shiraiwa_2003.htm

Bulletin of Glaciological Research 20 (2003) 57-63
©Japanese Society of Snow and Ice

Ice core drilling at King Col, Mount Logan 2002　

Takayuki SHIRAIWA¹, Kumiko GOTO-AZUMA², Sumito MATOBA², Tetsuhide YAMASAKI³, Takahiro SEGAWA⁴, Syosaku KANAMORI¹, Kenichi MATSUOKA⁵ and Yoshiyuki FUJII²

1 Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 Japan
2 National Institute of Polar Research, Kaga 1-9-10, Itabashi-ku, Tokyo 173-8515 Japan
3 Avangnaq, House 2 Toki101, Koyama 1-19-11, Nerima-ku, Tokyo 176-0022 Japan
4 Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 Japan
5 Research Institute for Humanity and Nature, Kyoto 606-8502 Japan

Abstract

　An ice core of 220.52 m was drilled at King Col (60°35’ 20” N, 140°36’ 15’’W; 4135m), a saddle near Mount Logan (5959 m), the Canada’s highest mountain, in order to better understand 1) anthropogenic impact on the Pacific sector of the Arctic, 2) decadal and interdecadal climate changes in the North Pacific, and 3) dynamical behavior of cold mountain glaciers. The thickness of the glacier was estimated by an ice-penetrating radar survey at five points and the drilling site was decided at the flattest surface of which depth was calculated as 222 m. The recovered ice cores showed the site was located at dry snow zone with a very limited amount of melt-freeze ice layers. Temperature of the borehole was -18.0 ℃ at 10 m-depth and 17.7 ℃ at 220.52 m. The Nye time scale suggested that the ice core covers approximately several hundreds years to a millennium record of past climate and atmospheric proxy signals, provided annual accumulation rates from 0.4 to 1.0 m a-1 in ice.