Untangling the environmental and tectonic drivers of the Noto earthquake swarm in Japan

Autor(en)
Q.-Y. Wang, Xin Cui, William B. Frank, Yang Lu, Hirose Hirose, Obara Obara
Abstrakt

The underlying mechanism of the ongoing seismic swarm in the Noto Peninsula, Japan, which generates earthquakes at 10 times the average regional rate, remains elusive. We capture the evolution of the subsurface stress state by monitoring changes in seismic wave velocities over an 11-year period. A sustained long-term increase in seismic velocity that is seasonally modulated drops before the earthquake swarm. We use a three-dimensional hydromechanical model to quantify environmentally driven variations in excess pore pressure, revealing its crucial role in governing the seasonal modulation with a stress sensitivity of 6 × 10-9 per pascal. The decrease in seismic velocity aligns with vertical surface uplift, suggesting potential fluid migration from a high-pore pressure zone at depth. Stress changes induced by abnormally intense snow falls contribute to initiating the swarm through subsequent perturbations to crustal pore pressure.

Organisation(en)
Institut für Meteorologie und Geophysik
Externe Organisation(en)
Massachusetts Institute of Technology, Tohoku University, University of Tokyo, Université Grenoble-Alpes
Journal
Science Advances
Band
10
ISSN
2375-2548
DOI
https://doi.org/10.1126/sciadv.ado1469
Publikationsdatum
05-2024
Peer-reviewed
Ja
ÖFOS 2012
105122 Seismik
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/2daf810e-f100-4605-a40b-d54ed8a00215