Mechanism of co-seismic water level change following four great earthquakes – insights from co-seismic responses throughout the Chinese mainland

Journal Article · Mon Aug 24 00:00:00 EDT 2015 · Earth and Planetary Science Letters

DOI:https://doi.org/10.1016/j.epsl.2015.08.012· OSTI ID:1480696

Shi, Zheming ^[1]; Wang, Guangcai ^[1]; Manga, Michael ^[2]; Wang, Chi-Yuen ^[2]

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1. China University of Geosciences, Beijing (China). School of Water Resources and Environment and MOE Key Laboratory of Groundwater Circulation and Environment Evolution & State Key Laboratory of Biogeology and Environmental Geology
2. Univ. of California, Berkeley, CA (United States). Department of Earth and Planetary Science

In this study, we analyze the co-seismic groundwater level responses to four great earthquakes recorded by China's network of groundwater monitoring wells. The large number of operational wells (164 wells for the 2007 Mw 8.5 Sumatra earthquake, 245 wells for the Mw 7.9 Wenchuan earthquake, 228 wells for the Mw 9.0 Tohoku earthquake and 223 wells for 2012 Mw 8.6 Sumatra earthquake) and co-seismic responses provide an opportunity to test hypotheses on mechanisms for co-seismic water level changes. Overall, the co-seismic water level responses are complex over large spatial scales, and there is great variability both in the sign and amplitude of water level responses in the data set. As shown in previous studies, permeability change, rather than static strain, is a more plausible mechanism to explain most of the co-seismic responses. However, we find through tidal analysis of water level responses to solid Earth tide that only one third of these wells that showed a sustained post-seismic response can be explained by earthquake-induced permeability change in aquifers, and these wells had sustained (>30 days) water level changes. Lastly, wells that did not show sustained changes are more likely affected by permeability changes only immediately adjacent to the wellbore.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1480696
• Journal Information: Earth and Planetary Science Letters, Journal Name: Earth and Planetary Science Letters Journal Issue: C Vol. 430; ISSN 0012-821X
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
hydrological responses to earthquakes
monitoring wells
permeability changes
tidal analysis