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Sample records for alaska range alaska

  1. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  2. Reindeer ranges inventory in western Alaska

    NASA Technical Reports Server (NTRS)

    George, T. H.

    1981-01-01

    The use of LANDSAT data as a tool for reindeer range inventory on the tundra of northwestern Alaska is addressed. The specific goal is to map the range resource and estimate plant productivity of the Seward Peninsula. Information derived from these surveys is needed to develop range management plans for reindeer herding and to evaluate potential conflicting use between reindeer and caribou. The development of computer image classification techniques is discussed.

  3. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

    NASA Astrophysics Data System (ADS)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

    2013-12-01

    Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

  4. Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska

    USGS Publications Warehouse

    Taylor, Ryan D.; Graham, Garth E.; Anderson, Eric D.; Selby, David

    2014-01-01

    This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions of years ago (Ma). Additionally, a rhenium-osmium age of molybdenite from the Miss Molly molybdenum occurrence is reported (approx. 59 Ma). All of the granitic plutons in this study host gold-, copper-, and (or) molybdenum-rich prospects. These new ages modify previous interpretations regarding the age of magmatic activity and mineralization within the study area. The new ages show that the majority of the gold-quartz vein-hosting plutons examined in this study formed in the Late Cretaceous. Further work is necessary to establish the ages of ore-mineral deposition in these deposits.

  5. Devonian volcanogenic massive sulfide deposits and occurrences, southern Yukon-Tanana Terrace, eastern Alaska Range, Alaska

    USGS Publications Warehouse

    Lange, I.M.; Nokleberg, W.J.; Newkirk, S.R.; Aleinikoff, J.N.; Church, S.E.; Krouse, H.R.

    1993-01-01

    A belt of volcanogenic massive sulfide deposits extends for over 150km along the southern margin of the Yukon-Tanana terrane of the eastern Alaska Range. Located north of the Denali fault, the Yukon-Tanana terrane forms a major basement unit in east-central Alaska. The volcanogenic massive sulfide deposits are primarily in the Jarvis Creek Glacier subterrane, which consists of a volcanogenic massive sulfide-bearing metavolcanic rock member and a metasedimentary rock member. Two periods of regional metamorphism and penetrative deformation are indicated: an older, Early Cretaceous, amphibolite facies event and a younger, mid-Cretaceous lower greenschist facies event. The occurrence, mineralogy and sulphur isotope values are discussed. -from Authors

  6. Photogrammetrically Derived Estimates of Glacier Mass Loss in the Upper Susitna Drainage Basin, Alaska Range, Alaska

    NASA Astrophysics Data System (ADS)

    Wolken, G. J.; Whorton, E.; Murphy, N.

    2014-12-01

    Glaciers in Alaska are currently experiencing some of the highest rates of mass loss on Earth, with mass wastage rates accelerating during the last several decades. Glaciers, and other components of the hydrologic cycle, are expected to continue to change in response to anticipated future atmospheric warming, thus, affecting the quantity and timing of river runoff. This study uses sequential digital elevation model (DEM) analysis to estimate the mass loss of glaciers in the upper Susitna drainage basin, Alaska Range, for the purpose of validating model simulations of past runoff changes. We use mainly stereo optical airborne and satellite data for several epochs between 1949 and 2014, and employ traditional stereo-photogrammetric and structure from motion processing techniques to derive DEMs of the upper Susitna basin glaciers. This work aims to improve the record of glacier change in the central Alaska Range, and serves as a critical validation dataset for a hydrological model that simulates the potential effects of future glacier mass loss on changes in river runoff over the lifespan of the proposed Susitna-Watana Hydroelectric Project.

  7. Paleoseismic study of the Cathedral Rapids fault in the northern Alaska Range near Tok, Alaska

    NASA Astrophysics Data System (ADS)

    Koehler, R. D.; Farrell, R.; Carver, G. A.

    2010-12-01

    The Cathedral Rapids fault extends ~40 km between the Tok and Robertson River valleys and is the easternmost fault in a series of active south-dipping imbricate thrust faults which bound the northern flank of the Alaska Range. Collectively, these faults accommodate a component of convergence transferred north of the Denali fault and related to the westward (counterclockwise) rotation of the Wrangell Block driven by relative Pacific/North American plate motion along the eastern Aleutian subduction zone and Fairweather fault system. To the west, the system has been defined as the Northern Foothills Fold and Thrust Belt (NFFTB), a 50-km-wide zone of east-west trending thrust faults that displace Quaternary deposits and have accommodated ~3 mm/yr of shortening since latest Pliocene time (Bemis, 2004). Over the last several years, the eastward extension of the NFFTB between Delta Junction and the Canadian border has been studied by the Alaska Division of Geological & Geophysical Surveys to better characterize faults that may affect engineering design of the proposed Alaska-Canada natural gas pipeline and other infrastructure. We summarize herein reconnaissance field observations along the western part of the Cathedral Rapids fault. The western part of the Cathedral Rapids fault extends 21 km from Sheep Creek to Moon Lake and is characterized by three roughly parallel sinuous traces that offset glacial deposits of the Illinoian to early Wisconsinan Delta glaciations and the late Wisconsinan Donnelly glaciation, as well as, Holocene alluvial deposits. The northern trace of the fault is characterized by an oversteepened, beveled, ~2.5-m-high scarp that obliquely cuts a Holocene alluvial fan and projects into the rangefront. Previous paleoseismic studies along the eastern part of the Cathedral Rapids fault and Dot “T” Johnson fault indicate multiple latest Pleistocene and Holocene earthquakes associated with anticlinal folding and thrust faulting (Carver et al., 2010

  8. Geochemical evidence for a brooks range mineral belt, Alaska

    USGS Publications Warehouse

    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.

  9. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range

    NASA Astrophysics Data System (ADS)

    Newman, Stephen Delmont, Jr.

    I investigated active deep-seated gravitational slope deformation (DSGSD) near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. I documented the presence, spatial extent, and rates of DSGSD using field-geology methods and optical, SAR, and D-InSAR remote-sensing images. I also documented and mapped many of the morphological, geological, and structural characteristics of slopes undergoing DSGSD, and constructed conceptual numerical models to better understand potential deformation mechanisms. Results confirm that many large DSGSD slopes in the study area are actively deforming. Deformation rates range from less than a millimetre per month to more than ten centimetres per month, and are spatially and temporally varient within each slope. Deforming slopes are characterized by differential movement of kilometre-scale rock blocks. Recent climatic changes and strong seismic shaking, especially during the recent 2002 Denali Fault earthquake, have exacerbated ongoing deformation. Study-area DSGSDs should be considered capable of generating long-runout rock avalanches that could directly sever the Trans-Alaska Pipeline and Richardson Highway, or that could dam up valleys and lead to the buildup and catastrophic failure of landslide-dammed lakes capable of impacting said infrastructure. Keywords: Deep-seated gravitational slope deformation; sackung; Trans-Alaska Pipeline; geomorphology; InSAR; Alaska Range.

  10. Cretaceous Olistostrome Model, Brooks Range, Alaska

    SciTech Connect

    Crane, R.C.

    1985-04-01

    The foothills area of the Brooks Range thrust belt in the area between the Itkillik River and the Etivluk River is composed dominantly of shallow, thrusted olistostrome sheets. Three olistostrome units can be recognized based on the dominant lithology of contained olistoliths and age of the matrix shales. The lower unit is Thithonian to mid-Valanginian in age and is characterized by abundant graywacke and turbidite, mafic rocks, black cherts, olistoliths of Norian-Rhaetic shales, Nuka sands, and glide sheets of Upper Devonian to Lower Mississippian rocks. Olistolights were derived from the Misheguk, Ipnavik, and Nuka Ridge allochthonous sequences. The middle unit is of late Valanginian age and has olistoliths of Norian shales; more abundant Upper Triassic chert; Otuk Formation; variegated, radiolarian, black and white cherts; Siksikpuk facies red, green and black shales; Upper Jurassic graywacke; and minor occurrences of mafic rocks. The unit is characterized by glide sheets of Triassic white and multicolor cherts. Olistoliths are derived from Nuka Ridge and Brooks Range sequences. The upper unit is Hauterivian in age and olistoliths included reworked material from all older units. Olistoliths are few and widely scattered. Isolated outcrops of white chert and conglomerate boulders are characteristic.

  11. 2014 Earthquake Swarm in Northwest Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Ruppert, N. A.; Holtkamp, S. G.

    2014-12-01

    An unusual sequence of earthquakes in NW Brooks Range region of Alaska began with two magnitude 5.7 earthquakes within minutes of each other on April 18, 2014. These events were followed by a vigorous aftershock sequence with many aftershocks reaching magnitude 4 and higher. Later, three more magnitude 5.7 earthquakes occurred in the same source region on May 3, June 7 and June 16. Earthquake source mechanisms indicate normal faulting on SE-NW striking fault planes. The source region is located ~20 km NE of the Noatak village and ~40 km S of the Red Dog Mine. A magnitude 5.5 occurred in this area in 1981. The 1981 sequence also exhibited a swarm-like behavior over the course of 6 months. Detection and reporting of these earthquakes is complicated by sparseness of seismic network in NW Alaska. At the time of April 18 earthquake the nearest seismic site was located at the Red Dog Mine, with the next nearest station 350 km away. Following the May 3 event, the Alaska Earthquake Center installed two additional temporary stations, one in Noatak and another in Kotzebue, 85 km S of the source area. Overall, 450 events were reported in this sequence through end of July. The catalog magnitude of completeness with the additional stations was about ~2.2. We applied waveform template matching algorithm to detect additional events in this sequence that could not be detected with the standard network processing. The template matching resulted in ~600 additional event detections. The waveform cross-correlation indicates that most of the events are not repeating sources. From the catalogued events, only 6% of event pairs have correlation coefficients of 0.75 or higher. We were able to identify only a few families of repeating events. Only one family seemed to be present throughout the entire sequence, while other event families were mostly short-lived. We find preliminary evidence that the earthquakes migrated to shallower depths throughout the sequence, consistent with the

  12. The Cold Surface Layer of Kahiltna Glacier, Central Alaska Range

    NASA Astrophysics Data System (ADS)

    Harrison, W. D.; Gusmeroli, A.; Arendt, A. A.; Atwood, D. K.; Kampes, B.; Sanford, M.; Young, J. C.; Aschwanden, A.; Truffer, M.; Herreid, S. J.; Hock, R. M.

    2011-12-01

    In Arctic, sub-Arctic and high-Alpine settings the ablation area of many mountain glaciers is rarely entirely temperate, and a cold near-surface layer of variable thickness, whose temperature remains below freezing throughout the year, can be found. This occurs when summer ablation rates do not melt the near-surface ice enough to remove the cold layer from the previous winter. A cold near-surface layer is a useful climatological parameter because, for example, its thinning over time can be related to climatic warming. In April 2011 we conducted several 100 MHz ground penetrating radar (GPR) surveys in the upper ablation area (˜1200 m a.s.l.) of the Kahiltna glacier, in the central Alaska Range. Surface ice temperatures, measured continuously during the preceding winter remained at ˜-4°C for 6 months. The GPR data showed the presence of a spatially variable, ˜20 m thick, transparent layer which we interpret to be the cold surface layer. A layer of similar thickness was retrieved by airborne IFSAR P-band radar surveys on several Alaskan glaciers. We use these observations to discuss the occurrence of a cold-surface layer in the Alaska Range and its usefulness for glacier monitoring studies.

  13. UNIT, ALASKA.

    ERIC Educational Resources Information Center

    Louisiana Arts and Science Center, Baton Rouge.

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

  14. Long Range Program, Library Development in Alaska 1973-1978.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Div. of State Libraries.

    A statewide library development program designed to provide total library services to meet educational, informational, and cultural needs of the people of Alaska is outlined in this document. The body of the report is divided into three sections. In the first, the purpose, scope, and development of the plan are summarized. The second section…

  15. 76 FR 77300 - Alaska Federal Lands Long Range Transportation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... transportation planning and decision-making processes. Such cooperation is accomplished through developing common... LRTP--This draft plan describes the benefits of and actions for coordinated planning and decision making among federal land management agencies (FLMA) involved in this Alaska Federal Lands Long...

  16. The topographically asymmetrical Alaska Range: Multiple tectonic drivers through space and time

    NASA Astrophysics Data System (ADS)

    Benowitz, Jeffrey

    The topographically segmented, ˜700 km long Alaska Range evolved over the last ˜50 Ma in response to both far-field driving mechanisms and near-field boundary conditions. The eastern Alaska Range follows the curve of the Denali Fault strike-slip system, forming a large arc of high topography across southern Alaska. The majority of the topography in the eastern Alaska Range lies north of the Fault. A region of low topography separates the eastern Alaska Range from the central Alaska Range, where most of the high topography lies south of the Denali Fault. To the west, there is a restraining bend in the Fault. Southwest of the bend, the north-south trending western Alaska Range takes an abrupt 90 degree turn away from the Denali Fault. I applied 40Ar/39Ar thermochronology to over forty granitic samples to constrain the thermal history of the western and eastern Alaska Range. I combine the 40Ar/39Ar analyses with available apatite fission track and apatite (U-Th)/He dating. I then inferred the Alaska Range's exhumation history from the region's rates and patterns of rock cooling. Periods of mountain building within the Alaska Range are related to Paleocene-Eocene ridge subduction and an associated slab window (˜50 Ma to ˜35 Ma), Neogene flat-slab subduction of the Yakutat microplate (˜24 Ma to present), Yakutat microplate latitudinal variation in thickness (˜6 Ma to present), block rotation/migration, and fault reorganization along the Denali Fault. However, it is clear from basin, petrological and thermochronological constraints that not all of the far-field driving mechanisms affected every segment of the Alaska Range to the same degree or at the same time. Alaska Range tectonic reconstruction is also complicated by near-field structural controls on both the timing and extent of deformation. Fault geometry affects both the amount of exhumation (e.g., ˜14 km in the Susitna Glacier region of the eastern Alaska Range) and location of topographic development (e

  17. Northern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Seasonal ice in the Beaufort Sea off Alaska's North Slope has begun its spring retreat. This true color MODIS image from March 18, 2002, shows the pack ice in the Chuckchi Sea (left) and Beaufort Sea (top) backing away from its winter position snug up against Alaska's coasts, beginning its retreat into the Arctic Ocean. While not as pronounced in the Beaufort and Chukchi Seas as other part of the Arctic, scientists studying Arctic sea ice over the course of the century have documented dramatic changes in the extent of Arctic sea ice. It retreats farther in the summer and does not advance as far in the winter than it did a half-century ago. Both global warming and natural variation in regional weather systems have been proposed as causes. Along the coastal plain of the North Slope, gray-brown tracks (see high-resolution image) hint at melting rivers. South of the North Slope, the rugged mountains of the Brooks Range make a coast-to-coast arc across the state. Coming in at the lower right of the image, the Yukon River traces a frozen white path westward across half the image before veering south and out of view. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  18. Cement stratigraphy of the Lisburne Group, northeastern Brooks Range, Alaska

    SciTech Connect

    Carlson, R.C.; Goldstein, R.H. . Geology Dept.)

    1992-01-01

    Cement stratigraphy serves as a descriptive framework for the interpretation of the diagenetic history of the Carboniferous Lisburne Group, northeastern Brooks Range, Alaska. The Lisburne is a sequence of shallow-water, marine carbonate rocks that have experienced a wide spectrum of diagenetic events: early marine diagenesis, early subaerial exposure, significant erosion and karstification following final Lisburne deposition, deep burial of at least 3,000 meters, compressional tectonism, and final uplift into modern mountain ranges. Compositional zones in the calcite cements were identified by using stains for ferroan calcite and cathodoluminescence microscopy. The cements are, from oldest to youngest: A1-nonferroan, nonluminescent or multibanded calcite; B1-nonferroan to low-ferroan, dull luminescent calcite; C1-ferroan, very-dull luminescent calcite; B2-nonferroan, dull luminescent calcite; A2-nonferroan calcite with 1 or 2 sets of nonluminescent and bright zones; C2-ferroan, very-dull luminescent calcite; Be-nonferroan, dull luminescent calcite. Petrographic studies of cross-cutting relationships show that A1 cements predate or are synchronous with surfaces of subaerial exposure within the Lisburne Group. The cross-cutting relationships include truncation of cements by early fractures, non-marine fissure fills, and at clast margins of autoclastic breccias. Similarly, B1 and C1 cements predate the major unconformity at the top of the Lisburne Group, hence, these cements are pre-Permian in age and may well have precipitated from fresh groundwaters introduced during development of the sub-Permian unconformity. B2 and C2 cements are present in the Permian Echooka formation overlying the Lisburne Group and, thus, can be dated as post-Pennsylvanian. B3 cements are Cretaceous or younger in age.

  19. A geochemical perspective of Red Mountain: an unmined volcanogenic massive sulfide deposit in the Alaska Range

    USGS Publications Warehouse

    Giles, Stuart A.; Eppinger, Robert G.

    2014-01-01

    The U.S. Geological Survey (USGS) has investigated the environmental geochemistry of a group of unmined volcanogenic massive sulfide (VMS) deposits in the Bonnifield mining district, Alaska Range, east-central Alaska. The spectacularly colored Red Mountain deposit is the best exposed of these and provides excellent baseline geochemical data for natural environmental impacts of acidic rock drainage, metal dissolution and transport, and acidic salt and metal precipitation from an exposed and undisturbed VMS deposit.

  20. Spring and aufeis (icing) hydrology in Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Kenji; Hinzman, Larry D.; Kane, Douglas L.

    2007-12-01

    Remote sensing studies and field hydrometeorological and geophysical investigations were employed to characterize several aufeis fields in the Brooks Range, Alaska. Geochemical studies were undertaken together with field hydrological measurements to better understand the chemical and thermal properties of stream base flow (groundwater spring) that contributes to winter aufeis development. The spring water temperature was measured at several major aufeis fields using data loggers throughout the year. Aufeis is an important water storage component in the Arctic and influences local ecology and geomorphology. Synthetic aperture radar (SAR) is a useful and sensitive sensor for aufeis detection and for estimating the total volume of storage as well as freeze/thaw conditions. The SAR analysis indicated that the volume of aufeis formed in winter is 27-30% of the annual groundwater discharge in the Kuparuk River. Visible and near-IR satellite imagery indicated many of the high-discharge springs (more than 10-1000 1/s) and aufeis fields are centered around an elevation of 600 m a.s.l. in limestone areas with glacial morphology. Geomorphological investigations indicate that many of springs have continually existed from at least the last glaciation. Microwave data (SAR), thermal infrared, short wave infrared, and visible and near-IR bands were all used to observe the growth, decay, and distribution of aufeis deposits. The remotely sensed data indicate that the distribution of the aufeis deposits today is nearly the same as it was in past colder periods; this was mainly determined by mapping the distributed carbonate precipitates. Also, spring water temperatures and discharge volumes are predictable from the aufeis field size using remotely sensed techniques.

  1. Structural problems of the Brooks Range ophiolite, Alaska

    SciTech Connect

    Harris, R.A.; Bickerstaff, D. . Dept. of Geology); Stone, D.B. . Geophysical Inst.)

    1993-04-01

    Structural and paleogeographic restorations of the Brooks Range ophiolite (hereafter BRO) and other associated mafic and ultramafic bodies of N. Alaska are difficult because of ambiguous relations between sheeted dikes, cover sediments, and steep NW and SE dipping magmatic flow fabrics. Paleomagnetically enhanced structural studies at Misheguk, Avan, and Siniktanneyak Mountains provide new constraints for the initial dip and sequence of deformation for various structural features of the BRO. The angle between magmatic layers near the petrologic moho and the paleomagnetic inclination of these layers is 50--63[degree] at Misheguk. High level gabbro layers that are disrupted by syn- and post-cooling intrusions display a greater variation. Assuming that the characteristic magnetization is primary, and that the primary inclination was > 80[degree], magmatic layers and the moho had initial dips from 17--40[degree]. These layers now dip 40--70[degree]SE suggesting some post-magmatic tilt. The variation of inclinations with depth in the ophiolite suggest that high level gabbro has tilted most. Sheeted dikes are documented at the Maiyumerak and Siniktanneyak ophiolite bodies. At both locations the dikes dip steeply and strike NE-SW. Sedimentary and volcanic flow layers associated with the dikes have the same strike and dip 0--30[degree]. Parallelism between various planar features throughout the BRO indicates that rotations about a vertical axis are either uniform throughout the ophiolite belt or negligible. Assuming the later, the BRO may represent a linear zone of SSZ magmatism that was oriented NE-SW prior to collision. Post-emplacement long wavelength folding of the ophiolite lid can account for its variation in facing direction and some steepening of magmatic layers.

  2. Structure of the Red Dog District, western Brooks Range, Alaska

    USGS Publications Warehouse

    de Vera, Jean-Pierre P.; McClay, K. R.

    2004-01-01

    The Red Dog district of the western Brooks Range of northern Alaska, which includes the sediment-hosted Zn-Pb-Ag ± Ba deposits at Red Dog, Su-Lik, and Anarraaq, contains one of the world's largest reserves of zinc. This paper presents a new model for the structural development of the area and shows that understanding the structure is crucial for future exploration efforts and new mineral discoveries in the district. In the Red Dog district, a telescoped Late Devonian through Jurassic continental passive margin is exposed in a series of subhorizontally stacked, internally imbricated, and regionally folded thrust sheets. These sheets were emplaced during the Middle Jurassic to Late Cretaceous Brookian orogeny and subsequently were uplifted by late tectonic activity in the Tertiary. The thrust sheet stack comprises seven tectonostratigraphically distinct allochthonous sheets, three of which have been subject to regional and detailed structural analysis. The lowermost of these is the Endicott Mountains allochthon, which is overlain by the structurally higher Picnic Creek and Kelly River allochthons. Each individual allochthon is itself internally imbricated into a series of tectonostratigraphically coherent and distinct thrust plates and subplates. This structural style gives rise to duplex development and imbrication at a range of scales, from a few meters to tens of kilometers. The variable mechanical properties of the lithologic units of the ancient passive margin resulted in changes in structural styles and scales of structures across allochthon boundaries. Structural mapping and analysis of the district indicate a dominant northwest to west-northwest direction of regional tectonic transport. Local north to north-northeast transport of thrust sheets is interpreted to reflect the influence of underlying lateral and/or oblique ramps, which may have been controlled by inherited basin margin structures. Some thrust-sheet stacking patterns suggest out

  3. Range expansion of nonindigenous caribou in the Aleutianarchipelago of Alaska

    USGS Publications Warehouse

    Ricca, Mark A.; Weckerly, Floyd W.; Duarte, Adam; Williams, Jeffrey C.

    2012-01-01

    Caribou (Rangifer tarandus) are nonindigenous to all but the eastern-most island of the Aleutian archipelago of Alaska. In 1958–1959, caribou were intentionally introduced to Adak Island in the central archipelago, and the population has at least tripled in recent years subsequent to the closure of a naval air facility. Although dispersal of caribou to adjacent islands has been suspected, no historical documentation has occurred to date. Herein, we report consistent detections of caribou sign on the adjacent island of Kagalaska over 2 summer field seasons (2010–2011), and visual detection of caribou on that island during the summer of 2011. Ecological impacts of caribou on Kagalaska are not strongly apparent at the present time and we do not know how many animals permanently occupy the island. However, establishment of a reproductively viable resident population on Kagalaska is worrisome and could set the stage for a step-wise invasion of additional nearby islands.

  4. Alaska Resource Data File, Noatak Quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.; Dumoulin, Julie A.

    2006-01-01

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

  5. Geospatial compilation of results from field sample collection in support of mineral resource investigations, Western Alaska Range, Alaska, July 2013

    USGS Publications Warehouse

    Johnson, Michaela R.; Graham, Garth E.; Hubbard, Bernard E.; Benzel, William M.

    2015-07-16

    This Data Series summarizes results from July 2013 sampling in the western Alaska Range near Mount Estelle, Alaska. The fieldwork combined in situ and camp-based spectral measurements of talus/soil and rock samples. Five rock and 48 soil samples were submitted for quantitative geochemi­cal analysis (for 55 major and trace elements), and the 48 soils samples were also analyzed by x-ray diffraction to establish mineralogy and geochemistry. The results and sample photo­graphs are presented in a geodatabase that accompanies this report. The spectral, mineralogical, and geochemical charac­terization of these samples and the sites that they represent can be used to validate existing remote-sensing datasets (for example, ASTER) and future hyperspectral studies. Empiri­cal evidence of jarosite (as identified by x-ray diffraction and spectral analysis) corresponding with gold concentrations in excess of 50 parts per billion in soil samples suggests that surficial mapping of jarosite in regional surveys may be use­ful for targeting areas of prospective gold occurrences in this sampling area.

  6. Geospatial compilation of results from field sample collection in support of mineral resource investigations, Western Alaska Range, Alaska, July 2013

    USGS Publications Warehouse

    Johnson, Michaela R.; Graham, Garth E.; Hubbard, Bernard E.; Benzel, William M.

    2015-01-01

    This Data Series summarizes results from July 2013 sampling in the western Alaska Range near Mount Estelle, Alaska. The fieldwork combined in situ and camp-based spectral measurements of talus/soil and rock samples. Five rock and 48 soil samples were submitted for quantitative geochemi­cal analysis (for 55 major and trace elements), and the 48 soils samples were also analyzed by x-ray diffraction to establish mineralogy and geochemistry. The results and sample photo­graphs are presented in a geodatabase that accompanies this report. The spectral, mineralogical, and geochemical charac­terization of these samples and the sites that they represent can be used to validate existing remote-sensing datasets (for example, ASTER) and future hyperspectral studies. Empiri­cal evidence of jarosite (as identified by x-ray diffraction and spectral analysis) corresponding with gold concentrations in excess of 50 parts per billion in soil samples suggests that surficial mapping of jarosite in regional surveys may be use­ful for targeting areas of prospective gold occurrences in this sampling area.

  7. Crustal implications of bedrock geology along the Trans-Alaska Crustal Transect (TACT) in the Brooks Range, northern Alaska

    USGS Publications Warehouse

    Moore, T.E.; Wallace, W.K.; Mull, C.G.; Adams, K.E.; Plafker, G.; Nokleberg, W.J.

    1997-01-01

    Geologic mapping of the Trans-Alaska Crustal Transect (TACT) project along the Dalton Highway in northern Alaska indicates that the Endicott Mountains allochthon and the Hammond terrane compose a combined allochthon that was thrust northward at least 90 km in the Early Cretaceous. The basal thrust of the combined allochthon climbs up section in the hanging wall from a ductile shear zone, in the south through lower Paleozoic rocks of the Hammond terrane and into Upper Devonian rocks of the Endicott Mountains allochthon at the Mount Doonerak antiform, culminating in Early Cretaceous shale in the northern foothills of the Brooks Range. Footwall rocks north of the Mount Doonerak antiform are everywhere parautochthonous Permian and Triassic shale of the North Slope terrane rather than Jurassic and Lower Cretaceous strata of the Colville Basin as shown in most other tectonic models of the central Brooks Range. Stratigraphic and structural relations suggest that this thrust was the basal detachment for Early Cretaceous deformation. Younger structures, such as the Tertiary Mount Doonerak antiform, deform the Early Cretaceous structures and are cored by thrusts that root at a depth of about 10 to 30 km along a deeper detachment than the Early Cretaceous detachment. The Brooks Range, therefore, exposes (1) an Early Cretaceous thin-skinned deformational belt developed during arc-continent collision and (2) a mainly Tertiary thick-skinned orogen that is probably the northward continuation of the Rocky Mountains erogenic belt. A down-to-the-south zone of both ductile and brittle normal faulting along the southern margin of the Brooks Range probably formed in the mid-Cretaceous by extensional exhumation of the Early Cretaceous contractional deformation. copyright. Published in 1997 by the American Geophysical Union.

  8. Logs and Geologic Data from a Paleoseismic Investigation of the Susitna Glacier fault, Central Alaska Range, Alaska

    USGS Publications Warehouse

    Personius, Stephen F.; Crone, Anthony J.; Burns, Patricia A.C.; Beget, James E.; Seitz, Gordon G.; Bemis, Sean P.

    2010-01-01

    This report contains field and laboratory data from a paleoseismic study of the Susitna Glacier fault, Alaska. The initial M 7.2 subevent of the November 3, 2002, M 7.9 Denali fault earthquake sequence produced a 48-km-long set of complex fault scarps, folds, and aligned landslides on the previously unknown, north-dipping Susitna Glacier thrust fault along the southern margin of the Alaska Range in central Alaska. Most of the 2002 folds and fault scarps are 1-3 m high, implying dip-slip thrust offsets (assuming a near-surface fault dip of approximately 20 degrees)of 3-5 m. Locally, some of the 2002 ruptures were superimposed on preexisting scarps that have as much as 5-10 m of vertical separation and are evidence of previous surface-rupturing earthquakes on the Susitna Glacier fault. In 2003-2005, we focused follow-up studies on several of the large scarps at the 'Wet fan' site in the central part of the 2002 rupture to determine the pre-2002 history of large surface-rupturing earthquakes on the fault. We chose this site for several reasons: (1) the presence of pre-2002 thrust- and normal-fault scarps on a gently sloping, post-glacial alluvial fan; (2) nearby natural exposures of underlying fan sediments revealed fine-grained fluvial silts with peat layers and volcanic ash beds useful for chronological control; and (3) a lack of permafrost to a depth of more than 1 m. Our studies included detailed mapping, fault-scarp profiling, and logging of three hand-excavated trenches. We were forced to restrict our excavations to 1- to 2-m-high splay faults and folds because the primary 2002 ruptures mostly were superimposed on such large scarps that it was impossible to hand dig through the hanging wall to expose the fault plane. Additional complications are the pervasive effects of cryogenic processes (mainly solifluction) that can mask or mimic tectonic deformation. The purpose of this report is to present photomosaics, trench logs, scarp profiles, and fault slip

  9. Flood frequency in Alaska

    USGS Publications Warehouse

    Childers, J.M.

    1970-01-01

    Records of peak discharge at 183 sites were used to study flood frequency in Alaska. The vast size of Alaska, its great ranges of physiography, and the lack of data for much of the State precluded a comprehensive analysis of all flood determinants. Peak stream discharges, where gaging-station records were available, were analyzed for 2-year, 5-year, 10-year, 25-year, and 50-year average-recurrence intervals. A regional analysis of the flood characteristics by multiple-regression methods gave a set of equations that can be used to estimate floods of selected recurrence intervals up to 50 years for any site on any stream in Alaska. The equations relate floods to drainage-basin characteristics. The study indicates that in Alaska the 50-year flood can be estimated from 10-year gaging- station records with a standard error of 22 percent whereas the 50-year flood can be estimated from the regression equation with a standard error of 53 percent. Also, maximum known floods at more than 500 gaging stations and miscellaneous sites in Alaska were related to drainage-area size. An envelope curve of 500 cubic feet per second per square mile covered all but 2 floods in the State.

  10. Alaska's Children, 1997.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1997-01-01

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

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

    ERIC Educational Resources Information Center

    Alaska Review of Social and Economic Conditions, 1987

    1987-01-01

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

  12. Alaska Natives & the Land.

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

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

  13. Alaska Women: A Databook.

    ERIC Educational Resources Information Center

    White, Karen; Baker, Barbara

    This data book uses survey and census information to record social and economic changes of the past three decades and their effects upon the role of Alaska women in society. Results show Alaska women comprise 47% of the state population, an increase of 9% since 1950. Marriage continues as the predominant living arrangement for Alaska women,…

  14. Stratigraphy, structure, and graptolites of an Ordovician and Silurian sequence in the Terra Cotta Mountains, Alaska Range, Alaska

    USGS Publications Warehouse

    Churkin, Michael; Carter, Claire

    1996-01-01

    The geology and graptolite faunas of the Terra Cotta Mountains in south-central Alaska are described. Three new formations of Paleozoic age are named and described; they include graptolitiferous argillaceous rocks, sandstones, and limestones of the Dillinger Terrane. The structure and tectonics of the mapped area arc also discussed. Ninety-five species of Ordovician and Silurian graptolites, including four new species, are described and illustrated. The faunal succession is divided into nine Ordovician and ten Silurian biostratigraphic zones and is correlated with graptolite faunas found elsewhere.

  15. Solvent extraction treatment of PCB contaminated soil at Sparrevohn Long Range Radar Station, Alaska

    SciTech Connect

    Weimer, L.D.

    1999-07-01

    This technical paper describes an on-site soil treatment project at the Sparrevohn Long-Range Radar Station (LRRS), Alaska. The project was conducted during the summer of 1996. Sparrevohn LLRS is located approximately 200 miles west of Anchorage, Alaska and is accessible only by aircraft. Polychlorinated biphenyls (PCB) contaminated soil containing between 50 and 350 milligrams/kilogram (mg/kg) was stockpiled on-site. Terra Kleen Response Group, Inc.'s (Terra Kleen's) solvent extraction process successfully treated the stockpiled PCB contaminated soil ({approximately}290 yd{sup 3}). The PCB concentrations in the treated soil were reduced below the target treatment level of 15 mg/kg. On-site solvent extraction treatment realized considerable savings ({gt}$1,000,000) to the Government over the traditional method of hauling and off-site disposal.

  16. Thrust involvement of metamorphic rocks, southwestern Brooks Range, Alaska

    SciTech Connect

    Till, A.B.; Schmidt, J.M.; Nelson, S.W. )

    1988-10-01

    Most models for the tectonic history of the western Brooks Range treat Proterozoic and lower Paleozoic metamorphic rocks exposed in the southern part of the range as passive structural basement vertically uplifted late in the Mesozoic orogenic episode. Mapping in the metamorphic rocks shows that they can de divided into two structurally and metamorphically distinct belts, both of which were folded and thrust during the orogeny. Recognition of these belts and the nature of the contact separating them is critical to construction of accurate tectonic models of the Brooks Range fold and thrust belt.

  17. Alaska Volcano Observatory

    USGS Publications Warehouse

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

    2008-01-01

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

  18. Lower Paleozoic and Proterozoic rocks of Southern Brooks Range, Alaska

    SciTech Connect

    Dillion, J.T.

    1985-04-01

    Lower Paleozoic or Proterozoic basement rocks occur in windows and thrust plates in several areas of the Brooks Range. Uranium-lead radiometric analyses of highly metamorphosed rocks from the Baird Mountains and Ernie Lake area have yielded Proterozoic ages. Structural, stratigraphic, petrologic, and isotopic evidence exists for Proterozoic(.) rocks in the schist belt; around the Chandalar, Arrigetch,and Igikpak plutons; and in the Cosmos Hills window. Fossiliferous, Lower Paleozoic, low-grade metasedimentary rocks occur in the Romanzof Mountains, Doonerak window, and Baird Mountains, and may also surround the Chandalar plutons. Locally, the Lower Paleozoic rocks are unconformably overlain by Devonian to Mississippian metasediments and may stratigraphically overlie older, higher grade metamorphic rocks. Similarities in the stratigraphic settings and lithologies and in fossil ages and affinities allow correlation of the Lower Paleozoic rocks in the southern Brooks Range. Correlation of Lower Paleozoic rocks exposed beneath the Endicott allochthon at the Doonerak fenster with coeval rocks in an overlying thrust plate to the south at Snowsden Mountain is especially significant. A west-trending thrust fault, which is rooted in Lower Paleozoic basement, along the north side of Snowsden Mountain is postulated to account for these relationships. Apparently, the Endicott allochthon roots beneath the Snowsden Mountain thrust fault. Evidence form conodont samples currently being studied by A. Harris may bear on the extent of the Lower Paleozoic rocks in the upper plate of the Snowsden Mountain thrust and in the Chandalar area.

  19. Geological mapping in Doonerak Fenster, Central Brooks Range, Alaska

    SciTech Connect

    Mull, C.C.; Adams, K.E.; Dillon, J.T.

    1985-04-01

    Mapping of the north flank of the Doonerak fenster has traced the Amawk thrust, the sole fault of the Endicott Mountains allochthon, from the North Fork of the Koyukuk River - Mount Doonerak area eastward for more than 40 km (25 mi) to the east plunge of the Doonerak anticline at Koyuktuvuk Creek near the Dietrich River. Mapping has concentrated on the structural style of the area and on the autochthonous or parautochthonous Carboniferous Lisburne Group, Kayak shale, Kekiktuk Conglomerate - which are present along most of the anticline - and Triassic Karen Creek Sandstone, Triassic Shublik Formation, and Permian-Triassic Sadlerochit Group - which are present only in the west. This Triassic to Mississippian section closely resembles the coeval autochthonous to Parautochthonous Ellesmerian section of the subsurface to the north and in the Brooks Range to the northeast.

  20. Stratigraphy, structure, and palinspastic synthesis of the western Brooks Range, northwestern Alaska

    USGS Publications Warehouse

    Mayfield, Charles F.; Tailleur, Irvin L.; Ellersieck, Inyo

    1983-01-01

    This report is an effort to describe and decipher the mid-Paleozoic to Lower Cretaceous stratigraphy and the orogenic evolution of the western Brooks Range. The western Brooks Range primarily is composed of stacks of complexly deformed thrust sheets that contain mostly coeval sequences of rocks with slightly different lithologic facies. In order to simplify the thrust-faulted stratigraphy and palinspastic restoration, the rocks are grouped into eight principal structural levels. The lowest structural level is believed to be autochthonous or parautochthonous and above that, each succeeding level is designated allochthon one through seven. Allochthon seven is composed of the remnants of an extensive ophiolite sheet. Allochthon six is composed of pillow basalt with subordinate intermediate volcanic rocks, chert, and Devonian limestone. It is not certain whether this allochthon was formed in a continental or oceanic setting. Allochthons five through one consist of distinctive and coeval sequences of Devonian to Lower Cretaceous sedimentary rocks that were deposited in a continental setting. The present geographic distribution of each structural level is shown on the allochthon map of the western Brooks Range. The stratigraphy of the southern part of northern Alaska has been reconstructed by systematically unstacking lower allochthons to the north of higher allochthons. The palinspastic map that results from this procedure shows that the minimum thrust displacement between allochthon seven and the autochthon is approximately 700 to 800 km. Schematic cross sections drawn across the palinspastic map show how the stratigraphy of the southern part of northern. Alaska most likely appeared prior to the orogeny. During Devonian and Mississippian time, the sedimentary sequences that are now part of allochthons one to five are inferred to have been deposited in an ensialic basin with both northern and southern margins. During Pennsylvanian time, the sequences seem to have become

  1. Structural architecture of the central Brooks Range foothills, Alaska

    USGS Publications Warehouse

    Moore, Thomas E.; Potter, Christopher J.; O'Sullivan, Paul B.

    2002-01-01

    Five structural levels underlie the Brooks Range foothills, from lowest to highest: (1) autochthon, at a depth of ~9 km; (2) Endicott Mountains allochthon (EMA), thickest under the northern Brooks Range (>15 km) and wedging out northward above the autochthon; (3) higher allochthons (HA), with a composite thickness of 1.5+ km, wedging out northward at or beyond the termination of EMA; (4) Aptian-Albian Fortress Mountain Formation (FM), deposited unconformably on deformed EMA and HA and thickening northward into a >7-km-thick succession of deformed turbidites (Torok Formation); (5) gently folded Albian-Cenomanian deltaic deposits (Nanushuk Group). The dominant faulting pattern in levels 2-3 is thin-skinned thrusting and thrust-related folds formed before deposition of Cretaceous strata. These structures are cut by younger steeply south-dipping reverse faults that truncate and juxtapose structural levels 1-4 and expose progressively deeper structural levels to the south. Structural levels 4-5 are juxtaposed along a north-dipping zone of south-vergent folds and thrusts. Stratigraphic and fission-track age data suggest a kinematic model wherein the foothills belt was formed first, by thrusting of HA and EMA as deformational wedges onto the regionally south-dipping authochon at 140-120Ma. After deposition of FM and Torok during mid-Cretaceous hinterland extension and uplift, a second episode of contractional deformation at 60 Ma shortened the older allochthonous deformational wedges (EMA, HA) and overlying strata on north-vergent reverse faults. To the north, where the allochthons wedge out, shortening caused duplexing in the Torok and development of a triangle zone south of the Tuktu escarpment.

  2. Diagenesis of the Lisburne Group, northeastern Brooks Range, Alaska

    SciTech Connect

    Carlson, R.C.; Goldstein, R.H.; Enos, P.

    1995-05-01

    Petrographic cathodoluminescence studies of the cement stratigraphy of the Lisburne Group yield insights on its diagenetic history. Crosscutting relationships between features of subaerial exposure and calcite cements show that early generations of nonferroan, nonluminescent and multibanded-luminescent calcites are synchronous with or postdated by subaerial exposure surfaces within the Lisburne. Surfaces of subaerial exposure occur at 18 horizons within the Lisburne and are distinguished by features as laminated crusts, rhizoliths, autoclastic breccia, fissure fills, mud cracks, and erosional surfaces. Crosscutting relationships also occur between calcite cements and clasts in karst breccias and conglomerates that formed along the sub-Permian unconformity at the top of the Lisburne. The sub-Permian unconformity postdates later generations of calcite cement. These cements formed in the following sequence: nonferroan to low-ferroan, dully luminescent calcite; ferroan, very-dully luminescent calcite; and second generation of nonferroan, multibanded calcite. The crosscutting relationships not only constrain the timing of cement precipitation, but also suggest that the cements probably were precipitated from meteoric groundwaters introduced during subaerial exposure of the Lisburne platform. Late cements in the Lisburne postdate the Permian Echooka Formation. These cements are low-ferroan, moderately-bright to dully luminescent calcite, followed by a second generation of ferroan, very-dully luminescent calcite. Features of compaction and pressure solution are coincident with the precipitation of the late ferroan calcite and further constrain its timing to deep burial of the Lisburne. The youngest phase of calcite cement precipitated in the Lisburne Group is nonferroan, very-dully luminescent calcite. It commonly fills tectonically-induced shear fractures, indicating precipitation after the onset of Cretaceous (and/or Cenozoic) tectonism in the northeastern Brooks Range.

  3. Tectonic evolution of the Brooks Range ophiolite, Alaska

    SciTech Connect

    Harris, R.A. . Dept. of Geology)

    1993-04-01

    Detailed studies of the composition, internal structure, and age of the Brooks Range ophiolite (BRO) and its metamorphic sole reveal new constraints for its tectonic evolution. The BRO consists of six separate thrust masses of consanguineous composition, internal organization, structure and age. Subophiolite metamorphic rocks are locally preserved along its structural base, which is well exposed in several places. The metamorphic sole is locally transitional with mafic volcanic sequences, chert, tuffs, and minor clastic sedimentary material of the Copter Peak Complex, which is correlative with the Angayucham terrane. This terrane is much older than, and chemically distinct from the BRO. The internal structure of the BRO is characterized by NE-SW trending igneous layers that expose the transition zone from crust to mantle. Residual mantle material consists of tectonized peridotite in abrupt contact with dunite pods up to 4 km thick. Ductile and brittle structures of the BRO preserve various phases of its dynamic evolution from a magma body to a fragmented thrust sheet. The earliest deformational effects are recorded by ductile lattice and shape fabrics in dunites and the layered series of the BRO. Magmatic flow planes generally parallel the petrologic moho, and dip 40[degree]--70[degree] to the NW and SE. Flow lineations consistently plunge ESE-ENE from 39[degree]--54[degree]. Igneous laminations and compositional layers represent patterns of magmatic flow in, and plastic deformation of, a cumulate sequence -- not the deposition pattern of cumulate layers. In the upper layered series, amphiboles with a shape-preferred orientation yield Ar/Ar plateau ages of 163--169 Ma. These ages overlap with plateau ages of the same kind from amphibolite of the metamorphic sole. This concordance in age indicates that cooling of the BRO coincided with its tectonic emplacement.

  4. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

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

  5. Geologic map of Alaska

    USGS Publications Warehouse

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

    2015-12-31

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

  6. Metamorphic facies map of Alaska

    SciTech Connect

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

    1985-04-01

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

  7. A 2000 year varve-based climate record from the central Brooks Range, Alaska

    SciTech Connect

    Bird, B.W.; Abbott, M.B.; Finney, B.P.; Kutchko, Barbara

    2009-01-01

    Varved minerogenic sediments from glacial-fed Blue Lake, northern Alaska, are used to investigate late Holocene climate variability. Varve thickness measurements track summer temperature recorded at Atigun Pass, located 41 km east at a similar elevation (r2 = 0.31, P = 0.08). Results indicate that climate in the Brooks Range from 10 to 730 AD (varve year) was warm with precipitation inferred to be higher than during the twentieth century. The varve-temperature relationship for this period was likely compromised and not used in our temperature reconstruction because the glacier was greatly reduced, or absent, exposing sub-glacial sediments to erosion from enhanced precipitation.

  8. Devonian-Mississippian carbonate sequence in the Maiyumerak Mountains, western Brooks Range, Alaska

    SciTech Connect

    Dumoulin, J.A. ); Harris, A.G. )

    1990-05-01

    Essentially continuous, dominantly carbonate sedimentation occurred from at least the Early Devonian through the Mississippian in the area that is now the Maiyumerak Mountains, western Brooks Range. This succession is in striking contrast to Paleozoic sequences in the eastern Brooks Range and in the subsurface across northern Alaska, where uppermost Devonian-Mississippian clastic and Carboniferous carbonates unconformably overlie Proterozoic or lower Paleozoic metasedimentary or sedimentary rocks. Conodonts obtained throughout the Maiyumerak Mountains sequence indicate that any hiatus is less than a stage in duration, and there is no apparent physical evidence of unconformity within the succession. The sequence is best exposed northwest of the Eli River, where Emsian-Eifelian dolostones (Baird Group) are conformably overlain by Kinderhookian-Osagian sandy limestones (Utukok Formation) and Osagian-Chesterian fossiliferous limestones (Kogruk Formation) of the Lisburne Group. Conodont species assemblages and sedimentary structures indicate deposition in a range of shallow-water shelf environments. The sequence extends at least 30 km, from the Noatak Quadrangle northeast into the Baird Mountains Quadrangle; its easternmost extent has not been definitively determined. The Ellesmerian orogeny, thought to have produced the extensive middle Paleozoic unconformity seen through much of northern Alaska apparently had little effect on this western Brooks Range sedimentary succession.

  9. Lead exposure from indoor firing ranges among students on shooting teams--Alaska, 2002-2004.

    PubMed

    2005-06-17

    CDC recognizes blood lead levels (BLLs) of >/=25 microg/dL in adults and >/=10 microg/dL in children aged Alaska Environmental Public Health Program (EPHP) conducted lead-exposure assessments of school-based indoor shooting teams in the state, after a BLL of 44 microg/dL was reported in a man aged 62 years who coached a high school shooting team in central Alaska. This report summarizes the results of the EPHP investigation of potential lead exposure in 66 members of shooting teams, aged 7-19 years, who used five indoor firing ranges. The findings suggest that improper design, operation, and maintenance of ranges were the likely cause of elevated BLLs among team members at four of the five firing ranges. Public health officials should identify indoor firing ranges that have not implemented lead-safety measures and offer consultation to reduce the risk for lead exposure among shooters, coaches, and employees.

  10. Coal resources of Alaska

    SciTech Connect

    Sanders, R.B.

    1982-01-01

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

  11. Caledonian Deformation in Polydeformed Pre-Mississippian Rocks of the Northeast Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Johnson, B. G.; Toro, J.; Benowitz, J.

    2013-12-01

    In the northeastern Brooks Range of Alaska there are polydeformed metasedimentary and metavolcanic rocks exposed below a major pre-Mississippian unconformity. Elsewhere in northern Alaska it has been challenging to correlate the tectonic fabrics of these early Paleozoic to Neoproterozoic rocks to the different orogenic events of the Arctic because of the strong overprint of Mesozoic and Tertiary Brookian deformation. However, our recent field investigations along the Kongakut and Aichiklik rivers of ANWR have identified an older (pre-Brookian) structural event based on the orientation of penetrative cleavage planes and a contrast in folding style to Brookian structures. Many of the cleavage planes are north dipping and orientated parallel to the axial planes of south-vergent folds. Although metamorphic grade is generally low, in localized areas the cleavage planes contain white micas, whose petrologic and isotopic characteristics indicate that they crystallized during fabric formation. 40Ar/39Ar dating of the white micas yield a metamorphic age of ~400 Ma (Early Devonian). This is evidence for a south-directed structural event which is contemporaneous with Caledonian deformation in East Greenland and Svalbard. Stratigraphicaly, the basement consists of a diverse package of highly deformed marine clastic sediments, and a thick section of basaltic to andesitic flows and volcaniclastic rocks, the Whale Mountain volcanics, which have a sharp southern contact but grade northward and upwards into the clastic rocks. All units are metamorphosed to lower greenschist facies. We are currently investigating the age and geochemical characteristics of the Whale Mountain volcanics to determine their tectonic affinity and role in the assemblage of the North Slope block of Northern Alaska.

  12. Alaska Library Directory, 1996.

    ERIC Educational Resources Information Center

    Jennings, Mary, Ed.

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

  13. Renewable Energy in Alaska

    SciTech Connect

    Not Available

    2013-03-01

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

  14. Alaska geothermal bibliography

    SciTech Connect

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

    1987-05-01

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

  15. Range Expansion of Moose in Arctic Alaska Linked to Warming and Increased Shrub Habitat

    PubMed Central

    Tape, Ken D.

    2016-01-01

    Twentieth century warming has increased vegetation productivity and shrub cover across northern tundra and treeline regions, but effects on terrestrial wildlife have not been demonstrated on a comparable scale. During this period, Alaskan moose (Alces alces gigas) extended their range from the boreal forest into tundra riparian shrub habitat; similar extensions have been observed in Canada (A. a. andersoni) and Eurasia (A. a. alces). Northern moose distribution is thought to be limited by forage availability above the snow in late winter, so the observed increase in shrub habitat could be causing the northward moose establishment, but a previous hypothesis suggested that hunting cessation triggered moose establishment. Here, we use recent changes in shrub cover and empirical relationships between shrub height and growing season temperature to estimate available moose habitat in Arctic Alaska c. 1860. We estimate that riparian shrubs were approximately 1.1 m tall c. 1860, greatly reducing the available forage above the snowpack, compared to 2 m tall in 2009. We believe that increases in riparian shrub habitat after 1860 allowed moose to colonize tundra regions of Alaska hundreds of kilometers north and west of previous distribution limits. The northern shift in the distribution of moose, like that of snowshoe hares, has been in response to the spread of their shrub habitat in the Arctic, but at the same time, herbivores have likely had pronounced impacts on the structure and function of these shrub communities. These northward range shifts are a bellwether for other boreal species and their associated predators. PMID:27074023

  16. Range Expansion of Moose in Arctic Alaska Linked to Warming and Increased Shrub Habitat.

    PubMed

    Tape, Ken D; Gustine, David D; Ruess, Roger W; Adams, Layne G; Clark, Jason A

    2016-01-01

    Twentieth century warming has increased vegetation productivity and shrub cover across northern tundra and treeline regions, but effects on terrestrial wildlife have not been demonstrated on a comparable scale. During this period, Alaskan moose (Alces alces gigas) extended their range from the boreal forest into tundra riparian shrub habitat; similar extensions have been observed in Canada (A. a. andersoni) and Eurasia (A. a. alces). Northern moose distribution is thought to be limited by forage availability above the snow in late winter, so the observed increase in shrub habitat could be causing the northward moose establishment, but a previous hypothesis suggested that hunting cessation triggered moose establishment. Here, we use recent changes in shrub cover and empirical relationships between shrub height and growing season temperature to estimate available moose habitat in Arctic Alaska c. 1860. We estimate that riparian shrubs were approximately 1.1 m tall c. 1860, greatly reducing the available forage above the snowpack, compared to 2 m tall in 2009. We believe that increases in riparian shrub habitat after 1860 allowed moose to colonize tundra regions of Alaska hundreds of kilometers north and west of previous distribution limits. The northern shift in the distribution of moose, like that of snowshoe hares, has been in response to the spread of their shrub habitat in the Arctic, but at the same time, herbivores have likely had pronounced impacts on the structure and function of these shrub communities. These northward range shifts are a bellwether for other boreal species and their associated predators.

  17. Chronology of ophiolite crystallization, detachment, and emplacement: Evidence from the Brooks Range, Alaska

    SciTech Connect

    Wirth, K.R.; Bird, J.M. )

    1992-01-01

    {sup 40}Ar/{sup 39}Ar data from early Middle Jurassic ophiolites (187-184 Ma) in the western Brooks Range, Alaska, indicate that detachment - related metamorphism occurred {approximately}20 m.y. after crystallization and {approximately}20 m.y. before emplacement onto the Arctic Alaska margin. High-temperature metamorphic rocks along the basal surfaces of many ophiolites have ages that are contemporaneous with ophiolite crystallization, suggesting that detachment and thrust faulting occur while the lithosphere is young ({lt}10 Ma) and relatively hot. From these relations it has been generally assumed that detachment and initial overthrusting of oceanic lithosphere occur near the site of generation, such as a marginal basin or mid-ocean ridge. The new data from the Brooks Range ophiolites confirm previous indications that some ophiolites have much longer intervals between crystallization, thrust-related metamorphism, and emplacement. On the basis of these new results and data from other ophiolites, the authors propose that ophiolites originating within large ocean basins will generally have longer crystallization-to-emplacement intervals than the more commonly recognized marginal basin-type ophiolites.

  18. Range Expansion of Moose in Arctic Alaska Linked to Warming and Increased Shrub Habitat.

    PubMed

    Tape, Ken D; Gustine, David D; Ruess, Roger W; Adams, Layne G; Clark, Jason A

    2016-01-01

    Twentieth century warming has increased vegetation productivity and shrub cover across northern tundra and treeline regions, but effects on terrestrial wildlife have not been demonstrated on a comparable scale. During this period, Alaskan moose (Alces alces gigas) extended their range from the boreal forest into tundra riparian shrub habitat; similar extensions have been observed in Canada (A. a. andersoni) and Eurasia (A. a. alces). Northern moose distribution is thought to be limited by forage availability above the snow in late winter, so the observed increase in shrub habitat could be causing the northward moose establishment, but a previous hypothesis suggested that hunting cessation triggered moose establishment. Here, we use recent changes in shrub cover and empirical relationships between shrub height and growing season temperature to estimate available moose habitat in Arctic Alaska c. 1860. We estimate that riparian shrubs were approximately 1.1 m tall c. 1860, greatly reducing the available forage above the snowpack, compared to 2 m tall in 2009. We believe that increases in riparian shrub habitat after 1860 allowed moose to colonize tundra regions of Alaska hundreds of kilometers north and west of previous distribution limits. The northern shift in the distribution of moose, like that of snowshoe hares, has been in response to the spread of their shrub habitat in the Arctic, but at the same time, herbivores have likely had pronounced impacts on the structure and function of these shrub communities. These northward range shifts are a bellwether for other boreal species and their associated predators. PMID:27074023

  19. Neogene exhumation in the eastern Alaska Range and its relationship to splay fault activity in the Denali fault system

    NASA Astrophysics Data System (ADS)

    Waldien, T.; Roeske, S.; Benowitz, J.; Allen, W. K.; Ridgway, K.

    2015-12-01

    Dextral oblique convergence in the Denali fault system results from subduction zone strain in the Alaska syntaxis that is partitioned into the upper plate. This convergence is accommodated by dextral-reverse oblique slip on segments of the main strand of the Denali fault in the center of the Alaska Range and by splay faults north and south of the Denali fault at the margins of the Alaska Range. Low-temp. thermochronometry applied to basement rocks bounded by faults within the Denali fault system aids stratigraphic data to determine the timing and locations of exhumation in the Alaska Range, which augment regional seismicity studies aimed at resolving modern fault activity in the Denali fault system. The McCallum Creek and Broxson Gulch faults are north-dipping faults that splay southward from the Denali fault near the Delta River and mark the southern margin of the eastern Alaska Range. Apatite fission track thermochronometry on rocks north of the McCallum Creek fault shows rapid cooling in the hanging wall coeval with basin development in the footwall initiating at the Miocene-Pliocene boundary. Apatite fission track and apatite (U-Th)/He ages from plutonic rocks in the hanging wall of the Broxson Gulch fault, west of the McCallum Creek fault, show final cooling in the Miocene, slightly younger than hanging wall cooling associated with the Susitna Glacier thrust further to the west. Neogene low-temp. cooling ages in the hanging walls of the Susitna Glacier thrust, Broxson Gulch, and McCallum Creek faults suggest that these structures have been accommodating convergence in the Denali fault system throughout the Neogene. More recent cooling in the hanging wall of the McCallum Creek compared to the Susitna Glacier thrust suggests that this fault-related exhumation has migrated eastward throughout the Neogene. Convergence on these splay faults south of the Denali fault results in internal contraction of the crust south of the Denali fault, implying that the Southern

  20. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  1. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  2. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  3. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  4. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force....

  5. Reindeer range inventory in western Alaska from computer-aided digital classification of LANDSAT data

    NASA Technical Reports Server (NTRS)

    George, T. H.; Stringer, W. J.; Baldridge, J. N.

    1977-01-01

    An inventory of reindeer-range resources was conducted for the USDA Soil Conservation Service of 1.6 million hectares of wildlands in western Alaska using clustering techniques with digital Landsat data. Computer-aided digital analysis produced a provisional map of rangeland types which was used to design the field collection of vegetation and soil types data. This field data facilitated refinement of the inventory map and was used to describe the map units. The informational classes important to range resources were wet, moist and alpine tundra, tidal marsh, brush and open spruce forest. A significant feature of the study was the extraction of acreage figures by administrative boundaries within the study area. In addition to soil and vegetation association map products (at scales of 1:250,000 and 1:63,360) acreage values were tallied from the digital data for each of the four grazing permit areas established by the Bureau of Land Management.

  6. Upper triassic continental margin strata of the central alaska range: Implications for paleogeographic reconstruction

    USGS Publications Warehouse

    Till, A.B.; Harris, A.G.; Wardlaw, B.R.; Mullen, M.

    2007-01-01

    Reexamination of existing conodont collections from the central Alaska Range indicates that Upper Triassic marine slope and basin rocks range in age from at least as old as the late Carnian to the early middle Norian. The conodont assemblages typical of these rocks are generally cosmopolitan and do not define a distinct paleogeographic faunal realm. One collection, however, containsEpigondolella multidentata sensu Orchard 1991c, which appears to be restricted to western North American autochthonous rocks. Although paleogeographic relations cannot be determined with specificity, the present distribution of biofaces within the Upper Triassic sequence could not have been the result of simple accordion-style collapse of the Late Triassic margin.

  7. Alaska marine ice atlas

    SciTech Connect

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

    1982-01-01

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

  8. Libraries in Alaska: MedlinePlus

    MedlinePlus

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

  9. 75 FR 53331 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... Interest to Hadohdleekaga, Incorporated, for the Native village of Hughes, Alaska, pursuant to the Alaska... Hughes, Alaska, and are located in: Kateel River Meridian, Alaska T. 9 N., R. 23 E., Sec. 5....

  10. Alaska telemedicine: growth through collaboration.

    PubMed

    Patricoski, Chris

    2004-12-01

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

  11. Zoned Cr, Fe-spinel from the La Perouse layered gabbro, Fairweather Range, Alaska

    USGS Publications Warehouse

    Czamanske, G.K.; Himmelberg, G.R.; Goff, F.E.

    1976-01-01

    Zoned spinel of unusual composition and morphology has been found in massive pyrrhotite-chalcopyrite-pent-landite ore from the La Perouse layered gabbro intrusion in the Fairweather Range, southeastern Alaska. The spinel grains show continuous zoning from cores with up to 53 wt.% Cr2O3 to rims with less than 11 wt.% Cr2O3. Their composition is exceptional because they contain less than 0.32 wt.% MgO and less than 0.10 wt.% Al2O3 and TiO2. Also notable are the concentrations of MnO and V2O3, which reach 4.73 and 4.50 wt.%, respectively, in the cores. The spinel is thought to have crystallized at low oxygen fugacity and at temperatures above 900??C, directly from a sulfide melt that separated by immiscibility from the gabbroic parental magma. ?? 1976.

  12. Alaska: A frontier divided

    SciTech Connect

    O'Dell, R. )

    1986-09-01

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

  13. Range expansion of moose in arctic Alaska linked to warming and increased shrub habitat

    USGS Publications Warehouse

    Tape, Ken D.; Gustine, David D.; Reuss, Roger W.; Adams, Layne G.; Clark, Jason A.

    2016-01-01

    Twentieth century warming has increased vegetation productivity and shrub cover across northern tundra and treeline regions, but effects on terrestrial wildlife have not been demonstrated on a comparable scale. During this period, Alaskan moose (Alces alces gigas) extended their range from the boreal forest into tundra riparian shrub habitat; similar extensions have been observed in Canada (A. a. andersoni) and Eurasia (A. a. alces). Northern moose distribution is thought to be limited by forage availability above the snow in late winter, so the observed increase in shrub habitat could be causing the northward moose establishment, but a previous hypothesis suggested that hunting cessation triggered moose establishment. Here, we use recent changes in shrub cover and empirical relationships between shrub height and growing season temperature to estimate available moose habitat in Arctic Alaska c. 1860. We estimate that riparian shrubs were approximately 1.1 m tall c. 1860, greatly reducing the available forage above the snowpack, compared to 2 m tall in 2009. We believe that increases in riparian shrub habitat after 1860 allowed moose to colonize tundra regions of Alaska hundreds of kilometers north and west of previous distribution limits. The northern shift in the distribution of moose, like that of snowshoe hares, has been in response to the spread of their shrub habitat in the Arctic, but at the same time, herbivores have likely had pronounced impacts on the structure and function of these shrub communities. These northward range shifts are a bellwether for other boreal species and their associated predators.

  14. Changing exhumation patterns during Cenozoic growth and glaciation of the Alaska Range: Insights from detrital thermochronology and geochronology

    NASA Astrophysics Data System (ADS)

    Lease, Richard O.; Haeussler, Peter J.; O'Sullivan, Paul

    2016-04-01

    Cenozoic growth of the Alaska Range created the highest topography in North America, but the space-time pattern and drivers of exhumation are poorly constrained. We analyzed U/Pb and fission-track double dates of detrital zircon and apatite grains from 12 catchments that span a 450 km length of the Alaska Range to illuminate the timing and extent of exhumation during different periods. U/Pb ages indicate a dominant Late Cretaceous to Oligocene plutonic provenance for the detrital grains, with only a small percentage of grains recycled from the Mesozoic and Paleozoic sedimentary cover. Fission-track ages record exhumation during Alaska Range growth and incision and reveal three distinctive patterns. First, initial Oligocene exhumation was focused in the central Alaska Range at ~30 Ma and expanded outward along the entire length of the range until 18 Ma. Oligocene exhumation, coeval with initial Yakutat microplate collision >600 km to the southeast, suggests a far-field response to collision that was localized by the Denali Fault within a weak Mesozoic suture zone. Second, the variable timing of middle to late Miocene exhumation suggests independently evolving histories influenced by local structures. Time-transgressive cooling ages suggest successive rock uplift and erosion of Mounts Foraker (12 Ma) through Denali (6 Ma) as crust was advected through a restraining bend in the Denali Fault and indicate a long-term slip rate ~4 mm/yr. Third, Pliocene exhumation is synchronous (3.7-2.7 Ma) along the length of the Alaska Range but only occurs in high-relief, glacier-covered catchments. Pliocene exhumation may record an acceleration in glacial incision that was coincident with the onset of Northern Hemisphere glaciation.

  15. Alaska looks HOT!

    SciTech Connect

    Belcher, J.

    1997-07-01

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

  16. Geologic strip map along the Hines Creek Fault showing evidence for Cenozoic displacement in the western Mount Hayes and northeastern Healy quadrangles, eastern Alaska Range, Alaska

    USGS Publications Warehouse

    Nokleberg, Warren J.; Aleinikoff, John N.; Bundtzen, Thomas K.; Hanshaw, Maiana N.

    2013-01-01

    Geologic mapping of the Hines Creek Fault and the adjacent Trident Glacier and McGinnis Glacier Faults to the north in the eastern Alaska Range, Alaska, reveals that these faults were active during the Cenozoic. Previously, the Hines Creek Fault, which is considered to be part of the strike-slip Denali Fault system (Ridgway and others, 2002; Nokleberg and Richter, 2007), was interpreted to have been welded shut during the intrusion of the Upper Cretaceous Buchanan Creek pluton (Wahrhaftig and others, 1975; Gilbert, 1977; Sherwood and Craddock, 1979; Csejtey and others, 1992). Our geologic mapping along the west- to west-northwest-striking Hines Creek Fault in the northeastern Healy quadrangle and central to northwestern Mount Hayes quadrangle reveals that (1) the Buchanan Creek pluton is truncated by the Hines Creek Fault and (2) a tectonic collage of fault-bounded slices of various granitic plutons, metagabbro, metabasalt, and sedimentary rock of the Pingston terrane occurs south of the Hines Creek Fault.

  17. Alaska Resource Data File: Chignik quadrangle, Alaska

    USGS Publications Warehouse

    Pilcher, Steven H.

    2000-01-01

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

  18. A comprehensive inventory of the Gulf of Alaska sponge fauna with the description of two new species and geographic range extensions.

    PubMed

    Lehnert, Helmut; Stone, Robert P

    2016-01-01

    Two new species, Hamacantha (Vomerula) cassanoi n. sp. and Prosuberites salgadoi n. sp., are described from the eastern Gulf of Alaska in the North Pacific Ocean. These are the first records of the genera Hamacantha and Prosuberites from Alaska. We also report two geographic range extensions for the region. Geodia japonica Sollas, 1888 was previously known only from Japan and is now recorded from the Gulf of Alaska. We also document the first record of Rhizaxinella cervicornis Thiele, 1898 from the Gulf of Alaska. Our comprehensive inventory of the sponge fauna of the Gulf of Alaska confirms the presence of 52 taxa with an additional 38 taxa suspected of occurring in the region. This is a much lower number of species than that recorded from neighbouring regions like the Aleutian Islands and British Columbia. PMID:27470862

  19. Origin of narrow terranes and adjacent major terranes occurring along the denali fault in the eastern and central alaska range, alaska

    USGS Publications Warehouse

    Nokleberg, W.J.; Richter, D.H.

    2007-01-01

    Several narrow terranes occur along the Denali fault in the Eastern and Central Alaska Range in Southern Alaska. These terranes are the Aurora Peak, Cottonwood Creek, Maclaren, Pingston, and Windy terranes, and a terrane of ultramafic and associated rocks. Exterior to the narrow terranes to the south is the majorWrangellia island arc composite terrane, and to the north is the major Yukon Tanana metamorphosed continental margin terrane. Overlying mainly the northern margin of the Wrangellia composite terrane are the Kahiltna overlap assemblage to the west, and the Gravina- Nutzotin-Gambier volcanic-plutonic- sedimentary belt to the east and southeast. The various narrow terranes are interpreted as the result of translation of fragments of larger terranes during two major tectonic events: (1) Late Jurassic to mid-Cretaceous accretion of the Wrangellia island arc composite terrane (or superterrane composed of the Wrangellia, Peninsular, and Alexander terranes) and associated subduction zone complexes; and (2) starting in about the Late Cretaceous, dextral transport of the Wrangellia composite terrane along the Denali fault. These two major tectonic events caused: (1) entrapment of a lens of oceanic lithosphere along the suture belt between the Wrangellia composite terrane and the North American Craton Margin and outboard accreted terranes to form the ultramafic and mafic part of the terrane of ultramafic and associated rocks, (2) subsequent dextral translation along the Denali fault of the terrane of ultramafic and associated rocks, (3) dextral translation along the Denali fault of the Aurora Peak, Cottonwood Creek, and Maclaren and continental margin arc terranes from part of the Coast plutonic-metamorphic complex (Coast-North Cascade plutonic belt) in the southwest Yukon Territory or Southeastern Alaska, (4) dextral translation along the Denali fault of the Pingston passive continental margin from a locus along the North American Continental Margin, and (5

  20. Quantifying the spatial distribution of rapid exhumation from glacial detritus, St. Elias Range (Alaska)

    NASA Astrophysics Data System (ADS)

    Grabowski, D.; Enkelmann, E.; Ehlers, T. A.

    2012-04-01

    We present a provenance analysis, zircon (U-Th)/He thermochronometer cooling ages, and petrologic characterization of exhumation processes active under the Malaspina Glacier, St. Elias Range, Alaska. The collision of the Yakutat Terrane with North America formed the St. Elias Range in southeast Alaska. This region is subject to active faulting, high seismicity, and intense glacial erosion. Recent thermochronology studies document rapid rock exhumation at the Yakutat corner where strike-slip deformation transitions to convergence. Published detrital zircon fission track ages from sand samples of the Seward - Malaspina Glacier yielded a young age population of 2 Ma, suggesting a region of rapid exhumation somewhere in the glacier drainage basin. However, the glaciers cover the area and prevent direct observation and sampling, thereby inhibiting detailed bedrock exhumation studies of the Yakutat corner region. We investigate the lithologies of the bedrock at the Yakutat corner to quantify patterns of rock exhumation using clasts collected from the toe of the Malaspina Glacier. Seven different locations 50 km around the glacier were sampled and lithologies characterized by point counting in the field. In total, 1998 clasts were analyzed. We identified six main lithological groups that are assignable to specific geological units. Most of the detritus is gneiss and granulite (26%), micashist and phyllite (26%), and granite (11%) and are typical lithologies of the Chugach Terrane located at the southern margin of the North American plate. Mafic rocks of amphibolite, gabbro, and basalts (21%), and metapelite, sandstone, quartzite and breccia (14%) were also present and are typical for the colliding Yakutat Terrane. Two percent of the clasts are tightly foliated and mylonitic. These clasts are inferred to originate from the Contact Fault, an old suture zone that has been reactivated during Yakutat Terrane collision. Individual clasts from each sample locality and from all

  1. Magmatic responses to Late Cretaceous through Oligocene tectonic evolution of the western Alaska Range

    NASA Astrophysics Data System (ADS)

    Todd, E.; Jones, J. V., III; Karl, S.; Ayuso, R. A.; Bradley, D. C.; Box, S. E.; Haeussler, P. J.

    2014-12-01

    New geochemistry, U/Pb geochronology, and radiogenic isotopes, together with existing datasets, contribute to a refined model of the petrogenetic history of magmatism in the western Alaska Range. Plutons within the study area were emplaced into Kahiltna basin Mesozoic turbiditic strata. The Kahiltna sequence overlies Mesozoic Peninsular oceanic terrane rocks in the SE half of the basin and Proterozoic to Paleozoic Farewell continental terrane rocks to the NW. This study focuses on successive intrusion suites, most of which are thought to intrude Kahiltna or underlying Farewell terrane rocks, but include older, perhaps more deeply exhumed rocks emplaced in Peninsular terrane basement to the SE. The chemically diverse sequence records magmatism associated with major tectonic reorganization events on the southern Alaska circum-Pacific subduction margin. The oldest pluton suite (~100-80 Ma) is mostly intermediate to evolved calcalkaline granite and coincides with final closure of the Kahiltna basin and a regional transition to transpression-dominated tectonics. The post-closure magmatic pulse (~75-67 Ma) is compositionally varied, including primitive subalkaline melts, peraluminous high-K granites, and a subset of sodic, adakite-like granites. A Paleocene (~63-57 Ma) magmatic flare-up follows, dominated by extremely fractionated subalkaline melts. Rare, more primitive melts of this suite are metaluminous, from gabbro to syenite. This stage may represent relaxed melt productivity or shallowing of the slab dip, yielding more laterally diffuse melting. An early Eocene magmatic hiatus precedes middle Eocene circum-Pacific tectonic reorganization, regionally resulting in initiation of proto-Aleutian/Meshik arc magmatism, and locally in the 44-37 Ma emplacement of subalkaline intermediate to felsic plutons associated with andesite to rhyolite volcanic deposits. An Oligocene (~31-25 Ma) magmatic pulse involved emplacement of a compositionally variable suite ranging from

  2. Middle Jurassic U-Pb crystallization age for Siniktanneyak Mountain ophiolite, Brooks Range, Alaska

    SciTech Connect

    Moore, T.E. ); Aleinikoff, J.N.; Walter, M. )

    1993-04-01

    The authors report here a U-Pb age for the Siniktanneyak Mountain Ophiolite klippe in the west-central Brooks Range, the first U-Pb ophiolite age in northern Alaska. Like klippen of mafic and ultramafic rocks in the Brooks Range, the Siniktanneyak Mountain klippe is composed of a lower allochthon of Devonian and younger( ) diabase and metabasalt with trace-element characteristics of seamount basalts and an upper allochthon of ophiolite. The ophiolite is partial, consisting of (1) abundant dunite and subordinate harzburgite and wehrlite; (2) cumulate clinopyroxene gabbro, and (3) minor noncumulate clinopyroxene gabbro and subordinate plagiogranite; no sheeted dikes or volcanic rocks are known in the ophilitic allochthon. The plagiogranite forms small dikes and stocks that intrude the noncumulate gabbro and consists of zoned Na-rich plagioclase + clinopyroxene with interstial quartz and biotite. Five fractions of subhedral, tan zircon from the plagiogranite yield slightly discordant U-Pb data with an upper intercept age of 170 [+-] 3 Ma. The U-Pb data indicate that the Siniktanneyak Mountain ophiolite crystallized in the Middle Jurassic and was emplaced by thrusting onto mafic accretionary prism rocks within about 10 m.y. of crystallization. The U-Pb data provide an upper limit to the age of initiation of the Brookian orogeny.

  3. Accretion of southern Alaska

    USGS Publications Warehouse

    Hillhouse, J.W.

    1987-01-01

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

  4. USGS Alaska State Mosaic

    USGS Publications Warehouse

    ,

    2008-01-01

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

  5. Petroleum source potential and thermal maturity of Cantwell Formation (Paleocene), central Alaska Range: a reconnaissance study

    SciTech Connect

    Stanley, R.G.

    1987-05-01

    The Paleocene Cantwell Formation is a sequence of nonmarine sedimentary and volcanic rocks that is widely distributed in the central Alaska Range and locally is more than 3000 m thick. Mudstones and coals in the Cantwell were deposited in a variety of lacustrine and fluvial overbank environments and are of interest as potential source rocks of petroleum. Thirty-eight samples of mudstone and coal were collected from ten outcrops and analyzed using Rock-Eval pyrolysis, vitrinite reflectance (R/sub 0/), and thermal alteration index (TAI). The results suggest that these rocks may be potential sources of gas and possibly oil. Total organic carbon (TOC) in the samples is relatively high, averaging about 2.8% (range 0.5-14.2%) in the mudstones and about 28.8% (range 5.1-50.2%) in the coals. Plots of hydrogen and oxygen indices (HI and OI) on modified van Krevelen diagrams indicate kerogens of types III and IV. In addition, HI values are generally less than 150 and S2/S3 values are generally less than 3, indicating that these kerogens are gas prone. A few samples exhibit somewhat higher values of HI (up to 170) and S2/S3 (up to 18.6) and therefore may be capable of generating small amounts of oil. Values of T/sub max/ (range 437-537/sup 0/C), median R/sub 0/ (range 0.63-4.28), and TAI (range 2.3.-3.8) show that the thermal maturity of the samples varies from mature to postmature with respect to the oil and gas windows.

  6. Alaska volcanoes guidebook for teachers

    USGS Publications Warehouse

    Adleman, Jennifer N.

    2011-01-01

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

  7. Crustal structure of the alaska range orogen and denali fault along the richardson highway

    USGS Publications Warehouse

    Fisher, M.A.; Pellerin, L.; Nokleberg, W.J.; Ratchkovski, N.A.; Glen, J.M.G.

    2007-01-01

    A suite of geophysical data obtained along the Richardson Highway crosses the eastern Alaska Range and Denali fault and reveals the crustal structure of the orogen. Strong seismic reflections from within the orogen north of the Denali fault dip as steeply as 25?? north and extend downward to depths between 20 and 25 km. These reflections reveal what is probably a shear zone that transects most of the crust and is part of a crustal-scale duplex structure that probably formed during the Late Cretaceous. These structures, however, appear to be relict because over the past 20 years, they have produced little or no seismicity despite the nearby Mw = 7.9 Denali fault earthquake that struck in 2002. The Denali fault is nonreflective, but we interpret modeled magnetotelluric (MT), gravity, and magnetic data to propose that the fault dips steeply to vertically. Modeling of MT data shows that aftershocks of the 2002 Denali fault earthquake occurred above a rock body that has low electrical resistivity (>10 ohm-m), which might signify the presence of fluids in the middle and lower crust. Copyright ?? 2007 The Geological Society of America.

  8. Permian deposition in the north central Brooks Range, Alaska Constraints for tectonic reconstructions

    USGS Publications Warehouse

    Adams, K.E.; Mull, C.G.; Crowder, R.K.

    1997-01-01

    Two opposing tectonic models have been offered to explain the regional structural relations in the north central Brooks Range fold-thrust belt of northern Alaska. The first suggests that rocks of the northern Endicott Mountains were thrust from south to north over the area of the present Mount Doonerak high and are therefore highly allochthonous. The second implies that the rocks of the northern Endicott Mountains were deposited in a basin that lay north of the Mount Doonerak high and later were thrust a short distance southward onto the northern flank of the high and are thus parautochthonous. To provide stratigraphic constraints for these models, this study examines Permian facies of the north central Brooks Range. Permian rocks in the north central Brooks Range comprise a thin (40 to 160 m thick), fining-upward succession of clastic, storm-influenced shelf deposits. When the rocks of the northern Endicott Mountains are restored south of the Mount Doonerak area, a minimum distance of 80 km, the Permian deposits grade systematically from distal facies (Siksikpuk Formation) in the southwest to proximal facies (Echooka Formation) in the northeast. Facies trends in the reconstructed Permian basin include, from southwest to northeast, (1) an increase in carbonate content and corresponding decrease in silica content, (2) a general darkening and thickening of shaley intervals, (3) an increase in proximal features of storm beds, including coarser, thicker, more abundant, and more closely spaced beds, and (4) an increase in abundance and diversity of the faunal assemblage with a corresponding decrease in age. These stratigraphic relations imply that rocks of the northern Endicott Mountains are allochthonous and structurally overlie a proximal stratigraphic succession similar to that exposed in the Mount Doonerak area and northeastern Brooks Range. Copyright 1997 by the American Geophysical Union.

  9. Alaska Glaciers and Rivers

    NASA Technical Reports Server (NTRS)

    2007-01-01

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

  10. Alaska Mathematics Standards

    ERIC Educational Resources Information Center

    Alaska Department of Education & Early Development, 2012

    2012-01-01

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

  11. Suicide in Northwest Alaska.

    ERIC Educational Resources Information Center

    Travis, Robert

    1983-01-01

    Between 1975 and 1979 the Alaskan Native suicide rate (90.9 per 100,000) in Northwest Alaska was more than seven times the national average. Alienation, loss of family, low income, alcohol abuse, high unemployment, and more education were factors related to suicidal behavior. Average age for suicidal behavior was 22.5. (Author/MH)

  12. Alaska's Young Entrepreneurs.

    ERIC Educational Resources Information Center

    Knapp, Marilyn R.

    1989-01-01

    Describes Edgecumbe Enterprises, a four-year-old fish exporting venture run by Mt. Edgecumbe High School in Sitka, Alaska, and the students' meeting with business leaders in Tokyo, Japan. The young entrepreneurs spent two weeks studying the Japanese marketing structure. (JOW)

  13. Seismology Outreach in Alaska

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  14. Current Ethnomusicology in Alaska.

    ERIC Educational Resources Information Center

    Johnston, Thomas F.

    The systematic study of Eskimo, Indian, and Aleut musical sound and behavior in Alaska, though conceded to be an important part of white efforts to foster understanding between different cultural groups and to maintain the native cultural heritage, has received little attention from Alaskan educators. Most existing ethnomusical studies lack one or…

  15. Alaska's Cold Desert.

    ERIC Educational Resources Information Center

    Brune, Jeff; And Others

    1996-01-01

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

  16. Venetie, Alaska energy assessment.

    SciTech Connect

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

    2013-07-01

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

  17. Neocomian source and reservoir rocks in the western Brooks Range and Arctic Slope, Alaska

    SciTech Connect

    Mull, C.G.; Reifenstuhl, R.R.; Harris, E.E.; Crowder, R.K.

    1995-04-01

    Detailed (1:63,360) mapping of the Tingmerkpuk sandstone and associated rocks in the Misheguk Mountain and DeLong Mountains guadrangles of the western Brooks Range thrust belt documents potential hydrocarbon source and reservoir rocks in the northern foothills of the western Delong Mountains and adjacent Colville basin of northwest Alaska. Neocomian (?) to Albian micaceous shale, litharenite, and graywacke that overlies the Tingmerkpuk represents the onset of deposition of orogenic sediments derived from the Brooks Range to the south, and the merging of northern and southern sediment sources in the Colville basin. Both the proximal and distal Tingmerkpuk facies contain clay shale interbeds and overlie the Upper Jurassic to Neocomian Kingak Shale. Preliminary geochemical data show that in the thrust belt, these shales are thermally overmature (Ro 1.4-1.6), but are good source rocks with total organic content (TOC) that ranges from 1.2 to 1.8 percent. Shale in the overlying Brookian rocks is also thermally overmature (Ro 1.2-1.5 percent), but contains up to 1.8 percent TOC from a dominantly terrigenous source, and has generated gas. In outcrops at Surprise Creek, in the foothills north of the thrust belt, the Kingak (1.9 percent TOC) and underlying Triassic Shublik Formation (4.6 percent TOC) are excellent oil source rocks with thermal maturity close to peak oil generation stage (Ro0.75-0.9 percent). These rocks have lower thermal maturity values than expected for their stratigraphic position within the deeper parts of the Colville basin and indicate anomalous burial and uplift history in parts of the basin. Preliminary apatite fission-track (AFTA) data from the thrust belt indicate a stage of rapid uplift and cooling at about 53.61 Ma.

  18. Tularemia in Alaska, 1938 - 2010

    PubMed Central

    2011-01-01

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

  19. Tularemia in Alaska, 1938 - 2010.

    PubMed

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

    2011-01-01

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

  20. Automated detection of unstable glacier flow and a spectrum of speedup behavior in the Alaska Range

    NASA Astrophysics Data System (ADS)

    Herreid, Sam; Truffer, Martin

    2016-01-01

    Surge-type glaciers are loosely defined as glaciers that experience periodic alterations between slow and fast flow regimes. Glaciers from a variety of mountain ranges around the world have been classified as surge type, yet consensus of what defines a glacier as surge type has not always been met. A common source of dispute is the lack of a succinct and globally applicable delimiter between a surging and nonsurging glacier. The attempt is often a Boolean classification; however, glacier speedup events can vary significantly with respect to event magnitude, duration, and the fraction of the glacier that participates in the speedup. For this study, we first updated the inventory of glaciers that show flow instabilities in the Alaska Range and then quantified the spectrum of speedup behavior. We developed a new method that automatically detects glaciers with flow instabilities. Our automated results show a 91% success rate when compared to direct observations of speedup events and glaciers that are suspected to display unstable flow based on surface features. Through a combination of observations from the Landsat archive and previously published data, our inventory now contains 36 glaciers that encompass at least one branch exhibiting unstable flow and we document 53 speedup events that occurred between 1936 and 2014. We then present a universal method for comparing glacier speedup events based on a normalized event magnitude metric. This method provides a consistent way to include and quantify the full spectrum of speedup events and allows for comparisons with glaciers that exhibit clear surge characteristics yet have no observed surge event to date. Our results show a continuous spectrum of speedup magnitudes, from steady flow to clearly surge type, which suggests that qualitative classifications, such as "surge-type" or "pulse-type" behavior, might be too simplistic and should be accompanied by a standardized magnitude metric.

  1. Structural geology of the Big Bend anticline, Brooks Range Foothills, Alaska

    NASA Astrophysics Data System (ADS)

    Sanders, Cheryl M.

    Big Bend anticline is near the northern edge of the Brooks Range foothills of northern Alaska. The structure of the foothills is a low-taper triangle zone or passive-roof duplex within Brooks Range foreland basin deposits. The dominant structures are detachment folds locally cut by thrust faults and Big Bend anticline is one of these. This research combines detailed surface mapping (1:25,000) with interpretation of aerial photos and satellite imagery of the Big Bend anticline and seismic reflection data from the Umiat anticline to reconstruct its surface and subsurface geometry. The research area surrounds the Big Bend of the Chandler River and covers approximately 10 km2. The mechanical stratigraphy of the area consists of the competent Nanushuk sandstones between two incompetent units-the overlying Seabee and underlying Torok shales. The structure of the area consists of an east-trending anticline with a hinge that branches westward into two open, broad anticlines and an intervening syncline. A forethrust near the southern hinge and a backthrust near the northern hinge have broken through the anticline west of the branch point. Subsurface data of Umiat anticline combined with surface projected cross sections from the study area provide an analog of the subsurface structure in the Big Bend area. These cross sections show gentle anticlines separated by flat bottomed synclines in competent Nanushuk Formation sandstone. The anticlines overly Torok Formation thickened by north vergent folds and thrust faults above a detachment zone. Collectively, these structures form a low-taper triangle zone. Cross section restoration suggests more shortening in the Torok duplex than in the overlying folds and breakthrough faults. Results of this research provide an analog for other anticlines in the region that are currently the focus of oil and gas exploration.

  2. Fracture density as a controlling factor of postglacial fluvial incision rate, Granite Range, Alaska.

    NASA Astrophysics Data System (ADS)

    Champagnac, J.-D.; Sternai, P.; Herman, F.; Guralnik, B.; Beaud, F.

    2012-04-01

    The relations between lithosphere and atmosphere to shape the landscape are disputed since the last two decades. The classical "chicken or egg" problem raised the idea that erosion can promote creation of topography thanks to isostatic compensation of eroded material and subsequent positive feedback. Quaternary glaciations and high erosion rates are supposed to be the main agent of such process. More recently, "tectonic activity" has been considered not only as a rock uplift agent, but also as a rock crusher, that in turn promote erosion, thanks to the reduction of size of individual rock elements, more easily transported. The Granite Range in Alaska presents a contrasted morphology: its western part shows preserved glacial landscape, whereas its eastern part presents a strong fluvial / hillslope imprint, and only a few relicts of glacial surfaces. We quantify these differences by 1) qualitative appreciation of the landscape, 2) quantification of post-glacial erosion, and 3) hypsometric quantification of the landscape. On the field, the eastern part appears to be highly fractured, with many, large, penetrative faults, associated with km-thick fault gouges and cataclasites. The westernmost part shows massive bedrock, with minor, localised faults. Remote-sensed fracture mapping confirms this: fracture density is much higher to the east, where hypsometric parameters (HI and HIP) display anomalies, and where high post-glacial incision (up to 600m) is observed. We provide here an impressive case study for tectonic-erosion interactions through rock crushing effect, and document that half of the sediments coming out of the range come from the ~10% of the most fractured area, all other being equal. This challenges the usual view of tectonic "driving" rock uplift, while erosion removes material: In our case, tectonics is the main erosional agent, rivers and glaciers being (efficient) transport agents.

  3. Permian and Triassic sedimentation in the northeastern Brooks Range, Alaska: Deposition of the Sadlerochit Group: Reply

    SciTech Connect

    Crowder, R.K. )

    1991-12-01

    This paper was written in defense of this authors previous paper on the Ledge Sandstone member of the Ivishak Formation, Arctic National Wildlife Refuge, Alaska. This author has previously written a paper (Crowder, 1990) which discussed the depositional environments and sedimentation of these reservoir-quality sandstones and conglomerates, and developed a geologic model for source materials and deposition. As a response to this paper, another author (McMillen, 1991) questioned numerous conclusions reached by this author. The former author cited the lack of use of paleocurrent information to determine source areas and the misinterpretation of sandstone body geometry. Both papers and rebuttals have been individually entered into the data base.

  4. Asthma and American Indians/Alaska Natives

    MedlinePlus

    ... Minority Population Profiles > American Indian/Alaska Native > Asthma Asthma and American Indians/Alaska Natives In 2014, 218, ... Native American adults reported that they currently have asthma. American Indian/Alaska Native children are 30% more ...

  5. Conodont biostratigraphy and biofacies of the Wahoo Limestone (Carboniferous), Sadlerochit Mountains, northeast Brooks Range, Alaska

    SciTech Connect

    Krumhardt, A.P. ); Harris, A.G. )

    1990-05-01

    The Wahoo Limestone forms the upper part of the Lisburne Group (Carboniferous) in the Sadlerochit Mountains. The Lisburne Group is a thick (> 600 m) sequence of platform carbonate rocks that extends across the Brooks Range of northern Alaska and beneath the North Slope. At Prudhoe Bay, the Lisburne Group forms a major hydrocarbon reservoir. In the easternmost Sadlerochit Mountains, the Wahool Limestone is divisible into informal lower (64 m) and upper (192 m) members. The basal 46 m is chiefly bryozoan and pelmatozoan packstone that formed on a relatively shallow platform during the latest Mississippian lower muricatus subzone (as shown by the occurrence of the zonal index with representatives of Cavusgnathus). Cavusgnathus is dominant in this part of the section and occurs with representatives of Kladognathus, Ghathodus, Adetognathus, Hindeodus, and Rhachistognathus (in order of decreasing abundance). Declinognathodus noduliferus, the index for the base of the Pennsylvanian, first occurs at 49 m above the base of the Wahoo and 1 m above a discontinuity surface that marks the Mississippian-Pennsylvanian boundary. The unconformity represents the highest conodont subzone of the Mississippian and probably part of the earliest Pennsylvanian. Previously, the Mississippian-Pennsylvanian boundary was placed t the lower-upper Wahoo contact based on endothyroids; conodont data now indicate that this boundary is 15 m lower. The remaining lower Wahoo is possibly of noduliferus-primus zone age and chiefly yields, in order of decreasing abundance, species of Adetognathus, Declinognathodus, and Rhachistognathus, as well as redeposited Mississipian conodonts. The lower 15 m of the upper member of the Wahoo contains silty (5-40%) carbonate rock types that yield very few conodonts. Conodonts no older than the minutus-sinuatus zone are relatively abundant from 15 to 106 m above the base of the upper Wahoo.

  6. Frozen debris lobe morphology and movement: an overview of eight dynamic features, southern Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Darrow, Margaret M.; Gyswyt, Nora L.; Simpson, Jocelyn M.; Daanen, Ronald P.; Hubbard, Trent D.

    2016-05-01

    Frozen debris lobes (FDLs) are elongated, lobate permafrost features that mostly move through shear in zones near their bases. We present a comprehensive overview of eight FDLs within the Dalton Highway corridor (southern Brooks Range, Alaska), including their catchment geology and rock strengths, lobe soil characteristics, surface movement measurements collected between 2012 and 2015, and analysis of historic and modern imagery from 1955 to 2014. Field mapping and rock strength data indicate that the metasedimentary and metavolcanic bedrock forming the majority of the lobe catchments has very low to medium strength and is heavily fractured, thus easily contributing to FDL formation. The eight investigated FDLs consist of platy rocks typical of their catchments, organic debris, and an ice-poor soil matrix; massive ice, however, is present within FDLs as infiltration ice, concentrated within cracks open to the surface. Exposure of infiltration ice in retrogressive thaw slumps (RTSs) and associated debris flows leads to increased movement and various stages of destabilization, resulting in morphological differences among the lobes. Analysis of historic imagery indicates that movement of the eight investigated FDLs has been asynchronous over the study period, and since 1955, there has been an overall increase in movement rates of the investigated FDLs. The formation of surface features, such as cracks, scarps, and RTSs, suggests that the increased movement rates correlate to general instability, and even at their current distances, FDLs are impacting infrastructure through increased sediment mobilization. FDL-A is the largest of the investigated FDLs. As of August 2015, FDL-A was 39.2 m from the toe of the Dalton Highway embankment. Based on its current distance and rate of movement, we predict that FDL-A will reach the Dalton Highway alignment by 2023.

  7. Educating medical students for Alaska.

    PubMed

    Fortuine, R; Dimino, M J

    1998-01-01

    Because Alaska does not have its own medical school, it has become part of WAMI (Washington, Alaska, Montana, Idaho), an educational agreement with the University of Washington School of Medicine (UWSM). Each year, 10 Alaskans are accepted into the entering class of UWSM and spend their first year at the University of Alaska Anchorage (UAA). UWSM third- and fourth-year medical students can obtain some of their clinical experience in Alaska. To meet the needs of Alaska, students are chosen based on academic and personal records, as well as the likelihood of their returning to Alaska for practice. To this end, over the last seven years 30% of accepted students have come from rural communities and 10% are Alaska Natives. The curriculum for the first year includes several sessions dedicated to Alaska health problems, cross-cultural issues, and Alaska's unique rural health care delivery system. Students do two preceptorships--one with a private primary care physician and one with a physician at the Alaska Native Medical Center. Additionally, students have the option to spend a week at a rural site to learn about the community's health care system. An Alaska track is being developed whereby an Alaskan UWSM student can do most of the third year in state via clerkships in family medicine, obstetrics/gynecology, psychiatry, internal medicine, and pediatrics. All UWSM students at the end of their first year can elect to participate for one month in the R/UOP (Rural/Underserved Opportunities Program), which includes several Alaska sites. The overall goals of these approaches are to educate UWSM students, especially Alaskans, about the state's health needs and health care system and to encourage UWSM graduates to practice in the state.

  8. A serologic survey for antibodies to three canine viruses in wolverines (Gulo gulo) from the Brooks Range, Alaska.

    PubMed

    Dalerum, Fredrik; Shults, Brad; Kunkel, Kyran

    2005-10-01

    Canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), and canine adenovirus type 1 (CAV-1) are pathogens that are typically associated with canids but may cause serious disease in a wide range of other carnivores. From 1998 to 2002, serum samples from 64 wolverines (Gulo gulo) from the Brooks Range, Alaska, were tested for antibodies to CDV, CPV-2, and canine adenovirus (CAV). Four animals tested positive for antibodies to CDV (7%), one for antibodies to CPV-2 (2%), and none for antibodies to CAV. These are similar to antibody prevalence estimates for other large and medium carnivores in North America. PMID:16456170

  9. Spectral Characteristics of Vegetation Functional Traits across a Range of Thaw Gradients on Alaska's Seward Peninsula

    NASA Astrophysics Data System (ADS)

    Goswami, S.; Hayes, D. J.; Sloan, V. L.; Liebig, J. A.; Norby, R. J.; Wullschleger, S. D.

    2014-12-01

    The Arctic and Boreal regions are warming rapidly, leading to the thawing of the underlying permafrost and associated changes in vegetation structure and composition. The thawing of ice-rich permafrost drives land surface dynamics called thermokarst, characterized by a variety of geomorphic surface features across high latitude landscapes. The development of these thermokarst or thermo-erosional features depends on factors such as local permafrost conditions, hydrology, geomorphology, vegetation, and climate, but their degree of dependence are not well understood across scales. The structure, functions and traits of the vegetation can work as effective indicators of these landscape changes. Our ability to characterize these vegetation characteristics across a wide range of thaw gradients at the local scale could help us to better understand the dependency as well as the impacts of thermokarst processes on them. This will also help us to develop capabilities to quantify these characteristics and dependencies from local to regional scales by using remote sensing and ecosystem modeling techniques. During the months of June - July of 2013 and 2014, we conducted field surveys at various sites across the central Seward Peninsula in Alaska covering a range of thaw gradients to collect data for vegetation functional traits, ancillary data and also hyperspectral data in the 400-2500 nm range using a field spectrometer. Data were collected from plots established along 50 m transects to capture transitional states of these thaw features from the upland zone, transition zone, and thaw lake basins as well as in polygonal features. Here we discuss the characteristics of vegetation functional traits and how they relate to the ground-based spectral measurements. Some of these findings could be scaled up using airborne and satellite remote sensing data. The findings from this study can improve our understanding of disturbance patterns and their feedbacks to local scale plant and

  10. Significant Alaska minerals

    SciTech Connect

    Robinson, M.S.; Bundtzen, T.K.

    1982-01-01

    Alaska ranks in the top four states in gold production. About 30.5 million troy oz have been produced from lode and placer deposits. Until 1930, Alaska was among the top 10 states in copper production; in 1981, Kennecott Copper Company had prospects of metal worth at least $7 billion. More than 85% of the 20 million oz of silver derived have been byproducts of copper mining. Nearly all lead production has been as a byproduct of gold milling. Molybdenum is a future Alaskan product; in 1987 production is scheduled to be about 12% of world demand. Uranium deposits discovered in the Southeast are small but of high grade and easily accessible; farther exploration depends on improvement of a depressed market. Little has been done with Alaskan iron and zinc, although large deposits of the latter were discovered. Alaskan jade has a market among craftspeople. A map of the mining districts is included. 2 figures, 1 table.

  11. Seabirds in Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Piatt, John F.

    1995-01-01

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

  12. Aniakchak Crater, Alaska Peninsula

    USGS Publications Warehouse

    Smith, Walter R.

    1925-01-01

    The discovery of a gigantic crater northwest of Aniakchak Bay (see fig. 11) closes what had been thought to be a wide gap in the extensive series of volcanoes occurring at irregular intervals for nearly 600 miles along the axial line of the Alaska Peninsula and the Aleutian Islands. In this belt there are more active and recently active volcanoes than in all the rest of North America. Exclusive of those on the west side of Cook Inlet, which, however, belong to the same group, this belt contains at least 42 active or well-preserved volcanoes and about half as many mountains suspected or reported to be volcanoes. The locations of some of these mountains and the hot springs on the Alaska Peninsula and the Aleutian Islands are shown on a map prepared by G. A. Waring. Attention has been called to these volcanoes for nearly two centuries, but a record of their activity since the discovery of Alaska is far from being complete, and an adequate description of them as a group has never been written. Owing to their recent activity or unusual scenic beauty, some of the best known of the group are Mounts Katmai, Bogoslof, and Shishaldin, but there are many other beautiful and interesting cones and craters.

  13. Hyperspectral surveying for mineral resources in Alaska

    USGS Publications Warehouse

    Kokaly, Raymond F.; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E.

    2016-07-07

    Alaska is a major producer of base and precious metals and has a high potential for additional undiscovered mineral resources. However, discovery is hindered by Alaska’s vast size, remoteness, and rugged terrain. New methods are needed to overcome these obstacles in order to fully evaluate Alaska’s geology and mineral resource potential. Hyperspectral surveying is one method that can be used to rapidly acquire data about the distributions of surficial materials, including different types of bedrock and ground cover. In 2014, the U.S. Geological Survey began the Alaska Hyperspectral Project to assess the applicability of this method in Alaska. The primary study area is a remote part of the eastern Alaska Range where porphyry deposits are exposed. In collaboration with the Alaska Division of Geological and Geophysical Surveys, the University of Alaska Fairbanks, and the National Park Service, the U.S. Geological Survey is collecting and analyzing hyperspectral data with the goals of enhancing geologic mapping and developing methods to identify and characterize mineral deposits elsewhere in Alaska.

  14. Mafic and ultramafic rocks of the northwestern Brooks Range of Alaska produce nearly symmetric gravity anomalies

    SciTech Connect

    Morin, R.L. )

    1993-04-01

    An arc of mafic and ultramafic rocks is mapped from Asik Mountain to Siniktanneyak Mountain in the northwestern Brooks Range of Alaska. Gravity data, although not very detailed, have been collected over the region and show some very conspicuous circular or oval gravity highs over portions of the mapped mafic-ultramafic bodies. Bodies which have large associated gravity anomalies are Asik Mountain (80 mGal), Avon Hills (20 mGal), Misheguk Mountain (30 mGal), and Siniktanneyak Mountain (20 mGal). Gabbros of the Siniktanneyak Mountain complex, where the gravity coverage is best, have densities of about 3.0 g/cm[sup 3] while the densities of the surrounding sedimentary rocks are about 2.6 g/cm[sup 3]. Volcanic rocks in the area have average densities of about 2.7 g/cm[sup 3]. Three-dimensional modeling indicates that the largest anomaly, on the southwestern part of the complex, could be caused by a polygonal prism of gabbro with vertical sides, about 6 km across and about 4.5 km deep. A smaller lobe of the anomaly on the northeast of the complex could be caused by another oblong polygonal prism about 4 km long and 2 km wide trending northeast and about 1.5 km deep. Modeling this anomaly with densities lower than gabbro would require greater thicknesses to produce the same anomaly. Modeling each anomaly along this arc in 2 1/2-dimensions shows many possible solutions using different body shapes and different density contrasts. There are several other gravity anomalies in this vicinity which could represent unexposed high density rocks. One such anomaly is in the Maiyumerak Mountains northeast of Asik Mountain (30 mGal). Another anomaly is to the northwest of Asik Mountain (20 mGal). There is also an anomaly at Uchugrak (20 mGal) east of Avan Hills. Although many of the anomalies in this region are poorly controlled, an attempt has been made to interpret the data to show possible solutions.

  15. A 2000 year varve-based climate record from the central Brooks Range, Alaska

    SciTech Connect

    Bird, BW; Abbott, MB; Finney, BP; Kutchko, B

    2009-01-01

    Varved minerogenic sediments from glacial-fed Blue Lake, northern Alaska, are used to investigate late Holocene climate variability. Varve-thickness measurements track summer temperature recorded at Atigun Pass, located 41 km east at a similar elevation (r (2) = 0.31, P = 0.08). Results indicate that climate in the Brooks Range from 10 to 730 AD (varve year) was warm with precipitation inferred to be higher than during the twentieth century. The varvetemperature relationship for this period was likely compromised and not used in our temperature reconstruction because the glacier was greatly reduced, or absent, exposing sub-glacial sediments to erosion from enhanced precipitation. Varve-inferred summer temperatures and precipitation decreased after 730 AD, averaging 0.4A degrees C above the last millennial average (LMA = 4.2A degrees C) from 730 to 850 AD, and 0.1A degrees C above the LMA from 850 to 980 AD. Cooling culminated between 980 and 1030 AD with temperatures 0.7A degrees C below the LMA. Varve-inferred summer temperatures increased between 1030 and 1620 AD to the LMA, though the period between 1260 and 1350 AD was 0.2A degrees C below the LMA. Although there is no equivalent to the European Medieval Warm Period in the Blue Lake record, two warm intervals occurred from 1350 to 1450 AD and 1500 to 1620 AD (0.4 and 0.3A degrees C above the LMA, respectively). During the Little Ice Age (LIA; 1620 to 1880 AD), inferred summer temperature averaged 0.2A degrees C below the LMA. After 1880 AD, inferred summer temperature increased to 0.8A degrees C above the LMA, glaciers retreated, but aridity persisted based on a number of regional paleoclimate records. Despite warming and glacial retreat, varve thicknesses have not achieved pre-730 AD levels. This reflects limited sediment availability and transport due to a less extensive retreat compared to the first millennium, and continued relative aridity. Overall, the Blue Lake record is similar to varve records from the

  16. Digital Data for the Geology of the Southern Brooks Range, Alaska

    USGS Publications Warehouse

    Geologic map compiled by Till, Alison B.; Dumoulin, Julie A.; Harris, Anita G.; Moore, Thomas E.; Bleick, Heather; Siwiec, Benjamin; Digital files prepared by Labay, Keith A.; Wilson, Frederic H.; Shew, Nora

    2008-01-01

    The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. The files named __geol contain geologic polygons and line (contact) attributes; files named __fold contain fold axes; files named __lin contain lineaments; and files named __dike contain dikes as lines. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make

  17. Rural Alaska Mentoring Project (RAMP)

    ERIC Educational Resources Information Center

    Cash, Terry

    2011-01-01

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

  18. Alaska Native Land Claims. [Textbook].

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Written for students at the secondary level, this textbook on Alaska Native land claims includes nine chapters, eight appendices, photographs, maps, graphs, bibliography, and an index. Chapters are titled as follows: (1) Earliest Times (Alaska's first settlers, eighteenth century territories, and other claimants); (2) American Indians and Their…

  19. Sedimentology and stratigraphy of the Kanayut Conglomerate, central Brooks Range, Alaska; report of 1980 field season

    USGS Publications Warehouse

    Nilsen, T.H.; Moore, T.E.; Balin, D.F.; Johnson, S.Y.

    1982-01-01

    The Upper Devonian Kanayut Conglomerate crops out along the crest of the Brooks Range of northern Alaska for a distance of almost 1000 km. It ranges in thickness from 2600 m in the Atigun River area to 700 m south of Anaktuvuk Pass and has been subdivided into four regionally persistent members: (a) the basal sandstone member, consisting of marine sandstone and shale with some conglomerate; (b) the lower shale member, consisting of nonmarine quartzite, conglomerate and shale; (c) the middle conglomerate member, consisting of nonmarine pebble and cobble conglomerate and quartzite; and (d) the Stuver Member, consisting of nonmarine sandstone and shale. The Kanayut conformably overlies the Upper Devonian marine Hunt Fork Shale and is conformably overlain by the Mississippian marine Kayak Shale. The Kanayut is wholly allochthonous and has probably been transported northward on a series of thrust plates. The basal sandstone member of the Kanayut Conglomerate, which overlies prodelta turbidites of the Hunt Fork Shale, contains marginal-marine coarsening-upward channel-mouth bar sequences. It is conformably overlain by the lower shale member. Measured sections of the nonmarine members of the Kanayut show that the lower shale member ranges in thickness from 120 m to 1115 m and consists of fining-upward cycles interpreted to have been deposited by meandering streams on a broad floodplain. These cycles contain, in ascending order, channelized basal conglomerate, trough cross-stratified sandstone, and ripple-marked siltstone. The cycles are interpreted to be channel and point-bar deposits. Individual cycles average about 10 m in thickness and are separated by intervals of black, brown or maroon floodplain shale deposits. These typically contain thin coarsening-upward units that probably represent prograding levee sequences and irregular and ungraded sandstone bodies interpreted to be crevasse-splay deposits. In the Okokmilaga River area, the lower shale member contains a

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

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2012-12-01

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

  1. Lithostratigraphy, microlithofacies, and conodont biostratigraphy and biofacies of the Wahoo Limestone (Carboniferous), eastern Sadlerochit Mountains, Northeast Brooks Range, Alaska

    SciTech Connect

    Krumhardt, A.P.; Harris, A.G.; Watts, K.F.

    1996-12-31

    The Lisburne Group (chiefly Carboniferous) is a wide-spread succession of platform carbonate rocks that apparently developed along a south-facing passive continental margin in northern Alaska. Marine transgressions onlapped northward across northeast Alaska allowing the Lisburne platform to extend over terrigenous deposits of the Endicott Group and local pre-Mississippian paleotopographic highs. The Wahoo Limestone is the youngest formation of the Lisburne Group in northeasternmost Alaska, ranging from latest Mississippian (latest Chesterian) to Middle Pennsylvanian (at least early Atokan) in age. The Wahoo Limestone was systematically sampled for lithostratigraphy and conodont biostratigraphy and biofacies at a relatively continuous section (about 262 m in thickness) in the eastern Sadlerochit Mountains. Existing Carboniferous conodont zonations could not be readily applied to the study section because most zonal indicators are absent. Species diversity is low for a section that spans at least 10 million years. Twenty-four species, distributed among 14 genera, were identified in 72 productive samples; no new species were distinguished. The following biostratigraphic zones and faunal intervals were recognized: Upper muricatus Subzone (latest Chesterian); noduliferus-primus Zone (earliest Morrowan); minutus Fauna (Morrowan) containing a lower subdivision (lower minutus Fauna of early to middle? Morrowan age); and an Idiognathodus Fauna (Morrowan? to early Atokan). The presence of Idiognathodus incurvus? and Rhachistognathus minutus subspp. above the first occurrence of the foraminifer Pseudostaffella sp. in the uppermost part of the Wahoo Limestone indicates that the youngest beds are early Atokan in age. The Mississippian-Pennsylvanian boundary is placed at 56 m above the base of the lower member of the Wahoo Limestone on the basis of the lowest occurrence of Declinognathodus noduliferus japonicus above forms transitional from Gnathodus girtyl simplex.

  2. 2013 Alaska Performance Scholarship Outcomes Report

    ERIC Educational Resources Information Center

    Rae, Brian

    2013-01-01

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

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

    USGS Publications Warehouse

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

    2015-01-01

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

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

    USGS Publications Warehouse

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

    2015-01-01

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

  5. Thermal structure of the Brooks Ranges and Seward Peninsula, Alaska HP-LT units : insights from RSCM thermometry

    NASA Astrophysics Data System (ADS)

    nicolas, Lemonnier; loic, Labrousse; philippe, Agard; Buschendorf Maelianna, Bigot; Frédéric, Mouthereau; Alison, Till

    2013-04-01

    Inner parts of mountain belts expose metamorphic rocks that record the thermal evolution of orogenic wedges, from burial to final exhumation. As such, they provide key constraints for paleogeographic and tectonic reconstructions of convergent zones. In order to understand the relationships between the Pacific subduction system and the Arctic geodynamics, we herein reappraise the key tectonic evolution of the Brooks Ranges (Northern Alaska). High-pressure low-temperature metamorphic rocks cropping out in the Schist belt of the Brooks Ranges, and the Nome Complex schists (Seward Peninsula), were exposed during Early Cretaceous to Paleocene times. Processes and structures responsible for their exhumation (i.e., syn-collisional nappe-stacking or post-collisional extensional detachment), which are still a matter of debate, have direct implications in terms of orogenic boundary conditions and mechanical coupling between subduction processes in southern Alaska and basin response to the north (North Slope). In this study systematic thermometry via Raman Spectrometry (RSCM) of Carbonaceous material along two regional transects in the Schist Belt and Seward Penisula (Nome area) allows the identification of units with contrasting thermal histories and a comparison of the thermal evolutions of the two areas. Geodynamic implications are finally discussed.

  6. Depositional settings, correlation, and age carboniferous rocks in the western Brooks Range, Alaska

    USGS Publications Warehouse

    Dumoulin, J.A.; Harris, A.G.; Blome, C.D.; Young, L.E.

    2004-01-01

    The Kuna Formation (Lisburne Group) in northwest Alaska hosts the Red Dog and other Zn-Pb-Ag massive sulfide deposits in the Red Dog district. New studies of the sedimentology and paleontology of the Lisburne Group constrain the setting, age, and thermal history of these deposits. In the western and west-central Brooks Range, the Lisburne Group includes both deep- and shallow-water sedimentary facies and local volcanic rocks that are exposed in a series of thrust sheets or allochthons. Deep-water facies in the Red Dog area (i.e., the Kuna Formation and related rocks) are found chiefly in the Endicott Mountains and structurally higher Picnic Creek allochthons. In the Red Dog plate of the Endicott Mountains allochthon, the Kuna consists of at least 122 m of thinly interbedded calcareous shale, calcareous spiculite, and bioclastic supportstone (Kivalina unit) overlain by 30 to 240 m of siliceous shale, mudstone, calcareous radiolarite, and calcareous lithic turbidite (Ikalukrok unit). The Ikalukrok unit in the Red Dog plate hosts all massive sulfide deposits in the area. It is notably carbonaceous, is generally finely laminated, and contains siliceous sponge spicules and radiolarians. The Kuna Formation in the Key Creek plate of the Endicott Mountains allochthon (60-110 m) resembles the Ikalukrok unit but is unmineralized and has thinner carbonate layers that are mainly organic-rich dolostone. Correlative strata in the Picnic Creek allochthon include less shale and mudstone and more carbonate (mostly calcareous spiculite). Conodonts and radiolarians indicate an age range of Osagean to early Chesterian (late Early to Late Mississippian) for the Kuna in the Red Dog area. Sedimentologic, faunal, and geochemical data imply that most of the Kuna formed in slope and basin settings characterized by anoxic or dysoxic bottom water and by local high productivity. Shallow-water facies of th e Lisburne Group in the Red Dog area are present locally in the Endicott Mountains

  7. Accretion tectonics and crustal structure in Alaska

    USGS Publications Warehouse

    Coney, P.J.; Jones, D.L.

    1985-01-01

    The entire width of the North American Cordillera in Alaska is made up of "suspect terranes". Pre-Late Cretaceous paleogeography is poorly constrained and the ultimate origins of the many fragments which make up the state are unclear. The Prince William and Chugach terranes accreted since Late Cretaceous time and represent the collapse of much of the northeast Pacific Ocean swept into what today is southern Alaska. Greater Wrangellia, a composite terrane now dispersed into fragments scattered from Idaho to southern Alaska, apparently accreted into Alaska in Late Cretaceous time crushing an enormous deep-marine flysch basin on its inboard side. Most of interior eastern Alaska is the Yukon Tanana terrane, a very large entirely fault-bounded metamorphic-plutonic assemblage covering thousands of square kilometers in Canada as well as Alaska. The original stratigraphy and relationship to North America of the Yukon-Tanana terrane are both obscure. A collapsed Mesozoic flysch basin, similar to the one inboard of Wrangellia, lies along the northern margin. Much of Arctic Alaska was apparently a vast expanse of upper Paleozoic to Early Mesozoic deep marine sediments and mafic volcanic and plutonic rocks now scattered widely as large telescoped sheets and Klippen thrust over the Ruby geanticline and the Brooks Range, and probably underlying the Yukon-Koyukuk basin and the Yukon flats. The Brooks Range itself is a stack of north vergent nappes, the telescoping of which began in Early Cretaceous time. Despite compelling evidence for thousands of kilometers of relative displacement between the accreted terranes, and large amounts of telescoping, translation, and rotation since accretion, the resulting new continental crust added to North America in Alaska carries few obvious signatures that allow application of currently popular simple plate tectonic models. Intraplate telescoping and strike-slip translations, delamination at mid-crustal levels, and large-scale lithospheric

  8. 78 FR 53137 - Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ...Phillips Transportation Alaska, Inc., ExxonMobil Pipeline Company; Notice of Complaint Take notice that on... formal complaint against BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc.,...

  9. The Effects of Changing Climate on Glaciers in the Central Alaska Range, Alaska, USA: A Case Study on the Kahiltna Glacier

    NASA Astrophysics Data System (ADS)

    Young, J. C.; Arendt, A. A.

    2010-12-01

    This study will develop a set of modeling tools to provide estimates of melt evolution for the Kahiltna Glacier and glaciers of the Central Alaska Range (CAKR), over a number of future climate change scenarios. To parameterize the model, field measurements of mass balance and meteorological variables are being collected on the Kahiltna Glacier. These measurements include winter accumulation surveys along both a centerline transect and several lateral profiles of the main glacier branch, and summer ablation measurements at ten centerline index locations spaced evenly over a range of elevations. Snow density measurements are also being recorded at three elevations. Temperature and relative humidity is being sampled at five of the index locations, and a full meteorological station (measuring temperature, humidity, wind speed and direction, snow accumulation, ice ablation, and solar radiation) will be positioned on the lower ablation area. Here we present preliminary results from the 2010 melt season, comparing data collected on the Kahiltna Glacier to measurements from nearby sites within the CAKR. Data from a single index site monitored by the National Park Service (NPS) is compared to the accumulation and ablation measurements taken at the ten sites visited during 2010 as part of this study, to show the NPS index site’s representativeness at different elevations. Accumulation at these locations is also compared to a nearby snow telemetry (SNOTEL) site to determine whether there is a systematic offset between station data and conditions on the glacier. Lapse rates are calculated from temperature readings at five different elevations, for comparison with data from a meteorological station located in an adjacent glacier basin. From these analyses we provide a preliminary assessment of the extent to which our in situ measurements on the Kahiltna Glacier are representative of regional trends. The project will leverage 20 years of NPS mass balance data for the Kahiltna

  10. Trans-Alaska pipeline

    SciTech Connect

    Not Available

    1991-07-01

    The Trans-Alaska Pipeline system transports nearly 25 percent of the nation's domestically produced crude oil. Since operations began in 1977, the system has delivered over 8 billion barrels of oil to Port Veldez for shipment. This paper reports that concerns have been raised about whether the system is meeting special engineering design and operations requirements imposed by federal and state regulators. GAO found that the five principal federal and state regulatory agencies have not pursued a systematic, disciplined, and coordinated approach to regulating the Trans-Alaska Pipeline System. Instead, these agencies have relied on the Alyeska Pipeline Service Company, which runs the system, to police itself. It was only after the Exxon Valdez spill and the discovery of corrosion that the regulators began to reevaluate their roles and focus on issues such as whether Alyeska's operating and maintenance procedures meet the pipelines, special engineering design and operating requirements, or whether Alyeska can adequately respond to a large oil spill. In January 1990, the regulators established a joint office to provide more effective oversight of the system. GAO believes that central leadership and a secured funding sources may help ensure that this office provides adequate oversight.

  11. Terrain, vegetation, and landscape evolution of the R4D research site, Brooks Range Foothills, Alaska

    USGS Publications Warehouse

    Walker, D. A.; Binnian, Emily F.; Evans, B. M.; Lederer, N. D.; Nordstrand, E.; Webber, P. J.

    1989-01-01

    Maps of the vegetation and terrain of a 22 km2 area centered on the Department of Energy (DOE) R4D (Response, Resistance, Resilience to and Recovery from Disturbance in Arctic Ecosystems) study site in the Southern Foothills Physiographic Province of Alaska were made using integrated geobotanical mapping procedures and a geographic-information system. Typical land forms and surface f orms include hillslope water tracks, Sagavanirktok-age till deposits, nonsorted stone stripes, and colluvial-basin deposits. Thirty-two plant communities are described; the dominant vegetation (51% of the mapped area) is moist tussock-sedge, dwarf-shrub tundra dominated by Eriophorum vaginatum or Carex bigelowii. Much of the spatial variation in the mapped geobotanical characters reflects different-aged glaciated surfaces. Shannon-Wienerin dices indicate that the more mature landscapes, represented by retransported hillslope deposits and basin colluvium, are less heterogeneous than newer landscapes such as surficial till deposits and floodplains. A typical toposequence on a mid-Pleistocene-age surface is discussed with respect to evolution of the landscape. Thick Sphagnum moss layers occur on lower hillslopes, and the patterns of moss-layer development, heat flux, active layer thickness, and ground-ice are seen as keys to developing thermokarst-susceptibility maps.

  12. Glaciers of North America - Glaciers of Alaska

    USGS Publications Warehouse

    Molnia, Bruce F.

    2008-01-01

    Glaciers cover about 75,000 km2 of Alaska, about 5 percent of the State. The glaciers are situated on 11 mountain ranges, 1 large island, an island chain, and 1 archipelago and range in elevation from more than 6,000 m to below sea level. Alaska's glaciers extend geographically from the far southeast at lat 55 deg 19'N., long 130 deg 05'W., about 100 kilometers east of Ketchikan, to the far southwest at Kiska Island at lat 52 deg 05'N., long 177 deg 35'E., in the Aleutian Islands, and as far north as lat 69 deg 20'N., long 143 deg 45'W., in the Brooks Range. During the 'Little Ice Age', Alaska's glaciers expanded significantly. The total area and volume of glaciers in Alaska continue to decrease, as they have been doing since the 18th century. Of the 153 1:250,000-scale topographic maps that cover the State of Alaska, 63 sheets show glaciers. Although the number of extant glaciers has never been systematically counted and is thus unknown, the total probably is greater than 100,000. Only about 600 glaciers (about 1 percent) have been officially named by the U.S. Board on Geographic Names (BGN). There are about 60 active and former tidewater glaciers in Alaska. Within the glacierized mountain ranges of southeastern Alaska and western Canada, 205 glaciers (75 percent in Alaska) have a history of surging. In the same region, at least 53 present and 7 former large ice-dammed lakes have produced jokulhlaups (glacier-outburst floods). Ice-capped volcanoes on mainland Alaska and in the Aleutian Islands have a potential for jokulhlaups caused by subglacier volcanic and geothermal activity. Because of the size of the area covered by glaciers and the lack of large-scale maps of the glacierized areas, satellite imagery and other satellite remote-sensing data are the only practical means of monitoring regional changes in the area and volume of Alaska's glaciers in response to short- and long-term changes in the maritime and continental climates of the State. A review of the

  13. New U/Pb ages from granite and granite gneiss in the Ruby geanticline and southern Brooks Range, Alaska ( USA).

    USGS Publications Warehouse

    Patton, W.W.; Stern, T.W.; Arth, Joseph G.; Carlson, C.

    1987-01-01

    New U/Pb zircon ages from the Ray Mountains of central Alaska clarify the plutonic history of the Ruby geanticline and support earlier suggestions that the Ruby geanticline and S Brooks Range were once parts of the same tectonostratigraphic terrane. U/Pb zircon ages of 109 to 112 Ma from the Ray Mountains pluton confirm previously reported mid-Cretaceous K/Ar ages and rule out the possibility that the earliest intrusive phase of the pluton is older than mid-Cretaceous K/Ar ages and rule out the possibility that the earliest intrusive phase of the pluton is older than mid- Cretaceous. New U/Pb zircon ages from 4 granite gneiss samples in the Ray Mountains indicate a Devonian protolith age of 390+ or -12 Ma and suggest that the Ruby geanticline, like the S Brooks Range, underwent a major plutonic event in mid-Paleozoic time.-Authors

  14. Spatial variations in focused exhumation along a continental-scale strike-slip fault: The Denali fault of the eastern Alaska Range

    USGS Publications Warehouse

    Benowitz, J.A.; Layer, P.W.; Armstrong, P.; Perry, S.E.; Haeussler, P.J.; Fitzgerald, P.G.; VanLaningham, S.

    2011-01-01

    40Ar/39Ar, apatite fission-track, and apatite (U-Th)/He thermochronological techniques were used to determine the Neogene exhumation history of the topographically asymmetric eastern Alaska Range. Exhumation cooling ages range from ~33 Ma to ~18 Ma for 40Ar/39Ar biotite, ~18 Ma to ~6 Ma for K-feldspar minimum closure ages, and ~15 Ma to ~1 Ma for apatite fission-track ages, and apatite (U-Th)/He cooling ages range from ~4 Ma to ~1 Ma. There has been at least ~11 km of exhumation adjacent to the north side of Denali fault during the Neogene inferred from biotite 40Ar/39Ar thermochronology. Variations in exhumation history along and across the strike of the fault are influenced by both far-field effects and local structural irregularities. We infer deformation and rapid exhumation have been occurring in the eastern Alaska Range since at least ~22 Ma most likely related to the continued collision of the Yakutat microplate with the North American plate. The Nenana Mountain region is the late Pleistocene to Holocene (~past 1 Ma) primary locus of tectonically driven exhumation in the eastern Alaska Range, possibly related to variations in fault geometry. During the Pliocene, a marked increase in climatic instability and related global cooling is temporally correlated with an increase in exhumation rates in the eastern Alaska Range north of the Denali fault system.

  15. Size and perspective in Alaska.

    PubMed

    Towle, Jim

    2006-01-01

    By far America's largest state, Alaska has only 350 members, so effective communication matters in overcoming distance. Alaska has led the way in direct reimbursement, diversity in leadership, member involvement, and a distinctive lifestyle for its practitioners. The tripartite structure of organized dentistry is crucial in building understanding the issues involved in providing oral health care to the members of this vast state. PMID:17585733

  16. Alaska Athabascan stellar astronomy

    NASA Astrophysics Data System (ADS)

    Cannon, Christopher M.

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

  17. Alaska Interagency Ecosystem Health Work Group

    USGS Publications Warehouse

    Shasby, Mark

    2009-01-01

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

  18. Operation IceBridge Alaska

    NASA Astrophysics Data System (ADS)

    Larsen, C.

    2015-12-01

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

  19. Climate Change Impacts on the Cryosphere of Mountain Regions: Validation of a Novel Model Using the Alaska Range

    NASA Astrophysics Data System (ADS)

    Mosier, T. M.; Hill, D. F.; Sharp, K. V.

    2015-12-01

    Mountain regions are natural water towers, storing water seasonally as snowpack and for much longer as glaciers. Understanding the response of these systems to climate change is necessary in order to make informed decisions about prevention or mitigation measures. Yet, mountain regions are often data sparse, leading many researchers to implement simple or enhanced temperature index (ETI) models to simulate cryosphere processes. These model structures do not account for the thermal inertia of snowpack and glaciers and do not robustly capture differences in system response to climate regimes that differ from those the model was calibrated for. For instance, a temperature index calibration parameter will differ substantially in cold-dry conditions versus warm-wet ones. To overcome these issues, we have developed a cryosphere hydrology model, called the Significantly Enhanced Temperature Index (SETI), which uses an energy balance structure but parameterizes energy balance components in terms of minimum, maximum and mean temperature, precipitation, and geometric inputs using established relationships. Additionally, the SETI model includes a glacier sliding model and can therefore be used to estimate long-term glacier response to climate change. Sensitivity of the SETI model to changing climate is compared with an ETI and a simple temperature index model for several partially-glaciated watersheds within Alaska, including Wolverine glacier where multi-decadal glacier stake measurements are available, to highlight the additional fidelity attributed to the increased complexity of the SETI structure. The SETI model is then applied to the entire Alaska Range region for an ensemble of global climate models (GCMs), using representative concentration pathways 4.5 and 8.5. Comparing model runs based on ensembles of GCM projections to historic conditions, total annual snowfall within the Alaska region is not expected to change appreciably, but the spatial distribution of snow

  20. U/Pb dating of subduction-collision in the Brooks Range: implications for Mesozoic geodynamics of Arctic Alaska

    NASA Astrophysics Data System (ADS)

    Lemonnier, Nicolas; Labrousse, Loic; Agard, Philippe; McClelland, Bill; Cobble, Mattew; Till, Alison; Roeske, Sarah

    2016-04-01

    The paleogeographic and geodynamic evolution of Northern Alaska is crucial to understand the connection between the Arctic and Pacific realms. The opening of the Canada Basin (CB) is debated both in terms of inception time (between 190 and 140 Ma) and driving mechanisms. The prevalent model assumes that CB opened in a back-arc position within the Arctic-Alaska-Chukotka (AAC) terrane following a change in subduction polarity from S- to N-dipping subduction The adjacent Brooks Range orogen (BRO) is thought to have formed when the Koyukuk volcanic arc collided with the southern extension of AAC. This collision therefore potentially provides key information for Arctic geodynamics, and for the mechanisms of CB opening, but neither the detailed timing of this collisional history nor its duration are well known. In order to constrain the timing of the collision, we performed in-situ zircon U-Pb SIMS analyses on eclogites from the BRO s.l. (BR and Seward Peninsula), which indicate that peak burial (at 510 ± 60°C, 1.6 ± 0.2 GPa) during continental subduction and subsequent collision occurred at 141 ± 6 Ma (n=10, MSWD = 1.6). Eclogite metamorphism therefore postdates the initial rifting stage of the CB but predates effective sea-floor spreading. Younger zircon domains (114 ± 13 Ma) associated with retrograde assemblages could indicate a late thermal pulse or recrystallisation during exhumation in the collisional wedge. Combined with all available information on timing, these new age constraints are used to build a tectonic model for coeval evolution of the Brooks Range and the Canada Basin. The intra-Kingak "Jurassic Unconformity" at the Jurassic Cretaceous Boundary (Houseknecht, pers. communication) could actually be considered as the signature of the AAC-Koyukuk arc collision stage in the CB.

  1. A geochemical sampling technique for use in areas of active alpine glaciation: an application from the central Alaska Range

    USGS Publications Warehouse

    Stephens, G.C.; Evenson, E.B.; Detra, D.E.

    1990-01-01

    In mountainous regions containing extensive glacier systems there is a lack of suitable material for conventional geochemical sampling. As a result, in most geochemical sampling programs a few stream-sediment samples collected at, or near, the terminus of valley glaciers are used to evaluate the mineral potential of the glaciated area. We have developed and tested a technique which utilizes the medial moraines of valley glaciers for systematic geochemical exploration of the glacial catchment area. Moraine sampling provides geochemical information that is site-specific in that geochemical anomalies can be traced directly up-ice to bedrock sources. Traverses were made across the Trident and Susitna glaciers in the central Alaska Range where fine-grained (clay to sand size) samples were collected from each medial moraine. These samples were prepared and chemically analyzed to determine the concentration of specific elements. Fifty pebbles were collected at each moraine for archival purposes and for subsequent lithologic identification. Additionally, fifty cobbles and fifty boulders were examined and described at each sample site to determine the nature and abundance of lithologies present in the catchment area, the extent and nature of visible mineralization, the presence and intensity of hydrothermal alteration and the existence of veins, dikes and other minor structural features. Results from the central Alaska Range have delineated four distinct multi-element anomalies which are a response to potential mineralization up-ice from the medial moraine traverse. By integrating the lithologic, mineralogical and geochemical data the probable geological setting of the geochemical anomalies is determined. ?? 1990.

  2. Late Mesozoic and Cenozoic thermotectonic evolution of the central Brooks Range and adjacent North Slope foreland basin, Alaska: Including fission track results from the Trans-Alaska Crustal Transect (TACT)

    USGS Publications Warehouse

    O'Sullivan, P. B.; Murphy, J.M.; Blythe, A.E.

    1997-01-01

    Apatite fission track data are used to evaluate the thermal and tectonic history of the central Brooks Range and the North Slope foreland basin in northern Alaska along the northern leg of the Trans-Alaska Crustal Transect (TACT). Fission track analyses of the detrital apatite grains in most sedimentary units resolve the timing of structures and denudation within the Brooks Range, ranging in scale from the entire mountain range to relatively small-scale folds and faults. Interpretation of the results indicates that rocks exposed within the central Brooks Range cooled rapidly from paleotemperatures 110?? to 50??C during discrete episodes at ???100??5 Ma, ???60??4 Ma, and ???24??3 Ma, probably in response to kilometer-scale denudation. North of the mountain front, rocks in the southern half of the foreland basin were exposed to maximum paleotemperatures 110??C in the Late Cretaceous to early Paleocene as a result of burial by Upper Jurassic and Cretaceous sedimentary rocks. Rapid cooling from these elevated paleotemperatures also occurred due to distinct episodes of kilometer-scale denudation at ???60??4 Ma, 46??3 Ma, 35??2 Ma, and ???24??3 Ma. Combined, the apatite analyses indicate that rocks exposed along the TACT line through the central Brooks Range and foreland basin experienced episodic rapid cooling throughout the Late Cretaceous and Cenozoic in response to at least three distinct kilometer-scale denudation events. Future models explaining orogenic events in northern Alaska must consider these new constraints from fission track thermochronology. Copyright 1997 by the American Geophysical Union.

  3. Spatial variability of biotic and abiotic tree establishment constraints across a treeline ecotone in the Alaska Range

    USGS Publications Warehouse

    Stueve, K.M.; Isaacs, R.E.; Tyrrell, L.E.; Densmore, R.V.

    2011-01-01

    Throughout interior Alaska (USA), a gradual warming trend in mean monthly temperatures occurred over the last few decades (;2-48C). The accompanying increases in woody vegetation at many alpine treeline (hereafter treeline) locations provided an opportunity to examine how biotic and abiotic local site conditions interact to control tree establishment patterns during warming. We devised a landscape ecological approach to investigate these relationships at an undisturbed treeline in the Alaska Range. We identified treeline changes between 1953 (aerial photography) and 2005 (satellite imagery) in a geographic information system (GIS) and linked them with corresponding local site conditions derived from digital terrain data, ancillary climate data, and distance to 1953 trees. Logistic regressions enabled us to rank the importance of local site conditions in controlling tree establishment. We discovered a spatial transition in the importance of tree establishment controls. The biotic variable (proximity to 1953 trees) was the most important tree establishment predictor below the upper tree limit, providing evidence of response lags with the abiotic setting and suggesting that tree establishment is rarely in equilibrium with the physical environment or responding directly to warming. Elevation and winter sun exposure were important predictors of tree establishment at the upper tree limit, but proximity to trees persisted as an important tertiary predictor, indicating that tree establishment may achieve equilibrium with the physical environment. However, even here, influences from the biotic variable may obscure unequivocal correlations with the abiotic setting (including temperature). Future treeline expansion will likely be patchy and challenging to predict without considering the spatial variability of influences from biotic and abiotic local site conditions. ?? 2011 by the Ecological Society of America.

  4. Improving Student Achievement in Alaska. Alaska Goals 2000 Annual Report, 1997-98.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    Alaska Goals 2000 is part of a coordinated, statewide effort to improve public education for all students in Alaska. In 1997-1998, 90% of Alaska's federal funding was used to fund grants to local school districts, and 10% was used to fund state-level activities through the Alaska Department of Education. During 1997-1998, curriculum frameworks and…

  5. Alaska GeoFORCE, A New Geologic Adventure in Alaska

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2011-12-01

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

  6. Alaska Native Education Study: A Statewide Study of Alaska Native Values and Opinions Regarding Education in Alaska.

    ERIC Educational Resources Information Center

    McDowell Group, Juneau, AK.

    This document contains four reports detailing a four-phase research project on Alaska Natives' attitudes and values toward education. A literature review examines the history of Native education in Alaska, issues in research on American Indian and Alaska Native education, dropout studies, student assessment, language and culture, learning styles,…

  7. Profile: American Indian/Alaska Native

    MedlinePlus

    ... million American Indians and Alaska Natives. Typically, this urban clientele has less accessibility to hospitals; health clinics ... IHS and tribal health programs. Studies on the urban American Indian and Alaska Native population have documented ...

  8. Review: groundwater in Alaska (USA)

    USGS Publications Warehouse

    Callegary, J.B.; Kikuchi, C.P.; Koch, J.C.; Lilly, M.R.; Leake, S.A.

    2013-01-01

    Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to continental in the Interior, and arctic on the North Slope. During the Quaternary period, topography and rock type have combined with glacial and periglacial processes to develop the unconsolidated alluvial aquifers of Alaska and have resulted in highly heterogeneous hydrofacies. In addition, the long persistence of frozen ground, whether seasonal or permanent, greatly affects the distribution of aquifer recharge and discharge. Because of high runoff, a high proportion of groundwater use, and highly variable permeability controlled in part by permafrost and seasonally frozen ground, understanding groundwater/surface-water interactions and the effects of climate change is critical for understanding groundwater availability and the movement of natural and anthropogenic contaminants.

  9. Malaspina Glacier, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

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

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

  10. Trends in Alaska's People and Economy.

    ERIC Educational Resources Information Center

    Leask, Linda; Killorin, Mary; Martin, Stephanie

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

  11. Alaska Pipeline Insulation

    NASA Technical Reports Server (NTRS)

    1979-01-01

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

  12. Alexander Archipelago, Southeastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  13. Geology of the Alaska-Juneau lode system, Alaska

    USGS Publications Warehouse

    Twenhofel, William Stephens

    1952-01-01

    The Alaska-Juneau lode system for many years was one of the worlds leading gold-producing areas. Total production from the years 1893 to 1946 has amounted to about 94 million dollars, with principal values in contained gold but with some silver and lead values. The principal mine is the Alaska-Juneau mine, from which the lode system takes its name. The lode system is a part of a larger gold-bearing belt, generally referred to as the Juneau gold belt, along the western border of the Coast Range batholith. The rocks of the Alaska-Juneau lode system consist of a monoclinal sequence of steeply northeasterly dipping volcanic, state, and schist rocks, all of which have been metamorphosed by dynamic and thermal processes attendant with the intrusion of the Coast Range batholith. The rocks form a series of belts that trend northwest parallel to the Coast Range. In addition to the Coast Range batholith lying a mile to the east of the lode system, there are numerous smaller intrusives, all of which are sill-like in form and are thus conformable to the regional structure. The bedded rocks are Mesozoic in age; the Coast Range batholith is Upper Jurassic and Lower Cretaceous in age. Some of the smaller intrusives pre-date the batholith, others post-date it. All of the rocks are cut by steeply dipping faults. The Alaska-Juneau lode system is confined exclusively to the footwall portion of the Perseverance slate band. The slate band is composed of black slate and black phyllite with lesser amounts of thin-bedded quartzite. Intrusive into the slate band are many sill-like bodies of rocks generally referred to as meta-gabbro. The gold deposits of the lode system are found both within the slate rocks and the meta-gabbro rocks, and particularly in those places where meta-gabbro bodies interfinger with slate. Thus the ore bodies are found in and near the terminations of meta-gabbro bodies. The ore bodies are quartz stringer-lodes composed of a great number of quartz veins from 6

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

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

  15. Range overlap and individual movements during breeding season influence genetic relationships of caribou herds in south-central Alaska

    USGS Publications Warehouse

    Roffler, Gretchen H.; Adams, Layne G.; Talbot, Sandra L.; Sage, George K.; Dale, Bruce W.

    2012-01-01

    North American caribou (Rangifer tarandus) herds commonly exhibit little nuclear genetic differentiation among adjacent herds, although available evidence supports strong demographic separation, even for herds with seasonal range overlap. During 1997–2003, we studied the Mentasta and Nelchina caribou herds in south-central Alaska using radiotelemetry to determine individual movements and range overlap during the breeding season, and nuclear and mitochondrial DNA (mtDNA) markers to assess levels of genetic differentiation. Although the herds were considered discrete because females calved in separate regions, individual movements and breeding-range overlap in some years provided opportunity for male-mediated gene flow, even without demographic interchange. Telemetry results revealed strong female philopatry, and little evidence of female emigration despite overlapping seasonal distributions. Analyses of 13 microsatellites indicated the Mentasta and Nelchina herds were not significantly differentiated using both traditional population-based analyses and individual-based Bayesian clustering analyses. However, we observed mtDNA differentiation between the 2 herds (FSTM = 0.041, P

  16. Seasonal variability and detection range modeling of baleen whale calls in the Gulf of Alaska, 1999-2002.

    PubMed

    Stafford, Kathleen M; Mellinger, David K; Moore, Sue E; Fox, Christopher G

    2007-12-01

    Five species of large whales, including the blue (Balaenoptera musculus), fin (B. physalus), sei (B. borealis), humpback (Megaptera novaeangliae), and North Pacific right (Eubalaena japonica), were the target of commercial harvests in the Gulf of Alaska (GoA) during the 19th through mid-20th Centuries. Since this time, there have been a few summer time visual surveys for these species, but no overview of year-round use of these waters by endangered whales primarily because standard visual survey data are difficult and costly. From October 1999-May 2002, moored hydrophones were deployed in six locations in the GoA to record whale calls. Reception of calls from fin, humpback, and blue whales and an unknown source, called Watkins' whale, showed seasonal and geographic variation. Calls were detected more often during the winter than during the summer, suggesting that animals inhabit the GoA year-round. To estimate the distance at which species-diagnostic calls could be heard, parabolic equation propagation loss models for frequencies characteristic of each of each call type were run. Maximum detection ranges in the subarctic North Pacific ranged from 45 to 250 km among three species (fin, humpback, blue), although modeled detection ranges varied greatly with input parameters and choice of ambient noise level.

  17. THIAFENTANIL-AZAPERONE-XYLAZINE AND CARFENTANIL-XYLAZINE IMMOBILIZATIONS OF FREE-RANGING CARIBOU (RANGIFER TARANDUS GRANTI) IN ALASKA, USA.

    PubMed

    Lian, Marianne; Beckmen, Kimberlee B; Bentzen, Torsten W; Demma, Dominic J; Arnemo, Jon M

    2016-04-28

    Carfentanil-xylazine (CX) has been the primary drug combination used for immobilizing free-ranging ungulates in Alaska, US since 1986. We investigated the efficacy of a potential new drug of choice, thiafentanil (Investigational New Animal Drug A-3080). Captive trials indicated that thiafentanil-azaperone-medetomidine could provide good levels of immobilization. However, field trials conducted in October 2013 on free-ranging caribou ( Rangifer tarandus granti) calves showed the combination too potent, causing three respiratory arrests and one mortality. The protocol was revised to thiafentanil-azaperone-xylazine (TAX), with good results. The induction time was not significantly different between the two combinations. However, the recovery time was significantly shorter for the TAX group than for the CX group. A physiologic evaluation was performed on 12 animals immobilized on CX and 15 animals on TAX. Arterial blood was collected after induction and again after 10 min of intranasal oxygen supplements (1 L/min). Both groups had significant increases in partial pressure of arterial oxygen after oxygen treatment. There was a concurrent significant increase in partial pressure of arterial carbon dioxide in both groups. Rectal temperature increased significantly in both groups during the downtime, which is consistent with other studies of potent opioids in ungulates. On the basis of our results, we found TAX to be a potential alternative for the current CX protocol for immobilizing free-ranging caribou calves via helicopter darting.

  18. THIAFENTANIL-AZAPERONE-XYLAZINE AND CARFENTANIL-XYLAZINE IMMOBILIZATIONS OF FREE-RANGING CARIBOU (RANGIFER TARANDUS GRANTI) IN ALASKA, USA.

    PubMed

    Lian, Marianne; Beckmen, Kimberlee B; Bentzen, Torsten W; Demma, Dominic J; Arnemo, Jon M

    2016-04-28

    Carfentanil-xylazine (CX) has been the primary drug combination used for immobilizing free-ranging ungulates in Alaska, US since 1986. We investigated the efficacy of a potential new drug of choice, thiafentanil (Investigational New Animal Drug A-3080). Captive trials indicated that thiafentanil-azaperone-medetomidine could provide good levels of immobilization. However, field trials conducted in October 2013 on free-ranging caribou ( Rangifer tarandus granti) calves showed the combination too potent, causing three respiratory arrests and one mortality. The protocol was revised to thiafentanil-azaperone-xylazine (TAX), with good results. The induction time was not significantly different between the two combinations. However, the recovery time was significantly shorter for the TAX group than for the CX group. A physiologic evaluation was performed on 12 animals immobilized on CX and 15 animals on TAX. Arterial blood was collected after induction and again after 10 min of intranasal oxygen supplements (1 L/min). Both groups had significant increases in partial pressure of arterial oxygen after oxygen treatment. There was a concurrent significant increase in partial pressure of arterial carbon dioxide in both groups. Rectal temperature increased significantly in both groups during the downtime, which is consistent with other studies of potent opioids in ungulates. On the basis of our results, we found TAX to be a potential alternative for the current CX protocol for immobilizing free-ranging caribou calves via helicopter darting. PMID:26967141

  19. Pressure-temperature history of the Brooks Range and Seward Peninsula, Alaska HP-LT units and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Lemonnier, N.; Labrousse, L.; Agard, P.; Till, A. B.

    2013-12-01

    Metamorphic rocks in the inner zones of mountain belts constitute a marker of vertical movements within orogenic wedges, themselves controled by balance between boundary conditions and volume forces. They provide key evidence for paleogeographic and tectonic reconstruction of convergence zones. In the Arctic, the Amerasian basin opened in cretaceous time and evolved in the upper plate of the Pacific subduction system. The tectonic evolution of the Brooks Range, northern Alaska, is a key issue for understanding possible coupling between these two dynamics. HP-LT metamorphic rocks, now exposed in the Schist belt, Brooks Range, and the Nome Complex, Seward Peninsula, were brought to the surface during Early Cretaceous to Paleocene time. The processes responsible for their exhumation (syn-collisional nappe-stacking or post-collisional extensional detachment) are still a matter of debate, and have direct implications in terms of orogenic boundary conditions and coupling between subduction processes (to the south) and basin response (to the north; the North Slope). Systematic thermometry via Raman Spectrometry (RSCM) on carbonaceous material from regional transects in the Schist Belt and the Seward Peninsula as well as pseudosections calculations allow the determination of units with contrasting pressure-temperature histories and a comparison of thermal evolution of the two areas. Geodynamic implications of their exhumation is then discussed.

  20. Teshekpuk Lake, Alaska

    NASA Technical Reports Server (NTRS)

    2006-01-01

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

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

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

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

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

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

  1. Deformation and the timing of gas generation and migration in the eastern Brooks Range foothills, Arctic National Wildlife Refuge, Alaska

    USGS Publications Warehouse

    Parris, T.M.; Burruss, R.C.; O'Sullivan, P. B.

    2003-01-01

    Along the southeast border of the 1002 Assessment Area in the Arctic National Wildlife Refuge, Alaska, an explicit link between gas generation and deformation in the Brooks Range fold and thrust belt is provided through petrographic, fluid inclusion, and stable isotope analyses of fracture cements integrated with zircon fission-track data. Predominantly quartz-cemented fractures, collected from thrusted Triassic and Jurassic rocks, contain crack-seal textures, healed microcracks, and curved crystals and fluid inclusion populations, which suggest that cement growth occurred before, during, and after deformation. Fluid inclusion homogenization temperatures (175-250??C) and temperature trends in fracture samples suggest that cements grew at 7-10 km depth during the transition from burial to uplift and during early uplift. CH4-rich (dry gas) inclusions in the Shublik Formation and Kingak Shale are consistent with inclusion entrapment at high thermal maturity for these source rocks. Pressure modeling of these CH4-rich inclusions suggests that pore fluids were overpressured during fracture cementation. Zircon fission-track data in the area record postdeposition denudation associated with early Brooks Range deformation at 64 ?? 3 Ma. With a closure temperature of 225-240??C, the zircon fission-track data overlap homogenization temperatures of coeval aqueous inclusions and inclusions containing dry gas in Kingak and Shublik fracture cements. This critical time-temperature relationship suggests that fracture cementation occurred during early Brooks Range deformation. Dry gas inclusions suggest that Shublik and Kingak source rocks had exceeded peak oil and gas generation temperatures at the time structural traps formed during early Brooks Range deformation. The timing of hydrocarbon generation with respect to deformation therefore represents an important exploration risk for gas exploration in this part of the Brooks Range fold and thrust belt. The persistence of gas high at

  2. Tuberculosis among Children in Alaska.

    ERIC Educational Resources Information Center

    Gessner, Bradford D.

    1997-01-01

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

  3. A Title I Refinement: Alaska.

    ERIC Educational Resources Information Center

    Hazelton, Alexander E.; And Others

    Through joint planning with a number of school districts and the Region X Title I Technical Assistance Center, and with the help of a Title I Refinement grant, Alaska has developed a system of data storage and retrieval using microcomputers that assists small school districts in the evaluation and reporting of their Title I programs. Although this…

  4. Adventures in the Alaska Economy.

    ERIC Educational Resources Information Center

    Jackstadt, Steve; Huskey, Lee

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

  5. Tertiary tectonics of the Border Ranges Fault system, north-central Chugach Mountains, Alaska: Sedimentation, deformation and uplift along the inboard edge of a subduction complex

    SciTech Connect

    Little, T.A.

    1988-01-01

    In south-central Alaska the Border Ranges Fault system (BRFS) separates lower Paleogene rocks of a forearc basin sequence from a Cretaceous subduction complex. In a north-central part of the Chugach Mountains the upper Paleocene-lower Eocene Chickaloon Formation was deposited along the seaward margin of the forearc basin as an alluvial fan complex. A field study combining geologic mapping of a {approximately}200 km{sup 2} region, stratigraphic studies, K-Ar and fission-track geochronology, metamorphic petrology, and detailed structural analysis of deformed rocks on both sides of the BRFS has been used to reconstruct the Tertiary history of displacements and uplift events along the inboard edge of Alaska's subduction-accretion complex.

  6. Gas hydrate resources of northern Alaska

    USGS Publications Warehouse

    Collett, T.S.

    1997-01-01

    Large amounts of natural gas, composed mainly of methane, can occur in arctic sedimentary basins in the form of gas hydrates under appropriate temperature and pressure conditions. Gas hydrates are solids, composed of rigid cages of water molecules that trap molecules of gas. These substances are regarded as a potential unconventional source of natural gas because of their enormous gas-storage capacity. Most published gas hydrate resource estimates are highly simplified and based on limited geological data. The gas hydrate resource assessment for northern Alaska presented in this paper is based on a "play analysis" scheme, in which geological factors controlling the accumulation and preservation of gas hydrates are individually evaluated and risked for each hydrate play. This resource assessment identified two gas hydrate plays; the in-place gas resources within the gas hydrates of northern Alaska are estimated to range from 6.7 to 66.8 trillion cubic metres of gas (236 to 2,357 trillion cubic feet of gas), at the 0.50 and 0.05 probability levels respectively. The mean in-place hydrate resource estimate for northern Alaska is calculated to be 16.7 trillion cubic metres of gas (590 trillion cubic feet of gas). If this assessment is valid, the amount of natural gas stored as gas hydrates in northern Alaska could be almost seven times larger then the estimated total remaining recoverable conventional natural gas resources in the entire United States.

  7. Ocean Observing System Demonstrated in Alaska

    NASA Astrophysics Data System (ADS)

    Schoch, G. Carl; Chao, Yi

    2010-05-01

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

  8. Integrated resource inventory for southcentral Alaska (INTRISCA)

    NASA Technical Reports Server (NTRS)

    Burns, T.; Carson-Henry, C.; Morrissey, L. A.

    1981-01-01

    The Integrated Resource Inventory for Southcentral Alaska (INTRISCA) Project comprised an integrated set of activities related to the land use planning and resource management requirements of the participating agencies within the southcentral region of Alaska. One subproject involved generating a region-wide land cover inventory of use to all participating agencies. Toward this end, participants first obtained a broad overview of the entire region and identified reasonable expectations of a LANDSAT-based land cover inventory through evaluation of an earlier classification generated during the Alaska Water Level B Study. Classification of more recent LANDSAT data was then undertaken by INTRISCA participants. The latter classification produced a land cover data set that was more specifically related to individual agency needs, concurrently providing a comprehensive training experience for Alaska agency personnel. Other subprojects employed multi-level analysis techniques ranging from refinement of the region-wide classification and photointerpretation, to digital edge enhancement and integration of land cover data into a geographic information system (GIS).

  9. The Border Ranges shear zone, Glacier Bay National Park, Alaska: An example of an ancient brittle-ductile transition zone

    SciTech Connect

    Smart, K.J. . Dept. of Geological Sciences)

    1992-01-01

    The Border Ranges fault system in southern Alaska forms the tectonic boundary between the Peninsular-Alexander-Wrangellia (PAW) composite terrane and the Chugach terrane. In Glacier Bay National Park, the Border Ranges fault system is a north-northwest trending, 10 kilometer wide zone of ductile shear zones and brittle faults hereafter referred to as the Border Ranges shear zone. Three-dimensional strain analyses of plagioclase lathes in the foliated calc-alkaline plutons reveals a strong flattening fabric with the plane of maximum flattening (XY-plane) oriented northwest-southeast and dipping steeply to the southwest. The distribution and shapes of sub-elliptical mafic enclaves in the calc-alkaline plutons show a similarly oriented flattening fabric. Coeval brittle and ductile deformational processes are indicated by: (1) ductile shear zones narrowing to brittle faults at the outcrop scale; and (2) undulose quartz with subgrain development, kinked biotite, twinned and undulose feldspar, and fractured and twinned hornblende often within a single thin-section. Amphibole geobarometry indicates that two of the calc-alkaline plutons deformed by the shear zone crystallized at pressures of approximately 3 kilobars equivalent to 10 to 12 kilometers depth. Metamorphic mineral assemblages within the mylonites indicate deformation under lower greenschist facies conditions (300--400 C). The shear zone may represent a snapshot of the brittle-ductile transition of an ancient convergent-transform plate boundary. As such, this unique exposure may be an ancient analogue for the brittle-ductile transition of the present day San Andreas fault system.

  10. Seismic images of the Brooks Range fold and thrust belt, Arctic Alaska, from an integrated seismic reflection/refraction experiment

    USGS Publications Warehouse

    Levander, A.; Fuis, G.S.; Wissinger, E.S.; Lutter, W.J.; Oldow, J.S.; Moore, T.E.

    1994-01-01

    We describe results of an integrated seismic reflection/refraction experiment across the Brooks Range and flanking geologic provinces in Arctic Alaska. The seismic acquisition was unusual in that reflection and refraction data were collected simultaneously with a 700 channel seismograph system deployed numerous times along a 315 km profile. Shot records show continuous Moho reflections from 0-180 km offset, as well as numerous upper- and mid-crustal wide-angle events. Single and low-fold near-vertical incidence common midpoint (CMP) reflection images show complex upper- and middle-crustal structure across the range from the unmetamorphosed Endicott Mountains allochthon (EMA) in the north, to the metamorphic belts in the south. Lower-crustal and Moho reflections are visible across the entire reflection profile. Travel-time inversion of PmP arrivals shows that the Moho, at 33 km depth beneath the North Slope foothills, deepens abruptly beneath the EMA to a maximum of 46 km, and then shallows southward to 35 km at the southern edge of the range. Two zones of upper- and middle-crustal reflections underlie the northern Brooks Range above ~ 12-15 km depth. The upper zone, interpreted as the base of the EMA, lies at a maximum depth of 6 km and extends over 50 km from the range front to the north central Brooks Range where the base of the EMA outcrops above the metasedimentary rocks exposed in the Doonerak window. We interpret the base of the lower zone, at ~ 12 km depth, to be from carbonate rocks above the master detachment upon which the Brooks Range formed. The seismic data suggest that the master detachment is connected to the faults in the EMA by several ramps. In the highly metamorphosed terranes south of the Doonerak window, the CMP section shows numerous south-dipping events which we interpret as a crustal scale duplex involving the Doonerak window rocks. The basal detachment reflections can be traced approximately 100 km, and dip southward from about 10-12 km

  11. High fidelity does not preclude colonization: range expansion of molting Black Brant on the Arctic coast of Alaska

    USGS Publications Warehouse

    Flint, Paul L.; Meixell, Brandt W.; Mallek, Edward J.

    2014-01-01

    High rates of site fidelity have been assumed to infer static distributions of molting geese in some cases. To test this assumption, we examined movements of individually marked birds to understand the underlying mechanisms of range expansion of molting Black Brant (Branta bernicla nigricans) on the Arctic Coastal Plain (ACP) of Alaska. The Teshekpuk Lake Special Area (TLSA) on the ACP was created to protect the primary molting area of Brant. When established in 1977, the TLSA was thought to include most, if not all, wetlands used by molting Brant on the ACP. From 2010 to 2013, we surveyed areas outside the TLSA and counted an average of 9800 Brant per year, representing 29–37% of all molting Brant counted on the ACP. We captured and banded molting Brant in 2011 and 2012 both within the TLSA and outside the TLSA at the Piasuk River Delta and Cape Simpson to assess movements of birds among areas across years. Estimates of movement rates out of the TLSA exceeded those into the TLSA, demonstrating overall directional dispersal. We found differences in sex and age ratios and proportions of adult females with brood patches, but no differences in mass dynamics for birds captured within and outside the TLSA. Overall fidelity rates to specific lakes (0.81, range = 0.49–0.92) were unchanged from comparable estimates obtained in the early 1990s. We conclude that Brant are dispersing from the TLSA into new molting areas while simultaneously redistributing within the TLSA, likely as a consequence of changes in relative habitat quality. Shifts in distribution resulted from colonization of new areas by young birds as well as low levels of directional dispersal of birds that previously molted in the TLSA. Based on combined counts, the overall number of molting Brant across the ACP has increased substantially.

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

    MedlinePlus

    ... Health > American Indians/Alaska Natives Minority Women's Health American Indians/Alaska Natives Related information How to Talk to ... disease. Return to top Health conditions common in American Indian and Alaska Native women Accidents Alcoholism and drug ...

  13. Persistent organic pollutants in the blood of free-ranging sea otters (Enhydra lutris ssp.) in Alaska and California

    USGS Publications Warehouse

    Jessup, David A.; Johnson, Christine K.; Estes, James; Carlson-Bremer, Daphne; Jarman, Walter M.; Reese, Stacey; Dodd, Erin; Tinker, M. Tim; Ziccardi, Michael H.

    2010-01-01

    As part of tagging and ecologic research efforts in 1997 and 1998, apparently healthy sea otters of four age-sex classes in six locations in Alaska and three in California were sampled for persistent organic pollutants (POPs) and other chemicals of ecologic or environmental concern (COECs). Published techniques for the detection of POPs (specifically Σpolychlorinated biphenyls [PCBs], ΣDDTs, Σhexachlorocyclohexanes [HCHs], Σpolycyclic aromatic hydrocarbons [PAHs], Σchlordanes [CHLs], hexachlorobenzene [HCB], dieldrin, and mirex) in the tissue of dead otters were modified for use with serum from live sea otters. Toxic equivalencies (TEQs) were calculated for POPs with proven bioactivity. Strong location effects were seen for most POPs and COECs; sea otters in California generally showed higher mean concentrations than those in Alaska. Differences in contaminant concentrations were detected among age and sex classes, with high levels frequently observed in subadults. Very high levels of ΣDDT were detected in male sea otters in Elkhorn Slough, California, where strong freshwater outflow from agricultural areas occurs seasonally. All contaminants except mirex differed among Alaskan locations; only ΣDDT, HCB, and chlorpyrifos differed within California. High levels of ΣPCB (particularly larger, more persistent congeners) were detected at two locations in Alaska where associations between elevated PCBs and military activity have been established, while higher PCB levels were found at all three locations in California where no point source of PCBs has been identified. Although POP and COEC concentrations in blood may be less likely to reflect total body burden, concentrations in blood of healthy animals may be more biologically relevant and less influenced by state of nutrition or perimortem factors than other tissues routinely sampled.

  14. Persistent organic pollutants in the blood of free-ranging sea otters (Enhydra lutris ssp.) in Alaska and California.

    PubMed

    Jessup, David A; Johnson, Christine K; Estes, James; Carlson-Bremer, Daphne; Jarman, Walter M; Reese, Stacey; Dodd, Erin; Tinker, M Tim; Ziccardi, Michael H

    2010-10-01

    As part of tagging and ecologic research efforts in 1997 and 1998, apparently healthy sea otters of four age-sex classes in six locations in Alaska and three in California were sampled for persistent organic pollutants (POPs) and other chemicals of ecologic or environmental concern (COECs). Published techniques for the detection of POPs (specifically ∑polychlorinated biphenyls [PCBs], ∑DDTs, ∑hexachlorocyclohexanes [HCHs], ∑polycyclic aromatic hydrocarbons [PAHs], ∑chlordanes [CHLs], hexachlorobenzene [HCB], dieldrin, and mirex) in the tissue of dead otters were modified for use with serum from live sea otters. Toxic equivalencies (TEQs) were calculated for POPs with proven bioactivity. Strong location effects were seen for most POPs and COECs; sea otters in California generally showed higher mean concentrations than those in Alaska. Differences in contaminant concentrations were detected among age and sex classes, with high levels frequently observed in subadults. Very high levels of ∑DDT were detected in male sea otters in Elkhorn Slough, California, where strong freshwater outflow from agricultural areas occurs seasonally. All contaminants except mirex differed among Alaskan locations; only ∑DDT, HCB, and chlorpyrifos differed within California. High levels of ∑PCB (particularly larger, more persistent congeners) were detected at two locations in Alaska where associations between elevated PCBs and military activity have been established, while higher PCB levels were found at all three locations in California where no point source of PCBs has been identified. Although POP and COEC concentrations in blood may be less likely to reflect total body burden, concentrations in blood of healthy animals may be more biologically relevant and less influenced by state of nutrition or perimortem factors than other tissues routinely sampled.

  15. Sedimentology and stratigraphy of the Kanayut Conglomerate, central and western Brooks Range, Alaska; report of 1981 field season

    USGS Publications Warehouse

    Nilsen, T.H.; Moore, T.E.

    1982-01-01

    The Upper Devonian and Lower Mississippian(?) Kanayut Conglomerate forms a major stratigraphic unit along the crest of the Brooks Range of northern Alaska. It crops out for an east-west distance of about 900 km and a north-south distance of about 65 km. The Kanayut is wholly allochthonous and has probably been transported northward on a series of thrust plates. The Kanayut is as thick as 2,600 m in the east-central Brooks Range. It thins and fines to the south and west. The Kanayut forms the middle part of the allochthonous sequence of the Endicott Group, an Upper Devonian and Mississippian clastic sequence underlain by platform limestones of the Baird Group and overlain by platform limestone, carbonaceous shale, and black chert of the Lisburne Group. The Kanayut overlies the marine Upper Devonian Noatak Sandstone or, where it is missing, the marine Upper Devonian Hunt Fork Shale. It is overlain by the marine Mississippian Kayak Shale. The Kanayut Conglomerate forms the fluvial part of a large, coarse-grained delta that prograded to the southwest in Late Devonian time and retreated in Early Mississippian time. Four sections of the Kanayut Conglomerate in the central Brooks Range and five in the western Brooks Range were measured in 1981. The sections from the western Brooks Range document the presence of fluvial cycles in the Kanayut as far west as the shores of the Chukchi Sea. The Kanayut in this area is generally finer grained than it is in the central and eastern Brooks Range, having a maximum clast size of 3 cm. It is probably about 300 m thick. The upper and lower contacts of the Kanayut are gradational. The lower Kanayut contains calcareous, marine-influenced sandstone within channel deposits, and the upper Kanayut contains probable marine interdistributary-bay shale sequences. The members of the Kanayut Conglomerate cannot be differentiated in this region. In the central Brooks Range, sections of the Kanayut Conglomerate at Siavlat Mountain and Kakivilak

  16. 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.

  17. Mesozoic and Cenozoic tectonics of the eastern and central Alaska Range: Progressive basin development and deformation in a suture zone

    USGS Publications Warehouse

    Ridgway, K.D.; Trop, J.M.; Nokleberg, W.J.; Davidson, C.M.; Eastham, K.R.

    2002-01-01

    Analysis of late Mesozoic and Cenozoic sedimentary basins, metamorphic rocks, and major faults in the eastern and central Alaska Range documents the progressive development of a suture zone that formed as a result of collision of an island-arc assemblage (the Wrangellia composite terrane) with the former North American continental margin. New basin-analysis, structural, and geochronologic data indicate the following stages in the development of the suture zone: (1) Deposition of 3-5 km of Upper Jurassic-Upper Cretaceous marine strata (the Kahiltna assemblage) recorded the initial collision of the island-arc assemblage with the continental margin. The Kahiltna assemblage exposed in the northern Talkeetna Mountains represents a Kimmeridgian-Valanginian backarc basin that was filled by northwestward-flowing submarine-fan systems that were transporting sediment derived from Mesozoic strata of the island-arc assemblage. The Kahiltna assemblage exposed in the southern Alaska Range represents a Valanginian-Cenomanian remnant ocean basin filled by west-southwestward-flowing submarine-fan systems that were transporting sediment derived from Paleozoic continental-margin strata uplifted in the along-strike suture zone. A belt of retrograde metamorphism and a regional anticlinorium developed along the continental margin from 115 to 106 Ma, roughly coeval with the end of widespread deposition in the Kahiltna sedimentary basins. (2) Metamorphism of submarine-fan deposits of the Kahiltna basin, located near the leading edge of the island-arc assemblage, occurred at ca. 74 Ma, as determined from a new U-Pb zircon age for a synkinematic sill. Coeval with metamorphism of deposits of the Kahiltna basin in the southern part of the suture zone was development of a thrust-top basin, the Cantwell basin, in the northern part of the suture zone. Geologic mapping and compositional data suggest that the 4 km of Upper Cretaceous nonmarine and marginal marine sedimentary strata in this basin

  18. Drought-induced stomatal closure probably cannot explain divergent white spruce growth in the Brooks Range, Alaska, USA.

    PubMed

    Brownlee, Annalis H; Sullivan, Patrick F; Csank, Adam Z; Sveinbjörnsson, Bjartmar; Ellison, Sarah B Z

    2016-01-01

    Increment cores from the boreal forest have long been used to reconstruct past climates. However, in recent years, numerous studies have revealed a deterioration of the correlation between temperature and tree growth that is commonly referred to as divergence. In the Brooks Range of northern Alaska, USA, studies of white spruce (Picea glauca) revealed that trees in the west generally showed positive growth trends, while trees in the central and eastern Brooks Range showed mixed and negative trends during late 20th century warming. The growing season climate of the eastern Brooks Range is thought to be drier than the west. On this basis, divergent tree growth in the eastern Brooks Range has been attributed to drought stress. To investigate the hypothesis that drought-induced stomatal closure can explain divergence in the Brooks Range, we synthesized all of the Brooks Range white spruce data available in the International Tree Ring Data Bank (ITRDB) and collected increment cores from our primary sites in each of four watersheds along a west-to-east gradient near the Arctic treeline. For cores from our sites, we measured ring widths and calculated carbon isotope discrimination (δ13C), intrinsic water-use efficiency (iWUE), and needle intercellular CO2 concentration (C(i)) from δ13C in tree-ring alpha-cellulose. We hypothesized that trees exhibiting divergence would show a corresponding decline in δ13C, a decline in C(i), and a strong increase in iWUE. Consistent with the ITRDB data, trees at our western and central sites generally showed an increase in the strength of the temperature-growth correlation during late 20th century warming, while trees at our eastern site showed strong divergence. Divergent tree growth was not, however, associated with declining δ13C. Meanwhile, estimates of C(i) showed a strong increase at all of our study sites, indicating that more substrate was available for photosynthesis in the early 21st than in the early 20th century. Our

  19. Drought-induced stomatal closure probably cannot explain divergent white spruce growth in the Brooks Range, Alaska, USA.

    PubMed

    Brownlee, Annalis H; Sullivan, Patrick F; Csank, Adam Z; Sveinbjörnsson, Bjartmar; Ellison, Sarah B Z

    2016-01-01

    Increment cores from the boreal forest have long been used to reconstruct past climates. However, in recent years, numerous studies have revealed a deterioration of the correlation between temperature and tree growth that is commonly referred to as divergence. In the Brooks Range of northern Alaska, USA, studies of white spruce (Picea glauca) revealed that trees in the west generally showed positive growth trends, while trees in the central and eastern Brooks Range showed mixed and negative trends during late 20th century warming. The growing season climate of the eastern Brooks Range is thought to be drier than the west. On this basis, divergent tree growth in the eastern Brooks Range has been attributed to drought stress. To investigate the hypothesis that drought-induced stomatal closure can explain divergence in the Brooks Range, we synthesized all of the Brooks Range white spruce data available in the International Tree Ring Data Bank (ITRDB) and collected increment cores from our primary sites in each of four watersheds along a west-to-east gradient near the Arctic treeline. For cores from our sites, we measured ring widths and calculated carbon isotope discrimination (δ13C), intrinsic water-use efficiency (iWUE), and needle intercellular CO2 concentration (C(i)) from δ13C in tree-ring alpha-cellulose. We hypothesized that trees exhibiting divergence would show a corresponding decline in δ13C, a decline in C(i), and a strong increase in iWUE. Consistent with the ITRDB data, trees at our western and central sites generally showed an increase in the strength of the temperature-growth correlation during late 20th century warming, while trees at our eastern site showed strong divergence. Divergent tree growth was not, however, associated with declining δ13C. Meanwhile, estimates of C(i) showed a strong increase at all of our study sites, indicating that more substrate was available for photosynthesis in the early 21st than in the early 20th century. Our

  20. Three-dimensional model of an ultramafic feeder system to the Nikolai Greenstone mafic large igneous province, central Alaska Range

    USGS Publications Warehouse

    Glen, J.M.G.; Schmidt, J.M.; Connard, G.G.

    2011-01-01

    The Amphitheater Mountains and southern central Alaska Range expose a thick sequence of Triassic Nikolai basalts that is underlain by several mafic-ultramafic complexes, the largest and best exposed being the Fish Lake and Tangle (FL-T) mafic-ultramafic sills that flank the Amphitheater Mountains synform. Three-dimensional (3-D) modeling of gravity and magnetic data reveals details of the structure of the Amphitheater Mountains, such as the orientation and thickness of Nikolai basalts, and the geometry of the FL-T intrusions. The 3-D model (50 ?? 70 km) includes the full geographic extent of the FL-T complexes and consists of 11 layers. Layer surfaces and properties (density and magnetic susceptibility) were modified by forward and inverse methods to reduce differences between the observed and calculated gravity and magnetic grids. The model suggests that the outcropping FL-T sills are apparently connected and traceable at depth and reveals variations in thickness, shape, and orientation of the ultramafic bodies that may identify paths of magma flow. The model shows that a significant volume (2000 km3) of ultramafic material occurs in the subsurface, gradually thickening and plunging westward to depths exceeding 4 km. This deep ultramafic material is interpreted as the top of a keel or root system that supplied magma to the Nikolai lavas and controlled emplacement of related magmatic intrusions. The presence of this deep, keel-like structure, and asymmetry of the synform, supports a sag basin model for development of the Amphitheater Mountains structure and reveals that the feeders to the Nikolai are much more extensive than previously known. Copyright 2011 by the American Geophysical Union.

  1. 76 FR 303 - Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... From the Federal Register Online via the Government Publishing Office ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 239 and 258 Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit... proposes to approve Alaska's modification of its approved Municipal Solid Waste Landfill (MSWLF)...

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

    ERIC Educational Resources Information Center

    Smoker, William W., Ed.

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

  3. Alaska Native Participation in the Civilian Conservation Corps. Alaska Historical Commission Studies in History No. 206.

    ERIC Educational Resources Information Center

    Sorensen, Connor; And Others

    The report is a finding aid to the sources which document the 1937 federal policy decision mandating that 50% of the enrollees in the Civilian Conservation Corps (CCC) in Alaska must be Alaska Natives and provides a list of the Native CCC projects in Alaska. The finding aid section is organized according to the location of the collections and…

  4. Pingos in the Brooks Range, northern Alaska, U.S.A.

    USGS Publications Warehouse

    Hamilton, T.D.; Obi, Curtis M.

    1982-01-01

    Some 70 pingos occur at 27 separate localities within and near the Brooks Range. The pingos are distributed through mountain valleys at altitudes up to 725m and in terrain glaciated as recently as late Wisconsinan time. Pingos are particularly abundant in the Koyukuk and Chandalar drainage systems of the south-central Brooks Range, where they may be associated with structural features of regional extent.-from Authors

  5. Unified Ecoregions of Alaska: 2001

    USGS Publications Warehouse

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

    2003-01-01

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

  6. Alaska Natural Gas Transportation System

    SciTech Connect

    Jones, V.T.

    1984-04-27

    The proven reserves of natural gas in Prudhoe Bay remain the single largest block of reserves under US control. The sponsors of the Alaska Natural Gas Transportation System, including The Williams Companies, remain convinced that Alaskan gas will be increasingly important to meet future needs here in the lower 48 states. Both Canada and the US will increasingly have to turn to more costly supplies of gas as the closer, traditional areas of gas supply are exhausted. A principal motivation for Canada's participation in the ANGTS was the prospect of a jointly sponsored pipeline through Canada which would facilitate bringing frontier gas to market - through the so-called Dempster lateral. The high cost of transportation systems in the Artic necessitates pipelines with large capacities in order to minimize the cost of transportation per unit of gas delivered. It is clear that Canada still strongly supports the ANGTS project as a means of opening up the frontier resources of both Alaska and Canada.

  7. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    USGS Publications Warehouse

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

    2014-01-01

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

  8. Geophysical investigation of a Suture Zone: The Border Ranges Fault of southern Alaska

    NASA Astrophysics Data System (ADS)

    Fisher, Michael A.; von Huene, Roland

    1984-12-01

    The Border Ranges fault separates structurally complex accreted Cretaceous rocks from less deformed middle or late Paleozoic and younger rocks in the Cook-Shelikof basin. Of the five types of geophysical data used to investigate this fault, gravity data give the clearest indication of its presence and crustal structure. For at least 400 km along the fault, gravity anomalies include a +20 to +30 mGal peak along the fault's upper plate and a -40 mGal trough along the lower plate. The paired anomaly can be modeled satisfactorily by a simple step, in a deep dense layer, that lies within 3 km of the projected offshore location of the fault. Relatively low-density rocks lie along the fault's lower plate to a depth of about 10 km, and the upper part of the fault dips within 20° of vertical. Satellite altimetry data show that two circular geoid lows lie along the Border Ranges fault and coincide with lows in free air gravity data. Seismic refraction and seismic reflection data suggest that the large-scale density anomalies that cause both types of lows must lie at depths greater than about 1 km within the margin. Three regional magnetic anomalies (Knik Arm, Seldovia, and Shelikof) terminate at the Border Ranges fault, suggesting that the fault truncates obliquely rocks that lie along its northwest side. Six seismic reflection lines cross the Border Ranges fault, but none of them shows reflections from it. The absence of such reflections probably results from the fault's steep dip and from the presence of strong water bottom multiples in the data. From the Late Jurassic until the early Late Cretaceous, the magmatic arc near the Cook-Shelikof basin was inactive, and we infer that the predominant motion along the Border Ranges fault was strike slip. Resurgent Late Cretaceous magmatism was contemporaneous with uplift of rocks along the northwest side of the Border Ranges fault and with deformation of turbidite sequences in the fault's lower plate. We propose that during the

  9. Lisburne Group (Mississippian-Lower Permian) petrography, paragenesis, and hydrocarbon potential, central Brooks Range, Alaska

    SciTech Connect

    Krutak, P.R.

    1989-03-01

    Subsurface Lisburne Group (Wahoo) rocks at Prudhoe Bay-Kuparuk fields produce 2 million bbl of oil/day and contain 2-3 billion bbl of oil in place. Lisburne reservoirs are early diagenetic dolomites encased in thick platform carbonates. Petrographic and geochemical study of 264 samples from eight newly discovered surface Lisburne sections comprising 4568 ft of strata in the Central Brooks Range provide new data concerning paragenesis and hydrocarbon potential of Lisburne facies farther west. A generalized paragenetic sequence for Lisburne equivalents of this region is (1) initial carbonate skeletal growth (both aragonite and calcite) during the Carboniferous, (2) subsequent recrystallization and inversion of aragonite to calcite, the change to calcite proceeding throughout late Paleozoic and Permian-Triassic time, (3) dolomitization in the Middle and Late Carboniferous, (4) chertification and silicification, postdating slightly or overlapping dolomitization, (5) development of porosity (moldic, intracrystal, etc.) in the middle to late Mesozoic, (6) formation of fracture porosity concurrent with the Brooks Range orogeny during Middle Jurassic-Cretaceous time, (7) oil generation, migration, and emplacement in Late Cretaceous-Tertiary time. Lisburne dolomites from the Central Brooks Range bear heavy hydrocarbons. Rock-Eval pyrolysis indicates part of the section is in the oil window and near the peak wet-gas generation zone. Shale samples from this region display thermal alteration indices and vitrinite reflectance values near the oil floor and also indicate potential for sourcing dry gas. Conodont color alteration indices show part of the Lisburn could produce dry gas.

  10. Facies comparison of autochthonous and allochthonous Permian and Triassic units, north-central Brooks Range, Alaska

    SciTech Connect

    Adams, K.E.

    1985-04-01

    Eight stratigraphic sections of Permian and Triassic rocks have been studied over a 30 km by 150 km area in the Endicott and Philip Smith Mountains of the central Brooks Range. Six of the sections are located on the Endicott Mountains allochthon, and the remaining two are parautochthonous columns in the Mount Doonerak area. The sections record a facies transition between the autochthonous Sadlerochit Group and Shublik Formation of the northeastern Brooks Range and the characteristically siliceous rocks of the allochthonous Siksikpuk and Otuk formations of the western Brooks Range. Laterally continuous and bioturbated beds of fine-grained sandstone, siltstone, and shale dominantly compose the Permian sequence, whereas the Triassic rocks consist of black shales, thin rhythmically bedded siliceous mudstones, and fossiliferous limestones. When the allochthonous sections are restored to a position south of the Mount Doonerak area, a general shallowing trend from southwest to northwest becomes evident within the reconstructed marine basin. To the south and west, the Permian sediments show a marked increase in silica content, with the occurrence of barite and a corresponding decrease in the thickness of the basal, coarser grained clastics. The Triassic formations also document an increase in silica and the presence of barite to the south and west, while becoming significantly sooty and phosphatic to the north and east. Ongoing petrographic and micropaleontologic studies of the field data will clarify these general paleogeographic relationships.

  11. Holocene coastal glaciation of Alaska

    NASA Astrophysics Data System (ADS)

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

    2001-01-01

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

  12. Sandia National Laboratories land use permit for operations at Oliktok Alaska Long Range Radar Station.

    SciTech Connect

    Catechis, Christopher Spyros

    2013-02-01

    The property subject to this Environmental Baseline Survey (EBS) is located at the Oliktok Long Range Radar Station (LRRS). The Oliktok LRRS is located at 70À 30 W latitude, 149À 53 W longitude. It is situated at Oliktok Point on the shore of the Beaufort Sea, east of the Colville River. The purpose of this EBS is to document the nature, magnitude, and extent of any environmental contamination of the property; identify potential environmental contamination liabilities associated with the property; develop sufficient information to assess the health and safety risks; and ensure adequate protection for human health and the environment related to a specific property.

  13. Structural provinces of the northeastern Brooks Range, Arctic National Wildlife Refuge, Alaska

    SciTech Connect

    Wallace, W.K.; Hanks, C.L. )

    1990-07-01

    The dominant Cenozoic structures of the northeastern Brooks Range are anticlinoria with cores of sub-Mississippian rocks, reflecting a regional north-vergent duplex with a floor thrust in the sub-Mississippian sequence and a roof thrust in the Mississippian Kayak Shale. The number of horses forming each anticlinorium and the structural style of the overlying Mississippian and younger cover sequence varies regionally, providing a basis for dividing the northeastern Brooks Range into structural provinces. In the western province, each anticlinorium contains a single horse, and shortening above the Kayak Shale was accommodated mainly by detachment folds. To the north in the Sadlerochit Mountains, the Kayak Shale is depositionally discontinuous and rocks elsewhere separated by this detachment deformed together. In the eastern province, each anticlinorium contains multiple horses, and shortening above the Kayak Shale was accommodated largely by thrust duplication of Mississippian through Triassic rocks. In the narrow central province, the Devonian Okpilak batholith was detached from its roots, internally shortened along shear zones and by penetrative strain, and transported northward. Because the Kayak Shale is locally absent, the Mississippian and younger cover sequence deformed in part penetratively along with the batholith. 13 figs.

  14. The Cenozoic structural evolution of a fold-and-thrust belt, northeastern Brooks Range, Alaska

    SciTech Connect

    Hanks, C.L. )

    1993-03-01

    A Cenozoic fold-and-thrust belt in the eastern structural province of the northeastern Brooks Range exposes polydeformed low-grade metasedimentary and metavolcanic rocks of the pre-Mississippian basement and its sedimentary cover immediately adjacent to much younger foredeep deposits. Analysis of mesoscopic and map-scale structures in the range-front region suggests that at least one pre-Mississippian deformational event was recorded into the basement sequence by north-vergent fold-and-thrust structures and associated penetrative structures. Most of later Cenozoic shortening of the pre-Mississippian rocks was accommodated by thrust duplication, with little development of penetrative mesoscopic structures. Although separated from the underlying basement rocks by a major regional decollement horizon, Cenozoic deformation in the overlying Mississippian through Lower Cretaceous cover sequence also was primarily by thrust duplication. Although local and regional structural trends within the cover sequence suggest that Cenozoic deformation was north-northwest directed, east-west Cenozoic structural trends within the pre-Mississippian rocks may reflect an inherited pre-Mississippian structural grain and/or pre-Mississippian-age structures reactivated during Cenozoic deformation. A regional balanced cross section of the eastern structural province was constructed. 29 refs., 14 figs.

  15. Plutonic rocks of Jurassic age in the Alaska-Aleutian Range batholith: chemical variation and polarity.

    USGS Publications Warehouse

    Reed, B.I.; Miesch, A.T.; Lanphere, M.A.

    1983-01-01

    Plutonic rocks of Jurassic age exposed on the Pacific side of this batholith form a compositionally continuous calc-alkaline suite that ranges from hornblende gabbro to quartz monzonite. Tonalite and quartz diorite are the dominant rock types. Trend-surface analysis of 102 samples indicates that the direction of slope of the trend is approximately normal to the Jurassic magmatic arc. K2O and SiO2 increase towards the E-SE and the other oxides towards the W-NW. If the chemical trends reflect the approximate geometry of a palaeo-subduction zone, the polarity of the Jurassic magmatic arc is to the NW, i.e. subduction was directed towards the SE. Thus the palaeo-subduction zone is on the opposite side of the arc from the position that has generally been assumed, indicating that the Jurassic plutonic rocks were not generated in response to classical Andean-type convergent plate margins. The magmatic arc may have been formed in an intra-ocean environment and subsequently has been rafted northwards and accreted to this part of the N Pacific rim during the late Mesozoic. Middle and Upper Jurassic clastics underlying Cook Inlet to the SE and derived from the magmatic arc are classified as back-arc deposits, rather than as an arc-trench gap sequence.-L.C.H.

  16. The crustal section of the Siniktanneyak Mountain ophiolite, Brooks Range, Alaska

    SciTech Connect

    Bickerstaff, D.; Harris, R.A.; Miller, M.A. . Dept. of Geology and Geography)

    1993-04-01

    Fragments of the upper crustal section of the Brooks Range Ophiolite on the west flank of Siniktanneyak Mountain expose important contact relations and paleohorizontal indicators. The nearly complete crustal sequence faces northwest. Based on field observations, the crustal units encountered at Siniktanneyak Mountain from bottom to top are: (1) layered gabbro, (2) isotropic gabbro, (3) high level and late-stage intrusions of diorite and diabase, (4) rare sheeted dikes, (5) basalt, and (6) a bedded volcanic tuff. Potassium feldspar-bearing pegmatites are also found. Of particular interest is the orientation of the layered gabbro, sheeted dikes, and the bedded volcanic tuff. The steeply dipping gabbro layers strike N-S, the adjacent vertical sheeted dikes strike NE-SW. Bedded volcanic tuff and lavas are flat lying. Contacts within the upper crust units are often covered by talus. Contacts between various plutonic rocks are both sharp and gradational, suggesting syn- and post-cooling intrusions. Contacts between plutonic rock and higher volcanic rock appear to be fault contacts.

  17. Lateral continuity of the Blarney Creek Thrust, Doonerak Windown, Central Brooks Range, Alaska

    SciTech Connect

    Seidensticker, C.M.; Julian, F.E.; Phelps, J.C.; Oldow, J.S.; Avellemant, H.G.

    1985-04-01

    The contact between Carboniferous and lower Paleozoic rocks, exposed along the northern margin of the Doonerak window in the central Brooks Range, is a major thrust fault called the Blarney Creek thrust (BCT). The BCT has been traced over a distance of 25 km, from Falsoola Mountain to Wien Mountain. The tectonic nature of this contact is demonstrated by: (1) omission of stratigraphic units above and below the BCT; (2) large angular discordance in orientation of first-generation cleavage at the BCT; (3) numerous thrust imbricates developed in the upper-plate Carboniferous section that sole into the BCT; and (4) truncation of an upper-plate graben structure at the BCT. Lack of evidence for pre-Carboniferous deformation in the lower plate casts doubt on the interpretation of the contact as an angular unconformity. However, the localized presence below the BCT of Mississippian Kekiktuk Conglomerate and Kayak Shale, in apparent depositional contact with lower Paleozoic rocks, suggests that the BCT follows an originally disconformable contact between the Carboniferous and lower Paleozoic rocks. The juxtaposition of younger over older rocks at the BCT is explained by calling upon the BCT to act as the upper detachment surface of a duplex structure. Duplex development involves initial imbrication of the Carboniferous section using the BCT as a basal decollement, followed by formation of deeper thrusts in the lower Paleozoic section, which ramp up and merge into the BCT.

  18. Structure and petrology of the La Perouse gabbro intrusion, Fairweather Range, southeastern Alaska.

    USGS Publications Warehouse

    Loney, R.A.; Himmelberg, G.R.

    1983-01-01

    The gabbro was intruded during the Middle Tertiary into a Mesozoic granulite-facies metamorphic environment dominated by strike-slip fault movement, compression and possible minor subduction. The asymmetric funnel form of the intrusion is due to subsidence from magmatic loading at high T, coupled with control from pre-existing structures, and not from tectonic compression. The intrusion is 12 X 27 km and has exposed cumulate layering of approx 6000 m. Probe analyses of olivines (24), Ca-poor pyroxenes (28), augites (22) and plagioclases (35) are tabulated. Cumulus mineral compositions in the basal cumulates are: olivine Fo86-71, plagioclase An81-63, bronzite Ca3Mg82Fe15 - Ca4Mg75Fe21, augite Ca45Mg47Fe8 - Ca42Mg48Fe10. The layered gabbro above the basal cumulates consists dominantly of lenticularly interlayered plagioclase-augite-orthopyroxene-olivine, plagioclase-augite- olivine and plagioclase-orthopyroxene-augite cumulates, the composition ranges being olivine Fo75-50, plagioclase An78-42, orthopyroxene and inverted pigeonite Ca2.8Mg76.4Fe20.8 - Ca1.4Mg31.0Fe67.6, augite Ca43.1Mg46.9Fe10.0 - Ca40.5Mg27.1Fe32.4. The most iron-rich pyroxene and albite-rich plagioclase occur in a zone near the margin of the intrusion and are probably related to exchange reactions with the country rock. It is considered that the gabbro did not accumulate by simple fractional crystallization of a single or even several large batches of magma, but by numerous influxes of previously fractionated magma from a deeper reservoir. Conditions of crystallization are interpreted as approx 1055oC, 5.4 kbar and fO2 near the wustite-magnetite buffer.-R.A.H.

  19. Multistory duplexes with forward dipping roofs, north central Brooks Range, Alaska

    USGS Publications Warehouse

    Wallace, W.K.; Moore, T.E.; Plafker, G.

    1997-01-01

    The Endicott Mountains allochthon has been thrust far northward over the North Slope parautochthon in the northern Brooks Range. Progressively younger units are exposed northward within the allochthon. To the south, the incompetent Hunt Fork Shale has thickened internally by asymmetric folds and thrust faults. Northward, the competent Kanayut Conglomerate forms a duplex between a floor thrust in Hunt Fork and a roof thrust in the Kayak Shale. To the north, the competent Lisburne Group forms a duplex between a floor thrust in Kayak and a roof thrust in the Siksikpuk Formation. Both duplexes formed from north vergent detachment folds whose steep limbs were later truncated by south dipping thrust faults that only locally breach immediately overlying roof thrusts. Within the parautochthon, the Kayak, Lisburne, and Siksikpuk-equivalent Echooka Formation form a duplex identical to that in the allochthon. This duplex is succeeded abruptly northward by detachment folds in Lisburne. These folds are parasitic to an anticlinorium interpreted to reflect a fault-bend folded horse in North Slope "basement," with a roof thrust in Kayak and a floor thrust at depth. These structures constitute two northward tapered, internally deformed wedges that are juxtaposed at the base of the allochthon. Within each wedge, competent units have been shortened independently between detachments, located mainly in incompetent units. The basal detachment of each wedge cuts upsection forward (northward) to define a wedge geometry within which units dip regionally forward. These dips reflect forward decrease in internal structural thickening by forward vergent folds and hindward dipping thrust faults. Copyright 1997 by the American Geophysical Union.

  20. Amchitka, Alaska Site Fact Sheet

    SciTech Connect

    2011-12-15

    Amchitka Island is near the western end of the Aleutian Island chain and is the largest island in the Rat Island Group that is located about 1,340 miles west-southwest of Anchorage, Alaska, and 870 miles east of the Kamchatka Peninsula in eastern Russia. The island is 42 miles long and 1 to 4 miles wide, with an area of approximately 74,240 acres. Elevations range from sea level to more than 1,100 feet above sea level. The coastline is rugged; sea cliffs and grassy slopes surround nearly the entire island. Vegetation on the island is low-growing, meadow-like tundra grasses at lower elevations. No trees grow on Amchitka. The lowest elevations are on the eastern third of the island and are characterized by numerous shallow lakes and heavily vegetated drainages. The central portion of the island has higher elevations and fewer lakes. The westernmost 3 miles of the island contains a windswept rocky plateau with sparse vegetation.

  1. Frozen debris lobes, permafrost slope instability, and a potential infrastructure hazard in the south-central Brooks Range of Alaska

    NASA Astrophysics Data System (ADS)

    Daanen, R. P.; Darrow, M.; Grosse, G.; Jones, B. M.

    2012-12-01

    Here we report on investigations carried out at unusual debris mass-movement features (frozen debris lobes) on permafrost slopes in the south central portion of the Brooks Range of northern Alaska. The features under investigation are located in mountainous terrain near the southern border of continuous permafrost. The frozen debris lobes consist mainly of boulders, cobles, platy gravel sand and silt frozen debris derived from weathering mountain tops. The general dimensions of these lobes are either lobate or tongue shaped with widths up to 500 m and lengths up to 1200 m. In accumulation zones where slopes converge, the debris slowly moves as solifluction lobes, mud flows and potentially sliding toward the valley. These features were previously referred to as stable rock glaciers in the past, as evidenced by a dense cover of vegetation, and exhibiting no known downslope movement. Our investigations however, have shown that these features are indeed moving downslope as a result of creep, slumping, viscous flow, blockfall and leaching of fines in the summer; and in cold seasons by creep and sliding of frozen sediment slabs. Movement indicators observed in the field include toppling trees, slumps and scarps, detachment slides, striation marks on frozen sediment slabs, recently buried trees and other vegetation, mudflows, and large cracks in the lobe surface. Ground-based measurements on one frozen debris-lobe over three years (2008-2010) revealed average movement rates of approximately 1 cm day-1, which is substantially larger than rates measured in historic aerial photography from the 1950s to 1980s. Current observations , through lidar, ifsar, insar and ground based measurements using boreholes, geophysics and repeat photography of these features show an increase in movement activity that could be the result of rising summer temperatures in the region. Warming of ice rich permafrost slopes and frozen debris lobes in the Brooks Range pose a direct threat to the

  2. VEGETATION MEDIATED THE IMPACTS OF POSTGLACIAL CLIMATIC CHANGE ON FIRE REGIMES IN THE SOUTHCENTRAL BROOKS RANGE, ALASKA

    SciTech Connect

    Higuera, P E; Brubaker, L B; Anderson, P M; Hu, F S; Brown, T A

    2008-10-28

    We examine direct and indirect impacts of millennial-scale climatic change on fire regimes in the southcentral Brooks Range, Alaska, using four lake-sediment records and existing paleoclimate interpretations. New techniques are introduced to identify charcoal peaks semi-objectively and detect statistical differences in fire regimes. Peaks in charcoal accumulation rates (CHARs) provide estimates of fire return intervals (FRIs) which are compared between vegetation zones described by fossil pollen and stomata. Climatic warming from ca 15-9 ka BP (calendar years before CE 1950) coincides with shifts in vegetation from herb tundra to shrub tundra to deciduous woodlands, all novel species assemblages relative to modern vegetation. Two sites cover this period and show increased CHARs and decreased FRIs with the transition from herb to shrub tundra ca 13.3-14.3 ka BP. Short FRIs in the Betula-dominated shrub tundra (mean [m] FRI 144 yr; 95% CI 119-170) primarily reflect the effects of flammable, continuous fuels on the fire regime. FRIs increased significantly with the transition to Populus-dominated deciduous woodlands ca 10.5 ka BP (mFRI 251 yr [158-352]), despite evidence of warmer- and drier-than-present summers. We attribute reduced fire activity under these conditions to low flammability of deciduous fuels. Three sites record the mid to late Holocene, when cooler and moister conditions allowed Picea glauca forest-tundra and P. mariana boreal forests to establish ca 8 and 5.5 ka BP. Forest-tundra FRIs did not differ significantly from the previous period (mFRIs range from 131-238 yr), but FRIs decreased with the transition to boreal forest (mFRI 145 yr [129-163]). Overall, fire-regime shifts in the study area showed greater correspondence with vegetation characteristics than with inferred climate, and we conclude that vegetation mediated the impacts of millennial-scale climatic change on fire regimes by modifying landscape flammability. Our findings emphasize the

  3. Regional variations in the fluvial Upper Devonian and Lower Mississippian(?) Kanayut Conglomerate, Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Moore, Thomas E.; Nilsen, Tor H.

    1984-03-01

    The wholly allochthonous Upper Devonian and Lower Mississippian(?) Kanayut Conglomerate is one of the most extensive fluvial deposits in North America. It crops out for 950 km along the crest of the Brooks Range in a series of thrust plates and is as thick as 2615 m. The Kanayut forms the fluvial part of a large, coarse-grained delta. The lower part of the Kanayut (the Ear Peak Member) overlies marginal-marine and prodelta turbidite deposits and consists of fining-upward meandering-stream-channel cycles of conglomerate and sandstone within black to maroon floodplain shale deposits. The middle part of the Kanayut (the Shainin Lake Member) lacks shale and consists of fining-upward couplets of channelized conglomerate and parallel- to cross-stratified sandstone interpreted as braidplain deposits. These deposits contain the largest clasts (23 cm) and were deposited during maximum progradation of the fluvial sequence. The upper part of the Kanayut (the Stuver Member), which consists of fining-upward meandering stream cycles similar to those of the lower part, grades upward into overlying Lower Mississippian tidal and marginal-marine deposits. Paleocurrent data and distribution of largest clasts indicate that the Kanayut was deposited by southwest-flowing streams fed by at least two major trunk streams that drained a mountainous region to the north and east. Comparison of stratigraphic and sedimentologic data collected at three selected locations representative of proximal, intermediate and distal parts of the Kanayut basin reveal regional variations in its fluvial character. These include a decrease in total thickness of fluvial strata, an increase in total thickness of associated marine sandstone, the pinch-out of the coarse-grained middle part of the Kanayut and decreases in the conglomerate/sandstone and sandstone/shale ratios from proximal to distal areas of the basin. The coarse-grained parts of the fluvial cycles decrease in thickness and lateral extent from

  4. Regional variations in the fluvial Upper Devonian and Lower Mississippian(?) Kanayut Conglomerate, Brooks Range, Alaska

    USGS Publications Warehouse

    Moore, T.E.; Nilsen, T.H.

    1984-01-01

    The wholly allochthonous Upper Devonian and Lower Mississippian(?) Kanayut Conglomerate is one of the most extensive fluvial deposits in North America. It crops out for 950 km along the crest of the Brooks Range in a series of thrust plates and is as thick as 2615 m. The Kanayut forms the fluvial part of a large, coarse-grained delta. The lower part of the Kanayut (the Ear Peak Member) overlies marginal-marine and prodelta turbidite deposits and consists of fining-upward meandering-stream-channel cycles of conglomerate and sandstone within black to maroon floodplain shale deposits. The middle part of the Kanayut (the Shainin Lake Member) lacks shale and consists of fining-upward couplets of channelized conglomerate and parallel- to cross-stratified sandstone interpreted as braidplain deposits. These deposits contain the largest clasts (23 cm) and were deposited during maximum progradation of the fluvial sequence. The upper part of the Kanayut (the Stuver Member), which consists of fining-upward meandering stream cycles similar to those of the lower part, grades upward into overlying Lower Mississippian tidal and marginal-marine deposits. Paleocurrent data and distribution of largest clasts indicate that the Kanayut was deposited by southwest-flowing streams fed by at least two major trunk streams that drained a mountainous region to the north and east. Comparison of stratigraphic and sedimentologic data collected at three selected locations representative of proximal, intermediate and distal parts of the Kanayut basin reveal regional variations in its fluvial character. These include a decrease in total thickness of fluvial strata, an increase in total thickness of associated marine sandstone, the pinch-out of the coarse-grained middle part of the Kanayut and decreases in the conglomerate/sandstone and sandstone/shale ratios from proximal to distal areas of the basin. The coarse-grained parts of the fluvial cycles decrease in thickness and lateral extent from

  5. Alaska Volcano Observatory at 20

    NASA Astrophysics Data System (ADS)

    Eichelberger, J. C.

    2008-12-01

    The Alaska Volcano Observatory (AVO) was established in 1988 in the wake of the 1986 Augustine eruption through a congressional earmark. Even within the volcanological community, there was skepticism about AVO. Populations directly at risk in Alaska were small compared to Cascadia, and the logistical costs of installing and maintaining monitoring equipment were much higher. Questions were raised concerning the technical feasibility of keeping seismic stations operating through the long, dark, stormy Alaska winters. Some argued that AVO should simply cover Augustine with instruments and wait for the next eruption there, expected in the mid 90s (but delayed until 2006), rather than stretching to instrument as many volcanoes as possible. No sooner was AVO in place than Redoubt erupted and a fully loaded passenger 747 strayed into the eruption cloud between Anchorage and Fairbanks, causing a powerless glide to within a minute of impact before the pilot could restart two engines and limp into Anchorage. This event forcefully made the case that volcano hazard mitigation is not just about people and infrastructure on the ground, and is particularly important in the heavily traveled North Pacific where options for flight diversion are few. In 1996, new funding became available through an FAA earmark to aggressively extend volcano monitoring far into the Aleutian Islands with both ground-based networks and round-the-clock satellite monitoring. Beyond the Aleutians, AVO developed a monitoring partnership with Russians volcanologists at the Institute of Volcanology and Seismology in Petropavlovsk-Kamchatsky. The need to work together internationally on subduction phenomena that span borders led to formation of the Japan-Kamchatka-Alaska Subduction Processes (JKASP) consortium. JKASP meets approximately biennially in Sapporo, Petropavlovsk, and Fairbanks. In turn, these meetings and support from NSF and the Russian Academy of Sciences led to new international education and

  6. Geophysical data reveal the crustal structure of the Alaska Range orogen within the aftershock zone of the Mw 7.9 Denali fault earthquake

    USGS Publications Warehouse

    Fisher, M.A.; Ratchkovski, N.A.; Nokleberg, W.J.; Pellerin, L.; Glen, J.M.G.

    2004-01-01

    Geophysical information, including deep-crustal seismic reflection, magnetotelluric (MT), gravity, and magnetic data, cross the aftershock zone of the 3 November 2002 Mw 7.9 Denali fault earthquake. These data and aftershock seismicity, jointly interpreted, reveal the crustal structure of the right-lateral-slip Denali fault and the eastern Alaska Range orogen, as well as the relationship between this structure and seismicity. North of the Denali fault, strong seismic reflections from within the Alaska Range orogen show features that dip as steeply as 25?? north and extend downward to depths between 20 and 25 km. These reflections reveal crustal structures, probably ductile shear zones, that most likely formed during the Late Cretaceous, but these structures appear to be inactive, having produced little seismicity during the past 20 years. Furthermore, seismic reflections mainly dip north, whereas alignments in aftershock hypocenters dip south. The Denali fault is nonreflective, but modeling of MT, gravity, and magnetic data suggests that the Denali fault dips steeply to vertically. However, in an alternative structural model, the Denali fault is defined by one of the reflection bands that dips to the north and flattens into the middle crust of the Alaska Range orogen. Modeling of MT data indicates a rock body, having low electrical resistivity (>10 ??-m), that lies mainly at depths greater than 10 km, directly beneath aftershocks of the Denali fault earthquake. The maximum depth of aftershocks along the Denali fault is 10 km. This shallow depth may arise from a higher-than-normal geothermal gradient. Alternatively, the low electrical resistivity of deep rocks along the Denali fault may be associated with fluids that have weakened the lower crust and helped determine the depth extent of the after-shock zone.

  7. Neogene transpressional foreland basin development on the north side of the central alaska range, usibelli group and nenana gravel, tanana basin

    USGS Publications Warehouse

    Ridgway, K.D.; Thoms, E.E.; Layer, P.W.; Lesh, M.E.; White, J.M.; Smith, S.V.

    2007-01-01

    Neogene strata of the Tanana basin provide a long-term record of a northwardpropagating, transpressional foreland-basin system related to regional shortening of the central Alaska Range and strike-slip displacement on the Denali fault system. These strata are ???2 km thick and have been deformed and exhumed in thrust faults that form the foothills on the north side of the Alaska Range. The lower part of the sedimentary package, the Usibelli Group, consists of 800 m of mainly Miocene strata that were deposited in fluvial, lacustrine, and peat bog environments of the foredeep depozone of the foreland-basin system. Compositional data from conglomerate and sandstone, as well as recycled Upper Cretaceous palynomorphs, indicate that the Miocene foreland-basin system was supplied increasing amounts of sediment from lithologies currently exposed in thrust sheets located south of the basin. The upper part of the sedimentary package, the Nenana Gravel, consists of 1200 m of mainly Pliocene strata that were deposited in alluvial-fan and braidplain environments in the wedge-top depozone of the foreland-basin system. Compositional data from conglomerate and sandstone, as well as 40Ar/39Ar dating of detrital feldspars in sandstone and from granitic clasts in conglomerate, indicate that lithologies exposed in the central Alaska Range provided most of the detritus to the Pliocene foreland-basin system. 40Ar/39Ar dates from detrital feldspar grains also show that two main suites of plutons contributed sediment to the Nenana Gravel. Detrital feldspars with an average age of 56 Ma are interpreted to have been derived from the McKinley sequence of plutons located south of the Denali fault. Detrital feldspars with an average age of 34 Ma are interpreted to have been derived from plutons located north of the Denali fault. Plutons located south of the Denali fault provided detritus for the lower part of the Nenana Gravel, whereas plutons located north of the Denali fault began to

  8. Alaska School District Cost Study Update

    ERIC Educational Resources Information Center

    Tuck, Bradford H.; Berman, Matthew; Hill, Alexandra

    2005-01-01

    The Legislative Budget and Audit Committee of the Alaska Legislature has asked The Institute of Social and Economic Research (ISER) at the University of Alaska Anchorage to make certain changes and adjustments to the Geographic Cost of Education Index (GCEI) that the American Institutes for Research (AIR) constructed and reported on in Alaska…

  9. Bill Demmert and Native Education in Alaska

    ERIC Educational Resources Information Center

    Barnhardt, Ray

    2011-01-01

    This article describes the influences of William Demmert's formative years growing up in Alaska and his years as an educator of Native American students upon his career in Native education policy. It focuses on Alaska Native education during a ten-year period between 1980 and 1990 during which time he served as the director of the Center for…

  10. Women's Legal Rights in Alaska. Reprint.

    ERIC Educational Resources Information Center

    Tatter, Sue Ellen; Saville, Sandra K.

    This publication is intended to help women in Alaska learn about their legal rights. Some of the information is of a general nature and will be of interest to women in other states. Some of the laws and resources are relevant to Alaska only. The publication can serve as a model to other states wanting to develop a resource to inform women about…

  11. Culturally Responsive Guidelines for Alaska Public Libraries.

    ERIC Educational Resources Information Center

    Alaska Univ., Fairbanks. Alaska Native Knowledge Network.

    These guidelines are predicated on the belief that culturally appropriate service to indigenous peoples is a fundamental principle of Alaska public libraries. While the impetus for developing the guidelines was service to the Alaska Native community, they can also be applied to other cultural groups. A culturally responsive library environment is…

  12. Building a Workforce Development System in Alaska

    ERIC Educational Resources Information Center

    Spieker, Sally

    2004-01-01

    The Alaska Human Resources Investment Council developed a blueprint to guide a system that is needs-driven, accessible, interconnected, accountable, sustainable, and has collaborative governance. Vocational Technical Education Providers (VTEP) representing secondary education, technical schools, proprietary institutions, the University of Alaska,…

  13. Distance Learning in Alaska's Rural Schools.

    ERIC Educational Resources Information Center

    Bramble, William J.

    1986-01-01

    The distance education and instructional technology projects that have been undertaken in Alaska over the last decade are detailed in this paper. The basic services offered by the "Learn Alaska Network" are described in relation to three user groups: K-12 education; postsecondary education; and general public education and information. The audio…

  14. 77 FR 16314 - Alaska Disaster #AK-00024

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... ADMINISTRATION Alaska Disaster AK-00024 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Alaska dated 03/13/2012... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  15. 78 FR 39822 - Alaska Disaster #AK-00028

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... ADMINISTRATION Alaska Disaster AK-00028 AGENCY: U.S. Small Business Administration. ACTION: Notice SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Alaska (FEMA-4122-DR... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  16. 75 FR 43199 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... approving the conveyance of surface estate for certain lands to Beaver Kwit'chin Corporation, pursuant to... Doyon, Limited when the surface estate is conveyed to Beaver Kwit'chin Corporation. The lands are in the vicinity of Beaver, Alaska, and are located in: Fairbanks Meridian, Alaska T. 16 N., R. 1 E., Secs. 1 to...

  17. 77 FR 21802 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... Kongnikilnomuit Yuita Corporation. The lands are in the vicinity of Bill Moore's Slough, Alaska, and are located... conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq). The subsurface... hours. Jennifer Noe, Land Law Examiner, Land Transfer Adjudication II Branch. BILLING CODE 4310-JA-P...

  18. Alaska Head Start. Annual Report for 1998.

    ERIC Educational Resources Information Center

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

    This annual report details the accomplishments of the Alaska Head Start Program for fiscal year 1998. The report begins with a graphic presentation of the locations of Alaska Head Start programs and a table delineating the administrative and program partners of Head Start, its service population, eligibility requirements, funding sources, service…

  19. Facts & Figures about Education in Alaska, 1992.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    This collection of tables presents selected facts and figures about education in Alaska. General and district school information about Alaska's 469 public schools in 54 districts and its 276 private and denominational schools is followed by tables of general student information, including average daily membership, enrollment, graduates, and…

  20. Integrating Intercultural Education: The Anchorage Alaska Experience.

    ERIC Educational Resources Information Center

    Fenton, Ray

    The desire for students to understand and respect each other is a primary motivation for the effort to integrate multicultural education into all aspects of the Anchorage School District (Alaska) curriculum. The Anchorage curriculum emphasizes the cultural heritage of Alaska Natives, other resident ethnic groups and Pacific Rim cultures. In recent…

  1. Viewpoints: Reflections on the Principalship in Alaska.

    ERIC Educational Resources Information Center

    Hagstrom, David A., Ed.

    In this collection, 32 Alaskan principals, retired principals, assistant principals, and principals-to-be share their experiences as administrators and reflect on their feelings about the nature of the work and about schooling issues in Alaska. Nine of the writings were selected from "Totem Tales," the newsletter of Alaska's Association of…

  2. Regional structural framework and petroleum assessment of the Brooks Range foothills and southern coastal plain, National Petroleum Reserve, Alaska

    USGS Publications Warehouse

    Potter, Christopher J.; Moore, Thomas E.; O'Sullivan, Paul B.; Miller, John J.

    2002-01-01

    The transects, along with other seismic-reflection examples, illustrate four play concepts being used in the deformed area for the 2002 U.S. Geological Survey oil and gas assessment of the National Petroleum Reserve-Alaska (NPRA). The Brookian topset structural play includes broad west-northwest-trending anticlines in the Cretaceous Nanushuk Group, developed above structurally thickened Torok mudstones in the incipiently-deformed, most northerly part of the thrust system. The Torok structural play includes prominent anticlines affecting deep-basin sandstones, many of which are detached from folds exposed at the surface. The Ellesmerian structural play includes closures developed in the clastic part of the Ellesmerian sequence, mainly above a detachment in the Shublik Formation. The thrust belt play includes antiformal stacks of allochthonous Endicott Group clastic rocks and Lisburne Group carbonates; these stacks were assembled at about 120 Ma, and were transported to their present positions in the foothills at about 60 Ma.

  3. Mantle Transition Zone Discontinuities Beneath Alaska

    NASA Astrophysics Data System (ADS)

    Dahm, H. H.; Gao, S. S.; Liu, K. H.; Yang, B.

    2015-12-01

    The 410 and 660 km discontinuities (d410 and d660) beneath Alaska and adjacent areas are imaged by stacking radial receiver functions recorded by about 400 broadband seismic stations with up to 30 years of recording period, using the 1D IASP91 earth model. Significant and spatially systematic variations in the apparent depths of the d410 and d660 are observed. The mean apparent depth of d410 and d660 for the entire study area is 416±1.87 km and 664±1.83 km, respectively. The variations of the apparent depths of d410 and d660 result in a complex mantle transition zone (MTZ) structure. Central and south-central Alaska are characterized by a normal MTZ thickness, suggesting that the subducting Pacific slab does not thermally affect the upper MTZ. Beneath the Yakutat microplate, a complex MTZ structure is observed with an overall thin MTZ thickness, coinciding with a low velocity zone and thin lithospheric thickness revealed by previous seismic tomography and receiver function studies. Two large regions with hot MTZ are mapped beneath NNW and NNE Alaska with abnormal temperature ranges between +360 and +390 °K. Despite of the complexity of the MTZ structure beneath Alaska, the mean MTZ thickness for the entire Alaskan orocline is 247 ±2.76 km, suggesting normal MTZ temperature on average. For the majority of the areas, our study shows that lateral upper mantle velocity variations contribute the bulk of the observed apparent undulations of the MTZ discontinuities.

  4. Tracking glaciers with the Alaska seismic network

    NASA Astrophysics Data System (ADS)

    West, M. E.

    2015-12-01

    More than 40 years ago it was known that calving glaciers in Alaska created unmistakable seismic signals that could be recorded tens and hundreds of kilometers away. Their long monochromatic signals invited studies that foreshadowed the more recent surge in glacier seismology. Beyond a handful of targeted studies, these signals have remained a seismic novelty. No systematic attempt has been made to catalog and track glacier seismicity across the years. Recent advances in understanding glacier sources, combined with the climate significance of tidewater glaciers, have renewed calls for comprehensive tracking of glacier seismicity in coastal Alaska. The Alaska Earthquake Center has included glacier events in its production earthquake catalog for decades. Until recently, these were best thought of as bycatch—accidental finds in the process of tracking earthquakes. Processing improvements a decade ago, combined with network improvements in the past five years, have turned this into a rich data stream capturing hundreds of events per year across 600 km of the coastal mountain range. Though the source of these signals is generally found to be iceberg calving, there are vast differences in behavior between different glacier termini. Some glaciers have strong peaks in activity during the spring, while others peak in the late summer or fall. These patterns are consistent over years pointing to fundamental differences in calving behavior. In several cases, changes in seismic activity correspond to specific process changes observed through other means at particular glacier. These observations demonstrate that the current network is providing a faithful record of the dynamic behavior of several glaciers in coastal Alaska. With this as a starting point, we examine what is possible (and not possible) going forward with dedicated detection schemes.

  5. Silver in the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Gallon, C.; Flegal, A.

    2009-12-01

    Dramatic increases in coal combustion in Asia over the last three decades have induced the transport of substantial atmospheric emissions over the North Pacific Ocean, where they can potentially alter trace element biogeochemical cycles in oceanic surface waters and North America. These perturbations have recently been evidenced by measurements of elevated silver, which is a geochemical marker of coal combustion, in surface waters of the North Pacific, where this metal now appears to be the most contaminated trace element, relative to its natural concentration. However measurements there have been few and far between since they were first made over two decades ago. We partially fill this void by presenting vertical profiles of silver concentration (HR-ICPMS) measured in archived samples from the VERTEX VII (Vertical Transport and Exchange) cruise (1989), which covered a North South transect extending to the Alaska Gyre, as well as in new samples from the GoA (Gulf of Alaska) cruise (2007) collected in the Alaska Gyre. Our results confirm that within the water column, silver exhibits a nutrient type behavior, as was previously observed in other oceanic waters. In intermediate depth waters, concentrations in all the profiles are higher than those measured in the southern hemisphere and North East Pacific in the early 1980s, and in the range of those reported more recently in the Western and Central North Pacific. In the Alaska Gyre, water samples collected 20 years apart present comparable silver concentrations. Measurements from this study also confirm that silver is significantly correlated with dissolved silica, with plots of Ag versus Si showing a concave shape typical of Pacific waters, suggesting that the biogeochemical cycles of these two elements are linked.

  6. Bryophytes from Tuxedni Wilderness area, Alaska

    USGS Publications Warehouse

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

    2002-01-01

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

  7. Native Pathways to Education: Alaska Rural Systemic Initiative.

    ERIC Educational Resources Information Center

    Alaska Univ., Fairbanks.

    The Alaska Federation of Natives, in cooperation with the University of Alaska, received funding to implement the Alaska Rural Systemic Initiative (AKRSI). Over a 5-year period (1995-2000), AKRSI initiatives are systematically documenting the indigenous knowledge systems of Alaska Native people and developing educational policies and practices…

  8. Infant Mortality and American Indians/Alaska Natives

    MedlinePlus

    ... Heath & Mortality Infant Mortality and American Indians/Alaska Natives American Indian/Alaska Natives have 1.5 times the ... Cause of Death (By rank) # American Indian/Alaska Native Deaths American Indian/Alaska Native Death Rate #Non- Hispanic White ...

  9. The Alaska State Writing Consortium: The First Five Years.

    ERIC Educational Resources Information Center

    Parson, Gail

    This booklet documents the first 5 years of the Alaska State Writing Consortium, an association made up of 45 Alaska school districts, the Alaska Department of Education, and the University of Alaska. The Consortium, which oversees the organization and implementation of teacher training programs in writing and the teaching of writing, has five…

  10. 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.

  11. Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska

    USGS Publications Warehouse

    Daanen, R.P.; Grosse, G.; Darrow, M.M.; Hamilton, T.D.; Jones, Benjamin M.

    2012-01-01

    We present the results of a reconnaissance investigation of unusual debris mass-movement features on permafrost slopes that pose a potential infrastructure hazard in the south-central Brooks Range, Alaska. For the purpose of this paper, we describe these features as frozen debris-lobes. We focus on the characterisation of frozen debris-lobes as indicators of various movement processes using ground-based surveys, remote sensing, field and laboratory measurements, and time-lapse observations of frozen debris-lobe systems along the Dalton Highway. Currently, some frozen debris-lobes exceed 100 m in width, 20 m in height and 1000 m in length. Our results indicate that frozen debris-lobes have responded to climate change by becoming increasingly active during the last decades, resulting in rapid downslope movement. Movement indicators observed in the field include toppling trees, slumps and scarps, detachment slides, striation marks on frozen sediment slabs, recently buried trees and other vegetation, mudflows, and large cracks in the lobe surface. The type and diversity of observed indicators suggest that the lobes likely consist of a frozen debris core, are subject to creep, and seasonally unfrozen surface sediment is transported in warm seasons by creep, slumping, viscous flow, blockfall and leaching of fines, and in cold seasons by creep and sliding of frozen sediment slabs. Ground-based measurements on one frozen debris-lobe over three years (2008–2010) revealed average movement rates of approximately 1 cm day−1, which is substantially larger than rates measured in historic aerial photography from the 1950s to 1980s. We discuss how climate change may further influence frozen debris-lobe dynamics, potentially accelerating their movement. We highlight the potential direct hazard that one of the studied frozen debris-lobes may pose in the coming years and decades to the nearby Trans Alaska Pipeline System and the Dalton Highway, the main artery for transportation

  12. Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Daanen, R. P.; Grosse, G.; Darrow, M. M.; Hamilton, T. D.; Jones, B. M.

    2012-05-01

    We present the results of a reconnaissance investigation of unusual debris mass-movement features on permafrost slopes that pose a potential infrastructure hazard in the south-central Brooks Range, Alaska. For the purpose of this paper, we describe these features as frozen debris-lobes. We focus on the characterisation of frozen debris-lobes as indicators of various movement processes using ground-based surveys, remote sensing, field and laboratory measurements, and time-lapse observations of frozen debris-lobe systems along the Dalton Highway. Currently, some frozen debris-lobes exceed 100 m in width, 20 m in height and 1000 m in length. Our results indicate that frozen debris-lobes have responded to climate change by becoming increasingly active during the last decades, resulting in rapid downslope movement. Movement indicators observed in the field include toppling trees, slumps and scarps, detachment slides, striation marks on frozen sediment slabs, recently buried trees and other vegetation, mudflows, and large cracks in the lobe surface. The type and diversity of observed indicators suggest that the lobes likely consist of a frozen debris core, are subject to creep, and seasonally unfrozen surface sediment is transported in warm seasons by creep, slumping, viscous flow, blockfall and leaching of fines, and in cold seasons by creep and sliding of frozen sediment slabs. Ground-based measurements on one frozen debris-lobe over three years (2008-2010) revealed average movement rates of approximately 1 cm day-1, which is substantially larger than rates measured in historic aerial photography from the 1950s to 1980s. We discuss how climate change may further influence frozen debris-lobe dynamics, potentially accelerating their movement. We highlight the potential direct hazard that one of the studied frozen debris-lobes may pose in the coming years and decades to the nearby Trans Alaska Pipeline System and the Dalton Highway, the main artery for transportation

  13. Metalliferous lode deposits of Alaska

    USGS Publications Warehouse

    Berg, Henry C.; Cobb, Edward Huntington

    1967-01-01

    This report summarizes from repoAs of Federal and State agencies published before August 31, 1965, the geology of Alaska's metal-bearing lodes, including their structural or stratigraphic control, host rock, mode of origin, kinds of .Q minerals, grade, past production, and extent of exploration. In addition, the lists of mineral occurrences that accompany the 35 mineral-deposit location maps constitute an inventory of the State's known lodes. A total of 692 localities where m&alliferous deposits have been found are shown on the maps. The localities include 1,739 mines, prospects, and reported occurrences, of which 821 are described individually or otherwise cited in the text.

  14. 78 FR 57106 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 95 to the Fishery Management Plan for... implement Amendment 95 to the Fishery Management Plan for Groundfish of the Gulf of Alaska (FMP). This proposed action would modify halibut prohibited species catch (PSC) management in the Gulf of Alaska...

  15. Multi-resolution Changes in the Spatial Extent of Perennial Arctic Alpine Snow and Ice Fields with Potential Archaeological Significance in the Central Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Tedesche, M. E.; Freeburg, A. K.; Rasic, J. T.; Ciancibelli, C.; Fassnacht, S. R.

    2015-12-01

    Perennial snow and ice fields could be an important archaeological and paleoecological resource for Gates of the Arctic National Park and Preserve in the central Brooks Range mountains of Arctic Alaska. These features may have cultural significance, as prehistoric artifacts may be frozen within the snow and ice. Globally significant discoveries have been made recently as ancient artifacts and animal dung have been found in melting alpine snow and ice patches in the Southern Yukon and Northwest Territories in Canada, the Wrangell mountains in Alaska, as well as in other areas. These sites are melting rapidly, which results in quick decay of biological materials. The summer of 2015 saw historic lows in year round snow cover extent for most of Alaska. Twenty mid to high elevation sites, including eighteen perennial snow and ice fields, and two glaciers, were surveyed in July 2015 to quantify their areal extent. This survey was accomplished by using both low flying aircraft (helicopter), as well as with on the ground in-situ (by foot) measurements. By helicopter, visual surveys were conducted within tens of meters of the surface. Sites visited by foot were surveyed for extent of snow and ice coverage, melt water hydrologic parameters and chemistry, and initial estimates of depths and delineations between snow, firn, and ice. Imagery from both historic aerial photography and from 5m resolution IKONOS satellite information were correlated with the field data. Initial results indicate good agreement in permanent snow and ice cover between field surveyed data and the 1985 to 2011 Landsat imagery-based Northwest Alaska snow persistence map created by Macander et al. (2015). The most deviation between the Macander et al. model and the field surveyed results typically occurred as an overestimate of perennial extent on the steepest aspects. These differences are either a function of image classification or due to accelerated ablation rates in perennial snow and ice coverage

  16. Alaska Seismic Network Upgrade and Expansion

    NASA Astrophysics Data System (ADS)

    Sandru, J. M.; Hansen, R. A.; Estes, S. A.; Fowler, M.

    2009-12-01

    AEIC (Alaska Earthquake Information Center) has begun the task of upgrading the older regional seismic monitoring sites that have been in place for a number of years. Many of the original sites (some dating to the 1960's) are still single component analog technology. This was a very reasonable and ultra low power reliable system for its day. However with the advanced needs of today's research community, AEIC has begun upgrading to Broadband and Strong Motion Seismometers, 24 bit digitizers and high-speed two-way communications, while still trying to maintain the utmost reliability and maintaining low power consumption. Many sites have been upgraded or will be upgraded from single component to triaxial broad bands and triaxial accerometers. This provided much greater dynamic range over the older antiquated technology. The challenge is compounded by rapidly changing digital technology. Digitizersand data communications based on analog phone lines utilizing 9600 baud modems and RS232 are becoming increasingly difficult to maintain and increasingly expensive compared to current methods that use Ethernet, TCP/IP and UDP connections. Gaining a reliable Internet connection can be as easy as calling up an ISP and having a DSL connection installed or may require installing our own satellite uplink, where other options don't exist. LANs are accomplished with a variety of communications devices such as spread spectrum 900 MHz radios or VHF radios for long troublesome shots. WANs are accomplished with a much wider variety of equipment. Traditional analog phone lines are being used in some instances, however 56K lines are much more desirable. Cellular data links have become a convenient option in semiurban environments where digital cellular coverage is available. Alaska is slightly behind the curve on cellular technology due to its low population density and vast unpopulated areas but has emerged into this new technology in the last few years. Partnerships with organizations

  17. Environmental geochemistry at Red Mountain, an unmined volcanogenic massive sulphide deposit in the Bonnifield district, Alaska Range, east-central Alaska

    USGS Publications Warehouse

    Eppinger, R.G.; Briggs, P.H.; Dusel-Bacon, C.; Giles, S.A.; Gough, L.P.; Hammarstrom, J.M.; Hubbard, B.E.

    2007-01-01

    The unmined, pyrite-rich Red Mountain (Dry Creek) deposit displays a remarkable environmental footprint of natural acid generation, high metal and exceedingly high rate earth element (REE) concentrations in surface waters. The volcanogenic massive sulphide deposit exhibits well-constrained examples of acid-generating, metal-leaching, metal-precipitation and self-mitigation (via co-precipitation, dilution and neutralization) processes that occur in an undisturbed natural setting, a rare occurrence in North America. Oxidative dissolution of pyrite and associated secondary reactions under near-surface oxidizing conditions are the primary causes for the acid generation and metal leaching. The deposit is hosted in Devonian to Mississippian felsic metavolcanic rocks of the Mystic Creek Member of the Totatlanika Schist. Water samples with the lowest pH (many below 3.5), highest specific conductance (commonly >2500 ??S/cm) and highest major- and trace-element concentrations are from springs and streams within the quartz-sericite-pyrite alteration zone. Aluminum, Cd, Co, Cu, Fe, Mn, Ni, Pb, Y, Zn and, particularly, the REEs are found in high concentrations, ranging across four orders of magnitude. Waters collected upstream from the alteration zone have near-neutral pH, lower specific conductance (370 to 830 ??S/cm), lower metal concentrations and measurable alkalinities. Water samples collected downstream of the alteration zone have pH and metal concentrations intermediate between these two extremes. Stream sediments are anomalous in Zn, Pb, S, Fe, Cu, As, Co, Sb and Cd relative to local and regional background abundances. Red Mountain Creek and its tributaries do not, and probably never have, supported significant aquatic life. ?? 2007 AAG/ Geological Society of London.

  18. 40Ar/39Ar Dating of Zn-Pb-Ag Mineralization in the Northern Brooks Range, Alaska

    USGS Publications Warehouse

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

    2004-01-01

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

  19. Geophysical investigation of the Denali fault and Alaska Range orogen within the aftershock zone of the October-November 2002, M = 7.9 Denali fault earthquake

    USGS Publications Warehouse

    Fisher, M.A.; Nokleberg, W.J.; Ratchkovski, N.A.; Pellerin, L.; Glen, J.M.; Brocher, T.M.; Booker, J.

    2004-01-01

    The aftershock zone of the 3 November 2002, M = 7.9 earthquake that ruptured along the right-slip Denali fault in south-central Alaska has been investigated by using gravity and magnetic, magnetotelluric, and deep-crustal, seismic reflection data as well as outcrop geology and earthquake seismology. Strong seismic reflections from within the Alaska Range orogen north of the Denali fault dip as steeply as 25°N and extend to depths as great as 20 km. These reflections outline a relict crustal architecture that in the past 20 yr has produced little seismicity. The Denali fault is nonreflective, probably because this fault dips steeply to vertical. The most intriguing finding from geophysical data is that earthquake aftershocks occurred above a rock body, with low electrical resistivity (>10 Ω·m), that is at depths below ∼10 km. Aftershocks of the Denali fault earthquake have mainly occurred shallower than 10 km. A high geothermal gradient may cause the shallow seismicity. Another possibility is that the low resistivity results from fluids, which could have played a role in locating the aftershock zone by reducing rock friction within the middle and lower crust.

  20. Re-Os sulfide geochronology of the Red Dog sediment-hosted Zn-Pb-Ag deposit, Brooks Range, Alaska

    USGS Publications Warehouse

    Morelli, R.M.; Creaser, R.A.; Selby, D.; Kelley, K.D.; Leach, D.L.; King, A.R.

    2004-01-01

    The Red Dog sediment-hosted deposit in the De Long Mountains of northern Alaska is the largest Zn producer in the world. Main stage mineralization is characterized by massive sulfide ore and crosscutting subvertical veins. Although the vein mineralization is clearly younger than the massive ore, the exact temporal relationship between the two is unclear. Re-Os geochronology of pyrite is used to determine the absolute age of main stage ore at Red Dog. A 10-point isochron on both massive and vein pyrite yields an age of 338.3 ?? 5.8 Ma and is interpreted to represent the age of main stage ore. The Re-Os data indicate that both massive and vein ore types are coeval within the resolution of the technique. Formation of the Red Dog deposit was associated with extension along a passive continental margin, and therefore the Re-Os age of main stage ore constrains the timing of rifting as well as the age of the host sedimentary rocks. Sphalerite from both massive and vein ore yields imprecise ages and shows a high degree of scatter compared to pyrite. We suggest that the Re-Os systematics of sphalerite can be disturbed and that this mineral is not reliable for Re-Os geochronology. ?? 2004 by Economic Geology.

  1. Alaska and Yukon Fires

    Atmospheric Science Data Center

    2014-05-15

    ... south to the Wrangell Mountains. The first panel in the series is a natural-color image from MISR's 60° forward viewing camera. Smoke ... the Wrangell Mountain range. The next panel in the series is a stereoscopic height field, in which topography, smoke plumes and ...

  2. 77 FR 50712 - Information Collection: Southern Alaska Sharing Network and Subsistence Study; Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... Bureau of Ocean Energy Management Information Collection: Southern Alaska Sharing Network and Subsistence... in Alaska, ``Southern Alaska Sharing Network and Subsistence Study.'' DATES: Submit written comments.... Title: Southern Alaska Sharing Network and Subsistence Study. Abstract: The Bureau of Ocean...

  3. Recent sedimentation, northeastern Port Valdez, Alaska

    NASA Astrophysics Data System (ADS)

    Palmer, Harold D.

    1981-09-01

    Sediments accumulating on the northeastern shore of Port Valdez, a fjord leading to Prince William Sound in southern Alaska, are derived from both deltaic and alluvial fan processes. The resulting thick wedge of Recent silts, sands, shells and gravels lies atop irregular ridges of local graywacke bedrock and scattered till deposits. Seismic reflection profiling augmented by soil borings indicates that rapid infilling and upbuilding has occurred at this site. Evidence of slumping suggests general instability of steep submarine slopes in an area characterized by strong earthquakes and large tidal ranges.

  4. Columbia Glacier, Alaska, 1986-2011

    NASA Video Gallery

    The Columbia Glacier in Alaska is one of many vanishing around the world. Glacier retreat is one of the most direct and understandable effects of climate change. The consequences of the decline in ...

  5. 77 FR 35998 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Nunapiglluraq Corporation (Native Village of Hamilton). The decision approves the surface estate in the lands... is conveyed to Nunapiglluraq Corporation. The lands are in the vicinity of Hamilton, Alaska, and...

  6. Alaska Simulator - A Journey to Planning

    NASA Astrophysics Data System (ADS)

    Weber, Barbara; Pinggera, Jakob; Zugal, Stefan; Wild, Werner

    The Alaska Simulator is an interactive software tool developed at the University of Innsbruck which allows people to test, analyze and improve their own planning behavior. In addition, the Alaska Simulator can be used for studying research questions in the context of software project management and other related fields. Thereby, the Alaska Simulator uses a journey as a metaphor for planning a software project. In the context of software project management the simulator can be used to compare traditional rather plan-driven project management methods with more agile approaches. Instead of pre-planning everything in advance agile approaches spread planning activities throughout the project and provide mechanisms for effectively dealing with uncertainty. The biggest challenge thereby is to find the right balance between pre-planning activities and keeping options open. The Alaska Simulator allows to explore how much planning is needed under different circumstances.

  7. 76 FR 72212 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq). The subsurface... published four times in The Delta Discovery. DATES: Any party claiming a property interest in the...

  8. 78 FR 64002 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... for conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq.). The... decision will also be published once a week for four ] consecutive weeks in the Delta Discovery. DATES:...

  9. 77 FR 20046 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... described below pursuant to the Alaska Native Claims Settlement Act (ANCSA) (43 U.S.C. 1601, et seq.). The lands being approved for conveyance are lands originally selected under ANCSA in the withdrawal area...

  10. Advancing Efforts to Energize Native Alaska (Brochure)

    SciTech Connect

    Not Available

    2013-04-01

    This brochure describes key programs and initiatives of the DOE Office of Indian Energy Policy and Programs to advance energy efficiency, renewable energy, and energy infrastructure projects in Alaska Native villages.

  11. Cross Cultural Scientific Communication in Alaska

    NASA Astrophysics Data System (ADS)

    Bertram, K. B.

    2006-12-01

    An example of cross-cultural education is provided by the Aurora Alive curriculum. Aurora Alive communicates science to Alaska Native students through cross-cultural educational products used in Alaska schools for more than a decade, including (1) a CDROM that provides digital graphics, bilingual (English and Athabascan language) narration-over-text and interactive elements that help students visualize scientific concepts, and (2) Teacher's Manuals containing more than 150 hands-on activities aligned to national science standards, and to Alaska Standards for Culturally Responsive Schools. Created by Native Elders and teachers working together with University Alaska Fairbanks Geophysical Institute scientists, Aurora Alive blends Native "ways of knowing" with current "western" research to teach the physics and math of the aurora.

  12. Propagation measurements in Alaska using ACTS beacons

    NASA Technical Reports Server (NTRS)

    Mayer, Charles E.

    1991-01-01

    The placement of an ACTS propagation terminal in Alaska has several distinct advantages. First is the inclusion of a new and important climatic zone to the global propagation model. Second is the low elevation look angle from Alaska to ACTS. These two unique opportunities also present problems unique to the location, such as extreme temperatures and lower power levels. These problems are examined and compensatory solutions are presented.

  13. Mercury in polar bears from Alaska

    SciTech Connect

    Lentfer, J.W.; Galster, W.A.

    1987-04-01

    Alaskan polar bear (Ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. Bears north of Alaska had more mercury than bears west of Alaska. The only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. Levels were probably not high enough to be a serious threat to bears.

  14. Coastal geomorphology of arctic Alaska

    USGS Publications Warehouse

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

    1988-01-01

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

  15. Exporting Alaska's oil and gas

    SciTech Connect

    Singer, S.F.; Copulos, M.; Watkins, D.J.

    1983-02-22

    Federal legislation that prohibits the commercial export of oil and gas is creating a glut and discouraging oil production in California, while raising energy costs by shipping the fuel to the East and Gulf Coasts. The historical security reasons for blocking the export of Alaskan oil no longer exist, yet they continue to impose costs for the taxpayer. The optimum solution appears to be to export liquefied natural gas, using a pipeline paralleling the oil pipeline to Valdez. This would encourage the use and manufacture in Alaska of urea and ammonia fertilizer for export to the Far East, which would enhance US/Japan relations. The possibility of exports of additional oil, bringing a higher return for producers, will encourage production, reduce the need for OPEC oil, and moderate world oil prices. 5 references.

  16. Seasonal and altitudinal variations in snow algal communities on an Alaskan glacier (Gulkana glacier in the Alaska range)

    NASA Astrophysics Data System (ADS)

    Takeuchi, Nozomu

    2013-09-01

    Snow and ice algae are cold tolerant algae growing on the surface of snow and ice, and they play an important role in the carbon cycles for glaciers and snowfields in the world. Seasonal and altitudinal variations in seven major taxa of algae (green algae and cyanobacteria) were investigated on the Gulkana glacier in Alaska at six different elevations from May to September in 2001. The snow algal communities and their biomasses changed over time and elevation. Snow algae were rarely observed on the glacier in May although air temperature had been above 0 ° C since the middle of the month and surface snow had melted. In June, algae appeared in the lower areas of the glacier, where the ablation ice surface was exposed. In August, the distribution of algae was extended to the upper parts of the glacier as the snow line was elevated. In September, the glacier surface was finally covered with new winter snow, which terminated algal growth in the season. Mean algal biomass of the study sites continuously increased and reached 6.3 × 10 μl m-2 in cell volume or 13 mg carbon m-2 in September. The algal community was dominated by Chlamydomonas nivalis on the snow surface, and by Ancylonema nordenskiöldii and Mesotaenium berggrenii on the ice surface throughout the melting season. Other algae were less abundant and appeared in only a limited area of the glacier. Results in this study suggest that algae on both snow and ice surfaces significantly contribute to the net production of organic carbon on the glacier and substantially affect surface albedo of the snow and ice during the melting season.

  17. Mississippian clastic-to-carbonate transition in the northeastern Brooks Range, Alaska: Depositional cycles of the Endicott and Lisburne Groups

    SciTech Connect

    Lepain, D.L.; Crowden, R.K.; Watts, K.F. )

    1990-05-01

    The Ellesmerian sequence in northeastern Alaska consists of a thick succession of Mississippian to Lower Cretaceous platform carbonate and terrigenous clastic rocks. At the base of the Ellesmerian sequence, clastic rocks of the Endicott Group are the lower part of a major transgressive sequence that passes gradationally upward into carbonates of the Lisburne Group. In the Endicott Group, the basal Kekiktuk Conglomerate was deposited in fluvial and marginal marine environments. A broad suite of tidally influenced, shallow-marine environments are recorded in the overlying Kayak Shale. The transition into carbonate platform rocks of the Lisburne Group is recorded in a series of depositional cycles developed within the upper half of the Kayak Shale. In the lower beds of the transition, the depositional cycles are multiple upward-thickening and upward-coarsening successions composed of (1) organic-rich siltstone containing flaser-bedded and lenticular-bedded fine-grained sandstone, (2) fine-grained, ripple-laminated quartzarenite, and (3) an intensely bioturbated horizon of medium- to coarse-grained quartzarenite that contains scattered brachiopods, bryozoa, and crinoids. Each cycle is terminated by a sharp transgressive surface that consists of a thin shale drape. Near the top of the Kayak Shale, the coarse-grained horizons become increasingly replaced by wackestone, grainstone, and coralline boundstone. Despite the lithologic change, the vertical upward-thickening and upward-coarsening cycles continue in the basal limestone of the Lisburne Group. Repeated upward-shallowing episodes, followed by coastal onlap, are likely mechanisms for this cyclicity and suggests a genetic relation between both the clastic and carbonate depositional cycles.

  18. Crustal structure of Bristol Bay Region, Alaska

    SciTech Connect

    Cooper, A.K.; McLean, H.; Marlow, M.S.

    1985-04-01

    Bristol Bay lies along the northern side of the Alaska Peninsula and extends nearly 600 km southwest from the Nushagak lowlands on the Alaska mainland to near Unimak Island. The bay is underlain by a sediment-filled crustal downwarp known as the north Aleutian basin (formerly Bristol basin) that dips southeast toward the Alaska Peninsula and is filled with more than 6 km of strata, dominantly of Cenozoic age. The thickest parts of the basin lie just north of the Alaska Peninsula and, near Port Mollar, are in fault contact with older Mesozoic sedimentary rocks. These Mesozoic rocks form the southern structural boundary of the basin and extend as an accurate belt from at least Cook Inlet to Zhemchug Canyon (central Beringian margin). Offshore multichannel seismic-reflection, sonobuoy seismic-refraction, gravity, and magnetic data collected by the USGS in 1976 and 1982 indicate that the bedrock beneath the central and northern parts of the basin comprises layered, high-velocity, and highly magnetic rocks that are locally deformed. The deep bedrock horizons may be Mesozoic(.) sedimentary units that are underlain by igneous or metamorphic rocks and may correlate with similar rocks of mainland western Alaska and the Alaska Peninsula. Regional structural and geophysical trends for these deep horizons change from northeast-southwest to northwest-southeast beneath the inner Bering shelf and may indicate a major crustal suture along the northern basin edge.

  19. Geologic Map of Central (Interior) Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Dover, James H.; Bradley, Dwight C.; Weber, Florence R.; Bundtzen, Thomas K.; Haeussler, Peter J.

    1998-01-01

    Introduction: This map and associated digital databases are the result of a compilation and reinterpretation of published and unpublished 1:250,000- and limited 1:125,000- and 1:63,360-scale mapping. The map area covers approximately 416,000 sq km (134,000 sq mi) and encompasses 25 1:250,000-scale quadrangles in central Alaska. The compilation was done as part of the U.S. Geological Survey National Surveys and Analysis project, whose goal is nationwide assemble geologic, geochemical, geophysical, and other data. This map is an early product of an effort that will eventually encompass all of Alaska, and is the result of an agreement with the Alaska Department of Natural Resources, Division of Oil And Gas, to provide data on interior basins in Alaska. A paper version of the three map sheets has been published as USGS Open-File Report 98-133. Two geophysical maps that cover the identical area have been published earlier: 'Bouguer gravity map of Interior Alaska' (Meyer and others, 1996); and 'Merged aeromagnetic map of Interior Alaska' (Meyer and Saltus, 1995). These two publications are supplied in the 'geophys' directory of this report.

  20. Alaska

    Atmospheric Science Data Center

    2014-05-15

    ... This image appears three-dimensional when viewed through red/blue glasses with the red filter over the left eye. It may help to darken the room lights when viewing the image on a computer screen. The Yukon River is ...

  1. Kilbuck terrane: Oldest known rocks in Alaska

    SciTech Connect

    Box, S.E. ); Moll-Stalcup, E.J.; Wooden, J.L. ); Bradshaw, J.Y. )

    1990-12-01

    The Kilbuck terrane in southwestern Alaska is a narrow, thin crustal sliver or flake of amphibolite facies orthogneiss. The igneous protolith of this gneiss was a suite of subduction-related plutonic rocks. U-Pb data on zircons from trondhjemitic and granitic samples yield upper-intercept (igneous) ages of 2,070 {plus minus}16 and 2,040 {plus minus}74 Ma, respectively. Nd isotope data from these rocks suggest that a diorite-tonalite-trondhjemite suite ({epsilon}{sub Nd}(T) = +2.1 to +2.7; T is time of crystallization) evolved from partial melts of depleted mantle with no discernible contamination by older crust, whereas a coeval granitic pluton ({epsilon}{sub Nd}(T) = {minus}5.7) contains a significant component derived from Archean crust. Orthogneisses with similar age and Nd isotope characteristics are found in the Idono complex 250 km to the north. Early Proterozoic rocks are unknown elsewhere in Alaska. However, Phanerozoic plutons cutting several continental terranes in Alaska (southern Brooks Range and Ruby, Seward, and Yukon-Tanana terranes) have Nd isotope compositions indicative of Early Proterozoic (or older) crustal components that could be correlative with rocks of the Kilbuck terrane. Rocks with similar igneous ages in cratonal North America are rare, and those few that are known have Nd isotope compositions distinct from those of the Kilbuck terrane. Conversely, provinces with Nd model ages of 2.0-2.1 Ga are characterized by extensive 1.8 Ga or younger plutonism, which is unknown in the Kilbuck terrane. At present the case for a North American parentage of the Kilbuck terrane is not compelling. The possibility that the Kilbuck terrane was displaced from provinces of similar age in other cratons (e.g., Australian, Baltic, Guiana, and west African shields), or from the poorly dated Siberian craton, cannot be excluded.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  3. New/Emerging Pests in Alaska: Will Climate Change Favor Insect Expansion Into Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because of its geographical isolation and climatic constraints, Alaska agriculture is considered relatively free of diseases and insect pests. However, since 1973, the winter temperatures in Alaska have increased by 2-3 C'. It is logical to assume that continued global climate change could produce ...

  4. Systems Performance Analyses of Alaska Wind-Diesel Projects; Kotzebue, Alaska (Fact Sheet)

    SciTech Connect

    Baring-Gould, I.

    2009-04-01

    This fact sheet summarizes a systems performance analysis of the wind-diesel project in Kotzebue, Alaska. Data provided for this project include wind turbine output, average wind speed, average net capacity factor, and optimal net capacity factor based on Alaska Energy Authority wind data, estimated fuel savings, and wind system availability.

  5. Building Alaska's Science and Engineering Pipeline: Evaluation of the Alaska Native Science & Engineering Program

    ERIC Educational Resources Information Center

    Bernstein, Hamutal; Martin, Carlos; Eyster, Lauren; Anderson, Theresa; Owen, Stephanie; Martin-Caughey, Amanda

    2015-01-01

    The Urban Institute conducted an implementation and participant-outcomes evaluation of the Alaska Native Science & Engineering Program (ANSEP). ANSEP is a multi-stage initiative designed to prepare and support Alaska Native students from middle school through graduate school to succeed in science, technology, engineering, and math (STEM)…

  6. Alaska Native Languages: Past, Present, and Future. Alaska Native Language Center Research Papers No. 4.

    ERIC Educational Resources Information Center

    Krauss, Michael E.

    Three papers (1978-80) written for the non-linguistic public about Alaska Native languages are combined here. The first is an introduction to the prehistory, history, present status, and future prospects of all Alaska Native languages, both Eskimo-Aleut and Athabaskan Indian. The second and third, presented as appendixes to the first, deal in…

  7. 2011 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Maharrey, J. Zebulon; Neal, Christina A.

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near three separate volcanic centers in Alaska during 2011. The year was highlighted by the unrest and eruption of Cleveland Volcano in the central Aleutian Islands. AVO annual summaries no longer report on activity at Russian volcanoes.

  8. 77 FR 2972 - City and Borough of Sitka, Alaska, Alaska; Notice of Availability of Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission City and Borough of Sitka, Alaska, Alaska; Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory Commission's (Commission...

  9. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Register on November 20, 2009 (74 FR 60228), to propose migratory bird subsistence harvest regulations in... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife...

  10. Ellesmerian (. ) and Brookian deformation in the Franklin Mountains, northeastern Brooks Range, Alaska, and its bearing on the origin of the Canada Basin

    SciTech Connect

    Oldow, J.S.; Ave Lallemant, H.G.; Julian, F.E.; Seidensticker, C.M.

    1987-01-01

    Structural analysis of deformed rocks in the Franklin Mountains, northeastern Alaska, indicates that (1) pre-Carboniferous rocks were transported southeastward during mid-Devonian (Ellesmerian.) thrusting, (2) Cretaceous and older rocks were transported northward during Mesozoic-Cenozoic Brookian thrusting, and (3) the pre-Carboniferous rocks were strongly involved in the Brookian deformation. The strong involvement of these rocks in Brookian structures suggests that the magnitude of northward thrusting during Brookian tectonism is virtually uniform from west to east along the axis of the Brooks Range fold and thrust belt. In addition, the newly recognized southern vergence of pre-Carboniferous structures is comparable with that of coeval structures exposed in Arctic Canada to the east. These data are not easily reconciled with the orocline model for the origin of the Canada Basin but are consistent with left-lateral transport on a north-south-striking transform fault along the Canadian Arctic islands. 19 references.

  11. The Middle Fork Plutonic Complex: A plutonic association of coeval peralkaline and metaluminous magmas in the north-central Alaska Range

    SciTech Connect

    Solie, D.N.

    1988-01-01

    The 57 m.y. Middle Fork Plutonic Complex (MFPC) intrudes Paleozoic metasedimentary rocks south of the Farewell Fault zone in the north-central Alaska Range. Though spatially related to the late Cretaceous - Early Tertiary subduction-related Alaska Range batholith, MFPC is more characteristic of an extensional or anorogenic setting. A swarm of basalt, hawaiite and rhyolite dikes east of the complex intruded, and was intruded by, the plutonic rocks. Approximately 30% of the exposed rock in the 125 km[sup 2] complex is hedenbergite - fayalite syenite, [approx equal]20% is peralkalin arfvedsonite-biotite alkali-feldspar granite (AF granite), and [le]20% is pyroxene-olivine-biotite gabbro. The rest is a mixed unit including clinopyroxene-biotite-amphibole diorite, and hornblende-biotite granite (HB granite). K-Ar and Rb-Sr radiometric dating of rock types shows that they are coeval. Their close spatial and temporal relationships led to complex magmatic interactions. Calculated initial [sup 87]Sr/[sup 86]Sr for gabbro and diorite group is around 0.705 to 0.706. HB granites are heterogeneous, but fall mostly around 0.707 to 0.708. Hypersolvus syenites and AF granites form an isochron with initial [sup 87]Sr/[sup 86]Sr of 0.70965. These groupings suggest that at least three different magmas formed the MFPC; scatter of isotopic data reflects mutual contamination and assimilation. Consanguinous hypersolvus syenite and AF granite mineralogy appears to be controlled by fluorine in the magma chamber. Eruptive stratigraphy, as predicted by intrusive history of MFPC, compares favorably with volcanic stratigraphies of peralkaline volcanic systems worldwide, and MFPC may be modelled as the root zone of a peralkaline volcanic system.

  12. NASA's DESDynI in Alaska

    NASA Astrophysics Data System (ADS)

    Sauber, J. M.; Hofton, M. A.; Bruhn, R. L.; Forster, R. R.; Burgess, E. W.; Cotton, M. M.

    2010-12-01

    In 2007 the National Research Council Earth Science Decadal Survey, Earth Science Applications from Space, recommended an integrated L-band InSAR and multibeam Lidar mission called DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice) and it is scheduled for launch in 2017. The NASA InSAR and Lidar mission is optimized for studying geohazards and global environmental change. The complex plate boundary in southern coastal Alaska provides an excellent setting for testing DESDynI capabilities to recover fundamental parameters of glacio-seismotectonic processes. Also, aircraft and satellites acquisitions of Lidar and L-band SAR have been made in this region in the last decade that can be used for DESDynI performance simulations. Since the Lidar observations would penetrate most vegetation, the accurate bald Earth elevation profiles will give new elevation information beyond the standard 30-m digital elevation models (DEM) and the Lidar-derived elevations will provide an accurate georeferenced surface for local and regional scale studies. In an earlier study we demonstrated how the Lidar observations could be used in combination with SAR to generate an improved InSAR derived DEM in the Barrow, Alaska region [Atwood et al., 2007]; here we discuss how Lidar could be fused with L-band SAR in more rugged, vegetated terrane. Based on simulations of multi-beam Lidar instrument performance over uplifted marine terraces, active faults and folds, uplift associated with the 1899 Yakataga seismic event (M=8), and elevation change on the glaciers in southern, coastal Alaska, we report on the significance of the DESDynI Lidar contiguous 25 m footprint elevation profiles for EarthScope related studies in Alaska. We are using the morphology and dynamics of glaciers derived from L-band SAR ice velocities to infer the large scale sub-ice structures that form the structural framework of the Seward-Bagley Basins. Using primarily winter acquisitions of L-band SAR data from ALOS

  13. Tectonic framework of petroliferous rocks in Alaska: hydrocarbons

    USGS Publications Warehouse

    Grantz, Arthur; Kirschner, C.E.

    1976-01-01

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

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

    USGS Publications Warehouse

    Kelley, K.D.; Hudson, T.

    2007-01-01

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

  15. Stratigraphic and structural implications of conodont and detrital zircon U-Pb ages from metamorphic rocks of the Coldfoot terrane, Brooks Range, Alaska

    USGS Publications Warehouse

    Moore, T.E.; Aleinikoff, J.N.; Harris, A.G.

    1997-01-01

    New paleontologic and isotopic data from the Emma Creek and Marion Creek schists of the Coldfoot terrane, Arctic Alaska superterrane, central Brooks Range, suggest Devonian and possibly younger ages of deposition for their sedimentary protoliths. Conodonts from marble of the Emma Creek schist, intruded by a roughly 392 Ma orthogneiss, are late Lochkovian (early Early Devonian, between about 408 and 396 Ma) and Silurian to Devonian at two other locations. Spherical to oblong detrital zircons from quartz-mica schist of the overlying Marion Creek schist yield mostly discordant U-Pb data suggestive of provenance ages of 3.0, 2.0-1.8, and 1.5-1.4 Ga; however, several euhedral grains of zircon from Marion Creek quartz-mica schist have concordant U-Pb ages from 370 to 360 Ma. The Marion Creek schist in our study area therefore is at least 26 m.y. younger than the Emma Creek schist. The age data imply that the protolith of the Emma Creek schist is age correlative with Devonian carbonate rocks in the Hammond and North Slope terranes, whereas the Marion Creek schist is age correlative with Upper Devonian and Lower Mississippian clastic sedimentary rocks of the Endicott Group in the Endicott Mountains terrane and shale and carbonate units in the De Long Mountains and Sheenjek River terranes. Consequently, tectonic models restoring the entire Coldfoot terrane beneath partly or wholly coeval rocks of the Hammond, Endicott Mountains, De Long Mountains, and Sheenjek River terranes of the Arctic Alaska superterrane require revision. Alternative reconstructions, including restoration of the Coldfoot terrane inboard of the Endicott Mountains terrane or outboard of the De Long Mountains and Sheenjek River terranes are plausible but require either larger amounts of shortening than previously suggested or indicate problematic facies relations. copyright. Published in 1997 by the American Geophysical Union.

  16. Gallstones in American Indian/Alaska Native Women

    MedlinePlus

    ... Asian-Americans Native Hawaiians and other Pacific Islanders American Indians/Alaska Natives Immigrant and migrant issues Taking care ... Enter email address Submit Home > Minority Women's Health > American Indians/Alaska Natives Minority Women's Health Gallstones Health conditions ...

  17. Geologic map of the Christian quadrangle, Alaska

    USGS Publications Warehouse

    Brosge, W.P.; Reiser, H.N.

    2000-01-01

    Most of the Christian quadrangle is in the Porcupine Plateau; the northwestern part is in the southern Brooks Range, and the southern quarter is in the Yukon Flats. Outcrops of bedrock are poor or lacking, except in the Brooks Range. Although large valley glaciers have moved through the Porcupine Plateau, along the East Fork Chandalar and Vanticlese Creek, most of the upland areas in the Porcupine Plateau have not been eroded by ice. Consequently the rocks are deeply weathered and many outcrops in the low hills east of the East Fork are only soil and rubble. The southern quarter of the quadrangle in the Yukon Flats is covered with unconsolidated glacial and alluvial deposits. The Christian quadrangle is at the east end of the southern Brooks Range schist belt. Here three geologic terranes that originate well south of the Brooks Range intersect the subterranes of the southern Brooks Range along northward-directed thrust faults and northeast-striking strike slip faults. The displaced terranes from the south have been mapped by Jones and others (1987), as the schist of the Ruby terrane, the mafic rocks and phyllite of the Tozitna terrane, and the graywacke of the Venetie terrane. The typical rocks of the southern Brooks Range Arctic Alaska terrane at this intersection are the carbonate and clastic rocks of the Hammond subterrane, and the schist of the Coldfoot subterrane. The Coldfoot schist ends at a probable strike-slip fault about 10 miles west of the Christian quadrangle. At that place the mafic rocks and phyllites of the Angayucham terrane that form the south flank of most of the Brooks Range veer sharply northeastward across the Coldfoot subterrane schist and terminate it. A small fragment of the Endicott Mountains subterrane of the Arctic Alaska terrane also lies within the Christian quadrangle, but the main body of this subterrane lies north of the quadrangle.

  18. Earthquake Hazard and Risk in Alaska

    NASA Astrophysics Data System (ADS)

    Black Porto, N.; Nyst, M.

    2014-12-01

    Alaska is one of the most seismically active and tectonically diverse regions in the United States. To examine risk, we have updated the seismic hazard model in Alaska. The current RMS Alaska hazard model is based on the 2007 probabilistic seismic hazard maps for Alaska (Wesson et al., 2007; Boyd et al., 2007). The 2015 RMS model will update several key source parameters, including: extending the earthquake catalog, implementing a new set of crustal faults, updating the subduction zone geometry and reoccurrence rate. First, we extend the earthquake catalog to 2013; decluster the catalog, and compute new background rates. We then create a crustal fault model, based on the Alaska 2012 fault and fold database. This new model increased the number of crustal faults from ten in 2007, to 91 faults in the 2015 model. This includes the addition of: the western Denali, Cook Inlet folds near Anchorage, and thrust faults near Fairbanks. Previously the subduction zone was modeled at a uniform depth. In this update, we model the intraslab as a series of deep stepping events. We also use the best available data, such as Slab 1.0, to update the geometry of the subduction zone. The city of Anchorage represents 80% of the risk exposure in Alaska. In the 2007 model, the hazard in Alaska was dominated by the frequent rate of magnitude 7 to 8 events (Gutenberg-Richter distribution), and large magnitude 8+ events had a low reoccurrence rate (Characteristic) and therefore didn't contribute as highly to the overall risk. We will review these reoccurrence rates, and will present the results and impact to Anchorage. We will compare our hazard update to the 2007 USGS hazard map, and discuss the changes and drivers for these changes. Finally, we will examine the impact model changes have on Alaska earthquake risk. Consider risk metrics include average annual loss, an annualized expected loss level used by insurers to determine the costs of earthquake insurance (and premium levels), and the

  19. A History of Schooling for Alaska Native People.

    ERIC Educational Resources Information Center

    Barnhardt, Carol

    2001-01-01

    Reviews the geographic and demographic contexts of Alaska schooling, federal policies that have affected education in Alaska, and the evolution of schooling for Alaska Native people. Describes the development of a dual federal/territorial system of schools, the initiation of federal and state reform efforts, Native-sponsored educational…

  20. Chronic Liver Disease and American Indians/Alaska Natives

    MedlinePlus

    ... Disease Chronic Liver Disease and American Indians/Alaska Natives Among American Indians and Alaska Natives, chronic liver disease is ... 54. 1 At a glance – Cancer Rates for American Indian/Alaska Natives (2008-2012) Cancer Incidence Rates per 100,000 – ...

  1. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  2. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  3. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  4. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  5. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  6. Minorities in Higher Education. The Changing North: Alaska.

    ERIC Educational Resources Information Center

    Kleinfeld, Judith; And Others

    This report examines the educational status of ethnic and racial minorities in Alaska and draws attention to the ways demographic changes in Alaska may affect these groups. The Alaska Native population, as opposed to other ethnic minorities, is the focal point of this study. This is the largest minority group in the state and the one experiencing…

  7. 47 CFR 80.387 - Frequencies for Alaska fixed stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Frequencies for Alaska fixed stations. 80.387... SERVICES STATIONS IN THE MARITIME SERVICES Frequencies Alaska Fixed Stations § 80.387 Frequencies for Alaska fixed stations. (a) The carrier frequencies listed in (b) of this section are assignable for...

  8. 47 CFR 80.387 - Frequencies for Alaska fixed stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Frequencies for Alaska fixed stations. 80.387... SERVICES STATIONS IN THE MARITIME SERVICES Frequencies Alaska Fixed Stations § 80.387 Frequencies for Alaska fixed stations. (a) The carrier frequencies listed in (b) of this section are assignable for...

  9. 47 CFR 80.387 - Frequencies for Alaska fixed stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequencies for Alaska fixed stations. 80.387... SERVICES STATIONS IN THE MARITIME SERVICES Frequencies Alaska Fixed Stations § 80.387 Frequencies for Alaska fixed stations. (a) The carrier frequencies listed in (b) of this section are assignable for...

  10. 47 CFR 80.387 - Frequencies for Alaska fixed stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Frequencies for Alaska fixed stations. 80.387... SERVICES STATIONS IN THE MARITIME SERVICES Frequencies Alaska Fixed Stations § 80.387 Frequencies for Alaska fixed stations. (a) The carrier frequencies listed in (b) of this section are assignable for...

  11. 30 CFR 716.6 - Coal mines in Alaska.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal mines in Alaska. 716.6 Section 716.6... PROGRAM REGULATIONS SPECIAL PERFORMANCE STANDARDS § 716.6 Coal mines in Alaska. (a) Permittees of surface coal mining operations in Alaska from which coal has been mined on or after August 3, 1977,...

  12. 30 CFR 716.6 - Coal mines in Alaska.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal mines in Alaska. 716.6 Section 716.6... PROGRAM REGULATIONS SPECIAL PERFORMANCE STANDARDS § 716.6 Coal mines in Alaska. (a) Permittees of surface coal mining operations in Alaska from which coal has been mined on or after August 3, 1977,...

  13. 30 CFR 716.6 - Coal mines in Alaska.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Coal mines in Alaska. 716.6 Section 716.6... PROGRAM REGULATIONS SPECIAL PERFORMANCE STANDARDS § 716.6 Coal mines in Alaska. (a) Permittees of surface coal mining operations in Alaska from which coal has been mined on or after August 3, 1977,...

  14. 30 CFR 716.6 - Coal mines in Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mines in Alaska. 716.6 Section 716.6... PROGRAM REGULATIONS SPECIAL PERFORMANCE STANDARDS § 716.6 Coal mines in Alaska. (a) Permittees of surface coal mining operations in Alaska from which coal has been mined on or after August 3, 1977,...

  15. 30 CFR 716.6 - Coal mines in Alaska.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Coal mines in Alaska. 716.6 Section 716.6... PROGRAM REGULATIONS SPECIAL PERFORMANCE STANDARDS § 716.6 Coal mines in Alaska. (a) Permittees of surface coal mining operations in Alaska from which coal has been mined on or after August 3, 1977,...

  16. 43 CFR 3101.5-3 - Alaska wildlife areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Alaska wildlife areas. 3101.5-3 Section... § 3101.5-3 Alaska wildlife areas. No lands within a refuge in Alaska open to leasing shall be available until the Fish and Wildlife Service has first completed compatability determinations....

  17. 43 CFR 3101.5-3 - Alaska wildlife areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Alaska wildlife areas. 3101.5-3 Section... § 3101.5-3 Alaska wildlife areas. No lands within a refuge in Alaska open to leasing shall be available until the Fish and Wildlife Service has first completed compatability determinations....

  18. 43 CFR 3101.5-3 - Alaska wildlife areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Alaska wildlife areas. 3101.5-3 Section... § 3101.5-3 Alaska wildlife areas. No lands within a refuge in Alaska open to leasing shall be available until the Fish and Wildlife Service has first completed compatability determinations....

  19. 43 CFR 3101.5-3 - Alaska wildlife areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Alaska wildlife areas. 3101.5-3 Section... § 3101.5-3 Alaska wildlife areas. No lands within a refuge in Alaska open to leasing shall be available until the Fish and Wildlife Service has first completed compatability determinations....

  20. Anchorage Kindergarten Profile: Implementing the Alaska Kindergarten Developmental Profile.

    ERIC Educational Resources Information Center

    Fenton, Ray

    This paper discusses the development of the Anchorage Kindergarten Developmental Profile in the context of the Alaska Kindergarten Developmental Profile and presents some evaluation results from studies of the Anchorage measure. Alaska mandated the completion of an Alaska Developmental Profile (ADP) on each kindergarten student and each student…

  1. 33 CFR 110.233 - Prince William Sound, Alaska.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Prince William Sound, Alaska. 110... ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.233 Prince William Sound, Alaska. (a) The anchorage grounds. In Prince William Sound, Alaska, beginning at a point at latitude 60°40′00″ N., longitude...

  2. 33 CFR 110.233 - Prince William Sound, Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Prince William Sound, Alaska. 110... ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.233 Prince William Sound, Alaska. (a) The anchorage grounds. In Prince William Sound, Alaska, beginning at a point at latitude 60°40′00″ N., longitude...

  3. 33 CFR 110.233 - Prince William Sound, Alaska.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Prince William Sound, Alaska. 110... ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.233 Prince William Sound, Alaska. (a) The anchorage grounds. In Prince William Sound, Alaska, beginning at a point at latitude 60°40′00″ N., longitude...

  4. 33 CFR 110.233 - Prince William Sound, Alaska.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Prince William Sound, Alaska. 110... ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.233 Prince William Sound, Alaska. (a) The anchorage grounds. In Prince William Sound, Alaska, beginning at a point at latitude 60°40′00″ N., longitude...

  5. 33 CFR 110.233 - Prince William Sound, Alaska.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Prince William Sound, Alaska. 110... ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.233 Prince William Sound, Alaska. (a) The anchorage grounds. In Prince William Sound, Alaska, beginning at a point at latitude 60°40′00″ N., longitude...

  6. Heavy minerals in surficial sediments from lower Cook Inlet, Alaska

    USGS Publications Warehouse

    Wong, F.L.

    1984-01-01

    Amphiboles, orthopyroxenes, and clinopyroxenes dominate the heavy mineral suite of surficial sediments in lower Cook Inlet, Alaska. Sources for these sediments include the igneous arc terrane of the northeast Alaska Range, reworked intrabasinal sediments, and local drainages in lower Cook Inlet. The distribution of these deposits is a reflection of both the tidal currents and the prevailing southerly net movement from the head of Cook Inlet. The heavy mineral studies concur with similar findings from gravel analyses, clay mineral investigations, and quartz microtexture observations. ?? 1984 Springer-Verlag New York Inc.

  7. Geologic Map of the Nulato Quadrangle, West-Central Alaska

    USGS Publications Warehouse

    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.

  8. Pillar Mountain Landslide, Kodiak, Alaska

    USGS Publications Warehouse

    Kachadoorian, Reuben; Slater, Willard H.

    1978-01-01

    Pillar Mountain landslide on the southeast face of Pillar Mountain is about 915 m (3,000 ft) southwest of the city of Kodiak, Alaska. The landslide is about 520 m (1,700 ft) wide at its base and extends approximately from sea level to an altitude of about 343 m (1,125 ft). The slide developed on an ancient and apparently inactive landslide. Renewed movement was first detected on December 5, 1971, following removal of about 230,000 m3 (300,000 yd3) of material from the base of the slope. Although movement of the landslide has decreased since December, 1971, movement continues and the possibility exists that it could increase as a result of an earthquake, water saturation of the landslide mass, or other causes. In the most extreme case, as much as 3.8 to 7.6 million m (5-10 million ) of debris could fall into the sea at Inner Anchorage. If this took place suddenly, it could generate a wave comparable in height to the tsunami that damaged Kodiak during the Alaskan Earthquake of 1964. Therefore, we believe that the Pillar landslide is a potential hazard to the city of Kodiak and its environs that merits a thorough investigation and evaluation.

  9. Chariot, Alaska Site Fact Sheet

    SciTech Connect

    2013-01-16

    The Chariot site is located in the Ogotoruk Valley in the Cape Thompson region of northwest Alaska. This region is about 125 miles north of (inside) the Arctic Circle and is bounded on the southwest by the Chukchi Sea. The closest populated areas are the Inupiat villages of Point Hope, 32 miles northwest of the site, and Kivalina,41 miles to the southeast. The site is accessible from Point Hope by ATV in the summer and by snowmobile in the winter. Project Chariot was part of the Plowshare Program, created in 1957 by the U.S. Atomic Energy Commission (AEC), a predecessor agency of the U.S. Department of Energy (DOE), to study peaceful uses for atomic energy. Project Chariot began in 1958 when a scientific field team chose Cape Thompson as a potential site to excavate a harbor using a series of nuclear explosions. AEC, with assistance from other agencies, conducted more than40 pretest bioenvironmental studies of the Cape Thompson area between 1959 and 1962; however, the Plowshare Program work at the Project Chariot site was cancelled because of strong public opposition. No nuclear explosions were conducted at the site.

  10. Southeastern Alaska tectonostratigraphic terranes revisited

    SciTech Connect

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

    1985-04-01

    The presence of only three major tectonostratigraphic terranes (TSTs) in southeastern Alaska and northwestern British Columbia (Chugach, Wrangell, and Alexander) is indicated by critical analysis of available age, stratigraphic, and structural data. A possible fourth TST (Stikine) is probably an equivalent of part or all of the Alexander. The Yakutat block belongs to the Chugach TST, and both are closely linked to the Wrangell and Alexander(-Stikine) TSTs; the Gravina TST is an overlap assemblage. THe Alexander(-Stikine) TSTs is subdivided on the basis of age and facies. The subterranes within it share common substrates and represent large-scale facies changes in a long-lived island-arc environment. The Taku TSTs is the metamorphic equivalent of the upper part (Permian and Upper Triassic) of the Alexander(-Stikine) TSTs with some fossil evidence preserved that indicates the age of protoliths. Similarly, the Tracy Arm TST is the metamorphic equivalent of (1) the lower (Ordovician to Carboniferous) Alexander TST without any such fossil evidence and (2) the upper (Permian to Triassic) Alexander(-Stikine) with some newly discovered fossil evidence. Evidence for the ages of juxtaposition of the TSTs is limited. The Chugach TST deformed against the Wrangell and Alexander TSTs in late Cretaceous. Gravina rocks were deformed at the time and also earlier. The Wrangell TST was stitched to the Alexander(-Stikine) by middle Cretaceous plutons but may have arrived before its Late Jurassic plutons were emplaced. The Alexander(-Stikine) and Cache Creek TSTs were juxtaposed before Late Triassic.

  11. 77 FR 38013 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ...--FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA 0 1. The authority citation for part 679 continues to... National Oceanic and Atmospheric Administration 50 CFR Part 679 RIN 0648-BC23 Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 88; Correction AGENCY:...

  12. 77 FR 4290 - TransCanada Alaska Company, LLC; Notice of Public Scoping Meeting for the Planned Alaska Pipeline...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TransCanada Alaska Company, LLC; Notice of Public Scoping Meeting for the... cancelled on January 4, 2012, because TransCanada Alaska Company, LLC (TC Alaska) had not filed its...

  13. The Alaska experience using store-and-forward telemedicine for ENT care in Alaska.

    PubMed

    Kokesh, John; Ferguson, A Stewart; Patricoski, Chris

    2011-12-01

    This article discusses the development, evaluation, and growth of telemedicine in Alaska. Store-and-forward telemedicine has been used to deliver ear, nose, and throat (ENT) care to rural Alaska since 2002. It has proved valuable in the treatment of many conditions of the head and neck, and it is particularly well suited for the diagnosis and treatment of ear disease. Usage has grown steadily as telemedicine has become widely accepted. Store-and-forward telemedicine has been shown within the Alaska Native Health System to improve access for care and reduce wait times, as well as decrease travel-associated costs for patients. PMID:22032488

  14. The Alaska experience using store-and-forward telemedicine for ENT care in Alaska.

    PubMed

    Kokesh, John; Ferguson, A Stewart; Patricoski, Chris

    2011-12-01

    This article discusses the development, evaluation, and growth of telemedicine in Alaska. Store-and-forward telemedicine has been used to deliver ear, nose, and throat (ENT) care to rural Alaska since 2002. It has proved valuable in the treatment of many conditions of the head and neck, and it is particularly well suited for the diagnosis and treatment of ear disease. Usage has grown steadily as telemedicine has become widely accepted. Store-and-forward telemedicine has been shown within the Alaska Native Health System to improve access for care and reduce wait times, as well as decrease travel-associated costs for patients.

  15. Late Quaternary glacial relief evolution and fracture-density control on erosion revealed by low-temperature thermochronometry and remote sensing (Granite Range, Alaska)

    NASA Astrophysics Data System (ADS)

    Valla, Pierre; Champagnac, Jean-Daniel; Herman, Frédéric; Lowick, Sally; Guralnik, Benny; Shuster, David; Fellin, Giuditta

    2013-04-01

    Long-term erosion and topographic evolution of mountain belts arise from complex coupling between tectonics, climate and surface processes. The Granite Range (Wrangell-St Elias National Park, Alaska) presents an ideal setting to study such interactions. Its alpine landscape, preserving typical glacial features (U-shaped valleys, cirques), appears highly smoothed in the west, and progressively more rugged towards the east. In the field, this is evidenced by minor and only localized faulting of massive bedrock (granite and paragneiss) in the west, while the eastern part shows highly fractured bedrock (penetrative faults, fault gouges). Remote-sensing analysis confirms that fracture density is much higher towards east, and also reveals high post-glacial incision only in areas associated with high fracture density. To quantify our morphometric observations, we sampled four elevation profiles (~15 samples in total) over an 80-km East-West transect for low-temperature thermochrometry. Apatite (U-Th-Sm)/He dating provides ages between ~10 and 30 Ma, in agreement with published data, and shows apparent low long-term exhumation rates (~0.05-0.1 km/Ma). Preliminary 4He/3He thermochronometry data reveal a more complex exhumation history, with a significant increase since ~6-5 Ma which can be related to either onset of glaciations in Alaska or a major change in tectonic activity occurring at that period. Further data collected within the Granite Range will help to decipher the origin of this late-Miocene acceleration in exhumation. We also performed luminescence thermochronometry measured on feldspar separates from bedrock samples. Our results show a strong East-West gradient in samples saturation ratio. Apparent ages vary from ~250 ka in the western part of the range, towards younger ages of ~30 ka in the east. This pattern reveals spatially variable erosion rates during the late Quaternary associated with a major fracture-density control on erosion, and further supports the

  16. 47 CFR 80.469 - Maritime mobile repeater stations in Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maritime mobile repeater stations in Alaska. 80... Maritime mobile repeater stations in Alaska. (a) Maritime mobile repeater stations are authorized to extend...) On a secondary basis, maritime mobile repeater stations may be authorized to extend the range of...

  17. Water availability, quality, and use in Alaska

    USGS Publications Warehouse

    Balding, G.O.

    1976-01-01

    The Alaska Water Assessment, sponsored by the Water Resources Council, is a specific problem analysis for Alaska of the National Assessment of Water and Related Land Resources. The Alaska region has been divided into six hydrologic subregions and eighteen subareas. For each subarea, estimated mean annual runoff per square mile, suspended-sediment concentrations that can be expected during ' normal ' summer runoff, flood magnitudes and frequencies, and ground-water yields are illustrated on maps. Tables show water quality of both ground water and surface water from selected wells and streams. Water use according to the type of use is discussed, and estimates are given for the amounts used. Water-use categories include domestic, irrigation, livestock, seafood processing, oil and gas development, petrochemical processing, pulp mills, hydroelectric , coal processing, steam electric, mineral processing, sand and gravel mining, and fish-hatchery operations. (Woodard-USGS)

  18. Analysis of Alaska hydro power development

    SciTech Connect

    Sieber, O.V.

    1983-12-01

    Alaska leads the world in terms of total potential for hydropower development, yet Alaska is 91% dependent on fossil fuels. A mix of gas, diesel and coal-fired power plants generate all but 9% of its electricity. This dependence on fossil fuels stems from the abundance of cheap gas, coal and oil-nonrenewable resources that are becoming more costly. Hydro power is also costly; however, most hydro projects are justified by long term returns. Once the water hits the turbine in a hydro project, the operating and maintenance cost is practically nil. The successful completion of two complex thin-arch concrete dams and several other hydro projects are discussed in order to meet Alaska's power demand.

  19. Paleoindians in beringia: evidence from arctic alaska.

    PubMed

    Kunz, M L; Reanier, R E

    1994-02-01

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

  20. Regional Observations of Alaska Glacier Dynamics

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  1. The Border Ranges fault system in Glacier Bay National Park, Alaska: Evidence for major early Cenozoic dextral strike-slip motion

    USGS Publications Warehouse

    Smart, K.J.; Pavlis, T.L.; Sisson, V.B.; Roeske, S.M.; Snee, L.W.

    1996-01-01

    The Border Ranges fault system of southern Alaska, the fundamental break between the arc basement and the forearc accretionary complex, is the boundary between the Peninsular-Alexander-Wrangellia terrane and the Chugach terrane. The fault system separates crystalline rocks of the Alexander terrane from metamorphic rocks of the Chugach terrane in Glacier Bay National Park. Mylonitic rocks in the zone record abundant evidence for dextral strike-slip motion along north-northwest-striking subvertical surfaces. Geochronologic data together with regional correlations of Chugach terrane rocks involved in the deformation constrain this movement between latest Cretaceous and Early Eocene (???50 Ma). These findings are in agreement with studies to the northwest and southeast along the Border Ranges fault system which show dextral strike-slip motion occurring between 58 and 50 Ma. Correlations between Glacier Bay plutons and rocks of similar ages elsewhere along the Border Ranges fault system suggest that as much as 700 km of dextral motion may have been accommodated by this structure. These observations are consistent with oblique convergence of the Kula plate during early Cenozoic and forearc slivering above an ancient subduction zone following late Mesozoic accretion of the Peninsular-Alexander-Wrangellia terrane to North America.

  2. An integrated model for the tectonic development of the frontal Brooks Range and Colville Basin 250 km west of the Trans-Alaska Crustal Transect

    USGS Publications Warehouse

    Cole, F.; Bird, K.J.; Toro, J.; Roure, F.; O'Sullivan, P. B.; Pawlewicz, M.; Howell, D.G.

    1997-01-01

    We present a kinematic model for the sequence of deformation and sedimentation in the frontal Brooks Range and adjacent Colville Basin in the Etivluk River region, 250 km west of the Trans-Alaska Crustal Transect (TACT). The model is based on a tectonic subsidence analysis of the foreland basin, combined with structural, stratigraphic, and thermal studies of the northern edge of the Brooks Range thrust belt. We interpret six discrete tectonic events that led to the present-day configuration of the thrust belt in this area: (1) emplacement of ophiolitic allochthons over the distal continental margin rocks in Valanginian time, hundreds of kilometers south of this study, (2) Hauterivian uplift of the Barrow Arch rift margin, affecting the northern part of the Colville Basin, (3) Barremian contraction involving emplacement of distal continental margin and ophiolitic allochthons onto the Endicott Mountains allochthon and creation of a southward dipping flexural basin on the North Slope autochthon, (4) mid-Cretaceous exhumation of imbricated rocks in the Brooks Range during northward propagation of the thrust front into the foreland, (5) minor thrusting in Late Cretaceous-Paleocene in the northern foreland to the northern limit of contractional structures, and (6) regional exhumation of the orogen and the foreland in Paleocene-Eocene time. This sequence of deformation agrees well with a simple model of a forward propagating thrust system. Copyright 1997 by the American Geophysical Union.

  3. Alaska Natives assessing the health of their environment.

    PubMed

    Garza, D

    2001-11-01

    The changes in Alaska's ecosystems caused by pollution, contaminants and global climate change are negatively impacting Alaska Natives and rural residents who rely on natural resources for food, culture and community identity. While Alaska commerce has contributed little to these global changes and impacts, Alaska and its resources are nonetheless affected by the changes. While Alaska Natives have historically relied on Alaska's land, water and animals for survival and cultural identity, today their faith in the safety and quality of these resources has decreased. Alaska Natives no longer believe that these wild resources are the best and many are turning to alternative store-bought foods. Such a change in diet and activity may be contributing to a decline in traditional activities and a decline in general health. Contaminants are showing up in the animals, fish and waters that Alaska Natives use. Efforts need to be expanded to empower Alaska Native Tribes to collect and analyze local wild foods for various contaminants. In addition existing information on contaminants and pollution should be made readily available to Alaska residents. Armed with this type of information Alaska Native residents will be better prepared to make informed decisions on using wild foods and materials. PMID:11768422

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

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

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

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

  5. Perspective View of Umnak Island, Aleutian Islands, Alaska (#1)

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is a perspective view of Umnak Island, one of Alaska's Aleutian Islands. The active Okmok volcano appears in the center of the island.

    The image was created by draping a Landsat 7 Thematic Mapper image over a digital elevation mosaic derived from Airsar data.

    This work was conducted as part of a NASA-funded Alaska Digital Elevation Model Project at the Alaska Synthetic Aperture Radar Facility (ASF) at the University of Alaska Geophysical Institute in Fairbanks, Alaska.

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

  6. Perspective View of Umnak Island, Aleutian Islands, Alaska (#2)

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is a perspective view of Umnak Island, one of Alaska's Aleutian Islands. The active Okmok volcano appears in the center of the island.

    The image was created by draping a Landsat 7 Thematic Mapper image over a digital elevation mosaic derived from Airsar data.

    This work was conducted as part of a NASA-funded Alaska Digital Elevation Model Project at the Alaska Synthetic Aperture Radar Facility (ASF) at the University of Alaska Geophysical Institute in Fairbanks, Alaska.

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

  7. A native corporation evaluates potential of Alaska`s Kandik area

    SciTech Connect

    Hite, D.M.

    1997-11-17

    Alaska`s regional Native corporations control large tracts of land with significant mineral and hydrocarbon potential. One of these 12 corporations, Doyon Ltd., has extensive holdings with the potential for large oil and gas accumulations. The most promising is the Kandik region of east-central Alaska. Recent compilations and research involving the organic geochemistry, stratigraphy, and timing of structural deformation in the Kandik area have resulted in much more optimistic appraisals of the oil potential. These studies indicate that known oil-prone source units may have generated 50--100 billion bbl of oil. Some of these data have recently been made available to the public through the Alaska Division of Geological and Geophysical Surveys. The paper discusses the exploration history, stratigraphy, geologic structure, hydrocarbon potential, and prospective areas.

  8. Volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory 1993

    USGS Publications Warehouse

    Neal, Christina A.; McGimsey, Robert G.; Doukas, Michael P.

    1996-01-01

    During 1993, the Alaska Volcano Observatory (AVO) responded to episodes of eruptive activity or false alarms at nine volcanic centers in the state of Alaska. Additionally, as part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also responded to eruptions on the Kamchatka Peninsula, details of which are summarized in Miller and Kurianov (1993). In 1993, AVO maintained seismic instrumentation networks on four volcanoes of the Cook Inlet region--Spurr, Redoubt, Iliamna, and Augustine--and two stations at Dutton Volcano near King Cove on the Alaska Peninsula. Other routine elements of AVO's volcano monitoring program in Alaska include periodic airborne measurement of volcanic SO2 and CO2 at Cook Inlet volcanoes (Doukas, 1995) and maintenance of a lightning detection system in Cook Inlet (Paskievitch and others, 1995).

  9. Birds and Wetlands of Alaska. Alaska Sea Week Curriculum Series. Alaska Sea Grant Report 88-1.

    ERIC Educational Resources Information Center

    King, James G.; King, Mary Lou

    This curriculum guide is the fourth (Series V) in a six-volume set that comprises the Sea Week Curriculum Series developed in Alaska. Twelve units contain 45 activities with worksheets that cover the following topics: (1) bird lists and field guides; (2) definitions of a bird; (3) parts of a bird; (4) bird watching; (5) bird migration; (6) wetland…

  10. Digital Shaded-Relief Image of Alaska

    USGS Publications Warehouse

    Riehle, J.R.; Fleming, Michael D.; Molnia, B.F.; Dover, J.H.; Kelley, J.S.; Miller, M.L.; Nokleberg, W.J.; Plafker, George; Till, A.B.

    1997-01-01

    Introduction One of the most spectacular physiographic images of the conterminous United States, and the first to have been produced digitally, is that by Thelin and Pike (USGS I-2206, 1991). The image is remarkable for its crispness of detail and for the natural appearance of the artificial land surface. Our goal has been to produce a shaded-relief image of Alaska that has the same look and feel as the Thelin and Pike image. The Alaskan image could have been produced at the same scale as its lower 48 counterpart (1:3,500,000). But by insetting the Aleutian Islands into the Gulf of Alaska, we were able to print the Alaska map at a larger scale (1:2,500,000) and about the same physical size as the Thelin and Pike image. Benefits of the 1:2,500,000 scale are (1) greater resolution of topographic features and (2) ease of reference to the U.S. Geological Survey (USGS) (1987) Alaska Map E and the statewide geologic map (Beikman, 1980), which are both 1:2,500,000 scale. Manually drawn, shaded-relief images of Alaska's land surface have long been available (for example, Department of the Interior, 1909; Raisz, 1948). The topography depicted on these early maps is mainly schematic. Maps showing topographic contours were first available for the entire State in 1953 (USGS, 1:250,000) (J.H. Wittmann, USGS, written commun., 1996). The Alaska Map E was initially released in 1954 in both planimetric (revised in 1973 and 1987) and shaded-relief versions (revised in 1973, 1987, and 1996); topography depicted on the shaded-relief version is based on the 1:250,000-scale USGS topographic maps. Alaska Map E was later modified to include hypsometric tinting by Raven Maps and Images (1989, revised 1993) as copyrighted versions. Other shaded-relief images were produced for The National Geographic Magazine (LaGorce, 1956; 1:3,000,000) or drawn by Harrison (1970; 1:7,500,000) for The National Atlas of the United States. Recently, the State of Alaska digitally produced a shaded-relief image

  11. An inverted metamorphic field gradient in the central Brooks Range, Alaska and implications for exhumation of high-pressure/low-temperature metamorphic rocks

    USGS Publications Warehouse

    Patrick, B.; Till, A.B.; Dinklage, W.S.

    1994-01-01

    During exhumation of the Brooks Range internal zone, amphibolite-facies rocks were emplaced atop the blueschist/greenschist facies schist belt. The resultant inverted metamorphic field gradient is mappable as a series of isograds encountered as one traverses up structural section. Amphibolite-facies metamorphism occurred at ??? 110 Ma as determined from 40Ar 39Ar analysis of hornblende. This contrasts with 40Ar 39Ar phengite cooling ages from the uderlying schist belt, which are clearly older (by 17-22 m.y.). Fabrics in both the amphibolite-facies rocks and schist belt are characterized by repeated cycles of N-vergent crenulation and transposition that was likely associated with out-of-sequence ductile thrusting in the internal zone of the Brooks Range orogen. Contractional deformation occurred in an overall environment of foreland-directed tectonic transport, broadly synchronous with exhumation of the internal zone, and shortening within the thin-skinned fold and thrust belt. These data are inconsistent with a recently postulated mid-Cretaceous episode of lithospheric extension in northern Alaska. ?? 1994.

  12. Geochronology of the western and central Brooks Range, Alaska: Implications for the geologic evolution of the Anarraaq and Red Dog Zn-Pb-Ag deposits

    USGS Publications Warehouse

    Rombach, C.S.; Layer, P.W.

    2004-01-01

    A compilation of published geochronology of rocks and minerals from the western and central Brooks Range provides a framework for understanding the complex history of the Brooks Range and northern Alaska. A simplified timeline of events comprises (1) Devonian extension, (2) Mississippian extension and Zn-Pb-Ag mineralization, (3) a passive interval, (4) pre-Brooks Range orogeny rock-formation and thermal event, (5) inception of Brooks Range orogeny, (6) exhumation and the end of main-stage deformation, and (7) subsequent episodic deformation. This compilation is supplemented by new 40Ar/39Ar dates of white mica from the Anarraaq and Red Dog Zn-Pb-Ag (+ barite) deposits from the western Brooks Range. The deposits are hosted in black shale and carbonate rocks of the Late Mississippian-Early Pennsylvanian Kuna Formation. Quartz-pyrite-white mica grains in sedimentary rocks above the Anarraaq deposit yield an age of 195.0 ?? 2.0 Ma, and paragenetically late quartz-pyrite-white mica from the Main orebody at the Red Dog deposit has an age of 126.1 ?? 0.7 Ma. These white micas are much younger than the age of Zn-Pb-Ag mineralization at Red Dog (338 ?? 5.8 Ma Re-Os age of pyrite). The date for white mica from Anarraaq (???195 Ma) appears to be related to a large-scale thermal event in the region immediately before the inception of the Brooks Range orogeny. The white mica from the Red Dog deposit (???126 Ma) correlates with the later stages of the orogeny, a period of blueschist metamorphism, extension, and rapid exhumation, which varied with geographic location. These dates suggest that the Red Dog deposits underwent significant hydrothermal overprinting during multiple episodes of the Brooks Range orogeny. ?? 2004 by Economic Geology.

  13. Population structure and genetic diversity of moose in Alaska.

    PubMed

    Schmidt, Jennifer I; Hundertmark, Kris J; Bowyer, R Terry; McCracken, Kevin G

    2009-01-01

    Moose (Alces alces) are highly mobile mammals that occur across arboreal regions of North America, Europe, and Asia. Alaskan moose (Alces alces gigas) range across much of Alaska and are primary herbivore consumers, exerting a prominent influence on ecosystem structure and functioning. Increased knowledge gained from population genetics provides insights into their population dynamics, history, and dispersal of these unique large herbivores and can aid in conservation efforts. We examined the genetic diversity and population structure of moose (n = 141) with 8 polymorphic microsatellites from 6 regions spanning much of Alaska. Expected heterozygosity was moderate (H(E) = 0.483-0.612), and private alleles ranged from 0 to 6. Both F(ST) and R(ST) indicated significant population structure (P < 0.001) with F(ST) < 0.109 and R(ST) < 0.125. Results of analyses from STRUCTURE indicated 2 prominent population groups, a mix of moose from the Yakutat and Tetlin regions versus all other moose, with slight substructure observed among the second population. Estimates of dispersal differed between analytical approaches, indicating a high level of historical or current gene flow. Mantel tests indicated that isolation-by-distance partially explained observed structure among moose populations (R(2) = 0.45, P < 0.01). Finally, there was no evidence of bottlenecks either at the population level or overall. We conclude that weak population structure occurs among moose in Alaska with population expansion from interior Alaska westward toward the coast.

  14. Geologic map of Saint Lawrence Island, Alaska

    USGS Publications Warehouse

    Patton, William W.; Wilson, Frederic H.; Taylor, Theresa A.

    2011-01-01

    Saint Lawrence Island is located in the northern Bering Sea, 190 km southwest of the tip of the Seward Peninsula, Alaska, and 75 km southeast of the Chukotsk Peninsula, Russia (see index map, map sheet). It lies on a broad, shallow-water continental shelf that extends from western Alaska to northeastern Russia. The island is situated on a northwest-trending structural uplift exposing rocks as old as Paleozoic above sea level. The submerged shelf between the Seward Peninsula and Saint Lawrence Island is covered mainly with Cenozoic deposits (Dundo and Egiazarov, 1982). Northeast of the island, the shelf is underlain by a large structural depression, the Norton Basin, which contains as much as 6.5 km of Cenozoic strata (Grim and McManus, 1970; Fisher and others, 1982). Sparse test-well data indicate that the Cenozoic strata are underlain by Paleozoic and Proterozoic rocks, similar to those exposed on the Seward Peninsula (Turner and others, 1983). Saint Lawrence Island is 160 km long in an east-west direction and from 15 km to 55 km wide in a north-south direction. The east end of the island consists largely of a wave-cut platform, which has been elevated as much as 30 m above sea level. Isolated upland areas composed largely of granitic plutons rise as much as 550 m above the wave-cut platform. The central part of the island is dominated by the Kookooligit Mountains, a large Quaternary shield volcano that extends over an area of 850 km2 and rises to an elevation of 630 m. The west end of the island is composed of the Poovoot Range, a group of barren, rubble-covered hills as high as 450 m that extend from Boxer Bay on the southwest coast to Taphook Mountain on the north coast. The Poovoot Range is flanked on the southeast by the Putgut Plateau, a nearly flat, lake-dotted plain that stands 30?60 m above sea level. The west end of the island is marked by uplands underlain by the Sevuokuk pluton (unit Kg), a long narrow granite body that extends from Gambell on the

  15. The Work of the Bureau of Education for the Natives of Alaska. Bulletin, 1921, No. 35

    ERIC Educational Resources Information Center

    Bureau of Education, Department of the Interior, 1921

    1921-01-01

    The work of the Bureau of Education for the natives of Alaska includes the Alaska school service, the Alaska medical service, and the Alaska reindeer service, with a field force in Alaska, in 1920, of 6 superintendents, 133 teachers, 9 physicians, and 13 nurses. This bulletin provides details on the following topics: (1) Extent of territory; (2)…

  16. Address to Yukon-Kuskokwim Delta Regional Summit on Native Education (Bethel, Alaska, April 24, 2002).

    ERIC Educational Resources Information Center

    Ongtooguk, Paul

    Remarks of Alaska Native researcher and educator Paul Ongtooguk are presented. Alaska Native students perform worse on exit exams than any other population in the state. In the past, formal education was offered to Alaska Natives only if they gave up being Alaska Natives. The current system is not designed to solve the problems of Alaska Native…

  17. The Alaska Journal of Art, 1989.

    ERIC Educational Resources Information Center

    Welter, Cole H., Ed.

    1989-01-01

    The inaugural issue of this annual journal explores issues affecting art education practices in Alaska and seeks to contribute to a national dialogue on art education policy. "Art as General Education" (Harry S. Broudy) addresses the essential value and nature of the arts in general education. It argues for visual arts education as a key to…

  18. Alaska Performance Scholarship Outcomes Report 2014

    ERIC Educational Resources Information Center

    Rae, Brian

    2014-01-01

    The 2014 Alaska Performance Scholarship (APS) Outcomes Report analyzes the characteristics of high school graduates, those who were eligible to receive the scholarship, and those who went on to make use of it during the three years of the scholarship's existence. The analysis includes their geographic, gender, ethnic, and socioeconomic…

  19. Subgroup Achievement and Gap Trends: Alaska

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    Alaska showed improvement in reading and math in grade 8 at the proficient level for almost all racial/ethnic subgroups, low income students, and boys and girls (subgroup trends were not available at the basic or advanced levels). Most student subgroups had upward trends in percentages proficient, with a few exceptions. Gains in math tended to be…

  20. 50 CFR 17.5 - Alaska natives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS Introduction and General Provisions § 17.5 Alaska... accomplished in a wasteful manner. (b) Edible portions of endangered or threatened wildlife taken or...

  1. 50 CFR 17.5 - Alaska natives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS Introduction and General Provisions § 17.5 Alaska... accomplished in a wasteful manner. (b) Edible portions of endangered or threatened wildlife taken or...

  2. Kids Count Alaska Data Book: 1996.

    ERIC Educational Resources Information Center

    Alaska Univ., Anchorage. Inst. of Social and Economic Research.

    This statistical report examines findings on 15 indicators of children's well-being in Alaska: (1) percent of births with low birth weight; (2) infant mortality rate; (3) child poverty rate; (4) children in single parent families; (5) births to teenagers age 15 to 17; (6) teen (age 16 to 19) high school dropout rate; (7) teens not in school and…

  3. Tsunami Inundation Mapping of Coastal Alaska

    NASA Astrophysics Data System (ADS)

    Suleimani, E.; Hansen, R.; Marriott, D.; Combellick, R.

    2004-05-01

    Seismic events that occur within the Alaska-Aleutian subduction zone have a high potential for generating both local and Pacific-wide tsunamis. To help mitigate the large risk these earthquakes and tsunamis pose to Alaskan coastal communities, the Alaska Tsunami Modeling Team addresses the problem of predicting runup of tsunami waves using a numerical modeling technique. The model solves nonlinear shallow-water equations with a finite-difference method. Embedded grids of different resolution are employed to increase spatial resolution in the shelf area. Numerical simulations yield runup heights, extent of maximum inundation for chosen tsunami scenarios, depths of inundation on dry land, and maximum velocity current distribution in inundation zones. The communities for inundation mapping are selected in coordination with the Alaska Division of Emergency Services with consideration to location, infrastructure, availability of bathymetric and topographic data, and community involvement.The communities of Homer and Seldovia are located in Kachemak Bay, which is one of the high-priority region for Alaska inundation mapping. We modeled two hypothetical earthquake scenarios as potential sources of tsunami waves that affect the Kachemak Bay communities. They represent both distant and local sources, and we model them using the multiple fault approach. Seward, a community in the Prince William Sound area, suffered an extensive damage and 12 fatalities during the 1964 tsunami. The most destructive waves in Seward were local slump-generated tsunamis. We consider several tsunami scenarios for Seward inundation mapping that include both tectonic and landslide sources.

  4. 1996 annual report on Alaska's mineral resources

    USGS Publications Warehouse

    Schneider, Jill L.

    1997-01-01

    This is the fifteenth annual report that has been prepared in response to the Alaska National Interest Lands Conservation Act. Current Alaskan mineral projects and events that occurred during 1995 are summarized. For the purpose of this document, the term 'minerals' encompasses both energy resources (oil and gas, coal and peat, uranium, and geothermal) and nonfuel-mineral resources (metallic and industrial minerals).

  5. Fact Book 1992: University of Alaska Fairbanks.

    ERIC Educational Resources Information Center

    Gaylord, Thomas; And Others

    This publication presents information on the University of Alaska Fairbanks in seven sections. The first section, "Historical and General Information" details the legal establishment, mission, historical highlights, map, organizational structure, accreditation, Board of Regents, Standing Committees and advisory groups, songs, presidents and…

  6. 76 FR 43340 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-6682-B, AA-6682-D, AA-6682-E, AA-6682-G, AA-6682-H, AA-6682-I, AA- 6682-A2; LLAK965000-L14100000-KC0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management,...

  7. 77 FR 72383 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-10282, AA-10291, AA-10292, AA-10369; LLAK-944000-L14100000-HY0000- P] Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice of...

  8. 76 FR 55415 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-9428, AA-9752, AA-11237, AA-9755, AA-9837, AA-10075, AA-11467; LLAK-965000-L14100000-HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior....

  9. 78 FR 16527 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-10782, AA-11132, AA-10784, AA-12440, AA-11020, AA-10783, AA-10774; LLAK-944000-L14100000-HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management,...

  10. 75 FR 65644 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-11937, AA-11938, AA-11939, AA-11940, AA-11944, AA-11943, AA-11941, AA-11936, AA-11933, AA-11928, AA-11929, AA-11931, AA-11932; LLAK- 962000-L14100000-HY0000-P] Alaska...

  11. 76 FR 16804 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-8102-05, AA-8102-08, AA-8102-10, AA-8102-25, AA-8102-28, AA-8102- 37, AA-8102-47; LLAK965000-L14100000-KC0000-P] Alaska Native Claims Selection AGENCY: Bureau of...

  12. 78 FR 10634 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-14

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-10756, AA-11061, AA-10764, AA-10765, AA-10766, AA-11083; LLAK- 944000-L14100000-HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior....

  13. 75 FR 21033 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-6670-F, AA-6670-L, AA-6670-M, AA-6670-A2; LLAK964000-L14100000- HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice of...

  14. 75 FR 26784 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ... Bureau of Land Management [AA-11973, AA-11993, AA-11968, AA-11972, AA-12018, AA-12013, AA-12014, AA-12015, AA-12016, AA-12017, AA-11984, AA-11994, AA-11995, AA-11996, AA-12003, AA-12012, AA-11967, AA-12020, AA-12021; LLAK-962000- L14100000-HY0000-P] Alaska......

  15. 75 FR 80838 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-11908, AA-11915, AA-11916, AA-11917, AA-11909, AA-11913, AA-11914; LLAK-962000-L14100000-HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management,...

  16. An Overall Education Plan for Rural Alaska.

    ERIC Educational Resources Information Center

    Alaska Governor's Committee of Education, Juneau.

    A report submitted by the Alaskan Governor's Committee on Education indicates that the quality of education in rural schools, both state-sponsored and Bureau of Indian Affairs-sponsored, is in need of improvement. This plan for school reorganization in Alaska recommends consolidation of small rural schools in favor of wider curricular offerings…

  17. Quilts of Alaska--Student Activities.

    ERIC Educational Resources Information Center

    Alaska State Museum, Juneau.

    This student activities booklet, "Quilts of Alaska," contains historical and educational information on quilts. It is colorfully illustrated with examples of different types of quilts. The booklet describes album or signature quilts, which from 1840 to the 1890s, were a U.S. fad, such as were autograph albums. As the name suggests, these quilts…

  18. 77 FR 530 - Alaska Disaster # AK-00022

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-05

    ... State of Alaska (FEMA-4050- DR), dated 12/22/2011. Incident: Severe Winter Storms and Flooding. Incident... disaster declaration on 12/22/2011, Private Non- Profit organizations that provide essential services of... REAA. The Interest Rates are: Percent For Physical Damage: Non-Profit Organizations with...

  19. Alaska's Adolescents: A Plan for the Future.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Health and Social Services, Anchorage.

    The goal of this first comprehensive report on adolescent health in Alaska is to stimulate interest, activity, and support for improved health among teenagers (ages 10-19). This plan was developed as a tool for use by governments, organizations, and communities. The plan seeks to provide information on the scope and nature of adolescent health…

  20. 76 FR 67635 - Alaska Regulatory Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    ... March 23, 1983, Federal Register (48 FR 12274). You can also find later actions concerning Alaska's...)(1), concerning construction plans for ponds, impoundments, dams, and embankments; 11 AAC 90.101(a... AAC 90.331(d), concerning sedimentation ponds; 11 AAC 90.331(e), concerning removal of...

  1. The Alaska Mineral Resource Assessment Program

    SciTech Connect

    Detterman, R.L.; Case, J.E.; Church, S.E.; Frisken, J.G.; Wilson, F.H.; Yount, M.E.

    1990-01-01

    This book provides background information for the folio of maps that covers the geology, paleontology, geochronology, geochemistry, aeromagnetics, and mineral and energy resources of the Ugashik, Bristol Bay, and western Karluk quadrangles, Alaska Peninsula. Information on two U.S. Geological Survey miscellaneous investigations series maps and three derivative bulletins that resulted from this investigation are described also.

  2. Pacific Rim Partnerships: Alaska's Bold Initiative.

    ERIC Educational Resources Information Center

    Parrett, William H.; Calkins, Annie

    1989-01-01

    Describes the Alaska Sister Schools Network, formed in 1985 to create opportunities for Alaskan students to experience more directly the cultural and economic perspectives of their Pacific Rim neighbors. Network organizers go beyond the "pen-pal" approach to encourage three partnership levels: initial acquaintance, curriculum development, and…

  3. USGS US topo maps for Alaska

    USGS Publications Warehouse

    Anderson, Becci; Fuller, Tracy

    2014-01-01

    In July 2013, the USGS National Geospatial Program began producing new topographic maps for Alaska, providing a new map series for the state known as US Topo. Prior to the start of US Topo map production in Alaska, the most detailed statewide USGS topographic maps were 15-minute 1:63,360-scale maps, with their original production often dating back nearly fifty years. The new 7.5-minute digital maps are created at 1:25,000 map scale, and show greatly increased topographic detail when compared to the older maps. The map scale and data specifications were selected based on significant outreach to various map user groups in Alaska. This multi-year mapping initiative will vastly enhance the base topographic maps for Alaska and is possible because of improvements to key digital map datasets in the state. The new maps and data are beneficial in high priority applications such as safety, planning, research and resource management. New mapping will support science applications throughout the state and provide updated maps for parks, recreation lands and villages.

  4. The State of Adolescent Health in Alaska.

    ERIC Educational Resources Information Center

    Alaska State Office of the Commissioner, Juneau.

    A survey was conducted to provide a profile of the health status and risk behaviors of youth in Alaska. The goal was to develop a statewide database which, when coupled with morbidity and mortality data, would provide information that would allow those who plan and develop services at state and local levels to better target those services. During…

  5. 78 FR 39821 - Alaska Disaster #AK-00029

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... ADMINISTRATION Alaska Disaster AK-00029 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for the..., Fort Worth, TX 76155. FOR FURTHER INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance,...

  6. 76 FR 5395 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-12252, AA-12250, AA-12280, AA-12291, AA-12292, AA-12293; LLAK- 962000-L14100000-HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior....

  7. The Alaska Eskimos. A Selected, Annotated Bibliography.

    ERIC Educational Resources Information Center

    Hippler, Arthur E.; Wood, John R.

    This annotated bibliography, containing approximately 732 entries, provides a general overview of English literature concerning Alaska Eskimos and cities. Although the earliest date of publication is 1843, the majority of the works have been done since 1900; there are no entries published later than 1975. Section I lists the works alphabetically…

  8. 76 FR 35936 - Alaska Disaster #AK-00020

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    ... From the Federal Register Online via the Government Publishing Office U.S. SMALL BUSINESS ADMINISTRATION Alaska Disaster AK-00020 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This... completed loan applications to: U.S. Small Business Administration, Processing and Disbursement...

  9. Alaska Standards for School Library Media Programs.

    ERIC Educational Resources Information Center

    American Association of School Librarians--Alaska, Juneau.

    Developed to encourage and promote the establishment and maintenance of standards of excellence in all school library media centers, standards presented here are designed to be the minimum acceptable for Alaska schools. Each school is urged to use the standards as a base to develop a quality library media program which reflects the unique…

  10. Prevention in Alaska: Issues and Innovations.

    ERIC Educational Resources Information Center

    Mohatt, Gerald; Hazel, Kelly L.; Mohatt, Justin W.

    Diversity of geography, climate, and culture dictate the nature of the service delivery systems in Alaska, including the provision of prevention programming in substance abuse, alcoholism, health, and behavioral health. Described here are training programs, conferences and symposia, health fairs, and culturally derived interventions that meet the…

  11. Alaska Head Start Annual Program Report, 1999.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education and Early Devolopment, Juneau. Head Start State Collaboration Office.

    This annual report details the accomplishments of the Alaska Head Start Program for fiscal year 1999. The report begins with a description of the Head Start program and its core values, and delineates the administrative and program partners of Head Start, its service population, eligibility requirements, funding sources, service models, and…

  12. Educational Programming at Alaska Psychiatric Institute.

    ERIC Educational Resources Information Center

    Konopasek, Dean E.

    The background, organization, and operation of the Alaska Psychiatric Institute (API), a residential program for behavior disordered and emotionally disturbed children and adolescents, are described. Components of the educational program at API, including academic and social assessment, individual education plans, and elementary and secondary…

  13. State Teacher Policy Yearbook, 2009. Alaska

    ERIC Educational Resources Information Center

    National Council on Teacher Quality, 2009

    2009-01-01

    The Alaska edition of the National Council on Teacher Quality's (NCTQ's) 2009 "State Teacher Policy Yearbook" is the third annual look at state policies impacting the teaching profession. It is hoped that this report will help focus attention on areas where state policymakers can make changes that will have a positive impact on teacher quality and…

  14. 78 FR 53158 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ...) to Sea Lion Corporation. The decision approves the surface estate in the lands described below for... estate in these lands will be conveyed to Calista Corporation when the surface estate is conveyed to Sea Lion Corporation. The lands are in the vicinity of Hooper Bay, Alaska, and are located in:...

  15. Discovering Alaska's Salmon: A Children's Activity Book.

    ERIC Educational Resources Information Center

    Devaney, Laurel

    This children's activity book helps students discover Alaska's salmon. Information is provided about salmon and where they live. The salmon life cycle and food chains are also discussed. Different kinds of salmon such as Chum Salmon, Chinook Salmon, Coho Salmon, Sockeye Salmon, and Pink Salmon are introduced, and various activities on salmon are…

  16. 40 CFR 81.302 - Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... affecting § 81.302 see the List of CFR Sections Affected which appears in the Finding Aids section of the...) Unclassifiable/Attainment Barrow Election District Fairbanks N. Star Borough Area other than portion of Fairbanks... 09 Northern Alaska Intrastate Unclassifiable/Attainment Denali Borough Fairbanks North Star...

  17. University of Alaska 1997 Facilities Inventory.

    ERIC Educational Resources Information Center

    Alaska Univ., Fairbanks. Statewide Office of Institutional Research.

    This facilities inventory report presents a comprehensive listing of physical assets owned and operated by the University of Alaska and includes, for each asset, data on average age, weighted average age, gross square footage, original total project funding, and the asset's plant investment value adjusted to the current year. Facilities are listed…

  18. 75 FR 13296 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-6679-B, AA-6679-C, AA-6679-F, AA-6679-G, AA-6679-K, AA-6679-M, AA- 6679-A2, LLAK964000-L14100000-KC0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management,...

  19. 76 FR 75899 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [AA-9915, AA-9916, AA-9921, AA-9936, AA-9937, AA-9965; LLAK-965000- L14100000-HY0000-P] Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice...

  20. Alaska Teens Prepare for Future with FCS

    ERIC Educational Resources Information Center

    Vik, Kathleen L.

    2007-01-01

    Living in Alaska offers many extreme challenges and opportunities for family and consumer sciences (FCS) teachers to step up to the challenges of facing the future. In this article, the author describes how she started the "Stepping Up For Our Future" program. She relates that as the sole FCS teacher in Chugiak High School, she was challenged to…

  1. American Indians and Alaska Natives with Disabilities.

    ERIC Educational Resources Information Center

    Johnson, Marilyn J.

    American Indian and Alaska Native children with special needs experience the same ineffective and inefficient services as other minority language children. This paper discusses the special needs of Native children, assessment and curriculum issues, and recommendations for improvement. It provides statistics for various categories of handicaps and…

  2. 75 FR 53332 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ..., Land Transfer Resolution Specialist, Branch of Preparation and Resolution. BILLING CODE 4310-JA-P ... Bureau of Land Management Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice of decision approving lands for conveyance. SUMMARY: As required by 43 CFR...

  3. 75 FR 28816 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-24

    ..., Land Transfer Resolution Specialist, Branch of Preparation and Resolution. BILLING CODE 4310-JA-P ... Bureau of Land Management Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice of decision approving lands for conveyance. SUMMARY: As required by 43 CFR...

  4. 75 FR 65644 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ... hours a day, 7 days a week. Dina L. Torres, Land Transfer Resolution Specialist, Branch of Preparation... Bureau of Land Management Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior. ACTION: Notice of decision approving lands for conveyance. SUMMARY: As required by 43 CFR...

  5. Investigation of a slowly deforming, glacially debuttressed rock slope in the Alaska Range using InSAR, LiDAR and two-dimensional numerical modeling

    NASA Astrophysics Data System (ADS)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Shugar, D. H.

    2010-12-01

    Field investigation of a large, actively deforming rock slope at Fels Glacier in the east-central Alaska Range during summer 2010 confirmed the presence of more than 100 normal and antislope scarps and numerous other deformation features indicative of deep-seated gravitational slope deformation. Movement is occurring on foliation planes in micaceous schist in response to debuttressing of the slope by rapid downwasting and retreat of Fels Glacier during the twentieth and early twenty-first centuries. Deformation at this slope poses a hazard to strategic infrastructure, including the Alyeska Pipeline and Richardson Highway, both of which are less than 4 km away. We have analyzed RADARSAT-1 (RSAT-1) datasets from the summers of 2003-2008 and confirmed average line-of-sight displacement rates as large as 1 cm/month using the D-InSAR technique. Additionally, speckle-tracking analysis of 2002 RSAT-1 data confirms significant deformation of the slope in response to the 2002 Denali Earthquake (M 7.9), which ruptured the Denali fault less than 4 km from the site. We have recently acquired 45 single-look-complex and spotlight RADARSAT-2 (RSAT-2) scenes spanning the period from January to December 2010 to further characterize recent slope deformation using D-InSAR. We have also constructed preliminary 2-D numerical models of the deforming slope, constrained by field, LiDAR and InSAR datasets, to better characterize the nature of past, present and future deformation at the site.

  6. Frequency dependent Lg attenuation in south-central Alaska

    USGS Publications Warehouse

    McNamara, D.E.

    2000-01-01

    The characteristics of seismic energy attenuation are determined using high frequency Lg waves from 27 crustal earthquakes, in south-central Alaska. Lg time-domain amplitudes are measured in five pass-bands and inverted to determine a frequency-dependent quality factor, Q(f), model for south-central Alaska. The inversion in this study yields the frequency-dependent quality factor, in the form of a power law: Q(f) = Q0fη = 220(±30) f0.66(±0.09) (0.75≤f≤12Hz). The results from this study are remarkably consistent with frequency dependent quality factor estimates, using local S-wave coda, in south-central Alaska. The consistency between S-coda Q(f) and Lg Q(f) enables constraints to be placed on the mechanism of crustal attenuation in south-central Alaska. For the range of frequencies considered in this study both scattering and intrinsic attenuation mechanisms likely play an equal role.

  7. Methane emissions from Alaska in 2012 from CARVE airborne observations

    PubMed Central

    Chang, Rachel Y.-W.; Miller, Charles E.; Dinardo, Steven J.; Karion, Anna; Sweeney, Colm; Daube, Bruce C.; Henderson, John M.; Mountain, Marikate E.; Eluszkiewicz, Janusz; Miller, John B.; Bruhwiler, Lori M. P.; Wofsy, Steven C.

    2014-01-01

    We determined methane (CH4) emissions from Alaska using airborne measurements from the Carbon Arctic Reservoirs Vulnerability Experiment (CARVE). Atmospheric sampling was conducted between May and September 2012 and analyzed using a customized version of the polar weather research and forecast model linked to a Lagrangian particle dispersion model (stochastic time-inverted Lagrangian transport model). We estimated growing season CH4 fluxes of 8 ± 2 mg CH4⋅m−2⋅d−1 averaged over all of Alaska, corresponding to fluxes from wetlands of 56−13+22 mg CH4⋅m−2⋅d−1 if we assumed that wetlands are the only source from the land surface (all uncertainties are 95% confidence intervals from a bootstrapping analysis). Fluxes roughly doubled from May to July, then decreased gradually in August and September. Integrated emissions totaled 2.1 ± 0.5 Tg CH4 for Alaska from May to September 2012, close to the average (2.3; a range of 0.7 to 6 Tg CH4) predicted by various land surface models and inversion analyses for the growing season. Methane emissions from boreal Alaska were larger than from the North Slope; the monthly regional flux estimates showed no evidence of enhanced emissions during early spring or late fall, although these bursts may be more localized in time and space than can be detected by our analysis. These results provide an important baseline to which future studies can be compared. PMID:25385648

  8. Terranes and suture zones in east central Alaska

    NASA Astrophysics Data System (ADS)

    Churkin, M., Jr.; Foster, H. L.; Chapman, R. M.; Weber, F. R.

    1982-05-01

    East central Alaska, with its 17 terranes, forms a part of the mosaic of allochthonous terranes that join the North American and Siberian plates. These terranes range from continental and continental margin, such as the Tatonduk with its thick well-bedded succession of marine shelf rocks, to seamount, arc, and ocean floor terranes. The Yukon crystalline terrane, the largest described here, is a composite of at least four subterranes juxtaposed across the Tintina fault with the Tatonduk terrane, a northwestern extension of the North American plate in Alaska. Inboard of the Yukon crystalline terrane are packets of closely appressed microterranes separated from the Tatonduk and other terranes belonging to North America by major suture zones. These microterranes lie between North America and the mosaic of accretionary terranes that form the more southerly part of Alaska. The most obviously allochthonous microterranes within the suture zones are the Woodchopper Canyon, an Early Devonian basaltic seamount, and the White Mountains, an Ordovician volcanic arc terrane capped by Silurian and Devonian carbonate bank deposits. The nearest counterpart of these terranes is the Alexander terrane in southeastern Alaska. The Tintina fault of Mesozoic and Cenozoic age, like the Denali fault, primarily follows old suture zones that separate terranes. Strike slip faulting developed after collision in places where further convergence was oblique to the terrane margins. Where terranes met head-on, their leading edges lie along a multiple set of high-angle faults that outline microterranes in accretion zones.

  9. Indicators of recent environmental change in Alaska

    SciTech Connect

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

    1997-12-31

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

  10. Thermal evolution of sedimentary basins in Alaska

    USGS Publications Warehouse

    Johnsson, Mark J.; Howell, D.G.

    1996-01-01

    The complex tectonic collage of Alaska is reflected in the conjunction of rocks of widely varying thermal maturity. Indicators of the level of thermal maturity of rocks exposed at the surface, such as vitrinite reflectance and conodont color alteration index, can help constrain the tectonic evolution of such complex regions and, when combined with petrographic, modern heat flow, thermogeochronologic, and isotopic data, allow for the detailed evaluation of a region?s burial and uplift history. We have collected and assembled nearly 10,000 vitrinite-reflectance and conodont-color-alteration index values from the literature, previous U.S. Geological Survey investigations, and our own studies in Alaska. This database allows for the first synthesis of thermal maturity on a broadly regional scale. Post-accretionary sedimentary basins in Alaska show wide variability in terms of thermal maturity. The Tertiary interior basins, as well as some of the forearc and backarc basins associated with the Aleutian Arc, are presently at their greatest depth of burial, with immature rocks exposed at the surface. Other basins, such as some backarc basins on the Alaska Peninsula, show higher thermal maturities, indicating modest uplift, perhaps in conjunction with higher geothermal gradients related to the arc itself. Cretaceous ?flysch? basins, such as the Yukon-Koyukuk basin, are at much higher thermal maturity, reflecting great amounts of uplift perhaps associated with compressional regimes generated through terrane accretion. Many sedimentary basins in Alaska, such as the Yukon-Koyukuk and Colville basins, show higher thermal maturity at basin margins, perhaps reflecting greater uplift of the margins in response to isostatic unloading, owing to erosion of the hinterland adjacent to the basin or to compressional stresses adjacent to basin margins.

  11. EarthScope's Transportable Array in Alaska and Western Canada

    NASA Astrophysics Data System (ADS)

    Enders, M.; Miner, J.; Bierma, R. M.; Busby, R.

    2015-12-01

    EarthScope's Transportable Array (TA) in Alaska and Canada is an ongoing deployment of 261 high quality broadband seismographs. The Alaska TA is the continuation of the rolling TA/USArray deployment of 400 broadband seismographs in the lower 48 contiguous states and builds on the success of the TA project there. The TA in Alaska and Canada is operated by the IRIS Consortium on behalf of the National Science Foundation as part of the EarthScope program. By Sept 2015, it is anticipated that the TA network in Alaska and Canada will be operating 105 stations. During the summer 2015, TA field crews comprised of IRIS and HTSI station specialists, as well as representatives from our partner agencies the Alaska Earthquake Center and the Alaska Volcano Observatory and engineers from the UNAVCO Plate Boundary Observatory will have completed a total of 36 new station installations. Additionally, we will have completed upgrades at 9 existing Alaska Earthquake Center stations with borehole seismometers and the adoption of an additional 35 existing stations. As the array doubles in Alaska, IRIS continues to collaborate closely with other network operators, universities and research consortia in Alaska and Canada including the Alaska Earthquake Center (AEC), the Alaska Volcano Observatory (AVO), the UNAVCO Plate Boundary Observatory (PBO), the National Tsunami Warning Center (NTWC), Natural Resources Canada (NRCAN), Canadian Hazard Information Service (CHIS), the Yukon Geologic Survey (YGS), the Pacific Geoscience Center of the Geologic Survey, Yukon College and others. During FY14 and FY15 the TA has completed upgrade work at 20 Alaska Earthquake Center stations and 2 AVO stations, TA has co-located borehole seismometers at 5 existing PBO GPS stations to augment the EarthScope observatory. We present an overview of deployment plan and the status through 2015. The performance of new Alaska TA stations including improvements to existing stations is described.

  12. Digital data for the geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

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

    1999-01-01

    These digital databases are the result of the compilation and reinterpretation of published and unpublished 1:250,000- and 1:63,360-scale mapping. The map area covers approximately 62,000 sq km (23,000 sq mi) in land area and encompasses much of 13 1:250,000-scale quadrangles on the Alaska Peninsula in southwestern Alaska. The compilation was done as part of the U.S. Geological Survey's Alaska Mineral Resource Assessment project (AMRAP), whose goal was create and assemble geologic, geochemical, geophysical, and other data in order to perform mineral resource assessments on a quadrangle, regional or statewide basis. The digital data here was created to assist in the completion of a regional mineral resource assessment of the Alaska Peninsula. Mapping on the Alaska Peninsula under AMRAP began in 1977 in the Chignik and Sutwik Island 1:250,000 quadrangles (Detterman and others, 1981). Continued mapping in the Ugashik, bristol bay, and northwestern Karluk quadrangles (Detterman and others, 1987) began in 1979, followed by the Mount Katmai, eastern Naknek, and northwestern Afognak quadrangles (Riehle and others, 1987; Riehle and others, 1993), the Port Moller, Stepovak bay, and Simeonof Island quadrangles (Wilson and others, 1995) beginning in 1983. Work in the Cold bay and False Pass quadrangles (Wilson and others, 1992 [Superceded by Wilson and others 1997, but not incorporated herein]) began in 1986. The reliability of the geologic mapping is variable, based, in part, on the field time spent in each area of the map, the available support, and the quality of the existing base maps. In addition, our developing understanding of the geology of the Alaska Peninsula required revision of earlier maps, such as the Chignik and Sutwik Island quadrangles map (Detterman and others, 1981) to reflect this new knowledge. We have revised the stratigraphic nomenclature (Detterman and others, 1996) and our assignment of unit names to some rocks has been changed. All geologic maps on

  13. Preliminary results, Central Gneiss Complex of the Coast Range batholith, southeastern Alaska: the roots of a high-K, calc-alkaline arc?

    USGS Publications Warehouse

    Barker, F.; Arth, Joseph G.

    1984-01-01

    The Central Gneiss Complex (CGC) of the Coast Range batholith is the oldest unit of the batholith east of Ketchikan, Alaska, being dated by the zircon UPb method (by T.W. Stern) at 128-140 Ma. Heterogeneous, layered, commonly migmatitic, orthogneiss of hornblende-biotite quartz diorite, tonalite, quartz monzodiorite and granodiorite compositions (IUGS terminology) form the major part of the CGC. These gneisses show a range of 50-65% SiO2 and are high in Al2O3 (c. 15-19%), K2O (1.5-4%) and Sr (800-900 ppm). Most major elements show coherent, typically magmatic trends with SiO2. La and Rb show maxima at ??? 58% SiO2. Initial 87Sr/86Sr ratios are relatively high and range from 0.7052 to 0.7066. Wallrocks of the CGC are mostly metagraywacke, pelite and metavolcanic rocks at amphibolite facies; they are geochemically dissimilar to the CGC. Major and minor elements of the CGC are very similar to those of high-K orogenic, calc-alkaline andesitic suites. The CGC may have formed largely by fractionation of mantle-derived, high AlKSr basaltic liquid in an ascending diapir, having hornblende, plagioclase, and biotite as major precipitating phases. The CGC probably represents the plutonic equivalent of a continental-margin or Andean arc that formed when the Taku terrane of the Insular belt on the west collided with the previously emplaced (but also allochthonous) Stikine terrane on the east in Late Jurassic or Early Cretaceous time. ?? 1984.

  14. Textural and mineralogical study of sandstones from the onshore Gulf of Alaska Tertiary Province, southern Alaska

    USGS Publications Warehouse

    Winkler, Gary R.; McLean, Hugh; Plafker, George

    1976-01-01

    Petrographic examination of 74 outcrop samples of Paleocene through Pliocene age from the onshore Gulf of Alaska Tertiary Province indicates that sandstones of the province characteristically are texturally immature and mineralogically unstable. Diagenetic alteration of framework grains throughout the stratigraphic sequence has produced widespread zeolite cement or phyllosilicate grain coatings and pseudomatrix. Multiple deformation and deep burial of the older Tertiary sequence--the Orca Group, the shale of Haydon Peak, and the Kulthieth and Tokun Formations--caused extensive alteration and grain interpenetration, resulting in low porosity values. Less intense deformation and intermediate depth of burial of the younger Tertiary sequence--the Katalla, Poul Creek, Redwood, and Yakataga Formations--has resulted in a greater range in textural properties. Most sandstone samples in the younger Tertiary sequence are poorly sorted, tightly packed, and have strongly appressed framework grains, but some are less tightly packed and contain less matrix. Soft and mineralogically unstable framework grains have undergone considerable alteration, reducing pore space even in the youngest rocks. Measurements of porosity, permeability, grain density, and sonic velocity of outcrop samples of the younger Tertiary sequence indicate a modest up-section improvement in sandstone reservoir characteristics. Nonetheless porosity and permeability values typically are below 16 percent and 15 millidarcies respectively and grain densities are consistently high, about 2.7 gm/cc. Low permeability and porosity values, and high grain densities and sonic velocities appear to be typical of most outcrop areas throughout the onshore Gulf of Alaska Tertiary Province.

  15. 25 CFR 243.12 - Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Are Alaska reindeer trust assets maintained by the U.S..., DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.12 Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska Natives? Only the titles to Alaskan...

  16. 25 CFR 243.12 - Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Are Alaska reindeer trust assets maintained by the U.S..., DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.12 Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska Natives? Only the titles to Alaskan...

  17. 25 CFR 243.12 - Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Are Alaska reindeer trust assets maintained by the U.S..., DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.12 Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska Natives? Only the titles to Alaskan...

  18. 25 CFR 243.12 - Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Are Alaska reindeer trust assets maintained by the U.S..., DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.12 Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska Natives? Only the titles to Alaskan...

  19. 25 CFR 243.12 - Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Are Alaska reindeer trust assets maintained by the U.S..., DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.12 Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska Natives? Only the titles to Alaskan...

  20. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... AND RESTRICTED AREA REGULATIONS § 334.1300 Blying Sound area, Gulf of Alaska, Alaska;...

  1. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... AND RESTRICTED AREA REGULATIONS § 334.1300 Blying Sound area, Gulf of Alaska, Alaska;...

  2. 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.

  3. ESCD/Alaska: An Educational Demonstration -- The Far North.

    ERIC Educational Resources Information Center

    Orvik, James M.

    1977-01-01

    Evaluates the Educational Satellite Communications Demonstration in Alaska project in educational television within the context of the rapid social change in land ownership, employment, and schooling. (JMF)

  4. Lead-alpha age determinations of granitic rocks from Alaska

    USGS Publications Warehouse

    Matzko, John J.; Jaffe, H.W.; Waring, C.L.

    1957-01-01

    Lead-alpha activity age determinations were made on zircon from seven granitic rocks of central and southeastern Alaska. The results of the age determinations indicate two periods of igneous intrusion, one about 95 million years ago, during the Cretaceous period, and another about 53 million years ago, during the early part of the Tertiary. The individual ages determined on zircon from 2 rocks from southeastern Alaska and 1 from east-central Alaska gave results of 90, 100, and 96 million years; those determined on 4 rocks from central Alaska gave results of 47, 56, 58, and 51 million years.

  5. The Alaska Volcano Observatory - Expanded Monitoring of Volcanoes Yields Results

    USGS Publications Warehouse

    Brantley, Steven R.; McGimsey, Robert G.; Neal, Christina A.

    2004-01-01

    Recent explosive eruptions at some of Alaska's 52 historically active volcanoes have significantly affected air traffic over the North Pacific, as well as Alaska's oil, power, and fishing industries and local communities. Since its founding in the late 1980s, the Alaska Volcano Observatory (AVO) has installed new monitoring networks and used satellite data to track activity at Alaska's volcanoes, providing timely warnings and monitoring of frequent eruptions to the aviation industry and the general public. To minimize impacts from future eruptions, scientists at AVO continue to assess volcano hazards and to expand monitoring networks.

  6. Diurnal and seasonal patterns of ecosystem CO{sub 2} efflux from upland tundra in the foothills of the Brooks Range, Alaska, U.S.A.

    SciTech Connect

    Oberbauer, S.F.; Gillespie, C.T.; Cheng, Weixin

    1996-08-01

    Carbon dioxide efflux and soil microenvironment were measured in three upland tundra communities in the foothills of the Brooks Range in arctic Alaska to determine the magnitude of CO{sub 2} efflux rates and the relative importance of the belowground factors that influence them. Gas exchange and soil microenvironment measurements were made weekly between 14 June and 31 July 1990. The study communities included lichen-heath, a sparse community vegetated by lichens and dwarf ericaceous shrubs on rocky soils, moist Cassiope dwarf-shrub heath tundra, dominated by Carex and evergreen and deciduous shrubs on relatively deep organic soils, and dry Cassiope dwarf-shrub heath of stone-stripe areas, which was of intermediate character. Rates of CO{sub 2} efflux were similar for the three communities until mid-season when they peaked at rates between 4.9 and 5.9 g m{sup {minus}2} d{sup {minus}1}. Following the mid-season peak, the rates in all three communities declined, particularly in the lichen-heath. Seasonal patterns of CO{sub 2} efflux, soil temperature, and soil moisture suggest changing limitations to CO{sub 2} efflux, soil temperature, and soil moisture suggest changing limitations to CO{sub 2} efflux over the course of the season. Rates of carbon dioxide efflux followed changes in soil temperature early in the season when soil moisture was highest. Mid-season efflux appeared to be limited by soil, moss, and lichen hydration until the end of July, when temperature again limited efflux. Differences between the communities were related to microenvironmental differences and probable differences in carbon quality. The presence of peat-forming mosses is suggested to play an important role in differences in efflux and micro-environment among the communities. 32 refs., 3 figs., 4 tab.

  7. Drivers and Estimates of Terrain Suitability for Active Layer Detachment Slides and Retrogressive Thaw Slumps in the Brooks Range and Foothills of Northwest Alaska, USA

    NASA Astrophysics Data System (ADS)

    Balser, A.; Jones, J.

    2015-12-01

    Active layer detachment sliding and retrogressive thaw slumping are important modes of upland permafrost degradation and disturbance in permafrost regions, and have been linked with climate warming trends, ecosystem impacts, and permafrost carbon release. In the Brooks Range and foothills of northwest Alaska, these features are widespread, with distribution linked to multiple landscape properties. Inter-related and co-varying terrain properties, including surficial geology, topography, geomorphology, vegetation and hydrology, are generally considered key drivers of permafrost landscape characteristics and responses to climate perturbation. However, these inter-relationships as collective drivers of terrain suitability for active layer detachment and retrogressive thaw slump processes are poorly understood in this region. We empirically tested and refined a hypothetical model of terrain factors driving active layer detachment and retrogressive thaw slump terrain suitability, and used final model results to generate synoptic terrain suitability estimates across the study region. Spatial data for terrain properties were examined against locations of 2,492 observed active layer detachments and 805 observed retrogressive thaw slumps using structural equation modelling and integrated terrain unit analysis. Factors significant to achieving model fit were found to substantially hone and constrain region-wide terrain suitability estimates, suggesting that omission of relevant factors leads to broad overestimation of terrain suitability. Resulting probabilistic maps of terrain suitability, and a threshold-delineated mask of suitable terrain, were used to quantify and describe landscape settings typical of these features. 51% of the study region is estimated suitable terrain for retrogressive thaw slumps, compared with 35% for active layer detachment slides, while 29% of the study region is estimated suitable for both. Results improve current understanding of arctic landscape

  8. Trace elements in Zn Pb Ag deposits and related stream sediments, Brooks Range Alaska, with implications for Tl as a pathfinder element

    USGS Publications Warehouse

    Graham, G.E.; Kelley, K.D.; Slack, J.F.; Koenig, A.E.

    2009-01-01

    The Zn-Pb-Ag metallogenic province of the western and central Brooks Range, Alaska, contains two distinct but mineralogically similar deposit types: shale-hosted massive sulphide (SHMS) and smaller vein-breccia occurrences. Recent investigations of the Red Dog and Anarraaq SHMS deposits demonstrated that these deposits are characterized by high trace-element concentrations of As, Ge, Sb and Tl. This paper examines geochemistry of additional SHMS deposits (Drenchwater and Su-Lik) to determine which trace elements are ubiquitously elevated in all SHMS deposits. Data from several vein-breccia occurrences are also presented to see if trace-element concentrations can distinguish SHMS deposits from vein-breccia occurrences. Whole-rock geochemical data indicate that Tl is the most consistently and highly concentrated characteristic trace element in SHMS deposits relative to regional unmineralized rock samples. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of pyrite and sphalerite indicate that Tl is concentrated in pyrite in SHMS. Stream sediment data from the Drenchwater and Su-Lik SHMS show that high Tl concentrations are more broadly distributed proximal to known or suspected mineralization than As, Sb, Zn and Pb anomalies. This broader distribution of Tl in whole-rock and particularly stream sediment samples increases the footprint of exposed and shallowly buried SHMS mineralization. High Tl concentrations also distinguish SHMS mineralization from the vein-breccia deposits, as the latter lack high concentrations of Tl but can otherwise have similar trace-element signatures to SHMS deposits. ?? 2009 AAG/Geological Society of London.

  9. Influence of the Kingak Shale ultimate shelf margin on frontal structures of the Brooks Range in the National Petroleum Reserve in Alaska

    USGS Publications Warehouse

    Stier, Natalie E.; Connors, Christopher D.; Houseknecht, David W.

    2014-01-01

    The Jurassic–Lower Cretaceous Kingak Shale in the National Petroleum Reserve in Alaska (NPRA) includes several southward-offlapping depositional sequences that culminate in an ultimate shelf margin, which preserves the depositional profile in southern NPRA. The Kingak Shale thins abruptly southward across the ultimate shelf margin and grades into condensed shale, which is intercalated with underlying condensed shale and chert of the Upper Triassic Shublik Formation and overlying condensed shale of the Lower Cretaceous pebble shale unit and the gamma-ray zone (GRZ) of the Hue Shale. This composite of condensed shale forms a thin (≈300-meter) and mechanically weak section between much thicker and mechanically stronger units, including the Sadlerochit and Lisburne Groups below and the sandstone-prone foredeep wedge of the Torok Formation above. Seismic interpretation indicates that the composite condensed section acted as the major detachment during an Early Tertiary phase of deformation in the northern foothills of the Brooks Range and that thrust faults step up northward to the top of the Kingak, or to other surfaces within the Kingak or the overlying Torok. The main structural style is imbricate fault-bend folding, although fault-propagation folding is evident locally, and large-displacement thrust faults incorporate backthrusting to form structural wedges. The Kingak ultimate shelf margin served as a ramp to localize several thrust faults, and the spatial relationship between the ultimate shelf margin and thrust vergence is inferred to have controlled many structures in southern NPRA. For example, the obliqueness of the Carbon Creek anticline relative to other structures in the foothills is the result of northward-verging thrust faults impinging obliquely on the Kingak ultimate shelf margin in southwestern NPRA.

  10. Horizontal drilling techniques at Prudhoe Bay, Alaska

    SciTech Connect

    Wilkirson, J.P.; Smith, J.H.; Stagg, T.O.; Walters, D.A.

    1986-01-01

    Three extended departure horizontal wells have been drilled and completed at Prudhoe Bay, Alaska by Standard Alaska Production Company. Horizontal slotted liner completions of 1575 feet (480 m), 1637 feet (499 m), and 1163 feet (354 m) were accomplished at an average vertical depth of 9000 feet (2743 m). Improvements in technology and operating procedures have resulted in a cost per foot reduction of 40% over the three well program. When compared to conventional completions, initial production data indicates rate benefits of 300% and a major increase in ultimate recovery. This paper discusses the development of the techniques used to drill horizontal wells at Prudhoe Bay and reviews the drilling operations for each well.

  11. Caribou and petroleum development in arctic Alaska

    SciTech Connect

    Cameron, R.D.

    1983-01-01

    The intensive development of oil deposits in Alaska's northern slope (SKA) is not always being conducted with consideration of the characteristics of the caribou which inhabit the region. Although to date the losses of the customary pastures as a result of the change in the conditions in them has had only a local nature and has not negatively affected the productivity of the heart, uncontrolled and incorrectly planned operations by oil companies in the future may lead to a substantial limitation in the habitation of the caribou and may produce serious losses for all the herds in Alaska. The agencies which control the federal lands and the state lands must understand the situation which is taking shape here with respect to the activity of the oil companies and must adhere to a conservation policy in issuing exploration licenses and in developing the deposits.

  12. Surface melt dominates Alaska glacier mass balance

    USGS Publications Warehouse

    Larsen Chris F,; Burgess, E; Arendt, A.A.; O'Neel, Shad; Johnson, A.J.; Kienholz, C.

    2015-01-01

    Mountain glaciers comprise a small and widely distributed fraction of the world's terrestrial ice, yet their rapid losses presently drive a large percentage of the cryosphere's contribution to sea level rise. Regional mass balance assessments are challenging over large glacier populations due to remote and rugged geography, variable response of individual glaciers to climate change, and episodic calving losses from tidewater glaciers. In Alaska, we use airborne altimetry from 116 glaciers to estimate a regional mass balance of −75 ± 11 Gt yr−1 (1994–2013). Our glacier sample is spatially well distributed, yet pervasive variability in mass balances obscures geospatial and climatic relationships. However, for the first time, these data allow the partitioning of regional mass balance by glacier type. We find that tidewater glaciers are losing mass at substantially slower rates than other glaciers in Alaska and collectively contribute to only 6% of the regional mass loss.

  13. Water Resources Data, Alaska, Water Year 2001

    USGS Publications Warehouse

    Meyer, D.F.; Solin, G.L.; Apgar, M.L.; Hess, D.L.; Swenson, W.A.

    2002-01-01

    Water-resources data for the 2001 water year for Alaska consists of records of stage, discharge, and water quality of streams; stages of lakes; and water levels and water quality of ground-water wells. This volume contains records for water discharge at 112 gaging stations; stage or contents only at 4 gaging stations; water quality at 37 gaging stations; and water levels for 30 observation wells. Also included are data for 51 crest-stage partial-record stations. Additional water data were collected at various sites not involved in the systematic data-collection program and are published as miscellaneous measurements and analyses. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Alaska.

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

    SciTech Connect

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

    1985-04-01

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

  15. 77 FR 2998 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ...As required by 43 CFR 2650.7(d), notice is hereby given that the Bureau of Land Management (BLM) will issue an appealable decision to Sea Lion Corporation. The decision approves the surface estate in the lands described below for conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq.). These lands lie entirely within the Clarence Rhode National Wildlife Refuge......

  16. EarthScope's Transportable Array in Alaska

    NASA Astrophysics Data System (ADS)

    Busby, R. W.; Woodward, R.; Hafner, K.

    2013-12-01

    Since 2003, EarthScope has been installing a network of seismometers, known as the Transportable Array-across the continental United States and southern Canada. The station deployments will be completed in the Conterminous US in the fall of 2013. Beginning in October, 2013, and continuing for 5 years, EarthScope's Transportable Array plans to create a grid of seismic sensors in approximately 300 locations In Alaska and Western Canada. The proposed station grid is 85 km, and target locations will supplement or enhance existing seismic stations operating in Alaska. When possible, they will also be co-located with existing GPS stations constructed by the Plate Boundary Observatory. We review the siting plans for stations, the progress towards reconnaissance and permitting, and detail the engineering concept of the stations. In order to be able to determine the required site conditions and descriptions of installation methods to the permitting agencies, the National Science Foundation (NSF) has been supporting exploratory work on seismic station design, sensor emplacement and communication concepts appropriate for the challenging high-latitude environment that is proposed for deployment. IRIS has installed several experimental stations to evaluate different sensor emplacement schemes both in Alaska and the lower-48 U.S. The goal of these tests is to maintain or enhance a station's noise performance while minimizing its footprint and the equipment, materials, and overall expense required for its construction. Motivating this approach are recent developments in posthole broadband seismometer design and the unique conditions for operating in Alaska, where most areas are only accessible by small plane or helicopter, and permafrost underlies much of the region. IRIS has experimented with different portable drills and drilling techniques to create shallow holes (1-5M) in permafrost and rock outcrops. Seasonal changes can affect the performance of seismometers in different

  17. Preserving Alaska's early Cold War legacy.

    SciTech Connect

    Hoffecker, J.; Whorton, M.

    1999-03-08

    The US Air Force owns and operates numerous facilities that were constructed during the Cold War era. The end of the Cold War prompted many changes in the operation of these properties: missions changed, facilities were modified, and entire bases were closed or realigned. The widespread downsizing of the US military stimulated concern over the potential loss of properties that had acquired historical value in the context of the Cold War. In response, the US Department of Defense in 1991 initiated a broad effort to inventory properties of this era. US Air Force installations in Alaska were in the forefront of these evaluations because of the role of the Cold War in the state's development and history and the high interest on the part of the Alaska State Historic Preservation Officer (SHPO) in these properties. The 611th Air Support Group (611 ASG) owns many of Alaska's early Cold War properties, most were associated with strategic air defense. The 611 ASG determined that three systems it operates, which were all part of the integrated defense against Soviet nuclear strategic bomber threat, were eligible for the National Register of Historic Places (NRHP) and would require treatment as historic properties. These systems include the Aircraft Control and Warning (AC&W) System, the Distant Early Warning (DEW) Line, and Forward Operating Bases (FOBs). As part of a massive cleanup operation, Clean Sweep, the 611 ASG plans to demolish many of the properties associated with these systems. To mitigate the effects of demolition, the 611 ASG negotiated agreements on the system level (e.g., the DEW Line) with the Alaska SHPO to document the history and architectural/engineering features associated with these properties. This system approach allowed the US Air Force to mitigate effects on many individual properties in a more cost-effective and efficient manner.

  18. Sea Ice, Bristol Bay, Alaska, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This north looking view shows the coast of Alaska, north of the Aleutians, and the eastern margin of the Bering Sea (58.0N, 159.5W). Bristol Bay is apparent in the foreground and Nunivak Island can be seen just below the Earth's horizon, at a distance of about 300 nautical miles. Similar views, photographed during previous missions, when analyzed with these recent views may yield information about regional ice drift and breakup of ice packs.

  19. Southwest Alaska Regional Geothermal Energy Projec

    SciTech Connect

    Holdmann, Gwen

    2015-04-30

    Drilling and temperature logging campaigns between the late 1970's and early 1980’s measured temperatures at Pilgrim Hot Springs in excess of 90°C. Between 2010 and 2014 the University of Alaska used a variety of methods including geophysical surveys, remote sensing techniques, heat budget modeling, and additional drilling to better understand the resource and estimate the available geothermal energy.

  20. 78 FR 76174 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-16

    ...As required by 43 CFR 2650.7(d), notice is hereby given that an appealable decision will be issued by the Bureau of Land Management (BLM) to Paimiut Corporation. The decision approves the surface estate in certain lands for conveyance pursuant to the Alaska Native Claims Settlement Act (ANCSA) (43 U.S.C. 1601, et seq.). The lands approved for conveyance lie partially within a national wildlife......

  1. Jurassic-Neocomian biostratigraphy, North Slope, Alaska

    SciTech Connect

    Mickey, M.B.; Haga, H.

    1985-04-01

    The foraminiferal and palynological biostratigraphy of subsurface Jurassic and Neocomian (Early Cretaceous) age strata from the North Slope were investigated to better define biostratigraphic zone boundaries and to help clarify the correlation of the stratigraphic units in the National Petroleum Reserve in Alaska (NPRA). Through use of micropaleontologic data, eight principal biostratigraphic units have been identified. The Neocomian and Jurassic strata have each been subdivided into four main units.

  2. Alaska SAR Facility mass storage, current system

    NASA Technical Reports Server (NTRS)

    Cuddy, David; Chu, Eugene; Bicknell, Tom

    1993-01-01

    This paper examines the mass storage systems that are currently in place at the Alaska SAR Facility (SAF). The architecture of the facility will be presented including specifications of the mass storage media that are currently used and the performances that we have realized from the various media. The distribution formats and media are also discussed. Because the facility is expected to service future sensors, the new requirements and possible solutions to these requirements are also discussed.

  3. 78 FR 7807 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ...As required by 43 CFR 2650.7(d), notice is hereby given that an appealable decision will be issued by the Bureau of Land Management (BLM) to Sitnasuak Native Corporation. The decision approves the surface estate in the lands described below for conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq). The subsurface estate in these lands will be conveyed to......

  4. Wildlife disease and environmental health in Alaska

    USGS Publications Warehouse

    Van Hemert, Caroline; Pearce, John; Oakley, Karen; Whalen, Mary

    2013-01-01

    Environmental health is defined by connections between the physical environment, ecological health, and human health. Current research within the U.S. Geological Survey (USGS) recognizes the importance of this integrated research philosophy, which includes study of disease and pollutants as they pertain to wildlife and humans. Due to its key geographic location and significant wildlife resources, Alaska is a critical area for future study of environmental health.

  5. 76 FR 57759 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ...As required by 43 CFR 2650.7(d), notice is hereby given that the Bureau of Land Management (BLM) will issue an appealable decision to Sitnasuak Native Corporation. The decision approves the surface estate in the lands described below for conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1604 et seq.). The subsurface estate in these lands will be conveyed to Bering......

  6. Distribution of recoveries of Steller's Eiders banded on the lower Alaska Peninsula, Alaska

    USGS Publications Warehouse

    Dau, C.P.; Flint, P.L.; Petersen, M.R.

    2000-01-01

    Molting adult Steller's Eiders (Polysticta stelleri) were banded at Izembek Lagoon (1961-1998) and Nelson Lagoon (1995-1997) along the lower Alaska Peninsula to determine breeding distribution and movements. Of 52,985 Steller's Eiders banded, 347 were recovered. The overall low recovery rate may not be indicative of harvest levels but may be due to low reporting rates of bands. Almost all recoveries during summer were from Russia and recovery rates did not differ between sexes. We found no evidence that Steller's Eiders molting in specific locations were more likely to be recovered in specific geographic locations in Russia. Our recoveries suggest that Steller's Eiders molting along the Alaska Peninsula were from Russian breeding sites and from remnant breeding populations in Alaska.

  7. 1994 Volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Neal, Christina A.; Doukas, Michael P.; McGimsey, Robert G.

    1995-01-01

    During 1994, the Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, or false alarms at nine volcanic centers-- Mount Sanford, Iliamna, the Katmai group, Kupreanof, Mount Veniaminof, Shishaldin, Makushin, Mount Cleveland and Kanaga (table 1). Of these volcanoes, AVO has a real time, continuously recording seismic network only at Iliamna, which is located in the Cook Inlet area of south-central Alaska (fig. 1). AVO has dial-up access to seismic data from a 5-station network in the general region of the Katmai group of volcanoes. The remaining unmonitored volcanoes are located in sparsely populated areas of the Wrangell Mountains, the Alaska Peninsula, and the Aleutian Islands (fig. 1). For these volcanoes, the AVO monitoring program relies chiefly on receipt of pilot reports, observations of local residents and analysis of satellite imagery.

  8. Triggered tremor sweet spots in Alaska

    USGS Publications Warehouse

    Gomberg, Joan; Prejean, Stephanie

    2013-01-01

    To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (<~0.03 Hz), may enhance the probability of triggering tremor. However, neither the maximum amplitude in the time domain or in a particular frequency band, nor the geometric relationship of the wavefield to the tremor source faults alone ensures a high probability of triggering. Triggered tremor at the two sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

  9. A new magnetic view of Alaska

    USGS Publications Warehouse

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

    1999-01-01

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

  10. Developing Gyrfalcon surveys and monitoring for Alaska

    USGS Publications Warehouse

    Fuller, Mark R.; Schempf, Philip F.; Booms, Travis L.

    2011-01-01

    We developed methods to monitor the status of Gyrfalcons in Alaska. Results of surveys and monitoring will be informative for resource managers and will be useful for studying potential changes in ecological communities of the high latitudes. We estimated that the probability of detecting a Gyrfalcon at an occupied nest site was between 64% and 87% depending on observer experience and aircraft type (fixed-wing or helicopter). The probability of detection is an important factor for estimating occupancy of nesting areas, and occupancy can be used as a metric for monitoring species' status. We conclude that surveys of nesting habitat to monitor occupancy during the breeding season are practical because of the high probability of seeing a Gyrfalcon from aircraft. Aerial surveys are effective for searching sample plots or index areas in the expanse of the Alaskan terrain. Furthermore, several species of cliff-nesting birds can be surveyed concurrently from aircraft. Occupancy estimation also can be applied using data from other field search methods (e.g., from boats) that have proven useful in Alaska. We believe a coordinated broad-scale, inter-agency, collaborative approach is necessary in Alaska. Monitoring can be facilitated by collating and archiving each set of results in a secure universal repository to allow for statewide meta-analysis.

  11. Geomorphic consequences of volcanic eruptions in Alaska: A review

    NASA Astrophysics Data System (ADS)

    Waythomas, Christopher F.

    2015-10-01

    Eruptions of Alaska volcanoes have significant and sometimes profound geomorphic consequences on surrounding landscapes and ecosystems. The effects of eruptions on the landscape can range from complete burial of surface vegetation and preexisting topography to subtle, short-term perturbations of geomorphic and ecological systems. In some cases, an eruption will allow for new landscapes to form in response to the accumulation and erosion of recently deposited volcaniclastic material. In other cases, the geomorphic response to a major eruptive event may set in motion a series of landscape changes that could take centuries to millennia to be realized. The effects of volcanic eruptions on the landscape and how these effects influence surface processes has not been a specific focus of most studies concerned with the physical volcanology of Alaska volcanoes. Thus, what is needed is a review of eruptive activity in Alaska in the context of how this activity influences the geomorphology of affected areas. To illustrate the relationship between geomorphology and volcanic activity in Alaska, several eruptions and their geomorphic impacts will be reviewed. These eruptions include the 1912 Novarupta-Katmai eruption, the 1989-1990 and 2009 eruptions of Redoubt volcano, the 2008 eruption of Kasatochi volcano, and the recent historical eruptions of Pavlof volcano. The geomorphic consequences of eruptive activity associated with these eruptions are described, and where possible, information about surface processes, rates of landscape change, and the temporal and spatial scale of impacts are discussed. A common feature of volcanoes in Alaska is their extensive cover of glacier ice, seasonal snow, or both. As a result, the generation of meltwater and a variety of sediment-water mass flows, including debris-flow lahars, hyperconcentrated-flow lahars, and sediment-laden water floods, are typical outcomes of most types of eruptive activity. Occasionally, such flows can be quite large

  12. Geomorphic Consequences of Volcanic Eruptions in Alaska: A Review

    USGS Publications Warehouse

    Waythomas, Christopher F.

    2015-01-01

    Eruptions of Alaska volcanoes have significant and sometimes profound geomorphic consequences on surrounding landscapes and ecosystems. The effects of eruptions on the landscape can range from complete burial of surface vegetation and preexisting topography to subtle, short-term perturbations of geomorphic and ecological systems. In some cases, an eruption will allow for new landscapes to form in response to the accumulation and erosion of recently deposited volcaniclastic material. In other cases, the geomorphic response to a major eruptive event may set in motion a series of landscape changes that could take centuries to millennia to be realized. The effects of volcanic eruptions on the landscape and how these effects influence surface processes has not been a specific focus of most studies concerned with the physical volcanology of Alaska volcanoes. Thus, what is needed is a review of eruptive activity in Alaska in the context of how this activity influences the geomorphology of affected areas. To illustrate the relationship between geomorphology and volcanic activity in Alaska, several eruptions and their geomorphic impacts will be reviewed. These eruptions include the 1912 Novarupta–Katmai eruption, the 1989–1990 and 2009 eruptions of Redoubt volcano, the 2008 eruption of Kasatochi volcano, and the recent historical eruptions of Pavlof volcano. The geomorphic consequences of eruptive activity associated with these eruptions are described, and where possible, information about surface processes, rates of landscape change, and the temporal and spatial scale of impacts are discussed.A common feature of volcanoes in Alaska is their extensive cover of glacier ice, seasonal snow, or both. As a result, the generation of meltwater and a variety of sediment–water mass flows, including debris-flow lahars, hyperconcentrated-flow lahars, and sediment-laden water floods, are typical outcomes of most types of eruptive activity. Occasionally, such flows can be quite

  13. Deglacial Warming and Wetting of Northern Alaska

    NASA Astrophysics Data System (ADS)

    Daniels, W.; Russell, J. M.; Longo, W. M.; Giblin, A. E.; Holland-Stergar, P.; Morrill, C.; Huang, Y.

    2015-12-01

    Aeolian sand dunes swept across northern Alaska during the last glacial maximum. Today, summer temperatures are moderate and soils can remain waterlogged all summer long. How did the transition from a cold and dry glacial to a warm and wet interglacial take place? To answer this question we reconstructed temperature and precipitation changes during the last deglaciation using biomarker hydrogen isotopes from a new 28,000 year-long sediment core from Lake E5, located in the central Brooks Range of Alaska. We use terrestrial leaf waxes (dDterr, C28-acid), informed by dD measurements of modern vegetation, to infer dD of precipitation, an indicator of relative temperature change. Biomarkers from aquatic organisms (dDaq, C18-acid) are used as a proxy for lake water isotopes. The offset between the two (eterr-aq) is used to infer relative changes in evaporative enrichment of lake water, and by extension, moisture balance. dDterr during the last glacial period was -282‰ compared to -258‰ during the Holocene, suggesting a 5.6 ± 2.7 °C increase in summer temperature using the modern local temperature-dD relationship. Gradual warming began at ~18.5 ka, and temperature increased abruptly at 11.5 ka, at the end of the Younger Dryas. Warming peaked in the early Holocene from 11.5 to 9.1 ka, indicating a Holocene thermal maximum associated with peak summer insolation. The eterr-aq supports a dry LGM and moist Holocene. Other sediment proxies (TIC, TOC, redox-sensitive elements) support the eterr-aq, and reveal a shift to more positive P-E beginning around 17 ka, suggesting rising temperature led increases in precipitation during the last deglaciation. Moreover, differing patterns of dDterr and eterr-aq during the deglaciation suggest that the relationship between temperature and precipitation changed through time. Such decoupling, likely due to regional atmospheric reorganization as the Laurentide ice sheet waned, illustrates the importance of atmospheric dynamics in

  14. Kinematics of the mosquito terrane, Coldfoot Area, Alaska: Keys to Brooks Range tectonics: Final report, Project No. 2

    SciTech Connect

    Harms, T.A.; Coney, P.J.

    1988-04-01

    Within the large-scale geometry of the Brooks Range, the Angayucham terrane occurs as a vast overthrust sheet. From the north flank of the Ruby terrane it underlies the Koyukuk basin and stretches north as the roof thrust to the various nappe terranes of the Brooks Range. The tectonic relationship of the Ruby terrane to the south flank of the Brooks Range lies largely obscured beneath the Angayucham in the eastern apex of the Koyukuk basin. The Mosquito terrane occurs as a window through the Angayucham at this juncture. The composition and structures of the Mosquito terrane reveal that is the result of shear along a sub-horizontal step or flange within the prominent, through-going dextral strike-slip fault system which cuts across the eastern Koyukuk basin and southeastern Brooks Range. Units of the Mosquito were derived from both the Angayucham and Ruby terranes. A consistent tectonic fabric imposed upon them is kinematically linked to the strike-slip system and indicates a northeasterly direction of transport across the terrane. The presence of Ruby-correlative units within the Mosquito suggests the Ruby underlies the Angayucham and that it is in contact with terrances of the southern Brooks Range at that structural level along high-angle strike-slip faults. These relationships demonstrate that an episode of dextral transpression is the latest in the history of terrane accretion and tectonic evolution of the Brooks Range. 35 refs.

  15. Lichens from Simeonof Wilderness, Shumagin Island, Southwestern Alaska

    USGS Publications Warehouse

    Talbot, Stephen S.; Talbot, Sandra L.; Thomson, J.W.; Daniels, F.J.A.; Schofield, W.B.

    2002-01-01

    One hundred eighty-eight taxa of lichens are reported from Simeonof Island in the Shumagin Islands of southwestern Alaska. Wide-ranging arctic-alpine and boreal species dominate the lichens; a coastal element is moderately represented, while amphi-Beringian species form a minor element. The lichen component of Empetrum nigrum dwarf shrub heath, the dominant vegetation type, was analyzed to identify the most frequently occurring lichens within this community.

  16. Can nutrient limitations explain low and declining white spruce growth near the Arctic treeline in the eastern Brooks Range, Alaska?

    NASA Astrophysics Data System (ADS)

    Ellison, S.; Sullivan, P. F.

    2014-12-01

    The position of the Arctic treeline is of critical importance for global carbon cycling and surface energy budgets. However, controls on tree growth at treeline remain uncertain. In the Alaskan Brooks Range, 20th century warming has caused varying growth responses among treeline trees, with trees in the west responding positively, while trees in the east have responded negatively. The prevailing explanation of this trend ascribes the negative growth response to warming-induced drought stress in the eastern Brooks Range. However, recent measurements of carbon isotope discrimination in tree rings, xylem sap flow and needle gas exchange suggest that drought stress cannot explain these regional growth declines. Additionally, evidence from the western Brooks Range suggests that nutrient availability, rather than drought stress, may be the proximate control on tree growth. In this study, we investigated the hypothesis that low and declining growth of eastern Brooks Range trees is due to low and declining soil nutrient availability, which may continue to decrease with climate change as soils become drier and microbial activity declines. We compared microclimate, tree performance, and a wide range of proxies for soil nutrient availability in four watersheds along a west-east transect in the Brooks Range during the growing seasons of 2013 and 2014. We hypothesized that soil nutrient availability would track closely with the strong west-east precipitation gradient, with higher rainfall and greater soil nutrient availability in the western Brooks Range. We expected to find that soil water contents in the west are near optimum for nitrogen mineralization, while those in the east are below optimum. Needle nitrogen concentration, net photosynthesis, branch extension growth, and growth in the main stem are expected to decline with the hypothesized decrease in soil nutrient availability. The results of our study will elucidate the current controls on growth of trees near the

  17. Vegetation and terrain mapping in Alaska using Landsat MSS and digital terrain data

    USGS Publications Warehouse

    Shasby, Mark; Carneggie, David M.

    1986-01-01

    During the past 5 years, the U.S. Geological Survey's (USGS) Earth Resources Observation Systems (EROS) Data Center Field Office in Anchorage, Alaska has worked cooperatively with Federal and State resource management agencies to produce land-cover and terrain maps for 245 million acres of Alaska. The need for current land-cover information in Alaska comes principally from the mandates of the Alaska National Interest Lands Conservation Act (ANILCA), December 1980, which requires major land management agencies to prepare comprehensive management plans. The land-cover mapping projects integrate digital Landsat data, terrain data, aerial photographs, and field data. The resultant land-cover and terrain maps and associated data bases are used for resource assessment, management, and planning by many Alaskan agencies including the U.S. Fish and Wildlife Service, U.S. Forest Service, Bureau of Land Management, and Alaska Department of Natural Resources. Applications addressed through use of the digital land-cover and terrain data bases range from comprehensive refuge planning to multiphased sampling procedures designed to inventory vegetation statewide. The land-cover mapping programs in Alaska demonstrate the operational utility of digital Landsat data and have resulted in a new land-cover mapping program by the USGS National Mapping Division to compile 1:250,000-scale land-cover maps in Alaska using a common statewide land-cover map legend.

  18. Origin of gasoline-range hydrocarbons and their migration by solution in carbon dioxide in Norton basin, Alaska.

    USGS Publications Warehouse

    Kvenvolden, K.A.; Claypool, G.E.

    1980-01-01

    Carbon dioxide from a submarine seep in Norton Sound carries a minor component of gas- and gasoline-range hydrocarbons. The molecular and isotopic compositions of the hydrocarbon gases and the presence of gasoline-range hydrocarbons indicate that these molecules are derived from thermal alteration of marine and/or nonmarine organic matter buried within Norton basin. The gasoline-range hydrocarbon distribution suggests that the hydrocarbon mixture is an immature petroleum-like condensate of lower temperature origin than normal crude oil. The submarine seep provides a natural example in support of a carbon dioxide solution transport mechanism thought to be operative in the migration of hydrocarbons in certain reservoirs.-Authors

  19. Potential tight gas resources in a frontier province - Jurassic through Tertiary strata beneath the Brooks Range foothills, Arctic Alaska

    USGS Publications Warehouse

    Nelson, Philip H.; Bird, Kenneth J.; Houseknecht, David W.; Potter, Christopher J.; Moore, Thomas E.

    2006-01-01

    Beneath the foothills of the Brooks Range, rocks of the Lower Cretaceous-Tertiary Brookian and Jurassic-Lower Cretaceous Beaufortian megasequences have been deeply buried and exhumed, and now exhibit characteristics of 'tight gas sandstones'. The data recovered from drilling, well tests, and cores exhibit the potential for substantial gas reserves over a large area. These data include recovery of gas from drillstem tests, indications of overpressure from well tests and mud weights, low porosity and permeability in sandstones, and vitrinite reflectance values ranging from 1.0 to 2.0 percent throughout substantial depth intervals.

  20. Lithostratigraphy, microlithofacies, and conodont biostratigraphy and biofacies of the Wahoo Limestone (Carboniferous), eastern Sadlerochit Mountains, Northeast Brooks Range, Alaska

    USGS Publications Warehouse

    Krumhardt, A.P.; Harris, A.G.; Watts, K.F.

    1996-01-01

    The lithostratigraphy, microlithofacies, and conodonts are described in a key section of the Wahoo Limestone (Middle Carboniferous); this unit forms a hydrocarbon reservoir at Prudhoe Bay. The Wahoo was deposited in a range of environments on the inner part of a high-energy carbonate ramp. Microfacies and conodont biofacies used together refine paleoenvironmental interpretations. Only 24 conodont species distributed among 14 genera were recognized in a section that spans about 10 million years. Significant conodont collections from the Wahoo across the Northeast Brooks Range are described in an appendix.

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

    USGS Publications Warehouse

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

    1992-01-01

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

  2. Pulmonary Mast Cell Tumor and Possible Paraganglioma in a Free-ranging Pacific Walrus ( Odobenus rosmarus divergens), Barrow, Alaska, USA.

    PubMed

    Seguel, Mauricio; Stimmelmayr, Raphaela; Howerth, Elizabeth; Gottdenker, Nicole

    2016-04-28

    We describe a pulmonary mast cell tumor in a subsistence-harvested free-ranging Pacific walrus (Odobenus rosmarus divergens). Neoplastic cells effacing a focal area of pulmonary parenchyma were characterized by rare metachromatic granules and positive staining for C-kit. We also report co-occurrence of a peribronchial mass with a morphologic and immunohistochemical profile compatible with paraganglioma. PMID:27054472

  3. Pulmonary Mast Cell Tumor and Possible Paraganglioma in a Free-ranging Pacific Walrus ( Odobenus rosmarus divergens), Barrow, Alaska, USA.

    PubMed

    Seguel, Mauricio; Stimmelmayr, Raphaela; Howerth, Elizabeth; Gottdenker, Nicole

    2016-04-28

    We describe a pulmonary mast cell tumor in a subsistence-harvested free-ranging Pacific walrus (Odobenus rosmarus divergens). Neoplastic cells effacing a focal area of pulmonary parenchyma were characterized by rare metachromatic granules and positive staining for C-kit. We also report co-occurrence of a peribronchial mass with a morphologic and immunohistochemical profile compatible with paraganglioma.

  4. Use of LANDSAT imagery for wildlife habitat mapping in northeast and eastcentral Alaska. [winter and summer moose range

    NASA Technical Reports Server (NTRS)

    Lent, P. C. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. Winter and summer moose range maps of three selected areas were produced (1:63,360 scale). The analytic approach is very similar to modified clustering. Preliminary results indicate that this method is not only more accurate but considerably less expensive than supervised classification techniques.

  5. Evaluation of feasibility of mapping seismically active faults in Alaska

    NASA Technical Reports Server (NTRS)

    Gedney, L. D.; Vanwormer, J. D. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. The sharp bend in the Alaska Range near 65 deg N, 150 deg W in now thought to enclose a corner of the northwesterly migrating north Pacific lithospheric plate. Subduction of the plate beneath the continent is believed, on the basis of hypocentral distribution, to occur along Cook Inlet and the eastern flanks of the Aleutian and Alaska Ranges as far northward as Mt. McKinley. The nature of tectonic deformation here, particularly in the area of the bend in the Alaska Range, is understandably complex. The Denali fault is thought to be a transform character in the vicinity of Mt. McKinley (i.e., it is thought to be the surface along which the oceanic plate separates from the continental plate). On the ERTS-1 imagery, however, it appears that there are a number of sub-parallel faults which branch off of the Denali fault in a southwesterly direction. Slippage along these would tend to squeeze material around the inside of the band rather than the plate being directly underthrust. All of these sub-parallel faults are seismically active. The right-lateral fault-plane solution obtained for this event is consistent with the concept of slippage around the bend on a set of sub-parallel faults in the manner postulated. The best images to show these features are 1066-20444 and 1266-20572.

  6. Foraminiferal zonation and carbonate facies of Carboniferous (Mississippian and Pennsylvanian) Lisburne group, central and eastern Brooks range, Arctic Alaska

    USGS Publications Warehouse

    Armstrong, Augustus K.; Mamet, Bernard L.; Dutro, J. Thomas

    1970-01-01

    The Lisburne Group carbonate rocks of the central and eastern Brooks Range contain foraminiferal assemblages assigned to zones of late Tournaisian (Osage) to early Moscovian (Atoka) age. Representatives of both Eurasiatic and American cratonic microfaunas permit correlation with the original Carboniferous type sections in western Europe as well as with the standard Mississippian and Pennsylvanian sequences in the Mid-Continent region of North America. Correlation anomalies in the lower part of the sequence are discussed.

  7. Encouraging Involvement of Alaska Natives in Geoscience Careers

    NASA Astrophysics Data System (ADS)

    Hanks, C. L.; Fowell, S. J.; Kowalsky, J.; Solie, D.

    2003-12-01

    Geologically, Alaska is a dynamic state, rich in mineral and energy resources. The impact of natural geologic hazards and mineral resource development can be especially critical in rural areas. While Alaska Natives comprise a large percentage of Alaska's rural population, few have the training to be leaders in the decision-making processes regarding natural hazard mitigation or mineral resource evaluation and exploitation. UAF, with funding from the National Science Foundation, has embarked on a three year integrated program aimed at encouraging young Alaska Natives to pursue geosciences as a career. The program combines the geologic expertise at UAF with established Alaska Native educational outreach programs. The Rural Alaska Honors Institute (RAHI) is a bridging program specifically designed to prepare rural high school students for college. To attract college-bound Alaska Native students into the geosciences, geoscience faculty have developed a college-level, field-intensive, introductory RAHI geoscience course that will fulfill geoscience degree requirements at UAF. In years two and three, this class will be supplemented by a one week field course that will focus on geologic issues encountered in most Alaskan rural communities, such as natural hazards, ground water, mineral and energy resources. In order to retain Alaska Native undergraduate students as geoscience majors, the program is providing scholarships and internship opportunities in cooperation with the Alaska Native Science and Engineering Program (ANSEP). Undergraduate geoscience majors participating in ANSEP can intern as teaching assistants for both the classroom and field courses. Besides being mentors for the RAHI students, the Alaska Native undergraduate geoscience majors have the opportunity to interact with faculty on an individual basis, examine the geologic issues facing Alaska Natives, and explore geology as a profession.

  8. The 2007 Eruption of Pavlof Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    McNutt, S. R.

    2007-12-01

    Pavlof Volcano on the Alaska Peninsula began to erupt on August 15, 2007 after a 10.7 year repose. Precursor signals consisted of low-frequency earthquakes that began on August 14 and thermal anomalies that were likely coincident with the beginning of the eruption. The mainly strombolian eruptions are occurring from a new vent high on the SE flank of the volcano, separate from the NNE vent that had been active over the last several decades. Seismic activity, monitored by a network of 6 local instruments, consists of low-frequency events, explosion earthquakes, volcanic tremor, and lahar-generated signals. One station, PVV, is located only 220 m from a lahar channel, and lahars generate an easily distinguished high-frequency seismic signal. A commonly observed sequence is an increase in eruptive activity at the vent, accompanied by stronger tremor visible on all stations, and followed 12-30 minutes later by a lahar at PVV. This suggests that the eruption pulse ejects fresh hot material, which melts additional ice and snow to form new lahars. Steam and ash plumes have generally been below 15,000 ft, but rose as high as 20,000 ft on August 29 and 30. AVHRR remote sensing data showed an ash signal on these days, consistent with pilot reports. On August 30 lightning was observed in the plume from Cold Bay, 59 km SW. In response to the eruptions, AVO has been conducting 24 hr per day surveillance. Fieldwork to date has fortified seismic stations, and installed a new webcam, pressure sensor, and electric field meter. Collaborating scientists from the University of Alaska Fairbanks have installed aerosol sampling equipment at four locations, and collaborating scientists from New Mexico Tech have installed lightning detection equipment at four stations surrounding the volcano. Based on recent eruptions of Pavlof in 1981, 1986, 1996, etc., the eruptive activity is likely to last several months and may include one or more episodes of ash columns to heights of 30,000 ft or

  9. Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA

    USGS Publications Warehouse

    Hinkley, T.K.

    1994-01-01

    Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (??? 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples. ?? 1994.

  10. Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA

    NASA Astrophysics Data System (ADS)

    Hinkley, Todd K.

    1994-08-01

    Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (≈ 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples.

  11. K-Ar geochronology of the Survey Pass, Ambler River and Eastern Baird Mountains quadrangles, southwestern Brooks Range, Alaska

    USGS Publications Warehouse

    Turner, Donald L.; Forbes, R.B.; Mayfield, C.F.

    1978-01-01

    We report 76 previously unpublished K-Ar mineral ages from 47 metamorphic and igneous rocks in the southwestern Brooks Range. The pattern of radiometric ages is complex, reflecting the complex geologic history of this area. Local and regional radiometric evidence suggests that the southern Brooks Range schist belt has, at least in part, undergone a late Precambrian metamorphism and that the parent sedimentary and igneous rocks for the metamorphic rocks dated as late Precambrian are at least this old (Precambrian Z). This schist terrane experienced a major thermal event in mid-Cretaceous time, causing widespread resetting of nearly all K-Ar mica ages. A series of apparent ages intermediate between late Precambrian and mid-Cretaceous are interpreted as indicating varying amounts of partial argon loss from older rocks during the Cretaceous event. The schist belt is characterized by dominant metasediments and subordinate metabasites and metafelsites. Blueschists occur within the schist belt from the Chandalar quadrangle westward to the Baird Mountains quadrangle, but geologic evidence does not support the existence of a fossil subduction zone.

  12. K-Ar ages of allochthonous mafic and ultramafic complexes and their metamorphic aureoles, Western Brooks Range, Alaska

    SciTech Connect

    Boak, J.L.; Turner, D.L.; Wallace, W.K.; Moore, T.E.

    1985-04-01

    New K-Ar ages from allochthonous mafic and ultramafic complexes of the western Brooks Range (Brooks Range ophiolite) show that igneous rocks yielded ages nearly identical to those of underlying metamorphic aureole rocks. Dated rocks of the Misheguk igneous sequence from Tumit Creek consist of (1) hornblende gabbro with minor greenschist and lower grade alteration, hornblende age 147.2 +/- 4.4 Ma; and (2) hornblende-bearing diorite, also slightly altered, age 155.8 +/- 4.7 Ma. Both samples come from presumed higher levels of the Misheguk sequence. Dated samples of metamorphic aureole rocks come from outcrops near Kismilot Creek and lie structurally beneath the Iyikrok Mountain peridotite body. The rocks consist of amphibolite and garnet-bearing biotite-hornblende gneiss considered to be metamorphosed Copter igneous sequence and related sedimentary rocks. Hornblende ages are 154.2 +/- 4.6 Ma and 153.2 +/- 4.6 Ma. metamorphism is clearly related to the structurally overlying perioditite, as the degree of alteration decreases downward. The authors suggest that the K-Ar ages of these rocks represent the effects of thermal metamorphism post-dating igneous crystallization, and are related to tectonic emplacement of the complex. Earlier K-Ar data on igneous rocks give similar ages and have been interpreted as reflecting tectonothermal events. The age of igneous crystallization of the mafic and ultramafic rocks of the Misheguk igneous sequence remains uncertain.

  13. Board-foot and cubic-foot volume tables for Alaska-cedar in southeast Alaska. Forest Service research note

    SciTech Connect

    DeMars, D.J.

    1996-03-01

    Four tables give cubic-foot and board-foot volume estimates for Alaska-cedar given breast-height diameter outside bark (DBHOB) and either total tree height or number of logs to a 6-inch top. The values for DBHOB and total tree height (or number of logs in the tree) that are in the tables have been limited to the ranges these variables had in the sample data.

  14. Pronounced climatic variations in Alaska during the last two millennia

    PubMed Central

    Hu, Feng Sheng; Ito, Emi; Brown, Thomas A.; Curry, B. Brandon; Engstrom, Daniel R.

    2001-01-01

    Paired oxygen-isotopic analyses of abiotic carbonate and benthic-ostracode shells from lake sediments provide a continuous quantitative record of growing-season temperature for the past 2000 years in the northwestern foothills of the Alaska Range. This record reveals three time intervals of comparable warmth: anno Domini (A.D.) 0–300, 850-1200, and post-1800, the latter two of which correspond to the Medieval Climatic Anomaly and climatic amelioration after the end of the Little Ice Age. The Little Ice Age culminated at A.D. 1700, when the climate was ≈1.7°C colder than at present. A marked climatic cooling also occurred around A.D. 600, coinciding with extensive glacial advances in Alaska. Comparisons of this temperature record with ostracode trace-element ratios (Mg/Ca, Sr/Ca) further suggest that colder periods were wetter and vice versa during the past 2000 years. PMID:11517320

  15. Reconnaissance geologic map of Kodiak Island and adjacent islands, Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.

    2013-01-01

    Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best available mapping compiled in an integrated fashion. The map and associated digital files represent part of a systematic effort to release geologic map data for the United States in a uniform manner. The geologic data have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The map data are presented for use at a nominal scale of 1:500,000, although individual datasets (see Wilson and others, 2005) may contain data suitable for use at larger scales.

  16. Subsurface temperatures and geothermal gradients on the North Slope, Alaska

    USGS Publications Warehouse

    Collett, Timothy S.; Bird, Kenneth J.; Magoon, Leslie B.

    1989-01-01

    Geothermal gradients as interpreted from a series of high-resolution stabilized well-bore-temperature surveys from 46 North Slope, Alaska, wells vary laterally and vertically throughout the near-surface sediment (0-2,000 m). The data from these surveys have been used in conjunction with depths of ice-bearing permafrost, as interpreted from 102 well logs, to project geothermal gradients within and below the ice-bearing permafrost sequence. The geothermal gradients calculated from the projected temperature profiles are similar to the geothermal gradients measured in the temperature surveys. Measured and projected geothermal gradients in the ice-bearing permafrost sequence range from 1.5??C/100m in the Prudhoe Bay area to 5.1??C/100m in the National Petroleum Reserve in Alaska (NPRA).

  17. Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska.

    PubMed

    Beckmen, Kimberlee B; Keogh, Mandy J; Burek-Huntington, Kathleen A; Ylitalo, Gina M; Fadely, Brian S; Pitcher, Kenneth W

    2016-01-15

    The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy. PMID:26524270

  18. Micromorphologic evidence for paleosol development in the Endicott group, Siksikpuk formation, Kingak(?) shale, and Ipewik formation, western Brooks range, Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.; White, Tim

    2005-01-01

    Micromorphologic evidence indicates the presence of paleosols in drill-core samples from four sedimentary units in the Red Dog area, western Brooks Range. Well-developed sepic-plasmic fabrics and siderite spherules occur in claystones of the Upper Devonian through Lower Mississippian(?) Kanayut Conglomerate (Endicott Group), the Pennsylvanian through Permian Siksikpuk Formation (Etivluk Group), the Jurassic through Lower Cretaceous Kingak(?) Shale, and the Lower Cretaceous Ipewik Formation. Although exposure surfaces have been previously recognized in the Endicott Group and Kingak Shale on the basis of outcrop features, our study is the first microscopic analysis of paleosols from these units, and it provides the first evidence of subaerial exposure in the Siksikpuk and Ipewik Formations. Regional stratigraphic relations and geochemical data support our interpretations. Paleosols in the Siksikpuk, Kingak, and Ipewik Formations likely formed in nearshore coastal-plain environments, with pore waters subjected to inundation by the updip migration of slightly brackish ground water, whereas paleosols in the Kanayut Conglomerate probably formed in a more distal setting relative to a marine basin.

  19. Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska.

    PubMed

    Beckmen, Kimberlee B; Keogh, Mandy J; Burek-Huntington, Kathleen A; Ylitalo, Gina M; Fadely, Brian S; Pitcher, Kenneth W

    2016-01-15

    The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy.

  20. Towards a 90-Day Monthly Storm Outlook for Alaska

    NASA Astrophysics Data System (ADS)

    Partain, J. L.

    2011-12-01

    In all seasons, storms represent high-impact weather events in Alaska. Alaska's extensive coastline makes the region especially vulnerable to coastal flooding and erosion, particularly where a protective sea ice buffer is absent. There exists a major need for an expanded temporal range of storm outlooks to enable proactive responses by coastal communities and the various industries noted above. The expansion envisioned here is to the 90-day range. The NOAA Climate Prediction Center's (CPC) Storm Tracks website presently includes summaries of storm tracks and accumulated precipitation for the past 10-, 30- and 90-day periods, together with Week-1 and Week-2 forecast storm tracks from the Global Forecast System's (GFS) operational run and the GFS ensemble. Given the limits of deterministic predictability, we will extend the window of the storm outlook to 90 days by drawing upon the present and CPC-predicted states of ENSO, the Pacific Decadal Oscillation, and the Arctic Oscillation -- three large-scale modes of variability known to affect Alaska. In order to link the large-scale modes of variability to storm probabilities in various Alaskan sub-regions, we will explore the use of composites and analog years based on the states of the major teleconnection modes. This presentation will include an end-to-end plan for the development and testing of this product.

  1. Association of deformation and fluid events in the central Brooks Range fold-and-thrust belt, Northern Alaska

    USGS Publications Warehouse

    Moore, Thomas E.; Potter, Christopher J.; O'Sullivan, Paul B.; Shelton, Kevin L.; Underwood, Michael B.

    2003-01-01

    Ocentral Brooks Range consists of two superposed north-directed contractional orogens, one formed between 140-120 Ma and the other at ~60-45 Ma. The older orogen was an arc-continent collisional zone characterized by far-traveled allochthons and relatively low structural relief. The younger orogen is a retroarc thrust belt with relatively low amounts of shortening and high structural relief. Folding and thrusting of the younger episode is superimposed on the thin-skinned deformational wedge of the earlier orogen and also produced a frontal triangle zone in a thick sequence of mid-Cretaceous foreland basin sediments to the north. Stable isotope compositions of calcite and quartz veins indicate two fluid events including: (1) an earlier, higher-temperature (~250-300° C) event that produced veins in deformed Devonian clastic rocks, and (2) a younger, lower-temperature (~150° C) event that deposited veins in deformed Mississippian through Albian strata. The fluids in the first event had variable d18O values, but nearly constant d13C values buffered by limestone lithologies. The vein-forming fluids in the second event had similarly variable d18O values, but with distinctly lower d13C values as a result of oxidation of organic matter and/or methane. Zircon fission track ages demonstrate cooling to temperatures below 200° C between 140-120 Ma for the Devonian rocks, whereas zircon and apatite fission track ages show that Mississippian to Albian rocks were never heated above 200° C and cooled below 110-90° C at ~60-45 Ma. These data are interpreted as indicating that the older, high-temperature fluid event was active during thrusting at 120-140 Ma, and the younger fluid event during deformation at ~60-45 Ma. The data and results presented in this poster will be published in early 2004 in Moore and others (in press).

  2. Economic Education Experiences of Award Winning Alaska Teachers.

    ERIC Educational Resources Information Center

    Thomas, Monica, Ed.

    Award-winning economic education projects devised by Alaska teachers included three elementary (K-6) projects and three second level (7-12) ones. Faith Greenough's students (Chinook Elementary School, Anchorage) compared Tlingit traditional and market economies in Alaska, so economics became an integrated part of elementary instruction. Marie…

  3. First Report of Tobacco Rattle Virus in Peony in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2007, scattered peony (Paeonia lactiflora ‘Sarah Bernhardt’) plants cultivated on plots at the University of Alaska Experimental Station in Fairbanks, Alaska, contained distinct leaf ringspot patterns. Leaf samples from symptomatic plants were collected in early July (6 plants) and late September...

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  5. Alaska Humans Factors Safety Study: The Northern Area

    NASA Technical Reports Server (NTRS)

    Connell, Linda; Reynard, William (Technical Monitor)

    1995-01-01

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

  6. Enrollment Trends at University of Alaska Community Campuses

    ERIC Educational Resources Information Center

    Goldsmith, Scott; Hill, Alexandra; Killorin, Mary

    2005-01-01

    In this report, Institute of Social and Economic Research, University of Alaska Anchorage, investigated the factors that explain change over time in enrollments and credit hours (participation) at the community campuses of the University of Alaska using both quantitative and qualitative methods. Sections include: (1) Background; (2) Factors…

  7. Wetlands & Wildlife: Alaska Wildlife Curriculum Primary Teacher's Guide K-3.

    ERIC Educational Resources Information Center

    Sigman, Marilyn; And Others

    This curriculum guide was designed to give students at the primary level an awareness of Alaska's wetlands and the fish and wildlife that live there. This guide is divided into 13 sections consisting of learning activities covering the following topics: (1) wetland areas in Alaska; (2) water cycles; (3) plants and wildlife found in wetlands; (4)…

  8. American Indian/Alaska Native College Student Retention Strategies

    ERIC Educational Resources Information Center

    Guillory, Raphael M.

    2009-01-01

    This article presents findings from a qualitative study examining the similarities and differences between American Indian/Alaska Native student perceptions and the perceptions of state representatives, university presidents, and faculty about persistence factors and barriers to degree completion specific to American Indian/Alaska Native students…

  9. Alaska Education Directory, School Year 1999-2000.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    This 1999-2000 directory provides information on Alaska's public schools, school districts, education organizations, and institutions of higher education. A statistical summary indicates that in 1998-99, Alaska enrolled 132,905 students in 503 public schools. Breakdowns by grade configuration and enrollment show that about half the schools served…

  10. Rope culture of the kelp Laminaria groenlandica in Alaska

    SciTech Connect

    Ellis, R.J.; Calvin, N.I.

    1981-02-01

    This paper is an account of rope culture of the brown seaweed or kelp, Laminaria groenlandica, in Alaska. It describes the placement of the ropes, time of first appearance of young L. groenlandica, size of the plants at various ages, and other life history features applicable to the use of rope for the culture of seaweeds in Alaska. (Refs. 3).

  11. The Alaska Public School Fund: A Permanent Fund for Education.

    ERIC Educational Resources Information Center

    Coon, E. Dean

    This paper examines the development of Alaska's Public School Fund, its current status, and its potential as a major revenue source for elementary and secondary education. The fund, which was created following the 1915 federal school lands grant to Alaska, is examined for the 1916-58 territorial period, the 1959-78 early statehood period, and the…

  12. Alaska School-to-Work Opportunities Development Grant. Final Report.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    In 1994, Alaska began the process of using its grant funds from the National School-to-Work Opportunities Act to design a school-to-work system to meet the following objectives: obtain commitment and involvement from Alaska's governor and officials involved in human resource development; develop an implementation plan for a statewide system to…

  13. Alaska oil and gas: Energy wealth or vanishing opportunity

    SciTech Connect

    Thomas, C.P.; Doughty, T.C.; Faulder, D.D.; Harrison, W.E.; Irving, J.S.; Jamison, H.C.; White, G.J.

    1991-01-01

    The purpose of the study was to systematically identify and review (a) the known and undiscovered reserves and resources of arctic Alaska, (b) the economic factors controlling development, (c) the risks and environmental considerations involved in development, and (d) the impacts of a temporary shutdown of the Alaska North Slope Oil Delivery System (ANSODS). 119 refs., 45 figs., 41 tabs.

  14. Authentic Alaska: Voices of Its Native Writers. American Indian Lives.

    ERIC Educational Resources Information Center

    Andrews, Susan B., Ed.; Creed, John, Ed.

    This book compiles the best selections from the Chukchi News and Information Service, a University of Alaska project that for the past decade, has published the writings of Native college students from rural and remote regions of Alaska. The writers are primarily nontraditional older students who are Inupiaq, Yup'ik, or Siberian Yup'ik Eskimos or…

  15. Age determination of late Pleistocene marine transgression in western Alaska

    USGS Publications Warehouse

    Szabo, B. J.

    1982-01-01

    Dating molluscs from sediments representing the Kotzebuan marine transgression in Alaska yields an average uranium-series age of 104,000 ?? 22,000 yrs B.P. This and other selected Pleistocene marine deposits of western Alaska are tentatively correlated with radiometrically dated units of eastern Baffin Island, Arctic Canada. ?? 1982.

  16. A Summary of Changes in the Status of Alaska Natives.

    ERIC Educational Resources Information Center

    Alaska Univ., Anchorage. Inst. of Social and Economic Research.

    Replication of 78 tables from the 1973 2(c) Report by the Secretary of the Interior using 1980 census information provided data to document the social and economic changes in the status of Alaska Natives since the passage of the Alaska Native Claims Settlement Act. Comparison of 1970 and 1980 data showed an average 2.4% growth rate in the Native…

  17. Sharing Ideas. Southeast Alaska Cultures: Teaching Ideas and Resource Information.

    ERIC Educational Resources Information Center

    Hinckley, Kay, Comp.; Kleinert, Jean, Comp.

    The product of two 1975 workshops held in Southeastern Alaska (Fairbanks and Sitka), this publication presents the following: (1) papers (written by the educators in attendance at the workshops) which address education methods and concepts relevant to the culture of Southeastern Alaska ("Tlingit Sea Lion Parable"; "Using Local Knowledge in…

  18. 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;…

  19. Statewide Educator Supply & Demand Report, State of Alaska, 1998.

    ERIC Educational Resources Information Center

    LaBerge, MaryEllen

    In 1998, the demand for educators in Alaska reached an all-time high. The shortage was most critical for music, math, and special education teachers, as well as for counselors. Filling positions in rural areas is especially difficult. An early retirement incentive program has caused a drain on Alaska's pool of teachers. Factors that inhibit…

  20. Expanding Job Opportunities for Alaska Natives. (Interim Report).

    ERIC Educational Resources Information Center

    McDiarmid, G. Williamson; Goldsmith, Scott; Killorin, Mary; Sharp, Suzanne; Hild, Carl

    A majority of adults in most Alaska Native villages were without jobs in 1990, and the situation was probably not substantially better in 1998. This report summarizes current Alaska Native employment data and employment trends, provides information on public and private programs that target Native hire, and describes promising approaches for…

  1. 46 CFR 2.01-80 - Vessel inspections in Alaska.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Vessel inspections in Alaska. 2.01-80 Section 2.01-80 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC VESSEL INSPECTIONS Inspecting and Certificating of Vessels § 2.01-80 Vessel inspections in Alaska. (a) The waters...

  2. A Storm-by-Storm Analysis of Alpine and Regional Precipitation Dynamics at the Mount Hunter Ice Core Site, Denali National Park, Central Alaska Range

    NASA Astrophysics Data System (ADS)

    Saylor, P. L.; Osterberg, E. C.; Kreutz, K. J.; Wake, C. P.; Winski, D.

    2014-12-01

    In May-June 2013, an NSF-funded team from Dartmouth College and the Universities of Maine and New Hampshire collected two 1000-year ice cores to bedrock from the summit plateau of Mount Hunter in Denali National Park, Alaska (62.940291, -151.087616, 3912 m). The snow accumulation record from these ice cores will provide key insight into late Holocene precipitation variability in central Alaska, and compliment existing precipitation paleorecords from the Mt. Logan and Eclipse ice cores in coastal SE Alaska. However, correct interpretation of the Mt. Hunter accumulation record requires an understanding of the relationships between regional meteorological events and micrometeorological conditions at the Mt. Hunter ice core collection site. Here we analyze a three-month window of snow accumulation and meteorological conditions recorded by an Automatic Weather Station (AWS) at the Mt. Hunter site during the summer of 2013. Snow accumulation events are identified in the Mt. Hunter AWS dataset, and compared on a storm-by-storm basis to AWS data collected from the adjacent Kahiltna glacier 2000 m lower in elevation, and to regional National Weather Service (NWS) station data. We also evaluate the synoptic conditions associated with each Mt. Hunter accumulation event using NWS surface maps, NCEP-NCAR Reanalysis data, and the NOAA HYSPLIT back trajectory model. We categorize each Mt. Hunter accumulation event as pure snow accumulation, drifting, or blowing snow events based on snow accumulation, wind speed and temperature data using the method of Knuth et al (2009). We analyze the frequency and duration of events within each accumulation regime, in addition to the overall contribution of each event to the snowpack. Preliminary findings indicate that a majority of Mt. Hunter accumulation events are of pure accumulation nature (55.5%) whereas drifting (28.6%) and blowing (15.4%) snow events play a secondary role. Our results will characterize the local accumulation dynamics on

  3. 1984 Results of trans-Alaska crustal transect in Chugach Mountains and Copper River Basin, Alaska

    SciTech Connect

    Nokleberg, W.J.; Ambos, E.L.; Fuis, G.S.; Mooney, W.D.; Page, R.A.; Plafker, G.; Campbell, D.L.

    1985-04-01

    The Trans-Alaska Crustal Transect (TACT) program, a multidisciplinary investigation of the continental crust and its evolution along the Trans-Alaska pipeline corridor was started by the USGS during 1984. Preliminary results of geologic, geophysical, and wide-angle reflection/refraction data obtained across the Chugach terrane (CGT) and the composite Wrangellia/Peninsular terrane (WRT/PET) suggest the following: (a) the CGT is composed of accretionary sequences that include, from south to north, Late Cretaceous schistose flysch, uppermost Jurassic to Early Cretaceous sheared melange, and Early(.) Jurassic blueschist/greenschist. (b) The CGT accretionary sequences have local broad, low-amplitude magnetic or gravity anomalies. (c) Seismic data show that the CGT along latitude 61/sup 0/N, by alternating high- (6.9-8.0. km/sec) and low-velocity layers is suggestive of multiple thin slices of subducted oceanic crust and upper mantle. (d) Mafic and ultramafic cumulate rocks along the south margin of the WRT/PET have strong magnetic and gravity signatures and are interpreted as the uplifted root of a Jurassic magmatic arc superimposed on a late Paleozoic volcanic arc. Magnetic data suggest that comparable rocks underlie most of the PET. (e) The Northdipping border Ranges fault (BRF) marks the suture along which the northern margin of the CGT was relatively underthrust at least 40 km beneath the WRT/PET. (f) Beneath the northern CGT and southern WRT/PET, a prominent seismic reflector (v = 7.7 km/sec), suggestive of oceanic upper mantle rocks, dips about 3/sup 0/N and extends from a depth of 12 km beneath the Tasnuna River to 16 km beneath the BRF, where the dip appears to steepen to about 15/sup 0/ beneath the southern margin of the PET.

  4. Alaska Geochemical Database - Mineral Exploration Tool for the 21st Century - PDF of presentation

    USGS Publications Warehouse

    Granitto, Matthew; Schmidt, Jeanine M.; Labay, Keith A.; Shew, Nora B.; Gamble, Bruce M.

    2012-01-01

    The U.S. Geological Survey has created a geochemical database of geologic material samples collected in Alaska. This database is readily accessible to anyone with access to the Internet. Designed as a tool for mineral or environmental assessment, land management, or mineral exploration, the initial version of the Alaska Geochemical Database - U.S. Geological Survey Data Series 637 - contains geochemical, geologic, and geospatial data for 264,158 samples collected from 1962-2009: 108,909 rock samples; 92,701 sediment samples; 48,209 heavy-mineral-concentrate samples; 6,869 soil samples; and 7,470 mineral samples. In addition, the Alaska Geochemical Database contains mineralogic data for 18,138 nonmagnetic-fraction heavy mineral concentrates, making it the first U.S. Geological Survey database of this scope that contains both geochemical and mineralogic data. Examples from the Alaska Range will illustrate potential uses of the Alaska Geochemical Database in mineral exploration. Data from the Alaska Geochemical Database have been extensively checked for accuracy of sample media description, sample site location, and analytical method using U.S. Geological Survey sample-submittal archives and U.S. Geological Survey publications (plus field notebooks and sample site compilation base maps from the Alaska Technical Data Unit in Anchorage, Alaska). The database is also the repository for nearly all previously released U.S. Geological Survey Alaska geochemical datasets. Although the Alaska Geochemical Database is a fully relational database in Microsoft® Access 2003 and 2010 formats, these same data are also provided as a series of spreadsheet files in Microsoft® Excel 2003 and 2010 formats, and as ASCII text files. A DVD version of the Alaska Geochemical Database was released in October 2011, as U.S. Geological Survey Data Series 637, and data downloads are available at http://pubs.usgs.gov/ds/637/. Also, all Alaska Geochemical Database data have been incorporated into

  5. Discovery: An Introduction. Alaska Sea Week Curriculum Series. Alaska Sea Grant Report 83-6.

    ERIC Educational Resources Information Center

    Mickelson, Belle; And Others

    This curriculum guide is the first (Series I) in a six-volume set that comprises the Sea Week Curriculum Series developed in Alaska. As a basic introduction, this first book in the series lends itself to the kindergarten level but can be adapted to preschool, secondary, and adult education. Six units contain 32 activities with worksheets that…

  6. 77 FR 58731 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ..., and a history, was originally addressed in the Federal Register on August 16, 2002 (67 FR 53511) and most recently on March 26, 2012 (77 FR 17353). Recent Federal Register documents, which are all... migratory birds in Alaska in a proposed rule published in the Federal Register on April 17, 2012, (77...

  7. 76 FR 68263 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ..., and a history, was originally addressed in the Federal Register on August 16, 2002 (67 FR 53511) and most recently on March 29, 2011 (76 FR 17353). Recent Federal Register documents, which are all final... migratory birds in Alaska in a proposed rule published in the Federal Register on April 8, 2011 (76 FR...

  8. Alaska Broad Scale Orthoimagery and Elevation Mapping - Current Statewide Project Progress and Historic Work in Alaska

    NASA Astrophysics Data System (ADS)

    Heinrichs, T. A.; Broderson, D.; Johnson, A.; Slife, M.

    2014-12-01

    This presentation describes the overall program goals and current status of broad scale, statewide orthoimagery and digital elevation model (DEM) projects currently underway in Alaska. As context, it will also describe the history and successes of previous statewide Alaska mapping efforts over the preceding 75 years. A new statewide orthomosaic imagery baselayer at 1:24,000 NMAS accuracy (12.2-meters CE90) is nearing completion. The entire state (1.56 million square kilometers) has been imaged with the SPOT 5 satellite, and a 2.5-meter spatial resolution, multi-spectral, nearly cloud-free, pan-sharpened orthoimage will be produced by mid-2015. A second major project is collection of an improved accuracy DEM statewide. Airborne interferometric synthetic aperture radar (IfSAR) data has been collected for about half of the state of Alaska and completion of the rest of the state is anticipated within a few years. A 5-meter post spacing, 20-foot contour interval accuracy equivalent (3-meter vertical LE90) DEM and radar backscatter intensity image is being delivered. Historic projects to be described include the 1950's USGS Alaska topographic mapping program, one of the largest and most pioneering, challenging, and successful ever undertaken in North America. These historic and current mapping programs have served as both a baselayer framework and as feedstock for science for virtually every geologic, geophysical, and terrestrial natural science project in the state.

  9. Fish and Fisheries. Alaska Sea Week Curriculum Series VI. Alaska Sea Grant Report 83-7.

    ERIC Educational Resources Information Center

    Mickelson, Belle; Barr, Nancy

    This curriculum guide is the fifth (Series VI) in a six-volume set that comprises the Sea Week Curriculum Series developed in Alaska. The book lends itself to the fifth-grade level but can be adapted to preschool, secondary, and adult education. Seven units contain 48 activities with worksheets that cover the following topics: (1) fish, their…

  10. Shells and Insects. Alaska Sea Week Curriculum Series III. Alaska Sea Grant Report 84-4.

    ERIC Educational Resources Information Center

    Kelsey, Claudia; And Others

    This curriculum guide is the third (Series III) in a six-volume set that comprises the Sea Week Curriculum Series developed in Alaska. The book lends itself to the second-grade level but can be adapted to preschool, secondary, and adult education. Ten units contain 77 activities with worksheets that cover the following topics: (1) introduction to…

  11. Systems Performance Analyses of Alaska Wind-Diesel Projects; St. Paul, Alaska (Fact Sheet)

    SciTech Connect

    Baring-Gould, I.

    2009-04-01

    This fact sheet summarizes a systems performance analysis of the wind-diesel project in St. Paul, Alaska. Data provided for this project include load data, average wind turbine output, average diesel plant output, dump (controlling) load, average net capacity factor, average net wind penetration, estimated fuel savings, and wind system availability.

  12. Alaska Native Water Rights as Affected by the Alaska Native Claims Settlement Act

    ERIC Educational Resources Information Center

    Stoebner, Kerry; And Others

    1978-01-01

    A strong legal claim exists for retained Native water rights on Alaska Native-selected lands which are paramount to subsequent competing users. Water rights are critical to the maintenance of Native subsistence economies and continued commercial developments. These water rights can and must be asserted and secured now. (Author/JC)

  13. Flood-prone area maps of three sites along the Trans-Alaska Pipeline, Alaska

    USGS Publications Warehouse

    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)

  14. Native Alaska's Floating Factoryship--She Plies the Pacific Ocean for Native Alaska.

    ERIC Educational Resources Information Center

    Wassaja, The Indian Historian, 1980

    1980-01-01

    Describes the history of the Al-Ind-Esk-A Sea, a floating fish processing factory representing a major hope for the economic independence of Alaska Natives residing outside the state. Discusses employment practices in effect on the ship. Notes interesting facts about the ship's engines and fittings. (SB)

  15. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zavodsky, B. T.; Zhang, X.; Heinrichs, T.; Broderson, D.

    2014-01-01

    Data assimilation has been demonstrated very useful in improving both global and regional numerical weather prediction. Alaska has very coarser surface observation sites. On the other hand, it gets much more satellite overpass than lower 48 states. How to utilize satellite data to improve numerical prediction is one of hot topics among weather forecast community in Alaska. The Geographic Information Network of Alaska (GINA) at University of Alaska is conducting study on satellite data assimilation for WRF model. AIRS/CRIS sounder profile data are used to assimilate the initial condition for the customized regional WRF model (GINA-WRF model). Normalized standard deviation, RMSE, and correlation statistic analysis methods are applied to analyze one case of 48 hours forecasts and one month of 24-hour forecasts in order to evaluate the improvement of regional numerical model from Data assimilation. The final goal of the research is to provide improved real-time short-time forecast for Alaska regions.

  16. Evidence for multiple mechanisms of crustal contamination of magma from compositionally zoned plutons and associated ultramafic intrusions of the Alaska Range

    USGS Publications Warehouse

    Reiners, P.W.; Nelson, B.K.; Nelson, S.W.

    1996-01-01

    Models of continental crustal magmagenesis commonly invoke the interaction of mafic mantle-derived magma and continental crust to explain geochemical and petrologic characteristics of crustal volcanic and plutonic rocks. This interaction and the specific mechanisms of crustal contamination associated with it are poorly understood. An excellent opportunity to study the progressive effects of crustal contamination is offered by the composite plutons of the Alaska Range, a series of nine early Tertiary, multiply intruded, compositionally zoned (peridotite to granite) plutons. Large initial Sr and Nd isotopic contrasts between the crustal country rock and likely parental magmas allow evaluation of the mechanisms and extents of crustal contamination that accompanied the crystallization of these ultramafic through granitic rocks. Three contamination processes are distinguished in these plutons. The most obvious of these is assimilation of crustal country rock concurrent with magmatic fractional crystallization (AFC), as indicated by a general trend toward crustal-like isotopic signatures with increasing differentiation. Second, many ultramafic and mafic rocks have late-stage phenocryst reaction and orthocumulate textures that suggest interaction with felsic melt. These rocks also have variable and enriched isotopic compositions that suggest that this felsic melt was isotopically enriched and probably derived from crustal country rock. Partial melt from the flysch country rock may have reacted with and contaminated these partly crystalline magmas following the precipitation and accumulation of the cumulus phenocrysts but before complete solidification of the magma. This suggests that in magmatic mush (especially of ultramafic composition) crystallizing in continental crust, a second distinct process of crustal contamination may be super-imposed on AFC or magma mixing involving the main magma body. Finally, nearly all rocks, including mafic and ultramafic rocks, have (87Sr

  17. Future Biome Projections in Alaska and East Russia

    NASA Astrophysics Data System (ADS)

    Hendricks, A.; Saito, K.; Bigelow, N. H.; Walsh, J. E.

    2014-12-01

    We projected Arctic biomes across a region including Alaska and Eastern Russia using the BIOME4 biogeochemical and biogeography vegetation model. BIOME4, which produces an equilibrium vegetation distribution under a given climate condition, was forced by CMIP5/PMIP3 climate data considered in IPCC AR5. We are exploring vegetation and permafrost distributions during the last 21,000 years and future projections (2100 C.E.) to gain an understanding of the effects of climate shifts on this complex subsystem. When forced with the baseline climatology, compiled from the University of Delaware temperature and precipitation climatology and ERA-40 sunshine data, our biome simulations were generally consistent with current vegetation observations in the study region. The biomes in this region are mostly evergreen and deciduous taiga capped by shrub and graminoid tundras to the north. The more noticeable differences were the tree line simulated north of the Brooks Range in Alaska and evergreen taiga in southwest Alaska where we know these biomes do not exist today. The projected changes in climate conditions in the region under a RCP8.5 climate scenario (significant warming upwards of 10°C by some models, an increase in precipitation by as much as 40%, and carbon dioxide concentration reaching approximately 940 ppm) drive shifts in Arctic biomes. The tree line shifts northward while shrub tundra and graminoid tundra regions decrease significantly. An intrusion of cool mixed, deciduous, and conifer forests above 60° north, especially in southwest Alaska, were marked and were not modeled for present day. Across eastern Russia, deciduous taiga begins to overtake evergreen taiga, except along the coastal regions where evergreen taiga remains the favored biome. The implications of vegetation shifts in the Arctic are vast and include effects on snow cover, soil properties, permafrost distribution, and albedo, not to mention impacts on local fauna and people of the Artic.

  18. Current & future medical costs of childhood obesity in Alaska.

    PubMed

    Guettabi, Mouhcine

    2014-09-01

    This study examines the medical costs of childhood obesity in Alaska, today and in the future. We estimate that 15.2 percent of those ages 2 to 19 in Alaska are obese. Using parameters from published reports and studies, we estimate that the total excess medical costs due to obesity for both adults and children in Alaska in 2012 were $226 million, with medical costs of obese children and adolescents accounting for about $7 million of that total. And those medical costs will get much higher over time, as today's children transition into adulthood. Aside from the 15.2 percent currently obese, another estimated 20 percent of children who aren't currently obese will become obese as adults, if current national patterns continue. We estimate that the 20-year medical costs--discounted to present value--of obesity among the current cohort of Alaska children and adolescents will be $624 million in today's dollars. But those future costs could be decreased if Alaskans found ways to reduce obesity. We consider how reducing obesity in several ways could reduce future medical costs: reducing current rates of childhood obesity, rates of obese children who become obese adults, or rates of non-obese children and adolescents who become obese adults. We undertake modest reductions to showcase the potential cost savings associated with each of these channels. Clearly the financial savings are a direct function of the obesity reductions and therefore the magnitude of the realized savings will vary accordingly. Also keep in mind that these figures are only for the current cohort of children and adolescents; over time more generations of Alaskans will grow from children into adults, repeating the same cycle unless rates of obesity decline. And finally, remember that medical costs are only part of the broader range of social and economic costs obesity creates.

  19. Vegetation and paleoclimate of the last interglacial period, central Alaska

    USGS Publications Warehouse

    Muhs, D.R.; Ager, T.A.; Beget, J.E.

    2001-01-01

    The last interglacial period is thought to be the last time global climate was significantly warmer than present. New stratigraphic studies at Eva Creek, near Fairbanks, Alaska indicate a complex last interglacial record wherein periods of loess deposition alternated with periods of soil formation. The Eva Forest Bed appears to have formed about the time of or after deposition of the Old Crow tephra (dated to ??? 160 to ??? 120 ka), and is therefore correlated with the last interglacial period. Pollen, macrofossils, and soils from the Eva Forest Bed indicate that boreal forest was the dominant vegetation and precipitation may have been greater than present around Fairbanks during the peak of the last interglacial period. A new compilation of last interglacial localities indicates that boreal forest was extensive over interior Alaska and Yukon Territory. Boreal forest also extended beyond its present range onto the Seward and Baldwin Peninsulas, and probably migrated to higher elevations, now occupied by tundra, in the interior. Comparison of last interglacial pollen and macrofossil data with atmospheric general circulation model results shows both agreement and disagreement. Model results of warmer-than-present summers are in agreement with fossil data. However, numerous localities with boreal forest records are in conflict with model reconstructions of an extensive cool steppe in interior Alaska and much of Yukon Territory during the last interglacial. ?? 2000 Elsevier Science Ltd.

  20. Facilitating Adaptation to Changing Storm Surge Patterns in Western Alaska.

    NASA Astrophysics Data System (ADS)

    Murphy, K. A.; Holman, A.; Reynolds, J.

    2014-12-01

    Coastal regions of North America are already experiencing the effects of climate change and the consequences of new storm patterns and sea level rise. These climate change effects are even more pronounced in western Alaska where the loss of sea ice in early winter and spring are exposing the coast to powerful winter storms that are visibly altering the landscape, putting coastal communities at risk, and are likely impacting important coastal wildlife habitat in ways we don't yet understand. The Western Alaska Landscape Conservation Cooperative has funded a suite of projects to improve the information available to assist managers and communities to adapt changes in coastal storms and their impacts. Projects range from modeling tide, wave and storm surge patters, to ShoreZone and NHD mapping, to bathymetry mapping, community vulnerability assessments and risks to important wildlife habitat. This group of diverse projects has helped stimulate momentum among partners which will lead to better tools for communities to respond to dangerous storms. For example, the State of Alaska and NOAA are working together to compile a series of community-scale maps that utilize best-available datasets to streamline communication about forecasted storm surges, local elevations and potentially impacted infrastructure during storm events that may lead to coastal flooding.