Study on the Boso slow slip events through observation using ocean bottom pressure gauges and model simulation

2017 Fiscal Year Final Research Report

• Project/Area Number: 25287109
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Chiba University
• Principal Investigator: SATO Toshinori 千葉大学, 大学院理学研究院, 教授 (70222015)
• Co-Investigator(Kenkyū-buntansha): 篠原 雅尚 東京大学, 地震研究所, 教授 (90242172)
• Co-Investigator(Renkei-kenkyūsha): SHIBAZAKI Bunichiro 建築研究所, 国際地震工学センター, 上席研究員 (20344012) ; MOCHIZUKI Kimihiro 東京大学, 地震研究所, 准教授 (80292861) ; YAMADA Tomoaki 東京大学, 地震研究所, 助教 (40323654) ; ITO Hisao 海洋研究開発機構, 地球深部探査センター, 調査役 (10356470) ; KOBAYASHI Reiji 鹿児島大学, 理工学研究科, 准教授 (50433066) ; YAMAMOTO Yuzuru 海洋研究開発機構, 地球内部ダイナミクス領域, 研究員 (10435753)
• Project Period (FY): 2013-04-01 – 2018-03-31
• Keywords: スロースリップ / 海底圧力計 / シミュレーション / 房総沖 / 海底地殻変動 / プレート境界構造 / 反射波強度分布

Outline of Final Research Achievements

We conducted the following studies to reveal the Boso slow slip events (SSEs).We observed crustal movements using ocean bottom pressure gauges to estimate slip distribution of the Boso SSE, and obtained them successfully caused by the 2014 Boso SSE. We developed an analysis method using a parametric model for data of pressure gauges.
We conducted analyses on seismic structure of off the Boso area and simulation studies that reproduce a series of the Boso SSEs. We obtained a configuration of the upper surface of the Philippine Sea plate at off the Boso area. We found strong reflections from the upper surface around the Boso SSE region. We could make a simulation model which reproduced the Boso SSEs before 2011, but could not reproduce the 2014 SSE. To make a simulation model reproducing all of the Boso SSEs is an issue to be addressed to the future.

Free Research Field

地震学