K-12 education; postsecondary education; and general public education and information.…

  17. Building a Workforce Development System in Alaska

    ERIC Educational Resources Information Center

    Spieker, Sally

    2004-01-01

    The Alaska Human Resources Investment Council developed a blueprint to guide a system that is needs-driven, accessible, interconnected, accountable, sustainable, and has collaborative governance. Vocational Technical Education Providers (VTEP) representing secondary education, technical schools, proprietary institutions, the University of Alaska,…

  18. 75 FR 43199 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... approving the conveyance of surface estate for certain lands to Beaver Kwit'chin Corporation, pursuant to... Doyon, Limited when the surface estate is conveyed to Beaver Kwit'chin Corporation. The lands are in the vicinity of Beaver, Alaska, and are located in: Fairbanks Meridian, Alaska T. 16 N., R. 1 E., Secs. 1 to...

  19. Alaska interim land cover mapping program

    USGS Publications Warehouse

    ,

    1987-01-01

    In order to meet the requirements of the Alaska National Interest Lands Conservation Act (ANILCA) for comprehensive resource and management plans from all major land management agencies in Alaska, the USGS has begun a program to classify land cover for the entire State using Landsat digital data. Vegetation and land cover classifications, generated in cooperation with other agencies, currently exist for 115 million acres of Alaska. Using these as a base, the USGS has prepared a comprehensive plan for classifying the remaining areas of the State. The development of this program will lead to a complete interim vegetation and land cover classification system for Alaska and allow the dissemination of digital data for those areas classified. At completion, 153 Alaska 1:250,000-scale quadrangles will be published and will include land cover from digital Landsat classifications, statistical summaries of all land cover by township, and computer-compatible tapes. An interagency working group has established an Alaska classification system (table 1) composed of 18 classes modified from "A land use and land cover classification system for use with remote sensor data" (Anderson and others, 1976), and from "Revision of a preliminary classification system for vegetation of Alaska" (Viereck and Dyrness, 1982) for the unique ecoregions which are found in Alaska.

  20. Women's Legal Rights in Alaska. Reprint.

    ERIC Educational Resources Information Center

    Tatter, Sue Ellen; Saville, Sandra K.

    This publication is intended to help women in Alaska learn about their legal rights. Some of the information is of a general nature and will be of interest to women in other states. Some of the laws and resources are relevant to Alaska only. The publication can serve as a model to other states wanting to develop a resource to inform women about…

  1. Bill Demmert and Native Education in Alaska

    ERIC Educational Resources Information Center

    Barnhardt, Ray

    2011-01-01

    This article describes the influences of William Demmert's formative years growing up in Alaska and his years as an educator of Native American students upon his career in Native education policy. It focuses on Alaska Native education during a ten-year period between 1980 and 1990 during which time he served as the director of the Center for…

  2. Caledonian Deformation in Polydeformed Pre-Mississippian Rocks of the Northeast Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Johnson, B. G.; Toro, J.; Benowitz, J.

    2013-12-01

    In the northeastern Brooks Range of Alaska there are polydeformed metasedimentary and metavolcanic rocks exposed below a major pre-Mississippian unconformity. Elsewhere in northern Alaska it has been challenging to correlate the tectonic fabrics of these early Paleozoic to Neoproterozoic rocks to the different orogenic events of the Arctic because of the strong overprint of Mesozoic and Tertiary Brookian deformation. However, our recent field investigations along the Kongakut and Aichiklik rivers of ANWR have identified an older (pre-Brookian) structural event based on the orientation of penetrative cleavage planes and a contrast in folding style to Brookian structures. Many of the cleavage planes are north dipping and orientated parallel to the axial planes of south-vergent folds. Although metamorphic grade is generally low, in localized areas the cleavage planes contain white micas, whose petrologic and isotopic characteristics indicate that they crystallized during fabric formation. 40Ar/39Ar dating of the white micas yield a metamorphic age of ~400 Ma (Early Devonian). This is evidence for a south-directed structural event which is contemporaneous with Caledonian deformation in East Greenland and Svalbard. Stratigraphicaly, the basement consists of a diverse package of highly deformed marine clastic sediments, and a thick section of basaltic to andesitic flows and volcaniclastic rocks, the Whale Mountain volcanics, which have a sharp southern contact but grade northward and upwards into the clastic rocks. All units are metamorphosed to lower greenschist facies. We are currently investigating the age and geochemical characteristics of the Whale Mountain volcanics to determine their tectonic affinity and role in the assemblage of the North Slope block of Northern Alaska.

  3. Alaska Volcano Observatory at 20

    NASA Astrophysics Data System (ADS)

    Eichelberger, J. C.

    2008-12-01

    The Alaska Volcano Observatory (AVO) was established in 1988 in the wake of the 1986 Augustine eruption through a congressional earmark. Even within the volcanological community, there was skepticism about AVO. Populations directly at risk in Alaska were small compared to Cascadia, and the logistical costs of installing and maintaining monitoring equipment were much higher. Questions were raised concerning the technical feasibility of keeping seismic stations operating through the long, dark, stormy Alaska winters. Some argued that AVO should simply cover Augustine with instruments and wait for the next eruption there, expected in the mid 90s (but delayed until 2006), rather than stretching to instrument as many volcanoes as possible. No sooner was AVO in place than Redoubt erupted and a fully loaded passenger 747 strayed into the eruption cloud between Anchorage and Fairbanks, causing a powerless glide to within a minute of impact before the pilot could restart two engines and limp into Anchorage. This event forcefully made the case that volcano hazard mitigation is not just about people and infrastructure on the ground, and is particularly important in the heavily traveled North Pacific where options for flight diversion are few. In 1996, new funding became available through an FAA earmark to aggressively extend volcano monitoring far into the Aleutian Islands with both ground-based networks and round-the-clock satellite monitoring. Beyond the Aleutians, AVO developed a monitoring partnership with Russians volcanologists at the Institute of Volcanology and Seismology in Petropavlovsk-Kamchatsky. The need to work together internationally on subduction phenomena that span borders led to formation of the Japan-Kamchatka-Alaska Subduction Processes (JKASP) consortium. JKASP meets approximately biennially in Sapporo, Petropavlovsk, and Fairbanks. In turn, these meetings and support from NSF and the Russian Academy of Sciences led to new international education and

  4. Greenland ice sheet motion insensitive to exceptional meltwater forcing.

    PubMed

    Tedstone, Andrew J; Nienow, Peter W; Sole, Andrew J; Mair, Douglas W F; Cowton, Thomas R; Bartholomew, Ian D; King, Matt A

    2013-12-03

    Changes to the dynamics of the Greenland ice sheet can be forced by various mechanisms including surface-melt-induced ice acceleration and oceanic forcing of marine-terminating glaciers. We use observations of ice motion to examine the surface melt-induced dynamic response of a land-terminating outlet glacier in southwest Greenland to the exceptional melting observed in 2012. During summer, meltwater generated on the Greenland ice sheet surface accesses the ice sheet bed, lubricating basal motion and resulting in periods of faster ice flow. However, the net impact of varying meltwater volumes upon seasonal and annual ice flow, and thus sea level rise, remains unclear. We show that two extreme melt events (98.6% of the Greenland ice sheet surface experienced melting on July 12, the most significant melt event since 1889, and 79.2% on July 29) and summer ice sheet runoff ~3.9 σ above the 1958-2011 mean resulted in enhanced summer ice motion relative to the average melt year of 2009. However, despite record summer melting, subsequent reduced winter ice motion resulted in 6% less net annual ice motion in 2012 than in 2009. Our findings suggest that surface melt-induced acceleration of land-terminating regions of the ice sheet will remain insignificant even under extreme melting scenarios.

  5. Cultural adaptation, compounding vulnerabilities and conjunctures in Norse Greenland.

    PubMed

    Dugmore, Andrew J; McGovern, Thomas H; Vésteinsson, Orri; Arneborg, Jette; Streeter, Richard; Keller, Christian

    2012-03-06

    Norse Greenland has been seen as a classic case of maladaptation by an inflexible temperate zone society extending into the arctic and collapse driven by climate change. This paper, however, recognizes the successful arctic adaptation achieved in Norse Greenland and argues that, although climate change had impacts, the end of Norse settlement can only be truly understood as a complex socioenvironmental system that includes local and interregional interactions operating at different geographic and temporal scales and recognizes the cultural limits to adaptation of traditional ecological knowledge. This paper is not focused on a single discovery and its implications, an approach that can encourage monocausal and environmentally deterministic emphasis to explanation, but it is the product of sustained international interdisciplinary investigations in Greenland and the rest of the North Atlantic. It is based on data acquisitions, reinterpretation of established knowledge, and a somewhat different philosophical approach to the question of collapse. We argue that the Norse Greenlanders created a flexible and successful subsistence system that responded effectively to major environmental challenges but probably fell victim to a combination of conjunctures of large-scale historic processes and vulnerabilities created by their successful prior response to climate change. Their failure was an inability to anticipate an unknowable future, an inability to broaden their traditional ecological knowledge base, and a case of being too specialized, too small, and too isolated to be able to capitalize on and compete in the new protoworld system extending into the North Atlantic in the early 15th century.

  6. 34 First Callisto solar burst spectrometer station in Greenland

    NASA Astrophysics Data System (ADS)

    Monstein, Christian

    2016-04-01

    In mid of March 2016 a new long wavelength station in Greenland was set into operation. It is a dual circular polarization, frequency agile solar radio burst spectrometer based on two Callisto spectrometers and the Long Wavelength Array antenna. During the commissioning phase several nice radio burst observations proved that the system works as expected.

  7. A study of Glacial Isostatic Adjustment in Greenland

    NASA Astrophysics Data System (ADS)

    Nielsen, Jens Emil; Sandberg Sørensen, Louise; Adalgeirsdottir, Gudfinna; Spada, Giorgio

    2010-05-01

    Glacial isostatic adjustment (GIA) is the viscoelastic response of the Earth caused by changes in ice loads during glaciations and deglaciations. Knowledge of the GIA signal is particularly important in cryospheric applications of satellite gravimetry and altimetry, where the origin of the observed changes must be separated into past and present response. Modeling the present-day GIA signal must include knowledge of both the ice loading history and the Earth's rheology. Neither of these models are well constrained in Greenland, and hence the GIA estimates here are uncertain. In this paper we implement a loading history of the Greenland Ice Sheet derived from the ice sheet model SICOPOLIS, and we study the present-day gravity changes and vertical crustal motion derived from using this ice history. The results are compared with those derived from the widely used ICE-5G ice history. For calculation of present day GIA signal, we assume the Earth's rheology to be a simplified version of the VM2 Earth model. The calculated GIA signal in Greenland, derived from the two ice loading histories are compared with geodetic measurements of vertical crustal motion from GPS time series and with repeated gravity measurements in Greenland. The free code SELEN is used for calculating the effects of the Earth model and different ice loading histories. This study is performed within the Working Group 4 of the ESF COST Action ES0701 "Improved constraints on models of Glacial Isostatic Adjustment".

  8. Cultural adaptation, compounding vulnerabilities and conjunctures in Norse Greenland

    PubMed Central

    Dugmore, Andrew J.; McGovern, Thomas H.; Vésteinsson, Orri; Arneborg, Jette; Streeter, Richard; Keller, Christian

    2012-01-01

    Norse Greenland has been seen as a classic case of maladaptation by an inflexible temperate zone society extending into the arctic and collapse driven by climate change. This paper, however, recognizes the successful arctic adaptation achieved in Norse Greenland and argues that, although climate change had impacts, the end of Norse settlement can only be truly understood as a complex socioenvironmental system that includes local and interregional interactions operating at different geographic and temporal scales and recognizes the cultural limits to adaptation of traditional ecological knowledge. This paper is not focused on a single discovery and its implications, an approach that can encourage monocausal and environmentally deterministic emphasis to explanation, but it is the product of sustained international interdisciplinary investigations in Greenland and the rest of the North Atlantic. It is based on data acquisitions, reinterpretation of established knowledge, and a somewhat different philosophical approach to the question of collapse. We argue that the Norse Greenlanders created a flexible and successful subsistence system that responded effectively to major environmental challenges but probably fell victim to a combination of conjunctures of large-scale historic processes and vulnerabilities created by their successful prior response to climate change. Their failure was an inability to anticipate an unknowable future, an inability to broaden their traditional ecological knowledge base, and a case of being too specialized, too small, and too isolated to be able to capitalize on and compete in the new protoworld system extending into the North Atlantic in the early 15th century. PMID:22371594

  9. Greenland ice sheet motion insensitive to exceptional meltwater forcing

    PubMed Central

    Tedstone, Andrew J.; Nienow, Peter W.; Sole, Andrew J.; Mair, Douglas W. F.; Cowton, Thomas R.; Bartholomew, Ian D.; King, Matt A.

    2013-01-01

    Changes to the dynamics of the Greenland ice sheet can be forced by various mechanisms including surface-melt–induced ice acceleration and oceanic forcing of marine-terminating glaciers. We use observations of ice motion to examine the surface melt–induced dynamic response of a land-terminating outlet glacier in southwest Greenland to the exceptional melting observed in 2012. During summer, meltwater generated on the Greenland ice sheet surface accesses the ice sheet bed, lubricating basal motion and resulting in periods of faster ice flow. However, the net impact of varying meltwater volumes upon seasonal and annual ice flow, and thus sea level rise, remains unclear. We show that two extreme melt events (98.6% of the Greenland ice sheet surface experienced melting on July 12, the most significant melt event since 1889, and 79.2% on July 29) and summer ice sheet runoff ∼3.9σ above the 1958–2011 mean resulted in enhanced summer ice motion relative to the average melt year of 2009. However, despite record summer melting, subsequent reduced winter ice motion resulted in 6% less net annual ice motion in 2012 than in 2009. Our findings suggest that surface melt–induced acceleration of land-terminating regions of the ice sheet will remain insignificant even under extreme melting scenarios. PMID:24248343

  10. Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

    PubMed

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

    2016-04-01

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

  11. Assessment of Glacial Isostatic Adjustment in Greenland using GPS

    NASA Astrophysics Data System (ADS)

    Khan, S. A.; Bevis, M. G.; Sasgen, I.; van Dam, T. M.; Wahr, J. M.; Wouters, B.; Bamber, J. L.; Willis, M. J.; Knudsen, P.; Helm, V.; Kuipers Munneke, P.; Muresan, I. S.

    2015-12-01

    The Greenland GPS network (GNET) was constructed to provide a new means to assess viscoelastic and elastic adjustments driven by past and present-day changes in ice mass. Here we assess existing glacial isostatic adjustments (GIA) predictions by analysing 1995-2015 data from 61 continuous GPS receivers located along the margin of the Greenland ice sheet. Since GPS receivers measure both the GIA and elastic signals, we isolate GIA, by removing the elastic adjustments of the lithosphere due to present-day mass changes using high-resolution fields of ice surface elevation change derived from satellite and airborne altimetry measurements (ERS1/2, ICESat, ATM, ENVISAT, and CryoSat-2). For most GPS stations, our observed GIA rates contradict GIA predictions; particularly, we find huge uplift rates in southeast Greenland of up to 14 mm/yr while models predict rates of 0-2 mm/yr. Our results suggest possible improvements of GIA predictions, and hence of the poorly constrained ice load history and Earth structure models for Greenland.

  12. A high-resolution record of Greenland mass balance

    NASA Astrophysics Data System (ADS)

    McMillan, Malcolm; Leeson, Amber; Shepherd, Andrew; Briggs, Kate; Armitage, Thomas W. K.; Hogg, Anna; Kuipers Munneke, Peter; Broeke, Michiel; Noël, Brice; Berg, Willem Jan; Ligtenberg, Stefan; Horwath, Martin; Groh, Andreas; Muir, Alan; Gilbert, Lin

    2016-07-01

    We map recent Greenland Ice Sheet elevation change at high spatial (5 km) and temporal (monthly) resolution using CryoSat-2 altimetry. After correcting for the impact of changing snowpack properties associated with unprecedented surface melting in 2012, we find good agreement (3 cm/yr bias) with airborne measurements. With the aid of regional climate and firn modeling, we compute high spatial and temporal resolution records of Greenland mass evolution, which correlate (R = 0.96) with monthly satellite gravimetry and reveal glacier dynamic imbalance. During 2011-2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland's area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.

  13. Ground penetrating radar (GPR) measurements at Mittivakkat Gletscher, Southeast Greenland

    NASA Astrophysics Data System (ADS)

    Clement Yde, Jacob; Løland, Ronny; Ruud, Henry; Mernild, Sebastian H.; Riger-Kusk, Mette; de Villiers, Simon; Tvis Knudsen, N.; Malmros, Jeppe K.

    2014-05-01

    Here, we present ground penetrating radar (GPR) measurements conducted on the surface of Mittivakkat Gletscher in Southeast Greenland (the only long-term mass balance observed glacier in Greenland) and estimate the change in ice volume over an 18 year period. Between a previous direct volume survey in 1994 and the new GPR survey in 2012, the glacier has changed its volume from 2.02 ± 0.10 to 1.50 ± 0.08 km3 while the study area has decreased from 17.6 to 15.8 km2. These results are in accordance with the cumulative mass loss observed by long-term mass balance measurements (1995/1996 - 2011/2012) at Mittivakkat Gletscher and confirms that the glacier is in severe climatic disequilibrium (AAR = 0.17). The observed volume-area scaling exponent γ and coefficient c are outside the range of global scaling parameters, but are sensitive to small uncertainties. As Mittivakkat Gletscher is generally considered as representative of glaciers in Southeast Greenland, these findings could indicate that a regional volume-area scaling approach would provide a more accurate total glacier volume estimate for Greenland than using parameters given by global scaling relationships.

  14. Insights into the virulence-related genes of Edwardsiella tarda isolated from turbot in Europe: genetic homogeneity and evidence for vibrioferrin production.

    PubMed

    Castro, N; Osorio, C R; Buján, N; Fuentes, J C; Rodríguez, J; Romero, M; Jiménez, C; Toranzo, A E; Magariños, B

    2016-05-01

    Edwardsiella tarda has long been known as a pathogen that causes severe economic losses in aquaculture industry. Insights gained on E. tarda pathogenesis may prove useful in the development of new methods for the treatment of infections as well as preventive measures against future outbreaks. In this report, we have established the correlation between the presence of virulence genes, related with three aspects typically involved in bacterial pathogenesis (chondroitinase activity, quorum sensing and siderophore-mediated ferric uptake systems), in the genome of E. tarda strains isolated from turbot in Europe and their phenotypic traits. A total of 8 genes were tested by PCR for their presence in 73 E. tarda isolates. High homogeneity was observed in the presence/absence pattern of all the strains. Positive results in the amplification of virulence-related genes were correlated with the detection of chondroitinase activity in agar plates, in vivo AHL production during fish infection and determination of type of siderophore produced by E. tarda. To the best of our knowledge, this is the first study carried out with European strains on potential virulence factors. Furthermore, we demonstrated for the first time that E. tarda produces the siderophore vibrioferrin.

  15. Adjuvant Effect of Quillaja saponaria Saponin (QSS) on Protective Efficacy and IgM Generation in Turbot (Scophthalmus maximus) upon Immersion Vaccination

    PubMed Central

    Wang, Yujuan; Wang, Xiuhua; Huang, Jie; Li, Jun

    2016-01-01

    The adjuvant effect of Quillaja saponaria saponin (QSS) on protection of turbot fry was investigated with immersion vaccination of formalin-killed Vibrio anguillarum O1 and various concentrations of QSS (5, 25, 45 and 65 mg/L). Fish were challenged at days 7, 14 and 28 post-vaccination. Significantly high relative percent of survival (RPS) ((59.1 ± 13.6)%, (81.7 ± 8.2)%, (77.8 ± 9.6)%) were recorded in the fish that received bacterins immersion with QSS at 45 mg/L, which is comparable to the positive control group vaccinated by intraperitoneal injection (IP). Moreover, a remarkably higher serum antibody titer was also demonstrated after 28 days in the vaccinated fish with QSS (45 mg/L) than those vaccinated fish without QSS (p < 0.05), but lower than the IP immunized fish (p < 0.05). Significant upregulation of IgM gene expression has also been identified in the tissues of skin, gill, spleen and kidney from the immunized fish in comparison to the control fish. Taken together, the present study indicated that QSS was able to dramatically evoke systemic and mucosal immune responses in immunized fish. Therefore, QSS might be a promising adjuvant candidate for fish vaccination via an immersion administering route. PMID:26950114

  16. Role of H(+)-pyrophosphatase activity in the regulation of intracellular pH in a scuticociliate parasite of turbot: Physiological effects.

    PubMed

    Mallo, Natalia; Lamas, Jesús; de Felipe, Ana-Paula; Sueiro, Rosa-Ana; Fontenla, Francisco; Leiro, José-Manuel

    2016-10-01

    The scuticociliatosis is a very serious disease that affects the cultured turbot, and whose causal agent is the anphizoic and marine euryhaline ciliate Philasterides dicentrarchi. Several protozoans possess acidic organelles that contain high concentrations of pyrophosphate (PPi), Ca(2+) and other elements with essential roles in vesicular trafficking, pH homeostasis and osmoregulation. P. dicentrarchi possesses a pyrophosphatase (H(+)-PPase) that pumps H(+) through the membranes of vacuolar and alveolar sacs. These compartments share common features with the acidocalcisomes described in other parasitic protozoa (e.g. acid content and Ca(2+) storage). We evaluated the effects of Ca(2+) and ATP on H (+)-PPase activity in this ciliate and analyzed their role in maintaining intracellular pH homeostasis and osmoregulation, by the addition of PPi and inorganic molecules that affect osmolarity. Addition of PPi led to acidification of the intracellular compartments, while the addition of ATP, CaCl2 and bisphosphonates analogous of PPi and Ca(2+) metabolism regulators led to alkalinization and a decrease in H(+)-PPase expression in trophozoites. Addition of NaCl led to proton release, intracellular Ca(2+) accumulation and downregulation of H(+)-PPase expression. We conclude that the regulation of the acidification of intracellular compartments may be essential for maintaining the intracellular pH homeostasis necessary for survival of ciliates and their adaptation to salt stress, which they will presumably face during the endoparasitic phase, in which the salinity levels are lower than in their natural environment.

  17. Seasonal changes in Fe along a glaciated Greenlandic fjord.

    NASA Astrophysics Data System (ADS)

    Hopwood, Mark; Connelly, Douglas; Arendt, Kristine; Juul-Pedersen, Thomas; Stinchcombe, Mark; Meire, Lorenz; Esposito, Mario; Krishna, Ram

    2016-03-01

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

  18. Radiostratigraphy and age structure of the Greenland Ice Sheet.

    PubMed

    MacGregor, Joseph A; Fahnestock, Mark A; Catania, Ginny A; Paden, John D; Prasad Gogineni, S; Young, S Keith; Rybarski, Susan C; Mabrey, Alexandria N; Wagman, Benjamin M; Morlighem, Mathieu

    2015-02-01

    Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the Greenland Ice Sheet from airborne deep ice-penetrating radar data collected over Greenland by The University of Kansas between 1993 and 2013. To map this radiostratigraphy efficiently, we developed new techniques for predicting reflection slope from the phase recorded by coherent radars. When integrated along track, these slope fields predict the radiostratigraphy and simplify semiautomatic reflection tracing. Core-intersecting reflections were dated using synchronized depth-age relationships for six deep ice cores. Additional reflections were dated by matching reflections between transects and by extending reflection-inferred depth-age relationships using the local effective vertical strain rate. The oldest reflections, dating to the Eemian period, are found mostly in the northern part of the ice sheet. Within the onset regions of several fast-flowing outlet glaciers and ice streams, reflections typically do not conform to the bed topography. Disrupted radiostratigraphy is also observed in a region north of the Northeast Greenland Ice Stream that is not presently flowing rapidly. Dated reflections are used to generate a gridded age volume for most of the ice sheet and also to determine the depths of key climate transitions that were not observed directly. This radiostratigraphy provides a new constraint on the dynamics and history of the Greenland Ice Sheet.

  19. Radiostratigraphy and age structure of the Greenland Ice Sheet

    PubMed Central

    MacGregor, Joseph A; Fahnestock, Mark A; Catania, Ginny A; Paden, John D; Prasad Gogineni, S; Young, S Keith; Rybarski, Susan C; Mabrey, Alexandria N; Wagman, Benjamin M; Morlighem, Mathieu

    2015-01-01

    Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the Greenland Ice Sheet from airborne deep ice-penetrating radar data collected over Greenland by The University of Kansas between 1993 and 2013. To map this radiostratigraphy efficiently, we developed new techniques for predicting reflection slope from the phase recorded by coherent radars. When integrated along track, these slope fields predict the radiostratigraphy and simplify semiautomatic reflection tracing. Core-intersecting reflections were dated using synchronized depth-age relationships for six deep ice cores. Additional reflections were dated by matching reflections between transects and by extending reflection-inferred depth-age relationships using the local effective vertical strain rate. The oldest reflections, dating to the Eemian period, are found mostly in the northern part of the ice sheet. Within the onset regions of several fast-flowing outlet glaciers and ice streams, reflections typically do not conform to the bed topography. Disrupted radiostratigraphy is also observed in a region north of the Northeast Greenland Ice Stream that is not presently flowing rapidly. Dated reflections are used to generate a gridded age volume for most of the ice sheet and also to determine the depths of key climate transitions that were not observed directly. This radiostratigraphy provides a new constraint on the dynamics and history of the Greenland Ice Sheet. Key Points Phase information predicts reflection slope and simplifies reflection tracing Reflections can be dated away from ice cores using a simple ice flow model Radiostratigraphy is often disrupted near the onset of fast ice flow PMID:26213664

  20. Muscle plasticity of Inuit sled dogs in Greenland.

    PubMed

    Gerth, Nadine; Sum, Steffen; Jackson, Sue; Starck, J Matthias

    2009-04-01

    This study examined flexible adjustments of skeletal muscle size, fiber structure, and capillarization in Inuit sled dogs responding to seasonal changes in temperature, exercise and food supply. Inuit dogs pull sleds in winter and are fed regularly throughout this working season. In summer, they remain chained to rocks without exercise, receiving food intermittently and often fasting for several days. We studied two dog teams in Northern Greenland (Qaanaaq) where dogs are still draught animals vital to Inuit hunters, and one dog team in Western Greenland (Qeqertarsuaq) where this traditional role has been lost. Northern Greenland dogs receive more and higher quality food than those in Western Greenland. We used ultrasonography for repeated muscle size measurements on the same individuals, and transmission electron microscopy on micro-biopsies for summer-winter comparisons of muscle histology, also within individuals. At both study sites, dogs' muscles were significantly thinner in summer than in winter - atrophy attributable to reduced fiber diameter. Sarcomeres from West Greenland dogs showed serious myofilament depletion and expansion of the sarcoplasmatic space between myofibrils during summer. At both study sites, summer samples showed fewer interfibrillar and subsarcolemmal mitochondria, and fewer lipid droplets between myofibrils, than did winter samples. In summer, capillary density was higher and inter-capillary distance smaller than in winter, but the capillary-to-fiber-ratio and number of capillaries associated with single myofibers were constant. Increased capillary density was probably a by-product of differential tissue responses to condition changes rather than a functional adaptation, because thinning of muscle fibers in summer was not accompanied by reduction in the capillary network. Thus, skeletal muscle of Inuit dogs responds flexibly to changes in functional demands. This flexibility is based on differential changes in functional components

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

  2. Mycobacterium tuberculosis outbreak strain of Danish origin spreading at worrying rates among greenland-born persons in Denmark and Greenland.

    PubMed

    Lillebaek, T; Andersen, A B; Rasmussen, E M; Kamper-Jørgensen, Z; Pedersen, M K; Bjorn-Mortensen, K; Ladefoged, K; Thomsen, V O

    2013-12-01

    Transmission of Mycobacterium tuberculosis continues at high rates among Greenland-born persons in Greenland and Denmark, with 203 and 450 notified cases per 10(5) population, respectively, in the year 2010. Here, we document that the predominant M. tuberculosis outbreak strain C2/1112-15 of Danish origin has been transmitted to Greenland-born persons in Denmark and subsequently to Greenland, where it is spreading at worrying rates and adding to the already heavy tuberculosis burden in this population group. It is now clear that the C2/1112-15 strain is able to gain new territories using a new population group as the "vehicle." Thus, it might have the ability to spread even further, considering the potential clinical consequences of strain diversity such as that seen in the widely spread Beijing genotype. The introduction of the predominant M. tuberculosis outbreak strain C2/1112-15 into the Arctic circumpolar region is a worrying tendency which deserves attention. We need to monitor whether this strain already has, or will, spread to other countries.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Liu, X.; Bassis, J. N.

    2015-12-01

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

  5. Miocene uplift of the NE Greenland margin linked to plate tectonics: Seismic evidence from the Greenland Fracture Zone, NE Atlantic.

    NASA Astrophysics Data System (ADS)

    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.

  6. Miocene uplift of the NE Greenland margin linked to plate tectonics: Seismic evidence from the Greenland Fracture Zone, NE Atlantic

    NASA Astrophysics Data System (ADS)

    Døssing, Arne; Japsen, Peter; Watts, Anthony B.; Nielsen, Tove; Jokat, Wilfried; Thybo, Hans; Dahl-Jensen, Trine

    2016-02-01

    Tectonic models predict that following breakup, rift margins undergo only decaying thermal subsidence during their postrift evolution. However, postbreakup 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 synrift deposition in the deep-sea basins and onset of (i) thermomechanical 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 thermomechanical 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 intraplate stresses related to global tectonics.

  7. Alaska Village Electric Load Calculator

    SciTech Connect

    Devine, M.; Baring-Gould, E. I.

    2004-10-01

    As part of designing a village electric power system, the present and future electric loads must be defined, including both seasonal and daily usage patterns. However, in many cases, detailed electric load information is not readily available. NREL developed the Alaska Village Electric Load Calculator to help estimate the electricity requirements in a village given basic information about the types of facilities located within the community. The purpose of this report is to explain how the load calculator was developed and to provide instructions on its use so that organizations can then use this model to calculate expected electrical energy usage.

  8. Metalliferous lode deposits of Alaska

    USGS Publications Warehouse

    Berg, Henry C.; Cobb, Edward Huntington

    1967-01-01

    This report summarizes from repoAs of Federal and State agencies published before August 31, 1965, the geology of Alaska's metal-bearing lodes, including their structural or stratigraphic control, host rock, mode of origin, kinds of .Q minerals, grade, past production, and extent of exploration. In addition, the lists of mineral occurrences that accompany the 35 mineral-deposit location maps constitute an inventory of the State's known lodes. A total of 692 localities where m&alliferous deposits have been found are shown on the maps. The localities include 1,739 mines, prospects, and reported occurrences, of which 821 are described individually or otherwise cited in the text.

  9. Organic geochemistry data of Alaska

    USGS Publications Warehouse

    complied by Threlkeld, Charles N.; Obuch, Raymond C.; Gunther, G.L.

    2000-01-01

    In order to archive the results of various petroleum geochemical analyses of the Alaska resource assessment, the USGS developed an Alaskan Organic Geochemical Data Base (AOGDB) in 1978 to house the data generated from USGS and subcontracted laboratories. Prior to the AOGDB, the accumulated data resided in a flat data file entitled 'PGS' that was maintained by Petroleum Information Corporation with technical input from the USGS. The information herein is a breakout of the master flat file format into a relational data base table format (akdata).

  10. Hyperspectral surveying for mineral resources in Alaska

    USGS Publications Warehouse

    Kokaly, Raymond F.; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E.

    2016-07-07

    Alaska is a major producer of base and precious metals and has a high potential for additional undiscovered mineral resources. However, discovery is hindered by Alaska’s vast size, remoteness, and rugged terrain. New methods are needed to overcome these obstacles in order to fully evaluate Alaska’s geology and mineral resource potential. Hyperspectral surveying is one method that can be used to rapidly acquire data about the distributions of surficial materials, including different types of bedrock and ground cover. In 2014, the U.S. Geological Survey began the Alaska Hyperspectral Project to assess the applicability of this method in Alaska. The primary study area is a remote part of the eastern Alaska Range where porphyry deposits are exposed. In collaboration with the Alaska Division of Geological and Geophysical Surveys, the University of Alaska Fairbanks, and the National Park Service, the U.S. Geological Survey is collecting and analyzing hyperspectral data with the goals of enhancing geologic mapping and developing methods to identify and characterize mineral deposits elsewhere in Alaska.

  11. Joint Science Education Project: Learning about polar science in Greenland

    NASA Astrophysics Data System (ADS)

    Foshee Reed, Lynn

    2014-05-01

    The Joint Science Education Project (JSEP) is a successful summer science and culture opportunity in which students and teachers from the United States, Denmark, and Greenland come together to learn about the research conducted in Greenland and the logistics involved in supporting the research. They conduct experiments first-hand and participate in inquiry-based educational activities alongside scientists and graduate students at a variety of locations in and around Kangerlussuaq, Greenland, and on the top of the ice sheet at Summit Station. The Joint Committee, a high-level forum involving the Greenlandic, Danish and U.S. governments, established the Joint Science Education Project in 2007, as a collaborative diplomatic effort during the International Polar Year to: • Educate and inspire the next generation of polar scientists; • Build strong networks of students and teachers among the three countries; and • Provide an opportunity to practice language and communication skills Since its inception, JSEP has had 82 student and 22 teacher participants and has involved numerous scientists and field researchers. The JSEP format has evolved over the years into its current state, which consists of two field-based subprograms on site in Greenland: the Greenland-led Kangerlussuaq Science Field School and the U.S.-led Arctic Science Education Week. All travel, transportation, accommodations, and meals are provided to the participants at no cost. During the 2013 Kangerlussuaq Science Field School, students and teachers gathered data in a biodiversity study, created and set geo- and EarthCaches, calculated glacial discharge at a melt-water stream and river, examined microbes and tested for chemical differences in a variety of lakes, measured ablation at the edge of the Greenland Ice Sheet, and learned about fossils, plants, animals, minerals and rocks of Greenland. In addition, the students planned and led cultural nights, sharing food, games, stories, and traditions of

  12. High-resolution Greenland ice core data show abrupt climate change happens in few years.

    PubMed

    Steffensen, Jørgen Peder; Andersen, Katrine K; Bigler, Matthias; Clausen, Henrik B; Dahl-Jensen, Dorthe; Fischer, Hubertus; Goto-Azuma, Kumiko; Hansson, Margareta; Johnsen, Sigfús J; Jouzel, Jean; Masson-Delmotte, Valérie; Popp, Trevor; Rasmussen, Sune O; Röthlisberger, Regine; Ruth, Urs; Stauffer, Bernhard; Siggaard-Andersen, Marie-Louise; Sveinbjörnsdóttir, Arny E; Svensson, Anders; White, James W C

    2008-08-01

    The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.

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

    PubMed Central

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

    2015-01-01

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

  14. Age of Magmatism and Eurekan Deformation in North Greenland

    NASA Astrophysics Data System (ADS)

    Tegner, Christian; Storey, Michael; Holm, Paul M.; Thorarinsson, Sigurjon; Knudsen, Mads F.

    2014-05-01

    The alpine mountains of Northernmost Greenland are composed of Phanerozoic sediments and volcanic rocks that make up a broadly East-West striking orogenic belt. The major components include: 1) Cambrian-Devonian sediments deposited in the Franklinian Basin; 2) Ellesmerian (365-345 Ma) deformation of these sediments into a fold belt; 3) renewed extension and deposition of Carboniferous-Cretaceous sediments and Cretaceous-Paleogene volcanic rocks of the Kap Washington Group; and 4) Eurekan deformation of sediments and volcanic rocks. We present results of 40Ar-39Ar, U-Pb and Rb-Sr dating of volcanic rocks of the Kap Washington Group. This volcanic succesion is part of the High Arctic Large Igneous Province, exceeds 5 km in thickness, and is composed of bimodal alkaline flows, agglomerates and ignimbrites including peralkaline compositions typical of continental rifts such as the East African Rift. Based on zircon U-Pb and amphibole 40Ar-39Ar ages most volcanics were emplaced at 71-68 Ma, but activity continued down to 61 Ma. A thermal resetting age of 49-47 Ma is also identified in 40Ar-39Ar whole-rock data for trachyte flows. Patch perthite feldspars and coeval resetting of Rb-Sr isotopes by hydrothermal fluids provide further support for thermal overprinting, interpreted as a result of Eurekan compressional tectonism. It is striking that North Greenland volcanism terminated at about the same time (c. 61 Ma) as magmatism in the North Atlantic Large Igneous Province began. We suggest that this was a corollary of a change from extensional to compressional tectonism in the High Arctic. In the period when Greenland moved together with Eurasia (>60 Ma), the separation from North America resulted in rift-related alkaline magmatism in the High Arctic. When Greenland subsequently moved as a separate plate (60-35 Ma), overlapping spreading on both sides pushed it northwards and volcanism in the High Arctic stopped due to compression. Evaluation of plate kinematic models

  15. Alaska LandCarbon wetland distribution map

    USGS Publications Warehouse

    Wylie, Bruce K.; Pastick, Neal J.

    2017-01-01

    This product provides regional estimates of specific wetland types (bog and fen) in Alaska. Available wetland types mapped by the National Wetlands Inventory (NWI) program were re-classed into bog, fen, and other. NWI mapping of wetlands was only done for a portion of the area so a decision tree mapping algorithm was then developed to estimate bog, fen, and other across the state of Alaska using remote sensing and GIS spatial data sets as inputs. This data was used and presented in two chapters on the USGS Alaska LandCarbon Report.

  16. Review: groundwater in Alaska (USA)

    USGS Publications Warehouse

    Callegary, J.B.; Kikuchi, C.P.; Koch, J.C.; Lilly, M.R.; Leake, S.A.

    2013-01-01

    Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to continental in the Interior, and arctic on the North Slope. During the Quaternary period, topography and rock type have combined with glacial and periglacial processes to develop the unconsolidated alluvial aquifers of Alaska and have resulted in highly heterogeneous hydrofacies. In addition, the long persistence of frozen ground, whether seasonal or permanent, greatly affects the distribution of aquifer recharge and discharge. Because of high runoff, a high proportion of groundwater use, and highly variable permeability controlled in part by permafrost and seasonally frozen ground, understanding groundwater/surface-water interactions and the effects of climate change is critical for understanding groundwater availability and the movement of natural and anthropogenic contaminants.

  17. Diachronous retreat of the Greenland ice sheet during the last deglaciation

    NASA Astrophysics Data System (ADS)

    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.

  18. Ocean Melting Greenland (OMG) bathymetric survey of northwest Greenland and implications for the recent evolution of its glaciers

    NASA Astrophysics Data System (ADS)

    Wood, M.; Rignot, E. J.; Willis, J. K.; Fenty, I. G.

    2015-12-01

    Oceans Melting Greenland (OMG) is a five-year Earth Ventures Suborbital Mission funded by NASA to investigate the role of the oceans in ice loss around the margins of the Greenland Ice Sheet, which includes measurements of seafloor bathymetry from multibeam surveys and airborne gravity, glacier surface elevation from high-frequency radar interferometry, and temperature/salinity/depth from vessels and airborne-dropped probes. Here, we describe the results of the 2016 bathymetry survey of northwest Greenland that took place in the summer of 2015: july 22-August 19 and Sept 2-Sept 16 spanning from Ilulissat to Thule AFB in north Greenland, and to be complemented by a survey of southeast Greenland in 2016. We deployed a multibeam Reson 7160 with 512 beams installed on the hull of the Cape Race vessel, with enhanced capabilities for fjord wall and ice face mapping. The survey tracks were optimized based on the IBCAO3 database, recent cruises, airborne gravity data collected by NASA Operation IceBridge which indicated the presence of troughs, bed topography mapped inland using a mass conservation approach, the spatial distribution of ice discharge to locate the largest outlets and maximizing the number of major fjords sampled during the survey, with the goal to identify all troughs that are major pathways for subsurface ocean heat, and constrain as many glacier ice front thickness as permitted by time and the practicality of navigating the ice-choked fjords. The data reveal many deep, U-shaped, submarine valleys connected to the glaciers, intercut with sills and over deepened in narrower passages where former glaciers and ice streams merged into larger units; as well as fjords ending in shallow plateaus with glaciers in retreated positions. The presence of warm, salty water of Atlantic origin (AW) in the fjords is documented using CTD. Some glaciers sit on shallow plateaus in cold, fresh polar waters (PW) at the end of deep fjords, while others are deeper and standing in

  19. North Atlantic warming and the retreat of Greenland's outlet glaciers.

    PubMed

    Straneo, Fiammetta; Heimbach, Patrick

    2013-12-05

    Mass loss from the Greenland ice sheet quadrupled over the past two decades, contributing a quarter of the observed global sea-level rise. Increased submarine melting is thought to have triggered the retreat of Greenland's outlet glaciers, which is partly responsible for the ice loss. However, the chain of events and physical processes remain elusive. Recent evidence suggests that an anomalous inflow of subtropical waters driven by atmospheric changes, multidecadal natural ocean variability and a long-term increase in the North Atlantic's upper ocean heat content since the 1950s all contributed to a warming of the subpolar North Atlantic. This led, in conjunction with increased runoff, to enhanced submarine glacier melting. Future climate projections raise the potential for continued increases in warming and ice-mass loss, with implications for sea level and climate.

  20. Potential Climatic Effects on the Greenland Ice Sheet

    NASA Technical Reports Server (NTRS)

    Bindschadler, R. A.

    1984-01-01

    The Greenland Ice Sheet covers an area of 1,720,000 sq. km and contains approximately 2,600,000 cu km of ice. Most of the ice sheet receives an excess of snow accumulation over the amount of ice lost to wind, meltwater run-off or other ablative processes. The majority of mass loss occurs at the margin of the ice sheet as either surface melt, which flows into the sea or calving of icebergs from the tongues of outlet glaciers. Many estimates of these processes were published. An average of five published estimates is summarized. If these estimates are correct, then the Greenland Ice Sheet is in approximate equilibrium and contributes 490 cu km/a of fresh water to the North Atlantic and Arctic Oceans. Climate effects, ice sheet flow, and application of remote sensing to tracking of the ice sheet are discussed.

  1. Deformation of Eemian and Glacial ice at NEEM, Greenland

    NASA Astrophysics Data System (ADS)

    Keegan, Kaitlin; Dahl-Jensen, Dorthe; Montagnat, Maurine; Weikusat, Ilka; Kipfstuhl, Sepp

    2015-04-01

    New findings from deep Greenland ice cores and airborne radio echo sounding (RES) images show that basal ice flow is very unstable, and a basal layer of disturbed ice is often observed. At NEEM, Greenland this folding occurs at the boundary between the Eemian and glacial ice regimes, suggesting that differences in physical properties of the ice play a role in the disturbance. Past work in metallurgy (Burke, 1957) and ice (Hammer et al., 1978; Langway et al., 1988; Dahl-Jensen et al., 1997), suggests that impurity content controls grain evolution, and therefore deformation, which we hypothesize to be analogous to the differences in ice flow seen deep in the NEEM ice core. Here we present results of fabric, grain size, impurity content, and deformation studies from samples above and below this unstable boundary in the ice sheet.

  2. Recent warming at Summit, Greenland: Global context and implications

    NASA Astrophysics Data System (ADS)

    McGrath, Daniel; Colgan, William; Bayou, Nicolas; Muto, Atsuhiro; Steffen, Konrad

    2013-05-01

    at Summit, Greenland suggest that the annual mean near-surface air temperature increased at 0.09 ± 0.01°C/a over the 1982-2011 climatology period. This rate of warming, six times the global average, places Summit in the 99th percentile of all globally observed warming trends over this period. The rate of warming at Summit is increasing over time. During the instrumental period (1987-2011), warming has been greatest in the winter season, although the implications of summer warming are more acute. The annual maximum elevation of the equilibrium line and dry snow line has risen at 44 and 35 m/a over the past 15 and 18 years, respectively. Extrapolation of this observed trend now suggests, with 95% confidence intervals, that the dry snow facies of the Greenland Ice Sheet will inevitably transition to percolation facies. There is a 50% probability of this transition occurring by 2025.

  3. Large Fluctuations in Speed on Jakobshavn Isbrae, Greenland

    NASA Technical Reports Server (NTRS)

    Joughin, Ian; Abdalati, Waleed; Fahnestock, Mark

    2003-01-01

    We have assembled an 18-year velocity record for Jakobshavn Isbrae, Greenland. From a 1985 speed of approx. 7000 m/yr, the glacier had slowed by approx. 1000 m/ yr in 1992, which coincided with independently observed thickening in the early 1990s . The glacier then sped up by approx. 4000 m/yr between 1997 and 2000, during which time other measurements show rapid thinning . From 2000 to 2003, the glacier s floating ice tongue almost entirely disintegrated, as speed increased to 12,600 m/yr. If the retreat of the ice tongue caused the acceleration, then similar losses of floating ice tongues since the Little Ice Age may explain the current rapid thinning observed for many of Greenland s outlet glaciers.

  4. Geology of the Alaska-Juneau lode system, Alaska

    USGS Publications Warehouse

    Twenhofel, William Stephens

    1952-01-01

    The Alaska-Juneau lode system for many years was one of the worlds leading gold-producing areas. Total production from the years 1893 to 1946 has amounted to about 94 million dollars, with principal values in contained gold but with some silver and lead values. The principal mine is the Alaska-Juneau mine, from which the lode system takes its name. The lode system is a part of a larger gold-bearing belt, generally referred to as the Juneau gold belt, along the western border of the Coast Range batholith. The rocks of the Alaska-Juneau lode system consist of a monoclinal sequence of steeply northeasterly dipping volcanic, state, and schist rocks, all of which have been metamorphosed by dynamic and thermal processes attendant with the intrusion of the Coast Range batholith. The rocks form a series of belts that trend northwest parallel to the Coast Range. In addition to the Coast Range batholith lying a mile to the east of the lode system, there are numerous smaller intrusives, all of which are sill-like in form and are thus conformable to the regional structure. The bedded rocks are Mesozoic in age; the Coast Range batholith is Upper Jurassic and Lower Cretaceous in age. Some of the smaller intrusives pre-date the batholith, others post-date it. All of the rocks are cut by steeply dipping faults. The Alaska-Juneau lode system is confined exclusively to the footwall portion of the Perseverance slate band. The slate band is composed of black slate and black phyllite with lesser amounts of thin-bedded quartzite. Intrusive into the slate band are many sill-like bodies of rocks generally referred to as meta-gabbro. The gold deposits of the lode system are found both within the slate rocks and the meta-gabbro rocks, and particularly in those places where meta-gabbro bodies interfinger with slate. Thus the ore bodies are found in and near the terminations of meta-gabbro bodies. The ore bodies are quartz stringer-lodes composed of a great number of quartz veins from 6

  5. Cross Cultural Scientific Communication in Alaska

    NASA Astrophysics Data System (ADS)

    Bertram, K. B.

    2006-12-01

    An example of cross-cultural education is provided by the Aurora Alive curriculum. Aurora Alive communicates science to Alaska Native students through cross-cultural educational products used in Alaska schools for more than a decade, including (1) a CDROM that provides digital graphics, bilingual (English and Athabascan language) narration-over-text and interactive elements that help students visualize scientific concepts, and (2) Teacher's Manuals containing more than 150 hands-on activities aligned to national science standards, and to Alaska Standards for Culturally Responsive Schools. Created by Native Elders and teachers working together with University Alaska Fairbanks Geophysical Institute scientists, Aurora Alive blends Native "ways of knowing" with current "western" research to teach the physics and math of the aurora.

  6. Advancing Efforts to Energize Native Alaska (Brochure)

    SciTech Connect

    Not Available

    2013-04-01

    This brochure describes key programs and initiatives of the DOE Office of Indian Energy Policy and Programs to advance energy efficiency, renewable energy, and energy infrastructure projects in Alaska Native villages.

  7. 75 FR 43198 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... Alaska Native Claims Settlement Act. The subsurface estate in these lands will be conveyed to Bristol Bay... times in the Bristol Bay Times. DATES: Any party claiming a property interest in the lands affected...

  8. 76 FR 67472 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... lands are located east of Teller, Alaska, and contain 47.87 acres. Notice of the decision will also be... email at ak.blm.conveyance@blm.gov . Persons who use a Telecommunications Device for the Deaf (TDD)...

  9. American Indians, Alaska Natives, and the Flu

    MedlinePlus

    ... CDC Features American Indians, Alaska Natives, and the Flu Recommend on Facebook Tweet Share Compartir Vaccination against ... the flu. Protect Indian Country by Getting Your Flu Vaccine A flu vaccine not only protects you ...

  10. Columbia Glacier, Alaska, 1986-2011

    NASA Video Gallery

    The Columbia Glacier in Alaska is one of many vanishing around the world. Glacier retreat is one of the most direct and understandable effects of climate change. The consequences of the decline in ...

  11. Alaska Simulator - A Journey to Planning

    NASA Astrophysics Data System (ADS)

    Weber, Barbara; Pinggera, Jakob; Zugal, Stefan; Wild, Werner

    The Alaska Simulator is an interactive software tool developed at the University of Innsbruck which allows people to test, analyze and improve their own planning behavior. In addition, the Alaska Simulator can be used for studying research questions in the context of software project management and other related fields. Thereby, the Alaska Simulator uses a journey as a metaphor for planning a software project. In the context of software project management the simulator can be used to compare traditional rather plan-driven project management methods with more agile approaches. Instead of pre-planning everything in advance agile approaches spread planning activities throughout the project and provide mechanisms for effectively dealing with uncertainty. The biggest challenge thereby is to find the right balance between pre-planning activities and keeping options open. The Alaska Simulator allows to explore how much planning is needed under different circumstances.

  12. Renewed unrest at Mount Spurr Volcano, Alaska

    USGS Publications Warehouse

    Power, John A.

    2004-01-01

    The Alaska Volcano Observatory (AVO),a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys, has detected unrest at Mount Spurr volcano, located about 125 km west of Anchorage, Alaska, at the northeast end of the Aleutian volcanic arc.This activity consists of increased seismicity melting of the summit ice cap, and substantial rates of C02 and H2S emission.The current unrest is centered beneath the volcano's 3374-m-high summit, whose last known eruption was 5000–6000 years ago. Since then, Crater Peak, 2309 m in elevation and 4 km to the south, has been the active vent. Recent eruptions occurred in 1953 and 1992.

  13. Cardiovascular Disease Among Alaska Native Peoples

    PubMed Central

    Jolly, Stacey E.; Howard, Barbara V.; Umans, Jason G.

    2013-01-01

    Although Alaska Native peoples were thought to be protected from cardiovascular disease (CVD), data now show that this is not the case, despite traditional lifestyles and high omega-3 fatty acid intake. In this article, the current understanding of CVD and its risk factors among Alaska Native peoples, particularly among the Yupik and Inupiat populations, will be discussed, using data from three major studies funded by the National Institutes of Health: Genetics of Coronary Artery Disease among Alaska Natives (GOCADAN), Center for Native Health Research (CANHR), and Education and Research Towards Health (EARTH). Data from these epidemiologic studies have focused concern on CVD and its risk factors among Alaska Native peoples. This review will summarize the findings of these three principal studies and will suggest future directions for research and clinical practice. PMID:24367710

  14. 78 FR 53158 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ...) to Sea Lion Corporation. The decision approves the surface estate in the lands described below for... Lion Corporation. The lands are in the vicinity of Hooper Bay, Alaska, and are located in:...

  15. SAGE: A tool for time-series analysis of Greenland

    NASA Astrophysics Data System (ADS)

    Duerr, R. E.; Gallaher, D. W.; Khalsa, S. S.; Lewis, S.

    2011-12-01

    The National Snow and Ice Data Center (NSIDC) has developed an operational tool for analysis. This production tool is known as "Services for the Analysis of the Greenland Environment" (SAGE). Using an integrated workspace approach, a researcher has the ability to find relevant data and perform various analysis functions on the data, as well as retrieve the data and analysis results. While there continues to be compelling observational evidence for increased surface melting and rapid thinning along the margins of the Greenland ice sheet, there are still uncertainties with respect to estimates of mass balance of Greenland's ice sheet as a whole. To better understand the dynamics of these issues, it is important for scientists to have access to a variety of datasets from multiple sources, and to be able to integrate and analyze the data. SAGE provides data from various sources, such as AMSR-E and AVHRR datasets, which can be analyzed individually through various time-series plots and aggregation functions; or they can be analyzed together with scatterplots or overlaid time-series plots to provide quick and useful results to support various research products. The application is available at http://nsidc.org/data/sage/. SAGE was built on top of NSIDC's existing Searchlight engine. The SAGE interface gives users access to much of NSIDC's relevant Greenland raster data holdings, as well as data from outside sources. Additionally, various web services provide access for other clients to utilize the functionality that the SAGE interface provides. Combined, these methods of accessing the tool allow scientists the ability to devote more of their time to their research, and less on trying to find and retrieve the data they need.

  16. Services for the Analysis of the Greenland Environment (SAGE)

    NASA Astrophysics Data System (ADS)

    Lewis, S.; Gallaher, D. W.; Khalsa, S. S.; Duerr, R. E.

    2010-12-01

    While there continues to be compelling observational evidence for increased surface melting and rapid thinning along the margins of the Greenland ice sheet, there are still uncertainties with respect to estimates of mass balance of Greenland's ice sheet as a whole. To better understand the dynamics of these issues, it is important for scientists to have access to a variety of datasets from multiple sources, and to be able to integrate and analyze the data. To address this need, the National Snow and Ice Data Center (NSIDC) has the Services for the Analysis of the Greenland Environment (SAGE). Using an integrated workspace approach, a researcher has the ability to find relevant data and perform various analysis functions on the data, as well as retrieve the data and analysis results. Data from various sources, such as AMSR-E and AVHRR datasets, can be analyzed individually through various time-series plots and aggregation functions; or they can be analyzed together with scatterplots or overlaid time-series plots to provide quick and useful results to support various research products. Built on top of NSIDC's Searchlight engine, the SAGE interface gives users access to much of NSIDC's relevant Greenland raster data holdings, as well as data from several outside sources. Additionally, various web services provide access for other clients to utilize the functionality that the SAGE interface provides. Combined, these methods of accessing the tool allow scientists the ability to devote more of their time to their research, and less on trying to find and retrieve the data they need.

  17. Surface-atmosphere decoupling limits accumulation at Summit, Greenland

    PubMed Central

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

    2016-01-01

    Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland. PMID:27386509

  18. The Nitrate Content of Greenland Ice and Solar Activity

    NASA Astrophysics Data System (ADS)

    Kocharov, G. E.; Kudryavtsev, I. V.; Ogurtsov, M. G.; Sonninen, E.; Jungner, H.

    2000-12-01

    Past solar activity is studied based on analysis of data on the nitrate content of Greenland ice in the period from 1576 1991. Hundred-year (over the entire period) and quasi-five-year (in the middle of the 18th century) variations in the nitrate content are detected. These reflect the secular solar-activity cycle and cyclicity in the flare activity of the Sun.

  19. Ice Core Records of Recent Northwest Greenland Climate

    NASA Astrophysics Data System (ADS)

    Osterberg, E. C.; Wong, G. J.; Ferris, D.; Lutz, E.; Howley, J. A.; Kelly, M. A.; Axford, Y.; Hawley, R. L.

    2014-12-01

    Meteorological station data from NW Greenland indicate a 3oC temperature rise since 1990, with most of the warming occurring in fall and winter. According to remote sensing data, the NW Greenland ice sheet (GIS) and coastal ice caps are responding with ice mass loss and margin retreat, but the cryosphere's response to previous climate variability is poorly constrained in this region. We are developing multi-proxy records (lake sediment cores, ice cores, glacial geologic data, glaciological models) of Holocene climate change and cryospheric response in NW Greenland to improve projections of future ice loss and sea level rise in a warming climate. As part of our efforts to develop a millennial-length ice core paleoclimate record from the Thule region, we collected and analyzed snow pit samples and short firn cores (up to 21 m) from the coastal region of the GIS (2Barrel site; 76.9317o N, 63.1467o W, 1685 m el.) and the summit of North Ice Cap (76.938o N, 67.671o W, 1273 m el.) in 2011, 2012 and 2014. The 2Barrel ice core record has statistically significant relationships with regional spring and fall Baffin Bay sea ice extent, summertime temperature, and annual precipitation. Here we evaluate relationships between the 2014 North Ice Cap firn core glaciochemical record and climate variability from regional instrumental stations and reanalysis datasets. We compare the coastal North Ice Cap record to more inland records from 2Barrel, Camp Century and NEEM to evaluate spatial and elevational gradients in recent NW Greenland climate change.

  20. Lively Earthquake Activity in North-Eastern Greenland

    NASA Astrophysics Data System (ADS)

    Larsen, Tine B.; Dahl-Jensen, Trine; Voss, Peter H.

    2016-04-01

    The seismograph at the Danish military outpost, Station Nord (NOR) in North East Greenland, records many regional/local earthquakes every day. Most of these events originate at the Arctic plate boundary between the Eurasian and the North American plates. The plate boundary has a particularly active segment approximately 200 km from the seismograph. Additionally we find a seismically very active region 20-30 km from NOR on the Kronprins Christian Land peninsula. The BB seismograph at NOR was installed in 2002 and later upgraded with real-time telemetry as part of the GLISN-project. Since late 2013 data from NOR have been included in routine processing at GEUS. Phase readings on some of the older data, primarily 2002-2003, have been carried out previously in connection with other projects. As a result, phase readings for more than 6000 local events, recorded exclusively at NOR, were found in the GEUS data base. During the years 2004 to 2007 four locations were occupied by temporary BB seismographs on the North coast of Greenland as part of the Law of the Sea preparatory work. Data from these stations have not previously been analyzed for local and regional events. In this study we combine the recordings from NOR with phase readings from the temporary seismographs in Northern Greenland. The local events on Kronprins Christian Land range in magnitude from less than 2 to a 4.8 event widely recorded in the region and felt by the personnel at Station Nord on August 30, 2005. Station Nord is located in the seismically most active region of Greenland.

  1. Climate Change and Baleen Whale Trophic Cascades in Greenland

    DTIC Science & Technology

    2009-09-30

    approach by combining observations of movements, foraging ecology and phenology collected by satellite and archival telemetry with intensive and...whale species in West Greenland. We use a multidisciplinary approach by combining observations of movements, foraging ecology and phenology collected...including the time individuals spend feeding in each site and the phenology of the use of the focal areas. These data are related to long-term physical

  2. Climate Change and Baleen Whale Trophic Cascades in Greenland

    DTIC Science & Technology

    2012-03-19

    approach by combining observations of movements, foraging ecology and phenology collected by satellite and archival telemetry with intensive and localized... phenology of the use of the focal areas. These data were related to long-term physical and biological monitoring program in Nuuk Fjord and on the coast...of West Greenland, where long-term fishery data are collected to quantify seasonal and inter-annual variations in the biological and geophysical

  3. Climate Change and Baleen Whale Trophic Cascades in Greenland

    DTIC Science & Technology

    2010-01-01

    species in West Greenland. We use a multidisciplinary approach by combining observations of movements, foraging ecology and phenology collected by...along the coast using probabilistic spatial techniques, including the time individuals spend feeding in each site and the phenology of the use of...where long-term fishery data are collected to quantify seasonal and inter-annual variations in the biological and geophysical properties of the marine

  4. Major disruption of D'' beneath Alaska: D'' Beneath Alaska

    SciTech Connect

    Sun, Daoyuan; Helmberger, Don; Miller, Meghan S.; Jackson, Jennifer M.

    2016-05-01

    D'' represents one of the most dramatic thermal and compositional layers within our planet. In particular, global tomographic models display relatively fast patches at the base of the mantle along the circum-Pacific which are generally attributed to slab debris. Such distinct patches interact with the bridgmanite (Br) to post-bridgmanite (PBr) phase boundary to generate particularly strong heterogeneity at their edges. Most seismic observations for the D'' come from the lower mantle S wave triplication (Scd). Here we exploit the USArray waveform data to examine one of these sharp transitions in structure beneath Alaska. From west to east beneath Alaska, we observed three different characteristics in D'': (1) the western region with a strong Scd, requiring a sharp δVs = 2.5% increase; (2) the middle region with no clear Scd phases, indicating a lack of D'' (or thin Br-PBr layer); and (3) the eastern region with strong Scd phase, requiring a gradient increase in δVs. To explain such strong lateral variation in the velocity structure, chemical variations must be involved. We suggest that the western region represents relatively normal mantle. In contrast, the eastern region is influenced by a relic slab that has subducted down to the lowermost mantle. In the middle region, we infer an upwelling structure that disrupts the Br-PBr phase boundary. Such an interpretation is based upon a distinct pattern of travel time delays, waveform distortions, and amplitude patterns that reveal a circular-shaped anomaly about 5° across which can be modeled synthetically as a plume-like structure rising about 400 km high with a shear velocity reduction of ~5%, similar to geodynamic modeling predictions of upwellings.

  5. Propagation measurements in Alaska using ACTS beacons

    NASA Technical Reports Server (NTRS)

    Mayer, Charles E.

    1991-01-01

    The placement of an ACTS propagation terminal in Alaska has several distinct advantages. First is the inclusion of a new and important climatic zone to the global propagation model. Second is the low elevation look angle from Alaska to ACTS. These two unique opportunities also present problems unique to the location, such as extreme temperatures and lower power levels. These problems are examined and compensatory solutions are presented.

  6. Mercury in polar bears from Alaska

    SciTech Connect

    Lentfer, J.W.; Galster, W.A.

    1987-04-01

    Alaskan polar bear (Ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. Bears north of Alaska had more mercury than bears west of Alaska. The only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. Levels were probably not high enough to be a serious threat to bears.

  7. Oil-and-gas resources of Alaska

    SciTech Connect

    Not Available

    1985-01-01

    This is a short information circular on the history of oil-and-gas development in Alaska. It discusses the past discoveries and the future prospects and the estimated reserve base of the state. It also briefly discusses the oil-and-gas leasing program and exploration activity in the Arctic National Wildlife Refuge. A map of Alaska showing oil-and-gas fields, reserves, and lease boundaries is also provided.

  8. Accretion tectonics and crustal structure in Alaska

    USGS Publications Warehouse

    Coney, P.J.; Jones, D.L.

    1985-01-01

    The entire width of the North American Cordillera in Alaska is made up of "suspect terranes". Pre-Late Cretaceous paleogeography is poorly constrained and the ultimate origins of the many fragments which make up the state are unclear. The Prince William and Chugach terranes accreted since Late Cretaceous time and represent the collapse of much of the northeast Pacific Ocean swept into what today is southern Alaska. Greater Wrangellia, a composite terrane now dispersed into fragments scattered from Idaho to southern Alaska, apparently accreted into Alaska in Late Cretaceous time crushing an enormous deep-marine flysch basin on its inboard side. Most of interior eastern Alaska is the Yukon Tanana terrane, a very large entirely fault-bounded metamorphic-plutonic assemblage covering thousands of square kilometers in Canada as well as Alaska. The original stratigraphy and relationship to North America of the Yukon-Tanana terrane are both obscure. A collapsed Mesozoic flysch basin, similar to the one inboard of Wrangellia, lies along the northern margin. Much of Arctic Alaska was apparently a vast expanse of upper Paleozoic to Early Mesozoic deep marine sediments and mafic volcanic and plutonic rocks now scattered widely as large telescoped sheets and Klippen thrust over the Ruby geanticline and the Brooks Range, and probably underlying the Yukon-Koyukuk basin and the Yukon flats. The Brooks Range itself is a stack of north vergent nappes, the telescoping of which began in Early Cretaceous time. Despite compelling evidence for thousands of kilometers of relative displacement between the accreted terranes, and large amounts of telescoping, translation, and rotation since accretion, the resulting new continental crust added to North America in Alaska carries few obvious signatures that allow application of currently popular simple plate tectonic models. Intraplate telescoping and strike-slip translations, delamination at mid-crustal levels, and large-scale lithospheric

  9. Environmental Assessment for North Warning System (Alaska)

    DTIC Science & Technology

    1986-11-10

    native villages; thus, an Environmental Impact Statement (EIS) on the Alaskan portion of the NWS was judged necessary. A recent reconfiguration of tile... Native and non- Native individuals. Thaw lake - A lake or pond formed by localized thawing of permafrost. Thermokarst - Refers to irregular topography...Preservation AFOSH - Air Force Occupational Safety and Health Standard AFR - Air Force Regulation AHRS - Alaska Heritage Resource Survey ANCSA - Alaska Native

  10. Alaska Native Parkinson’s Disease Registry

    DTIC Science & Technology

    2007-11-01

    Questionable 0 DK f. seborrheic dermatitis 0 Yes 0 No 0 Questionable 0 DK Exclusion criteria O Prominent postural instability in the first 3...4 A. Introduction Parkinsonism (PS) is a syndrome characterized by tremor, rigidity, slowness of movement, and problems with walking and balance...the Alaska Native Medical Center. B. Body The intent of this proposal is to establish a registry of parkinsonism cases among Alaska native

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  12. Greenland ice sheet melting during the last interglacial

    NASA Astrophysics Data System (ADS)

    Langebroek, Petra M.; Nisancioglu, Kerim H.

    2016-04-01

    During the last interglacial period (LIG) peak temperatures over Greenland were several degrees warmer than today. The Greenland ice sheet (GIS) retreated causing a global sea-level rise in the order of several meters. Large uncertainties still exist in the exact amount of melt and on the source location of this melt. Here we examine the GIS response to LIG temperature and precipitation patterns using the SICOPOLIS ice sheet model. The LIG climate was simulated by forcing the Norwegian Earth System Model (NorESM) with the appropriate greenhouse gases and orbital settings. The resulting LIG ice volume evolution strongly depends on the chosen value of uncertain model parameters for the ice sheet (e.g. basal sliding parameter, PDD factors, and atmospheric temperature lapse rate). We reduce the uncertainty by evaluating an ensemble of model results against present-day observations of ice sheet size, elevation and stability, together with paleo information from deep ice cores. We find a maximum GIS reduction equivalent to 0.8 to 2.2m of global sea-level rise. In this model set-up most of the melting occurs in southwestern Greenland.

  13. Factors Controlling Methane in Arctic Lakes of Southwest Greenland

    PubMed Central

    2016-01-01

    We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region. PMID:27454863

  14. Spatial variation in energy exchange across coastal environments in Greenland

    NASA Astrophysics Data System (ADS)

    Lund, M.; Abermann, J.; Citterio, M.; Hansen, B. U.; Larsen, S. H.; Stiegler, C.; Sørensen, L. L.; van As, D.

    2015-12-01

    The surface energy partitioning in Arctic terrestrial and marine areas is a crucial process, regulating snow, glacier ice and sea ice melt, and permafrost thaw, as well as modulating Earth's climate on both local, regional, and eventually, global scales. The Arctic region has warmed approximately twice as much as the global average, due to a number of feedback mechanisms related to energy partitioning, most importantly the snow and ice-albedo feedback. However, direct measurements of surface energy budgets in the Arctic are scarce, especially for the cold and dark winter period and over transects going from the ice sheet and glaciers to the sea. This study aims to describe annual cycles of the surface energy budget from various surface types in Arctic Greenland; e.g. glacier, snow, wet and dry tundra and sea ice, based on data from a number of measurement locations across coastal Greenland related to the Greenland Ecosystem Monitoring (GEM) program, including Station Nord/Kronprins Christians Land, Zackenberg/Daneborg, Disko, Qaanaq, Nuuk/Kobbefjord and Upernaviarsuk. Based on the available time series, we will analyze the sensitivity of the energy balance partitioning to variations in meteorological conditions (temperature, cloudiness, precipitation). Such analysis would allow for a quantification of the spatial variation in the energy exchange in aforementioned Arctic environments. Furthermore, this study will identify uncertainties and knowledge gaps in Arctic energy budgets and related climate feedback effects.

  15. Mineralogy and composition of Archean Crust, Greenland: A pilot study

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Curtiss, Brian

    1989-01-01

    The Portable Instant Display and Analysis Spectrometer (PIDAS) was taken to southwestern Greenland to investigate in situ the potential application of AVIRIS to estimate the mineralogy and composition of rocks exposed in Archean terranes. The goal was to determine the feasibility of using a high spectral resolution scanner to find and study pristine rocks, those that have not been altered by subsequent deformation and metamorphism. The application of AVIRIS data to the problems in Greenland is logical. However, before a costly deployment of the U-2 aircraft to Greenland is proposed, this study was undertaken to acquire the spectral data necessary to verify that mineralogical mapping in the environmental conditions found there is possible. Although field conditions were far from favorable, all of the major objectives of the study were addressed. One of the major concerns was that lichens would obscure the rock surfaces. It was found that the spectral signature of the lichens was distinct from the underlying rocks. Thus, a spectrum of a rock outcrop, with its partial cover of lichens, can be un-mixed into rock and lichen components. The data acquired during the course of this study supports the conclusion that areas of pristine Archean crust can be differentiated from that which has experienced low grade alteration associated with Proterizoic faulting.

  16. Self-inhibiting growth of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Langen, P. L.; Solgaard, A. M.; Hvidberg, C. S.

    2012-04-01

    The build-up of the Greenland Ice Sheet from ice free conditions is studied in an ice sheet model (ISM) driven by fields from an atmospheric general circulation model (GCM). Experiments where the two are coupled offline are performed and augmented by one where an intermediate ice sheet configuration, taken as a snap shot during the regrowth in the ISM, is coupled back to the GCM. It is found that several open questions regarding reversibility or irreversibility of a disintegration of the Greenland Ice Sheet may be reconciled with these experiments. Running the ISM with GCM fields corresponding to a present day ice sheet configuration leads to regrowth, while considerations of the GCM's snow accumulation in an ice free run point to irreversibility. Forcing the ISM with the GCM fields corresponding to the ice free state leads to extensive regrowth which, however, is halted when an intermediate recoupling step is included. This inhibition of further growth is believed to be due to a Föhn effect of moist air parcels being lifted over the intermediate ice sheet and arriving in the Greenland interior with high temperatures.

  17. Unmanned Aircraft System (UAS) Assessment of Melt Lakes in Greenland

    NASA Astrophysics Data System (ADS)

    Adler, J.; Steffen, K.

    2007-12-01

    The objective of this August 2007 week-long test campaign was to assess the viability of supraglacial lake depths with high-resolution hyperspectral measurements. The knowledge of melt lake depth is essential in determining the volume of water which forms on top of glacial surfaces during the annual melt season. The assessment of melt water volume is a crucial input parameter for modeling the Greenland ice sheet dynamics. UAS operations were flown out of western Greenland. Preliminary results from five hyperspectral data cubes are presented, indicating that supraglacial water depths can be determined from low altitude, high-resolution hyperspectral imaging. The pixel resolution of the hyperspectral sensor is 0.2 meters at an altitude of 300 meters above the ice surface; this provides accuracy that is two orders of magnitude better than imagery obtained by the MODIS sensor or other similar satellite-based methods. Further, a UAS-based hyperspectral approach enables the measurement of supraglacial lake depths under most cloud cover conditions. The capabilities of three UAS types (Manta, Silver Fox, and electric Silver Fox) flight tested in Greenland are discussed. Also, we present future field planning (2008 and 2009) to measure supraglacial lake depths with hyperspectral imagery in conjunction with a green laser altimeter.

  18. Laser altimetry reveals complex pattern of Greenland Ice Sheet dynamics.

    PubMed

    Csatho, Beata M; Schenk, Anton F; van der Veen, Cornelis J; Babonis, Gregory; Duncan, Kyle; Rezvanbehbahani, Soroush; van den Broeke, Michiel R; Simonsen, Sebastian B; Nagarajan, Sudhagar; van Angelen, Jan H

    2014-12-30

    We present a new record of ice thickness change, reconstructed at nearly 100,000 sites on the Greenland Ice Sheet (GrIS) from laser altimetry measurements spanning the period 1993-2012, partitioned into changes due to surface mass balance (SMB) and ice dynamics. We estimate a mean annual GrIS mass loss of 243 ± 18 Gt ⋅ y(-1), equivalent to 0.68 mm ⋅ y(-1) sea level rise (SLR) for 2003-2009. Dynamic thinning contributed 48%, with the largest rates occurring in 2004-2006, followed by a gradual decrease balanced by accelerating SMB loss. The spatial pattern of dynamic mass loss changed over this time as dynamic thinning rapidly decreased in southeast Greenland but slowly increased in the southwest, north, and northeast regions. Most outlet glaciers have been thinning during the last two decades, interrupted by episodes of decreasing thinning or even thickening. Dynamics of the major outlet glaciers dominated the mass loss from larger drainage basins, and simultaneous changes over distances up to 500 km are detected, indicating climate control. However, the intricate spatiotemporal pattern of dynamic thickness change suggests that, regardless of the forcing responsible for initial glacier acceleration and thinning, the response of individual glaciers is modulated by local conditions. Recent projections of dynamic contributions from the entire GrIS to SLR have been based on the extrapolation of four major outlet glaciers. Considering the observed complexity, we question how well these four glaciers represent all of Greenland's outlet glaciers.

  19. Unusual radar echoes from the Greenland ice sheet

    NASA Technical Reports Server (NTRS)

    Rignot, E. J.; Vanzyl, J. J.; Ostro, S. J.; Jezek, K. C.

    1993-01-01

    In June 1991, the NASA/Jet Propulsion Laboratory airborne synthetic-aperture radar (AIRSAR) instrument collected the first calibrated data set of multifrequency, polarimetric, radar observations of the Greenland ice sheet. At the time of the AIRSAR overflight, ground teams recorded the snow and firn (old snow) stratigraphy, grain size, density, and temperature at ice camps in three of the four snow zones identified by glaciologists to characterize four different degrees of summer melting of the Greenland ice sheet. The four snow zones are: (1) the dry-snow zone, at high elevation, where melting rarely occurs; (2) the percolation zone, where summer melting generates water that percolates down through the cold, porous, dry snow and then refreezes in place to form massive layers and pipes of solid ice; (3) the soaked-snow zone where melting saturates the snow with liquid water and forms standing lakes; and (4) the ablation zone, at the lowest elevations, where melting is vigorous enough to remove the seasonal snow cover and ablate the glacier ice. There is interest in mapping the spatial extent and temporal variability of these different snow zones repeatedly by using remote sensing techniques. The objectives of the 1991 experiment were to study changes in radar scattering properties across the different melting zones of the Greenland ice sheet, and relate the radar properties of the ice sheet to the snow and firn physical properties via relevant scattering mechanisms. Here, we present an analysis of the unusual radar echoes measured from the percolation zone.

  20. Greenland Ice Sheet flow response to runoff variability

    NASA Astrophysics Data System (ADS)

    Stevens, Laura A.; Behn, Mark D.; Das, Sarah B.; Joughin, Ian; Noël, Brice P. Y.; Broeke, Michiel R.; Herring, Thomas

    2016-11-01

    We use observations of ice sheet surface motion from a Global Positioning System network operating from 2006 to 2014 around North Lake in west Greenland to investigate the dynamical response of the Greenland Ice Sheet's ablation area to interannual variability in surface melting. We find no statistically significant relationship between runoff season characteristics and ice flow velocities within a given year or season. Over the 7 year time series, annual velocities at North Lake decrease at an average rate of -0.9 ± 1.1 m yr-2, consistent with the negative trend in annual velocities observed in neighboring regions over recent decades. We find that net runoff integrated over several preceding years has a negative correlation with annual velocities, similar to findings from the two other available decadal records of ice velocity in western Greenland. However, we argue that this correlation is not necessarily evidence for a direct hydrologic mechanism acting on the timescale of multiple years but could be a statistical construct. Finally, we stress that neither the decadal slowdown trend nor the negative correlation between velocity and integrated runoff is predicted by current ice-sheet models, underscoring that these models do not yet capture all the relevant feedbacks between runoff and ice dynamics needed to predict long-term trends in ice sheet flow.

  1. The diel cycle of water vapor in west Greenland

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We present a study of the dynamics of small-scale (~100 km) atmospheric circulation in west Greenland which is dominated by interactions of marine and continental air masses. Water vapor concentration and isotopic ratios measured continuously over a 25 day period in Kangerlussuaq, Greenland were used to monitor the convergence of easterly katabatic winds and westerly sea breezes that form a front between the dry, isotopically depleted, glacial air mass and the moist, isotopically enriched, marine air mass. During the latter 16 days of the measurement period, an interval with no large-scale synoptic interference, the inland penetration of the sea breeze controlled the largest day-to-day humidity and vapor isotopic variations. Kangerlussuaq experienced sea breezes in the afternoon on 9 days, consistent with the long-term average of such occurrences on 56% of days in July and August. The inland position of the sea breeze front is controlled by the katabatic wind strength, which is stronger during times of reduced cloud coverage and/or higher-pressure gradient between the coast and the Greenland ice sheet. The position and movement of the front will likely respond to changes in the general atmospheric circulation and regional radiation balance resulting from global warming, which will, in turn, impact the local hydrological cycle and ecosystem processes.

  2. Radar attenuation and temperature within the Greenland Ice Sheet

    USGS Publications Warehouse

    MacGregor, Joseph A; Li, Jilu; Paden, John D; Catania, Ginny A; Clow, Gary D.; Fahnestock, Mark A; Gogineni, Prasad S.; Grimm, Robert E.; Morlighem, Mathieu; Nandi, Soumyaroop; Seroussi, Helene; Stillman, David E

    2015-01-01

    The flow of ice is temperature-dependent, but direct measurements of englacial temperature are sparse. The dielectric attenuation of radio waves through ice is also temperature-dependent, and radar sounding of ice sheets is sensitive to this attenuation. Here we estimate depth-averaged radar-attenuation rates within the Greenland Ice Sheet from airborne radar-sounding data and its associated radiostratigraphy. Using existing empirical relationships between temperature, chemistry, and radar attenuation, we then infer the depth-averaged englacial temperature. The dated radiostratigraphy permits a correction for the confounding effect of spatially varying ice chemistry. Where radar transects intersect boreholes, radar-inferred temperature is consistently higher than that measured directly. We attribute this discrepancy to the poorly recognized frequency dependence of the radar-attenuation rate and correct for this effect empirically, resulting in a robust relationship between radar-inferred and borehole-measured depth-averaged temperature. Radar-inferred englacial temperature is often lower than modern surface temperature and that of a steady state ice-sheet model, particularly in southern Greenland. This pattern suggests that past changes in surface boundary conditions (temperature and accumulation rate) affect the ice sheet's present temperature structure over a much larger area than previously recognized. This radar-inferred temperature structure provides a new constraint for thermomechanical models of the Greenland Ice Sheet.

  3. Continental ice in Greenland during the Eocene and Oligocene.

    PubMed

    Eldrett, James S; Harding, Ian C; Wilson, Paul A; Butler, Emily; Roberts, Andrew P

    2007-03-08

    The Eocene and Oligocene epochs (approximately 55 to 23 million years ago) comprise a critical phase in Earth history. An array of geological records supported by climate modelling indicates a profound shift in global climate during this interval, from a state that was largely free of polar ice caps to one in which ice sheets on Antarctica approached their modern size. However, the early glaciation history of the Northern Hemisphere is a subject of controversy. Here we report stratigraphically extensive ice-rafted debris, including macroscopic dropstones, in late Eocene to early Oligocene sediments from the Norwegian-Greenland Sea that were deposited between about 38 and 30 million years ago. Our data indicate sediment rafting by glacial ice, rather than sea ice, and point to East Greenland as the likely source. Records of this type from one site alone cannot be used to determine the extent of ice involved. However, our data suggest the existence of (at least) isolated glaciers on Greenland about 20 million years earlier than previously documented, at a time when temperatures and atmospheric carbon dioxide concentrations were substantially higher.

  4. Investigations of The Stable Boundary Layer At Summit, Greenland

    NASA Astrophysics Data System (ADS)

    Ohmura, A.

    The investigation of the exchange processes in the stable atmospheric boundary layer has been hampered by lack of clean experimental data and by the separate treatment of radiative transfer and the turbulent heat transport. An experimental site was chosen at Summit, Greenland which is the highest point in the middle of the Greenland ice sheet. The site is located in the permanently dry snow zone the Greenland. The site is horizontal and very homogeneous with almost unlimited fetch. The atmospheric profiles both for the conventional scalar values and vertical fluxes are measured with a 50 m meteorological tower. The tower is also equipped by three radiation stations; one at the ground, the other at 50 m level; and the third mounted on a vertically mo- bile elevator to measure the divergence. A sensitive micro-barometer is installed at the foot of the tower for the observation of the pressure fluctuations which are caused by internal waves. The tower experiments are augmented by a wind-profiler and ra- diosonde observations to reach higher altitudes. Considerations on a length-scale as well as dimensionless gradients in a stable boundary layer will be presented. The site at Summit offers a very wide range of stability. In addition of extremely stable strat- ification at night and in winter as envisaged, extremely strong instability is found to prevail between 10 and 15 O'clock local time in summer, as net radiation at Summit turns strongly positive.

  5. NGRIP methane record and its relation to Greenland temperature

    NASA Astrophysics Data System (ADS)

    Baumgartner, Matthias; Kindler, Philippe; Eicher, Olivier; Schilt, Adrian; Schwander, Jakob; Spahni, Renato; Capron, Emilie; Chappellaz, Jérôme; Landais, Amaelle; Leuenberger, Markus; Fischer, Hubertus; Stocker, Thomas F.

    2013-04-01

    During the last glacial cycle, Greenland temperature showed many rapid temperature variations, the so called Dansgaard-Oeschger (DO) events. The past atmospheric methane concentration closely follows these temperature variations, which implies that the warmings recorded in Greenland were probably hemispheric in extent. Here, we present 931 new methane measurements along the North Greenland Ice Core Project (NGRIP) ice core. We therefore substantially extend and complete the NGRIP methane record from Termination 1 back to the end of the last interglacial period in high resolution. We relate the amplitudes of the methane increases associated with DO events to the amplitudes of the temperature increases derived from stable nitrogen isotope (δ15N) measurements, which have been performed along the same ice core (see poster by P. Kindler). We find the sensitivity to oscillate between 5 and 20 ppbv/°C with the approximate frequency of the precessional cycle. A remarkable high sensitivity of 26 ppbv/°C is reached during Termination 1. Conservative analysis of the timing of the fast methane and temperature increases reveals significant lags of the methane increases for the DO events 5, 9, 10, 11, 13, and 15.

  6. Microarray-based identification of differentially expressed genes in families of turbot (Scophthalmus maximus) after infection with viral haemorrhagic septicaemia virus (VHSV).

    PubMed

    Díaz-Rosales, P; Romero, A; Balseiro, P; Dios, S; Novoa, B; Figueras, A

    2012-10-01

    Viral haemorrhagic septicaemia virus (VHSV) is one of the major threats to the development of the aquaculture industry worldwide. The present study was aimed to identify genes differentially expressed in several turbot (Scophthalmus maximus) families showing different mortality rates after VHSV. The expression analysis was conducted through genome-wide expression profiling with an oligo-microarray in the head kidney. A significant proportion of the variation in the gene expression profiles seemed to be explained by the genetic background, indicating that the mechanisms by which particular species and/or populations can resist a pathogen(s) are complex and multifactorial. Before the experimental infections, fish from resistant families (low mortality rates after VHSV infection) showed high expression of different antimicrobial peptides, suggesting that their pre-immune state may be stronger than fish of susceptible families (high mortality rates after VHSV infection). After infection, fish from both high- and low-mortality families showed an up-modulation of the interferon-induced Mx2 gene, the IL-8 gene and the VHSV-induced protein 5 gene compared with control groups. Low levels of several molecules secreted in the mucus were observed in high-mortality families, but different genes involved in viral entrance into target cells were down-regulated in low-mortality families. Moreover, these families also showed a strong down-modulation of marker genes related to VHSV target organs, including biochemical markers of renal dysfunction and myocardial injury. In general, the expression of different genes involved in the metabolism of sugars, lipids and proteins were decreased in both low- and high-mortality families after infection. The present study serves as an initial screen for genes of interest and provides an extensive overview of the genetic basis underlying the differences between families that are resistant or susceptible to VHSV infection.

  7. Crustal structure of Bristol Bay Region, Alaska

    SciTech Connect

    Cooper, A.K.; McLean, H.; Marlow, M.S.

    1985-04-01

    Bristol Bay lies along the northern side of the Alaska Peninsula and extends nearly 600 km southwest from the Nushagak lowlands on the Alaska mainland to near Unimak Island. The bay is underlain by a sediment-filled crustal downwarp known as the north Aleutian basin (formerly Bristol basin) that dips southeast toward the Alaska Peninsula and is filled with more than 6 km of strata, dominantly of Cenozoic age. The thickest parts of the basin lie just north of the Alaska Peninsula and, near Port Mollar, are in fault contact with older Mesozoic sedimentary rocks. These Mesozoic rocks form the southern structural boundary of the basin and extend as an accurate belt from at least Cook Inlet to Zhemchug Canyon (central Beringian margin). Offshore multichannel seismic-reflection, sonobuoy seismic-refraction, gravity, and magnetic data collected by the USGS in 1976 and 1982 indicate that the bedrock beneath the central and northern parts of the basin comprises layered, high-velocity, and highly magnetic rocks that are locally deformed. The deep bedrock horizons may be Mesozoic(.) sedimentary units that are underlain by igneous or metamorphic rocks and may correlate with similar rocks of mainland western Alaska and the Alaska Peninsula. Regional structural and geophysical trends for these deep horizons change from northeast-southwest to northwest-southeast beneath the inner Bering shelf and may indicate a major crustal suture along the northern basin edge.

  8. Reconnaissance for radioactive deposits in Alaska, 1953

    USGS Publications Warehouse

    Matzko, John J.; Bates, Robert G.

    1955-01-01

    During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska where carnotite-type minerals had been reported; in the headwaters of the Peace River in the eastern part of the Seward Peninsula and at Gold Bench on the South Fork of the Koyukuk River in east-central Alaska, where uranothorianite occurs in places associated with base metal sulfides and hematite; in the vicinity of Port Malmesbury in southeastern Alaska to check a reported occurrence of pitchblende; and, in the Miller House-Circle Hot Springs area of east-central Alaska where geochemical studies were made. No significant lode deposits of radioactive materials were found. However, the placer uranothorianite in the headwaters of the Peace River yet remains as an important lead to bedrock radioactive source materials in Alaska. Tundra cover prevents satisfactory radiometric reconnaissance of the area, and methods of geochemical prospecting such as soil and vegetation sampling may ultimately prove more fruitful in the search for the uranothorianite-sulfide lode source than geophysical methods.

  9. Geologic Map of Central (Interior) Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Dover, James H.; Bradley, Dwight C.; Weber, Florence R.; Bundtzen, Thomas K.; Haeussler, Peter J.

    1998-01-01

    Introduction: This map and associated digital databases are the result of a compilation and reinterpretation of published and unpublished 1:250,000- and limited 1:125,000- and 1:63,360-scale mapping. The map area covers approximately 416,000 sq km (134,000 sq mi) and encompasses 25 1:250,000-scale quadrangles in central Alaska. The compilation was done as part of the U.S. Geological Survey National Surveys and Analysis project, whose goal is nationwide assemble geologic, geochemical, geophysical, and other data. This map is an early product of an effort that will eventually encompass all of Alaska, and is the result of an agreement with the Alaska Department of Natural Resources, Division of Oil And Gas, to provide data on interior basins in Alaska. A paper version of the three map sheets has been published as USGS Open-File Report 98-133. Two geophysical maps that cover the identical area have been published earlier: 'Bouguer gravity map of Interior Alaska' (Meyer and others, 1996); and 'Merged aeromagnetic map of Interior Alaska' (Meyer and Saltus, 1995). These two publications are supplied in the 'geophys' directory of this report.

  10. The future of successful aging in Alaska

    PubMed Central

    Lewis, Jordan

    2013-01-01

    Background There is a paucity of research on Alaska Natives and their views on whether or not they believe they will age successfully in their home and community. There is limited understanding of aging experiences across generations. Objective This research explores the concept of successful aging from an urban Alaska Native perspective and explores whether or not they believe they will achieve a healthy older age. Design A cultural consensus model (CCM) approach was used to gain a sense of the cultural understandings of aging among young Alaska Natives aged 50 years and younger. Results Research findings indicate that aging successfully is making the conscious decision to live a clean and healthy life, abstaining from drugs and alcohol, but some of Alaska Natives do not feel they will age well due to lifestyle factors. Alaska Natives see the inability to age well as primarily due to the decrease in physical activity, lack of availability of subsistence foods and activities, and the difficulty of living a balanced life in urban settings. Conclusions This research seeks to inform future studies on successful aging that incorporates the experiences and wisdom of Alaska Natives in hopes of developing an awareness of the importance of practicing a healthy lifestyle and developing guidelines to assist others to age well. PMID:23984300

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

    SciTech Connect

    Mernild, Sebastian Haugard; Hasholt, Bent

    2009-01-01

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

  12. Systems Performance Analyses of Alaska Wind-Diesel Projects; Selawik, Alaska (Fact Sheet)

    SciTech Connect

    Baring-Gould, I.

    2009-04-01

    This fact sheet summarizes a systems performance analysis of the wind-diesel project in Selawik, Alaska. Data provided for this project include community load data, wind turbine output, diesel plant output, thermal load data, average wind speed, average net capacity factor, optimal net capacity factor based on Alaska Energy Authority wind data, average net wind penetration, and estimated fuel savings.

  13. 2011 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Maharrey, J. Zebulon; Neal, Christina A.

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near three separate volcanic centers in Alaska during 2011. The year was highlighted by the unrest and eruption of Cleveland Volcano in the central Aleutian Islands. AVO annual summaries no longer report on activity at Russian volcanoes.

  14. 78 FR 73144 - Subsistence Management Program for Public Lands in Alaska; Western Interior Alaska Federal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ... Subsistence Management Program for Public Lands in Alaska; Western Interior Alaska Federal Subsistence... purpose of the Council is to provide recommendations and information to the Federal Subsistence Board, to review policies and management plans, and to provide a public forum for subsistence issues. DATES:...

  15. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife Service... Wildlife Service, are reopening the public comment period on our proposed rule to establish migratory...

  16. 77 FR 2972 - City and Borough of Sitka, Alaska, Alaska; Notice of Availability of Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission City and Borough of Sitka, Alaska, Alaska; Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory Commission's (Commission...

  17. Building Alaska's Science and Engineering Pipeline: Evaluation of the Alaska Native Science & Engineering Program

    ERIC Educational Resources Information Center

    Bernstein, Hamutal; Martin, Carlos; Eyster, Lauren; Anderson, Theresa; Owen, Stephanie; Martin-Caughey, Amanda

    2015-01-01

    The Urban Institute conducted an implementation and participant-outcomes evaluation of the Alaska Native Science & Engineering Program (ANSEP). ANSEP is a multi-stage initiative designed to prepare and support Alaska Native students from middle school through graduate school to succeed in science, technology, engineering, and math (STEM)…

  18. Alaska Native Languages: Past, Present, and Future. Alaska Native Language Center Research Papers No. 4.

    ERIC Educational Resources Information Center

    Krauss, Michael E.

    Three papers (1978-80) written for the non-linguistic public about Alaska Native languages are combined here. The first is an introduction to the prehistory, history, present status, and future prospects of all Alaska Native languages, both Eskimo-Aleut and Athabaskan Indian. The second and third, presented as appendixes to the first, deal in…

  19. Trophic ecology of introduced populations of Alaska blackfish (Dallia pectoralis) in the Cook Inlet Basin, Alaska.

    PubMed

    Eidam, Dona M; von Hippel, Frank A; Carlson, Matthew L; Lassuy, Dennis R; López, J Andrés

    2016-07-01

    Introduced non-native fishes have the potential to substantially alter aquatic ecology in the introduced range through competition and predation. The Alaska blackfish (Dallia pectoralis) is a freshwater fish endemic to Chukotka and Alaska north of the Alaska Range (Beringia); the species was introduced outside of its native range to the Cook Inlet Basin of Alaska in the 1950s, where it has since become widespread. Here we characterize the diet of Alaska blackfish at three Cook Inlet Basin sites, including a lake, a stream, and a wetland. We analyze stomach plus esophageal contents to assess potential impacts on native species via competition or predation. Alaska blackfish in the Cook Inlet Basin consume a wide range of prey, with major prey consisting of epiphytic/benthic dipteran larvae, gastropods, and ostracods. Diets of the introduced populations of Alaska blackfish are similar in composition to those of native juvenile salmonids and stickleback. Thus, Alaska blackfish may affect native fish populations via competition. Fish ranked third in prey importance for both lake and stream blackfish diets but were of minor importance for wetland blackfish.

  20. Alaska public health law reform.

    PubMed

    Meier, Benjamin Mason; Hodge, James G; Gebbie, Kristine M

    2008-04-01

    The Turning Point Model State Public Health Act (Turning Point Act), published in September 2003, provides a comprehensive template for states seeking public health law modernization. This case study examines the political and policy efforts undertaken in Alaska following the development of the Turning Point Act. It is the first in a series of case studies to assess states' consideration of the Turning Point Act for the purpose of public health law reform. Through a comparative analysis of these case studies and ongoing legislative tracking in all fifty states, researchers can assess (1) how states codify the Turning Point Act into state law and (2) how these modernized state laws influence or change public health practice, leading to improved health outcomes.

  1. Late-Holocene Fluctuations of the Greenland Ice Sheet: Insights from a south Greenland threshold lake

    NASA Astrophysics Data System (ADS)

    Sinclair, G.; Carlson, A. E.; Reilly, B.

    2015-12-01

    Several centennial-scale climate fluctuations during the late-Holocene make it an ideal test case for examining the effects of climate change on sea level at societally-relevant timescales. Across much of the Arctic, glaciers and ice sheets reached their maximum late-Holocene extent during the Little Ice Age (LIA, 1400-1900 C.E.), approximately coincident with the global temperature minima observed during this time. However, ongoing work suggests the south Greenland Ice Sheet (sGrIS) may have behaved differently during the late-Holocene, with several outlet glaciers retreating, rather than advancing, during the LIA, possibly due to regional warming in the region different from the Arctic trend. The Qassimiut lobe, a low-lying piedmont-like extension of the sGrIS, may be especially sensitive to late-Holocene climate changes. Geomorphic evidence outboard of Naujaat Sermia, an outlet glacier draining the Qassimiut lobe, suggests three distinct periods of land exposure. We hypothesize these occurred during the last deglacial period, after an advance from near or behind the present margin during the Neoglacial, and during warming following the Little Ice Age in the last 1-2 centuries. Here, we present data from threshold lake cores immediately outboard of the presumed Neoglacial moraine. A sharp contact divides glacial sands and silts from organic gyttja, indicating glacial retreat from the moraine and subsequent meltwater diversion. The contact is accompanied by several geochemical changes, including increased Fe/Ti ratios, increased Br, and decreased Si and K, indicating a switch from more clastic to organic sedimentation. Radiocarbon ages from eight macrofossils immediately above this contact are calibrated to 1350-1950 C.E., suggesting the ice sheet may have retreated from its late-Holocene maximum during the Little Ice Age, but the wide range in ages suggests reworking of organic material may be significant in this region.

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

    PubMed

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

    2014-10-15

    The Greenland shark Somniosus microcephalus is an opportunistic feeder, a top predator, and a very long-lived species. The brain, liver, red and white muscle, gonads, fat, skin, pancreas, and spleen of Greenland sharks from NE Greenland fjords were analysed for PCBs, PCDDs/DFs, PBDEs; DDT isomers; HCH isomers; dieldrin; endrin; HCB; Cd, Hg, Pb, and Se. PCBs (2.01-103 ng/g wet wt) and PBDEs (7.9-3050 pg/g wet wt) were detected in most of the samples. PCDDs/DFs showed high values when detected. DDTs, HCB and HCHs were only detected in some tissues. The ΣTEQ was 5.76 pg/g in muscle. Cadmium mainly accumulated in the pancreas and liver (19.6 and 10.7 mg/kg dry wt, respectively); mercury in red muscle (4.10-6.91 mg/kg dry wt); selenium in the pancreas (3.57 mg/kg dry wt) and spleen (1.95 mg/kg dry wt); lead in the skin (0.358 mg/kgd ry wt). The selenium-mercury ratio in the liver was also evaluated.

  3. Has dynamic thinning switched off in south-east Greenland?

    NASA Astrophysics Data System (ADS)

    Murray, T.; Scharrer, K.; James, T.; Luckman, A.; Selmes, N.; Cook, S.; Hughes, A.; Cordero Llana, L.; Booth, A.; McGovern, J.; Rutt, I.

    2008-12-01

    Following a relatively stable period during the 1990s, dramatic changes have been reported for many tidewater outlets in SE Greenland. Some of the most important results come from measurements using the GRACE (Gravity Recovery and Climate Experiment) mission (1, 2). These data clearly identified the SE of the Greenland Ice Sheet (GrIS) as having the highest rates of mass loss. Two of the major outlet glaciers in this area, Helheim and Kangerdlugssuaq accelerated by about 100% and 40%, respectively, and their calving fronts retreated by several km (3, 4). Retreat and acceleration occurred in two phases during summer 2003 and 2005 at Helheim, and in a single period between late 2004 and early 2005 at Kangerdlugssuaq. Further south, widespread glacier acceleration between 1996 and 2005 affected most of the outlet glaciers, and Greenland's mass loss doubled in the period (5). Increased discharge due to thinning in the marginal areas, coupled to rapid changes in ice dynamics and synchronous retreat of calving front positions, led to speculations that the GrIS had crossed a "tipping point" induced by global warming. However, subsequent studies in summer 2006 showed that Helheim and Kangerdlugssuaq had simultaneously slowed down again and thinning stopped (6). In summer 2007, we collected lidar data over Helheim and Kangerdlugssuaq flown by the NERC Airborne Research and Survey Facility. Data collected were single swaths over mountain areas, as well as centerline profiles. In cooperation with NASA Goddard Space Flight Center, we conducted a similar but extended campaign in 2008, collecting lidar and radar data for the 16 largest outlet glaciers in SE Greenland, targeting the full extent of the major GRACE anomaly. We used lidar swaths from bedrock as ground-control for extracting DEMs from ASTER satellite images covering the period with major changes in 2004 to 2006, and compared them to lidar and SPOT 5 DEMs to produce the most recent volume change and velocity estimates

  4. Has dynamic thinning switched off in south-east Greenland?

    NASA Astrophysics Data System (ADS)

    Murray, T.; Scharrer, K.; James, T. D.; Dye, S. R.; Hanna, E.; Booth, A. D.; Selmes, N.; Luckman, A.; Hughes, A. L. C.; Huybrechts, P.

    2009-04-01

    Following a relatively stable period during the 1990's, dramatic changes have been reported for many tidewater outlets in the south-eastern part of the Greenland Ice Sheet (GrIS). Results from measurements using the GRACE (Gravity Recovery and Climate Experiment) mission clearly identified the south-eastern part of the GrIS as having the highest rates of mass loss (1, 2). Two of the major outlet glaciers in this area, Helheim and Kangerdlugssuaq, accelerated by about 100 percent and 40 percent, respectively, and their calving fronts retreated by several km (3). Retreat and acceleration occurred in two phases during summer 2003 and 2005 at Helheim, and in a single period between late 2004 and early 2005 at Kangerdlugssuaq. Further south widespread glacier acceleration between 1996 and 2005 affected most of the outlet glaciers (4). In all Greenland's mass loss was calculated to have doubled in the period (4). Increased discharge due to thinning in the marginal areas, coupled to rapid changes in ice dynamics and synchronous retreat of their calving front positions, led to speculations that the GrIS had crossed a "tipping point" induced by global warming. However, subsequent studies showed that during summer 2006 Helheim and Kangerlugssuaq had simultaneously slowed down and their thinning had stopped. Because variability in the ice sheet's mass loss results mostly from the SE Greenland sector, further understanding of the nature, distribution, and controls of dynamic change in this region is essential. In order to examine the extent of the dynamic changes and to identify their cause we used satellite data to measure glacier surface elevation and calving front positions of 24 outlets of 14 major tidewater terminating glaciers, as well as speeds of 9 outlets in SE Greenland. We concentrate on the region where the GRACE data show highest rates of mass change and our data cover the period during and after the cessation of fast flow and thinning at Helheim and

  5. Holocene history of North Ice Cap, northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Corbett, L. B.; Kelly, M. A.; Osterberg, E. C.; Axford, Y.; Bigl, M.; Roy, E. P.; Thompson, J. T.

    2013-12-01

    Although much research has focused on the past extents of the Greenland Ice Sheet, less is known about the smaller ice caps on Greenland and how they have evolved over time. These small ice caps respond sensitively to summer temperatures and, to a lesser extent, winter precipitation, and provide valuable information about climatic conditions along the Greenland Ice Sheet margins. Here, we investigate the Holocene history of North Ice Cap (76°55'N 68°00'W), located in the Nunatarssuaq region near Thule, northwest Greenland. Our results are based on glacial geomorphic mapping, 10Be dating, and analyses of sediment cores from a glacially fed lake. Fresh, unweathered and unvegetated boulders comprise moraines and drift that mark an extent of North Ice Cap ~25 m outboard of the present ice margin. It is likely that these deposits were formed during late Holocene time and we are currently employing 10Be surface exposure dating to examine this hypothesis. Just outboard of the fresh moraines and drift, boulders and bedrock show significant weathering and are covered with lichen. Based on glacial geomorphic mapping and detailed site investigations, including stone counts, we suggest that the weathered boulders and bedrock were once covered by erosive Greenland Ice Sheet flow from southeast to northwest over the Nunatarssuaq region. Five 10Be ages from the more weathered landscape only 100-200 m outboard of the modern North Ice Cap margin are 52 and 53 ka (bedrock) and 16, 23, and 31 ka (boulders). These ages indicate that recent ice cover has likely been cold-based and non-erosive, failing to remove inherited cosmogenic nuclides from previous periods of exposure, although the youngest boulder may provide a maximum limiting deglaciation age. Sediment cores collected from Delta Sø, a glacially-fed lake ~1.5 km outside of the modern North Ice Cap margin, contain 130 cm of finely laminated sediments overlying coarse sands and glacial till. Radiocarbon ages from just above

  6. The Alaska resource data files: Mount Katmai (MK) quadrangle

    USGS Publications Warehouse

    Wilson, Frederic H.; Church, Stanley E.; Bickerstaff, Damon P.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Mount Katmai 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  7. Glaciers of North America - Glaciers of Alaska

    USGS Publications Warehouse

    Molnia, Bruce F.

    2008-01-01

    Glaciers cover about 75,000 km2 of Alaska, about 5 percent of the State. The glaciers are situated on 11 mountain ranges, 1 large island, an island chain, and 1 archipelago and range in elevation from more than 6,000 m to below sea level. Alaska's glaciers extend geographically from the far southeast at lat 55 deg 19'N., long 130 deg 05'W., about 100 kilometers east of Ketchikan, to the far southwest at Kiska Island at lat 52 deg 05'N., long 177 deg 35'E., in the Aleutian Islands, and as far north as lat 69 deg 20'N., long 143 deg 45'W., in the Brooks Range. During the 'Little Ice Age', Alaska's glaciers expanded significantly. The total area and volume of glaciers in Alaska continue to decrease, as they have been doing since the 18th century. Of the 153 1:250,000-scale topographic maps that cover the State of Alaska, 63 sheets show glaciers. Although the number of extant glaciers has never been systematically counted and is thus unknown, the total probably is greater than 100,000. Only about 600 glaciers (about 1 percent) have been officially named by the U.S. Board on Geographic Names (BGN). There are about 60 active and former tidewater glaciers in Alaska. Within the glacierized mountain ranges of southeastern Alaska and western Canada, 205 glaciers (75 percent in Alaska) have a history of surging. In the same region, at least 53 present and 7 former large ice-dammed lakes have produced jokulhlaups (glacier-outburst floods). Ice-capped volcanoes on mainland Alaska and in the Aleutian Islands have a potential for jokulhlaups caused by subglacier volcanic and geothermal activity. Because of the size of the area covered by glaciers and the lack of large-scale maps of the glacierized areas, satellite imagery and other satellite remote-sensing data are the only practical means of monitoring regional changes in the area and volume of Alaska's glaciers in response to short- and long-term changes in the maritime and continental climates of the State. A review of the

  8. Alaska

    Atmospheric Science Data Center

    2014-05-15

    ... help to darken the room lights when viewing the image on a computer screen. The Yukon River is seen wending its way from upper left to ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

  9. Levels and temporal trends of HCH isomers in ringed seals from West and East Greenland.

    PubMed

    Rigét, Frank; Vorkamp, Katrin; Dietz, Rune; Muir, Derek C G

    2008-08-01

    Levels and temporal trends of the hexachlorocyclohexane isomers alpha-, beta- and gamma-HCH were analysed in blubber of juvenile ringed seals from West Greenland (1994 to 2006) and juvenile and adult ringed seals from East Greenland (1986 to 2006). No significant differences in the concentration levels in the juvenile seals were found between East and West Greenland for any of the three isomers. alpha-HCH concentrations were not significantly different between juvenile and adult ringed seals from East Greenland, whereas beta- and gamma-HCH concentrations were significantly higher in adult ringed seals. alpha- and beta-HCH in Greenland ringed seals were approximately a factor two lower than in the Canadian Arctic, and alpha-HCH was a factor 2-3 higher than in ringed seals from an area east of Svalbard, Norway. Annual decreases in ringed seals from Greenland during the study periods were detected to be 9.1-11.7%, 1.4-3.9% and 6.0-6.4% for alpha-, beta- and gamma-HCH, respectively, being quite similar in both East and West Greenland. Similar levels and trends in East and West Greenland support the general understanding of the pathways of HCH isomers to and in the Arctic.

  10. Addressing Systemic Oppression in Greenland's Preschools: The Adaptation of a Coaching Model

    ERIC Educational Resources Information Center

    Wyatt, Tasha R.; Lyberth, Naussunguaq

    2011-01-01

    For most of the last two centuries, Native Greenlandic teachers had been left out of the decision-making process regarding effective education for Greenlandic students. Rather, Danish education and church officials, living in Denmark, made important pedagogical and curricular decisions with little to no input from local teachers (Jakobsen, 1999).…

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  13. L3 English Acquisition in Denmark and Greenland: Gender-Related Tendencies

    ERIC Educational Resources Information Center

    Spellerberg, Stine Marie

    2011-01-01

    This paper presents findings of gender-related tendencies found in a study of factors influential in third language acquisition of English in Denmark and Greenland. A survey consisting of a questionnaire and an English test was carried out amongst pupils in their last year of compulsory schooling in Copenhagen, Denmark, and Nuuk, Greenland. In…

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

    PubMed

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

    2012-03-23

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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. 77 FR 13683 - Alaska Federal Lands Long Range Transportation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Federal Highway Administration Alaska Federal Lands Long Range Transportation Plan AGENCY: Federal Highway..., announced the availability of the draft Alaska Federal Lands Long Range Transportation Plans (LRTP) for... Alaska Federal Lands draft Long Range Transportation Plans. The draft Plans are available on our...

  17. Alaska Native Population and Manpower: 1975. A Report.

    ERIC Educational Resources Information Center

    Bland, Laurel L.

    Numbering approximately 62,005 and representing 15.3% of the total Alaska population in 1975, Alaska Natives are a finite and predominately rural subpopulation. However, a significant portion of the Alaska Native Work Force (estimated at 13,854) now resides in the major urban areas and is available to the Statewide Work Force. Statistics from May,…

  18. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  19. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  20. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...