Publications - STATEMAP Project | Alaska Division of Geological &
., 2008, Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska , Engineering - geologic map, Alaska Highway corridor, Delta Junction to Dot Lake, Alaska: Alaska Division of geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska Division of Geological
River conservation and terrestrial mammals: key ecological processes
Thomas A. Hanley
2008-01-01
Key ecological processes affecting interactions between rivers and terrestrial mammals are identified and explained, using flood plains of Alaska as examples of relatively pristine systems. Both coastal (southeast Alaska) and interior Alaska examples are used. Coastal Alaskan rivers tend to be relatively short, flashy, rain-driven systems, whereas interior Alaska...
Publications - MP 126 | Alaska Division of Geological & Geophysical Surveys
DGGS MP 126 Publication Details Title: 400 MHz ground-penetrating radar, Itkillik River, North Slope , Itkillik River, North Slope, Alaska: Alaska Division of Geological & Geophysical Surveys Miscellaneous , North Slope, Alaska, scale 1:100 (8.6 M) Keywords Fluvial; Ground-Penetrating Radar; Itkillik River
33 CFR 162.245 - Kenai River, Kenai, Alaska; use, administration, and navigation.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Kenai River, Kenai, Alaska; use... § 162.245 Kenai River, Kenai, Alaska; use, administration, and navigation. (a) The area. The main channel area of the river, having a width of 150 feet, beginning at a point directly offshore from the...
Monitoring winter flow conditions on the Ivishak River, Alaska : final report.
DOT National Transportation Integrated Search
2017-09-01
The Sagavanirktok River, a braided river on the Alaska North Slope, flows adjacent to the trans-Alaska pipeline for approximately 100 miles south of Prudhoe Bay. During an unprecedented flooding event in mid-May 2015, the pipeline was exposed in an a...
Publications - GMC 257 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ARCO Alaska Inc. Colville River #1 well Authors: Unknown Publication Date: 1995 Publisher: Alaska reflectance data from cuttings (1,470-7,300') of the ARCO Alaska Inc. Colville River #1 well: Alaska Division
Publications - RI 2011-3B | Alaska Division of Geological & Geophysical
structural cross sections for the Kavik River map area, Alaska Authors: Wallace, W.K., Wartes, M.A., Decker Kavik River map area, Alaska: Alaska Division of Geological & Geophysical Surveys Report of area, Alaska (144.0 M) Sheet 2 Interpretations of seismic reflection data and structural cross sections
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.
Publications - GMC 93 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a Alaska Inc. ARCO/Ciri Funny River #1 well Authors: Makada, R. Publication Date: 1988 Publisher: Alaska , Vitrinite reflectance data of ditch cuttings from the ARCO Alaska Inc. ARCO/Ciri Funny River #1 well: Alaska
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-27
... ENVIRONMENTAL PROTECTION AGENCY [EPA-R10-OAR-2010-1914; FRL-9664-7] Adequacy Status of the Eagle River, Alaska Particulate Matter Limited Maintenance Plan for Transportation Conformity Purposes AGENCY... notifying the public of its finding that the Eagle River, Alaska, Particulate Matter (PM 10 ) Limited...
Publications - PIR 2009-7 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS PIR 2009-7 Publication Details Title: Geologic map of the Kanayut River area, Chandler Lake ., and Burns, P.C., 2009, Geologic map of the Kanayut River area, Chandler Lake Quadrangle, Alaska
Flood-prone area maps of three sites along the Trans-Alaska Pipeline, Alaska
Lamke, Robert D.; Jones, Stanley H.
1980-01-01
Flood-prone areas in Alaska are delineated on aerial photographs for the Sagavanirktok River near Pump Station 3, Middle Fork Koyukuk River at Coldfoot, and Jim River near Pump Station 5. An analysis of available flood data and a description of recent flood evidence and maximum evident flood marks are included. (Kosco-USGS)
The Climatology and Impacts of Atmospheric Rivers near the Coast of Southern Alaska
NASA Astrophysics Data System (ADS)
Nardi, K.; Barnes, E. A.; Mundhenk, B. D.
2015-12-01
Atmospheric rivers, narrow plumes of anomalously high tropospheric water vapor transport, frequently appear over the Pacific Ocean. Popularized by colloquialisms such as the "Pineapple Express," atmospheric rivers often interact with synoptic-scale disturbances to produce significant precipitation events over land masses. Previous research has focused extensively on the impacts of this phenomenon with respect to high-precipitation storms, namely during boreal winter, on the western coast of the contiguous United States. These events generate great scientific, political, and economic concerns for nearby cities, farms, and tourist destinations. Recently, researchers have investigated similar high-precipitation events along the southern coast of Alaska. Specifically, previous work has discussed several major events occurring during the September-November timeframe. One particular event, in October 2006, produced an all-time record for water levels at several river observation sites. This study examines the climatology of atmospheric rivers in the vicinity of southern Alaska. Data (1979-2014) from the Modern-Era Retrospective Analysis for Research and Applications (MERRA) is used to detect atmospheric rivers approaching, and making landfall on, the southern Alaskan coast from the Kenai Peninsula to the Gulf of Alaska region. A seasonal cycle in the strength and frequency of atmospheric rivers over Alaska is shown. Furthermore, the study assesses the synoptic conditions coincident with atmospheric rivers and examines several instances of particularly strong precipitation events. For example, wintertime atmospheric river events tend to occur when a blocking high exists over southeastern Alaska. These results have the potential to help forecasters and emergency managers predict high-precipitation events and lessen potential negative impacts.
Publications - RI 2011-3A | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS RI 2011-3A Publication Details Title: Geologic map of the Kavik River area, northeastern ., Delaney, P.R., LePain, D.L., and Carson, E.C., 2011, Geologic map of the Kavik River area, northeastern
Geochemical evidence for the origin of late Quaternary loess in central Alaska
Muhs, D.R.; Budahn, J.R.
2006-01-01
Loess is extensive in central Alaska, but there are uncertainties about its source and the direction of paleo-winds that deposited it. Both northerly and southerly winds have been inferred. The most likely sources of loess are the Tanana River (south), the Nenana River (southeast), and the Yukon River (north). Late Quaternary loess in central Alaska has immobile trace-element compositions (Cr/Sc, Th/Ta, Th/ Sc, Th/U, Eu/Eu*, GdN/YbN) that indicate derivation mostly from the Tanana River. However, other ratios (As/Sb, Zr/Hf, LaN/YbN) and quantitative modeling indicate that the Yukon River was also a source. During the last glacial period, there may have been a longer residence time of the Siberian and Canadian high-pressure cells, along with a strengthened Aleutian low-pressure cell. This would have generated regional-scale northeasterly winds and explains derivation of loess from the Yukon River. However, superim-posed upon this synoptic-scale circulation, there may have been strong, southerly katabatic winds from expanded glaciers on the northern flank of the Alaska Range. These winds could have provided eolian silt from the Tanana River. Yukon River and Tanana River sediments are highly calcareous, whereas Fairbanks-area loess is not. This suggests that carbonate leaching in loess kept ahead of sedimentation and that late Quaternary loess in central Alaska was deposited relatively slowly. ?? 2006 NRC Canada.
Guide to Geologic Hazards in Alaska | Alaska Division of Geological &
content Guide to Geologic Hazards in Alaska Glossary Coastal and river hazards image Coastal and river Storm surge Tsunami Earthquake related hazards image Earthquake related hazards Earthquake Earthquake Subsidence Surface fault rupture Tsunami Uplift Glacier hazards image Glacier hazards Avalanche Debris flow
Publications - GMC 132 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a . Kustatan River #1 well Authors: Edison, T.A. Publication Date: 1989 Publisher: Alaska Division of data of cuttings from the Shell Oil Co. Kustatan River #1 well: Alaska Division of Geological &
Timber harvest in interior Alaska.
Tricia L. Wurtz; Robert A. Ott; John C. Maisch
2006-01-01
The most active period of timber harvesting in the history of Alaska's interior occurred nearly a century ago (Roessler 1997). The beginning of this era was the year 1869, when steam-powered, stern-wheeled riverboats first operated on the Yukon River (Robe 1943). Gold was discovered in Alaska in the 40-Mile River area in 1886, a find that was overshadowed 10 years...
Publications - GMC 193 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical materials: Alaska State F #1, washed cuttings (13,980' - 13,990'); West Mikkelsen State #1, Canning River
Reconnaissance for radioactive deposits in Alaska, 1953
Matzko, John J.; Bates, Robert G.
1955-01-01
During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska where carnotite-type minerals had been reported; in the headwaters of the Peace River in the eastern part of the Seward Peninsula and at Gold Bench on the South Fork of the Koyukuk River in east-central Alaska, where uranothorianite occurs in places associated with base metal sulfides and hematite; in the vicinity of Port Malmesbury in southeastern Alaska to check a reported occurrence of pitchblende; and, in the Miller House-Circle Hot Springs area of east-central Alaska where geochemical studies were made. No significant lode deposits of radioactive materials were found. However, the placer uranothorianite in the headwaters of the Peace River yet remains as an important lead to bedrock radioactive source materials in Alaska. Tundra cover prevents satisfactory radiometric reconnaissance of the area, and methods of geochemical prospecting such as soil and vegetation sampling may ultimately prove more fruitful in the search for the uranothorianite-sulfide lode source than geophysical methods.
Publications - GMC 4 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 4 Publication Details Title: Organic carbon and pyrolysis data for the AMOCO Cathedral River , Organic carbon and pyrolysis data for the AMOCO Cathedral River Unit #1: Alaska Division of Geological
Birds of the major mainland rivers of southeast Alaska.
James A. Johnson; Brad A. Andres; John A. Bissonette
2008-01-01
This publication describes the bird communities of major mainland rivers of southeast Alaska and is based on a review of all known relevant studies as well as recent fieldwork. We synthesized information on the composition, structure, and habitat relationships of bird communities at 11 major mainland rivers. Information on current management concerns and research needs...
Publications - MP 133 v. 2 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Maps; Alaska, State of; Aleutian Arc; Aleutian Islands; Coastal and River; Coastal and River Hazards
Brabets, Timothy P.
2001-01-01
Flow data were collected from two adjacent rivers in Yukon?Charley Rivers National Preserve, Alaska?the Nation River (during 1991?2000) and the Kandik River (1994?2000)?and from the Yukon River (1950?2000) at Eagle, Alaska, upstream from the boundary of the preserve. These flow records indicate that most of the runoff from these rivers occurs from May through September and that the average monthly discharge during this period ranges from 1,172 to 2,210 cubic feet per second for the Nation River, from 1,203 to 2,633 cubic feet per second for the Kandik River, and from 112,000 to 224,000 cubic feet per second for the Yukon River. Water-quality data were collected for the Nation River and several of its tributaries from 1991 to 1992 and for the Yukon River at Eagle from 1950 to 1994. Three tributaries to the Nation River (Waterfall Creek, Cathedral Creek, and Hard Luck Creek) have relatively high concentrations of calcium, magnesium, and sulfate. These three watersheds are underlain predominantly by Paleozoic and Precambrian rocks. The Yukon River transports 33,000,000 tons of suspended sediment past Eagle each year. Reflecting the inputs from its major tributaries, the water of the Yukon River at Eagle is dominated by calcium?magnesium bicarbonate.
Zimmerman, Christian E.; Ramey, Andy M.; Turner, S.; Mueter, Franz J.; Murphy, S.; Nielsen, Jennifer L.
2013-01-01
Arctic cisco Coregonus autumnalis have a complex anadromous life history, many aspects of which remain poorly understood. Some life history traits of Arctic cisco from the Colville River, Alaska, and Mackenzie River basin, Canada, were investigated using molecular genetics, harvest data, and otolith microchemistry. The Mackenzie hypothesis, which suggests that Arctic cisco found in Alaskan waters originate from the Mackenzie River system, was tested using 11 microsatellite loci and a single mitochondrial DNA gene. No genetic differentiation was found among sample collections from the Colville River and the Mackenzie River system using molecular markers (P > 0.19 in all comparisons). Model-based clustering methods also supported genetic admixture between sample collections from the Colville River and Mackenzie River basin. A reanalysis of recruitment patterns to Alaska, which included data from recent warm periods and suspected changes in atmospheric circulation patterns, still finds that recruitment is correlated to wind conditions. Otolith microchemistry (Sr/Ca ratios) confirmed repeated, annual movements of Arctic cisco between low-salinity habitats in winter and marine waters in summer.
Phytosociology and succession on earthquake-uplifted coastal wetlands, Copper River Delta, Alaska.
T.F. Thilenius
1995-01-01
The delta formed by the Copper River stretches more than 75 kilometers along the south-central coastline of Alaska. It is the terminus of the outwash deposits from a large part of the most heavily glaciated region of North American, and all major rivers that flow into the delta carry extremely high levels of suspended sediments. Coastal wetlands extend inland for as...
Jonathan A. O' Donnell; George R. Aiken; Evan S. Kane; Jeremy B. Jones
2010-01-01
Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate DOC chemical composition....
Publications - PIR 2008-1A | Alaska Division of Geological & Geophysical
of recent geologic field investigations in the Brooks Range Foothills and North Slope, Alaska: Alaska Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska ; Tectonics; Thermal History; Thrust; Toolik River; Torok Formation; Turbidites; Turonian; Valanginian Top of
Publications - Quadrangle Search | Alaska Division of Geological &
Publication Sales. Access bibliography for: Quadrangle name will appear as your mouse scrolls across Alaska Long Mountains Misheguk Mountain Howard Pass Killik River Chandler Lake Philip Smith Mountains Arctic Table Mountain Noatak Baird Mountains Ambler River Survey Pass Wiseman Chandalar Christian Coleen
Dornblaser, Mark M.; Striegl, Robert G.
2009-01-01
Loads and yields of suspended sediment and carbonate were measured and modeled at three locations on the Yukon, Tanana, and Porcupine Rivers in Alaska during water years 2001–2005 (1 October 2000 to 30 September 2005). Annual export of suspended sediment and carbonate upstream from the Yukon Delta averaged 68 Mt a−1 and 387 Gg a−1, respectively, with 50% of the suspended sediment load originating in the Tanana River Basin and 88% of the carbonate load originating in the White River Basin. About half the annual suspended sediment export occurred during spring, and half occurred during summer‐autumn, with very little export in winter. On average, a minimum of 11 Mt a−1 of suspended sediment is deposited in floodplains between Eagle, Alaska, and Pilot Station, Alaska, on an annual basis, mostly in the Yukon Flats. There is about a 27% loss in the carbonate load between Eagle and Yukon River near Stevens Village, with an additional loss of about 29% between Stevens Village and Pilot Station, owing to a combination of deposition and dissolution. Comparison of current and historical suspended sediment loads for Tanana River suggests a possible link between suspended sediment yield and the Pacific decadal oscillation.
NASA Astrophysics Data System (ADS)
Dornblaser, Mark M.; Striegl, Robert G.
2009-06-01
Loads and yields of suspended sediment and carbonate were measured and modeled at three locations on the Yukon, Tanana, and Porcupine Rivers in Alaska during water years 2001-2005 (1 October 2000 to 30 September 2005). Annual export of suspended sediment and carbonate upstream from the Yukon Delta averaged 68 Mt a-1 and 387 Gg a-1, respectively, with 50% of the suspended sediment load originating in the Tanana River Basin and 88% of the carbonate load originating in the White River Basin. About half the annual suspended sediment export occurred during spring, and half occurred during summer-autumn, with very little export in winter. On average, a minimum of 11 Mt a-1 of suspended sediment is deposited in floodplains between Eagle, Alaska, and Pilot Station, Alaska, on an annual basis, mostly in the Yukon Flats. There is about a 27% loss in the carbonate load between Eagle and Yukon River near Stevens Village, with an additional loss of about 29% between Stevens Village and Pilot Station, owing to a combination of deposition and dissolution. Comparison of current and historical suspended sediment loads for Tanana River suggests a possible link between suspended sediment yield and the Pacific decadal oscillation.
Alaska Melilotus invasions: Distribution, origin, and susceptibility of plant communities
Conn, J.S.; Beattie, K.L.; Shephard, M.A.; Carlson, M.L.; Lapina, I.; Hebert, M.; Gronquist, R.; Densmore, R.; Rasy, M.
2008-01-01
Melilotus alba and M. officinalis were introduced to Alaska in 1913 as potential forage crops. These species have become naturalized and are now invading large, exotic plant-free regions of Alaska. We determined distributions of M. alba and M. officinalis in Alaska from surveys conducted each summer from 2002 to 2005. Melilotus alba and M. officinalis occurred at 721 and 205 sites, respectively (39,756 total sites surveyed). The northward limit for M. alba and M. officinalis was 67.15??N and 64.87??N, respectively. Both species were strictly associated with soil disturbance. Melilotus alba extended no farther than 15 m from road edges except where M. alba on roadsides met river floodplains and dispersed downriver (Matanuska and Nenana Rivers). Melilotus has now reached the Tanana River, a tributary of the Yukon River. Populations on floodplains were most extensive on braided sections. On the Nenana River, soil characteristics did not differ between where M. alba was growing versus similar areas where it had not yet reached. The pH of river soils (7.9-8.3) was higher than highway soils (7.3). Upland taiga plant communities grow on acid soils which may protect them from invasion by Melilotus, which prefer alkaline soils; however, early succession communities on river floodplains are susceptible because soils are alkaline. ?? 2008 Regents of the University of Colorado.
Publications - DDS 10 | Alaska Division of Geological & Geophysical Surveys
Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Alaska Products Interactive Interactive Map Alaska Tsunami Inundation Maps Keywords Coastal and River; Geologic
International board-foot volume tables for trees in the Susitna River Basin, Alaska.
Frederic R. Larson
1990-01-01
International 1/4-inch board-foot volume equations and tables were derived from fall, buck, and scale data for 374 trees at 78 locations in the Susitna River Basin, Alaska. Tree species included white and black spruce, paper birch, black cottonwood, and quaking aspen.
DOT National Transportation Integrated Search
2012-12-01
The Chulitna River Bridge, built in 1970, is located at Historic Mile Post 132.7 on the Alaska Parks Highway between Fairbanks and Anchorage, Alaska. The Parks : Highway is the most direct route connecting Anchorage, Fairbanks, and Prudhoe Bay. Heavy...
Dorava, J.M.; Milner, A.M.
1999-01-01
Numerous drainages supporting productive salmon habitat are surrounded by active volcanoes on the west side of Cook Inlet in south-central Alaska. Eruptions have caused massive quantities of flowing water and sediment to enter the river channels emanating from glaciers and snowfields on these volcanoes. Extensive damage to riparian and aquatic habitat has commonly resulted, and benthic macroinvertebrate and salmonid communities can be affected. Because of the economic importance of Alaska's fisheries, detrimental effects on salmonid habitat can have significant economic implications. The Drift River drains glaciers on the northern and eastern flanks of Redoubt Volcano: During and following eruptions in 1989-1990, severe physical disturbances to the habitat features of the river adversely affected the fishery. Frequent eruptions at other Cook Inlet region volcanoes exemplify the potential effects of volcanic activity on Alaska's important commercial, sport, and subsistence fisheries. Few studies have documented the recovery of aquatic habitat following volcanic eruptions. The eruptions of Redoubt Volcano in 1989-1990 offered an opportunity to examine the recovery of the macroinvertebrate community. Macroinvertebrate community composition and structure in the Drift River were similar in both undisturbed and recently disturbed sites. Additionally, macroinvertebrate samples from sites in nearby undisturbed streams were highly similar to those from some Drift River sites. This similarity and the agreement between the Drift River macroinvertebrate community composition and that predicted by a qualitative model of typical macroinvertebrate communities in glacier-fed rivers indicate that the Drift River macroinvertebrate community is recovering five years after the disturbances associated with the most recent eruptions of Redoubt Volcano.
Presentations - Delaney, P.R. and others, 2008 | Alaska Division of
, northeastern Alaska (poster): AAPG Abstracts with Programs, San Antonio, Texas Authors: Delaney, P.R., Loveland thrust belt, Kavik River area, northeastern Alaska (poster): AAPG Abstracts with Programs, San Antonio
Natural Science of Alaska Handbook. Revised. Anchorage School District Elementary Science Program.
ERIC Educational Resources Information Center
Oliver, Valerie Smith; Sumner, Jim
This handbook is a collection of printed materials that are available to students about the geology, weather, plants, animals and people of Alaska. Topics included are: (1) "Alaska History Line"; (2) "Geography of Alaska" (including maps, rivers, and islands); (3) "Geologic Time"; (4) "Geology" (including…
Publications - GMC 9 | Alaska Division of Geological & Geophysical Surveys
; Texaco West Kavik #1; Canning River B-1; ARCO Kavik #1; Forest Kemik #1; BP Kemik #2; Canning River A-1 ; Toolik Federal #1 Authors: Curiale, J.A. Publication Date: 1982 Publisher: Alaska Division of Geological eight North Slope wells: Mobil West Staines #2; Texaco West Kavik #1; Canning River B-1; ARCO Kavik #1
Publications - PDF 94-40 | Alaska Division of Geological & Geophysical
content DGGS PDF 94-40 Publication Details Title: Geology of the Gagaryah River area, Lime Hills C-5 and C ., Clautice, K.H., and Harris, E.E., 1994, Geology of the Gagaryah River area, Lime Hills C-5 and C-6 Sheet 1 Geologic map of the Gagaryah River Area, Lime Hills C-5 and C-6 quadrangles, Southwestern Alaska
Publications - PIR 2008-1 | Alaska Division of Geological & Geophysical
investigations in the Brooks Range Foothills and North Slope, Alaska: Alaska Division of Geological & interpretations of the Nanushuk Formation exposed along the Colville River near the confluences with the Awuna and Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska
Publications - PIR 2003-1 | Alaska Division of Geological & Geophysical
, Alluvial facies and paleosols in the Cretaceous Nanushuk formation, Kanayut River, North Slope, Alaska Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS PIR 2003-1 Publication Details Title: Alluvial facies and paleosols in the Cretaceous
Publications - GMC 170 | Alaska Division of Geological & Geophysical
core (7902'-7918') from the Atlantic Richfield Co. Itkillik River Unit #1 well Authors: Pawlewicz, Mark Reference Pawlewicz, Mark, 1990, Vitrinite reflectance data of cuttings (5200'-15310') and of core (7902 '-7918') from the Atlantic Richfield Co. Itkillik River Unit #1 well: Alaska Division of Geological &
Blaine T. Spellman; Tricia L. Wurtz
2011-01-01
Sweetclover (Melilotus alba) is a nonnative legume that has formed dense and extensive patches along several rivers in Alaska. Our research objective was to determine if sweetclover impacts recruitment of native seedlings in floodplain habitats. To determine if sweetclover impacted recruitment, we conducted a removal experiment along two rivers in...
Publications - GMC 411 | Alaska Division of Geological & Geophysical
outcrop samples from the 2001 DGGS Salcha River-Pogo project, Big Delta Quadrangle, Alaska Authors . Quadrangle(s): Big Delta Bibliographic Reference Newberry, R.J., 2012, Whole-rock and trace element analyses of two amphibolite outcrop samples from the 2001 DGGS Salcha River-Pogo project, Big Delta Quadrangle
Land ownership patterns in the Tanana River basin, Alaska, 1984.
Willem W.S. Van Hees
1985-01-01
Aerial photo sampling coupled with information taken on the ground provided data for development of estimates of land and forest area by ownership group within the boundaries of the 1971-75 Tanana River Basin timber inventory unit, Alaska. Area of privately owned timberland is estimated at 280,634 acres (113 569 hectares).
Tables and equations for estimating volumes of trees in the Susitna River Basin, Alaska.
Frederic R. Larson; Kenneth C. Winterberger
1988-01-01
Scribner board-foot, merchantable cubic-foot, and total cubic-foot volume equations were derived from fall, buck, and scale data for 441 trees at 78 locations in the Susitna River basin, Alaska. Tree species included white and black spruce, paper birch, black cottonwood, and quaking aspen.
Forest statistics for the upper Koyukuk River, Alaska, 1971.
Karl M. Hegg
1974-01-01
Area and volume statistics from the first intensive forest inventory of the upper Koyukuk River drainage, in north-central Alaska, are given. Observations are made on forest location, description, defect, regeneration, growth, and mortality. Commercial forests, although generally restricted to a narrow band along drainages, were found as far as 70 miles (113 kilometers...
Management needs assessment for the Copper River Delta, Alaska.
L.E. Kruger; C.B. Tyler
1995-01-01
This report assesses needs, problems, and perceptions relevant to management for the Copper River Delta (Alaska)the largest coastal wetland on the Pacific coast of North America. The assessment provides a basis for planning and decisionmaking and a framework for ongoing research, development, and application. It also underscores concerns about human impacts...
78 FR 900 - Approval and Promulgation of Air Quality Implementation Plans; Alaska: Eagle River PM10
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-07
...-7] Approval and Promulgation of Air Quality Implementation Plans; Alaska: Eagle River PM 10... National Ambient Air Quality Standards (NAAQS) for particulate matter with an aerodynamic diameter less... under section 110 and part D of the CAA? D. Has the State demonstrated that the air quality improvement...
Publications - GMC 241 | Alaska Division of Geological & Geophysical
ARCO Alaska Inc. Kuparuk River Unit 36-10-7 #1 (Bermuda #1) well Authors: Unknown Publication Date Reference Unknown, 1995, Vitrinite reflectance data from cuttings (700-6,760') of the ARCO Alaska Inc
NASA Astrophysics Data System (ADS)
Dorava, Joseph M.; Milner, Alexander M.
2000-10-01
Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation.Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat.
Ager, T.A.; Matthews, J.V.; Yeend, W.
1994-01-01
Gravels deposited by the ancestral Yukon River are preserved in terrace remnants on the margins of the Yukon River valley near the village of Circle in east-central Alaska. Plant fossils recovered from sandy silt lenses within these gravels include cones and needles of Picea and Larix and a variety of seeds. Seed types include several taxa which no longer grow in Alaska, such as Epipremnum, Prunus and Weigela. Pollen types recovered from these deposits represent tree and shrub taxa that grow in interior Alaska today, such as Picea, Larix, Betula and Alnus, as well as several taxa that no longer grow in interior Alaska today, such as Pinus, Tsuga, Abies and Corylus. Pollen of herb taxa identified include Gramineae, Cyperaceae, Caryophyllaceae, Compositae, Polemonium and Epilobium. The fossil flora from the gravels near Circle are similar and probably age-equivalent to the flora recovered from the Nenana Gravel in the Alaska Range 250 km to the south. Palynological and tectonic evidence summarized in this paper now suggests that the Nenana Gravel was deposited during the early and middle Pliocene. The presence of plant fossils of Tsuga, Abies, Pinus, Weigela and Prunus suggests that the mean annual temperature (MAT) of eastern interior Alaska during the early and middle Pliocene was perhaps 7-9??C warmer and less continental than today's MAT of -6.4??C. ?? 1994.
DORAVA; MILNER
1999-02-01
/ Numerous drainages supporting productive salmon habitat are surrounded by active volcanoes on the west side of Cook Inlet in south-central Alaska. Eruptions have caused massive quantities of flowing water and sediment to enter the river channels emanating from glaciers and snowfields on these volcanoes. Extensive damage to riparian and aquatic habitat has commonly resulted, and benthic macroinvertebrate and salmonid communities can be affected. Because of the economic importance of Alaska's fisheries, detrimental effects on salmonid habitat can have significant economic implications. The Drift River drains glaciers on the northern and eastern flanks of Redoubt Volcano. During and following eruptions in 1989-1990, severe physical disturbances to the habitat features of the river adversely affected the fishery. Frequent eruptions at other Cook Inlet region volcanoes exemplify the potential effects of volcanic activity on Alaska's important commercial, sport, and subsistence fisheries. Few studies have documented the recovery of aquatic habitat following volcanic eruptions. The eruptions of Redoubt Volcano in 1989-1990 offered an opportunity to examine the recovery of the macroinvertebrate community. Macroinvertebrate community composition and structure in the Drift River were similar in both undisturbed and recently disturbed sites. Additionally, macroinvertebrate samples from sites in nearby undisturbed streams were highly similar to those from some Drift River sites. This similarity and the agreement between the Drift River macroinvertebrate community composition and that predicted by a qualitative model of typical macroinvertebrate communities in glacier-fed rivers indicate that the Drift River macroinvertebrate community is recovering five years after the disturbances associated with the most recent eruptions of Redoubt Volcano. KEY WORDS: Aquatic habitat; Volcanoes; Lahars; Lahar-runout flows; Macroinvertebrates; Community structure; Community composition; Taxonomic similarity
D.A. Saiget; M.R. Sloat; Reeves. G.H.
2007-01-01
We studied the movement patterns of migratory coastal cutthroat trout Oncorhynchus clarkii clarkii in the western Copper River delta, Alaska, near the northern extent of the subspecies' distribution. Life history information for coastal cutthroat trout is scarce within this region. Movement of coastal cutthroat trout was monitored from 1994 to...
Nesting biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska
Craig R. Ely; John M. Pearce; Roger W. Ruess
2008-01-01
Lesser Canada Geese (Brania canadensis parvipes) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in...
Water Quality in the Tanana River Basin, Alaska, Water Years 2004-06
Moran, Edward H.
2007-01-01
OVERVIEW This report contains water-quality data collected from 84 sites in Tanana River basin during water years 2004 through 2006 (October 2003 through September 2006) as part of a cooperative study between the U.S. Geological Survey (USGS) and Alaska Department of Environmental Conservation (ADEC) Alaska Monitoring and Assessment Program (AKMAP), supported in part through the U.S. Environmental Protection Agency (USEPA) Office of Water, Cooperative Assistance Agreement X7-97078801. A broad range of chemical analyses are presented for 93 sets of samples collected at 59 tributaries to the Tanana River and at 25 locations along the mainstem. These data are to provide a means to assess baseline characteristics and establish indicators that are ecologically important, affordable, and relevant to society.
Publications - GMC 351 | Alaska Division of Geological & Geophysical
DGGS GMC 351 Publication Details Title: Geochemical analysis of Alaska North Slope NPR-A oil samples at Reservoir, and North Slope Borough US Navy South Barrow #12 - Sag River Reservoir Authors: Organic analysis of Alaska North Slope NPR-A oil samples at the Alaska GMC from: Umiat (generic) Nanushuk Reservoir
Publications - RI 2004-1C | Alaska Division of Geological & Geophysical
, Big Delta Quadrangle, Alaska Authors: Reger, R.D., Burns, P.C., and Staft, L.A. Publication Date: Dec Delta Bibliographic Reference Reger, R.D., Burns, P.C., and Staft, L.A., 2008, Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska Division of Geological &
Hupp, C.R.
2000-01-01
Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation. Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat. Copyright ?? 2000 John Wiley & Sons, Ltd.Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation. Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat.
Timber resource statistics for the Copper River inventory unit, Alaska, 1968.
Karl M. Hegg
1975-01-01
This first intensive forest inventory of Alaska's Copper River Valley found a commercial forest area of 287,800 acres with 303.8 million cubic feet of growing stock. Additionally, a noncommercial stratum was examined that had substantial standing volume but did not meet the growth criteria for commercial forest land. This stratum contained 152,800 acres with a...
Publications - GMC 300 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a Alaska Inc. Kavik Unit #3 (5325'-5440') well, and Exxon Corporation Canning River Unit Block A-1 well '-5440') well, and Exxon Corporation Canning River Unit Block A-1 well (4875'-4876' and 4882'-4883
A survey of sport fish use on the Copper River Delta, Alaska.
Dirk W. Lang
2010-01-01
Aerial counts, in-person interviews, and mail-in questionnaires were used to survey sport fish use during the coho salmon (Oncorhynchus kisutch Walbaum) season on the Copper River Delta, Alaska from 2002 through 2006. Angler counts provided an index of use on individual streams and were used to develop a spatial database exhibiting patterns of use...
Conaway, Jeffrey S.; Moran, Edward H.
2004-01-01
Bathymetric and hydraulic data were collected by the U.S. Geological Survey on the Tanana River in proximity to Alaska Department of Transportation and Public Facilities' bridge number 505 at mile 80.5 of the Alaska Highway. Data were collected from August 7-9, 2002, over an approximate 5,000- foot reach of the river. These data were combined with topographic data provided by Alaska Department of Transportation and Public Facilities to generate a two-dimensional hydrodynamic model. The hydrodynamic model was calibrated with water-surface elevations, flow velocities, and flow directions collected at a discharge of 25,600 cubic feet per second. The calibrated model was then used for a simulation of the 100-year recurrence interval discharge of 51,900 cubic feet per second. The existing bridge piers were removed from the model geometry in a second simulation to model the hydraulic conditions in the channel without the piers' influence. The water-surface elevations, flow velocities, and flow directions from these simulations can be used to evaluate the influence of the piers on flow hydraulics and will assist the Alaska Department of Transportation and Public Facilities in the design of a replacement bridge.
Distribution and character of naleds in northeastern Alaska
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.
Geohydrology of the Delta-Clearwater area, Alaska
Wilcox, Dorothy E.
1980-01-01
The alluvial aquifer in the Delta-Clearwater area, Alaska, is composed of lenticular, interbedded deposits of silt, sand, and gravel. Ground water occurs under both confined and unconfined conditions in the area. The potentiometric surface slopes approximately northward at gradients ranging from about 1 to 25 feet per mile. The aquifer is recharge by seepage through the streambeds of rivers and creeks and by infiltration of precipitation. Water is discharged from the aquifer into the Clearwater Creek network and Clearwater Lake, which are almost entirely spring-fed, at the mouth of the Delta River, and into the Tanana River along the northern boundary of the study area. Year-round ground-water discharge from the aquifer is estimated to exceed 1,200 cubic feet per second. The following ground-water flow system is hypothesized: Channel losses from the Gerstle River, several small creeks draining the Alaska Range, and the Tanana River to the east of Clearwater Creek recharge the sections of the aquifer discharging at the Clearwater Creek network. Channel losses from the Delta River and Jarvis Creek are the main source of recharge to the sections of the aquifer discharging in the vicinity of Clearwater Lake and Big Delta. Additional work is needed to verify these hypotheses. (USGS)
Matthew J. Macander; Tricia L. Wurtz
2007-01-01
Alaska has relatively few invasive plants, and most of them are found only along the state's limited road system. Melilotus alba, or sweetclover, is one of the most widely distributed invasives in the state. Melilotus has recently moved from roadsides to the flood plains of at least three glacial rivers. We developed a network...
Publications - GMC 384 | Alaska Division of Geological & Geophysical
Bay St #13-09-19, W Mikkelsen St #1, and Sag River St #1, Lisburne to total depth Authors: Boyer, D , Thin section photomicrographs and descriptions for Mikkelsen Bay St #13-09-19, W Mikkelsen St #1, and Sag River St #1, Lisburne to total depth: Alaska Division of Geological & Geophysical Surveys
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…
Publications - PIR 2007-1 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS PIR 2007-1 Publication Details Title: Geologic map of the Siksikpuk River area, Chandler Lake ., Harris, E.E., Finzel, E.S., Reifenstuhl, R.R., and Loveland, A.M., 2007, Geologic map of the Siksikpuk
Publications - PDF 95-33A | Alaska Division of Geological & Geophysical
the B-1 quadrangles, east-central Alaska Authors: Clough, J.G., Reifenstuhl, R.R., Mull, C.G., Pinney -1, C-1, and part of the B-1 quadrangles, east-central Alaska: Alaska Division of Geological & :63,360 (10.0 M) Sheet 2 Geologic map of the Charley River C-1 and part of the B-1 Quadrangle, east
Wang, Bronwen; Gough, L.P.; Wanty, R.B.; Lee, G.K.; Vohden, James; O'Neill, J. M.; Kerin, L.J.
2008-01-01
We report chemical analyses of stream-water, stream-sediment, soil, soil-water, bedrock, and vegetation samples collected from the headwaters of the Delta River (Tangle Lakes District, Mount Hayes 1:250,000-scale quadrangle) in east-central Alaska for the period June 20-25, 2006. Additionally, we present mineralogic analyses of stream sediment, concentrated by panning. The study area includes the southwestward extent of the Bureau of Land Management (BLM) Delta River Mining District (Bittenbender and others, 2007), including parts of the Delta River Archeological District, and encompasses an area of about 500 km2(approximately bordered by the Denali Highway to the south, near Round Tangle Lake, northward to the foothills of the Alaska Range (fig. 1). The primary focus of this study was the chemical characterization of native materials, especially surface-water and sediment samples, of first-order streams from the headwaters of the Delta River. The impetus for this work was the need, expressed by the Alaska Department of Natural Resources (ADNR), for an inventory of geochemical and hydrogeochemical baseline information about the Delta River Mining District. This information is needed because of a major upturn in exploration, drilling, and general mineral-resources assessments in the region since the late 1990s. Currently, the study area, called the 'MAN Project' area is being explored by Pure Nickel, Inc. (http://www.purenickel.com/s/MAN_Alaska.asp), and includes both Cu-Au-Ag and Ni-Cu-PGE (Pt-Pd-Au-Ag) mining claims. Geochemical data on surface-water, stream-sediment, soil, soil-water, grayleaf willow (Salix glauca L.), and limited bedrock samples are provided along with the analytical methodologies used and panned-concentrate mineralogy. We are releasing the data at this time with only minimal interpretation.
Campbell, Matthew A; Takebayashi, Naoki; López, J Andrés
2015-07-19
Pleistocene climatic instability had profound and diverse effects on the distribution and abundance of Arctic organisms revealed by variation in phylogeographic patterns documented in extant Arctic populations. To better understand the effects of geography and paleoclimate on Beringian freshwater fishes, we examined genetic variability in the genus Dallia (blackfish: Esociformes: Esocidae). The genus Dallia groups between one and three nominal species of small, cold- and hypoxia-tolerant freshwater fishes restricted entirely in distribution to Beringia from the Yukon River basin near Fairbanks, Alaska westward including the Kuskokwim River basin and low-lying areas of Western Alaska to the Amguema River on the north side of the Chukotka Peninsula and Mechigmen Bay on the south side of the Chukotka Peninsula. The genus has a non-continuous distribution divided by the Bering Strait and the Brooks Range. We examined the distribution of genetic variation across this range to determine the number and location of potential sub-refugia within the greater Beringian refugium as well as the roles of the Bering land bridge, Brooks Range, and large rivers within Beringia in shaping the current distribution of populations of Dallia. Our analyses were based on DNA sequence data from two nuclear gene introns (S7 and RAG1) and two mitochondrial genome fragments from nineteen sampling locations. These data were examined under genetic clustering and coalescent frameworks to identify sub-refugia within the greater Beringia refugium and to infer the demographic history of different populations of Dallia. We identified up to five distinct genetic clusters of Dallia. Four of these genetic clusters are present in Alaska: (1) Arctic Coastal Plain genetic cluster found north of the Brooks Range, (2) interior Alaska genetic cluster placed in upstream locations in the Kuskokwim and Yukon river basins, (3) a genetic cluster found on the Seward Peninsula, and (4) a coastal Alaska genetic cluster encompassing downstream Kuskokwim River and Yukon River basin sample locations and samples from Southwest Alaska not in either of these drainages. The Chukotka samples are assigned to their own genetic cluster (5) similar to the coastal Alaska genetic cluster. The clustering and ordination analyses implemented in Discriminant Analysis of Principal Components (DAPC) and STRUCTURE showed mostly concordant groupings and a high degree of differentiation among groups. The groups of sampling locations identified as genetic clusters correspond to geographic areas divided by likely biogeographic barriers including the Brooks Range and the Bering Strait. Estimates of sequence diversity (θ) are highest in the Yukon River and Kuskokwim River drainages near the Bering Sea. We also infer asymmetric migration rates between genetic clusters. The isolation of Dallia on the Arctic Coastal Plain of Alaska is associated with very low estimated migration rates between the coastal Alaska genetic cluster and the Arctic Coastal Plain genetic cluster. Our results support a scenario with multiple aquatic sub-refugia in Beringia during the Pleistocene and the preservation of that structure in extant populations of Dallia. An inferred historical presence of Dallia across the Bering land bridge explains the similarities in the genetic composition of Dallia in West Beringia and western coastal Alaska. In contrast, historic and contemporary isolation across the Brooks Range shaped the distinctiveness of present day Arctic Coastal Plain Dallia. Overall this study uncovered a high degree of genetic structuring among populations of Dallia supporting the idea of multiple Beringian sub-refugia during the Pleistocene and which appears to be maintained to the present due to the strictly freshwater nature and low dispersal ability of this genus.
Lem G. Butler; Knut Kielland; T. Scott Rupp; Thomas A. Hanley
2007-01-01
We examined the interactive effects of mammalian herbivory and fluvial dynamics on vegetation dynamics and composition along the Tanana River in interior Alaska between Fairbanks and Manley Hot Springs. We used a spatially explicit model of landscape dynamics (ALFRESCO) to simulate vegetation changes on a 1-year time-step. The model was run for 250 years and was...
Benjamin M. Jones; Crystal A. Kolden; Randi Jandt; John T. Abatzoglu; Frank Urban; Christopher D. Arp
2009-01-01
In 2007, the Anaktuvuk River Fire (ARF) became the largest recorded tundra fire on the North Slope of Alaska. The ARF burned for nearly three months, consuming more than 100,000 ha. At its peak in early September, the ARF burned at a rate of 7000 ha d-1. The conditions potentially responsible for this large tundra fire include modeled record high...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-01
...The Bureau of Land Management (BLM) announces the availability of the Decision Record (DR) for the Delta River Special Recreation Management Area and East Alaska Resource Management Plan Amendment (Approved Plan). The BLM-Alaska State Director, Bud C. Cribley, signed the DR on March 29, 2013. The DR constitutes the final decision of the Department on the plan and is effective immediately.
Climate Drivers of Alaska Summer Stream Temperature
NASA Astrophysics Data System (ADS)
Bieniek, P.; Bhatt, U. S.; Plumb, E. W.; Thoman, R.; Trammell, E. J.
2016-12-01
The temperature of the water in lakes, rivers and streams has wide ranging impacts from local water quality and fish habitats to global climate change. Salmon fisheries in Alaska, a critical source of food in many subsistence communities, are sensitive to large-scale climate variability and river and stream temperatures have also been linked with salmon production in Alaska. Given current and projected climate change, understanding the mechanisms that link the large-scale climate and river and stream temperatures is essential to better understand the changes that may occur with aquatic life in Alaska's waterways on which subsistence users depend. An analysis of Alaska stream temperatures in the context of reanalysis, downscaled, station and other climate data is undertaken in this study to fill that need. Preliminary analysis identified eight stream observation sites with sufficiently long (>15 years) data available for climate-scale analysis in Alaska with one station, Terror Creek in Kodiak, having a 30-year record. Cross-correlation of summer (June-August) water temperatures between the stations are generally high even though they are spread over a large geographic region. Correlation analysis of the Terror Creek summer observations with seasonal sea surface temperatures (SSTs) in the North Pacific broadly resembles the SST anomaly fields typically associated with the Pacific Decadal Oscillation (PDO). A similar result was found for the remaining stations and in both cases PDO-like correlation patterns also occurred in the preceding spring. These preliminary results demonstrate that there is potential to diagnose the mechanisms that link the large-scale climate system and Alaska stream temperatures.
Beck, R.A.; Rettig, A.J.; Ivenso, C.; Eisner, Wendy R.; Hinkel, Kenneth M.; Jones, Benjamin M.; Arp, C.D.; Grosse, G.; Whiteman, D.
2010-01-01
Ice formation and breakup on Arctic rivers strongly influence river flow, sedimentation, river ecology, winter travel, and subsistence fishing and hunting by Alaskan Natives. We use time-series ground imagery ofthe Meade River to examine the process at high temporal and spatial resolution. Freezeup from complete liquid cover to complete ice cover ofthe Meade River at Atqasuk, Alaska in the fall of 2008 occurred in less than three days between 28 September and 2 October 2008. Breakup in 2009 occurred in less than two hours between 23:47 UTC on 23 May 2009 and 01:27 UTC on 24 May 2009. All times in UTC. Breakup in 2009 and 2010 was ofthe thermal style in contrast to the mechanical style observed in 1966 and is consistent with a warming Arctic. ?? 2010 Taylor & Francis.
Publications - PDF 95-33D | Alaska Division of Geological & Geophysical
D-1, C-1, and part of the B-1 quadrangles, east-central Alaska Authors: Pinney, D.S., Clough, J.G ., Reifenstuhl, R.R., and Liss, S.A., 1995, Derivative geologic materials map of the Charley River D-1, C-1, and part of the B-1 quadrangles, east-central Alaska: Alaska Division of Geological & Geophysical
Publications - GMC 44 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a DGGS GMC 44 Publication Details Title: Carbon isotope analysis of carbonates from Ahtna #1 well, Copper of carbonates from Ahtna #1 well, Copper River Valley, Alaska: Alaska Division of Geological &
Water Quality and Streamflow of the Indian River, Sitka, Alaska, 2001-02
Neal, Edward J.; Brabets, Timothy P.; Frenzel, Steven A.
2004-01-01
The Indian River Basin, located near Sitka Alaska, drains an area of 12.3 square miles. This watershed is an important natural resource of Sitka National Historic Park. At the present time, the watershed faces possible development on large tracts of private land upstream of the park that could affect the water quality of Indian River. Due to this concern, a study was conducted cooperatively with the National Park Service. The approach was to examine the water quality of the Indian River in the upper part of the watershed where no development has occurred and in the lower part of the basin where development has taken place. Measurements of pH, water temperature, and dissolved oxygen concentrations of the Indian River were within acceptable ranges for fish survival. The Indian River is calcium bicarbonate type water with a low buffering capacity. Concentrations of dissolved ions and nutrients generally were low and exhibited little variation between the two study sites. Analysis of bed sediment trace element concentrations at both sampling sites indicates the threshold effect concentration was exceeded for arsenic, chromium, copper, nickel, and zinc; while the probable effect concentration was exceeded by arsenic, chromium and nickel. However, due to relatively large amounts of organic carbon present in the bed sediments, the potential toxicity from trace elements is low. Discharge in the Indian River is typical of coastal southeast Alaska streams where low flows generally are in late winter and early spring and greater flows are during the wetter fall months. Alaska Department of Fish and Game has established instream flow reservations on the lower 2.5 miles of the Indian River. Discharge data indicate minimum flow requirements were not achieved during 236 days of the study period. Natural low flows are frequently below the flow reservations, but diversions resulted in flow reservations not being met a total of 140 days. Thirty-five algae species were identified from the sample collected at Indian River near Sitka while 24 species were identified from the sample collected at Indian River at Sitka. Most species of algae identified in the Indian River samples were diatoms and the majority were pinnate diatoms; however, green algae and (or) blue-green algae accounted for much of the algal biomass at the two sites. The trophic condition of the Indian River is oligotrophic, and algal productivity likely is limited by low concentrations of dissolved nitrogen. Few invertebrate taxa were collected relative to many high-quality streams in the contiguous United States, but the number of taxa in Indian River appears to be typical of Alaska streams. Ephemeroptera was the most abundant order sampled followed by Diptera.
Publications - GMC 256 | Alaska Division of Geological & Geophysical
in the Paint River drainage of southwest Alaska Authors: Unknown Publication Date: 1995 Publisher or please see our publication sales page for more information. Bibliographic Reference Unknown, 1995
Publications - PDF 95-33C | Alaska Division of Geological & Geophysical
content DGGS PDF 95-33C Publication Details Title: Surficial geologic map of the Charley River D-1, C-1 , and part of the B-1 quadrangles, east-central Alaska Authors: Pinney, D.S., Clough, J.G., and Liss ., 1995, Surficial geologic map of the Charley River D-1, C-1, and part of the B-1 quadrangles, east
Dirk W. Lang; Gordon H. Reeves; James D. Hall; Mark S. Wipfli
2006-01-01
This study examined the influence of fall-spawning coho salmon (Oncorhynchrcs kisutch) on the density, growth rate, body condition, and survival to outmigration of juvenile coho salmon on the Copper River Delta, Alaska, USA. During the fall of 1999 and 2000, fish rearing in beaver ponds that received spawning salmon were compared with fish from...
Characteristics of sediment discharge in the subarctic Yukon River, Alaska
Chikita, K.A.; Kemnitz, R.; Kumai, R.
2002-01-01
The characteristics of sediment discharge in the Yukon River, Alaska were investigated by monitoring water discharge, water turbidity and water temperature. The river-transported sediment, 90 wt.% or more, consists of silt and clay (grain size ??? 62.5 ??m), which probably originated in the glacier-covered mountains mostly in the Alaska Range. For early June to late August 1999, we continuously measured water turbidity and temperature near the estuary and in the middle of Yukon River by using self-recording turbidimeters and temperature data loggers. The water turbidity (ppm) was converted to suspended sediment concentration (SSC; mg/l) of river water, using a relation between simultaneous turbidity and SSC at each of the two sites, and then, the suspended sediment discharge, approximately equal to water discharge times SSC, was numerically obtained every 1 or 2 h. It should be noted that the sediment discharge in the Yukon River is controlled by SSC rather than water discharge. As a result, a peak sediment discharge occurred in mid or late August by local sediment runoffs due to glacier-melt (or glacier-melt plus rainfall), while a peak water discharge was produced by snowmelt in late June or early July. Application of the "extended Shields diagram" indicates that almost all the river-transported sediments are under complete suspension. ?? 2002 Elsevier Science B.V. All rights reserved.
Yesterday Still Lives...Our Native People Remember Alaska.
ERIC Educational Resources Information Center
DeMarco, Pat, Ed.; And Others
In the summer of 1978, seven teenagers and several staff members from the Fairbanks Native Association-Johnson O'Malley program set out to record some of Alaska's past by interviewing a number of older Alaska Natives and writing their biographical sketches. Some of the students spent a week along the Yukon River taping and photographing people;…
First Steps to the Last Frontier: Programming Suggestions for Alaskan Adventures.
ERIC Educational Resources Information Center
Miner, Todd
This article provides an overview of trip programming in Alaska for those seeking a low-cost wilderness adventure. Alaska is a land of glaciers, mountains, lakes, rivers, forests, and wildlife. Safety is a major concern when traveling in Alaska. A local guide or outdoor educator can assist with safety and logistical planning. Travelers should plan…
Publications - GMC 39 | Alaska Division of Geological & Geophysical Surveys
the Pan Am David River #1-A Authors: Unknown Publication Date: 1982 Publisher: Alaska Division of Geological & Geophysical Surveys Comments: Publication date is estimated. Total Price: $3.00 Ordering
Characterization of stormwater runoff in Sioux Falls, South Dakota, 1995-96
Niehus, C.A.
1997-01-01
The Kenai River in southcentral Alaska is an economically important salmon river generating as much as $78 million annually in direct benefits. Resource-management agencies are concerned that increased sedimentation and loss of streamside cover associated with accelerated erosion rates caused by boat activity may threaten salmon returns to the river. Bank loss and boat activity were characterized during 1996 along 67 miles of the Kenai River, including a segment of the river several miles long where boat activity is restricted to non-motorized uses. Bank loss in the non-motorized segment of the river was about 75 percent less than that observed in the highest boat-use area of the river and 33 per cent less than that observed in the lowest boat-use area of the river. Dates of peak boat activity coincided closely with chinook salmon returns to the Kenai River and with peaks in measured bank erosion. The boat activity period began in late May, peaked on weekend days in mid-July, and declined in early August. Observed boat traffic on the Kenai River included boats from 10 to 26 feet in length that transported 1 to 8 passengers. The most commonly observed boats were between 16 and 20 feet long and carried 4 or 5 passengers. The number of boats operated by commercial fishing guides represented 40 percent of the boats counted by the Alaska Department of Natural Resources, 55 percent of the boats counted by the Alaska Department of Fish and Game, and 57 percent of those recorded by observers during this study. The maximum boat activity and the maximum bank loss were measured at the RW's Campground study site about 16 river miles upstream from the mouth of the Kenai River. Between July 12 and September 10, 1996, more than 20,100 boats traveled by this site and the streambank along the inside of the meander bend was undercut to a depth of 45 inches at one measuring point. Boat activity and bank loss were greatest in areas of the river between about river miles 9 and 18 and river miles 39 and 46. These two segments of the river are popular residential and fishing areas and have banks composed of non-cohesive soils. In addition, a meandering, un-armored channel makes the banks along these two segments susceptible to erosion. The Kenai River in southcentral Alaska is an economically important salmon river generating as much as $78 million annually in direct benefits. Resource-management agencies are concerned that increased sedimentation and loss of streamside cover associated with accelerated erosion rates caused by boat activity may threaten salmon returns to the river. Bank loss and boat activity were characterized during 1996 along 67 miles of the Kenai River, including a segment of the river several miles long where boat activity is restricted to non-motorized uses. Bank loss in the non-motorized segment of the river was about 75 percent less than that observed in the highest boat-use area of the river and 33 percent less than that observed in the lowest boat-use area of the river. Dates of peak boat activity coincided closely with chinook salmon returns to the Kenai River and with peaks in measured bank erosion. The boat activity period began in late May, peaked on weekend days in mid-July, and declined in early August. Observed boat traffic on the Kenai River included boats from 10 to 26 feet in length that transported 1 to 8 passengers. The most commonly observed boats were between 16 and 20 feet long and carried 4 or 5 passengers. The number of boats operated by commercial fishing guides represented 40 percent of the boats counted by the Alaska Department of Natural Resources, 55 percent of the boats counted by the Alaska Department of Fish and Game, and 57 percent of those recorded by observers during this study. The maximum boat activity and the maximum bank loss were measured at the RW's Campground study site about 16 river miles upstream from the mouth of the Kenai River. Between July 12 and September 10, 1996, more than 20,10
Impacts of Colville River dynamics on river navigability near Nuiqsut, Alaska: 1955-present
NASA Astrophysics Data System (ADS)
Whitley, M. A.; Panda, S. K.; Prakash, A.; Brinkman, T. J.
2016-12-01
Climate-driven changes in river systems are challenging access to ecosystem services such as access to traditional hunting grounds and other subsistence food sources on the North Slope of Alaska. This work studies the dynamics of the Colville River and assesses the impacts on traditional harvest practices and subsistence travel of the Native community of Nuiqsut. Recent reports from Nuiqsut residents indicate accelerated changes in the environment, limiting river travel and their ability to harvest subsistence food. This study explores how channel migration, gravel bars, and bank erosion have evolved since the 1950s, and their impact on water depth and navigability. In an area of ice-rich permafrost, warmer summer temperatures exacerbate lateral bank erosion, resulting in river siltation. The study focuses on selected key areas south of Nuiqsut that have shown significant change in river geomorphology. Since 1955, some areas proximate to ice wedge exposures show channel migration in excess of 1 km. Panchromatic aerial photography acquired by US Geological Surveys in the mid 1950s, color infrared aerial photography from 1979 and 1982 acquired by the Alaska High Altitude Photography (AHAP) mission, and high resolution satellite images from Digital Globe, Inc. were used in this study. We mapped water, vegetation, and gravel/non-vegetated classes to identify risk areas for river navigability. River bathymetry was also mapped using a multispectral ratio-based water depth retrieval algorithm to identify problem sites for boat travel. Remote sensing products and analyses were validated with field data for mapping risk areas along the river. This study has the potential to be implemented on a larger scale for predictive mapping to aid river navigation. Findings from this study will provide insight whether recent changes are anomalies, or if they are part of a directional trend that will require local adaptation.
NASA Astrophysics Data System (ADS)
Valentin, M. M.; Hay, L.; Van Beusekom, A. E.; Viger, R. J.; Hogue, T. S.
2016-12-01
Forecasting the hydrologic response to climate change in Alaska's glaciated watersheds remains daunting for hydrologists due to sparse field data and few modeling tools, which frustrates efforts to manage and protect critical aquatic habitat. Approximately 20% of the 64,000 square kilometer Copper River watershed is glaciated, and its glacier-fed tributaries support renowned salmon fisheries that are economically, culturally, and nutritionally invaluable to the local communities. This study adapts a simple, yet powerful, conceptual hydrologic model to simulate changes in the timing and volume of streamflow in the Copper River, Alaska as glaciers change under plausible future climate scenarios. The USGS monthly water balance model (MWBM), a hydrologic tool used for two decades to evaluate a broad range of hydrologic questions in the contiguous U.S., was enhanced to include glacier melt simulations and remotely sensed data. In this presentation we summarize the technical details behind our MWBM adaptation and demonstrate its use in the Copper River Basin to evaluate glacier and streamflow responses to climate change.
Nagorski, Sonia A.; Neal, Edward G.; Brabets, Timothy P.
2013-01-01
Glacier Bay National Park and Preserve (GBNPP), Alaska, like many pristine high latitude areas, is exposed to atmospherically deposited contaminants such as mercury (Hg). Although the harmful effects of Hg are well established, information on this contaminant in southeast Alaska is scarce. Here, we assess the level of this contaminant in several aquatic components (water, sediments, and biological tissue) in three adjacent, small streams in GBNPP that drain contrasting landscapes but receive similar atmospheric inputs: Rink Creek, Salmon River, and Good River. Twenty water samples were collected from 2009 to 2011 and processed and analyzed for total mercury and methylmercury (filtered and particulate), and dissolved organic carbon quantity and quality. Ancillary stream water parameters (discharge, pH, dissolved oxygen, specific conductance, and temperature) were measured at the time of sampling. Major cations, anions, and nutrients were measured four times. In addition, total mercury was analyzed in streambed sediment in 2010 and in juvenile coho salmon and several taxa of benthic macroinvertebrates in the early summer of 2010 and 2011.
Hydraulic survey and scour assessment of Bridge 524, Tanana River at Big Delta, Alaska
Heinrichs, Thomas A.; Langley, Dustin E.; Burrows, Robert L.; Conaway, Jeffrey S.
2007-01-01
Bathymetric and hydraulic data were collected August 26–28, 1996, on the Tanana River at Big Delta, Alaska, at the Richardson Highway bridge and Trans-Alaska Pipeline crossing. Erosion along the right (north) bank of the river between the bridge and the pipeline crossing prompted the data collection. A water-surface profile hydraulic model for the 100- and 500-year recurrence-interval floods was developed using surveyed information. The Delta River enters the Tanana immediately downstream of the highway bridge, causing backwater that extends upstream of the bridge. Four scenarios were considered to simulate the influence of the backwater on flow through the bridge. Contraction and pier scour were computed from model results. Computed values of pier scour were large, but the scour during a flood may actually be less because of mitigating factors. No bank erosion was observed at the time of the survey, a low-flow period. Erosion is likely to occur during intermediate or high flows, but the actual erosion processes are unknown at this time.
Influence of the Yukon River on the Bering Sea
NASA Technical Reports Server (NTRS)
Dean, K.; Mcroy, C. P.
1986-01-01
The purpose is to use satellite data to study relationships between discharge of the Yukon River to currents and biologic productivity in the northern Bering Sea. Amended specific objectives are: to develop thermal, sediment and chlorophyll surface maps using thematic mapping (TM) data of the discharge of the Yukon River and the Alaska Coastal Current during the ice free season; to develop a historical model of the distribution of the Yukon River discharge and the Alaska Coastal Current using LANDSAT multispectral scanner (MMS) and NOAA satellite imagery; and to use high resolution TM data to define the surface dynamics of the front between the Alaska Coastal Current and the Bering Shelf/Anadyr Current. LANDSAT MSS and TM, and Advanced Very High Resolution Radiometer (AVHRR) data were recorded during the 1985 ice-free period. The satellite data coincided with shipboard measurements acquired by Inner Self Transfer and Recycling scientists. Circumstances were such, that on July 5 and July 22, all three sensors recorded data that has been registered to a common map projection and map base, then contrast stretched, color composited, and density sliced.
Burrows, Robert L.
1980-01-01
In an effort to relate river processes to vertical and lateral erosion at two sites on the Tanana River in the vicinity of Fairbanks, Alaska, measurements of depth, velocity, and bedload-transport rates were made at several sections at each site. To facilitate comparison of the river processes and ongoing erosion, compilation and graphic presentation of the velocity distributions and bedload-transport rates are presented in conjunction with cross-section configuration immediately adjacent to the area of erosion. Dry sieve analyses of the bedload samples give particle-size distribution. Approximately 85 to 95% of the material in transport at both sites was in the sand range (>0.062 millimeter <2.0 millimeter). (USGS)
Muhs, Daniel; Budahn, James R.; Skipp, Gary L.; McGeehin, John
2016-01-01
Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to the east, which rules out the Susitna River as a source. Knik and Matanuska River silts can be distinguished using Sc–Th–La, LaN/YbN vs. Eu/Eu∗, Cr/Sc, and As/Sb. Matanuska Valley loess falls clearly within the range of values for these ratios found in Matanuska River silt. Dust storms from the Matanuska River are most common in autumn, when river discharge is at a minimum and silt-rich point bars are exposed, wind speed from the north is beginning to increase after a low-velocity period in summer, snow depth is still minimal, and soil temperatures are still above freezing. Thus, seasonal changes in climate and hydrology emerge as critical factors in the timing of aeolian silt transport in southern Alaska. These findings could be applicable to understanding seasonal controls on Pleistocene loess accretion in Europe, New Zealand, South America, and elsewhere in North America.
Publications - PDF 95-33E | Alaska Division of Geological & Geophysical
content DGGS PDF 95-33E Publication Details Title: Geologic hazards map of the Charley River D-1, C-1, and part of the B-1 quadrangles, east-central Alaska Authors: Pinney, D.S., Clough, J.G., Reifenstuhl, R.R ., Reifenstuhl, R.R., and Liss, S.A., 1995, Geologic hazards map of the Charley River D-1, C-1, and part of the B
Presentations - Smith, J.R. and others, 2013 | Alaska Division of
Engineering Geology Alaska Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to (1.4 M) Keywords Coastal; Coastal and River; Engineering Geology Posters and Presentations; Seward
Publications - GMC 135 | Alaska Division of Geological & Geophysical
DGGS GMC 135 Publication Details Title: Vitrinite reflectance data and a description of organic matter description of organic matter of cuttings from the Pan American Chuitna River State 3193 #1 well: Alaska
Creating a Strong, Healthy Community: Ella B. Vernetti School, Koyukuk. Case Study.
ERIC Educational Resources Information Center
Leonard, Beth
As part of a larger study of systemic educational reform in rural Alaska, this case study examines implementation of the Alaska Onward to Excellence (AOTE) process in Koyukuk, a small Athabascan village on the Yukon River in western interior Alaska. The village has a K-10 school with an enrollment of 19-41 students during the study period. A…
R.W. Ruess; J.M. McFarland; L.M. Trummer; J.K. Rohrs-Richey
2009-01-01
Atmospheric nitrogen (N) fixation by Alnus tenuifolia can account for up to 70 percent of the N accumulated during vegetation development along river flood plains in interior Alaska. We assessed disease incidence and related mortality of a recent outbreak or fungal stem cankers on A. tenuifolia across three regions in Alaska...
1984-01-01
concentration-depth profiles for suspended sand sizes at Fairbanks gauge . 5.1 Apparent downstream migration of main channel loops upstream of Goose Island, 1938...at the Fairbanks gauging station is plotted in Figure 3.1. Table 3.1 shows year-by-year and period-of-record statistics for mean, minimum and maximum...Associated Relationships Figure 3.3 shows a plot of stage vs. discharge data for the Fairbanks gauging station.* There has been considerable scatter
Applications of ERTS-1 imagery to terrestrial and marine environmental analyses in Alaska
NASA Technical Reports Server (NTRS)
Anderson, D. M.; Mckim, H. L.; Crowder, W. K.; Haugen, R. K.; Gatto, L. W.; Marlar, T. L.
1974-01-01
ERTS-1 imagery provides a means of distinguishing and monitoring estuarine surface water circulation patterns and changes in the relative sediment load of discharging rivers on a regional basis. It also will aid local fishing industries by augmenting currently available hydrologic and navigation charts. The interpretation of geologic and vegetation features resulted in preparation of improved surficial geology, vegetation and permafrost terrain maps at a scale of 1:1 million utilizing ERTS-1 band 7 imagery. This information will be further utilized in a route and site selection study for the Nome to Kobuk Road in central Alaska. Large river icings along the proposed Alaska pipeline route have been monitored. Sea ice deformation and drift northeast of Point Barrow, Alaska has been measured and shorefast ice accumulation and ablation along the west coast of Alaska is being mapped for the spring and early summer seasons. These data will be used for route and site selection, regional environmental analysis, identification and inventory of natural resources, land use planning, and in land use regulation and management.
Forecast Tools for Alaska River Ice Breakup Timing and Severity
NASA Astrophysics Data System (ADS)
Moran, E. H.; Lindsey, S.; van Breukelen, C. M.; Thoman, R.
2016-12-01
Spring Breakup on the large interior rivers in Alaska means a time of nervous anticipation for many of the residents in the villages alongside those rivers. On the Yukon and Kuskokwim Rivers the record flood for most villages occurred as a result of ice jams that backed up water and dump truck sized ice floes into the village. Those floods can occur suddenly and can literally wipe out a village. The challenge is that with a limited observation network (3 automated USGS gages along the 1200 miles of the Yukon River flowing through Alaska) and the inherently transient nature of ice jam formation, prediction of the timing and severity of these events has been a tremendous challenge. Staff at the Alaska Pacific River Forecast Center as well as the Alaska Region Climate Program Manager have been developing more quantitative tools to attempt to provide a longer lead time for villages to prepare for potentially devastating flooding. In the past, a very qualitative assessment of the primary drivers of Spring Breakup (snow pack, river ice thickness and forecast spring weather) have led to the successful identification of years when flood severity was likely to be elevated or significantly decreased. These qualitative assessments have also allowed the forecasting of the probability of either a thermal or a dynamic breakup. But there has continued to be a need for an objective tool that can handle weather patterns that border on the tails of the climatic distributions as well as the timing and flood potential from weather patterns that are closer to the median of the distribution. Over the past 8 years there have been a significant number of years with anomalous spring weather patterns including cold springs followed by rapid warmups leading to record flooding from ice jams during spring breakup (2009, 2013), record late breakup (2013), record early breakup (2016), record high snowfall (2012), record snowmelt and aufeis flooding (2015) and record low snowfall (2015). The need for improved tools that can handle these events over the full breadth of the distribution has never been greater. This talk will describe efforts to incorporate climate signals into the spring breakup outlook and show results of some temperature based indices as an indicator of breakup timing.
ERIC Educational Resources Information Center
Mickelson, Belle
This curriculum guide is the last (Series VII) in a six-volume set that comprises the Sea Week Curriculum Series developed in Alaska. The guide lends itself to the sixth-grade curriculum but can be adapted to preschool, secondary, and adult education. Eight units contain 43 activities with worksheets that cover the following topics: (1) the values…
Geotechnical reconnaissance of the 2002 Denali fault, Alaska, earthquake
Kayen, R.; Thompson, E.; Minasian, D.; Moss, R.E.S.; Collins, B.D.; Sitar, N.; Dreger, D.; Carver, G.
2004-01-01
The 2002 M7.9 Denali fault earthquake resulted in 340 km of ruptures along three separate faults, causing widespread liquefaction in the fluvial deposits of the alpine valleys of the Alaska Range and eastern lowlands of the Tanana River. Areas affected by liquefaction are largely confined to Holocene alluvial deposits, man-made embankments, and backfills. Liquefaction damage, sparse surrounding the fault rupture in the western region, was abundant and severe on the eastern rivers: the Robertson, Slana, Tok, Chisana, Nabesna and Tanana Rivers. Synthetic seismograms from a kinematic source model suggest that the eastern region of the rupture zone had elevated strong-motion levels due to rupture directivity, supporting observations of elevated geotechnical damage. We use augered soil samples and shear-wave velocity profiles made with a portable apparatus for the spectral analysis of surface waves (SASW) to characterize soil properties and stiffness at liquefaction sites and three trans-Alaska pipeline pump station accelerometer locations. ?? 2004, Earthquake Engineering Research Institute.
Wearing surface testing : Yukon River bridge.
DOT National Transportation Integrated Search
2012-12-01
The Yukon River Bridge, also known as the E.L. Patton Bridge, carries the twolane Dalton Highway and the trans-Alaska oil pipeline across the Yukon River at a 6% : grade. It is 30 feet wide, with 6 spans; it was designed to withstand -60 degrees Fahr...
Publications - IC 50 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey ic050.pdf (999.0 K) Keywords Aeromagnetic; Aeromagnetic Map; Aeromagnetic Survey; Alaska Peninsula ; Coal; Conductivity Survey; Construction Materials; Copper; Cretaceous; Delta River; Diamonds; Drilling
DOT National Transportation Integrated Search
2000-02-01
This report presents the results of the technology and safety assessment of the Bethel/Kuskokwim River hovercraft service,operated by the Alaska Hovercraft Joint Venture (AHJV). The primary purpose of the service was a two-year demonstration of bypas...
Origin of last-glacial loess in the western Yukon-Tanana Upland, central Alaska, USA
Muhs, Daniel; Pigati, Jeffrey S.; Budahn, James R.; Skipp, Gary L.; Bettis, E. Arthur; Jensen, Britta
2018-01-01
Loess is widespread over Alaska, and its accumulation has traditionally been associated with glacial periods. Surprisingly, loess deposits securely dated to the last glacial period are rare in Alaska, and paleowind reconstructions for this time period are limited to inferences from dune orientations. We report a rare occurrence of loess deposits dating to the last glacial period, ~19 ka to ~12 ka, in the Yukon-Tanana Upland. Loess in this area is very coarse grained (abundant coarse silt), with decreases in particle size moving south of the Yukon River, implying that the drainage basin of this river was the main source. Geochemical data show, however, that the Tanana River valley to the south is also a likely distal source. The occurrence of last-glacial loess with sources to both the south and north is explained by both regional, synoptic-scale winds from the northeast and opposing katabatic winds that could have developed from expanded glaciers in both the Brooks Range to the north and the Alaska Range to the south. Based on a comparison with recent climate modeling for the last glacial period, seasonality of dust transport may also have played a role in bringing about contributions from both northern and southern sources.
Traces of Old Glaciations in East-central Alaska
NASA Astrophysics Data System (ADS)
Duk-Rodkin, A.; Barendregt, R. W.; Weber, F.
2001-12-01
The East-central Alaska record of glaciations is similar to that preserved in the west-central Yukon. Surficial geologic mapping of the Yukon-Tanana upland has indicated at least 5 glacial periods including at least one early Holocene. The two earliest glaciations are of pre-Mid Pleistocene age and followed regional erosion and renewed uplift ca.4 Ma. The earliest glaciation of west-central Yukon occurred between 2.6 and 2.9 Ma, forming a continuous carapace of ice covering all the mountain ranges except for a small part of the Dawson Range. This first glaciation was also the most extensive in the region, and resulted in the NW diversion of Yukon River into Alaska by the Cordilleran Ice Sheet. Stratigraphic evidence of 6 glaciations of pre-Mid Pleistocene age is preserved in the western Canadian sector of the Tintina Trench. The limits of these glaciations have been mapped in Yukon on the basis of glacial landforms and the distribution of erratics. Although morphological features of older glaciations (Plio-Pleistocene) are generally not well preserved, there is relatively good control on the distribution of glacial features for two of the older glaciations in Mt.Harper, Alaska. Stratigraphic evidence of at least 3 older glaciations is found in the Goodpastor River. An initial magnetostratigraphic study of three sites in east-central Alaska have yielded normal magnetic polarities only. The sites are:(1) a relatively weathered lowermost till outcropping along Goodpastor River on the Yukon-Tanana upland,(2) an extremely weathered high level moraine (609m) on the western side of the Gerstle River, near Granite Mt.in the Alaska Range and (3)ca.914m pediment containing glacial erratics and a luvisol at its surface, located on Tok River, Tanana Valley, Alaska Range. The normal polarity of the first site likely indicates a Brunhes age rather than a normal subchron within the Matuyama Reversed Chron based on the modest degree of weathering of the till and lack of any reversed overprint. The second site may be related to an older glacial event based on the high degree of clast weathering (>90%) and the presence of a luvisol over 1m depth. Clasts at the third site are better preserved suggesting the normal magnetization of these sediments may be Brunhes age. Deeply weathered clasts and red soils (Wounded Moose Paleosol)are found on pre-Mid Pleistocene glacial drift surfaces in west-central Yukon and appear also to be present on the older drift surfaces in east-central Alaska (for example, the well developed paleosol exposed in a borrow pit at the Tok town site). The presence of relatively old (early Brunhes) glacial deposits at high elevations (third site) could be explained by tectonic uplift, however a minimum of 300m of post depositional uplift would be required to account for the present elevation of these surfaces. Evidence for the diversion of the Yukon River by the first glaciation is seen near Circle, Alaska where lower fluvial gravels free of argillites of eastern (Ogilvie Mountains) provenance, are overlain by glacial outwash gravels containing approximately 8% argillites. The lower gravels are considered Late Pliocene (Gauss) based on plant macro fossils and normal polarity, and based on the absence of argillites, are clearly preglacial. Normally magnetized Late Pliocene pre-glacial fluvial gravels, the White Channel gravels, are found in the Tintina Trench and Klondike Plateau, which are conformably overlain by the Klondike outwash gravels associated with the first glaciation.
2000-04-01
Alaska.) Stricker, G.D., M.E. Brownfield, L.A. Yehle, and J.A. Wolfe (1988) Mineralogy and stage assign- ment of some Tertiary coal from the Tikishla... originates at the mouth of the Eagle River Valley near the city of Eagle River (Fig. 1, Plate 1). The fan slopes gently to the west– southwest, underlying...south, several low hills of ground moraine protrude through younger glacial depos- its of various origins from the most recent glacia- tion of this area
Publications - RI 97-15D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Coastal and River; Coastal and River Hazards; Construction Materials; Derivative; Engineering; Engineering
Overview of environmental and hydrogeologic conditions at Fort Yukon, Alaska
Nakanishi, Allan S.; Dorava, Joseph M.
1994-01-01
The village of Fort Yukon along the Yukon River in east-central Alaska has long cold winters and short summers. The Federal Aviation Administration operates and supports some airport facilities in Fort Yukon and is evaluating the severity of environmental contamination and options for remediation of such contamination at their facilites. Fort Yukon is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available from local surface-water bodies or from presently unidentified confined aquifers.
Overview of environmental and hydrogeologic conditions at Tanana, Alaska
Nakanishi, Allan S.; Dorava, Joseph M.
1994-01-01
The remote Native village of Tanana along the Yukon River in west-central Alaska has long cold winters and short summers. The Federal Aviation Administration owns or operates airway support facilities near Tanana and wishes to consider the subsistence lifestyle of the residents and the quality of the current environment when evaluating the severity of environmental contamination at these facilities. Tanana is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available, but may cost more than existing supplies.
Multiple crossings of a large glacial river by Canada Lynx (Lynx canadensis)
D. Feierabend; K. Kielland
2014-01-01
Rivers may act as barriers to the movement of terrestrial mammals, which could limit dispersal and gene flow. Glacial rivers are particularly hazardous because of the cold water temperature and swift current. Yet, we determined that 2 Canada Lynx (Lynx canadensis) equipped with GPS collars repeatedly swam across the main channel of the Tanana River in interior Alaska...
Soil Organic Carbon Storage in Five Different Arctic Permafrost Environments
NASA Astrophysics Data System (ADS)
Fuchs, M.; Grosse, G.; Jones, B. M.; Maximov, G.; Strauss, J.
2016-12-01
Arctic river deltas and ice-rich permafrost regions are highly dynamic environments which will be strongly affected by future climate change. Rapid thaw of permafrost (thermokarst and thermo-erosion) may cause significant mobilization of organic carbon, which is assumed to be stored in large amounts in Arctic river deltas and ice-rich permafrost. This study presents and compares new data on organic carbon storage in thermokarst landforms and Arctic river delta deposits for the first two meters of soils for five different study areas in Alaska and Siberia. The sites include the Ikpikpuk river delta (North Alaska), Fish Creek river delta (North Alaska), Teshekpuk Lake Special Area (North Alaska), Sobo-Sise Island (Lena river delta, Northeast Siberia), and Bykovsky Peninsula (Northeast Siberia). Samples were taken with a SIPRE auger along transects covering the main geomorphological landscape units in the study regions. Our results show a high variability in soil organic carbon storage among the different study sites. The studied profiles in the Teshekpuk Lake Special Area - dominated by drained thermokarst lake basins - contained significantly more carbon than the other areas. The Teshekpuk Lake Special Area contains 44 ± 9 kg C m-2 (0-100 cm, mean value of profiles ± Std dev) compared to 20 ± 7 kg C m-2 kg for Sobo-Sise Island - a Yedoma dominated island intersected by thaw lake basins and 24 ± 6 kg C m-2 for the deltaic dominated areas (Fish Creek and Ikpikpuk). However, especially for the Ikpikpuk river delta, a significant amount of carbon (25 ± 9 kg C m-2) is stored in the second meter of soil (100-200cm). This study shows the importance of including deltaic and thermokarst-affected landscapes as considerable carbon pools, but indicates that these areas are heterogeneous in terms of organic carbon storage and cannot be generalized. As a next step, the site-level carbon stocks will be upscaled to the landscape level using remote sensing-based land cover classifications to calculate the carbon storage potential for Arctic deltas and larger thermokarst regions, to estimate mobilization potentials from thermokarst and thermo-erosion, and to provide input data for future permafrost carbon feedback models.
Precipitation and streamwater chemistry in an undisturbed watershed in southeast Alaska.
John D. Stednick
1981-01-01
Water chemistry samples have been taken from streamflow since 1976 and precipitation since 1978 in Indian River, an undisturbed watershed on Chichagof Island in Southeast Alaska. Volume weighted concentrations of total nitrogen, ammonium nitrogen, nitrate nitrogen, total phosphorus, orthophosphate, sulfate sulfur, chloride, bicarbonate, silica, calcium, magnesium,...
Publications - PIR 2002-1C | Alaska Division of Geological & Geophysical
fortymile_eaglea1_surficial Shapefile 3.3 M Metadata - Read me Keywords Alaska, State of; Alluvial Deposits; Bison Fossils ; Boundary (Place); Caribou Fossils; Cenozoic; Colluvial Deposits; Complex Deposits; Cretaceous; Devonian ; Fortymile Mining District; Fortymile River; Geologic Map; Geology; Glacial Deposits; Holocene; Horse Fossils
DOT National Transportation Integrated Search
2014-09-01
In this study, we will monitor the behavior of the Alaska Chulitna Bridge for the specific purpose of assisting the DOT in performing an accurate : condition assessment of this bridge. : Based on the state-of-the-art SHM knowledge and technologies wi...
Climate sensitivity of thinleaf alder growth on an interior Alaska floodplain
Dana R. Nossov; Roger W. Ruess; Teresa N. Hollingsworth
2010-01-01
This study examined the climate sensitivity of the growth of riparian Alnus incana ssp. tenuifolia (thinleaf alder), a keystone nitrogen-fixer, on the Tanana River floodplain of interior Alaska. We investigated correlations between alder radial growth and inter-annual variation in monthly meteorology and hydrology, spatial...
Publications - GMC 54 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 54 Publication Details Title: Source rock evaluation/TAI for ARCO Itkillik River Unit #1 information. Bibliographic Reference Texaco, Inc., [n.d.], Source rock evaluation/TAI for ARCO Itkillik River
Publications - GMC 250 | Alaska Division of Geological & Geophysical
cuttings from the following Copper River basin oil and gas exploratory wells: Eureka #2, Ahtna Inc. #1 , Chronostratigraphic summaries based on palynological content of cuttings from the following Copper River basin oil and
Publications - RI 97-15E | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Metadata - Read me Keywords Avalanche; Coastal and River; Coastal and River Hazards; Derivative; Earthquake
Publications - PDF 98-37D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in - Read me Keywords Coastal and River; Coastal and River Hazards; Construction Materials; Decorative Stone
50 CFR 92.5 - Who is eligible to participate?
Code of Federal Regulations, 2012 CFR
2012-10-01
... located within the Alaska Peninsula, Kodiak Archipelago, the Aleutian Islands, or in areas north and west... with the Johnson and Delta Rivers, west of the east bank of the Johnson River, and north and west of...
50 CFR 92.5 - Who is eligible to participate?
Code of Federal Regulations, 2014 CFR
2014-10-01
... located within the Alaska Peninsula, Kodiak Archipelago, the Aleutian Islands, or in areas north and west... with the Johnson and Delta Rivers, west of the east bank of the Johnson River, and north and west of...
50 CFR 92.5 - Who is eligible to participate?
Code of Federal Regulations, 2010 CFR
2010-10-01
... located within the Alaska Peninsula, Kodiak Archipelago, the Aleutian Islands, or in areas north and west... with the Johnson and Delta Rivers, west of the east bank of the Johnson River, and north and west of...
50 CFR 92.5 - Who is eligible to participate?
Code of Federal Regulations, 2013 CFR
2013-10-01
... located within the Alaska Peninsula, Kodiak Archipelago, the Aleutian Islands, or in areas north and west... with the Johnson and Delta Rivers, west of the east bank of the Johnson River, and north and west of...
50 CFR 92.5 - Who is eligible to participate?
Code of Federal Regulations, 2011 CFR
2011-10-01
... located within the Alaska Peninsula, Kodiak Archipelago, the Aleutian Islands, or in areas north and west... with the Johnson and Delta Rivers, west of the east bank of the Johnson River, and north and west of...
Overview of environmental and hydrogeologic conditions at McGrath, Alaska
Dorava, J.M.
1994-01-01
The remote village of McGrath along the Kuskokwim River in southwestern Alaska has long cold winters and short summers. The village is located on the flood plain of the Kuskokwim River and obtains drinking water for its 533 residents from the Kuskokwim River. Surface spills and disposal of hazardous materials combined with frequent flooding of the Kuskokwim River could affect the quality of the drinking water. Alternative drinking-water sources are available but at greater cost than existing supplies. The Federal Aviation Administration (FAA) owns or operates airport support facilities in McGrath and wishes to consider the subsistence lifestyle of the residents and the quality of the current environ- ment when evaluating options for remediation of environmental contamination at their facilities. This report describes the history, socioeconomics, physical setting, ground- and surface-water hydrology, geology, climate, vegetation, soils, and flood potential of the areas surrounding the FAA facilities near McGrath.
Potential industrial sites in the Lynn Canal area, Alaska
Johnson, Arthur; Twenhofel, William Stephens
1953-01-01
Full development of a proposal to divert the headwaters of the Yukon River drainage from Canada into the Taiya River valley of Alaska would make available more than a half million kilowatts of electrical energy. Utilization of this block of power, for which there is at present no local market, will require an industrial and community development of appreciable magnitude. Suitable sites for industrial and community development near the proposed power source are limited because of the extremely rugged and mountainous terrain of the Lynn Canal area. This report considers potential industrial areas at Skagway, Taiya River, Ferebee River, Lutak Inlet, Haines and vicinity, Klukwan and vicinity, Haines to Klukwan along the Haines cutoff, Berners Bay, and Juneau and vicinity. The factors considered in their evaluation are topography, geology, climate, water supply, transportation facilities, and transmission-line routes from the source of power.
Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska
Lilledahl, Anna K.; Gadeke, Anne; O'Neel, Shad; Gatesman, T. A.; Douglas, T. A.
2017-01-01
Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15–28%) of total annual streamflow despite low glacier cover (3%). About half of annual headwater streamflow is lost to the aquifer (38 to 56%). The estimated long-term change in glacier-derived aquifer recharge exceeds the observed increase in Tanana River base flow. Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year-round base flow of lowland rivers.
Kraemer, Thomas F.; Brabets, Timothy P.
2012-01-01
The ability to detect hydrologic variation in large arctic river systems is of major importance in understanding and predicting effects of climate change in high-latitude environments. Monitoring uranium isotopes (234U and 238U) in river water of the Yukon River Basin of Alaska and northwestern Canada (2001–2005) has enhanced the ability to identify water sources to rivers, as well as detect flow changes that have occurred over the 5-year study. Uranium isotopic data for the Yukon River and major tributaries (the Porcupine and Tanana rivers) identify several sources that contribute to river flow, including: deep groundwater, seasonally frozen river-valley alluvium groundwater, and high-elevation glacial melt water. The main-stem Yukon River exhibits patterns of uranium isotopic variation at several locations that reflect input from ice melt and shallow groundwater in the spring, as well as a multi-year pattern of increased variability in timing and relative amount of water supplied from higher elevations within the basin. Results of this study demonstrate both the utility of uranium isotopes in revealing sources of water in large river systems and of incorporating uranium isotope analysis in long-term monitoring of arctic river systems that attempt to assess the effects of climate change.
Nesting biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska
Ely, Craig R.; Pearce, J.M.; Ruess, Roger W.
2008-01-01
Lesser Canada Geese (Branta canadensis parvipes) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in interior Alaska. Fieldwork was conducted in May of 2003, and consisted of locating nests along the riparian corridor between Fairbanks and Northpole, Alaska. Nests were found on gravel islands and shore habitats along the Tanana River, and were most commonly observed among driftwood logs associated with patches of alder (Alnus spp.) and willow (Salix spp.). Peak of nest initiation was 3-8 May, with a range from 27 April to 20 May; renesting was likely. Clutches ranged in size from 2 to 7 eggs and averaged 4.6 eggs. There was a negative correlation between clutch size and date of nest initiation. Egg size (mean mass = 128 g) was similar to other medium-sized Canada Geese. A positive correlation between egg size and clutch size was likely related to female age. Nineteen of 28 nests (68%) were active when visited; nests located on islands with nesting Mew Gulls (Larus canus) were more likely to be active than nests located elsewhere. Evidence at nest sites implicated Bald Eagles (Haliaeetus leucocephalus) and Red Foxes (Vulpes vulpes) as nest predators.
Publications - GMC 150 | Alaska Division of Geological & Geophysical
with gas chromatograms mass spectroscopy data of samples from the following 4 wells: Itkillik River spectroscopy data of samples from the following 4 wells: Itkillik River Unit #1, KRU W. Sak #26, Toolik Fed #2
Publications - GMC 247 | Alaska Division of Geological & Geophysical
from the following Copper River basin oil and gas wells: Eureka #2, Ahtna Inc. and Salmonberry Lake , Potassium-argon whole rock age determinations of core samples from the following Copper River basin oil and
Publications - PIR 2001-3D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Shapefile 1.4 M Metadata - Read me Keywords Coastal and River; Coastal and River Hazards; Construction
Publications - GMC 64 | Alaska Division of Geological & Geophysical Surveys
sample from the AMOCO Production Company Cathedral River Unit #1 well Authors: Henning, Mitchel, and determination for a 10,650' deep cutting sample from the AMOCO Production Company Cathedral River Unit #1 well
Overview of environmental and hydrogeologic conditions at Galena, Alaska
Nakanishi, Allan S.; Dorava, Joseph M.
1994-01-01
The remote Native village of Galena along the Yukon River in west-central Alaska has long cold winters and short summers that affects the hydrology of the area. The Federal Aviation Administration owns or operates airport support facilities in Galena and wishes to consider the subsistence lifestyle of the residents and the quality of the current environment when evaluating options for remediation of environmental contamination at these facilities. Galena is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available but at significantly greater cost than existing supplies.
Phytomass in southwest Alaska.
Bert R. Mead
2000-01-01
Phytomass tables are presented for southwest Alaska. The methods used to estimate plant weight and occurrence in the river basin are described and discussed. Average weight is shown for each sampled species of tree, shrub, grass, forb, lichen, and moss in 19 forest and 48 nonforest vegetation types. Species frequency of occurrence and species constancy within the type...
O. Keith Hutchison
1968-01-01
Alaska's romantic past includes the magnetic lure of gold; the mad stampede to strike it rich; success and heartbreak; men and animals battling snow, ice, spring breakup, insects, and loneliness; dog teams at work and on desperate missions; river steamers battling the Yukon; bush pilots performing miraculous flights; and hordes of salmon taken by traps and seine...
Sodium bromide and Rhodamine WT were used as conservative tracers to examine the hydrologic characteristics of seven tundra streams in Arctic Alaska, during the summers of 1994-1996. Continuous tracer additions were conducted in seven rivers ranging from 1st to 5th order with sam...
The recent warming of permafrost in Alaska
NASA Astrophysics Data System (ADS)
Osterkamp, T. E.
2005-12-01
This paper reports results of an experiment initiated in 1977 to determine the effects of climate on permafrost in Alaska. Permafrost observatories with boreholes were established along a north-south transect of Alaska in undisturbed permafrost terrain. The analysis and interpretation of annual temperature measurements in the boreholes and daily temperature measurements of the air, ground and permafrost surfaces made with automated temperature loggers are reported. Permafrost temperatures warmed along this transect coincident with a statewide warming of air temperatures that began in 1977. At two sites on the Arctic Coastal Plain, the warming was seasonal, greatest during "winter" months (October through May) and least during "summer" months (June through September). Permafrost temperatures peaked in the early 1980s and then decreased in response to slightly cooler air temperatures and thinner snow covers. Arctic sites began warming again typically about 1986 and Interior Alaska sites about 1988. Gulkana, the southernmost site, has been warming slowly since it was drilled in 1983. Air temperatures were relatively warm and snow covers were thicker-than-normal from the late 1980s into the late 1990s allowing permafrost temperatures to continue to warm. Temperatures at some sites leveled off or cooled slightly at the turn of the century. Two sites (Yukon River Bridge and Livengood) cooled during the period of observations. The magnitude of the total warming at the surface of the permafrost (through 2003) was 3 to 4 °C for the Arctic Coastal Plain, 1 to 2 °C for the Brooks Range including its northern and southern foothills, and 0.3 to 1 °C south of the Yukon River. While the data are sparse, permafrost is warming throughout the region north of the Brooks Range, southward along the transect from the Brooks Range to the Chugach Mountains (except for Yukon River and Livengood), in Interior Alaska throughout the Tanana River region, and in the region south of the Alaska Range from Tok westward to Gulkana (in the Copper River Valley) and beyond to the Talkeetna Mountains. Thermal offset allows permafrost to survive in the presence of positive annual mean ground surface temperatures and was observed repeatedly since 1987 at two sites. The observed warming has not produced an increasing trend in maximum active layer thicknesses due to its seasonality. Near Healy, permafrost has been thawing at the top since the late 1980s at about 10 cm/yr. At Gulkana, permafrost was thawing from the bottom at a rate of 4 cm/yr that accelerated to 9 cm/yr after 2000.
Fiorillo, Anthony R.; Fanti, Federico; Hults, Chad; Hasiotis, Stephen T
2014-01-01
A paleontological reconnaissance survey on Cretaceous and Paleogene terrestrial units along the Yukon River drainage through much of east-central Alaska has provided new chronostratigraphic constraints, paleoclimatological data, and the first information on local biodiversity within an ancient, high-latitude ecosystem. The studied unnamed rock unit is most notable for its historic economic gold placer deposits, but our survey documents its relevance as a source rock for Mesozoic terrestrial vertebrates, invertebrates, and associated flora. Specifically, new U-Pb ages from detrital zircons combined with ichnological data are indicative of a Late Cretaceous age for at least the lower section of the studied rock unit, previously considered to be representative of nearly exclusively Paleogene deposition. Further, the results of our survey show that this sedimentary rock unit preserves the first record of dinosaurs in the vast east-central Alaska region. Lastly, paleobotanical data, when compared to correlative rock units, support previous interpretations that the Late Cretaceous continental ecosystem of Alaska was heterogeneous in nature and seasonal.
Arctic and subarctic environmental analyses utilizing ERTS-1 imagery
NASA Technical Reports Server (NTRS)
Anderson, D. M. (Principal Investigator); Mckim, H. L.; Gatto, L. W.; Haugen, R. K.; Crowder, W. K.; Slaughter, C. W.; Marlar, T. L.
1974-01-01
The author has identified the following significant results. ERTS-1 imagery provides a means of distinguishing and monitoring estuarine surface water circulation patterns and changes in the relative sediment load of discharging rivers on a regional basis. Physical boundaries mapped from ERTS-1 imagery in combination with ground truth obtained from existing small scale maps and other sources resulted in improved and more detailed maps of permafrost terrain and vegetation for the same area. Snowpack cover within a research watershed has been analyzed and compared to ground data. Large river icings along the proposed Alaska pipeline route from Prudhoe Bay to the Brooks Range have been monitored. Sea ice deformation and drift northeast of Point Barrow, Alaska have been measured during a four day period in March and shore-fast ice accumulation and ablation along the west coast of Alaska have been mapped for the spring and early summer seasons.
NASA Astrophysics Data System (ADS)
Kontar, Y. Y.; Bhatt, U. S.; Lindsey, S. D.; Plumb, E. W.; Thoman, R. L.
2015-06-01
In May 2013, a massive ice jam on the Yukon River caused flooding that destroyed much of the infrastructure in the Interior Alaska village of Galena and forced the long-term evacuation of nearly 70% of its residents. This case study compares the communication efforts of the out-of-state emergency response agents with those of the Alaska River Watch program, a state-operated flood preparedness and community outreach initiative. For over 50 years, the River Watch program has been fostering long-lasting, open, and reciprocal communication with flood prone communities, as well as local emergency management and tribal officials. By taking into account cultural, ethnic, and socioeconomic features of rural Alaskan communities, the River Watch program was able to establish and maintain a sense of partnership and reliable communication patterns with communities at risk. As a result, officials and residents in these communities are open to information and guidance from the River Watch during the time of a flood, and thus are poised to take prompt actions. By informing communities of existing ice conditions and flood threats on a regular basis, the River Watch provides effective mitigation efforts in terms of ice jam flood effects reduction. Although other ice jam mitigation attempts had been made throughout US and Alaskan history, the majority proved to be futile and/or cost-ineffective. Galena, along with other rural riverine Alaskan communities, has to rely primarily on disaster response and recovery strategies to withstand the shock of disasters. Significant government funds are spent on these challenging efforts and these expenses might be reduced through an improved understanding of both the physical and climatological principals behind river ice breakup and risk mitigation. This study finds that long term dialogue is critical for effective disaster response and recovery during extreme hydrological events connected to changing climate, timing of river ice breakup, and flood occurrence in rural communities of the Far North.
Publications - GMC 234 | Alaska Division of Geological & Geophysical
following North Slope wells: Itkillik River Unit #1, Nora Fed #1, Toolik Fed #1, Kemik Unit #1, Lupine Unit following North Slope wells: Itkillik River Unit #1, Nora Fed #1, Toolik Fed #1, Kemik Unit #1, Lupine Unit
NASA Astrophysics Data System (ADS)
Vas, D. A.; Toniolo, H. A.; Bailey, J.; Kemnitz, R.
2013-12-01
Abstract The National Petroleum Reserve-Alaska (NPR-A) is a vast 22.8 million acre area that extends from the foot hills of the Brooks Range to the Beaufort Sea. The United States Department of Interior, Bureau of Land Management (BLM) in association with University of Alaska Fairbanks (UAF) is conducting hydrological research to establish baseline conditions to aid future infrastructure development related to oil and gas in the NPR-A region. Field measurements (discharge, cross-sectional area, top width, water slope) were carried out in Spring 2011, 2012 and 2013, during receding water levels in the streams when the flows were ice-free. The river gauges are located approximately 15 miles south of the rivers mouth on Beaufort Sea and 13 miles from each other. The contributing watershed areas upstream of the gauging stations are 620 and 128 square miles for Judy Creek and Ublutuoch River respectively. The streams have very different channel characteristics and sediment loads. The Judy Creek channel is somewhat unstable; bed sediment contains sand and fine gravel with a heavy sediment load during spring. Bed sediment on Ublutuoch River mainly comprise of coarse gravel, with heavily brush-vegetated steep banks and very limited sediment load during spring. We present a preliminary set of hydraulic geometric relationships describing the variation of channel width, depth, and velocity as function of discharge at the gauging sites on the rivers. Empirical equations indicate that exponents for channel width have similar values in both rivers (approximately 0.38), while exponents for velocity display different values and signs. Exponents for channel depth range from 0.55 to 0.71. Differences in prevailing sediment transport conditions seem to be, at least partially, responsible for the variation in the exponents. Additionally, roughness coefficients are reported.
Wanty, Richard B.; Wang, Bronwen; Vohden, Jim; Briggs, Paul H.; Meier, Allen L.
2000-01-01
A systematic water-quality study of the Fortymile River and many of its major tributaries in eastern Alaska was conducted in June of 1997 and 1998. Surface-water samples were collected for chemical analyses to establish regional baseline geochemistry values and to evaluate the possible environmental effects of suction-dredge placer gold mining and bulldozer-operated placer gold mining (commonly referred to as “cat mining”). In general, the water quality of the Fortymile River is very good, with low total dissolved solids and only two cases in which the concentration of any element exceeded primary or secondary drinking-water quality standards. In both cases, iron exceeded secondary drinking-water limits. At the time this work was conducted, only a handful of suction dredges were operating on the lower Fortymile River, and cat mining was being conducted along Uhler Creek and Canyon Creek, two major tributaries to the river. Based on the water-quality and turbidity data, the suction dredges have no apparent impact on the Fortymile River system, although possible effects on biota have not been evaluated in this study. In contrast, the cat-mining operations in Canyon Creek appear to have a dramatic impact on water quality and stream-bed morphology, based on the field water-quality and turbidity measurements, on comparisons to adjacent unmined drainages, and on field observations of stream-bed morphology. The cat mining in Uhler Creek appears to have had less impact, perhaps because the main stream channel was not as heavily disrupted by the bulldozers, and the stability of the channel was mostly preserved.
Geologic map of the Wrangell-Saint Elias National Park and Reserve, Alaska
Richter, Donald H.; Preller, Cindi C.; Labay, Keith A.; Shew, Nora B.
2006-01-01
Wrangell-Saint Elias National Park and Preserve, the largest national park within the U.S. National Park Service system, extends from the northern Pacific Ocean to beyond the eastern Alaska Range into interior Alaska. It features impressively spectacular scenery such as high and craggy mountains, active and ancient volcanoes, expansive ice fields, immense tidewater glaciers, and a myriad of alpine glaciers. The park also includes the famous Kennecott Mine, a world-class copper deposit that was mined from 1911 to 1938, and remnant ghost town, which is now a National Historic Landmark. Geologic investigations encompassing Wrangell-Saint Elias National Park and Preserve began in 1796, with Dmitriv Tarkhanov, a Russian mining engineer, who unsuccessfully ventured up the Copper River in search of rumored copper. Lieutenant H.T. Allen (1897) of the U.S. Army made a successful epic summer journey with a limited military crew up the Copper River in 1885, across the Alaska Range, and down the Tanana and Yukon Rivers. Allen?s crew was supported by a prospector named John Bremner and local Eyak and Ahtna native guides whose tribes controlled access into the Copper River basin. Allen witnessed the Ahtnas? many uses of the native copper. His stories about the copper prompted prospectors to return to this area in search of the rich copper ore in the years following his journey. The region boasts a rich mining and exploration history prior to becoming a park in 1980. Several U.S. Geological Survey geologists have conducted reconnaissance surveys in the area since Allen?s explorations. This map is the result of their work and is enhanced by more detailed investigations, which began in the late 1950s and are still continuing. For a better understanding of the processes that have shaped the geology of the park and a history of the geologic investigations in the area, we recommend U.S. Geological Survey Professional Paper 1616, ?A Geologic Guide to Wrangell-Saint Elias National Park and Preserve, Alaska,? an exceptionally well illustrated and informative book by Gary R. Winkler, 2000. Geologically, the park consists of a collage of seven tectonostratigraphic terranes that formed south in the equatorial Pacific Ocean and rafted northward on oceanic plates, eventually accreting to Alaska and the North American continent. Each terrane features a distinct stratigraphy and is separated from neighboring terranes by major strike-slip or thrust faults.
Temporal effects of mechanical treatment on winter moose browse in south-central Alaska
Sharon Smythe; Dana Sanchez; Ricardo Mata-Gonzalez
2015-01-01
Sites containing winter browse species utilized by moose on the Copper River Delta of south-central Alaska were mechanically treated (hydraulic-axed) to counteract possible earthquake related increases in less-preferred forage species, and to measure treatment effects on biomass, height, nutritional quality (crude protein, lignin, and tannin), utilization, and snow...
50 CFR 18.122 - In what specified geographic region does this subpart apply?
Code of Federal Regulations, 2010 CFR
2010-10-01
..., Alaska, and includes all Alaska coastal areas, State waters, and Outer Continental Shelf waters east of that line to the Canadian border and an area 25 miles inland from Barrow on the west to the Canning River on the east. The Arctic National Wildlife Refuge is not included in the area covered by this...
Dispersal of white spruce seed on Willow Island in interior Alaska.
Andrew Youngblood; Timothy A. Max
1992-01-01
The seasonal and spatial patterns of dispersal of white spruce (Picea glauca (Moench) Voss) seed were studied from 1986 to 1989 in floodplain stands along the Tanana River near Fairbanks, Alaska. Analysis of the 1987 crop showed that production of filled seed was strongly related to estimated production of total seed and unrelated to selected stand...
McCloskey, Sarah E.; Jones, Benjamin M.
2014-01-01
Koyukon Athabascan peoples have settled along the Koyukuk River in Western Interior Alaska for thousands of years using the surrounding landscape for subsistence and cultural resources. However, recent changes in climate, technology, resource availability, and way of life have affected land-use patterns in the region, as well as use of the Denaakk'e (Koyukon) language. The current Koyukon population is about 2,300, and about 150 still speak the language (the youngest of whom are in their fifties). In addition, Elders, important keepers of both language and traditional subsistence-use areas, are aging, and opportunities to record their knowledge are diminishing.
A whole ecosystem approach to studying climate change in interior Alaska
Riggins, Susan; Striegl, Robert G.; McHale, Michael
2011-01-01
Yukon River Basin Principal Investigators Workshop; Portland, Oregon, 18-20 January 2011; High latitudes are known to be particularly susceptible to climate warming, leading to an emphasis of field and modeling research on arctic regions. Subarctic and boreal regions such as the Yukon River Basin (YRB) of interior Alaska and western Canada are less well studied, although they encompass large areas that are vulnerable to changes in forest composition, permafrost distribution, and hydrology. There is an urgent need to understand the resiliency and vulnerability of these complex ecosystems as well as their feedbacks to the global climate system. Consequently, U.S. Geological Survey scientists, with other federal agency, university, and private industry partners, is focusing subarctic interdisciplinary studies on the Beaver Creek Wild and Scenic River watershed (http://www.blm.gov/pgdata/content/ak/en/prog/nlcs/beavercrk_nwsr.html) and Yukon Flats National Wildlife Refuge (http://yukonflats.fws.gov/) in the YRB, south and west of Fort Yukon, Alaska. These areas are national treasures of wetlands, lakes, and uplands that support large populations of wildlife and waterfowl and are home to vibrant native Alaskan communities that depend on the area for a subsistence lifestyle.
NASA Astrophysics Data System (ADS)
Lininger, K. B.; Wohl, E.; Rose, J. R.
2018-03-01
Floodplains accumulate and store organic carbon (OC) and release OC to rivers, but studies of floodplain soil OC come from small rivers or small spatial extents on larger rivers in temperate latitudes. Warming climate is causing substantial change in geomorphic process and OC fluxes in high latitude rivers. We investigate geomorphic controls on floodplain soil OC concentrations in active-layer mineral sediment in the Yukon Flats, interior Alaska. We characterize OC along the Yukon River and four tributaries in relation to geomorphic controls at the river basin, segment, and reach scales. Average OC concentration within floodplain soil is 2.8% (median = 2.2%). Statistical analyses indicate that OC varies among river basins, among planform types along a river depending on the geomorphic unit, and among geomorphic units. OC decreases with sample depth, suggesting that most OC accumulates via autochthonous inputs from floodplain vegetation. Floodplain and river characteristics, such as grain size, soil moisture, planform, migration rate, and riverine DOC concentrations, likely influence differences among rivers. Grain size, soil moisture, and age of surface likely influence differences among geomorphic units. Mean OC concentrations vary more among geomorphic units (wetlands = 5.1% versus bars = 2.0%) than among study rivers (Dall River = 3.8% versus Teedrinjik River = 2.3%), suggesting that reach-scale geomorphic processes more strongly control the spatial distribution of OC than basin-scale processes. Investigating differences at the basin and reach scale is necessary to accurately assess the amount and distribution of floodplain soil OC, as well as the geomorphic controls on OC.
Flooding in the middle Koyukuk River basin, Alaska, August 1994
Meyer, David F.
1995-01-01
During August 1994, a flood on the Koyukuk River, Alaska, inundated the villages of Allakaket and Alatna and parts of Hughes. Topographic maps of the inundated areas, showing peak water-surface elevations and depths of water, indicate that flooding ranged from 2 to more than 10 feet deep in Allakaket, from 8 to more than 10 feet deep in Alatna, and from 0 to more than 10 feet deep in Hughes. Severe damage to buildings occurred in Allakaket and Alatna; minor damage occurred in Hughes, although some homes were irreparably damaged by inundation. Between the mouth of the Kanuti River, about 10 miles downstream from Allakaket, to Hughes, the peak discharge was about 330,000 cubic feet per second. A flow of that magnitude at Hughes has an annual probability of occurrence of 1 percent.
Publications - GMC 421 | Alaska Division of Geological & Geophysical
#2K-10, Kavearak Pt. #32-25, Long Island #1, NW Eileen St. #1, Sak River #1, W. Sak River St. #1 , Socal #33-29E, and W. Kuparuk St. #3-11-11 wells Authors: ConocoPhillips Publication Date: Dec 2013 -10, Kavearak Pt. #32-25, Long Island #1, NW Eileen St. #1, Sak River #1, W. Sak River St. #1, Socal
Identification, definition and mapping of terrestrial ecosystems in interior Alaska
NASA Technical Reports Server (NTRS)
Anderson, J. H. (Principal Investigator)
1973-01-01
The author has identified the following significant results. A transect of the Tanana River Flats to Murphy Dome, Alaska was accomplished. The transect includes an experimental forest and information on the range of vegetation-land form types. Multispectral black and white prints of the Eagle Summit Research Area, Alaska, were studied in conjunction with aerial photography and field notes to determine the characteristics of the vegetation. Black and white MSS prints were compared with aerial photographs of the village of Wiseman, Alaska. No positive identifications could be made without reference to aerial photographs or ground truth data. Color coded density slice scenes of the Eagle Summit Research Area were produced from black and white NASA aerial photographs. Infestations of the spruce beetle in the Cook Inlet, Alaska, were studied using aerial photographs.
Interactions between brown bears and chum salmon at McNeil River, Alaska
Peirce, Joshua M.; Otis, Edward O.; Wipfli, Mark S.; Follmann, Erich H.
2013-01-01
Predation on returning runs of adult salmon (Oncorhynchus spp.) can have a large influence on their spawning success. At McNeil River State Game Sanctuary (MRSGS), Alaska, brown bears (Ursus arctos) congregate in high numbers annually along the lower McNeil River to prey upon returning adult chum salmon (O. keta). Low chum salmon escapements into McNeil River since the late 1990s have been proposed as a potential factor contributing to concurrent declines in bear numbers. The objective of this study was to determine the extent of bear predation on chum salmon in McNeil River, especially on pre-spawning fish, and use those data to adjust the escapement goal for the river. In 2005 and 2006, 105 chum salmon were radiotagged at the river mouth and tracked to determine cause and location of death. Below the falls, predators consumed 99% of tagged fish, killing 59% of them before they spawned. Subsequently, the escapement goal was nearly doubled to account for this pre-spawning mortality and to ensure enough salmon to sustain both predators and prey. This approach to integrated fish and wildlife management at MRSGS can serve as a model for other systems where current salmon escapement goals may not account for pre-spawning mortality.
Landsat time series analysis documents beaver migration into permafrost landscapes of arctic Alaska
NASA Astrophysics Data System (ADS)
Jones, B. M.; Tape, K. D.; Nitze, I.; Arp, C. D.; Grosse, G.; Zimmerman, C. E.
2017-12-01
Landscape-scale impacts of climate change in the Arctic include increases in growing season length, shrubby vegetation, winter river discharge, snowfall, summer and winter water temperatures, and decreases in river and lake ice thickness. Combined, these changes may have created conditions that are suitable for beaver colonization of low Arctic tundra regions. We developed a semi-automated workflow that analyzes Landsat imagery time series to determine the extent to which beavers may have colonized permafrost landscapes in arctic Alaska since 1999. We tested this approach on the Lower Noatak, Wulik, and Kivalina river watersheds in northwest Alaska and identified 83 locations representing potential beaver activity. Seventy locations indicated wetting trends and 13 indicated drying trends. Verification of each site using high-resolution satellite imagery showed that 80 % of the wetting locations represented beaver activity (damming and pond formation), 11 % were unrelated to beavers, and 9 % could not readily be distinguished as being beaver related or not. For the drying locations, 31 % represented beaver activity (pond drying due to dam abandonment), 62 % were unrelated to beavers, and 7 % were undetermined. Comparison of the beaver activity database with historic aerial photography from ca. 1950 and ca. 1980 indicates that beavers have recently colonized or recolonized riparian corridors in northwest Alaska. Remote sensing time series observations associated with the migration of beavers in permafrost landscapes in arctic Alaska include thermokarst lake expansion and drainage, thaw slump initiation, ice wedge degradation, thermokarst shore fen development, and possibly development of lake and river taliks. Additionally, beaver colonization in the Arctic may alter channel courses, thermal regimes, hyporheic flow, riparian vegetation, and winter ice regimes that could impact ecosystem structure and function in this region. In particular, the combination of beaver activity and permafrost dynamics may play an important role in the formation of habitats conducive to colonization by Pacific salmon. Beaver activity in arctic tundra regions may amplify the effects of climate change on permafrost landscapes and lead to landscape-scale responses not currently being considered in ecosystem models.
Environmental and hydrologic overview of the Yukon River basin, Alaska and Canada
Brabets, Timothy P.; Wang, Bronwen; Meade, Robert H.
2000-01-01
The Yukon River, located in northwestern Canada and central Alaska, drains an area of more than 330,000 square miles, making it the fourth largest drainage basin in North America. Approximately 126,000 people live in this basin and 10 percent of these people maintain a subsistence lifestyle, depending on the basin's fish and game resources. Twenty ecoregions compose the Yukon River Basin, which indicates the large diversity of natural features of the watershed, such as climate, soils, permafrost, and geology. Although the annual mean discharge of the Yukon River near its mouth is more than 200,000 cubic feet per second, most of the flow occurs in the summer months from snowmelt, rainfall, and glacial melt. Eight major rivers flow into the Yukon River. Two of these rivers, the Tanana River and the White River, are glacier-fed rivers and together account for 29 percent of the total water flow of the Yukon. Two others, the Porcupine River and the Koyukuk River, are underlain by continuous permafrost and drain larger areas than the Tanana and the White, but together contribute only 22 percent of the total water flow in the Yukon. At its mouth, the Yukon River transports about 60 million tons of suspended sediment annually into the Bering Sea. However, an estimated 20 million tons annually is deposited on flood plains and in braided reaches of the river. The waters of the main stem of the Yukon River and its tributaries are predominantly calcium magnesium bicarbonate waters with specific conductances generally less than 400 microsiemens per centimeter. Water quality of the Yukon River Basin varies temporally between summer and winter. Water quality also varies spatially among ecoregions
Publications - RI 2004-1B | Alaska Division of Geological & Geophysical
Delta Quadrangle, Alaska Authors: Werdon, M.B., Newberry, R.J., Athey, J.E., and Szumigala, D.J page for more information. Quadrangle(s): Big Delta Bibliographic Reference Werdon, M.B., Newberry, R.J ., Athey, J.E., and Szumigala, D.J., 2004, Bedrock geologic map of the Salcha River-Pogo area, Big Delta
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-03
... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLAK927000 L54200000 FR0000 LVDIL09L0430; AA... River in Alaska AGENCY: Bureau of Land Management, Interior. ACTION: Notice. SUMMARY: The State of Alaska has filed an application with the Bureau of Land Management (BLM) for a Recordable Disclaimer of...
Radioactivity at the Copper Creek copper lode prospect, Eagle district, east-central Alaska
Wedow, Helmuth; Tolbert, Gene Edward
1952-01-01
Investigation of radioactivity anomalies at the Copper Creek copper lode prospect, Eagle district, east-central Alaska, during 1949 disclosed that the radioactivity is associated with copper mineralization in highly metamorphosed sedimentary rocks. These rocks are a roof pendant in the Mesozoic "Charley River" batholith. The radioactivity is probably all due to uranium associated with bornite and malachite.
Charles Rhoades; Dan Binkley; Hlynur Oskarsson; Robert Stottlemyer
2008-01-01
Nitrogen enters terrestrial ecosystems through multiple pathways during primary succession. We measured accumulation of total soil nitrogen and changes in inorganic nitrogen (N) pools across a 300-y sequence of river terraces in northwest Alaska and assessed the contribution of the nitrogen-fixing shrub Shepherdia canadensis. Our work compared 5...
Seismicity and plate tectonics in south central Alaska
NASA Technical Reports Server (NTRS)
Van Wormer, J. D.; Davies, J.; Gedney, L.
1974-01-01
Hypocenter distribution shows that the Benioff zone associated with the Aleutian arc terminates in interior Alaska some 75 km north of the Denali fault. There appears to be a break in the subducting Pacific plate in the Yentna River-Prince William Sound area which separates two seismically independent blocks, similar to the segmented structure reported for the central Aleutian arc.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-29
... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLAK927000 L54200000 FR0000 LVDIL09L0410; FF... River in Alaska AGENCY: Bureau of Land Management, Interior. ACTION: Notice. SUMMARY: The State of Alaska has filed an application with the Bureau of Land Management (BLM) for a Recordable Disclaimer of...
Geologic Map of the Utukok River Quadrangle, Alaska
Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.
2006-01-01
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.
Identification of unrecognized tundra fire events on the north slope of Alaska
Jones, Benjamin M.; Breen, Amy L.; Gaglioti, Benjamin V.; Mann, Daniel H.; Rocha, Adrian V.; Grosse, Guido; Arp, Christopher D.; Kunz, Michael L.; Walker, Donald A.
2013-01-01
Characteristics of the natural fire regime are poorly resolved in the Arctic, even though fire may play an important role cycling carbon stored in tundra vegetation and soils to the atmosphere. In the course of studying vegetation and permafrost-terrain characteristics along a chronosequence of tundra burn sites from AD 1977, 1993, and 2007 on the North Slope of Alaska, we discovered two large, previously unrecognized tundra fires. The Meade River fire burned an estimated 500 km2 and the Ketik River fire burned an estimated 1200 km2. Based on radiocarbon dating of charred twigs, analysis of historic aerial photography, and regional climate proxy data, these fires likely occurred between AD 1880 and 1920. Together, these events double the estimated burn area on the North Slope of Alaska over the last ~100 to 130 years. Assessment of vegetation succession along the century-scale chronosequence of tundra fire disturbances demonstrates for the first time on the North Slope of Alaska that tundra fires can facilitate the invasion of tundra by shrubs. Degradation of ice-rich permafrost was also evident at the fire sites and likely aided in the presumed changes of the tundra vegetation postfire. Other previously unrecognized tundra fire events likely exist in Alaska and other Arctic regions and identification of these sites is important for better understanding disturbance regimes and carbon cycling in Arctic tundra.
NASA Astrophysics Data System (ADS)
Smith, K.; Tape, C.; Bruton, C. P.; West, M. E.
2016-12-01
Continuous seismic recordings-or ambient noise-provide means for time-dependent monitoring of site conditions. Frequency-domain amplitude spectra of seismic recordings can be used to characterize time-dependent variations as a function of period (or frequency). Spatial variations can be characterized by using a set of stations across a large region. We analyze time-dependent ambient noise spectra from stations across central Alaska with three purposes. First, we are interested in monitoring the station performance and quality of a new array (FLATS) of 13 posthole seismometers near the Tanana River in Minto Flats. Second, we want to understand time-dependent threshold levels for earthquake detection: when noise is high, earthquake detections are low. Third, we are interested in identifying the effects of nature and Earth structure on seismic stations at different spatial-temporal scales. Our results show that seismic stations are sensitive to variations in wind speed and river flow. Correlations between wind speed and long-period (>10 seconds) seismic noise variations are probably due to tilt effects that have been previously documented. We identify a seismic signal at 10 Hz that is present only on stations close (<100 m) to the main channel of the Tanana river. The 10-Hz signal is strongly correlated with river gage height during summer and weakly correlated during the winter, when the river surface is covered in 1 m of ice. Spatial correlations among stations reveal large variations at shorter time scales (days); these could be due to weather anomalies. The amplitude of seismic noise at periods 2-10 s is strongly influenced by the thickness of sediment, which ranges from 0 m at bedrock sites to 6000 m at sites in the deepest part of Nenana basin. Our analysis allows us to better monitor the performance of temporary and permanent seismic stations, and to understand the physical causes of time-dependent noise variations in Alaska. Our findings show that seismic stations near rivers can potentially be used to monitor the flow of the river during summer and during ice-covered winter, raising the possibility for monitoring river ice break-up during April.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-14
...). d. Name of Project: Microturbine Hydrokinetic River-In-Stream Energy Conversion Power Project (also.... Selvaggio, Whitestone Power and Communications, P.O. Box 1630, Delta Junction, Alaska 99737; (907) 895- 4938...: The proposed Microturbine Hydrokinetic River-In-Stream Energy Conversion Power Project would consist...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-11
... Communications. e. Name of Project: Whitestone Poncelet River-In-Stream-Energy- Conversion Project (also known as the Microturbine Hydrokinetic River- In-Stream-Energy-Conversion Project) f. Location: The proposed.... Selvaggio, Whitestone Power and Communications, P.O. Box 1630, Delta Junction, Alaska 99737; phone: (907...
Adkison, M.; Peterman, R.; Lapointe, M.; Gillis, D.; Korman, J.
1996-01-01
We compare alternative models of sockeye salmon (Oncorhynchus nerka) productivity (returns per spawner) using more than 30 years of catch and escapement data for Bristol Bay, Alaska, and the Fraser River, British Columbia. The models examined include several alternative forms of models that incorporate climatic influences as well as models not based on climate. For most stocks, a stationary stock-recruitment relationship explains very little of the interannual variation in productivity. In Bristol Bay, productivity co-varies among stocks and appears to be strongly related to fluctuations in climate. The best model for Bristol Bay sockeye involved a change in the 1970s in the parameters of the Ricker stock-recruitment curve; the stocks generally became more productive. In contrast, none of the models of Fraser River stocks that we examined explained much of the variability in their productivity.
Channel erosion surveys along the TAPS route, Alaska, 1977
Loeffler, Robert M.; Childers, Joseph M.
1977-01-01
Channel surveys were made along the trans-Alaska pipeline system (TAPS) route during 1977 at the same 28 sites that were studied in 1976. In addition, a new site at pipeline mile 22 near Deadhorse (alignment No 134) along the Sagavanirktok River was put under surveillance. Except for changes wrought by the completion of construction, most of the sites showed very little change. Significant events include virtual completion of all construction activities along the pipeline, the pipeline startup , and the breakup flood along the Sagavanirktok River which breached many river-training structures. In general, 1977 saw heavy flooding on streams draining the north and south slopes of the Brooks Range and only moderate flooding on streams further south. Aerial photogrammetric surveys were used again in 1977 on the same seven sites as in 1976. Results document the applicability of the method for channel erosion studies. (Woodard-USGS)
Remote identification of polar bear maternal den habitat in northern Alaska
Durner, George M.; Amstrup, Steven C.; Ambrosius, Ken 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.
NASA Astrophysics Data System (ADS)
Vas, D. A.; Toniolo, H. A.; Kemnitz, R.; Brailey, D.; Lamb, E. K.
2011-12-01
The National Petroleum Reserve - Alaska (NPR - A) expands from the North side of the Brooks Range to the Arctic Ocean over 23.5 million acres. There is a renewed interest in opening NPR -A for oil and gas exploration and hydrological data is critical to the development of pipelines, roads, and bridges. A set of hydraulic measurements, which includes discharge measurements using Acoustic Doppler Current Profiler (ADCP), water slope, and suspended sediment sampling during breakup were conducted on Otuk Creek, Seabee Creek, Prince Creek, Ikpikpuk River, Judy Creek, Fish Creek, and Ublutuoch River in the NPR - A region. We will present preliminary results, grouped by stream characteristics.
Dumoulin, Julie A.; Harris, Anita G.
1988-01-01
Lithofacies changes in coeval upper Paleozoic rocks have been used to unravel the tectonic history of northern Alaska (for example, Mayfield and others, 1983). Conodont biostratigraphy and detailed petrologic studies are now revealing facies differences in lower Paleozoic rocks that can also be used to constrain their tectono-sedimentary framework (Dumoulin and Harris, 1987). A basic element of basin analysis is the discrimination of shallow-water shelf and platform sequences from deeper water slope and basinal deposits. This report documents several new localities of deeper water, off-platform Silurian deposits in the Ambler River quadrangle and briefly outlines some of their paleogeographic implications.
Mayfield, Charles F.; Tailleur, I.L.; Albert, N.R.; Ellersieck, Inyo; Grybeck, Donald; Hackett, S.W.
1983-01-01
The Ambler River quadrangle, consisting of 14,290 km2 (5,520 mi2) in northwest Alaska, was investigated by an interdisciplinary research team for the purpose of assessing the mineral resource potential of the quadrangle. This report provides background information for a folio of maps on the geology, reconnaissance geochemistry, aeromagnetics, Landsat imagery, and mineral resource evaluation of the quadrangle. A summary of the geologic history, radiometric dates, and fossil localities and a comprehensive bibliography are also included. The quadrangle contains jade reserves, now being mined, and potentially significant resources of copper, zinc, lead, and silver.
Ichthyophoniasis: An emerging disease of Chinook salmon in the Yukon River
Kocan, R.; Hershberger, P.; Winton, J.
2004-01-01
Before 1985, Ichthyophonus was unreported among Pacific salmon Oncorhynchus spp. from the Yukon River; now it infects more than 40% of returning adult Chinook salmon O. tshawytscha. Overall infection prevalence reached about 45% in the Yukon River and about 30% in the Tanana River between 1999 and 2003. Mean infection prevalence was greater in females than males in the main-stem Yukon River during each of the 5 years of the study, but the infection prevalence in males increased each year until the difference was no longer significant. Clinical signs of ichthyophoniasis (presence of visible punctate white lesions in internal organs) were least at the mouth of the Yukon River (∼10%) but increased to 29% when fish reached the middle Yukon River and was 22% at the upper Tanana River. However, clinical signs increased each year from 7% in 1999 to 27% in 2003 at the mouth of the river. As fish approached the upper reaches of the Yukon River (Canada) and the spawning areas of the Chena and Salcha rivers (Alaska), infection prevalence dropped significantly to less than 15% in females on the Yukon River and less than 10% for both sexes in the Chena and Salcha rivers, presumably because of mortality among infected prespawn fish. Age was not a factor in infection prevalence, nor was the position of fish within the run. The source of infection was not determined, but Ichthyophonus was not found in 400 Pacific herring Clupea pallasi from the Bering Sea or in 120 outmigrating juvenile Chinook salmon from two drainages in Alaska and Canada. Freshwater burbot Lota lota from the middle Yukon River were subclinically infected with Ichthyophonus, but the origin and relationship of this agent to the Chinook salmon isolate is unknown.
Crusius, John; Schroth, A.W.; Gasso, S.; Moy, C.M.; Levy, R.C.; Gatica, M.
2011-01-01
Iron is an essential micronutrient that limits primary productivity in much of the ocean, including the Gulf of Alaska (GoA). However, the processes that transport iron to the ocean surface are poorly quantified. We combine satellite and meteorological data to provide the first description of widespread dust transport from coastal Alaska into the GoA. Dust is frequently transported from glacially-derived sediment at the mouths of several rivers, the most prominent of which is the Copper River. These dust events occur most frequently in autumn, when coastal river levels are low and riverbed sediments are exposed. The dust plumes are transported several hundred kilometers beyond the continental shelf into iron-limited waters. We estimate the mass of dust transported from the Copper River valley during one 2006 dust event to be between 25–80 ktons. Based on conservative estimates, this equates to a soluble iron loading of 30–200 tons. We suggest the soluble Fe flux from dust originating in glaciofluvial sediment deposits from the entire GoA coastline is two to three times larger, and is comparable to the annual Fe flux to GoA surface waters from eddies of coastal origin. Given that glaciers are retreating in the coastal GoA region and in other locations, it is important to examine whether fluxes of dust are increasing from glacierized landscapes to the ocean, and to assess the impact of associated Fe on marine ecosystems.
NASA Astrophysics Data System (ADS)
Alix, Claire
2005-07-01
Driftwood that originates in the Siberian and North American boreal forest is the major source of wood to people in the treeless Arctic. It archives various kinds of data about climate, river flow, ocean and ice circulation, and other critical environmental and cultural characteristics in the north. Unlike wood in most other regions, it is often well preserved in arctic archaeological sites. The existence and renewal of driftwood are closely linked to specific climatic and ecological conditions that have changed through time (e.g., floods, river banks, storms, prevailing currents and winds, sea-ice circulation, etc.). These conditions differently affect the fall, circulation and delivery of driftwood to the coast, resulting in changes in abundance, distribution and intrinsic properties of the wood. Based on a review of existing literature supplemented by new data from Alaska, this paper details factors underlying the "dynamic of driftwood production" in terms of driftwood abundance and quality, and indigenous people's use of the resource. Oral history interviews in coastal and river communities of Alaska recorded knowledge on driftwood use and ecology. Driftwood samples were collected from accumulations along the northwest coast of Alaska and the south of the Chukotka Peninsula. Results show that the timing of treefall and river transport are crucial to the subsequent ocean circulation and may determine the size and quality of the wood. Ultimately, it conditions what coastal people could build or manufacture.
Defining interactions of in-stream hydrokinetic devices in the Tanana River, Alaska
NASA Astrophysics Data System (ADS)
Johnson, J.; Toniolo, H.; Seitz, A. C.; Schmid, J.; Duvoy, P.
2012-12-01
The acceptance, performance, and sustainability of operating in-stream hydrokinetic power generating devices in rivers depends on the impact of the river environment on hydrokinetic infrastructure as well as its impact on the river environment. The Alaska Hydrokinetic Energy Research Center (AHERC) conducts hydrokinetic "impact" and technology studies needed to support a sustainable hydrokinetic industry in Alaska. These include completed and ongoing baseline studies of river hydrodynamic conditions (river stage, discharge, current velocity, power, and turbulence; suspended and bed load sediment transport), ice, fish populations and behavior, surface and subsurface debris flows, and riverbed conditions. Technology and methods studies to minimize the effect of debris flows on deployed turbine system are in-progress to determine their effectiveness at reducing the probability of debris impact, diverting debris and their affect on available river power for conversion to electricity. An anchor point has been placed in the main flow just upstream of Main (Figure 1) to support projects and in preparation for future projects that are being planned to examine hydrokinetic turbine performance including power conversion efficiency, turbine drag and anchor chain loads, wake generation and effects on fish. Baseline fish studies indicate that hydrokinetic devices at the test site will have the most potential interactions with Pacific salmon smolts during their down-migration to the ocean in May and June. At the AHERC test site, the maximum turbulent kinetic energy (TKE) occurs just down stream from the major river bends (e.g., 000 and near the railroad bridge [upper center of the figure]) and over a deep hole at 440 (Figure 1), Minimum TKE occurs between main and 800. River current velocity measurements and simulations of river flow from 000 downstream past the railroad bridge indicate that the most stable current in the river reach is between Main and 800. The stable current and low TKE between Main and 800 indicate that this section of river may be the best site for deploying hydrokinetic devices. Woody debris exists as individual pieces or as large tangled masses on the surface, as full depth vertically oriented debris moving down river and as submerged debris posing a potential hazard to surface or subsurface deployed hydrokinetic devices. Submerged debris consists of logs, root balls, and small (mulch-like) debris. A surface debris diversion device has been tested and shown to be effective at diverting isolated debris and may reduce hazards for surface mounted devices.Figure 1. AHERC Tanana River test site at Nenana, AK.
McGimsey, Robert G.; Richter, Donald H.; DuBois, Gregory D.; Miller, T.P.
1992-01-01
The White River Ash (Lerbekmo and others, 1968), product of two of the most voluminous pyroclastic eruptions in North America in the past 2,000 yr, blankets much of the Yukon Terrtory, Canada, and a small part of adjoining eastern Alaska. Lerbekmo and Campbell (1969) narrowed the source of the ash to an area northeast of the Mt. Bona-Mt. Churchill massif in the St. Elias Mountains of southern Alaska. Based on indirect evidence, Lerbekmo and Campbell (1969) further suggested that the vent was beneath the Klutlan Glacier, adjacent to a mound of coarse pumice, 16 km northeast of Mt. Bona. Recently discovered pumice and ash deposits and a possible vent structure near the summit of Mt. Churchill suggest an alternate source area. The White River Ash is a bilobate plinian fallout deposit covering more than 340,000 km2 and containing an estimated 25-50 km3 of tephra (Bostock, 1952; Berger, 1960; fig. 1). Radiocarbon ages indicate that the northern lobe was deposited about 1,887 yr B.P. and the eastern, and larger, lobe about 1,250 yr B.P. (Lerbekmo and others, 1975). The axes of the two lobes converge near Mt. Bona (16,420 ft (5,005 m)) and Mt. Churchill [15,638 ft (4,766 m)], which together form a prominent massif in the St. Elias Mountains. The Klutlan Glacier, a large valley glacier that flows eastward into Canada, has its principal source on the eastern flank of the massif.
John Yarie
1983-01-01
The forest vegetation of 3,600,000 hectares in northeast interior Alaska was classified. A total of 365 plots located in a stratified random design were run through the ordination programs SIMORD and TWINSPAN. A total of 40 forest communities were described vegetatively and, to a limited extent, environmentally. The area covered by each community was similar, ranging...
Life in Alaska: The Reminiscences of a Kansas Woman, 1916-1919.
ERIC Educational Resources Information Center
Lamb, May Wynne; Zimmerman, Dorothy Wynne, Ed.
In 1916, May Wynne, a 27-year-old teacher, traveled from Seattle, Washington, to Akiak, Alaska, to teach in a government native school. This book presents her account of the 3 years she spent in Akiak, which consisted of an Eskimo village on one side of the Kuskokwim River and a white settlement of miners, trappers, and traders on the other. Her…
Spread of invasive plants from roads to river systems in Alaska: a network model
Tricia L. Wurtz; Matt J. Spellman Macander
2010-01-01
Alaska has relatively few invasive plants, and most of them are found only along the stateâs limited road system. One of the most widely distributed invasives in the state, Melilotus alba Medik., or sweetclover, has been sown both as a forage crop and as a roadside stabilization species. Melilotus has recently been found to...
Matthew R. Sloat; Gordon H. Reeves; Kelly R. Christiansen
2016-01-01
In rivers supporting Pacific salmon in southeast Alaska, USA, regional trends toward a warmer, wetter climate are predicted to increase mid- and late-21st-century mean annual flood size by 17% and 28%, respectively. Increased flood size could alter stream habitats used by Pacific salmon for reproduction, with negative consequences for the substantial economic, cultural...
Epiguruk: a late Quaternary environmental record from northwestern Alaska
Hamilton, T.D.; Ashley, G.M.
1993-01-01
Epiguruk, a prominent bluff along the Kobuk River in northwestern Alaska, exposes a rich depositional record of Quaternary eolian and fluvial sand, with associated loess, paleosols, and periglacial features. Three major complexes of alluvial and eolian deposits are separated by two conspicuous organic-rich paleosols which formed during cool-moist interstadial intervals. Sediments between the two paleosols include eolian, channel, and floodplain deposits that formed during alluviation of the Kobuk River to a height of about 12m above the present level. The youngest depositional complex, which overlies the upper paleosol, is divisible into late Wisconsinan and Holocene components and into fluvial-channel, flood-plain, eolian-dune, sand-sheet, loess, and pond facies. Eolian sand from the active Kobuk sand sea overloaded the river during late Wisconsinan time, causing it to alluviate to about 13m above its modern level. The Holocene record reflects erosion and deposition by a small southern Tributary to the Kobuk River, downcutting by the Kobuk River toward its modern level, and subsequent erosion across a meander belt nearly 8km wide. 66 radiocarbon ages, many from rooted shrubs, provide a firm chronology for the past 35 k.y. at Epiguruk. -from Authors
Ferrians, Oscar J.
1966-01-01
The Copper River Basin area is in south-central Alaska and covers 17,800 square miles. It includes most of the Copper River Basin and parts of the surrounding Alaska Range and the Talkeetna, Chugach, and Wrangell Mountains. On March 27, 1964, shortly after 5:36 p.m. Alaska standard time, a great earthquake having a Richter magnitude of about 8.5 struck south-central Alaska. Computations by the U.S. Coast and Geodetic Survey place the epicenter of the main shock at lat 61.1° N. and long 147.7° W., and the hypocenter, or actual point of origin, from 20 to 50 kilometers below the surface. The epicenter is near the western shore of Unakwik Inlet in northern Prince William Sound; it is 30 miles from the closest point within the area of study and 180 miles from the farthest point. Releveling data obtained in 1964 after the earthquake indicates that broad areas of south-central Alaska were warped by uplift and subsidence. The configuration of these areas generally parallels the trend of the major tectonic elements of the region. Presumably a large part of this change took place during and immediately after the 1964 earthquake. The water level in several wells in the area lowered appreciably, and the water in many became turbid; generally, however, within a few days after the earthquake the water level returned to normal and the suspended sediment settled out. Newspaper reports that the Copper River was completely dammed and Tazlina Lake drained proved erroneous. The ice on most lakes was cracked, especially around the margins of the lakes where floating ice broke free from the ice frozen to the shore. Ice on Tazlina, Klutina, and Tonsina Lakes was intensely fractured by waves generated by sublacustrine landslides off the fronts of deltas. These waves stranded large blocks of ice above water level along the shores. River ice was generally cracked in the southern half of the area and was locally cracked in the northern half. In the area of study, the majority of the ground cracks occurred within a radius of 100 miles from the epicenter of the earthquake. Ground cracks formed in flood plains of rivers, in deltas, and along the toes of alluvial fans. They also occurred locally in low terraces adjacent to flood plains, in highway and other fill material, along the margins of lakes, along the faces of steep slopes of river bluffs and hillsides, and in areas cleared of vegetation for several years. The ground cracks were restricted to areas underlain by unconsolidated deposits where one or more of the following conditions existed: (1) permafrost was absent or deep lying, (2) the ground-water table was near the surface, (3) bedrock was relatively deep lying, and (4) slopes were steep. Because the earthquake occurred in March, seasonal frost was present throughout the area. Despite the diversity of local conditions, the origin of most of the ground cracks can be explained by the following mechanisms: (1) lateral extension, caused by materials moving toward an unconfined face such as a lakeshore, river bluff, hillside, or terrace escarpment; (2) horizontal compaction, caused by repeated alternate compression and dilation (in the horizontal direction) of materials in flat-lying areas where there are no unconfined faces; (3) differential vertical compaction, caused by the shaking of materials that vary laterally in thickness or character; and (4) combinations of the above. Snowslides, avalanches, and rockslides were restricted to the mountainous areas surrounding the Copper River Basin. They were especially numerous in the Chugach Mountains which are closest to the epicenter of the earthquake. The large amount of snow and rock debris that has cascaded onto the icefield and glaciers of these mountains, and, probably even more important, the overall disturbance to the ice field will affect the regimen of the glaciers. Most of the damage to manmade structures occurred in the southern half of the area, and, primarily because of the sparsity of population and manmade structures, property damage was not great and no lives were lost.
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.
Geologic Map of the Nulato Quadrangle, West-Central Alaska
Patton, W.W.; Moll-Stalcup, E. J.
2000-01-01
Introduction The Nulato quadrangle encompasses approximately 17,000 km2 (6,500 mi2) of west-central Alaska within the Yukon River drainage basin. The quadrangle straddles two major geologic features-the Yukon-Koyukuk sedimentary basin, a huge triangle-shaped Cretaceous depression that stretches across western Alaska from the Brooks Range to the Yukon delta; and the Ruby geanticline,a broad uplift of pre-Cretaceous rocks that borders the Yukon-Koyukuk basin on the southeast. The Kaltag Fault crosses the quadrangle diagonally from northeast to southwest and dextrally offsets all major geologic features as much as 130 km.
Halm, Douglas R.; Dornblaser, Mark M.
2007-01-01
The Yukon River basin is the fourth largest watershed in North America at 831,400 square kilometers (km2). Approximately 126,000 people live within the basin and depend on the Yukon River and its tributaries for drinking water, commerce, subsistence, and recreational fish and game resources. Climate warming in the Arctic and Subarctic regions encompassing the Yukon basin has recently become a concern because of possible far-reaching effects on the ecosystem. Large amounts of carbon and nutrients are stored in permafrost and have potential for release in response to this warming. These changes in carbon and nutrient cycling may result in changes in stream chemistry and productivity, including salmon populations, and ultimately changes in the chemistry and productivity of the Bearing Sea. To address these concerns, the U.S. Geological Survey (USGS) conducted a 5-year comprehensive water-quality study of the Yukon River and its major tributaries starting in 2000. The study included frequent water-quality sampling at a fixed site network as well as intensive sampling along the Yukon River and its major tributaries. This report contains observations of water and sediment quantity and quality of the Yukon River and its tributaries in Canada during 2004. Chemical, biological, physical, and discharge data are presented for the reach of river between Atlin, British Columbia, Canada, and Eagle, Alaska, USA.
Estimating aboveground biomass in the boreal forests of the Yukon River Basin, Alaska
NASA Astrophysics Data System (ADS)
Ji, L.; Wylie, B. K.; Nossov, D.; Peterson, B.; Waldrop, M. P.; McFarland, J.; Alexander, H. D.; Mack, M. C.; Rover, J. A.; Chen, X.
2011-12-01
Quantification of aboveground biomass (AGB) in Alaska's boreal forests is essential to accurately evaluate terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. However, regional AGB datasets with spatially detailed information (<500 m) are not available for this extensive and remote area. Our goal was to map AGB at 30-m resolution for the boreal forests in the Yukon River Basin of Alaska using recent Landsat data and ground measurements. We collected field data in the Yukon River Basin from 2008 to 2010. Ground measurements included diameter at breast height (DBH) or basal diameter (BD) for live and dead trees and shrubs (>1 m tall), which were converted to plot-level AGB using allometric equations. We acquired Landsat Enhanced Thematic Mapper Plus (ETM+) images from the Web Enabled Landsat Data (WELD) that provides multi-date composites of top-of-atmosphere reflectance and brightness temperature for Alaska. From the WELD images, we generated a three-year (2008 - 2010) image composite for the Yukon River Basin using a series of compositing criteria including non-saturation, non-cloudiness, maximal normalize difference vegetation index (NDVI), and maximal brightness temperature. Airborne lidar datasets were acquired for two sub-regions in the central basin in 2009, which were converted to vegetation height datasets using the bare-earth digital surface model (DSM) and the first-return DSM. We created a multiple regression model in which the response variable was the field-observed AGB and the predictor variables were Landsat-derived reflectance, brightness temperature, and spectral vegetation indices including NDVI, soil adjusted vegetation index (SAVI), enhanced vegetation index (EVI), normalized difference infrared index (NDII), and normalized difference water index (NDWI). Principal component analysis was incorporated in the regression model to remedy the multicollinearity problems caused by high correlations between predictor variables. The model fitted the observed data well with an R-square of 0.62, mean absolute error of 29.1 Mg/ha, and mean bias error of 3.9 Mg/ha. By applying this model to the Landsat mosaic, we generated a 30-m AGB map for the boreal forests in the Yukon River Basin. Validation of the Landsat-derived AGB using the lidar dataset indicated a significant correlation between the AGB estimates and the lidar-derived canopy height. The production of a basin-wide boreal forest AGB dataset will provide an important biophysical parameter for the modeling and investigation of Alaska's ecosystems.
Methane Emissions from the Inland Waters of Alaska
NASA Astrophysics Data System (ADS)
Striegl, R. G.; Butman, D. E.; Stackpoole, S. M.; Dornblaser, M.
2017-12-01
Inland waters at high latitudes generally emit methane (CH4) continuously to the atmosphere during the open water season and build-up CH4 under ice during winter that is released over a short period following ice melt. Landscape position, stream and river size, water source, and turbulence created by water flow largely control CH4 emissions from streams and rivers. Organic carbon sources for CH4 production in lakes vary widely among lakes and landscapes and include hydrologic inputs from terrestrial sources, releases from permafrost thaw (thermokarst), and autochthonous inputs from aquatic macrophytes and algae. Lake emissions are therefore controlled by the balance between within-lake CH4 production and consumption, surface turbulence at the water-air interface, and CH4 ebullition. This creates a complex range of conditions that are difficult to characterize, where dissolved CH4 concentrations may vary by up to 4 orders of magnitude among lakes and/or within a single lake over an annual seasonal cycle. Moreover, large inputs of organic matter from permafrost thaw or other sources commonly result in high rates of bubble production and ebullition from some lakes, while other lakes have negligible ebullition. We quantified water surface areas and estimated CH4 emission rates for lakes, streams and rivers for the six major hydrologic regions of Alaska and determined that they collectively emit about 0.124 Tg C per year as CH4 to the atmosphere. Lake emissions comprise about 75% of the total. When adjusted for total land surface area in Alaska, our lake emission estimate is substantially smaller than previous global estimates for inland waters north of 50 degrees North latitude. We attribute this to incorporation of results that cover a broad range of lake conditions in interior Alaska and to new data from lakes in southwest Alaska that have very low CH4 concentration but very large surface area.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-02
... of Project: Microturbine Hydrokinetic River-In-Stream Energy Conversion Power Project (also known as... Contact: Steven M. Selvaggio, Whitestone Power and Communications, P.O. Box 1630, Delta Junction, Alaska... Hydrokinetic River-In-Stream Energy Conversion Power Project) and number (P-13305-002), and bear the heading...
Alaska's Copper River: humankind in a changing world.
Harriet H. Christensen; J. Louise Mastrantonio; John C. Gordon; Bernard T. Bormann
2000-01-01
Opportunities for natural and social science research were assessed in the Copper River ecosystem including long-term, integrated studies of ecosystem structure and function. The ecosystem is one where change, often rapid, cataclysmic change, is the rule rather than the exception. The ecosystem also contains a variety of people pursuing various human purposes. Although...
Nielsen, J.L.; Turner, S.M.; Zimmerman, C.E.
2011-01-01
Acoustic and archival tags examined freshwater and marine migrations of postspawn steelhead kelts (Oncorhynchus mykiss) in the Ninilchik River, Alaska, USA. Postspawn steelhead were captured at a weir in 2002-2005. Scale analysis indicated multiple migratory life histories and spawning behaviors. Acoustic tags were implanted in 99 kelts (2002-2003), and an array of acoustic receivers calculated the average speed of outmigration, timing of saltwater entry, and duration of residency in the vicinity of the river mouth. Ocean migration data were recovered from two archival tags implanted in kelts in 2004 (one male and one female). Archival tags documented seasonal differences in maximum depth and behavior with both fish spending 97% of time at sea <6 m depth (day and night). All study fish were double tagged with passive integrated transponder (PIT) tags implanted in the body cavity. Less than 4% of PIT tags were retained in postspawn steelhead. Molecular genetics demonstrated no significant differences in genetic population structure across years or among spawning life history types, suggesting a genetically panmictic population with highly diverse life history characteristics in the Ninilchik River.
A retrospective on hydroacoustic assessment of fish passage in Alaskan rivers
NASA Astrophysics Data System (ADS)
Burwen, Debby; Fleischman, Steve; Maxwell, Suzanne; Pfisterer, Carl
2005-04-01
The Alaska Department of Fish and Game (ADFG) has enumerated fish stocks in rivers for over 30 years using a variety of acoustic technologies including single-, dual-, and split-beam sonar. Most recently, ADFG has evaluated a relatively new sonar technology at several sites in Alaska to determine its applicability to counting migrating fish in rivers. The new system, called a Dual frequency IDentification SONar (DIDSON), is a high-definition imaging sonar designed and manufactured by the University of Washington's Applied Physics Lab for military applications such as diver detection and underwater mine identification. Results from experiments conducted in 2002-2004 indicate that DIDSON provides significant improvements in our ability to detect, track, and determine the direction of travel of migrating fish in rivers. One of the most powerful uses of the DIDSON has been to combine its camera-like images of fish swimming behavior with corresponding split-beam data. These linked datasets have allowed us to evaluate the effects of fish orientation and swimming behavior on echo shape parameters that have proven useful in the classification of certain fish species.
Grizzly bears and calving caribou: What is the relation with river corridors?
Young, Donald D.; McCabe, Thomas R.
1998-01-01
Researchers have debated the effect of the Trans-Alaska Pipeline (TAP) and associated developments to caribou (Rangifer tarandus) of the central Arctic herd (CAH) since the 1970s. Several studies have demonstrated that cows and calves of the CAH avoided the TAP corridor because of disturbance associated with the pipeline, whereas others have indicated that female caribou of the CAH avoided riparian habitats closely associated with the pipeline. This avoidance was explained as a predator-avoidance strategy. We investigated the relation between female caribou and grizzly bear (Ursus arctos) use of river corridors on the yet undisturbed calving grounds of the Porcupine caribou herd (PCH) in northeastern Alaska. On the coastal plain, caribou were closer to river corridors than expected (P = 0.038), but bear use of river corridors did not differ from expected (P = 0.740). In the foothills, caribou use of river corridors did not differ from expected (P = 0.520), but bears were farther from rivers than expected (P = 0.001). Our results did not suggest an avoidance of river corridors by calving caribou or a propensity for bears to be associated with riparian habitats, presumably for stalking or ambush cover. We propose that PCH caribou reduce the risks of predation to neonates by migrating to a common calving grounds, where predator swamping is the operational antipredator strategy. Consequently, we hypothesize that nutritional demands, not predator avoidance strategies, ultimately regulate habitat use patterns (e.g., use of river corridors) of calving PCH caribou.
Genetic variation in caribou and reindeer (Rangifer tarandus).
Cronin, M A; Patton, J C; Balmysheva, N; MacNeil, M D
2003-02-01
Genetic variation at seven microsatellite DNA loci was quantified in 19 herds of wild caribou and domestic reindeer (Rangifer tarandus) from North America, Scandinavia and Russia. There is an average of 2.0-6.6 alleles per locus and observed individual heterozygosity of 0.33-0.50 in most herds. A herd on Svalbard Island, Scandinavia, is an exception, with relatively few alleles and low heterozygosity. The Central Arctic, Western Arctic and Porcupine River caribou herds in Alaska have similar allele frequencies and comprise one breeding population. Domestic reindeer in Alaska originated from transplants from Siberia, Russia, more than 100 years ago. Reindeer in Alaska and Siberia have different allele frequencies at several loci, but a relatively low level of genetic differentiation. Wild caribou and domestic reindeer in Alaska have significantly different allele frequencies at the seven loci, indicating that gene flow between reindeer and caribou in Alaska has been limited.
John Yarie; Bert R. Mead
1988-01-01
Equations are presented for estimating the twig, foliage, and combined biomass for 58 plant species in interior Alaska. The equations can be used for estimating biomass from percentage of foliar cover of 10-centimeter layers in a vertical profile from 0 to 6 meters. Few differences were found in regressions of the same species between layers except when the ratio of...
Overview of environmental and hydrogeologic conditions at Saint Marys, Alaska
Nakanishi, Allan S.; Dorava, Joseph M.
1994-01-01
The Federal Aviation Administration (FAA) owns or operates airway support facilities near Saint Marys along the Yukon River in west-central Alaska. The FAA is evaluating the severity of environmental contamination and options for remediation of environmental contamination at their facilities. Saint Marys is on a flood plain near the continence of the Yukon and Andreafsky Rivers and has long cold winters and short summers. Residents obtain their drinking water from an infiltration gallery fed by a creek near the village. Surface spills and disposal of hazardous materials combined with potential flooding may affect the quality of the surface and ground water. Alternative drinking-water sources are available, but would likely cost more than existing supplies to develop.
Carrara, Paul E.
2007-01-01
The Tok area 1:100,000-scale map, through which the Alaska Highway runs, is in east-central Alaska about 160 km west of the Yukon border. The surficial geologic mapping in the map area is in support of the 'Geologic Mapping in support of land, resources, and hazards issues in Alaska' Project of the USGS National Cooperative Geologic Mapping Program. The Tok map area contains parts of three physiographic provinces, the Alaska Range, the Yukon-Tanana Upland, and the Northway-Tanana Lowland. The high, rugged, glaciated landscape of the eastern Alaska Range dominates the southwestern map area. The highest peak, an unnamed summit at the head of Cathedral Rapids Creek No. 2, rises to 2166 m. The gently rolling hills of the Yukon-Tanana Upland, in the northern map area, rise to about 1000 m. The Northway-Tanana Lowland contains the valley of the westerly flowing Tanana River. Elevations along the floor of the lowland generally range between 470 and 520 m. The dominant feature within the map is the Tok fan, which occupies about 20 percent of the map area. This large (450 km2), nearly featureless fan contains a high percentage of volcanic clasts derived from outside the present-day drainage of the Tok River. Because the map area is dominated by various surficial deposits, the map depicts 26 different surficial units consisting of man-made, alluvial, colluvial, eolian, lacustrine, organic, glaciofluvial, glacial, and periglacial deposits. The accompanying table provides information concerning the various units including their properties, characteristics, resource potential, and associated hazards in this area of the upper Tanana valley.
Annual Coded Wire Tag Program; Oregon Missing Production Groups, 1995 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Garrison, Robert L.; Mallette, Christine; Lewis, Mark A.
1995-12-01
Bonneville Power Administration is the funding source for the Oregon Department of Fish and Wildlife`s Annual Coded Wire Tag Program - Oregon Missing Production Groups Project. Tule brood fall chinook were caught primarily in the British Columbia, Washington and northern Oregon ocean commercial fisheries. The up-river bright fall chinook contributed primarily to the Alaska and British Columbia ocean commercial fisheries and the Columbia River gillnet fishery. Contribution of Rogue fall chinook released in the lower Columbia River system occurred primarily in the Oregon ocean commercial and Columbia river gillnet fisheries Willamette spring chinook salmon contributed primarily to the Alaska andmore » British Columbia ocean commercial, Oregon freshwater sport and Columbia River gillnet fisheries. Restricted ocean sport and commercial fisheries limited contribution of the Columbia coho released in the Umatilla River that survived at an average rate of 1.05% and contributed primarily to the Washington, Oregon and California ocean sport and commercial fisheries and the Columbia River gillnet fishery. The 1987 to 1991 brood years of coho released in the Yakima River survived at an average rate of 0.64% and contributed primarily to the Washington, Oregon and California ocean sport and commercial fisheries and the Columbia River gillnet fishery. Survival rates of salmon and steelhead are influenced, not only by factors in the hatchery, disease, density, diet and size and time of release, but also by environmental factors in the river and ocean. These environmental factors are controlled by large scale weather patterns such as El Nino over which man has no influence. Man could have some influence over river flow conditions, but political and economic pressures generally out weigh the biological needs of the fish.« less
Foster, Helen L.; Karlstrom, Thor N.V.
1967-01-01
The great 1964 Alaska earthquake caused considerable ground breakage in the Cook Inlet area of south-central Alaska. The breakage occurred largely in thick deposits of unconsolidated sediments. The most important types of ground breakage were (1) fracturing or cracking and the extrusion of sand and gravel with ground water along fractures in various types of landforms, and (2) slumping and lateral extension of unconfined faces, particularly along delta fronts. The principal concentration of ground breakage within the area covered by this report was in a northeast-trending zone about 60 miles long and 6 miles wide in the northern part of the Kenai Lowland. The zone cut across diverse topography and stratigraphy. Cracks were as much as 30 feet across and 25 feet deep. Sand, gravel, and pieces of coal and lignite were extruded along many fissures. It is suggested that the disruption in this zone may be due to movement along a fault in the underlying Tertiary rocks. The outwash deltas of Tustumena and Skilak Lakes in the Kenai Lowland, of Eklutna Lake and Lake George in the Chugach Mountains, of Bradley Lake in the Kenai Mountains, and at the outlet of upper Beluga Lake at the base of the Alaska Range showed much slumping, as did the delta of the Susitna River. Parts of the flood plains of the Skilak River, Fox River, and Eagle River were extensively cracked. A few avalanches and slumps occurred along the coast of Cook Inlet in scattered localities. Some tidal flats were cracked. However, in view of the many thick sections of unconsolidated sediments and the abundance of steep slopes, the cracking was perhaps less than might have been expected. Observations along the coasts indicated changes in sea level which, although caused partly by compaction of unconsolidated sediments, may largely be attributed to crus1tal deformation accompanying the earthquake. Most of the Cook Inlet area was downwarped, although the northwest side of Cook Inlet may have been slightly unwarped. Maximum change in the Cook Inlet area was probably less than 6 feet. Little or no regional tilting was detected in the lake basins of Tustumena and Skilak Lakes.
Introduced northern pike predation on salmonids in southcentral Alaska
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.
Geologic Map of the Ikpikpuk River Quadrangle, Alaska
Mull, Charles G.; Houseknecht, David W.; Pessel, G.H.; Garrity, Christopher P.
2005-01-01
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.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-22
... Federal Power Act, proposing to study the feasibility of the Silver Lake Hydroelectric Project, located on Silver Lake and Duck River, in the Valdez-Cordova Census Area, Alaska. The sole purpose of a preliminary...-high roller-compacted concrete dam constructed at the outfall of Silver Lake to Duck River; (2) Silver...
High salmon density and low discharge create periodic hypoxia in coastal rivers
Christopher J. Sergeant; J. Ryan Bellmore; Casey McConnell; Jonathan W. Moore
2017-01-01
Dissolved oxygen (DO) is essential to the survival of almost all aquatic organisms. Here, we examine the possibility that abundant Pacific salmon (Oncorhynchus spp.) and low streamflow combine to create hypoxic events in coastal rivers. Using high-frequency DO time series from two similar watersheds in southeastern Alaska, we summarize DO regimes...
Plant biomass in the Tanana River Basin, Alaska.
Bert R. Mead
1995-01-01
Vegetation biomass tables are presented for the Tanana River basin. Average biomass for each species of tree, shrub, grass, forb, lichen, and moss in the 13 forest and 30 nonforest vegetation types is shown. These data combined with area estimates for each vegetation type provide a tool for estimating habitat carrying capacity for many wildlife species. Tree biomass is...
Teresa N. Hollingsworth; Andrea H. Lloyd; Dana R. Nossov; Roger W. Ruess; Brian A. Charlton; Knut Kielland
2010-01-01
Along the Tanana River floodplain, several turning points have been suggested to characterize the changes in ecosystem structure and function that accompany plant community changes through primary succession. In the past, much of tills research focused on a presumed chronosequence that uses space for time substitutions. Within this chronosequence, permanent vegetation...
Publications - RDF 2001-1 | Alaska Division of Geological & Geophysical
geochemical data from rocks collected in the Salcha River-Pogo area in 2000, Big Delta and northwestern Eagle more information. Quadrangle(s): Big Delta; Eagle Bibliographic Reference Werdon, M.B., Athey, J.E , and geochemical data from rocks collected in the Salcha River-Pogo area in 2000, Big Delta and
Effects of hydraulic roughness on surface textures of gravel-bed rivers
John M. Buffington; David R. Montgomery
1999-01-01
Field studies of forest gravel-bed rivers in northwestern Washington and southeastern Alaska demonstrate that bed-surface grain size is responsive to hydraulic roughness caused by bank irregularities, bars, and wood debris. We evaluate textural response by comparing reach-average median grain size (D50) to that predicted from the total bank-full boundary shear stress (...
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.
Publications - PDF 95-33B | Alaska Division of Geological & Geophysical
D-1, C-1, and part of the B-1 quadrangles, east-central Alaska Authors: Clough, J.G., Mull, C.G , Interpretive bedrock geologic map of the Charley River D-1, C-1, and part of the B-1 quadrangles, east-central 1:63,360. http://doi.org/10.14509/1713 Publication Products Maps & Other Oversized Sheets Maps
Radiotelemetry to estimate stream life of adult chum salmon in the McNeil River, Alaska
Peirce, Joshua M.; Otis, Edward O.; Wipfli, Mark S.; Follmann, Erich H.
2011-01-01
Estimating salmon escapement is one of the fundamental steps in managing salmon populations. The area-under-the-curve (AUC) method is commonly used to convert periodic aerial survey counts into annual salmon escapement indices. The AUC requires obtaining accurate estimates of stream life (SL) for target species. Traditional methods for estimating SL (e.g., mark–recapture) are not feasible for many populations. Our objective in this study was to determine the average SL of chum salmon Oncorhynchus keta in the McNeil River, Alaska, through radiotelemetry. During the 2005 and 2006 runs, 155 chum salmon were fitted with mortality-indicating radio tags as they entered the McNeil River and tracked until they died. A combination of remote data loggers, aerial surveys, and foot surveys were used to determine the location of fish and provide an estimate of time of death. Higher predation resulted in tagged fish below McNeil Falls having a significantly shorter SL (12.6 d) than those above (21.9 d). The streamwide average SL (13.8 d) for chum salmon at the McNeil River was lower than the regionwide value (17.5 d) previously used to generate AUC indices of chum salmon escapement for the McNeil River. We conclude that radiotelemetry is an effective tool for estimating SL in rivers not well suited to other methods.
LePain, David L.; Stanley, Richard G.
2017-01-01
This report summarizes reconnaissance sedimentologic and stratigraphic observations made during six days of helicopter-supported fieldwork in 2002 on Tertiary sedimentary rocks exposed in the upland region around the flanks of the Yukon Flats basin in east-central Alaska (fig. 1). This project was a cooperative effort between the Alaska Division of Geological & Geophysical Surveys (DGGS) and the U.S. Geological Survey (USGS) to investigate the geology of the basin in preparation for an assessment of the undiscovered, technically recoverable hydrocarbon resources (Stanley and others, 2004). Field observations and interpretations summarized in this report are reconnaissance level. At most, no more than a few hours were spent on the ground at any location. Measured sections included in this report are sketch sec- tions and thicknesses shown are approximate. Relatively detailed observations were made by the authors at only three locations, including The Mudbank (Hodzana River), Rampart (east bank of the Yukon River), and Bryant Creek (along the Tintina fault near the Canada border). These three locations are described first in relative detail, then followed by general descriptions of other locations.
NASA Astrophysics Data System (ADS)
Blank, Justin J.
High resolution digital aerial photographs (1 foot pixel size) of the Colville River Delta, Alaska were examined in 3D, with the use of a digital photogrammetric workstation. Topographic features meeting the criteria required for adequate snow accumulation, and subsequent construction of terrestrial polar bear maternal dens, were identified and digitized into an ArcGIS line shapefile. Effectiveness, efficiency, and accuracy were improved when compared to previous polar bear denning habitat efforts which utilized contact photo prints and a pocket stereoscope in other geographic areas of northern Alaska. Accuracy of photograph interpretation was systematically evaluated visually from the air with the use of a helicopter and physically on the ground. Results show that the mapping efforts were successful in identifying den habitat 91.3% of the time. Knowledge denning habitat can improve and inform decision making by managers and regulators when considering travel and development in the study area. An understanding of polar bear denning habitat extent and location will be a crucial tool for planning activities within the study area in a way that minimizes conflicts with maternal dens.
Burger, C.V.; Wilmot, R.L.; Wangaard, D.B.
1985-01-01
From 1979 to 1982,188 chinook salmon (Oncorhynchus tshawytscha) were tagged with radio transmitters to locate spawning areas in the glacial Kenai River, southcentral Alaska. Results confirmed that an early run entered the river in May and June and spawned in tributaries, and a late run entered the river from late June through August and spawned in the main stem. Spawning peaked during August in tributaries influenced by lakes, but during July in other tributaries. Lakes may have increased fall and winter temperatures of downstream waters, enabling successful reproduction for later spawning fish within these tributaries. This hypothesis assumes that hatching and emergence can be completed in a shorter time in lake-influenced waters. The time of upstream migration and spawning (mid- to late August) of the late run is unique among chinook stocks in Cook Inlet. This behavior may have developed only because two large lakes (Kenai and Skilak) directly influence the main-stem Kenai River. If run timing is genetically controlled, and if the various components of the two runs are isolated stocks that have adapted to predictable stream temperatures, there are implications for stock transplantation programs and for any activities of man that alter stream temperatures.
Adams, Noah S.; Spearman, William J.; Burger, Carl V.; Currens, Kenneth P.; Schreck, Carl B.; Li, Hiram W.
1994-01-01
Genetic differences between early and late forms of Alaskan chinook salmon (Oncorhynchus tshawytscha) were identified using two genetic approaches: mitochondrial DNA (mtDNA) analysis, and protein electrophoresis. Study populations consisted of early and late runs in each of the Kenai and Kasilof rivers in Alaska, and a population from the Minam River, Oregon. Two segments of mtDNA were amplified using the polymerase chain reaction (PCR) and digested with 14–16 restriction enzymes. Results showed that early runs were genetically similar to each other but different from the late runs. The late runs were different from each other based on the frequency of the common haplotypes. Frequency differences in shared haplotypes together with the presence of a unique haplotype separated the Minam River stock from those in Alaska. In the protein analysis, each population was examined at 30 allozyme loci. Based on 14 polymorphic loci, Minam River salmon were genetically distinct from the Alaskan populations. Within the Alaskan populations, early runs were most similar to each other but different from the late runs; the late runs were also genetically most similar to each other. Both mtDNA and allozyme analysis suggest that chinook salmon may segregate into genetically different early and late forms within a drainage.
Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.
2015-01-01
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 653 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering portions of the Inmachuk, Kugruk, Kiwalik, and Koyuk river drainages, Granite Mountain, and the northern Darby Mountains, located in the Bendeleben, Candle, Kotzebue, and Solomon quadrangles of eastern Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.
Physical, chemical, and biological data for two sites on the upper Kenai River, Alaska, 1998
Dorava, Joseph M.; Ness, Lee
1999-01-01
Water-quality data were collected and stream characteristics were documented from two sites along the upper Kenai River in the Kenai National Wildlife Refuge, Alaska. These data were collected to describe the current status of the sites and to provide baseline information from which changes in the future could be evaluated. Physical characteristics included channel geometry surveys, and measurements of channel widths and water discharge at each site. Chemical data included stream water temperature, dissolved-oxygen concentration, pH, specific conductance, E. coli and fecal coliform counts, and nutrient concentration. Data on concentrations of trace elements and various organic compounds in bed sediments and the tissue of slimy sculpin were also collected. Biological characteristics were evaluated using measurements of the bacteria, benthic macroinvertebrate, and fish communities.
The 1977 tundra fire in the Kokolik River area of Alaska
NASA Technical Reports Server (NTRS)
1981-01-01
Presumably caused by lightning, a large fire occurred due east of Point Lay several kilometers southwest of the Kokolik River, the farthest north a fire was ever fought by Bureau of Land Management personnel in Alaska. The progress and area extent of the fire were determined by analysis of LANDSAT MSS band 5 and 7 imagery. Low altitude observations from helicopter showed the fire burned a range of vegetation and relief types which included low polygonized and upland tussock tundras. The burned area appeared wetter on the surface than the unburned area, due to a lack of moisture absorbing organic matter and the possible release of moisture from the deeper thawed zone. Suggestions for future investigations of the effects of fire on tundra and permafrost terrains are discussed.
Lin, Jocelyn E; Hilborn, Ray; Quinn, Thomas P; Hauser, Lorenz
2011-12-01
Small populations can provide insights into ecological and evolutionary aspects of species distributions over space and time. In the Wood River system in Alaska, USA, small aggregates of Chinook (Oncorhynchus tshawytscha) and chum salmon (O. keta) spawn in an area dominated by sockeye salmon (O. nerka). Our objective was to determine whether these Chinook and chum salmon are reproductively isolated, self-sustaining populations, population sinks that produce returning adults but receive immigration, or strays from other systems that do not produce returning adults. DNA samples collected from adult chum salmon from 16 streams and Chinook salmon from four streams in the Wood River system over 3 years were compared to samples from large populations in the nearby Nushagak River system, a likely source of strays. For both species, microsatellite markers indicated no significant genetic differentiation between the two systems. Simulations of microsatellite data in a large source and a smaller sink population suggested that considerable immigration would be required to counteract the diverging effects of genetic drift and produce genetic distances as small as those observed, considering the small census sizes of the two species in the Wood River system. Thus, the Wood River system likely receives substantial immigration from neighbouring watersheds, such as the Nushagak River system, which supports highly productive runs. Although no data on population productivity in the Wood River system exist, our results suggest source-sink dynamics for the two species, a finding relevant to other systems where salmonid population sizes are limited by habitat factors. © 2011 Blackwell Publishing Ltd.
AirSWOT flights and field campaigns for the 2017 Arctic-Boreal Vulnerability Experiment (ABoVE)
NASA Astrophysics Data System (ADS)
Smith, L. C.; Pavelsky, T.; Lettenmaier, D. P.; Gleason, C. J.; Pietroniro, A.; Applejohn, A.; Arvesen, J. C.; Bjella, K.; Carter, T.; Chao, R.; Cooley, S. W.; Cooper, M. G.; Cretaux, J. F.; Douglass, T.; Faria, D.; Fayne, J.; Fiset, J. M.; Goodman, S.; Hanna, B.; Harlan, M.; Langhorst, T.; Marsh, P.; Moreira, D. M.; Minear, J. T.; Onclin, C.; Overstreet, B. T.; Peters, D.; Pettit, J.; Pitcher, L. H.; Russell, M.; Spence, C.; Topp, S.; Turner, K. W.; Vimal, S.; Wilcox, E.; Woodward, J.; Yang, D.; Zaino, A.
2017-12-01
Some 50% of Canada and 80% of Alaska is thought to be underlain by permafrost, influencing the hydrology, ecology and carbon cycles of Arctic-Boreal landscapes. This influence includes enhanced presence of millions of lakes and wetlands, which release trace gases while supporting critical ecosystems and traditional subsistence economies. Permafrost is challenging to infer from remote sensing and difficult to sample in the field. A series of 2017 AirSWOT flights flown for the NASA Arctic-Boreal Vulnerability Experiment (ABoVE) will study whether small variations in water surface elevations (WSEs) of Arctic-Boreal lakes are sensitive to presence and/or disturbance of permafrost. AirSWOT is an experimental NASA airborne radar designed to map WSE and a precursor to SWOT, a forthcoming NASA/CNES/CSA satellite mission to map WSE globally with launch in 2021. The ABoVE AirSWOT flight experiments adopted long flight lines of the broader ABoVE effort to traverse broad spatial gradients of permafrost, climate, ecology, and geology. AirSWOT acquisitions consisted of long (1000s of kilometers) strips of Ka-band interferometric radar imagery, and high resolution visible/NIR imagery and DEMs from a digital Cirrus CIR camera. Intensive AirSWOT mapping and ground-based GPS field surveys were conducted at 11 field sites for eight study areas of Canada and Alaska: 1) Saint-Denis, Redberry Lake, North Saskatchewan River (Saskatchewan); 2) Peace-Athabasca Delta (Alberta); 3) Slave River Delta (N.W.T.); 4) Canadian Shield (Yellowknife area, Daring Lake, N.W.T.); 5) Mackenzie River (Inuvik-Tuktoyaktuk corridor, N.W.T.); 6) Old Crow Flats (Yukon Territory); 7) Sagavanirktok River (Alaska); 8) Yukon Flats (Alaska). Extensive ground campaigns were conducted by U.S. and Canadian collaborators to collect high quality surveys of lake WSE, river WSE and discharge, and shoreline locations. Field experiments included traditional and novel GPS surveying methods, including custom-built GPS buoys that float or drift upon water surfaces. Other ABoVE flight packages flown along AirSWOT lines included LVIS, AVIRIS, UAVSAR and AirMOSS. Processing and integration of ABoVE remote sensing and field datasets may provide new scientific insights about the influence of permafrost on surface water hydrology, over broad spatial scales.
Controls on the size and occurrence of pools in coarse-grained forest rivers
John M. Buffington; Thomas E. Lisle; Richard D. Woodsmith; Sue Hilton
2002-01-01
Controls on pool formation are examined in gravel- and cobble-bed rivers in forest mountain drainage basins of northern California, southern Oregon, and southeastern Alaska. We demonstrate that the majority of pools at our study sites are formed by flow obstructions and that pool geometry and frequency largely depend on obstruction characteristics (size, type, and...
Keith. Boggs
2000-01-01
A classification of community types, successional sequences, and landscapes is presented for the piedmont of the Copper River Delta. The classification was based on a sampling of 471 sites. A total of 75 community types, 42 successional sequences, and 6 landscapes are described. The classification of community types reflects the existing vegetation communities on the...
J.R. Sedell; W.S. Duval
1985-01-01
Environmental effects of water transportation of logs in western North America include the historical driving of logs in rivers and streams, and the current dumping, sorting, transportation, and storage of logs in rivers and estuaries in British Columbia and southeastern Alaska. The historical discussion focuses on habitat losses and volumes of...
Publications - GMC 248 | Alaska Division of Geological & Geophysical
from cuttings of the following Copper River basin oil and gas exploratory wells: Aledo Oil Co. Eureka #2 (2000' - 8545'); and Mobil Oil Corp. Salmonberry Lake Unit #2 (1500' - 7900') Authors: DGSI, Inc the following Copper River basin oil and gas exploratory wells: Aledo Oil Co. Eureka #2 (2000' - 8545
Rine, Kristin M.; Wipfli, Mark S.; Schoen, Erik R.; Nightengale, Timothy L.; Stricker, Craig A.
2016-01-01
Contributions of terrestrial-, freshwater-, and marine-derived prey resources to stream fishes vary over time and space, altering the energy pathways that regulate production. In this study, we determined large-scale use of these resources by juvenile Chinook and coho salmon (Oncorhynchus tshawytscha and Oncorhynchus kisutch, respectively) in the glacial Susitna River, Alaska. We resolved spatial and temporal trophic patterns among multiple macrohabitat types along a 97 km segment of the river corridor via stable isotope and stomach content analyses. Juvenile salmon were supported primarily by freshwater-derived resources and secondarily by marine and terrestrial sources. The relative contribution of marine-derived prey to rearing salmon was greatest in the fall within off-channel macrohabitats, whereas the contributions of terrestrial invertebrate prey were generally greatest during midsummer, across all macrohabitats. No longitudinal (upstream–downstream) diet pattern was discernable. These results highlight large-scale spatial and seasonal patterns of energy flow and the dynamic interplay of pulsed marine and terrestrial prey subsidies to juvenile Chinook and coho salmon in a large, complex, and relatively pristine glacial river.
Belukha whale (delphinapterus leucas) responses to industrial noise in Nushagak Bay, Alaska: 1983
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stewart, B.S.; Awbrey, F.T.; Evans, W.E.
1983-01-01
Between 15 June and 14 July 1983 the authors conducted playback experiments with belukha whales in the Snake River, Alaska, using sounds recorded near an operating oil-drilling rig. The objectives of these experiments were to quantify behavioral responses of belukha whales to oil drilling noise in an area where foreign acoustic stimuli were absent, and to test the hypothesis that beluhka whales would not approach a source of loud sound.
Indigenous observations of climate change in the Lower Yukon River Basin, Alaska
Herman-Mercer, Nicole M.; Schuster, Paul F.; Maracle, Karonhiakt'tie
2011-01-01
Natural science climate change studies have led to an overwhelming amount of evidence that the Arctic and Subarctic are among the world's first locations to begin experiencing climate change. Indigenous knowledge of northern regions is a valuable resource to assess the effects of climate change on the people and the landscape. Most studies, however, have focused on coastal Arctic and Subarctic communities with relatively little focus on inland communities. This paper relates the findings from fieldwork conducted in the Lower Yukon River Basin of Alaska in the spring of 2009. Semi-structured interviews were conducted with hunters and elders in the villages of St. Mary's and Pitka's Point, Alaska to document observations of climate change. This study assumes that scientific findings and indigenous knowledge are complementary and seeks to overcome the false dichotomy that these two ways of knowing are in opposition. The observed changes in the climate communicated by the hunters and elders of St. Mary's and Pitka's Point, Alaska are impacting the community in ways ranging from subsistence (shifting flora and fauna patterns), concerns about safety (unpredictable weather patterns and dangerous ice conditions), and a changing resource base (increased reliance on fossil fuels). Here we attempt to address the challenges of integrating these two ways of knowing while relating indigenous observations as described by elders and hunters of the study area to those described by scientific literature.
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.
Rare Clear View of Alaska [high res
2017-12-08
On most days, relentless rivers of clouds wash over Alaska, obscuring most of the state’s 6,640 miles (10,690 kilometers) of coastline and 586,000 square miles (1,518,000 square kilometers) of land. The south coast of Alaska even has the dubious distinction of being the cloudiest region of the United States, with some locations averaging more than 340 cloudy days per year. That was certainly not the case on June 17, 2013, the date that the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this rare, nearly cloud-free view of the state. The absence of clouds exposed a striking tapestry of water, ice, land, forests, and even wildfires. Snow-covered mountains such as the Alaska Range and Chugach Mountains were visible in southern Alaska, while the arc of mountains that make up the Brooks Range dominated the northern part of the state. The Yukon River—the longest in Alaska and the third longest in the United States—wound its way through the green boreal forests that inhabit the interior of the state. Plumes of sediment and glacial dust poured into the Gulf of Alaska from the Copper River. And Iliamna Lake, the largest in Alaska, was ice free. The same ridge of high pressure that cleared Alaska’s skies also brought stifling temperatures to many areas accustomed to chilly June days. Talkeetna, a town about 100 miles north of Anchorage, saw temperatures reach 96°F (36°C) on June 17. Other towns in southern Alaska set all-time record highs, including Cordova, Valez, and Seward. The high temperatures also helped fuel wildfires and hastened the breakup of sea ice in the Chukchi Sea. NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC. Caption by Adam Voiland. Instrument: Terra - MODIS More info: 1.usa.gov/102MAEj Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Rare Clear View of Alaska [annotated
2017-12-08
On most days, relentless rivers of clouds wash over Alaska, obscuring most of the state’s 6,640 miles (10,690 kilometers) of coastline and 586,000 square miles (1,518,000 square kilometers) of land. The south coast of Alaska even has the dubious distinction of being the cloudiest region of the United States, with some locations averaging more than 340 cloudy days per year. That was certainly not the case on June 17, 2013, the date that the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this rare, nearly cloud-free view of the state. The absence of clouds exposed a striking tapestry of water, ice, land, forests, and even wildfires. Snow-covered mountains such as the Alaska Range and Chugach Mountains were visible in southern Alaska, while the arc of mountains that make up the Brooks Range dominated the northern part of the state. The Yukon River—the longest in Alaska and the third longest in the United States—wound its way through the green boreal forests that inhabit the interior of the state. Plumes of sediment and glacial dust poured into the Gulf of Alaska from the Copper River. And Iliamna Lake, the largest in Alaska, was ice free. The same ridge of high pressure that cleared Alaska’s skies also brought stifling temperatures to many areas accustomed to chilly June days. Talkeetna, a town about 100 miles north of Anchorage, saw temperatures reach 96°F (36°C) on June 17. Other towns in southern Alaska set all-time record highs, including Cordova, Valez, and Seward. The high temperatures also helped fuel wildfires and hastened the breakup of sea ice in the Chukchi Sea. NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC. Caption by Adam Voiland. Instrument: Terra - MODIS More info: 1.usa.gov/102MAEj Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Code of Federal Regulations, 2010 CFR
2010-07-01
... only on the Naknek River during times and dates established by the Alaska Department of Fish and Game, and only from markers located just above Trefon's cabin downstream to the park boundary. (b...
Glaciers along proposed routes extending the Copper River Highway, Alaska
Glass, R.L.
1996-01-01
Three inland highway routes are being considered by the Alaska Department of Transportation and Public Facilities to connect the community of Cordova in southcentral Alaska to a statewide road system. The routes use part of a Copper River and Northwest Railway alignment along the Copper River through mountainous terrain having numerous glaciers. An advance of any of several glaciers could block and destroy the roadway, whereas retreating glaciers expose large quantities of unconsolidated, unvegetated, and commonly ice-rich sediments. The purpose of this study was to map historical locations of glacier termini near these routes and to describe hazards associated with glaciers and seasonal snow. Historical and recent locations of glacier termini along the proposed Copper River Highway routes were determined by reviewing reports and maps and by interpreting aerial photographs. The termini of Childs, Grinnell, Tasnuna, and Woodworth Glaciers were 1 mile or less from a proposed route in the most recently available aerial photography (1978-91); the termini of Allen, Heney, and Schwan Glaciers were 1.5 miles or less from a proposed route. In general, since 1911, most glaciers have slowly retreated, but many glaciers have had occasional advances. Deserted Glacier and one of its tributary glaciers have surge-type medial moraines, indicating potential rapid advances. The terminus of Deserted Glacier was about 2.1 miles from a proposed route in 1978, but showed no evidence of surging. Snow and rock avalanches and snowdrifts are common along the proposed routes and will periodically obstruct the roadway. Floods from ice-dammed lakes also pose a threat. For example, Van Cleve Lake, adjacent to Miles Glacier, is as large as 4.4 square miles and empties about every 6 years. Floods from drainages of Van Cleve Lake have caused the Copper River to rise on the order of 20 feet at Million Dollar Bridge.
Lemke, Richard Walter; Yehle, Lynn A.
1972-01-01
The Alaska earthquake of March 27, 1964, brought into sharp focus the need for engineering geologic studies in urban areas. Study of the Haines area constitutes an integral part of an overall program to evaluate earthquake and other geologic hazards in most of the larger Alaska coastal communities. The evaluations of geologic hazards that follow, although based only upon reconnaissance studies and, therefore, subject to revision, will provide broad guidelines useful in city and land-use planning. It is hoped that the knowledge gained will result in new facilities being built in the best possible geologic environments and being designed so as to minimize future loss of life and property damage. Haines, which is in the northern part of southeastern Alaska approximately 75 miles northwest of Juneau, had a population, of about 700 people in 1970. It is built at the northern end of the Chilkat Peninsula and lies within the Coast Mountains of the Pacific Mountain system. The climate is predominantly marine and is characterized by mild winters and cool summers. The mapped area described in this report comprises about 17 square miles of land; deep fiords constitute most of the remaining mapped area that is evaluated in this study. The Haines area was covered by glacier ice at least once and probably several times during the Pleistocene Epoch. The presence of emergent marine deposits, several hundred feet above sea level, demonstrates that the land has been uplifted relative to sea level since the last major deglaciation of the region about 10,000 years ago. The rate of relative uplift of the land at Haines during the past 39 years is 2.26 cm per year. Most or all of this uplift appears to be due to rebound as a result of deglaciation. Both bedrock and surficial deposits are present in the area. Metamorphic and igneous rocks constitute the exposed bedrock. The metamorphic rocks consist of metabasalt of Mesozoic age and pyroxenite of probable early middle Cretaceous age. The igneous rocks consist of diorite and quartz diorite (tonalite) of Cretaceous age. Sedimentary rocks of Tertiary age may be present in the mapped area but are not exposed. The surficial deposits of Quaternary age,-have been divided into the following map units on the basis of time Of deposition, mode of origin, and grain size: (1) undifferentiated drift deposits, (2) outwash and Ice-contact deposits; (3) elevated fine-grained marine deposits, (4) elevated shore and delta deposits, (5) alluvial fan deposits, (6) colluvial deposits, (7) modern beach deposits, (8) Chilkat River flood-plain and delta deposits, and (9) manmade fill. Offshore deposits are described but are not mapped. Southeastern Alaska lies within the tectonically active belt that rims the northern Pacific Basin and has been active since at least early Paleozoic time. The outcrop pattern is the result of late Mesozoic and Tertiary deformational, metamorphic, and intrusive events. Large-scale faulting has been common. The two most prominent inferred fault systems in southeastern Alaska and surrounding regions are: (1) The Denali fault system and (2) the Fairweather-Queen Charlotte Islands fault system. In the general area of Haines, rocks of Mesozoic age northeast of Chilkat River have a simple monoclinal structure. Paleozoic-Mesozoic rocks southwest of Chilkat River are gently to rather complexly folded. Several major and numerous minor faults probably transect the general area of Haines but their exact location and character can only be inferred because their traces are coincident to the long axes of fiords and river valleys, where they are concealed by water or by valley-floor deposits. Inferred faults in or near the Haines mapped area are: (1) Chilkat River fault, (2) Chilkoot fault, (3) Takhin fault, and (4) faults in the saddle area at Haines. Southeastern Alaska lies in one of the two most seismically active zones in Alaska, a State where 6 percent of the world's shallow earthqua
Powell, James E.; Wipfli, Mark S.; Criddle, Keith R.; Schoen, Erik R.
2018-01-01
Alaska’s sheries regulatory regime, one of the strongest, most science- based sheries management systems in the world, is often held up as an example of sheries management “done right” (Worm etal. 2011). Faced with a barrage of oncoming threats, ranging from budget cuts to climate change, will this system prove to be truly resilient? To answer this question, we examined the results of the research pertaining to governance from a larger 5- year social- ecological study of the Alaska Experimental Program to Stimulate Competitive Research’s (AK-EPSCoR) Alaska Adapting to Changing Environments series (see Schoen etal. 2017).
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.
Publications - GMC 37 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 37 Publication Details Title: Petrologic description of AMOCO Cathedral River Unit #1 sands for more information. Bibliographic Reference Dutrow & Associates, 1982, Petrologic description of
Theodore S. Setzer; Bert R. Mead; Gary L. Carroll
1984-01-01
A multiresource inventory of the Willow block, Susitna River basin inventory unit, was conducted in 1978. Statistics on forest area, timber volumes, and growth and mortality from this inventory are presented. Timberland area is estimated at 230,200 acres and net growing stock volume, mostly birch, at 231.9 million cubic feet. Net annual growth of growing stock is...
Bert R. Mead; Theodore S. Setzer; Gary L. Carroll
1985-01-01
A multiresource inventory of the Upper Susitna block, Susitna River basin inventory unit, was conducted in 1980. Statistics on forest area, timber volumes, and annual growth from this inventory are presented. Timberland area is estimated at 112,130 acres, and net growing stock volume, mostly hardwood, is 84.6 million cubic feet. Net annual growth of growing stock is...
Gary L. Carroll; Theodore S. Setzer; Bert R. Mead
1985-01-01
A multiresource inventory of the Beluga block, Susitna River basin inventory unit, was conducted in 1980. Statistics on forest area, timber volumes, and growth and mortality from this inventory are presented. Timberland area is estimated at 131,740 acres and net growing stock volume, mostly hardwood, is 99.4 million cubic feet. Net annual growth of growing stock is...
Theodore S. Setzer; Gary L. Carroll; Bert R. Mead
1984-01-01
A multiresource inventory of the Talkeetna block, Susitna River basin inventory unit, was conducted in 1979. Statistics on forest area, timber volumes, and growth and mortality from this inventory are presented. Timberland area is estimated at 562,105 acres and net growing stock volume, mostly hardwood, at 574.7 million cubic feet. Net annual growth of growing stock is...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-25
... Denali Highway at milepost 21.5 and lies within the nationally designated Delta Wild and Scenic River... designated campsites with tables, tent or trailer space and fire rings, as well as a picnic area, parking... the update of the Delta Wild and Scenic River management plan. The public was provided details of the...
Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska
NASA Astrophysics Data System (ADS)
Fee, David; Haney, Matthew M.; Matoza, Robin S.; Van Eaton, Alexa R.; Cervelli, Peter; Schneider, David J.; Iezzi, Alexandra M.
2017-01-01
The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity.
NASA Technical Reports Server (NTRS)
Meier, M. F. (Principal Investigator)
1973-01-01
The author has identified the following significant results. The standard error of measurement of snow covered areas in major drainage basins in the Cascade Range, Washington, using single measurements of ERTS-1 images, was found to range from 11% to 7% during a typical melt season, but was as high as 32% in midwinter. Many dangerous glacier situations in Alaska, Yukon, and British Columbia were observed on ERTS-1 imagery. Glacier dammed lakes in Alaska are being monitored by ERTS-1. Embayments in tidal glaciers show changes detectable by ERTS-1. Surges of Russell and Tweedsmuir Glaciers, now in progress, are clearly visible. The Tweedsmuir surge is likely to dam the large Alsek River by mid-November, producing major floods down-river next summer. An ERTS-1 image of the Pamir Mountains, Tadjik S.S.R., shows the surging Medvezhii (Bear) Glacier just after its surge of early summer which dammed the Abdukagor Valley creating a huge lake and later a flood in the populous Vanch River Valley. A map was compiled from an ERTS-1 image of the Lowell Glacier after its recent surge, compared with an earlier map compiled from pain-stakingly compiled from a mosaic of many aerial photographs, in a total elapsed time of 1.5 hours. This demonstrates the value of ERTS-1 for rapid mapping of large features.
NASA Astrophysics Data System (ADS)
Pitcher, L. H.; Pavelsky, T.; Smith, L. C.; Moller, D.; Altenau, E. H.; Lion, C.; Bertram, M.; Cooley, S. W.
2017-12-01
AirSWOT is an airborne, Ka-band synthetic aperture radar interferometer (InSAR) intended to quantify surface water fluxes by mapping water surface elevations (WSE). AirSWOT will also serve as a calibration/validation tool for the Surface Water and Ocean Topography (SWOT) satellite mission (scheduled for launch in 2021). The hydrology objectives for AirSWOT and SWOT are to measure WSE with accuracies sufficient to estimate hydrologic fluxes in lakes, wetlands and rivers. However, current understanding of the performance of these related though not identical instruments when applied to complex river-lake-wetland fluvial environments remains predominantly theoretical. We present AirSWOT data acquired 15-June-2015 over the Yukon Flats, Alaska, USA, together with in situ field surveys, to assess the accuracy of AirSWOT WSE measurements in lakes and rivers. We use these data to demonstrate that AirSWOT can be used to estimate large-scale hydraulic gradients across wetland complexes. Finally, we present key lessons learned from this AirSWOT analysis for consideration in future campaigns, including: maximizing swath overlap for spatial averaging to minimize uncertainty as well as orienting flight paths parallel to river flow directions to reduce along track aircraft drift for neighboring flight paths. We conclude that spatially dense AirSWOT measurements of river and lake WSEs can improve geospatial understanding of surface water hydrology and fluvial processes.
Decrease in glacier coverage contributes to increased winter baseflow of Arctic rivers
NASA Astrophysics Data System (ADS)
Liljedahl, A. K.; Gaedeke, A.; Baraer, M.; Chesnokova, A.; Lebedeva, L.; Makarieva, O.; O'Neel, S.
2016-12-01
Rising minimum daily flows in northern Eurasian and North American rivers suggest a growing influence of groundwater in the Arctic hydrological cycle, while the impact of a warmer high-latitude climate system is evident in decreased glacier coverage and increasing permafrost temperatures. Multiple mechanisms have been proposed to explain the increased discharge, which is well documented but relatively poorly understood. Here we assess the long-term (up to 88 yrs) linkages between climate, glaciers and hydrology in Alaska, Canadian and Russian glacierized (from 0.3 to 60% glacier cover) and non-glacierized watersheds (31 to 186 000 km2). We are specifically interested in analyzing trends in late winter discharge from larger watersheds to refine our understanding of the regional aquifer status and annual discharge from smaller headwater basins. Field measurements of differential runoff in Interior Alaska show that glaciated headwater streams can lose significant amounts of water in summer to the underlying aquifer. The aquifer is in turn feeding the larger lowland river system throughout the year. Groundwater storage status in Arctic regions is especially prominent through winter river discharge as it is typically the only source of water to the river system for at least 6 months of the year. Our analyses aim to explore the hypothesis that the documented increase in later winter river discharge of larger watersheds can be explained at least partly, by increased glacier melt in summer as observed by long-term decreases in glacier coverage. If true, a decrease in winter freshwater exports to the Arctic Ocean could potentially follow as glaciers retreat to higher (cooler) elevations. Increased Arctic river baseflow can favor sea ice growth and fish habitats, while negatively impacting local communities in their river ice travel.
Resilience of Alaska's Boreal Forest to Climatic Change
NASA Technical Reports Server (NTRS)
Chapin, F. S., III; McGuire, A. D.; Ruess, R. W.; Hollingsworth, T. N.; Mack, M. C.; Johnstone, J. F.; Kasischke, E. S.; Euskirchen, E. S.; Jones, J. B.; Jorgenson, M. T.;
2010-01-01
This paper assesses the resilience of Alaska s boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska s boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities.
Arctic-Yukon-Kuskokwim Salmon Research and Restoration Plan
2006-01-01
The Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative (AYK SSI) is an innovative partnership between public and private institutions which provides a forum for non-governmental organizations and state and federal agencies to cooperatively identify and address salmon research and restoration needs. The affected region encompasses over 40% of the State of Alaska; the AYK region includes the watersheds of the Norton Sound region up to and including the village of Shishmaref, the Yukon River Watershed within Alaska, and the Kuskokwim River Watershed (including the coastal watersheds north of Cape Newenham), plus the Bering Sea marine ecosystem. The AYK SSI is a response to disastrously low salmon returns to western Alaska in the late 1990s and early 2000s, which created numerous hardships for the people and communities that depend heavily on the salmon fishery. Some stocks in the region have been in a decline for more than a decade and a half, leading to severe restrictions on commercial and subsistence fisheries. The first step for the AYK SSI has been to collaboratively develop and implement a comprehensive research plan to understand the causes of the declines and recoveries of AYK salmon.
Carbon export and cycling by the Yukon, Tanana, and Porcupine rivers, Alaska, 2001-2005
Striegl, Robert G.; Dornblaser, Mark M.; Aiken, George R.; Wickland, Kimberly P.; Raymond, Peter A.
2007-01-01
Loads and yields of dissolved and particulate organic and inorganic carbon (DOC, POC, DIC, PIC) were measured and modeled at three locations on the Yukon River (YR) and on the Tanana and Porcupine rivers (TR, PR) in Alaska during 2001–2005. Total YR carbon export averaged 7.8 Tg C yr−1, 30% as OC and 70% as IC. Total C yields (0.39–1.03 mol C m−2 yr−1) were proportional to water yields (139–356 mm yr−1; r2 = 0.84) at all locations. Summer DOC had an aged component (fraction modern (FM) = 0.94–0.97), except in the permafrost wetland‐dominated PR, where DOC was modern. POC had FM = 0.63–0.70. DOC had high concentration, high aromaticity, and high hydrophobic content in spring and low concentration, low aromaticity, and high hydrophilic content in winter. About half of annual DOC export occurred during spring. DIC concentration and isotopic composition were strongly affected by dissolution of suspended carbonates in glacial meltwater during summer.
Publications - GMC 253 | Alaska Division of Geological & Geophysical
of the following Copper River basin oil and gas exploratory wells: Amoco Production Company Ahtna Inc Reference Unknown, 1995, Source rock geochemical and visual kerogen data from cuttings of the following
Publications - RI 97-14B | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in , State of; Alluvial Deposits; Avalanche; Cambrian; Carboniferous; Cenozoic; Coastal and River; Coastal
Publications - RI 2016-2 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in ; Bathymetry; Coastal; Coastal and River; Earthquake Related Slope Failure; Emergency Preparedness; Engineering
Two Dimensional Hydrodynamic Analysis of the Moose Creek Floodway
2012-09-01
HEC -2 model used during the design and recertification of the Tanana River Levee. 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4...ER D C/ CH L TR -1 2 -2 0 Two Dimensional Hydrodynamic Analysis of the Moose Creek Floodway C oa st al a n d H yd ra u lic s La b or at...approximately 17 miles East of Fairbanks, Alaska, and is part of the Chena River Lakes Flood Control project. The Chena River floodway is designed to
Muhs, D.R.; Ager, T.A.; Skipp, G.; Beann, J.; Budahn, J.; McGeehin, J.P.
2008-01-01
Chemical weathering in soils has not been studied extensively in high-latitude regions. Loess sequences with modern soils and paleosols are present in much of subarctic Alaska, and allow an assessment of present and past chemical weathering. Five sections were studied in detail in the Fairbanks, Alaska, area. Paleosols likely date to mid-Pleistocene interglacials, the last interglacial, and early-to-mid-Wisconsin interstadiale. Ratios of mobile (Na, Ca, Mg, Si) to immobile (Ti or Zr) elements indicate that modern soils and most interstadial and interglacial paleosols are characterized by significant chemical weathering. Na2O/TiO2 is lower in modern soils and most paleosols compared to parent loess, indicating depletion of plagioclase. In the clay fraction, smectite is present in Tanana and Yukon River source sediments, but is absent or poorly expressed in modern soils and paleosols, indicating depletion of this mineral also. Loss of both plagioclase and smectite is well expressed in soils and paleosols as lower SiO 2/TiO2. Carbonates are present in the river source sediments, but based on CaO/TiO2, they are depleted in soils and most paleosols (with one exception in the early-to-mid-Wisconsin period). Thus, most soil-forming intervals during past interglacial and interstadial periods in Alaska had climatic regimes that were at least as favorable to mineral weathering as today, and suggest boreal forest or acidic tundra vegetation. ?? 2008 Regents of the University of Colorado.
Migration and stopover strategies of individual Dunlin along the Pacific coast of North America
Warnock, N.; Takekawa, John Y.; Bishop, M.A.
2004-01-01
We radio-marked 18 Dunlin, Calidris alpina (L., 1758), at San Francisco Bay, California, and 11 Dunlin at Grays Harbor, Washington, and relocated 90% of them along the 4200 km long coastline from north of San Francisco Bay to the Yukon-Kuskokwim Delta, Alaska. The Copper River Delta, Alaska, was the single most important stopover site, with 79% of the marked birds detected there. Our second most important site was the Willapa Bay and Grays Harbor complex of wetlands in Washington. The mean length of stay past banding sites ranged from 1.0 to 3.8 days. Controlling for date of departure, birds banded at San Francisco Bay had higher rates of travel to the Copper River Delta than those banded at Grays Harbor. The later a bird left a capture site, the faster it traveled to the Copper River Delta. Length of stay at the Copper River Delta was inversely related to arrival date. We did not find any effect of sex on travel rate or length of stay. Combining the results of this study with our previous work on Western Sandpipers, Calidris mauri (Cabanis, 1875), reveals variation of migration strategies used within and among shorebird species along the eastern Pacific Flyway. ?? 2004 NRC.
Channel erosion surveys along TAPS route, Alaska, 1974
Childers, Joseph; Jones, Stanley H.
1975-01-01
Repeated site surveys and aerial photographs at 26 stream crossings along the trans-Alaska pipeline system (TAPS) route during the period 1969-74 provide chronologie records of channel changes that predate pipeline-related construction at the sites. The 1974 surveys and photographs show some of the channel changes wrought by construction of the haul road from the Yukon River to Prudhoe Bay and by construction of camps and working pads all along the pipeline route. No pipeline crossings were constructed before 1975. These records of channel changes together with flood and icing measurements are part of the United States Department of the lnterior's continuing surveillance program to document the hydrologic aspects of the trans-Alaska pipeline and its environmental impacts.
High Resolution Regional Climate Simulations over Alaska
NASA Astrophysics Data System (ADS)
Monaghan, A. J.; Clark, M. P.; Arnold, J.; Newman, A. J.; Musselman, K. N.; Barlage, M. J.; Xue, L.; Liu, C.; Gutmann, E. D.; Rasmussen, R.
2016-12-01
In order to appropriately plan future projects to build and maintain infrastructure (e.g., dams, dikes, highways, airports), a number of U.S. federal agencies seek to better understand how hydrologic regimes may shift across the country due to climate change. Building on the successful completion of a series of high-resolution WRF simulations over the Colorado River Headwaters and contiguous USA, our team is now extending these simulations over the challenging U.S. States of Alaska and Hawaii. In this presentation we summarize results from a newly completed 4-km resolution WRF simulation over Alaska spanning 2002-2016 at 4-km spatial resolution. Our aim is to gain insight into the thermodynamics that drive key precipitation processes, particularly the extremes that are most damaging to infrastructure.
Publications - GMC 110 | Alaska Division of Geological & Geophysical
foot interval of the Richfield Oil Corporation White River Unit #2 well Authors: Bujak Davies Group Reference Bujak Davies Group, 1989, Vitrinite reflectance data and analysis of the 120 - 12,100 foot
Environmental overview and hydrogeologic conditions at Aniak, Alaska
Dorava, J.M.
1994-01-01
The remote Native village of Aniak, on the flood plain of the Kuskokwim River in southwestern Alaska, has long cold winters and short summers that affect both the hydrology of the area and the lifestyle of the residents. Aniak obtains its drinking water from a shallow aquifer in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Kuskokwim River may affect the quality of the ground water. Alternative drinking water sources are available but at significantly greater cost than existing supplies. The Federal Aviation Administration (FAA) owns or operates airport support facilities in Aniak. The subsistence lifestyle of the villagers and the quality of the current environment must be taken into consideration when the FAA evaluates options for remediation of environmental contamination at these facilities. This report describes the ground- and surface-water hydrology, geology, climate, vegetation, soils, and flood potential of the areas surrounding the FAA sites.
Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska.
Fee, David; Haney, Matthew M; Matoza, Robin S; Van Eaton, Alexa R; Cervelli, Peter; Schneider, David J; Iezzi, Alexandra M
2017-01-06
The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity. Copyright © 2017, American Association for the Advancement of Science.
Effectiveness of streambank-stabilization techniques along the Kenai River, Alaska
Dorava, Joseph M.
1999-01-01
The Kenai River in southcentral Alaska is the State's most popular sport fishery and an economically important salmon river that generates as much as $70 million annually. Boatwake-induced streambank erosion and the associated damage to riparian and riverine habitat present a potential threat to this fishery. Bank-stabilization techniques commonly in use along the Kenai River were selected for evaluation of their effectiveness at attenuating boatwakes and retarding streambank erosion. Spruce trees cabled to the bank and biodegradable man-made logs (called 'bio-logs') pinned to the bank were tested because they are commonly used techniques along the river. These two techniques were compared for their ability to reduce wake heights that strike the bank and to reduce erosion of bank material, as well as for the amount and quality of habitat they provide for juvenile chinook salmon. Additionally, an engineered bank-stabilization project was evaluated because this method of bank protection is being encouraged by managers of the river. During a test that included 20 controlled boat passes, the spruce trees and the bio-log provided a similar reduction in boatwake height and bank erosion; however, the spruce trees provided a greater amount of protective habitat than the bio-log. The engineered bank-stabilization project eroded less during nine boat passes and provided more protective cover than the adjacent unprotected natural bank. Features of the bank-stabilization techniques, such as tree limbs and willow plantings that extended into the water from the bank, attenuated the boatwakes, which helped reduce erosion. These features also provided protective cover to juvenile salmon.
River chemistry as a monitor of Yosemite Park mountain hydroclimates
Peterson, David; Smith, Richard; Hager, Stephen; Hicke, Jeffrey A.; Dettinger, Michael; Huber, King
2005-01-01
Climate is the major source of variability in U.S. and global water resources. For example, large-scale variations in the global atmosphere and the Pacific Ocean are responsible for much of the variability in river discharge in Hawaii, Alaska, the U.S. Pacific Northwest, and the U.S. Southwest [Cayan and Peterson, 1989], and thus are closely linked to water and energy resources of the western United States [Cayan et al., 2003].
Atmospheric Science Data Center
2014-05-15
... help to darken the room lights when viewing the image on a computer screen. The Yukon River is seen wending its way from upper left to ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...
Publications - RDF 2014-20 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Download golovin-lidar-las-index Shapefile 71.0 K Metadata - Read me Keywords Coastal; Coastal and River
Publications - RI 2000-1D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in - Read me Keywords Arctic National Wildlife Refuge; Aufeis; Brooks Range; Coastal and River; Coastal and
Dusel-Bacon, Cynthia; Aleinikoff, John N.; Premo, Wayne R.; Paradis, Suzanne; Lohr-Schmidt, Ilana; Gough, Larry P.; Day, Warren C.
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 rocks of the Wood River assemblage. We suggest that elevated HFSE and REE trace-element contents of metavolcanic rocks, whose major-element composition may have been altered, are an important prospecting tool for rocks of VMS deposit potential in east-central Alaska.
Natural Disaster Risk and Engagement in the Arctic
NASA Astrophysics Data System (ADS)
Eichelberger, J. C.
2015-12-01
The Arctic is beset with natural hazards no less than other regions of Earth, but there are some special aspects that require attention. The presence of ice leads to spring river flooding and dynamics of coastal erosion not present in warmer climates. Vast boreal forests are subject to wildfires that are huge pollution events and a positive feedback to climate change through production of CO2, other gases, and black carbon. Darkness and extreme cold that prevail for a significant portion of the year is a challenge to disaster response. Special societal aspects of the Arctic produce vulnerabilities on two scales. One is the development of infrastructure in support of growing extractive industries and Arctic shipping. Reliance on such facilities, which often lack redundancy, and on long supply lines for food and fuel from the south impedes resilience. In 1964, Alaska lost much of its infrastructure to the 9.2 magnitude earthquake and subsequent tsunamis. Today, Alaska has greater dependency on external supplies and less internal redundancy. Planning that affects vulnerability of infrastructure is often done by corporations and regulated by government agencies based outside the Arctic. The work of scientists who understood Alaska, both within and outside government, provided information to energy corporations persuading them to include expensive design measures into the Trans Alaska Pipeline for crossing an active fault and preventing thawing of permafrost. This is a success story that should not be forgotten. At the other end of the size scale are isolated off-grid and off-road remote communities with fragile power, water, and sanitation facilities. A disaster there can pose an immediate threat to health and even life. Long-term evacuation and the cost a reconstruction may mean that the community is never re-established. Where such communities are centers of indigneous culture, the culture is threatened. With the goal of identifying best practices with these communities, we are conducting a novel all-stakeholder and cross-cultural case study engaging paired towns inundated by ice jam-caused floods of the Lena River in Siberia and Yukon River in Alaska. We anticipate that linking these communities will be empowering for them, as they begin to share their common problems and together look for long-term solutions.
Frenzel, Steven A.; Dorava, Joseph M.
1999-01-01
Five streams in the Cook Inlet Basin, Alaska, were sampled in 1998 to provide the National Park Service with baseline information on water quality. Four of these streams drain National Park Service land: Costello and Colorado Creeks in Denali National Park and Preserve, Johnson River in Lake Clark National Park and Preserve, and Kamishak River in Katmai National Park and Preserve. The fifth site was on the Talkeetna River, outside of national park boundaries. Samples of stream water, streambed sediments, and fish tissues were collected for chemical analyses. Biological and geomorphic information was also collected at each site. Nutrient concentrations in stream water were low and commonly were less than analytical detection limits. Analyses of fish tissues for 28 organochlorine compounds at Talkeetna River and Costello Creek produced just one detection. Hexachlorobenzene was detected at a concentration of 5.70 micrograms per kilogram in slimy sculpin from the Talkeetna River. Streambed sediment samples from the Talkeetna River had three organochlorine compounds at detectable levels; hexachlorobenzene was measured at 13 micrograms per kilogram and two other compounds were below the minimum reporting levels. At Colorado Creek, Johnson River, and Kamishak River, where fish samples were not collected, no organochlorine compounds were detected in streambed sediment samples. Several semivolatile organic compounds were detected at Colorado Creek and Costello Creek. Only one compound, dibenzothiophene, detected at Costello Creek at a concentration of 85 micrograms per kilogram was above the minimum reporting limit. No semivolatile organic compounds were detected at the Talkeetna, Kamishak, or Johnson Rivers. Trace elements were detected in both fish tissues and streambed sediments. Macroinvertebrate and fish samples contained few taxa at all sites. Total numbers of macroinvertebrate taxa ranged from 19 at the Johnson River to 38 at the Talkeetna River. Diptera were the most abundant and diverse order of macroinvertebrates at all sites. Total numbers of diptera taxa ranged from 8 at the Kamishak River to 19 at the Talkeetna River. Fish communities were represented by a maximum of nine taxa at the Talkeetna River and were absent at Colorado Creek. The Johnson River sampling site produced small numbers of juvenile Dolly Varden, and Costello Creek produced small numbers of both juvenile Dolly Varden and slimy sculpin.
A summary of ERTS data applications in Alaska
NASA Technical Reports Server (NTRS)
Miller, J. M.; Belon, A. E.
1974-01-01
ERTS has proven to be an exceedingly useful tool for the preparation of urgently needed resource surveys in Alaska. For this reason the wide utilization of ERTS data by federal, state and industrial agencies in Alaska is increasingly directed toward the solution of operational problems in resource inventories, environmental surveys, and land use planning. Examples of some applications are discussed in connection with surveys of potential agricultural lands; mapping of predicted archaeological sites; permafrost terrain and aufeis mapping; snow melt enhancement from Prudhoe Bay roads; geologic interpretations correlated ith possible new petroleum fields, with earthquake activity, and with plate tectonic motion along the Denali fault system; hydrology in monitoring surging glaciers and the break-up characteristics of the Chena River watershed; sea-ice morphology correlated with marine mammal distribution; and coastal sediment plume circulation patterns.
Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2001
Schuster, Paul F.
2003-01-01
Overview -- This report contains water-quality and sediment-quality data from samples collected in the Yukon River Basin during water year 2001 (October 2000 through September 2001). A broad range of chemical and biological analyses from three sets of samples are presented. First, samples were collected throughout the year at five stations in the basin (three on the mainstem Yukon River, one each on the Tanana and Porcupine Rivers). Second, fecal indicators were measured on samples from drinking-water supplies collected near four villages. Third, sediment cores from five lakes throughout the Yukon Basin were sampled to reconstruct historic trends in the atmospheric deposition of trace elements and hydrophobic organic compounds.
Sformo, Todd L.; Adams, Billy; Seigle, John C.; Ferguson, Jayde A.; Purcell, Maureen; Stimmelmayr, Raphaela; Welch, Joseph H.; Ellis, Leah M.; Leppi, Jason C.; George, John C.
2017-01-01
We report the first confirmed cases (2013–2016) of saprolegniosis caused by water mold from the genus Saprolegnia in Aanaakłiq, broad whitefish (Coregonus nasus), from the Colville River near Nuiqsut, Alaska. While this mold is known to be worldwide, these instances represent the first cases in Nuiqsut and only the second instance on a single fish on the North Slope, occurring in 1980. We describe the collaborative work on monitoring this emerging disease. Because fish constitute a critical component of the diet in Nuiqsut and fishing is an integral part of Inupiaq nutritional and cultural subsistence activities overall, individual subsistence fishers, local governmental entities, and Alaska Native organizations representing Nuiqsut requested an examination of affected fish and information on possible drivers of this emerging disease. The collaborative work described here ranges from recording fishermen observations, acquiring fish and mold specimens, histopathology, and molecular identification of the mold. This work, not currently grant-funded, begins with Native observation that incorporates western scientific methods and involves local, state, and federal departments as well as for-profit and non-profit organizations. Additionally, we report the more recent (2016) observation of this disease in a second species of whitefish, Pikuktuuq, humpback whitefish (Coregonus pidschain).
NASA Astrophysics Data System (ADS)
Sformo, Todd L.; Adams, Billy; Seigle, John C.; Ferguson, Jayde A.; Purcell, Maureen K.; Stimmelmayr, Raphaela; Welch, Joseph H.; Ellis, Leah M.; Leppi, Jason C.; George, John C.
2017-12-01
We report the first confirmed cases (2013-2016) of saprolegniosis caused by water mold from the genus Saprolegnia in Aanaakłiq, broad whitefish (Coregonus nasus), from the Colville River near Nuiqsut, Alaska. While this mold is known to be worldwide, these instances represent the first cases in Nuiqsut and only the second instance on a single fish on the North Slope, occurring in 1980. We describe the collaborative work on monitoring this emerging disease. Because fish constitute a critical component of the diet in Nuiqsut and fishing is an integral part of Inupiaq nutritional and cultural subsistence activities overall, individual subsistence fishers, local governmental entities, and Alaska Native organizations representing Nuiqsut requested an examination of affected fish and information on possible drivers of this emerging disease. The collaborative work described here ranges from recording fishermen observations, acquiring fish and mold specimens, histopathology, and molecular identification of the mold. This work, not currently grant-funded, begins with Native observation that incorporates western scientific methods and involves local, state, and federal departments as well as for-profit and non-profit organizations. Additionally, we report the more recent (2016) observation of this disease in a second species of whitefish, Pikuktuuq, humpback whitefish (Coregonus pidschain).
NASA Astrophysics Data System (ADS)
Gerlach, S.; Loring, P. A.; Murray, M. S.
2009-12-01
2009 was a particularly devastating year for rural communities of the Yukon River in Alaska. For a number of reasons, including annual variability in Chinook and Chum salmon runs, imperfect monitoring and information, “best practices” management decisions by regulatory agencies, and international treaty obligations related to conservation and total allowable catch allocation, the smokehouses and freezers of many Alaska Native families, particularly those in up-river communities in the Yukon Flats region, are empty; a problem that has prompted Alaska’s Governor Sean Parnell to ask the US Federal Government to declare a disaster. However, depending on whom you ask, this year’s management of these resources, which provide food security and enable self-reliance in rural communities, may be evaluated as a failure or as a success. How can we reconcile an institutional assessment that claims success as defined in terms of internationally-agreed upon conservation and escapement goals, with the negative economic and health impacts on communities? We use this case to illustrate how the whole Yukon River watershed and drainage, including Alaska and Canada, provides an elegant, geographic context for the discussion and analysis of the human dimensions of environmental change and regional sustainability. Policymakers have arguably gone to great lengths to reconcile competing ‘uses’ of the Yukon River, including commercial and subsistence uses as well as conservation goals, but while managers continue to strive to be ‘adaptive learners’ in their approach to balancing these goals, the impacts on rural communities are immediate and cumulative, synergistic, temporally and spatially scaled, and directly related to rural livelihoods, community health, well-being and sustainability. The cost of this ‘adaptive’ process may be too high, both for the ecosystem and for the people who live there. Are we asking too much of the Yukon River? Are we asking too much of the regulatory agencies and managers? And are we asking too much of local communities who depend on the fishery for subsistence and security? The answers to these questions, though regionally-scaled, have great importance for how we define and address sustainability and conservation goals at pan-Arctic and global scales.
Surficial Geologic Map of the Tanacross B-4 Quadrangle, East-Central Alaska
Carrara, Paul E.
2006-01-01
The Tanacross B-4 1:63,360-scale quadrangle, through which the Alaska Highway runs, is in east-central Alaska about 100 mi west of the Yukon border. The surficial geologic mapping in the quadrangle is in support of the 'Geologic Mapping in support of land, resources, and hazards issues in Alaska' Project of the USGS National Cooperative Geologic Mapping Program. The Tanacross B-4 quadrangle contains parts of two physiographic provinces, the Yukon-Tanana Upland and the Northway-Tanana Lowland. The gently rolling hills of the Yukon-Tanana Upland, in the northern and eastern map area, rise to about 3,100 ft. The Northway-Tanana Lowland, in the western and southern map area, contains the westerly flowing Tanana River. Elevations along the floor of the lowland generally range between 1,540 and 1,700 ft. The dominant feature within the map is the Tok fan, which occupies about 20 percent of the map area. This large, nearly featureless fan contains a high percentage of volcanic clasts derived from outside the present-day drainage of the Tok River. The map provides interpretations of the Quaternary surficial deposits and associated geologic hazards in this area of the upper Tanana valley. Because the map area is dominated by various surficial deposits, the map depicts 13 different Quaternary surficial units consisting of man-made, alluvial, colluvial, organic, lacustrine, and eolian deposits. Deposits shown on this map are generally greater than 1 m thick. The map is accompanied by a text containing unit descriptions incorporating information pertaining to material type, location, associated hazards, resource use (if any), and thickness.
Publications - GMC 420 | Alaska Division of Geological & Geophysical
DGGS GMC 420 Publication Details Title: X-Ray fluorescence spectroscopy and 40Ar/39Ar analyses of core more information. Quadrangle(s): Ikpikpuk River; Umiat Bibliographic Reference Shimer, G., 2013, X-Ray
Cost Effectiveness Of Selected Roadway Dust Control Methods For Eagle River, Alaska
DOT National Transportation Integrated Search
1988-01-01
The U.S. Environmental Protection Agency has set air quality standards for airborne particulates with diameters equal to or less than ten microns (PM10 particulates). These particulates have been correlated with respiratory illnesses. The primary sta...
Publications - PIR 2008-1E | Alaska Division of Geological & Geophysical
River--Evidence for a thermogenic origin Authors: Decker, P.L., and Wartes, M.A. Publication Date: Mar thermogenic origin, in Wartes, M.A., and Decker, P.L., eds., Preliminary results of recent geologic field
Chemical complexity and source of the White River Ash, Alaska and Yukon
Preece, S.J.; McGimsey, Robert G.; Westgate, J.A.; Pearce, N.J.G.; Hartmann, W.K.; Perkins, W.T.
2014-01-01
The White River Ash, a prominent stratigraphic marker bed in Alaska (USA) and Yukon (Canada), consists of multiple compositional units belonging to two geochemical groups. The compositional units are characterized using multiple criteria, with combined glass and ilmenite compositions being the best discriminators. Two compositional units compose the northern group (WRA-Na and WRA-Nb), and two units are present in the eastern group (WRA-Ea and the younger, WRA-Eb). In the proximal area, the ca. 1900 yr B.P. (Lerbekmo et al., 1975) WRA-Na displays reverse zoning in the glass phase and systematic changes in ilmenite composition and estimated oxygen fugacity from the base to the top of the unit. The eruption probably tapped different magma batches or bodies within the magma reservoir with limited mixing or mingling between them. The 1147 cal yr B.P. (calibrated years, approximately equivalent to calendric years) (Clague et al., 1995) WRA-Ea eruption is only weakly zoned, but pumices with different glass compositions are present, along with gray and white intermingled glass in individual pumice clasts, indicating the presence of multiple magmatic bodies or layers. All White River Ash products are high-silica adakites and are sourced from the Mount Churchill magmatic system.
NASA Astrophysics Data System (ADS)
Vas, D. A.; Toniolo, H. A.; Kemnitz, R.; Lamb, E.
2012-12-01
National Petroleum Reserve-Alaska (NPR-A) is an extensive 22.8 million acre oil, gas, and coal rich area that extends from the north foothills of the Brooks range all the way to the Arctic Ocean. Due to increasing demand for oil and natural gas the United States Department of Interior, Bureau of Land Management (BLM) is holding annual oil and gas lease sales in the NPR-A region. BLM is also supporting research to aid responsible oil exploration in the NPR-A region. We conducted a set of hydraulic measurements, which includes discharge measurements using Acoustic Doppler Current Profiler (ADCP), water slope, and suspended sediment sampling during breakup, the most important hydrologic event of the year, from 2010 to 2012 on Otuk Creek, Seabee Creek, Prince Creek, Ikpikpuk River, Judy Creek, Fish Creek, and Ublutuoch River in the NPR - A region. The hydraulic data we collected helped us understand how rivers change yearly which is useful for the development of new infrastructure such as pipe lines, bridges, and roads in the NPR-A region. The goal of this work is to present the results of our 2010 to 2012 spring breakup measurements.
Edwards, M.E.; Hamilton, T.D.; Elias, S.A.; Bigelow, N.H.; Krumhardt, A.P.
2003-01-01
Numerous exposures of Pleistocene sediments occur in the Noatak basin, which extends for 130 km along the Noatak River in northwestern Alaska. Nk-37, an extensive bluff exposure near the west end of the basin, contains a record of at least three glacial advances separated by interglacial and interstadial deposits. An ancient river-cut bluff and associated debris apron is exposed in profile through the central part of Nk-37. The debris apron contains a rich biotic record and represents part of an interglaciation that is probably assignable to marine-isotope stage 5. Pollen spectra from the lower part of the debris apron closely resemble modern samples taken from the Noatak floodplain in spruce gallery forest, and macrofossils of spruce are also present at this level. Fossil bark beetles and carpenter ants occur higher in the debris apron. Mutual Climatic Range (MCR) estimates from the fossil beetles suggest temperatures similar to or warmer than today. Together, these fossils indicate the presence of an interglacial spruce forest in the western part of the Noatak Basin, which lies about 80 km upstream of the modern limit of spruce forest.
Hydrologic reconnaissance of the Unalakleet River basin, Alaska, 1982-83
Sloan, C.E.; Kernodle, D.R.; Huntsinger, Ronald
1986-01-01
The Unalakleet River, Alaska, from its headwaters to the confluence of the Chiroskey River has been designated as a wild river and is included in the National Wild and Scenic Rivers System. Yearly low flow, which occurs during the winter, is sustained by groundwater discharge; there are few lakes in the basin and the cold climate prevents winter runoff. The amount of winter streamflow was greatest in the lower parts of streams with the exception of the South River and was apparently proportional to the amount of unfrozen alluvium upstream from the measuring sites. Unit discharge in late winter ranged from nearly zero at the mouth of the South River to 0.24 cu ft/sec/sq mi in the Unalakleet River main stem below Tenmile River. Summer runoff at the time of the reconnaissance may have been slightly higher than normal owing to recent rains. Unit runoff ranged from a low of 1.0 cu ft/sec/sq mi at the South River, to a high value of 2.4 cu ft/sec/sq mi at the North Fork Unalakleet River. Flood marks were present in the basin well above streambank levels but suitable sections to measure the maximum evident flood by slope-area methods were not found. Flood peaks were calculated for the Unalakleet River and its tributaries using basin characteristics. Calculated unit runoff for the 50-year flood ranged from about 17 to 45 cu ft/sec/sq mi. Water quality was good throughout the basin, and an abundant and diversified community of benthic invertebrates was found in samples collected during the summer reconnaissance. Permafrost underlies most of the basin, but groundwater can be found in unfrozen alluvium in the stream valleys, most abundantly in the lower part of the main tributaries and along the main stem of the Unalakleet River. Groundwater sustains river flow through the winter; an estimate of its quantity can be found through low-flow measurements. Groundwater quality in the basin appears to be satisfactory for most uses. Currently, little groundwater is used within the basin. The water supply for Unalakleet is obtained from a well and gallery in a small valley north of the airport, outside the Unalakleet River basin. (Author 's abstract)
Spatial distribution of chemical constituents in the Kuskokwim River, Alaska
Wang, Bronwen
1999-01-01
The effects of lithologic changes on the water quality of the Kuskokwim River, Alaska, were evaluated by the U.S. Geological Survey in June 1997. Water, suspended sediments, and bed sediments were sampled from the Kusko-kwim River and from three tributaries, the Holitna River, Red Devil Creek, and Crooked Creek. Dissolved boron, chromium, copper, manganese, zinc, aluminum, lithium, barium, iron, antimony, arsenic, mercury, and strontium were detected. Dissolved manganese and iron concentrations were three and four times higher in the Holitna River than in the Kusko-kwim River. Finely divided ferruginous materials found in the graywacke and shale units of the Kuskokwim Group are the probable source of the iron. The highest concentrations of dissolved strontium and barium were found at McGrath, and the limestone present in the upper basin was the most probable source of strontium. The total mercury concentrations on the Kuskokwim River decreased downstream from McGrath. Dissolved mercury was 24 to 32 percent of the total concentration. The highest concentrations of total mercury, and of dissolved antimony and arsenic were found in Red Devil Creek. The higher concentrations from Red Devil Creek did not affect the main stem mercury transport because the tributary was small relative to the Kuskokwim River. In Red Devil Creek, total mercury exceeded the concentration at which the U.S. Environmental Protection Agency (USEPA) indicates that aquatic life is affected and dissolved arsenic exceeded the USEPA's drinking-water standard. Background mercury and antimony concentrations in bed sediments ranged from 0.09 to 0.15 micrograms per gram for mercury and from 1.6 to 2.1 micrograms per gram for antimony. Background arsenic concentrations were greater than 27 micrograms per gram. Sites near the Red Devil mercury mine had mercury and antimony concentrations greater than background concentrations. These concentrations probably reflect the proximity to the ore body and past mining. Crooked Creek had mercury concentrations greater than the background concentration. The transport of suspended sediment-associated trace elements was lower for all elements in the lower river than in the upper river, indicating storage of sediments and their associated metals within the river system.
Hydrologic information for land-use planning; Fairbanks vicinity, Alaska
Nelson, Gordon L.
1978-01-01
The flood plain on the Chena and Tanana Rivers near Fairbanks, Alaska, has abundant water in rivers and in an unconfined alluvial aquifer. The principal source of ground water is the Tanana River, from which ground water flows northwesterly to the Chena River. Transmissivity of the aquifer commonly exceed 100 ,000 sq ft. The shallow water table (less than 15 ft below land surface), high hydraulic conductivity of the sediments and cold soil give the flood plain a high susceptibility to pollution by onsite sewerage systems. The Environmental Protection Agency recommended maximum concentrations for drinking water may be exceeded in surface water for manganese and bacteria and in ground water for iron, manganese, and bacteria. Residents of the uplands obtain water principally from a widely-distributed fractured schist aquifer. The aquifer is recharged by local infiltration of precipitation and is drained by springs on the lower slopes and by ground-water flow to alluvial aquifers of the valleys. The annual base flow from basins in the uplands ranged from 3,000 to 100,000 gallons per acre; the smallest base flows occur in basins nearest the city of Fairbanks. The thick silt cover and great depth to the water table give much of the uplands a low susceptibility to pollution by onsite sewage disposal. Ground water is locally high in nitrate, arsenic, iron , and manganese. (Woodard-USGS)
Water quality in the Yukon River Basin, Alaska, water years 2006-2008
Schuster, Paul F.; Maracle, Karonhiakta'tie Bryan; Herman-Mercer, Nicole
2010-01-01
The Yukon River Inter-Tribal Watershed Council and the U.S. Geological Survey developed a water-quality monitoring program to address a shared interest in the water quality of the Yukon River and its relation to climate. This report contains water-quality data from samples collected in the Yukon River Basin during water years 2006 through 2008. A broad range of chemical analyses from 44 stations throughout the YRB are presented. On August 8, 2009 the USGS signed a Memorandum of Understanding with the Yukon River Inter-Tribal Watershed Council representing the culmination of 5 years of dedicated efforts to forge a working collaboration and partnership with expectations of continuing into the foreseeable future. The Memorandum of Understanding may be viewed at http://www.usgs.gov/mou/docs/yritwc_mou.pdf.
Overview of surface-water resources at the U.S. Coast Guard Support Center Kodiak, Alaska, 1987-89
Solin, G.L.
1996-01-01
Hydrologic data at a U.S. Coast Guard Support Center on Kodiak Island, Alaska, were collected from 1987 though 1989 to determine hydrologic conditions and if contamination of soils, ground water, or surface water has occurred. This report summarizes the surface-water-discharge data collected during the study and estimates peak, average, and low-flow values for Buskin River near its mouth. Water-discharge measurements were made at least once at 48 sites on streams in or near the Center. Discharges were measured in the Buskin River near its mouth five times during 1987-89 and ranged from 27 to 367 cubic feet per second. Tributaries of Buskin River below Buskin Lake that had discharges greater than 1 cubic foot per second include Bear Creek, Alder Creek, Magazine Creek, Devils Creek and an outlet from Lake Louise. Streams having flows generally greater than 0.1 cubic foot per second but less than 1 cubic foot per second include an unnamed tributary to Buskin River, an unnamed tributary to Lake Catherine and a drainage channel at Kodiak airport. Most other streams flowing into Buskin River, and all streams on Nyman Peninsula, usually had little or no flow except during periods of rainfall or snowmelt. During a low-flow period in February 1989, discharge measurements in Buskin River and its tributaries indicate that three reaches of Buskin River below Buskin Lake lost water to the ground-water system, whereas two reaches gained water; the net gain in streamflow attributed to ground-water inflow at a location near the mouth was estimated to be 2.2 cubic feet per second. The 100-year peak flow for Buskin River near its mouth was estimated to be 4,460 cubic feet per second. Average discharge was estimated to be 125 cubic feet per second and the 7-day 10-year low flow was estimated to be 5.8 cubic feet per second.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-29
..., Anchorage, Alaska 99513-7504. FOR FURTHER INFORMATION CONTACT: Jack Frost, Navigable Waters Specialist, 907... affected lands. A final decision on the merits of the application will not be made before October 27, 2011...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-29
...) 414-6500, or Guy Wagner, Refuge Manager, at (775) 779-2237. Further information may also be found at... the Mississippi River outside Alaska, and is a vital waterfowl nesting area. More than 200 springs...
Rickman, R.L.; Rosenkrans, D.S.
1997-01-01
McCarthy, Alaska, is on the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. Most visitors to McCarthy and the park cross the West Fork Kennicott River using a hand-pulled tram and cross the East Fork Kennicott River on a temporary footbridge. Outburst floods from glacier-dammed lakes result in channel erosion, aggradation, and migration of the Kennicott River, which disrupt transportation links, destroy property, and threaten life. Hidden Creek Lake, the largest of six glacier-dammed lakes in the Kennicott River Basin, has annual outbursts that cause the largest floods on the Kennicott River. Outbursts from Hidden Creek Lake occur from early fall to mid-summer, and lake levels at the onset of the outbursts have declined between 1909 and 1995. Criteria for impending outbursts for Hidden Creek Lake include lake stage near or above 3,000 to 3,020 feet, stationary or declining lake stage, evidence of recent calving of large ice blocks from the ice margin, slush ice and small icebergs stranded on the lakeshore, and fresh fractures in the ice-margin region. The lower Kennicott Glacier has thinned and retreated since about 1860. The East and West Fork Kennicott River channels migrated in response to changes in the lower Kennicott Glacier. The largest channel changes occur during outburst floods from Hidden Creek Lake, whereas channel changes from the other glacier-dammed lake outbursts are small. Each year, the West Fork Kennicott River conveys a larger percentage of the Kennicott Glacier drainage than it did the previous year. Outburst floods on the Kennicott River cause the river stage to rise over a period of several hours. Smaller spike peaks have a very rapid stage rise. Potential flood magnitude was estimated by combining known maximum discharges from Hidden Creek Lake and Lake Erie outburst floods with a theoretical large regional flood. Flood hazard areas at the transportation corridor were delineated, and possible future geomorphological changes were hypothesized. McCarthy, Alaska, is on the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. Most visitors to McCarthy and the park cross the West Fork Kennicott River using a hand-pulled tram and cross the East Fork Kennicott River on a temporary footbridge. Outburst floods from glacier-dammed lakes result in channel erosion, aggradation, and migration of the Kennicott River, which disrupt transportation links, destroy property, and threaten life. Hidden Creek Lake, the largest of six glacier-dammed lakes in the Kennicott River Basin, has annual outbursts that cause the largest floods on the Kennicott River. Outbursts from Hidden Creek Lake occur from early fall to mid-summer, and lake levels at the onset of the outbursts have declined between 1909 and 1995. Criteria for impending outbursts for Hidden Creek Lake include lake stage near or above 3,000 to 3,020 feet, stationary or declining lake stage, evidence of recent calving of large ice blocks from the ice margin, slush ice and small icebergs stranded on the lakeshore, and fresh fractures in the ice-margin region. The lower Kennicott Glacier has thinned and retreated since about 1860. The East and West Fork Kennicott River channels migrated in response to changes in the lower Kennicott Glacier. The largest channel changes occur during outburst floods from Hidden Creek Lake, whereas channel changes from the other glacier-dammed lake outbursts are small. Each year, the West Fork Kennicott River conveys a larger percentage of the Kennicott Glacier drainage than it did the previous year. Outburst floods on the Kennicott River cause the river stage to rise over a period of several hours. Smaller spike peaks have a very rapid stage rise. Potential flood magnitude was estimated by combining known maximum discharges from Hidden Creek Lake and Lake Erie outburst floods with
Hornig, S.; Sterling, A.; Smith, Styles
1989-01-01
Geographic range: The ghost shrimp is found in intertidal areas along the west coast of North America from Mutiny Bay, Alaska, to the mouth of the Tijuana River, San Diego County, California; MacGinitie (1934) and Ricketts and Calvin (1968) reported finding specimens as far south as El Estuario de Punto Banda, Baja California Norte, Mexico. The blue mud shrimp is found from southeastern Alaska to San Quentin Bay (Bahia de San Quentin) in Baja California Norte. The general distribution of the two species in the Pacific Northwest is identical (Figure 3).
NASA Technical Reports Server (NTRS)
Zimmermann, R.; McDonald, K.; Way, J.; Oren, R.
1994-01-01
Tree canopy microclimate, xylem water flux and xylem dielectric constant have been monitored in situ since June 1993 in two adjacent natural forest stands in central Alaska. The deciduous stand represents a mature balsam poplar site on the Tanana River floodplain, while the coniferous stand consists of mature white spruce with some black spruce mixed in. During solstice in June and later in summer, diurnal changes of xylem water potential were measured to investigate the occurrence and magnitude of tree transpiration and dielectric constant changes in stems.
Wedow, Helmuth
1956-01-01
In the period 1945-1954 over 100 investigations for radioactive source materials were made in Alaska. The nature of these investigations ranged from field examinations of individual prospects or the laboratory analysis of significantly radioactive samples submitted by prospectors to reconnaissance studies of large districts. In this period no deposits of uranium or thorium that would warrant commercial exploitation were discovered. The investigations, however, disclosed that radioactive materials occur in widely scattered areas of Alaska and in widely diverse environments. Many igneous rocks throughout Alaska are weakly radioactive because of uranium- and thorium-bearing accessory minerals, such as allanite, apatite, monazite, sphene, xenotime, and zircon; more rarely the radioactivity of these rocks is due to thorianite or thorite and their uranoan varieties. The felsic rocks, for example, granites and syenites, are generally more radioactive than the mafic igneous rocks. Pegmatites, locally, have also proved to be radioactive, but they have little commercial significance. No primary uranium oxide minerals have been found yet in Alaskan vein deposits, except, perhaps, for a mineral tentatively identified as pitchblende in the Hyder district of southeastern Alaska. However, certain occurrences of secondary uranium minerals, chiefly those of the uranite group, on the Seward Peninsula, in the Russian Mountains, and in the vicinity of Kodiak suggest that pitchblende-type ores may occur at depth beneath zones of alteration. Thorite-bearing veins have been discovered on Prince of Wales Island in southeastern Alaska. Although no deposits or carnotite-type minerals have been found in Alaska, several samples containing such minerals have been submitted by Alaskan prospectors. Efforts to locate the deposits from which these minerals were obtained have been unsuccessful, but review of available geologic data suggests that several Alaskan areas are potentially favorable for carnotite-type deposits. The chief of these areas is the Alaska Peninsula-Cook Inlet area which encompasses most of the reported occurrences of the prospectors' carnotite-type samples. Alaska is also potentially favorable for the occurrence of large bodies of the very low-grade uraniferous sedimentary rocks, such as phosphorites and black shales. This type of deposit, however, has not received much study because of the emphasis on the search for bonanza-type high-grade ores. Uraniferous phosphorites similar to those of Idaho, Montana, and Wyoming occur in northern Alaska on the north flank of the Brooks Range; black shales comparable to the uraniferous shales of the Chattanooga formation of southeastern United States have been noted along the Yukon River near the international boundary. Placer deposits in Alaska have some small potential for the production of the radioactive elements as byproducts of gold- and tin-placer mining. the placer area believed to have the relatively greatest potential in Alaska lies in the Kahiltna River valley where concentrates are known to contain such commercial minerals as ilmenite, cassiterite, platinum, and gold in addition to uranothorianite and monazite. The possibilities of the natural fluids--water and petroleum--have not yet been tested in Alaska to any great extent. Studies of fluids are in progress to determine whether they may be used to discover and define areas potentially favorable for the occurrence of uraniferous lodes.
Winkler, Gary R.; Plafker, George; Goldfarb, R.J.; Case, J.E.
1992-01-01
report summarizes recent results of integrated geological, geochemical, and geophysical field and laboratory studies conducted by the U.S. Geological Survey in the Cordova and Middleton Island 1?x3 ? quadrangles of coastal southern Alaska. Published open-file reports and maps accompanied by descriptive and interpretative texts, tables, diagrams, and pertinent references provide background information for a mineral-resource assessment of the two quadrangles. Mines in the Cordova and Middleton Island quadrangles produced copper and byproduct gold and silver in the first three decades of the 20th century. The quadrangles may contain potentially significant undiscovered resources of precious and base metals (gold, silver, copper, zinc, and lead) in veins and massive sulfide deposits hosted by Cretaceous and Paleogene sedimentary and volcanic rocks. Resources of manganese also may be present in the Paleogene rocks; uranium resources may be present in Eocene granitic rocks; and placer gold may be present in beach sands near the mouth of the Copper River, in alluvial sands within the canyons of the Copper River, and in smaller alluvial deposits underlain by rocks of the Valdez Group. Significant coal resources are present in the Bering River area, but difficult access and structural complexities have discouraged development. Investigation of numerous oil and gas seeps near Katalla in the eastern part of the area led to the discovery of a small, shallow field from which oil was produced between 1902 and 1933. The field has been inactive since, and subsequent exploration and drilling onshore near Katalla in the 1960's and offshore near Middleton Island on the outer continental shelf in the 1970's and 1980's was not successful.
Dynamic Change in Glacial Dammed Lake Behavior of Suicide Basin, Mendenhall Glacier, Juneau Alaska
NASA Astrophysics Data System (ADS)
Jacobs, A. B.; Moran, T.; Hood, E. W.
2016-12-01
Suicide Basin Jökulhlaups, since 2011, have resulted in moderate flooding on the Mendenhall Lake and River in Juneau, AK. At this time, the USGS recorded peak streamflow of 20,000 cfs in 2014, the highest flows officially reported by the USGS which was attributed to a Suicide Basin glacial-dammed lake release. However, the USGS estimated a peak flow of 27,000 cfs in 1961 and we suspect this event is partially the result of a glacial dammed lake release. From 2011 to 2015, data indicates that yearly outburst from Suicide Basin were the norm; however, in 2015 and 2016, multiple outbursts during the summer were observed suggesting a dynamic change in glacial behavior. For public safety and awareness, the University of Alaska Southeast and U.S. Geologic Survey began monitoring real-time Suicide Basin lake levels. A real-time model was developed by the National Weather Service Alaska-Pacific River Forecast Center capable of forecasting potential timing and magnitude of the flood-wave crest from this Suicide Basin release. However, the model now is being modified because data not previously available has become available and adapted to the change in state of glacial behavior. The importance of forecasting time and level of crest on the Mendenhall River system owing to these outbursts floods is an essential aid to emergency managers and the general public to provide impact decision support services (IDSS). The National Weather Service has been able to provide 36 to 24 hour forecasts for these large events, but with the change in glacial state on the Mendenhall Glacier, the success of forecasting these events is getting more challenging. We will show the success of the hydrologic model but at the same time show the challenges we have seen with the changing glacier dynamics.
Emmenegger, E.J.; Kurath, G.
2002-01-01
Infectious hematopoietic necrosis virus (IHNV) is a pathogen that infects many Pacific salmonid stocks from the watersheds of North America. Previous studies have thoroughly characterized the genetic diversity of IHNV isolates from Alaska and the Hagerman Valley in Idaho. To enhance understanding of the evolution and viral transmission patterns of IHNV within the Pacific Northwest geographic range, we analyzed the G gene of IHNV isolates from the coastal watersheds of Washington State by ribonuclease protection assay (RPA) and nucleotide sequencing. The RPA analysis of 23 isolates indicated that the Skagit basin IHNV isolates were relatively homogeneous as a result of the dominance of one G gene haplotype (S). Sequence analysis of 303 bases in the middle of the G gene (midG region) of 61 isolates confirmed the high frequency of a Skagit River basin sequence and identified another sequence commonly found in isolates from the Lake Washington basin. Overall, both the RPA and sequence analysis showed that the Washington coastal IHNV isolates are genetically homogeneous and have little genetic diversity. This is similar to the genetic diversity pattern of IHNV from Alaska and contrasts sharply with the high genetic diversity demonstrated for IHNV isolates from fish farms along the Snake River in Idaho. The high degree of sequence and haplotype similarity between the Washington coastal IHNV isolates and those from Alaska and British Columbia suggests that they have a common viral ancestor. Phylogenetic analyses of the isolates we studied and those from different regions throughout the virus's geographic range confirms a conserved pattern of evolution of the virus in salmonid stocks north of the Columbia River, which forms Washington's southern border.
Energy insurance for Anchorage, Alaska - Beluga river gas field, Cook Inlet
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stone, N.D.; Lindblom, R.G.
1987-05-01
The Beluga River gas field is the primary energy source for Anchorage, Alaska. The field is located 40 mi west of Anchorage astride the northwest shoreline of the Cook Inlet. Gas was discovered in December 1962 by Chevron's Beluga River unit (BRU) 1 well in section 35, T13N, R10W, S.B. and M. There are 16 producing wells in the field capable of a total gas potential of 140,000 MCFD. The current production averages 75,000 MCFD and the field has produced 220 BCF gas. Chevron, Shell, and ARCO have equal interests in the field. The Beluga River unit was formed inmore » 1962 with Chevron as operator. The produced gas is sold to the Chugach Electric Company and the Enstar Gas Company, both Anchorage-based utilities. The gas accumulation is trapped by a doubly plunging, slightly asymmetric anticlinal fold trending northeast-southwest. Gas is found from 3000 to 6000 ft vertical depth in sands within the lower Sterling (Pliocene) and Beluga River (upper Miocene) Formations. Reservoir sands range in thickness from 5 to 85 ft with average porosities of 24 to 30%. The Sterling sands were deposited in broad sand channels in a fluvial-deltaic setting, whereas Beluga sands were deposited in a high-energy fluvial environment in shifting stream courses. The use of the wireline repeat formation tester has aided in correlation, evaluation, and management of the multiple sand reservoirs. New gas sand reservoirs and partly depleted reservoirs are recognized, enabling completion from reservoirs of similar pressures and reducing risks associated with cross flow between reservoirs.« less
Spencer, R.G.M.; Aiken, G.R.; Butler, K.D.; Dornblaser, M.M.; Striegl, Robert G.; Hernes, P.J.
2009-01-01
The quality and quantity of dissolved organic matter (DOM) exported by Arctic rivers is known to vary with hydrology and this exported material plays a fundamental role in the biogeochemical cycling of carbon at high latitudes. We highlight the potential of optical measurements to examine DOM quality across the hydrograph in Arctic rivers. Furthermore, we establish chromophoric DOM (CDOM) relationships to dissolved organic carbon (DOC) and lignin phenols in the Yukon River and model DOC and lignin loads from CDOM measurements, the former in excellent agreement with long-term DOC monitoring data. Intensive sampling across the historically under-sampled spring flush period highlights the importance of this time for total export of DOC and particularly lignin. Calculated riverine DOC loads to the Arctic Ocean show an increase from previous estimates, especially when new higher discharge data are incorporated. Increased DOC loads indicate decreased residence times for terrigenous DOM in the Arctic Ocean with important implications for the reactivity and export of this material to the Atlantic Ocean. Citation: Spencer, R. G. M., G. R. Aiken, K. D. Butler, M. M. Dornblaser, R. G. Striegl, and P. J. Hernes (2009), Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska, Geophys. Res. Lett., 36, L06401, doi:10.1029/ 2008GL036831. Copyright 2009 by the American Geophysical Union.
Curran, Janet H.; McTeague, Monica L.; Burril, Sean E.; Zimmerman, Christian E.
2011-01-01
Turbid, glacially influenced rivers are often considered to be poor salmon spawning and rearing habitats and, consequently, little is known about salmon habitats that do occur within rivers of this type. To better understand salmon spawning habitats in the Matanuska River of southcentral Alaska, the distribution and characteristics of clearwater side-channel spawning habitats were determined and compared to spawning habitats in tributaries. More than 100 kilometers of clearwater side channels within the braided mainstem of the Matanuska River were mapped for 2006 from aerial images and ground-based surveys. In reaches selected for historical analysis, side channel locations shifted appreciably between 1949 and 2006, but the relative abundance of clearwater side channels was fairly stable during the same period. Geospatial analysis of side channel distribution shows side channels typically positioned along abandoned bars at the braid plain margin rather than on bars between mainstem channels, and shows a strong correlation of channel abundance with braid plain width. Physical and geomorphic characteristics of the channel and chemical character of the water measured at 19 side channel sites, 6 tributary sites, 4 spring sites, and 5 mainstem channel sites showed conditions suitable for salmon spawning in side channels and tributaries, and a correlation of side channel characteristics with the respective tributary or groundwater source water. Autumn-through-spring monitoring of intergravel water temperatures adjacent to salmon redds (nests) in three side channels and two tributaries indicate adequate accumulated thermal units for incubation and emergence of salmon in side channels and relatively low accumulated thermal units in tributaries.
Long-term observations of Alaska Coastal Current in the northern Gulf of Alaska
NASA Astrophysics Data System (ADS)
Stabeno, Phyllis J.; Bell, Shaun; Cheng, Wei; Danielson, Seth; Kachel, Nancy B.; Mordy, Calvin W.
2016-10-01
The Alaska Coastal Current is a continuous, well-defined system extending for 1700 km along the coast of Alaska from Seward, Alaska to Samalga Pass in the Aleutian Islands. The currents in this region are examined using data collected at >20 mooring sites and from >400 satellite-tracked drifters. While not continuous, the mooring data span a 30 year period (1984-2014). Using current meter data collected at a dozen mooring sites spread over four lines (Seward, Gore Point, Kennedy and Stevenson Entrances, and the exit to Shelikof Strait) total transport was calculated. Transport was significantly correlated with alongshore winds, although the correlation at the Seward Line was weak. The largest mean transport in the Alaska Coastal Current occurred at Gore Point (1.4×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer), with the transport at the exit to Shelikof Strait (1.3×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer) only slightly less. The transport was modified at the Seward Line in late summer and fall by frontal undulations associated with strong river discharge that enters onto the shelf at that time of year. The interaction of the Alaska Coastal Current and tidal currents with shallow banks in the vicinity of Kodiak Archipeligo and in Kennedy-Stevenson Entrance results in mixing and prolonged primary production throughout the summer.
The circulation of Prince William Sound
NASA Technical Reports Server (NTRS)
Muench, R. D. (Principal Investigator)
1973-01-01
The author has identified the following significant results. Results suggest that sediment-laden plumes of fresh water from rivers may be useful tracers, due to their high visibility, of surface water motion. The two useable images obtained to date corroborate that westerly flow was occurring in the Gulf of Alaska just south of Prince William Sound, and that an inflow into Prince William Sound was occurring concurrently with flood tides on both occasions. River plumes are useful tracers, but poor weather conditions somewhat limit the use of satellite imagery.
NASA Astrophysics Data System (ADS)
Herman-Mercer, N. M.; Mutter, E. A.; Wilson, N. J.; Toohey, R.; Schuster, P. F.
2017-12-01
The Indigenous Observation Network (ION) is a collaborative Community-Based Monitoring (CBM) program with both permafrost and water-quality monitoring components operating in the Yukon River Basin (YRB) of Alaska and Canada. ION is jointly facilitated by the Yukon River Inter-Tribal Watershed Council (YRITWC), an indigenous non-profit organization, and the US Geological Survey (USGS), a federal agency. The YRB is the fourth largest drainage basin in North America encompassing 855,000 square kilometers in northwestern Canada and central Alaska and is essential to the ecosystems of the Bering and Chuckchi Seas. Water is also fundamental to the subsistence and culture of the 76 Tribes and First Nations that live in the YRB providing sustenance in the form of drinking water, fish, wildlife, and vegetation. Despite the ecological and cultural significance of the YRB, the remote geography of sub-Arctic and Arctic Alaska and Canada make it difficult to collect scientific data in these locations and led to a lack of baseline data characterizing this system until recently. In response to community concerns about the quality of the YR and a desire by USGS scientists to create a long term water-quality database, the USGS and YRITWC collaborated to create ION in 2005. Surface water samples are collected by trained community technicians from Tribal Environmental Programs or First Nation Lands and Resources staff from over 35 Alaska Native Tribes and First Nations that reside along the YR and/or one of the major tributaries. Samples are analyzed at USGS laboratories in Boulder, CO and results are disseminated to participating YRB communities and the general public. This presentation will focus on the factors that have enabled the longevity and success of this program over the last decade, as well as the strategies ION uses to ensure the credibility of the data collected by community members and best practices that have facilitated the collection of surface water data in remote locations through the collaborative efforts of community members, government agencies, and non-profit organizations. Finally, we will also discuss the challenges currently facing ION such as funding sustainability and data use by communities including linkages to decision-making
Estimating River Surface Elevation From ArcticDEM
NASA Astrophysics Data System (ADS)
Dai, Chunli; Durand, Michael; Howat, Ian M.; Altenau, Elizabeth H.; Pavelsky, Tamlin M.
2018-04-01
ArcticDEM is a collection of 2-m resolution, repeat digital surface models created from stereoscopic satellite imagery. To demonstrate the potential of ArcticDEM for measuring river stages and discharges, we estimate river surface heights along a reach of Tanana River near Fairbanks, Alaska, by the precise detection of river shorelines and mapping of shorelines to land surface elevation. The river height profiles over a 15-km reach agree with in situ measurements to a standard deviation less than 30 cm. The time series of ArcticDEM-derived river heights agree with the U.S. Geological Survey gage measurements with a standard deviation of 32 cm. Using the rating curve for that gage, we obtain discharges with a validation accuracy (root-mean-square error) of 234 m3/s (23% of the mean discharge). Our results demonstrate that ArcticDEM can accurately measure spatial and temporal variations of river surfaces, providing a new and powerful data set for hydrologic analysis.
Travel Information, Transportation & Public Facilities, State of Alaska
outside site Report Potholes Road Conditions (511) Road Maintenance Central Region Maintenance & ; Operations Northern Region Maintenance & Operations Southcoast Region Maintenance & Operations Road Weather Information System Street Sweeping - Anchorage & Eagle River Winter Road Maintenance Priority
OIL SPILL RESPONSE SCENARIOS FOR REMOTE ARCTIC ENVIRONMENTS
Special problems occur during oil spill cleanup in remote inland areas in cold climates. In Alaska these problems result from the harsh climate, the unusual terrain features, and the special problems of spills along swift rivers. The analysis begins with a description of the envi...
Dorava, J.M.; Sokup, J.M.
1994-01-01
Air service to Cordova, Alaska and the surrounding region is provided by the Merle K. "Mudhole" Smith Airport, 21 kilometers east of the townsite. The Federal Aviation Administration owns or operates support facilities at the airport and wishes to consider the environmental setting and hydro- geologic conditions when evaluating options for remediation of potential contamination at these facilities. The airport is within the Copper River Delta wetlands area and the Chugach National Forest. Silts, sands, and gravels of fluvial origin underlie the airport. Potential flooding may be caused by outbursts of glacier-dammed lakes, glacier icemelt, snowmelt runoff, or precipitation. Surface spills and disposal of hazardous materials in conjunction with precipitation or flooding may adversely affect the quality of ground water. Drinking water at the airport is currently supplied by wells. Alternative drinking-water sources include local rivers and streams, transporting city water from Cordova, or undiscovered aquifers. Each alternative source, however, would likely cost significantly more to develop than using the existing shallow aquifer supply.
Late quaternary environments, Denali National Park and Preserve, Alaska
Elias, S.A.; Short, S.K.; Waythomas, C.F.
1996-01-01
Late Quaternary pollen, plant macrofossils, and insect fossils were studied from sites along three rivers in the foothills north of the Alaska Range in Denali National Park and Preserve. The aim was to carry out a reconaissance of late Quaternary organic sediments in the region, emphasizing the mid-Wisconsin, or Boutellier interstadial interval. Samples of probable early- to mid-Boutellier age (ca. 60 000 to 40 000 B.P.) from Unit 2 at the Toklat High Bluffs site indicate open boreal woodland with dense alder shrub vegetation. Organic Unit 1 at the Foraker River Slump site indicates open taiga with shrubs of probable Boutellier age. Fossil evidence from the youngest horizon in this unit indicates graminoid tundra environments, marking the transition from interstadial to late Wisconsin glacial environments. Early Holocene samples from the Foraker exposures suggest birch shrub tundra; coniferous forest apparently became established only alter 6500 B.P. Local variations in forest composition at the Foraker and Sushana sites were probably the result of disturbances, such as fire.
Lavers, David A.; Waliser, Duane E.; Ralph, F. Martin; Dettinger, Michael
2016-01-01
The western United States is vulnerable to socioeconomic disruption due to extreme winter precipitation and floods. Traditionally, forecasts of precipitation and river discharge provide the basis for preparations. Herein we show that earlier event awareness may be possible through use of horizontal water vapor transport (integrated vapor transport (IVT)) forecasts. Applying the potential predictability concept to the National Centers for Environmental Prediction global ensemble reforecasts, across 31 winters, IVT is found to be more predictable than precipitation. IVT ensemble forecasts with the smallest spreads (least forecast uncertainty) are associated with initiation states with anomalously high geopotential heights south of Alaska, a setup conducive for anticyclonic conditions and weak IVT into the western United States. IVT ensemble forecasts with the greatest spreads (most forecast uncertainty) have initiation states with anomalously low geopotential heights south of Alaska and correspond to atmospheric rivers. The greater IVT predictability could provide warnings of impending storminess with additional lead times for hydrometeorological applications.
Moran, Edward H.; Brabets, Timothy P.
2005-01-01
The headwaters of the John River are located near the village ofAnaktuvuk Pass in the central Brooks Range of interior Alaska. With the recent construction of a water-supply system and a wastewater-treatment plant, most homes in Anaktuvuk Pass now have modern water and wastewater systems. The effluent from the treatment plant discharges into a settling pond near a tributary of the John River. The headwaters of the John River are adjacent to Gates of the Arctic National Park and Preserve, and the John River is a designated Wild River. Due to the concern about possible water-quality effects from the wastewater effluent, the hydrology of the John River near Anaktuvuk Pass was studied from 2002 through 2003. Three streams form the John River atAnaktuvuk Pass: Contact Creek, Giant Creek, and the John RiverTributary. These streams drain areas of 90.3 km (super 2) , 120 km (super 2) , and 4.6 km (super 2) , respectively. Water-qualitydata collected from these streams from 2002-03 indicate that the waters are a calcium-bicarbonate type and that Giant Creek adds a sulfate component to the John River. The highest concentrations of bicarbonate, calcium, sodium, sulfate, and nitrate were found at the John River Tributary below the wastewater-treatment lagoon. These concentrations have little effect on the water quality of the John River because the flow of the John River Tributary is only about 2 percent of the John River flow. To better understand the ground-water/surface-water interactions of the upper John River, a numerical groundwater-flow model of the headwater area of the John River was constructed. Processes that occur during spring break-up, such as thawing of the active layer and the frost table and the resulting changes of storage capacity of the aquifer, were difficult to measure and simulate. Application and accuracy of the model is limited by the lack of specific hydrogeologic data both spatially and temporally. However, during the mid-winter and open-water periods, the model provided acceptable results and was coupled with a particle-movement model to simulate the movement and possible extent of conservative particles from the wastewater-treatment-plant lagoon.
Neal, Edward G.
2007-01-01
The Taku River Basin originates in British Columbia, Canada, and drains an area of 6,600 square miles at the U.S. Geological Survey's Taku River gaging station. Several mines operated within the basin prior to 1957, and mineral exploration has resumed signaling potential for future mining developments. The U.S. Geological Survey in cooperation with the Douglas Indian Association, Alaska Department of Environmental Conservation, and the U.S. Environmental Protection Agency conducted a water-quality and flood-hydrology study of the Taku River. Water-quality sampling of the Taku River from 1998 through 2003 established a baseline for assessing potential effects of future mining operations on water quality. The annual mean discharge of the Taku River is 13,700 cubic feet per second. The monthly mean discharge ranges from a minimum of 1,940 cubic feet per second in February to a maximum of 34,400 cubic feet per second in June. Nearly 90 percent of the annual discharge is from May through November. The highest spring discharges are sourced primarily from snowmelt and moderate discharges are sustained throughout the summer by glacial meltwaters. An ice cover usually forms over the Taku River in December persisting through the winter into March and occasionally into April. Glacier-lake-outburst floods originating from two glacier-dammed lakes along the margin of the Tulsequah Glacier in British Columbia, Canada, are the source of the greatest peak discharges on the Taku River. The largest flood during the period of record was 128,000 cubic feet per second on June 25, 2004, resulting from an outburst of Lake No Lake. Lake No Lake is the larger of the two lakes. The outburst-flood contribution to peak discharge was 80,000 cubic feet per second. The volume discharged from Lake No Lake is relatively consistent indicating drainage may be triggered when the lake reaches a critical stage. This suggests prediction of the timing of these outburst floods might be possible if lake-stage data were available. Further increases in the volume of Lake No Lake are unlikely as all tributary glaciers have retreated out of the lake basin. Decreasing outburst-flood volumes from Tulsequah Lake suggests a continued decline in the volume of this lake. Physical and chemical parameters and concentrations of basic water-quality constituents indicate good water quality. Samples collected at the Taku River gaging station contained low concentrations of trace elements in the dissolved phase. Trace elements sampled were within acceptable limits when compared with the Alaska Department of Environmental Conservation aquatic-life criteria for fresh waters. The highest concentrations of total trace elements sampled were collected during glacial-outburst floods and likely are associated with suspended sediments. Total trace-element concentrations generally increase with increasing water discharge, although a high correlation for all constituents sampled does not always exist.
NASA Technical Reports Server (NTRS)
Gryc, G. (Principal Investigator); Lathram, E. H.
1972-01-01
The authors have identified the following significant results. As a precursor to the ERTS-1 investigation, the spatial relationship of geostructures seen on Nimbus IDCS photographs to the distribution of mineralized areas in Alaska and western Canada was analyzed to determine the possible metallogenic significance of the geostructures. In Canada, mercury and porphyry molybdenum deposits are closely associated with strong northwest-trending fault systems; the development of mineralized regions seems related to major crustal zones or fractures trending southwestward across the Cordillera from the Precambrian shield. In Alaska, comparison of the northeast- and northwest-trending set of possible crustal structures shown on the Nimbus photo, with the distribution of known mineral deposits suggests a similar relationship. The mineralized region of massive sulfides in Prince William Sound and upper Copper River areas and of porphyry coppers in the Nabesna area forms a broad northeast-trending belt possibly related to the Minto Arch on the Shield. The belt of metalliferous deposits in the western Alaska Range follows a comparable northeast trend. Mercury deposits, suggested by many to be fault-controlled, together with most tin and tungsten deposits, occupy a northeast-trending belt between the Bristol Bay-Mackenzie Bay linear and extensions of a linear along the lower Yukon River. This belt intersects the northwest-trending Canadian belt of similar deposits in the Fairbanks area.
Characteristics of fall chum salmon spawning habitat on a mainstem river in Interior Alaska
Burril, Sean E.; Zimmerman, Christian E.; Finn, James E.
2010-01-01
Chum salmon (Oncorhynchus keta) are the most abundant species of salmon spawning in the Yukon River drainage system, and they support important personal use, subsistence, and commercial fisheries. Chum salmon returning to the Tanana River in Interior Alaska are a significant contribution to the overall abundance of Yukon River chum salmon and an improved understanding of habitat use is needed to improve conservation of this important resource. We characterized spawning habitat of chum salmon using the mainstem Tanana River as part of a larger study to document spawning distributions and habitat use in this river. Areas of spawning activity were located using radiotelemetry and aerial helicopter surveys. At 11 spawning sites in the mainstem Tanana River, we recorded inter-gravel and surface-water temperatures and vertical hydraulic gradient (an indication of the direction of water flux) in substrate adjacent to salmon redds. At all locations, vertical hydraulic gradient adjacent to redds was positive, indicating that water was upwelling through the gravel. Inter-gravel temperatures adjacent to redds generally were warmer than surface water at most locations and were more stable than surface-water temperature. Inter-gravel water temperature adjacent to redds ranged from 2.6 to 5.8 degrees Celsius, whereas surface-water temperature ranged from greater than 0 to 5.5 degrees Celsius. Some sites were affected more by extremes in air temperature than others. At these sites, inter-gravel water temperature profiles were variable (with ranges similar to those observed in surface water), suggesting that even though upwelling habitats provide a stable thermal incubation environment, eggs and embryos still may be affected by extremes in air temperature. Fine sand and silt covered redds at multiple sites and were evidence of increased river flow during the winter months, which may be a potential source of increased mortality during egg-to-fry development. This study provides documentation of spawning by fall chum salmon and is the first study to continuously measure inter-gravel water temperature at sites in the mainstem Tanana River.
Catalog of the historically active volcanoes of Alaska
Miller, T.P.; McGimsey, R.G.; Richter, D.H.; Riehle, J.R.; Nye, C.J.; Yount, M.E.; Dumoulin, Julie A.
1998-01-01
Alaska hosts within its borders over 80 major volcanic centers that have erupted during Holocene time (< 10,000 years). At least 29 of these volcanic centers (table 1) had historical eruptions and 12 additional volcanic centers may have had historical eruptions. Historical in Alaska generally means the period since 1760 when explorers, travelers, and inhabitants kept written records. These 41 volcanic centers have been the source for >265 eruptions reported from Alaska volcanoes. With the exception of Wrangell volcano, all the centers are in, or near, the Aleutian volcanic arc, which extends 2500 km from Hayes volcano 145 km west of Anchorage in the Alaska-Aleutian Range to Buldir Island in the western Aleutian Islands (fig. 1). The volcanic arc, a subduction-related feature associated with underthrusting of the Pacific plate beneath the North American plate is divided between oceanic island arc and continental margin segments, the boundary occurring at about 165° W longitude (fig. 1). An additional 7 volcanic centers in the Aleutian arc (table 2; fig. 1 A) have active fumarole fields but no reported historical eruptions.This report discusses the location, physiography and structure, eruptive history, and geology of those volcanoes in Alaska that have experienced one or more eruptions that have been recorded in the written history (i.e., in historical time). It is part of the group of catalogs entitled Catalogue of Active Volcanoes of the World published beginning in 1951 under the auspices of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI). A knowledge of the information contained in such catalogs aids in understanding the type and scale of activity that might be expected during a particular eruption, the hazards the eruption may pose, and even the prediction of eruptions. The catalog will thus be of value not only to the inhabitants of Alaska but to government agencies concerned with emergency response, air traffic operations, and weather, as well as to industry and scientists. The combination of the hazard posed by volcanic ash to jet aircraft and the heavy use of international air routes located parallel to, and on either side of, the Aleutian volcanic arc means that even remote volcanoes in Alaska now pose significant hazards to life and property.Although this report is concerned with historical eruptions from Alaskan volcanoes, other volcanoes in Alaska have erupted in the past 10,000 years and might therefore be expected to erupt again. Several Holocene volcanic centers in the Aleutian arc have no reported historical activity. Elsewhere in Alaska the Bering Sea basalt fields cover large areas of the Yukon Delta, Seward Peninsula, and several of the islands of the Bering Sea. Holocene centers also occur in the Wrangell Mountains and in isolated occurrences in the interior and southeastern Alaska. Eruptions from these centers have occurred within the past several hundred years but none were transcribed in the written record. Moodie and others (1992), however, report oral traditions among the Northern Athapaskan Indians of the southwestern Yukon Territory that may record the second and younger deposition of the White River Ash circa A.D. 720. This lobe of the White River Ash was deposited during the paroxysmal eruption of Churchill volcano in the Wrangell Mountains of eastcentral Alaska (McGimsey and others, 1992; Richter and others, 1995).
NASA Technical Reports Server (NTRS)
Crusium, John; Levy, Rob; Wang, Jun; Campbell, Rob; Schroth, Andrew W.
2012-01-01
Transport of Alaskan dust into the Gulf of Alaska and comparison with similar high-latitude dust environments. An airborne flux of the micronutrient iron, derived from dust originating from coastal regions may be an important contributor of iron to the Gulf of Alaska's (GoA) oligotrophic waters. Dust blowing off glacier termini and dry riverbeds is a recurring phenomenon in Alaska, usually occurring in the autumn. Since previous studies assumed that dust originating in the deserts of Asia was the largest source of . airborne iron to the GoA, the budget of aeolian deposition of iron needs to be reassessed. Since late 20 I 0, our group has been monitoring dust activity using satellites over the Copper River Delta (CRD) where the most vigorous dust plumes have been observed. Since 2011, sample aerosol concentration and their composition are being collected at Middleton Island (100km off shore of CRD). This presentation will show a summary of the ongoing dust observations and compare with other similar environments (Patagonia, Iceland) by showing case studies. Common features will be highlighted
Miller, Marti L.; Dumoulin, Julie A.; Nelson, S.W.
1984-01-01
The lower Tertiary Orca Group is juxtaposed against the Upper Cretaceous Valdez Group along the Contact fault system (Winkler and Plafker, 1974, 198; Plafker and others, 1977)(fig. 33). In both groups, turbidites are the dominant rock type, with lesser mafic volcanic rocks (table 10). The Valdez Group, on the north, has traditionally been considered to be of higher metamorphic grade than the Orca Group (Moffit, 1954; Tysdal and Case, 1979; Winkler and Plafker, 198; Winkler and others, 1981). In 1982, we made a transect across the regional strike of the rocks and the contact between the two groups. The transect area follows the Copper River for 85 km from the Cordova quadrangle north into the Valdez quadrangle and extends for about 25 km on either side of the river (fig. 33). We planned, by systematic sampling of the area, to examine the metamorphic differences between the Orca and Valdez Groups. We found, however, that a strong thermal metamorphic event has overprinted and obscured regional metamorphic relations. We believe intrusion of Tertiary granite (fig. 33) to be responsible for this metamorphism. (Figures 33 and 34 and tables follow this article.)
Wilson, Frederic H.; Weber, Florence R.; Rennick, Penny
1994-01-01
Many Alaskans know the dynamic nature of Alaska’s landscape firsthand. The 1964 earthquake, the 1989 eruption of Mount Redoubt volcano, the frequent earthquakes in the Aleutians and the ever-shifting meanders of the Yukon and Kuskokwim rivers remind them of constant changes to the land. These changes are part of the continuing story of the geologic growth and development of Alaska during hundreds of millions of years. By geologic time, Alaska has only recently come into existence and the dynamic processes that formed it continue to affect it. The landscape we see today has been shaped by glacier and stream erosion or their indirect effects, and to a lesser extent by volcanoes. Most prominently, if less obviously, Alaska has been built by slow movements of the Earth’s crust we call tectonic or mountain-building.During 5 billion years of geologic time, the Earth’s crust has repeatedly broken apart into plates. These plates have recombined, and have shifted positions relative to each other, to the Earth’s rotational axis and to the equator. Large parts of the Earth’s crust, including Alaska, have been built and destroyed by tectonic forces. Alaska is a collage of transported and locally formed fragments of crusts As erosion and deposition reshape the land surface, climatic changes, brought on partly by changing ocean and atmospheric circulation patterns, alter the location and extent of tropical, temperate and arctic environments. We need to understand the results of these processes as they acted upon Alaska to understand the formation of Alaska. Rocks can provide hints of previous environments because they contain traces of ocean floor and lost lands, bits and pieces of ancient history.
Geomorphology and river dynamics of the lower Copper River, Alaska
Brabets, Timothy P.; Conaway, Jeffrey S.
2009-01-01
Located in south-central Alaska, the Copper River drains an area of more than 24,000 square miles. The average annual flow of the river near its mouth is 63,600 cubic feet per second, but is highly variable between winter and summer. In the winter, flow averages approximately 11,700 cubic feet per second, and in the summer, due to snowmelt, rainfall, and glacial melt, flow averages approximately 113,000 cubic feet per second, an order of magnitude higher. About 15 miles upstream of its mouth, the Copper River flows past the face of Childs Glacier and enters a large, broad, delta. The Copper River Highway traverses this flood plain, and in 2008, 11 bridges were located along this section of the highway. The bridges cross several parts of the Copper River and in recent years, the changing course of the river has seriously damaged some of the bridges.Analysis of aerial photography from 1991, 1996, 2002, 2006, and 2007 indicates the eastward migration of a channel of the Copper River that has resulted in damage to the Copper River Highway near Mile 43.5. Migration of another channel in the flood plain has resulted in damage to the approach of Bridge 339. As a verification of channel change, flow measurements were made at bridges along the Copper River Highway in 2005–07. Analysis of the flow measurements indicate that the total flow of the Copper River has shifted from approximately 50 percent passing through the bridges at Mile 27, near the western edge of the flood plain, and 50 percent passing through the bridges at Mile 36–37 to approximately 5 percent passing through the bridges at Mile 27 and 95 percent through the bridges at Mile 36–37 during average flow periods.The U.S. Geological Survey’s Multi-Dimensional Surface-Water Modeling System was used to simulate water-surface elevation and velocity, and to compute bed shear stress at two areas where the Copper River is affecting the Copper River Highway. After calibration, the model was used to examine the effects that betterments, such as guide banks or bridge extensions, would have on flow conditions and to provide sound conceptual information that could help decide if a proposed betterment will work or determine potential problems that need to be addressed for a particular betterment. The ability of the model to simulate these hydraulic conditions was constrained by the accuracy and level of channel geometry detail, which is constantly changing in the lower Copper River.
Dusel-Bacon, Cynthia; Slack, John F.; Koenig, Alan E.; Foley, Nora K.; Oscarson, Robert L.; Gans, Kathleen D.
2011-01-01
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of sulfide minerals determined by electron microprobe and laser ablation—inductively coupled plasma—mass spectrometry (LA-ICP-MS) techniques. The PDF consists of text, appendix explaining the analytical methods used for the analyses presented in the data tables, a sample location map, and seven data tables. The seven tables are also available as spreadsheets in several file formats. Descriptions and discussions of the Bonnifield deposits are given in Dusel-Bacon and others (2004, 2005, 2006, 2007, 2010).
Exploring Options for an Integrated Water Level Observation Network in Alaska
NASA Astrophysics Data System (ADS)
McCammon, M.
2016-02-01
Portions' of Alaska's remote coastlines are among the Nation's most vulnerable to geohazards such as tsunami, extra-tropical storm surge, and erosion; and the availability of observations of water levels, ocean waves, and river discharge are severely lacking to support water level warnings and forecasts. Alaska is experiencing dramatic reductions in sea ice cover, changes in extra-tropical storm surge patterns, and thawing permafrost. These conditions are endangering coastal populations throughout the State. Gaps in the ocean observing system limit our State's ability to provide useful marine and sea ice forecasts, especially in the Arctic. A spectrum of observation platforms may provide an optimal solution for filling the most critical gaps in these coastal and ocean areas. The collaborations described in this talk and better leveraging of resources and capabilities across federal, state, and academic partners will provide the best opportunity for advancing our science capacity and capabilities in this remote region.
Best, Heather; McNamara, J.P.; Liberty, Lee M.
2005-01-01
We collected ground-penetrating radar data at 10 sites along the Kuparuk River and its main tributary, the Toolik River, to detect unfrozen water beneath river ice. We used 250 MHz and 500 MHz antennas to image both the ice-water interface and the river channel in late April 2001, when daily high temperatures were consistently freezing and river ice had attained its maximum seasonal thickness. The presence of water below the river ice appears as a strong, horizontal reflection observed in the radar data and is confirmed by drill hole data. A downstream transition occurs from ice that is frozen to the bed, called bedfast ice, to ice that is floating on unfrozen water, called floating ice. This transition in ice type corresponds to a downstream change in channel size that was detected in previously conducted hydraulic geometry surveys of the Kuparuk River. We propose a conceptual model wherein the downstream transition from bedfast ice to floating ice is responsible for an observed step change in channel size due to enhanced bank erosion in large channels by floating ice.
Predation of Karluk River sockeye salmon by coho salmon and char
McIntyre, J.D.; Reisenbichler, R.R.; Emlen, J.M.; Wilmot, R.L.; Finn, J.E.
1988-01-01
The number of sockeye salmon, Oncorhynchus nerka, in Alaska's Karluk River (Fig. 1) declined from millions to thousands during the early part of the present century. Rounsefell (1958) discussed alternative explanations for the decline including a general loss offertility ofthe system as the number of salmon carcasses declined, competition, overfishing, subtle changes in climate, and predation; he concluded that the combined effect of predation and fishing was the most probable explanation. Later, Van Cleave and Bevan (1973) suggested that the weir constructed in the river each year to facilitate counting the fish as they entered the system was the most probable cause ofthe decline. Itprevented free movement of both adults and juveniles in the river. All of these hypotheses remain as potential explanations for the decline
Mitochondrial DNA phylogeography of least cisco Coregonus sardinella in Alaska.
Padula, V M; Causey, D; López, J A
2017-03-01
This study presents the first detailed analysis of the mitochondrial DNA diversity of least cisco Coregonus sardinella in Alaska using a 678 bp segment of the control region (D-loop) of the mitochondrial genome. Findings suggest that the history of C. sardinella in Alaska differs from that of other species of Coregonus present in the state and surrounding regions. The examined populations of C. sardinella are genetically diverse across Alaska. Sixty-eight distinct mitochondrial haplotypes were identified among 305 individuals sampled from nine locations. The haplotype minimum spanning network and phylogeny showed a modest level of geographic segregation among haplotypes, suggesting high levels of on-going or recent connectivity among distant populations. Observed Φ ST values and the results of homogeneity and AMOVAs indicate incipient genetic differentiation between aggregations in three broad regional groups. Sites north of the Brooks Range formed one group, sites in the Yukon and Selawik Rivers formed a second group and sites south of the Yukon drainage formed the third group. Overall, the sequence data showed that a large proportion of mtDNA genetic variation in C. sardinella is shared across Alaska, but this variation is not homogeneously distributed across all regions and for all haplotype groups. © 2017 The Fisheries Society of the British Isles.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-14
... Rivers system; management of wilderness characteristics; protection of resources important to maintaining a subsistence lifestyle; the importance of subsistence to local economies and traditional lifestyles... BLM-managed lands in the planning area for wilderness characteristics using criteria established by...
Publications - GMC 40 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 40 Publication Details Title: X-ray diffraction analysis of the Pan Am Hoodoo Lake #2; Pan Am , X-ray diffraction analysis of the Pan Am Hoodoo Lake #2; Pan Am David River #1-A; and the AMOCO
Hydrologic controls on nitrogen availability in a high-latitude, semi-arid floodplain.
Nicholas J. Lisuzzo; Knut Kielland; Jeremy B. Jones
2008-01-01
Past research shows a discrepancy between apparent nitrogen supply and the annual growth requirements for early successional plant communities along the Tanana River floodplain in interior Alaska. Because previous measurements of nitrogen fixation, mineralization, and deposition can only account for approximately 26% of these communities' nitrogen requirements,...
36 CFR 13.550 - Wildlife distance conditions.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Wildlife distance conditions. 13.550 Section 13.550 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Alagnak Wild River § 13.550 Wildlife...
36 CFR 13.550 - Wildlife distance conditions.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Wildlife distance conditions. 13.550 Section 13.550 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Alagnak Wild River § 13.550 Wildlife...
36 CFR 13.550 - Wildlife distance conditions.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Wildlife distance conditions. 13.550 Section 13.550 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Alagnak Wild River § 13.550 Wildlife...
36 CFR 13.550 - Wildlife distance conditions.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Wildlife distance conditions. 13.550 Section 13.550 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Alagnak Wild River § 13.550 Wildlife...
36 CFR 13.550 - Wildlife distance conditions.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Wildlife distance conditions. 13.550 Section 13.550 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Alagnak Wild River § 13.550 Wildlife...
ORPC RivGen Acoustic Measurements
Brian Polagye
2016-06-06
Drifting hydrophone measurements obtained around the Ocean Renewable Power Company RivGen turbine near the village of Igiugig, Alaska in August, 2014. Each data set contains hydrophone voltage (as well as gain and sensitivity), position on the river (LAT, LONG, and proximity to turbine [xt, yt]), drift velocity, and contextual meteorological data.
Dornblaser, Mark M.; Halm, Douglas R.
2006-01-01
The Yukon River basin is a vast and diverse ecosystem covering more than 330,000 square miles, an area larger than Texas. Approximately 126,000 people live within the basin and depend on the Yukon River and its tributaries for drinking water, commerce, and recreational and subsistence fish and game resources. Much of the Yukon River basin is underlain by permafrost containing vast amounts of organic carbon and nutrients. Recent climatic warming of the basin has resulted in lengthening of the growing season, melting of permafrost, deepening of the soil active layer, drying of upland soils, and shrinking of wetlands. These mostly terrestrial effects also affect the hydrology of the basin, changing the timing, magnitude, and fate of water and dissolved and particulate materials delivery to the Yukon River and its tributaries. As permafrost melts, stored carbon and nutrients are expected to become available for decomposition by soil organisms or for export downstream and to the Bering Sea. Such changes can have numerous, far-reaching effects on the ecosystem, including increased emission of greenhouse gases such as carbon dioxide and methane; changes in stream productivity, including salmon populations; changes in the productivity and chemistry of the Bering Sea; and increased fire frequency. One important question is whether organic carbon export to rivers will increase or decrease downstream from large wetland areas presently having substantial carbon storage, such as Yukon Flats. Because very few historical water-quality data are available for the Yukon River basin, scientists are unable to quantitatively assess potential effects of climate warming on aquatic ecosystems in the basin. In order to address these concerns, the U.S. Geological Survey conducted a comprehensive baseline water-quality characterization of the Yukon River and its major tributaries during 2000-05. The study included frequent water-quality sampling at a fixed-site network. In addition to the fixed-site sampling, intensive synoptic sampling of tributaries draining directly into the Yukon River was conducted along its entire length. This report contains observations of water and sediment quality made in the Yukon River basin during the synoptic sampling cruises in years 2002 and 2003. Chemical and biological data are presented for the Yukon River and its major tributaries between the towns of Eagle and St. Marys, Alaska.
NASA Astrophysics Data System (ADS)
Hanna, Andrea J. M.; Shanahan, Timothy M.; Allison, Mead A.
2016-07-01
Significant climate fluctuations in the Arctic over the recent past, and additional predicted future temperature changes, highlight the need for high-resolution Arctic paleoclimate records. Arctic coastal environments supplied with terrigenous sediment from Arctic rivers have the potential to provide annual to subdecadal resolution records of climate variability over the last few millennia. A potential tool for paleotemperature reconstructions in these marine sediments is the revised methylation index of branched tetraethers (MBT')/cyclization ratio of branched tetraethers (CBT) proxy based on branched glycerol dialkyl glycerol tetraethers (brGDGTs). In this study, we examine the source of brGDGTs in the Colville River, Alaska, and the adjacent Simpson Lagoon and reconstruct temperatures from Simpson Lagoon sediments to evaluate the applicability of this proxy in Arctic estuarine environments. The Colville catchment soils, fluvial sediments, and estuarine sediments contain statistically similar brGDGT distributions, indicating that the brGDGTs throughout the system are soil derived with little alteration from in situ brGDGT production in the river or coastal waters. Temperatures reconstructed from the MBT'/CBT indices for surface samples show good agreement with regional summer (June through September) temperatures, suggesting a seasonal bias in Arctic temperature reconstructions from the Colville system. In addition, we reconstruct paleotemperatures from an estuarine sediment core that spans the last 75 years, revealing an overall warming trend in the twentieth century that is consistent with trends observed in regional instrumental records. These results support the application of this brGDGT-based paleotemperature proxy for subdecadal-scale summer temperature reconstructions in Arctic estuaries containing organic material derived from sediment-laden, episodic rivers.
Fouch, T.D.; Carter, L.D.; Kunk, Michael J.; Smith, C.A.S.; White, J.M.
1994-01-01
Cenozoic strata exposed along the Porcupine River between the Upper Ramparts and Canyon Village, Alaska, can be divided into five unconformity-bounded units (sequences) which are: lower and middle Miocene unit A, the white sandy fluvial sequence with peat beds; middle Miocene unit B, the basalt sequence-part B1 is basalt, and part B2 is organic-rich sedimentary beds; upper Miocene unit C, mudrock-dominated lake sequence; late Miocene or Pliocene to Pleistocene unit D, terrace gravels, detrital organic matter and associated sediments, and Holocene unit E, mixed sand and gravel-rich sediment and other sedimentary material including peat and eolian silt. The sequence (unit A) of lower and middle Miocene fluvial deposits formed in streams and on flood plains, just before the inception of local volanism. Fossil pollen from unit A suggests conifer-dominated regional forests and cool temperate climates. Peat beds and lake deposits from unit B contain pollen that indicates a warmer temperate climate coinciding with the middle Miocene thermal maximum. The lake deposits (unit C) downstream from the basalts accumulated in a small basin which resulted from a hydrologic system that was dammed in the late Miocene but breached soon thereafter. The lower part of the terrace gravels (unit D) expresses breaching of the dammed hydrologic system (of unit C). The Porcupine River became a major tributary of the Yukon River in late Pleistocene time when Laurentide ice blocked drainage from the Yukon interior basins causing meltwater to spill over the low divide separating it from the Porcupine River drainage initiating erosion and capture of the Yukon interior basins. ?? 1994.
Hydrologic reconnaissance of the Noatak River basin, Alaska, 1978
Childers, Joseph M.; Kernodle, Donald R.
1981-01-01
Hydrologic data were collected in 1978 described water resources of the Noatak River basin, Alaska. Streamflow varies seasonally. No flow was observed from the upper part of the basin in late winter (April). In the lower part of the basin springs support perennial flow in the Kugururok River and downstream along the Noatak. The discharge of the Noatak was 150 cubic feet per second in April 1978. During the summer, rainstorms are common, and runoff produces high flow. During August 1978, flow was normal in the basin; unit runoff averaged about 1 cubic foot per second per square mile. The Noatak is a gravel-bed stream of moderate slope. It drops about 1,800 feet in elevation from a point near the head waters to the mouth, a distance of 400 miles. Streambed material in most places is gravel, cobbles, and boulders, maximum riffle depths and pool widths increase in a downstream direction. Stream velocity in August 1978 increased from about 1 foot per second in the upper basin to about 4 feet per second in the lower reaches. High-water marks of the maximum evident flood were found at elevations from bankfull to 5 feet above bankfull. Maximum evident flood unit runoff rates were estimated to be less than 50 cubic feet per second per square mile. Scars produced by ice jams were seldom seen above bankfull. Bank erosion appears to be most active in the lowlands. Water in the Noatak River basin is virtually unaffected by man 's activity. Water quality varies with location, weather, season, and source; the water is normally clear, cool, and hard. During late winter sea water intrudes into the Lower Noatak Canyon. Benthic invertebrate community composition and variability suggest the river 's undiminished natural quality. (USGS)
Nakanishi, Allen S.; Lilly, Michael R.
1998-01-01
MODFLOW, a finite-difference model of ground-water flow, was used to simulate the flow of water between the aquifer and the Chena River at Fort Wainwright, Alaska. The model was calibrated by comparing simulated ground-water hydrographs to those recorded in wells during periods of fluctuating river levels. The best fit between simulated and observed hydrographs occurred for the following: 20 feet per day for vertical hydraulic conductivity, 400 feet per day for horizontal hydraulic conductivity, 1:20 for anisotropy (vertical to horizontal hydraulic conductivity), and 350 per feet for riverbed conductance. These values include a 30 percent adjustment for geometry effects. The estimated values for hydraulic conductivities of the alluvium are based on assumed values of 0.25 for specific yield and 0.000001 per foot for specific storage of the alluvium; the values assumed for bedrock are 0.1 foot per day horizontal hydraulic conductivity, 0.005 foot per day vertical hydraulic conductivity, and 0.0000001 per foot for specific storage. The resulting diffusivity for the alluvial aquifer is 1,600 feet per day. The estimated values of these hydraulic properties are nearly proportional to the assumed value of specific yield. These values were not found to be sensitive to the assumed values for bedrock. The hydrologic parameters estimated using the cross-sectional model are only valid when taken in context with the other values (both estimated and assumed) used in this study. The model simulates horizontal and vertical flow directions near the river during periods of varying river stage. This information is useful for interpreting bank-storage effects, including the flow of contaminants in the aquifer near the river.
Brabets, Timothy P.; Conaway, Jeffrey S.
2009-01-01
The Copper River Basin, the sixth largest watershed in Alaska, drains an area of 24,200 square miles. This large, glacier-fed river flows across a wide alluvial fan before it enters the Gulf of Alaska. Bridges along the Copper River Highway, which traverses the alluvial fan, have been impacted by channel migration. Due to a major channel change in 2001, Bridge 339 at Mile 36 of the highway has undergone excessive scour, resulting in damage to its abutments and approaches. During the snow- and ice-melt runoff season, which typically extends from mid-May to September, the design discharge for the bridge often is exceeded. The approach channel shifts continuously, and during our study it has shifted back and forth from the left bank to a course along the right bank nearly parallel to the road.Maintenance at Bridge 339 has been costly and will continue to be so if no action is taken. Possible solutions to the scour and erosion problem include (1) constructing a guide bank to redirect flow, (2) dredging approximately 1,000 feet of channel above the bridge to align flow perpendicular to the bridge, and (3) extending the bridge. The USGS Multi-Dimensional Surface Water Modeling System (MD_SWMS) was used to assess these possible solutions. The major limitation of modeling these scenarios was the inability to predict ongoing channel migration. We used a hybrid dataset of surveyed and synthetic bathymetry in the approach channel, which provided the best approximation of this dynamic system. Under existing conditions and at the highest measured discharge and stage of 32,500 ft3/s and 51.08 ft, respectively, the velocities and shear stresses simulated by MD_SWMS indicate scour and erosion will continue. Construction of a 250-foot-long guide bank would not improve conditions because it is not long enough. Dredging a channel upstream of Bridge 339 would help align the flow perpendicular to Bridge 339, but because of the mobility of the channel bed, the dredged channel would likely fill in during high flows. Extending Bridge 339 would accommodate higher discharges and re-align flow to the bridge.
Slaty-backed Gull in Sullivan Co., NY
Freer, V.; Haas, J.; Buckley, P.A.
2002-01-01
An adult Slaty-backed Gull (Larus schistisagus) was found and photographed at Neversink Reservoir, Sullivan Co., NY on 20 February 2002. A native of northeastern Eurasia and northern Japan, this species is rare along the Bering coast of Alaska, and there are only a handful of scattered records in the lower 48 state since the first in St Louis along the Mississippi River in late 1983. There is one previous New York State occurrence, in the Niagara River Gorge area of NY/ONT, 24 November-29 December 1992. The Sullivan Co. adult is the closest confirmed Slaty-backed Gull to the Atlantic Coast; recent single individuals along the Susquehanna River in MD, and at Cape Hatteras NC remain in dispute.
1992-03-31
ponds (Bread Truck Pond) were significantly higher than those from the other ponds. Area C and the Bread Truck ponds, covering an area of about 15 ha (37...Figure 1-12. Aerial view of Eagle River Flats in January 1991 viewed to the north showing Knik Arm and ice- covered ERF. Figure 11-13. Ice core...levees of some distributaries are tall stands of beach rye (Elymus arenarius). Inside or landward of this sparsely vegetated mudflat zone is a low sedge
1984-07-01
field book for scale). Figure 2 (cont’d). Figure 3. Upstream portion of reach 2, 9 May 1980; USGS gauging station (A) and the approximate location...eral information was taken from maps, and site-specific data were obtained from the logs of wells drilled by the Corps of Engineers. The well log data...were drilled along or near this route, which runs approximately parallel to the bank, but not near the riverbank aL most locations (Fig. 1). The
Earth observations during Space Shuttle Mission STS-42 - Discovery's mission to planet earth
NASA Technical Reports Server (NTRS)
Lulla, Kamlesh P.; Helfert, Michael; Amsbury, David; Pitts, David; Jaklitch, Pat; Wilkinson, Justin; Evans, Cynthia; Ackleson, Steve; Helms, David; Chambers, Mark
1993-01-01
The noteworthy imagery acquired during Space Shuttle Mission STS-42 is documented. Attention is given to frozen Tibetan lakes, Merapi Volcano in Java, Mt. Pinatubo in the Philippines, the coastline east of Tokyo Japan, land use in southern India, and the Indus River Delta. Observations of Kamchatka Peninsula, Lake Baikal, Moscow, Katmai National Park and Mt. Augustine, Alaska, the Alaskan coast by the Bering Sea, snow-covered New York, the Rhone River valley, the Strait of Gibraltar, and Mt. Ararat, Turkey, are also reported.
NASA Astrophysics Data System (ADS)
Brooks, J. F.; Trainor, S.
2017-12-01
Over 20,000 residents in Alaska and Yukon Territory rely upon the Yukon River to provide them harvests of Pacific salmon each year. Salmon are a highly valued food resource and the practice of salmon fishing along the Yukon is deep rooted in local cultures and traditions. Potential future impacts of climate change on the health of Yukon River salmon stocks could be significant. Collaborative managerial processes which incorporate the viewpoints of subsistence stakeholders will be crucial in enabling communities and managerial institutions to adapt and manage these impacts. However, the massive extent of the Yukon River makes it difficult for communities rich with highly localized knowledge to situate themselves within a drainage-wide context of resource availability, and to fully understand the implications that management decisions may have for their harvest. Differences in salmon availability and abundance between the upper and lower Yukon, commercial vs. subsistence fishery interests, and enforcement of the international Pacific Salmon Treaty further complicate understanding and makes the topic of salmon as a subsistence resource a highly contentious issue. A map which synthesizes the presence and absence of Pacific salmon throughout the entire Yukon River drainage was requested by both subsistence fishers and natural resource managers in Alaska in order to help facilitate productive conversations about salmon management decisions. Interviews with Alaskan stakeholders with managerial, biological, and subsistence harvest backgrounds were carried out and a literature review was conducted in order to understand what such a map should and could accomplish. During the research process, numerous data gaps concerning the distribution of salmon along the Yukon River were discovered, and insights about the complexities involved in translating science when it is situated within a charged political, economic, and cultural context were revealed. Preliminary maps depicting the timing of salmon pulses, the data gaps present, and the political landscape of the Yukon River were created. A future step of developing an interactive online mapping tool has been identified as a way to most clearly communicate the complexity of the interwoven systems involved in the status of Yukon River salmon and their management.
Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.
2015-01-01
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 212 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Chilkat, Klehini, Tsirku, and Takhin river drainages, as well as smaller drainages flowing into Chilkat and Chilkoot Inlets near Haines, Skagway Quadrangle, Southeast Alaska. Additionally some samples were also chosen from the Juneau gold belt, Juneau Quadrangle, Southeast Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.
Leake, S.A.; Lilly, M.R.
1995-01-01
The Fairbanks, Alaska, area has many contaminated sites in a shallow alluvial aquifer. A ground-water flow model is being developed using the MODFLOW finite-difference ground-water flow model program with the River Package. The modeled area is discretized in the horizontal dimensions into 118 rows and 158 columns of approximately 150-meter square cells. The fine grid spacing has the advantage of providing needed detail at the contaminated sites and surface-water features that bound the aquifer. However, the fine spacing of cells adds difficulty to simulating interaction between the aquifer and the large, braided Tanana River. In particular, the assignment of a river head is difficult if cells are much smaller than the river width. This was solved by developing a procedure for interpolating and extrapolating river head using a river distance function. Another problem is that future transient simulations would require excessive numbers of input records using the current version of the River Package. The proposed solution to this problem is to modify the River Package to linearly interpolate river head for time steps within each stress period, thereby reducing the number of stress periods required.
Dusel-Bacon, C.; Lanphere, M.A.; Sharp, W.D.; Layer, P.W.; Hansen, V.L.
2002-01-01
We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the Yukon-Tanana Upland, Alaska. Integration of our data with published 40Ar/39Ar, kinematic, and metamorphic pressure (P) and temperature (T) data confirms and refines the complex interaction of metamorphism and tectonism proposed for the region. The oldest metamorphic episode(s) postdates Middle Permian magmatism and predates the intrusion of Late Triassic (215-212 Ma) granitoids into the Fortymile River assemblage (Taylor Mountain assemblage of previous papers). In the eastern Eagle quadrangle, rapid and widespread Early Jurassic cooling is indicated by ???188-186 Ma 40Ar/39Ar plateau ages for hornblende from plutons that intrude the Fortymile River assemblage, and for metamorphic minerals from the Fortymile River assemblage and the structurally underlying Nasina assemblage. We interpret these Early Jurassic ages to represent cooling resulting from northwest-directed contraction that emplaced the Fortymile River assemblage onto the Nasina assemblage to the north as well as the Lake George assemblage to the south. This cooling was the final stage of a continuum of subduction-related contraction that produced crustal thickening, intermediate- to high-P metamorphism within both the Fortymile River assemblage and the structurally underlying Lake George assemblage, and Late Triassic and Early Jurassic plutonism in the Fortymile River and Nasina assemblages. Although a few metamorphic samples from the Lake George assemblage yield Jurassic 40Ar/39Ar cooling ages, most yield Early Cretaceous 40Ar/39Ar ages: hornblende ???135-115 Ma, and muscovite and biotite ???110-108 Ma. We interpret the Early Cretaceous metamorphic cooling, in most areas, to have resulted from regional extension and exhumation of the lower plate, previously tectonically thickened during Early Jurassic and older convergence.
Publications - GMC 12 | Alaska Division of Geological & Geophysical Surveys
- 11,850 feet; total organic carbon, rock-eval pyrolysis and visual kerogen/vitrinite reflectance Authors River #1 well 10,255 - 11,850 feet; total organic carbon, rock-eval pyrolysis and visual kerogen gmc012.pdf (384.0 K) Keywords Kerogen; Pyrolysis; Rock-Eval Pyrolysis; Total Organic Carbon; Vitrinite
Publications - GMC 20 | Alaska Division of Geological & Geophysical Surveys
, rock-eval/pyrolysis, total organic carbon) and core logs for the David River USA #1-A, Hoodoo Lake Unit , 1969, Geochemical analysis (vitrinite reflectance, visual kerogen, rock-eval/pyrolysis, total organic gmc020.pdf (3.2 M) Keywords Kerogen; Pyrolysis; Rock-Eval Pyrolysis; Total Organic Carbon; Vitrinite
Meaning in Mud: Yup'ik Eskimo Girls at Play.
ERIC Educational Resources Information Center
deMarrais, Kathleen Bennett; And Others
1992-01-01
Describes storyknifing, a traditional way of storytelling illustrated through pictures traced in mud, by young girls in a Yup'ik Eskimo village on the Kuskokwim River (Alaska). Storyknifing provides a forum in which young girls learn cultural and cognitive knowledge. Storyknifing maintains a link with traditional society in this village. (SLD)
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-24
... BLM will announce future meetings or hearings and any other public participation activities at least..., Attention--Eastern Interior Draft RMP/EIS, Bureau of Land Management, 1150 University Avenue, Fairbanks... interior Alaska and is divided into four geographic areas: The Fortymile, Steese, Upper Black River, and...
1999-01-05
KENNEDY SPACE CENTER, FLA. -- An osprey perches on a treetop at Kennedy Space Center. This long-winged "fish hawk" inhabits lakes, rivers and seacoasts, surviving solely on fish which it captures from the water, grasping them in its talons when they near the surface. They range from Alaska and Newfoundland south to Florida and the Gulf Coast
catalogued from various sites; (4) the celebration of various holidays was observed; (5) the changes in land use during the past 100 years; and (6) the biographies of the oldest woman and one of the oldest men in a village were recorded.
Managing brown bears and wilderness recreation on the Kenai Peninsula, Alaska, USA
NASA Astrophysics Data System (ADS)
Jacobs, Michael J.; Schloeder, Catherine A.
1992-03-01
The Russian River-Cooper Lake-Resurrection River trail system, on the Kenai Peninsula, Alaska, traverses essential brown bear habitat. To set management guidelines for this area, the trail system was monitored using questionnaire cards and electronic trail counters from 1984 through 1987. This helped to determine the extent and type of human use and human-bear encounters in the area. Management recommendations were intended to reduce the potential displacement of brown bears by hikers and to inform wilderness users of the proper camping techniques to avoid attracting bears to the campsite. An average of 5800 visitors hiked or camped along the trail system each year. Encounters between hikers and brown bears averaged 7/yr while encounters with black bears averaged 35/yr. Minor problems occurred with both the electronic trail counters and the questionnaire. Modilications to these methods are discussed. A Limits of Acceptable Change format should be considered for the trail system to determine the character and future direction of recreational activities and monitoring of the trail system should continue in the future.
Fraley, Kevin M.; Falke, Jeffrey A.; McPhee, Megan V.; Prakash, Anupma
2018-01-01
We used spatially continuous field-measured and remotely-sensed aquatic habitat characteristics paired with weekly ground-based telemetry tracking and snorkel surveys to describe movements and habitat occupancy of adult rainbow trout (N = 82) in a runoff-fed, salmon-influenced southcentral Alaska river system. We found that during the ice-free feeding season (June through September) rainbow trout occurrence was associated more with fine-scale (channel unit) characteristics relative to coarse-scale (stream reach) variables. The presence of Pacific salmon (which provide an important seasonal food subsidy), and habitat size were particularly useful predictors. Weekly movement distance differed between pre- and post- spawning salmon arrival, but did not vary by sex. Habitat quality, season, and the arrival of spawning salmon influenced the likelihood of rainbow trout movement, and fish moved farther to seek out higher quality habitats. Because rainbow trout respond to habitat factors at multiple scales and seek out salmon-derived subsidies, it will be important to take a multiscale approach in protecting trout and salmon populations and managing the associated fisheries.
White, Max Gregg; West, W.S.; Matzko, J.J.
1953-01-01
Placer-mining areas and bedrock exposures near Teller on the Seward Peninsula, Alaska, were investigated in June and July, 1946, for possible sources of radioactive materials. The areas that were investigated are: Dese Creek, southeast of Teller; Bluestone River basin, south and southeast of Teller; Sunset Creek and other small streams flowing south into Grantley Harbor, northeast of Teller; and, also northeast of Teller, Swanson Creek and its tributaries, which flow north into the Agiapuk River basin. No significant amount of radioactive material was found, either in the stream gravels or in the bedrock of any of the areas. A heavy-mineral fraction obtained from a granite boulder probably derived from a bench gravel on Gold Run contains 0. 017 percent equivalent uranium, but the radioactivity is due to allanite and zircon. The types of bedrock tested include schist, slate, and greenstone. Readings on fresh surfaces of rock were the same as, or only slightly above the background count. The maximum radioactivity in stream concentrates is 0. 004 percent equivalent uranium in a sluice concentrate from Sunset Creek.
2013-11-18
Dust storm in Alaska captured by Aqua/MODIS on Nov. 17, 2013 at 21:45 UTC. When glaciers grind against underlying bedrock, they produce a silty powder with grains finer than sand. Geologists call it “glacial flour” or “rock flour.” This iron- and feldspar-rich substance often finds its ways into rivers and lakes, coloring the water brown, grey, or aqua. When river or lake levels are low, the flour accumulates on drying riverbanks and deltas, leaving raw material for winds to lift into the air and create plumes of dust. Scientists are monitoring Arctic dust for a number of reasons. Dust storms can reduce visibility enough to disrupt air travel, and they can pose health hazards to people on the ground. Dust is also a key source of iron for phytoplankton in regional waters. Finally, there is the possibility that dust events are becoming more frequent and severe due to ongoing recession of glaciers in coastal Alaska. To read more about dust storm in this region go to: earthobservatory.nasa.gov/IOTD/view.php?id=79518 Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Mineral precipitation in north slope aufeis
NASA Technical Reports Server (NTRS)
Hall, D. K.
1978-01-01
The Canning and Shaviovik river aufeis fields were studied on the ground and with aircraft data. Powdered calcium carbonate (CaCO3) patches, a few cm in thickness, were found in discrete locations on both aufeis fields. This is indicative of chemical weathering of limestone bedrock which is known to underlie much of the eastern arctic coastal plain of Alaska. Spring or river water which remains unfrozen throughout much of the winter carries CaCO3 in solution; as the river ice freezes more deeply the CaCO3 in solution is forced upwards through cracks in the river ice. Upon exposure to the cold air CaCO3 is excluded as the water freezes, forming successive layers during aufeis growth. In the melt season CaCO3, slush/powder accumulates in patches on top of the ice as the aufeis melts downward.
Simulating Glacial Outburst Lake Releases for Suicide Basin, Mendenhall Glacier, Juneau, Alaska
NASA Astrophysics Data System (ADS)
Jacobs, A. B.; Moran, T.; Hood, E. W.
2017-12-01
Glacial Lake outbursts from Suicide Basin are recent phenomenon first characterized in 2011. The 2014 event resulted in record river stage and moderate flooding on the Mendenhall River in Juneau. Recognizing that these events can adversely impact residential areas of Juneau's Mendenhall Valley, the Alaska-Pacific River Forecast Center developed a real-time modeling technique capable of forecasting the timing and magnitude of the flood-wave crest due to releases from Suicide Basin. The 2014 event was estimated at about 37,000 acre feet with water levels cresting within 36 hours from the time the flood wave hit Mendenhall Lake. Given the magnitude of possible impacts to the public, accurate hydrological forecasting is essential for public safety and Emergency Managers. However, the data needed to effectively forecast magnitudes of specific jökulhlaup events are limited. Estimating this event as related to river stage depended upon three variables: 1) the timing of the lag between Suicide Basin water level declines and the related rise of Mendenhall Lake, 2) continuous monitoring of Mendenhall Lake water levels, and 3) estimating the total water volume stored in Suicide Basin. Real-time modeling of the event utilized a Time of Concentration hydrograph with independent power equations representing the rising and falling limbs of the hydrograph. The initial accuracy of the model — as forecasted about 24 hours prior to crest — resulted in an estimated crest within 0.5 feet of the actual with a timing error of about six hours later than the actual crest.
Floyd-Rump, T P; Horstmann-Dehn, L A; Atkinson, S; Skaugstad, C
2017-01-24
Ichthyophonus is a protozoan parasite of Alaska Chinook salmon Oncorhynchus tshawytscha. In this study, we determined whether spawning Chinook salmon in the Yukon River drainage exhibited a measurable stress response (i.e. elevated plasma cortisol concentrations) and detectable changes in selected blood plasma chemistry parameters when infected with Ichthyophonus. The resulting alevin were also analyzed for any differences in blood plasma chemistry caused by parental infection with Ichthyophonus. In 2010, 2011, and 2012, spawning adult Chinook salmon were collected from the Salcha River, Alaska, USA, and the prevalence of Ichthyophonus in these fish was 7.8, 6.3, and 8.3%, respectively. Fish with no clinical signs of Ichthyophonus and Ichthyophonus-positive parents were cross-fertilized to investigate potential second-generation effects as a result of Ichthyophonus infection. We found no significant difference in cortisol concentrations in blood plasma between Ichthyophonus-positive and -negative adults or between alevin from Ichthyophonus-positive and -negative parents. There were no significant differences in blood plasma parameters (e.g. alanine aminotransferase, creatine kinase, glucose) of Ichthyophonus-negative and -positive adults, with the exception of aspartate aminotransferase, which was significantly higher in plasma of Ichthyophonus-negative adults. All clinical chemistry parameters for alevin resulting from both Ichthyophonus-negative and -positive parents were not significantly different. Based on this study, which has a limited sample size and low prevalence of Ichthyophonus, offspring of Chinook salmon appear to suffer no disadvantage as a result of Ichthyophonus infection in their parents on the Salcha River.
The Quaternary thrust system of the northern Alaska Range
Bemis, Sean P.; Carver, Gary A.; Koehler, Richard D.
2012-01-01
The framework of Quaternary faults in Alaska remains poorly constrained. Recent studies in the Alaska Range north of the Denali fault add significantly to the recognition of Quaternary deformation in this active orogen. Faults and folds active during the Quaternary occur over a length of ∼500 km along the northern flank of the Alaska Range, extending from Mount McKinley (Denali) eastward to the Tok River valley. These faults exist as a continuous system of active structures, but we divide the system into four regions based on east-west changes in structural style. At the western end, the Kantishna Hills have only two known faults but the highest rate of shallow crustal seismicity. The western northern foothills fold-thrust belt consists of a 50-km-wide zone of subparallel thrust and reverse faults. This broad zone of deformation narrows to the east in a transition zone where the range-bounding fault of the western northern foothills fold-thrust belt terminates and displacement occurs on thrust and/or reverse faults closer to the Denali fault. The eastern northern foothills fold-thrust belt is characterized by ∼40-km-long thrust fault segments separated across left-steps by NNE-trending left-lateral faults. Altogether, these faults accommodate much of the topographic growth of the northern flank of the Alaska Range.Recognition of this thrust fault system represents a significant concern in addition to the Denali fault for infrastructure adjacent to and transecting the Alaska Range. Although additional work is required to characterize these faults sufficiently for seismic hazard analysis, the regional extent and structural character should require the consideration of the northern Alaska Range thrust system in regional tectonic models.
Inundation Mapping and Hazard Assessment of Tectonic and Landslide Tsunamis in Southeast Alaska
NASA Astrophysics Data System (ADS)
Suleimani, E.; Nicolsky, D.; Koehler, R. D., III
2014-12-01
The Alaska Earthquake Center conducts tsunami inundation mapping for coastal communities in Alaska, and is currently focused on the southeastern region and communities of Yakutat, Elfin Cove, Gustavus and Hoonah. This activity provides local emergency officials with tsunami hazard assessment, planning, and mitigation tools. At-risk communities are distributed along several segments of the Alaska coastline, each having a unique seismic history and potential tsunami hazard. Thus, a critical component of our project is accurate identification and characterization of potential tectonic and landslide tsunami sources. The primary tectonic element of Southeast Alaska is the Fairweather - Queen Charlotte fault system, which has ruptured in 5 large strike-slip earthquakes in the past 100 years. The 1958 "Lituya Bay" earthquake triggered a large landslide into Lituya Bay that generated a 540-m-high wave. The M7.7 Haida Gwaii earthquake of October 28, 2012 occurred along the same fault, but was associated with dominantly vertical motion, generating a local tsunami. Communities in Southeast Alaska are also vulnerable to hazards related to locally generated waves, due to proximity of communities to landslide-prone fjords and frequent earthquakes. The primary mechanisms for local tsunami generation are failure of steep rock slopes due to relaxation of internal stresses after deglaciation, and failure of thick unconsolidated sediments accumulated on underwater delta fronts at river mouths. We numerically model potential tsunami waves and inundation extent that may result from future hypothetical far- and near-field earthquakes and landslides. We perform simulations for each source scenario using the Alaska Tsunami Model, which is validated through a set of analytical benchmarks and tested against laboratory and field data. Results of numerical modeling combined with historical observations are compiled on inundation maps and used for site-specific tsunami hazard assessment by emergency planners.
AmeriFlux US-ICs Imnavait Creek Watershed Wet Sedge Tundra
Bret-Harte, Syndonia [University of Alaska Fairbanks; Euskirchen, Eugenie [University of Alaska Fairbanks; Shaver, Gaius [Marine Biological Laboratory
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-ICs Imnavait Creek Watershed Wet Sedge Tundra. Site Description - The Imnavait Creek Watershed Wet Sedge Tundra (Fen Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Fen Station was deployed at the end of Summer 2007.
AmeriFlux US-ICh Imnavait Creek Watershed Heath Tundra
Bret-Harte, Syndonia [University of Alaska Fairbanks; Euskirchen, Eugenie [University of Alaska Fairbanks; Shaver, Gaius [Marine Biological Laboratory
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-ICh Imnavait Creek Watershed Heath Tundra. Site Description - The Imnavait Creek Watershed Heath Tundra (Ridge Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Ridge Station was deployed at the end of Summer 2007.
Are bison exotic in the Wrangell-St. Elias National Park and Preserve?
NASA Astrophysics Data System (ADS)
Peek, James M.; Miquelle, Dale G.; Wright, R. Gerald
1987-03-01
The effect of past distributions of animal populations now extinct in an area from unknown causes is considered relative to their status as exotic or native in national parks. The example is the bison (Bison bison) on the Copper and Chitina river drainages in Alaska in the USA which was introduced prior to establishment of Wrangell-St. Elias National Park and Preserve. The fossil record suggests that bison were present as recently as 500 years ago in Alaska. The policy of the US National Park Service to maintain natural ecosystems and restrict or eliminate exotic species raises the issue of whether this species should be treated as exotic or native.
Kachadoorian, Reuben
1968-01-01
The great earthquake that struck Alaska about 5:36 p.m., Alaska standard time, Friday, March 27, 1964 (03:36:1.3.0, Greenwich mean time, March 28, 1964), severely crippled the highway system in the south-central part of the State. All the major highways and most secondary roads were impaired. Damage totaled more than $46 million, well over $25 million to bridges and nearly $21 million to roadways. Of the 204 bridges in south-central Alaska, 141 were damaged; 92 were severely damaged or destroyed. The earthquake damaged 186 of the 830 miles of roadway in south-central Alaska, 83 miles so severely that replacement or relocation was required. Earthquake damage to the roadways and bridges was chiefly by (1) seismic shaking, (2) compaction of fills as well as the underlying sediments, (3) lateral displacement of the roadway and bridges, (4) fractures, (5) landslides, (6) avalanches, (7) inundation by seismic sea waves, (8) scouring by seismic sea waves, (9) regional tectonic subsidence, causing inundation and erosion by high tides in subsided areas. The intensity of damage was controlled primarily by the geologic environment (including the depth of the water table) upon which the highway structures rested, and secondarily by the engineering characteristics of the structures. Structures on bedrock were only slightly damaged if at all, whereas those on unconsolidated sediments were slightly to severely damaged, or were completely destroyed by seismic shaking. The low-lying areas underlain by saturated sediments, such as the Snow River Crossing and Turnagain Arm sections of the Seward-Anchorage Highway, were the most severely damaged stretches of the highway system in south-central Alaska. At Snow River and Turnagain Arm, the sediments underlying the roadway are fine grained and the water table is shallow. These factors were responsible for the intense damage along this stretch of the highway. All the bridges on the Copper River Highway except for one on bedrock were damaged by seismic shaking. Lateral displacement of sediments toward a free face, which placed the bridges in compression, was the chief cause for the damage. This type of failure was extensive and widespread throughout the highway system. The chief engineering characteristics responsible for the type and intensity of damage include (1) thickness of roadway fills, (2) type of pile bents and masonry piers, (3) the weight ratio between the substructure and superstructure, and (4) the tie between the substructure and superstructure. The thicker the roadway fills, the more severe the damage. Wood piles did not break as extensively as piles constructed of three railroad rails welded together. Bridges that had relatively heavy superstructures, for example those with concrete decks on wood piles, were more severely damaged than those with all-wood or concrete decks or concrete piers. Failure first occurred at the tie between the superstructure and the substructure; the poorer this tie, the sooner the failure. Seismic sea waves destroyed 12 bridges on the Chiniak Highway on Kodiak Island, one bridge on Point Whitshed road near Cordova, and about 14 miles of roadway. The combination of regional tectonic subsidence and local subsidence and compaction of sediments caused inundation of many miles of highway by high tides, especially around Turnagain Arm. Total subsidence in some places amounted to more than 13 feet.
Preliminary Volcano-Hazard Assessment for Redoubt Volcano, Alaska
Waythomas, Christopher F.; Dorava, Joseph M.; Miller, Thomas P.; Neal, Christina A.; McGimsey, Robert G.
1997-01-01
Redoubt Volcano is a stratovolcano located within a few hundred kilometers of more than half of the population of Alaska. This volcano has erupted explosively at least six times since historical observations began in 1778. The most recent eruption occurred in 1989-90 and similar eruptions can be expected in the future. The early part of the 1989-90 eruption was characterized by explosive emission of substantial volumes of volcanic ash to altitudes greater than 12 kilometers above sea level and widespread flooding of the Drift River valley. Later, the eruption became less violent, as developing lava domes collapsed, forming short-lived pyroclastic flows associated with low-level ash emission. Clouds of volcanic ash had significant effects on air travel as they drifted across Alaska, over Canada, and over parts of the conterminous United States causing damage to jet aircraft. Economic hardships were encountered by the people of south-central Alaska as a result of ash fallout. Based on new information gained from studies of the 1989-90 eruption, an updated assessment of the principal volcanic hazards is now possible. Volcanic hazards from a future eruption of Redoubt Volcano require public awareness and planning so that risks to life and property are reduced as much as possible.
The mineral resources of the Mount Wrangell district, Alaska
Mendenhall, W.C.; Schrader, F.C.
1903-01-01
The Tenth Census, taken in 1880, gives the number of white inhabitants of the Territory of Alaska as 430. In the decade from 1880 to 1890 this number had increased to 4,298, and in the following decade, that between 1890 and 1900, a further increase to 30,493 is recorded. The Director of the Mint in his report for 1891 gives the value of the yield of the Territory in precious metals as $772,197. By 1900 these figures were increased to $8,265,772. These statistics of the growth in population and in mineral output of Alaska serve as an index to the general increase in the importance and· commercial value of the Territory as an integral part of the domain of the United States. The larger part of this growth began with the discovery, late in the autumn of 1896, of the placer deposits of Klondike River in Canadian Yukon territory. Soon after this discovery there was a great influx of prospectors, miners, and, business men to all parts of Alaska, but particularly to the regions tributary to the Yukon, and with this increase in population came a proportional increase in transportation facilities and business interests.
Burril, Sean E.; Zimmerman, Christian E.; Finn, James E.; ,; Gillikin, Daniel; ,
2010-01-01
To better understand and partition mortality among life stages of chum salmon (Oncorhynchus keta), we used inclined-plane traps to monitor the migration of juveniles in the Kwethluk River, Alaska in 2007 and 2008. The migration of juvenile chum salmon peaked in mid-May and catch rates were greatest when water levels were rising. Movement of chum salmon was diurnal with highest catch rates occurring during the hours of low light (that is, 22:00 to 10:00). Trap efficiency ranged from 0.37 to 4.04 percent (overall efficiency = 1.94 percent). Total abundance of juvenile chum salmon was estimated to be 2.0 million fish in 2007 and 2.9 million fish in 2008. On the basis of the estimate of chum salmon females passing the Kwethluk River weir and age-specific fecundity, we estimated the potential egg deposition (PED) upstream of the weir and trapping site. Egg-to-smolt survival, calculated by dividing the estimate of juvenile chum salmon emigrating past the weir site by the estimate of PED, was 4.6 percent in 2007 and 5.2 percent in 2008. In addition to chum salmon, Chinook salmon O. tshawytscha), coho salmon (O. kisutch), sockeye salmon (O. nerka), and pink salmon (O. gorbuscha), as well as ten other fish species, were captured in the traps. As with chum salmon, catch of these species increased during periods of increasing discharge and peaked during hours of low light. This study successfully determined the characteristics of juvenile salmon migrations and estimated egg-to-smolt survival for chum salmon. This is the first estimate of survival for any juvenile salmon in the Arctic-Yukon-Kuskokwim region of Alaska and demonstrates an approach that can help to partition mortality between freshwater and marine life stages, information critical to understanding the dynamics of salmon in this region.
NASA Astrophysics Data System (ADS)
Hanna, Andrea J. M.; Allison, Mead A.; Bianchi, Thomas S.; Marcantonio, Franco; Goff, John A.
2014-02-01
Arctic coastal environments near major river outfalls, like Simpson Lagoon, Alaska and the adjacent Colville River Delta, potentially contain high-resolution sediment records useful in elucidating late Holocene Arctic sediment transport pathways and coupled terrestrial-ocean evidence of paleoclimate variability. This study utilizes a multi-tracer geochronology approach (137Cs, 239,240Pu, and 14C) tailored for high-latitude environments to determine the age models for cores collected from Simpson Lagoon, and to date seismic boundaries in shallow acoustic reflection data (CHIRP) to examine late Holocene infill patterns. Modern (~100 y) sediment accumulation rates range from <0.02 to 0.46±0.04 cm y-1, with a primary depocenter in western Simpson Lagoon adjacent to the Colville Delta and a secondary depocenter in eastern Simpson Lagoon. CHIRP reflectors, age-constrained by 14C analysis, reveal rapid late Holocene (0-3500 y BP) transgression consistent with high modern shoreline retreat rates. The western depocenter contains >5 m of late Holocene interbedded sediments, likely derived primarily from the Colville River, with onset of accumulation occurring prior to ~3500 y BP. A paleo-high in central Simpson Lagoon, separating the two depocenters, was subaerially exposed prior to ~600 y BP. The millimeters-per-year sedimentation rates across the lagoon, coupled with the undisturbed, interbedded sediment record, indicate that these settings hold great potential to develop new Arctic paleoenvironmental records.
Analysis of the origin of Aufeis feed-water on the arctic slope of Alaska
NASA Technical Reports Server (NTRS)
Hall, D. K.; Roswell, C. (Principal Investigator)
1980-01-01
The origin of water feeding large aufeis fields (overflow river ice) on the Arctic Slope of Alaska is analyzed. Field measurements of two large aufeis fields on the eastern Arctic Slope were taken during July of 1978 and 1979. Measurements of aufeis extent and distribution were made using LANDSAT Multispectral Scanner Subsystem (MSS) satellite data from 1973 through 1979. In addition, ice cores were analyzed in the laboratory. Results of the field and laboratory studies indicate that the water derived from aufeis melt water has a chemical composition different from the adjacent upstream river water. Large aufeis fields are found in association with springs and faults thus indicating a subterranean origin of the feed water. In addition, the maximum extent of large aufeis fields was not found to follow meteorological patterns which would only be expected if the origin of the feed water were local. It is concluded that extent of large aufeis in a given river channel on the Arctic Slope is controlled by discharge from reservoirs of groundwater. It seems probable that precipitation passes into limestone aquifers in the Brooks Range, through an interconnecting system of subterranean fractures in calcareous rocks and ultimately discharges into alluvial sediments on the coastal plain to form aufeis. It is speculated that only small aufeis patches are affected by local meteorological parameters in the months just prior to aufeis formation.
Dissolved Organic Carbon in the Yukon, Tanana and Porcupine Rivers, Alaska
NASA Astrophysics Data System (ADS)
Aiken, G. R.; Striegl, R. G.; Wickland, K. P.; Dornblaser, M. M.; Raymond, P. A.
2006-12-01
The spatial and temporal variability of dissolved organic carbon (DOC) in the Yukon River (YR) and two major tributaries, the Porcupine River (PR), a black water river draining a watershed almost entirely underlain by permafrost, and the Tanana River (TR), a glacial dominated river, are being studied to better define processes controlling DOC in these systems. Five-year seasonal averages indicate DOC concentrations follow the discharge hydrograph, with highest daily and seasonal flux occurring during spring in YR and PR and during summer-autumn in TR. Largest DOC concentrations and specific UV absorption (SUVA) values, a measure of aromatic carbon content of the DOC and an indicator of DOC source, occurred at all locations during spring snowmelt. Lowest DOC concentration and SUVA occurred during low-flow in winter due to greatly reduced contributions of soil organic matter and to relatively greater influences of ground water. While all sites had comparable DOC concentration during winter, DOC concentration was greatest at PR during spring and summer-autumn, whereas TR had the lowest average DOC and SUVA values. Within the YR, average DOC concentration and SUVA values in spring and summer-autumn increase downriver due to contributions from organic carbon rich tributaries, such as PR, that increase in number and significance as the river flows through Alaska. Most the DOC in each system was comprised of hydrophobic organic acids (HPOA) derived from terrestrial vegetation. During winter, the hydrophilic fraction, determined to be the most biodegradable, was a larger percentage of the DOC than during spring-autumn. During spring, HPOA concentration and SUVA increased significantly at all sites, suggesting that most DOC in spring is derived from terrestrial organic matter that was frozen on the land surface over winter. During spring-autumn, PR had the largest concentration of HPOA and TR had the least. Like DOC concentration, HPOA concentration and SUVA increased down river. 14C-DOC values correspond to radiocarbon ages of modern (PR), 282 (TR), and 328 (YR) yrs B.P, indicating the presence of some aged DOC in YR and TR. Comparison of the chemical character of DOC from sites along the YR suggests that most DOC is transported from its source to the Bering Sea with little within river chemical or biological alteration, a result supported by laboratory biodegradation experiments.
Annual Coded Wire Tag Program; Oregon Stock Assessment, 2000 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lewis, Mark; Mallette, Christine; Murray, William
2002-03-01
This annual report is in fulfillment of contract obligations with Bonneville Power Administration which is the funding source for the Oregon Department of Fish and Wildlife's Annual Stock Assessment - Coded Wire Tag Program (ODFW) Project. Tule stock fall chinook were caught primarily in British Columbia and Washington ocean, and Columbia Basin fisheries. Up-river bright stock fall chinook contributed primarily to Alaska and British Columbia ocean commercial, Columbia Basin gillnet and freshwater sport fisheries. Contribution of Rogue stock fall chinook released in the lower Columbia River occurred primarily in Oregon ocean commercial, Columbia Basin gillnet and freshwater sport fisheries. Willamettemore » stock spring chinook contributed primarily to Alaska and British Columbia ocean, and Columbia Basin sport fisheries. Willamette stock spring chinook released by CEDC contributed to similar ocean fisheries, but had much higher catch in Columbia Basin gillnet fisheries than the same stocks released in the Willamette Basin. Up-river stocks of spring chinook contributed almost exclusively to Columbia Basin fisheries. The up-river stocks of Columbia River summer steelhead contributed almost exclusively to the Columbia Basin gillnet and freshwater sport fisheries. Coho ocean fisheries from Washington to California were closed or very limited from 1994 through 1999 (1991 through 1996 broods). This has resulted in a lower percent of catch in Washington, Oregon and California ocean fisheries, and a higher percent of catch in Alaska and British Columbia ocean and Columbia Basin freshwater fisheries. Coho stocks released by ODFW below Bonneville Dam were caught mainly in Oregon, Washington, and British Columbia ocean, Columbia Gillnet and freshwater sport fisheries. Coho stocks released in the Klaskanine River and Youngs Bay area had similar ocean catch distributions, but a much higher percent catch in gillnet fisheries than the other coho releases. Ocean catch distribution of coho stocks released above Bonneville Dam was similar to the other coho groups. However, they had a higher percent catch in gillnet fisheries above Bonneville Dam than coho released below the dam. Survival rates of salmon and steelhead are influenced, not only by factors in the hatchery (disease, density, diet, size and time of release) but also by environmental factors in the river and ocean. These environmental factors are influenced by large scale oceanic and weather patterns such as El Nino. Changes in rearing conditions in the hatchery do impact survival, however, these can be offset by impacts caused by environmental factors. Coho salmon released in the Columbia River generally experience better survival rates when released later in the spring. However, for the 1990 brood year June releases of Columbia River coho had much lower survival than May releases, for all ODFW hatcheries. In general survival of ODFW Columbia River hatchery coho has declined to low levels in recent years. Preliminary results from the evaluation of Visual Implant Elastomer (VIE) tags showed tagging rate and pre-release tag retention improved from the first to second years of tagging. Tagging rate remained identical from 1999 to 2000 while pre-release tag retention dropped to 95%. Returning jack and adult salmon were sampled for CWT and VIE tags in the fall of 2000. Of 606 adults recovered at Sandy Fish Hatchery in 2000, only 1 or 0.2%, retained their VIE tag. Of 36 jacks recovered in 2000, 13 or 36.1% retained their VIE tag.« less
Assssment and Mapping of the Riverine Hydrokinetic Resource in the Continental United States
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jacobson, Paul T.; Ravens, Thomas M.; Cunningham, Keith W.
2012-12-14
The U.S. Department of Energy (DOE) funded the Electric Power Research Institute and its collaborative partners, University of Alaska ? Anchorage, University of Alaska ? Fairbanks, and the National Renewable Energy Laboratory, to provide an assessment of the riverine hydrokinetic resource in the continental United States. The assessment benefited from input obtained during two workshops attended by individuals with relevant expertise and from a National Research Council panel commissioned by DOE to provide guidance to this and other concurrent, DOE-funded assessments of water based renewable energy. These sources of expertise provided valuable advice regarding data sources and assessment methodology. Themore » assessment of the hydrokinetic resource in the 48 contiguous states is derived from spatially-explicit data contained in NHDPlus ?a GIS-based database containing river segment-specific information on discharge characteristics and channel slope. 71,398 river segments with mean annual flow greater than 1,000 cubic feet per second (cfs) mean discharge were included in the assessment. Segments with discharge less than 1,000 cfs were dropped from the assessment, as were river segments with hydroelectric dams. The results for the theoretical and technical resource in the 48 contiguous states were found to be relatively insensitive to the cutoff chosen. Raising the cutoff to 1,500 cfs had no effect on estimate of the technically recoverable resource, and the theoretical resource was reduced by 5.3%. The segment-specific theoretical resource was estimated from these data using the standard hydrological engineering equation that relates theoretical hydraulic power (Pth, Watts) to discharge (Q, m3 s-1) and hydraulic head or change in elevation (??, m) over the length of the segment, where ? is the specific weight of water (9800 N m-3): ??? = ? ? ?? For Alaska, which is not encompassed by NPDPlus, hydraulic head and discharge data were manually obtained from Idaho National Laboratory?s Virtual Hydropower Prospector, Google Earth, and U.S. Geological Survey gages. Data were manually obtained for the eleven largest rivers with average flow rates greater than 10,000 cfs and the resulting estimate of the theoretical resource was expanded to include rivers with discharge between 1,000 cfs and 10,000 cfs based upon the contribution of rivers in the latter flow class to the total estimate in the contiguous 48 states. Segment-specific theoretical resource was aggregated by major hydrologic region in the contiguous, lower 48 states and totaled 1,146 TWh/yr. The aggregate estimate of the Alaska theoretical resource is 235 TWh/yr, yielding a total theoretical resource estimate of 1,381 TWh/yr for the continental US. The technically recoverable resource in the contiguous 48 states was estimated by applying a recovery factor to the segment-specific theoretical resource estimates. The recovery factor scales the theoretical resource for a given segment to take into account assumptions such as minimum required water velocity and depth during low flow conditions, maximum device packing density, device efficiency, and flow statistics (e.g., the 5 percentile flow relative to the average flow rate). The recovery factor also takes account of ?back effects? ? feedback effects of turbine presence on hydraulic head and velocity. The recovery factor was determined over a range of flow rates and slopes using the hydraulic model, HEC-RAS. In the hydraulic modeling, presence of turbines was accounted for by adjusting the Manning coefficient. This analysis, which included 32 scenarios, led to an empirical function relating recovery factor to slope and discharge. Sixty-nine percent of NHDPlus segments included in the theoretical resource estimate for the contiguous 48 states had an estimated recovery factor of zero. For Alaska, data on river slope was not readily available; hence, the recovery factor was estimated based on the flow rate alone. Segment-specific estimates of the theoretical resource were multiplied by the corresponding recovery factor to estimate the technically recoverable resource. The resulting technically recoverable resource estimate for the continental United States is 120 TWh/yr.« less
Waythomas, C.F.; Wallace, K.L.
2002-01-01
An areally extensive volcanic mass-flow deposit of Pleistocene age, known as the Chetaslina volcanic mass-flow deposit, is a prominent and visually striking deposit in the southeastern Copper River lowland of south-central Alaska. The mass-flow deposit consists of a diverse mixture of colorful, variably altered volcanic rocks, lahar deposits, glaciolacustrine diamicton, and till that record a major flank collapse on the southwest flank of Mount Wrangell. The deposit is well exposed near its presumed source, and thick, continuous, stratigraphic exposures have permitted us to study its sedimentary characteristics as a means of better understanding the origin, significance, and evolution of the deposit. Deposits of the Chetaslina volcanic mass flow in the Chetaslina River drainage are primary debris-avalanche deposits and consist of two principal facies types, a near-source block facies and a distal mixed facies. The block facies is composed entirely of block-supported, shattered and fractured blocks with individual blocks up to 40 m in diameter. The mixed facies consists of block-sized particles in a matrix of poorly sorted rock rubble, sand, and silt generated by the comminution of larger blocks. Deposits of the Chetaslina volcanic mass flow exposed along the Copper, Tonsina, and Chitina rivers are debris-flow deposits that evolved from the debris-avalanche component of the flow and from erosion and entrainment of local glacial and glaciolacustrine diamicton in the Copper River lowland. The debris-flow deposits were probably generated through mixing of the distal debris avalanche with the ancestral Copper River, or through breaching of a debris-avalanche dam across the ancestral river. The distribution of facies types and major-element chemistry of clasts in the deposit indicate that its source was an ancestral volcanic edifice, informally known as the Chetaslina vent, on the southwest side of Mount Wrangell. A major sector collapse of the Chetaslina vent initiated the Chetaslina volcanic mass flow forming a debris avalanche of about 4 km3 that subsequently transformed to a debris flow of unknown volume.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, A.V.; Coney, P.J.
1987-11-01
Late Devonian sandstone beds are exposed as allochthonous sequences that extend for over 1000 km along the east-west strike of the Brooks Range in northern Alaska. These horizons, at least in part, record Late Devonian tectonism and deposition along the southern margin of the Arctic Alaska block. This study identifies clastic petrofacies in the western Philip Smith Mountains and southern Arctic quadrangles and infers the composition of the source terrane. The paleogeography is not known and the original distribution of lithofacies is uncertain, owing to the extensive post-depositional tectonism. In the study area the sandstones are exposed along rugged mountainmore » tops and high ridges. Although exposures are excellent, access is often difficult. Samples were collected from exposures near the western end of the Chandalar Shelf, Atigun Pass, and the Atigun River valley in the Philip Smith Mountains quadrangle and from the Crow Nest Creek and Ottertail Creek areas in the Arctic quadrangle. 34 refs., 17 figs.« less
Changing Arctic ecosystems: ecology of loons in a changing Arctic
Uher-Koch, Brian; Schmutz, Joel; Whalen, Mary; Pearce, John M.
2014-01-01
The U.S. Geological Survey (USGS) Changing Arctic Ecosystems (CAE) initiative informs key resource management decisions for Arctic Alaska by providing scientific information on current and future ecosystem response to a changing climate. From 2010 to 2014, a key study area for the USGS CAE initiative has been the Arctic Coastal Plain of northern Alaska. This region has experienced rapid warming during the past 30 years, leading to the thawing of permafrost and changes to lake and river systems. These changes, and projections of continued change, have raised questions about effects on wildlife populations that rely on northern lake ecosystems, such as loons. Loons rely on freshwater lakes for nesting habitat and the fish and invertebrates inhabiting the lakes for food. Loons live within the National Petroleum Reserve-Alaska (NPR-A) on Alaska’s northern coast, where oil and gas development is expected to increase. Research by the USGS examines how breeding loons use the Arctic lake ecosystem and the capacity of loons to adapt to future landscape change.
NASA Technical Reports Server (NTRS)
Anderson, D. M. (Principal Investigator); Haugen, R. K.; Gatto, L. W.; Slaughter, C. W.; Marlar, T. L.; Mckim, H. L.
1972-01-01
There are no author-identified significant results in this report. An overriding problem in arctic and subarctic environmental research has been the absence of long-term observational data and the sparseness of geographical coverage of existing data. A first look report is presented on the use of ERTS-1 imagery as a major tool in two large area environmental studies: (1) investigation of sedimentation and other nearshore marine processes in Cook Inlet, Alaska; and (2) a regional study of permafrost regimes in the discontinuous permafrost zone of Alaska. These studies incorporate ground truth acquisition techniques that are probably similar to most ERTS investigations. Studies of oceanographic processes in Cook Inlet will be focused on seasonal changes in nearshore bathymetry, tidal and major current circulation patterns, and coastal sedimentation processes, applicable to navigation, construction, and maintenance of harbors. Analyses will be made of the regional permafrost distribution and regimes in the Upper Koyukuk-Kobuk River area located in NW Alaska.
Post, Austin
1967-01-01
The 1964 Alaska earthquake occurred in a region where there are many hundreds of glaciers, large and small. Aerial photographic investigations indicate that no snow and ice avalanches of large size occurred on glaciers despite the violent shaking. Rockslide avalanches extended onto the glaciers in many localities, seven very large ones occurring in the Copper River region 160 kilometers east of the epicenter. Some of these avalanches traveled several kilometers at low gradients; compressed air may have provided a lubricating layer. If long-term changes in glaciers due to tectonic changes in altitude and slope occur, they will probably be very small. No evidence of large-scale dynamic response of any glacier to earthquake shaking or avalanche loading was found in either the Chugach or Kenai Mountains 16 months after the 1964 earthquake, nor was there any evidence of surges (rapid advances) as postulated by the Earthquake-Advance Theory of Tarr and Martin.
Sediment distribution and coastal processes in Cook Inlet, Alaska
NASA Technical Reports Server (NTRS)
Anderson, D. M.; Gatto, L. W.; Mckim, H. L.; Petrone, A.
1973-01-01
Regional hydrologic and oceanographic relationships in Cook Inlet, Alaska have been recognized from sequential ERTS-1 MSS imagery. Current patterns are visible in the inlet because of differential concentrations of suspended sediment. The circulation patterns within Cook Inlet are controlled primarily by the interaction between the semi-diurnal tides and the counter clockwise Alaska current. In general, heavily sediment laden water is seen to be confined to portions of the inlet north of the Forelands and west of Kalgin Island. Tongues of clear oceanic water are observed to enter the inlet through Kennedy Channel along the east shoreline in the vicinity of Cape Elizabeth. A recurring counterclockwise circulation pattern observed around Kalgin Island seems to result from the interplay of the northerly moving water along the east shore and the southerly moving, sediment laden, water along the west side of the inlet. Prominent, fresh water plumes, heavily laden with sediment are visible at the mouths of all major rivers. Relect plumes from as many as three tidal stages have been recognized.
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.
Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.
2015-01-01
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 302 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Kougarok River drainage as well as smaller adjacent drainages in the Bendeleben and Teller quadrangles, Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.
Abraham, Jared E.
2011-01-01
In the area of Fort Yukon, the AEM survey shows elevated resistivities extending to depth, likely indicative of thick permafrost. This depth corresponds well to observations from a borehole drilled in the area in the late 1990s, which detected permafrost to a depth of about 100 meters (Clark and others, 2009). In contrast to the area of Fort Yukon, the Yukon River and its floodplain are not associated with deep resistive sediments, suggesting a lack of deep permafrost, at least within the depth range of the AEM mapping (fig. 3).
ERIC Educational Resources Information Center
Warfield, Duane
2010-01-01
The Hiland Mountain Correctional Center, a 400-bed facility for multi-level adult female offenders in Eagle River, Alaska, offers a unique educational programme to its prisoners: an orchestra. Founded in 2003, by volunteer Pati Crofut, orchestra membership grew from eight to 22 female offenders between 2003 and 2009. Crofut has devoted her time…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-13
... Conservation Act of 1980 (ANILCA), and the BLM policies. The BLM will work collaboratively with interested...: The BLM-administered Squirrel River SRMA is located in western Alaska, approximately 30 miles... amendment and associated EA will meet the requirements of the National Environmental Policy Act of 1969...
M.D. Bryant; R.T. Edwards; R.D. Woodsmith
2005-01-01
Rivers and streams that support anadromous salmonids are an important part of land management planning in southeastern Alaska and the Pacific Northwest of North America. Land managers and planners require a consistent set of protocols that include both the physical and biological aspects of the stream for effectiveness monitoring procedures to evaluate management...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-24
... Supply Creek Hydroelectric Project. f. Location: The proposed Water Supply Creek Hydroelectric Project will be located on Water Supply Creek, near the town of Hoonah on Chichagof Island, Alaska, affecting T... proposed run-of-river Water Supply Creek Hydroelectric Project will consist of: (1) A proposed 8-foot- high...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-21
... study the feasibility of the Nenana RivGen Power Project (Nenana Project) to be located on the Tanana... RivGen turbine-generator modules with a combined capacity of 300 kilowatts; (2) an approximately 450... north bank of the Tanana River, or an alternate transmission cable configuration that is yet to be...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-31
... subjected to hazardous levels of noise during certain training exercises; Army control of this area is also... within Fort Richardson. The restricted area is necessary to protect the public against hazardous noise... Flats Weapons Training Range Impact Area, Fort Richardson, Alaska; Restricted Area. (a) The area. The...
Wetland succession in a permafrost collapse: interations between fire and thermokarst
I.H. Myers-Smith; J.W. Harden; M. Wilmking; C.C. Fuller; A.D. McGuire; F.S. III Chapin
2008-01-01
To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ~600 years of vegetation...
Publications - GMC 277 | Alaska Division of Geological & Geophysical
from the following: Shell Oil Company Kustatan Ridge #1, Shell Oil Company Middle River State #1 , Superior Oil Three Mile Creek State #1, Texas International Pet. Corp. Pretty Creek State #1 Authors reflectance analyses for Cook Inlet well cuttings from the following: Shell Oil Company Kustatan Ridge #1
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-08
... Bristol Bay watershed provides habitat for one of the largest wild salmon populations in the world. In... resident fish populations of the Kvichak and Nushagak River drainages, and if these effects are likely to affect wildlife and human populations in the region. Additional information describing the assessment...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-24
... populations in the world. In February 2011, EPA began a scientific assessment of the Bristol Bay watershed to... on salmon and resident fish populations of the Kvichak and Nushagak River drainages, and if these effects are likely to affect wildlife and human populations in the region. Additional information...
Hydraulic characteristics near streamside structures along the Kenai River, Alaska
Dorava, Joseph M.
1995-01-01
Hydraulic characteristics, water velocity, depth, and flow direction were measured near eight sites along the Kenai River in southcentral Alaska. Each of the eight sites contained a different type of structure: a road-type boat launch, a canal-type boat launch, a floating dock, a rock retaining wall, a pile-supported dock, a jetty, a concrete retaining wall, and a bank stabilization project near the city of Soldotna. Measurements of hydraulic characteristics were made to determine to what extent the structures affected natural or ambient stream hydraulic characteristics. The results will be used by the Alaska Department of Fish and Game to evaluate assumptions used in their Habitat Evaluation Procedure assessment of juvenile chinook salmon habitat along the river and to improve their understanding of stream hydraulics for use in permitting potential projects. The study included structures along the Kenai River from about 12 to 42 miles upstream from the mouth. Hydraulic characteristics were measured during medium-, high-, and low-flow conditions, as measured at the Kenai River at Soldotna: (1) discharge ranged from 6,310 to 6,480 cubic feet per second during medium flow conditions that were near mean annual flow on June 9-10, 1994; (2) discharge ranged from 14,000 to 14,400 cubic feet per second during high flow conditions that were near peak annual flow conditions on August 2-3, 1994; and (3) discharge ranged from 3,470 to 3,660 cubic feet per second during open-water low-flow conditions on May 8-9, 1995. Measurements made at the structures were compared with measurements made at nearby unaffected natural sites. The floating dock, pile-supported dock, road-type boat launch, and concrete retaining wall did not significantly alter the stream channel area. These structures contributed only hydraulic-roughness type changes. The structures occupied a much smaller area than that of the wetted perimeter of the channel and thus typically had little effect on velocity, depth, or flow direction. During this investigation, many of these subtle effects could not be separated from ambient hydraulic conditions. The jetty significantly altered stream channel area and therefore affected stream hydraulics more than the other structures that were investigated. Data indicated that velocity increased from 1.9 to 5.8 feet per second near the point of the jetty during measurements in May, June, and August. Rock wall and jetty structures also divert flow away from near-shore areas in proportion to their projection lengths into the river. For the jetty, the effect on surface flow was observed downstream for a distance of about 10 times the length of the jetty's projection into the river and upstream for about 4 to 5 times the length of the projection. For the rock wall, the diversion of flow was evident for 10 to 15 feet downstream.
Active Tectonics of the Far North Pacific Observed with GPS
NASA Astrophysics Data System (ADS)
Elliott, J.; Freymueller, J. T.; Jiang, Y.; Leonard, L. J.; Hyndman, R. D.; Mazzotti, S.
2017-12-01
The idea that the tectonics of the northeastern Pacific is defined by relatively discrete deformation along the boundary between the Pacific and North American plates has given way to a more complex picture of broad plate boundary zones and distributed deformation. This is due in large part to the Plate Boundary Observatory and several focused GPS studies, which have greatly increased the density of high-quality GPS data throughout the region. We will present an updated GPS velocity field in a consistent reference frame as well as a new, integrated block model that sheds light on regional tectonics and provides improved estimates of motion along faults and their potential seismic hazard. Crustal motions in southern Alaska are strongly influenced by the collision and flat-slab subduction of the Yakutat block along the central Gulf of Alaska margin. In the area nearest to the collisional front, small blocks showing evidence of internal deformation are required. East of the front, block motions show clockwise rotation into the Canadian Cordillera while west of the front there are counterclockwise rotations that extend along the Alaska forearc, suggesting crustal extrusion. Farther from the convergent margin, the crust appears to move as rigid blocks, with uniform motion over large areas. In western Alaska, block motions show a southwesterly rotation into the Bering Sea. Arctic Alaska displays southeasterly motions that gradually transition into easterly motion in Canada. Much of the southeastern Alaska panhandle and coastal British Columbia exhibit northwesterly motions. Although the relative plate motions are mainly accommodated along major faults systems, including the Fairweather-Queen Charlotte transform system, the St. Elias fold-and-thrust belt, the Denali-Totschunda system, and the Alaska-Aleutian subduction zone, a number of other faults accommodate lesser but still significant amounts of motion in the model. These faults include the eastern Denali/Duke River system, the Castle Mountain fault, the western Denali fault, the Kaltag fault, and the Kobuk fault. Based on the expanded GPS data set, locked or partially locked sections of the Alaska subduction zone may extend as far north and east as the eastern Alaska Range.
The 1964 Great Alaska Earthquake and tsunamis: a modern perspective and enduring legacies
Brocher, Thomas M.; Filson, John R.; Fuis, Gary S.; Haeussler, Peter J.; Holzer, Thomas L.; Plafker, George; Blair, J. Luke
2014-01-01
The magnitude 9.2 Great Alaska Earthquake that struck south-central Alaska at 5:36 p.m. on Friday, March 27, 1964, is the largest recorded earthquake in U.S. history and the second-largest earthquake recorded with modern instruments. The earthquake was felt throughout most of mainland Alaska, as far west as Dutch Harbor in the Aleutian Islands some 480 miles away, and at Seattle, Washington, more than 1,200 miles to the southeast of the fault rupture, where the Space Needle swayed perceptibly. The earthquake caused rivers, lakes, and other waterways to slosh as far away as the coasts of Texas and Louisiana. Water-level recorders in 47 states—the entire Nation except for Connecticut, Delaware, and Rhode Island— registered the earthquake. It was so large that it caused the entire Earth to ring like a bell: vibrations that were among the first of their kind ever recorded by modern instruments. The Great Alaska Earthquake spawned thousands of lesser aftershocks and hundreds of damaging landslides, submarine slumps, and other ground failures. Alaska’s largest city, Anchorage, located west of the fault rupture, sustained heavy property damage. Tsunamis produced by the earthquake resulted in deaths and damage as far away as Oregon and California. Altogether the earthquake and subsequent tsunamis caused 129 fatalities and an estimated $2.3 billion in property losses (in 2013 dollars). Most of the population of Alaska and its major transportation routes, ports, and infrastructure lie near the eastern segment of the Aleutian Trench that ruptured in the 1964 earthquake. Although the Great Alaska Earthquake was tragic because of the loss of life and property, it provided a wealth of data about subductionzone earthquakes and the hazards they pose. The leap in scientific understanding that followed the 1964 earthquake has led to major breakthroughs in earth science research worldwide over the past half century. This fact sheet commemorates Great Alaska Earthquake and examines the advances in knowledge and technology that have helped to improve earthquake preparation and response both in Alaska and around the world.
NASA Astrophysics Data System (ADS)
Walvoord, M. A.; Jepsen, S. M.; Rover, J.; Voss, C. I.; Briggs, M. A.
2015-12-01
Permafrost influence on the hydrologic connectivity of surface water bodies in high-latitude lowlands is complicated by subsurface heterogeneity and the propensity of the system to change over time. In general, permafrost limits the subsurface exchange of water, solute, and nutrients between lakes and rivers. It follows that permafrost thaw could enhance subsurface hydrologic connectivity among surface water bodies, but the impact of this process on lake distribution is not well known. Changes in the extent of lakes in interior Alaska have important ecological and societal impacts since lakes provide (1) critical habitat for migratory arctic shorebirds and waterfowl, fish, and wildlife, and (2) provisional, recreational, and cultural resources for local communities. We utilize electromagnetic imaging of the shallow subsurface and remote sensing of lake level dynamics in the Yukon Flats of interior Alaska, USA, together with water balance modeling, to gain insight into the influence of discontinuous permafrost on lowland lake systems. In the study region with relatively low precipitation, observations suggest that lakes that are hydrologically isolated during normal conditions are sustained by periodic river flooding events, including ice-jam floods that occur during river ice break-up. Climatically-influenced alterations in flooding frequency and intensity, as well as depth to permafrost, are quantitatively assessed in the context of lake maintenance. Scenario modeling is used to evaluate lake level evolution under plausible changing conditions. Model results demonstrate how permafrost degradation can reduce the dependence of typical lowland lakes on flooding events. Study results also suggest that river flooding may recharge a more spatially widespread zone of lakes and wetlands under future scenarios of permafrost table deepening and enhanced subsurface hydrologic connectivity.
NASA Astrophysics Data System (ADS)
O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle A.; Raymond, Peter A.; Butler, Kenna D.; Dornblaser, Mark M.; Heckman, Katherine
2014-11-01
Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting permafrost thaw in three rivers (Beaver, Birch, and Hess Creeks) within the discontinuous permafrost zone of interior Alaska. We observed strong temporal controls on Δ14C content of hydrophobic acid isolates (Δ14C-HPOA) across all rivers, with the most enriched values occurring during spring snowmelt (75 ± 8‰) and most depleted during winter flow (-21 ± 8‰). Radiocarbon ages of winter flow samples ranged from 35 to 445 yr BP, closely tracking estimated median base flow travel times for this region (335 years). During spring snowmelt, young DOM was composed of highly aromatic, high molecular-weight compounds, whereas older DOM of winter flow had lower aromaticity and molecular weight. We observed a significant correlation between Δ14C-HPOA and UV absorbance coefficient at 254 nm (α254) across all study rivers. Using α254 as an optical indicator for Δ14C-HPOA, we also observed a long-term decline in α254 during maximum annual thaw depth over the last decade at the Hess Creek study site. These findings suggest a shift in watershed hydrology associated with increasing active layer thickness. Further development of DOM optical indicators may serve as a novel and inexpensive tool for detecting permafrost degradation in northern watersheds.
Waythomas, C.F.
2001-01-01
The formation of lahars and a debris avalanche during Holocene eruptions of the Spurr volcanic complex in south-central Alaska have led to the development of volcanic debris dams in the Chakachatna River valley. Debris dams composed of lahar and debris-avalanche deposits formed at least five times in the last 8000-10,000 years and most recently during eruptions of Crater Peak vent in 1953 and 1992. Water impounded by a large debris avalanche of early Holocene (?) age may have destabilized an upstream glacier-dammed lake causing a catastrophic flood on the Chakachatna River. A large alluvial fan just downstream of the debris-avalanche deposit is strewn with boulders and blocks and is probably the deposit generated by this flood. Application of a physically based dam-break model yields estimates of peak discharge (Qp) attained during failure of the debris-avalanche dam in the range 104 < Qp < 106 m3 s-1 for plausible breach erosion rates of 10-100 m h-1. Smaller, short-lived, lahar dams that formed during historical eruptions in 1953, and 1992, impounded smaller lakes in the upper Chakachatna River valley and peak flows attained during failure of these volcanic debris dams were in the range 103 < Qp < 104 m3 s-1 for plausible breach erosion rates. Volcanic debris dams have formed at other volcanoes in the Cook Inlet region, Aleutian arc, and Wrangell Mountains but apparently did not fail rapidly or result in large or catastrophic outflows. Steep valley topography and frequent eruptions at volcanoes in this region make for significant hazards associated with the formation and failure of volcanic debris dams. Published by Elsevier Science B.V.
Walvoord, Michelle Ann; Voss, Clifford I.; Wellman, Tristan P.
2012-01-01
Understanding the role of permafrost in controlling groundwater flow paths and fluxes is central in studies aimed at assessing potential climate change impacts on vegetation, species habitat, biogeochemical cycling, and biodiversity. Recent field studies in interior Alaska show evidence of hydrologic changes hypothesized to result from permafrost degradation. This study assesses the hydrologic control exerted by permafrost, elucidates modes of regional groundwater flow for various spatial permafrost patterns, and evaluates potential hydrologic consequences of permafrost degradation. The Yukon Flats Basin (YFB), a large (118,340 km2) subbasin within the Yukon River Basin, provides the basis for this investigation. Model simulations that represent an assumed permafrost thaw sequence reveal the following trends with decreasing permafrost coverage: (1) increased groundwater discharge to rivers, consistent with historical trends in base flow observations in the Yukon River Basin, (2) potential for increased overall groundwater flux, (3) increased spatial extent of groundwater discharge in lowlands, and (4) decreased proportion of suprapermafrost (shallow) groundwater contribution to total base flow. These trends directly affect the chemical composition and residence time of riverine exports, the state of groundwater-influenced lakes and wetlands, seasonal river-ice thickness, and stream temperatures. Presently, the YFB is coarsely mapped as spanning the continuous-discontinuous permafrost transition that model analysis shows to be a critical threshold; thus, the YFB may be on the verge of major hydrologic change should the current permafrost extent decrease. This possibility underscores the need for improved characterization of permafrost and other hydrogeologic information in the region via geophysical techniques, remote sensing, and ground-based observations.
O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle Ann; Raymond, Peter A.; Butler, Kenna D.; Dornblaser, Mark M.; Heckman, Katherine
2014-01-01
Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting permafrost thaw in three rivers (Beaver, Birch, and Hess Creeks) within the discontinuous permafrost zone of interior Alaska. We observed strong temporal controls on Δ14C content of hydrophobic acid isolates (Δ14C-HPOA) across all rivers, with the most enriched values occurring during spring snowmelt (75 ± 8‰) and most depleted during winter flow (−21 ± 8‰). Radiocarbon ages of winter flow samples ranged from 35 to 445 yr BP, closely tracking estimated median base flow travel times for this region (335 years). During spring snowmelt, young DOM was composed of highly aromatic, high molecular-weight compounds, whereas older DOM of winter flow had lower aromaticity and molecular weight. We observed a significant correlation between Δ14C-HPOA and UV absorbance coefficient at 254 nm (α254) across all study rivers. Usingα254 as an optical indicator for Δ14C-HPOA, we also observed a long-term decline in α254 during maximum annual thaw depth over the last decade at the Hess Creek study site. These findings suggest a shift in watershed hydrology associated with increasing active layer thickness. Further development of DOM optical indicators may serve as a novel and inexpensive tool for detecting permafrost degradation in northern watersheds.
Overview of environmental and hydrogeologic conditions at Moses Point, Alaska
Dorava, J.M.; Ayres, R.P.; Sisco, W.C.
1994-01-01
The Federal Aviation Administration facility at Moses Point is located at the mouth of the Kwiniuk River on the Seward Peninsula in northwestern Alaska. This area has long cold winters and short summers which affect the hydrology of the area. The Federal Aviation Administration owns or operates airport support facilities at the Moses Point site and wishes to consider the subsistence lifestyles of area residents and the quality of the current environment when evaluating options for remediation of environmental contamination at their facilities. Currently no operating wells are in the area, but the vulnerability of the aquifer and other alternative water supplies are being evaluated because the Federal Aviation Administration has a potential liability for the storage and use of hazardous materials in the area.
AmeriFlux US-ICt Imnavait Creek Watershed Tussock Tundra
Bret-Harte, Syndonia [University of Alaska Fairbanks; Euskirchen, Eugenie [University of Alaska Fairbanks; Shaver, Gaius [Marine Biological Laboratory
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-ICt Imnavait Creek Watershed Tussock Tundra. Site Description - The Imnavait Creek Watershed Tussock Tundra (Biocomplexity Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Biocomplexity Station was deployed in 2004, and it has been in operation during the melt seasons ever since.
Perinatal mortality in caribou from the Porcupine herd, Alaska
Roffe, T.J.
1993-01-01
During the 1989 caribou (Rangifer tarandus) calving season on the Arctic National Wildlife Refuge, Alaska (USA), 61 calf carcasses were examined for cause of death and associated pathology. Dead calves were located by low-level aerial searches with two fixed-wing aircraft and a helicopter over high density calving areas between the Hulahula and Aichilik rivers. Primary diagnoses included emaciation (39%), malnutrition (8%), stillbirth (21%), trauma (16%), other primary causes (7%), and undetermined causes (8%). Twenty calves had contributory renal tubular degeneration. The findings indicate that factors contributing to nutritional deprivation in calves were the major cause of neonatal mortality; however, factors affecting stillbirth, abortion, or the urogenital system may have major effects on neonatal caribou and warrant further investigation.
Wind Energy Resource Assessment on Alaska Native Lands in Cordova Region of Prince William Sound
DOE Office of Scientific and Technical Information (OSTI.GOV)
Whissel, John C.; Piche, Matthew
The Native Village of Eyak (NVE) has been monitoring wind resources around Cordova, Alaska in order to determine whether there is a role for wind energy to play in the city’s energy scheme, which is now supplies entirely by two run-of-the-river hydro plants and diesel generators. These data are reported in Appendices A and B. Because the hydro resources decline during winter months, and wind resources increase, wind is perhaps an ideal counterpart to round out Cordova’s renewable energy supply. The results of this effort suggests that this is the case, and that developing wind resources makes sense for ourmore » small, isolated community.« less
Perinatal mortality in caribou from the Porcupine herd, Alaska.
Roffe, T J
1993-04-01
During the 1989 caribou (Rangifer tarandus) calving season on the Arctic National Wildlife Refuge, Alaska (USA), 61 calf carcasses were examined for cause of death and associated pathology. Dead calves were located by low-level aerial searches with two fixed-wing aircraft and a helicopter over high density calving areas between the Hulahula and Aichilik rivers. Primary diagnoses included emaciation (39%), malnutrition (8%), stillbirth (21%), trauma (16%), other primary causes (7%), and undetermined causes (8%). Twenty calves had contributory renal tubular degeneration. The findings indicate that factors contributing to nutritional deprivation in calves were the major cause of neonatal mortality; however, factors affecting stillbirth, abortion, or the urogenital system may have major effects on neonatal caribou and warrant further investigation.
Muhs, Daniel R.; Budahn, James R.; McGeehin, John P.; Bettis, E. Arthur; Skipp, Gary L.; Paces, James B.; Wheeler, Elisabeth A.
2013-01-01
Contemporary glaciogenic dust has not received much attention, because most research has been on glaciogenic dust of the last glacial period or non-glaciogenic dust of the present interglacial period. Nevertheless, dust from modern glaciogenic sources may be important for Fe inputs to primary producers in the ocean. Adjacent to the subarctic Pacific Ocean, we studied a loess section near Chitina, Alaska along the Copper River in Wrangell-St. Elias National Park, where dust has been accumulating over the past ∼10,000 years. Mass accumulation rates for the fine-grained (<20 μm) fraction of this loess section are among the highest reported for the Holocene of high-latitude regions of the Northern Hemisphere. Based on mineralogy and geochemistry, loess at Chitina is derived from glacial sources in the Wrangell Mountains, the Chugach Mountains, and probably the Alaska Range. Concentrations of Fe in the silt-plus-clay fraction of the loess at Chitina are much higher than in all other loess bodies in North America and higher than most loess bodies on other continents. The very fine-grained (<2 μm) portion of this sediment, capable of long-range transport, is dominated by Fe-rich chlorite, which can yield Fe readily to primary producers in the ocean. Examination of satellite imagery shows that dust from the Copper River is transported by wind on a regular basis to the North Pacific Ocean. This Alaskan example shows that high-latitude glaciogenic dust needs to be considered as a significant Fe source to primary producers in the open ocean.
Riehle, J.R.; Dumond, D.E.; Meyer, C.E.; Schaaf, J.M.
2000-01-01
The Brooks River Archaeological District (BRAD) in Katmai National Park and Preserve is a classical site for the study of early humans in Alaska. Because of proximity to the active Aleutian volcanic arc, there are numerous tephra deposits in the BRAD, which are potentially useful for correlating among sites of archaeological investigations. Microprobe analyses of glass separates show, however, that most of these tephra deposits are heterogeneous mixtures of multiple glass populations. Some glasses are highly similar to pyroclasts of Aniakchak Crater (160 km to the south), others are similar to pyroclasts in the nearby Valley of Ten Thousand Smokes, and some are similar to no other tephra samples from the Alaska Peninsula. Moreover, tephra deposits in any one archaeological study site are not always similar to those from nearby sites, indicating inconsistent preservation of these mainly thin, fine-grained deposits. At least 15, late Holocene tephra deposits are inferred at the BRAD. Their heterogeneity is the result of either eruptions of mixed or heterogeneous magmas, like the 1912 Katmai eruption, or secondary mixing of closely succeeding tephra deposits. Because most cannot be reliably distinguished from one another on the basis of megascopic properties, their utility for correlations is limited. At least one deposit can be reliably identified because of its thickness (10 cm) and colour stratification. Early humans seem not to have been significantly affected by these tephra falls, which is not surprising in view of the resilience exhibited by both plants and animals following the 1912 Katmai eruption.
Crossman, Jill; Futter, Martyn N.; Whitehead, Paul G.
2013-01-01
In glacier-fed systems climate change may have various effects over a range of time scales, including increasing river discharge, flood frequency and magnitude. This study uses a combination of empirical monitoring and modelling to project the impacts of climate change on the glacial-fed Middle Fork Toklat River, Denali National Park, Alaska. We use a regional calibration of the model HBV to account for a paucity of long term observed flow data, validating a local application using glacial mass balance data and summer flow records. Two Global Climate Models (HADCM3 and CGCM2) and two IPCC scenarios (A2 and B2) are used to ascertain potential changes in meteorological conditions, river discharge, flood frequency and flood magnitude. Using remote sensing methods this study refines existing estimates of glacial recession rates, finding that since 2000, rates have increased from 24m per year to 68.5m per year, with associated increases in ablation zone ice loss. GCM projections indicate that over the 21st century these rates will increase still further, most extensively under the CGCM2 model, and A2 scenarios. Due to greater winter precipitation and ice and snow accumulation, glaciers release increasing meltwater quantities throughout the 21st century. Despite increases in glacial melt, results indicate that it is predominantly precipitation that affects river discharge. Three of the four IPCC scenarios project increases in flood frequency and magnitude, events which were primarily associated with changing precipitation patterns, rather than extreme temperature increases or meltwater release. Results suggest that although increasing temperatures will significantly increase glacial melt and winter baseflow, meltwater alone does not pose a significant flood hazard to the Toklat River catchment. Projected changes in precipitation are the primary concern, both through changing snow volumes available for melt, and more directly through increasing catchment runoff. PMID:24023925
Gehrels, G.E.; Johnsson, M.J.; Howell, D.G.
1999-01-01
The Cambrian Adams Argillite and the Devonian Nation River Formation are two sandstone-bearing units within a remarkably complete Paleozoic stratigraphic section in east-central Alaska. These strata, now foreshortened and fault-bounded, were originally contiguous with miogeoclinal strata to the east that formed as a passive-margin sequence along the northwestern margin of the North American continent. Seventy-five detrital zircon grains from the Adams Argillite and the Nation River Formation were analyzed in an effort to provide constraints on the original sources of the grains, and to generate a detrital zircon reference for miogeoclinal strata in the northern Cordillera. Thirty-five single zircon grains from a quartzite in the Adams Argillite yield dominant age clusters of 1047-1094 (n = 6), 1801-1868 (n = 10), and 2564-2687 (n = 5) Ma. Forty zircons extracted from a sandstone in the Nation River Formation yield clusters primarily of 424-434 (n = 6), 1815-1838 (n = 6), 1874-1921 (n = 7), and 2653-2771 (n = 4) Ma. The Early Proterozoic and Archean grains in both units probably originated in basement rocks in a broad region of the Canadian Shield. In contrast, the original igneous sources for mid-Protcrozoic grains in the Adams Argillite and ??? 430 Ma grains in the Nation River Formation are more difficult to identify. Possible original sources for the mid-Proterozoic grains include: (1) the Grenville Province of eastern Laurentia, (2) the Pearya terrane along the Arctic margin, and (3) mid-Proterozoic igneous rocks that may have been widespread along or outboard of the Cordilleran margin. The ??? 430 Ma grains may have originated in: (1) arc-type sources along the Cordilleran margin, (2) the Caledonian orogen, or (3) a landmass, such as Pearya, Siberia, or crustal fragments now in northern Asia, that resided outboard of the Innuitian orogen during mid-Paleozoic time. Copyright ?? 1999, SEPM (Society for Sedimentary Geology).
Reconnaissance of surface-water resources in the Kobuk River basin, Alaska, 1979-80
Childers, J.M.; Kernodle, D.R.
1983-01-01
Surface water data were collected at selected sites in the Kobuk River Basin in northwest Alaska in August 1979 and April 1980. In August 1979, frequent heavy rains caused abnormally high flows in the basin; unit runoff values, computed from discharge measurements at 25 sites, ranged from 0.08 to 12.2 cu ft/sec/sq mi. Mean unit runoff for August computed from 13 years of record at a stream gaging station on the Kobuk River ranged from 1 to 3 cu ft/sec/sq mi. Unit runoff computed from discharge measurements made at eight sites in April 1980 ranged from 0 to 0.30 cubic feet per second per square mile. These values are in reasonable agreement with those derived from the record at the gaging station. High-water marks of maximum evident floods and evidence of ice-affected flooding were found at near bankfull stages at 17 sites on the Kobuk River and its tributaries. Computed unit runoff for the maximum evident floods generally decreases with increasing drainage area. Unit runoff ranges from about 50 to 75 cu ft/sec/sq mi for drainage areas < 1,000 sq mi to < 25 cu ft/sec/sq mi for larger areas. Field determinations were made of water temperature, pH, alkalinity, dissolved-oxygen concentration, and specific conductance, and discharge was measured at about 40 stream sites and one spring. Water samples for laboratory analysis of dissolved inorganic constituents and biological samples were collected in August 1979. Water quality data indicate that the surface waters would be acceptable for most uses; they are a calcium bicarbonate type having dissolved-solids concentrations between 50 and 140 milligm/liter. The pristine nature of the waters is also indicated by the overall diversity and composition of its benthic invertebrate community. A more highly mineralized (about 550 milligm/liter dissolved solids) sodium bicarbonate water flows from Reed River Hot Spring. (USGS)
Crossman, Jill; Futter, Martyn N; Whitehead, Paul G
2013-01-01
In glacier-fed systems climate change may have various effects over a range of time scales, including increasing river discharge, flood frequency and magnitude. This study uses a combination of empirical monitoring and modelling to project the impacts of climate change on the glacial-fed Middle Fork Toklat River, Denali National Park, Alaska. We use a regional calibration of the model HBV to account for a paucity of long term observed flow data, validating a local application using glacial mass balance data and summer flow records. Two Global Climate Models (HADCM3 and CGCM2) and two IPCC scenarios (A2 and B2) are used to ascertain potential changes in meteorological conditions, river discharge, flood frequency and flood magnitude. Using remote sensing methods this study refines existing estimates of glacial recession rates, finding that since 2000, rates have increased from 24 m per year to 68.5m per year, with associated increases in ablation zone ice loss. GCM projections indicate that over the 21(st) century these rates will increase still further, most extensively under the CGCM2 model, and A2 scenarios. Due to greater winter precipitation and ice and snow accumulation, glaciers release increasing meltwater quantities throughout the 21(st) century. Despite increases in glacial melt, results indicate that it is predominantly precipitation that affects river discharge. Three of the four IPCC scenarios project increases in flood frequency and magnitude, events which were primarily associated with changing precipitation patterns, rather than extreme temperature increases or meltwater release. Results suggest that although increasing temperatures will significantly increase glacial melt and winter baseflow, meltwater alone does not pose a significant flood hazard to the Toklat River catchment. Projected changes in precipitation are the primary concern, both through changing snow volumes available for melt, and more directly through increasing catchment runoff.
NASA Astrophysics Data System (ADS)
Lininger, K.; Wohl, E.; Rose, J. R.
2016-12-01
High latitude permafrost regions contain large amounts of organic carbon (OC) in the subsurface, but little work has quantified OC storage in floodplain sediment in the high latitudes. Floodplains influence the export of OC to the ocean by temporarily storing OC at timescales of 101 to 103 years. To fully understand terrestrial carbon cycling, the storage and residence time of OC in floodplains, and the geomorphic controls on OC storage, must be taken into account. Small-scale spatial variations in OC storage within floodplains likely reflect geomorphic processes of deposition and floodplain development. We present results of floodplain OC storage and residence time in sediment along 5 rivers in the Yukon Flats National Wildlife Refuge in interior Alaska, a region with discontinuous permafrost. We collected sediment samples within the active layer along tributaries to the Yukon River and the mainstem Yukon River and analyzed the sediment samples for OC content. We classified sample locations by geomorphic type (filled secondary channels, levees, point bars) and vegetation type (herbaceous, deciduous/shrub, white spruce, and black spruce wetlands), and found that both geomorphology and vegetation influence OC concentration and OC mass per area. Preliminary results suggest that filled secondary channels contain more OC per area compared to other geomorphic types. We present results of radiocarbon dates from river cutbanks associated with our sampling sites, which give a maximum age for residence times of OC in sediment before erosion and transport. The radiocarbon dates also provide estimates of long-term OC accretion within the Yukon Flats floodplains. Small-scale variations within floodplains as a result of floodplain depositional processes and vegetation communities shed light on the geomorphic controls on OC storage. This work will help constrain the spatial variation in OC storage and OC residence time across the landscape in a region experiencing rapid climate change and permafrost thaw.
Geomorphology of the lower Copper River, Alaska
Brabets, T.P.
1996-01-01
The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1996, 11 bridges were located along this section of the highway. These bridges cross parts or all of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. At the peak outflow rate from Van Cleve Lake, the flow of the Copper River will increase an additional 140,000 and 190,000 cubic feet per second. Bedload sampling and continuous seismic reflection were used to show that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lakes, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow- gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. A flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.
Geomorphology of the lower Copper River, Alaska
Brabets, Timothy P.
1997-01-01
The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1995, 11 bridges were located along this section of the highway. These bridges cross parts of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lake, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow-gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. However, a flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.
Yup'ik Women's Ways of Knowing.
ERIC Educational Resources Information Center
Bennett, Kathleen; And Others
This paper describes storyknifing activities practiced by a small group of young girls in a Yup'ik Eskimo village on the Kuskokwim River in Alaska. Storyknifing is a form of play in which girls tell stories to one another, while making drawings and designs in mud or snow. The girls will sit in a circle for hours at a time, taking turns telling…
Baseline data on the oceanography of Cook Inlet, Alaska
NASA Technical Reports Server (NTRS)
Gatto, L. W.
1975-01-01
Regional relationships between river hydrology, sediment transport, circulation and coastal processes were analyzed utilizing aircraft, ERTS-1 and N.O.A.A. -2 and -3 imagery and corroborative ground truth data. The use of satellite and aircraft imagery provides a means of acquiring synoptic information for analyzing the dynamic processes of Cook Inlet in a fashion not previously possible.
76 FR 12558 - Amendment to Special Use Airspace Restricted Areas R-2203, and R-2205; Alaska
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-08
...-0055; Airspace Docket No. 11-AAL-2] Amendment to Special Use Airspace Restricted Areas R-2203, and R... amendment. SUMMARY: This action amends the using agency of Restricted Areas R-2203 A, B, & C; Eagle River, AK, and R-2205, Stuart Creek, AK. These changes reflect the U.S. Army's current organization in...
Glaciers as a source of ancient and labile organic matter to the marine environment.
Eran Hood; Jason Fellman; Robert G.M. Spencer; Peter J. Hernes; Rick Edwards; David D' Amore; Durelle Scott
2009-01-01
Riverine organic matter supports of the order of one-fifth of estuarine metabolism. Coastal ecosystems are therefore sensitive to alteration of both the quantity and lability of terrigenous dissolved organic matter (DOM) delivered by rivers. Here we characterize streamwater DOM from 11 coastal watersheds on the Gulf of Alaska that vary widely in glacier coverage. In...
Amy C. Angell; Knut Kielland
2009-01-01
White spruce (Picea glauca (Moench) Voss) is a dominant species in late-successional ecosystems along the Tanana River, interior Alaska, and the most important commercial timber species in these boreal floodplain forests. Whereas white spruce commonly seed in on young terraces in early primary succession, the species does not become a conspicuous...
Lem G. Butler; Knut Kielland
2008-01-01
1. We examined the effects of browsing by moose and snowshoe hares on vegetation structure, species composition, plant demography and element cycling in 25 riparian (willow) vegetation stands along the Tanana River, interior Alaska, across a 250-km gradient that represented a fivefold range in moose densities (0.2 to 1.0 km-2). 2. Browsing...
Boat-Wave-Induced Bank Erosion on the Kenai River, Alaska
2008-03-01
with coir log habitat restoration. .....................................................................75 Figure 51. Type 1 bank with willow...various types of streambank stabilization. Common stabilization techniques consist of root wads, spruce tree revetments, coir logs, and riprap...restoration. ERDC TR-08-5 75 Figure 50. Type 1 bank with coir log habitat restoration. Figure 51. Type 1 bank with willow plantings/ladder access habitat
ERIC Educational Resources Information Center
McBeath, Jerry; Shepro, Carl E.
2007-01-01
This article presents the research conducted by the authors in an Inupiat Eskimo village on the Alaska North Slope and describes the research in two substantive parts. In the first section, the authors present what subsistence hunters and fishers observed concerning changes to seas, lands, and inland lakes and rivers. Then, they mention changes of…
Dana R. Nossov; Teresa N. Hollingsworth; Roger W. Ruess; Knut Kielland
2011-01-01
We investigated the population dynamics of the keystone symbiotic N-fixing species Alnus tenuifolia (thinleaf alder) and the patterns of primary succession on the Tanana River floodplains of interior Alaska, USA. The goals of this study were to characterize (i) the variation in the population structure of thinleaf alder and its influence on...
Gravel pit ponds as habitat enhancement for juvenile coho salmon.
M.D. Bryant
1988-01-01
Gravel pits built during road construction in the early 1970's near Yakutat, Alaska, filled with water and were connected to nearby rivers to allow juvenile salmonids to enter. Seasonal changes in population size, length and weight, and length frequencies of the coho salmon population were evaluated over a 2-year period. Numbers of coho salmon fluctuated, but two...
USDA-ARS?s Scientific Manuscript database
Arctic charr were obtained as eggs from two North American sources, an eastern (Fraser River, Canada) and a western (Bristol Bay, Alaska) stock. Fish from each family (n=38) were pit tagged at approximately 12 months post-hatch (eastern mean+SE=247+/-13g, western mean+SE=220+/-g) and stocked commun...
Multispectral remote observations of hydrologic features on the North Slope of Alaska
NASA Technical Reports Server (NTRS)
Hall, D. K.; Bryan, M. L.
1977-01-01
Visible and near-infrared satellite data and active and passive microwave aircraft data are used to analyze some hydrologic features in Arctic Alaska. The following features have been studied: the small thaw lakes on the Arctic Coastal Plain (oriented lakes), Chandalar Lake in the Brooks Range, several North Slope rivers, surface water on the tundra, and snowcover on the North Slope and in the Brooks Range. Passive microwave brightness temperatures (T sub b) as seen on Electrically Scanned Microwave Radiometer (ESMR) imagery are shown to increase with increasing ice thickness on all of the lakes studied. Aufeis, an important hydrologic parameter in the Arctic, is observable in the Sagavanirktok River channel on April ESMR imagery. LANDSAT imagery with better (80 m) resolution is useful for measuring aufeis extent using band 5 imagery obtained just after snowmelt in June. It is shown that the extent of aufeis (as measured on LANDSAT imagery) varies with meteorological conditions and, therefore, may be a useful indicator of annual climate fluctuations on the North Slope. Snow and ice breakup has been traced from the Brooks Range Mountains to the Arctic Ocean Coast using LANDSAT band 7 imagery in May when melting begins in the mountains.
Late Quaternary megafloods from Glacial Lake Atna, Southcentral Alaska, U.S.A.
NASA Astrophysics Data System (ADS)
Wiedmer, Michael; Montgomery, David R.; Gillespie, Alan R.; Greenberg, Harvey
2010-05-01
Geomorphic, stratigraphic, geotechnical, and biogeographic evidence indicate that failure of a Pleistocene ice dam between 15.5 and 26 ka generated a megaflood from Glacial Lake Atna down the Matanuska Valley. While it has long been recognized that Lake Atna occupied ≥ 9000 km 2 of south-central Alaska's Copper River Basin, little attention has focused on the lake's discharge locations and behaviors. Digital elevation model and geomorphic analyses suggest that progressive lowering of the lake level by decanting over spillways exposed during glacial retreat led to sequential discharges down the Matanuska, Susitna, Tok, and Copper river valleys. Lake Atna's size, ˜ 50 ka duration, and sequential connection to four major drainages likely made it a regionally important late Pleistocene freshwater refugium. We estimate a catastrophic Matanuska megaflood would have released 500-1400 km 3 at a maximum rate of ≥ 3 × 10 6 m 3 s - 1 . Volumes for the other outlets ranged from 200 to 2600 km 3 and estimated maximum discharges ranged from 0.8 to 11.3 × 10 6 m 3 s - 1 , making Lake Atna a serial generator of some of the largest known freshwater megafloods.
Woody, Carol Ann; Johnson, D.H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.
2007-01-01
Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers.
Hope, A.S.; Boynton, W.L.; Stow, D.A.; Douglas, David C.
2003-01-01
Interannual above-ground production patterns are characterized for three tundra ecosystems in the Kuparuk River watershed of Alaska using NOAA-AVHRR Normalized Difference Vegetation Index (NDVI) data. NDVI values integrated over each growing season (SINDVI) were used to represent seasonal production patterns between 1989 and 1996. Spatial differences in ecosystem production were expected to follow north-south climatic and soil gradients, while interannual differences in production were expected to vary with variations in seasonal precipitation and temperature. It was hypothesized that the increased vegetation growth in high latitudes between 1981 and 1991 previously reported would continue through the period of investigation for the study watershed. Zonal differences in vegetation production were confirmed but interannual variations did not covary with seasonal precipitation or temperature totals. A sharp reduction in the SINDVI in 1992 followed by a consistent increase up to 1996 led to a further hypothesis that the interannual variations in SINDVI were associated with variations in stratospheric optical depth. Using published stratospheric optical depth values derived from the SAGE and SAGE-II satellites, it is demonstrated that variations in these depths are likely the primary cause of SINDVI interannual variability.
Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska
Ji, Lei; Wylie, Bruce K.; Brown, Dana R. N.; Peterson, Birgit E.; Alexander, Heather D.; Mack, Michelle C.; Rover, Jennifer R.; Waldrop, Mark P.; McFarland, Jack W.; Chen, Xuexia; Pastick, Neal J.
2015-01-01
Quantification of aboveground biomass (AGB) in Alaska’s boreal forest is essential to the accurate evaluation of terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. Our goal was to map AGB at 30 m resolution for the boreal forest in the Yukon River Basin of Alaska using Landsat data and ground measurements. We acquired Landsat images to generate a 3-year (2008–2010) composite of top-of-atmosphere reflectance for six bands as well as the brightness temperature (BT). We constructed a multiple regression model using field-observed AGB and Landsat-derived reflectance, BT, and vegetation indices. A basin-wide boreal forest AGB map at 30 m resolution was generated by applying the regression model to the Landsat composite. The fivefold cross-validation with field measurements had a mean absolute error (MAE) of 25.7 Mg ha−1 (relative MAE 47.5%) and a mean bias error (MBE) of 4.3 Mg ha−1(relative MBE 7.9%). The boreal forest AGB product was compared with lidar-based vegetation height data; the comparison indicated that there was a significant correlation between the two data sets.
McGuire, A. David; Ruess, Roger W.; Lloyd, A.; Yarie, J.; Clein, Joy S.; Juday, G.P.
2010-01-01
This paper integrates dendrochronological, demographic, and experimental perspectives to improve understanding of the response of white spruce (Picea glauca (Moench) Voss) tree growth to climatic variability in interior Alaska. The dendrochronological analyses indicate that climate warming has led to widespread declines in white spruce growth throughout interior Alaska that have become more prevalent during the 20th century. Similarly, demographic studies show that white spruce tree growth is substantially limited by soil moisture availability in both mid- and late-successional stands. Interannual variability in tree growth among stands within a landscape exhibits greater synchrony than does growth of trees that occupy different landscapes, which agrees with dendrochronological findings that the responses depend on landscape position and prevailing climate. In contrast, the results from 18 years of a summer moisture limitation experiment showed that growth in midsuccessional upland stands was unaffected by moisture limitation and that moisture limitation decreased white spruce growth in floodplain stands where it was expected that growth would be less vulnerable because of tree access to river water. Taken together, the evidence from the different perspectives analyzed in this study clearly indicates that white spruce tree growth in interior Alaska is vulnerable to the effects of warming on plant water balance.
NASA Astrophysics Data System (ADS)
Schroth, A. W.; Crusius, J.; Kroeger, K. D.; Hoyer, I. R.; Osburn, C. L.
2010-12-01
Iron (Fe) is a micronutrient that is thought to limit phytoplankton productivity in offshore waters of the Gulf of Alaska (GoA). However, it has been proposed that in coastal regions where offshore, Fe-limited, nitrate-rich waters mix with relatively Fe-rich river plumes, productive ecosystems and fisheries result. Indeed, an observed northward increase in phytoplankton biomass along the pacific coast of North America has been attributed to higher input of riverine Fe to coastal waters, suggesting that many of the coastal ecosystems of the North Pacific rely heavily on this input of Fe as a nutrient source. Based on our studies of the Copper River (the largest point source of freshwater to the GoA) and its tributaries, it is clear that riverine Fe delivered to the GoA is primarily derived from fine glacial flour generated by glacial weathering, which imparts a unique partitioning of Fe species and Fe size fractionation in coastal river plumes. Furthermore, the distribution of Fe species and size fractionation exhibits significant seasonal and spatial variability based on the source of iron within the watershed, which varies from glacial mechanical weathering of bedrock to internal chemical processing in portions of watersheds with forest and wetland land covers. These findings are relevant to our understanding of the GoA biogeochemical system as it exists today and can help to predict how the system may evolve as glaciers within the GoA watershed continue to recede.
Human dispersal into interior Alaska: antecedent conditions, mode of colonization, and adaptations
NASA Astrophysics Data System (ADS)
Yesner, David R.
2001-01-01
In spite of more than a half-century of exploration, no definitive evidence has yet come to light for human occupation in eastern Beringia preceding 12,000 yr BP. The oldest dates — between 11,500 and 12,000 yr BP — are from sites in interior and northern Alaska. Archaeological sites dating to this time period, such as the Broken Mammoth site in the central Tanana River Valley, have yielded evidence of pioneer colonization by groups with relatively little knowledge of lithic resources. Three possibly older cave sites — Bluefish Caves, Lime Hills Caves, and Trail Creek Caves — have stratigraphic and taphonomic problems that are not easily resolved. No sites in the glaciated coastal zone of southern Alaska are Pleistocene in date, and numerous objections can be raised to the viability of the coastal migration hypothesis, particularly in the western Gulf of Alaska region. For northern and interior Alaska, the earliest colonization appears to have been a "push-pull" phenomenon, linked to the dissolution of the Bering Land Bridge through a combination of rising sea levels and ameliorating climate. The climate of the "Birch-Poplar" rise in the terminal Pleistocene may have forced the extinction of obligate grazers such as mammoth and horse, but it seems to have favored other taxa such as bison and elk, at least until 9000 yr BP. Faunal data from the Broken Mammoth site in the central Tanana valley, with good organic preservation, demonstrate the utilization of a wide diversity of taxa, including small game, waterfowl, and fish. Faunal and sedimentological data give slight support to a Younger Dryas reversal, but this was dwarfed by the mid-Holocene period of dry, windy conditions during which interior Alaska may have been largely abandoned.
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 practice sessions at the University and then in an actual competition in a Regional High School Science Fair at which they could qualify to compete at the Intel International Science and Engineering fair. Thirty-four teachers, 30 high school students (over 40 percent of whom were Alaska Native) and over 1000 middle school students (25 percent Alaska natives) participated in EDGE activities, increasing their knowledge of Earth science, GIS skills, and data management and analysis. More information on the EDGE project is available at www.edge.alaska.edu.
Tephrochronolgical Studies of Late Neogene Sediments in Interior Alaska and the Yukon Territory
NASA Astrophysics Data System (ADS)
Westgate, J. A.; Preece, S. J.; Froese, D. G.; Schweger, C. E.
2004-12-01
Our tephra studies of Late Neogene sediments in interior Alaska and Yukon are motivated by the need to provide a reliable time-stratigraphic framework for on-going palaeoenvironmental projects. Key sites are located in the Fairbanks, Chicken (Alaska) and Klondike (Yukon) goldfields, Old Crow Basin (Yukon), and the numerous bluffs along the Yukon River in Canada and eastern Alaska. Tephra beds are characterized by their field setting, petrography, geochemical composition of glass (majors and traces) and mineral phases (especially FeTi oxides), palaeomagnetic properties, and age (determined mostly by glass-fission-track methods). Two compositional groups are recognized. Type I beds have abundant bubble-wall glass shards and a small crop of crystals with pyroxene > hornblende. Its glass has a rhyolitic to dacitic composition with relatively high FeOt, Cs, Hf and low Al2O3, CaO, and Sr. REE profiles have a well-developed Eu anomaly with La/Yb < 13. Volcanics with this chemical signature are common throughout the Aleutian Alaska Peninsula arc (AAPA), which is, therefore, the presumed source of the type I distal beds. In contrast, type II beds have more abundant crystals (hornblende > > pyroxene) and the rhyolitic glass is mainly in the form of highly inflated pumice with high Al2O3, CaO, and Sr. REE profiles are steep with low heavy REE content along with a very weakly developed Eu anomaly, if present. The type II beds are unusual and have many of the characteristics of adakites, known to occur at Mount Drum and Mount Churchill in the Wrangell volcanic field (WVF), and at Hayes volcano at the northeastern end of the Alaska Peninsula arc. It is likely, therefore, that the source vents for the type II beds in interior Alaska and Yukon are located in or near the WVF. Twenty-five distinctive tephra beds have been recognized in the Gold Hill Loess at Fairbanks and a comparable number have been discovered in the Klondike goldfields, although few beds are common to both regions. Tephra beds related to large-magnitude explosive eruptions with inferred widespread distributions, given their location, thickness, and presumed source, respectively, include, from the WVF: White River Ash (1-2 ka), Sheep Creek tephra in Alaska (190 ka), Gold Run (700 ka), SP (870 ka), WP (1.0 Ma), Paradise Hill (1.5 Ma), Fort Selkirk (1.5 Ma), Little Timber (2.3 Ma), Lost Chicken (2.8 Ma), and Quartz Creek (3.0 Ma). Corresponding units from the AAPA include: Dawson tephra (24 ka), VT (80 ka), Old Crow (140 ka), Ester (800 ka), Mosquito Gulch (1.5 Ma), PA (2.0 Ma), and Dago Hill (3.2 Ma). Application of the tephrochronological method to the Late Neogene sediments of eastern Beringia has placed several important palaeoenvironmental events into a precise chronologic context. (1) Preglacial vegetation of Pinus and Picea, with rare Abies, Larix, Alnus, Betula, and Corylus existed in eastern Beringia as late as 2.8 Ma; (2) loess deposition in interior Alaska began ˜ 3.0 Ma; (3) permafrost was established in the area by 3.0 Ma; (4) the first continental glacier invaded Yukon between 3.0 to 2.6 Ma; and (5) the characteristic interglacial boreal forest, dominated by Picea, Abies, Betula, and Alnus, was established by 2.3 Ma.
Geomorphology and bank erosion of the Matanuska River, southcentral Alaska
Curran, Janet H.; McTeague, Monica L.
2011-01-01
Bank erosion along the Matanuska River, a braided, glacial river in southcentral Alaska, has damaged or threatened houses, roadways, and public facilities for decades. Mapping of river geomorphology and bank characteristics for a 65-mile study area from the Matanuska Glacier to the river mouth provided erodibility information that was assessed along with 1949-2006 erosion to establish erosion hazard data. Braid plain margins were delineated from 1949, 1962, and 2006 orthophotographs to provide detailed measurements of erosion. Bank material and height and geomorphic features within the Matanuska River valley (primarily terraces and tributary fans) were mapped in a Geographic Information System (GIS) from orthophotographs and field observations to provide categories of erodibility and extent of the erodible corridor. The braid plain expanded 861 acres between 1949 and 2006. Erosion in the highest category ranged from 225 to 1,043 feet at reaches of bank an average of 0.5 mile long, affecting 8 percent of the banks but accounting for 64 percent of the erosion. Correlation of erosion to measurable predictor variables was limited to bank height and material. Streamflow statistics, such as peak streamflow or mean annual streamflow, were not clearly linked to erosion, which can occur during the prolonged period of summer high flows where channels are adjacent to an erodible braid plain margin. The historical braid plain, which includes vegetated braid plain bars and islands and active channels, was identified as the greatest riverine hazard area on the basis of its historical occupation. In 2006, the historical braid plain was an average of 15 years old, as determined from the estimated age of vegetation visible in orthophotographs. Bank erosion hazards at the braid plain margins can be mapped by combining bank material, bank height, and geomorphology data. Bedrock bluffs at least 10 feet high (31 percent of the braid plain margins) present no erosion hazard. At unconsolidated banks (63 percent of the braid plain margins), erosion hazards are great and the distinction in hazards between banks of varying height or geomorphology is slight.
Ely, Craig R.; Nieman, Daniel J.; Alisauskas, Ray T.; Schmutz, Joel A.; Hines, James E.
2013-01-01
We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during autumn, winter, and spring. Temporal and spatial differences in migratory behavior may allow management practices that accommodate potential demographic differences between taiga and tundra populations.
Vorhis, Robert C.; Rexin, Elmer E.; Coble, R.W.
1967-01-01
The Alaska earthquake of March 27, 1964, had widespread hydrologic effects throughout practically all of the United States. More than 1,450 water-level recorders, scattered throughout all the 50 States except Connecticut, Delaware, and Rhode Island, registered the earthquake. Half of the water-level records were obtained from ground-water observation wells and half at surface-water gaging stations. The earthquake is also known to have registered on water-level recorders on wells in Canada, England, Denmark, Belgium, Egypt, Israel, Libya, Philippine Islands, South-West Africa, South Africa, and Northern Territory of Australia. The Alaska earthquake is the first for which widespread surface-water effects are known. The effects were recorded at stations on flowing streams, rivers, reservoirs, lakes, and ponds. The 755 surface-water stations recording effects are spread through 38 States, but are most numerous in the south-central and southeastern States, especially in Florida and Louisiana. Most of the fluctuations recorded can be referred to more precisely as seismic seiches; however, a few stations recorded the quake as a minor change in stage. The largest recorded seiche outside Alaska was 1.83 feet on a reservoir in Michigan. The next largest was 1.45 feet on Lake Ouachita in Arkansas. The largest fluctuation in a well was 23 feet registered by a pressure recorder near Belle Fourche, S. Dak. Fluctuations of more than 10 feet were reported from wells in Alabama, Florida, Georgia, Illinois, Missouri, and Pennsylvania. A 3.40-foot fluctuation was recorded in a well in Puerto Rico. The Alaska earthquake was registered by about seven times as many water-level recorders as recorded the Hebgen Lake, Mont., earthquake of August 19, 1959.
Irving, David B.; Finn, James E.; Larson, James P.
1995-01-01
We began a three year study in 1987 to test the feasibility of using sonar in the Togiak River to estimate salmon escapements. Current methods rely on periodic aerial surveys and a counting tower at river kilometer 97. Escapement estimates are not available until 10 to 14 days after the salmon enter the river. Water depth and turbidity preclude relocating the tower to the lower river and affect the reliability of aerial surveys. To determine whether an alternative method could be developed to improve the timeliness and accuracy of current escapement monitoring, Bendix sonar units were operated during 1987, 1988, and 1990. Two sonar stations were set up opposite each other at river kilometer 30 and were operated 24 hours per day, seven days per week. Catches from gill nets with 12, 14, and 20 cm stretch mesh, a beach seine, and visual observations were used to estimate species composition. Length and sex data were collected from salmon caught in the nets to assess sampling bias.In 1987, sonar was used to select optimal sites and enumerate coho salmon. In 1988 and 1990, the sites identified in 1987 were used to estimate the escapement of five salmon species. Sockeye salmon escapement was estimated at 512,581 and 589,321, chinook at 7,698 and 15,098, chum at 246,144 and 134,958, coho at 78,588 and 28,290, and pink at 96,167 and 131,484. Sonar estimates of sockeye salmon were two to three times the Alaska Department of Fish and Game's escapement estimate based on aerial surveys and tower counts. The source of error was probably a combination of over-estimating the total number of targets counted by the sonar and by incorrectly estimating species composition.Total salmon escapement estimates using sonar may be feasible but several more years of development are needed. Because of the overlapped salmon run timing, estimating species composition appears the most difficult aspect of using sonar for management. Possible improvements include using a larger beach seine or selecting gill net mesh sizes evenly spaced between 10 and 20 cm stretch mesh.Salmon counts at river kilometer 30 would reduce the lag time between salmon river entry and the escapement estimate to 2-5 days. Any further decrease in lag time, however, would require moving the sonar operations downriver into less desirable braided portions of the river.
Wivell, Charles E.; Olmsted, Coert; Steinwand, Daniel R.; Taylor, Christopher
1993-01-01
Because the pixel location in a line of Synthetic Aperture Radar (SAR) image data is directly related to the distance the pixel is from the radar, terrain elevations cause large displacement errors in the geo-referenced location of the pixel. This is especially true for radar systems with small angles between the nadir and look vectors. Thus, to geo-register a SAR image accurately, the terrain of the area must be taken into account. (Curlander et al., 1987; Kwok et al., 1987, Schreier et al., 1990; Wivell et al., 1992). As part of the 1992 National Aeronautics and Space Administration's Earth Observing System Version 0 activities, a prototype SAR geocod-. ing and terrain correction system was developed at the US. Geological Survey's (USGS) E~os Data Center (EDC) in Sioux Falls, South Dakota. Using this system with 3-arc-second digital elevation models (DEMs) mosaicked at the ED^ Alaska Field Office, 21 ERS-I s.4~ scenes acquired at the Alaska SAR Facility were automatically geocoded, terrain corrected, and mosaicked. The geo-registered scenes were mosaicked using a simple concatenation.
Witter, Robert C.; LeWinter, Adam; Bender, Adrian M.; Glennie, Craig; Finnegan, David
2017-05-22
Within Glacier Bay National Park in southeastern Alaska, the Fairweather Fault represents the onshore boundary between two of Earth’s constantly moving tectonic plates: the North American Plate and the Yakutat microplate. Satellite measurements indicate that during the past few decades the Yakutat microplate has moved northwest at a rate of nearly 5 centimeters per year relative to the North American Plate. Motion between the tectonic plates results in earthquakes on the Fairweather Fault during time intervals spanning one or more centuries. For example, in 1958, a 260-kilometer section of the Fairweather Fault ruptured during a magnitude 7.8 earthquake, causing permanent horizontal (as much as 6.5 meters) and vertical (as much as 1 meter) displacement of the ground surface across the fault. Thousands to millions of years of tectonic plate motion, including earthquakes like the one in 1958, raised and shifted the ground surface across the Fairweather Fault, while rivers, glaciers, and ocean waves eroded and sculpted the surrounding landscape along the Gulf of Alaska coast in Glacier Bay National Park.
Effects of Intensified 21st Century Drought on the Boreal Forest of Alaska
NASA Astrophysics Data System (ADS)
Juday, G. P.; Alix, C. M.; Jess, R.; Grant, T. A., III
2014-12-01
A long term perspective on several quasi-decadal cycles of intensifying drought stress across boreal Alaska has been synthesized from monitoring of forest reference stands at Bonanza Creek LTER, Interior Alaska Research Natural Areas, and tree ring sampling across Alaska. The Alaska boreal forest is largely made up of tree populations with two growth responses to temperature increases. Negative responders are more common, and found across the warm, dry Interior. Positive responders are largely in western Alaska, a maritime climate region near the Bering Sea, and at high elevation of the Brooks and Alaska Ranges. Following the North Pacific climate regime shift in 1976-77, negative responder Interior white and black spruce, aspen, and birch all experienced major growth reductions, particularly in warm drought years. Elevated summer temperatures and low annual precipitation of recent decades at low elevations of the Tanana and central Yukon Valleys were outside the values which previously defined the species distributions limits, Long term survival prospects are questionable. Simultaneously, recent elevated temperatures were associated with growth increases of positive responders. On fertile floodplain sites of the lower Yukon and Kuskokwim Rivers, the growth rate of positive responding white spruce is now greater than negative responders for the first time in centuries. NDVI trends in recent decades confirm these opposite growth trends in their respective regions. During peak warm/dry anomalies, forest disturbance, an important process for tree regeneration over the long term, intensified in boreal Alaska. Several insect outbreaks of wood-boring and defoliating species associated with warm temperature/drought stress anomalies appeared, many of them severe, and some not previously known to outbreak. Significant tree injury (e.g. top dieback) and mortality resulted. Wildfire extent and severity increased and reached record levels. The overall pattern has been described as biome shift. Future research is needed on the distribution of boreal forest refuge habitats in the Interior, drought effects on natural tree regeneration and growth/health of young tree populations, carbon accumulation profiles under the modern drought regime compared to earlier, and the genetic disruption of biome shift.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-04
...). Juveniles resemble non-breeding adults, except that the feathers of the scapulars and wing coverts of... stopover sites are Grays Harbor and Willapa Bay in Washington, and Yukon-Kuskokwim Delta and Copper River Delta in Alaska (Isleib 1979, p. 128; Gill and Handel 1990, p. 712; Page et al. 1999, p. 467). Smaller...
Nematodes from terrestrial and freshwater habitats in the Arctic
2014-01-01
Abstract We present an updated list of terrestrial and freshwater nematodes from all regions of the Arctic, for which records of properly identified nematode species are available: Svalbard, Jan Mayen, Iceland, Greenland, Nunavut, Northwest territories, Alaska, Lena River estuary, Taymyr and Severnaya Zemlya and Novaya Zemlya. The list includes 391 species belonging to 146 genera, 54 families and 10 orders of the phylum Nematoda. PMID:25197239
Neuswanger, Jason R.; Wipfli, Mark S.; Evenson, Matthew J.; Hughes, Nicholas F.; Rosenberger, Amanda E.
2015-01-01
Yukon River Chinook salmon (Oncorhynchus tshawytscha) populations are declining for unknown reasons, creating hardship for thousands of stakeholders in subsistence and commercial fisheries. An informed response to this crisis requires understanding the major sources of variation in Chinook salmon productivity. However, simple stock–recruitment models leave much of the variation in this system’s productivity unexplained. We tested adding environmental predictors to stock–recruitment models for two Yukon drainage spawning streams in interior Alaska — the Chena and Salcha rivers. Low productivity was strongly associated with high stream discharge during the summer of freshwater residency for young-of-the-year Chinook salmon. This association was more consistent with the hypothesis that sustained high discharge negatively affects foraging conditions than with acute mortality during floods. Productivity may have also been reduced in years when incubating eggs experienced major floods or cold summers and falls. These freshwater effects — especially density dependence and high discharge — helped explain population declines in both rivers. They are plausible as contributors to the decline of Chinook salmon throughout the Yukon River drainage.
Fleming, Sean W.; Hood, Eran; Dalhke, Helen; O'Neel, Shad
2016-01-01
The northern portion of the Pacific coastal temperate rainforest (PCTR) is one of the least anthropogenically modified regions on earth and remains in many respects a frontier area to science. Rivers crossing the northern PCTR, which is also an international boundary region between British Columbia, Canada and Alaska, USA, deliver large freshwater and biogeochemical fluxes to the Gulf of Alaska and establish linkages between coastal and continental ecosystems. We evaluate interannual flow variability in three transboundary PCTR watersheds in response to El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Arctic Oscillation (AO), and North Pacific Gyre Oscillation (NPGO). Historical hydroclimatic datasets from both Canada and the USA are analyzed using an up-to-date methodological suite accommodating both seasonally transient and highly nonlinear teleconnections. We find that streamflow teleconnections occur over particular seasonal windows reflecting the intersection of specific atmospheric and terrestrial hydrologic processes. The strongest signal is a snowmelt-driven flow timing shift resulting from ENSO- and PDO-associated temperature anomalies. Autumn rainfall runoff is also modulated by these climate modes, and a glacier-mediated teleconnection contributes to a late-summer ENSO-flow association. Teleconnections between AO and freshet flows reflect corresponding temperature and precipitation anomalies. A coherent NPGO signal is not clearly evident in streamflow. Linear and monotonically nonlinear teleconnections were widely identified, with less evidence for the parabolic effects that can play an important role elsewhere. The streamflow teleconnections did not vary greatly between hydrometric stations, presumably reflecting broad similarities in watershed characteristics. These results establish a regional foundation for both transboundary water management and studies of long-term hydroclimatic and environmental change.
Pyenson, Nicholas D.
2016-01-01
The diversification of crown cetacean lineages (i.e., crown Odontoceti and crown Mysticeti) occurred throughout the Oligocene, but it remains an ongoing challenge to resolve the phylogenetic pattern of their origins, especially with respect to stem lineages. One extant monotypic lineage, Platanista gangetica (the Ganges and Indus river dolphin), is the sole surviving member of the broader group Platanistoidea, with many fossil relatives that range from Oligocene to Miocene in age. Curiously, the highly threatened Platanista is restricted today to freshwater river systems of South Asia, yet nearly all fossil platanistoids are known globally from marine rocks, suggesting a marine ancestry for this group. In recent years, studies on the phylogenetic relationships in Platanistoidea have reached a general consensus about the membership of different sub-clades and putative extinct groups, although the position of some platanistoid groups (e.g., Waipatiidae) has been contested. Here we describe a new genus and species of fossil platanistoid, Arktocara yakataga, gen. et sp. nov. from the Oligocene of Alaska, USA. The type and only known specimen was collected from the marine Poul Creek Formation, a unit known to include Oligocene strata, exposed in the Yakutat City and Borough of Southeast Alaska. In our phylogenetic analysis of stem and node-based Platanistoidea, Arktocara falls within the node-based sub-clade Allodelphinidae as the sister taxon to Allodelphis pratti. With a geochronologic age between ∼29–24 million years old, Arktocara is among the oldest crown Odontoceti, reinforcing the long-standing view that the diversification for crown lineages must have occurred no later than the early Oligocene. PMID:27602287
Historical trends and extremes in boreal Alaska river basins
Bennett, Katrina E.; Cannon, Alex J.; Hinzman, Larry
2015-05-12
Climate change will shift the frequency, intensity, duration and persistence of extreme hydroclimate events and have particularly disastrous consequences in vulnerable systems such as the warm permafrost-dominated Interior region of boreal Alaska. This work focuses on recent research results from nonparametric trends and nonstationary generalized extreme value (GEV) analyses at eight Interior Alaskan river basins for the past 50/60 years (1954/64–2013). Trends analysis of maximum and minimum streamflow indicates a strong (>+50%) and statistically significant increase in 11-day flow events during the late fall/winter and during the snowmelt period (late April/mid-May), followed by a significant decrease in the 11-day flowmore » events during the post-snowmelt period (late May and into the summer). The April–May–June seasonal trends show significant decreases in maximum streamflow for snowmelt dominated systems (<–50%) and glacially influenced basins (–24% to –33%). Annual maximum streamflow trends indicate that most systems are experiencing declines, while minimum flow trends are largely increasing. Nonstationary GEV analysis identifies time-dependent changes in the distribution of spring extremes for snowmelt dominated and glacially dominated systems. Temperature in spring influences the glacial and high elevation snowmelt systems and winter precipitation drives changes in the snowmelt dominated basins. The Pacific Decadal Oscillation was associated with changes occurring in snowmelt dominated systems, and the Arctic Oscillation was linked to one lake dominated basin, with half of the basins exhibiting no change in response to climate variability. The paper indicates that broad scale studies examining trend and direction of change should employ multiple methods across various scales and consider regime dependent shifts to identify and understand changes in extreme streamflow within boreal forested watersheds of Alaska.« less
Stanley, Richard G.; Helmold, Kenneth P.; LePain, David L.
2015-01-01
Middle Jurassic strata of the Gaikema Sandstone were deposited about 170 million years ago on a delta that was located on the western shoreline of the Cook Inlet basin (Detterman and Hartsock, 1966; LePain and others, 2011, 2013). The delta was built by swift, sediment-laden rivers that flowed southeastward from a mountainous volcanic terrane west of the Bruin Bay fault (fig. 6-1). Upon reaching the edge of the Jurassic sea, the rivers dumped abundant sand, gravel, and mud into a depocenter on the northern Iniskin Peninsula, about 240 km southwest of Anchorage (figs. 6-1, 6-2). This report provides a preliminary description and interpretation of a detailed, 34-m-thick measured section in the Gaikema Sandstone on the south shore of Chinitna Bay at latitude 59.816°N, longitude 153.168°W (figs. 6-1–6-3). The sandstone in this measured section exhibits hummocky cross lamination and other features suggestive of storm-influenced deposition on the shallow-marine, seaward margin of the Gaikema delta. Our field studies of the Gaikema Sandstone were conducted during 2013 and 2014 as part of a collaborative effort by the Alaska Division of Geological & Geophysical Surveys (DGGS), Alaska Division of Oil and Gas (DOG), and U.S. Geological Survey (USGS) to provide the public with reliable information on the geologic framework and petroleum resource potential of Cook Inlet basin (Gillis, 2013, 2014). Jurassic rocks in Cook Inlet, including the Gaikema Sandstone, are of economic interest because they could contain significant undiscovered petroleum resources (Bureau of Ocean Energy Management, 2011; Stanley and others, 2011a, 2011b, 2013a; LePain and others, 2013).
Mineralization, watershed geochemistry, and metals in fish from a Subarctic River, Alaska
Gough, L.P.; Wang, B.; Crock, J.G.; Seal, R.R.; Weber-Scannell, P.
2005-01-01
We report on the levels of trace metals and metalloids in Arctic grayling (Thymallus arcticus), an important freshwater sport and subsistence fish in the Fortymile River, east-central Alaska. Functional biogeochemical baseline values and (or) ranges are presented for 38 major- and trace-elements in the muscle (fillet) and liver of 34 fish collected from 11 sampling sites in the watershed. In addition, we present N-, C-, and S-isotopic data for muscle samples. These data are the first to be reported for Arctic grayling in this region of Alaska. Geometric means for total Hg in muscle and liver tissue are 0.069 and 0.062 ppm, respectively. These levels are more than an order of magnitude below the FDA permissible value for methylmercury in fish fillets. In general, we noted little variation in the elemental concentrations in muscle tissue among samples at each of the 11 fish-sampling sites. No definitive link could be attributed between biogeochemical patterns and regional lithology. Stomach-content chemistry varied widely (relative muscle tissue or liver) and generally reflected sediment chemistry - a component of the ingested material. Stomach-content material was examined for the occurrence and frequency of macroinvertebrates and their chemical composition in three fish. Results showed considerable diversity, with 9 to 15 invertebrate taxa of which both aquatic and terrestrial individuals were found. The N-isotopic compositions of muscle fillet samples are homogeneous (??15N = 7.6 - 9.7 permil), reflecting a restricted, low trophic (primary predator) position for the grayling. C and S isotopic compositions (??13C and ??34S) of fillet samples range from -33.1 to -25.8 permil and -8.4 to 8.2 permil, respectively, suggesting heterogeneity of food sources (both aquatic and terrestrial). Copyright ASCE 2005.
AmeriFlux US-An2 Anaktuvuk River Moderate Burn
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hobbie, John; Rocha, Adrian; Shaver, Gaius
This is the AmeriFlux version of the carbon flux data for the site US-An2 Anaktuvuk River Moderate Burn. Site Description - The Anaktuvuk River fire on the North Slope of Alaska started on July 16, 2007 by lightning. It continued until the end of September when nearby lakes had already frozen over and burned >256,000 acres, creating a mosaic of patches that differed in burn severity. The Anaktuvuk River Severe Burn, Moderate Burn, and Unburned sites are 40 km to the west of the nearest road and were selected in late May 2008 to determine the effects of the firemore » on carbon, water, and energy exchanges during the growing season. Because the fire had burned through September of the previous year, initial deployment of flux towers occurred prior to any significant vegetative regrowth, and our sampling campaign captured the full growing season in 2008. The Moderate Burn site consisted of a large area with small patches of completely and partially burned tundra intermixed across the landscape.« less
AmeriFlux US-An3 Anaktuvuk River Unburned
Hobbie, John [Marine Biological Laboratory; Rocha, Adrian [Marine Biological Laboratory; Shaver, Gaius [Marine Biological Laboratory
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-An3 Anaktuvuk River Unburned. Site Description - The Anaktuvuk River fire on the North Slope of Alaska started on July 16, 2007 by lightning. It continued until the end of September when nearby lakes had already frozen over and burned >256,000 acres, creating a mosaic of patches that differed in burn severity. The Anaktuvuk River Severe Burn, Moderate Burn, and Unburned sites are 40 km to the west of the nearest road and were selected in late May 2008 to determine the effects of the fire on carbon, water, and energy exchanges during the growing season. Because the fire had burned through September of the previous year, initial deployment of flux towers occurred prior to any significant vegetative regrowth, and our sampling campaign captured the full growing season in 2008. The Unburned site was located in a large area of tundra that was unaffected by the fire.
Habitat characteristics of polar bear terrestrial maternal den sites in northern Alaska
Durner, George 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.
Floodplain soil organic carbon storage in the central Yukon River Basin
NASA Astrophysics Data System (ADS)
Lininger, K.; Wohl, E.
2017-12-01
As rivers transport sediment, organic matter, and large wood, they can deposit those materials in their floodplains, storing carbon. One aspect of the carbon cycle that isn't well understood is how much carbon is stored in rivers and floodplains. There may be more carbon in rivers and floodplains than previously thought. This is important for accounting for all aspects of the carbon cycle, which is the movement of carbon among the land, ocean, and atmosphere. We are quantifying that storage in high latitude floodplains through fieldwork along five rivers in the central Yukon River Basin within the Yukon Flats National Wildlife Refuge in interior Alaska. We find that the geomorphic environment and geomorphic characteristics of rivers influence the spatial distribution of carbon on the landscape, and that floodplains may be disproportionally important for carbon storage compared to other areas. Our study area contains discontinuous permafrost, which is soil that is perennially frozen, and is warming quickly due to climate change, as in other high latitude regions. The large amount of carbon stored in the subsurface and in permafrost in the high latitudes highlights the importance of understanding where carbon is stored within rivers and floodplains in these regions and how long that carbon remains in storage. Our research helps inform how river systems influence the carbon cycle in a region undergoing rapid change.
Ecology of invasive Melilotus albus on Alaskan glacial river floodplains
Conn, Jeff S.; Werdin-Pfisterer, Nancy R.; Beattie, Katherine L.; Densmore, Roseann V.
2011-01-01
Melilotus albus (white sweetclover) has invaded Alaskan glacial river floodplains. We measured cover and density of plant species and environmental variables along transects perpendicular to the Nenana, Matanuska, and Stikine Rivers to study interactions between M. albus and other plant species and to characterize the environment where it establishes. Melilotus albus was a pioneer species on recently disturbed sites and did not persist into closed canopy forests. The relationships between M. albus cover and density and other species were site-specific.Melilotus albus was negatively correlated with native species Elaeagnus commutata at the Nenana River, but not at the Matanuska River. Melilotus albus was positively correlated with the exotic species Crepis tectorumand Taraxacum officinale at the Matanuska River and T. officinale on the upper Stikine River. However, the high density of M. albus at a lower Stikine River site was negatively correlated with T. officinale and several native species including Lathyrus japonicus var. maritimus and Salix alaxensis. Glacial river floodplains in Alaska are highly disturbed and are corridors for exotic plant species movement. Melilotus albus at moderate to low densities may facilitate establishment of exotic species, but at high densities can reduce the cover and density of both exotic and native species.
Annual Coded Wire Tag Program; Oregon Missing Production Groups, 1996 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lewis, Mark A.; Mallette, Christine; Murray, William M.
1998-03-01
This annual report is in fulfillment of contract obligations with Bonneville Power Administration which is the funding source for the Oregon Department of Fish and Wildlife's Annual Coded Wire Tag Program - Oregon Missing Production Groups Project. Tule stock fall chinook were caught primarily in British Columbia and Washington ocean, and Oregon freshwater fisheries. Up-river bright stock fall chinook contributed primarily to Alaska and British Columbia ocean commercial, and Columbia River gillnet and other freshwater fisheries. Contribution of Rogue stock fall chinook released in the lower Columbia River occurred primarily in Oregon ocean commercial and Columbia river gillnet fisheries. Willamettemore » stock spring chinook contributed primarily to Alaska and British Columbia ocean commercial, Oregon freshwater sport and Columbia River gillnet fisheries. Willamette stock spring chinook released by CEDC contributed to similar fisheries as the same stocks released in the Willamette system. Up-river stocks of spring chinook contributed almost exclusively to Columbia River sport fisheries and other freshwater recovery areas. The up-river stocks of Columbia River summer steelhead contributed primarily to the Columbia River gillnet and other freshwater fisheries. Coho ocean fisheries from Washington to California were closed or very limited in 1994 and 1995 (1991 and 1992 broods). This has resulted in a greater average percent of catch for other fishery areas. Coho stocks released by ODFW below Bonneville Dam contributed mainly to Oregon and Washington ocean, Columbia Gillnet and other freshwater fisheries. Coho stocks released in the Klaskanine River and Youngs Bay area had much higher contribution to gillnet fisheries than the other coho releases. Coho stocks released above Bonneville Dam contributed to the same fisheries as those released below Bonneville Dam. Survival rates of salmon and steelhead are influenced, not only by factors in the hatchery (disease, density, diet, size and time of release) but also by environmental factors in the river and ocean. These environmental factors are controlled by large scale weather patterns such as El Nino over which man has no influence. Changes in rearing conditions in the hatchery, over which man has some influence, do impact the survival rates. However, these impacts can be offset by impacts caused by environmental factors. Brood years of salmon and steelhead that were in the ocean during the 1983 El Nino event exhibited poor survival all along the Pacific coast of California, Oregon, and Washington. However, stocks of chinook and coho that entered the ocean in the fall of 1984 following the El Nino experienced remarkably improved survival rates. In some instances, tule fall chinook experienced survival rates almost ten times higher than for the previous brood years of the same stock. Coho salmon released in the Columbia River generally experience better survival rates when released later in the spring. However, for the 1990 brood year June releases of Columbia River coho had much lower survival than May releases, for all ODFW hatcheries. In general survival of ODFW Columbia River hatchery coho has declined to low levels since the 1989 brood year.« less
Susitna Hydroelectric Project: terrestrial environmental workshop and preliminary simulation model
Everitt, Robert R.; Sonntag, Nicholas C.; Auble, Gregory T.; Roelle, James E.; Gazey, William
1982-01-01
The technical feasibility, economic viability, and environmental impacts of a hydroelectric development project in the Susitna River Basin are being studied by Acres American, Inc. on behalf of the Alaska Power Authority. As part of these studies, Acres American recently contracted LGL Alaska Research Associates, Inc. to coordinate the terrestrial environmental studies being performed by the Alaska Department of Fish and Game and, as subcontractors to LGL, several University of Alaska research groups. LGL is responsible for further quantifying the potential impacts of the project on terrestrial wildlife and vegetation, and for developing a plan to mitigate adverse impacts on the terrestrial environment. The impact assessment and mitigation plan will be included as part of a license application to the Federal Energy Regulatory Commission (FERC) scheduled for the first quarter of 1983. The quantification of impacts, mitigation planning, and design of future research is being organized using a computer simulation modelling approach. Through a series of workshops attended by researchers, resource managers, and policy-makers, a computer model is being developed and refined for use in the quantification of impacts on terrestrial wildlife and vegetation, and for evaluating different mitigation measures such as habitat enhancement and the designation of replacement lands to be managed by wildlife habitat. This report describes the preliminary model developed at the first workshop held August 23 -27, 1982 in Anchorage.
Geochemical evidence for a brooks range mineral belt, Alaska
Marsh, S.P.; Cathrall, J.B.
1981-01-01
Geochemical studies in the central Brooks Range, Alaska, delineate a regional, structurally controlled mineral belt in east-west-trending metamorphic rocks and adjacent metasedimentary rocks. The mineral belt extends eastward from the Ambler River quadrangle to the Chandalar and Philip Smith quadrangles, Alaska, from 147?? to 156??W. longitude, a distance of more than 375 km, and spans a width from 67?? to 69??N. latitude, a distance of more than 222 km. Within this belt are several occurrences of copper and molybdenum mineralization associated with meta-igneous, metasedimentary, and metavolcanic rocks; the geochemical study delineates target areas for additional occurrences. A total of 4677 stream-sediment and 2286 panned-concentrate samples were collected in the central Brooks Range, Alaska, from 1975 to 1979. The -80 mesh ( 2.86) nonmagnetic fraction of the panned concentrates from stream sediment were analyzed by semiquantitative spectrographic methods. Two geochemical suites were recognized in this investigation; a base-metal suite of copper-lead-zinc and a molybdenum suite of molybdenum-tin-tungsten. These suites suggest several types of mineralization within the metamorphic belt. Anomalies in molybdenum with associated Cu and W suggest a potential porphyry molybdenum system associated with meta-igneous rocks. This regional study indicates that areas of metaigneous rocks in the central metamorphic belt are target areas for potential mineralized porphyry systems and that areas of metavolcanic rocks are target areas for potential massive sulfide mineralization. ?? 1981.
Geology of the Prince William Sound and Kenai Peninsula region, Alaska
Wilson, Frederic H.; Hults, Chad P.
2012-01-01
The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world’s largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska and Aleutian Ranges and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper River delta. Structurally, the map area is cut by a number of major faults and postulated faults, the most important of which are the Border Ranges, Contact, and Bruin Bay Fault systems. The rocks of the map area belong to the Southern Margin composite terrane, a Tertiary and Cretaceous or older subduction-related accretionary complex, and the Alaska Peninsula terrane. Mesozoic rocks between these two terranes have been variously assigned to the Peninsular or the Hidden terranes. The oldest rocks in the map area are blocks of Paleozoic age within the mélange of the McHugh Complex; however, the protolith age of the greenschist and blueschist within the Border Ranges Fault zone is not known. Extensive glacial deposits mantle the Kenai Peninsula and the lowlands on the west side of Cook Inlet and are locally found elsewhere in the map area. This map was compiled from existing mapping, without generalization, and new or revised data was added where available.
Brown bear response to elevated viewing structures at Brooks River, Alaska
DeBruyn, T.D.; Smith, T.S.; Proffitt, K.; Partridge, S.; Drummer, T.D.
2004-01-01
The increasing popularity of brown bear (Ursus arctos) viewing at Brooks River in Katmai National Park, Alaska has resulted in overcrowded facilities, increasing bear-human conflicts, displacement of bears from important habitats, and degradation of cultural resources. To partially address these issues, the National Park Service (NPS) constructed a 300-m-long elevated boardwalk with interconnected viewing platforms in August 2000. To determine what effects the new structures might have on individual bears, we observed bear movements and behaviors before and after construction. We used direct observations and motion-detection cameras to construct temporal-spatial profiles of bear activity. Although bear numbers were similar (59 bears in 2000 and 56 bears in 2001) and bear activity within the greater Brooks River area did not differ (P = 0.62, n = 29) between the 2 years of this study, trail crossings in the vicinity of the new structures decreased 78% (7,436 crossings in 2000 and 1,646 crossings in 2001; ??2 = 762, df = 14, P < 0.001). Bear temporal use of the boardwalk area changed such that when human use was highest, bear use was proportionally lower in the post- versus pre-construction phase (??2 = 34, df = 3, P < 0.005). Of 123 direct observations of bears approaching to pass beneath the structures, only 19.5% rerouted or avoided crossing under the structures. Bears' responses to the new structures were influenced by the behavior of visitors upon the structures. Potential management tools to minimize impacts of these structures on bears include enhanced public education regarding visitor conduct on the boardwalk, as well as visitor management and monitoring.
O'Donnell, Jonathan A.; Aiken, George R.; Kane, Evan S.; Jones, Jeremy B.
2010-01-01
Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate the relationship between source water (shallow versus deep groundwater flow paths) and DOC chemical composition. Using base cation chemistry and principal component analysis, we observed high contributions of deep groundwater to glacial and clearwater streams, whereas blackwater streams received larger contributions from shallow groundwater sources. DOC concentration and specific ultraviolet absorbance peaked during spring snowmelt in all streams, and were consistently higher in blackwater streams than in glacial and clearwater streams. The hydrophobic acid fraction of DOC dominated across all streams and seasons, comprising between 35% and 56% of total DOC. The hydrophilic acid fraction of DOC was more prominent in glacial (23% ± 3%) and clearwater streams (19% ± 1%) than in blackwater streams (16% ± 1%), and was enriched during winter base flow (29% ± 1%) relative to snowmelt and summer base flow. We observed that an increase in the contribution of deep groundwater to streamflow resulted in decreased DOC concentration, aromaticity, and DOC-to-dissolved organic nitrogen ratio, and an increase in the proportion of hydrophilic acids relative to hydrophobic acids. Our findings suggest that future permafrost degradation and higher contributions of groundwater to streamflow may result in a higher fraction of labile DOM in streams of the Yukon basin.
Flores, Romeo M.; Myers, Mark D.; Houseknecht, David W.; Stricker, Gary D.; Brizzolara, Donald W.; Ryherd, Timothy J.; Takahashi, Kenneth I.
2007-01-01
Stratigraphic and sedimentologic studies of facies of the Upper Cretaceous rocks along the Colville River Bluffs in the west-central North Slope of Alaska identified barrier shoreface deposits consisting of vertically stacked, coarsening-upward parasequences in the Schrader Bluff Formation. This vertical stack of parasequence deposits represents progradational sequences that were affected by shoaling and deepening cycles caused by fluctuations of sea level. Further, the vertical stack may have served to stabilize accumulation of voluminous coal deposits in the Prince Creek Formation, which formed braided, high-sinuosity meandering, anastomosed, and low-sinuosity meandering fluvial channels and related flood plain deposits. The erosional contact at the top of the uppermost coarsening-upward sequence, however, suggests a significant drop of base level (relative sea level) that permitted a semiregional subaerial unconformity to develop at the contact between the Schrader Bluff and Prince Creek Formations. This drop of relative sea level may have been followed by a relative sea-level rise to accommodate coal deposition directly above the unconformity. This rise was followed by a second drop of relative sea level, with formation of incised valley topography as much as 75 ft deep and an equivalent surface of a major marine erosion or mass wasting, or both, either of which can be traced from the Colville River Bluffs basinward to the subsurface in the west-central North Slope. The Prince Creek fluvial deposits represent late Campanian to late Maastrichtian depositional environments that were affected by these base level changes influenced by tectonism, basin subsidence, and sea-level fluctuations.
Penney, Zachary L.; Moffitt, Christine M.; Jones, Bryan; Marston, Brian
2016-01-01
The physiological status of migrating steelhead kelts (Oncorhynchus mykiss) from the Situk River, Alaska, and two tributaries of the Clearwater River, Idaho, was evaluated to explore potential differences in post-spawning survival related to energy reserves. Blood plasma samples were analyzed for metrics related to nutritional and osmotic status, and samples of white muscle tissue collected from recent mortalities at weirs were analyzed for proximate constituents. Female kelts from the Situk River had significantly higher plasma cholesterol, triglycerides, glucose and calcium concentrations, all of which suggested higher lipid and energy stores. Additional support for energy limitation in kelts was provided by evaluating the presence of detectable proteins in the plasma. Most all kelts sampled from the Situk River populations had detectable plasma proteins, in contrast to kelts sampled from the Clearwater River tributary populations where 27 % of kelts from one tributary, and 68 % of the second tributary were below the limits of detection. We found proximate constituents of kelt mortalities were similar between the Situk and Clearwater River populations, and the lipid fraction of white muscle averaged 0.1 and 0.2 %. Our findings lend support to the hypothesis that energetic limitations likely affect post-spawn survival in the Clearwater River kelts.
Winton, J.R.; Arakawa, C.N.; Lannan, C.N.; Fryer, J.L.
1988-01-01
eutralizing monoclonal antibodies were developed against strains of infectious hematopoietic necrosis virus (IHNV) from steelhead trout Salmo gairdneri in the Deschutes River of Oregon, chinook salmon Oncorhynchus tshawytscha in the Sacramento River of California, and rainbow trout Salmo gairdneri reared in the Hagerman Valley of Idaho, USA. These antibodies were tested for neutralization of 12 IHNV isolates obtained from salmonids in Japan, Alaska, Washington, Oregon, California, and Idaho. The antibodies recognized antigenic variants among the isolates and could be used to separate the viruses into 4 groups. The members of each group tended to be related by geographic area rather than by source host species, virulence, or date of isolation.
Observations and analysis of self-similar branching topology in glacier networks
Bahr, D.B.; Peckham, S.D.
1996-01-01
Glaciers, like rivers, have a branching structure which can be characterized by topological trees or networks. Probability distributions of various topological quantities in the networks are shown to satisfy the criterion for self-similarity, a symmetry structure which might be used to simplify future models of glacier dynamics. Two analytical methods of describing river networks, Shreve's random topology model and deterministic self-similar trees, are applied to the six glaciers of south central Alaska studied in this analysis. Self-similar trees capture the topological behavior observed for all of the glaciers, and most of the networks are also reasonably approximated by Shreve's theory. Copyright 1996 by the American Geophysical Union.
Code of Federal Regulations, 2010 CFR
2010-07-01
..., Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve Motor Vehicle Permits § 13.930 Do I... 14.8) and continues to the former Mt. McKinley National Park boundary north of Wonder Lake (mile 87.9). ...
Code of Federal Regulations, 2011 CFR
2011-07-01
..., Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve Motor Vehicle Permits § 13.930 Do I... 14.8) and continues to the former Mt. McKinley National Park boundary north of Wonder Lake (mile 87.9). ...
Code of Federal Regulations, 2014 CFR
2014-07-01
..., Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Denali National Park and Preserve Motor Vehicle Permits § 13.930 Do I... 14.8) and continues to the former Mt. McKinley National Park boundary north of Wonder Lake (mile 87.9). ...
Yuan, W.; Liu, S.; Liu, H.; Randerson, J.T.; Yu, G.; Tieszen, L.L.
2010-01-01
Evapotranspiration (ET) is the largest component of water loss from terrestrial ecosystems; however, large uncertainties exist when estimating the temporal and spatial variations of ET because of concurrent shifts in the magnitude and seasonal distribution of precipitation as well as differences in the response of ecosystem ET to environmental variabilities. In this study, we examined the impacts of precipitation seasonality and ecosystem types on ET quantified by eddy covariance towers from 2002 to 2004 in three ecosystems (grassland, deciduous broadleaf forest, and evergreen needleleaf forest) in the Yukon River Basin, Alaska. The annual precipitation changed greatly in both magnitude and seasonal distribution through the three investigated years. Observations and model results showed that ET was more sensitive to precipitation scarcity in the early growing season than in the late growing season, which was the direct result of different responses of ET components to precipitation in different seasons. The results demonstrated the importance of seasonal variations of precipitation in regulating annual ET and overshadowing the function of annual precipitation. Comparison of ET among ecosystems over the growing season indicated that ET was largest in deciduous broadleaf, intermediate in evergreen needleleaf, and lowest in the grassland ecosystem. These ecosystem differences in ET were related to differences in successional stages and physiological responses.
Recurring middle Pleistocene outburst floods in east-central Alaska
Froese, D.G.; Smith, D.G.; Westgate, J.A.; Ager, T.A.; Preece, S.J.; Sandhu, A.; Enkin, R.J.; Weber, F.
2003-01-01
Recurring glacial outburst floods from the Yukon-Tanana Upland are inferred from sediments exposed along the Yukon River near the mouth of Charley River in east-central Alaska. Deposits range from imbricate gravel and granules indicating flow locally extending up the Yukon valley, to more distal sediments consisting of at least 10 couplets of planar sands, granules, and climbing ripples with up-valley paleocurrent indicators overlain by massive silt. An interglacial organic silt, occurring within the sequence, indicates at least two flood events are associated with an earlier glaciation, and at least three flood events are associated with a later glaciation which postdates the organic silt. A minimum age for the floods is provided by a glass fission track age of 560,000 ?? 80,000 yr on the GI tephra, which occurs 8 m above the flood beds. A maximum age of 780,000 yr for the floods is based on normal magnetic polarity of the sediments. These age constraints allow us to correlate the flood events to the early-middle Pleistocene. And further, the outburst floods indicate extensive glaciation of the Yukon-Tanana Upland during the early-middle Pleistocene, likely representing the most extensive Pleistocene glaciation of the area. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.
NASA scientists are flying over Alaska
2017-08-29
As part of the Arctic Boreal Vulnerability Experiment (ABoVE), NASA scientists are flying over Alaska and Canada, measuring the elevation of rivers and lakes to study how thawing permafrost affects hydrology in the landscape. This view of was taken from NASA’s DC-8 “flying laboratory” as part of the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) experiment. Scientists on NASA’s Air Surface, Water and Ocean Topography (AirSWOT) mission have been flying over the same location, investigating how water levels in the Arctic landscape change as permafrost thaws. Under typical conditions, the frozen layer of soil keeps water from sinking into the ground and percolating away. As permafrost thaws, the water has new ways to move between rivers and lakes, which can raise or lower the elevation of the bodies of water. These changes in water levels will have effects on Arctic life— plants, animals, and humans—in the near future. Credit: NASA/Peter Griffith NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Snow and ice volume on Mount Spurr Volcano, Alaska, 1981
March, Rod S.; Mayo, Lawrence R.; Trabant, Dennis C.
1997-01-01
Mount Spurr (3,374 meters altitude) is an active volcano 130 kilometers west of Anchorage, Alaska, with an extensive covering of seasonal and perennial snow, and glaciers. Knowledge of the volume and distribution of snow and ice on a volcano aids in assessing hydrologic hazards such as floods, mudflows, and debris flows. In July 1981, ice thickness was measured at 68 locations on the five main glaciers of Mount Spurr: 64 of these measurements were made using a portable 1.7 megahertz monopulse ice-radar system, and 4 measurements were made using the helicopter altimeter where the glacier bed was exposed by ice avalanching. The distribution of snow and ice derived from these measurements is depicted on contour maps and in tables compiled by altitude and by drainage basins. Basal shear stresses at 20 percent of the measured locations ranged from 200 to 350 kilopascals, which is significantly higher than the 50 to 150 kilopascals commonly referred to in the literature as the 'normal' range for glaciers. Basal shear stresses higher than 'normal' have also been found on steep glaciers on volcanoes in the Cascade Range in the western United States. The area of perennial snow and ice coverage on Mount Spurr was 360 square kilometers in 1981, with an average thickness of 190?50 meters. Seasonal snow increases the volume about 1 percent and increases the area about 30 percent with a maximum in May or June. Runoff from Mount Spurr feeds the Chakachatna River and the Chichantna River (a tributary of the Beluga River). The Chakachatna River drainage contains 14 cubic kilometers of snow and ice and the Chichantna River drainage contains 53 cubic kilometers. The snow and ice volume on the mountain was 67?17 cubic kilometers, approximately 350 times more snow and ice than was on Mount St. Helens before its May 18, 1980, eruption, and 15 times more snow and ice than on Mount Rainier, the most glacierized of the measured volcanoes in the Cascade Range. On the basis of these relative quantities, hazard-producing glaciovolcanic phenomena at Mount Spurr could be significantly greater than similar phenomena at Cascade Volcanoes.
Inland waters and their role in the carbon cycle of Alaska
Stackpoole, Sarah M.; Butman, David E.; Clow, David W.; Verdin, Kristine L.; Gaglioti, Benjamin V.; Genet, Hélène; Striegl, Robert G.
2017-01-01
The magnitude of Alaska (AK) inland waters carbon (C) fluxes is likely to change in the future due to amplified climate warming impacts on the hydrology and biogeochemical processes in high latitude regions. Although current estimates of major aquatic C fluxes represent an essential baseline against which future change can be compared, a comprehensive assessment for AK has not yet been completed. To address this gap, we combined available data sets and applied consistent methodologies to estimate river lateral C export to the coast, river and lake carbon dioxide (CO2) and methane (CH4) emissions, and C burial in lakes for the six major hydrologic regions in the state. Estimated total aquatic C flux for AK was 41 Tg C/yr. Major components of this total flux, in Tg C/yr, were 18 for river lateral export, 17 for river CO2 emissions, and 8 for lake CO2 emissions. Lake C burial offset these fluxes by 2 Tg C/yr. River and lake CH4 emissions were 0.03 and 0.10 Tg C/yr, respectively. The Southeast and South central regions had the highest temperature, precipitation, terrestrial net primary productivity (NPP), and C yields (fluxes normalized to land area) were 77 and 42 g C·m−2·yr−1, respectively. Lake CO2 emissions represented over half of the total aquatic flux from the Southwest (37 g C·m−2·yr−1). The North Slope, Northwest, and Yukon regions had lesser yields (11, 15, and 17 g C·m2·yr−1), but these estimates may be the most vulnerable to future climate change, because of the heightened sensitivity of arctic and boreal ecosystems to intensified warming. Total aquatic C yield for AK was 27 g C·m−2·yr−1, which represented 16% of the estimated terrestrial NPP. Freshwater ecosystems represent a significant conduit for C loss, and a more comprehensive view of land-water-atmosphere interactions is necessary to predict future climate change impacts on the Alaskan ecosystem C balance.
Gray, J.E.; Gent, C.A.; Snee, L.W.
2000-01-01
A belt of small but numerous mercury deposits extends for about 500 km in the Kuskokwim River region of southwestern Alaska. The southwestern Alaska mercury belt is part of widespread mercury deposits of the circumPacific region that are similar to other mercury deposits throughout the world because they are epithermal with formation temperatures of about 200??C, the ore is dominantly cinnabar with Hg-Sb-As??Au geochemistry, and mineralized forms include vein, vein breccias, stockworks, replacements, and disseminations. The southwestern Alaska mercury belt has produced about 1,400 t of mercury, which is small on an international scale. However, additional mercury deposits are likely to be discovered because the terrain is topographically low with significant vegetation cover. Anomalous concentrations of gold in cinnabar ore suggest that gold deposits are possible in higher temperature environments below some of the Alaska mercury deposits. We correlate mineralization of the southwestern Alaska mercury deposits with Late Cretaceous and early Tertiary igneous activity. Our 40Ar/39Ar ages of 70??3 Ma from hydrothermal sericites in the mercury deposits indicate a temporal association of igneous activity and mineralization. Furthermore, we suggest that our geological and geochemical data from the mercury deposits indicate that ore fluids were generated primarily in surrounding sedimentary wall rocks when they were cut by Late Cretaceous and early Tertiary intrusions. In our ore genesis model, igneous activity provided the heat to initiate dehydration reactions and expel fluids from hydrous minerals and formational waters in the surrounding sedimentary wall rocks, causing thermal convection and hydrothermal fluid flow through permeable rocks and along fractures and faults. Our isotopic data from sulfide and alteration minerals of the mercury deposits indicate that ore fluids were derived from multiple sources, with most ore fluids originating from the sedimentary wall rocks.
Geologic Map of the Yukon-Koyukuk Basin, Alaska
Patton, William W.; Wilson, Frederic H.; Labay, Keith A.; Shew, Nora B.
2009-01-01
This map and accompanying digital files represent part of a systematic effort to release geologic data for the United States in a uniform manner. All the geologic data in this series will be published as parts of the U.S. Geological Survey Data Series. The geologic data in this series have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The data are presented for use at a nominal scale of 1:500,000, although individual datasets may contain data suitable for use at larger scales. The metadata associated with each release will provide more detailed information on sources and appropriate scales for use. Associated attribute databases accompany the spatial database of the geology and are uniformly structured for ease in developing regional- and national-scale maps. The 1:500,000-scale geologic map of the Yukon-Koyukuk Basin, Alaska, covers more than 200,000 square kilometers of western Alaska or nearly 15 percent of the total land area of the state. It stretches from the Brooks Range on the north to the Kuskokwim River and lower reaches of the Yukon River on the south and from Kotzebue Sound, Seward Peninsula, and Norton Sound on the west to the Yukon-Tanana Uplands and Tanana-Kuskokwim Lowlands on the east. It includes not only the northern and central part of the basin, but also the lands that border the basin. The area is characterized by isolated clusters of hills and low mountain ranges separated by broad alluviated interior and coastal lowlands. Most of the lowlands, except those bordering Kotzebue Sound and Norton Sound, support a heavy vegetation cover. Exposures of bedrock are generally limited to rubble-strewn ridgetops and to cutbanks along the rivers. The map of the Yukon-Koyukuk Basin was prepared largely from geologic field data collected between 1953 and 1988 by the U.S. Geological Survey and published as 1:250,000-scale geologic quadrangle maps. Additional data for parts of the Wiseman, Ruby, Medfra, and Ophir quadrangles came from 1:63,360-scale quadrangle maps published by the Alaska Division of Geological and Geophysical Surveys. The map also incorporates some unpublished field data for the Ruby quadrangle collected by R.M. Chapman between 1944 and 1977 and for parts of the Tanana, Bettles, Norton Bay, and Candle quadrangles collected by W.W. Patton, Jr. and others between 1954 and 1985. Sources of geologic map data for each of the eighteen 1:250,000-scale quadrangles used in compiling this 1:500,000-scale map of the Yukon-Koyukuk Basin as well as sources of general geologic information pertaining to the entire map area are provided in the 'Sources of Information' section.
Bathymetric and hydraulic survey of the Matanuska River near Circle View Estates, Alaska
Conaway, Jeffrey S.
2008-01-01
An acoustic Doppler current profiler interfaced with a differentially corrected global positioning system was used to map bathymetry and multi-dimensional velocities on the Matanuska River near Circle View Estates, Alaska. Data were collected along four spur dikes and a bend in the river during a period of active bank erosion. These data were collected as part of a larger investigation into channel processes being conducted to aid land managers with development of a long-term management plan for land near the river. The banks and streambed are composed of readily erodible material and the braided channels frequently scour and migrate. Lateral channel migration has resulted in the periodic loss of properties and structures along the river for decades.For most of the survey, discharge of the Matanuska River was less than the 25th percentile of long-term streamflow. Despite this relatively low flow, measured water velocities were as high as 15 feet per second. The survey required a unique deployment of the acoustic Doppler current profiler in a tethered boat that was towed by a small inflatable raft. Data were collected along cross sections and longitudinal profiles. The bathymetric and velocity data document river conditions before the installation of an additional spur dike in 2006 and during a period of bank erosion. Data were collected along 1,700 feet of river in front of the spur dikes and along 1,500 feet of an eroding bank.Data collected at the nose of spur dikes 2, 3, and 4 were selected to quantify the flow hydraulics at the locations subject to the highest velocities. The measured velocities and flow depths were greatest at the nose of the downstream-most spur dike. The maximum point velocity at the spur dike nose was 13.3 feet per second and the maximum depth-averaged velocity was 11.6 feet per second. The maximum measured depth was 12.0 feet at the nose of spur dike 4 and velocities greater than 10 feet per second were measured to a depth of 10 feet.Data collected along an eroding bank provided details of the spatial distribution and variability in magnitude of velocities and flow depths while erosion was taking place. Erosion was concentrated in an area just downstream of the apex of a river bend. Measured velocities and flow depths were greater in the apex of the bend than in the area of maximum bank erosion. The maximum measured velocity was 12.9 feet per second at the apex and 11.2 feet per second in front of the eroding bank. The maximum measured depth was 10.2 feet at the apex and 5.2 feet in front of the eroding bank.
Fuis, Gary S.; Haeussler, Peter J.; Atwater, Brian F.
2015-01-01
In a long and distinguished career, George Plafker made fundamental advances in understanding of megathrust tectonics, tsunami generation, paleoseismology, crustal neotectonics, and Alaskan geology, chiefly by means of geological field observations. George discovered that giant earthquakes result from tens of meters of seismic slip on subduction megathrusts, and he did this before the theory of plate tectonics had become a paradigm. The discovery was founded on George's comprehensive mapping of land-level changes in the aftermath of the 1964 earthquake in Alaska, and on his follow-up mapping, in 1968, in the region of the 1960 earthquakes in Chile. The mapping showed paired, parallel belts of coseismic uplift largely offshore and coseismic subsidence mostly onshore – a pattern now familiar as the initial condition assumed in simulations of subduction-zone tsunamis. George recognized, moreover, that splay faulting can play a major role in tsunami generation, and he also distinguished carefully between tectonic and landslide sources for the multiple tsunamis that accounted for nearly all the fatalities associated with the 1964 Alaska earthquake. George's classic monographs on the 1964 earthquake include findings on subduction-zone paleoseismology that he soon extended to include stratigraphic evidence for cyclic vertical deformation at the Copper River Delta, as well as recurrent uplift evidenced by flights of marine terraces at Middleton Island. As a geologist of earthquakes, George also clarified the tectonics and hazards of crustal faulting in Alaska, California, and other areas worldwide. All the while, George was mapping bedrock geology in Alaska, where he contributed importantly to today's understanding of how terranes were accreted and modified. Especially important was his documentation of the origin, movement, subduction, and collision of the Yakutat terrane in southern Alaska.
Dusel-Bacon, Cynthia; Holm-Denoma, Christopher S.; Jones, James V.; Aleinikoff, John N.; Mortensen, James K.
2017-01-01
We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the Healy schist, all have dominant detrital zircon populations of 1.9–1.8 Ga and a subordinate population of 2.7–2.6 Ga. Three zircons from Totatlanika Schist yield the youngest age of ca. 780 Ma. The anomalous Healy schist sample has abundant 1.6–0.9 Ga detrital zircon, as well as populations at 2.0–1.8 Ga and 2.7–2.5 Ga that overlap the ages from the rest of our samples; it has a minimum age population of ca. 1007 Ma.Detrital zircon age populations from all but the anomalous sample are statistically similar to those from (1) other peri-Laurentian units in east-central Alaska; (2) the Snowcap assemblage in Yukon, basement of the allochthonous Yukon-Tanana terrane; (3) Neoproterozoic to Ordovician Laurentian passive margin strata in southern British Columbia, Canada; and (4) Proterozoic Laurentian Sequence C strata of northwestern Canada. Recycling of zircon from the Paleoproterozoic Great Bear magmatic zone in the Wopmay orogen and its Archean precursors could explain both the Precambrian zircon populations and arc trace element signatures of our samples. Zircon from the anomalous Healy schist sample resembles that in Nation River Formation and Adams Argillite in eastern Alaska, suggesting recycling of detritus in those units.
Evaluation of feasibility of mapping seismically active faults in Alaska
NASA Technical Reports Server (NTRS)
Gedney, L. D. (Principal Investigator); Vanwormer, J. D.
1973-01-01
The author has identified the following significant results. ERTS-1 imagery is proving to be exceptionally useful in delineating structural features in Alaska which have never been recognized on the ground. Previously unmapped features such as seismically active faults and major structural lineaments are especially evident. Among the more significant results of this investigation is the discovery of an active strand of the Denali fault. The new fault has a history of scattered activity and was the scene of a magnitude 4.8 earthquake on October 1, 1972. Of greater significance is the disclosure of a large scale conjugate fracture system north of the Alaska Range. This fracture system appears to result from compressive stress radiating outward from around Mt. McKinley. One member of the system was the scene of a magnitude 6.5 earthquake in 1968. The potential value of ERTS-1 imagery to land use planning is reflected in the fact that this earthquake occurred within 10 km of the site which was proposed for the Rampart Dam, and the fault on which it occurred passes very near the proposed site for the bridge and oil pipeline crossing of the Yukon River.
ERTS imagery applied to Alaskan coastal problems. [surface water circulation
NASA Technical Reports Server (NTRS)
Wright, F. F.; Sharma, G. D.; Burbank, D. C.; Burns, J. J.
1974-01-01
Along the Alaska coast, surface water circulation is relatively easy to study with ERTS imagery. Highly turbid river water, sea ice, and fluvial ice have proven to be excellent tracers of the surface waters. Sea truth studies in the Gulf of Alaska, Cook Inlet, Bristol Bay, and the Bering Strait area have established the reliability of these tracers. ERTS imagery in the MSS 4 and 5 bands is particularly useful for observing lower concentrations of suspended sediment, while MSS 6 data is best for the most concentrated plumes. Ice features are most clearly seen on MSS 7 imagery; fracture patterns and the movement of specific floes can be used to map circulation in the winter when runoff is restricted, if appropriate allowance is made for wind influence. Current patterns interpreted from satellite data are only two-dimensional, but since most biological activity and pollution are concentrated near the surface, the information developed can be of direct utility. Details of Alaska inshore circulation of importance to coastal engineering, navigation, pollution studies, and fisheries development have been clarified with satellite data. ERTS has made possible the analysis of circulation in many parts of the Alaskan coast.
An overview of paleogene molluscan biostratigraphy and paleoecology of the Gulf of Alaska region
Marincovich, L.; McCoy, S.
1984-01-01
Paleogene marine strata in the Gulf of Alaska region occur in three geographic areas and may be characterized by their molluscan faunal composition and paleoecology: a western area consisting of the Alaska Peninsula, Kodiak Island, and adjacent islands; a central area encompassing Prince William Sound; and an eastern area extending from the mouth of the Copper River to Icy Point in the Lituya district. Strata in the western area include the Ghost Rocks, Narrow Cape (in part), Sitkalidak, Stepovak, Belkofski, and Tolstoi Formations; in the central area Paleogene strata are assigned entirely to the Orca Group; Paleogene strata in the eastern area include the Kulthieth and Poul Creek Formations and several coeval units. Environments ranging from marginal marine to bathyal and from subtropical to cool-temperate are inferred for the various molluscan faunas. Sediments range from interbedded coal and marine sands to deep-water turbidites. The known Paleogene molluscan faunas of these three southern Alaskan areas permit recognition of biostratigraphic schemes within each area, preliminary correlations between faunas of the three areas, and more general correlations with faunas of the Pacific Northwest, the Far Eastern U.S.S.R., and northern Japan. ?? 1984.
Polar bear maternal den habitat in the Arctic National Wildlife Refuge, Alaska
Durner, George M.; Amstrup, Steven C.; Ambrosius, Ken J.
2006-01-01
Polar bears (Ursus maritimus) give birth during mid-winter in dens of ice and snow. Denning polar bears subjected to human disturbances may abandon dens before their altricial young can survive the rigors of the Arctic winter. Because the Arctic coastal plain of Alaska is an area of high petroleum potential and contains existing and planned oil field developments, the distribution of polar bear dens on the plain is of interest to land managers. Therefore, as part of a study of denning habitats along the entire Arctic coast of Alaska, we examined high-resolution aerial photographs (n = 1655) of the 7994 km2 coastal plain included in the Arctic National Wildlife Refuge (ANWR) and mapped 3621 km of bank habitat suitable for denning by polar bears. Such habitats were distributed uniformly and comprised 0.29% (23.2 km2) of the coastal plain between the Canning River and the Canadian border. Ground-truth sampling suggested that we had correctly identified 91.5% of bank denning habitats on the ANWR coastal plain. Knowledge of the distribution of these habitats will help facilitate informed management of human activities and minimize disruption of polar bears in maternal dens.
Bradley, Dwight C.; Miller, Marti L.; Friedman, Richard M.; Layer, Paul W.; Bleick, Heather A.; Jones, James V.; Box, Steven E.; Karl, Susan M.; Shew, Nora B.; White, Timothy S.; Till, Alison B.; Dumoulin, Julie A.; Bundtzen, Thomas K.; O'Sullivan, Paul B.; Ullrich, Thomas D.
2017-03-02
In support of regional geologic framework studies, we obtained 50 new argon-40/argon-39 (40Ar/39Ar) ages and 33 new uranium-lead (U-Pb) ages from igneous rocks of southwestern Alaska. Most of the samples are from the Sleetmute and Taylor Mountains quadrangles; smaller collections or individual samples are from the Bethel, Candle, Dillingham, Goodnews Bay, Holy Cross, Iditarod, Kantishna River, Lake Clark, Lime Hills, McGrath, Medfra, Talkeetna, and Tanana quadrangles.A U-Pb zircon age of 317.7±0.6 million years (Ma) reveals the presence of Pennsylvanian intermediate igneous (probably volcanic) rocks in the Tikchik terrane, Bethel quadrangle. A U-Pb zircon age of 229.5±0.2 Ma from gabbro intruding the Rampart Group of the Angayucham-Tozitna terrane, Tanana quadrangle, confirms and tightens a previously cited Triassic age for this intrusive suite. A fresh mafic dike in Goodnews Bay quadrangle yielded a 40Ar/39Ar whole rock age of 155.0±1.9 Ma; this establishes a Jurassic or older age for the previously unconstrained (Paleozoic? to Mesozoic?) sandstone unit that it intrudes. A thick felsic tuff in the Gemuk Group in Taylor Mountains quadrangle yielded a U-Pb zircon age of 153.0±2.0 Ma, extending the age of magmatism in this part of the Togiak terrane back into the Late Jurassic. We report three new U-Pb zircon ages between 120 and 110 Ma—112.0±0.9 Ma from syenite in the Candle quadrangle, 114.9±0.3 Ma from orthogneiss assigned to the Ruby terrane in Iditarod quadrangle, and 116.6±0.1 Ma from a gabbro of the Dishna River mafic-ultramafic complex in Iditarod quadrangle. The latter result requires a substantial age revision, from Triassic to Cretaceous, for at least some rocks that have been mapped as the Dishna River mafic-ultramafic complex. A tuff in the Upper Cretaceous Kuskokwim Group yielded a U-Pb zircon (sensitive high-resolution ion microprobe, SHRIMP) age of 88.3±1.0 Ma; we speculate that the eruptive source was an arc along the trend of the Pebble porphyry copper deposit along the Gulf of Alaska continental margin. More than half of the new ages fall between 75 and 65 Ma, confirming the existence, based on conventional potassium-argon (K-Ar) ages, of a 70-Ma igneous flare-up across southwestern Alaska. Our new ages hint that during this pulse, the locus of magmatism shifted toward the Gulf of Alaska, that is, toward a more outboard position. This shift is consistent with the hypothesis that magmatism was the product of rollback of a subducted slab, which at that time would have been the Resurrection Plate. Intrusive rocks in the Taylor Mountains and Sleetmute quadrangles in the age range of 63 to 59 Ma were emplaced shortly before the onset of ridge subduction as dated by near-trench plutons in the adjacent part of the Chugach accretionary complex. Southwestern Alaska at this time would have been positioned above a very young subducted slab belonging to the Resurrection Plate; magmas, in this scenario, were generated near the edge of the slab window related to ridge subduction. A 56.3±0.2 Ma granite in Taylor Mountains quadrangle and a 54.7±0.7 Ma ashfall tuff in McGrath quadrangle were likely emplaced above the Resurrection-Kula slab window, which by this time is inferred to have entered the region. Another ashfall tuff in McGrath quadrangle, at 42.8±0.5 Ma, likely belongs to the Meshik Arc, the product of renewed subduction after inferred passage of the slab window. A 49.0±0.3-Ma rhyolite in Taylor Mountains quadrangle is about the age of the transition from slab window to renewed subduction. Two plutons in the western Alaska Range, at 31.8±0.4 and 30.9±0.6 Ma, belong to a suite of gabbro to peralkaline granite of unknown origin. Finally, a 4.6±0.1-Ma basalt from a flow in Taylor Mountains quadrangle belongs to the Neogene basaltic province of western Alaska. These rocks were erupted in a distal retroarc setting; the cause of magmatism is unknown.
1980-09-01
the past when these ties. zones were thought to have shifted in response In this study 21 maps (scale 1:6,000) of repre- to climatic changes . sentative...Alaska Grasses Roads Climate Permafrost Soil erosion Drainage Pipelines Vegetation Environmental engineering Restoration Erosion control Revegetation 20...of changes in the environment associated with the road, 3) documentation of flora and vegetation along the 577-km-long transect, 4) methodologies for
A review of water resources of the Umiat area, northern Alaska
Williams, John R.
1970-01-01
Surface-water supplies from the Colville River, small tributary creeks, and lakes are abundant in summer but limited in winter by low or zero flow in streams and thick ice cover on lakes. Fresh ground water occurs in unfrozen zones in alluvium and in the upper part of bedrock beneath the Colville River and beneath lakes that do not freeze to the bottom in winter. These unfrozen zones, forming depressions in the upper surface of permafrost, are maintained by flow of heat from bodies of surface water into subjacent alluvium and bedrock. Brackish or saline ground water occurs in bedrock beneath as much as 1,055 feet of permafrost in the Arctic foothills and beneath 750 to 800 feet of permafrost beneath low terraces of the Colville River valley. The foothill area is unfavorable for developing supplies of potable ground water because of the great depth to water, predominance of brackish or saline water, and low potential yield of the bedrock. In the Colville River valley, shallow unfrozen alluvium beneath the river and deep lakes will yield abundant year-round supplies of ground water, but the bedrock below permafrost yields less than 10 gpm (gallons per minute) of saline or brackish water.
Annual Coded Wire Tag Program; Oregon Missing Production Groups, 1997 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lewis, Mark A.; Mallette, Christine; Murray, William M.
1998-03-01
This annual report is in fulfillment of contract obligations with Bonneville Power Administration which is the funding source for the Oregon Department of Fish and Wildlife's Annual Coded Wire Tag Program - Oregon Missing Production Groups Project. Tule stock fall chinook were caught primarily in British Columbia and Washington ocean, and Oregon freshwater fisheries. Up-river bright stock fall chinook contributed primarily to Alaska and British Columbia ocean commercial, and Columbia River gillnet and other freshwater fisheries. Contribution of Rogue stock fall chinook released in the lower Columbia River occurred primarily in Oregon ocean commercial and Columbia river gillnet fisheries. Willamettemore » stock spring chinook contributed primarily to Alaska and British Columbia ocean commercial, Oregon freshwater sport and Columbia River gillnet fisheries. Willamette stock spring chinook released by CEDC contributed to similar ocean fisheries, but had much higher catch in gillnet fisheries than the same stocks released in the Willamette system. Up-river stocks of spring chinook contributed almost exclusively to Columbia River sport fisheries and other freshwater recovery areas. The up-river stocks of Columbia River summer steelhead contributed primarily to the Columbia River gillnet and other freshwater fisheries. Coho ocean fisheries from Washington to California were closed or very limited from 1994 through 1997 (1991 through 1994 broods). This has resulted in a greater average percent of catch for other fishery areas. Coho stocks released by ODFW below Bonneville Dam contributed mainly to Oregon and Washington ocean, Columbia Gillnet and other freshwater fisheries. Coho stocks released in the Klaskanine River and Youngs Bay area had similar ocean catch, but much higher contribution to gillnet fisheries than the other coho releases. Coho stocks released above Bonneville Dam had similar contribution to ocean fisheries as other coho releases. However, they contributed more to gillnet fisheries above Bonneville Dam than coho released below the dam. Survival rates of salmon and steelhead are influenced, not only by factors in the hatchery (disease, density, diet, size and time of release) but also by environmental factors in the river and ocean. These environmental factors are influenced by large scale weather patterns such as El Nino over which man has no influence. Changes in rearing conditions in the hatchery, over which man has some influence, do impact the survival rates. However, these impacts can be offset by impacts caused by environmental factors. Coho salmon released in the Columbia River generally experience better survival rates when released later in the spring. However, for the 1990 brood year June releases of Columbia River coho had much lower survival than May releases, for all ODFW hatcheries. In general survival of ODFW Columbia River hatchery coho has declined to low levels since the 1989 brood year. In an effort to evaluate photonic marking as a tool to mass mark salmonids, two groups of 1995 brood juvenile coho salmon were marked at Sandy Hatchery. The first group (Group A) received a fluorescent red mark, adipose fin clip and coded-wire tag. The second group (Group B) received a cryptic blue mark, adipose fin clip and coded-wire tag. Both groups were released in the spring of 1997. No photonic marks were detected in the precocious males (jacks) returning to Sandy hatchery in the fall of 1997.« less
NASA Astrophysics Data System (ADS)
Dunn, Catherine A.; Enkelmann, Eva; Ridgway, Kenneth D.; Allen, Wai K.
2017-03-01
In this study, we present a source to sink evaluation of sediment routing at the glaciated convergent margin in Southeast Alaska. We investigate the efficacy of thermochronology to record spatial and temporal exhumation patterns in synorogenic sediment using Neogene strata drilled by Integrated Ocean Drilling Program Expedition 341 in the Gulf of Alaska. We present 1641 and 529 new detrital zircon and apatite fission track ages, respectively, from strata deposited on the continental shelf, slope, and deep-sea fans. These data are compared to results from the proposed source terrains, including the St. Elias Mountains and new data from the Alsek River. We find that the offshore Bagley-Bering sediment contains grains recording cooling ages much older (80-35 Ma) than those reported from the St. Elias syntaxis (3-2 Ma), indicating that extreme rapid exhumation does not extend west of the Seward-Bagley divide. Data from the sediment on the continental shelf, slope, and proximal deep sea all yield similar results, suggesting the same general source region since 1.2 Ma and limited sediment mixing along this glaciated margin. Data from sediment in the distal deep sea show that extreme, rapid, and deep-seated exhumation was ongoing at 11-8 Ma. Overall, this study demonstrates the strengths and limitations of using detrital fission track thermochronology to understand sediment routing on a glaciated convergent margin and to record changes in exhumation rates over geologic time scales.
NASA Astrophysics Data System (ADS)
Glaser, D. R., II; Wagner, A. M.; Gelvin, A.; Saari, S.; Staples, A.; Larsen, G.
2017-12-01
A US Army legacy munitions waste site was identified adjacent to a river near a small arms range in Alaska. As part of remediation efforts, geophysical studies were conducted to characterize the extent of buried metal debris at the site. Time-domain electromagnetic surveys were completed over the site to meet the regulatory guidance for site cleanup. Time-domain and frequency-domain electromagnetic induction, magnetic gradiometry, and ground penetrating radar subsurface geophysical studies were deployed over soil, water, and snow surface conditions throughout the impacted area. The time-domain electromagnetic induction results acquired during summer months, presented clear indications of trenches located directly perpendicular to and adjacent to the river. However, in the follow up investigation where the snow-pack was greater than one meter, the response amplitude of the metallic debris was dampened and possible targets were missed. This was confirmed by the subsequent magnetic gradiometry survey which identified a suspected extension of one of the trenches through the river on to the seasonal sand bar island. The region is subject to extremely cold temperatures as well as significant snow pack and permafrost soil conditions. The snow presented a negative impact to the accurate assessment of the site by changing the effective investigation depth. To address this we developed an approach using ground penetrating radar data calibrated with physical snow depth measurements to generate continuous estimates of snow depth and spatially correct the electromagnetic induction data to the corresponding regulatory amplitude limit as if the snow were not present. Limitations of the approach as related to the signal floor of the electromagnetic induction response were also assessed.
Williams, I.; Reeves, G.H.; Graziano, S.L.; Nielsen, J.L.
2007-01-01
Molecular genetic methods were used to quantify natural hybridization between rainbow trout Oncorhynchus mykiss or steelhead (anadromous rainbow trout) and coastal cutthroat trout O. clarkii clarkii collected in the Copper River delta, Southeast Alaska. Eleven locations were sampled to determine the extent of hybridization and the distribution of hybrids. Four diagnostic nuclear microsatellite loci and four species-specific simple sequence repeat markers were used in combination with restriction fragment length polymorphism analyses of NADH dehydrogenase 5/6 (ND5/6) mitochondrial DNA (mtDNA) to investigate the genetic structure of trout from both species and identify putative interspecific hybrids. Hybrids were found in 7 of the 11 streams sampled in the Copper River delta, the extent of hybridization across all streams varying from 0% to 58%. Hybrid trout distribution appeared to be nonrandom, most individuals of mixed taxonomic ancestry being detected in streams containing rainbow trout rather than in streams containing coastal cutthroat trout. Genotypic disequilibrium was observed among microsatellite loci in populations with high levels of hybridization. We found no significant correlation between unique stream channel process groups and the number of hybrid fish sampled. Eighty-eight percent of fish identified as first-generation hybrids (F1) in two populations contained coastal cutthroat trout mtDNA, suggesting directionality in hybridization. However, dominance of coastal cutthroat trout mtDNA was not observed at a third location containing F1 hybrids, indicating that interspecific mating behavior varied among locations. Backcrossed individuals were found in drainages lacking F1 hybrids and in populations previously thought to contain a single species. The extent and distribution of backcrossed individuals suggested that at least some hybrids are reproductively viable and backcrossed hybrid offspring move throughout the system.
Dusel-Bacon, Cynthia; Day, Warren C.; Aleinikoff, John N.
2013-01-01
We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and Fortymile River assemblages. Whole-rock trace-element data from the tonalitic gneiss, whose igneous protolith was dated by SHRIMP U–Pb zircon geochronology at 332.6 ± 5.6 Ma, indicate derivation from tholeiitic arc basalt. Whole-rock analyses of the mafic rocks suggest that greenschist-facies rocks from the Chicken metamorphic complex, a mafic metavolcanic rock from the Nasina assemblage, and an amphibolite from the Fortymile River assemblage formed as island-arc tholeiite in a back-arc setting; another Nasina assemblage greenschist has MORB geochemical characteristics, and another mafic metaigneous rock from the Fortymile River assemblage has geochemical characteristics of calc-alkaline basalt. Our geochemical results imply derivation in an arc and back-arc spreading region within the allochthonous YTT crustal fragment, as previously proposed for correlative units in other parts of the terrane. We also describe the petrography and geochemistry of a newly discovered tectonic lens of Alpine-type metaharzburgite. The metaharzburgite is interpreted to be a sliver of lithospheric mantle from beneath the Seventymile ocean basin or from sub-continental mantle lithosphere of the allochthonous YTT or the western margin of Laurentia that was tectonically emplaced within crustal rocks during closure of the Seventymile ocean basin and subsequently displaced and fragmented by faults.
Rhoades, Charles; Binkley, Dan; Oskarsson, Hlynur; Stottlemyer, Robert
2008-01-01
Nitrogen enters terrestrial ecosystems through multiple pathways during primary succession. We measured accumulation of total soil nitrogen and changes in inorganic nitrogen (N) pools across a 300-y sequence of river terraces in northwest Alaska and assessed the contribution of the nitrogen-fixing shrub Shepherdia canadensis. Our work compared 5 stages of floodplain succession, progressing from a sparsely vegetated silt cap to dense shrubby vegetation, balsam poplar-dominated (Populus balsamifera) and white spruce-dominated (Picea glauca) mixed forests, and old-growth white spruce forest. Total soil N (0–30 cm depth) increased throughout the age sequence, initially by 2.4 g N·m−2·y−1 during the first 120 y of terrace development, then by 1.6 g N·m−2·y−1 during the subsequent 2 centuries. Labile soil N, measured by anaerobic incubation, increased most rapidly during the first 85 y of terrace formation, then remained relatively constant during further terrace development. On recently formed terraces, Shepherdia shrubs enriched soil N pools several-fold compared to soil beneath Salix spp. shrubs or intercanopy sites. Total and labile soil N accretion was proportional to Shepherdia cover during the first century of terrace development, and mineral soil δ15N content indicated that newly formed river terraces receive substantial N through N-fixation. About half the 600 g total N·m−2 accumulated across the river terrace chronosequence occurred during the 120 y when S. canadensis was dominant. Sediment deposited by periodic flooding continued to add N to terrace soils after the decline in Shepherdia abundance and may have contributed 25% of the total N found in the floodplain terrace soils.
Chronic effects of the Exxon Valdez oil spill on blood and enzyme chemistry of river otters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Duffy, L.K.; Bowyer, R.T.; Testa, J.W.
1994-04-01
River otters (Lutra canadensis) living in marine environments of Prince William Sound, Alaska, and exposed to crude oil from the Exxon Valdez spill in March 1989 showed elevated levels of blood haptoglobins, and interleukin-6 ir, as well as elevated activities of aspartate aminotransferase, alanine aminotransferase, and creatine kinase in summer 1991. Stepwise logistic regression, using a subset of these and other blood proteins and enzyme activities as potential independent variables, correctly classified 86.4% of 22 otters as inhabiting oiled or nonoiled areas. River otters abandoned latrine sites (an index to their abundance) over three times more often in oiled thanmore » in nonoiled areas, suggesting there may have been a delayed response in river otter populations to exposure to crude oil. This is the first clear model for the long-term effects of an oil spill on blood parameters of a free-ranging mammal using a nonlethal methodology. These effects occurred two years after the spill and following a major effort to clean oil from the shorelines of Prince William Sound.« less
NASA Astrophysics Data System (ADS)
Zhang, X.; Bianchi, T. S.; Cui, X.; Rosenheim, B. E.; Ping, C. L.; Kanevskiy, M. Z.; Hanna, A. M.; Allison, M. A.
2016-12-01
As temperatures in the Arctic rise abnormally fast, permafrost in the region is vulnerable to extensive thawing. This could release previously frozen organic carbon (OC) into the contemporary carbon cycle, giving a positive feedback on global warming. Recent research has found the presence of particulate permafrost in rivers, deltas, and continental shelves in the Arctic, but little direct evidence exists on the mechanism of transportation of previously frozen soils from watershed to the coast. The Colville River in northern Alaska is the largest North American Arctic River with a continuous permafrost within its watershed. Previous work has found evidence for the deposition of previously frozen soils in the Colville River delta (Schreiner et al., 2014). Here, we compared the bulk organic carbon thermal properties, ages of soils and river and delta sediments from the Colville River drainage system using 14C Ramped Pyrolysis and chemical biomarkers. Our data show that deep permafrost soils as well as river and delta sediments had similar pyrograms and biomarker signatures, reflecting transport of soils from watershed to the delta. Surface soil had pyrograms indicative of less stable (more biodegradable) OC than deeper soil horizons. Similarity in pyrograms of deep soils and river sediment indicated the limited contribution of surface soils to riverine particulate OC inputs. Sediments in the delta showed inputs of yedoma (ice-rich syngenetic permafrost with large ice wedges) from the watershed sources (e.g., river bank erosion) in addition to peat inputs, that were largely from coastal erosion.
Garver, K.A.; Troyer, R.M.; Kurath, G.
2003-01-01
Infectious hematopoietic necrosis virus (IHNV), an aquatic rhabdovirus, causes a highly lethal disease of salmonid fish in North America. To evaluate the genetic diversity of IHNV from throughout the Columbia River basin, excluding the Hagerman Valley, Idaho, the sequences of a 303 nt region of the glycoprotein gene (mid-G) of 120 virus isolates were determined. Sequence comparisons revealed 30 different sequence types, with a maximum nucleotide diversity of 7.3% (22 mismatches) and an intrapopulational nucleotide diversity of 0.018. This indicates that the genetic diversity of IHNV within the Columbia River basin is 3-fold higher than in Alaska, but 2-fold lower than in the Hagerman Valley, Idaho. Phylogenetic analyses separated the Columbia River basin IHNV isolates into 2 major clades, designated U and M. The 2 clades geographically overlapped within the lower Columbia River basin and in the lower Snake River and tributaries, while the upper Columbia River basin had only U clade and the upper Snake River basin had only M clade virus types. These results suggest that there are co-circulating lineages of IHNV present within specific areas of the Columbia River basin. The epidemiological significance of these findings provided insight into viral traffic patterns exhibited by IHNV in the Columbia River basin, with specific relevance to how the Columbia River basin IHNV types were related to those in the Hagerman Valley. These analyses indicate that there have likely been 2 historical events in which Hagerman Valley IHNV types were introduced and became established in the lower Columbia River basin. However, the data also clearly indicates that the Hagerman Valley is not a continuous source of waterborne virus infecting salmonid stocks downstream.
Mendenhall, W.C.
1902-01-01
The reconnaissance described in the following pages was carried out in pursuance of a plan which has been followed for some years by the United States Geological Survey in the topographic and geologic exploration of the little-known parts of Alaska and in the collection of such information as will be of value not only to the scientific world, but to the prospector, the miner, and the trader. Capital disappears and years are wasted by prospectors who push out beyond the shifting frontier and pursue their search for gold where gold is not to be expected, and lives are being continually lost because the location and character of trails, drainage ways, and mountain ranges and passes are unknown, or because the knowledge which a few possess is not in a form available for the use of others.
Faulting and instability of shelf sediments: eastern Gulf of Alaska
DOE Office of Scientific and Technical Information (OSTI.GOV)
Carlson, P.R.; Molnia, B.F.
1976-04-01
Faults and submarine slides or slumps are potential environmental hazards on the outer continental shelf of the northern Gulf of Alaska. Submarine slides or slumps have been found in two places in the OCS region: (1) seaward of the Malaspina Glacier and Icy Bay, an area of 1770 square kilometers, that has a slope of less than one-half degree, and (2) across the entire span of the Copper River prodelta, an area of 1730 square kilometers, that has a slope of about one-half degree. Seismic profiles across these areas show disrupted reflectors and irregular topography commonly associated with submarine slidesmore » or slumps. Other potential slide or slum areas have been delineated in areas of thick sediment accumulation and relatively steep slopes. These areas include Kayak Trough, parts of Hinchinbrook Entrance and Sea Valley, parts of the outer shelf and upper slope between Kayak Island and Yakutat Bay and Bering Trough.« less
Trabant, Dennis C.; March, Rod S.; Thomas, Donald S.
2003-01-01
Hubbard Glacier, the largest calving glacier on the North American Continent (25 percent larger than Rhode Island), advanced across the entrance to 35-mile-long Russell Fiord during June 2002, temporarily turning it into a lake. Hubbard Glacier has been advancing for more than 100 years and has twice closed the entrance to Russell Fiord during the last 16 years by squeezing and pushing submarine glacial sediments across the mouth of the fiord. Water flowing into the cutoff fiord from mountain streams and glacier melt causes the level of Russell Lake to rise. However, both the 1986 and 2002 dams failed before the lake altitude rose enough for water to spill over a low pass at the far end of the fiord and enter the Situk River drainage, a world-class sport and commercial fishery near Yakutat, Alaska.