Science.gov

Sample records for alaska northern rockfish

  1. 75 FR 38937 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish and Pelagic Shelf Rockfish...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ...NMFS is prohibiting directed fishing for northern rockfish and pelagic shelf rockfish (PSR) for trawl catcher vessels participating in the entry level rockfish fishery in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent exceeding the 2010 allocation of northern rockfish and PSR allocated to trawl catcher vessels participating in the entry level......

  2. 76 FR 54716 - Fisheries of the Exclusive Economic Zone off Alaska; Northern Rockfish, Pacific Ocean Perch, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... Economic Zone off Alaska; Northern Rockfish, Pacific Ocean Perch, and Pelagic Shelf Rockfish for Vessels... prohibiting directed fishing for northern rockfish, Pacific ocean perch, and pelagic shelf rockfish for... northern rockfish, Pacific ocean perch, and pelagic shelf rockfish allocated to vessels participating...

  3. 75 FR 53875 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish for Vessels Participating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ...NMFS is prohibiting directed fishing for northern rockfish for vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent exceeding the 2010 total allowable catch (TAC) of northern rockfish allocated to vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the......

  4. 75 FR 38938 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and Pelagic Shelf Rockfish for Catcher... northern rockfish, Pacific ocean perch, and pelagic shelf rockfish for catcher vessels participating in the... necessary to prevent exceeding the 2010 total allowable catch (TAC) of northern rockfish, Pacific...

  5. 76 FR 39793 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Economic Zone Off Alaska; Northern Rockfish, Pacific Ocean Perch, and Pelagic Shelf Rockfish for Catcher... northern rockfish, Pacific ocean perch, and pelagic shelf rockfish for catcher vessels participating in the... necessary to prevent exceeding the 2011 total allowable catch (TAC) of northern rockfish, Pacific...

  6. 76 FR 39792 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch, Northern Rockfish, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Economic Zone Off Alaska; Pacific Ocean Perch, Northern Rockfish, and Pelagic Shelf Rockfish in the Western...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch, northern rockfish, and... exceeding the ] 2011 sideboard limits of Pacific ocean perch, northern rockfish, and pelagic shelf...

  7. 76 FR 44283 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish for Catcher/Processors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... established by the final 2011 and 2012 harvest specifications for groundfish of the GOA (76 FR 11111, March 1... Economic Zone Off Alaska; Northern Rockfish for Catcher/Processors Participating in the Rockfish Limited...; closure. SUMMARY: NMFS is prohibiting directed fishing for northern rockfish by...

  8. 75 FR 42336 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish for Catcher/Processors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... established by the final 2010 and 2011 harvest specifications for groundfish of the GOA (75 FR 11749, March 12... Economic Zone Off Alaska; Northern Rockfish for Catcher/Processors Participating in the Rockfish Limited...; closure. SUMMARY: NMFS is prohibiting directed fishing for northern rockfish by...

  9. 77 FR 40816 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    ... GOA (77 FR 15194, March 14, 2012). In accordance with Sec. 679.20(d)(1)(i), the Administrator, Alaska... Economic Zone Off Alaska; Northern Rockfish in the Western Regulatory Area of the Gulf of Alaska AGENCY... the Western Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent...

  10. 77 FR 32037 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-31

    ... specifications for groundfish in the BSAI (77 FR 10669, February 23, 2012), NMFS closed the directed fishery for... Economic Zone Off Alaska; Northern Rockfish in the Bering Sea and Aleutian Islands Management Area AGENCY... RIN 0648-XC052 in the keyword search. Locate the document you wish to comment on from the...

  11. 78 FR 35572 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-13

    ... the BSAI (78 FR 13813, March 1, 2013), NMFS closed the directed fishery for northern rockfish under... anonymous). Attachments to electronic comments will be accepted in Microsoft Word or Excel, WordPerfect, or... use the 2013 total allowable catch (TAC) of northern rockfish in the BSAI. DATES: Effective 1200...

  12. 76 FR 39789 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish and Pelagic Shelf Rockfish...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... 2012 harvest specifications for groundfish in the GOA (76 FR 11111, March 1, 2011). Consequently, in accordance with Sec. 679.83(a)(3), the Administrator, Alaska Region, NMFS, deems it appropriate for.... ACTION: Temporary rule; closure. SUMMARY: NMFS deems it appropriate to not open directed fishing...

  13. 78 FR 42024 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish and Dusky Rockfish in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ... Regulatory Area of the GOA under Sec. 679.20(d)(1)(iii) on July 3, 2013 (78 FR 40638 July 8, 2013). As of...). Attachments to electronic comments will be accepted in Microsoft Word or Excel, WordPerfect, or Adobe PDF file..., Alaska local time (A.l.t.), July 10, 2013, through 1200 hrs, A.l.t., July 12, 2013. Comments must...

  14. 75 FR 39638 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... (75 FR 11749, March 12, 2010) and as posted as the 2010 Rockfish Program Catcher/Processor Sideboards... catcher/processors participating in the limited access or opt-out fisheries that are subject to sideboard... rockfish established for catcher/processors participating in the limited access or opt-out fisheries in...

  15. 75 FR 53874 - Fisheries of the Exclusive Economic Zone Off Alaska; Pelagic Shelf Rockfish for Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ...NMFS is prohibiting directed fishing for pelagic shelf rockfish for vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary to prevent exceeding the 2010 total allowable catch (TAC) of pelagic shelf rockfish allocated to vessels participating in the rockfish entry level fishery in the Central Regulatory Area......

  16. 76 FR 43934 - Fisheries of the Exclusive Economic Zone Off Alaska; Pelagic Shelf Rockfish for Catcher...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... of the GOA (76 FR 11111, March 1, 2011), and as posted as the 2011 Rockfish Program Allocations at... Economic Zone Off Alaska; Pelagic Shelf Rockfish for Catcher/Processors Participating in the Rockfish.../processors participating in the rockfish limited access fishery in the Central Regulatory Area of the Gulf...

  17. 75 FR 39861 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... GOA (75 FR 11749, March 12, 2010). In accordance with Sec. 679.20(d)(1)(i), the Administrator, Alaska... fishery. The Assistant Administrator for Fisheries, NOAA (AA), finds good cause to waive the requirement... comment because the most recent, relevant data only became available as of July 7, 2010. The AA also...

  18. 76 FR 45217 - Fisheries of the Exclusive Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program; Amendment 88 AGENCY: National Marine... submitted Amendment 88 to the Fishery Management Plan for Groundfish of the Gulf of Alaska (FMP) for review... gains realized under the Rockfish Pilot Program and viability of the Gulf of Alaska fisheries....

  19. 77 FR 72995 - Fisheries of the Exclusive Economic Zone Off Alaska; Other Flatfish, Other Rockfish, Pacific...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ... Economic Zone Off Alaska; Other Flatfish, Other Rockfish, Pacific Ocean Perch, Sculpin, and Squid in the... initial total allowable catch of Bering Sea Pacific ocean perch, Aleutian Islands other rockfish, Bering.... The 2012 initial total allowable catch (ITAC) of Bering Sea (BS) Pacific ocean perch in the BSAI...

  20. 76 FR 40836 - Fisheries of the Exclusive Economic Zone Off Alaska; Pelagic Shelf Rockfish by Vessels Subject to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ... GOA (76 FR 11111, March 1, 2011). In accordance with Sec. 679.20(d)(1)(v)(A), the Administrator... Economic Zone Off Alaska; Pelagic Shelf Rockfish by Vessels Subject to Amendment 80 Sideboard Limits in the... prohibiting directed fishing for pelagic shelf rockfish (PSR) by Amendment 80 vessels subject to...

  1. Composition of Heads and Livers of Yelloweye Rockfish (Sebastes ruberrimus) Harvested in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to their large size and fillet quality, yelloweye rockfish (YER) are a highly prized species in both commercial and recreational Alaska fisheries. Processing yields for YER are relatively low, thus by-product volume is significant at up to 77% of whole fish weight (WFW). The objective of this re...

  2. Bathymetric-based habitat model for yelloweye rockfish (Sebastes ruberrimus) on Alaska's outer Kenai Peninsula

    NASA Astrophysics Data System (ADS)

    Mumm, Joshua D.

    Motivated primarily as part of a habitat-based stock assessment, we explored the feasibility of modeling yelloweye rockfish (Sebastes ruberrimus) habitat in Southcentral Alaska using high-resolution multibeam bathymetry. A generalized linear model was developed with bathymetrically derived terrain metrics (rugosity, slope, bathymetric position index, and distance-to-rock) as predictor variables. The model was parameterized and validated using remotely operated vehicle observations. When evaluated for the Chiswell Island training area, the model correctly classified 96.0% (n = 100) of a reserved set of presence/absence validation points (Cohen's Kappa = 0.92; AUC = 0.98). When evaluated for the independent Nuka Island testing area, the overall accuracy was 82.5% (n=332; Kappa = 0.65; AUC = 0.95). This study demonstrates that suitable yelloweye habitat can be modeled with reasonable accuracy using high-resolution multibeam bathymetry, and such a model is fairly portable among sites along the Kenai Peninsula's outer coast.

  3. Radiocarbon in otoliths of yelloweye rockfish (Sebastes ruberrimus): a reference time series for the coastal waters of southeast Alaska

    SciTech Connect

    Kerr-Ferrey, L A; Andrews, A H; Frantz, B R; Coale, K H; Brown, T A; Cailliet, G M

    2003-10-14

    Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the environment that has provided a useful tracer and chronological marker in oceanic systems and organisms. The bomb-generated {sup 14}C signal retained in fish otoliths can be used as a permanent, time-specific recorder of the 14C present in ambient seawater, making it a useful tool in age validation of fishes. The goal of this study was to determine {sup 14}C levels in otoliths of the age-validated yelloweye rockfish (Sebastes ruberrimus) to establish a reference time series for the coastal waters of southeast Alaska. Radiocarbon values from the first year's growth of 43 yelloweye rockfish otoliths were plotted against estimated birth year to produce a 14C time series for these waters spanning 1940 to 1990. The time series shows the initial rise of bomb 14C occurred in 1958 in coastal southeast Alaskan waters and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values (60-70%) between 1966 and 1971, with a subsequent declining trend through the end of the record in 1990 (-3.2%). In addition, the radiocarbon data, independent of the radiometric study, confirms the longevity of the yelloweye rockfish up to a minimum of 44 years and strongly supports higher age estimates. The yelloweye rockfish record provides a {sup 14}C chronology that will be useful for the interpretation of {sup 14}C accreted in biological samples from these waters and in future rockfish age validation studies.

  4. Retrospective analysis: bile hydrocarbons and histopathology of demersal rockfish in Prince William Sound, Alaska, after the Exxon Valdez oil spill.

    PubMed

    Marty, Gary D; Hoffmann, Andy; Okihiro, Mark S; Hepler, Kelly; Hanes, David

    2003-12-01

    Demersal rockfish are the only fish species that have been found dead in significant numbers after major oil spills, but the link between oil exposure and effect has not been well established. After the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska, several species of rockfish (Sebastes spp.) from oiled and reference sites were analyzed for hydrocarbon metabolites in bile (1989-1991) and for microscopic lesions (1990 and 1991). Biliary hydrocarbons consistent with exposure to Exxon Valdez oil were elevated in 1989, but not in 1990 or 1991. Significant microscopic findings included pigmented macrophage aggregates and hepatic megalocytosis, fibrosis, and lipid accumulation. Site differences in microscopic findings were significant with respect to previous oil exposure in 1991 (P=0.038), but not in 1990. However, differences in microscopic findings were highly significant with respect to age and species in both years (P<0.001). We conclude that demersal rockfish were exposed to Exxon Valdez oil in 1989, but differences in microscopic changes in 1990 and 1991 were related more to age and species differences than to previous oil exposure. PMID:12927739

  5. 50 CFR 679.82 - Rockfish Program use caps and sideboard limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... fishing in the Western GOA and West Yakutat District for northern rockfish, Pacific ocean perch, and... rockfish, Pacific ocean perch, and pelagic shelf rockfish by that vessel is deducted from the Federal TAC... directed fishing for northern rockfish, Pacific ocean perch, and pelagic shelf rockfish in the Western...

  6. 50 CFR 679.82 - Rockfish Program use caps and sideboard limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... fishing in the Western GOA and West Yakutat District for northern rockfish, Pacific ocean perch, and... rockfish, Pacific ocean perch, and pelagic shelf rockfish by that vessel is deducted from the Federal TAC... directed fishing for northern rockfish, Pacific ocean perch, and pelagic shelf rockfish in the Western...

  7. 75 FR 39639 - Fisheries of the Exclusive Economic Zone Off Alaska; Pelagic Shelf Rockfish in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... groundfish of the GOA (75 FR 11749, March 12, 2010) and as posted as the 2010 Rockfish Program Catcher... rockfish by catcher/processors participating in the limited access or opt-out fisheries that are subject to... pelagic shelf rockfish established for catcher/processors participating in the limited access or...

  8. Chemical composition of black rockfish (Sebastes melanops) fillets and byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black rockfish are important in the near shore fishery of Southeast Alaska. They are the only species among the pelagic shelf rockfishes for which there is a directed fishery in state waters. The purpose of this study was to determine the composition black rockfish fillets and its major processing b...

  9. Enzymatic Digestion of Eye and Brain Tissues of Sockeye and Coho Salmon, and Dusky Rockfish Commercially Harvested in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potential feed ingredients with high lipid content were made by enzymatic digestion followed by centrifugation of eye tissue from dusky rockfish (Sebastes ciliatos), coho salmon (Oncorhynchus kisutch), and sockeye salmon (Oncorhynchus nerka) and brain tissue from sockeye salmon. Materials with high ...

  10. 76 FR 53840 - Fisheries of the Exclusive Economic Zone Off Alaska; Other Rockfish, Other Flatfish, Sharks, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... specifications for groundfish of the BSAI (76 FR 11139, March 1, 2011). In accordance with Sec. 679.20(a)(3) the... FR 11139, March 1, 2011). The harvest specification for the 2011 AI other rockfish, BSAI other..., respectively. This apportionment is consistent with Sec. 679.20(b)(1)(i) and does not result in overfishing...

  11. 76 FR 52301 - Fisheries of the Exclusive Economic Zone Off Alaska; Allocating Gulf of Alaska Fishery Resources...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ...NMFS will present two public workshops on the Central Gulf of Alaska Rockfish Program (Rockfish Program) for potentially eligible participants and other interested parties. At each workshop, NMFS will provide an overview of the proposed Rockfish Program, discuss the key differences between the Rockfish Program and the Rockfish Pilot Program, provide information on the proposed rule comment......

  12. 50 CFR 679.83 - Rockfish Program entry level longline fishery.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Rockfish Program entry level longline... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Rockfish Program § 679.83 Rockfish Program entry level longline fishery....

  13. 50 CFR 679.83 - Rockfish Program entry level longline fishery.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Rockfish Program entry level longline... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Rockfish Program § 679.83 Rockfish Program entry level longline fishery....

  14. 50 CFR Table 28c to Part 679 - Allocation of Rockfish Secondary Species

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Allocation of Rockfish Secondary Species... ZONE OFF ALASKA Pt. 679, Table 28c Table 28c to Part 679—Allocation of Rockfish Secondary Species For the following rockfish secondary species . . . The following percentage of the Central GOA TAC...

  15. 50 CFR Table 28c to Part 679 - Allocation of Rockfish Secondary Species

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Allocation of Rockfish Secondary Species... ZONE OFF ALASKA Pt. 679, Table 28c Table 28c to Part 679—Allocation of Rockfish Secondary Species For the following rockfish secondary species . . . The following percentage of the Central GOA TAC...

  16. 50 CFR Table 28c to Part 679 - Allocation of Rockfish Secondary Species

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Allocation of Rockfish Secondary Species... ZONE OFF ALASKA Pt. 679, Table 28c Table 28c to Part 679—Allocation of Rockfish Secondary Species For the following rockfish secondary species . . . The following percentage of the Central GOA TAC...

  17. 50 CFR 679.80 - Initial allocation of rockfish QS.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Initial allocation of rockfish QS. 679.80 Section 679.80 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Rockfish Program § 679.80...

  18. Alaska Humans Factors Safety Study: The Northern Area

    NASA Technical Reports Server (NTRS)

    Connell, Linda; Reynard, William (Technical Monitor)

    1995-01-01

    At the request of the Alaska Air Carriers Association, researchers from the NASA Aviation Safety Reporting System, at NASA Ames Research Center, conducted a study on aspects of safety in Alaskan Part 135 air taxi operations. An interview form on human factors safety issues was created by a representative team from the FAA-Alaska, NTSB-Alaska, NASAASRS, and representatives of the Alaska Air Carriers Association which was subsequently used in the interviews of pilots and managers. Because of the climate and operational differences, the study was broken into two geographical areas, the southern coastal areas and the northern portion of the state. This presentation addresses the northern area, specifically: Bethel, Fairbanks, Nome, Kotzebue, and Barrow. The interview questions dealt with many of the potential pressures on pilots and managers associated with the daily air taxi operations in Alaska. The impact of the environmental factors such as the lack of available communication, navigation and weather information systems was evaluated. The results of this study will be used by government and industry working in Alaska. These findings will contribute important information on specific Alaska safety issues for eventual incorporation into training materials and policies that will help to assure the safe conduct of air taxi flights in Alaska.

  19. 77 FR 40305 - Fisheries of the Exclusive Economic Zone Off Alaska; Pelagic Shelf Rockfish in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-09

    ... GOA (77 FR 15194, March 14, 2012). In accordance with Sec. 679.20(d)(1)(i), the Administrator, Alaska... from the fishery. The acting Assistant Administrator for Fisheries, NOAA (AA), finds good cause to... became available as of June 29, 2012. ] The AA also finds good cause to waive the 30-day delay in...

  20. 77 FR 2478 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 88

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 88 Correction Sec. 679.81 In rule... requirements? submit an annual rockfish cooperative report to NMFS by December 15 of that year. See Sec. 679.5... report the annual rockfish must include at a minimum: cooperative report? (A) The rockfish...

  1. 50 CFR Table 28e to Part 679 - Rockfish Entry Level Longline Fishery Allocations

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Rockfish Entry Level Longline Fishery... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28e Table 28e to Part 679—Rockfish Entry Level Longline...

  2. 50 CFR Table 28e to Part 679 - Rockfish Entry Level Longline Fishery Allocations

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Rockfish Entry Level Longline Fishery... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28e Table 28e to Part 679—Rockfish Entry Level Longline...

  3. 50 CFR 679.82 - Rockfish Program use caps and sideboard limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Rockfish Program use caps and sideboard limits. 679.82 Section 679.82 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Rockfish Program §...

  4. Mortality of arctic fox pups in northern Alaska

    SciTech Connect

    Not Available

    1982-01-01

    Reports of mortality among arctic foxes, Alopex lagopus, generally consist of isolated incidents of predation by bald eagles, Haliaeetus leucocephalus, snowy owls, Nyctea scandiaca, red foxes, Vulpes vulpes, and dogs, Canis familiaris. This is a report of observations made on mortality of arctic fox pups observed at dens in the Prudhoe Bay and Colville River Delta areas of northern Alaska during summers of 1975 to 1978 and 1976 to 1979, respectively.

  5. Subsurface Tectonics and Pingos of Northern Alaska

    NASA Astrophysics Data System (ADS)

    Skirvin, S.; Casavant, R.; Burr, D.

    2008-12-01

    We describe preliminary results of a two-phase study that investigated links between subsurface structural and stratigraphic controls, and distribution of hydrostatic pingos on the central coastal plain of Arctic Alaska. Our 2300 km2 study area is underlain by a complete petroleum system that supports gas, oil and water production from 3 of the largest oil fields in North America. In addition, gas hydrate deposits exist in this area within and just below the permafrost interval at depths of 600 to 1800 feet below sea level. Phase 1 of the study compared locations of subsurface faults and pingos for evidence of linkages between faulting and pingo genesis and distribution. Several hundred discrete fault features were digitized from published data and georeferenced in a GIS database. Fault types were determined by geometry and sense of slip derived from well log and seismic maps. More than 200 pingos and surface sediment type associated with their locations were digitized from regional surficial geology maps within an area that included wire line and seismic data coverage. Beneath the pingos lies an assemblage of high-angle normal and transtensional faults that trend NNE and NW; subsidiary trends are EW and NNW. Quaternary fault reactivation is evidenced by faults that displaced strata at depths exceeding 3000 meters below sea level and intersect near-surface units. Unpublished seismic images and cross-section analysis support this interpretation. Kinematics and distribution of reactivated faults are linked to polyphase deformational history of the region that includes Mesozoic rift events, succeeded by crustal shortening and uplift of the Brooks Range to the south, and differential subsidence and segmentation of a related foreland basin margin beneath the study area. Upward fluid migration, a normal process in basin formation and fault reactivation, may play yet unrecognized roles in the genesis (e.g. fluid charging) of pingos and groundwater hydrology. Preliminary

  6. Future distribution of tundra refugia in northern Alaska

    USGS Publications Warehouse

    Hope, Andrew G.; Waltari, Eric; Payer, David C.; Cook, Joseph A.; Talbot, Sandra L.

    2013-01-01

    Climate change in the Arctic is a growing concern for natural resource conservation and management as a result of accelerated warming and associated shifts in the distribution and abundance of northern species. We introduce a predictive framework for assessing the future extent of Arctic tundra and boreal biomes in northern Alaska. We use geo-referenced museum specimens to predict the velocity of distributional change into the next century and compare predicted tundra refugial areas with current land-use. The reliability of predicted distributions, including differences between fundamental and realized niches, for two groups of species is strengthened by fossils and genetic signatures of demographic shifts. Evolutionary responses to environmental change through the late Quaternary are generally consistent with past distribution models. Predicted future refugia overlap managed areas and indicate potential hotspots for tundra diversity. To effectively assess future refugia, variable responses among closely related species to climate change warrants careful consideration of both evolutionary and ecological histories.

  7. Evaluation of the stability of gas hydrates in Northern Alaska

    USGS Publications Warehouse

    Kamath, A.; Godbole, S.P.; Ostermann, R.D.; Collett, T.S.

    1987-01-01

    The factors which control the distribution of in situ gas hydrate deposits in colder regions such as Northern Alaska include; mean annual surface temperatures (MAST), geothermal gradients above and below the base of permafrost, subsurface pressures, gas composition, pore-fluid salinity and the soil condition. Currently existing data on the above parameters for the forty-six wells located in Northern Alaska were critically examined and used in calculations of depths and thicknesses of gas hydrate stability zones. To illustrate the effect of gas hydrate stability zones, calculations were done for a variable gas composition using the thermodynamic model of Holder and John (1982). The hydrostatic pressure gradient of 9.84 kPa/m (0.435 lbf/in2ft), the salinity of 10 parts per thousand (ppt) and the coarse-grained soil conditions were assumed. An error analysis was performed for the above parameters and the effect of these parameters on hydrate stability zone calculations were determined. After projecting the hydrate stability zones for the forty-six wells, well logs were used to identify and to obtain values for the depth and thickness of hydrate zones. Of the forty-six wells, only ten wells showed definite evidence of the presence of gas hydrates. ?? 1987.

  8. Eliminating the "divergence problem" at Alaska's northern treeline

    NASA Astrophysics Data System (ADS)

    Wilmking, M.; Singh, J.

    2008-06-01

    Recently, an increasing off-set between tree-ring based temperature reconstructions and measured temperatures at high latitudes has been reported, the so called "divergence problem" (here "divergence effect"). This "divergence effect" seriously questions the validity of tree-ring based climate reconstructions, since it seems to violate the assumption of a stable response of trees to changing climate over time. In this study we eliminated the "divergence effect" in northern Alaska by careful selection of individual trees with consistently significant positive relationships with climate (17% of sample) and successfully attempted a divergence-free climate reconstruction using this sub-set. However, the majority of trees (83%) did not adhere to the uniformitarian principle as usually applied in dendroclimatology. Our results thus support the notion, that factors acting on an individual tree basis are the primary causes for the "divergence effect" (at least in northern Alaska). Neither different detrending methods nor factors acting on larger scales such as global dimming or an increase in UV-B radiation could explain our results. Our results also highlight the necessity to adapt the methods of paleoreconstruction using tree rings to account for non-stable climate growth relationships as these are found in the vast majority of sampled trees and seem to be the norm rather than the exception.

  9. Observing a catastrophic thermokarst lake drainage in northern Alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Arp, Christopher D.

    2015-01-01

    The formation and drainage of thermokarst lakes have reshaped ice-rich permafrost lowlands in the Arctic throughout the Holocene. North of Teshekpuk Lake, on the Arctic Coastal Plain of northern Alaska, thermokarst lakes presently occupy 22.5% of the landscape, and drained thermokarst lake basins occupy 61.8%. Analysis of remotely sensed imagery indicates that nine lakes (>10 ha) have drained in the 1,750 km2 study area between 1955 and 2014. The most recent lake drainage was observed using in situ data loggers providing information on the duration and magnitude of the event, and a nearby weather station provided information on the environmental conditions preceding the lake drainage. Lake 195 (L195), an 80 ha thermokarst lake with an estimated water volume of ~872,000 m3, catastrophically drained on 05 July 2014. Abundant winter snowfall and heavy early summer precipitation resulted in elevated lake water levels that likely promoted bank overtopping, thermo-erosion along an ice-wedge network, and formation of a 9 m wide, 2 m deep, and 70 m long drainage gully. The lake emptied in 36 hours, with 75% of the water volume loss occurring in the first ten hours. The observed peak discharge of the resultant flood was 25 m3/s, which is similar to that in northern Alaska river basins whose areas are more than two orders of magnitude larger. Our findings support the catastrophic nature of sudden lake drainage events and the mechanistic hypotheses developed by J. Ross Mackay.

  10. Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon

    SciTech Connect

    Kerr, L A; Andrews, A H; Munk, K; Coale, K H; Frantz, B R; Cailliet, G M; Brown, T A

    2005-01-05

    Rockfishes (Sebastes spp.) support one of the most economically important fisheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated {sup 14}C signal by emphasizing the utility of the time-specific marker created by the initial rise of bomb-{sup 14}C. Second, the bomb-generated {sup 14}C signal retained in fish otoliths was used to validate the age and age estimation methodology of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year's growth of quillback rockfish otoliths were plotted against estimated birth year producing a {sup 14}C time series spanning 1950 to 1985. The initial rise of bomb-{sup 14}C from pre-bomb levels ({approx} -90 {per_thousand}) occurred in 1959 {+-} 1 year and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values in 1967 (+105.4 {per_thousand}), with a subsequent declining trend through the end of the record in 1985 (+15.4 {per_thousand}). The agreement between the year of initial rise of {sup 14}C levels from the quillback rockfish record and the chronometer determined for the waters of southeast Alaska from yelloweye rockfish (S. ruberrimus) otoliths validated the ageing methodology for the quillback rockfish. The concordance of the entire quillback rockfish {sup 14}C record with the yelloweye rockfish time series demonstrated the effectiveness of this age validation technique, confirmed the longevity of the quillback rockfish up to a minimum of 43 years, and strongly supports higher age estimates of up to 90 years.

  11. Breeding ecology of Spectacled Eiders Somateria fischeri in Northern Alaska

    USGS Publications Warehouse

    Bart, J.; Earnst, S.L.

    2005-01-01

    Spectacled Eiders Somateria fischeri were studied on the Colville River delta during 1994-1999, prior to oil field development, to document aspects of breeding biology that are poorly known, especially for northern-nesting populations. Both sexes arrived June 6-12; many males remained for only about 10 days. Density on the 178-km2 study area was 0.48 birds/km 2, comparable to densities reported from extensive surveys in western Alaska and Russia. Wetlands with numerous islands and peninsulas were utilised prior to incubation, a little-studied period. Females spent considerably more time feeding than males (56% vs. 18%). Males travelled, rested and were alert more than females, and actively defended females from intruding males. Whole nest survival was 31% and varied substantially between years, as has been demonstrated in other studies. Brood size showed no detectable decline from hatch about July 10 to mid-August, suggesting low mortality during this period, a sharp contrast with results from a study in a lead-contaminated area of western Alaska in which duckling survival to 30 days post-hatch was 34%. The likelihood of adverse impacts on this threatened species, from oil-related or other activities, can be reduced by industry avoiding areas, throughout the summer, with numerous islands, peninsulas and deep water. ?? Wildfowl & Wetlands Trust.

  12. Micropaleontology of selected wells and seismic shot holes, northern Alaska

    USGS Publications Warehouse

    Mickey, Michael B.; Haga, Hideyo; Bird, Kenneth J.

    2006-01-01

    This report provides micropaleontologic data (foraminifera, pollen, spores, and microplankton) and interpretations of the rocks penetrated by 49 wells and 3,134 seismic shot holes distributed among 73 seismic lines (figs. 1, 2; table 1). All shot holes and 30 wells are located within the National Petroleum Reserve in Alaska (NPRA); the remaining 19 wells are located adjacent to the NPRA. The biostratigraphic zonation scheme, stratigraphy, and geologic ages followed in this study are summarized in figure 3. This update brings paleontologic analyses performed at various times over several decades to a current, unified set of interpretations that benefit from the evolution of northern Alaska biostratigraphic understanding developed during the past 33-years by Mickey and Haga. For each well, paleontologic information includes microfossil distribution charts, data spreadsheets, diversity graphs, and interpretive reports describing age and environments of deposition. Three biostratigraphic well-correlation sections that relate Chukchi Sea wells to onshore northwestern NPRA wells are also included. For all analyzed seismic shot hole samples, foraminiferal age and environmental interpretations are provided; palynological interpretations are provided only for those shot hole samples collected and analyzed after 1976, a little less than half of the total number of samples.

  13. Heavy-mineral analysis of sedimentary rocks of northern Alaska

    USGS Publications Warehouse

    Morris, Robert Hamilton

    1952-01-01

    The Navy Oil Unit of the United States Geological Survey has been investigating the geology of Naval Petroleum Reserve No. 4, northern Alaska. As part of this program, heavy-mineral samples were prepared from cores of the test wells and core holes and studied to determine stratigraphic correlations. Using the following criteria: (1) presence of diagnostic minerals or mineral suites; (2) relative abundance of specific minerals; (3) degree of rounding of mineral grains; (4) distinction as to grain form; eight heavy-mineral zones have been recognized in Triassic, Jurassic, Cretaceous, and Quaternary sedimentary rocks. Correlations based on these zones are shown. Source areas and rocks are discussed in relation to geologic history and genesis of the Mesozoic and Quaternary sedimentary rocks.

  14. Construction guidelines for oil and gas exploration in northern Alaska

    SciTech Connect

    Crory, F.E.

    1991-11-01

    This report addresses the unique problems associated with oil and gas explorations in northern Alaska and provides background information on the climate and environment, including the permanently frozen ground that exists throughout the area. Information on exploration efforts in the 1940s and 1950s is also included to demonstrate what happens when summertime operations disturb the surface vegetation and thermal regime of the frozen tundra, being the basis for why such operations are no longer permitted. Separate chapters are provided on the design, construction and operation of winter trails, roads, airfields and drill pads, including a separate chapter on their abandonment. Emphasis is placed on how, why and when to accomplish the various tasks to successfully accomplish an exploration.

  15. Mortality of arctic fox pups in northern Alaska

    SciTech Connect

    Garrott, R.A.; Eberhardt, L.E.

    1982-01-01

    Reports of mortality among arctic foxes, Alopex lagopus, generally consist of isolated incidents of predation by bald eagles, Haliaeetus leucocephalus, snowy owls, Nyctea scandiaca, red foxes, Vulpes vulpes, and dogs, Canis familiaris. This is a report of observations made on mortality of arctic fox pups observed at dens in the Prudhoe Bay and Colville River Delta areas of northern Alaska during summers of 1975 to 1978 and 1976 to 1979, respectively. Pup mortality was noted amng 15 (19%) of 79 families whose dens we visited. Evidence of at least 20 dead pups was found with remains ranging from intact carcasses to a few bone fragments and tufts of hair. Undoubtedly, researchers failed to detect some dead pups, as predators sometimes carry small pups away from the den before consuming them and adult foxes were observed to dispose of bodies of dead pups within den burrows.

  16. 78 FR 40638 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ... GOA (78 FR 13162, February 26, 2013). In accordance with Sec. 679.20(d)(1)(i), the Administrator... from the fishery. The acting Assistant Administrator for Fisheries, NOAA (AA), finds good cause to... available as of July 1, 2013. The AA also finds good cause to waive the 30-day delay in the effective...

  17. 78 FR 44033 - Fisheries of the Exclusive Economic Zone Off Alaska; Northern Rockfish in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... groundfish of the GOA (78 FR 13162, February 26, 2013). In accordance with Sec. 679.20(d)(2), the... recently obtained from the fishery. The Acting Assistant Administrator for Fisheries, NOAA (AA), finds good... available as of July 17, 2013. The AA also finds good cause to waive the 30-day delay in the effective...

  18. Introduced northern pike predation on salmonids in southcentral Alaska

    USGS Publications Warehouse

    Sepulveda, Adam J.; Rutz, David S.; Ivey, Sam S.; Dunker, Kristine J.; Gross, Jackson A.

    2013-01-01

    Northern pike (Esox lucius) are opportunistic predators that can switch to alternative prey species after preferred prey have declined. This trophic adaptability allows invasive pike to have negative effects on aquatic food webs. In Southcentral Alaska, invasive pike are a substantial concern because they have spread to important spawning and rearing habitat for salmonids and are hypothesised to be responsible for recent salmonid declines. We described the relative importance of salmonids and other prey species to pike diets in the Deshka River and Alexander Creek in Southcentral Alaska. Salmonids were once abundant in both rivers, but they are now rare in Alexander Creek. In the Deshka River, we found that juvenile Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) dominated pike diets and that small pike consumed more of these salmonids than large pike. In Alexander Creek, pike diets reflected the distribution of spawning salmonids, which decrease with distance upstream. Although salmonids dominated pike diets in the lowest reach of the stream, Arctic lamprey (Lampetra camtschatica) and slimy sculpin (Cottus cognatus) dominated pike diets in the middle and upper reaches. In both rivers, pike density did not influence diet and pike consumed smaller prey items than predicted by their gape-width. Our data suggest that (1) juvenile salmonids are a dominant prey item for pike, (2) small pike are the primary consumers of juvenile salmonids and (3) pike consume other native fish species when juvenile salmonids are less abundant. Implications of this trophic adaptability are that invasive pike can continue to increase while driving multiple species to low abundance.

  19. Regional Fluid Flow and Basin Modeling in Northern Alaska

    USGS Publications Warehouse

    Kelley, Karen D., (Edited By)

    2007-01-01

    INTRODUCTION The foothills of the Brooks Range contain an enormous accumulation of zinc (Zn) in the form of zinc sulfide and barium (Ba) in the form of barite in Carboniferous shale, chert, and mudstone. Most of the resources and reserves of Zn occur in the Red Dog deposit and others in the Red Dog district; these resources and reserves surpass those of most deposits worldwide in terms of size and grade. In addition to zinc and lead sulfides (which contain silver, Ag) and barite, correlative strata host phosphate deposits. Furthermore, prolific hydrocarbon source rocks of Carboniferous and Triassic to Early Jurassic age generated considerable amounts of petroleum that may have contributed to the world-class petroleum resources of the North Slope. Deposits of Zn-Pb-Ag or barite as large as those in the Brooks Range are very rare on a global basis and, accordingly, multiple coincident favorable factors must be invoked to explain their origins. To improve our understanding of these factors and to contribute to more effective assessments of resources in sedimentary basins of northern Alaska and throughout the world, the Mineral Resources Program and the Energy Resources Program of the U.S. Geological Survey (USGS) initiated a project that was aimed at understanding the petroleum maturation and mineralization history of parts of the Brooks Range that were previously poorly characterized. The project, titled ?Regional Fluid Flow and Basin Modeling in Northern Alaska,? was undertaken in collaboration with industry, academia, and other government agencies. This Circular contains papers that describe the results of the recently completed project. The studies that are highlighted in these papers have led to a better understanding of the following: *The complex sedimentary facies relationships and depositional settings and the geochemistry of the sedimentary rocks that host the deposits (sections 2 and 3). *The factors responsible for formation of the barite and zinc deposits

  20. Isotropic Thaw Subsidence in Natural Landscapes of Northern Alaska

    NASA Astrophysics Data System (ADS)

    Shiklomanov, N. I.; Streletskiy, D. A.; Nelson, F. E.; Little, J.

    2013-12-01

    Recent research documents warming of permafrost, increased emissions of greenhouse gases in permafrost regions, and damage to civil infrastructure induced by melting of ground ice. Particular attention has been focused on 'thermokarst terrain,' localized systems of irregular pits, mounds, and ponds caused by differential subsidence accompanying thaw of ice-rich permafrost. Development of thermokarst terrain is often triggered by discrete, geographically constrained disturbance of vegetative cover or hydrological patterns. Here, we describe landscape-scale, thaw-induced subsidence in northern Alaska lacking the topographic contrasts associated with thermokarst terrain. Observations in some regions of the Arctic reveal little correlation between increasing air temperature and active-layer thickness (ALT) above permafrost in undisturbed terrain. The apparent stability of ALT in many Arctic landscapes may, however, be illusory if thaw penetrates into an ice-rich layer underlying the long-term base of the active layer. The apparent stability in ALT is attributable to the presence in many permafrost regions of an ice-rich 'transition layer' that resists thaw owing to the large amounts of latent heat involved in melting it. During warm summers, this layer protects underlying permafrost from thaw and creates nonlinearities in the response of the permafrost system to climatic forcing. We sought to determine whether widespread, relatively homogeneous, decadal-scale thaw subsidence, possibly attributable to climatic change, is occurring in natural, undisturbed landscapes and, if so, to estimate its magnitude and evaluate its role in the response of permafrost to atmospheric forcing. Field investigations designed to track interannual vertical movements associated with formation and ablation of ice near the permafrost table were begun in the summer of 2001 and continued annually at two 1 ha Circumpolar Active Layer Monitoring (CALM) sites representative of landscapes in the

  1. Introduced northern pike consumption of salmonids in Southcentral Alaska

    USGS Publications Warehouse

    Sepulveda, Adam J.; Rutz, David S.; Dupuis, Aaron W; Shields, Patrick A; Dunker, Kristine J.

    2015-01-01

    The impacts of introduced northern pike (Esox lucius) on salmonid populations have attracted much attention because salmonids are popular subsistence, sport and commercial fish. Concern over the predatory effects of introduced pike on salmonids is especially high in Southcentral Alaska, where pike were illegally introduced to the Susitna River basin in the 1950s. We used pike abundance, growth, and diet estimates and bioenergetics models to characterise the realised and potential consumptive impacts that introduced pike (age 2 and older) have on salmonids in Alexander Creek, a tributary to the Susitna River. We found that juvenile salmonids were the dominant prey item in pike diets and that pike could consume up to 1.10 metric tons (realised consumption) and 1.66 metric tons (potential consumption) of juvenile salmonids in a summer. Age 3–4 pike had the highest per capita consumption of juvenile salmonids, and age 2 and age 3–4 pike had the highest overall consumption of juvenile salmonid biomass. Using historical data on Chinook salmon and pike potential consumption of juvenile salmonids, we found that pike consumption of juvenile salmonids may lead to collapsed salmon stocks in Alexander Creek. Taken together, our results indicate that pike consume a substantial biomass of juvenile salmonids in Alexander Creek and that coexistence of pike and salmon is unlikely without management actions to reduce or eliminate introduced pike.

  2. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  3. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  4. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  5. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  6. 50 CFR Table 29 to Part 679 - Initial Rockfish QS Pools

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Initial Rockfish QS Pools 29 Table 29 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 29 Table 29 to Part...

  7. 40 CFR 81.246 - Northern Alaska Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northern Alaska Intrastate Air Quality Control Region. 81.246 Section 81.246 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... 1956 Election Districts 18-23, inclusive, as described in Article XIV, section 3 of the Constitution...

  8. Habitat characteristics of polar bear terrestrial maternal den sites in northern Alaska

    USGS Publications Warehouse

    Durner, G.M.; Amstrup, Steven C.; Fischbach, Anthony S.

    2003-01-01

    Polar bears (Ursus maritimus) give birth to and nurture their young in dens of ice and snow. During 1999-2001, we measured the structure of 22 dens on the coastal plain of northern Alaska after polar bear families had evacuated their dens in the spring. During the summers of 2001 and 2002, we revisited the sites of 42 maternal and autumn exploratory dens and recorded characteristics of the under-snow habitat. The structure of polar bear snow dens was highly variable. Most were simple chambers with a single entrance/egress tunnel. Others had multiple chambers and additional tunnels. Thickness of snow above and below dens was highly variable, but most dens were overlain by less than 1 m of snow. Dens were located on, or associated with, pronounced landscape features (primarily coastal and river banks, but also a lake shore and an abandoned oil field gravel pad) that are readily distinguished from the surrounding terrain in summer and catch snow in early winter. Although easily identified, den landforms in northern Alaska were more subtle than den habitats in many other parts of the Arctic. The structure of polar bear dens in Alaska was strikingly similar to that of dens elsewhere and has remained largely unchanged in northern Alaska for more than 25 years. Knowledge of den structure and site characteristics will allow resource managers to identify habitats with the greatest probability of holding dens. This information may assist resource managers in preventing negative impacts of mineral exploration and extraction on polar bears.

  9. Locally acquired disseminated histoplasmosis in a northern sea otter (Enhydra lutris kenyoni) in Alaska, USA.

    PubMed

    Burek-Huntington, Kathy A; Gill, Verena; Bradway, Daniel S

    2014-04-01

    Histoplasmosis of local origin has not been reported in humans or wildlife in Alaska, and the disease has never been reported in a free-ranging marine mammal. In 2005 a northern sea otter (Enhydra lutris kenyoni) was found on Kodiak Island, Alaska, at 57° latitude north, far outside the known distribution of Histoplasma capsulatum. The animal died of disseminated histoplasmosis. Microorganisms consistent with Histoplasma sp. were observed on histopathology, and H. capsulatum was identified by PCR and sequencing. We suggest migratory seabirds or aerosol transmission through prevailing winds may have resulted in transmission to the sea otter. PMID:24484503

  10. Bartonella spp. Exposure in Northern and Southern Sea Otters in Alaska and California

    PubMed Central

    Chomel, Bruno B.; Gill, Verena A.; Doroff, Angela M.; Miller, Melissa A.; Burek-Huntington, Kathleen A.; Kasten, Rickie W.; Byrne, Barbara A.; Goldstein, Tracey; Mazet, Jonna A.K.

    2014-01-01

    Abstract Since 2002, an increased number of northern sea otters (Enhydra lutris kenyoni) from southcentral Alaska have been reported to be dying due to endocarditis and/or septicemia with infection by Streptococcus infantarius subsp. coli. Bartonella spp. DNA was also detected in northern sea otters as part of mortality investigations during this unusual mortality event (UME) in Kachemak Bay, Alaska. To evaluate the extent of exposure to Bartonella spp. in sea otters, sera collected from necropsied and live-captured northern sea otters, as well as necropsied southern sea otters (Enhydra lutris nereis) unaffected by the UME, were analyzed using an immunofluorescent antibody assay. Antibodies against Bartonella spp. were detected in sera from 50% of necropsied and 34% of presumed healthy, live-captured northern sea otters and in 16% of necropsied southern sea otters. The majority of sea otters with reactive sera were seropositive for B. washoensis, with antibody titers ranging from 1:64 to 1:256. Bartonella spp. antibodies were especially common in adult northern sea otters, both free-living (49%) and necropsied (62%). Adult stranded northern sea otters that died from infectious causes, such as opportunistic bacterial infections, were 27 times more likely to be Bartonella seropositive than adult stranded northern sea otters that died from noninfectious causes (p<0.001; 95% confidence interval 2.62–269.4). Because Bartonella spp. antibodies were detected in necropsied northern sea otters from southcentral (44%) and southwestern (86%) stocks of Alaska, as well as in necropsied southern sea otters (16%) in southcentral California, we concluded that Bartonella spp. exposure is widely distributed among sea otter populations in the Eastern Pacific, providing context for investigating future disease outbreaks and monitoring of Bartonella infections for sea otter management and conservation. PMID:25514118

  11. Bartonella spp. exposure in northern and southern sea otters in Alaska and California.

    PubMed

    Carrasco, Sebastian E; Chomel, Bruno B; Gill, Verena A; Doroff, Angela M; Miller, Melissa A; Burek-Huntington, Kathleen A; Kasten, Rickie W; Byrne, Barbara A; Goldstein, Tracey; Mazet, Jonna A K

    2014-12-01

    Since 2002, an increased number of northern sea otters (Enhydra lutris kenyoni) from southcentral Alaska have been reported to be dying due to endocarditis and/or septicemia with infection by Streptococcus infantarius subsp. coli. Bartonella spp. DNA was also detected in northern sea otters as part of mortality investigations during this unusual mortality event (UME) in Kachemak Bay, Alaska. To evaluate the extent of exposure to Bartonella spp. in sea otters, sera collected from necropsied and live-captured northern sea otters, as well as necropsied southern sea otters (Enhydra lutris nereis) unaffected by the UME, were analyzed using an immunofluorescent antibody assay. Antibodies against Bartonella spp. were detected in sera from 50% of necropsied and 34% of presumed healthy, live-captured northern sea otters and in 16% of necropsied southern sea otters. The majority of sea otters with reactive sera were seropositive for B. washoensis, with antibody titers ranging from 1:64 to 1:256. Bartonella spp. antibodies were especially common in adult northern sea otters, both free-living (49%) and necropsied (62%). Adult stranded northern sea otters that died from infectious causes, such as opportunistic bacterial infections, were 27 times more likely to be Bartonella seropositive than adult stranded northern sea otters that died from noninfectious causes (p<0.001; 95% confidence interval 2.62-269.4). Because Bartonella spp. antibodies were detected in necropsied northern sea otters from southcentral (44%) and southwestern (86%) stocks of Alaska, as well as in necropsied southern sea otters (16%) in southcentral California, we concluded that Bartonella spp. exposure is widely distributed among sea otter populations in the Eastern Pacific, providing context for investigating future disease outbreaks and monitoring of Bartonella infections for sea otter management and conservation. PMID:25514118

  12. HEAVY METAL, ORGANOCHLORINE PESTICIDE AND POLYCHLORINATED BIPHENYL CONTAMINATION IN ARCTIC GROUND SQUIRRELS (SPERMOPHILUS PARRYI) IN NORTHERN ALASKA

    EPA Science Inventory

    Heavy metal and organochlorine (OC)concentrations, including organochlorine pesticides and polychlorinated biphenyl congeners (PCBs), were determined in arctic ground squirrels (Spermophilus parryi) from three sites in the Brooks Range of northern Alaska in 1991-93. Heavy metals ...

  13. Landscape Level Analyses of Vegetation Cover in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Botting, T.; Hollister, R. D.

    2013-12-01

    Many International Tundra Experiment (ITEX) studies have been conducted to identify vegetation changes due to warming. However, knowledge gaps remain. For example, most of these studies are conducted at the plot level, not the landscape level, potentially masking larger scale impacts of climate change. An Arctic Systems Science (ARCSS) grid was established in Atqasuk, Alaska and Barrow, Alaska in the mid 1990's. In 2010, approximately 100 untreated vegetation plots were implemented at each grid site. These vegetation plots are 1 meter squared, spaced 100 meters apart, and span 1 kilometer squared. Each vegetation plot represents 100 square meters along the grid. This project will focus on how vegetation cover has changed at the landscape level, using the point frame method, from 2010 to 2013. Preliminary data analysis indicates that in Atqasuk, graminoids, deciduous shrubs, and evergreen shrubs show increased cover, while little change has occurred with bryophytes, forbs and lichens. In Barrow, graminoids, lichens and forbs have shown an increase in cover, while little change has occurred with bryophytes and deciduous shrubs. At both sites, graminoids represent the greatest increase in cover of all growth forms analyzed. This study will be the foundation for later work, with the purpose of predicting what ARCSS grid vegetation community compositions will be in the future. These expectations will be based on anticipated warming data from ITEX passively warmed vegetation plots. This will be the first time that ITEX vegetation warming research is applied to landscape level research in Barrow and Atqasuk.

  14. Structure and petroleum potential of the Yakutat segment of the northern Gulf of Alaska continental margin

    SciTech Connect

    Bruns, T.R.

    1983-01-01

    This report discusses the structure, geologic history, and petroleum potential of the Yakutat segment, the part of the continental margin between Cross Sound and Icy Bay, northern Gulf of Alaska. As part of a program of geological and geophysical investigations of the continental margin in the northern Gulf of Alaska, the US Geological Survey collected multichannel seismic reflection data along about 2000 km of tracklines in the study area during 1975, 1977, and 1978. In addition, dredge samples from the continental slope were acquired during the 1977, 1978, and 1979 field seasons. The first part of this paper presents an interpretation of the seismic reflection and refraction data, including structure contour maps, isopach maps, and interpreted seismic sections; the second part is a discussion of the implications for petroleum potential. The primary area of interest is the continental shelf and slope, but some data from strata at the base of the slope are also included.

  15. Residence time and movements of postbreeding shorebirds on the northern coast of Alaska

    USGS Publications Warehouse

    Taylor, Audrey R.; Lanctot, Richard B.; Powell, A.N.; Kendall, S.J.; Nigro, Debora A.

    2011-01-01

    Relatively little is known about shorebird movements across the coast of northern Alaska, yet postbreeding shorebirds use this coastline extensively prior to fall migration. We deployed 346 radio transmitters on 153 breeding and 193 postbreeding shorebirds of five species from 2005 to 2007.We examined two hypotheses regarding postbreeding shorebirds' movements: (1) whether such movements reflect ultimate routes of southbound migration and (2) whether migration strategy (length of flights) or timing of molt in relation to migration (molt occurring in breeding or winter range) are more influential in determining postbreeding shorebirds' behavior. Semipalmated Sandpipers (Calidris pusilla) moved east, consistent with the direction of their ultimate migration, but patterns of other species' movements did not reflect ultimate migration direction. Timing of postnuptial molt appeared to have more influence over residence time and movements than did migration strategy. Postcapture residence time for the Semipalmated Sandpiper was less than for the Western Sandpiper (C. mauri) and significantly less than for Dunlin (C. alpina), and the Semipalmated Sandpiper's movements between were quicker and more frequent than those of the Dunlin. We expected to see the opposite patterns if migration strategy were more influential. Our data shed light on how different shorebird species use the northern Alaska coast after breeding: most species are likely to be stopping over at postbreeding areas, whereas the Dunlin and some Western Sandpipers may be staging. We suggest the coast of northern Alaska be viewed as an interconnected network of postbreeding sites that serve multiple populations of breeding shorebirds. ?? The Cooper Ornithological Society 2011.

  16. Dynamic ice-wallow relief of northern Alaska's nearshore.

    USGS Publications Warehouse

    Reimnitz, E.; Kempema, E.

    1982-01-01

    Contour maps with 0.5m depth interval were prepared for a small area seaward of Reindeer Island, a barrier island in the Beaufort Sea, Alaska, by repeated surveys with very accurate navigation and very close trackline spacing. The maps reveal numerous closed depressions and mounds, presumably related to grounded ice floes common in the area year round. These bedforms represent erosion and deposition caused by: a) intensified flow around stationary ice floes serving as obstacles and b) pulsating currents generated by vertical oscillations or rocking motions of grounded floes in a seaway. Because sediment transport occurs around the ice, not where it directly touches the sea floor, the depressions are much larger than the base of the acting floes. Ice-wallow bedforms, are characteristic of arctic nearshore regions with non-cohesive sediments. The bedforms studied here are highly active and must be considered in planning nearshore construction activities. -from Authors

  17. 50 CFR Table 28b to Part 679 - Qualifying Season Dates for Central GOA Rockfish Primary Species

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Qualifying Season Dates for Central GOA Rockfish Primary Species 28b Table 28b to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28b Table 28b to Part 679—Qualifying...

  18. 50 CFR Table 28 to Part 679 - Qualifying Season Dates in the Central GOA Primary Rockfish Species

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Qualifying Season Dates in the Central GOA Primary Rockfish Species 28 Table 28 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28 Table 28 to Part 679—Qualifying Season...

  19. 50 CFR Table 28a to Part 679 - Qualifying Season Dates for Central GOA Rockfish Primary Species

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Qualifying Season Dates for Central GOA Rockfish Primary Species 28a Table 28a to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28a Table 28a to Part 679—Qualifying...

  20. 50 CFR Table 28 to Part 679 - Qualifying Season Dates in the Central GOA Primary Rockfish Species

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Qualifying Season Dates in the Central GOA Primary Rockfish Species 28 Table 28 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28 Table 28 to Part 679—Qualifying Season...

  1. 50 CFR Table 28a to Part 679 - Qualifying Season Dates for Central GOA Rockfish Primary Species

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Qualifying Season Dates for Central GOA Rockfish Primary Species 28a Table 28a to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28a Table 28a to Part 679—Qualifying...

  2. 50 CFR Table 28b to Part 679 - Qualifying Season Dates for Central GOA Rockfish Primary Species

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Qualifying Season Dates for Central GOA Rockfish Primary Species 28b Table 28b to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 28b Table 28b to Part 679—Qualifying...

  3. 50 CFR Table 28a to Part 679 - Qualifying Season Dates for Central GOA Rockfish Primary Species

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Qualifying Season Dates for Central GOA Rockfish Primary Species 28a Table 28a to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  4. 50 CFR Table 28b to Part 679 - Qualifying Season Dates for Central GOA Rockfish Primary Species

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Qualifying Season Dates for Central GOA Rockfish Primary Species 28b Table 28b to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

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

    USGS Publications Warehouse

    Marincovich, L., Jr.; 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

  6. Changing arctic ecosystems—What is causing the rapid increase of snow geese in northern Alaska?

    USGS Publications Warehouse

    Hupp, Jerry W.; Ward, David H.; Whalen, Mary E.; Pearce, John M.

    2015-01-01

    Through the Changing Arctic Ecosystems (CAE) initiative, the U.S. Geological Survey (USGS) informs key resource management decisions for Arctic Alaska by providing scientific information on current and future ecosystem response to a warming climate. The Arctic Coastal Plain (ACP) of northern Alaska is a key study area within the USGS CAE initiative. This region has experienced a warming trend over the past decades, leading to decreased sea ice, permafrost thaw, and an advancement of spring phenology. The number of birds on the ACP also is changing, marked by increased populations of the four species of geese that nest in the region. The Snow Goose (Chen caerulescens) is the most rapidly increasing of these species. USGS CAE research is quantifying these changes and their implications for management agencies.

  7. Basement geology of the National Petroleum Reserve Alaska (NPRA), Northern Alaska

    USGS Publications Warehouse

    Saltus, R.W.; Hudson, T.L.; Phillips, J.D.; Kulander, C.; Dumoulin, J.A.; Potter, C.

    2002-01-01

    Gravity, aeromagnetic, seismic, and borehole information enable mapping of crustal basement characteristics within the National Petroleum Reserve Alaska (NPRA). In general, the pre-Mississippian basement of the southern portion of the NPRA is different from that in the north in that it is deeper and thinner, is made up of dense magnetic rocks, is cut by more normal faults, and underlies thicker accumulations of Mississippian to Triassic Ellesmerian sequence sedimentary rocks. Mafic igneous rocks within the basement and locally within the deeper Ellesmerian sequence sedimentary section could explain the observed density and magnetic variations. Because these variations spatially overlap thicker Ellesmerian sequence sediment accumulations, they may have developed, at least in part, during Mississippian to Triassic extension and basin formation. If this period of extension, and postulated mafic magmatism, was accompanied by higher heat flow, then early Ellesmerian sequence clastic sediments may have become mature for hydrocarbon generation (Magoon and Bird, 1988). This could have produced an early petroleum system in the Colville basin.

  8. Revised megafossil biostratigraphic zonation for Carboniferous of northern Alaska

    SciTech Connect

    Dutro, J.T. Jr.

    1985-04-01

    Carboniferous megafossils are widely distributed in the Kayak Shale and Lisburne Group throughout the northern Brooks Range. Diverse assemblages of brachiopods, corals, and mollusks, with subordinate echinoderms and bryozoans, were collected from 40 measured sections. The combined stratigraphic ranges and abundances of more than 300 species were assessed to construct a biostratigraphic zonation that can be applied regionally for correlation. Preliminary zonations, used for more than a quarter century, were revised to account for the rapidly accumulating data. In the central and western Brooks Range, the deeper water Kuna formation contains a low-diversity fauna of mollusks and brachiopods. Goniatites are found at several levels but never more than two zones in any partial section. Regionally, these goniatite zones, from youngest to oldest, are: Delephinoceras (late Chesterian), Goniatites americanus (late Meramecian - early Chesterian), Beyrichoceras (early to middle Meramecian), Ammonellipsites (Osagean) and Muensteroceras-Protocanites (late Kinderhookian.). Correlations of megafossil zones with the foraminiferal zones of Mamet are discussed. The 15 Mississippian zones have an average age-resolution of about 2 m.y. By themselves, the goniatite zones give an ageresolution of about 6 m.y. zone.

  9. 75 FR 53873 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Vessels Participating in the Rockfish Entry Level Fishery...: NMFS is prohibiting directed fishing for Pacific ocean perch for vessels participating in the rockfish... to prevent exceeding the 2010 total allowable catch (TAC) of Pacific ocean perch allocated to...

  10. Aerial Photography as a Tool to Document Coastal Change Along Eroding Shorelines in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Gibbs, A.; Richmond, B. M.; Nolan, M.

    2014-12-01

    Chronic and widespread coastal erosion along the northern coast of Alaska is threatening traditional lifestyles, sensitive ecosystems, energy and defense related infrastructure, and large tracts of Native Alaskan, State, and Federally managed land. Recent USGS historical shoreline position studies have documented shoreline change rates along most of northern Alaska for the period from 1947 to circa 2000. Rates vary from an erosional high of -18.6 m/yr along vulnerable bluffed coasts, to accretion up to +10.9 m/yr along prograding sand-rich coasts (average rate for entire study area is -1.4 m/yr). The historical analysis gives valuable information regarding long-term rates of change but does not provide details on the timing and processes driving the change. Oblique and vertical aerial photography contains valuable coastal information on such things as bluff failure mechanisms, presence or absence of shorefast ice, beach characteristics including erosional scarps and ice-push ridges, wrack lines produced during storm surge events, and habitat identification. Recent advances in digital photogrammetry applied to oblique aerial photography can be used to construct high quality DEMs at a relatively low cost. Repeat aerial surveys and resultant DEM construction serve as a potential monitoring tool that can be used to quantify volumetric change, and, if conducted frequently enough, provide insights into the mechanisms responsible for coastal change in the Arctic. We provide examples from a few selected sites in northern Alaska where oblique aerial photography has been used to better understand coastal change in remote and threatened areas.

  11. Paleomagnetism of the Red Dog Zn-Pb massive sulfide deposit in northern Alaska

    USGS Publications Warehouse

    Lewchuk, Michael T.; Leach, D.L.; Kelley, K.D.; Symons, David T. A.

    2004-01-01

    Paleomagnetic methods have isolated two ancient magnetizations in and around the Paleozoic shale-hosted Red Dog ore deposit in northern Alaska. A high-latitude, westerly magnetization carried by magnetite, termed characteristic remanent magnetization A, was found in rocks that have barite and/or substantial quartz replacement of barite. An intermediate- to low-latitude, southerly magnetization (characteristic remanent magnetization B) is carried by pyrrhotite and was found in rocks dominated by galena and sphalerite. The ages the two components are constrained by their relationship with geochemistry, radiometric age dating, and hypotheses for the Mesozoic tectonic history of the Brooks Range. Characteristic remanent magnetization A fails the fold test so it must postdate the end of Brookian orogenesis (??? 150 Ma). It is always found with replacement quartz that has a radiometric date (white mica from a vug, 39Ar/40Ar) of 126 Ma. The paleolatitude for characteristic remanent magnetization B is too shallow to be Mesozoic or younger, regardless of the model for the tectonic origin of northern Alaska, and must predate Brookian orogenesis. Geologic mapping suggests that most of the ore is syngenetic, formed at 330 to 340 Ma, and a radiometric date (Re-Os on pyrite) yields an age of 338 Ma. Since characteristic remanent magnetization B predates deformation, is found in mineralized rocks and is carried by pyrrhotite, it was probably acquired during the mineralizing process as well. The combined radiometric ages and paleomagnetic data sets can be best interpreted by assuming that northern Alaska was part of an accreted terrane that was translated northward by about 30?? into its current location relative to the rest of North America and then rotated counterclockwise by 50?? to 70??. This tectonic interpretation yields plausible magnetization ages for both characteristic remanent magnetization A and B. Geologic evidence, isotopic ages, and paleomagnetic data indicate

  12. Population size and trend of Yellow-billed Loons in northern Alaska

    USGS Publications Warehouse

    Earnst, Susan L.; Stehn, R.A.; Platte, Robert; Larned, W.W.; Mallek, E.J.

    2005-01-01

    The Yellow-billed Loon (Gavia adamsii) is of conservation concern due to its restricted range, small population size, specific habitat requirements, and perceived threats to its breeding and wintering habitat. Within the U.S., this species breeds almost entirely within the National Petroleum Reserve-Alaska, nearly all of which is open, or proposed to be opened, for oil development. Rigorous estimates of Yellow-billed Loon population size and trend are lacking but essential for informed conservation. We used two annual aerial waterfowl surveys, conducted 1986a??2003 and 1992a??2003, to estimate population size and trend on northern Alaskan breeding grounds. In estimating population trend, we used mixed-effects regression models to reduce bias and sampling error associated with improvement in observer skill and annual effects of spring phenology. The estimated population trend on Alaskan breeding grounds since 1986 was near 0 with an estimated annual change of a??0.9% (95% CI of a??3.6% to +1.8%). The estimated population size, averaged over the past 12 years and adjusted by a correction factor based on an intensive, lake-circling, aerial survey method, was 2221 individuals (95% CI of 1206a??3235) in early June and 3369 individuals (95% CI of 1910a??4828) in late June. Based on estimates from other studies of the proportion of loons nesting in a given year, it is likely that <1000 nesting pairs inhabit northern Alaska in most years. The highest concentration of Yellow-billed Loons occurred between the Meade and Ikpikpuk Rivers; and across all of northern Alaska, 53% of recorded sightings occurred within 12% of the area.

  13. Flora development in Northeastern Asia and Northern Alaska during the Cretaceous-Paleogene transitional epoch

    NASA Astrophysics Data System (ADS)

    Herman, A. B.; Akhmetiev, M. A.; Kodrul, T. M.; Moiseeva, M. G.; Iakovleva, A. I.

    2009-02-01

    Study of floral succession from the Cretaceous-Paleogene boundary interval in Russian Far East (Zeya-Bureya depression), Northeastern Russia (Koryak Upland), and Northern Alaska (Sagavanirktok River basin) is crucial for better understanding palaeoclimatic and palaeogeographic factors, which controlled events in vegetation evolution at that time. The succession of fossil floras in the Zeya-Bureya depression includes plant assemblages of the Santonian, Campanian, early Danian, Danian, and Danian-Selandian age. The early Danian Boguchan Flora keeps continuity in composition and dominating taxa with the Campanian Late Kundur Flora. The Koryak Flora of the Amaam Lagoon area (Northeastern Russia) is dated as late Maastrichtian based on correlation of plant-bearing beds with marine biostratigraphy, whereas the Early and Late Sagwon floras of Northern Alaska are dated back to the Danian-Selandian and early Paleocene based on palynological and macrofloristic data. The Early Sagwon Flora is most close to the late Maastrichtian Koryak Flora of the Amaam Lagoon area in composition and main dominants, while the Late Sagwon Flora is comparable with the Danian or Danian-(?) Selandian flora from the Upper Tsagayan Subformation of the Amur area. In a florogenic aspect, trans-Beringian plant migrations from northeastern Asia and southern palaeolatitudes of the Far East, which became possible due to Paleocene climate warming in Arctic, have played an important role in forming of the Paleocene floras of Northern Alaska. Floras of the Far East and high latitudes of Asia and North America show no evidence of catastrophic event at the Cretaceous-Paleogene boundary. Their development was most probably controlled by climate changes, plant evolution and migration.

  14. Dynamics of the Thermal State of Active Layer at the Alaska North Slope and Northern Yakutia

    NASA Astrophysics Data System (ADS)

    Kholodov, A. L.; Romanovsky, V. E.; Marchenko, S.; Shiklomanov, N. I.; Fedorov-Davydov, D.

    2010-12-01

    Dynamics of the active layer is one of the most important indexes, reflecting permafrost response to the modern climate changes. Monitoring of active layer thickness dynamics is the main goal of CALM (Circumpolar Active Layer Monitoring) project. But, from different points of view, it is very important to know not only maximal depth of seasonal thawing but also dynamics of thermal field of active layer and duration of its staying in the unfrozen state. Current research was aimed on the analyzing data of temperature measurements have been done during the more then 10 years at the North Slope of Brooks Range (Alaska) and 2 years at the selected sites at the Northern Yakutia (Russia) and its comparison with the 17 to 10 years records of active layer thickness dynamics at the corresponding sites (http://www.udel.edu/Geography/calm/data/north.html). The area of investigation characterized by the typical tundra landscape and different kinds of micro topography. Reported observation sites located at the latitudinal range from 68.5 to 70.3N in Alaska and 70.5 to 71.75N in the Northern Yakutia. Observation have been done using the 1 meter long MRC probe with 11 sensors (every 10 cm) and single Campbell SCI A107 sensors in Alaska and 2-channel HOBO U23 data loggers with TMC-HD thermistors in the Northern Yakutia. Analyses of CALM data show what most observation sites in Alaska (except located near the Brooks Range and at the Arctic Ocean coast) do not subjected to the significant sustainable changes of active layer thickness over the last 10 years. At the same time active layer thickness at the Yakutian sites was increasing. Temperature observations show decreasing of the mean annual temperature at the average depth of active layer bottom at the Alaskan sites. But, because of general trend to increasing of period of thawing it does not lead to the decreasing of active layer thickness. Recent equipment deployment at the Tiksi and Allaikha sites (Northern Yakutia) does not

  15. Ophiolitic terranes of northern and central Alaska and their correlatives in Canada and northeastern Russia

    SciTech Connect

    Patton, W.W. Jr. )

    1993-04-01

    All of the major ophiolitic terranes (Angayucham, Tozitna, Innoko, Seventymile, and Goodnews terranes) in the northern and central Alaska belong to the Tethyan-type' of Moores (1982) and were obducted onto Paleozoic and Proterozoic continental and continental margin terranes in Mesozoic time. Tethyan-type' ophiolitic assemblages also occur in the Slide Mountain terrane in the Canadian Cordillera and extend from western Alaska into northeastern Russia. Although investigators have suggested widely different ages from their times of abduction onto the continent, these ophiolitic terranes display some remarkably similar features: (1) they consist of a stack of imbricated thrust slices dominated by ocean floor sediments, basalt, and high-level gabbro of late Paleozoic and Triassic age; (2) their mafic-ultramafic complexes generally are confined to the uppermost thrust sheets; (3) they lack the large tectonic melanges zones and younger accretionary flysch deposits associated with the ophiolitic terranes of southern Alaska and the Koryak region of northeastern Russia; (4) blueschist mineral assemblages occur in the lower part of these ophiolite terranes and (or) in the underlying continental terranes; and (5) they are bordered on their outboard' side by Mesozoic intraoceanic volcanic arc terranes. Recent geochemical and geologic studies of the mafic-ultramafic complexes in the Anagayucham and Tozitna terranes strongly suggest they were generated in a supra-subduction zone (SSZ) and that they are directly overlain by volcanic rocks of the Koyukuk terrane.

  16. Seismic observations from a Yakutat eddy in the northern Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Tang, Q.; Gulick, S. P.; Sun, L.

    2013-12-01

    Finescale structure of a surface anticyclonic eddy has been unveiled by reprocessing two seismic transects acquired in the northern Gulf of Alaska using an 8-km hydrophone streamer and 6600 cu in linear airgun array in September 2008. The eddy was a typical bowl-like structure with around 55 km width and 700 m depth. It has two fringes around the eddy base and a spiral arm at the NE edge. The in situ sea surface temperature and salinity data from a shipboard thermosalinograph help to confirm a spiral arm shed from the warm eddy and the entrained cold water from elsewhere. Nearby the eddy and offshore the shelf-break, there is a strong frontal feature, probably the Alaska Current. The eddy likely formed offshore Yakutat shelf and transported along the offshore shelf-break by tracking the sea level anomalies. Its equivalent diameter of 65 km was measured using the along-track altimeter and the seismic constrains. It was comparable with results from the representative conventional algorithms of eddy detections. Geostrophic velocities of the eddy were estimated from the tilted seismic reflections under the assumptions of approximate isopycnals and geostrophic balance. Water properties, like sea surface temperature, salinity, and chlorophyll, revealed the water transports from the coastal into the pelagic regions through the eddy translation. Structures synthesized from CTD profiles that sampled a second eddy suggest that thin laminae around the base might be a common feature in Gulf of Alaska eddies.

  17. Loess ecosystems of northern Alaska: Regional gradient and toposequence at Prudhoe Bay

    SciTech Connect

    Walker, D.A. ); Everett, K.R. )

    1991-12-01

    Loess-dominated ecosystems cover {approx} 14% (11,000 km{sup 2}) of the Arctic Coastal Plain and much of the northern portion of the Arctic Foothills. Knowledge of this poorly known ecosystem is important for sound land-use planning of the expanding developments in the region and for understanding the paleoecological dynamics of eolian systems that once dominated much of northern Alaska. A conceptual alkaline-tundra toposequence includes eight common vegetation types and associated soils and vegetation downwind of the Sagavanirktok River. Properties of loess tundra important for land-use planning include: (1) its high ice content, which contributes to its susceptibility to thermokarst; (2) high salinities, which hamper revegetation efforts; and (3) presence of certain plant species such as Dryas intergrifolia, which are particularly sensitive to disturbance. The loess gradient provides a natural analogue for road dust, and extensive disturbance associated with oil-field development.

  18. ENSO events in the northern Gulf of Alaska, and effects on selected marine fisheries

    USGS Publications Warehouse

    Bailey, K.M.; Macklin, S.A.; Reed, R.K.; Brodeur, R.D.; Ingraham, W.J.; Piatt, J.F.; Shima, M.; Francis, R.C.; Anderson, P.J.; Royer, T.C.; Hollowed, A.; Somerton, D.A.; Wooster, W.S.

    1995-01-01

    The 1991-93 El Nino-Southern Oscillation (ENSO) event first appeared in the northern Gulf of Alaska in autumn 1991 with warm sea-surface temperatures. In winter 1992, there were pulses of increased sea level and anomalous circulation. El Nino conditions persisted at least through summer 1993. The effects of this ENSO event on major groundfish species and Pacific herring in the northern Gulf of Alaska were examined and compared with the effects of previous ENSO events. There is little evidence that the 1991-93 or 1982-83 ENSO events affected landings of walleye pollock, Pacific cod, Pacific halibut, or arrowtooth flounder. Some changes in distribution of groundfish species were observed in 1993, but the effect was similar to changes observed in non-ENSO warm years. In general, warm ocean conditions have a positive effect on recruitment of northern stocks, but ENSO events appear to have an inconsistent effect on year-class strength within species and among different species. For example, strong year classes of halibut and arrowtooth flounder sometimes, but not always, coincide with ENSO events; ENSO events are associated with moderate to weak year classes of cod and pollock. However, post-ENSO warm years often are associated with strong recruitment of many groundfish species. Major changes have occurred in the Gulf of Alaska ecosystem since 1977. The influence of the 1976 ENSO event in precipitating these changes and the role of the frequency or strength of subsequent El Nino events is presently unknown. Herring and other stocks of small pelagic fishes may be more affected by ENSO events. In particular, decreased catches, recruitment, and weight-at-age of herring are sometimes associated with ENSO events. Furthermore, a variety of seabirds which feed mostly on pelagic forage fishes or the pelagic juvenile stages of groundfish suffered widespread mortalities and breeding failures in the Gulf of Alaska during the ENSO years of 1983 and 1993. These effects on seabirds

  19. Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in northern Alaska

    SciTech Connect

    Dusel-Bacon, C.; Brosge, W.P.; Till, A.B.; Doyle, E.O.; Mayfield, C.F.; Reiser, H.N.; Miller, T.P.

    1989-01-01

    Approximately half of the exposed bedrock in northern Alaska has been regionally metamorphosed. In the southern Brooks Range and on the Seward Peninsula, continental rocks experienced a clockwise pressure-temperature path that evolved during Middle Jurassic to late Early Cretaceous time from the low- to high-temperature subfacies of the blueschist facies and, finally, due to decreasing pressure, evolved to the greenschist facies. Metamorphism in the southern Brooks Range was associated with north-vergent compression along a south-dipping subduction zone that emplaced the oceanic rocks of the Angayucham terrane onto the continental margin. High-pressure metamorphism on the Seward Peninsula probably had a similar origin to that in the southern Brooks Range, but remnants of the overriding plate have not been identified, and the mechanism by which the high-pressure rocks in the two areas were separated is not known. In the Ruby geanticline, glaucophane, attesting to high-pressure metamorphism, is sporadically developed both within the continental rocks of the lower plate and, less commonly, near the base of the overlying oceanic thrust sheets. Although the majority of the metamorphic episodes that affected northern Alaska occurred during the Mesozoic, older episodes have been documented or are suspected in a few areas.

  20. Does winter region affect spring arrival time and body mass of king eiders in northern Alaska?

    USGS Publications Warehouse

    Powell, Abby N.; Oppel, Steffen

    2009-01-01

    Events during the non-breeding season may affect the body condition of migratory birds and influence performance during the following breeding season. Migratory birds nesting in the Arctic often rely on endogenous nutrients for reproductive efforts, and are thus potentially subject to such carry-over effects. We tested whether king eider (Somateria spectabilis) arrival time and body mass upon arrival at breeding grounds in northern Alaska were affected by their choice of a winter region in the Bering Sea. We captured birds shortly after arrival on breeding grounds in early June 2002–2006 at two sites in northern Alaska and determined the region in which individuals wintered using satellite telemetry or stable isotope ratios of head feathers. We used generalized linear models to assess whether winter region explained variation in arrival body mass among individuals by accounting for sex, site, annual variation, and the date a bird was captured. We found no support for our hypothesis that either arrival time or arrival body mass of king eiders differed among winter regions. We conclude that wintering in different regions in the Bering Sea is unlikely to have reproductive consequences for king eiders in our study areas.

  1. Land-Water-Atmosphere Linkages in the Landscape of Northern Alaska

    NASA Astrophysics Data System (ADS)

    Shaver, G. R.

    2014-12-01

    The landscape of northern Alaska holds very large stores of organic matter, carbon, and nitrogen, most of it in the soils of terrestrial tundra ecosystems including the upper 1-2 meters of underlying permafrost. Although much of this organic matter and its element content accumulates and cycles relatively slowly, understanding the dynamics of these stores at a landscape scale requires a perspective that includes not only the vertical exchanges with the atmosphere but also the lateral movement and processing of carbon and nitrogen as they as they are transported down hillslopes and into and through lakes and streams. The pool sizes and residence times of C and N differ greatly among lakes, streams, and the terrestrial ecosystems at different locations along hillslopes and in catchments, yet they are all linked through this lateral transport and through the stoichiometry of organic matter cycling. Landscape-scale C and N budgets for the northern foothills of the Brooks Range, Alaska, indicate that significant amounts of C removed from the atmosphere by photosynthesis on land are later returned to the atmosphere from lakes and streams. Nitrogen, on the other hand, is much more strongly retained by terrestrial ecosystems and moves much more slowly across the land surface; this N retention and recycling is an important regulator of terrestrial productivity and C accumulation. These relationships are likely to change with climate and especially with climate-related disturbances including wildfire and thermal erosion of permafrost.

  2. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this spectacular MODIS image from November 7, 2001, the skies are clear over Alaska, revealing winter's advance. Perhaps the most interesting feature of the image is in its center; in blue against the rugged white backdrop of the Alaska Range, Denali, or Mt. McKinley, casts its massive shadow in the fading daylight. At 20,322 ft (6,194m), Denali is the highest point in North America. South of Denali, Cook Inlet appears flooded with sediment, turning the waters a muddy brown. To the east, where the Chugach Mountains meet the Gulf of Alaska, and to the west, across the Aleutian Range of the Alaska Peninsula, the bright blue and green swirls indicate populations of microscopic marine plants called phytoplankton. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  3. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this spectacular MODIS image from November 7, 2001, the skies are clear over Alaska, revealing winter's advance. Perhaps the most interesting feature of the image is in its center; in blue against the rugged white backdrop of the Alaska Range, Denali, or Mt. McKinley, casts its massive shadow in the fading daylight. At 20,322 ft (6,194m), Denali is the highest point in North America. South of Denali, Cook Inlet appears flooded with sediment, turning the waters a muddy brown. To the east, where the Chugach Mountains meet the Gulf of Alaska, and to the west, across the Aleutian Range of the Alaska Peninsula, the bright blue and green swirls indicate populations of microscopic marine plants called phytoplankton.

  4. 77 FR 39649 - Fisheries of the Exclusive Economic Zone Off Alaska; “Other Rockfish” in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... GOA (77 FR 15194, March 14, 2012). In accordance with Sec. 679.20(d)(2), the Administrator, Alaska... Economic Zone Off Alaska; ``Other Rockfish'' in the Western Regulatory Area of the Gulf of Alaska AGENCY... Western Regulatory Area of the Gulf of Alaska (GOA). This action is necessary because the 2012...

  5. 77 FR 50389 - Fisheries of the Exclusive Economic Zone Off Alaska; “Other Rockfish” in the Central Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... Economic Zone Off Alaska; ``Other Rockfish'' in the Central Regulatory Area of the Gulf of Alaska AGENCY... Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary because the 2012 total... Groundfish of the Gulf of Alaska (FMP) prepared by the North Pacific Fishery Management Council...

  6. 76 FR 46207 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ...NMFS is opening directed fishing for Pacific ocean perch by trawl catcher vessels participating in the rockfish entry level fishery in the Central Regulatory Area of the Gulf of Alaska (GOA) for 48 hours. This action is necessary to fully use the 2011 directed fishing allowance of Pacific ocean perch for trawl catcher vessels participating in the rockfish entry level fishery in the Central......

  7. 76 FR 40838 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level...; modification of a closure. SUMMARY: NMFS is opening directed fishing for Pacific ocean perch by trawl catcher... Pacific ocean perch for trawl catcher vessels participating in the rockfish entry level fishery in...

  8. 50 CFR Figure 3 to Subpart E of... - Northern Southeast Alaska Rural and Non-Rural Areas

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Northern Southeast Alaska Rural and Non-Rural Areas 3 Figure 3 to Subpart E of Part 300 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS Pacific Halibut Fisheries Pt. 300, Subpt. E, Fig. 3 Figure...

  9. 50 CFR Figure 3 to Subpart E of... - Northern Southeast Alaska Rural and Non-Rural Areas

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Northern Southeast Alaska Rural and Non-Rural Areas 3 Figure 3 to Subpart E of Part 300 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS Pacific Halibut Fisheries Pt. 300, Subpt. E, Fig. 3 Figure...

  10. Identification of metapopulation dynamics among Northern Goshawks of the Alexander Archipelago, Alaska, and Coastal British Columbia

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; McClaren, Erica L.; Doyle, Frank I.; Titus, K.; Sage, George K.; Wilson, Robert E.; Gust, J.R.; Talbot, Sandra L.

    2012-01-01

    Northern Goshawks occupying the Alexander Archipelago, Alaska, and coastal British Columbia nest primarily in old-growth and mature forest, which results in spatial heterogeneity in the distribution of individuals across the landscape. We used microsatellite and mitochondrial data to infer genetic structure, gene flow, and fluctuations in population demography through evolutionary time. Patterns in the genetic signatures were used to assess predictions associated with the three population models: panmixia, metapopulation, and isolated populations. Population genetic structure was observed along with asymmetry in gene flow estimates that changed directionality at different temporal scales, consistent with metapopulation model predictions. Therefore, Northern Goshawk assemblages located in the Alexander Archipelago and coastal British Columbia interact through a metapopulation framework, though they may not fit the classic model of a metapopulation. Long-term population sources (coastal mainland British Columbia) and sinks (Revillagigedo and Vancouver islands) were identified. However, there was no trend through evolutionary time in the directionality of dispersal among the remaining assemblages, suggestive of a rescue-effect dynamic. Admiralty, Douglas, and Chichagof island complex appears to be an evolutionarily recent source population in the Alexander Archipelago. In addition, Kupreanof island complex and Kispiox Forest District populations have high dispersal rates to populations in close geographic proximity and potentially serve as local source populations. Metapopulation dynamics occurring in the Alexander Archipelago and coastal British Columbia by Northern Goshawks highlight the importance of both occupied and unoccupied habitats to long-term population persistence of goshawks in this region.

  11. 50 CFR 679.81 - Rockfish Program annual harvester privileges.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE... that rockfish primary species (TACs) is assigned for use by the rockfish entry level longline fishery... rockfish entry level longline fishery is established in Table 28e to this part. (iii) The allocation...

  12. Stream temperature response to variable glacier coverage in coastal watersheds of northern southeast Alaska

    NASA Astrophysics Data System (ADS)

    Hood, E. W.; Fellman, J. B.; Nagorski, S. A.; Vermilyea, A.; Pyare, S.; Scott, D.

    2012-12-01

    moderating summer stream temperatures, future reductions in glacier runoff may actually improve the thermal suitability of some streams in northern southeast Alaska for salmon.

  13. Seismic observations from a Yakutat eddy in the northern Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Tang, Q. S.; Gulick, S. P. S.; Sun, L. T.

    2014-06-01

    Recent works show that the seismic oceanography technique allows us to relate water column seismic reflections to oceanic finescale structures. In this study, finescale structures of a surface anticyclonic eddy have been unveiled by reprocessing two seismic transects acquired in the northern Gulf of Alaska using an 8 km hydrophone streamer and 6600 cu in linear airgun array in September 2008. The eddy was a typical bowl-like structure with around 55 km width and 700 m depth. It has two fringes around the eddy base and a spiral arm at the NE edge. The in situ sea surface temperature and salinity data from a shipboard thermosalinograph help to confirm our interpretations of a spiral arm shed from the warm eddy and the entrained cold water from elsewhere. Nearby the eddy and offshore the shelf-break, there is a strong frontal feature, probably the Alaska Current. The eddy likely formed offshore Yakutat shelf and transported along the offshore shelf-break by tracking the sea level anomalies. Its equivalent diameter of 65 km was measured using the along-track altimeter and the seismic constraints. It was comparable with results from the representative conventional algorithms of eddy detection. Geostrophic velocities of the eddy were estimated from the dipping seismic reflections under the assumptions of approximate isopycnals and geostrophic balance. Measured water properties including sea surface temperature, salinity, and chlorophyll revealed that eddy translation transports coastal water to the pelagic regions. Structures synthesized from CTD profiles that sampled an earlier eddy suggest that thin striae around the base might be a common feature in Gulf of Alaska eddies.

  14. Remote identification of polar bear maternal den habitat in northern Alaska

    USGS Publications Warehouse

    Durner, G.M.; Amstrup, Steven C.; Ambrosius, K.J.

    2001-01-01

    Polar bears (Ursus maritimus) give birth in dens of ice and snow to protect their altricial young. During the snow-free season, we visited 25 den sites located previously by radiotelemetry and characterized the den site physiognomy. Seven dens occurred in habitats with minimal relief. Eighteen dens (72%) were in coastal and river banks. These "banks" were identifiable on aerial photographs. We then searched high-resolution aerial photographs (n = 3000) for habitats similar to those of the 18 dens. On aerial photos, we mapped 1782 km of bank habitats suitable for denning. Bank habitats comprised 0.18% of our study area between the Colville River and the Tamayariak River in northern Alaska. The final map, which correctly identified 88% of bank denning habitat in this region, will help minimize the potential for disruptions of maternal dens by winter petroleum exploration activities.

  15. 78 FR 14076 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Central...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-04

    ...NMFS publishes the standard ex-vessel prices and fee percentage for cost recovery under the Central Gulf of Alaska Rockfish Program. This action is intended to provide participants in a rockfish cooperative with the standard prices and fee percentage for the 2012 fishing year, which was authorized from May 1 through November 15. The fee percentage is 1.4 percent. The fee liability payments......

  16. Organohalogen Contaminants and Vitamins in Northern Fur Seals (Callorhinus ursinus) Collected During Subsistence Hunts in Alaska.

    PubMed

    Reiner, Jessica L; Becker, Paul R; Gribble, Matthew O; Lynch, Jennifer M; Moors, Amanda J; Ness, Jennifer; Peterson, Danielle; Pugh, Rebecca S; Ragland, Tamika; Rimmer, Catherine; Rhoderick, Jody; Schantz, Michele M; Trevillian, Jennifer; Kucklick, John R

    2016-01-01

    During native subsistence hunts from 1987 to 2007, blubber and liver samples from 50 subadult male northern fur seals (Callorhinus ursinus) were collected on St. Paul Island, Alaska. Samples were analyzed for legacy persistent organic pollutants (POPs), recently phased-out/current-use POPs, and vitamins. The legacy POPs measured from blubber samples included polychlorinated biphenyl congeners, DDT (and its metabolites), chlorobenzenes, chlordanes, and mirex. Recently phased-out/current-use POPs included in the blubber analysis were the flame retardants, polybrominated diphenyl ethers, and hexabromocyclododecanes. The chemical surfactants, perfluorinated alkyl acids, and vitamins A and E were assessed in the liver samples. Overall, concentrations of legacy POPs are similar to levels seen in seal samples from other areas of the North Pacific Ocean and the Bering Sea. Statistically significant correlations were seen between compounds with similar functions (pesticides, flame retardants, vitamins). With sample collection spanning two decades, the temporal trends in the concentrations of POPs and vitamins were assessed. For these animals, the concentrations of the legacy POPs tend to decrease or stay the same with sampling year; however, the concentrations of the current-use POPs increased with sampling year. Vitamin concentrations tended to stay the same across the sampling years. With the population of northern fur seals from St. Paul Island on the decline, a detailed assessment of exposure to contaminants and the correlations with vitamins fills a critical gap for identifying potential population risk factors that might be associated with health effects. PMID:26142120

  17. 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.

  18. Annual survival and site fidelity of northern pintails banded on the Yukon-Kuskokwim Delta, Alaska

    USGS Publications Warehouse

    Nicolai, Christopher A.; Flint, Paul L.; Wege, Michael L.

    2005-01-01

    We banded northern pintails (Anas acuta; n = 13,645) at a single site on the Yukon-Kuskokwim Delta (YKD), Alaska, USA, from 1990 to 2001. We used recaptures from our site in combination with hunter recoveries to model annual survival, recovery rates, and fidelity to our capture location. Most recoveries (>90%) occurred in the Pacific Flyway with 64% reported from California's Central Valley. Our top candidate models allowed survival to vary by sex but not by age or year. Estimated annual survival was 77.6% (95% CI: 73.9-81.0%) for males and 60.2% (95% CI: 53.2-67.0%) for females. Reporting rates varied by age, sex, and year; estimates for adult males exceeded those for adult females by 3.5 times. Within sexes, reporting rates of hatch-year pintails exceeded those of adults. Estimated recovery rates were considerably lower than those estimated during the 1950s-1970s for winter banded pintails (Hestbeck 1993b), but there were no differences in survival rates. This suggests that changes in harvest regulations may not have influenced annual survival in this population. The propensity of banded pintails to return to our capture site (fidelity rate) varied between sexes and was positively correlated with water conditions in prairie Canada. Our estimates of fidelity rates varied from 77.4% to 87.2% for males and 89.8% to 94.3% for females. Our fidelity estimates suggest that some level of subpopulation structuring may exist for northern pintails. Additionally, our estimates of fidelity support previous observations of northern pintails overflying poor wetland habitat conditions on the Canadian prairies.

  19. 50 CFR 679.82 - Rockfish Program use caps and sideboard limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... rockfish species initial rockfish QS pool established by NMFS. (2) Eligible rockfish harvester use cap. An...; (ii) Arrowtooth flounder; (iii) Flathead sole; (iv) Other flatfish; (v) Pacific ocean perch; (vi)...

  20. 50 CFR 679.82 - Rockfish Program use caps and sideboard limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... rockfish species initial rockfish QS pool established by NMFS. (2) Eligible rockfish harvester use cap. An...; (ii) Arrowtooth flounder; (iii) Flathead sole; (iv) Other flatfish; (v) Pacific ocean perch; (vi)...

  1. Intercontinental reassortment and genomic variation of low pathogenic avian influenza viruses isolated from northern pintails (Anas acuta) in Alaska: examining the evidence through space and time

    USGS Publications Warehouse

    Ramey, Andrew M.; Pearce, John M.; Flint, Paul L.; Ip, Hon S.; Derksen, Dirk V.; Franson, J. Christian; Petrula, Michael J.; Scotton, Bradley D.; Sowl, Kristine M.; Wege, Michael L.; Trust, Kimberly A.

    2010-01-01

    Migration and population genetic data for northern pintails (Anas acuta) and phylogenetic analysis of low pathogenic avian influenza (LPAI) viruses from this host in Alaska suggest that northern pintails are involved in ongoing intercontinental transmission of avian influenza. Here, we further refine this conclusion through phylogenetic analyses which demonstrate that detection of foreign lineage gene segments is spatially dependent and consistent through time. Our results show detection of foreign lineage gene segments to be most likely at sample locations on the Alaska Peninsula and least likely along the Southern Alaska Coast. Asian lineages detected at four gene segments persisted across years, suggesting maintenance in avian hosts that migrate to Alaska each year from Asia or in hosts that remain in Alaska throughout the year. Alternatively, live viruses may persist in the environment and re-infect birds in subsequent seasons.

  2. Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.

    SciTech Connect

    Andrews, A H; Kerr, L A; Cailliet, G M; Brown, T A; Lundstrom, C C; Stanley, R D

    2007-11-04

    Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

  3. The Effects of Changing Sea Ice on Marine Mammals and Their Hunters in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Huntington, H.; Quakenbush, L.; Nelson, M.

    2015-12-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information and insight relevant to ecological understanding, conservation action, and the regulation of human activity. We interviewed hunters in villages from northern Bering Sea to the Beaufort Sea, focusing on bowhead whales, walrus, and ice seals. Hunters reported extensive changes in sea ice, with resulting effects on the timing of marine mammal migrations, the distribution and behavior of the animals, and the efficacy of certain hunting methods, for example the difficulty of finding ice thick enough to support a bowhead whale for butchering. At the same time, hunters acknowledged impacts and potential impacts from changing technology such as more powerful outboard engines and from industrial activity such as shipping and oil and gas development. Hunters have been able to adapt to some changes, for example by hunting bowhead whales in fall as well as spring on St. Lawrence Island, or by focusing their hunt in a shorter period in Nuiqsut to accommodate work schedules and worse weather. Other changes, such as reduced availability of ice seals due to rapid retreat of pack ice after spring break-up, continue to defy easy responses. Continued environmental changes, increased disturbance from human activity, and the introduction of new regulations for hunting may further challenge the ability of hunters to provide food as they have done to date, though innovation and flexibility may also provide new sources of adaptation.

  4. Brucella placentitis and seroprevalence in northern fur seals (Callorhinus ursinus) of the Pribilof Islands, Alaska.

    PubMed

    Duncan, Colleen G; Tiller, Rebekah; Mathis, Demetrius; Stoddard, Robyn; Kersh, Gilbert J; Dickerson, Bobette; Gelatt, Tom

    2014-05-01

    Brucella species infect a wide range of hosts with a broad spectrum of clinical manifestations. In mammals, one of the most significant consequences of Brucella infection is reproductive failure. There is evidence of Brucella exposure in many species of marine mammals, but the outcome of infection is often challenging to determine. The eastern Pacific stock of northern fur seals (NFSs, Callorhinus ursinus) has declined significantly, spawning research into potential causes for this trend, including investigation into reproductive health. The objective of the current study was to determine if NFSs on St. Paul Island, Alaska have evidence of Brucella exposure or infection. Archived DNA extracted from placentas (n = 119) and serum (n = 40) samples were available for testing by insertion sequence (IS) 711 polymerase chain reaction (PCR) and the Brucella microagglutination test (BMAT), respectively. As well, placental tissue was available for histologic examination. Six (5%) placentas were positive by PCR, and a single animal had severe placentitis. Multilocus variable number tandem repeat analysis profiles were highly clustered and closely related to other Brucella pinnipedialis isolates. A single animal was positive on BMAT, and 12 animals had titers within the borderline range; 1 borderline animal was positive by PCR on serum. The findings suggest that NFSs on the Pribilof Islands are exposed to Brucella and that the organism has the ability to cause severe placental disease. Given the population trend of the NFS, and the zoonotic nature of this pathogen, further investigation into the epidemiology of this disease is recommended. PMID:24803576

  5. Characterizing the nutritional strategy of incubating king eiders Somateria spectabilis in northern Alaska

    USGS Publications Warehouse

    Bentzen, R.L.; Powell, A.N.; Williams, T.D.; Kitaysky, A.S.

    2008-01-01

    We measured plasma concentrations of variables associated with lipid metabolism (free fatty acids, glycerol, triglyceride, and ??- hydroxybutyrate), protein metabolism (uric acid), and baseline corticosterone to characterize the nutritional state of incubating king eiders Somateria spectabilis and relate this to incubation constancy at two sites, Kuparuk and Teshekpuk, in northern Alaska. King eiders at both sites appeared to employ a partial-income incubation strategy, relying on both endogenous and exogenous energy resources. Females maintained high invariant levels of free fatty acids, ??-hydroxybutyrate, and glycerol throughout incubation, indicating that fat reserves were a major energy source, and not completely depleted during incubation. Similarly, uric acid did not increase, suggesting effective protein sparing or protein ingestion and adequate lipid reserves throughout incubation. Baseline corticosterone and triglyceride levels increased during incubation, indicative of an increase in foraging during late stages of incubation. Incubating females at Kuparuk had higher triglyceride concentrations but also had higher ??-hydroxybutyrate concentrations than females at Teshekpuk. This dichotomy may reflect a short-term signal of feeding overlaying the longer-term signal of reliance on endogenous lipid reserves due to higher food intake yet higher metabolic costs at Kuparuk because of its colder environment. Incubation constancy was not correlated with plasma concentrations of lipid or protein metabolites. ?? 2008 The Authors.

  6. Shifting balance of thermokarst lake ice regimes across the Arctic Coastal Plain of northern Alaska

    NASA Astrophysics Data System (ADS)

    Arp, C. D.; Jones, B. M.; Lu, Z.; Whitman, M. S.

    2012-08-01

    The balance of thermokarst lakes with bedfast- and floating-ice regimes across Arctic lowlands regulates heat storage, permafrost thaw, winter-water supply, and over-wintering aquatic habitat. Using a time-series of late-winter synthetic aperture radar (SAR) imagery to distinguish lake ice regimes in two regions of the Arctic Coastal Plain of northern Alaska from 2003-2011, we found that 18% of the lakes had intermittent ice regimes, varying between bedfast-ice and floating-ice conditions. Comparing this dataset with a radar-based lake classification from 1980 showed that 16% of the bedfast-ice lakes had shifted to floating-ice regimes. A simulated lake ice thinning trend of 1.5 cm/yr since 1978 is believed to be the primary factor driving this form of lake change. The most profound impacts of this regime shift in Arctic lakes may be an increase in the landscape-scale thermal offset created by additional lake heat storage and its role in talik development in otherwise continuous permafrost as well as increases in over-winter aquatic habitat and winter-water supply.

  7. Facies analysis of yedoma thermokarst lakes on the northern Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Farquharson, Louise; Anthony, Katey Walter; Bigelow, Nancy; Edwards, Mary; Grosse, Guido

    2016-07-01

    Thermokarst lakes develop as a result of the thaw and collapse of ice-rich, permanently frozen ground (permafrost). Of particular sedimentological importance are thermokarst lakes forming in late Pleistocene icy silt (yedoma), which dramatically alter the land surface by lowering surface elevation and redistributing upland sediment into lower basins. Our study provides the first description of yedoma thermokarst lake sedimentology based on the cross-basin sampling of an existing lake. We present lake sediment facies descriptions based on data from sediment cores from two thermokarst lakes of medium depth, Claudi and Jaeger (informal names), which formed in previously non thermokarst-affected upland yedoma on the northern Seward Peninsula, Alaska. We identify four prominent facies using sedimentological, biogeochemical, and macrofossil indicators: a massive silt lacking aquatic macrofossils and other aquatic indicators situated below a sub-lacustrine unconformity (Facies 1); two basal deposits: interbedded organic silt and chaotic silt (Facies 2-3); and a silt-rich mud (Facies 4). Facies 1 is interpreted as yedoma that has thawed during lake formation. Facies 3 formed adjacent to the margin due to thaw and collapse events from the lake shore. Material from Facies 3 was reworked by wave action to form Facies 2 in a medium energy margin environment. Facies 4 formed in a lower energy environment toward the lake basin center. This facies classification and description should enhance our ability (i) to interpret the spatial and temporal development of lakes and (ii) to reconstruct long-term patterns of landscape change.

  8. Application of Acoustic Telemetry to Assess Residency and Movements of Rockfish and Lingcod at Created and Natural Habitats in Prince William Sound

    PubMed Central

    Reynolds, Brad F.; Powers, Sean P.; Bishop, Mary Anne

    2010-01-01

    Loss and/or degradation of nearshore habitats have led to increased efforts to restore or enhance many of these habitats, particularly those that are deemed essential for marine fishes. Copper rockfish (Sebastes caurinus) and lingcod (Ophiodon enlongatus) are dominant members of the typical reef fish community that inhabit rocky and high-relief substrates along the Pacific Northwest. We used acoustic telemetry to document their residency and movements in the nearshore waters of Prince William Sound, Alaska in order to assess use of created reef habitat in an individual-based manner. A total of 57 fish were surgically implanted with acoustic transmitters. Forty-five fish were captured and monitored in three habitats: artificial reef, low-relief natural reef, and patchy high-relief natural reef. Within each habitat, both rockfish and lingcod exhibited long periods of residency with limited movements. Twelve rockfish were captured at the natural reefs and displaced a distance of 4.0 km to the artificial reef. Five of the 12 rockfish returned within 10 d of their release to their initial capture site. Another five of the 12 displaced fish established residency at the artificial reef through the duration of our study. Our results suggest the potential for artificial reefs to provide rockfish habitat in the event of disturbances to natural habitat. PMID:20730090

  9. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Southwest): Brown rockfish, copper rockfish, and black rockfish

    SciTech Connect

    Stein, D.; Hassler, T.J. . Coll. of Oceanography; Humboldt State Univ., Arcata, CA . California Cooperative Fishery Research Unit)

    1989-09-01

    Species profiles are literature summaries of the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. They are designed to assist in environmental impact assessment. Rockfishes are the basis of very important sport and commercial fisheries in the northeastern Pacific. Exploitation is increasing. Brown rockfish (Sebastes auriculatus), copper rockfish (S. caurinus), and black rockfish (S. melanops) are three important members of this family. Two of the species occur throughout the Pacific Southwest region; the black rockfish occurs only from about Santa Barbara northward. The habitats and foods differ significantly among species, although at certain time and places they may overlap. Black rockfish tend to be pelagic; the other two species are benthic. Their foods generally reflect these differences in habitats. These species may compete with one another and with other rockfish and benthic species for habitat. The environmental factors determining distribution, growth, and survival are generally unknown. All rockfish have internal fertilization and bear live young. The reproductive behavior, spawning times, and spawning areas of these species are poorly known, although larvae of all have been described. Growth patterns are not well understood. All three species are apparently rather long-lived.

  10. Concentrations of metals and trace elements in blood of spectacled and king eiders in northern Alaska, USA

    USGS Publications Warehouse

    Wilson, H.M.; Petersen, M.R.; Troy, D.

    2004-01-01

    In 1996, we measured concentrations of arsenic, barium, cadmium, lead, mercury, and selenium in blood of adult king (Somateria spectabilis) and spectacled (Somateria fischeri) eiders and duckling spectacled eiders from northern Alaska, USA. Concentrations of selenium exceeded background levels in all adults sampled and 9 of 12 ducklings. Mercury was detected in all adult spectacled eiders and 5 of 12 ducklings. Lead concentrations were above the clinical toxicity threshold in one duckling (0.64 ppm) and two adult female spectacled eiders (0.54 and 4.30 ppm). Concentrations of cadmium and mercury varied between species; barium, cadmium, mercury, and selenium varied between sexes. In female spectacled eiders, mercury concentrations increased during the breeding season and barium and selenium levels decreased through the breeding season. Selenium declined at 2.3 ?? 0.9% per day and levels were lower in spectacled eiders arriving to the breeding grounds in northern Alaska than in western Alaska. The variation in selenium levels between breeding areas may be explained by differences in timing and routes of spring migration. Most trace elements for which we tested were not at levels currently considered toxic to marine birds. However, the presence of mercury and elevated lead in ducklings and adult female spectacled eiders suggests these metals are available on the breeding grounds.

  11. Zinc isotopes in sphalerite from base metal deposits in the Red Dog district, northern Alaska

    USGS Publications Warehouse

    Kelley, K.D.; Wilkinson, J.J.; Chapman, J.B.; Crowther, H.L.; Weiss, D.J.

    2009-01-01

    Analyses of sphalerite samples from shale-hosted massive sulfide and stratigraphically underlying vein breccia deposits in the Red Dog district in northern Alaska show a range ??66Zn values from zero to 0.60 per mil. The lowest values are observed in the vein breccia deposits, and the stratigraphically overlying (but structurally displaced) shale-hosted massive sulfide deposits show a systematic trend of increasing ??66Zn values from south to north (Main-Aqqaluk-Paalaaq-Anarraaq). The ??66Zn values are inversely correlated with sphalerite Fe/Mn ratio and also tend to be higher in low Cu sphalerite, consistent with precipitation of lower ??66Zn sphalerite closer to the principal hydrothermal fluid conduits. The most likely control on isotopic variation is Rayleigh fractionation during sulfide precipitation, with lighter zinc isotopes preferentially incorporated in the earliest sphalerite to precipitate from ore fluids at deeper levels (vein breccias) and close to the principal fluid conduits in the orebodies, followed by precipitation of sulfides with higher ??66Zn values in shallower and/or more distal parts of the flow path. There is no systematic variation among the paragenetic stages of sphalerite from a single deposit, suggesting an isotopically homogeneous zinc source and consistent transport-deposition conditions and/or dissolution-reprecipitation of earlier sphalerite without significant fractionation. Decoupled Zn and S isotope compositions are best explained by mixing of separate metal- and sulfur-bearing fluids at the depositional site. The results confirm that Zn isotopes may be a useful tracer for distinguishing between the central and distal parts of large hydrothermal systems as previously suggested and could therefore be of use in exploration. ?? 2009 by Economic Geology.

  12. Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Grosse, G.; Arp, C.D.; Jones, M.C.; Walter, Anthony K.M.; Romanovsky, V.E.

    2011-01-01

    Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or -14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.

  13. Acoustic properties of northern Alaska shelves in relation to the regional geology

    NASA Astrophysics Data System (ADS)

    Houtz, Robert E.; Eittreim, Stephen; Grantz, Arthur

    1981-05-01

    More than 100 airgun-sonobuoy records from the northern Alaska shelves have been reduced to yield an average of six layers from each record. Seafloor sound velocities, regional velocity functions, and high-resolution velocity-depth inversions were computed. Low seafloor velocities in the northwest part of the otherwise Cretaceous seafloor of the Colville foredeep represent thin Tertiary sediments that overstep the Barrow arch from the north. Anticlinal cores of `mid-shelf arches' (Grantz et al., 1981) appear as 200-m/s velocity increases in the Neogene seafloor of the western Beaufort shelf. Very recent or currently, active sedimentation in the central Hope basin is indicated by low seafloor sound velocities. The value of K in the least squares determination of V = V0 + Kt (t is one-way vertical travel time) decreases toward the east from 1.74 km/s2 just east of Point Barrow of 1.67 km/s2 around Prudhoe Bay, to 1.53 km/s2 near the Mackenzie River. This decrease in K corresponds with an eastward increase in the thickness of the clastic rocks within the youngest part of the Brookian sequence (Early Cretaceous to Quaternary). A 2.1-km/s2 value of K is the Brookian sequence of the north Chukchi basin suggests a change in the relative proportions of Cretaceous and Tertiary sediments between the basin and the Beaufort shelf. High-resolution velocity-depth inversions, using closely digitized travel time data, yield velocities at about 40-m vertical spacings. Calculated values of near-surface velocity gradients determined by velocity-depth plots of these data are generally not in good agreement with the values predicted from the velocity functions, which are statistical generalizations based on conventional refraction picks that resolve layers no thinner than about 250 m. The discrepancies are minimized by use of independently determined seafloor velocities.

  14. Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Jones, B. M.; Grosse, G.; Arp, C. D.; Jones, M. C.; Walter Anthony, K. M.; Romanovsky, V. E.

    2011-06-01

    Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or -14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.

  15. Northern Cordilleran Ice Sheet Dynamics in Coastal Alaska from MIS 3 to the Present: Initial Results

    NASA Astrophysics Data System (ADS)

    Penkrot, M. L.; Jaeger, J. M.; LeVay, L.; St-Onge, G.; Mix, A. C.; Bahlburg, H.; Davies-Walczak, M.; Gulick, S. P. S.

    2014-12-01

    Establishing the timing of northwestern Cordilleran ice sheet (NCIS) advance-retreat cycles in southern Alaska allows for investigation of global synchronicity in glacial-age climate forcing. Integrated Ocean Drilling Program Expedition 341 targeted the glacial dynamics of the NCIS in the coastal St. Elias range. Sediment cores from Site U1419 encompass times of global ice advance and retreat from MIS 3 to the present, based on a preliminary age model with 5-kya resolution developed using oxygen isotopes from benthic and planktonic foraminifera and stratigraphic correlation with a previously C-14 dated site survey core (Davies et al., 2011; doi:10.1029/2010PA002051). CT images of cores were used to identify sedimentary facies and relative ice sheet proximity. Six sedimentary facies were identified in the images; massive mud with and without lonestones, laminations with and without lonestones, massive and stratified diamict (>1 clast/cm). Elemental scanning XRF data were used to delineate possible downcore changes in sediment provenance using provenance-sensitive transition metals. Diamict and gravelly mud are the most common facies, indicative of persistent glacial input interpreted as marine-terminating glacial systems. Stratified diamicts are interpreted as periods of maximum ice extent (~18-20 ka), whereas massive mud (~14 ka-present) suggests terminus retreat. Intervals of laminated mud with and without lonestones are interpreted as periods of reduced ice cover, with the most recent (~14.5 kya) coinciding with the Bølling Interstade of northern Europe/Greenland (Davies et al., 2011). Downcore changes in Al-normalized metal XRF counts vary along with sedimentary lithoficies, suggesting changes in sediment provenance that may be related to the quantity of glacigenic sediment delivery to this location.

  16. Patterns and rates of riverbank erosion involving ice-rich permafrost (yedoma) in northern Alaska

    NASA Astrophysics Data System (ADS)

    Kanevskiy, Mikhail; Shur, Yuri; Strauss, Jens; Jorgenson, Torre; Fortier, Daniel; Stephani, Eva; Vasiliev, Alexander

    2016-01-01

    Yedoma, a suite of syngenetically frozen silty ice- and organic-rich deposits with large ice wedges that accumulated during the late Pleistocene, is vulnerable to thermal degradation and erosion because of the extremely high ice contents. This degradation can result in significant surface subsidence and retreat of coastal bluffs and riverbanks with large consequences to landscape evolution, infrastructure damage, and water quality. We used remote sensing and field observations to assess patterns and rates of riverbank erosion at a 35-m-high active yedoma bluff along the Itkillik River in northern Alaska. The total volumetric ground-ice content-including wedge, segregated, and pore ice-was estimated to be ~ 86%. The process of riverbank erosion and stabilization include three main stages typical of the areas with ice-rich permafrost: (1) thermal erosion combined with thermal denudation, (2) thermal denudation, and (3) slope stabilization. Active riverbank erosion at the main study site started in July 1995, when the Itkillik River changed its channel. The total retreat of the riverbank during 1995-2010 within different segments of the bluff varied from 180 to 280 m; the average retreat rate for the most actively eroded part of the riverbank was almost 19 m/y. From August 2007 to August 2011, the total retreat varied from 10 to almost 100 m. The average retreat rate for the whole 680-m-long bluff was 11 m/y. For the most actively eroded central part of the bluff (150 m long) it was 20 m/y, ranging from 16 to 24 m/y. More than 180,000 m3 of ground ice and organic-rich frozen soil, or almost 70,000 metric tons (t) of soil solids including 880 t of organic carbon, were transported to the river from the retreating bank annually. This study reports the highest long-term rates of riverbank erosion ever observed in permafrost regions of Eurasia and North America.

  17. Stable Isotope Models Predict Foraging Habitat of Northern Fur Seals (Callorhinus ursinus) in Alaska.

    PubMed

    Zeppelin, T K; Johnson, D S; Kuhn, C E; Iverson, S J; Ream, R R

    2015-01-01

    We developed models to predict foraging habitat of adult female northern fur seals (Callorhinus ursinus) using stable carbon (δ13C) and nitrogen (δ15N) isotope values from plasma and red blood cells. Binomial generalized linear mixed models were developed using blood isotope samples collected from 35 adult female fur seals on three breeding colonies in Alaska during July-October 2006. Satellite location and dive data were used to define habitat use in terms of the proportion of time spent or dives made in different oceanographic/bathymetric domains. For both plasma and red blood cells, the models accurately predicted habitat use for animals that foraged exclusively off or on the continental shelf. The models did not perform as well in predicting habitat use for animals that foraged in both on- and off-shelf habitat; however, sample sizes for these animals were small. Concurrently collected scat, fatty acid, and dive data confirmed that the foraging differences predicted by isotopes were associated with diet differences. Stable isotope samples, dive data, and GPS location data collected from an additional 15 females during August-October 2008 validated the effective use of the models across years. Little within year variation in habitat use was indicated from the comparison between stable isotope values from plasma (representing 1-2 weeks) and red blood cells (representing the prior few months). Constructing predictive models using stable isotopes provides an effective means to assess habitat use at the population level, is inexpensive, and can be applied to other marine predators. PMID:26030280

  18. Stable Isotope Models Predict Foraging Habitat of Northern Fur Seals (Callorhinus ursinus) in Alaska

    PubMed Central

    Zeppelin, T. K.; Johnson, D. S.; Kuhn, C. E.; Iverson, S. J.; Ream, R. R.

    2015-01-01

    We developed models to predict foraging habitat of adult female northern fur seals (Callorhinus ursinus) using stable carbon (δ13C) and nitrogen (δ15N) isotope values from plasma and red blood cells. Binomial generalized linear mixed models were developed using blood isotope samples collected from 35 adult female fur seals on three breeding colonies in Alaska during July-October 2006. Satellite location and dive data were used to define habitat use in terms of the proportion of time spent or dives made in different oceanographic/bathymetric domains. For both plasma and red blood cells, the models accurately predicted habitat use for animals that foraged exclusively off or on the continental shelf. The models did not perform as well in predicting habitat use for animals that foraged in both on- and off-shelf habitat; however, sample sizes for these animals were small. Concurrently collected scat, fatty acid, and dive data confirmed that the foraging differences predicted by isotopes were associated with diet differences. Stable isotope samples, dive data, and GPS location data collected from an additional 15 females during August-October 2008 validated the effective use of the models across years. Little within year variation in habitat use was indicated from the comparison between stable isotope values from plasma (representing 1-2 weeks) and red blood cells (representing the prior few months). Constructing predictive models using stable isotopes provides an effective means to assess habitat use at the population level, is inexpensive, and can be applied to other marine predators. PMID:26030280

  19. Pre-settlement processes of northern rock sole (Lepidopsetta polyxystra) in relation to interannual variability in the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Fedewa, Erin J.; Miller, Jessica A.; Hurst, Thomas P.

    2016-05-01

    Understanding the effects of climate variability on growth dynamics and timing of early life history events in marine fishes can provide insights into survival, recruitment and productivity. We examined interannual variation in indicators of larval growth rates, size at hatch and metamorphosis, and the timing of metamorphosis of northern rock sole (Lepidopsetta polyxystra) over 5 years in two nurseries at Kodiak Island, Alaska, USA. Variation in early life characteristics was quantified using laboratory-validated otolith structural analysis and related to water temperature and spring bloom dynamics in the Gulf of Alaska. Overall, results indicated that temperature contributed more to interannual variation in northern rock sole growth, size and phenology patterns than phytoplankton dynamics. Size at hatch was positively related to winter-spring spawning temperatures. Larval growth metrics were generally consistent with thermal effects as temperatures above 4 °C appear necessary, but are not sufficient to support rapid growth. Reflecting the cumulative effects of temperature, the timing of metamorphosis was related to both seasonal and interannual variation in temperature with earlier dates of metamorphosis in warmer years. Conversely, fish size at metamorphosis was similar across years, suggesting that the competency to metamorphose is related to attainment of a minimum size. These results demonstrate the important role of temperature in regulating early life history phenology of northern rock sole and suggest that temperature-driven phenological shifts may also influence the time of spawning and hatching.

  20. 78 FR 47635 - Endangered and Threatened Species; Designation of Critical Habitat for Yelloweye Rockfish, Canary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... under the Endangered Species Act (ESA), and bocaccio as endangered (75 FR 22276). We are responsible for... yelloweye rockfish, canary rockfish, and bocaccio (74 FR 18516, April 23, 2009), we requested information on... Sound/Georgia Basin DPS for yelloweye rockfish, canary rockfish, and bocaccio (Drake et al. 2010; 75...

  1. A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska.

    PubMed

    Valentich-Scott, Paul; Powell, Charles L; Ii; Lorenson, Thomas D; Edwards, Brian E

    2014-01-01

    Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconchasarae. These new taxa are compared with known modern and fossil genera and species of thyasirds. PMID:25589851

  2. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    SciTech Connect

    Wallace, Wesley K.; Hanks, Catherine L.; Whalen, Michael T.; Jensen1, Jerry; Shackleton, J. Ryan; Jadamec, Margarete A.; McGee, Michelle M.; Karpov1, Alexandre V.

    2001-07-23

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively underformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding on fracture patterns, (3) The influence of deformation on fluid flow, and (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics.

  3. Self-Sufficiency in Northern Justice Issues. Proceedings of the Northern Justice Society Meeting (5th, Sitka, Alaska, April 1991).

    ERIC Educational Resources Information Center

    Griffiths, Curt Taylor, Ed.

    As indigenous peoples in the Arctic move closer to sovereignty, self-sufficiency in the realm of criminal justice assumes paramount importance. This book outlines initiatives and strategies to improve the delivery of justice services to aboriginal peoples in Canada, Alaska, and Greenland. Topics include: social and spiritual causes of alcoholism…

  4. 50 CFR 660.321 - Black rockfish harvest guideline.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Black rockfish harvest guideline. 660.321 Section 660.321 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Groundfish Fisheries § 660.321 Black rockfish harvest guideline. From the commercial harvest of...

  5. From Texas to Alaska: Leading Hearing Impaired Elementary Students in Texas to Engage in Science of the Northern Lights Performed in Alaska.

    NASA Astrophysics Data System (ADS)

    Jahn, J. M.; Ibarra, S.; Pfeifer, M. D.; Samara, M.; Michell, R.

    2014-12-01

    Interacting with hearing impaired students who communicate using auditory/oral methods provides challenges and opportunities to education/outreach activities. Despite many advances in assistive technologies, these hearing impaired students will learn much less incidentally than their peers with typical hearing. In other words, they will often require repeated auditory and perhaps visual reinforcement in order to learn a new word or a new concept. This need leads to a much more deliberate and conscious interaction between educators or scientists and the students. We are reporting from a unique joint project between the Sunshine Cottage School for Deaf Children and the Southwest Research Institute (SwRI), to bring actual space research to life for hearing impaired elementary school students. During this project, we combined the unique capabilities of Deaf Education educators with the excitement and wonder of researching the northern lights. For three consecutive winters, we conducted a series of informal yet structured activities each year with fourth and fifth grade students. Our interactions went beyond typical classroom activities and readily available educational materials. Our goal was to engage and excite the students. To do so, we set up a series of interactions and mini-projects that introduced the students to actual research and actual researchers. From "meet the scientists" visits to school over a field trip to the SwRI space research facilities to observing and predicting the aurora using real-time space weather data, we engaged students in the "who" and "how" of doing research and field work in Alaska's winter. Over the course of this project, students connected with a remote school in the interior of Alaska, participated in the excitement of a NASA sounding rocket campaign in in Poker Flat, AK, skyped with researchers and students in Alaska, and made aurora predictions using NOAA real time space weather data. The highlight of the program each year was

  6. Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Wetterich, Sebastian; Grosse, Guido; Schirrmeister, Lutz; Andreev, Andrei A.; Bobrov, Anatoly A.; Kienast, Frank; Bigelow, Nancy H.; Edwards, Mary E.

    2012-04-01

    A terrestrial sediment sequence exposed in an eroding pingo provides insights into the late-Quaternary environmental history of the northern Seward Peninsula, Alaska. We have obtained the first radiocarbon-dated evidence for a mid-Wisconsin thermokarst lake, demonstrating that complex landscape dynamics involving cyclic permafrost aggradation and thermokarst lake formation occurred over stadial-interstadial as well as glacial-interglacial time periods. High values of Picea pollen and the presence of Larix pollen in sediments dated to 50-40 ka BP strongly suggest the presence of forest or woodland early in MIS 3; the trees grew within a vegetation matrix dominated by grass and sedge, and there is indirect evidence of grazing animals. Thus the interstadial ecosystem was different in structure and composition from the Holocene or from the preceding Last Interglacial period. An early Holocene warm period is indicated by renewed thermokarst lake formation and a range of fossil taxa. Multiple extralimital plant taxa suggest mean July temperatures above modern values. The local presence of spruce during the early Holocene warm interval is evident from a radiocarbon-dated spruce macrofossil remain and indicates significant range extension far beyond the modern tree line. The first direct evidence of spruce in Northwest Alaska during the early Holocene has implications for the presence of forest refugia in Central Beringia and previously assumed routes and timing of post-glacial forest expansion in Alaska.

  7. Novel polyomaviral infection in the placenta of a northern fur seal (Callorhinus ursinus) on the Pribilof Islands, Alaska, USA.

    PubMed

    Duncan, Colleen; Goldstein, Tracey; Hearne, Carol; Gelatt, Tom; Spraker, Terry

    2013-01-01

    Viruses of the family Polyomaviridae infect a wide variety of avian and mammalian hosts with a broad spectrum of outcomes including asymptomatic infection, acute systemic disease, and tumor induction. In 2010, intranuclear viral inclusion bodies were identified in trophoblasts of a single northern fur seal (NFS; Callorhinus ursinus) placenta from a presumed healthy birth on St. Paul Island, Alaska. On transmission electron microscopy, virions were approximately 40 nm in diameter and were arranged in paracrystalline arrays within the nucleus. The tissue was positive for the polyomaviral major capsid gene (VP1) by PCR, and the sequenced product revealed a novel Orthopolyomavirus. Twenty-nine additional NFS placentas, devoid of viral inclusions on histologic examination, were tested for polyomavirus by PCR; all were negative. The significance of this novel virus for the infected animal is unknown, but the virus does not appear to be very prevalent within the placentas from newborn northern fur seal pups. PMID:23307383

  8. Conodont thermal maturation patterns in Paleozoic and Triassic rocks, Northern Alaska - geologic and exploration implications

    SciTech Connect

    Harris, A.G.; Lane, H.R.; Tailleur, I.L.

    1985-04-01

    Metamorphism and thermal maturation patterns of sedimentary rocks in the Brooks Range, Alaska are discussed. Thermal patterns are based on conodont color alteration indices (CAI). Exploration significance of this study is given.

  9. Long-Term Release of Carbon Dioxide from Arctic Tundra Ecosystems in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Euskirchen, E. S.; Bret-Harte, M. S.; Edgar, C.; Shaver, G. R.

    2014-12-01

    Recent data syntheses and modeling studies of arctic tundra carbon dioxide (CO2) balance have suggested that the tundra is a CO2 sink, a source or neutral. Much of this uncertainty arises from a lack of data pertaining to winter CO2 flux, as well as how these ecosystems have responded to recent warming trends. Due to a harsh, remote environment, long-term, continuous measurements of arctic tundra CO2 fluxes over the full annual cycle have been non-existent. In September 2007, we began eddy covariance measurements of net ecosystem exchange (NEE, where a negative value denotes a sink) of CO2 in northern Alaska at two ecosystems, heath and wet sedge tundra. These measurements continue to the present, and represent the longest continuous record of arctic tundra NEE currently available. From January 2008 - December 2013, the ecosystems were annual sources of CO2, with the wet sedge tundra acting as a greater source (mean ± standard deviation of 50 ± 30 g C m-2 y-1) than the heath tundra (16 ± 6 g C m-2 y-1). During these same years, the ecosystems were sinks of CO2 in the summer (June - August), with less variability between the ecosystems, -77 ± 15 g C m-2 in the wet sedge tundra, and -70 ± 12 g C m-2 in the heath. Environmental controls over NEE differed between ecosystems and seasons, with the wet sedge tundra acting particularly responsive in terms of CO2 release during periods with warm air temperatures from fall to early winter. During cold winter periods, CO2 release from the snowpack in both ecosystems was related to increases in wind speed and drops in atmospheric pressure. Overall, the measured differences in the annual versus summer NEE illustrate how the sink strength of the tundra can be overestimated if data are only collected during the growing season. Furthermore, eddy covariance measurements of methane (CH4) in the wet sedge tundra during late spring to early fall from 2012 to present show that this ecosystem releases 0.34 ± 11 mg CH4 m-2 d-1

  10. Urban Geocryology: Mapping Urban-Rural Contrasts in Active-Layer Thickness, Barrow Penninsula, Northern Alaska

    NASA Astrophysics Data System (ADS)

    Klene, A. E.; Nelson, F. E.

    2014-12-01

    As development proceeds in the high latitudes, information about interactions between urban influences and the thickness of the active layer above permafrost becomes vital, particularly given the possibility of increasing temperatures accompanying climate change. Permafrost characteristics are often mapped at small geographical scales (i.e., over large areas), at low resolution, and without extensive field validation. Although maps of active-layer thickness (ALT) have been created for areas of relatively undisturbed terrain, this has rarely been done within urbanized areas, even though ALT is a critical factor in the design of roads, buildings, pipelines, and other elements of infrastructure. The need for detailed maps of ALT is emphasized in work on potential hazards in permafrost regions associated with global warming scenarios. Northern Alaska is a region considered to be at moderate to high risk for thaw-induced damage under climatic warming. The Native Village of Barrow (71°17'44"N; 156°45' 59"W), the economic, transportation, and administrative hub of the North Slope Borough, is the northernmost community in the USA, and the largest native settlement in the circum-Arctic. A winter urban heat island in Barrow, earlier snowmelt in the village, and dust deposition downwind of gravel pads and roads are all urban effects that could increase ALT. A recent empirical study documented a 17 to 41 cm difference in ALT between locations in the village of Barrow and surrounding undeveloped tundra, even in similar land-cover classes. We mapped ALT in the Barrow Peninsula, with particular attention to contrasts between the urbanized village and relatively undisturbed tundra in the nearby Barrow Environmental Observatory. The modified Berggren solution, an advanced analytic solution to the general Stefan problem of calculating frost and thaw depth, was used in a geographic context to map ALT over the 150 km² area investigated in the Barrow Urban Heat Island Study. The

  11. Biomarkers of contaminant exposure in northern pike (Esox lucius) from the Yukon River Basin, Alaska

    USGS Publications Warehouse

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Myers, M.S.; Gross, T.S.; Tillitt, D.E.

    2007-01-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P < 0.01). Vitellogenin concentrations in female (0.09 to 5.32 mg/mL) and male (0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm2), size (812 to 1481 ??m2), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (???63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship

  12. Identifying uncertainties for quantifying shrub encroachment in Northern Alaska using LiDAR

    NASA Astrophysics Data System (ADS)

    Magney, T. S.; Vierling, L. A.; Eitel, J.; Greaves, H.; Boelman, N.; Griffin, K. L.; Praeger, C.

    2013-12-01

    Climatic warming in the tundra biome has occurred at rates two to three times higher than the global average during the last 150 years, and is continuing at an unprecedented pace. Over the past few decades, Arctic tundra ecosystems have responded to climatic warming via shifts in vegetation composition and increased woody biomass. The resulting increases in size, abundance, and range of deciduous shrubs has affected ecosystem processes, causing shifts in carbon (C) and nitrogen (N) pools that could result in both positive and negative climate feedbacks. In Northern Alaska, the expansion of shrubs has increased by roughly 16% in land area since 1950; however, progress towards quantifying the impact of shrub expansion on biogeochemical cycling at regional scales is limited. Satellite remote sensing of the arctic has been proposed by many as a key tool to better quantify change and ecosystem responses to a warming tundra over large spatial extents, but has primarily only been inferred from multi-year trends of the Normalized Difference Vegetation Index (NDVI). These, and other passive remote sensing studies, have been complicated by the high cloud cover, low solar angle, and low levels of sunlight inherent to the arctic. Additionally, many such studies lack necessary ground validation, resulting in high levels of error, uncertainty, and misinterpretation of results. Improved techniques are therefore needed to quantify and scale how the dramatic biophysical and ecological changes occurring in arctic tundra ecosystems will affect C and N pools at local and regional scales. To address these problems, we tested the ability of active remote sensing (terrestrial (TLS) and airborne lidar (ALS)) at multiple spatial resolutions to better quantify aboveground shrub biomass, vertical, and horizontal canopy cover. Uncertainties in the ability of ALS to quantify shrub allometrics was determined using regression analysis with a stepwise selection procedure to determine the ideal

  13. Digital recovery, modification, and analysis of Tetra Tech seismic horizon mapping, National Petroleum Reserve Alaska (NPRA), northern Alaska

    USGS Publications Warehouse

    Saltus, R.W.; Kulander, Christopher S.; Potter, Christopher J.

    2002-01-01

    We have digitized, modified, and analyzed seismic interpretation maps of 12 subsurface stratigraphic horizons spanning portions of the National Petroleum Reserve in Alaska (NPRA). These original maps were prepared by Tetra Tech, Inc., based on about 15,000 miles of seismic data collected from 1974 to 1981. We have also digitized interpreted faults and seismic velocities from Tetra Tech maps. The seismic surfaces were digitized as two-way travel time horizons and converted to depth using Tetra Tech seismic velocities. The depth surfaces were then modified by long-wavelength corrections based on recent USGS seismic re-interpretation along regional seismic lines. We have developed and executed an algorithm to identify and calculate statistics on the area, volume, height, and depth of closed structures based on these seismic horizons. These closure statistics are tabulated and have been used as input to oil and gas assessment calculations for the region. Directories accompanying this report contain basic digitized data, processed data, maps, tabulations of closure statistics, and software relating to this project.

  14. Deep seismic structure and tectonics of northern Alaska: Crustal-scale duplexing with deformation extending into the upper mantle

    USGS Publications Warehouse

    Fuis, G.S.; Murphy, J.M.; Lutter, W.J.; Moore, T.E.; Bird, K.J.; Christensen, N.I.

    1997-01-01

    Seismic reflection and refraction and laboratory velocity data collected along a transect of northern Alaska (including the east edge of the Koyukuk basin, the Brooks Range, and the North Slope) yield a composite picture of the crustal and upper mantle structure of this Mesozoic and Cenozoic compressional orogen. The following observations are made: (1) Northern Alaska is underlain by nested tectonic wedges, most with northward vergence (i.e., with their tips pointed north). (2) High reflectivity throughout the crust above a basal decollement, which deepens southward from about 10 km depth beneath the northern front of the Brooks Range to about 30 km depth beneath the southern Brooks Range, is interpreted as structural complexity due to the presence of these tectonic wedges, or duplexes. (3) Low reflectivity throughout the crust below the decollement is interpreted as minimal deformation, which appears to involve chiefly bending of a relatively rigid plate consisting of the parautochthonous North Slope crust and a 10- to 15-km-thick section of mantle material. (4) This plate is interpreted as a southward verging tectonic wedge, with its tip in the lower crust or at the Moho beneath the southern Brooks Range. In this interpretation the middle and upper crust, or all of the crust, is detached in the southern Brooks Range by the tectonic wedge, or indentor: as a result, crust is uplifted and deformed above the wedge, and mantle is depressed and underthrust beneath this wedge. (5) Underthrusting has juxtaposed mantle of two different origins (and seismic velocities), giving rise to a prominent sub-Moho reflector. Copyright 1997 by the American Geophysical Union.

  15. 78 FR 13161 - Fisheries of the Exclusive Economic Zone Off Alaska; Gulf of Alaska; Final 2013 and 2014 Harvest...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-26

    ... December 5, 2012 (77 FR 72297). Comments were invited and accepted through January 4, 2013. NMFS did not... 2014 than the 2012 ABC sum of 606,048 mt (77 FR 15194, March 14, 2012). Specification and Apportionment... conjunction with the implementation of the Central Gulf of Alaska Rockfish Program in 2011 (76 FR...

  16. 75 FR 41999 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level...; modification of closure. SUMMARY: NMFS is reopening directed fishing for Pacific ocean perch by trawl catcher... Alaska (GOA). This action is necessary to fully use the 2010 directed fishing allowance of Pacific...

  17. A Review of Psychological and Educational Assessment of Northern American Indian/Alaska Native Children.

    ERIC Educational Resources Information Center

    Amos, Terese Lipinski

    1997-01-01

    Reviews the literature on psychological and educational assessment of American Indian and Alaska Native children, including the background psychological factors of biological deprivation, motivation, attitudes toward self, and traditional nonformal education. Discusses brain hemispheres, visuospatial skills, otitis media, fetal alcohol syndrome,…

  18. Evaluation of the anthropogenic radionuclide concentrations in sediments and fauna collected in the Beaufort Sea and northern Alaska

    SciTech Connect

    Efurd, D.W.; Miller, G.G.; Rokop, D.J.

    1997-07-01

    This study was performed to establish a quality controlled data set about the levels of radio nuclide activity in the environment and in selected biota in the U.S. Arctic. Sediment and biota samples were collected by the National Oceanic and Atmospheric Administration (NOAA), the National Biological Service, and the North Slope Borough`s Department of Wildlife Management to determine the impact of anthropogenic radionuclides in the Arctic. The results summarized in this report are derived from samples collected in northwest Alaska with emphasis on species harvested for subsistence in Barrow, Alaska. Samples were analyzed for the anthropogenic radionuclides {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu and {sup 241}Am. The naturally occurring radionuclides {sup 40}K, {sup 212}Pb and {sup 214}Pb were also measured. One goal of this study was to determine the amounts of anthropogenic radionuclides present in the Beaufort Sea. Sediment samples were isotopically fingerprinted to determine the sources of radio nuclide activities. Biota samples of subsistence and ecological value were analyzed to search for evidence of bio-accumulation of radionuclides and to determine the radiation exposures associated with subsistence living in northern Alaska. The anthropogenic radio nuclide content of sediments collected in the Beaufort Sea was predominantly the result of the deposition of global fallout. No other sources of anthropogenic radionuclides could be conclusively identified in the sediments. The anthropogenic radio nuclide concentrations in fish, birds and mammals were very low. Assuming that ingestion of food is an important pathway leading to human contact with radioactive contaminants and given the dietary patterns in coastal Arctic communities, it can be surmised that marine food chains are presently not significantly affected.

  19. A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska

    PubMed Central

    Valentich-Scott, Paul; Powell, Charles L.; II; Lorenson, Thomas D.; Edwards, Brian E.

    2014-01-01

    Abstract Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds. PMID:25589851

  20. Surveys of murre colony attendance in the northern Gulf of Alaska following the Exxon Valdez oil spill

    SciTech Connect

    Erikson, D.E.

    1995-12-31

    Field surveys were conducted in July and August 1991 on 32 of the 36 murre (Uria spp.) colonies in the northern Gulf of Alaska to assess colony attendance (number of birds present at a colony) two years after the exxon Valdez oil spill. The surveys focused on murre colonies because murres represented 74% of the recovered seabird carcasses and because it had claimed that there was large-scale mortality of murres, leading to 60% to 70% decreases at some large colonies and population recovery periods of 20 to 70 years. Murres were present at all 32 colonies, and colony attendance estimates were generally similar to those from historical (prespill) surveys, particularly for those colonies in the direct path of the spill, i.e., the Barren Islands and Chiswell islands. Colony attendance levels in 1991 do not support the contention that murre colony attendance in the study area was drastically lower than historical levels. When colonies were grouped according to risk of oil exposure, the mean changes in attendance between 1991 and historical murre surveys did not differ significantly among the groups. Factors that could account for the observed similarity of 1991 and historical murre counts despite the high estimated mortality are (1) overestimation of mortality or (2) replacement of lost breeders through either recruitment of formerly nonbreeding individuals into the breeding population at spill-affected colonies or immigration of murres form nonaffected colonies. The findings of this study suggest that impacts of the Exxon Valdez oil spill on murre colony attendance in the northern Gulf of alaska were relatively short-term. 118 refs., 5 figs., 8 tabs.

  1. 50 CFR 679.81 - Rockfish Program annual harvester privileges.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) If my vessel is checked-out and fishing in a directed flatfish fishery in the Central GOA and I catch... a directed flatfish fishery and checked-out of the Rockfish Program fisheries, you are not...

  2. 50 CFR 679.81 - Rockfish Program annual harvester privileges.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) If my vessel is checked-out and fishing in a directed flatfish fishery in the Central GOA and I catch... a directed flatfish fishery and checked-out of the Rockfish Program fisheries, you are not...

  3. Combined High-Resolution LIDAR Topography and Multibeam Bathymetry for Northern Resurrection Bay, Seward, Alaska

    USGS Publications Warehouse

    Labay, Keith A.; Haeussler, Peter J.

    2008-01-01

    A new Digital Elevation Model was created using the best available high-resolution topography and multibeam bathymetry surrounding the area of Seward, Alaska. Datasets of (1) LIDAR topography collected for the Kenai Watershed Forum, (2) Seward harbor soundings from the U.S. Army Corp of Engineers, and (3) multibeam bathymetry from the National Oceanic and Atmospheric Administration contributed to the final combined product. These datasets were placed into a common coordinate system, horizontal datum, vertical datum, and data format prior to being combined. The projected coordinate system of Universal Transverse Mercator Zone 6 North American Datum of 1927 was used for the horizontal coordinates. Z-values in meters were referenced to the tidal datum of Mean High Water. Gaps between the datasets were interpolated to create the final seamless 5-meter grid covering the area of interest around Seward, Alaska.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zoonotic parasites have been recognized as important causes of endemic and emerging human disease in northern North America and Greenland, with increased prevalence of some parasites in Indigenous and northern residents as compared to the general North American population. This is in part due to tr...

  5. A petroleum system model for gas hydrate deposits in northern Alaska

    USGS Publications Warehouse

    Lorenson, T.D.; Collett, Timothy S.; Wong, Florence L.

    2011-01-01

    Gas hydrate deposits are common on the North Slope of Alaska around Prudhoe Bay, however the extent of these deposits is unknown outside of this area. As part of a United States Geological Survey (USGS) and the Bureau of Land Management (BLM) gas hydrate research collaboration, well cutting and mud gas samples have been collected and analyzed from mainly industry-drilled wells on the Alaska North Slope for the purpose of prospecting for gas hydrate deposits. On the Alaska North Slope, gas hydrates are now recognized as an element within a petroleum systems approach or TPS (Total Petroleum System). Since 1979, 35 wells have been samples from as far west as Wainwright to Prudhoe Bay in the east. Geochemical studies of known gas hydrate occurrences on the North Slope have shown a link between gas hydrate and more deeply buried conventional oil and gas deposits. Hydrocarbon gases migrate from depth and charge the reservoir rock within the gas hydrate stability zone. It is likely gases migrated into conventional traps as free gas, and were later converted to gas hydrate in response to climate cooling concurrent with permafrost formation. Gas hydrate is known to occur in one of the sampled wells, likely present in 22 others based gas geochemistry and inferred by equivocal gas geochemistry in 11 wells, and absent in one well. Gas migration routes are common in the North Slope and include faults and widespread, continuous, shallowly dipping permeable sand sections that are potentially in communication with deeper oil and gas sources. The application of this model with the geochemical evidence suggests that gas hydrate deposits may be widespread across the North Slope of Alaska.

  6. McCall Glacier record of Arctic climate change: Interpreting a northern Alaska ice core with regional water isotopes

    NASA Astrophysics Data System (ADS)

    Klein, E. S.; Nolan, M.; McConnell, J.; Sigl, M.; Cherry, J.; Young, J.; Welker, J. M.

    2016-01-01

    We explored modern precipitation and ice core isotope ratios to better understand both modern and paleo climate in the Arctic. Paleoclimate reconstructions require an understanding of how modern synoptic climate influences proxies used in those reconstructions, such as water isotopes. Therefore we measured periodic precipitation samples at Toolik Lake Field Station (Toolik) in the northern foothills of the Brooks Range in the Alaskan Arctic to determine δ18O and δ2H. We applied this multi-decadal local precipitation δ18O/temperature regression to ∼65 years of McCall Glacier (also in the Brooks Range) ice core isotope measurements and found an increase in reconstructed temperatures over the late-20th and early-21st centuries. We also show that the McCall Glacier δ18O isotope record is negatively correlated with the winter bidecadal North Pacific Index (NPI) climate oscillation. McCall Glacier deuterium excess (d-excess, δ2H - 8*δ18O) values display a bidecadal periodicity coherent with the NPI and suggest shifts from more southwestern Bering Sea moisture sources with less sea ice (lower d-excess values) to more northern Arctic Ocean moisture sources with more sea ice (higher d-excess values). Northern ice covered Arctic Ocean McCall Glacier moisture sources are associated with weak Aleutian Low (AL) circulation patterns and the southern moisture sources with strong AL patterns. Ice core d-excess values significantly decrease over the record, coincident with warmer temperatures and a significant reduction in Alaska sea ice concentration, which suggests that ice free northern ocean waters are increasingly serving as terrestrial precipitation moisture sources; a concept recently proposed by modeling studies and also present in Greenland ice core d-excess values during previous transitions to warm periods. This study also shows the efficacy and importance of using ice cores from Arctic valley glaciers in paleoclimate reconstructions.

  7. Pliocene to Recent alkalic volcanic centers in southeast Alaska: western component of the Northern Cordilleran Volcanic Province

    NASA Astrophysics Data System (ADS)

    Karl, S.; Baichtal, J.; Calvert, A. T.; Layer, P.

    2011-12-01

    More than 25 volcanic centers, including 11 newly identified flows, ranging in age from 6 Ma to 110 years old and scattered throughout southeast (SE) Alaska, constitute a previously unrecognized western component of the Northern Cordilleran Volcanic Province (NCVP). The volcanic rocks are dominantly mafic, locally bimodal, high-Na alkalic rocks that have "within plate" element ratios and primitive 87/86Sri ratios at 0.703. Mafic rocks have average MgO/SiO2 ratios of 0.13, TiO2/MnO ratios of 13.86, Nb/Zr ratios of 0.13, and La/Nb ratios of 0.93 (n=43). Trace element chemistry for obsidian from Suemez Island is indistinguishable from that of obsidian from Mount Edziza in British Columbia. These volcanic rocks have similar compositions, ages, isotopic signatures, and chemistry to rocks of the NCVP and are underlain by the same Northern Cordilleran (Pacific-Juan de Fuca) slab window. Some volcanic fields have associated warm springs. The volcanoes and warm springs are located along structures, commonly N-S and NW-SE striking faults, indicating that their plumbing systems are controlled by extension along the Pacific-North America transform margin in the vicinity of SE Alaska. Widely distributed thermal springs in SE Alaska reflect an elevated geothermal gradient under SE Alaska related to the slab window. Volcanic flows and tephra overlie and underlie glacial and marine deposits. Flows have subaerial, subaqueous, and ice contact features. Pollen, foraminifer, tree ring, C14, and 40Ar/39Ar ages bracket the timing of volcanic flows, glacial advances and retreats, and subsidence and uplift of marine terraces. Basalts in Behm Canal yielded K-Ar ages of 6.1±0.18 Ma and 5.0±2 Ma. On Suemez Island, 2 rhyolite domes that yielded 40Ar/39Ar ages of 842±11 ka and 851±17 ka lie between glacial deposits and have ice contact features. A basalt flow that yielded a 40Ar/39Ar age of 367.7± 8.7 ka fills a deeply incised pre-existing fiord in Rudyerd Bay and has been carved by

  8. Novel poxvirus infection in northern and southern sea otters (Enhydra lutris kenyoni and Enhydra lutris neiris), Alaska and California, USA.

    PubMed

    Tuomi, Pamela A; Murray, Michael J; Garner, Michael M; Goertz, Caroline E C; Nordhausen, Robert W; Burek-Huntington, Kathleen A; Getzy, David M; Nielsen, Ole; Archer, Linda L; Maness, Heather T D; Wellehan, James F X; Waltzek, Thomas B

    2014-07-01

    Small superficially ulcerated skin lesions were observed between October 2009 and September 2011 during captive care of two orphaned sea otter pups: one northern (Enhydra lutris kenyoni) in Alaska and one southern (Enhydra lutris nereis) in California. Inclusions consistent with poxviral infection were diagnosed by histopathology in both cases. Virions consistent with poxvirus virions were seen on electron microscopy in the northern sea otter, and the virus was successfully propagated in cell culture. DNA extraction, pan-chordopoxviral PCR amplification, and sequencing of the DNA-dependent DNA polymerase gene revealed that both cases were caused by a novel AT-rich poxvirus. Bayesian and maximum likelihood phylogenetic analyses found that the virus is divergent from other known poxviruses at a level consistent with a novel genus. These cases were self-limiting and did not appear to be associated with systemic illness. To our knowledge, this is the first report of a poxvirus in a mustelid species. The source of this virus, mode of transmission, zoonotic potential, and biological significance are undetermined. PMID:24807180

  9. Effects of changing sea ice on marine mammals and subsistence hunters in northern Alaska from traditional knowledge interviews

    PubMed Central

    Quakenbush, Lori T.; Nelson, Mark

    2016-01-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access to them by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information relevant to understanding the ecosystem to which humans belong. We interviewed hunters in 11 coastal villages from the northern Bering Sea to the Beaufort Sea. Hunters reported extensive changes in sea ice and weather that have affected the timing of marine mammal migrations, their distribution and behaviour and the efficacy of certain hunting methods. Amidst these changes, however, hunters cited offsetting technological benefits, such as more powerful and fuel-efficient outboard engines. Other concerns included potential impacts to subsistence hunting from industrial activity such as shipping and oil and gas development. While hunters have been able to adjust to some changes, continued environmental changes and increased disturbance from human activity may further challenge their ability to acquire food in the future. There are indications, however, that innovation and flexibility provide sources of resilience. PMID:27555644

  10. Effects of changing sea ice on marine mammals and subsistence hunters in northern Alaska from traditional knowledge interviews.

    PubMed

    Huntington, Henry P; Quakenbush, Lori T; Nelson, Mark

    2016-08-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access to them by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information relevant to understanding the ecosystem to which humans belong. We interviewed hunters in 11 coastal villages from the northern Bering Sea to the Beaufort Sea. Hunters reported extensive changes in sea ice and weather that have affected the timing of marine mammal migrations, their distribution and behaviour and the efficacy of certain hunting methods. Amidst these changes, however, hunters cited offsetting technological benefits, such as more powerful and fuel-efficient outboard engines. Other concerns included potential impacts to subsistence hunting from industrial activity such as shipping and oil and gas development. While hunters have been able to adjust to some changes, continued environmental changes and increased disturbance from human activity may further challenge their ability to acquire food in the future. There are indications, however, that innovation and flexibility provide sources of resilience. PMID:27555644

  11. Movements of Blue Rockfish (Sebastes mystinus) off Central California with Comparisons to Similar Species

    PubMed Central

    Green, Kristen M.; Greenley, Ashley P.; Starr, Richard M.

    2014-01-01

    Olive (Sebastes serranoides), black (Sebastes melanops), and blue rockfish (Sebastes mystinus) are all common inhabitants of nearshore ecosystems on the West coast of North America and important components of the recreational fishery off California. Acoustic monitoring studies indicate that olive rockfish are highly residential and that black rockfish are capable of long migrations and have less site fidelity; yet little is known about the long-term movements of blue rockfish. External tag-recapture studies indicate that blue rockfish may have intermediate movements relative to these congener nearshore species. To better understand the site fidelity, and daily and seasonal movements of blue rockfish over long (>1-year) time scales, we placed acoustic transmitters into 21 adult blue rockfish (30–41 cm total length) in Carmel Bay, California. Blue rockfish displayed intermediate movement patterns and residency relative to other similar kelp forest rockfish species. Two-thirds of tagged blue rockfish (13 fish) exhibited high residency to the study area (>12 mo). When in residence, mean home range of blue rockfish was 0.23 km2, however as many as 30% of tagged blue rockfish shifted their core home range area during the study. Most shifts in home range occurred during upwelling season, and tagged fish moved up to 3.1 km when in residence. Blue rockfish with short residence times were last detected in the study area in late winter and early spring. Blue rockfish were observed at shallower depths during day than night, likely indicative of diurnal feeding. However, over longer time scales, blue rockfish were detected at deeper depths during upwelling periods and with increased wave heights. Daily and seasonal vertical movements of blue rockfish may be influenced by upwelling conditions and local prey abundance. PMID:24902049

  12. The northern coast plutonic-metamorphic complex, southeastern Alaska and northwestern British Columbia

    NASA Astrophysics Data System (ADS)

    Brew, D. A.; Ford, A. B.

    The northern Coast plutonic-metamorphic complex is but one segment of an 8,000-km-long batholithic complex that extends the length of the North American Cordillera from Baja, California to the Aleutian Islands. Different segments of the Cordilleran batholithic complex have significantly different features. This report documents the main characteristics and inferred evolutionary history of the northern Coast plutonic-metamorphic complex that should facilitate comparisons between segments.

  13. Persistent organochlorine pollutants in ringed seals and polar bears collected from northern Alaska

    USGS Publications Warehouse

    Kucklick, J.R.; Struntz, W.D.J.; Becker, P.R.; York, G.W.; O'Hara, T. M.; Bohonowych, J.E.

    2002-01-01

    Blubber samples from ringed seal (Phoca hispida; n=8) and polar bear subcutaneous fat (Ursus maritimus; n=5) were collected near Barrow, Alaska in 1996 as part of the Alaska Marine Mammal Tissue Archival Project (AMMTAP) and retained in the National Biomonitoring Specimen Bank at the National Institute of Standards and Technology in Gaithersburg, Maryland (USA). The samples were analyzed for a variety of persistent organochlorine pollutants (POPs) including polychlorinated biphenyls (PCBs), hexachlorocyclohexanes (HCHs), chlordane and metabolites, hexachlorobenzene (HCB) and DDTs and metabolites. The geometric mean, on a wet mass basis, of ??PCBs (sum of 29 congeners and congener groups) were 732??282 ng/g (1 S.D.) in seals and 3395??1442 ng/g in polar bears. The geometric mean of ??DDTs, ??HCHs (??-, ??- and ??- HCH) and HCB concentrations (wet mass basis) in seals and bears were 562??261 ng/g vs. 74.8??39 ng/g, 380??213 ng/g vs. 515 ng/g, and 17.4??10.1 ng/g vs. 183??153 ng/g, respectively. The geometric mean sum of chlordane (??chlordane, sum of cis- and trans-chlordane, cis- and trans-nonachlor, oxychlordane and heptachlor epoxide) and dieldrin concentrations in ringed seals and polar bears were 753??617 ng/g vs. 720??315 ng/g and 38.6??22.8 ng/g vs. 130??65 ng/g, respectively. Apparent bioaccumulation factors (polar bear/ringed seal POP concentrations) were lower in the animals sampled near Barrow, Alaska than in those from locations in the Canadian Arctic. This suggests that polar bears are also preying on marine mammals from lower trophic levels than the ringed seals with correspondingly lower organochlorine levels, such as bowhead whale carcasses. PCB congener patterns in the samples demonstrated the metabolism of certain PCB congeners in the polar bear relative to the ringed seal in agreement with previous studies. Regional comparisons of animals collected in Alaska and Arctic Canada are presented. Copyright ?? 2002 Elsevier Science B.V.

  14. Stratigraphic contrasts and tectonic relationships between Carboniferous successions in the Trans-Alaska Crustal Transect corridor and adjacent areas, northern Alaska

    USGS Publications Warehouse

    Dumoulin, J.A.; Watts, K.F.; Harris, A.G.

    1997-01-01

    The Carboniferous succession along the Trans-Alaska Crustal Transect (TACT) corridor in the Atigun Gorge area of the central Brooks Range consists of the Kayak Shale (Kinderhookian) and the Lisburne Group (Kinderhookian through Chesterian). The Kayak Shale is at least 210 m thick; it is chiefly black, noncalcareous shale with several limestone beds of pelmatozoan-bryozoan packstone and formed in an open-marine setting. The Lisburne Group is a carbonate rock succession about 650 m thick and consists mainly of skeletal packstone, wackestone, and mudstone which contain locally abundant calcispheres, ostracodes, algae, and sponge spicules; it accumulated largely in a shallow water platform environment with restricted circulation. This restriction was probably produced by a coeval belt of skeletal sand shoals recognized 70 km to the west in the Shainin Lake area. Significant and apparently abrupt shifts in the age and lithofacies of Carboniferous strata occur across the central and eastern Brooks Range. These shifts are most marked in a zone roughly coincident with what is interpreted by many workers to be the leading edge of the Endicott Mountains allochthon. Notable lithologic contrasts are also observed, however, between sections in the northern and southern parts of the Endicott Mountains allochthon. This suggests that considerable tectonic shortening has taken place within the allochthon, as well as between it and parautochthonous rocks to the northeast. The Carboniferous section near Mount Doonerak is more similar in age and lithofacies to coeval sections in the central Brooks Range that are considered allochthonous than to parautochthonous sections to the northeast. Copyright 1997 by the American Geophysical Union.

  15. 50 CFR Table 29 to Part 679 - Initial Rockfish QS Pools

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Initial Rockfish QS Pools 29 Table 29 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Pelagic Shelf Rockfish Pacific Ocean Perch Aggregate Primary Species Initial Rockfish QS Pool...

  16. 50 CFR Table 29 to Part 679 - Initial Rockfish QS Pools

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Initial Rockfish QS Pools 29 Table 29 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Pelagic Shelf Rockfish Pacific ocean perch Aggregate Primary Species Initial Rockfish QS Pool...

  17. 50 CFR Table 29 to Part 679 - Initial Rockfish QS Pools

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Initial Rockfish QS Pools 29 Table 29 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Pelagic Shelf Rockfish Pacific ocean perch Aggregate Primary Species Initial Rockfish QS Pool...

  18. Mapping the megathrust beneath the northern Gulf of Alaska using wide-angle seismic reflection/refraction profiles

    SciTech Connect

    Brocher, T.M.; Fuis, G.S.; Fisher, M.A.; Plafker, G.; Moses, M.J.; Taber, J.J. ); Christensen, N.I. . Dept. of Earth and Atmospheric Sciences)

    1993-04-01

    In the northern Gulf of Alaska and Prince William Sound, wide-angle seismic reflection/refraction profiling, earthquake studies, and laboratory measurements of physical properties are used to determine the geometry of the Prince William and Yakutat terranes, and the subducting Pacific plate. In this complex region, the Yakutat terrane is underthrust beneath the Prince William terrane, and both terranes are interpreted to be underlain by the Pacific plate. Wide-angle seismic reflection/refraction profiles recorded along 5 seismic lines are used to unravel this terrane geometry. Modeled velocities in the upper crust of the Prince William terrane (to 18-km depth) agree closely with laboratory velocity measurements of Orca Group phyllites and quartzofeldspathic graywackes (the chief components of the Prince William terrane) to hydrostatic pressures as high as 600 MPa (6 KBAR). An interpretation consistent with these data extends the Prince William terrane to at least 18-km depth. A landward dipping reflection at depths of 16--24 km is interpreted as the base of the Prince William terrane. This reflector corresponds to the top of the Wadati-Benioff zone seismicity and is interpreted as the megathrust. Beneath this reflector is a 6.9-km/s refractor, that is strongly reflective and magnetic, and is interpreted to be gabbro in Eocene age oceanic crust of the underthrust Yakutat terrane. Both wide-angle seismic and magnetic anomaly data indicate that the Yakutat terrane has been underthrust beneath the Prince William terrane for at least a few hundred kilometers. Wide-angle seismic data are consistent with a 9 to 10[degree] landward dip of the subducting Pacific plate, distinctly different from the inferred average 3 to 4[degree] dip of the overlying 6.9-km/s refractor and Wadati-Benioff seismic zone. The preferred interpretation of the geophysical data is that one composite plate, composed of the Pacific and Yakutat plates, is subducting beneath southern Alaska.

  19. Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in tissues of harbor seals (Phoca vitulina) from the northern Gulf of Alaska.

    PubMed

    Wang, Dongli; Atkinson, Shannon; Hoover-Miller, Anne; Li, Qing X

    2007-05-01

    Blubber, liver and kidney samples of harbor seals (Phoca vitulina) from the northern Gulf of Alaska were collected during 2000-2001 for the analysis of polychlorinated naphthalenes (PCNs) and coplanar polychlorinated biphenyls (CoplPCBs). On the lipid weight (lw) base, the total concentrations of PCNs (Sigma PCNs) ranged from 0.3 to 27 ng/g lw, and the total concentrations of CoplPCBs (Sigma CoplPCBs) were 3.6-546 ng/g lw in all the tissue samples. Di-ortho PCBs and mono-ortho PCBs were dominant followed by non-ortho PCBs and PCNs. Sigma Mono-ortho PCBs and Sigma di-ortho PCBs in nursing seals were apparently lower than those in male adult seals, but Sigma PCNs and Sigma non-ortho PCBs in female adults were not significantly different from those in male adults. Differences in PCNs and CoplPCBs congener profiles in female and male adult seals are apparently related to their chemical structure and properties, animal's developmental stages and physiological conditions. A large quantity of mono-ortho and di-ortho PCBs might be transferred to newborns from the nursing seals during lactation, while non-ortho PCBs and PCNs were relatively accumulative in the mother seals. Sigma PCNs and Sigma CoplPCBs in the harbor seals correlated with ages, gender, body weight and blubber thickness, but the blubber Sigma PCNs and Sigma CoplPCBs in Kodiak Island and Southern Alaska Peninsula (KIAP) did not significantly differ from those in Prince William Sound (PWS). In addition to the new PCB data, this first report on PCN contamination in Alaskan harbor seal tissues is useful for the wildlife and ecosystem management and human health protection. PMID:17223166

  20. Distribution, size, and interannual, seasonal and diel food habits of northern Gulf of Alaska juvenile pink salmon, Oncorhynchus gorbuscha

    NASA Astrophysics Data System (ADS)

    Armstrong, Janet L.; Boldt, Jennifer L.; Cross, Alison D.; Moss, Jamal H.; Davis, Nancy D.; Myers, Katherine W.; Walker, Robert V.; Beauchamp, David A.; Haldorson, Lewis J.

    2005-01-01

    An integral part of assessing the northern Gulf of Alaska (GOA) ecosystem is the analysis of the food habits and feeding patterns of abundant zooplanktivorous fish. Juvenile pink salmon Oncorhynchus gorbuscha are highly abundant zooplanktivores, and support valuable commercial fisheries as adults. We document variability in pink salmon distribution and size from summer to early fall, and present major trends in their food habits by summarizing interannual (August 1999-2001), seasonal (July-October 2001) and diel (August 2000, and July-September 2001) feeding patterns based on analysis of stomach contents of juvenile pink salmon collected along the Seward Line (GOA) and in Prince William Sound (PWS), Alaska. Diets of juvenile pink salmon were more diverse in 2001 compared to either 1999 or 2000. Small pteropods ( Limacina helicina) composed the majority (>60%) of prey consumed in 1999 and 2000; whereas large copepods, euphausiids, and small pteropods composed the majority of prey in 2001. As juvenile pink salmon increased in size, they consumed increasingly larger prey from August to October 2001 in the GOA. The diet of GOA juvenile pink salmon was different and more diverse than the diet of fish caught in PWS. The dominant prey in PWS during July-October was hyperiid amphipods, whereas the primary prey in the GOA were larvaceans and euphausiids in July, then copepods plus small pteropods, amphipods, euphausiids, larval crabs, and shrimp in August. In September and October, diets in both PWS and GOA included high percentages of larger prey items, including fish, euphausiids, and large pteropods ( Clio pyramidata). Diel comparisons of stomach contents showed pink salmon fed during daylight hours with stomach fullness increasing from dawn to a maximum fullness 8-12 h after sunrise, and declining thereafter. We hypothesize that juvenile pink salmon in the northern GOA consumed distinct and varied prey from the suite of zooplankton available during summer months, July

  1. Historical and contemporary imagery to assess ecosystem change on the Arctic coastal plain of northern Alaska

    USGS Publications Warehouse

    Tape, Ken D.; Pearce, John M.; Walworth, Dennis; Meixell, Brandt W.; Fondell, Tom F.; Gustine, David D.; Flint, Paul L.; Hupp, Jerry W.; Schmutz, Joel A.; Ward, David H.

    2014-01-01

    In this report, we describe and make available a set of 61 georectified aerial images of the Arctic Coastal Plain (taken from 1948 to 2010) that were obtained by the USGS to inform research objectives of the USGS CAE Initiative. Here, we describe the origins, metadata, and public availability of these images that were obtained within four main study areas on the Arctic Coastal Plain: Teshekpuk Lake Special Area, Chipp River, the Colville River Delta, and locations along the Dalton Highway Corridor between the Brooks Range and Deadhorse. We also provide general descriptions of observable changes to the geomorphology of landscapes that are apparent by comparing historical and contemporary images. These landscape changes include altered river corridors, lake drying, coastal erosion, and new vegetation communities. All original and georectified images and metadata are available through the USGS Alaska Science Center Portal (search under ‘Project Name’ using title of this report) or by contacting ascweb@usgs.gov.

  2. Monitoring Climate Variability and Change in Northern Alaska: Updates to the U.S. Geological Survey (USGS) Climate and Permafrost Monitoring Network

    NASA Astrophysics Data System (ADS)

    Urban, F. E.; Clow, G. D.; Meares, D. C.

    2004-12-01

    Observations of long-term climate and surficial geological processes are sparse in most of the Arctic, despite the fact that this region is highly sensitive to climate change. Instrumental networks that monitor the interplay of climatic variability and geological/cryospheric processes are a necessity for documenting and understanding climate change. Improvements to the spatial coverage and temporal scale of Arctic climate data are in progress. The USGS, in collaboration with The Bureau of Land Management (BLM) and The Fish and Wildlife Service (FWS) currently maintains two types of monitoring networks in northern Alaska: (1) A 15 site network of continuously operating active-layer and climate monitoring stations, and (2) a 21 element array of deep bore-holes in which the thermal state of deep permafrost is monitored. Here, we focus on the USGS Alaska Active Layer and Climate Monitoring Network (AK-CLIM). These 15 stations are deployed in longitudinal transects that span Alaska north of the Brooks Range, (11 in The National Petroleum Reserve Alaska, (NPRA), and 4 in The Arctic National Wildlife Refuge (ANWR)). An informative overview and update of the USGS AK-CLIM network is presented, including insight to current data, processing and analysis software, and plans for data telemetry. Data collection began in 1998 and parameters currently measured include air temperature, soil temperatures (5-120 cm), snow depth, incoming and reflected short-wave radiation, soil moisture (15 cm), wind speed and direction. Custom processing and analysis software has been written that calculates additional parameters such as active layer thaw depth, thawing-degree-days, albedo, cloudiness, and duration of seasonal snow cover. Data from selected AK-CLIM stations are now temporally sufficient to begin identifying trends, anomalies, and inter-annual variability in the climate of northern Alaska.

  3. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  4. Zooplankton biomass, advection and production on the northern Gulf of Alaska shelf from simulations and field observations

    NASA Astrophysics Data System (ADS)

    Coyle, K. O.; Gibson, G. A.; Hedstrom, K.; Hermann, A. J.; Hopcroft, R. R.

    2013-12-01

    Interpretation of zooplankton field observations on the Gulf of Alaska (GOA) shelf is complicated by the complex physical environment of currents, eddies and meanders which mix oceanic and coastal water masses to varying degrees. We therefore developed a lower trophic level model embedded in an ocean circulation model to examine the effects of wind, runoff and temperature on transport, biomass and production of microzooplankton and copepods on the northern GOA shelf and adjacent ocean. Mean microzooplankton biomass varied from 10-90 and 10-50 mg C m- 3 in the upper 50 m for field measurements and simulations respectively. Mean simulated and measured copepod biomass in the upper 100 m was about 1-40 g C m- 3. Field data indicated that Neocalanus biomass was negatively correlated with salinity in May. Simulations indicated that the negative correlation was due to elevated primary and secondary production on the shelf relative to the adjacent ocean. Floats programmed to simulate the ontogenetic vertical migrations of Neocalanus indicated that ~ 10 to 50% of Neocalanus originating near the shelf break spend at least some time on the shelf, depending on location. Residence time of floats on the shelf was affected primarily by wind, secondarily by runoff. Primary and secondary production in the simulations were highly correlated (r > 0.9). Simulated secondary production was 10-90 g C m- 2 y- 1, with highest values in Lower Cook Inlet, around Kodiak and west of Kodiak.

  5. Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

    USGS Publications Warehouse

    Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

    2011-01-01

    Investigations on the northern Seward Peninsula in Alaska identified zones of recent (<50years) permafrost collapse that led to the formation of floating vegetation mats along thermokarst lake margins. The occurrence of floating vegetation mat features indicates rapid degradation of near-surface permafrost and lake expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.

  6. Spatial and temporal diet segregation in northern fulmars Fulmarus glacialis breeding in Alaska: Insights from fatty acid signatures

    USGS Publications Warehouse

    Wang, S.W.; Iverson, S.J.; Springer, A.M.; Hatch, Shyla A.

    2009-01-01

    Northern fulmars Fulmarus glacialis in the North Pacific Ocean are opportunistic, generalist predators, yet their diets are poorly described; thus, relationships of fulmars to supporting food webs, their utility as indicators of variability in forage fish abundances, and their sensitivity to ecosystem change are not known. We employed fatty acid (FA) signature analysis of adipose tissue from adults (n = 235) and chicks (n = 33) to compare spatial, temporal, and age-related variation in diets of fulmars breeding at 3 colonies in Alaska. FA signatures of adult fulmars differed between colonies within years, and between seasons at individual colonies. Seasonal and spatial differences in signatures were greater than interannual differences at all colonies. Differences in FA signatures reflect differences in diets, probably because the breeding colonies are located in distinct ecoregions which create unique habitats for prey assemblages, and because interannual variation in the physical environment affects the availability of forage species. Differences between FA signatures of adults and chicks in 2003 and 2004 suggest that adults fed chicks different prey than they consumed themselves. Alternatively, if adults relied on the same prey as those fed to chicks, the differences in signatures could have resulted from partial digestion of prey items by adults before chicks were fed, or direct metabolism of FAs by chicks for tissue synthesis before FAs could be deposited into adipose tissue. ?? Inter-Research 2009.

  7. Using SAR Interferometry to Assess Infrastructure Hazards From Frozen Debris Lobes in Northern Alaska

    NASA Astrophysics Data System (ADS)

    McAlpin, D. B.; Meyer, F. J.; Darrow, M. M.; Gong, W.; Daanen, R. P.

    2015-12-01

    Frozen debris lobes (FDLs) are slow-moving earth flows along permafrost-affected slopes. FDLs consist of soil, rock, debris, and potentially ice, although only preliminary surface investigations have been conducted on these features thus far. Within the corridor of the 667 km Dalton Highway in Alaska's Brooks Range, we have identified 43 FDLs, with 23 occurring less than one mile upslope of the Dalton Highway and the Trans-Alaska Oil Pipeline (TAP), which runs parallel to the Dalton Highway. Due to their proximity to the highway and pipeline, FDLs pose significant risks to these key infrastructure assets. The closest FDL to the highway, FDL-A, is less than 41.5 m from the embankment when measured in August 2014, and could encroach upon the Dalton Highway/TAP within one year. Upon reaching the highway, FDLs could significantly impede the flow of essential goods and services to the oil and gas fields on the North Slope, creating severe economic losses. This study addresses the following two research goals: In an initial step, we assessed the performance of InSAR for FDL analysis as a function of data resolution, season, and vegetation cover. We were able to conclude that moderate resolution SAR systems are sufficient for monitoring FDLs during winter, when top surfaces are frozen and slopes are moving more consistently. In summer, however, surface flows show stronger spatial variation, and higher resolution sensors are required to preserve coherence and examine details. Subsequently, we began a long-term analysis of FDL behavior using SAR acquisitions over the last 20 years, expanded to include more recent data from the high-resolution TerraSAR-X sensor. We calculated flow parameters from the InSAR data and combined them with geological information from field measurements to perform a geophysical analysis of FDLs and assess their hazard potential. Our preliminary results show that (1) FDLs have been progressively moving down slope since the 1990s; (2) the down slope

  8. Winter and early spring CO2 efflux from tundra communities of northern Alaska

    NASA Astrophysics Data System (ADS)

    Fahnestock, J. T.; Jones, M. H.; Brooks, P. D.; Walker, D. A.; Welker, J. M.

    1998-11-01

    Carbon dioxide concentrations through snow were measured in different arctic tundra communities on the North Slope of Alaska during winter and early spring of 1996. Subnivean CO2 concentrations were always higher than atmospheric CO2. A steady state diffusion model was used to generate conservative estimates of CO2 flux to the atmosphere. The magnitude of CO2 efflux differed with tundra community type, and rates of carbon release increased from March to May. Winter CO2 efflux was highest in riparian and snow bed communities and lowest in dry heath, upland tussock, and wet sedge communities. Snow generally accrues earlier in winter and is deeper in riparian and snow bed communities compared with other tundra communities, which are typically windswept and do not accumulate much snow during the winter. These results support the hypothesis that early and deep snow accumulation may insulate microbial populations from very cold temperatures, allowing sites with earlier snow cover to sustain higher levels of activity throughout winter compared to communities that have later developing snow cover. Extrapolating our estimates of CO2 efflux to the entire snow-covered season indicates that total carbon flux during winter in the Arctic is 13-109 kg CO2-C ha-1, depending on the vegetation community type. Wintertime CO2 flux is a potentially important, yet largely overlooked, part of the annual carbon cycle of tundra, and carbon release during winter should be accounted for in estimates of annual carbon balance in arctic ecosystems.

  9. Early Mississippian (Tournaisian) ostracodes from the Lisburne test well, northern Alaska

    SciTech Connect

    Sohn, I.G.

    1989-01-01

    Anita G. Harris processed limestone sample 27660-PC, core 18, from a depth of 4968.84 to 4970.98 m in the Lisburne No. 1 test well, National Petroleum Reserve in Alaska, and recovered poorly preserved silicified ostracodes. The well is located in the disturbed belt, SE{1/4} sec. 17, T. 11 S., R. 16 W., lat 68{degree}29 0.54381, long 155{degree}41 35.510. A crushed duplicate sample from a depth of 4968.84 to 4970.37 m yielded a few unidentifiable fragments and steinkerns and one carapace of Microcheilinella Geis, 1933. The crushed limestone was dissolved in acetic acid, from which the fine material was periodically removed, and yielded additional poorly preserved replaced ostracodes, including some that were not represented in the original sample. The ostracodes indicate a probable Kinderhookian and (or) Osagan age for the rocks. The assemblage differs, on the species level, from congeneric Meramecian ostracodes in the Brooks Range, and there are a few taxa not found in the Meramecian assemblages. In addition to the ostracodes, steinkerns of minute gastropods and pelecypods, brachiopod and echinoderm spines, fish teeth, fragments of bryozoans, and one conodont were recovered. These associated fossils confirm that marine shelf environment indicated by the ostracodes: Because of poor preservation and meager representation of conspecific specimens, the ostracodes are illustrated in open nomenclature. The presently known stratigraphic ranges of the known genera are indicated.

  10. Hypotheses testing of watershed/landscape dynamics in northern Alaska using digital analysis

    SciTech Connect

    Evans, B.M.; Petersen, G.W.; Connors, K.F.

    1989-09-01

    Since July of 1985, Penn State scientists have been cooperating with investigators from other universities in several ecosystem studies at an existing Department of Energy (DOE) study site on the North Slope of Alaska. The primary focus of the REFLEX program is to test new applications of remote sensing systems and allied digital database processing techniques for studying hydrologic/ecologic interactions. One of the goals of this particular REFLEX project was to complement ongoing R4D studies near Toolik Lake. Since their initial cooperative efforts with R4D investigators at the R4D study site in Phase I, scientists (primarily G. Petersen and B. Evans), have been intimately involved with the Landscape Ecology Working Group, one of several such groups established within the R4D program. As part of the R4D program, the Landscape Ecology Working Group is focusing on landscape-scale patterns and interactions that have applications to long slopes, watersheds, and large regions of the Alaskan North Slope.

  11. Distribution and community characteristics of staging shorebirds on the northern coast of Alaska

    USGS Publications Warehouse

    Taylor, Audrey R.; Lanctot, Richard B.; Powell, Abby N.; Huettmann, Falk; Nigro, Debora A.; Kendall, Steven J.

    2010-01-01

    Avian studies conducted in the 1970s on Alaska’s Arctic Coastal Plain (ACP) indicated that coastal littoral habitats are important to Arctic-breeding shorebirds for staging prior to fall migration. However, relatively little recent, broad-scale, or quantitative information exists on shorebird use of staging areas in this region. To locate possible shorebird concentration areas in the littoral zone of the ACP, we conducted aerial surveys from the southwest end of Kasegaluk Lagoon on the Chukchi Sea to Demarcation Point on the Beaufort Sea during the summers of 2005–07. These surveys identified persistent within- and between-year concentrations of staging shorebirds at Peard Bay, Point Barrow/Elson Lagoon, Cape Simpson, and Smith Bay to Cape Halkett. Among river deltas in the Beaufort Sea, the Sagavanirktok and Kongakut deltas had large concentrations of staging shorebirds. We also collected data on shorebird community characteristics, staging phenology, and habitat use in 2005 and 2006 by conducting land-based surveys at six camps: Kasegaluk Lagoon, Peard Bay, Point Barrow/Elson Lagoon, Colville Delta, Sagavanirktok Delta, and Okpilak Delta. The shorebird community was more even and diverse (evenness E and Shannon Weiner H’) along the Beaufort Sea compared to the Chukchi Sea and in 2005 versus 2006. Staging phenology varied by species and location and differed for several species from that reported in previous studies. Our results suggest the existence of three foraging habitat guilds among the shorebird species observed in this study: gravel beach, mudflat, and salt marsh/pond edge. A comparison to data collected in the mid-1970s suggests that these foraging associations are conserved through time. Results from this research will be useful to land managers for monitoring the effects of changing environmental conditions and human activity on shorebirds and their habitats in Arctic Alaska.

  12. Geomorphological characteristics of Yedoma terrains in the northern part of Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Stephani, E.; Dillon, M.; Fortier, D.; Jorgenson, T.; Kanevskiy, M. Z.; Shur, Y.

    2009-12-01

    Yedoma (Ice Complex) is a Late Pleistocene periglacial formation of syngenetic permafrost with large ice wedges. These extremely ice-rich stratigraphic sequences have been widely observed and studied in northern Siberia. However, very few studies have focused on Yedoma terrain in Northern America. Occurrence of Yedoma landscape has a great significance for paleoenvironmental reconstructions because the regions where Yedoma can be observed remained unglaciated during the late Pleistocene. Understanding the dynamics of Yedoma landscape and the geotechnical properties of this permafrost unit is necessary for modeling the evolution of the periglacial landscape in the context of climate change. Degradation of Yedoma terrain triggers several geomorphological processes such as thaw settlement due to deepening of the active layer, development of thermokarst lakes, thermo-erosion gullies, and active layer detachment slides. Degradation of yedoma terrain also releases greenhouse gases (e.g. methane, CO2), water from melting ice, and various types of mineral and organic sediments which need to be accounted for in climate warming scenarios. Yedoma terrains in their contemporary state can be identified by the presence of typical geomorphological features such as erosional remnants with specific shape, baidjarakhs (ground mounds formed as a result of wedge-ice thawing), abundance of thermokarst lakes, drained lakes basins, low-gradient streams and erosion-thermokarst valleys (alas valleys) with occasional pingos. We have studied and characterized in the field the metrics of two Yedoma sites at the northern part of Seward Peninsula. Geomorphic sub-units such as drained lake basins and Yedoma remnants have been characterized in detail via optical leveling surveys. Bathymetry of thermokarst lakes was measured by lake-based sonar and GPS surveys. Drilling was conducted in several locations along the survey transects. The cores retrieved were described in the field in terms of

  13. Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain

    USGS Publications Warehouse

    Bentzen, R.L.; Powell, A.N.; Suydam, R.S.

    2008-01-01

    King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2 sites, Teshekpuk and Kuparuk, Alaska, USA, 2002-2005. We evaluated both a priori and exploratory competing models of nest survival that considered importance of nest concealment, seclusion, and incubation constancy as strategies to avoid 2 primary egg predators, avian (Larus spp., Stercorarius spp., and Corvus corax) and fox (Alopex lagopus). We used generalized nonlinear techniques to examine factors affecting nest survival rates and information-theoretic approaches to select among competing models. Estimated nest survival, accounting for a nest visitation effect, varied considerably across sites and years (0.21-0.57); however, given our small sample size, much of this variation maybe attributable to sampling variation (??process = 0.007, 95% CI: 0.003-0.070). Nest survival was higher at Kuparuk than Teshekpuk in all years; however, due to the correlative nature of our data, we cannot determine the underlying causes with any certainty. We found mixed support for the concealed breeding strategy, females derived no benefit from nesting in areas with more willow (Salix spp.; measure of concealment) except that the observer effect diminished as willow cover increased. We suggest these patterns are due to conflicting predation pressures. Nest survival was not higher on islands (measure of seclusion) or with increased incubation constancy but was higher post-fox removal, indicating that predator control on breeding grounds could be a viable management option. Nest survival was negatively affected by our nest visitations, most likely by exposing the nest to avian scavengers. We recommend precautions be taken to limit the effects of nest

  14. Orogenic Response to Augmented Erosion Associated with Northern Hemisphere Glaciation: The St. Elias Orogen of Alaska

    NASA Astrophysics Data System (ADS)

    Berger, A. L.; Gulick, S. P.; Spotila, J. A.; Worthington, L. L.; Upton, P.; Jaeger, J. M.; Pavlis, T. L.

    2009-12-01

    Active orogens are thought to behave as internally deforming critical-taper wedges that are in rough long-term equilibrium with regional boundary conditions. Deformation, kinematics, and the thermal evolution of orogenic systems are therefore believed to be significantly influenced by spatial and temporal variations in climate. The exact role of cryosphere-geosphere interactions in natural systems, however, continues to be elusive. Here we quantify the spatial patterns of denudation and deformation, and their temporal variations, in the heavily glaciated St Elias orogen in southern Alaska. The tractable size and high latitude of the St. Elias orogen provides an ideal setting to address the real world orogenic response to focused denudation and climate change. Independent of any known change in regional tectonic convergence rate, the St. Elias orogen was subjected to the most severe transition in climate during Cenozoic time, the Late Neogene and Pleistocene onset and advance of glaciers. Low-temperature bedrock thermochronometry, thermokinematic modelling, and offshore seismic reflection and borehole data demonstrate an association between augmented glacial denudation and orogenic evolution. Coeval with the onset of enhanced glacier coverage in mid-Pleistocene time, onshore denudation and offshore sedimentation accelerated ~ten-fold, with the highest rates of exhumation (4 km/Myr (±25%)) located around a narrow zone where the mean Quaternary glacial equilibrium line altitude (ELA) intersects mean topography on the windward flank of the orogen. This climatically driven mass redistribution coincided with the transfer of strain away the seaward deformation front as well as accelerated motion along both a backthrust running the length of the orogen and a series of forethrusts that lie beneath the zone of highest glacial flux. In a cause and effect response, the expansion of glaciers thus appears to have driven an orogen scale structural reorganization leading to the

  15. Preservation of labile organic matter in soils of drained thaw lakes in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Mueller, Carsten W.; Rethemeyer, Janet; Kao-Kniffin, Jenny; Löppmann, Sebastian; Hinkel, Kenneth; Bockheim, James

    2014-05-01

    A large number of studies predict changing organic matter (OM) dynamics in arctic soils due to global warming. In contrast to rather slowly altering bulk soil properties, single soil organic matter (SOM) fractions can provide a more detailed picture of the dynamics of differently preserved SOM pools in climate sensitive arctic regions. By the study of the chemical composition of such distinctive SOM fractions using nuclear magnetic resonance spectroscopy (NMR) together with radiocarbon analyses it is possible to evaluate the stability of the major OM pools. Approximately 50-75% of Alaska's Arctic Coastal Plain is covered with thaw lakes and drained thaw lakes that follow a 5,000 yr cycle of development (between creation and final drainage), thus forming a natural soil chronosequence. The drained thaw lakes offer the possibility to study SOM dynamics affected by permafrost processes over millennial timescales. In April 2010 we sampled 16 soil cores (including the active and permanent layer) reaching from young drained lakes (0-50 years since drainage) to ancient drained lakes (3000-5500 years since drainage). Air dried soil samples from soil horizons of the active and permanent layer were subjected to density fractionation in order to differentiate particulate OM and mineral associated OM. The chemical composition of the SOM fractions was analyzed by 13C CPMAS NMR spectroscopy. For a soil core of a young and an ancient drained thaw lake basin we also analyzed the 14C content. For the studied soils we can show that up to over 25 kg OC per square meter are stored mostly as labile, easily degradable organic matter rich in carbohydrates. In contrast only 10 kg OC per square meter were sequestered as presumably more stable mineral associated OC dominated by aliphatic compounds. Comparable to soils of temperate regions, we found small POM (< 20 µm) occluded in aggregated soil structures which differed in the chemical composition from larger organic particles. This was

  16. Depositional setting and geochemistry of phosphorites and metalliferous black shales in the Carboniferous-Permian Lisburne Group, Northern Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.; Slack, John F.; Whalen, Michael T.; Harris, Anita G.

    2011-01-01

    Phosphatic rocks are distributed widely in the Lisburne Group, a mainly Carboniferous carbonate succession that occurs throughout northern Alaska. New sedimentologic, paleontologic, and geochemical data presented here constrain the geographic and stratigraphic extent of these strata and their depositional and paleogeographic settings. Our findings support models that propose very high oxygen contents of the Permo-Carboniferous atmosphere and oceans, and those that suggest enhanced phosphogenesis in iron-limited sediments; our data also have implications for Carboniferous paleogeography of the Arctic. Lisburne Group phosphorites range from granular to nodular, are interbedded with black shale and lime mudstone rich in radiolarians and sponge spicules, and accumulated primarily in suboxic outer- to middle-ramp environments. Age constraints from conodonts, foraminifers, and goniatite cephalopods indicate that most are middle Late Mississippian (early Chesterian; early late Visean). Phosphorites form 2- to 40-cm-thick beds of sand- to pebble-sized phosphatic peloids, coated grains, and (or) bioclasts cemented by carbonate, silica, or phosphate that occur through an interval =12 m thick. High gamma-ray response through this interval suggests strongly condensed facies related to sediment starvation and development of phosphatic hardgrounds. Phosphorite textures, such as unconformity-bounded coated grains, record multiple episodes of phosphogenesis and sedimentary reworking. Sharp bed bases and local grading indicate considerable redeposition of phosphatic material into deeper water by storms and (or) gravity flows. Lisburne Group phosphorites contain up to 37 weight percent P2O5, 7.6 weight percent F, 1,030 ppm Y, 517 ppm La, and 166 ppm U. Shale-normalized rare earth element (REE) plots show uniformly large negative Ce anomalies Ce/Ce*=0.11 + or - 0.03) that are interpreted to reflect phosphate deposition in seawater that was greatly depleted in Ce due to increased

  17. Methods to assess natural and anthropogenic thaw lake drainage on the western Arctic coastal plain of northern Alaska

    USGS Publications Warehouse

    Hinkel, Kenneth M.; Jones, Benjamin M.; Eisner, Wendy R.; Cuomo, Chris J.; Beck, R.A.; Frohn, R.

    2007-01-01

    Thousands of lakes are found on the Arctic Coastal Plain of northern Alaska and northwestern Canada. Developed atop continuous permafrost, these thaw lakes and associated drained thaw lake basins are the dominant landscape elements and together cover 46% of the 34,570 km2western Arctic Coastal Plain (WACP). Lakes drain by a variety of episodic processes, including coastal erosion, stream meandering, and headward erosion, bank overtopping, and lake coalescence. Comparison of Landsat multispectral scanner (MSS) imagery from the mid-1970s to Landsat 7 enhanced thematic mapper (ETM+) imagery from around 2000 shows that 50 lakes completely or partially drained over the approximately 25 year period, indicating landscape stability. The lake-specific drainage mechanism can be inferred in some cases and is partially dependant on geographic settings conducive to active erosion such as riparian and coastal zones. In many cases, however, the cause of drainage is unknown. The availability of high-resolution aerial photographs for the Barrow Peninsula extends the record back to circa 1950; mapping spatial time series illustrates the dynamic nature of lake expansion, coalescence, and drainage. Analysis of these historical images suggests that humans have intentionally or inadvertently triggered lake drainage near the village of Barrow. Efforts to understand landscape processes and identify events have been enhanced by interviewing Iñupiaq elders and others practicing traditional subsistence lifestyles. They can often identify the year and process by which individual lakes drained, thereby providing greater dating precision and accuracy in assessing the causal mechanism. Indigenous knowledge has provided insights into events, landforms, and processes not previously identified or considered.

  18. A landscape-scale model of yellow-billed loon (Gavia adamsii) habitat preferences in northern alaska

    USGS Publications Warehouse

    Earnst, S.L.; Platte, R.; Bond, L.

    2006-01-01

    We modeled yellow-billed loon (Gavia adamsii) habitat preferences in a 23,500 km2 area of northern Alaska using intensive aerial surveys and landscape-scale habitat descriptors. Of the 757 lakes censused, yellow-billed loons occupied 15% and Pacific loons (G. pacifica) 42%. Lake area, depth, proportion of shoreline in aquatic vegetation, shoreline complexity, hydrological connectivity (stream present within 100 m or absent), and an area-connectivity interaction were positive, significant predictors of yellow-billed loon presence in a multivariate logistic regression model, but distance to nearest river or Beaufort Sea coast were not. Predicted yellow-billed loon presence was 13 and 4.7 times more likely on deep and medium lakes, respectively, than on shallow lakes that freeze to the bottom. On small lakes (<60 ha), predicted yellow-billed loon presence was 4.8-1.7 times more likely on lakes with hydrological connectivity than without, but connectivity was not important at most lake sizes (65-750 ha). Yellow-billed loon broods depend on fish available in the brood-rearing lake, and we suggest that a dependable supply of fish is more likely in larger lakes, those deep enough to have open water under winter ice, and those near streams. Highly convoluted shorelines and those with aquatic vegetation provide loon nesting and brood-rearing sites, as well as fish habitat. Pacific loon absence was a significant, positive predictor when added to the habitat model, indicating that yellow-billed loons were four times more likely on lakes without Pacific loons. ?? Springer 2006.

  19. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    USGS Publications Warehouse

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

    2012-01-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  20. Methods to assess natural and anthropogenic thaw lake drainage on the western Arctic coastal plain of northern Alaska

    NASA Astrophysics Data System (ADS)

    Hinkel, Kenneth M.; Jones, Benjamin M.; Eisner, Wendy R.; Cuomo, Chris J.; Beck, Richard A.; Frohn, Robert

    2007-06-01

    Thousands of lakes are found on the Arctic Coastal Plain of northern Alaska and northwestern Canada. Developed atop continuous permafrost, these thaw lakes and associated drained thaw lake basins are the dominant landscape elements and together cover 46% of the 34,570 km2 western Arctic Coastal Plain (WACP). Lakes drain by a variety of episodic processes, including coastal erosion, stream meandering, and headward erosion, bank overtopping, and lake coalescence. Comparison of Landsat multispectral scanner (MSS) imagery from the mid-1970s to Landsat 7 enhanced thematic mapper (ETM+) imagery from around 2000 shows that 50 lakes completely or partially drained over the approximately 25 year period, indicating landscape stability. The lake-specific drainage mechanism can be inferred in some cases and is partially dependant on geographic settings conducive to active erosion such as riparian and coastal zones. In many cases, however, the cause of drainage is unknown. The availability of high-resolution aerial photographs for the Barrow Peninsula extends the record back to circa 1950; mapping spatial time series illustrates the dynamic nature of lake expansion, coalescence, and drainage. Analysis of these historical images suggests that humans have intentionally or inadvertently triggered lake drainage near the village of Barrow. Efforts to understand landscape processes and identify events have been enhanced by interviewing Iñupiaq elders and others practicing traditional subsistence lifestyles. They can often identify the year and process by which individual lakes drained, thereby providing greater dating precision and accuracy in assessing the causal mechanism. Indigenous knowledge has provided insights into events, landforms, and processes not previously identified or considered.

  1. 50 CFR 679.83 - Rockfish Program entry level fishery.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Rockfish Program entry level fishery. 679.83 Section 679.83 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE...

  2. 50 CFR 679.83 - Rockfish Program entry level fishery.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Rockfish Program entry level fishery. 679.83 Section 679.83 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE...

  3. 50 CFR 660.371 - Black rockfish fishery management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Black rockfish fishery management. 660.371 Section 660.371 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES West...

  4. A microsatellite genetic linkage map of black rockfish ( Sebastes schlegeli)

    NASA Astrophysics Data System (ADS)

    Chu, Guannan; Jiang, Liming; He, Yan; Yu, Haiyang; Wang, Zhigang; Jiang, Haibin; Zhang, Quanqi

    2014-12-01

    Ovoviviparous black rockfish ( Sebastes schlegeli) is an important marine fish species for aquaculture and fisheries in China. Genetic information of this species is scarce because of the lack of microsatellite markers. In this study, a large number of microsatellite markers of black rockfish were isolated by constructing microsatellite-enriched libraries. Female- and male-specific genetic linkage maps were constructed using 435 microsatellite markers genotyped in a full-sib family of the fish species. The female linkage map contained 140 microsatellite markers, in which 23 linkage groups had a total genetic length of 1334.1 cM and average inter-marker space of 13.3 cM. The male linkage map contained 156 microsatellite markers, in which 25 linkage groups had a total genetic length of 1359.6 cM and average inter-marker distance of 12.4 cM. The genome coverage of the female and male linkage maps was 68.6% and 69.3%, respectively. The female-to-male ratio of the recombination rate was approximately 1.07:1 in adjacent microsatellite markers. This paper presents the first genetic linkage map of microsatellites in black rockfish. The collection of polymorphic markers and sex-specific linkage maps of black rockfish could be useful for further investigations on parental assignment, population genetics, quantitative trait loci mapping, and marker-assisted selection in related breeding programs.

  5. Spatio-temporal analysis of gyres in oriented lakes on the Arctic Coastal Plain of northern Alaska based on remotely sensed images

    USGS Publications Warehouse

    Zhan, Shengan; Beck, Richard A.; Hinkel, Kenneth M.; Liu, Hongxing; Jones, Benjamin M.

    2014-01-01

    The formation of oriented thermokarst lakes on the Arctic Coastal Plain of northern Alaska has been the subject of debate for more than half a century. The striking elongation of the lakes perpendicular to the prevailing wind direction has led to the development of a preferred wind-generated gyre hypothesis, while other hypotheses include a combination of sun angle, topographic aspect, and/or antecedent conditions. A spatio-temporal analysis of oriented thermokarst lake gyres with recent (Landsat 8) and historical (Landsat 4, 5, 7 and ASTER) satellite imagery of the Arctic Coastal Plain of northern Alaska indicates that wind-generated gyres are both frequent and regionally extensive. Gyres are most common in lakes located near the Arctic coast after several days of sustained winds from a single direction, typically the northeast, and decrease in number landward with decreasing wind energy. This analysis indicates that the conditions necessary for the Carson and Hussey (1962) wind-generated gyre for oriented thermokarst lake formation are common temporally and regionally and correspond spatially with the geographic distribution of oriented lakes on the Arctic Coastal Plain. Given an increase in the ice-free season for lakes as well as strengthening of the wind regime, the frequency and distribution of lake gyres may increase. This increase has implications for changes in northern high latitude aquatic ecosystems, particularly if wind-generated gyres promote permafrost degradation and thermokarst lake expansion.

  6. Ecological, morphological, and molecular studies of Acanthocheilonema odendhali (Nematoda: Filarioidea) in northern fur seals (Callorhinus ursinus) on St. Paul Island, Alaska.

    PubMed

    Kuzmina, T A; Kuzmin, Y I; Tkach, V V; Spraker, T R; Lyons, E T

    2013-09-01

    Studies of northern fur seal (Callorhinus ursinus Linnaeus, 1758) infection by the filariid nematode Acanthocheilonema odendhali were carried out in 2011-2012 on St. Paul Island, Pribilof Archipelago, Alaska. Skins of 502 humanely harvested northern fur seals from haul-out areas of five rookeries, Polovina (n = 122), Morjovi (n = 54), Zapadni (n = 72), Lukanin (n = 109), and Gorbatch (n = 145), were examined. A. odendhali was found in 18% of northern fur seals. The prevalence of infection ranged from 12.5% up to 22.9% on different haul-out areas on the island. The mean intensity of infection was 1.3 (range 1-7). Detailed morphological examination of collected specimens was performed using light microscopy. Several characters were added to the morphological description of the species, among them lateral thickening of the body cuticle, especially prominent in males, variations in number and position of genital papillae in males, transverse striation of the cuticle, and terminal dilation on tail end in microfilariae. The adult specimens studied had a shorter esophagus than type specimens from the California sea lion described by Perry (1967). Comparison of partial sequences of the mitochondrial cox1 gene from specimens collected from five sampling sites on St. Paul Island and a specimen from the type host and territory in California showed no significant differences and strongly supported conspecificity of the material from Alaska with A. odendhali. PMID:23760875

  7. 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

  8. 76 FR 39790 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by trawl catcher vessels...). This action is necessary ] to prevent exceeding the 2011 directed fishing allowance of Pacific...

  9. 75 FR 38936 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher Vessels Participating in the Rockfish Entry Level...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by trawl catcher vessels...). This action is necessary to prevent exceeding the 2010 directed fishing allowance of Pacific...

  10. 76 FR 43934 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors Participating in the Rockfish Limited...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by catcher/processors...). This action is necessary to prevent exceeding the 2011 total allowable catch (TAC) of Pacific...

  11. 75 FR 42337 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... Economic Zone Off Alaska; Pacific Ocean Perch for Catcher/Processors Participating in the Rockfish Limited...; closure. SUMMARY: NMFS is prohibiting directed fishing for Pacific ocean perch by catcher/processors...). This action is necessary to prevent exceeding the 2010 total allowable catch (TAC) of Pacific...

  12. Lateglacial and Holocene isotopic and environmental history of northern coastal Alaska - Results from a buried ice-wedge system at Barrow

    NASA Astrophysics Data System (ADS)

    Meyer, Hanno; Schirrmeister, Lutz; Andreev, Andrei; Wagner, Dirk; Hubberten, Hans-W.; Yoshikawa, Kenji; Bobrov, Anatoly; Wetterich, Sebastian; Opel, Thomas; Kandiano, Evgeniya; Brown, Jerry

    2010-12-01

    Barrow, the northernmost point in Alaska, is one of the most intensively studied areas in the Arctic. However, paleoenvironmental evidence is limited for northern Alaska for the Lateglacial-Holocene transition. For a regional paleoenvironmental reconstruction, we investigated a permafrost ice-wedge tunnel near Barrow, Alaska. The studied site was first excavated in the early 1960s and intercepts a buried ice-wedge system at 3-6 m depth below the surface. A multi-methodological approach was applied to this buried ice-wedge system and the enclosing sediments, which in their combination, give new insight into the Late Quaternary environmental and climate history. Results of geochronological, sedimentological, cryolithological, paleoecological, isotope geochemical and microbiological studies reflect different stages of mid to late Wisconsin (MW to LW), Allerød (AD), Younger Dryas (YD), Preboreal (PB), and Late Holocene paleoenvironmental evolution. The LW age of the site is indicated by AMS dates in the surrounding sediments of 21.7 kyr BP at the lateral contact of the ice-wedge system as well as 39.5 kyr BP below the ice-wedge system. It is only recently that in this region, stable isotope techniques have been employed, i.e. to characterize different types of ground ice. The stable isotope record (oxygen: δ 18O; hydrogen: δ D) of two intersecting ice wedges suggests different phases of the northern Alaskan climate history from AD to PB, with radiocarbon dates from 12.4 to 9.9 kyr BP (ranging from 14.8 to 10.6 kyr cal BP). Stable isotope geochemistry of ice wedges reveals winter temperature variations of the Lateglacial-Holocene transition including a prominent YD cold period, clearly separated from the warmer AD and PB phases. YD is only weakly developed in summer temperature indicators (such as pollen) for the northern Alaska area, and by consequence, the YD cold stadial was here especially related to the winter season. This highlights that the combination of

  13. Changes in vegetation in northern Alaska under scenarios of climate change, 2003-2100: implications for climate feedbacks.

    PubMed

    Euskirchen, E S; McGuire, A D; Chapin, F S; Yi, S; Thompson, C C

    2009-06-01

    Assessing potential future changes in arctic and boreal plant species productivity, ecosystem composition, and canopy complexity is essential for understanding environmental responses under expected altered climate forcing. We examined potential changes in the dominant plant functional types (PFTs) of the sedge tundra, shrub tundra, and boreal forest ecosystems in ecotonal northern Alaska, USA, for the years 2003-2100. We compared energy feedbacks associated with increases in biomass to energy feedbacks associated with changes in the duration of the snow-free season. We based our simulations on nine input climate scenarios from the Intergovernmental Panel on Climate Change (IPCC) and a new version of the Terrestrial Ecosystem Model (TEM) that incorporates biogeochemistry, vegetation dynamics for multiple PFTs (e.g., trees, shrubs, grasses, sedges, mosses), multiple vegetation pools, and soil thermal regimes. We found mean increases in net primary productivity (NPP) in all PFTs. Most notably, birch (Betula spp.) in the shrub tundra showed increases that were at least three times larger than any other PFT. Increases in NPP were positively related to increases in growing-season length in the sedge tundra, but PFTs in boreal forest and shrub tundra showed a significant response to changes in light availability as well as growing-season length. Significant NPP responses to changes in vegetation uptake of nitrogen by PFT indicated that some PFTs were better competitors for nitrogen than other PFTs. While NPP increased, heterotrophic respiration (RH) also increased, resulting in decreases or no change in net ecosystem carbon uptake. Greater aboveground biomass from increased NPP produced a decrease in summer albedo, greater regional heat absorption (0.34 +/- 0.23 W x m(-2) x 10 yr(-1) [mean +/- SD]), and a positive feedback to climate warming. However, the decrease in albedo due to a shorter snow season (-5.1 +/- 1.6 d/10 yr) resulted in much greater regional heat

  14. Controls on northern wetland methane emissions: insights from regional synthesis studies and the Alaska Peatland Experiment (APEX)

    NASA Astrophysics Data System (ADS)

    Turetsky, M. R.; Euskirchen, E. S.; Czimczik, C. I.; Waldrop, M. P.; Olefeldt, D.; Fan, Z.; Kane, E. S.; McGuire, A. D.; Harden, J. W.

    2014-12-01

    Wetlands are the largest natural source of atmospheric methane. Static chambers have been used to quantify variation in wetland CH4 flux for many decades. Regional to global scale synthesis studies of static chamber measurements show that relationships between temperature, water availability and CH4 emissions depend on wetland type (bog, fen, swamp), region (tropical, temperate, arctic) and disturbance. For example, while water table position and temperature serve as the dominant controls on bog and swamp CH4 flux, vegetation is an important control on emissions from fens. These studies highlight the fact that wetland types have distinct controls on CH4 emissions; however, it is unlikely that modeling of wetland CH4 flux will improve without a better mechanistic understanding of the processes underlying CH4 production, transport, and oxidation. At the Alaska Peatland Experiment, we are quantifying CH4 emission using static chambers, automated chambers, and towers. Our sites vary in permafrost regime, including groundwater fens without permafrost, forested peat plateaus with intact permafrost, and collapse scar bogs formed through permafrost thaw. Experimental studies that examine plant and microbial responses to altered water table position and soil temperature are complemented by a gradient approach, where we use a space-for-time substitutions to examine the consequences of thaw on time-scales of decades to centuries. Our results thus far have documented the importance of soil rewetting in governing large CH4 fluxes from northern wetland soils. Accounting for CH4, our collapse scar bog significantly contributed to the global warming potential of the landscape. A major objective of our work is to explore the role of permafrost C release in greenhouse gas fluxes from wetland soils, which we are assessing using radiocarbon as a natural tracer. We have shown, for example, that ebullition of CH4 is dominated by recently fixed C, but a significant fraction of CH4 in

  15. Changes in vegetation in northern Alaska under scenarios of climate change, 2003-2100: implications for climate feedbacks

    USGS Publications Warehouse

    Euskirchen, Eugénie S.; McGuire, Anthony David; Chapin, F. Stuart, III; Yi, S.; Thompson, Catharine Copass

    2009-01-01

    Assessing potential future changes in arctic and boreal plant species productivity, ecosystem composition, and canopy complexity is essential for understanding environmental responses under expected altered climate forcing. We examined potential changes in the dominant plant functional types (PFTs) of the sedge tundra, shrub tundra, and boreal forest ecosystems in ecotonal northern Alaska, USA, for the years 2003–2100. We compared energy feedbacks associated with increases in biomass to energy feedbacks associated with changes in the duration of the snow-free season. We based our simulations on nine input climate scenarios from the Intergovernmental Panel on Climate Change (IPCC) and a new version of the Terrestrial Ecosystem Model (TEM) that incorporates biogeochemistry, vegetation dynamics for multiple PFTs (e.g., trees, shrubs, grasses, sedges, mosses), multiple vegetation pools, and soil thermal regimes. We found mean increases in net primary productivity (NPP) in all PFTs. Most notably, birch (Betula spp.) in the shrub tundra showed increases that were at least three times larger than any other PFT. Increases in NPP were positively related to increases in growing-season length in the sedge tundra, but PFTs in boreal forest and shrub tundra showed a significant response to changes in light availability as well as growing-season length. Significant NPP responses to changes in vegetation uptake of nitrogen by PFT indicated that some PFTs were better competitors for nitrogen than other PFTs. While NPP increased, heterotrophic respiration (RH) also increased, resulting in decreases or no change in net ecosystem carbon uptake. Greater aboveground biomass from increased NPP produced a decrease in summer albedo, greater regional heat absorption (0.34 ± 0.23 W·m−2·10 yr−1 [mean ± SD]), and a positive feedback to climate warming. However, the decrease in albedo due to a shorter snow season (−5.1 ± 1.6 d/10 yr) resulted in much greater regional heat

  16. A model study of the Copper River plume and its effects on the northern Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Wang, Yuan; Xue, Huijie; Chai, Fei; Chao, Yi; Farrara, John

    2014-01-01

    A three-level nested Regional Ocean Modeling System was used to examine the seasonal evolution of the Copper River (CR) plume and how it influences the along- and across-shore transport in the northern Gulf of Alaska (NGoA). A passive tracer was introduced in the model to delineate the growth and decay of the plume and to diagnose the spread of the CR discharge in the shelf, into Prince William Sound (PWS) and offshore. Furthermore, a model experiment with doubled discharge was conducted to investigate potential impacts of accelerated glacier melt in future climate scenarios. The 2010 and 2011 simulation revealed that the upstream (eastward) transport in the NGoA is negligible. About 60 % of the passive tracer released in the CR discharge is transported southwestward on the shelf, while another one third goes into PWS with close to 60 % of which exiting PWS to the shelf from Montague Strait. The rest few percent is transported across the shelf break and exported to the GoA basin. The downstream transport and the transport into PWS are strongly regulated by the downwelling-favorable wind, while the offshore transport is related to the accumulation of plume water in the shelf, frontal instability, and the Alaskan Stream. It takes weeks in spring for the buoyancy to accumulate so that a bulge forms outside of the CR estuary. The absence of strong storms as in the summer of 2010 allows the bulge continue growing to trigger frontal instability. These frontal features can interact with the Alaskan Stream to induce transport pulses across the shelf break. Alternatively as in 2011, a downwelling-favorable wind event in early August (near the peak discharge) accelerates the southwestward coastal current and produces an intense downstream transport event. Both processes result in fast drains of the buoyancy and the plume content, thereby rapid disintegration of the plume in the shelf. The plume in the doubled discharge case can be two to three times in size, which affects

  17. A model study of the Copper River plume and its effect on the northern Gulf of Alaska (Invited)

    NASA Astrophysics Data System (ADS)

    Xue, H.; Wang, Y.; Chai, F.; Chao, Y.

    2013-12-01

    Using a three-level nested Regional Ocean Modeling System coupled with the Carbon, Silicate, Nitrogen Ecosystem model, this study illustrated the seasonal evolution of the Copper River (CR) plume and how it influences the along- and across-shore transport in the northern Gulf of Alaska (NGoA). A passive tracer was introduced in the model to delineate the growth and decay of the plume and to diagnose the spread of the CR discharge in the shelf, into Prince William Sound (PWS) and offshore. Furthermore, a model experiment with doubled discharge was conducted to investigate potential impacts of accelerated glacier melt in future climate scenarios. The 2010 and 2011 simulation revealed that the upstream (eastward) transport in the NGoA is almost nil. About 60% of the passive tracer released in the CR discharge is transported southwestward on the shelf, while another one third goes into PWS with close to 60% of which exiting PWS to the shelf from Montague Strait. The rest few percent is transported across the shelf break and exported to the GoA basin. The downstream transport and the transport into PWS are regulated by the downwelling favorable wind, while the offshore transport is related to the accumulation of plume water in the shelf, frontal instability and the Alaskan Stream. The CR plume appears to decay much faster than its formation. It takes weeks for the buoyancy to accumulate so that a bulge forms outside of the CR estuary. If the wind remains calm as in the summer of 2010, the bulge continues growing to trigger frontal instability. These frontal features can interact with the Alaskan Stream to send intense transport pulses across the shelf break. Alternatively as in 2011, a downwelling favorable wind event in early August (near the peak discharge) accelerates the southwestward coastal current and produces an enormous downstream transport event. Both processes result in fast drains of the buoyancy and the plume content, thereby rapid disintegration of the

  18. Aboveground and belowground responses to nutrient additions and herbivore exclusion in Arctic tundra ecosystems in northern Alaska

    NASA Astrophysics Data System (ADS)

    Moore, J. C.; Gough, L.; Simpson, R.; Johnson, D. R.

    2011-12-01

    The Arctic has experienced significant increased regional warming over the past 30 years. Warming generally increases tundra soil nutrient availability by creating a more favorable environment for plant growth, decomposition and nutrient mineralization. Aboveground there has been a "greening" of the Arctic with increased net primary productivity (NPP), and an increase in woody vegetation. Concurrent with the changes aboveground has been an increase in root growth at lower depths and a loss of soil organic C (40 -100 g C m-2 yr-1). Given that arctic soils contain 14% of the global soil C pool, understanding the mechanisms behind shifts of this magnitude that are changing arctic soils from a net sink to a net source of atmospheric C is critical. We took an integrated multi-trophic level approach to examine how altering soil nutrients and mammalian herbivore activity affects vegetation, soil fauna, and microbial communities as well as soil physical characteristics in moist acidic (MAT) and dry heath (DH) tundra. Our work was conducted at the Arctic LTER site in northern Alaska. We sampled the nutrient (controls and annual N+P additions) and herbivore (controls and exclosures) manipulations established in 1996 after 10 years of treatment. Models that incorporated the biomass estimates from the field were used to characterize the trophic structure of the belowground food web and to estimate carbon flux among soil organisms and C-mineralization rates. Both MAT and DH exhibited significant increases in NPP and root growth and changes in vegetation structure with transitions from a mixed community to deciduous shrubs in MAT and from lichens to grasses and shrubs in DH, with nutrient additions and herbivore exclosures. Belowground responses to the treatments were dependent on ecosystem type, but exposed alterations in trophic structure that included changes in microbial biomass, the establishment of microbivorous enchytreaids, increases in root-feeding nematodes, and

  19. Cultural Implications of Out-of-Phase Weather across northern Alaska after 500 CE: Regional Variability during the Medieval Climate Anomaly and Little Ice Age

    NASA Astrophysics Data System (ADS)

    Mason, O. K.; Alix, C. M.; Bigelow, N. H.; Hoffecker, J. F.

    2014-12-01

    From a global perspective, a diverse mélange of paleoclimate data reveal that Northwest Alaska is partially out of phase with northwest Europe, witnessing cooler periods during the Medieval Climate Anomaly ca. CE 1000 and warmer conditions in the 16th and 17th centuries. The search for climatic forcers in northern Alaska relies on integration of data drawn from tree-rings, lacustrine varves and moraines, diatoms, beach ridges and dunes. At Cape Espenberg, northern Seward Peninsula, a 1500-year reconstruction of settlement, landscape evolution and climatic variability employs >100 14C ages from accreting dunes with shell-laden storm beds, intercalated driftwood and superimposed soils, archaeological sites and marsh peats within swale ponds. Large storms occurred along the Chukchi Sea from Cape Espenberg and Deering (Kotzebue Sound) to Point Barrow prior to 1000 CE, and at decadal intervals during the Little Ice Age (LIA) from 1300 to 1700. Architecural driftwood logs from several excavated houses capped by sand dunes yield several 14C dated floating chronologies covering intervals from 700 to 1700, suggest the identification of cooler intervals 800 to 1000 and intermittently after 1300. Peat aggradation followed isolation from the sea from 500 onward, and was interrupted by two pulses of fresh water, one ca. 1300 and a second ca. 1800, with diatoms suggesting relative aridity during the LIA. The occupation history of Cape Espenberg generally follows dune growth, and may be inversely related to cooler temperatures.

  20. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen; Michael T. Whalen

    2002-01-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. The Lisburne in the main axis of the Brooks Range is characteristically deformed into imbricate thrust sheets with asymmetrical hanging wall anticlines and footwall synclines. In contrast, the Lisburne in the northeastern Brooks Range is characterized by symmetrical detachment folds. The focus of our 2000 field studies was at the boundary between these structural styles in the vicinity of Porcupine Lake, in the Arctic National Wildlife Refuge. The northern edge of thrust-truncated folds in Lisburne is marked by a local range front that likely represents an eastward continuation of the central Brooks Range front. This is bounded to the north by a gently dipping panel of Lisburne with local asymmetrical folds. The leading edge of the flat panel is thrust over Permian to Cretaceous rocks in a synclinal depression. These younger rocks overlie symmetrically detachment-folded Lisburne, as is extensively exposed to the north. Six partial sections were measured in the Lisburne of the flat panel and local range front. The Lisburne here is about 700 m thick and is interpreted to consist primarily of the Wachsmuth and Alapah Limestones, with only a thin veneer of Wahoo Limestone. The Wachsmuth (200 m) is gradational between the underlying Missippian Kayak Shale and the overlying Mississippian Alapah, and

  1. Otolith patterns of rockfishes from the northeastern Pacific.

    PubMed

    Tuset, Victor M; Imondi, Ralph; Aguado, Guillermo; Otero-Ferrer, José L; Santschi, Linda; Lombarte, Antoni; Love, Milton

    2015-04-01

    Sagitta otolith shape was analysed in twenty sympatric rockfishes off the southern California coast (Northeastern Pacific). The variation in shape was quantified using canonical variate analysis based on fifth wavelet function decomposition of otolith contour. We selected wavelets because this representation allow the identifications of zones or single morphological points along the contour. The entire otoliths along with four subsections (anterior, ventral, posterodorsal, and anterodorsal) with morphological meaning were examined. Multivariate analyses (MANOVA) showed significant differences in the contours of whole otolith morphology and corresponding subsection among rockfishes. Four patterns were found: fusiform, oblong, and two types of elliptic. A redundancy analysis indicated that anterior and anterodorsal subsections contribute most to define the entire otolith shape. Complementarily, the eco-morphological study indicated that the depth distribution and strategies for capture prey were correlated to otolith shape, especially with the anterodorsal zone. PMID:25503537

  2. Post-glacial dispersal patterns of Northern pike inferred from an 8800 year old pike (Esox cf. lucius) skull from interior Alaska

    NASA Astrophysics Data System (ADS)

    Wooller, Matthew J.; Gaglioti, Benjamin; Fulton, Tara L.; Lopez, Andres; Shapiro, Beth

    2015-07-01

    The biogeography of freshwater fish species during and after late-Pleistocene glaciations relate to how these species are genetically organized today, and the management of these often disjunct populations. Debate exists concerning the biogeography and routes of dispersal for Northern pike (Esox lucius) after the last glaciation. A hypothesis to account for the relatively low modern genetic diversity for E. lucius is post-glacial radiation from refugia, including lakes from within the un-glaciated portions of eastern Beringia. We report the remains of a Northern pike (E. cf. lucius) skull, including bones, teeth, bone collagen and ancient DNA. The remains were preserved at a depth of between 440 and 446 cm in a 670 cm long core of sediment from Quartz Lake, which initiated at ˜11,200 cal yr BP in interior Alaska. A calibrated accelerator mass spectrometer (AMS) radiocarbon age of the collagen extracted from the preserved bones indicated that the organism was dated to 8820 cal yr BP and is bracketed by AMS values from analyses of terrestrial plant macrofossils, avoiding any potential aquatic reservoir effect that could have influenced the radiocarbon age of the bones. Scanning electron microscope images of the specimen show the hinged tooth anatomy typically of E. lucius. Molar C:N (3.5, 1σ = 0.1) value of the collagen from the specimen indicated well-preserved collagen and its mean stable nitrogen isotope value is consistent with the known predatory feeding ecology of E. lucius. Ancient DNA in the bones showed that the specimen was identical to modern E. lucius. Our record of E. lucius from interior Alaska is consistent with a biogeographic scenario involving rapid dispersal of this species from glacial refugia in the northern hemisphere after the last glaciation.

  3. 50 CFR 679.80 - Allocation and transfer of rockfish QS.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF... level longline fishery. Fishing by vessels participating in the rockfish entry level longline fishery is... during the season dates for the entry level trawl fishery in 2007, 2008, or 2009 for a rockfish...

  4. Dynamics of a parasite assemblage of the Vermilion Rockfish Sebastes miniatus from northwestern Baja California, México

    NASA Astrophysics Data System (ADS)

    Rodríguez-Santiago, M. A.; Rosales-Casián, J. A.; Grano-Maldonado, M. I.

    2014-06-01

    A parasite assemblage of Sebastes miniatus from northwestern Baja California, México, was composed of a total of 12 species: five ectoparasites (two monogeneans and three parasitic copepods) and seven endoparasites (two digeneans, one cestode, three nematodes, and one acanthocephala). Five of these parasites constituted new genera records to the genus Sebastes, and nine were new geographic records. The most abundant species were the endoparasites Parabothriocephalus sagitticeps, Hysterothylacium sp., and Anisakis sp., and the specific richness ranged from 1 to 8 parasite species per host. The most important parasite species in terms of prevalence were Microcotyle sebastis (93 %) and Anisakis sp. (92 %). The mean abundance of parasites found in S. miniatus showed significant variations over the year, with maximum values (31.7 individuals/host) in August, and minimum (0.39 individuals/host) in February. P. sagitticeps showed the highest mean intensity of infection (190.4 parasites/host), followed by Anisakis sp. (127.2 parasites/host) and Hysterothylacium sp. (46.6 parasites/host). The presence of larval stages of the nematodes Anisakis, Pseudoterranova, and Hysterothylacium is particularly important due to their high abundance and prevalence and because they may represent a human health risk (anisakiasis). Rockfishes (family Scorpaenidae) of the genus Sebastes constitute one of the most important groundfish resources in the American and Mexican northern Pacific Ocean, both for recreational and for the commercial fisheries of California and Baja California. These rockfish species makes up a substantial part of the Mexican cuisine.

  5. Widespread Degradation of Ice Wedges on the Arctic Coastal Plain in Northern Alaska in Response to the Recent Warmer Climate

    NASA Astrophysics Data System (ADS)

    Shur, Y.; Jorgenson, M. T.; Pullman, E. R.

    2003-12-01

    The continuous permafrost on the Arctic Coastal Plain in northern Alaska has been considered stable because permafrost temperatures remain low, even with an increase of several degrees during the last decades. Ice wedges, however, are particularly susceptible to degradation because only a very thin layer of permafrost (the transient layer) exists between the ice and the bottom of the active layer. An increase in the active layer during unusually warm periods causes the thawing front to encounter the underlying ice wedges and initiate degradation. Field observations and photogrammetric analysis of 1945, 1979, and 2001 aerial photography indicate that there has been widespread degradation of the ice wedges on the Arctic Coastal Plain west of the Colville Delta over the recent 57-year period, and indications are that most of the degradation occurred during the last two decades. Field sampling at 46 polygonal troughs and their intersections showed that ice wedge degradation has been relatively recent as indicated by newly drowned vegetation. We found thermokarst was widespread on a variety of terrain conditions, but most prevalent on, ice-rich centers of old drained lake basins and alluvial-marine terraces, which have the greatest ice wedge development in the studied landscape. Ice wedges on these terrains typically occupy from 10 to 20 % of the upper permafrost. We attributed the natural degradation to warm weather during the last decades, because disturbance of the ground surface, which could have similar impact on ice wedges, was not evident. While, ice-wedge degradation probably has been periodically occurring at low rates over the preceding centuries, it has greatly accelerated during the last several decades. We identified six stages of ice-wedge degradation and stabilization. They include: (1) the loss of transient layer of upper permafrost above ice wedges, leading to enhanced nutrient availability and vegetative growth; (2) thawing of ice wedges and surface

  6. 40Ar/39Ar Dating of Zn-Pb-Ag Mineralization in the Northern Brooks Range, Alaska

    USGS Publications Warehouse

    Werdon, Melanie B.; Layer, Paul W.; Newberry, Rainer J.

    2004-01-01

    The 40Ar/39Ar laser step-heating method potentially can be used to provide absolute ages for a number of formerly undatable, low-temperature ore deposits. This study demonstrates the use of this method by determining absolute ages for Zn-Pb-Ag sediment-hosted massive sulfide deposits and vein-breccia occurrences found throughout a 300-km-long, east-west-trending belt in the northern Brooks Range, Alaska. Massive sulfide deposits are hosted by Mississippian to Pennsylvanian(?) black carbonaceous shale, siliceous mudstone, and lesser chert and carbonate turbidites of the Kuna Formation (e.g., Red Dog, Anarraaq, Lik (Su), and Drenchwater). The vein-breccia occurrences (e.g., Husky, Story Creek, West Kivliktort Mountain, Vidlee, and Kady) are hosted by a deformed but only weakly metamorphosed package of Upper Devonian to Lower Mississippian mixed continental and marine clastic rocks (the Endicott Group) that stratigraphically underlie the Kuna Formation. The vein-breccias are mineralogically similar to, but not spatially associated with, known massive sulfide deposits. The region's largest shale-hosted massive sulfide deposit is Red Dog; it has reserves of 148 Mt grading 16.6 percent zinc, 4.5 percent lead, and 77 g of silver per tonne. Hydrothermally produced white mica in a whole-rock sample from a sulfide-bearing igneous sill within the Red Dog deposit yielded a plateau age of 314.5 Ma. The plateau age of this whole-rock sample records the time at which temperatures cooled below the argon closure temperature of the white mica and is interpreted to represent the minimum age limit for massive sulfide-related hydrothermal activity in the Red Dog deposit. Sulfide-bearing quartz veins at Drenchwater crosscut a hypabyssal intrusion with a maximum biotite age of 337.0 Ma. Despite relatively low sulfide deposition temperatures in the vein-breccia occurrences (162°-251°C), detrital white mica in sandstone immediately adjacent to large vein-breccia zones was partially to

  7. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Michael T. Whalen; Jerry Jensen; Paul K. Atkinson; Joseph S. Brinton

    2000-05-01

    The Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding and lithostratigraphy on fracture patterns. (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. (4) The influence of lithostratigraphy and deformation on fluid flow. The results of field work during the summer of 1999 offer some preliminary insights: The Lisburne Limestone displays a range of symmetrical detachment fold geometries throughout the northeastern Brooks Range. The variation in fold geometry suggests a generalized progression in fold geometry with increasing shortening: Straight-limbed, narrow-crested folds at low shortening, box folds at intermediate shortening, and folds with a large height-to-width ratio and thickened hinges at high shortening. This sequence is interpreted to represent a progressive change in the dominant shortening mechanism from flexural-slip at low shortening to bulk strain at higher shortening. Structural variations in bed thickness occur throughout this progression. Parasitic folding accommodates structural thickening at low shortening and is gradually succeeded by penetrative strain as shortening increases. The amount of structural thickening at low to intermediate shortening may be inversely related to the local amount of structural thickening of the Kayak Shale, the incompetent unit that underlies the Lisburne. The Lisburne Limestone displays a different structural style in the south, across the boundary between the northeastern Brooks Range and the main axis of the Brooks Range fold

  8. Structure and petroleum potential of the continental margin between Cross Sound and Icy Bay, northern Gulf of Alaska

    USGS Publications Warehouse

    Bruns, T.R.

    1982-01-01

    Major structural features of the Yakutat segment, the segment of the continental margin between Cross Sound and Icy Bay, northern Gulf of Alaska, are delineated by multichannel seismic reflection data. A large structural high is centered on Fairweather Ground and lies generally at the edge of the shelf from Cross Sound to west of the Alsek Valley. A basement uplift, the Dangerous River zone, along which the seismic acoustic basement shallows by up to two kilometers, extends north from the western edge of Fairweather Ground towards the mouth of the Dangerous River. The Dangerous River zone separates the Yakutat segment into two distinct subbasins. The eastern subbasin has a maximum sediment thickness of about 4 km, and the axis of the basin is near and parallel to the coast. Strata in this basin are largely of late Cenozoic age (Neogene and Quaternary) and approximately correlate with the onshore Yakataga Formation. The western subbasin has a maximum of at least 9 km of sediment, comprised of a thick (greater than 4.5 km) Paleogene section overlain by late Cenozoic strata. The Paleogene section is truncated along the Dangerous River zone by a combination of erosion, faulting, and onlap onto the acoustic basement. Within the western subbasin, the late Cenozoic basin axis is near and parallel to the coast, but the Paleogene basin axis appears to trend in a northwest direction diagonally across the shelf. Sedimentary strata throughout the Yakutat shelf show regional subsidence and only minor deformation except in the vicinity of the Fairweather Ground structural high, near and along the Dangerous River zone, and at the shoreline near Lituya Bay. Seismic data across the continental slope and adjacent deep ocean show truncation at the continental slope of Paleogene strata, the presence of a thick (to 6 km) undeformed or mildly deformed abyssal sedimentary section at the base of the slope that in part onlaps the slope, and a relatively narrow zone along the slope or at

  9. Decadal Estimates for Soil Carbon Inputs and Losses for Black Spruce Boreal Forests in Interior Alaska, USA and Northern Manitoba, Canada

    NASA Astrophysics Data System (ADS)

    Manies, K. L.; Harden, J. W.; Veldhuis, H.; Turetsky, M. R.

    2005-12-01

    Soil carbon stocks represent long-term net accumulations of carbon that result from plant inputs, decomposition losses, combustion losses, and local gains and losses from lateral flow of dissolved and particulate carbon. We use several chronosequences (time since last fire) of various soil drainage types from Thompson, Manitoba and Delta Junction, Alaska to estimate decadal averages of inputs and losses to soil. Because northern soils are generally not well mixed, the shallow organic layers of these soils can be thought as discrete accumulations since the most recent fire overlies more decomposed layers that represent longer histories of disturbance and stabilization. Accumulation since the most recent fire provides an estimate of net primary production (NPP) inputs to soil and decomposition loss from these shallow layers. Accumulation of all organic layers provides an estimate of long-term inputs and decay. Shallow inputs (0.011 - 0.014 g/cm2; SE = 0.002 - 0.005) and turnover times for carbon decay (78 - 94 yrs) did not differ between sites. Long-term inputs also do not differ between the well- to moderately well-drained Alaska sites and the moderately well-drained Thompson site (0.013 g/cm2; SE = 0.005). However, our wettest chronosequence site, located in Thompson, did see higher rates of long-term inputs (0.031 g/cm2; SE = 0.009). Long-term turnover times (50 - 60 yrs) did not differ among sites.

  10. An evaluation of petrogenic hydrocarbons in northern Gulf of Alaska continental shelf sediments - The role of coastal oil seep inputs

    USGS Publications Warehouse

    Short, J.W.; Kolak, J.J.; Payne, J.R.; Van Kooten, G. K.

    2007-01-01

    We compared hydrocarbons in water, suspended particulate matter (SPM), and riparian sediment collected from coastal watersheds along the Yakataga foreland with corresponding hydrocarbons in Gulf of Alaska benthic sediments. This comparison allows an evaluation of hydrocarbon contributions to marine sediments from natural oil seeps, coal and organic matter (e.g., kerogen) associated with eroding siliciclastic rocks. The samples from oil seeps show extensive loss of low-molecular weight n-alkanes (Alaska, but overall seep inputs are largely attenuated by the (non-seep) petrogenic hydrocarbon content of the high SPM loads. In contrast to the geochemical signature of seep oil, Gulf of Alaska benthic sediments are characterized by abundant alkylated naphthalene homologues, relatively smooth n-alkane envelopes (n-C9 through n-C34, but with elevated levels of n-C27, n-C29, and n-C31), and small UCMs. Further, hydrocarbons in benthic sediments are highly intercorrelated. Taken together, these characteristics indicate that seep oil is a negligible petrogenic hydrocarbon source to the Gulf of Alaska continental shelf. Coaly material separated from the benthic sediment samples using a dense liquid (???2.00 g cm-3) also accounted for a minor portion of the total PAH (1-6%) and total n-alkanes (0.4-2%) in the benthic samples. Most of the hydrocarbon burden in the sediments is found in the denser sediment fraction and likely derives from organic matter contributed by denudation of siliciclastic formations in

  11. The role of melano-macrophage aggregates in the storage of mercury and other metals: an example from yelloweye rockfish (Sebastes ruberrimus).

    PubMed

    Barst, Benjamin D; Bridges, Kristin; Korbas, Malgorzata; Roberts, Aaron P; Van Kirk, Kray; McNeel, Kevin; Drevnick, Paul E

    2015-08-01

    Melano-macrophage aggregates, collections of specialized cells of the innate immune system of fish, are considered a general biomarker for contaminant toxicity. To elucidate further the relationship between macrophage aggregates and metals exposure, yelloweye rockfish (Sebastes ruberrimus), a long-lived species, were sampled from the east and west coasts of Prince of Wales Island, Alaska. Metals concentrations in livers (inorganic Hg, methyl mercury, Se, Ni, Cd, Cu, Zn) and spleens (inorganic Hg and methyl mercury) were determined, as well as their correlations with melano-macrophage aggregate area. Sections of liver tissue were analyzed by laser ablation-inductively coupled plasma-mass spectrometry to determine how metals were spatially distributed between hepatocytes and macrophage aggregates. The concentration of inorganic Hg in whole tissue was the best predictor of macrophage area in yelloweye livers and spleens. Macrophage aggregates had higher relative concentrations than most metals compared with the surrounding hepatocytes. However, not all metals were accumulated to the same degree, as evidenced by differences in the ratios of metals in macrophages compared with hepatocytes. Laser ablation data were corroborated with the results of X-ray synchrotron fluorescence imaging of a yelloweye liver section. Hepatic macrophage aggregates in yelloweye rockfish may play an important role in the detoxification and storage of Hg and other metals. PMID:26177920

  12. Phytomass, LAI, and NDVI in northern Alaska: Relationships to summer warmth, soil pH, plant functional types, and extrapolation to the circumpolar Arctic

    NASA Astrophysics Data System (ADS)

    Walker, D. A.; Epstein, H. E.; Jia, G. J.; Balser, A.; Copass, C.; Edwards, E. J.; Gould, W. A.; Hollingsworth, J.; Knudson, J.; Maier, H. A.; Moody, A.; Raynolds, M. K.

    2003-01-01

    We examined the effects of summer warmth on leaf area index (LAI), total aboveground phytomass (TAP), and normalized difference vegetation index (NDVI) across the Arctic bioclimate zone in Alaska and extrapolated our results to the circumpolar Arctic. Phytomass, LAI, and within homogeneous areas of vegetation on acidic and nonacidic soils were regressed against the total summer warmth index (SWI) at 12 climate stations in northern Alaska (SWI = sum of mean monthly temperatures greater than 0°C). SWI varies from 9°C at Barrow to 37°C at Happy Valley. A 5°C increase in the SWI is correlated with about a 120 g m-2 increase in the aboveground phytomass for zonal vegetation on acidic sites and about 60 g m-2 on nonacidic sites. Shrubs account for most of the increase on acidic substrates, whereas mosses account for most of the increase on nonacidic soils. LAI is positively correlated with SWI on acidic sites but not on nonacidic sites. The NDVI is positively correlated with SWI on both acidic and nonacidic soils, but the NDVI on nonacidic parent material is consistently lower than the NDVI on acidic substrates. Extrapolation to the whole Arctic using a five-subzone zonation approach to stratify the circumpolar NDVI and phytomass data showed that 60% of the aboveground phytomass is concentrated in the low-shrub tundra (subzone 5), whereas the high Arctic (subzones 1-3) has only 9% of the total. Estimated phytomass densities in subzones 1-5 are 47, 256, 102, 454, and 791 g m-2, respectively. Climate warming will likely result in increased phytomass, LAI, and NDVI on zonal sites. These changes will be most noticeable in acidic areas with abundant shrub phytomass.

  13. Productivity and sedimentary δ15N variability for the last 17,000 years along the northern Gulf of Alaska continental slope

    USGS Publications Warehouse

    Addison, Jason A.; Finney, Bruce P.; Dean, Walter E.; Davies, Maureen H.; Mix, Alan C.; Stoner, Joseph S.; Jaeger, John M.

    2012-01-01

    Biogenic opal, organic carbon, organic matter stable isotope, and trace metal data from a well-dated, high-resolution jumbo piston core (EW0408–85JC; 59° 33.3′N, 144° 9.21′W, 682 m water depth) recovered from the northern Gulf of Alaska continental slope reveal changes in productivity and nutrient utilization over the last 17,000 years. Maximum values of opal concentration (∼10%) occur during the deglacial Bølling-Allerød (B-A) interval and earliest Holocene (11.2 to 10.8 cal ka BP), moderate values (∼6%) occur during the Younger Dryas (13.0 to 11.2 cal ka BP) and Holocene, and minimum values (∼3.5%) occur during the Late Glacial Interval (LGI). When converted to opal mass accumulation rates, the highest values (∼5000 g cm−2 kyr−1) occur during the LGI prior to 16.7 cal ka BP, which points to a strong influence by LGI glacimarine sedimentation regimes. Similar patterns are also observed in total organic carbon and cadmium paleoproductivity proxies. Mid-Holocene peaks in the terrestrial organic matter fraction at 5.5, 4.7, 3.5, and 1.2 cal ka BP indicate periods of enhanced delivery of glaciomarine sediments by the Alaska Coastal Current. The B-A and earliest Holocene intervals are laminated, and enrichments of redox-sensitive elements suggest dysoxic-to-anoxic conditions in the water column. The laminations are also associated with mildly enriched sedimentary δ15N ratios, indicating a link between productivity, nitrogen cycle dynamics, and sedimentary anoxia. After applying a correction for terrestrial δ15N contributions based on end-member mixing models of terrestrial and marine organic matter, the resulting B-A marine δ15N (6.3 ± 0.4 ‰) ratios are consistent with either mild denitrification, or increased nitrate utilization. These findings can be explained by increased micronutrient (Fe) availability during episodes of rapid rising sea level that released iron from the previously subaerial coastal plain; iron input from enhanced

  14. Severe winter cooling during the Younger Dryas in northern Alaska - evidence from the stable isotope composition of a buried ice-wedge system

    NASA Astrophysics Data System (ADS)

    Meyer, Hanno; Schirrmeister, Lutz; Yoshikawa, Kenji; Opel, Thomas; Wetterich, Sebastian; Hubberten, Hans-W.; Brown, Jerry

    2010-05-01

    The Younger Dryas (YD) interval, from approximately 12.9 to 11.5 kyr cal BP, a rapid reversion to glacial climate conditions at the Pleistocene-Holocene transition, has generally been attributed to the release of meltwater from the Laurentide Ice Sheet to the North Atlantic or Arctic oceans. The reaction of the North Pacific region to this "shutdown" of the thermohaline circulation in the North Atlantic during Younger Dryas is, however, little understood. The YD cold interval is of great interest for understanding rapid natural climate change, especially with regard to recent global warming scenarios. Various archives such as glacier ice, tree rings, lacustrine and marine sediments provide evidence for strong climate variability during the Late Glacial-Holocene transition. In our study, we investigated a relict, buried ice-wedge system within the continuous permafrost zone near Barrow, northern Alaska (71°18'N, 156°40'W). The Barrow ice-wedge system is buried under about three meters of Late Glacial/early Holocene ice-rich sediments. The ice wedges are accessible through a shaft which extends into an underground excavation, where a detailed description and sampling with an electrical chain saw were carried out. Permafrost is not only susceptible to recent climate change, it also may store evidence of these changes in ground ice, especially in ice wedges. Ice wedges can be assessed by stable water isotope methods similar to glacier ice climate reconstructions. Ice wedges are assumed to be indicative of winter climate conditions, because the seasonality of thermal contraction cracking and of the infill of frost cracks are generally related to winter and spring, respectively. In this paper, we present a winter climate record from ice wedges in permafrost of northern Alaska, a region, where paleoclimate records extending beyond the Late Glacial-Holocene transition are generally rather sparse, often restricted to lake sediments and rely mostly on summer indicators

  15. An integrated quantitative basin study of the northern part of the Arctic National Wildlife Refuge, northeastern Alaska

    SciTech Connect

    Yu Zhihuai; Lerche, I. )

    1991-03-01

    Using one- and two-dimensional basin modeling codes, the geological processes of sedimentary deposition, compaction, fluid flow, and paleoheat flux have been simulated in the NAWR, Alaska. To reconstruct the thermal history, the thrusting feature of the area has been allowed for and the thermal indicator (vitrinite reflectance) has been used in an inverse mode to estimate the impact of the thrust development. For the evolution of the coastal plain in the area, an inverse flexural plate model was applied to assess the subsidence of the postrift phase and the deformation and erosion events since Cretaceous. In this study, both well and seismic data were used, and the results were shown to be consistent with geologic data.

  16. Peat landforms along the Albany River, northern Ontario. An ecological study of peat landforms in Canada and Alaska

    NASA Technical Reports Server (NTRS)

    Glaser, P. H.

    1985-01-01

    During the summer of 1985 a field investigation was started in the Hudson Bay lowland region of northern Ontario, which represents the largest expanse of peatland in North America and is an important sink in the global carbon cycle. A key area in the lowlands is situated along the Albany River near the confluence of the Chepay River. Here the striking vegetation-landforms are transitional between those found on the bed of Glacial Lake Agassiz in northern Minnesota and southern Manitoba and the more northern peatlands in the Hudson Bay lowland region. In peatland studies elsewhere the landform patterns have been used not only to classify different peatland types but also as an indicator of potential developmetnal trends. The study area is generally defined by that covered by the TM scene E-40062-15532 taken on Sept. 16, 1982. The purpose of the field work is to acquire sufficent information to interpret the TM imagery and test various hypotheses on peatland development on the gasis of the pattern transitions.

  17. A Quantitative Ecological Risk Assessment of the Toxicological Risks from Exxon Valdez Subsurface Oil Residues to Sea Otters at Northern Knight Island, Prince William Sound, Alaska

    PubMed Central

    Harwell, Mark A.; Gentile, John H.; Johnson, Charles B.; Garshelis, David L.; Parker, Keith R.

    2010-01-01

    A comprehensive, quantitative risk assessment is presented of the toxicological risks from buried Exxon Valdez subsurface oil residues (SSOR) to a subpopulation of sea otters (Enhydra lutris) at Northern Knight Island (NKI) in Prince William Sound, Alaska, as it has been asserted that this subpopulation of sea otters may be experiencing adverse effects from the SSOR. The central questions in this study are: could the risk to NKI sea otters from exposure to polycyclic aromatic hydrocarbons (PAHs) in SSOR, as characterized in 2001–2003, result in individual health effects, and, if so, could that exposure cause subpopulation-level effects? We follow the U.S. Environmental Protection Agency (USEPA) risk paradigm by: (a) identifying potential routes of exposure to PAHs from SSOR; (b) developing a quantitative simulation model of exposures using the best available scientific information; (c) developing scenarios based on calculated probabilities of sea otter exposures to SSOR; (d) simulating exposures for 500,000 modeled sea otters and extracting the 99.9% quantile most highly exposed individuals; and (e) comparing projected exposures to chronic toxicity reference values. Results indicate that, even under conservative assumptions in the model, maximum-exposed sea otters would not receive a dose of PAHs sufficient to cause any health effects; consequently, no plausible toxicological risk exists from SSOR to the sea otter subpopulation at NKI. PMID:20862194

  18. Fatty acid signatures of stomach oil and adipose tissue of northern fulmars (Fulmarus glacialis) in Alaska: Implications for diet analysis of Procellariiform birds

    USGS Publications Warehouse

    Wang, S.W.; Iverson, S.J.; Springer, A.M.; Hatch, Shyla A.

    2007-01-01

    Procellariiforms are unique among seabirds in storing dietary lipids in both adipose tissue and stomach oil. Thus, both lipid sources are potentially useful for trophic studies using fatty acid (FA) signatures. However, little is known about the relationship between FA signatures in stomach oil and adipose tissue of individuals or whether these signatures provide similar information about diet and physiology. We compared the FA composition of stomach oil and adipose tissue biopsies of individual northern fulmars (N = 101) breeding at three major colonies in Alaska. Fatty acid signatures differed significantly between the two lipid sources, reflecting differences in dietary time scales, metabolic processing, or both. However, these signatures exhibited a relatively consistent relationship between individuals, such that the two lipid sources provided a similar ability to distinguish foraging differences among individuals and colonies. Our results, including the exclusive presence of dietary wax esters in stomach oil but not adipose tissue, are consistent with the notion that stomach oil FA signatures represent lipids retained from prey consumed during recent foraging and reflect little metabolic processing, whereas adipose tissue FA signatures represent a longer-term integration of dietary intake. Our study illustrates the potential for elucidating short- versus longer-term diet information in Procellariiform birds using different lipid sources. ?? 2007 Springer-Verlag.

  19. Color Shaded-Relief and Surface-Classification Maps of the Fish Creek Area, Harrison Bay Quadrangle, Northern Alaska

    USGS Publications Warehouse

    Mars, John L.; Garrity, Christopher P.; Houseknecht, David W.; Amoroso, Lee; Meares, Donald C.

    2007-01-01

    Introduction The northeastern part of the National Petroleum Reserve in Alaska (NPRA) has become an area of active petroleum exploration during the past five years. Recent leasing and exploration drilling in the NPRA requires the U.S. Bureau of Land Management (BLM) to manage and monitor a variety of surface activities that include seismic surveying, exploration drilling, oil-field development drilling, construction of oil-production facilities, and construction of pipelines and access roads. BLM evaluates a variety of permit applications, environmental impact studies, and other documents that require rapid compilation and analysis of data pertaining to surface and subsurface geology, hydrology, and biology. In addition, BLM must monitor these activities and assess their impacts on the natural environment. Timely and accurate completion of these land-management tasks requires elevation, hydrologic, geologic, petroleum-activity, and cadastral data, all integrated in digital formats at a higher resolution than is currently available in nondigital (paper) formats. To support these land-management tasks, a series of maps was generated from remotely sensed data in an area of high petroleum-industry activity (fig. 1). The maps cover an area from approximately latitude 70?00' N. to 70?30' N. and from longitude 151?00' W. to 153?10' W. The area includes the Alpine oil field in the east, the Husky Inigok exploration well (site of a landing strip) in the west, many of the exploration wells drilled in NPRA since 2000, and the route of a proposed pipeline to carry oil from discovery wells in NPRA to the Alpine oil field. This map area is referred to as the 'Fish Creek area' after a creek that flows through the region. The map series includes (1) a color shaded-relief map based on 5-m-resolution data (sheet 1), (2) a surface-classification map based on 30-m-resolution data (sheet 2), and (3) a 5-m-resolution shaded relief-surface classification map that combines the shaded

  20. Gulf of Alaska, Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This MODIS true-color image shows the Gulf of Alaska and Kodiak Island, the partially snow-covered island in roughly the center of the image. Credit: Jacques Descloitres, MODIS Land Rapid Response Team

  1. Remotely Sensed Active Layer Thickness (ReSALT) from InSAR data near Toolik Lake in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Chen, A. C.; Liu, L.; Schaefer, K. M.; Parsekian, A.; Jafarov, E. E.; Zebker, H. A.; Zhang, T.

    2014-12-01

    Toolik Field Station is built on spatially continuous permafrost on the north slope of Alaska. Seasonal surface subsidence and uplift occurs in permafrost regions due to thaw settlement and frost heave as the active layer thaws and refreezes. Using L-band (23.6 cm wavelength) InSAR data from ALOS-PALSAR acquired between 2006 and 2010, we use a small-baseline subset (SBAS) method to estimate seasonal surface subsidence and retrieve fine-resolution maps of active layer thickness (ALT) for a ~25x25 km area surrounding Toolik Field Station (located at 68.63°N, -149.60°E). We compare these remotely sensed ALT (ReSALT) results with in situ data from: 1) the Circumpolar Active Layer Monitoring (CALM) network showing mean ALT of ~40-50 cm in the region surrounding Toolik Field Station, corresponding to seasonal subsidence of 1 to 2 cm, and 2) mechanical probing measurements of ALT, obtained during field work in the study area in August 2014. We also solve for secular subsidence trends from the InSAR data. The trends are close to zero in most places, but larger subsidence trends in some isolated areas could be due to thermokarst processes (long-term thawing of ice-rich permafrost). We note, however, that downslope motion due to gelifluction cannot be separated from vertical thermokarst-related deformation without incorporating InSAR measurements from multiple look angles. Two key limitations to our method are the spatial variability of volumetric soil moisture content and the accuracy of the DEM needed to correct for topographic effects. We investigate the use of bulk volumetric water content inferred from ground-penetrating radar (GPR) data to improve the ReSALT retrieval algorithm. We also quantify the effect of DEM accuracy on ReSALT uncertainties, leads to requirements for DEM accuracy in InSAR-based ALT retrieval.

  2. Reconciling Phytoplankton Growth Rates and Standing Stocks in the Northern Gulf of Alaska: Evidence for a Physical-Biological Mosaic (Invited)

    NASA Astrophysics Data System (ADS)

    Kudela, R. M.; Peterson, T. D.; Blakely, M.

    2010-12-01

    We investigated the relationships between iron, light, and nitrogen availability in the highly productive waters of the northern Gulf of Alaska (nGOA). Even in coastal environments, low iron levels can limit phytoplankton growth. Since low nitrate concentrations tend to limit phytoplankton growth on the inner shelf of the nGOA and offshore waters are High Nitrate, Low Chlorophyll (HNLC) and thus possess low trace metal concentrations, it was hypothesized that waters of the mid-shelf would be stimulated when the near and offshore waters mixed, similar to the ‘green belt’ of the Bering Sea. Indeed, a mid-shelf chlorophyll maximum was observed; however, this mid-shelf maximum in chl was not associated with a peak in primary productivity, resulting in lower rates of chlorophyll-specific primary production compared to the inner or outer shelf waters. Data from grow out experiments suggest that low iron indeed limits primary production on the inner shelf: under both full light and darkened conditions, the addition of 4 nM iron stimulated primary productivity and resulted in higher chlorophyll (chl) standing stocks relative to controls, even without the addition of nitrogen. Iron, both in total and bioavailable forms, was highest in the inner shelf, and declined along the cross-shelf gradient (Lippiatt et al., 2010) as did the efficiency of photosynthesis as indicated by the initial slope of photosynthesis-irradiance curves. We reconcile the low chl associated with the inner shelf by invoking the importance of retention and its variability along the cross-shelf gradient. Estimate of phosphorus stress (using alkaline phosphatase activity) similarly identify differential responses on the shelf, in the cross-shelf gradient, and in the open (HNLC) waters, with more apparent stress in the gradient regions. The inner shelf is associated with the swift Alaska Coastal Current, which may dilute standing stocks, masking high primary productivity. We conclude that primary

  3. Stable carbon and nitrogen isotope variation in the northern lampfish and Neocalanus, marine survival rates of pink salmon, and meso-scale eddies in the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Kline, Thomas C., Jr.

    2010-10-01

    Northern lampfish (NLF), Stenobrachius leucopsarus (Myctophidae), the dominant pelagic fish taxon of the subarctic North Pacific Ocean, were sampled opportunistically in MOCNESS tows made on continental slope waters of the Gulf of Alaska (GOA) as well as in deep areas of Prince William Sound (PWS) during 1997-2006. The overall mean whole-body lipid-corrected stable carbon isotope value of NLF from the GOA was -21.4 (SD = 0.7) whereas that from PWS was -19.5 (SD = 0.9). This pattern is similar to that observed for late feeding stage Neocalanus cristatus copepods thus confirming a mean cross-shelf carbon stable isotope gradient. As well, there was a statistically significant positive correlation between the considerable temporal variation in the monthly mean carbon stable isotope composition of GOA Neocalanus and GOA NLF ( r = 0.69, P < 0.001). In contrast, NLF nitrogen stable isotope values were bi-modal with most data fitting the upper mode value of ∼+11.5. NLF nitrogen stable isotope values are a better indicator of trophic level or food chain length whereas carbon stable isotopes reflect organic carbon production. The carbon stable isotope values of NLF, measured in May, were positively correlated to marine survival rate of PWS hatchery salmon cohorts entering the marine environment the same year ( r = 0.84, P < 0.001). The carbon stable isotope values for Neocalanus in May were also positively correlated to salmon marine survival ( r = 0.82, P < 0.001). Processes thus manifested through the carbon stable isotope value of biota from the continental slope more closely predicted marine survival rate than that of the salmon themselves. The incipient relationships suggested by the correlations are consistent with the hypothesis that exchange between coastal and oceanic waters in the study area is driven by meso-scale eddies. These eddies facilitate the occurrence of slope phytoplankton blooms as well as drive oceanic zooplankton subsidies into coastal waters. The

  4. Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops)

    PubMed Central

    Lotterhos, Katie E; Dick, Stefan J; Haggarty, Dana R

    2014-01-01

    Marine reserves networks are implemented as a way to mitigate the impact of fishing on marine ecosystems. Theory suggests that a reserve network will function synergistically when connected by dispersal, but the scale of dispersal is often unknown. On the Pacific coast of the United States and Canada, both countries have recently implemented a number of rockfish conservation areas (RCAs) to protect exploited rockfish species, but no study has evaluated the connectivity within networks in each country or between the two countries. We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species. Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation. The distance between these two RCA networks, however, was greater than the average dispersal per generation. The data were also consistent with a genetic break between southern Oregon and central Oregon. We discuss whether additional nearshore RCAs in southern Oregon and Washington would help promote connectivity between RCA's for shallow-water rockfishes. PMID:24567745

  5. Natural versus anthropogenic dispersion of metals to the environment in the Wulik River area, western Brooks Range, northern Alaska

    USGS Publications Warehouse

    Kelley, K.D.; Hudson, T.

    2007-01-01

    Zinc-lead-silver mineral deposits in the Wulik River region, Alaska, contain an enormous accumulation of Zn. In addition to the giant deposits at Red Dog, at least nine other deposits are known. Natural weathering of these deposits has dispersed metals over a wide region over a long period of time (c. 10 000 years) through transport by stream and groundwater, stream sediments, formation of soils, and perhaps wind-blown atmospheric deposition from weathering of naturally enriched Pb-Zn surface deposits. Anthropogenic input also contributes metals to the environment. Mining of the Red Dog deposit, which began in 1989, produces fine-grained galena and sphalerite concentrates that are transported from the mine site by truck to a storage port facility. Wind-blown dispersion of concentrate dust along the road and around the port facility has been a source of local metal-rich surficial materials. Geochemical and mineralogical characteristics provide a means of distinguishing the natural versus anthropogenic metal sources. Soils over deposits have patterns of increasing metal contents with depth and proximity to the metal-bearing source, whereas ore concentrate dust is localized at the surface. The acidity produced by weathering of the sulphide deposits creates an environment in which elements such as Se and Mo are stable whereas Ca is not. Consequently, high Mo (up to 29 ppm) and Se (up to 17 ppm) and low Ca (<0.4%) concentrations characterize surficial materials near natural deposits. Acidic conditions also yield high Pb-Zn ratios (up to 70) because sphalerite is preferentially dissolved and Zn is mobilized during chemical weathering. In natural materials, secondary jarosite and anglesite are developed, and minor galena is etched and rounded due to a history of chemical and mechanical weathering. In contrast, dust-bearing samples have Pb/Zn ratios that are 0.4 or less, Ca contents are higher (0.2 to 3.6%), and Mo (<10 ppm) and Se (not detected) concentrations are low

  6. Soil bacterial community shifts in response to vegetation and soil temperature change in moist acidic tundra of Northern Alaska

    NASA Astrophysics Data System (ADS)

    Ricketts, M. P.; Gonzalez-Meler, M. A.

    2013-12-01

    The effects of rising temperatures on Earth's ecosystems remain largely unknown and are an active area of research. In temperate systems, plant species often respond directly to climate forcing factors causing complex cascading effects in ecosystem C and nutrient cycling. Similarly, in the Arctic tundra, shifts in aboveground species composition and distribution have been observed in response to warming and other climate change factors, following increases in active layer depth and soil temperature. These abiotic changes provide soil microorganisms access to previously unavailable soil organic matter via thawing soils and increases soil microbial mineralization rates, suggesting that soil microorganisms may be eliciting the plant response. It is hypothesized that this release of nutrients may be providing a competitive advantage to N rich woody species, such as dwarf birch and diamond-leaf willow, over grassy species such as cottongrass tussock. Here we examine how microbial communities respond to increases in soil thermal insulation and vegetative change caused by the accumulation of winter precipitation at a snowfence installed in 1998 at Toolik Field Station, Alaska. In addition to soil temperature, increased snow depth also results in increased surface moisture, soil temperature, and active layer depth. Bacterial phylogenies and relative abundances from soils collected in August of 2012 were determined by sequencing 16S rRNA genes and analyzed using the QIIME software package. We found many significant relative abundance shifts between snow depth treatments (deep, intermediate, low) and soil depths (organic, transition, mineral), most notable of which include in an increase in Deltaproteobacteria in the deep treatment zones, a decrease in Alphaproteobacteria with increased soil depth, and a marked increase in Chloroflexi Anaerolineae (a green non-sulfur bacteria found in a wide range of habitats) in the deep treatment and mineral layers. Other interesting

  7. Ichthyophonus in Puget Sound rockfish from the San Juan Islands archipelago and Puget Sound, Washington, USA

    USGS Publications Warehouse

    Halos, D.; Hart, S.A.; Hershberger, P.; Kocan, R.

    2005-01-01

    In vitro explant cultures identified Ichthyophonus in 10.9% of 302 Puget Sound rockfish Sebastes emphaeus sampled from five sites in the San Juan Islands archipelago and Puget Sound, Washington, in 2003. None of the infected fish exhibited visible lesions and only a single fish was histologically positive. Significantly more females were infected (12.4%) than males (6.8%), and while infected males were only detected at two of the five sites, infected females were identified at all sites, with no significant differences in infection prevalence. Genomic sequences of Ichthyophonus isolates obtained from Puget Sound rockfish, Pacific herring Clupea pallasii, and Yukon River Chinook salmon Oncorhynchus tshawytscha were identical in both the A and B regions of the small subunit 18S ribosomal DNA but were different from Ichthyophonus sequences previously isolated from four different species of rockfish from the northeastern Pacific Ocean. Ichthyophonus in Puget Sound rockfish may not have been previously detected because the infection is subclinical in this species and earlier investigators did not utilize in vitro techniques for diagnosis of ichthyophoniasis. However, since clinical ichthyophoniasis has recently been identified in several other species of northeast Pacific rockfishes, it is hypothesized that this either is an emerging disease resulting from changing marine conditions or the result of introduction by infected southern species that appear during periodic El Nin??o events. ?? Copyright by the American Fisheries Society 2005.

  8. Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, northwest Alaska

    USGS Publications Warehouse

    Lenz, Josefine; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey M. Walter; Bobrov, Anatoly; Wulf, Sabine; Wetterich, Sebastian

    2016-01-01

    Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyse a ~ 4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemical, geochronological, micropalaeontological (ostracoda, testate amoebae) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by the deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP and drained catastrophically in spring 2005. The present study emphasises that Arctic lake systems and periglacial landscapes are highly dynamic and that permafrost formation as well as degradation in central Beringia was controlled by regional to global climate patterns as well as by local disturbances.

  9. Assessment of pingo distribution and morphometry using an IfSAR derived digital surface model, western Arctic Coastal Plain, Northern Alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Grosse, G.; Hinkel, Kenneth M.; Arp, C.D.; Walker, S.; Beck, R.A.; Galloway, J.P.

    2012-01-01

    Pingos are circular to elongate ice-cored mounds that form by injection and freezing of pressurized water in near-surface permafrost. Here we use a digital surface model (DSM) derived from an airborne Interferometric Synthetic Aperture Radar (IfSAR) system to assess the distribution and morphometry of pingos within a 40,000km2 area on the western Arctic Coastal Plain of northern Alaska. We have identified 1247 pingo forms in the study region, ranging in height from 2 to 21m, with a mean height of 4.6m. Pingos in this region are of hydrostatic origin, with 98% located within 995 drained lake basins, most of which are underlain by thick eolian sand deposits. The highest pingo density (0.18km-2) occurs where streams have reworked these deposits. Morphometric analyses indicate that most pingos are small to medium in size (<200m diameter), gently to moderately sloping (<30??), circular to slightly elongate (mean circularity index of 0.88), and of relatively low height (2 to 5m). However, 57 pingos stand higher than 10m, 26 have a maximum slope greater than 30??, and 42 are larger than 200m in diameter. Comparison with a legacy pingo dataset based on 1950s stereo-pair photography indicates that 66 may have partially or completely collapsed over the last half-century. However, we mapped over 400 pingos not identified in the legacy dataset, and identified only three higher than 2m to have formed between ca. 1955 and ca. 2005, indicating that caution should be taken when comparing contemporary and legacy datasets derived by different techniques. This comprehensive database of pingo location and morphometry based on an IfSAR DSM may prove useful for land and resource managers as well as aid in the identification of pingo-like features on Mars. ?? 2011.

  10. Assessment of pingo distribution and morphometry using an IfSAR derived digital surface model, western Arctic Coastal Plain, Northern Alaska

    NASA Astrophysics Data System (ADS)

    Jones, Benjamin M.; Grosse, Guido; Hinkel, Kenneth M.; Arp, Christopher D.; Walker, Shane; Beck, Richard A.; Galloway, John P.

    2012-02-01

    Pingos are circular to elongate ice-cored mounds that form by injection and freezing of pressurized water in near-surface permafrost. Here we use a digital surface model (DSM) derived from an airborne Interferometric Synthetic Aperture Radar (IfSAR) system to assess the distribution and morphometry of pingos within a 40,000 km 2 area on the western Arctic Coastal Plain of northern Alaska. We have identified 1247 pingo forms in the study region, ranging in height from 2 to 21 m, with a mean height of 4.6 m. Pingos in this region are of hydrostatic origin, with 98% located within 995 drained lake basins, most of which are underlain by thick eolian sand deposits. The highest pingo density (0.18 km - 2 ) occurs where streams have reworked these deposits. Morphometric analyses indicate that most pingos are small to medium in size (< 200 m diameter), gently to moderately sloping (< 30°), circular to slightly elongate (mean circularity index of 0.88), and of relatively low height (2 to 5 m). However, 57 pingos stand higher than 10 m, 26 have a maximum slope greater than 30°, and 42 are larger than 200 m in diameter. Comparison with a legacy pingo dataset based on 1950s stereo-pair photography indicates that 66 may have partially or completely collapsed over the last half-century. However, we mapped over 400 pingos not identified in the legacy dataset, and identified only three higher than 2 m to have formed between ca. 1955 and ca. 2005, indicating that caution should be taken when comparing contemporary and legacy datasets derived by different techniques. This comprehensive database of pingo location and morphometry based on an IfSAR DSM may prove useful for land and resource managers as well as aid in the identification of pingo-like features on Mars.

  11. Constraining the age and magnitude of uplift in the northern National Petroleum Reserve in Alaska (NPRA)-apatite fission-track analysis of samples from three wells

    USGS Publications Warehouse

    Houseknecht, David W.; Bird, Kenneth J.; O'Sullivan, Paul

    2011-01-01

    A broad, post-mid-Cretaceous uplift is defined in the northern National Petroleum Reserve in Alaska (NPRA) by regional truncation of Cretaceous strata, thermal maturity patterns, and amounts of exhumation estimated from sonic logs. Apatite fission-track (AFT) analysis of samples from three wells (South Meade No. 1, Topagoruk No. 1, and Ikpikpuk No. 1) across the eastern flank of the uplift indicates Tertiary cooling followed by Quaternary heating. Results from all three wells indicate that cooling, presumably caused by uplift and erosion, started about 75-65 Ma (latest Cretaceous-earliest Tertiary) and continued through the Tertiary Period. Data from South Meade indicate more rapid cooling after about 35-15 Ma (latest Eocene-middle Miocene) followed by a significant increase in subsurface temperature during the Quaternary, probably the result of increased heat flow. Data from Topagoruk and Ikpikpuk include subtle evidence of accelerated cooling starting in the latest Eocene-middle Miocene and possible evidence of increased temperature during the Quaternary. Subsurface temperature perturbations related to the insulating effect of permafrost may have been responsible for the Quaternary temperature increase at Topagoruk and Ikpikpuk and may have been a contributing factor at South Meade. Multiple lines of geologic evidence suggest that the magnitude of exhumation resulting from uplift and erosion is 5,000-6,500 ft at South Meade, 4,000-5,500 ft at Topagoruk, and 2,500-4,000 ft at Ikpikpuk. The results from these wells help to define the broad geometry of the uplift, which increases in magnitude from less than 1,000 ft at the Colville River delta to perhaps more than 7,000 ft along the northwestern coast of NPRA, between Point Barrow and Peard Bay. Neither the origin nor the offshore extent of the uplift, west and north of the NPRA coast, have been determined.

  12. Soil and Plant Mercury Concentrations and Pools in the Arctic Tundra of Northern Alaska by Hedge Christine, Obrist Daniel, Agnan Yannick, Moore Christopher, Biester Harald, Helmig Detlev

    NASA Astrophysics Data System (ADS)

    Hedge, C.; Agnan, Y.

    2015-12-01

    We present vegetation, soil and runoff mercury (Hg) concentrations and pool sizes in vegetation and soils at several arctic tundra sites, an area that represents <7 x 106 km2 of land surface globally. The primary measurement location is at Toolik Field Station (TFS, 68° 38' N) in northern Alaska, with additional samples collected along a transect from TFS to the Arctic Ocean, and in Noatak National Preserve to be collected in August 2015. Soil and vegetation samples from all sites will be analyzed for total Hg concentration, pH, soil texture, bulk density, soil moisture content, organic and total carbon (C), nitrogen, along with major and trace elements. Initial results already obtained from TFS (characterized as moist to wet tundra with Typic Aquiturbel soils) show Hg concentrations in tundra vegetation (112±15 μg kg-1) and organic soil (140±8 μg kg-1) similar to those found in temperate sites. Calculation of plant-based Hg deposition rates by litterfall of 17.3 μg kg-1 yr-1 were surprisingly high, exceeding all other Hg deposition fluxes at this site. Hg concentrations in mineral soils (95±3 μg kg-1) were 2-3 times higher than those found at temperate sites. Hg concentrations showed weak relationships to organic C concentrations contrasting patterns from temperate soils where concentrations typically decline with depth following lower organic carbon contents. In fact, vertical mass profiles of Hg showed a strong increase with depth, with mineral layers storing over 90% (200-500 g ha-1) of Hg within these soils. A principle component analysis including major and trace elements indicated that soil Hg was not of lithogenic origin but from atmospheric sources, possibly by long-range transport. Carbon-14 dating results showed over 7,000 years old organic carbon in mineral soils of the active layer where highest concentrations of soil Hg were observed, suggesting long term retention of atmospheric Hg. These patterns suggest vertical translocation of Hg from the

  13. Reconnaissance exploration geochemistry in the central Brooks Range, northern Alaska: Implications for exploration of sediment-hosted zinc-lead-silver deposits

    USGS Publications Warehouse

    Kelley, K.D.; Kelley, D.L.

    1992-01-01

    A reconnaissance geochemical survey was conducted in the southern Killik River quadrangle, central Brooks Range, northern Alaska. The Brooks Range lies within the zone of continuous permafrost which may partially inhibit chemical weathering and oxidation. The minus 30-mesh and nonmagnetic heavy-mineral concentrate fractions of sediment samples were chosen as the sample media for the survey so that mechanical rather than chemical dispersion patterns would be enhanced. A total of 263 sites were sampled within the southern half of the Killik River quadrangle at an average sample density of approximately one sample per 12 km2. All samples were submitted for multi-element analyses. In the western and central Brooks Range, several known sediment-hosted Zn-Pb-Ag(-Ba) deposits occur within a belt of Paleozoic rocks of the Endicott Mountains allochthon. Exploration for this type of deposit in the Brook Range is difficult, due to the inherently high background values for Ba, Zn and Pb in shale and the common occurrence of metamorphic quartz-calcite veins, many of which contain traces of sulfide minerals. Stream sediments derived from these sources produce numerous geochemical anomalies which are not necessarily associated with significant mineralization. R-mode factor analysis provides a means of distinguishing between element associations related to lithology and those related to possible mineralization. Factor analysis applied to the multi-element data from the southern Killik River quadrangle resulted in the discovery of two additional Zn-Pb-Ag mineral occurrences of considerable areal extent which are 80-100 km east of any previously known deposit. These have been informally named the Kady and Vidlee. Several lithogeochemical element associations, or factors, and three factors which represent sulfide mineralization were identified: Ag-Pb-Zn (galena and sphalerite) and Fe-Ni-Co-Cu (pyrite ?? chalcopyrite) in the concentrate samples and Cd-Zn-Pb-As-Mn in the sediment

  14. Longevity Is Linked to Mitochondrial Mutation Rates in Rockfish: A Test Using Poisson Regression.

    PubMed

    Hua, Xia; Cowman, Peter; Warren, Dan; Bromham, Lindell

    2015-10-01

    The mitochondrial theory of ageing proposes that the cumulative effect of biochemical damage in mitochondria causes mitochondrial mutations and plays a key role in ageing. Numerous studies have applied comparative approaches to test one of the predictions of the theory: That the rate of mitochondrial mutations is negatively correlated with longevity. Comparative studies face three challenges in detecting correlates of mutation rate: Covariation of mutation rates between species due to ancestry, covariation between life-history traits, and difficulty obtaining accurate estimates of mutation rate. We address these challenges using a novel Poisson regression method to examine the link between mutation rate and lifespan in rockfish (Sebastes). This method has better performance than traditional sister-species comparisons when sister species are too recently diverged to give reliable estimates of mutation rate. Rockfish are an ideal model system: They have long life spans with indeterminate growth and little evidence of senescence, which minimizes the confounding tradeoffs between lifespan and fecundity. We show that lifespan in rockfish is negatively correlated to rate of mitochondrial mutation, but not the rate of nuclear mutation. The life history of rockfish allows us to conclude that this relationship is unlikely to be driven by the tradeoffs between longevity and fecundity, or by the frequency of DNA replications in the germline. Instead, the relationship is compatible with the hypothesis that mutation rates are reduced by selection in long-lived taxa to reduce the chance of mitochondrial damage over its lifespan, consistent with the mitochondrial theory of ageing. PMID:26048547

  15. 50 CFR Table 28e to Part 679 - Rockfish Entry Level Longline Fishery Allocations

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Rockfish Entry Level Longline Fishery Allocations 28e Table 28e to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE...

  16. 50 CFR 679.83 - Rockfish Program entry level longline fishery.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Rockfish Program entry level longline fishery. 679.83 Section 679.83 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE...

  17. 50 CFR 679.84 - Rockfish Program recordkeeping, permits, monitoring, and catch accounting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Rockfish Program recordkeeping, permits, monitoring, and catch accounting. 679.84 Section 679.84 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE...

  18. 50 CFR 679.84 - Rockfish Program recordkeeping, permits, monitoring, and catch accounting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Rockfish Program recordkeeping, permits, monitoring, and catch accounting. 679.84 Section 679.84 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE...

  19. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Shelf Rockfish Catcher/Processor and Catcher Vessel 4.0 percent Pacific ocean perch, Catcher/Processor... CQ permit. Pacific Cod Catcher/Processor 4.0 percent Shortraker/Rougheye aggregate catch Catcher.... Pacific Cod Catcher Vessel 8.0 percent Pacific Cod Catcher/Processor 4.0 percent Sablefish (trawl...

  20. Indirect effects of sea otters on rockfish (Sebastes spp.) in giant kelp forests.

    PubMed

    Markel, Russell W; Shurin, Jonathan B

    2015-11-01

    Sea otters are a classic example of a predator controlling ecosystem productivity through cascading effects on basal, habitat-forming kelp species. However, their indirect effects on other kelp-associated taxa like fishes are poorly understood. We examined the effects of sea otter (Enhydra lutris) reintroduction along the west coast of Vancouver Island, Canada on giant kelp (Macrocystis pyrifera) distributions and the trophic niches and growth of two common kelp forest fishes, black (Sebastes melanops) and copper (S. caurinus) rockfishes. We sampled 47 kelp forests, and found that red sea urchins (Strongylocentrotus franciscanus) were eliminated in the presence of otters, and that kelp forests were 3.7 times deeper and 18.8 times larger. Despite order-of-magnitude differences in kelp forest size, adult black and copper rockfishes contained less kelp-derived carbon in their tissues (as measured by stable isotopes of C and N) in regions with otters. Adults of both species had higher mean trophic positions in the presence of otters, indicating more frequent consumption of higher trophic level prey such as fishes. Smaller trophic niche space of rockfishes in the presence of otters indicated a higher degree of trophic specialization. Juvenile black rockfishes rapidly shifted to higher kelp-carbon contents, trophic positions, and body condition factors after settling in kelp forests. The relationships of growth to length, percentage of kelp carbon, and trophic position varied between the two regions, indicating that potential effects of kelp forest size on trophic ontogeny may also affect individual performance. Our results provide evidence that the indirect effects of otters on rockfishes arise largely through the creation of habitat for fishes and other prey rather than a direct trophic connection through invertebrates or other consumers of kelp productivity. PMID:27070008

  1. Multistage hydrothermal silicification and Fe-Tl-As-Sb-Ge-REE enrichment in the Red Dog Zn-Pb-Ag district, northern Alaska: Geochemistry, origin, and exploration applications

    USGS Publications Warehouse

    Slack, J.F.; Kelley, K.D.; Anderson, V.M.; Clark, J.L.; Ayuso, R.A.

    2004-01-01

    Geochemical analyses of major, trace, and rare earth elements (REE) in more than 200 samples of variably silicified and altered wall rocks, massive and banded sulfide, silica rock, and sulfide-rich and unmineralized barite were obtained from the Main, Aqqaluk, and Anarraaq deposits in the Red Dog Zn-Pb-Ag district of northern Alaska. Detailed lithogeochemical profiles for two drill cores at Aqqaluk display an antithetic relationship between SiO2/Al2O3 and TiO2/Zr which, together with textural information, suggest preferential silicification of carbonate-bearing sediments. Data for both drill cores also show generally high Tl, Sb, As, and Ge and uniformly positive Eu anomalies (Eu/Eu* > 1.0). Similar high Tl, Sb, As, Ge, and Eu/Eu* values are present in the footwall and shallow hanging wall of Zn-Pb-Ag sulfide intervals at Anarraaq but are not as widely dispersed. Net chemical changes for altered wall rocks in the district, on the basis of average Al-normalized data relative to unaltered black shales of the host Kuna Formation, include large enrichments (>50%) of Fe, Ba, Eu, V, S, Co, Zn, Pb, Tl, As, Sb, and Ge at both Red Dog and Anarraaq, Si at Red Dog, and Sr, U, and Se at Anarraaq. Large depletions (>50%) are evident for Ca at both Red Dog and Anarraaq, for Mg, P, and Y at Red Dog, and for Na at Anarraaq. At both Red Dog and Anarraaq, wall-rock alteration removed calcite and minor dolomite during hydrothermal decarbonation reactions and introduced Si, Eu, and Ge during silicification. Sulfidation reactions deposited Fe, S, Co, Zn, Pb, Tl, As, and Sb; barite mineralization introduced Ba, S, and Sr. Light REE and U were mobilized locally. This alteration and mineralization occurred during Mississippi an hydrothermal events that predated the Middle Jurassic-Cretaceous Brookian orogeny. Early hydrothermal silicification at Red Dog took place prior to or during massive sulfide mineralization, on the basis of the dominantly planar nature of Zn-Pb veins, which suggests

  2. Seasonal Control of Surface-Water Dissolved Iron Concentrations by Suspended Particle Concentrations on the Northern Gulf of Alaska Continental Shelf and Slope

    NASA Astrophysics Data System (ADS)

    Crusius, J.; Schroth, A. W.; Campbell, R.; Cullen, J. T.; Dillman, D.; Resing, J.

    2012-12-01

    The continental shelf region of the northern Gulf of Alaska (GoA) supports a productive ecosystem including an important commercial fishery. Downwelling winds during most of the year imply that some mechanism other than upwelling must be supplying the essential nutrients iron and nitrate. Although it is well known that iron limits productivity offshore in the GoA, we have a poor understanding of the controls on Fe supply. Data from cruises from 2010 provide some new insight into the mechanisms of Fe supply. Cruises were carried out along a transect extending from the mouth of the Copper River to ~40 km beyond the shelf break three times per year including early April, early May, and late July. High-resolution surface-water sampling was carried out, as well as bottle casts at 5 stations. High, fairly uniform concentrations of "total dissolvable iron" (TDFe; unfiltered sample acidified to pH=1.7) as well as "dissolved" Fe (dFe) were observed spanning the shelf in April, suggesting sediment resuspension is an important source of dFe to surface waters at that time. By contrast, high dFe and TDFe concentrations in late July coincide with low-salinity surface water, which in this location indicates a glacial meltwater source. Throughout spring and summer high particle concentrations across much of the shelf appear to "buffer" dFe concentrations to ~3 nmol/kg, which are close to those observed by Lippiatt et al (2010) in the region. This is consistent with dFe concentrations being determined by the organic ligand concentrations that, in turn, are fairly constant. In late July, surface water dFe concentrations are ~0.5 nmol/kg on the outer shelf and up to ~50 km further offshore. These dFe concentrations on the outer shelf are much lower in July than earlier in the year, owing to Fe removal by phytoplankton uptake and by scavenging, as well as by the lack of particulate Fe sources to surface waters in July. However, the high surface-water dFe observed ~50 km beyond the

  3. Structural Implications of new Geologic Mapping and a Detailed Gravity Traverse in the Brooks Range Foothills, Chandler Lake Quadrangle, Northern Alaska

    NASA Astrophysics Data System (ADS)

    Peapples, P. R.; Saltus, R. W.; Swenson, R.; Brown, P. J.

    2005-12-01

    A fold and thrust belt in northern Alaska occupies the structural transition from the imbricate thrust sheets (or allochthons) of the Brooks Range to the North Slope coastal plain. Understanding this complexly deformed zone is critical to hydrocarbon assessment in the state-owned lands south of Prudhoe Bay. New geologic mapping and geophysical studies are focused on this important region. Detailed (1:63,360 scale) geologic mapping along the drainages of Tiglukpuk Creek and the Siksikpuk River documents exposures of deep structural levels and provides important constraints for a structural model of this region. A south-to-north structural transect encompasses the transition from the highly deformed thrust sheets of the Endicott Mountains Allochthon (EMA) at the mountain front to the inferred triangle zone at the Tuktu Escarpment 45 miles to the north. Mississippian Carbonates to Triassic siliciclastics make up the EMA north of the mountain front where there is an abrupt transition in structural style from north-vergent asymmetric overturned folding to gentle warping above shallowly dipping fault ramps. Tiglukpuk Anticline represents a fenster where the EMA is overlain in thrust contact by a melange of more distal Ipnavik River Allochthon (IRA) rocks. Parallel synclinoria contain the Okpikruak siliciclastics of the IRA assemblage and the Brookian syntectonic siliciclastics of the Fortress Mountain formation, carried atop the EMA thrust sheets during the latest phase of deformation. This complex structural style abruptly ends at the Tuktu Escarpment which likely represents a backthrust/triangle zone that places shallow north dipping coarse clastics of the Nanushuk Formation over the less competent and highly deformed Torok shale. The structural complexity and associated steeply dipping strata in the foothills belt were not well imaged by existing conventional seismic data in this region. To provide additional subsurface control, we collected ground station gravity

  4. Extreme rates of riverbank erosion of the high bluff formed by the ice-rich syngenetic permafrost (yedoma), Itkillik River, Northern Alaska

    NASA Astrophysics Data System (ADS)

    Kanevskiy, M. Z.; Shur, Y.; Fortier, D.; Jorgenson, T.; Stephani, E.; Strauss, J.

    2013-12-01

    Riverbank erosion in areas underlain by ice-rich permafrost is strongly affected by the processes of thawing of ground ice, which include (1) thermal erosion, and (2) thermal denudation. Thermal erosion is a process of combined thermal and mechanical action of moving water, which results in simultaneous thawing of frozen soil and its removal by water. Thermal erosion can cause block collapse of eroded banks. Thermal denudation is a process of thawing of frozen soils exposed in the bluff due to solar energy and consequent removal of thawed soils by gravity. Studies of riverbank and coastal erosion revealed that the highest rates of erosion are typical of bluffs composed by yedoma (ice- and organic-rich syngenetically frozen silty deposits). Yedoma deposits can be up to 50 m thick, and they contain huge ice wedges up to 10 m wide. Since 2006, we have studied the process of riverbank erosion of the 35 m high exposure of yedoma along the Itkillik River in northern Alaska. Based on five measurements of the areas occupied by wedge ice in panoramic photographs taken in 2006, 2007, 2011, and 2012, the average wedge-ice volume makes 61% of the entire exposed bluff. The total volumetric ground ice content of the Itkillik yedoma, including wedge, segregated and pore ice, is 85%. We detect three main stages of the riverbank erosion for the study site and other similar sites in the areas of ice-rich permafrost: (1) thermal erosion combined with thermal denudation, (2) thermal denudation, and (3) slope stabilization. The first stage includes formation of thermoerosional niches; development of sub-vertical cracks and block-fall collapse of cornices; and thawing and disintegration of blocks of ground ice and frozen soil in the water. All these processes are accompanied by thermal denudation of the exposed bluff. On August 16, 2007, a big portion of the bluff fell down along the crack sub-parallel to the bluff. As a result, the vertical wall more than 65 m long entirely formed by

  5. 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…

  6. A reconnaissance in northern Alaska across the Rocky Mountains, along Koyukuk, John, Anaktuvuk, and Colville rivers and the Arctic coast to Cape Lisburne, in 1901, with notes

    USGS Publications Warehouse

    Schrader, F.C.; Peters, W.J.

    1904-01-01

    Since 1898 the United States Geological Survey has been carrying on systematic topographic and geologic surveys in Alaska under an appropriation made for the investigation of the mineral resources of the Territory. This work has included not only areal surveys of regions already being developed by the miner and prospector, but also explorations and investigations of regions that are little known or entirely unexplored. As a result of these explorations a network of reconnaissance traverses has been extended over a large part of Alaska, where route surveys of this character must necessarily precede more detailed topographic and geologic mapping. They serve to outline the main geographic features of the country and afford the pioneer or prospector a guide for his journeys as well as help him to select his field of operations. The present report and maps are the results of such an investigation.

  7. Molecular and isotopic analyses of the hydrocarbon gases within gas hydrate-bearing rock units of the Prudhoe Bay-Kuparuk River area in northern Alaska

    USGS Publications Warehouse

    Valin, Zenon C.; Collett, Timothy S.

    1992-01-01

    Gas hydrates, which are crystalline substances of water molecules that encase gas molecules, have the potential for being a significant source of natural gas. World-wide estimates for the amount of gas contained in hydrates range from 1.1 x 105 to 2.7 x 108 trillion cubic feet. Gas hydrates exist in many Arctic regions, including the North Slope of Alaska. The two primary objectives of the U.S. Geological Survey Gas Hydrate Research Project are (1) to map the distribution of in-situ gas hydrates on the North Slope of Alaska, and (2) to evaluate the geologic parameters that control the distribution of these gas hydrates. To aid in this study, British Petroleum Exploration, ARCO Alaska, Exxon Company USA, and the Continental Oil Company allowed the U.S. Geological Survey to collect geochemical samples from drilling North Slope production wells. Molecular analysis of gaseous drill cutting and free-flowing gas samples from 10 production wells drilled in the Prudhoe Bay, Kuparuk River, and Milne Point oil fields indicates that methane is the primary hydrocarbon gas in the gas hydrate-bearing stratigraphic units. Isotopic data for several of these rock units indicate that the methane within the inferred gas hydrate occurences originated from both microbial and thermogenic processes.

  8. Cloning and expression analysis of vasa during the reproductive cycle of Korean rockfish, Sebastes schlegeli

    NASA Astrophysics Data System (ADS)

    Mu, Weijie; Wen, Haishen; He, Feng; Li, Jifang; Liu, Miao; Ma, Ruiqin; Zhang, Yuanqing; Hu, Jian; Qi, Baoxia

    2013-03-01

    Vasa, which is a conserved member of the DEAD-box protein family, plays an indispensable role in primordial germ cell proliferation. However, the expression of vasa gene during the reproductive cycle in ovoviviparous fish has not been documented. In this study, the full-length sequence of vasa was obtained from the ovary of Korean rockfish ( Sebastes schlegeli) using reverse transcription-PCR and rapid amplification of cDNA ends. The Vasa with a mature protein of 650 amino acids showed greatest homology (84%) with giant gourami ( Osphronemus goramy) and Pacific bluefin tuna ( Thunnus orientalis). The expression of vasa mRNA in Korean rockfish was detected in gonads only, suggesting its specific role in gonadal development. In addition, seasonal changes in the vasa expression levels were examined in gonads by quantitative real-time PCR. The vasa transcript levels in adult testis were found higher during spermatogenesis than during spermiation. The vasa transcript levels remained relatively high at the early ovary stage but declined during ovary maturation in adult female fish. These results suggest that the vasa gene play an important role in spermatogenesis and early oogenesis during the reproductive cycle of Korean rockfish.

  9. 50 CFR Table 2b to Part 660... - 2010, and Beyond, Harvest Guidelines for Minor Rockfish by Depth Sub-groups (weights in metric tons)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... minor rockfish south. hh “Other rockfish” includes rockfish species listed in 50 CFR 660.302. A new... and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... 16,500 mt is less than the ABC. The OY is set at the MSY harvest level which is considerably...

  10. Investigations of belukha whales in coastal waters of western and northern Alaska, 1982-1983: marking and tracking of whales in Bristol Bay

    SciTech Connect

    Frost, K.J.; Lowry, L.F.; Nelson, R.R.

    1983-12-01

    A 2-year study was conducted in Bristol Bay, Alaska, to develop and test techniques for marking belukha whales with visual and radio tags. Information was also gathered on belukha distribution and abundance, foods and feeding, and rates and causes of mortality. Two types of radio packages were developed: an OAR backpack designed to be bolted through the dorsal ridge, and a Telonics barnacle tag with an umbrella-stake attachment. Testing of tags and attachments revealed that the more-powerful OAR radio could be received at longer distances and lower antenna heights, and the the umbrella-stake attachment penetrated too deeply for reliable use on belukhas.

  11. 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.

  12. Alaska Athabascan stellar astronomy

    NASA Astrophysics Data System (ADS)

    Cannon, Christopher M.

    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.

  13. Landscape- and decadal-scale changes in the composition and structure of plant communities in the northern foothills of the Brooks Range of Arctic Alaska

    NASA Astrophysics Data System (ADS)

    Mercado-Díaz, J. A.; Gould, W. A.

    2010-12-01

    Scientists have predicted an increase in vascular plant cover in some tundra ecosystems as a result of global climate change. In Arctic Alaska, observational studies have documented increases in shrub cover for some regions; however, only a few studies have provided detailed quantitative evidence supporting the existence such changes. To address these shortcomings, we analyzed plant community data from 156 1m2 vegetation plots located at two 1km2 grids in Toolik Lake, Alaska. This data covered the time period from 1989-2008. After 18 years, we found that the relative abundance of vascular vegetation have increased by 16%, while the relative abundance of nonvascular vegetation decreased by 19%. Mean plant canopy height has experienced an increase from 4.4 cm in 1990 to 6.5 cm in 2008 and the extent and complexity of the canopy have increased over time from about 60% to 80%. Species diversity was also significantly reduced. While major vegetation changes in other tundra regions have been attributed to gradual increases in surface air temperature, changes documented in this study were apparently promoted by increasing soil moisture conditions that resulted from increased summer rainfall in our region. These results support the idea that tundra ecosystems in this region of the Alaskan Arctic are experiencing significant increases in aboveground standing crop and a shift in carbon allocation to vascular plants vs. bryophytes. These changes will likely affect important ecosystem processes like snow re-deposition, winter biological activities, nutrient cycling and could ultimately result in significant feedbacks to climate.

  14. Cloning and expression analysis of a HSP70 gene from Korean rockfish (Sebastes schlegeli).

    PubMed

    Mu, Weijie; Wen, Haishen; Li, Jifang; He, Feng

    2013-10-01

    The gene encoding HSP70 was isolated from Korean rockfish Sebastes schlegeli by homologous cloning and rapid amplification of cDNA ends (RACE). The full-length of HSP70 cDNA was composed of 2259 bp and encoded a polypeptide of 639 amino acids. BLAST analysis showed that HSP70 of S. schlegeli shared high identities with those of the Lates calcarifer, Oreochromis niloticus, Seriola quinqueradiata HSP70s (88-89%). Our current study also revealed that HSP70 of Korean rockfish was expressed in many tissues by RT-PCR under unstressed condition. Quantitative real-time PCR showed that the expression patterns of Korean rockfish HSP70 were developmental stage-dependency. The expression of HSP70 was measured by quantitative real-time PCR after different oxygen treatments. The results showed that expression of HSP70 increased significantly after exposure to hypoxia for 30 min in gill and ovary, and then decreased for 60 min, and the level in spleen and liver gradually increased and reached the highest at 60 min. In addition, in gill, spleen and liver, the HSP70 mRNA level reached the maximum in hypoxia group after one hour different oxygen concentration stress. Increased amounts of serum thyroxine (T4), and triiodothyronine (T3) were also found during 30 min hypoxia treatment and 60 min normoxia group in our study. All of the results provide information to further study the mechanism of physiology and immune function under stress conditions of ovoviviparous teleosts. PMID:23877000

  15. Shaded Relief Mosaic of Umnak Island, Aleutian Islands, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is a shaded relief mosaic of Umnak Island in Alaska's Aleutian Islands.

    It was created with Airsar data that was geocoded and combined into this mosaic as part of a NASA-funded Alaska Digital Elevation Model Project at the Alaska Synthetic Aperture Radar Facility (ASF) at the University of Alaska Geophysical Institute in Fairbanks, Alaska.

    Airsar collected the Alaska data as part of its PacRim 2000 Mission, which took the instrument to French Polynesia, American and Western Samoa, Fiji, New Zealand, Australia, New Guinea, Indonesia, Malaysia, Cambodia, Philippines, Taiwan, South Korea, Japan, Northern Marianas, Guam, Palau, Hawaii and Alaska. Airsar, part of NASA's Airborne Science Program, is managed for NASA's Earth Science Enterprise by JPL. JPL is a division of the California Institute of Technology in Pasadena.

  16. Biozone Characterization of Foraminifera in Upper Pleistocene through Recent Shelf and Slope Sediments, Northern Gulf of Alaska: Integration of SHE-diversity and Polytopic Vector Analyses

    NASA Astrophysics Data System (ADS)

    Zellers, S.; Cowan, E. A.; Davies, M. H.

    2014-12-01

    Gulf of Alaska sediments contain distinct, low-diversity assemblages of benthic and planktic foraminifera, whose distribution is a function of food availability, water mass properties, ice proximity, transport/deposition, predation, and taphonomic processes. Spatial and temporal changes in diversity reflect these processes and provide insight into this margin's history. Two quantitative techniques are integrated to define and characterize benthic foraminferal biozones in Gulf of Alaska sediment core samples collected by the R/V Maurice Ewing in 2004 at shelf site EW0408-79JC (59.53° N, 141.76° W, 158 m depth), and slope site EW0408-85JC (59.56° N, 144.15° W, 682 m depth). Sediments date from the end of the most recent glaciation (diamict in 85JC) to the present (bioturbated, silty clay at both sites). We apply SHE analysis, a graphical, iterative technique, based on diversity trends in a plot of ln E vs. ln N, where E is species evenness and N is cumulative number of specimens. In each step, the plot is examined for the first change in slope between successive samples, representing a change in diversity. At this point a boundary is defined, samples before the break are removed, and the analysis is repeated until all samples are analyzed. Data are further analyzed using an unmixing algorithm known as polytopic vector analyses. This technique defines a small number of orthogonal end members that explain a majority of the variance, thus reducing data complexity and aiding interpretation. SHE-analysis of benthic foraminiferal data defines eighteen informal abundance biozones. Polytopic vector analyses indicate that the faunal assemblages reflect mixtures of up to seven distinct biofacies: outer neritic (2), upper bathyal (2), reduced oxygen (2), and inner neritic. Rapid changes in faunal diversity correspond with increased sedimentation rates, especially during the end of the most recent glaciation (17 to 16 ka). The same relationship occurs over the last 1000

  17. Plate Margin Deformation and Active Tectonics Along the Northern Edge of the Yakutat Terrane in the Saint Elias Orogen, Alaska and Yukon, Canada

    NASA Technical Reports Server (NTRS)

    Bruhn, Ronald L.; Sauber, Jeanne; Cotton, Michele M.; Pavlis, Terry L.; Burgess, Evan; Ruppert, Natalia; Forster, Richard R.

    2012-01-01

    The northwest directed motion of the Pacific plate is accompanied by migration and collision of the Yakutat terrane into the cusp of southern Alaska. The nature and magnitude of accretion and translation on upper crustal faults and folds is poorly constrained, however, due to pervasive glaciation. In this study we used high-resolution topography, geodetic imaging, seismic, and geologic data to advance understanding of the transition from strike-slip motion on the Fairweather fault to plate margin deformation on the Bagley fault, which cuts through the upper plate of the collisional suture above the subduction megathrust. The Fairweather fault terminates by oblique-extensional splay faulting within a structural syntaxis, allowing rapid tectonic upwelling of rocks driven by thrust faulting and crustal contraction. Plate motion is partly transferred from the Fairweather to the Bagley fault, which extends 125 km farther west as a dextral shear zone that is partly reactivated by reverse faulting. The Bagley fault dips steeply through the upper plate to intersect the subduction megathrust at depth, forming a narrow fault-bounded crustal sliver in the obliquely convergent plate margin. Since . 20 Ma the Bagley fault has accommodated more than 50 km of dextral shearing and several kilometers of reverse motion along its southern flank during terrane accretion. The fault is considered capable of generating earthquakes because it is linked to faults that generated large historic earthquakes, suitably oriented for reactivation in the contemporary stress field, and locally marked by seismicity. The fault may generate earthquakes of Mw <= 7.5.

  18. Geophysical investigation and reconstruction of lithospheric structure and its control on geology, structure, and mineralization in the Cordillera of northern Canada and eastern Alaska

    NASA Astrophysics Data System (ADS)

    Hayward, N.

    2015-10-01

    A reconstruction of the Tintina fault is applied to regional geophysical and topographic data, facilitating the definition of west trending lineaments within the lower crust and/or mantle lithosphere, oblique to the NW trending structure of the Cordilleran terranes. The lineaments, which exhibit a range of geophysical and geological signatures, are interpreted to be related to the Liard transfer zone, continuous to the Denali fault, that divided lower and upper plates during late Proterozoic-Cambrian rifting of the Laurentian margin. Three-dimensional gravity models show a density increase in the lower crust and mantle lithosphere to the north. The transfer zone also divides bimodal mantle xenolith suites to the south from unimodal suites to the north. These conclusions suggest that extended North American basement, related to Laurentian margin rifting that would have brought mantle lithosphere rocks to a shallow depth, continuously underlies a thin carapace of accreted terranes in western Yukon and eastern Alaska. The interpreted continuity of North American basement reaffirms that if oroclinal bending of the Intermontane terranes occurred, then it was prior to its emplacement upon the rifted basement. Examination of the spatial relationships between mineral occurrences and postaccretionary, Cretaceous lithospheric lineaments, from their manifestation in geophysical, geological, and topographic data, suggest that the late Proterozoic lineaments influenced Mesozoic mineralization through influence on the development of the shallow crustal structure, intrusion, and exhumation and erosion.

  19. CO2-induced ocean acidification increases anxiety in Rockfish via alteration of GABAA receptor functioning

    PubMed Central

    Hamilton, Trevor James; Holcombe, Adam; Tresguerres, Martin

    2014-01-01

    The average surface pH of the ocean is dropping at a rapid rate due to the dissolution of anthropogenic CO2, raising concerns for marine life. Additionally, some coastal areas periodically experience upwelling of CO2-enriched water with reduced pH. Previous research has demonstrated ocean acidification (OA)-induced changes in behavioural and sensory systems including olfaction, which is due to altered function of neural gamma-aminobutyric acid type A (GABAA) receptors. Here, we used a camera-based tracking software system to examine whether OA-dependent changes in GABAA receptors affect anxiety in juvenile Californian rockfish (Sebastes diploproa). Anxiety was estimated using behavioural tests that measure light/dark preference (scototaxis) and proximity to an object. After one week in OA conditions projected for the next century in the California shore (1125 ± 100 µatm, pH 7.75), anxiety was significantly increased relative to controls (483 ± 40 µatm CO2, pH 8.1). The GABAA-receptor agonist muscimol, but not the antagonist gabazine, caused a significant increase in anxiety consistent with altered Cl− flux in OA-exposed fish. OA-exposed fish remained more anxious even after 7 days back in control seawater; however, they resumed their normal behaviour by day 12. These results show that OA could severely alter rockfish behaviour; however, this effect is reversible. PMID:24285203

  20. Low-maturity Kulthieth Formation coal: A possible source of polycyclic aromatic hydrocarbons in benthic sediment of the northern Gulf of Alaska

    USGS Publications Warehouse

    Van Kooten, G. K.; Short, J.W.; Kolak, J.J.

    2002-01-01

    The successful application of forensic geology to contamination studies involving natural systems requires identification of appropriate endmembers and an understanding of the geologic setting and processes affecting the systems. Studies attempting to delineate the background, or natural, source for hydrocarbon contamination in Gulf of Alaska (GOA) benthic sediments have invoked a number of potential sources, including seep oils, source rocks, and coal. Oil seeps have subsequently been questioned as significant sources of hydrocarbons present in benthic sediments of the GOA in part because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Likewise, native coal has been dismissed in part because ratios of labile hydrocarbons to total organic carbon (e.g. PAH:TOC) for Bering River coal field (BRCF) sources are too low - i.e. the coals are over mature - to be consistent with GOA sediments. We present evidence here that native coal may have been prematurely dismissed, because BRCF coals do not adequately represent the geochemical signatures of coals elsewhere in the Kulthieth Formation. Contrary to previous thought, Kulthieth Formation coals east of the BRCF have much higher PAH: TOC ratios, and the patterns of labile hydrocarbons in these low thermal maturity coals suggest a possible genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analyses of low-maturity Kulthieth Formation coal indicate the low maturity coal is a significant source of PAH. Source apportionment models that neglect this source will underestimate the contribution of native coals to the regional background hydrocarbon signature. ?? Published by Elsevier Science Ltd. on behalf of AEHS.

  1. Quantitative Interpretation of Arctic Tundra Attributes Using Remote Sensing: Leveraging Field Data, Modern- and Legacy Landsat Data, and Commercial Imagery in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Frost, G. V., Jr.; Macander, M. J.; Nelson, P. R.

    2014-12-01

    Integrated analysis of ground-based vegetation data and remote sensing supports vegetation mapping, landscape-change detection, wildlife habitat assessment, and tracking of phenological events such as green-up and senescence. The life-cycles of tundra plants occur within a highly compressed seasonal window, making the quantitative assessment of vegetation and landscape attributes from ≤30m resolution remotely-sensed imagery, such as above-ground biomass, % shrub cover, and % surface water, a difficult task when applied across large study domains. To support mapping of vegetation and landscape attributes across ~100,000 km2 of Alaska's North Slope, we obtained ground data for tundra vegetation using a point-intercept sampling approach across a network of 107 field plots spanning gradients of bioclimate, landscape position (upland, lowland, riverine), and geomorphic setting (foothills, coastal plain). At each plot, vegetation data were collected along three 50-m linear transects, compatible with 30-m Landsat imagery. We summarized live vegetation, litter, and non-vegetated surfaces using three terms: top cover (uppermost "hit"), percent cover (total areal cover along transect), and hit density (all "hits" at a point). We then evaluated a suite of data models (e.g., General Additive Models, classification tree, clustering) and data-mining approaches (e.g., neural networks, random forest) using midsummer Landsat TM/ETM+ acquisitions since 1985, and OLI acquisitions for 2013-2014. The large size, frequent cloudiness, and interannual variability of the study area necessitated the compositing of a multitude of Landsat scenes. A median NDVI compositing technique was used to select Landsat observations from cloud- and shadow-free pixels that met day-of-year and year constraints. This technique produced seamless, phenologically consistent composites that are largely free of artifacts and suitable for regional-scale analysis. Ground-based training data and an archive of

  2. PERFORMANCE OF AERATED LAGOONS IN NORTHERN CLIMATES

    EPA Science Inventory

    Studies of cold climate aerated lagoons conducted by the Arctic Environmental Research Station, Fairbanks, Alaska are reported. Conclusions are based on these studies, observations of full scale aerated lagoons operating in Alaska and reports on lagoons in the northern tier of th...

  3. 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.

  4. New Perspectives of Permafrost Distribution and its Influence on Groundwater Flow and Ecosystem Performance for the Yukon Flats Area, Northern Alaska

    NASA Astrophysics Data System (ADS)

    Smith, B. D.; Walvoord, M. A.; Wylie, B. K.; Voss, C. I.; Pastick, N.; Minsley, B. J.; Jepsen, S. M.; Jorgenson, T. T.; Cannia, J. C.; Abraham, J. D.; Anderson, L.

    2011-12-01

    Permafrost is a predominant physical feature of the planet's Arctic and sub-Arctic regions and a major consideration that impacts climate processes, ecosystem function, water resources, and infrastructure engineering. The U.S. Geological Survey has conducted hydrological, geophysical, and geological studies of the Yukon Flats area within the discontinuous permafrost region of Interior Alaska. This is an area of low topographic relief that is populated with numerous streams, lakes and the braided meandering Yukon River with broad gravel-filled channels. Lake sediments and geological archives contain preserved sedimentary records of landscape changes in ecosystems, climate, and groundwater at decade-to-century and millennial time scales. The near-surface geology consists of unconsolidated Pliocene lacustrine silts and clays overlain by late Pleistocene and Holocene alluvial gravels and eolian deposits including extensive loess uplands and dunes. Remotely sensed data for the area from a variety of sensors provide information that is used for both static image interpretations and dynamic process modeling. An airborne electromagnetic survey (AEM) carried out in June of 2010 covered a large area (~1,800 line-km) with widely spaced reconnaissance lines and a 10 by 30 km block near Ft. Yukon. The AEM survey data was inverted to produce resistivity as a function of depth along the flight lines. The resistivity depth sections map the presence or absence of permafrost both laterally and with depth, as well as variations in subsurface lithology. The resulting depth images provide a unique detailed view of the subsurface that has previously only been conceptualized. One application of the remotely sensed data is to extrapolate the AEM data and interpretation between flight lines. Model development and independent test accuracies for 0-1 m electrical resistivity had training and test R2 values of 0.90 and 0.87 indicating accurate prediction models. Groundwater modeling of the

  5. Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    USGS Publications Warehouse

    Dusel-Bacon, Cynthia; Aleinikoff, John N.; Premo, Wayne R.; Paradis, Suzanne; Lohr-Schmidt, Ilana

    2007-01-01

    This paper summarizes the results of field and laboratory investigations, including whole-rock geochemistry and radiogenic isotopes, of outcrop and drill core samples from volcanogenic massive sulfide (VMS) deposits and associated metaigneous rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range (see fig. 1 of Editors’ Preface and Overview). U-Pb zircon igneous crystallization ages from felsic rocks indicate a prolonged period of Late Devonian to Early Mississippian (373±3 to 357±4 million years before present, or Ma) magmatism. This magmatism occurred in a basinal setting along the ancient Pacific margin of North America. The siliceous and carbonaceous compositions of metasedimentary rocks, Precambrian model ages based on U-Pb dating of zircon and neodymium ages, and for some units, radiogenic neodymium isotopic compositions and whole-rock trace-element ratios similar to those of continental crust are evidence for this setting. Red Mountain (also known as Dry Creek) and WTF, two of the largest VMS deposits, are hosted in peralkaline metarhyolite of the Mystic Creek Member of the Totatlanika Schist. The Mystic Creek Member is distinctive in having high concentrations of high-field-strength elements (HFSE) and rare-earth elements (REE), indicative of formation in a within-plate (extensional) setting. Mystic Creek metarhyolite is associated with alkalic, within-plate basalt of the Chute Creek Member; neodymium isotopic data indicate an enriched mantle component for both members of this bimodal (rhyolite-basalt) suite. Anderson Mountain, the other significant VMS deposit, is hosted by the Wood River assemblage. Metaigneous rocks in the Wood River assemblage span a wide compositional range, including andesitic rocks, which are characteristic of arc volcanism. Our data suggest that the Mystic Creek Member likely formed in an extensional, back-arc basin that was associated with an outboard continental-margin volcanic arc that included

  6. 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

  7. Tularemia in Alaska, 1938 - 2010

    PubMed Central

    2011-01-01

    Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state. PMID:22099502

  8. Tularemia in Alaska, 1938 - 2010.

    PubMed

    Hansen, Cristina M; Vogler, Amy J; Keim, Paul; Wagner, David M; Hueffer, Karsten

    2011-01-01

    Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state. PMID:22099502

  9. The complete mitochondrial genome of the oblong rockfish Sebastes oblongus (Scorpaenidae, Scorpaeniformes).

    PubMed

    Jang, Yo-Soon; Oh, Sung-Yong; Park, Kwang-Jae; Kim, Ki-Yong; Kim, Sung

    2016-01-01

    The complete mitogenome of the oblong rockfish Sebastes oblongus was constructed using next-generation sequencing. The full genome was 16,396 bp in length, including two rRNA, 22 tRNA, one control region and 13 protein-coding genes (PCGs). The genome consisted of 28.0% A, 26.4% T, 16.9% G and 28.6% C, showing a slight AT bias (54.4%). All PCGs contained an ATG start codon, excluding COX1 that contained a GTG. All PCGs contained the stop codon TAA, excluding ND3 (TAG stop codon) and Cytb (incomplete termination codon, T). All tRNAs contained the typical clover leaf structure, except for two tRNAs, serine (AGY) and threonine, which lacked the DHU arm. The complete mitogenome of S. oblongus will contribute to genetic analysis of the effective population size for aquaculture. PMID:24438255

  10. Antihelminthic potential of quinacrine and oxyclozanide against gill parasite Microcotyle sebastis in black rockfish Sebastes schlegeli.

    PubMed

    Kang, Yue Jai; Wakabayashi, Chizuha; Kim, Ki Hong

    2016-05-26

    The aim of this study was to assess the treatment potential of quinacrine and oxyclozanide against Microcotyle sebastis (Monogenea: Polyopisthocotylea) infection in cultured black rockfish Sebastes schlegeli. The oral administration of quinacrine led to a reduction in the mean abundance of M. sebastis infection in all quinacrine-treated groups, and the groups of fish administered quinacrine at 50, 100, and 200 mg kg(-1) for 3 consecutive days showed a parasite mean abundance that was 50 to 30% lower compared to that of the control group, suggesting that quinacrine has a therapeutic potential against M. sebastis. Although oxyclozanide showed a very high in vitro killing activity, in oral administration experiments, only the groups of fish administered 200 mg kg(-1) showed less than 50% mean abundance of M. sebastis compared to the control groups, suggesting that the absorption efficiency of orally administered oxyclozanide might be low in black rockfish and/or that M. sebastis might be less sensitive to orally ingested oxyclozanide. As praziquantel has been the sole therapeutic against M. sebastis infection in Korea for a long time, a broadening of available control measures is advisable in order to reduce the possible emergence of praziquantel-resistant M. sebastis. In our study, although quinacrine and oxyclozanide showed a therapeutic potential against M. sebastis, the treatment efficacy was not high enough to replace praziquantel. Thus, after investigations on the pathological effects and pharmacodynamics, use of quinacrine or oxyclozanide in combination with praziquantel may be considered as a way to prevent praziquantel resistance in M. sebastis. PMID:27225210

  11. 78 FR 40638 - Fisheries of the Exclusive Economic Zone Off Alaska; Dusky Rockfish in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ... established by the final 2013 and 2014 harvest specifications for groundfish of the GOA (78 FR 13162, February... Assistant Administrator for Fisheries, NOAA (AA), finds good cause to waive the requirement to provide prior... because the most recent, relevant data only became available as of July 1, 2013. The AA also finds...

  12. 75 FR 39861 - Fisheries of the Exclusive Economic Zone Off Alaska; Pelagic Shelf Rockfish in the Western...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... GOA (75 FR 11749, March 12, 2010). In accordance with Sec. 679.20(d)(1)(i) and Sec. 679.20(d)(1)(ii)(B... information recently obtained from the fishery. The Assistant Administrator for Fisheries, NOAA (AA), finds... of July 7, 2010. The AA also finds good cause to waive the 30-day delay in the effective date of...

  13. 78 FR 57537 - Fisheries of the Exclusive Economic Zone Off Alaska; Shortraker Rockfish in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... 2013 and 2014 final harvest specifications for groundfish of the BSAI (78 FR 13813, March 1, 2013). In... obtained from the fishery. The Assistant Administrator for Fisheries, NOAA (AA), finds good cause to waive... comment because the most recent, relevant data only became available as of September 13, 2013. The AA...

  14. 78 FR 42891 - Fisheries of the Exclusive Economic Zone Off Alaska; Rougheye Rockfish in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-18

    ... final 2013 and 2014 harvest specifications for groundfish of the BSAI (78 FR 13813, March 1, 2013). In... recently obtained from the fishery. The Acting Assistant Administrator for Fisheries, NOAA (AA), finds good..., 2013. The AA also finds good cause to waive the 30-day delay in the effective date of this action...

  15. Exxon Valdez oil spill. State/federal natural resource damage assessment. Injury to demersal rockfish and shallow reef habitats in Prince William Sound, 1989-1991. Subtidal study number 6. Fish/shellfish study number 17. Final report

    SciTech Connect

    1994-09-01

    Demersal rockfish (Sebastes spp.) in Prince William Sound were studied from 1989 through 1991 to assess injury due to the Exxon Valdez oil spill. Injury was assessed by establishing the exposure of rockfish to petroleum hydrocarbons and then determining if any histopathological lesions occurred with increased frequency in fish from sites with oil-exposed fish.

  16. Holocene coastal glaciation of Alaska

    NASA Astrophysics Data System (ADS)

    Calkin, Parker E.; Wiles, Gregory C.; Barclay, David J.

    2001-01-01

    Holocene fluctuations of the three cirque glaciers on the Seward Peninsula and five groups of tidewater- and land-terminating glaciers along the northernmost Gulf of Alaska, provide a proxy record of late Holocene climatic change. Furthermore, the movements of the coastal glaciers were relevant to late Holocene native American migration. The earliest expansion was recorded about 6850 yr BP by Hubbard Glacier at the head of Yakutat Bay in the Gulf of Alaska; however, its down-fjord advance to the bay mouth was delayed until ˜2700 BP. Similarly, expansions of the Icy Bay, Bering, and McCarty glaciers occurred near their present termini by ˜3600-3000 BP, compatible with marked cooling and precipitation increases suggested by the Alaskan pollen record. Decrease in glacier activity ˜2000 BP was succeeded by advances of Gulf coastal glaciers between 1500 and 1300 BP, correlative with early Medieval expansions across the Northern Hemisphere. A Medieval Optimum, encompassing at least a few centuries prior to AD 1200 is recognized by general retreat of land-terminating glaciers, but not of all tidewater glaciers. Little Ice Age advances of land-based glaciers, many dated with the precision of tree-ring cross-dating, were centered on the middle 13th or early 15th centuries, the middle 17th and the last half of the 19th century A.D. Strong synchrony of these events across coastal Alaska is evident.

  17. 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…

  18. 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…

  19. Paleoindians in beringia: evidence from arctic alaska.

    PubMed

    Kunz, M L; Reanier, R E

    1994-02-01

    Excavations at the Mesa site in arctic Alaska provide evidence for a Paleoindian occupation of Beringia, the region adjacent to the Bering Strait. Eleven carbon-14 dates on hearths associated with Paleoindian projectile points place humans at the site between 9,730 and 11,660 radiocarbon years before present (years B.P.). The presence of Paleoindians in Beringia at these times challenges the notion that Paleoindian cultures arose exclusively in mid-continental North America. The age span of Paleoindians at the Mesa site overlaps with dates from two other cultural complexes in interior Alaska. A hiatus in the record of human occupation occurs between 10,300 and 11,000 years B.P. Late Glacial climatic fluctuations may have made northern Alaska temporarily unfavorable for humans and spurred their southward dispersal. PMID:17747660

  20. Alaska coal geology, resources, and coalbed methane potential

    SciTech Connect

    Romeo M. Flores; Gary D. Stricker; Scott A. Kinney

    2005-11-15

    Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces, Northern Alaska-Slope, Central Alaska-Nenana, and Southern Alaska-Cook Inlet. Cretaceous resources, predominantly bituminous coal and lignite, are in the Northern Alaska-Slope coal province. Most of the Tertiary resources, mainly lignite to subbituminous coal with minor amounts of bituminous and semianthracite coals, are in the other two provinces. The combined measured, indicated, inferred, and hypothetical coal resources in the three areas are estimated to be 5,526 billion short tons (5,012 billion metric tons), which constitutes about 87 percent of Alaska's coal and surpasses the total coal resources of the conterminous United States by 40 percent. Coal mining has been intermittent in the Central Alaskan-Nenana and Southern Alaska-Cook Inlet coal provinces, with only a small fraction of the identified coal resource having been produced from some dozen underground and strip mines. Alaskan coals have a lower sulfur content (averaging 0.3 percent) than most coals in the conterminous United States and are within or below the minimum sulfur value mandated by the 1990 Clean Air Act amendments. Another untapped potential resource is coalbed methane estimated to total 1,000 trillion cubic feet (28 trillion cubic meters).

  1. Environmental geology of Harrison Bay, northern Alaska

    USGS Publications Warehouse

    Craig, J.D.; Thrasher, G.P.

    1982-01-01

    The surficial and shallow subsurface geology of Harrison Bay on the Beaufort Sea coast was mapped as part of the U.S. Geological Survey's prelease evaluation for Outer Continental Shelf (OCS) Oil and Gas Lease Sale 71. During the 1980 summer season, approximately 1600 km of multisensored, high-resolution geophysical profile data were collected along a rectangular grid with 4.8 km line spacing. Interpretation of these data is presented on five maps showing bathymetry, sea-floor microrelief, ice-gouge characteristics, Holocene sediment thickness, and geologic structure to depths of approximately 1000 m. On a broad scale, the seafloor is shallow and almost flat, although microrelief features produced by sediment transport and ice-gouge processes typically vary up to several meters in amplitude. Microrelief bedforms related to hydraulic processes are predominant in water depths less than 12 m. Microrelief caused by ice gouging generally increases with water depth, reaching a maximum of 2 m or more in water depths beyond the 20 m isobath. This intensely gouged area lies beneath the shear zone between the seasonal landfast ice and the mobile polar ice pack. The thickness of recent (Holocene) sediment increases offshore, from 2 m near the Colville River delta to 30 m or more on the outer shelf. The thin Holocene layer is underlain by a complex horizon interpreted to be the upper surface of a Pleistocene deposit similar in composition to the present Arctic Coastal Plain. The base of the inferred Pleistocene section is interpreted to be a low-angle unconformity 100 m below sea level. Beneath this Tertiary-Quaternary unconformity, strata are interpreted to be alluvial fan-delta plain deposits corresponding to the Colville Group and younger formations of Late Cretaceous to Tertiary age. Numerous high-angle faults downthrown to the north trend across the survey area. With few exceptions, these faults terminate at or below the 100 m unconformity, suggesting that most tectonism occurred before Quaternary time. Acoustic anomalies suggesting gas accumulation are rare, and where identified typically occur adjacent to faults. A laterally continuous zone of poor seismic data occurs in the nearshore area and is interpreted to be caused by subsea permafrost. This report describes these geologic conditions in Harrison Bay and discusses potential hazards that they may pose for future oil and gas operations in Sale 71 and adjacent Beaufort Sea shelf areas.

  2. Indicators of recent environmental change in Alaska

    SciTech Connect

    Jacoby, G.C.; D`Arrigo, R.D.; Juday, G.

    1997-12-31

    Climate models predict that global warming due to the effects of increasing trace gases will be amplified in northern high latitude regions, including Alaska. Several environmental indicators, including tree-ring based temperature reconstructions, borcal forest growth measurements and observations of glacial retreat all indicate that the general warming of the past century has been significant relative to prior centuries to millenia. The tree-ring records for central and northern Alaska indicate that annual temperature increased over the past century, peaked in the 1940s, and are still near the highest level for the past three centuries (Jacoby and D`Arrigo 1995). The tree-ring analyses also suggest that drought stress may now be a factor limiting growth at many northern sites. The recent warming combined with drier years may be altering the response of tree growth to climate and raising the likelihood of forest changes in Alaska and other boreal forests. Other tree-ring and forest data from southern and interior Alaska provide indices of the response of vegetation to extreme events (e.g., insect outbreaks, snow events) in Alaska (Juday and marler 1996). Historical maps, field measurements and satellite imagery indicate that Alaskan glaciers have receded over the past century (e.g., Hall and Benson 1996). Severe outbreaks of bark beetles may be on the increase due to warming, which can shorten their reproductive cycle. Such data and understanding of causes are useful for policy makers and others interested in evaluation of possible impacts of trace-gas induced warming and environmental change in the United States.

  3. Potential use of offshore marine structures in rebuilding an overfished rockfish species, bocaccio (Sebastes paucispinis)

    USGS Publications Warehouse

    Love, M.S.; Schroeder, D.M.; Lenarz, W.; MacCall, A.; Bull, A.S.; Thorsteinson, L.

    2006-01-01

    Although bocaccio (Sebastes paucispinis) was an economically important rockfish species along the west coast of North America, overfishing has reduced the stock to about 7.4% of its former unfished population. In 2003, using a manned research submersible, we conducted fish surveys around eight oil and gas platforms off southern California as part of an assessment of the potential value of these structures as fish habitat. From these surveys, we estimated that there was a minimum of 430,000 juvenile bocaccio at these eight structures. We determined this number to be about 20% of the average number of juvenile bocaccio that survive annually for the geographic range of the species. When these juveniles become adults, they will contribute about one percent (0.8%) of the additional amount of fish needed to rebuild the Pacific Coast population. By comparison, juvenile bocaccio recruitment to nearshore natural nursery grounds, as determined through regional scuba surveys, was low in the same year. This research demonstrates that a relatively small amount of artificial nursery habitat may be quite valuable in rebuilding an overfished species.

  4. Assessment of Gas Hydrate Resources on the North Slope, Alaska, 2008

    USGS Publications Warehouse

    Collett, Timothy S.; Agena, Warren F.; Lee, Myung W.; Zyrianova, Margarita V.; Bird, Kenneth J.; Charpentier, Ronald R.; Cook, Troy; Houseknect, David W.; Klett, Timothy R.; Pollastro, Richard M.; Schenk, Christopher J.

    2008-01-01

    The U.S. Geological Survey (USGS) recently completed the first assessment of the undiscovered technically recoverable gas-hydrate resources on the North Slope of Alaska. Using a geology-based assessment methodology, the USGS estimates that there are about 85 trillion cubic feet (TCF) of undiscovered, technically recoverable gas resources within gas hydrates in northern Alaska.

  5. Alaska Humans Factors Safety Study: The Southern Coastal Area

    NASA Technical Reports Server (NTRS)

    Chappell, Sheryl L.; Reynard, William (Technical Monitor)

    1995-01-01

    At the request of the Alaska Air Carriers Association, researchers from the NASA Aviation Safety Reporting System, at NASA Ames Research Center, conducted a study on aspects of safety in Alaskan Part 135 air taxi operations. An interview form on human factors safety issues was created by a representative team from the FAA-Alaska, NTSB-Alaska, NASA-ASRS, and representatives of the Alaska Air Carriers Association which was subsequently used in the interviews of pilots and managers. Because of the climate and operational differences, the study was broken into two geographical areas, the southern coastal areas and the northern portion of the state. This presentation addresses the southern coastal areas, specifically: Anchorage, Dillingham, King Salmon, Kodiak, Cold Bay, Juneau, and Ketchikan. The interview questions dealt with many of the potential pressures on pilots and managers associated with the daily air taxi operations in Alaska. The impact of the environmental factors such as the lack of available communication, navigation and weather information systems was evaluated. The results of this study will be used by government and industry working in Alaska. These findings will contribute important information on specific Alaska safety issues for eventual incorporation into training materials and policies that will help to assure the safe conduct of air taxi flights in Alaska.

  6. 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

  7. CO2 and CH4 fluxes along a latitudinal transect in Northern Alaska using eddy covariance technique in challenging conditions: first results of a long term experiment in the Arctic tundra

    NASA Astrophysics Data System (ADS)

    Moreaux, V.; Oechel, W. C.; Losacco, S.; McEwing, R.; Murphy, P.; Zona, D.

    2013-12-01

    the first year of a new long-term study that includes the results of the upgrading of 5 sites in Northern Alaska across a latitudinal transect (Barrow, Atqasuk, and Ivotuk) and across a moisture gradient (Barrow) in the Arctic. These sites are equipped with different eddy covariance systems to follow CO2 and CH4 fluxes, combined with a full data set of meteorological and soil measurements. The study summarizes a full analysis of energy balance, CO2 and CH4 fluxes correlated to changes in meteorological and soil conditions on the 5 sites of the transect. Based on the results available, CH4 fluxes averaged approximatively 8 mgC m-2 d-1 in the north (Barrow) to 13 mgC m-2 d-1 in the south (Ivotuk). In between these two sites, a daily value of about 20 mgC m-2 d-1 in the wetter, vegetated drained lake basin was observed. Surprisingly, from our preliminary data investigation, the southernmost and warmer site (Ivotuk) did not present the highest CH4 emission, which instead was the highest in the 200 km north site (Atqasuk) with a mean daily value of 25 mgC m-2 d-1. The importance of fall season CH4 emissions will also be presented and their importance relative to summertime emissions.

  8. 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.

  9. 50 CFR Table 2 (south) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear South of 40°10...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (South) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  10. 50 CFR Table 2 (north) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear North of 40°10...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (North) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  11. 50 CFR Table 2 (south) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear South of 40°10...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (South) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  12. 50 CFR Table 2 (north) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear North of 40°10...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (North) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  13. 50 CFR Table 2 (south) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear South of 40°10...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (South) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  14. 50 CFR Table 2 (north) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear North of 40°10...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (North) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  15. 50 CFR Table 1b to Part 660... - 2009, Harvest Guidelines for Minor Rockfish by Depth Sub-groups (weights in metric tons)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... listed in 50 CFR 660.302. A new stock assessment was conducted for blue rockfish in 2007. As a result of... Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT... the ABC. The OY of 16,500 mt is less than the ABC. The OY is set at the MSY harvest level which...

  16. The chromium accumulation and its physiological effects in juvenile rockfish, Sebastes schlegelii, exposed to different levels of dietary chromium (Cr(6+)) concentrations.

    PubMed

    Kim, Jun-Hwan; Kang, Ju-Chan

    2016-01-01

    Juvenile rockfish (mean length 13.7±1.7 cm, and mean weight 55.6±4.8 g) were exposed for 4 weeks with the different levels of dietary chromium (Cr(6+)) at 0, 30, 60, 120 and 240 mg/kg. The profile of chromium in the tissues of rockfish is dependent on the exposure periods and chromium concentration. After 4 weeks, the order of chromium accumulation in tissues was liver>kidney>spleen>intestine>gill>muscle. The dietary chromium exposure decreased the growth rate and hepatosomatic index of rockfish. The major hematological findings were significant decrease in the red blood cell (RBC) count, hematocrit (Ht) value, and hemoglobin (Hb) concentration exposed to ≥120 mg/kg chromium concentrations. The dietary chromium exposure (≥120 mg/kg) led to notable increase in glucose, cholesterol, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) in plasma, whereas there was no considerable change in calcium, magnesium, total protein, and alkaline phosphatase (ALP). The results indicated that the dietary chromium exposure to rockfish can induce significant chromium accumulation in the specific tissues, inhibition of growth, and hematological alterations. PMID:26705966

  17. 50 CFR Table 2b to Part 660... - 2010, and Beyond, Harvest Guidelines for Minor Rockfish by Depth Sub-groups (weights in metric tons)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false 2010, and Beyond, Harvest Guidelines for Minor Rockfish by Depth Sub-groups (weights in metric tons) 2b Table 2b to Part 660, Subpart G Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC...

  18. 50 CFR Table 1b to Part 660... - 2009, Harvest Guidelines for Minor Rockfish by Depth Sub-groups (weights in metric tons)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false 2009, Harvest Guidelines for Minor Rockfish by Depth Sub-groups (weights in metric tons) 1b Table 1b to Part 660, Subpart G Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION,...

  19. Daily growth increments in otoliths of juvenile black rockfish, Sebastes melanops: an evaluation of autoradiography as a new method of validation

    SciTech Connect

    Not Available

    1988-10-01

    This study evaluates the commonly used oxytetracycline hydrochloride (OTC) and an alternate chemical, the radioisotope calcium-45, in terms of their success as time-markers to validate daily growth increment formation in the otoliths of juvenile black rockfish, Sebastes melanops.

  20. 50 CFR Table 2 (north) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear North of 40°10...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (North) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  1. 50 CFR Table 2 (south) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Limited Entry Fixed Gear South of 40°10...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (South) to Part 660, Subpart E—Non-Trawl Rockfish Conservation Areas and Trip Limits for...

  2. Genomic characterization of sex-identification markers in Sebastes carnatus and Sebastes chrysomelas rockfishes.

    PubMed

    Fowler, Benjamin L S; Buonaccorsi, Vincent P

    2016-05-01

    Fish have evolved a variety of sex-determining (SD) systems including male heterogamy (XY), female heterogamy (ZW) and environmental SD. Little is known about SD mechanisms of Sebastes rockfishes, a highly speciose genus of importance to evolutionary and conservation biology. Here, we characterize the sex determination system in the sympatrically distributed sister species Sebastes chrysomelas and Sebastes carnatus. To identify sex-specific genotypic markers, double digest restriction site - associated DNA sequencing (ddRAD-seq) of genomic DNA from 40 sexed individuals of both species was performed. Loci were filtered for presence in all of the individuals of one sex, absence in the other sex and no heterozygosity. Of the 74 965 loci present in all males, 33 male-specific loci met the criteria in at least one species and 17 in both. Conversely, no female-specific loci were detected, together providing evidence of an XY sex determination system in both species. When aligned to a draft reference genome from Sebastes aleutianus, 26 sex-specific loci were interspersed among 1168 loci that were identical between sexes. The nascent Y chromosome averaged 5% divergence from the X chromosome and mapped to reference Sebastes genome scaffolds totalling 6.9Mbp in length. These scaffolds aligned to a single chromosome in three model fish genomes. Read coverage differences were also detected between sex-specific and autosomal loci. A PCR-RFLP assay validated the bioinformatic results and correctly identified sex of five additional individuals of known sex. A sex-determining gene in other teleosts gonadal soma-derived factor (gsdf) was present in the model fish chromosomes that spanned our sex-specific markers. PMID:26923740

  3. Use of tetracycline hydrochloride and alizarin complexone for immersion marking black rockfish Sebastes schlegelii

    NASA Astrophysics Data System (ADS)

    Lü, Hongjian; Zhang, Xiumei; Fu, Mei; Xi, Dan; Gao, Tianxiang

    2014-07-01

    We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone (ALC) solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water (salinity of 30) for 24 h, respectively. Otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of 200-400 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations (≥350 mg/L TC, ≥250 mg/L ALC for scales and ≥350 mg/L TC, ≥300 mg/L ALC for fin rays). The best mark quality (i.e., acceptable marks were observed in all sampled structures after immersion marking) were obtained following immersion in TC at between 350-500 mg/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking ( P > 0.05).

  4. 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.

  5. Histological observation of germ cell development and discovery of spermatophores in ovoviviparous black rockfish ( Sebastes schlegeli Hilgendorf) in reproductive season

    NASA Astrophysics Data System (ADS)

    Feng, Junrong; Liu, Liming; Jiang, Haibin; Wang, Maojian; Du, Rongbin

    2014-10-01

    Black rockfish ( Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season (October 2011-November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.

  6. Geologic Map of the Point Lay Quadrangle, Alaska

    USGS Publications Warehouse

    Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.

    2008-01-01

    This map is a product of the USGS Digital Geologic Maps of Northern Alaska project, which captures in digital format quadrangles across the entire width of northern Alaska. Sources include geologic maps previously published in hardcopy format and recent updates and revisions based on field mapping by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas, and the U.S. Geological Survey. Individual quadrangles are digitized at either 1:125,000 or 1:250,000 depending on the resolution of source maps. The project objective is to produce a set of digital geologic maps with uniform stratigraphic nomenclature and structural annotation, and publish those maps electronically. The paper version of this map is available for purchase from the USGS Store.

  7. Alaska coal geology, resources, and coalbed methane potential

    USGS Publications Warehouse

    Flores, Romeo M.; Stricker, Gary D.; Kinney, Scott A.

    2004-01-01

    Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces. Northern Alaska-Slope, Central Alaska-Nenana, and Southern Alaska-Cook Inlet. Cretaceous resources, predominantly bituminous coal and lignite, are in the Northern Alaska-Slope coal province. Most of the Tertiary resources, mainly lignite to subbituminous coal with minor amounts of bituminous and semianthracite coals, are in the other two provinces. The combined measured, indicated, inferred, and hypothetical coal resources in the three areas are estimated to be 5,526 billion short tons (5,012 billion metric tons), which constitutes about 87 percent of Alaska's coal and surpasses the total coal resources of the conterminous United States by 40 percent. Coal mining has been intermittent in the Central Alaskan-Nenana and Southern Alaska-Cook Inlet coal provinces, with only a small fraction of the identified coal resource having been produced from some dozen underground and strip mines in these two provinces. Alaskan coal resources have a lower sulfur content (averaging 0.3 percent) than most coals in the conterminous United States are within or below the minimum sulfur value mandated by the 1990 Clean Air Act amendments. The identified resources are near existing and planned infrastructure to promote development, transportation, and marketing of this low-sulfur coal. The relatively short distances to countries in the west Pacific Rim make them more exportable to these countries than to the lower 48 States of the United States. Another untapped but potential resource of large magnitude is coalbed methane, which has been estimated to total 1,000 trillion cubic feet (28 trillion cubic meters) by T.N. Smith 1995, Coalbed methane potential for Alaska and drilling results for the upper Cook Inlet Basin: Intergas, May 15 - 19, 1995, Tuscaloosa, University of Alabama, p. 1 - 21.

  8. 50 CFR Table 3 (south) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears South of 40°10′ N. Lat.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears South of 40°10â² N. Lat. 3 Table 3 (South) to Part 660, Subpart F...) to Part 660, Subpart F—Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access...

  9. 50 CFR Table 3 (north) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears North of 40°10′ N. Lat.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears North of 40°10â² N. Lat. 3 Table 3 (North) to Part 660, Subpart F...) to Part 660, Subpart F—Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access...

  10. 50 CFR Table 3 (south) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears South of 40°10′ N. Lat.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears South of 40°10â² N. Lat. 3 Table 3 (South) to Part 660, Subpart F...) to Part 660, Subpart F—Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access...

  11. 50 CFR Table 3 (north) to Part 660... - Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears North of 40°10′ N. Lat.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access Gears North of 40°10â² N. Lat. 3 Table 3 (North) to Part 660, Subpart F...) to Part 660, Subpart F—Non-Trawl Rockfish Conservation Areas and Trip Limits for Open Access...

  12. Coastal geomorphology of arctic Alaska

    USGS Publications Warehouse

    Barnes, Peter W.; Rawlinson, Stuart E.; Reimnitz, Erk

    1988-01-01

    The treeless, tundra-plain of northern Alaska merges with the Arctic Ocean along a coastal area characterized by low tundra bluffs, and sparse coastal and delta dunes. Coastal engineering projects that aggrade or degrade permafrost will alter the geomorphology and rates of coastal processes by changing coastal stability. Similarly, projects that modify the ice environment (artificial islands) or the coastal configuration (causeways) will cause nature to readjust to the new process regime, resulting in modification of the coast. In this paper the authors describe the coastal geomorphology from Barrow to the Canadian border. In addition, they provide a general outline and extensive references of the major coastal processes operating in this environment that will be useful on coastal environments elsewhere in the Arctic.

  13. Alaska Library Directory, 1996.

    ERIC Educational Resources Information Center

    Jennings, Mary, Ed.

    This directory of Alaska's Libraries lists: members of the Alaska Library Association (AkLA) Executive Council and Committee Chairs; State Board of Education members; members of the Governor's Advisory Council on Libraries; school, academic and public libraries and their addresses, phone and fax numbers, and contact persons; personal,…

  14. 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.

  15. 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.

  16. South Central Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Glacial silt along the Copper River in Alaska is picked up by the wind and carried out over the Gulf of Alaska. This true-color MODIS image from October 26, 2001, shows a large gray dust plume spreading out over the Gulf. West of the Copper River Delta, Cook Inlet is full of sediment.

  17. Ocean Observing System Demonstrated in Alaska

    NASA Astrophysics Data System (ADS)

    Schoch, G. Carl; Chao, Yi

    2010-05-01

    To demonstrate the utility of an ocean observing and forecasting system with diverse practical applications—such as search and rescue, oil spill response (perhaps relevent to the current Gulf of Mexico oil spill), fisheries, and risk management—a unique field experiment was conducted in Prince William Sound, Alaska, in July and August 2009. The objective was to quantitatively evaluate the performance of numerical models developed for the sound with an array of fixed and mobile observation platforms (Figure 1). Prince William Sound was chosen for the demonstration because of historical efforts to monitor ocean circulation following the 1989 oil spill from the Exxon Valdez tanker. The sound, a highly crenulated embayment of about 10,000 square kilometers at approximately 60°N latitude along the northern coast of the Gulf of Alaska, includes about 6900 kilometers of shoreline, numerous islands and fjords, and an extensive system of tidewater glaciers descending from the highest coastal mountain range in North America. Hinchinbrook Entrance and Montague Strait are the two main deep water connections with the Gulf of Alaska. The economic base of communities in the region is almost entirely resource-dependent. For example, Cordova's economy is based on commercial fishing and Valdez's economy is supported primarily by the trans-Alaska oil pipeline terminal.

  18. Bryophytes from Tuxedni Wilderness area, Alaska

    USGS Publications Warehouse

    Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

    2002-01-01

    The bryoflora of two small maritime islands, Chisik and Duck Island (2,302 ha), comprising Tuxedni Wilderness in western lower Cook Inlet, Alaska, was examined to determine species composition in an area where no previous collections had been reported. The field study was conducted from sites selected to represent the totality of environmental variation within Tuxedni Wilderness. Data were analyzed using published reports to compare the bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 286 bryophytes were identified: 230 mosses and 56 liverworts. Bryum miniatum, Dichodontium olympicum, and Orthotrichum pollens are new to Alaska. The annotated list of species for Tuxedni Wilderness expands the known range for many species and fills distribution gaps within Hulte??n's Central Pacific Coast district. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Tuxedni Wilderness primarily includes taxa of boreal (61%), montane (13%), temperate (11%), arctic-alpine (7%), cosmopolitan (7%), distribution; 4% of the total moss flora are North America endemics. A brief summary of the botanical exploration of the general area is provided, as is a description of the bryophytes present in the vegetation and habitat types of Chisik and Duck Islands.

  19. A new magnetic view of Alaska

    USGS Publications Warehouse

    Saltus, R.W.; Hudson, T.L.; Connard, G.G.

    1999-01-01

    A new, publicly available aeromagnetic data compilation spanning Alaska enables analysis of the regional crustal character of this tectonically diverse and poorly understood part of the North American Cordillera. The merged data were upward-continued by 10 km (mathematically smoothed without assumptions about sources) to enhance crustal-scale magnetic features and facilitate tectonic analysis. This analysis reveals a basic threefold magnetic character: (1) a southern region with arcuate magnetic domains closely tied to tectonostratigraphic elements, (2) a magnetically neutral interior region punctuated locally by intermediate and deep magnetic highs representing a complex history, and (3) a magnetically subdued northern region that includes a large deep magnetic high. Our tectonic view of the data supports interpretations that Paleozoic extension and continental rift basins played a significant role in the tectonic development of northern and interior Alaska. Accretion of oceanic and continental margin terranes could be restricted to the southern region. The new magnetic view of Alaska can be compared and contrasted with other Pacific margin regions where convergent margin and accretionary tectonic processes are important.

  20. 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 this…

  1. 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)

  2. 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.

  3. 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- ...

  4. Governance and Aboriginal Claims in Northern Canada.

    ERIC Educational Resources Information Center

    Cozzetto, Don

    1990-01-01

    Focuses on problems of organization and governance that may follow settlement of Canadian aboriginal land claims. Compares financial problems, cultural issues such as subsistence lifestyles, and intergovernmental relations following the Alaska Native Claims Settlement Act, James Bay and Northern Quebec Agreement, and Western Arctic (Inuvialuit)…

  5. Influence of habitat discontinuity, geographical distance, and oceanography on fine-scale population genetic structure of copper rockfish (Sebastes caurinus).

    PubMed

    Johansson, M L; Banks, M A; Glunt, K D; Hassel-Finnegan, H M; Buonaccorsi, V P

    2008-07-01

    The copper rockfish is a benthic, nonmigratory, temperate rocky reef marine species with pelagic larvae and juveniles. A previous range-wide study of the population-genetic structure of copper rockfish revealed a pattern consistent with isolation-by-distance. This could arise from an intrinsically limited dispersal capability in the species or from regularly-spaced extrinsic barriers that restrict gene flow (offshore jets that advect larvae offshore and/or habitat patchiness). Tissue samples were collected along the West Coast of the contiguous USA between Neah Bay, WA and San Diego, CA, with dense sampling along Oregon. At the whole-coast scale (approximately 2200 km), significant population subdivision (F(ST) = 0.0042), and a significant correlation between genetic and geographical distance were observed based on 11 microsatellite DNA loci. Population divergence was also significant among Oregon collections (approximately 450 km, F(ST) = 0.001). Hierarchical amova identified a weak but significant 130-km habitat break as a possible barrier to gene flow within Oregon, across which we estimated that dispersal (N(e)m) is half that of the coast-wide average. However, individual-based Bayesian analyses failed to identify more than a single population along the Oregon coast. In addition, no correlation between pairwise population genetic and geographical distances was detected at this scale. The offshore jet at Cape Blanco was not a significant barrier to gene flow in this species. These findings are consistent with low larval dispersal distances calculated in previous studies on this species, support a mesoscale dispersal model, and highlight the importance of continuity of habitat and adult population size in maintaining gene flow. PMID:18522692

  6. 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.

  7. Tectonic framework of petroliferous rocks in Alaska: hydrocarbons

    USGS Publications Warehouse

    Grantz, Arthur; Kirschner, C.E.

    1976-01-01

    Alaska, which contains about 28% of the land and continental shelf of the United States, is estimated by the U.S. Geological Survey to contain about one third of the nation's undiscovered oil and about one sixth of its undiscovered natural gas. The Survey estimates that fields discovered in Alaska through 1972 ultimately may produce about 26 billion bbl of oil and 68 Tcf of natural gas. In northern Alaska, Paleozoic and Mesozoic shelf and slope carbonate and clastic rocks of the Brooks Range orogen were thrust relatively northward over the depressed south margin of the Paleozoic and Mesozoic Arctic platform. A foredeep, the Colville geosyncline, developed across the depressed margin of the platform in earliest Cretaceous time. Detritus from the Brooks Range filled the foredeep and prograded northward to fill the Cretaceous and Tertiary North Chukchi and Umiat-Camden basins and form the progradational Beaufort shelf. The largest petroleum reserves (Prudhoe Bay and associated fields) and the best prospects for additional large discoveries in Alaska lie in the areally extensive upper Paleozoic to Tertiary carbonate and clastic rocks of northern Alaska. In southern Alaska, a series of arc-trench systems developed on oceanic rocks during Jurassic and Cretaceous time. Between these arcs and the metamorphic (continental) terranes of east-central and northern Alaska, large back-arc and arc-trench gap basins received thick volcanic and detrital deposits. These deposits were extensively, and commonly intensely, deformed and disrupted by mid-Jurassic to Tertiary plutonism, Laramide oroclinal bending, wrench faulting, and arc-related compression. This deformation, coupled with low porosity (in part produced by diagenetic mobilization of labile constituents), has left these rocks with only modest, local prospects for petroleum. Laramide events compressed and consolidated ("continentalized") the late Mesozoic back-arc basin deposits and welded them to the older continental

  8. Age, Distribution, and Style of Deformation in Alaska North of 60°N: Implications for Assembly of Alaska

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Box, S. E.

    2015-12-01

    The structural architecture of Alaska is the product of a complex history of deformation along both the Cordilleran and Arctic margins of North America through interactions with ocean plates and with continental elements of Laurentia, Siberia, and Baltica. We use geological constraints to assign areal deformation to 14 time intervals and map their distributions in Alaska. Alaska can be divided into three domains with differing histories of deformation. The northern domain experienced the Early Cretaceous Brookian orogeny, an oceanic arc-continent collisional orogeny, followed by a mid-Cretaceous extensional overprint. Opening of the oceanic Canada Basin rifted the orogen from the Canadian Arctic margin, producing the bent trends of the orogen. The second domain constitutes the Phanerozoic Peninsular-Wrangellia-Alexander arc terrane and its paired Mesozoic accretionary prisms. Its structural history is unrelated to domains to the north until a shared history of Late Cretaceous deformation. The third domain, situated between the first two domains and roughly bounded by the Cenozoic dextral Denali and Tintina faults, includes the Yukon Composite terrane (Laurentian origin) and the large Farewell (Baltica origin) terrane. These terranes are not linked until Late Cretaceous sedimentary overlap, but we have not identified a shared deformation between these two terranes that might mark their juxtaposition by collisional processes. Similar early Late Cretaceous sedimentary linkages stitch the northern and central domains. Late Late Cretaceous folding and thrusting across much of Alaska south of the Brooks Range correlates temporally with the collision of the southern domain with the remainder of Alaska. Early Cenozoic shortening is mild across much of the state but is significant in the Brooks Range, and correlates in time with dextral faulting, ridge subduction, and rotation of western Alaska. Late Cenozoic shortening is significant in southern Alaska inboard of the

  9. 50 CFR Table 1 (north) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10′ N....

  10. 50 CFR Table 1 (south) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10′ N....

  11. 50 CFR Table 1 (north) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10′ N....

  12. 50 CFR Table 1 (south) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10′ N....

  13. 50 CFR Table 1 (south) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10′ N....

  14. 50 CFR Table 1 (north) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10′ N....

  15. 50 CFR Table 1 (north) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10′ N....

  16. 50 CFR Table 1 (south) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10′ N....

  17. 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.

  18. Utilizing Multibeam Bathymetry and Geographic Information Systems (GIS) to Expand Our Mapping Ability of Potential Rockfish Benthic Habitats in the San Juan Islands, Washington

    NASA Astrophysics Data System (ADS)

    Kelly-Slatten, K.

    2013-12-01

    In order to construct an accurate cartographic representation of the potential rockfish habitat zone in the San Juan Archipelago, Washington, bathymetric data is needed to form layers within Geographic Information Systems (GIS) that include, but are not limited to, slope, hillshade, and aspect. Backscatter data is also important in order to demonstrate the induration of the marine floor, which in turn may tell the researcher what type of sediment and substrate makes up that part of the benthic region. Once these layers are added to the GIS map, another layer (referred to as Potential Benthic Habitats) is created and inserted. This layer uses the same induration data but groups them into polygons, which are then color-coded and displayed on the map. With all the layers now pictured, it is clear that the intertidal zones are not complete. Aerial photographs are then added to fill in the gaps according to the GPS coordinates associated with the middle section of each picture. When all pictures and layers have been included, the GIS map is a somewhat three-dimensional, color-coordinated, aerial photograph enhanced depiction of Skipjack, Waldron, Orcas, and Sucia Islands. The bathymetric and backscatter data are plugged into Excel to graphically illustrate specific numbers that represent the various potential habitats. The given data support the idea that potential rockfish habitat (Sedimentary Bedrock and Fractured Bedrock) must be closely monitored and maintained in attempt to preserve and conserve the three either threatened or endangered rockfish species within the Puget Sound locale.

  19. 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

  20. Facies patterns and conodont biogeography in Arctic Alaska and the Canadian Arctic Islands: Evidence against juxtaposition of these areas during early Paleozoic time

    USGS Publications Warehouse

    Dumoulin, J.A.; Harris, A.G.; Bradley, D.C.; De Freitas, T. A.

    2000-01-01

    Differences in lithofacies and biofacies suggest that lower Paleozoic rocks now exposed in Arctic Alaska and the Canadian Arctic Islands did not form as part of a single depositional system. Lithologic contrasts are noted in shallow- and deep-water strata and are especially marked in Ordovician and Silurian rocks. A widespread intraplatform basin of Early and Middle Ordovician age in northern Alaska has no counterpart in the Canadian Arctic, and the regional drowning and backstepping of the Silurian shelf margin in Canada has no known parallel in northern Alaska. Lower Paleozoic basinal facies in northern Alaska are chiefly siliciclastic, whereas resedimented carbonates are volumetrically important in Canada. Micro- and macrofossil assemblages from northern Alaska contain elements typical of both Siberian and Laurentian biotic provinces; coeval Canadian Arctic assemblages contain Laurentian forms but lack Siberian species. Siberian affinities in northern Alaskan biotas persist from at least Middle Cambrian through Mississippian time and appear to decrease in intensity from present-day west to east. Our lithologic and biogeographic data are most compatible with the hypothesis that northern Alaska-Chukotka formed a discrete tectonic block situated between Siberia and Laurentia in early Paleozoic time. If Arctic Alaska was juxtaposed with the Canadian Arctic prior to opening of the Canada basin, biotic constraints suggest that such juxtaposition took place no earlier than late Paleozoic time.

  1. Black brant from Alaska staging and wintering in Japan

    USGS Publications Warehouse

    Derksen, Dirk V.; Bollinger, K.S.; Ward, David H.; Sedinger, J.S.; Miyabayashi, Y.

    1996-01-01

    Black brant (Branta bernicla nigricans) nest in colonies in arctic Canada, Alaska, and Russia (Derksen and Ward 1993, Sedinger et al. 1993). Virtually the entire population stages in fall at Izembek Lagoon near the tip of the Alaska Peninsula (Bellrose 1976) before southward migration (Dau 1992) to winter habitats in British Columbia, Washington, Oregon, California, and Baja California (Subcommittee on Black Brant 1992). A small number of black brant winter in Japan, Korea, and China (Owen 1980). In Japan 3,000–5,000 brant of unknown origin stop over in fall, and a declining population (<1,000) of birds winter here, primarily in the northern islands (Brazil 1991, Miyabayashi et al. 1994). Here, we report sightings of brant in Japan that were marked in Alaska and propose a migration route based on historical and recent observations and weather patterns.

  2. Flood frequency in Alaska

    USGS Publications Warehouse

    Childers, J.M.

    1970-01-01

    Records of peak discharge at 183 sites were used to study flood frequency in Alaska. The vast size of Alaska, its great ranges of physiography, and the lack of data for much of the State precluded a comprehensive analysis of all flood determinants. Peak stream discharges, where gaging-station records were available, were analyzed for 2-year, 5-year, 10-year, 25-year, and 50-year average-recurrence intervals. A regional analysis of the flood characteristics by multiple-regression methods gave a set of equations that can be used to estimate floods of selected recurrence intervals up to 50 years for any site on any stream in Alaska. The equations relate floods to drainage-basin characteristics. The study indicates that in Alaska the 50-year flood can be estimated from 10-year gaging- station records with a standard error of 22 percent whereas the 50-year flood can be estimated from the regression equation with a standard error of 53 percent. Also, maximum known floods at more than 500 gaging stations and miscellaneous sites in Alaska were related to drainage-area size. An envelope curve of 500 cubic feet per second per square mile covered all but 2 floods in the State.

  3. The Late Triassic bivalve Monotis in accreted terranes of Alaska

    USGS Publications Warehouse

    Silberling, Norman J.; Grant-Mackie, J. A.; Nichols, K.M.

    1997-01-01

    Late Triassic bivalves of the genus Monotis occur in at least 16 of the lithotectonic terranes and subterranes that together comprise nearly all of Alaska, and they also occur in the Upper Yukon region of Alaska where Triassic strata are regarded as representing non-accretionary North America. On the basis of collections made thus far, 14 kinds of Monotis that differ at the species or subspecies level can be recognized from alaska. These are grouped into the subgenera Monotis (Monotis), M. (Pacimonotis), M. (Entomonotis), and M. (Eomonotis). In places, Monotis shells of one kind or another occur in rock-forming abundance. On the basis of superpositional data from Alaska, as well as from elsewhere in North America and Far Eastern Russia, at least four distince biostratigraphic levels can be discriminated utilizing Monotis species. Different species of M. (Eomonotis) characterize two middle Norian levels, both probably within the supper middle Norian Columbianus Ammonite Zone. Two additional levels are recognized in the lower upper Norian Cordilleranus Ammonite Zone utilizing species of M. (Monotis) or M. (Entomonotis), both of which subgenera are restricted to the late Norian. An attached-floating mode of life is commonly attributed to Monotis; thus, these bivalves would have been pseudoplanktonic surface dwellers that were sensitive to surface-water temperature and paleolatitude. Distinctly different kinds of Monotis occur at different paleolatitudes along the Pacific and Arctic margins of the North American craton inboard of the accreted terranes. Comparison between thse craton-bound Monotis faunas and those of the Alaskan terranes in southern Alaska south of the Denali fault were paleoequatorial in latitude during Late Triassic time. Among these terranes, the Alexander terrane was possibly in the southern hemisphere at that time. Terranes of northern Alaska, on the other hand, represent middle, possibly high-middle, northern paleolatitudes.

  4. 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.

  5. Northern Plains Patterns

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-513, 14 October 2003

    Patterns are common on the northern plains of Mars. Like their terrestrial counterparts in places like Siberia, Alaska, and northern Canada, patterned ground on Mars might be an indicator of the presence of ground ice. Whether it is true that the patterns on Mars are related to ground ice and whether the ice is still present beneath the martian surface are unknown. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows an example of patterned ground on the martian northern plains near 72.4oN, 252.6oW. The dark dots and lines are low mounds and chains of mounds. The circular feature near the center of the image is the location of a buried meteor impact crater; its presence today is marked only by the dark boulders on its rim and ejecta blanket that have managed to remain uncovered at the martian surface. The area shown is 3 km (1.9 mi) wide and illuminated by sunlight from the lower left.

  6. Alaska: A twenty-first-century petroleum province

    USGS Publications Warehouse

    Bird, K.J.

    2001-01-01

    Alaska, the least explored of all United States regions, is estimated to contain approximately 40% of total U.S. undiscovered, technically recoverable oil and natural-gas resources, based on the most recent U.S. Department of the Interior (U.S. Geological Survey and Minerals Management Service) estimates. Northern Alaska, including the North Slope and adjacent Beaufort and Chukchi continental shelves, holds the lion's share of the total Alaskan endowment of more than 30 billion barrels (4.8 billion m3) of oil and natural-gas liquids plus nearly 200 trillion cubic feet (5.7 trillion m3) of natural gas. This geologically complex region includes prospective strata within passive-margin, rift, and foreland-basin sequences. Multiple source-rock zones have charged several regionally extensive petroleum systems. Extensional and compressional structures provide ample structural objectives. In addition, recent emphasis on stratigraphic traps has demonstrated significant resource potential in shelf and turbidite systems in Jurassic to Tertiary strata. Despite robust potential, northern Alaska remains a risky exploration frontier - a nexus of geologic complexity, harsh economic conditions, and volatile policy issues. Its role as a major petroleum province in this century will depend on continued technological innovations, not only in exploration and drilling operations, but also in development of huge, currently unmarketable natural-gas resources. Ultimately, policy decisions will determine whether exploration of arctic Alaska will proceed.

  7. 2006 Compilation of Alaska Gravity Data and Historical Reports

    USGS Publications Warehouse

    Saltus, Richard W.; Brown, Philip J., II; Morin, Robert L.; Hill, Patricia L.

    2008-01-01

    Gravity anomalies provide fundamental geophysical information about Earth structure and dynamics. To increase geologic and geodynamic understanding of Alaska, the U.S. Geological Survey (USGS) has collected and processed Alaska gravity data for the past 50 years. This report introduces and describes an integrated, State-wide gravity database and provides accompanying gravity calculation tools to assist in its application. Additional information includes gravity base station descriptions and digital scans of historical USGS reports. The gravity calculation tools enable the user to reduce new gravity data in a consistent manner for combination with the existing database. This database has sufficient resolution to define the regional gravity anomalies of Alaska. Interpretation of regional gravity anomalies in parts of the State are hampered by the lack of local isostatic compensation in both southern and northern Alaska. However, when filtered appropriately, the Alaska gravity data show regional features having geologic significance. These features include gravity lows caused by low-density rocks of Cenozoic basins, flysch belts, and felsic intrusions, as well as many gravity highs associated with high-density mafic and ultramafic complexes.

  8. Ice core profiles of saturated fatty acids (C12:0-C30:0) and oleic acid (C18:1) from southern Alaska since 1734 AD: A link to climate change in the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Pokhrel, Ambarish; Kawamura, Kimitaka; Seki, Osamu; Matoba, Sumio; Shiraiwa, Takayuki

    2015-01-01

    An ice core drilled at Aurora Peak in southeast Alaska was analyzed for homologous series of straight chain fatty acids (C12:0-C30:0) including unsaturated fatty acid (oleic acid) using gas chromatography (GC/FID) and GC/mass spectrometry (GC/MS). Molecular distributions of fatty acids are characterized by even carbon number predominance with a peak at palmitic acid (C16:0, av. 20.3 ± SD. 29.8 ng/g-ice) followed by oleic acid (C18:1, 19.6 ± 38.6 ng/g-ice) and myristic acid (C14:0, 15.3 ± 21.9 ng/g-ice). The historical trends of short-chain fatty acids, together with correlation analysis with inorganic ions and organic tracers suggest that short-chain fatty acids (except for C12:0 and C15:0) were mainly derived from sea surface micro layers through bubble bursting mechanism and transported over the glacier through the atmosphere. This atmospheric transport process is suggested to be linked with Kamchatka ice core δD record from Northeast Asia and Greenland Temperature Anomaly (GTA). In contrast, long-chain fatty acids (C20:0-C30:0) are originated from terrestrial higher plants, soil organic matter and dusts, which are also linked with GTA. Hence, this study suggests that Alaskan fatty acids are strongly influenced by Pacific Decadal Oscillation/North Pacific Gyre Oscillation and/or extra tropical North Pacific surface climate and Arctic oscillation. We also found that decadal scale variability of C18:1/C18:0 ratios in the Aurora Peak ice core correlate with the Kamchatka ice core δD, which reflects climate oscillations in the North Pacific. This study suggests that photochemical aging of organic aerosols could be controlled by climate periodicity.

  9. 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,…

  10. Analysis of state of vehicular scars on Arctic Tundra, Alaska

    NASA Technical Reports Server (NTRS)

    Lathram, E. H.

    1974-01-01

    Identification on ERTS images of severe vehicular scars in the northern Alaska tundra suggests that, if such scars are of an intensity or have spread to a dimension such that they can be resolved by ERTS sensors (20 meters), they can be identified and their state monitored by the use of ERTS images. Field review of the state of vehicular scars in the Umiat area indicates that all are revegetating at varying rates and are approaching a stable state.

  11. 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…

  12. ECOREGIONS OF ALASKA

    EPA Science Inventory

    A map of ecoregions of Alaska has been produced as a framework for organizing and interpreting environmental data for state, national, and international inventory, monitoring, and research efforts. he map and descriptions for 20 ecological regions were derived by synthesizing inf...

  13. Customer Service in Alaska.

    ERIC Educational Resources Information Center

    Ogliore, Judy

    1997-01-01

    Examines how the child support enforcement program in Alaska has responded to the challenges of distance, weather, and cultural differences through training representatives, making waiting areas more comfortable, conducting random customer evaluation of services, establishing travel hubs in regional offices and meeting with community leaders and…

  14. Current Ethnomusicology in Alaska.

    ERIC Educational Resources Information Center

    Johnston, Thomas F.

    The systematic study of Eskimo, Indian, and Aleut musical sound and behavior in Alaska, though conceded to be an important part of white efforts to foster understanding between different cultural groups and to maintain the native cultural heritage, has received little attention from Alaskan educators. Most existing ethnomusical studies lack one or…

  15. 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.

  16. 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…

  17. 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.

  18. Alaska and Yukon Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Smoke Signals from the Alaska and Yukon Fires   ... the Yukon Territory from mid-June to mid-July, 2004. Thick smoke particles filled the air during these fires, prompting Alaskan officials to issue air quality warnings. Some of the smoke from these fires was detected as far away as New Hampshire. These ...

  19. Suicide in Northwest Alaska.

    ERIC Educational Resources Information Center

    Travis, Robert

    1983-01-01

    Between 1975 and 1979 the Alaskan Native suicide rate (90.9 per 100,000) in Northwest Alaska was more than seven times the national average. Alienation, loss of family, low income, alcohol abuse, high unemployment, and more education were factors related to suicidal behavior. Average age for suicidal behavior was 22.5. (Author/MH)

  20. Depletion of praziquantel in plasma and muscle tissue of cultured rockfish Sebastes schlegeli after oral and bath treatment.

    PubMed

    Kim, K H; Kim, C S; Kim, J W

    2001-08-01

    Depletion of praziquantel in plasma and muscle tissue after oral and bath treatments was studied in cultured rockfish Sebastes schlegeli. In the oral treatment, a single dose of 400 mg praziquantel kg(-1) body weight was administered by intubation of the stomach. A bath treatment at 100 ppm of praziquantel for 4 min was also carried out. Plasma and muscle tissue samples were collected at 3, 6, 12, 24, 48, 72, 96, 120, 144 and 168 h post-treatment, and analyzed for praziquantel by reversed-phase HPLC using diazepam as the internal standard. Following oral treatment, praziquantel was detected in plasma and muscle tissue until 96 h after treatment. In plasma the praziquantel concentration was highest at the 9 h sampling time and declined sharply at the 48 h sampling point. The concentrations of praziquantel in the muscle tissue were lower than those in the plasma, and the highest value was found at the 9 h sampling time. Following bath treatment, praziquantel was found in plasma and muscle tissue until 72 and 24 h after treatment, respectively. In plasma the praziquantel concentration was highest at the 12 h sampling time and declined sharply thereafter. The concentrations of praziquantel in the muscle tissue were significantly lower than those in the plasma, and the concentrations declined consistently with time. PMID:11558729

  1. Joint effects of crude oil and heavy metals on the gill filament EROD activity of marbled rockfish Sebastiscus marmoratus.

    PubMed

    Zheng, Ronghui; Chen, Huanbin; Bo, Jun; Xie, Qing; Hong, Fukun; Zhang, Yusheng

    2016-10-01

    The aim of this study was to characterize dose- and time-dependent responses of gill 7-ethoxyresorufin O-deethylase (EROD) activity from Juvenile marbled rockfish (Sebastiscus marmoratus) exposed to the water-accommodated fraction (WAF) of crude oil and heavy metal Cd(Ⅱ) or Pb(Ⅱ) alone or in mixture. Compared to the control group, gill filament EROD activity in S. marmoratus was significantly induced after exposure to the WAF from 80 to 320μg/L for 5 days in dose response experiment and after exposure to 40μg/L WAF for 6-10 days in time course experiment, respectively. In the other hand, gill filament EROD activity were not significantly affected compared to the control group or related WAF groups no matter in the dose response experiment or in the time course experiment of Cd(Ⅱ), Pb(Ⅱ) or its mixture with WAF. The results suggest the use of gill filament EROD activity as a biomarker of exposure to waterborne AhR agonists in marine ecosystems while simultaneously being exposed to environmental concentrations of Cd(Ⅱ) or Pb(Ⅱ). PMID:27290642

  2. Immunological and health-state parameters in the Patagonian rockfish Sebastes oculatus. Their relation to chemical stressors and seasonal changes.

    PubMed

    Sueiro, Maria Cruz; Palacios, María Gabriela

    2016-01-01

    We present the results of a field study that evaluates whether exposure to anthropogenic pollution impacts immunological and health-state parameters of wild marine fish during the breeding and non-breeding periods. We assessed aspects of innate immunity (bactericidal capacity, bacterial agglutination, and leukocyte profile) and general health-related parameters (neutrophil to lymphocyte ratio, hematocrit, and condition factor) in the Patagonian rockfish (Sebastes oculatus) sampled from polluted (exposed) and reference (control) sites during winter (i.e., coolest temperatures and active reproductive period) and in summer (i.e., warmest temperatures and non-reproductive period). Results showed lower bactericidal competence, hematocrit, and condition factor in fish from exposed sites independently of season, whereas lymphocytes were higher and monocytes lower at the exposed site only during summer. Moreover, fish sampled during winter displayed lower bactericidal competence, hematocrit, and condition factor than those sampled in summer independently of site, whereas the opposite pattern was found for bacterial agglutination. These results could be explained by life-history theory, which predicts a re-allocation of resources between reproduction and other physiological functions (including immunity) during the most energetically demanding season. The present results show an alteration in immunological and health-state parameters of wild marine fish exposed to anthropogenic pollution independently of season, which could potentially result in higher susceptibility to disease and in turn population decline. PMID:26584758

  3. Size distribution and genetic diversity of the offshore rockfish (Pontinus kuhlii) from three Atlantic archipelagos and seamounts

    NASA Astrophysics Data System (ADS)

    Catarino, Diana; Stefanni, Sergio; Menezes, Gui M.

    2013-12-01

    The offshore rockfish (Pontinus kuhlii) is a widespread demersal fish in the temperate eastern Atlantic. This species inhabits hard bottoms at depths between 100 and 600m and it is an important resource for the Azorean commercial fishing fleet. During several research fishing surveys in the Azores, Madeira and Cape Verde archipelagos diverse biological data on this species were collected. The degree of geographical population differentiation across the three Atlantic archipelagos was examined using two mitochondrial markers, control region (CR) and cytochrome b (cyt b). A total of 44 specimens were sequenced for each marker revealing high haplotypic diversity (CR: Hd=0.9736; cyt b: Hd=0.8520) and low nucleotide diversity (CR: π=0.0171; cyt b: π=0.0059). The sample size from the different subareas was limited but sufficient to reveal that no genetic structure was evident (ΦST=-0.0465 to -0.0224), suggesting the existence of one panmictic population. Despite very different exploitation rates between archipelagos, the size structure of P. kuhlii was very similar and inter-annual variation was also low. Exploitation rates are probably too low to significantly affect the size structure, even in the Azores where the species is a secondary target of the commercial fishery. In the Azores region this species is more abundant on seamounts, however bigger fishes tend to occur on island slope than on seamounts.

  4. Special structure of mitochondrial DNA control region and phylogenetic relationship among individuals of the black rockfish, Sebastes schlegelii.

    PubMed

    Zhang, Hui; Zhang, Yan; Zhang, Xiumei; Song, Na; Gao, Tianxiang

    2013-04-01

    This study deals with the structure of mitochondrial DNA (mtDNA) control region (CR) of the black rockfish, Sebastes schlegelii. Two termination-associated sequences (TASs), two complementary termination-associated sequences (cTASs), and conserved sequence block (CSB), such as CSB-F, CSB-E, CSB-D, CSB1, CSB2, and CSB3, were detected in S. schlegelii. The results indicated that the structures of these blocks are similar to most marine fishes, but it is special that there are two TASs and two cTASs in the CR of S. schlegelii. One conserved region was found from 450 bp to the end of the CR, which is also a special feature of S. schlegelii. All sequences of CSB1, CSB2, and CSB3 blocks are the consensus among different individuals, which is quite different from most vertebrates. In addition, the complete mtDNA CR sequences and the first 449 bp of the CR are used to analyze the phylogenetic relationships of S. schlegelii. The phylogenetic trees show a lack of genetic structure among individuals. This study also indicated a signal that the genetic diversity might be similar between the wild and cultured individuals, which may be helpful to the fisheries management. PMID:23072475

  5. Asthma and American Indians/Alaska Natives

    MedlinePlus

    ... Minority Population Profiles > American Indian/Alaska Native > Asthma Asthma and American Indians/Alaska Natives In 2014, 218, ... Native American adults reported that they currently have asthma. American Indian/Alaska Native children are 30% more ...

  6. Mitochondrial and microsatellite DNA analyses showed comparative genetic diversity between parent and offspring populations of Korean black rockfish in a hatchery facility.

    PubMed

    An, H S; Lee, J W; Park, J Y; Myeong, J I; An, C M

    2013-01-01

    The black rockfish, Sebastes inermis (Sebastidae), is an important commercial fishery resource in Korea. As a preliminary investigation into the effect of artificial reproduction in a hatchery facility, the genetic divergence between parent and offspring populations of black rockfish was accessed using 10 polymorphic nuclear microsatellite DNA loci and a mitochondrial (mt) control gene. All loci that were screened showed marked polymorphisms. mtDNA control region sequences were also highly variable. Of approximately 350 base pairs (bp) sequenced, 52 variable sites, comprising 56 base substitutions, were found among 233 individuals. Offspring populations showed less genetic variability than the parent population in terms of numbers of microsatellite alleles and mtDNA haplotypes, as well as mtDNA haplotype diversity. Statistical analysis of the fixation index (ΦST and F(ST)) and analysis of molecular variance using both DNA markers showed significant genetic differences between the parent and offspring populations. These results suggest that random genetic drift and/or inbreeding events, as well as artificial selection and founder effects, occurred when the offspring strain was reproduced in a hatchery facility despite thousands of males and females from different hatcheries being maintained for artificial reproduction. Therefore, it is necessary to improve current hatchery programs by monitoring genetic variation in both the broodstock and progeny and controlling inbreeding within stocks in commercial breeding facilities to maintain the production of high-quality black rockfish. This information will be useful for determining suitable guidelines for establishing and maintaining cultured stocks and the aquaculture industry of S. inermis. PMID:24390988

  7. Significant Alaska minerals

    SciTech Connect

    Robinson, M.S.; Bundtzen, T.K.

    1982-01-01

    Alaska ranks in the top four states in gold production. About 30.5 million troy oz have been produced from lode and placer deposits. Until 1930, Alaska was among the top 10 states in copper production; in 1981, Kennecott Copper Company had prospects of metal worth at least $7 billion. More than 85% of the 20 million oz of silver derived have been byproducts of copper mining. Nearly all lead production has been as a byproduct of gold milling. Molybdenum is a future Alaskan product; in 1987 production is scheduled to be about 12% of world demand. Uranium deposits discovered in the Southeast are small but of high grade and easily accessible; farther exploration depends on improvement of a depressed market. Little has been done with Alaskan iron and zinc, although large deposits of the latter were discovered. Alaskan jade has a market among craftspeople. A map of the mining districts is included. 2 figures, 1 table.

  8. 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.

  9. Aniakchak Crater, Alaska Peninsula

    USGS Publications Warehouse

    Smith, Walter R.

    1925-01-01

    The discovery of a gigantic crater northwest of Aniakchak Bay (see fig. 11) closes what had been thought to be a wide gap in the extensive series of volcanoes occurring at irregular intervals for nearly 600 miles along the axial line of the Alaska Peninsula and the Aleutian Islands. In this belt there are more active and recently active volcanoes than in all the rest of North America. Exclusive of those on the west side of Cook Inlet, which, however, belong to the same group, this belt contains at least 42 active or well-preserved volcanoes and about half as many mountains suspected or reported to be volcanoes. The locations of some of these mountains and the hot springs on the Alaska Peninsula and the Aleutian Islands are shown on a map prepared by G. A. Waring. Attention has been called to these volcanoes for nearly two centuries, but a record of their activity since the discovery of Alaska is far from being complete, and an adequate description of them as a group has never been written. Owing to their recent activity or unusual scenic beauty, some of the best known of the group are Mounts Katmai, Bogoslof, and Shishaldin, but there are many other beautiful and interesting cones and craters.

  10. Late Paleozoic orogeny in Alaska's Farewell terrane

    USGS Publications Warehouse

    Bradley, D.C.; Dumoulin, J.; Layer, P.; Sunderlin, D.; Roeske, S.; McClelland, B.; Harris, A.G.; Abbott, G.; Bundtzen, T.; Kusky, T.

    2003-01-01

    Evidence is presented for a previously unrecognized late Paleozoic orogeny in two parts of Alaska's Farewell terrane, an event that has not entered into published scenarios for the assembly of Alaska. The Farewell terrane was long regarded as a piece of the early Paleozoic passive margin of western Canada, but is now thought, instead, to have lain between the Siberian and Laurentian (North American) cratons during the early Paleozoic. Evidence for a late Paleozoic orogeny comes from two belts located 100-200 km apart. In the northern belt, metamorphic rocks dated at 284-285 Ma (three 40Ar/39Ar white-mica plateau ages) provide the main evidence for orogeny. The metamorphic rocks are interpreted as part of the hinterland of a late Paleozoic mountain belt, which we name the Browns Fork orogen. In the southern belt, thick accumulations of Pennsylvanian-Permian conglomerate and sandstone provide the main evidence for orogeny. These strata are interpreted as the eroded and deformed remnants of a late Paleozoic foreland basin, which we name the Dall Basin. We suggest that the Browns Fork orogen and Dall Basin comprise a matched pair formed during collision between the Farewell terrane and rocks to the west. The colliding object is largely buried beneath Late Cretaceous flysch to the west of the Farewell terrane, but may have included parts of the so-called Innoko terrane. The late Paleozoic convergent plate boundary represented by the Browns Fork orogen likely connected with other zones of plate convergence now located in Russia, elsewhere in Alaska, and in western Canada. Published by Elsevier B.V.

  11. Does macroalgal vegetation cover influence post-settlement survival and recruitment potential of juvenile black rockfish Sebastes cheni?

    NASA Astrophysics Data System (ADS)

    Kamimura, Yasuhiro; Shoji, Jun

    2013-09-01

    Seasonal change in vegetation coverage affected cohort-specific mortality of post-settlement juvenile black rockfish Sebastes cheni in a temperate macroalgal bed. A total of 14 fish and environmental surveys were conducted at an interval of one to two weeks from February to May, 2008 in the central Seto Inland Sea, southwestern Japan. The birth date of S. cheni was estimated by use of the otolith daily rings and then fish were divided into 7 cohorts (A to F), each covering a 7-day birth date period. Cohort-specific growth coefficient (G, d-1) of juvenile S. cheni from 20 to 60 mm in total length (TL) ranged between 0.031 and 0.048 and mortality coefficient (M, d-1) between 0.038 and 0.081, with significant increases in both values as the season progressed. The ratio of G:M, which is a proxy of the recruitment potential, ranged between 0.59 and 0.99 and was lower in later cohorts. Water temperature increased from 10.9 °C in March to 18.2 °C in May and vegetation coverage (bulk volume of Sargassum spp., %: as an index of the function for predation refuge) decreased from 60% in March to 2% in May. The later cohorts of juvenile S. cheni had high growth and mortality rates related to high temperature and low vegetation coverage. Since the seasonal increase in M was greater than that of G, the recruitment potential of the later cohorts was lower than that of the earlier cohorts.

  12. Identification of Geostructures of the Continental Crust Particularly as They Relate to Mineral Resource Evaluation. [Alaska

    NASA Technical Reports Server (NTRS)

    Lathram, E. H. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. A pattern of very old geostructures was recognized, reflecting structures in the crust. This pattern is not peculiar to Alaska, but can be recognized throughout the northern cordillera. A new metallogenic hypothesis for Alaska was developed, based on the relationship of space image linears to known mineral deposits. Using image linear analysis, regional geologic features were also recognized; these features may be used to guide in the location of undiscovered oil and/or gas accumulations in northern Alaska. The effectiveness of ERTS data in enhancing medium and small scale mapping was demonstrated. ERTS data were also used to recognize and monitor the state of large scale vehicular scars on Arctic tundra.

  13. 50 CFR Table 43 to Part 679 - Northern Bering Sea Research Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Northern Bering Sea Research Area 43 Table... ALASKA Pt. 679, Table 43 Table 43 to Part 679—Northern Bering Sea Research Area Longitude Latitude 1687... coordinate system is North American Datum 1983, Albers. * This boundary extends in a clockwise direction...

  14. Geographic Analysis of Alaska Lake Districts

    NASA Astrophysics Data System (ADS)

    Arp, C. D.; Jones, B. M.; Zimmerman, C. E.

    2007-12-01

    The state of Alaska has over 400,000 lakes greater than 0.01 km2 in surface area covering approximately 3.3% of the landscape. As in most lake-rich regions, these lakes are unevenly distributed on the landscape. So in order to better understand how lakes are organized on the landscape and relate this geographic organization to other climatologic, geologic, and biogeographic characteristics, we analyzed the spatial distribution of Alaska lakes. Using a combination of numerical abundance and surface-area extent of lakes, we selected lake density thresholds to identify and delineate 22 lake districts in Alaska. The total area of these 22 lakes districts occupy 16% of Alaska, yet encompass 64% of lakes and 76% of lake surface-area. The three largest lake districts are associated with the Yukon-Kuskokwin Delta, the Northern Arctic Coastal Plain, and the mountain front of the Alaskan Range on the Alaska Peninsula. Interestingly, these largest lake districts are covered by >17% lakes, while most of the smaller lake districts we identified have <10% lake cover. Of the remaining smaller lake districts, 9 are associated with mountain fronts or intermountain basins, 4 are associated with coastal plains, 3 are associated with floodplains and deltas, and 3 occur in high-elevation or mountain terrain. The highest numerical lake densities occur at deltas, while relatively lower densities occur in mountainous areas where individual lakes are often larger in surface area and likely volume. Comparison of these lake districts were made to permafrost distribution, glacial history, lithology, watershed position, and regional hydrologic budgets and regimes to better understand where lake-rich regions occur, why, and how they might change in the future. Ten of the 22 lake districts occur in areas dominated by continuous permafrost, 6 occur in areas of discontinuous or sporadic permafrost, and the other 6 occur in regions without perennially frozen soils. The majority of lake districts

  15. On the climate and climate change of Sitka, Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Wendler, Gerd; Galloway, Kevin; Stuefer, Martin

    2015-07-01

    Sitka, located in southeastern coastal Alaska, is the only meteorological station in Alaska and northern coastal British Columbia, with a long climatological record, going back to the first half of the nineteenth century. Sitka was the capital of Alaska, when it was part of the Russian Empire, to which Alaska belonged until 1867, when the American government purchased it. In 1827, the Russian established an observatory on Baranof Island, Sitka Harbor, which made 17-hourly observations, later extended to 19 and thereafter to all hours of the day. When analyzing the data, the 12-day time difference between the Russian (Julian) calendar, at which the observations were made, and ours (Gregorian) has to be considered. The climate of Sitka is maritime, with relative warm winter temperatures—there is no month with a mean temperature below freezing—and moderately warm summer temperatures with 4 months above the 10 °C level and plentiful precipitation all-year long. It is the warmest zone of Alaska. Even though there is a substantial break in observations in the late nineteenth century, these are the only observation, which started so early in the nineteenth century. Systematic US-based observations commenced much later normally in connection with the gold rush, whaling in Northern Alaska, and the fur trade, predominantly along the Yukon River. During the 186 years of observations from 1827 to 2013, the best linear fit gave a temperature increase of 1.56 °C for the whole period or 0.86 °C per century, somewhat lower than expected for the relatively high latitudes. The increase was nonlinear, with several multi-decadal variations. However, when comparing the first normal (1831-1860) to the last normal (1981-2010) and assuming a linear trend, a higher value of 1.06 °C per century was calculated. The discrepancy might be explained by nonlinearity and the fact that during the late nineteenth and early twentieth centuries, observations were sporadic. Furthermore, the

  16. 78 FR 54905 - Endangered and Threatened Wildlife and Plants; Southwest Alaska Distinct Population Segment of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ..., including infectious disease, biotoxins, contaminants, oil spills, food limitation, disturbance, bycatch in... important are predation (moderate to high importance) and oil spills (low to moderate importance). Threats... Alaska DPS of the northern sea otter as threatened on August 9, 2005 (70 FR 46366). For a description...

  17. Alaska's Children, 2000. Alaska Head Start State Collaboration Project. Quarterly Report.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    2000-01-01

    This document consists of the two 2000 issues of "Alaska's Children," which provides information on the Alaska Head Start State Collaboration Project and updates on Head Start activities in Alaska. Regular features include a calendar of conferences and meetings, a status report on Alaska's children, reports from the Alaska Children's Trust, and…

  18. 78 FR 53137 - Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ... formal complaint against BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc., and... Energy Regulatory Commission Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc., ExxonMobil Pipeline Company; Notice of Complaint Take notice that...

  19. The Northern Plains MSATT Meeting, and a call for a field-oriented successor to MSATT

    NASA Technical Reports Server (NTRS)

    Kargel, J. S.

    1993-01-01

    The workshop was devoted to a review of our knowledge of the Martian northern plains and presentation of recent ideas pertaining to the geologic and climatic evolution of this interesting region. The meeting was held in Fairbanks to allow easy access to Mars-like terrains in central and northern Alaska. There is no place on Earth that is a close analog of the Martian northern plains, but parts of Alaska come reasonably close in some respects, so we may expect that some of the processes occurring there are similar to processes that have occurred on Mars.

  20. 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…

  1. Alaska Native Land Claims. [Textbook].

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Written for students at the secondary level, this textbook on Alaska Native land claims includes nine chapters, eight appendices, photographs, maps, graphs, bibliography, and an index. Chapters are titled as follows: (1) Earliest Times (Alaska's first settlers, eighteenth century territories, and other claimants); (2) American Indians and Their…

  2. Preparing Teachers for Rural Alaska.

    ERIC Educational Resources Information Center

    Barnhardt, Ray

    1999-01-01

    This article discusses preparing teachers to teach in rural Alaska. An anecdote illustrates how outsiders who come to work in rural Alaska get into trouble because they are unprepared for conditions unique to the North. These conditions end up being viewed as impediments rather than opportunities. The same is true for the field of education. Of…

  3. Inconsistency in precipitation measurements across the Alaska-Yukon border

    NASA Astrophysics Data System (ADS)

    Scaff, L.; Yang, D.; Li, Y.; Mekis, E.

    2015-12-01

    This study quantifies the inconsistency in gauge precipitation observations across the border of Alaska and Yukon. It analyses the precipitation measurements by the national standard gauges (National Weather Service (NWS) 8 in. gauge and Nipher gauge) and the bias-corrected data to account for wind effect on the gauge catch, wetting loss and trace events. The bias corrections show a significant amount of errors in the gauge records due to the windy and cold environment in the northern areas of Alaska and Yukon. Monthly corrections increase solid precipitation by 136 % in January and 20 % for July at the Barter Island in Alaska, and about 31 % for January and 4 % for July at the Yukon stations. Regression analyses of the monthly precipitation data show a stronger correlation for the warm months (mainly rainfall) than for cold month (mainly snowfall) between the station pairs, and small changes in the precipitation relationship due to the bias corrections. Double mass curves also indicate changes in the cumulative precipitation over the study periods. This change leads to a smaller and inverted precipitation gradient across the border, representing a significant modification in the precipitation pattern over the northern region. Overall, this study discovers significant inconsistency in the precipitation measurements across the USA-Canada border. This discontinuity is greater for snowfall than for rainfall, as gauge snowfall observations have large errors in windy and cold conditions. This result will certainly impact regional, particularly cross-border, climate and hydrology investigations.

  4. 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

  5. 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…

  6. Young tectonics of a complex plate boundary zone: Indentation, rotation, and escape in Alaska

    NASA Astrophysics Data System (ADS)

    Wallace, W. K.; Ruppert, N. A.

    2012-12-01

    Convergence of thick crust of the Yakutat block with the southern margin of Alaska is widely recognized as a dominant influence on the tectonics of Alaska since at least late Miocene time. It is less clear how this convergence relates to the distribution, type, and orientation of geologic structures, and to the boundaries between the tectonic provinces that they define. We propose that convergence of Yakutat block includes two distinct components that influence deformation and topography in different ways: 1) The crust of the exposed, southern Yakutat block is too thick to subduct, which has caused the collisional St. Elias orogen. Detachment of the upper part of the mafic basement allows delamination and sinking of the remaining mafic crust and lithospheric mantle. The collisional orogen drives rigid counterclockwise rotation of the southern Alaska block south of the arcuate, right-lateral Denali fault. The western boundary of this block is a zone of distributed contraction in the western Alaska Range and Cook Inlet. 2) The northern part of the Yakutat block is thin enough to subduct but thick and buoyant enough to cause localized flat-slab subduction orthogonal to rotation of the southern Alaska block. Consequences include the gently antiformal Talkeetna Mountains that span the forearc basin, a gap in the magmatic arc, and a basement-involved fold-and-thrust belt in the northern Alaska Range. An arcuate oroclinal hinge from southern Alaska to the northeastern Brooks Range reflects indentation since at least Paleocene time. Traction above the subducted Yakutat block along the southern part of this hinge drives current indentation. North of the subducted Yakutat block, indentation is reflected by left-lateral block rotation that accommodates shortening between the Denali and Tintina faults and by contraction farther north along the northern edge of the arcuate northeastern Brooks Range. Western Alaska accommodates both northward indentation and westward convergence

  7. U.S. Global Climate Change Impacts Report, Alaska Region

    NASA Astrophysics Data System (ADS)

    McGuire, D.

    2009-12-01

    The assessment of the Global Climate Change Impacts in the United States includes analyses of the potential climate change impacts in Alaska. The resulting findings are discussed in this presentation, with the effects on water resources discussed separately. Major findings include: Summers are getting hotter and drier, with increasing evaporation outpacing increased precipitation. Climate changes are already affecting water, energy, transportation, agriculture, ecosystems, and health. These impacts are different from region to region and will grow under projected climate change. Wildfires and insect problems are increasing. Climate plays a key role in determining the extent and severity of insect outbreaks and wildfire. The area burned in North America’s northern forest that spans Alaska and Canada tripled from the 1960s to the 1990s. During the 1990s, south-central Alaska experienced the largest outbreak of spruce bark beetles in the world because of warmer weather in all seasons of the year. Under changing climate conditions, the average area burned per year in Alaska is projected to double by the middle of this century10. By the end of this century, area burned by fire is projected to triple under a moderate greenhouse gas emissions scenario and to quadruple under a higher emissions scenario. Close-bodied lakes are declining in area. A continued decline in the area of surface water would present challenges for the management of natural resources and ecosystems on National Wildlife Refuges in Alaska. These refuges, which cover over 77 million acres (21 percent of Alaska) and comprise 81 percent of the U.S. National Wildlife Refuge System, provide a breeding habitat for millions of waterfowl and shorebirds that winter in the lower 48 states. Permafrost thawing will damage public and private infrastructure. Land subsidence (sinking) associated with the thawing of permafrost presents substantial challenges to engineers attempting to preserve infrastructure in

  8. Climate Change Implications to Vegetation Production in Alaska

    NASA Technical Reports Server (NTRS)

    Neigh, Christopher S.R.

    2008-01-01

    Investigation of long-term meteorological satellite data revealed statistically significant vegetation response to climate drivers of temperature, precipitation and solar radiation with exclusion of fire disturbance in Alaska. Abiotic trends were correlated to satellite remote sensing observations of normalized difference vegetation index to understand biophysical processes that could impact ecosystem carbon storage. Warming resulted in disparate trajectories for vegetation growth due to precipitation and photosynthetically active radiation variation. Interior spruce forest low lands in late summer through winter had precipitation deficit which resulted in extensive fire disturbance and browning of undisturbed vegetation with reduced post-fire recovery while Northern slope moist alpine tundra had increased production due to warmer-wetter conditions during the late 1990s and early 2000s. Coupled investigation of Alaska s vegetation response to warming climate found spatially dynamic abiotic processes with vegetation browning not a result from increased fire disturbance.

  9. Utilization of remote sensing in Alaska permafrost studies

    NASA Technical Reports Server (NTRS)

    Hall, D. K.

    1981-01-01

    Permafrost related features such as: aufeis, tundra, thaw lakes and subsurface ice features were studied. LANDSAT imagery was used to measure the extent and distribution of aufeis in Arctic Slope rivers over a period of 7 years. Interannual extent of large aufeis fields was found to vary significantly. Digital LANDSAT data were used to study the short term effects of a tundra fire which burned a 48 sq km area in northwestern Alaska. Vegetation regrowth was inferred from Landsat spectral reflectance increases and compared to in-situ measurements. Aircraft SAR (Synethic Aperture Radar) imagery was used in conjunction with LANDSAT imagery used in conjunction with LANDSAT imagery to qualitatively determine depth categories for thaw lakes in northern Alaska.

  10. Distribution and character of naleds in northeastern Alaska

    USGS Publications Warehouse

    Harden, Deborah; Barnes, Peter W.; Reimnitz, Erk

    1977-01-01

    An examination of the distribution of river naleds seen in Landsat satellite imagery and high- and low-altitude aerial photography of Alaska's North Slope indicates that these features are widespread east of the Colville River and less abundant to the west. Where naleds occur, stream channels are wide and often form braided channels. Their distribution can be related to changes in stream gradient and to the occurrence of springs. Large naleds, such as on the Kongakut River, often remain through the summer melt season to form the nucleus of icing in the succeeding winter. Major naleds also are likely to significantly influence the nature of permafrost in their immediate vicinity. The map of naleds may serve as a guide to the occurrence of year-round flowing water, a sparse commodity in northern Alaska.

  11. 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.

  12. Molecular structure and immune-stimulated transcriptional modulation of the first teleostean IFP35 counterpart from rockfish (Sebastes schlegelii).

    PubMed

    Perera, N C N; Godahewa, G I; Nam, Bo-Hye; Lee, Jehee

    2016-09-01

    Interferons (IFNs) and IFN-inducible proteins play numerous physiological roles, particularly in antiviral defense mechanisms of the innate immune response with the presence of pathogens. IFN-induced protein-35 kDa (IFP35) is induced by Type II IFN (IFN-γ); it is a cytoplasmic protein that can be translocated to the nucleus via the stimulation of IFN. In this study, we report the complete molecular characterization of the IFP35 cDNA sequence from the black rockfish in an effort to understand its role in the immune response. The coding sequence of RfIFP35 encoded a putative peptide of 371 amino acids containing two characteristic Nmi/IFP 35 domains (NIDs), which are highly conserved among its counterparts. The protein showed a molecular mass of 42.2 kDa with a theoretical pI of 5.05 and was predicted to be unstable because of its high instability index (49.37). Therefore, the protein-protein interaction is essential for its stability, which may be facilitated by the intrinsically disordered regions in this protein. According to cellular location prediction, the RfIFP35 protein is cytosolic. Phylogenetic analysis showed that RfIFP35 was cladded within the fish counterparts. Tissue distribution profiling revealed a ubiquitous presence of the protein in all examined tissues, with highest expression in the blood followed by the spleen tissues. The expression of RfIFP35 during immune challenge with poly I:C and lipopolysaccharide treatments affirms its putative importance in the first-line host defense system. RfIFN-γ mRNA was significantly expressed at 6 h p.i. in blood and 3 h p.i. in the spleen following treatment with different immune stimulants, and its expression was higher compared to that of RfIFP35 mRNA. Therefore, the modulation patterns of both RfIFP35 and RfIFN-γ suggest that RfIFP35 may be induced by RfIFN-γ. PMID:27514784

  13. Short-Term Fidelity, Habitat Use and Vertical Movement Behavior of the Black Rockfish Sebastes schlegelii as Determined by Acoustic Telemetry.

    PubMed

    Zhang, Yingqiu; Xu, Qiang; Alós, Josep; Liu, Hui; Xu, Qinzeng; Yang, Hongsheng

    2015-01-01

    The recent miniaturization of acoustic tracking devices has allowed fishery managers and scientists to collect spatial and temporal data for sustainable fishery management. The spatial and temporal dimensions of fish behavior (movement and/or vertical migrations) are particularly relevant for rockfishes (Sebastes spp.) because most rockfish species are long-lived and have high site fidelity, increasing their vulnerability to overexploitation. In this study, we describe the short-term (with a tracking period of up to 46 d) spatial behavior, as determined by acoustic tracking, of the black rockfish Sebastes schlegelii, a species subject to overexploitation in the Yellow Sea of China. The average residence index (the ratio of detected days to the total period from release to the last detection) in the study area was 0.92 ± 0.13, and most of the tagged fish were detected by only one region of the acoustic receiver array, suggesting relatively high site fidelity to the study area. Acoustic tracking also suggested that this species is more frequently detected during the day than at night in our study area. However, the diel detection periodicity (24 h) was only evident for certain periods of the tracking time, as revealed by a continuous wavelet transform. The habitat selection index of tagged S. schlegelii suggested that S. schlegelii preferred natural reefs, mixed sand/artificial reef bottoms and mixed bottoms of boulder, cobble, gravel and artificial reefs. The preference of this species for the artificial reefs that were recently deployed in the study area suggests that artificial seascapes may be effective management tools to attract individuals. The vertical movement of tagged S. schlegelii was mostly characterized by bottom dwelling behavior, and there was high individual variability in the vertical migration pattern. Our results have important implications for S. schlegelii catchability, the implementation of marine protected areas, and the identification of key

  14. Short-Term Fidelity, Habitat Use and Vertical Movement Behavior of the Black Rockfish Sebastes schlegelii as Determined by Acoustic Telemetry

    PubMed Central

    Zhang, Yingqiu; Xu, Qiang; Alós, Josep; Liu, Hui; Xu, Qinzeng; Yang, Hongsheng

    2015-01-01

    The recent miniaturization of acoustic tracking devices has allowed fishery managers and scientists to collect spatial and temporal data for sustainable fishery management. The spatial and temporal dimensions of fish behavior (movement and/or vertical migrations) are particularly relevant for rockfishes (Sebastes spp.) because most rockfish species are long-lived and have high site fidelity, increasing their vulnerability to overexploitation. In this study, we describe the short-term (with a tracking period of up to 46 d) spatial behavior, as determined by acoustic tracking, of the black rockfish Sebastes schlegelii, a species subject to overexploitation in the Yellow Sea of China. The average residence index (the ratio of detected days to the total period from release to the last detection) in the study area was 0.92 ± 0.13, and most of the tagged fish were detected by only one region of the acoustic receiver array, suggesting relatively high site fidelity to the study area. Acoustic tracking also suggested that this species is more frequently detected during the day than at night in our study area. However, the diel detection periodicity (24 h) was only evident for certain periods of the tracking time, as revealed by a continuous wavelet transform. The habitat selection index of tagged S. schlegelii suggested that S. schlegelii preferred natural reefs, mixed sand/artificial reef bottoms and mixed bottoms of boulder, cobble, gravel and artificial reefs. The preference of this species for the artificial reefs that were recently deployed in the study area suggests that artificial seascapes may be effective management tools to attract individuals. The vertical movement of tagged S. schlegelii was mostly characterized by bottom dwelling behavior, and there was high individual variability in the vertical migration pattern. Our results have important implications for S. schlegelii catchability, the implementation of marine protected areas, and the identification of key

  15. Status and distribution of the Kittlitz's Murrelet Brachyramphus brevirostris along the Alaska Peninsula and Kodiak and Aleutian Islands, Alaska

    USGS Publications Warehouse

    Madison, Erica N.; Piatt, John F.; Arimitsu, Mayumi L.; Romano, Marc D.; van Pelt, Thomas I.; Nelson, S. Kim; Williams, Jeffrey C.; DeGange, Anthony R.

    2011-01-01

    The Kittlitz's Murrelet Brachyramphus brevirostris is adapted for life in glacial-marine ecosystems, being concentrated in the belt of glaciated fjords in the northern Gulf of Alaska from Glacier Bay to Cook Inlet. Most of the remaining birds are scattered along coasts of the Alaska Peninsula and Aleutian Islands, where they reside in protected bays and inlets, often in proximity to remnant glaciers or recently deglaciated landscapes. We summarize existing information on Kittlitz's Murrelet in this mainly unglaciated region, extending from Kodiak Island in the east to the Near Islands in the west. From recent surveys, we estimated that ~2400 Kittlitz's Murrelets were found in several large embayments along the Alaska Peninsula, where adjacent ice fields feed silt-laden water into the bays. On Kodiak Island, where only remnants of ice remain today, observations of Kittlitz's Murrelets at sea were uncommon. The species has been observed historically around the entire Kodiak Archipelago, however, and dozens of nest sites were found in recent years. We found Kittlitz's Murrelets at only a few islands in the Aleutian chain, notably those with long complex shorelines, high mountains and remnant glaciers. The largest population (~1600 birds) of Kittlitz's Murrelet outside the Gulf of Alaska was found at Unalaska Island, which also supports the greatest concentration of glacial ice in the Aleutian Islands. Significant populations were found at Atka (~1100 birds), Attu (~800) and Adak (~200) islands. Smaller numbers have been reported from Unimak, Umnak, Amlia, Kanaga, Tanaga, Kiska islands, and Agattu Island, where dozens of nest sites have been located in recent years. Most of those islands have not been thoroughly surveyed, and significant pockets of Kittlitz's Murrelets may yet be discovered. Our estimate of ~6000 Kittlitz's Murrelets along the Alaska Peninsula and Aleutian Islands is also likely to be conservative because of the survey protocols we employed (i.e. early

  16. Reconstruction of recent climate change in Alaska from the Aurora Peak ice core, central Alaska

    NASA Astrophysics Data System (ADS)

    Tsushima, A.; Matoba, S.; Shiraiwa, T.; Okamoto, S.; Sasaki, H.; Solie, D. J.; Yoshikawa, K.

    2014-04-01

    A 180.17 m ice core was drilled at Aurora Peak in the central part of the Alaska Range, Alaska, in 2008 to allow reconstruction of centennial-scale climate change in the northern North Pacific. The 10 m-depth temperature in the borehole was -2.2 °C, which corresponded to annual mean air temperature at the drilling site. In this ice core, there were many melt-refrozen layers due to high temperature and/or strong insolation during summer seasons. We analyzed stable hydrogen isotopes (δD) and chemical species in the ice core. The ice core age was determined by annual counts of δD and seasonal cycles of Na+, and we used reference horizons of tritium peaks in 1963 and 1964, major volcanic eruptions of Mount Spurr in 1992 and Mount Katmai in 1912, and a large forest fire in 2004 as age controls. Here, we show that the chronology of the Aurora Peak ice core from 95.61 m w.eq. to the top corresponds to the period from 1900 to the summer season of 2008, with a dating error of ±3 years. We estimated that the mean accumulation rate from 1997 to 2007 (except for 2004) was 1.88 m w.eq per year. Our results suggest that temporal variation in δD and annual accumulation rates are strongly related to shifts in the Pacific Decadal Oscillation index (PDOI). The remarkable increase in annual precipitation since the 1970s has likely been the result of enhanced storm activity associated with shifts in the PDOI during winter in the Gulf of Alaska.

  17. Reconstruction of recent climate change in Alaska from the Aurora Peak ice core, central Alaska

    NASA Astrophysics Data System (ADS)

    Tsushima, A.; Matoba, S.; Shiraiwa, T.; Okamoto, S.; Sasaki, H.; Solie, D. J.; Yoshikawa, K.

    2015-02-01

    A 180.17 m ice core was drilled at Aurora Peak in the central part of the Alaska Range, Alaska, in 2008 to allow reconstruction of centennial-scale climate change in the northern North Pacific. The 10 m depth temperature in the borehole was -2.2 °C, which corresponded to the annual mean air temperature at the drilling site. In this ice core, there were many melt-refreeze layers due to high temperature and/or strong insolation during summer seasons. We analyzed stable hydrogen isotopes (δD) and chemical species in the ice core. The ice core age was determined by annual counts of δD and seasonal cycles of Na+, and we used reference horizons of tritium peaks in 1963 and 1964, major volcanic eruptions of Mount Spurr in 1992 and Mount Katmai in 1912, and a large forest fire in 2004 as age controls. Here, we show that the chronology of the Aurora Peak ice core from 95.61 m to the top corresponds to the period from 1900 to the summer season of 2008, with a dating error of ± 3 years. We estimated that the mean accumulation rate from 1997 to 2007 (except for 2004) was 2.04 m w.eq. yr-1. Our results suggest that temporal variations in δD and annual accumulation rates are strongly related to shifts in the Pacific Decadal Oscillation index (PDOI). The remarkable increase in annual precipitation since the 1970s has likely been the result of enhanced storm activity associated with shifts in the PDOI during winter in the Gulf of Alaska.

  18. 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

  19. 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.

  20. 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.

  1. Use of acoustic classification of sidescan sonar data for mapping benthic habitat in the Northern Channel Islands, California

    USGS Publications Warehouse

    Cochrane, G.R.; Lafferty, K.D.

    2002-01-01

    Highly reflective seafloor features imaged by sidescan sonar in nearshore waters off the Northern Channel Islands (California, USA) have been observed in subsequent submersible dives to be areas of thin sand coverihg bedrock. Adjacent areas of rocky seafloor, suitable as habitat for endangered species of abalone and rockfish, and encrusting organisms, cannot be differentiated from the areas of thin sand on the basis of acoustic backscatter (i.e. grey level) alone. We found second-order textural analysis of sidescan sonar data useful to differentiate the bottom types where data is not degraded by near-range distortion (caused by slant-range and ground-range corrections), and where data is not degraded by far-range signal attenuation. Hand editing based on submersible observations is necessary to completely convert the sidescan sonar image to a bottom character classification map suitable for habitat mapping. ?? 2002 Elsevier Science Ltd. All rights reserved.

  2. Use of acoustic classification of sidescan sonar data for mapping benthic habitat in the Northern Channel Islands, California

    NASA Astrophysics Data System (ADS)

    Cochrane, Guy R.; Lafferty, Kevin D.

    2002-03-01

    Highly reflective seafloor features imaged by sidescan sonar in nearshore waters off the Northern Channel Islands (California, USA) have been observed in subsequent submersible dives to be areas of thin sand covering bedrock. Adjacent areas of rocky seafloor, suitable as habitat for endangered species of abalone and rockfish, and encrusting organisms, cannot be differentiated from the areas of thin sand on the basis of acoustic backscatter (i.e. grey level) alone. We found second-order textural analysis of sidescan sonar data useful to differentiate the bottom types where data is not degraded by near-range distortion (caused by slant-range and ground-range corrections), and where data is not degraded by far-range signal attenuation. Hand editing based on submersible observations is necessary to completely convert the sidescan sonar image to a bottom character classification map suitable for habitat mapping.

  3. A conceptual model for the impact of climate change on fox rabies in Alaska, 1980-2010.

    PubMed

    Kim, B I; Blanton, J D; Gilbert, A; Castrodale, L; Hueffer, K; Slate, D; Rupprecht, C E

    2014-02-01

    The direct and interactive effects of climate change on host species and infectious disease dynamics are likely to initially manifest\\ at latitudinal extremes. As such, Alaska represents a region in the United States for introspection on climate change and disease. Rabies is enzootic among arctic foxes (Vulpes lagopus) throughout the northern polar region. In Alaska, arctic and red foxes (Vulpes vulpes) are reservoirs for rabies, with most domestic animal and wildlife cases reported from northern and western coastal Alaska. Based on passive surveillance, a pronounced seasonal trend in rabid foxes occurs in Alaska, with a peak in winter and spring. This study describes climatic factors that may be associated with reported cyclic rabies occurrence. Based upon probabilistic modelling, a stronger seasonal effect in reported fox rabies cases appears at higher latitudes in Alaska, and rabies in arctic foxes appear disproportionately affected by climatic factors in comparison with red foxes. As temperatures continue a warming trend, a decrease in reported rabid arctic foxes may be expected. The overall epidemiology of rabies in Alaska is likely to shift to increased viral transmission among red foxes as the primary reservoir in the region. Information on fox and lemming demographics, in addition to enhanced rabies surveillance among foxes at finer geographic scales, will be critical to develop more comprehensive models for rabies virus transmission in the region. PMID:23452510

  4. Northern Nutrition.

    ERIC Educational Resources Information Center

    Northwest Territories Dept. of Education, Yellowknife.

    This guide contains nutrition information and nutrition education strategies aimed at residents of the Canadian Arctic. Section I: (1) defines nutrition terms; (2) describes the sources and functions of essential nutrients; (3) explains Canada's food guide and special considerations for the traditional northern Native diet and for lactose…

  5. Preliminary results of microearthquake survey, Northern Adak Island, Alaska

    SciTech Connect

    Mackelprang, Claron E.

    1982-01-01

    Nine MEQ-800 portable seismic systems were emplaced and recordings taken during the 30 day period between September 5 to October 4, 1982. During this interval 190 events were correlated on two or more stations by Mincomp. Twenty four of these, seen on four or more stations and considered to be local in origin, yielded, according to Mincomp, reasonable hypocenters and origin times using a homogeneous earth model having a velocity of 5 km/sec. A plot of these hypocenters showed much of the microearthquake activity recorded during the survey to be located beneath Mt. Adagdak. This is different from the events located by the Butler and Keller (1974) microearthquake survey which placed hypocenters beneath the sea in Andrew Bay north and northwest of Mt. Adagdak. Butler and Keller did project a fault plane to the surface which would project southwest through Mt. Adagdak and Andrew Bay Volcano. ESL hypocenter locations using the layered earth model show many of the identified events to occur on the northeast corner of the island at focal depths of 8-10 km. It is not obvious that the observed events are related to a single active fault. If so, the fault must be at a low dip angle as shown by the least-squares-fit to the data on Figure 3. Alternatively, the majority of the events occurring within a fairly restrictive range of focal depths may be more indicative of a magma chamber and the movement of magma. Further interpretation of the microearthquake data obtained during 1982 is, however, outside the scope of this report. The relatively small error ellipses for hypocenter locations, compared to the distribution of hypocenters shown on Plates V and VI lead us to question the validity of the projection of all hypocenters to define a single fault location and orientation. It is apparent that two or more structures could be indicated by the present data and that these structures intersect near the north end of Adak island. The occurrence of most events in a narrow depth range would lead to considerable error in projecting a single fault plane to its surface intersection.

  6. Summer food habits of juvenile Arctic foxes in northern Alaska

    SciTech Connect

    Garrott, R.A.; Eberhardt, L.E.; Hanson, W.C.

    1983-01-01

    The absence of garbage in fox scats collected in the Colville Delta area was expected because garbage was unavailable to these foxes. Foxes from Prudhoe Bay, however, had access to quantities of garbage as a result of petroleum development activities. Most occupied dens in the Prudhoe Bay area were littered with garbage. Telemetry investigations conducted in conjunction with our study of food habits indicated that foxes frequented areas of human activity to solicit handouts and forage garbage disposal sites. The reason for the low occurrence of garbage in Prudhoe Bay scats is undoubtedly related to the lack of undigestible matter in most forms of garbage. The small number of scats that were classified as containing garbage typically contained only packaging materials associated with processed food such as plastic wrap and aluminum foil. The highly digestible nature of most forms of garbage made it impossible to quantify its importance in the diet of foxes. Prudhoe Bay foxes undoubtedly use garbage; however, the diversity and abundance of natural prey in the scat indicates that these foxes only supplement their summer diet with garbage. Dependence on this food resource may increase during the winter when foxes must rely almost exclusively on the fluctuating lemming poulations for sustenance. 11 references, 2 tables.

  7. 1984 Results of trans-Alaska crustal transect in Chugach Mountains and Copper River Basin, Alaska

    SciTech Connect

    Nokleberg, W.J.; Ambos, E.L.; Fuis, G.S.; Mooney, W.D.; Page, R.A.; Plafker, G.; Campbell, D.L.

    1985-04-01

    The Trans-Alaska Crustal Transect (TACT) program, a multidisciplinary investigation of the continental crust and its evolution along the Trans-Alaska pipeline corridor was started by the USGS during 1984. Preliminary results of geologic, geophysical, and wide-angle reflection/refraction data obtained across the Chugach terrane (CGT) and the composite Wrangellia/Peninsular terrane (WRT/PET) suggest the following: (a) the CGT is composed of accretionary sequences that include, from south to north, Late Cretaceous schistose flysch, uppermost Jurassic to Early Cretaceous sheared melange, and Early(.) Jurassic blueschist/greenschist. (b) The CGT accretionary sequences have local broad, low-amplitude magnetic or gravity anomalies. (c) Seismic data show that the CGT along latitude 61/sup 0/N, by alternating high- (6.9-8.0. km/sec) and low-velocity layers is suggestive of multiple thin slices of subducted oceanic crust and upper mantle. (d) Mafic and ultramafic cumulate rocks along the south margin of the WRT/PET have strong magnetic and gravity signatures and are interpreted as the uplifted root of a Jurassic magmatic arc superimposed on a late Paleozoic volcanic arc. Magnetic data suggest that comparable rocks underlie most of the PET. (e) The Northdipping border Ranges fault (BRF) marks the suture along which the northern margin of the CGT was relatively underthrust at least 40 km beneath the WRT/PET. (f) Beneath the northern CGT and southern WRT/PET, a prominent seismic reflector (v = 7.7 km/sec), suggestive of oceanic upper mantle rocks, dips about 3/sup 0/N and extends from a depth of 12 km beneath the Tasnuna River to 16 km beneath the BRF, where the dip appears to steepen to about 15/sup 0/ beneath the southern margin of the PET.

  8. Improving Student Achievement in Alaska. Alaska Goals 2000 Annual Report, 1997-98.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    Alaska Goals 2000 is part of a coordinated, statewide effort to improve public education for all students in Alaska. In 1997-1998, 90% of Alaska's federal funding was used to fund grants to local school districts, and 10% was used to fund state-level activities through the Alaska Department of Education. During 1997-1998, curriculum frameworks and…

  9. 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... subsistence uses on Federal public lands and waters in Alaska. The Federal Subsistence Board, which includes... the subsistence management of fish and wildlife on Federal public lands in Alaska. The Board...

  10. 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 from the…

  11. 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

  12. Profile: American Indian/Alaska Native

    MedlinePlus

    ... million American Indians and Alaska Natives. Typically, this urban clientele has less accessibility to hospitals; health clinics ... IHS and tribal health programs. Studies on the urban American Indian and Alaska Native population have documented ...

  13. 76 FR 53151 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-25

    ... Kuskokwim Corporation, Successor in Interest to Red Devil Incorporated. The decision approves the surface... Devil, Alaska, and are located in: Seward Meridian, Alaska T. 22 N., R. 44 W., Secs. 27 to 34,...

  14. 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

  15. 77 FR 38013 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... level trawl fishery and is not repeated here (71 FR 67210; November 20, 2006). Need for Correction This... Program (Rockfish Program) final rule in the Federal Register on December 27, 2011 (76 FR 81248). The... FR Docket No. 110314196-1725-02 published on December 27, 2011. List of Subjects in 50 CFR Part...

  16. 78 FR 53419 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... is not repeated here (for the AFA see 67 FR 79692, December 30, 2002; for the Amendment 80 Program see 72 FR 52668, September 14, 2007; and for the Central GOA Rockfish Program, see 76 FR 81248....gov/#!docketDetail ;D=NOAA-NMFS-2012-0151 click the ``Comment Now!'' icon, complete the...

  17. Biomarkers in fish from Prince William Sound and the Gulf of Alaska: 1999-2000.

    PubMed

    Huggett, Robert J; Stegeman, John J; Page, David S; Parker, Keith R; Woodin, Bruce; Brown, John S

    2003-09-15

    To test the hypothesis that biomarker levels in fish collected at Prince William Sound (PWS) sites impacted by the 1989 Exxon Valdez oil spill were higher than those collected at unimpacted sites, a 1999-2000 study collected five fish species and associated benthic sediments from 21 sites in PWS and the eastern Gulf of Alaska (GOA). PWS sites were divided in three oiling categories based upon 1989 shoreline assessments: nonspill path (NSP), spill path oiled (SPO), and spill path not oiled (SPNO). Rockfish (N = 177), rock sole (N = 30), and kelp greenling (N = 49) were collected at near-shore locations (approximately 50-500 m from shore); Pacific halibut (N = 131) and Pacific cod (N = 81) were collected further offshore (approximately 500-7000 m). Fish were assayed for bile fluorescent aromatic contaminants (FAC) and cytochrome P4501A (CYP1A) levels measured as liver ethoxyresorufin O-deethylase (EROD) activity and by immunohistochemistry (IHC) of various tissues. For all species studied at all sites, bile FAC concentrations and CYP1A levels were low and in the same range for fish collected at PWS SPO and SPNO sites relative to NSP sites in PWS and the GOA. Consequently, the hypothesis is rejected for the species studied. The bile FAC results further indicate a pervasive exposure of fish at all sites, including those in the GOA far removed from the effects of the spill, to low levels of polycyclic aromatic hydrocarbons. Analysis of the benthic sediments indicates that the probable sources of this exposure are petrogenic hydrocarbons derived from natural oil seeps and eroding sedimentary rocks in the eastern GOA. PMID:14524434

  18. Rapid deglacial and early Holocene expansion of peatlands in Alaska

    PubMed Central

    Jones, Miriam C.; Yu, Zicheng

    2010-01-01

    Northern peatlands represent one of the largest biospheric carbon (C) reservoirs; however, the role of peatlands in the global carbon cycle remains intensely debated, owing in part to the paucity of detailed regional datasets and the complexity of the role of climate, ecosystem processes, and environmental factors in controlling peatland C dynamics. Here we used detailed C accumulation data from four peatlands and a compilation of peatland initiation ages across Alaska to examine Holocene peatland dynamics and climate sensitivity. We find that 75% of dated peatlands in Alaska initiated before 8,600 years ago and that early Holocene C accumulation rates were four times higher than the rest of the Holocene. Similar rapid peatland expansion occurred in West Siberia during the Holocene thermal maximum (HTM). Our results suggest that high summer temperature and strong seasonality during the HTM in Alaska might have played a major role in causing the highest rates of C accumulation and peatland expansion. The rapid peatland expansion and C accumulation in these vast regions contributed significantly to the peak of atmospheric methane concentrations in the early Holocene. Furthermore, we find that Alaskan peatlands began expanding much earlier than peatlands in other regions, indicating an important contribution of these peatlands to the pre-Holocene increase in atmospheric methane concentrations. PMID:20368451

  19. United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study: Oliktok Point Radar Installation, Alaska. Volume 1. (Includes appendices a - b)

    SciTech Connect

    1996-04-15

    This report presents the findings of Remedial Investigations and Feasibility Studies at sites located at the Oliktok Point radar installation in northern Alaska. The sites were characterized based on sampling and analyses conducted during Remedial Investigation activities performed during August and September 1993.

  20. From the utilization point of view, the two approaches seem to United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study Point Barrow Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-02-19

    This report presents the findings of Remedial Investigations and Feasibility Studies at sites located at the Point Barrow radar installation in northern Alaska. The sites were characterized based on sampling and analyses conducted during Remedial Investigation activities performed during August and September 1993.

  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. 50 CFR 32.21 - Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... WILDLIFE REFUGE SYSTEM HUNTING AND FISHING Refuge-Specific Regulations for Hunting and Fishing § 32.21 Alaska. Alaska refuges are opened to hunting, fishing and trapping pursuant to the Alaska National Interest Lands Conservation Act (Pub. L. 96-487, 94 Stat. 2371). Information regarding specific...

  3. 50 CFR 32.21 - Alaska.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Alaska. 32.21 Section 32.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM HUNTING AND FISHING Refuge-Specific Regulations for Hunting and Fishing § 32.21 Alaska. Alaska refuges are opened to...

  4. Some Books about Alaska Received in 1986.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Div. of State Libraries.

    This publication is an annotated listing of 143 books about Alaska or the Arctic, received by the Alaska Division of State Libraries in 1986. Most of the material is current or published in recent years, with the exception of government publications. Categories are juvenile, adult non-fiction, adult fiction, and reference. A few Alaska state and…

  5. 33 CFR 80.1705 - Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Alaska. 80.1705 Section 80.1705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Alaska § 80.1705 Alaska. The 72 COLREGS shall apply on all the sounds,...

  6. New insights into the influence of ice on the coastal marine environment of the Beaufort Sea, Alaska

    NASA Technical Reports Server (NTRS)

    Barnes, P. W.; Reimnitz, E.

    1973-01-01

    Areal patterns from field data and ERTS-1 imagery have shown a close relationship between geologic processes and the influence of sea ice along Alaska's northern coast, perhaps the nation's least known continental margin. Ice acts as; (1) a bottom-gouging agent; (2) an influence on water circulation; (3) a carrier of sediments; and (4) an influence on water types.

  7. 75 FR 30779 - Fisheries of the Exclusive Economic Zone off Alaska; Stock Assessment of Eastern Bering Sea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... Alaska; Stock Assessment of Eastern Bering Sea Pollock; Peer Review Meeting AGENCY: National Marine... a peer review of the agency's stock assessment of Eastern Bering Sea walleye pollock (Theragra chalcogramma). The CIE, operated by Northern Taiga Ventures, Inc., provides independent peer reviews of...

  8. 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.

  9. 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

  10. Movements of juvenile Gyrfalcons from western and interior Alaska following departure from their natal areas

    USGS Publications Warehouse

    McIntyre, C.L.; Douglas, D.C.; Adams, L.G.

    2009-01-01

    Juvenile raptors often travel thousands of kilometers from the time they leave their natal areas to the time they enter a breeding population. Documenting movements and identifying areas used by raptors before they enter a breeding population is important for understanding the factors that influence their survival. In North America, juvenile Gyrfalcons (Falco rusticolus) are routinely observed outside the species' breeding range during the nonbreeding season, but the natal origins of these birds are rarely known. We used satellite telemetry to track the movements of juvenile Gyrfalcons during their first months of independence. We instrumented nestlings with lightweight satellite transmitters within 10 d of estimated fledging dates on the Seward Peninsula in western Alaska and in Denali National Park (Denali) in interior Alaska. Gyrfalcons spent an average of 41.4 ?? 6.1 d (range = 30-50 d) in their natal areas after fledging. The mean departure date from natal areas was 27 August ?? 6.4 d. We tracked 15 individuals for an average of 70.5 ?? 28.1 d post-departure; Gyrfalcons moved from 105 to 4299 km during this period and tended to move greater distances earlier in the tracking period than later in the tracking period. Gyrfalcons did not establish temporary winter ranges within the tracking period. We identified several movement patterns among Gyrfalcons, including unidirectional long-distance movements, multidirectional long-and shortdistance movements, and shorter movements within a local region. Gyrfalcons from the Seward Peninsula remained in western Alaska or flew to eastern Russia with no movements into interior Alaska. In contrast, Gyrfalcons from Denali remained in interior Alaska, flew to northern and western Alaska, or flew to northern Alberta. Gyrfalcons from both study areas tended to move to coastal, riparian, and wetland areas during autumn and early winter. Because juvenile Gyrfalcons dispersed over a large geographic area and across three

  11. Geology and tectonic development of the continental margin north of Alaska

    USGS Publications Warehouse

    Grantz, A.; Eittreim, S.; Dinter, D.A.

    1979-01-01

    The continental margin north of Alaska, as interpreted from seismic reflection profiles, is of the Atlantic type and consists of three sectors of contrasting structure and stratigraphy. The Chukchi sector, on the west, is characterized by the deep late Mesozoic and Tertiary North Chukchi basin and the Chukchi Continental Borderland. The Barrow sector of central northern Alaska is characterized by the Barrow arch and a moderately thick continental terrace build of Albian to Tertiary clastic sediment. The terrace sedimentary prism is underlain by lower Paleozoic metasedimentary rocks. The Barter Island sector of northeastern Alaska and Yukon Territory is inferred to contain a very thick prism of Jurassic, Cretaceous and Tertiary marine and nonmarine clastic sediment. Its structure is dominated by a local deep Tertiary depocenter and two regional structural arches. We postulate that the distinguishing characteristics of the three sectors are inherited from the configuration of the rift that separated arctic Alaska from the Canadian Arctic Archipelago relative to old pre-rift highlands, which were clastic sediment sources. Where the rift lay relatively close to northern Alaska, in the Chukchi and Barter Island sectors, and locally separated Alaska from the old source terranes, thick late Mesozoic and Tertiary sedimentary prisms extend farther south beneath the continental shelf than in the intervening Barrow sector. The boundary between the Chukchi and Barrow sectors is relatively well defined by geophysical data, but the boundary between the Barrow and Barter Island sectors can only be inferred from the distribution and thickness of Jurassic and Cretaceous sedimentary rocks. These boundaries may be extensions of oceanic fracture zones related to the rifting that is postulated to have opened the Canada Basin, probably beginning during the Early Jurassic. ?? 1979.

  12. Snow cover surveys in Alaska from ERTS-1 data

    NASA Technical Reports Server (NTRS)

    Benson, C. S.

    1973-01-01

    September and October ERTS scenes have been analyzed to delineate snow cover patterns in northern Alaska's Brooks Range and on Mt. Wrangell, and active volcano in South Central Alaska. ERTS images demonstrate that the snow on the northern foothills of the Brooks Range are significantly more affected by katabatic wind action than are the southern foothills. Aufeis deposits along arctic rivers also can be identified in late summer. A survey of such aufeis deposits could identify additional summertime sources of fresh water supplies. Images of Mt. Wrangell permit monitoring of the interaction between volcanic heat and the mass balance of glaciers that exist on active volcanoes. Temporal changes in the areas of bare rock on the rim of the caldera on the summit reveal significant melting of new snow from an extensive storm on August 18. Digital analysis of data from subsequent passes over the summit on September 7, 23 and 24 revealed considerable bare rock exposed by melting, which is virtually impossible from solar heating at this altitude and date.

  13. Ordovician "sphinctozoan" sponges from Prince of Wales Island, southeastern Alaska

    USGS Publications Warehouse

    Rigby, J.K.; Karl, S.M.; Blodgett, R.B.; Baichtal, J.F.

    2005-01-01

    A faunule of silicified hypercalcified "sphinctozoan" sponges has been recovered from a clast of Upper Ordovician limestone out of the Early Devonian Karheen Formation on Prince of Wales Island in southeastern Alaska. Included in the faunule are abundant examples of the new genus Girtyocoeliana, represented by Girtyocoeliana epiporata (Rigby and Potter), and Corymbospongia adnata Rigby and Potter, along with rare Corymbospongia amplia n. sp., and Girtyocoelia(?) sp., plus common Amblysiphonella sp. 1 and rare Amblysiphonella(?) sp. 2. The assemblage is similar to that from Ordovician clasts from the eastern Klamath Mountains of northern California. This indicates that the Alexander terrane of southeastern Alaska is related paleogeographically to the lithologically and paleontologically similar terrane of the eastern Klamath Mountains. This lithology and fossil assemblage of the clast cannot be tied to any currently known local rock units on Prince of Wales Island. Other clasts in the conglomerate appear to have been locally derived, so it is inferred that the limestone clasts were also locally derived, indicating the presence of a previously undocumented Ordovician limestone unit on northern Prince of Wales Island. 

  14. Bryophytes from Simeonof Island in the Shumagin Islands, southwestern Alaska

    USGS Publications Warehouse

    Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

    2004-01-01

    Simeonof Island is located south of the Alaska Peninsula in the hyperoceanic sector of the middle boreal subzone. We examined the bryoflora of Simeonof Island to determine species composition in an area where no previous collections had been reported. This field study was conducted in sites selected to represent the spectrum of environmental variation within Simeonof Island. Data were analyzed using published reports to compare bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 271 bryophytes were identified: 202 mosses and 69 liverworts. The annotated list of species for Simeonof Island expands the known range for many species and fills distribution gaps within Hulte??n's Western Pacific Coast district. Maps and notes on the distribution of 14 significant distribution records are presented. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Simeonof Island primarily includes taxa of boreal (55%), temperate (20%), arctic (10%), and cosmopolitan (8%) distribution; 6% of the moss flora are western North America endemics. A description of the bryophytes present in the vegetation and habitat types is provided as is a quantitative analysis of the most frequently occurring bryophytes in crowberry heath.

  15. Permafrost-associated natural gas hydrate occurrences on the Alaska North Slope

    USGS Publications Warehouse

    Collett, T.S.; Lee, M.W.; Agena, W.F.; Miller, J.J.; Lewis, K.A.; Zyrianova, M.V.; Boswell, R.; Inks, T.L.

    2011-01-01

    In the 1960s Russian scientists made what was then a bold assertion that gas hydrates should occur in abundance in nature. Since this early start, the scientific foundation has been built for the realization that gas hydrates are a global phenomenon, occurring in permafrost regions of the arctic and in deep water portions of most continental margins worldwide. In 1995, the U.S. Geological Survey made the first systematic assessment of the in-place natural gas hydrate resources of the United States. That study suggested that the amount of gas in the gas hydrate accumulations of northern Alaska probably exceeds the volume of known conventional gas resources on the North Slope. Researchers have long speculated that gas hydrates could eventually become a producible energy resource, yet technical and economic hurdles have historically made gas hydrate development a distant goal. This view began to change in recent years with the realization that this unconventional resource could be developed with existing conventional oil and gas production technology. One of the most significant developments was the completion of the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well on the Alaska North Slope, which along with the Mallik project in Canada, have for the first time allowed the rational assessment of gas hydrate production technology and concepts. Almost 40 years of gas hydrate research in northern Alaska has confirmed the occurrence of at least two large gas hydrate accumulations on the North Slope. We have also seen in Alaska the first ever assessment of how much gas could be technically recovered from gas hydrates. However, significant technical concerns need to be further resolved in order to assess the ultimate impact of gas hydrate energy resource development in northern Alaska. ?? 2009 Elsevier Ltd.

  16. 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

  17. Late quaternary vegetational change in the Kotzebue sound area, northwestern Alaska

    SciTech Connect

    Anderson, P.M.

    1985-01-01

    Two sediment cores from Kaiyak and Squirrel lakes in northwestern Alaska yielded pollen records that date to ca. 39,000 and 27,000 yr B.P., respectively. Between 39,000 and 14,000 yr B.P., the vegetation around these lakes was dominated by Gramineae and Cyperaceae with some Salix and possibly Betula nana/glandulosa forming a local, shrub component of the vegetation. Betula pollen percentages increased about 14,000 yr B.P., indicating the presence of a birch-dominated shrub tundra. Alnus pollen appeared at both sites between 9000 and 8000 yr B.P., and Picea pollen (mostly P. mariana) arrived at Squirrel Lake about 5000 yr B.P. The current forest-tundra mosaic around Squirrel Lake was established at this time, whereas shrub tundra existed near Kaiyak Lake throughout the Holocene. When compared to other pollen records from northwestern North America, these cores (1) represent a meadow component of lowland, Beringian tundra between 39,000 and 14,000 yr B.P., (2) demonstrate an early Holocene arrival of Alnus in northwestern Alaska that predates most other Alnus horizons in northern Alaska or northwestern Canada, and (3) show an east-to-west migration of Picea across northern Alaska from 9000 to 5000 yr B.P.

  18. 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

  19. 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.

  20. Change in abundance of pacific brant wintering in alaska: evidence of a climate warming effect?

    USGS Publications Warehouse

    Ward, D.H.; Dau, C.P.; Lee, T.; Sedinger, J.S.; Anderson, B.A.; Hines, J.E.

    2009-01-01

    Winter distribution of Pacific Flyway brant (Branta bernicla nigricans) has shifted northward from lowtemperate areas to sub-Arctic areas over the last 42 years. We assessed the winter abundance and distribution of brant in Alaska to evaluate whether climate warming may be contributing to positive trends in the most northern of the wintering populations. Mean surface air temperatures during winter at the end of the Alaska Peninsula increased about 1??C between 1963 and 2004, resulting in a 23% reduction in freezing degree days and a 34% decline in the number of days when ice cover prevents birds from accessing food resources. Trends in the wintering population fluctuated with states of the Pacific Decadal Oscillation, increasing during positive (warm) phases and decreasing during negative (cold) phases, and this correlation provides support for the hypothesis that growth in the wintering population of brant in Alaska is linked to climate warming. The size of the wintering population was negatively correlated with the number of days of strong northwesterly winds in November, which suggests that the occurrence of tailwinds favorable for migration before the onset of winter was a key factor in whether brant migrated from Alaska or remained there during winter. Winter distribution of brant on the Alaska Peninsula was highly variable and influenced by ice cover, particularly at the heavily used Izembek Lagoon. Observations of previously marked brant indicated that the Alaska wintering population was composed primarily of birds originating from Arctic breeding colonies that appear to be growing. Numbers of brant in Alaska during winter will likely increase as temperatures rise and ice cover decreases at high latitudes in response to climate warming. ?? The Arctic Institute of North America.

  1. University of Alaska Coastal Marine Institute annual report number 5, fiscal year 1998

    SciTech Connect

    Alexander, V.

    1998-12-18

    The University of Alaska Coastal Marine Institute (CMI) was created by a cooperative agreement between the University of Alaska and the Minerals Management Service (MMS) in June 1993 and the first full funding cycle began late in (federal) fiscal year 1994. CMI is pleased to present this 1998 Annual Report for studies ongoing in Oct 1997--Sep 1998. Only abstracts and study products for ongoing projects are included here. They include: An Economic Assessment of the Marine Biotechnology; Kachemak Bay Experimental and Monitoring Studies; Historical Changes in Trace Metals and Hydrocarbons in the Inner Shelf Sediments; Beaufort Sea: Prior and Subsequent to Petroleum-Related Industrial Developments; Physical-Biological Numerical Modeling on Alaskan Arctic Shelves; Defining Habitats for Juvenile Flatfishes in Southcentral Alaska; Relationship of Diet to Habitat Preferences of Juvenile Flatfishes, Phase 1; Subsistence Economies and North Slope Oil Development; Wind Field Representations and Their Effect on Shelf Circulation Models: A Case Study in the Chukchi Sea; Interaction between Marine Humic Matter and Polycyclic Aromatic Hydrocarbons in Lower Cook Inlet and Port Valdez, Alaska; Correction Factor for Ringed Seal Surveys in Northern Alaska; Feeding Ecology of Maturing Sockeye Salmon (Oncorhynchus nerka) in Nearshore Waters of the Kodiak Archipelago; and Circulation, Thermohaline Structure, and Cross-Shelf Transport in the Alaskan Beaufort Sea.

  2. Avian cholera causes marine bird mortality in the Bering Sea of Alaska

    USGS Publications Warehouse

    Bodenstein, Barbara L.; Kimberlee Beckmen; Gay Sheffield; Kathy Kuletz; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.

    2015-01-01

    The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).

  3. Geologic Map of the Arctic Quadrangle, Alaska

    USGS Publications Warehouse

    Brosge, W.P.; Reiser, H.N.; Dutro, J.T., Jr.; Detterman, R.L.; Tailleur, I.L.

    2001-01-01

    Introduction The Arctic quadrangle is well located to shed light on the basic geologic relations of northern Alaska. The rocks represent all of the stratigraphic systems from Cambrian to Cretaceous and all but one of the tectono-stratigraphic subterranes of the Brooks Range, from the autochthonous subterrane in the north to the allochthonous subterranes farther south. Among the distinctive geologic features displayed in the Arctic quadrangle are voluminous volcanic rocks of probable Devonian age, a wide array of Carboniferous carbonate facies in the Lisburne Group (which here extends up into the Middle Pennsylvanian), the southward transition of Upper Devonian (Famennian) clastic facies from fluvial conglomerate to marine sandstone, a full display of Upper Devonian (Frasnian) reef-related strata, and fossiliferous Ordovician rocks in both carbonate and chert terranes. Most of the quadrangle is in the Arctic National Wildlife Refuge (ANWR) and Arctic Wildlife Refuge Wilderness. The quadrangle also includes Arctic Village, the only village in the region and a potential destination or transfer point for visitors to the wildlife refuge.

  4. 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…

  5. A Title I Refinement: Alaska.

    ERIC Educational Resources Information Center

    Hazelton, Alexander E.; And Others

    Through joint planning with a number of school districts and the Region X Title I Technical Assistance Center, and with the help of a Title I Refinement grant, Alaska has developed a system of data storage and retrieval using microcomputers that assists small school districts in the evaluation and reporting of their Title I programs. Although this…

  6. 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…

  7. Leafhoppers and potatoes in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research conducted from 2004 to 2006 in the main potato production areas of Alaska resulted in the identification of 41 leafhopper species associated with agricultural settings. Two species, Davisonia snowi (Dorst) and Macrosteles fascifrons (Stål), made up approximately 60% of the total number of i...

  8. 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

  9. Red-throated loons (Gavia stellata) breeding in Alaska, USA, are exposed to PCBs while on their Asian wintering grounds

    USGS Publications Warehouse

    Schmutz, J.A.; Trust, K.A.; Matz, A.C.

    2009-01-01

    Red-throated loons (Gavia stellata) breeding in Alaska declined 53% during 1977-1993. We compare concentrations of environmental contaminants in red-throated loons among four nesting areas in Alaska and discuss potential ramifications of exposure on reproductive success and population trends. Eggs from the four areas had similar total polychlorinated biphenyl (PCB) concentrations, but eggs from the Arctic coastal plain had different congener profiles and greater toxic equivalents (TEQs) than eggs from elsewhere. Satellite telemetry data indicate that red-throated loons from the Arctic coastal plain in northern Alaska winter in southeast Asia, while those breeding elsewhere in Alaska winter in North America. Different wintering areas may lead to differential PCB accumulation among red-throated loon populations. For eggs from the Arctic coastal plain, TEQs were great enough to postulate PCB-associated reproductive effects in piscivores. The correlation between migration patterns and PCB profiles suggests that red-throated loons breeding in northern Alaska are exposed to PCBs while on their Asian wintering grounds.

  10. Volcano seismicity in Alaska

    NASA Astrophysics Data System (ADS)

    Buurman, Helena

    I examine the many facets of volcano seismicity in Alaska: from the short-lived eruption seismicity that is limited to only the few weeks during which a volcano is active, to the seismicity that occurs in the months following an eruption, and finally to the long-term volcano seismicity that occurs in the years in which volcanoes are dormant. I use the rich seismic dataset that was recorded during the 2009 eruption of Redoubt Volcano to examine eruptive volcano seismicity. I show that the progression of magma through the conduit system at Redoubt could be readily tracked by the seismicity. Many of my interpretations benefited greatly from the numerous other datasets collected during the eruption. Rarely was there volcanic activity that did not manifest itself in some way seismically, however, resulting in a remarkably complete chronology within the seismic record of the 2009 eruption. I also use the Redoubt seismic dataset to study post-eruptive seismicity. During the year following the eruption there were a number of unexplained bursts of shallow seismicity that did not culminate in eruptive activity despite closely mirroring seismic signals that had preceded explosions less than a year prior. I show that these episodes of shallow seismicity were in fact related to volcanic processes much deeper in the volcanic edifice by demonstrating that earthquakes that were related to magmatic activity during the eruption were also present during the renewed shallow unrest. These results show that magmatic processes can continue for many months after eruptions end, suggesting that volcanoes can stay active for much longer than previously thought. In the final chapter I characterize volcanic earthquakes on a much broader scale by analyzing a decade of continuous seismic data across 46 volcanoes in the Aleutian arc to search for regional-scale trends in volcano seismicity. I find that volcanic earthquakes below 20 km depth are much more common in the central region of the arc

  11. Far-Northern Destination for Phoenix Mars Lander

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The planned landing site for NASA's Phoenix Mars Lander lies at a latitude on Mars equivalent to northern Alaska on Earth. It is within the region designated 'D' on this global image.

    This is an orthographic projection with color-coded elevation contours and shaded relief based on data from the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor orbiter. Total vertical relief is about 28 kilometers (17 miles) from the top of the highest volcano (red) to the northern lowlands (blue). North pole is where the longitude lines converge.

  12. Benthic reconnaissance of central and northern California OCS (Outer Continental Shelf) Areas. Volume 1. Technical report. Volume 2. Technical appendices. Final report

    SciTech Connect

    Lissner, A.; Barnett, A.; Johnson, T.; Kanter, R.; Smith, R.

    1989-07-01

    A biological reconnaissance was conducted in November and December 1987 of selected hard and soft substrate habitats at depths of 50-600 meters offshore central and northern California. Stations were located in four general offshore basins, including Eel River, Point Arena, Bodega, and Santa Cruz. The purpose of the survey was to obtain quantitative data on species distribution and community structure as related to geographic range, bottom depth, substrate type, and other environmental variables. Survey methods included a Remotely Operated Vehicle (ROV) outfitted with photographic and video recording systems to study hard substrate areas; box corers were used to sample soft substrate sites. Common hard substrate taxa included anemones (e.g., Metridium senile), feather stars (Florometra serratissima), cup corals (Paracyathus stearnsii), sponges, brachiopods (Laqueus californianus), ophiuroids (Ophiothrix sp./Ophiocanthasp.), and rockfishes (Sebastes spp).

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

    MedlinePlus

    ... Health > American Indians/Alaska Natives Minority Women's Health American Indians/Alaska Natives Related information How to Talk to ... disease. Return to top Health conditions common in American Indian and Alaska Native women Accidents Alcoholism and drug ...

  14. Assessment of Gas Hydrate Resources on the North Slope, Alaska, 2008

    NASA Astrophysics Data System (ADS)

    Collett, T. S.

    2008-12-01

    At the 2008 Fall Meeting of the American Geophysical Union, the USGS will release the results of the first assessment of the undiscovered technically recoverable gas hydrate resources on the North Slope of Alaska. This assessment indicates the existence of technically recoverable gas hydrate resources -- that is, resources that can be discovered, developed, and produced by using current technology. The assessment is based on the geologic elements used to define a Total Petroleum System (TPS), including hydrocarbon source rocks (source-rock type and maturation and hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy, petrophysical properties, seismic attribute development, and prospecting), and hydrocarbon traps (trap formation and timing). The area assessed in northern Alaska extends from the National Petroleum Reserve in Alaska (NPRA) on the west through the Arctic National Wildlife Refuge (ANWR) on the east and from the Brooks Range northward to the State-Federal offshore boundary (located about 4.8 km north of the coastline). This area consists mostly of Federal, State, and Native lands covering about 114,765 square km. For the first time, the USGS has assessed gas hydrates, a traditionally unconventional resource with no confirmed production history, as a producible resource occurring in discrete hydrocarbon traps and structures. The approach used to assess the gas hydrate resources in northern Alaska followed standard geology-based USGS assessment methodologies developed to assess conventional oil and gas resources. In order to use the USGS conventional assessment approach on gas hydrate resources, it was documented through the analysis of three-dimensional industry-acquired seismic data that the gas hydrates on the North Slope occupy limited, discrete volumes of rock bounded by faults and downdip water contacts. The USGS conventional assessment approach also assumes that the hydrocarbon resource being assessed can be produced by

  15. The application of stereo-video technology for the assessment on population change of black rockfish Sebastes schlegeli in a vessel reef area in Haizhou Bay, China

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Xu, Qiang; Xu, Qinzeng; Zhang, Yingqiu; Yang, Hongsheng

    2015-01-01

    The assessment of population structure and abundance of fish assemblages associated with artificial reefs (ARs) is an important aspect of AR management. In the present study, we used a Dive-Operated Stereo Video (stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic, and three wooden, vessel reefs in Haizhou Bay during 2012 and 2013. The study used video systems to obtain length measurements and estimates of abundance. The size composition of S. schlegeli differed among reefs and individuals around vessel reefs were all adults, with total lengths (TL) of >20 cm. Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs. The largest individual S. schlegeli (with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013. TL of S. s chlegeli from all reefs increased by an average of 3.2 cm ( P<0.05) from 2012 to 2013, with an estimated mean weight increase of 250.4 g ( P<0.05). The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years. Stereo-video technology was found to be suitable for rockfish surveys around the reefs.

  16. Prevalence and spatial distribution of intraerythrocytic parasite(s) in Puget Sound rockfish (Sebastes emphaeus) from the San Juan Archipelago, Washington (USA)

    USGS Publications Warehouse

    Van Der Straaten, N.; Jacobson, A.; Halos, D.; Hershberger, P.; Kocan, A.A.; Kocan, R.

    2005-01-01

    Two morphologically distinct forms of an intraerythrocytic parasite(s) were detected by microscopic observation of Giemsa-stained blood films in 45.7% of 119 rockfish (Sebastes emphaeus) from the San Juan Archipelago (Washington State, U.S.A.). Infection prevalence for both forms was 53% in males, 44% in females, and 33% in fish of undetermined gender. A binucleate "ring-stage" was present at all 4 geographic sites, with a mean prevalence of 45.7%, while mean prevalence of a larger gamont-like form from the same sites was 5.1%. The relationship of the 2 forms to each other could not be determined. Neither schizogony nor binary fission was evident in any of the infected erythrocytes and the parasites contained no obvious pigment. The possibility of the 2 morphologic forms being 2 distinct species is supported by the observation that no difference in parasitemia was seen in the binucleate form among sites (1.6-1.9%), while parasitemia of the gamont-like form varied significantly among sites, ranging from a high of 4% to a low of 0.1%. Taxonomic status of either form could not be determined at this time based on limited existing morphologic data. ?? American Society of Parasitologists 2005.

  17. Aerosol chemical components in Alaska air masses: 1. Aged pollution

    NASA Astrophysics Data System (ADS)

    Shaw, Glenn E.

    1991-12-01

    A 4-year Alaska chemical data set of aerosols or "dust" in the air clearly reveals a mixture of distinct aerosol components with different and interesting chemical composition, one or two being ascribed to pollution imported to Alaska by winds all the way from other continents. Of particular note is a strong chemical contrast between what we imagine to be highly scavenged, orographically lifted, northern Pacific air (Pacific marine air mass) and stagnant Arctic air (polar air mass), the latter containing seasonal average concentrations of between 2-4 times the concentration of the former, at least for pollution markers noncrustal vanadium, noncrustal manganese, arsenic, selenium, bromine, and antimony. The findings concur our old discovery that Arctic air is persistently polluted (Arctic haze), but Pacific air is relatively clean, in spite of the fact that Alaska is downwind of major pollution sources in the Orient. This is remarkable. In this the first of a two-part paper, we concentrate on the pollution component found primarily during incursion of Arctic polar air. Two major occurrences of visual haze with optical depths of approximately 0.2 and elevated aerosol concentration lasting about a month (spring 1985 and 1986) were affiliated with strong incoming transport of polar air, temperatures ranging from 10° to 20°C below normal (polar air) and air trajectory hindcasts leading back to industrial pollution sources in Eurasia. These long-range transport pollution events brought metal-rich aerosol of removal-resistant submicron particles. The size, chemistry, and meteorology all strongly suggest the presence of a well-aged (10-100 day) polluted air mass. An important implication is that in spring a large fraction of the Arctic polar air mass becomes charged with by-products of industrial pollution. In this multiyear chemical data set one finds a notable summer-winter contrast, changing by factors of 2 to 4 for pollution markers As, Se, Sb, and noncrustal

  18. Mineral investigations in the Colville Mining District and Southern National Petroleum Reserve in Alaska. Open file report (Final)

    SciTech Connect

    Kurtak, J.M.; Hicks, R.W.; Werdon, M.B.; Meyer, M.P.; Mull, C.G.

    1995-12-31

    The U.S. Bureau of Mines conducted a five-year mineral resource assessment of the 16.6 million acre Colville Mining District in northern Alaska, which includes part of the National Petroleum Reserve in Alaska. During fieldwork, 1593 rock, soil, and stream sediment samples were collected and four bulk samples taken for beneficiation studies. A total of 40 mineral occurrences were documented, including 27 which were previously undescribed. Moderate potential exists for development of zinc-lead-silver, barite, and phosphate deposits.

  19. 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.

  20. Siberian Origins of Neoproterozoic to Upper Triassic Rocks of Arctic Alaska

    NASA Astrophysics Data System (ADS)

    Clough, J. G.; Blodgett, R. B.

    2007-12-01

    found in the Canadian Arctic Islands Richly diverse Upper Triassic fauna (halobiid and monotid bivalves, brachiopods) are present in the both the Shublik Formation and Otuk Group. These show closer affinities with NE Siberia rather than to western or northern North America, suggesting close spatial relationships between Siberia and Arctic Alaska at least until Late Triassic time. Sedimentary provenance studies in eastern Brooks Range Precambrian rocks indicate age ranges that are dissimilar to Proterozoic detrital-zircon ages from clastic rocks of the northern Canadian Cordillera and Canadian Arctic Islands where a detrital source within the Grenville orogen is indicated. Paleocurrent directions for the Neoproterozoic Katakturuk Dolomite in the northeast Brooks Range and similar-age units in the adjacent Victoria Island and Amundsen Basin are in approximately 100 degree opposition for a counterclockwise rotational- restored Arctic Alaska. Upper Devonian clastics of northern Alaska are in 180 degree opposition to coeval units in the Canadian Arctic Islands when the Arctic Alaska plate is restored in the rotational model. Therefore, based on paleobiogeography, sediment provenance, stratigraphy and sedimentology, tectonic models for the opening of the Canada Basin must take into account that Triassic and older rocks in Arctic Alaska have Siberian origins or were deposited proximal to Siberia.

  1. Alaska Native Participation in the Civilian Conservation Corps. Alaska Historical Commission Studies in History No. 206.

    ERIC Educational Resources Information Center

    Sorensen, Connor; And Others

    The report is a finding aid to the sources which document the 1937 federal policy decision mandating that 50% of the enrollees in the Civilian Conservation Corps (CCC) in Alaska must be Alaska Natives and provides a list of the Native CCC projects in Alaska. The finding aid section is organized according to the location of the collections and…

  2. 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…

  3. 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...

  4. 76 FR 270 - Alaska: Adequacy of Alaska Municipal Solid Waste Landfill Permit Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ...: I. Background On March 22, 2004, EPA issued a final rule (69 FR 13242) amending the Municipal Solid... AGENCY 40 CFR Parts 239 and 258 Alaska: Adequacy of Alaska Municipal Solid Waste Landfill Permit Program... modification to Alaska's approved Municipal Solid Waste Landfill (MSWLF) permit program. The...

  5. Recruiting first generation college students into the Geosciences: Alaska's EDGE project

    NASA Astrophysics Data System (ADS)

    Prakash, A.; Connor, C.

    2008-12-01

    Funded in 2005-2008, by the National Science Foundation's Geoscience Education Division, the Experiential Discoveries in Geoscience Education (EDGE) project was designed to use glacier and watershed field experiences as venues for geospatial data collected by Alaska's grade 6-12 middle and high school teachers and their students. EDGE participants were trained in GIS and learned to analyze geospatial data to answer questions about the warming Alaska environment and to determine rates of ongoing glacier recession. Important emphasis of the program was the recruitment of Alaska Native students of Inupiat, Yup'ik, Athabascan, and Tlingit populations, living in both rural and urban areas around the state. Twelve of Alaska's 55 school districts have participated in the EDGE program. To engage EDGE students in the practice of scientific inquiry, each was required to carry out a semester scale research project using georeferenced data, guided by their EDGE teacher and mentor. Across Alaska students investigated several Earth systems processes including freezing conditions of lake ice; the changes in water quality in storm drains after rainfall events; movements of moose, bears, and bison across Alaskan landscapes; changes in permafrost depth in western Alaska; and the response of migrating waterfowl to these permafrost changes. Students correlated the substrate beneath their schools with known earthquake intensities; measured cutbank and coastal erosion on northern rivers and southeastern shorelines; tracked salmon infiltration of flooded logging roads; noted the changing behavior of eagles during late winter salmon runs; located good areas for the use of tidal power for energy production; tracked the extent and range of invasive plant species with warming; and the change of forests following deglaciation. Each cohort of EDGE students and teachers finished the program by attended a 3-day EDGE symposium at which students presented their research projects first in a

  6. 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.

  7. Alaska Volcano Observatory's KML Tools

    NASA Astrophysics Data System (ADS)

    Valcic, L.; Webley, P. W.; Bailey, J. E.; Dehn, J.

    2008-12-01

    Virtual Globes are now giving the scientific community a new medium to present data, which is compatible across multiple disciplines. They also provide scientists the ability to display their data in real-time, a critical factor in hazard assessment. The Alaska Volcano Observatory remote sensing group has developed Keyhole Markup Language (KML) tools that are used to display satellite data for volcano monitoring and forecast ash cloud movement. The KML tools allow an analyst to view the satellite data in a user-friendly web based environment, without a reliance on non-transportable, proprietary software packages. Here, we show how the tools are used operationally for thermal monitoring of volcanic activity, volcanic ash cloud detection and dispersion modeling, using the Puff model. animate.images.alaska.edu/

  8. North to Alaska: Evidence for conveyor belt transport of Dungeness crab larvae along the west coast of the United States and Canada

    USGS Publications Warehouse

    Park, W.; Douglas, D.C.; Shirley, T.C.

    2007-01-01

    We propose and evaluate the hypothesis that Dungeness crab (Cancer magister) larvae from the northwestern coast of the United States and Canada can be transported northward to southeastern Alaska. Larvae collected in southeastern Alaska during May and June 1997–2004 had abundances and stages that varied seasonally, interannually, and spatially. An unexpected presence of late-stage larvae in spring raises a question regarding their origin, and the most plausible explanation is that they hatched off the northern Washington and British Columbia coasts and were transported to southeastern Alaska. Buoy drift tracks support the hypothesis that larvae released off the northern Washington and British Columbia coasts during the peak hatching season can be physically transported to southeastern Alaska, arriving as late-stage larvae in May and June, when local larvae are only beginning to hatch. A northward spring progression of monthly mean 7°C SST isotherms and phytoplankton blooms provide further evidence that environmental conditions are conducive for larval growth and metabolism during the transport period. The proposed larval transport suggests possible unidirectional gene flow between southern and northern populations of Dungeness crabs in southeastern Alaska.

  9. 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

  10. Bering Strait, Alaska, United States

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Summer run off from the Yukon River, the source of which is hidden by clouds on image right, is filling the Norton Sound (image center) with brownish sediment. The Bering Sea (image left) appears to be supporting a large phytoplankton population, as blue-green swirls are evident from north to south in this true-color MODIS image of Alaska. Credit: Jacques Descloitres, MODIS Land Rapid Response Team

  11. Evaluation of long-term gas hydrate production testing locations on the Alaska north slope

    USGS Publications Warehouse

    Collett, T.S.; Boswell, R.; Lee, M.W.; Anderson, B.J.; Rose, K.; Lewis, K.A.

    2011-01-01

    The results of short duration formation tests in northern Alaska and Canada have further documented the energy resource potential of gas hydrates and justified the need for long-term gas hydrate production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally-occurring gas hydrate to depressurization-induced or thermal-, chemical-, and/or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gas hydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with U.S. Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas hydrate production test site. The test site assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas hydrate testing. The site selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas hydrate production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area, and provides new information on the nature of gas hydrate occurrence and potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well log analysis, geological correlation and mapping, and numerical simulation

  12. Evaluation of long-term gas hydrate production testing locations on the Alaska North Slope

    USGS Publications Warehouse

    Collett, Timothy; Boswell, Ray; Lee, Myung W.; Anderson, Brian J.; Rose, Kelly K.; Lewis, Kristen A.

    2011-01-01

    The results of short duration formation tests in northern Alaska and Canada have further documented the energy resource potential of gas hydrates and justified the need for long-term gas hydrate production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally-occurring gas hydrate to depressurization-induced or thermal-, chemical-, and/or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gas hydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with U.S. Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas hydrate production test site. The test site assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas hydrate testing. The site selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas hydrate production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area, and provides new information on the nature of gas hydrate occurrence and potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well log analysis, geological correlation and mapping, and numerical simulation.

  13. Evaluation of long-term gas hydrate production testing locations on the Alaska North Slope

    USGS Publications Warehouse

    Collett, Timothy S.; Boswell, Ray; Lee, Myung W.; Anderson, Brian J.; Rose, Kelly K.; Lewis, Kristen A.

    2012-01-01

    The results of short-duration formation tests in northern Alaska and Canada have further documented the energy-resource potential of gas hydrates and have justified the need for long-term gas-hydrate-production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally occurring gas hydrate to depressurization-induced or thermal-, chemical-, or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gashydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas-hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with the US Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk River, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas-hydrate-production test sites. The test-site-assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas-hydrate testing. The site-selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas-hydrate-production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area and provides new information on the nature of gas-hydrate occurrence and the potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well-log analysis, geological correlation and mapping, and numerical

  14. Southern Alaska Coastal Relief Model

    NASA Astrophysics Data System (ADS)

    Lim, E.; Eakins, B.; Wigley, R.

    2009-12-01

    The National Geophysical Data Center (NGDC), an office of the National Oceanic and Atmospheric Administration (NOAA), in conjunction with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado at Boulder, has developed a 24 arc-second integrated bathymetric-topographic digital elevation model of Southern Alaska. This Coastal Relief Model (CRM) was generated from diverse digital datasets that were obtained from NGDC, the United States Geological Survey, and other U.S. and international agencies. The CRM spans 170° to 230° E and 48.5° to 66.5° N, including the Gulf of Alaska, Bering Sea, Aleutian Islands, and Alaska’s largest communities: Anchorage, Fairbanks, and Juneau. The CRM provides a framework for enabling scientists to refine tsunami propagation and ocean circulation modeling through increased resolution of geomorphologic features. It may also be useful for benthic habitat research, weather forecasting, and environmental stewardship. Shaded-relief image of the Southern Alaska Coastal Relief Model.

  15. 77 FR 46338 - Fisheries of the Economic Exclusive Zone Off Alaska; Deep-Water Species Fishery by Vessels Using...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... groundfish of the GOA (77 FR 15194, March 14, 2012), for the period 1200 hrs, A.l.t., July 1, 2012, through..., rockfish, deep-water flatfish, rex sole, and arrowtooth flounder. This closure does not apply to fishing...

  16. 78 FR 30242 - Fisheries of the Economic Exclusive Zone Off Alaska; Deep-Water Species Fishery by Vessels Using...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... the GOA (78 FR 13162, February 26, 2013), for the period 1200 hours, A.l.t., April 1, 2013, through..., rockfish, deep-water flatfish, rex sole, and arrowtooth flounder. This closure does not apply to fishing...

  17. 75 FR 42337 - Fisheries of the Exclusive Economic Zone Off Alaska; “Other rockfish” in the Western Regulatory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... (mt) as established by the final 2010 and 2011 harvest specifications for groundfish of the GOA (75 FR... fisheries data in a timely fashion and would delay prohibiting the retention of ``other rockfish'' in...

  18. Polycyclic aromatic hydrocarbon sources related to biomarker levels in fish from Prince William Sound and the Gulf of Alaska.

    PubMed

    Page, David S; Huggett, Robert J; Stegeman, John J; Parker, Keith R; Woodin, Bruce; Brown, John S; Bence, A Edward

    2004-10-01

    Seafloor sediments in Prince William Sound (PWS) and the eastern Gulf of Alaska (GOA) have a substantial regional hydrocarbon background from natural sources including oil seeps and eroding sedimentary rocks along the eastern GOA coast. Polycyclic aromatic hydrocarbons (PAH) from that background appear to be bioavailable to fish. Fish collected from PWS and the GOA in a 1999--2000 biomarker study (bile fluorescent aromatic contaminants and liver ethoxyresorufin O-deethylase) show evidence of exposure to low levels of PAH at all categories of sites sampled. Seafloor sediments at fish sampling sites in the GOA east of PWS and at three PWS site categories (nonspill path, spill path oiled, and spill path not oiled) contain hydrocarbons from four principal sources: regional background, combustion products, residues from the 1989 Exxon Valdez oil spill (EVOS), and Monterey (CA) petroleum residues. GOA sediments between PWS and Yakutat Bay, approximately 350 km to the east, are dominated by regional petrogenic background hydrocarbons (total PAH (TPAH) range approximately 60-3400 ng/g) that are the probable cause of low biomarker levels measured in halibut from this area. PWS sediments contain varying proportions of regional background, combustion products, Monterey residues, and EVOS residues at some spill path sites. Rockfish caught in PWS embayments in 1999 have liver EROD activities that correlate positively with the pyrogenic PAH indicator ratio (FI+Py)/C24Ph. Although traces (<5-100 ng/g TPAH) of EVOS residues were detected in seafloor sediments at some nearshore spill path sites, biomarker levels in fish from those sites are not elevated relative to other sites in PWS. PMID:15506182

  19. Single nucleotide polymorphism (SNP) variation of wolves (Canis lupus) in Southeast Alaska and comparison with wolves, dogs, and coyotes in North America.

    PubMed

    Cronin, Matthew A; Cánovas, Angela; Bannasch, Danika L; Oberbauer, Anita M; Medrano, Juan F

    2015-01-01

    There is considerable interest in the genetics of wolves (Canis lupus) because of their close relationship to domestic dogs (C. familiaris) and the need for informed conservation and management. This includes wolf populations in Southeast Alaska for which we determined genotypes of 305 wolves at 173662 single nucleotide polymorphism (SNP) loci. After removal of invariant and linked SNP, 123801 SNP were used to quantify genetic differentiation of wolves in Southeast Alaska and wolves, coyotes (C. latrans), and dogs from other areas in North America. There is differentiation of SNP allele frequencies between the species (wolves, coyotes, and dogs), although differentiation is relatively low between some wolf and coyote populations. There are varying levels of differentiation among populations of wolves, including low differentiation of wolves in interior Alaska, British Columbia, and the northern US Rocky Mountains. There is considerable differentiation of SNP allele frequencies of wolves in Southeast Alaska from wolves in other areas. However, wolves in Southeast Alaska are not a genetically homogeneous group and there are comparable levels of genetic differentiation among areas within Southeast Alaska and between Southeast Alaska and other geographic areas. SNP variation and other genetic data are discussed regarding taxonomy and management. PMID:25429025

  20. Fracture character and distribution in the Nenana basin, Alaska

    NASA Astrophysics Data System (ADS)

    Rizzo, A. J.; Hanks, C. L.

    2012-12-01

    The NE-SW trending Tertiary aged Nenana basin is located in the southeastern portion of central Alaska, north of Alaska Range. Forming adjacent to the Alaska Range, the tectonic setting resembles a foreland or strike-slip basin. This seismically active basin is estimated to be ~20,000 ft deep and is filled with non-marine sediments and coal-bearing sequences. Fracture character and distribution studies have been used to determine reservoir properties of the basin. By analyzing characteristics such as aperture, height, length and orientation, the origin of the fractures can be better understood. The seal integrity and extent of fracturing throughout the basin can aid in the understanding of the basin's history and its capability to be used for CO2 sequestration. The tectonic setting of central Alaska consists of two master right-lateral strike-slip faults that are proposed to create a shear zone with subsidiary left-lateral strike-slip faults. The southeastern margin of the basin is characterized by one of the subsidiary left-lateral faults proposed due to the master faults acting as major slip surfaces; the Minto fault, a predominately normal fault with a left-lateral strike-slip component. Available seismic data throughout the basin shows a strong extensional component with some possible flower structures. The orientation of the basin and its location in respect to both the Tintina-Kaltag and Denali right-lateral fault systems suggest that the basin is extending in the NE-SW direction. A fracture model has been proposed suggesting fractures related to the extensional component of the basin, but also tied to the fold and thrust belt located in the northern foothills of the Alaska Range. Data was obtained from a variety of locations in central Alaska in relation to the location of the basin. Fracture data was collected along the southeastern and southern portions of the basin in predominately metamorphic basement rocks and sedimentary sequences along the margin