Crystal alignments in the fast ice of arctic Alaska
Weeks, W. F.; Gow, Anthony Jack.
CRREL ReportAbstract: Field observations at 60 sites located in the fast or near-fast ice along a 1200-km stretch of the north coast of Alaska between Bering Strait and Barter Island have shown that the great majority of the ice samples (95%) exhibit striking c-axis alignments within the horizontal plane. Such alignments were usually well developed by the time the ice was 50 cm thick and in some cases when the ice was 20 cm thick. In all cases the degree of preferred orientation increased with depth in the ice. Representative standard deviations around a mean direction in the horizontal plane are commonly less than ±10° for samples collected near the bottom of the ice. The general patterns of the alignments support a correlation between the preferred c-axis direction and the current direction at the ice/water interface. A comparison between c-axis alignments and spot current measurements made at 42 locations shows that the most frequent current direction coincides with the mean c-axis direction. Such alignments are believed to be the result of geometric selection with the most favored orientation being that in which the current flows normal to the (0001) plates of ice that compose the dendritic sea ice/sea water interface.
Cold Regions Research and Engineering Laboratory (U.S.)Engineer Research and Development Center (U.S.)
Beaufort Sea; Pack ice; Chukchi Sea; Sea ice; Ice; Ice crystals; Crystal growth; Ice crystal growth; Sea currents; Fast ice; Ice crystal structure; Crystal structure; Alaska; EPOLAR
CRREL report ; 79-22.
Approved for public release; distribution is unlimited.
Showing items related by title, author, creator and subject.
Ramseier, René O. (Cold Regions Research and Engineering Laboratory (U.S.)Engineer Research and Development Center (U.S.), 1967-10)
Kumai, Motoi. (Cold Regions Research and Engineering Laboratory (U.S.)Engineer Research and Development Center (U.S.), 1967-07)
Gow, Anthony Jack.; Langston, David. (Cold Regions Research and Engineering Laboratory (U.S.)Engineer Research and Development Center (U.S.), 1977-01)Abstract: Studies of the growth history and structural characteristics of winter ice covers on two New Hampshire lakes are described. These investigations included measurements of ice cover thickness, characterization of ...