

Osamu Sandanbata, University of Tokyo-Abnormal Tsunamis Caused by Trapdoor Faulting
- When:
- Thursday, Apr 8, 2021 12:00 PM
- Where:
- https://stanford.zoom.us/j/92246012053 Passcode: 467202
- Audience:
- General Public
- Sponsor:
- Geophysics Department
Osamu Sandanbata
Dept. of Earth and Planetary Sciences, University of Tokyo
Abnormal tsunamis caused by trapdoor faulting repeating at submarine volcanic calderas
At some submarine volcanoes, peculiar volcanic earthquakes occurred almost every ten years. Despite their seismic magnitudes of only < 5, the earthquakes generated tsunamis with amplitudes of up to about a half meter. Tsunami and seismic data from the earthquakes offered us evidence of so-called trapdoor faulting, that is, a large magma-induced fracture of complex intra-caldera fault structures of the volcanic calderas. The results suggest that the magma-rock interacted system of submarine calderas contributed to the abnormal tsunami genesis, and that plenty of magma has been supplied to the calderas at least for decades.
https://stanford.zoom.us/j/92246012053 Passcode: 467202