Glaciological characteristics of cores drilled on Jostedalsbreen, Southern Norway

• Main Authors: Toshiyuki Kawamura, Yoshiyuki Fujii, Kazuhide Satow, Kokichi Kamiyama, Kaoru Izumi, Takao Kameda, Okitsugu Watanabe, Sadao Kawaguchi, Bjoern Wold, Yugvar Gjessing
• Format: Report
• Language: English
• Published: Institute of Low Temperature Science, Hokkaido University/National Institute of Polar Research/Nagaoka College of Technology/Geophysical Research Station, Kyoto University/Research Institute for Hazards in Snowy Areas, Niigata University/Faculty of Engineering, Hokkaido University/National Institute of Polar Research/National Institute of Polar Research/Norwegian Water Resources and Energy Administration/Department of Geophysics, University of Bergen 1989
• Subjects: Arctic; Norway; glacier; ice core; Polar meteorology and glaciology; Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3576; http://id.nii.ac.jp/1291/00003576/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3576&item_no=1&attribute_id=18&file_no=1

Glaciological investigation was carried out on Jostedalsbreen (61°43' N, 7°08' E), Southern Norway, in early May, 1987, as a study of the Japanese Arctic Glaciological Expedition (JAGE 1987) which intended to define the glaciological characteristics in the martime cryosphere. The 46.9 m full depth ice core was recoverd at a dome of the glacier (1960 m a.s.l.). Then glaciological and geochemical in situ analyses of the cores were made to clarify the past climatic change. The cooperative study was with institutions of Norway. Several dirt layers were found in the cores; the dirt layers in the upper part indicate the corresponding maximum values of electrical conductivity, different from layers in the lower part. Infiltrating water of about 1 m thick appeared in the borehole, showing a confined aquifer on the bedrock. The temparature of the borehole was nearly 0℃ through the entire depth except at the upper part and the firn transformed abruptly into ice at 29.5 m; these results implied that the whole glacier has the property of a temperature glacier. The grain size increased on order of magnitude in a short interval just below the firn-ice interface, probably due to immerision of ice body into 0℃ water. A significantly large dip of foliation at the middle layer suggested existence of glacier flow at the boring site. The annual layers were not identified from seasonal variations of in situ analyses. However, from accumlation data for the last 20 years, the age of bottom ice was estimated to be about 17 years before the present investigation.