Call number:
ZSP-164-79
In:
Scientific reports
Description / Table of Contents:
Observations made during 1966 - 68 along a 70 km. flow line on the Brunt Ice Shelf are used to show that an average of 1 m. of ice is melted each year from beneath the ice shelf. Appreciable bottom melting occurs at all points along the flow line. Within the limits of observing errors, ice drainage into the ice shelf is found to balance surface accumulation over the catchment area. Particle trajectories indicate that snow falling at the hinge line takes about 190 yr. to reach the ice front and that, because of bottom melting, none of the snow falling at distances greater than 5 km. inland from the hinge line ever reaches the ice front. The high melting rates calculated at all points beneath the Brunt Ice Shelf suggest that bottom melting may be more widespread than previously suspected. The behaviour of the Brunt Ice Shelf is largely influenced by the rapidly moving "Dalgliesh Ice Stream" which supplies the northern part of the ice shelf, where the ice front advances up to 1 - 5 km. each year. Farther,south, ice movement is hindered by the grounded ice of the McDonald Ice Rumples. Between these two zones, large shear stresses have resulted in complete fracture of the ice shelf into isolated blocks separated by expanses of thin ice shelf, sea ice and leads that mark the lines of active separation. Large ice tongues may calve in response to tsunamis with a frequency equal to one of the natural frequencies of the ice tongue. Calving of long narrow ice tongues may be due to the prolonged action of stresses induced by sea currents.
Type of Medium:
Series available for loan
Pages:
45, [7] S. : Ill., graph. Darst., Kt.
ISBN:
0856650196
Series Statement:
Scientific reports / British Antarctic Survey 79
URL:
http://www.antarctica.ac.uk/about_bas/publications/scientific_reports/index.php
Branch Library:
AWI Library
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