Study on interplate slip properties by means of slow slip events

2015 Fiscal Year Final Research Report

• Project/Area Number: 25400452
• 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: Kobe University
• Principal Investigator: Hirose Hitoshi 神戸大学, 都市安全研究センター, 准教授 (00465965)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 地殻変動 / GNSS / 傾斜 / すべり過程 / 群発地震活動 / 地震の誘発

Outline of Final Research Achievements

Slow slip events (SSE) occur every 2-7 years off the east coast of the Boso Peninsula, Kanto area, Japan. Because SSEs are similar phenomena to megathrust earthquakes in subduction zones in a sense that a slip episode on a fault, they are a key to understand the physical characteristics of the plate interface. SSEs are found worldwide, mainly in subduction zones. The Boso SSEs have remarkable characteristics, that is, an earthquake swarm activity is coincident with an SSE. In order to examine the relation between an SSE and an earthquake swarm activity, we estimate spatiotemporal slip distributions of the Boso SSEs based on GNSS displacements and tilt changes, and compare them with the correlated earthquake swarm activities. We found a clear spatial and temporal correlation between them. This result suggests that slow slip directly triggers earthquakes during an SSE.

Free Research Field

地震学