抄録
Beneath the Kii Peninsula, the distribution of low-frequency earthquakes (LFEs) forms three clusters. A previous study shows that one of the clusters has anomalously less amount of cumulative slip than the others. To understand the cause of this variation, we applied a tomographic analysis using arrival times of earthquakes recorded by both ocean bottom seismometers and onshore stations. As a result, we identified segmentation about the Vp/Vs ratio around the subducting plate interface corresponding to the distribution of LFEs. One of the segments has low a Vp/Vs ratio that coincides with the small-slip LFE cluster. Another segment has a high Vp/Vs ratio in which almost no LFEs occur. We conclude that the relatively low pore fluid pressure within the low Vp/Vs segment contributes to the small-slip LFE cluster and that the gap of LFEs within the high Vp/Vs segment corresponds to stable slip area due to high pore fluid pressure. Key Points Segmentation of Vp/Vs ratio along subduction margin Spatial relationship between Vp/Vs ratio 3-D velocity structure from offshore to onshore around the Kii Peninsula
本文言語 | 英語 |
---|---|
ページ(範囲) | 1306-1310 |
ページ数 | 5 |
ジャーナル | Geophysical Research Letters |
巻 | 40 |
号 | 7 |
DOI | |
出版ステータス | 出版済み - 4月 16 2013 |
!!!All Science Journal Classification (ASJC) codes
- 地球物理学
- 地球惑星科学(全般)