Comparative analysis on coseismic response of water level in Shandong Province to several major earthquakes

In the form of multi-well to multi-earthquake, six wells with good coseismic responses in the underground fluid observation network of Shandong Province are selected to analyze the coseismic variations of water level caused by the Japan M_W9.0 earthquake, the Sumatra M_W8.6 earthquake and the Nepal M_W7.8 earthquake. We analyze the characteristics in the aspects of type and amplitude, and discuss the response mechanism. The results show that the major type of coseismic variations is oscillation. With quantitative analysis, we find that the rise of Liaogu-1 water level is due to the increase of permeability coefficient of aquifer. The different types between Liaogu-1 well and Lu-27 well on the same fault zone are due to the different regional geological conditions and seismic activities. The water level coseismic variation type of Lu-07 well is affected by local tectonic stress. The amplitude of water level coseismic variation is related to the magnitude and the distance between well and epicenter, and also depends on the change of hydrogeological condition.