LEVELING SURVEY ON EAST ONGUL ISLAND, ANTARCTICA AND ITS IMPLICATIONS

• Main Authors: カミヌマ カツタダ, キムラ イサオ, Katsutada KAMINUMA, Isao KIMURA
• Format: Report
• Language: English
• Published: National Institute of Polar Research 1997
• Subjects: leveling survey; crustal uplift; oceanic tide; elevated beach; local earthquake; Antarctic; East Antarctica; Syowa Station; Ongul; Ongul Island; East Ongul Island; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2840; http://id.nii.ac.jp/1291/00002840/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2840&item_no=1&attribute_id=18&file_no=1

A route for a repeat leveling survey was established on East Ongul Island (69°S, 39°E), East Antarctica by the 20th Japanese Antarctic Research Expedition (JARE-20) in 1979 and JARE-23 in 1982. One of the purposes for establishing the leveling route is to detect crustal movement in Antarctica. The leveling measurements were repeated in 1992 and in 1996. Because of the time limitation, only 2.3km out of the total length of 5.3km route was surveyed. The mean square error every one kilometer is obtained as ±0.57mm. Bench Mark (BM) 1040 is taken as a reference point which is also the reference point for oceanic tide observations at Syowa Station and is located on the westernmost point of the route. The height change between measurements in 1982 and 1996 at the easternmost point BM 1026 is -0.2mm. No appreciable change of height at BM 1026 was observed for the last 14 years. This fact supports the idea of a block movement of crust which is explained as a process of crustal uplift after deglaciation.