Untangling the environmental and tectonic drivers of the Noto earthquake swarm in Japan
- Author(s)
- Q.-Y. Wang, Xin Cui, William B. Frank, Yang Lu, Hirose Hirose, Obara Obara
- Abstract
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(s)
- Department of Meteorology and Geophysics
- External organisation(s)
- Massachusetts Institute of Technology, Tohoku University, University of Tokyo, University of Grenoble Alpes
- Journal
- Science Advances
- Volume
- 10
- ISSN
- 2375-2548
- DOI
- https://doi.org/10.1126/sciadv.ado1469
- Publication date
- 05-2024
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105122 Seismic
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/2daf810e-f100-4605-a40b-d54ed8a00215