2011 Fiscal Year Final Research Report
Estimation of fault strength based on fine-scale seismic structure of fault zone
| Project/Area Number |
21740320
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Solid earth and planetary physics
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
KATO Aitaro 東京大学, 地震研究所, 助教 (20359201)
|
|---|
| Project Period (FY) |
2009 – 2011
|
| Keywords | 地震 / 断層 / 構造 / 稠密アレイ観測 |
|---|
| Research Abstract |
We deployed a dense seismic array consisting of 120 portable stations, which crossed fault zones associated with the Iwate-Miyagi Nairiku Earthquake in 2008, and retrieved continuous seismic waveforms during about ten days. Based on tomographic analysis using the waveforms of small earthquakes located close to the array, we estimated a seismic structure of the fault zones. Bands of low-velocity layers were imaged roughly parallel to along pre-existing faults. We interpret that a likely-explanation of these low-velocity layers is presence of crustal fluids or cracks within the fault zones. It is thus inferred that the strength of fault might be weak.
|
