The characteristics recognition of preseismic groundwater fluctuation in Dor-Her station, Taiwan
Abstract
Before the occurrences of earthquakes, the changes of groundwater level could reflect the redistribution of tectonic stress and crustal strain. This study analyzed the2003-2009data of groundwater level in observation wells of Dor-Her, and compared the data with the seismic records of magnitude over 5.0. The results showed that the groundwater level of Dor-Her observation station decreased at 60~100 days and then increased at 20~50 days prior to the occurrences of earthquakes. According to this feature indicator, it was found that the product of the increase magnitude (GW) prior to the earthquake is directly proportioned to the product of earthquake occurrence time (D) and earthquake magnitude (M), while it is inversely proportional to the hypocentral distance (R) high a correlation coefficient of 0.9 was found. This study further explored the impacts of seismic or fault activities on the groundwater levels for shallow-focus earthquakes with magnitudes over 5.0. The statistical analysis of the frequencies and magnitudes of groundwater-level shows concluded the characteristics of groundwater-level changes with the magnitudes of earthquakes. Keyword: earthquake, groundwater anomaly, characteristics recognition
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.S53A1958C
- Keywords:
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- 1800 HYDROLOGY