Did the Kobe earthquake contribute to the Rokko movement?

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05267
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Kyoto University
• Principal Investigator: Hashimoto Manabu 京都大学, 防災研究所, 教授 (20293962)
• Co-Investigator(Kenkyū-buntansha): 小澤 拓 国立研究開発法人防災科学技術研究所, その他部局等, 主任研究員 (70455252) ; 西村 卓也 京都大学, 防災研究所, 准教授 (90370808)
• Co-Investigator(Renkei-kenkyūsha): MUNEKANE Hiroshi 国土地理院, 地理地殻活動研究センター, 研究室長 (50370812) ; TOBITA Mikio 国土地理院, 測地部, 部長 (40370811)
• Research Collaborator: NAGAOKA Airi 京都大学防災研究所, 技術室, 技術職員 ; TAKAHASHI Atsushi 京都大学, 大学院・理学研究科 ; SAKAUE Hiromu 京都大学, 大学院・理学研究科 ; ITOH Yuji 京都大学, 大学院・理学研究科
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 六甲変動 / 兵庫県南部地震 / 余効変動 / 宇宙測地技術 / GPS / SAR / 地形形成過程

Outline of Final Research Achievements

In order to clarify the contribution of postseismic deformation of the Kobe earthquake to the Rokko movement, we reanalyzed geodetic data after the earthquake and conducted GPS surveys on the top of the Rokko Mountains. We found that control points on the Rokko Mountains moved ESE-ward by ~40 cm and subsided by 0 - 4 cm during these 20 years. Continuous GPS sites slightly uplifted till March, 1995, but no significant movements were found. JERS-1 images revealed ~10 mm/yr decrease of distance to the satellite but it may be attributed to horizontal motion of the Rokko Mountains.
On the basis of the above results, we conclude that there is no contribution of the postseismic deformation to the orogeny of the Rokko Mountains.

Free Research Field

測地学