Results 261 to 270 of about 37,429 (292)

Acoustically derived ice-fracture velocity in central Arctic pack ice

The Journal of the Acoustical Society of America, 2000
Sounds radiated by fractures in Arctic ice (called acoustic events) are used to estimate fracture velocity. Both speed and orientation are obtained by measuring Doppler shifts induced by source motion. Data from the SIMI experiment of 1994 in the central Arctic are used in the frequency window 10 to 350 Hz.
C, Stamoulis, I, Dyer
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Vibrational Motion of Arctic Pack Ice,

1997
Abstract : There are many physical mechanisms responsible for vibrations of sea, and they force motions in a very wide band of frequencies from less than 0.01 Hz to greater than 100 Hz. Detailed measurements of the vertical velocity in this frequency band were previously shown to be produced by gravity waves, ridging events and wind turbulence. In this
Zandy Williams, William Morris, John Dugan   +2 more
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Pack-ice studies in the Arctic Ocean

Journal of Geophysical Research, 1959
The annual stratification of pack ice has been examined. Summer layers are formed either by arrested growth or by thin layers of fresh-water ice. The crystal structure and the salt content of the ice reflect the seasonal cycle. During the growth of ice a pronounced orientation of crystalline structure develops; it is determined by vertical as well as ...
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Elastic waves in Arctic pack ice

Eos, Transactions American Geophysical Union, 1954
Elastic wave propagation was studied in the Arctic ice pack, on the Beaufort Sea, the Arctic Ocean, and at near‐shore locations. Ice thicknesses varied from 0.1 to 2.1 meters and water depths from 1 ½ to 3800 meters. Values of the elastic constants were derived from the measured velocities of the longitudinal and shear waves and the density. Dispersive
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Sea-ice algae in Arctic pack ice during late winter

Polar Biology, 2007
Pack ice around Svalbard was sampled during the expedition ARK XIX/1 of RV “Polarstern” (March–April 2003) in order to determine environmental conditions, species composition and abundances of sea-ice algae and heterotrophic protists during late winter. As compared to other seasons, species diversity of algae (total 40 taxa) was not low, but abundances
Iris Werner, Johanna Ikävalko, Henrike Schünemann   +2 more
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Underwater Backscattering Strengths of Arctic Pack Ice

The Journal of the Acoustical Society of America, 1964
The backscattering strengths under Arctic sea ice for octave bands between 12 cps and 4 kc/sec were measured, using explosive sound sources. The measurements were made from a camp established in April 1962 on broken and pressure-packed one-year ice over the Canada Deep.
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Low‐frequency vibrational motion of Arctic pack ice

Journal of Geophysical Research: Oceans, 1992
The mechanisms responsible for vibrational motions of Arctic ice at frequencies below about 100 Hz are know to be a combination of wave types, namely, gravity waves, flexural waves, and a variety of acoustic and/or elastic waves. Surface motion measurements using geophones and accelerometers on multiyear pack ice are used to establish the energy level ...
J. P. Dugan, R. L. DiMarco, W. W. Martin
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Near-Field Ice Management Tactics for Floating Drilling in Arctic Pack Ice

Arctic Technology Conference, 2016
Abstract In order to be economically viable, Arctic floating drilling in high concentration pack ice requires very high confidence that ice interaction does not lead to costly, unanticipated emergency disconnections of the rig from the well.
Jed Hamilton, Ted Kokkinis, Curtis Holub, Dmitri Matskevitch, Tao Cheng, Matthew Harris, Svetlana Shafrova   +6 more
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The Effect of Tensile Strength in the Arctic Ice Pack

2001
The ice pack covering northern seas is composed of an aggregate of thick ridged and rafted ice, undeformed ice, and open water. Existing ice-ocean models of the Arctic ice pack are large-scale continuum models that use a plastic yield surface to characterize the constitutive behavior of the pack. An alternative approach, which captures far more detail,
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Winter Sightings of Marine Mammals in Arctic Pack Ice

ARCTIC, 1987
There is limited information about the winter distribution of some arctic marine mammals. In February-March 1976 six species of marine mammals were sighted in the pack ice of Baffin Bay and Davis Strait. Hooded seals were sighted along the ice edge in February, but in late March adults with pups were seen.
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