Seasonal Modulation of Crustal Seismicity in Northeastern Japan Driven by Snow Load

Technical Report · Thu Feb 29 04:00:00 EST 2024

DOI:https://doi.org/10.2172/2386903· OSTI ID:2386903

Ueda, Taku ^[1]; Kato, Aitaro ^[2]; Johnson, Christopher William ^[3]; Terekawa, Toshiko ^[4]

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1. Kyoto Univ. (Japan)
2. Univ. of Tokyo (Japan)
3. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
4. Nagoya Univ. (Japan)

Numerous studies have reported that surface hydrological loading can seasonally modulate seismicity rates at crustal depths. For example, substantial winter snow accumulation occurs across the Japanese Islands, and these snowy regions appear to have seasonally modulated the occurrence of previous large inland earthquakes. Therefore, it is important to investigate the impact of seasonal stress changes on crustal seismicity to deepen our understanding of earthquake generation. Here we constrain seasonal changes in the surface load across northeastern Japan using Global Navigation Satellite System surface displacements and evaluate the potential relationship between temporal trends in inland seismicity and estimated seasonal stress changes. The spatial distribution of the seasonal surface load is consistent with snow depth along the Sea of Japan. The inland seismicity beneath northeastern Japan is modestly modulated by the seasonal stress changes that are induced by the annual snow load. However, this seasonal response is weaker than that in other regions. This weak modulation may be due to the small surface-load-induced stress perturbation relative to the long-term-averaged stressing rate and/or the limited presence of crustal fluids to trigger seismicity in Japan.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); USDOE National Nuclear Security Administration (NNSA); Japan Society for the Promotion of Science (JSPS)
• DOE Contract Number: 89233218CNA000001
• OSTI ID: 2386903
• Report Number(s): LA-UR--23-32608
• Country of Publication: United States
• Language: English

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58 GEOSCIENCES