To clarify the process by which intraplate earthquakes are generated -A dense seismic observation in the northern part of the South Island in New Zealand-

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H05206
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Solid earth and planetary physics
• Research Institution: Kyoto University
• Principal Investigator: IIO Yoshihisa 京都大学, 防災研究所, 教授 (50159547)
• Co-Investigator(Kenkyū-buntansha): 岡田 知己 東北大学, 理学研究科, 准教授 (30281968) ; 松本 聡 九州大学, 理学研究院, 准教授 (40221593)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 内陸地震 / 水 / ニュージーランド / 断層 / 観測

Outline of Final Research Achievements

We continued a dense seismic observation in the northern part of the South Island in New Zealand, and installed 3 new stations around the north-western end of the South Island where no seismic stations are operated. By analyzing recorded data, we obtained the results that support the hypothesis that water upwelling from subducting plates reaches to the lower crust and generates intraplate earthquakes. The Kaikoura earthquake Mw(7.8) occurred within our seismic network on December, 14th, 2016. We installed 4 new stations near the hypocenter of the main shock, and succeeded the maintenance of seismic stations to which accesses are difficult owing to road closed, and obtained valuable data. We estimated detailed hypocentral distributions and stress fields before and after the main shock.

Free Research Field

固体地球惑星物理学