matsuoka_2003.htm

Bulletin of Glaciological Research 20 (2003) 49-55
©Japanese Society of Snow and Ice

Field-performance tests of a portable low-frequency ice-penetrating radar and a ground-penetrating radar at Athabasca Glacier, Canadian Rockies　

Kenichi MATSUOKA*, Tatsuto AOKI**, Tatsuya YAMAMOTO and Renji NARUSE

Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan.
*Present affrication: Research Institute for Humanity and Nature, Kyoto, 602-0878, Japan.
**Present affiliation : Department of Geography, Kanazawa University, Kanazawa, 920-1192, Japan.

Abstract

　Field tests of a novel portable low-frequency ice-penetrating radar (IPR) and a commercial ground-penetrating radar (GPR) were performed in September 2001 at Athabasca Glacier in Jasper National Park, Alberta, Canada. We measured about 110 m of ice thickness with the IPR at a point in the middle reaches of the glacier and acquired experiences for future practical usages. The GPR detected the bedrock reflection continuously beneath <15-m-thick ice at the glacier terminus and pseudo received power from the englacial and subglacial reflectors were calculated in this range. On the lateral ice-cored moraine, we traced with the GPR along two lines, where debris thickness changed from zero to 55 cm. The interface between debris and ice was clearly recognized when debris had sandy-silt matrix, whereas it was not identified when debris were composed of cobbles. It is probably due to large scattering of radio wave from the large gravels. Preliminary interpretations on the velocity and attenuation within ice and debris were also discussed.