Continental-scale water-level response to a large earthquake
Co‐seismic groundwater‐level changes induced by earthquakes have been reported for thousands of years. The M8.0 Wenchuan earthquake caused co‐seismic groundwater‐level responses across the Chinese mainland. Three types of changes were recorded in 197 monitoring wells: co‐seismic oscillations ranging...
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Published in | Geofluids Vol. 15; no. 1-2; pp. 310 - 320 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Chichester
Blackwell Publishing Ltd
01.02.2015
Hindawi Limited |
Subjects | |
Online Access | Get full text |
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Summary: | Co‐seismic groundwater‐level changes induced by earthquakes have been reported for thousands of years. The M8.0 Wenchuan earthquake caused co‐seismic groundwater‐level responses across the Chinese mainland. Three types of changes were recorded in 197 monitoring wells: co‐seismic oscillations ranging in amplitude from 0.004 to 1.1 m, immediate co‐seismic step changes ranging from 0.0039 to 9.188 m, and more gradual postseismic changes ranging from 0.014 to 1.087 m. We find that the co‐seismic groundwater‐level response is complex. There is neither a clear relationship between the response amplitude and the distance from the epicenter, nor a clear relationship between the groundwater response and lithology at the continental scale. Both the sign and amplitude of water‐level changes are random at the continental scale, and a poroelastic response to the co‐seismic static strain cannot explain most of the co‐seismic changes. However, wells located near the edges of tectonically active blocks have larger response amplitudes than those in the middle of these ‘stable’ blocks. Considered together, these observations indicate that permeability enhancement caused by the earthquake is a significant or dominant mechanism causing water‐level changes. These data indicate that large earthquakes can cause the widespread permeability changes in the shallow crust although the magnitude of permeability change is uncertain.
We report the co‐seismic groundwater level response to the M8.0 earthquake across the Chinese mainland. There is great variability in the relationship between water level changes, and epicentral distance or static strain. Permeability enhancement in the crust caused by the earthquake is a significant or dominant mechanism in causing water level changes. |
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Bibliography: | China Scholarship Council Table S1. Well information for 197 groundwater wells which show co-seismic response to the 2008 M8.0 Wenchuan earthquake. National Natural Science Foundation of China - No. 40930637; No. 41272269 US National Science Foundation The Specialized Research Fund for the Doctoral Program of Higher Education of China - No. 20100022110001 ark:/67375/WNG-FFMJLL0Z-S Fundamental Research Funds for the Central Universities - No. 2652013088 istex:A448B0185DDD195055AF10D15D3396D8FEE316E7 ArticleID:GFL12099 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 AC02-05CH11231 National Science Foundation (NSF) |
ISSN: | 1468-8115 1468-8123 |
DOI: | 10.1111/gfl.12099 |