Collaborative Research: Paleoseismic evidence of earthquakes and tsunamis along the southern part of the Japan Trench


Investigator: Jessica Pilarczyk, Yuki Sawai, Ben Horton
Graduate students: Thomas Kosciuch


National Science Foundation (NSF) EAR-1624612

Project Summary

There is an extensive instrumental, historical and geological record of tsunamigenic-earthquakes originating from the northern and middle parts of the Japan Trench. The record documents the last several thousand years of earthquakes and tsunamis of known recurrence intervals and magnitudes, including the 2011 Tohoku earthquake (M 9.0). The 2011 earthquake ruptured five segments along the northern and middle parts of the Japan Trench, but failed to rupture through the southern part. Uncertainty surrounds the seismic risk for coastlines facing the southern part of the Japan Trench near metropolitan Tokyo because of the potential transfer of stress southwards during the 2011 earthquake, coupled with the locked nature of this part of the subduction zone. Furthermore, there is only one southern trench tsunamigenic-earthquake within the instrumental and historical record (CE 1677 Empo earthquake) and an absence of long-term geological data. To address this knowledge gap for the southern part of the trench, we will apply an innovative combination of field, laboratory (sedimentary, microfossil, and radiometric analyses), statistical, and modeling techniques to a series of candidate tsunami deposits that our team recently discovered. These methods will be applied to test two hypotheses related to the long-term patterns of seismicity along the Japan Trench: (1) Precise dating of tsunami deposits distinguishes between Japan Trench and Sagami Trough tsunamis; and (2) Tsunami simulation models and stratigraphic correlations indicate previous ruptures along the southern part of the Japan Trench.

Key outcomes

This is a project in its first year. Stay tuned…


Supplementary Data

Coastal Hazards Research Lab
Division of Marine Science
School of Ocean Science and Technology
University of Southern Mississippi
1020 Balch Blvd., Stennis Space Center, MS 39529