Keisuke Yoshida
Associate Professor · Graduate School of Science, Tohoku University
I study how and why earthquakes happen — connecting earthquake repetition, rupture, and seismicity to the evolving stress, strength, and fluids in the Earth's crust.
Japan's recent earthquakes — the 2025 Aomori-oki and Sanriku-oki megathrust sequences and the 2024 Noto Peninsula earthquake — show how seismic and aseismic slip, crustal fluids, and the evolving stress field together control where and when earthquakes happen. I track this evolution by combining dense seismic observations with physical modeling, and openly share the resulting hypocenter catalogs, rupture models, and other datasets on the data page.
Two threads run through this work. One is a long-running study of repeating and quasi-repeating earthquakes as sensors of fault-state evolution — from the Mw 6.0–6.8 quasi-repeaters off Miyagi (Yoshida, 2023, JGR) to a systematic look at how rupture patterns respond to loading rate (Yoshida & Ide, 2025, GRL) and a re-examination of what counts as a true repeater versus an apparent one (Yoshida, 2025, JGR). The other is how ruptures propagate and stop as they cross heterogeneous stress and strength conditions — including rupture propagation across a stress-regime transition in the 2023 Mw 7.8 Kahramanmaraş earthquake (Yoshida, 2024, GJI) and the prevalence of updip rupture propagation along the Japan Trench (Yoshida et al., 2022, EPSL).
Highlights
The 2025 Mw 7.6 Aomori-oki megathrust sequence and a slip-parallel seismic belt to the trench.
Evolution of coupled seismic–aseismic slip during the 2025 Mw 6.8 Sanriku-oki sequence.
EPS special issue on the 2025 Mw 7.6 off-Aomori earthquake — open until 31 Mar 2027.
Featured
Recent publications
- Yoshida, K., 2026, Evolution of Coupled Seismic-Aseismic Slip During the 2025 Mw 6.8 Sanriku-Oki, Japan, Megathrust Sequence, .
- Yoshida, K., M. Uno, D. Bassett, 2026, The 2025 Mw 7.6 Aomori-Oki Megathrust Sequence and a Slip-Parallel Seismic Belt to the Trench, , 53, e2026GL122361, doi:10.1029/2026GL122361.
Related datasets
- Yoshida, K., M. Uno, D. Bassett, 2026, Data for the 2025 Mw 7.6 Aomori-Oki Earthquake Sequence: Relocated Hypocenters and Rupture Models, , doi:10.5281/zenodo.19963531.
- Yoshida, K., 2026, Data for the 2025 Mw 6.8 and Mw 6.4 Sanriku-Oki Earthquakes: Relocated Hypocenters, Rupture Models, and Strainmeter Data, , doi:10.5281/zenodo.19383821.
Research interests
- Earthquake cycles — repetition, energy radiation, stress drop, rupture patterns (directivity, complexity, slip evolution), and source time functions across a wide magnitude range. papers
- Stress fields and earthquake occurrence — causes, absolute values, and evolution of stress fields during earthquake cycles. papers
- Fluid processes and earthquake occurrence — swarm activity and large earthquakes, fluid migration after the 2011 M9 Tohoku earthquake, and the 2024 Noto Peninsula earthquake. papers
- Earthquake generation processes in Japan — papers