Work

Diverse Rupture Behaviors of M5 Earthquakes Reveal Heterogeneous Fluid Effects in Noto Peninsula, Central Japan

Year: 2025

Type: article

Abstract: The 15‐s‐long weak initial rupture of the 2024 M W 7.5 Noto earthquake overlapped with a fluid‐rich region of a preceding earthquake swarm and was accompanied by enhanced high‐frequency seismic radiation. To understand the radiation and related source processes, we investigate rupture behaviors of four nearby M5+ events. We find that the 5 May 2023 M W 5.7 event exhibits similar characteristic radiation, resulting in a relatively low source spectral decay rate. Apparent moment‐rate functions and dynamic rupture simulations, constrained from near‐source waveform data, consistently suggest a northeastward rupture with multiple asperities. Such rupture heterogeneities under a fluid‐rich condition can explain the weak, long seismic radiation but with enhanced high‐frequency signals in the M W 5.7 event and the initial rupture of the 2024 M W 7.5 Noto earthquake. The multi‐asperity model also holds implications for other observations, including the depth dependence of high‐frequency radiation and the low spectral falloff rates observed for low‐frequency earthquakes.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl117377

Authors: Suli Yao, Lingling Ye, Hongfeng Yang, Tao Xia

Institutions: Chinese University of Hong Kong, Southern University of Science and Technology, Chinese University of Hong Kong, Shenzhen

Language: English

Topic: earthquake and tectonic studies

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,190

Funder: National Natural Science Foundation of China