Publications
USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.
Filter Total Items: 2892
Sedimentary history of the Tethyan margins of eastern Gondwana during the Mesozoic
A composite Mesozoic geological history for the Gondwana margins to the Eastern Tethys Ocean can be assembled from stratigraphic successions on the Australian and Himalayan margins and from drill sites of Ocean Drilling Program Legs 122 and 123. During the Triassic, this region drifted northwards, entering tropical paleolatitudes during the Late Triassic-Early Jurassic, then returned to mid-latitu
Authors
James G. Ogg, Felix Gradstein, Julie A. Dumoulin, Massimo Sarti, Paul Brown
Changes in Alaskan soft-bottom prey communities along a gradient in sea otter predation
Sea Otter (Enhydra lutris), well documented as "keystone" predators in rocky marine communities, were found to exert a strong influence on infaunal prey communities in soft-sediment habitats. Direct and indirect effects of sea otter predation on subtidal soft-bottom prey communities were evaluated along a temporal gradient of sea otter occupancy around the Kodiak Archipelago. The results indicate
Authors
R.G. Kvitek, J.S. Oliver, A.R. DeGange, B.S. Anderson
Time allocation by Greater White-fronted Geese: Influence of diet, energy reserves and predation
I determined the amount of time Greater White-fronted Geese (Anser albifrons frontalis) allocated to various activities from September to May, 1980-1982 at their primary wintering areas in the Pacific Flyway of North America. The length of time spent on roosts during the day was positively correlated to day length. Geese at roost sites spent the majority of their time sleeping (24-46%), alert (17-
Authors
Craig R. Ely
Reproductive ecology of Emperor Geese: Survival of adult females
Life history theory predicts a decrease in survival with increased reproductive effort of individuals. This relationship, however, is highly variable among and within species. I studied the nesting success and survival of adult female Emperor Geese during 1982-1986 and found no direct evidence that differential reproductive effort as measured by the number of eggs laid or hatching success had a si
Authors
Margaret R. Petersen
Density of loons in central Alaska
Loons breed across North America from the high arctic south to about 43 north latitude. (AOU 1983). Populations, particularly of Common Loons (Gavia immer) have recently declined in the continental U.S. and southern Canada (Sutcliff 1979, Titus and VanDruff 1981, McIntyre 1988). As a result, state and private natural resource organizations began more intensive monitoring of loon populations (in Mc
Authors
Richard B. Lanctot, Pham Xuan Quang
Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula
This map of the Cold Bay and False Pass 1:250,000-scale quadrangles on the Alaska Peninsula is a compilation based in part on the mapping conducted as part of the Alaska Mineral Resource Assessment Program (AMRAP) and the Geothermal Energy Program. Field studies by the authors began as early as 1973 in the quadrangles, but systematic mapping was not begun until 1988. Systematic mapping remains to
Authors
Frederic H. Wilson, Thomas P. Miller, Robert L. Detterman
Intraspecific mitochondrial DNA variation in North American cervids
Intraspecific variation in mitochondrial DNA of North American cervids was assessed with restriction enzymes to determine relationships among populations and subspecies. No variation was detected in moose (Alces alces) and little in elk (Cervus elaphus). Caribou (Rangifer tarandus), white-tailed deer (Odocoileus virginianus), and mule deer (Odocoileus hemionus) possessed considerable variation. Ch
Authors
M. A. Cronin
The distribution of seabirds and fish in relation to ocean currents in the southeastern Chukchi Sea
In late August 1988, we studied the distribution of seabirds in the southeastern Chukchi Sea, particularly in waters near a major seabird colony at Cape Thompson. Foraging areas were characterized using hydrographic data obtained from hydroacoustic surveys for fish. Murres (Uria spp.) and Black-legged Kitttiwakes Rissa tridactyla breeding at Cape Thompson fed mostly on Arctic cod, which are known
Authors
John F. Piatt, John L. Wells, Andrea MacCharles, Brian S. Fadely
The velocity field along the San Andreas Fault in central and southern California
The velocity field within a 100‐km‐broad zone centered on the San Andreas fault between the Mexican border and San Francisco Bay has been inferred from repeated surveys of trilateration networks in the 1973–1989 interval. The velocity field has the appearance of a shear flow that remains parallel to the local strike of the fault even through such major deflections as the big bend of the San Andrea
Authors
Michael Lisowski, James C. Savage, W. H. Prescott
Variable first prebasic molt in Rio Grande and Merriam's wild turkeys
Gallinaceous birds typically retain the juvenal ninth (JIX) and tenth (JX) primary wing feathers during the first prebasic molt (Petrides 1945, terminology follows Humphrey and Parkes 1959). However, not all Wild Turkeys (Meleagris gallopavo) retain JIX and JX during this molt. Some retain only JX (reviewed by Lewis 1967), and in 21% of 125 Florida Wild Turkeys (M. g. osceola), all 10 juvenal pri
Authors
Joel A. Schmutz, Richard W. Hoffman
Effects of oil pollution on marine bird populations
Worldwide oil pollution has killed millions of marine birds in this century but it has been difficult to directly link these losses to population declines. Estimated bird losses from acute spills and chronic pollution are not precise because we usually do not know the proportion of birds killed at sea that are detected on beach surveys or the origin of those birds. Data required to assess effects
Authors
John F. Piatt, Harry R. Carter, David N. Nettleship
How do foraging seabirds sample their environment?
No abstract available.
Authors
G.L. Hunt, John F. Piatt, Kjell Einar Erikstad