Structural Studies Of Bare Ice Near The Allan Hills, Victoria Land, Antarctica: A Mechanism Of Meteorite Concentration

Abstract

Structural laboratory studies were made of ice collected at the surface and from a shallow bore hole in the bare ice near the Allan Hills, Victoria Land, Antarctica. The results obtained were combined with glaciological survey data to describe the mechanism of accumulation of meteorites by ice flow in a marginal area of the East Antarctic ice sheet. The age of the bare ice, approximately 20 ka, was estimated by fabric characteristics and grain size of the ice. This conforms to the minimum value of the terrestrial age of the meteorites found in the same area. The several hundred meteorite finds concentrated in the bare-ice area can be explained by an expanded catchment area during a previous ice age, or by a correction factor for the estimate of the influx rate of meteorite fall, or more probably by a combination of both.

Strain in the ice sheet deduced from the crystal-orientation fabrics from bare icefields adjacent to the Sør-Rondane Mountains, Dronning Maud Land, East Antarctica

“…2). In other bare icefields in the Antarctic ice sheet, it has also been reported that there is no significant difference in crystal structure between the surface ice and 10 m deep ice (Nishio and others, 1982; Azuma and others, 1985). Thus, neither solar heat, stress around the micro-cracks nor the seasonal variation of the ice temperature is thought to change the fabrics in surface ice compared with deeper ice, at least at the site El.…”

Introduction to the Annals of Glaciology ‘Ice in a Sustainable Society’ issue

“…For those still in doubt, all those topics are indeed relevant for glaciologists and their studies have been published in the Journal of Glaciology and the Annals of Glaciology (e.g. Nishio and others, 1982; Gayet and Bain, 1983; Krass, 1984; Delisle, 1993; Hvidberg, 2003; Velandia and others, 2021).…”