Long-term underground temperature measurements by quartz thermometers at Syowa Station, East Antarctica

• Main Authors: Toshiyasu Nagao, Katsutada Kaminuma, Kazuo Shibuya
• Format: Report
• Language: English
• Published: Earthquake Research Institute, the University of Tokyo 1985
• Subjects: Antarctic; East Antarctica; Syowa Station; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1780; http://id.nii.ac.jp/1291/00001780/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1780&item_no=1&attribute_id=18&file_no=1

Underground temperature measurements in two shallow boreholes were carried out by Japanese Antarctic Research Expedition at Syowa Station, East Antarctica from April 1981 to January 1984. Two quartz thermometers were installed in the first borehole at the depths of 2 and 5m and three were in the second one at the depths of 1,4 and 7m. Measurements of digital recording were made at one hour interval. From observed data, mean underground temperatures at each depth and thermal diffusivity for the observation area were calculated. Mean underground temperatures in the first borehole were -8.002 and -8.681℃ at the depths of 2 and 5m, and in the second one were -8.060 and -8.009℃ at the depths of 4 and 7m. Whereas the mean air temperature at Syowa Station was -10.3℃. The underground temperature is about two degrees higher than the air temperature. The difference might be related to the thermal balance at the earth's surface. The thermal diffusivities for the borehole area are determined by two independent methods. The first method uses decay of the maximum amplitude and the second the phase lag of the temperature wave propagating down the hole. The obtained thermal diffusivities of 2.58±0.69×(10)^<-2>(cm)^2/s and 2.20±0.19×(10)^<-2>(cm)^2/s are about two times larger than those of ordinary igneous and metamorphic rocks measured in the laboratory.