A numerical investigation of choked flow dynamics and its application to the triggering mechanism of long-period events at Redoubt Volcano, Alaska
M.M. Morrissey, B. A. Chouet
1997, Journal of Geophysical Research B: Solid Earth (102) 7965-7983
We use numerical simulations of transonic flow through a crack to study the dynamics of the formation of shock waves downstream from a nozzle-like constriction inside the crack. The model solves the full set of Navier-Stokes equations in two dimensions via an explicit multifield finite difference representation. The crack walls...
Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem
Theodore C. Foin, E. Jacqueline Garcia, Robert E. Gill Jr., Steven D. Culberson, Joshua N. Collins
1997, Landscape and Urban Planning (38) 229-243
The California clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing...
Hydrocarbons in hair, livers, and intestines of sea otters (Enhydra lutris) found dead along the path of the Exxon Valdez oil spill
Brenda E. Ballachey, Kimberly A. Kloecker
1997, Report MMS 6-3
No abstract available....
Nesting ecology of Townsend's warblers in relation to habitat characteristics in a mature boreal forest
Steven M. Matsuoka, Colleen M. Handel, Daniel D. Roby
1997, Condor (99) 271-281
We investigated the nesting ecology of Townsend's Warblers (Dendroica townsendi) from 1993-1995 in an unfragmented boreal forest along the lower slopes of the Chugach Mountains in southcentral Alaska. We examined habitat characteristics of nest sites in relation to factors influencing reproductive success. Almost all territory-holding males (98%, n = 40)...
Spatial and temporal variability of microgeographic genetic structure in white-tailed deer
Kim T. Scribner, Michael H. Smith, Ronald K. Chesser
1997, Journal of Mammalogy (78) 744-755
Techniques are described that define contiguous genetic subpopulations of white-tailed deer (Odocoileus virginianus) based on the spatial dispersion of 4,749 individuals that possessed discrete character values (alleles or genotypes) during each of 6 years (1974-1979). White-tailed deer were not uniformly distributed in space, but exhibited considerable spatial genetic structuring. Significant...
The relative importance of nesting and foraging sites in selection of breeding territories by Townsend's Warblers
Steven M. Matsuoka, Colleen M. Handel, Daniel D. Roby, D.L. Thomas
1997, The Auk (114) 657-667
We investigated habitat selection by the Townsend's Warbler (Dendroica townsendi), a Netropical-Nearctic migrant that breeds primarily in mature coniferous forests. From 1993 to 1994, we compared the features of habitat selected for nest sites and foraging sites with those selected for territories in mature, mixed coniferous-deciduous forests in south-central Alaska....
Experimental manipulations of snow-depth: Effects on nutrient content of caribou forage
Noreen E. Walsh, Thomas R. McCabe, J.M. Welker, A.N. Parsons
1997, Global Change Biology (3) 158-164
We investigated the potential effects of global climate change on arctic tundra vegetation used as caribou forage. A total of 96 experimental plots was established at six sites on the coastal plain of the Arctic National Wildlife Refuge, Alaska, in 1993 and 1994. We erected snow-fences to increase the amount...
Evaluation of conditions along the grounding line of temperate marine glaciers: An example from Muir Inlet, Glacier Bay, Alaska
K.C. Seramur, R.D. Powell, P.R. Carlson
1997, Marine Geology (140) 307-327
In the marine environment, stability of the glacier terminus and the location of subglacial streams are the dominant controls on the distribution of grounding-line deposits within morainal banks. A morainal bank complex in Muir Inlet, Glacier Bay, SE Alaska, is used to develop a model of terminus stability and location...
Late quaternary regional geoarchaeology of Southeast Alaska Karst: A progress report
E. J. Dixon, T. H. Heaton, T. E. Fifield, Thomas D. Hamilton, D. E. Putnam, F. Grady
1997, Geoarchaeology - An International Journal (12) 689-712
Karst systems, sea caves, and rock shelters within the coastal temperate rain forest of Alaska's Alexander Archipelago preserve important records of regional archaeology, sea level history, glacial and climatic history, and vertebrate paleontology. Two 14C AMS dates on human bone discovered in a remote cave (49-PET-408) on Prince of Wales...
Tectonic evolution of the central Brooks Range mountain front: Evidence from the Atigun Gorge region
C. G. Mull, R.K. Glenn, K.E. Adams
1997, Journal of Geophysical Research B: Solid Earth (102) 20749-20772
Atigun Gorge, at the northern front of the eastern Endicott Mountains, contains well-exposed rocks of the upper part of the Endicott Mountains allochthon and rocks of the structurally higher Picnic Creek or Ipnavik River allochthon. These allochthons contain rocks as young as Early Cretaceous (Valanginian) and are separated by a...
Gas hydrate resources of northern Alaska
Timothy S. Collett
1997, Bulletin of Canadian Petroleum Geology (45) 317-338
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...
Ecosystem development on terraces along the Kugururok River, northwest Alaska
Dan Binkley, F. Suarez, R. Stottlemyer, B. Caldwell
1997, Écoscience (4) 311-318
Riverside terraces along the Kugururok River in the Noatak National Preserve provided an opportunity to study primary succession, considering general trends that apply across all terraces, and unique events that influence individual terraces. The 30-year-old willow/poplar (Salix spp., Populus balsamifera L.) terrace had no trees taller than 1.5 m; the...
An integrated model for the tectonic development of the frontal Brooks Range and Colville Basin 250 km west of the Trans-Alaska Crustal Transect
F. Cole, K. J. Bird, J. Toro, F. Roure, P. B. O’Sullivan, M. Pawlewicz, D. G. Howell
1997, Journal of Geophysical Research B: Solid Earth (102) 20685-20708
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...
An 18 million year record of vegetation and climate change in northwestern Canada and Alaska: Tectonic and global climatic correlates
J. M. White, T. A. Ager, D.P. Adam, E. B. Leopold, Gaisheng Liu, H. Jette, C. E. Schweger
1997, Palaeogeography, Palaeoclimatology, Palaeoecology (130) 293-306
We reconstruct long-term vegetation/paleoclimatic trends, spanning the last 18 million years, in Alaska. Yukon and far western Northwest Territories. Twenty-one average percentage spectra for pollen and spores are assembled from eight surface/subsurface sections. The sections are dated independently or by correlation. Pollen and spore ratios indicate the direction of change...
Genetic differentiation of sockeye salmon subpopulations from a geologically young Alaskan lake system
C. V. Burger, William J. Spearman, M. A. Cronin
1997, Transactions of the American Fisheries Society (126) 926-938
The Tustumena lake drainage in southcentral Alaska is glacially turbid and geologically young (<2,000 years old). Previous field studies identified at least three subpopulations of sockeye salmon Oncorhynchus nerka at Tustumena Lake, based on the distribution and timing of spawners. The subpopulations included early-run salmon that spawned in six clearwater...
Deep seismic structure and tectonics of northern Alaska: Crustal-scale duplexing with deformation extending into the upper mantle
G. S. Fuis, J.M. Murphy, W. J. Lutter, Thomas E. Moore, K. J. Bird, N.I. Christensen
1997, Journal of Geophysical Research B: Solid Earth (102) 20873-20896
Seismic reflection and refraction and laboratory velocity data collected along a transect of northern Alaska (including the east edge of the Koyukuk basin, the Brooks Range, and the North Slope) yield a composite picture of the crustal and upper mantle structure of this Mesozoic and Cenozoic compressional orogen. The following...
Productivity of nesting spectacled eiders on the lower Kashunuk River, Alaska
J.B. Grand, Paul L. Flint
1997, Condor (99) 926-932
We studied the chronology and success of nesting Spectacled Eiders (Somateria fischeri) along the lower Kashunuk River on the Yukon-Kuskokwim Delta from 1991-1995. Nest initiation dates ranged from 16 May-22 June. Median nest initiation dates were correlated with the break-up of ice on the Kashunuk River. Clutch sizes declined...
Hydrocarbon residues in tissues of sea otters (Enhydra lutris) collected from southeast Alaska
Brenda E. Ballachey, Kimberly A. Kloecker
1997, Report MMS 6-2
No abstract available....
Migration by radio-tagged pacific golden-plovers from hawaii to Alaska, and their subsequent survival
O.W. Johnson, N. Warnock, M.A. Bishop, A.J. Bennett, P.M. Johnson, R.J. Kienholz
1997, The Auk (114) 521-524
Many Pacific Golden-Plovers (Pluvialis fulva) and other shorebirds winter in the Hawaiian Islands. This is the first landfall for mid-Pacific migrants after overwater flights of 4,000 km or more from Alaska (Johnson et al. 1989, Johnson and Connors 1996). Previous findings (sightings of marked birds and wing-length measurements) showed Alaska...
Stratigraphic contrasts and tectonic relationships between Carboniferous successions in the Trans-Alaska Crustal Transect corridor and adjacent areas, northern Alaska
Julie A. Dumoulin, K.F. Watts, A. G. Harris
1997, Journal of Geophysical Research B: Solid Earth (102) 20709-20726
The Carboniferous succession along the Trans-Alaska Crustal Transect (TACT) corridor in the Atigun Gorge area of the central Brooks Range consists of the Kayak Shale (Kinderhookian) and the Lisburne Group (Kinderhookian through Chesterian). The Kayak Shale is at least 210 m thick; it is chiefly black, noncalcareous shale with several...
Population genetic studies of the polar bear (Ursus maritimus): A summary of available data and interpretation of results
Kim T. Scribner, G.W. Garner, Steven C. Amstrup, M.A. Cronin
Andrew E. Dizon, Susan J. Chivers, William F. Perrin, editor(s)
1997, Book chapter, Molecular Genetics of Marine Mammals: Special Publication 3
A summary of existing population genetics literature is presented for polar bears (Ursus maritimus) and interpreted in the context of the species' life-history characteristics and regional heterogeneity in environmental regimes and movement patterns. Several nongenetic data sets including morphology, contaminant levels, geographic variation in reproductive characteristics, and the location and...
Crustal implications of bedrock geology along the Trans-Alaska Crustal Transect (TACT) in the Brooks Range, northern Alaska
Thomas E. Moore, W. K. Wallace, C. G. Mull, K.E. Adams, George Plafker, W. J. Nokleberg
1997, Journal of Geophysical Research B: Solid Earth (102) 20645-20684
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...
Epithermal mercury-antimony and gold-bearing vein lodes of southwestern Alaska
John E. Gray, Carol A. Gent, Lawrence W. Snee, Frederic H. Wilson
Richard J. Goldfarb, Lance D. Miller, editor(s)
1997, Book chapter, Mineral Deposits of Alaska (Economic Geology Monographs, volume 9)
Epithermal mineral deposits and occurrences of southwestern Alaska consist of Hg-Sb and gold- and sulfide-bearing vein lodes. Numerous Hg-Sb lodes are located throughout a region measuring several tens of thousands of square kilometers in and surrounding the Kuskokwim River basin in southwestern Alaska. The Hg-Sb lodes are hosted in sedimentary...
Population genetics studies of the walrus (Odobenus rosmarus): A summary and interpretation of results and research needs
Kim T. Scribner, Susan Hills, Steven R. Fain, Matthew A. Cronin
Andrew E. Dizon, Susan J. Chivers, William F. Perrin, editor(s)
1997, Book chapter, Molecular Genetics of Marine Mammals: Special Publication 3
A summary of population genetics data is presented for the walrus (Odobenus rosmarus). Current information on the ecology and behavior of the species is highlighted to aid in the interpretation of genetics results and to suggest future areas of research. Walruses are discontinuously distributed across the Arctic and are currently...
Relative effects of survival and reproduction on the population dynamics of emperor geese
Joel A. Schmutz, Robert F. Rockwell, Margaret R. Petersen
1997, Journal of Wildlife Management (61) 191-201
Populations of emperor geese (Chen canagica) in Alaska declined sometime between the mid-1960s and the mid-1980s and have increased little since. To promote recovery of this species to former levels, managers need to know how much their perturbations of survival and/or reproduction would affect population growth rate (λ). We constructed...
