Distribution and movements of Alaska-breeding Steller's Eiders in the nonbreeding period
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Alaska↗
Geology topics
Research about Barrow, Alaska
Source-linked reports with geographic coverage including Barrow, Alaska.
Application of ground-penetrating radar imagery for three-dimensional visualisation of near-surface structures in ice-rich permafrost, Barrow, Alaska
Three-dimensional ground-penetrating radar (3D GPR) was used to investigate the subsurface structure of ice-wedge polygons and other features of the frozen active layer and near-surface permafrost near Barrow, Alaska. Surveys were conducted at three sites located on landscapes of different geomorphic age. At each site, sediment cores were collected and characterised to aid interpretation of GPR data. At two sites, 3D GPR was able to delineate subsurface ice-wedge networks with high fidelity. Three-dimensional GPR data also revealed a fundamental difference in ice-wedge morphology between these two sites that is consistent with differences in landscape age. At a third site, the combination of two-dimensional and 3D GPR revealed the location of an active frost boil with ataxitic cryostructure. When supplemented by analysis of soil cores, 3D GPR offers considerable potential for imaging, interpreting and 3D mapping of near-surface soil and ice structures in permafrost environments.
Alaska↗
Energy budget and prey requirements of breeding lapland longspurs Calcarius lapponicus near Barrow Alaska, U.S.A.
Breeding Lapland longspurs, Calcarius lapponicus , near Barrow, Alaska, have relatively constant energy demands throughout the summer; the average estimated daily energy budgets (DEBs) were 132 and 118 kJ for the male and female. Thermoregulation accounted consistently for one-quarter to one-third of the total DEB. Flight in the male and incubation in the female were major components of the DEB early in the season, whereas cost of molt was a major component for both sexes near the end of the season. Our estimates of longspur DEB based on a time-activity approach were similar to those based on a cage existence model. Minor differences are explained by increased male territorial activity, by energy savings of the female during incubation, and by contraction of the molt for both sexes within the short summer season. Male and female longspurs were estimated to capture 3000 to 10,000 seeds and insects d -1 (3-20 items min -1 foraging) for self maintenance while in summer residence near Barrow. Each adult was estimated to capture an additional 3000 insects d -1 ( 6-7 insects min -1 foraging) during the peak energy requirements to raise five young. While raising young, the maximum required capture rate of prey per time foraging for each adult occurred during the nestling stage; young are just achieving independence, however, when food supply is at a maximum.
Alaska↗