Behavior of water in the Brogger Glacier, Spitsbergen (abstract)

元データ 国立極地研究所

概要

Measurements of the water permeability through glacier ice at Br∅gger Glacier in Spitsbergen were carried out in August 1991. The melt-water permeating through a glacier body plays an important role in the glacier gliding and glacier surge. However, very few measurements have been made in situ on the behavior of melt-water in a glacier body. The measurements were at made four points on the glacier from the terminus to the upper part of the glacier. To study the behavior of melt-water through the glacier ice, an auger hole method was used. The melt-water oozed out from the entire wall of the bore-hole and gradually filled it. The water was bailed out of the hole and the ascending speed of the water level in the hole was measured. Kirkham's formula was used to calculate the coefficient of permeability, k, of glacier ice, k=0.617×(R/SD)×(dh/dt), where R is the radius of the hole, D is the depth of the hole from the final water level, dh is the increment of the water level within dt seconds, and S is a coefficient which is determined from the values of R, h and D. The calculated values of the permeability coefficient were 2×(10)^<-4>cm/s to 3.0×(10)^<-3>cm/s, equivalent to that of fine grained sand and in agreement with the values obtained from Mendenhall Glacier in Alaska. Also, the flow speed of melt-water through the glacier body was directly measured by the "two-bore-holes method". About 100g of NaCl was poured into the water in the upper hole and then the water was rapidly stirred by an auger-rod to make it homogeneous. The electric conductivity of the water taken from two holes was measured with time, so that the value of conductivity of the water taken from the upper hole decreased exponentially with time. On the other hand, the conductivity of the water in the lower hole increased suddenly when water saturated with NaCl in the upper hole reached the water in the lower hole. From this measurement the average flow speed of melt-water in the glacier body was estimated to be 8cm/min to 50cm/min, which was larger than the values obtained from Mendenhall Glacier in summer.

著者

Shiraiwa T Institute Of Low Temperature Science Hokkaido University
Watanabe Okitsugu National Institute of Polar Research, Research Organization of Information and Systems
Goto-Azuma Kumiko National Institute of Polar Research, Research Organization of Information and Systems
Enomoto Hiroyuki Kitami Institute Of Technology
Takahashi Shuhei Kitami Institute of Technology
Shiraiwa T Disaster Prevention Research Institute Kyoto University
Watanabe Okitsugu National Institute Of Polar Research
Goto‐azuma K National Institute Of Polar Research Research Organization Of Information And Systems
Saito T Institute Of Low Temperature Science Hokkaido University
Goto-azuma Kumiko Nagaoka Institute Of Snow And Ice Studies National Research Institute For Earth Science And Disaster
Goto-azuma Kumiko National Institute Of Polar Research
Kawaguchi Sadao Fac. Of Agr. Kyushu Univ.
Enomoto H Kitami Institute Of Technology
Kanamori Satoru National Institute of Polar Research
Satow Kazuhide Nagoya Technical College
Kobayashi Shunichi Research Institute Of Hazards In Snowy Area Niigata University
Kawaguchi S Kyushu Univ.
Koga S National Inst. Resources And Environment Tsukuba
Kobayashi Shin'ichi Research Institute Of Hazards In Snowy Areas Niigata University

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