1 Institute of Geophysics, China Earthquake Administration, Beijing 100081, China 2 Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China 3 Earthquake Administration of Tangshan City, Tangshan 063000, China 4 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 5 China Earthquake Networks Center, China Earthquake Administration, Beijing 100036, China
Characteristics of coseismic water level changes at Tangshan well for the Wenchuan MS8.0 earthquake and its larger aftershocks
1 Institute of Geophysics, China Earthquake Administration, Beijing 100081, China 2 Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China 3 Earthquake Administration of Tangshan City, Tangshan 063000, China 4 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 5 China Earthquake Networks Center, China Earthquake Administration, Beijing 100036, China
摘要Coseismic water level changes which may have been induced by the Wenchuan MS8.0 earthquake and its 15 larger aftershocks (MS≥5.4) have been observed at Tangshan well. We analyze the correlation between coseismic parameters (maximum amplitude, duration, coseismic step and the time when the coseismic reach its maximum amplitude) and earthquake parameters (magnitude, well-epicenter distance and depth), and then compare the time when the coseismic oscillation reaches its maximum amplitude with the seismogram from Douhe seismic station which is about 16.3 km away from Tangshan well. The analysis indicates that magnitude is the main factor influencing the induced coseismic water level changes, and that the well-epicenter distance and depth have less influence. MS magnitude has the strongest correlation with the coseismic water level changes comparing to MW and ML magnitudes. There exists strong correlation between the maximum amplitude, step size and the oscillation duration. The water level oscillation and step are both caused by dynamic strain sourcing from seismic waves. Most of the times when the oscillations reach their maximum amplitudes are between S and Rayleigh waves. The coseismic water level changes are due to the co-effect of seismic waves and hydro-geological environments.
Abstract:Coseismic water level changes which may have been induced by the Wenchuan MS8.0 earthquake and its 15 larger aftershocks (MS≥5.4) have been observed at Tangshan well. We analyze the correlation between coseismic parameters (maximum amplitude, duration, coseismic step and the time when the coseismic reach its maximum amplitude) and earthquake parameters (magnitude, well-epicenter distance and depth), and then compare the time when the coseismic oscillation reaches its maximum amplitude with the seismogram from Douhe seismic station which is about 16.3 km away from Tangshan well. The analysis indicates that magnitude is the main factor influencing the induced coseismic water level changes, and that the well-epicenter distance and depth have less influence. MS magnitude has the strongest correlation with the coseismic water level changes comparing to MW and ML magnitudes. There exists strong correlation between the maximum amplitude, step size and the oscillation duration. The water level oscillation and step are both caused by dynamic strain sourcing from seismic waves. Most of the times when the oscillations reach their maximum amplitudes are between S and Rayleigh waves. The coseismic water level changes are due to the co-effect of seismic waves and hydro-geological environments.
基金资助:National Natural Science Foundation of China (No. 40574020) and Basic Research item of Institute of Earthquake Science, China Earthquake Administration (No. 0207690236)
通讯作者:
Baojun Yin
E-mail: yinbaojun@seis.ac.cn
引用本文:
Baojun Yin, Li Ma, Huizhong Chen, Jianping Huang, Chaojun Zhang, Wuxing Wang. Characteristics of coseismic water level changes at Tangshan well for the Wenchuan MS8.0 earthquake and its larger aftershocks[J]. 《地震学报》英文版, 2009, 22(2): 149-157.
Baojun Yin, Li Ma, Huizhong Chen, Jianping Huang, Chaojun Zhang, Wuxing Wang. Characteristics of coseismic water level changes at Tangshan well for the Wenchuan MS8.0 earthquake and its larger aftershocks. Earthquake Science, 2009, 22(2): 149-157.