Source Modeling of Strong Ground Motion Prediction for Megathrust Earthquake Sequence

2015 Fiscal Year Final Research Report

• Project/Area Number: 25750143
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: The University of Tokyo
• Principal Investigator: MIYAKE Hiroe 東京大学, 大学院情報学環, 准教授 (90401265)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 地震動 / 超巨大地震 / 東北地方太平洋沖地震 / 震源 / 強震動予測 / ハザード

Outline of Final Research Achievements

Broadband source modeling for predicting ground motions is a key role for seismic hazard assessment. Recent megathrust earthquakes motivated us to establish a recipe for subduction earthquake scenarios. Based on slip inversions, scaling of source parameters and acceleration source spectral levels, we propose candidates for the broadband source of subduction earthquakes: Single-corner or double-corner characterized source models. The latter model, where the size and stress drop for short-period source patches are respectively 1/N times and N times of those for long-period source patches, worked to reproduce broadband ground motions for megathrust earthquakes. The short-period source patches partly superimpose on the long-period source patches for M8-class, then shift to the edge of the long-period source patches for M9-class earthquakes with increasing N value.

Free Research Field

強震動地震学