HR: 16:00h
AN: S24A-01    [Abstracts]
TI: Observations of Water-Level Fluctuations Induced by Local and Distant Earthquakes at Two Wells in Hualien, Eastern Taiwan
AU: Liu, C
EM: cliu@ms01.dahan.edu.tw
AF: Institute of Geophysics, National Central University, No.300, JungDa Road, Chung-Li, 320 Taiwan
AU: Liu, C
EM: cliu@ms01.dahan.edu.tw
AF: Department of Civil Engineering, Dahan Institute of Technology, No.1, Shuren St., Sincheng Township, Hualien, 971 Taiwan
AU: Huang, M
EM: mwhuang@earth.sinica.edu.tw
AF: Institute of Geophysics, National Central University, No.300, JungDa Road, Chung-Li, 320 Taiwan
AU: * Tsai, Y
EM: yibentsai@gmail.com
AF: Geosciences Department, Pacific Gas and Electric Company, Geosciences Department, Pacific Gas and Electric Company, San Francisco, CA 94177 United States
AU: Lee, C
EM: cplee@earth.sinica.edu.tw
AF: Institute of Earth Sciences, Academia Sinica, No.128, Section 2, Academia Road, Nakang, Taipei, 115 Taiwan
AB: Sustained water level fluctuations may occur in response to local changes of volumetric strain associated with passage of seismic waves or ground deformation. Two wells, namely HLC-05 and HLC-03, with high sampling rates (1 and 6 second) have been deployed for the purpose of monitoring the dynamic response of water level and static steps induced by earthquakes in Hualien area, eastern Taiwan since 2002. Through our observations, we have found the following results. (1) The water level changes may occur with earthquakes of magnitude M>=0.43+2.39log10(D), where D is the distance from the well; (2) the peak water level fluctuations (PWL) are apparently proportional to the peak ground velocity (PGV) and peak ground displacement (PGD) on logarithmic scales, but no clear trend with the peak ground acceleration (PGA). We performed regression to obtain the relationships between PWL and PGV, and PWL and PGD, respectively, as follows: For the HLC-05 well: ln(PWL)=0.83­¥ln(PGVH)-3.22, ln(PWL)=0.97­¥ln(PGVV)-2.27, ln(PWL)=0.80­¥ln(PGDH)-1.70, ln(PWL)=0.91­¥ln(PGDV)-0.83 For the HLC-03 well: ln(PWL)=0.73­¥ln(PGVH)-3.29, ln(PWL)=0.73­¥ln(PGVV)-2.65, ln(PWL)=0.53­¥ln(PGDH)-2.44, ln(PWL)=0.57­¥ln(PGDV)-1.93 where the subscripts H and V represent the horizontal and the vertical component, of ground motion respectively.
DE: 1829 Groundwater hydrology
DE: 7200 SEISMOLOGY
DE: 7212 Earthquake ground motions and engineering seismology
SC: Seismology [S]
MN: Fall Meeting 2005