HR: 0800h
AN: S31A-0216    [Abstracts]
TI: Co-seismic strain changes inferred from the groundwater level in Chinese mainland induced by the 2004 Sumatra Earthquake
AU: * Huang, F
EM: hfqiong@seis.ac.cn
AF: China Earthquake Network Center, No.5 Nanhengjie Sanlihe Road The west district of Beijing, Beijing, 100045, China
AU: * Huang, F
EM: hfqiong@seis.ac.cn
AF: Institute of Geophysics, CEA, No.5 Minzudaxue Nanlu, Beijing, 100081,
AU: Chen, Y
EM: yongchen@seis.ac.cn
AF: China Earthquake Administration, No.63 Fuxing Avenue, Beijing, 100036,
AU: Yu, S
EM: yusheng@nsfc.gov.cn
AF: National Natural Science Foundation of China, No.88 Shuangqing Road, Beijing, 100085,
AU: Wu, Z
EM: wuzhl@gucas.ac.cn
AF: College of Earth Science, Graduate University of Chinese Academy of Science, No.19 Yuquan Road, Beijing, 100049,
AB: The 2004 great Sumatra earthquake induced prominent water level steps in at least 50 wells of the Earthquake Monitoring Network in Chinese Mainland. We compiled the water level data and analyzed the amplitude of the water level. We found that the amplitude of well water level changes was not consistent with the epicentral distance but the wells contributed along the tectonics. We use earth tides information recorded by water level to standardize the water level steps and name the standardized water level changes as equivalent strain. We found that the amplitudes of those equivalent strain changes showed prominent difference between the west and the east. The amplitudes in the west of China are larger than those in the east of China. We compared the equivalent strain of the well water level with the co-seismic surface displace measured by GPS, the result showed that the trends of them are consistent with each other. We compared the equivalent strain with the distribution of apparent stress in China which was inferred from the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue from January 1987 to December 1998 finished by Wu Zhongliang et al. in 2002. The amplitudes and their distribution are well consistent with each other. That means that the co-seismic strain from ground water was controlled by the tectonic stress state that was expressed by apparent stress, which can be as one of the mechanism of induced groundwater changes by remote earthquakes. Our conclusion is that the seismic induced groundwater changes can be as one of the approaches for active tectonic investigation. This research is supported by National Natural Science Foundation of China with Contracts No.40674024 and 40374019.
DE: 0994 Instruments and techniques
DE: 1895 Instruments and techniques: monitoring
DE: 7200 SEISMOLOGY
DE: 7294 Seismic instruments and networks (0935, 3025)
DE: 8123 Dynamics: seismotectonics
SC: Seismology [S]
MN: 2007 Fall Meeting