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: 3095
Lower Cretaceous smarl turbidites of the Argo Abyssal Plain, Indian Ocean Lower Cretaceous smarl turbidites of the Argo Abyssal Plain, Indian Ocean
Sediments recovered during Ocean Drilling Program (ODP) Leg 123 from the Argo Abyssal Plain (AAP) consist largely of turbidites derived from the adjacent Australian continental margin. The oldest abundant turbidites are Valanginian-Aptian in age and have a mixed (smarl) composition; they contain subequal amounts of calcareous and siliceous biogenic components, as well as clay and lesser...
Authors
Julie A. Dumoulin
Intraspecific variation in egg shape among individual emperor geese Intraspecific variation in egg shape among individual emperor geese
Within-clutch variability in shape of 1743 eggs from 301 nests of Emperor Geese (Chen canagicus) laid over a 5-yr period was measured. Individual females laid similar shaped eggs in successive years, and eggs among clutches within females could not be distinguished. Cluster analysis correctly identified 69.9% of 136 known conspecific parasitic eggs. Repeatability estimates of elongation...
Authors
Margaret R. Petersen
Sedimentary history of the Tethyan margins of eastern Gondwana during the Mesozoic 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...
Authors
James G. Ogg, Felix Gradstein, Julie A. Dumoulin, Massimo Sarti, Paul Brown
Breeding distribution of the Black Turnstone Breeding distribution of the Black Turnstone
Eighty-five percent of the world population of Black Turnstones (Arenaria melanocephala) nest on the central Yukon-Kuskokwim Delta, Alaska, 65% concentrated in a narrow band of salt grass, graminoid, and dwarf shrub meadows within two km of the coast. An estimated 61,000 to 99,000 birds (95% CI), with a point estimate of 80,000 birds, breed on the central delta. About 15,000 others nest...
Authors
Colleen M. Handel, Robert E. Gill
Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula 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...
Authors
Frederic H. Wilson, Thomas P. Miller, Robert L. Detterman
Paleomagnetism of the Late Triassic Hound Island Volcanics: Revisited Paleomagnetism of the Late Triassic Hound Island Volcanics: Revisited
The collision and accretion of the Alexander terrane profoundly influenced the geologic history of Alaska and western Canada; however, the terrane's displacement history is only poorly constrained by sparse paleomagnetic studies. We studied the paleomagnetism of the Hound Island Volcanics in order to evaluate the location of the Alexander terrane in Late Triassic time. We collected 618...
Authors
Peter J. Haeussler, Robert S. Coe, T.C. Onstott
Reproductive implications of egg-size variation in Black Brant Reproductive implications of egg-size variation in Black Brant
We analyzed variation in egg size of Black Brant (Branta bernicla nigricans) in relation to clutch size, laying date, female age, year, and position in the laying sequence. A total of 3,478 eggs was measured over three years. Egg size increased with clutch size and female age, and decreased with laying date, year, and position in the laying sequence. We did not detect a negative...
Authors
Paul L. Flint, James S. Sedinger
Threshold foraging behavior of baleen whales Threshold foraging behavior of baleen whales
We conducted hydroacoustic surveys for capelin Mallotus villosus in Witless Bay, Newfoundland, Canada, on 61 days during the summers of 1983 to 1985. On 32 of those days in whlch capelin surveys were conducted, we observed a total of 129 baleen whales - Including 93 humpback Megaptera novaeangliae, 31 minke Balaenoptera acutorostrata and 5 fin whales B. phvsalus. Although a few whales...
Authors
John F. Piatt, David A. Methven
Change-in-ratio methods for estimating population size Change-in-ratio methods for estimating population size
Change-in-ratio (CIR) methods can provide an effective, low cost approach for estimating the size of wildlife populations. They rely on being able to observe changes in proportions of population subclasses that result from the removal of a known number of individuals from the population. These methods were first introduced in the 1940’s to estimate the size of populations with 2...
Authors
Mark S. Udevitz, Kenneth H. Pollock
Depositional history, nannofossil biostratigraphy, and correlation of Argo Abyssal Plain Sites 765 and 261 Depositional history, nannofossil biostratigraphy, and correlation of Argo Abyssal Plain Sites 765 and 261
Sediments from the Argo Abyssal Plain (AAP), northwest of Australia, are the oldest known from the Indian Ocean and were recovered from ODP Site 765 and DSDP Site 261. New biostratigraphic and sedimentologic data from these sites, as well as reinterpretations of earlier findings, indicate that basal sediments at both localities are of Late Jurassic age and delineate a history of starved
Authors
Julie A. Dumoulin, Paul R. Bown
Change-in-ratio Change-in-ratio
Change-in-ratio (CIR) methods are used to estimate parameters for ecological populations subject to differential removals from population subclasses. Subclasses can be defined according to criteria such as sex, age, or size of individuals. Removals are generally in the form of closely monitored sport or commercial harvests. Estimation is based on observed changes in subclass proportions...
Authors
Mark S. Udevitz
Structural evolution of an arc-basin: The Gravina Belt in central southeastern Alaska Structural evolution of an arc-basin: The Gravina Belt in central southeastern Alaska
The upper Middle Jurassic-Lower Cretaceous Gravina belt lies along the eastern margin of the Alexander terrane in southeastern Alaska. This group of turbidites and mafic to intermediate volcanic rocks was deformed during mid to Late Cretaceous time during the closing of a basin of unknown size between the Alexander terrane on the west and the Stikine terrane to the east. Therefore...
Authors
Peter J. Haeussler