Groundwater Level Changes in the Chinese Mainland Following the 2011 Tohoku Japan Earthquake and the 2015 Gorkha Nepal Earthquake
Session: New Insights Into the Preparatory Phase of Earthquakes From Tectonic, Field and Lab Experiments [Poster]
Type: Poster
Date: 4/19/2021
Presentation Time: 03:45 PM Pacific
Description:
Groundwater level oscillations, or step-like rises and step-like drops were recorded in 184 wells throughout the Chinese mainland due to the 2011 Tohoku Japan earthquake, and 159 wells for the 2015 Gorkha Nepal earthquake. The earthquake magnitude, and the associated dynamic stresses, has positive roles in both the sensitivity of water level to earthquake induced change, and the amplitude and duration of resulting coseismic water level changes. Wells whose water levels are sensitive to Earth tides have high potential to response to earthquakes. Polarities of step-like changes (rises or drops) are locally controlled and spatially variable, with artesian wells generally recording water-level rises. Permeability enhancement was assessed as a mechanism responsible for step-like changes by analyzing the tidal phase responses. Permeability variations are inferred for 32 out of 105 wells with step-like changes during the Tohoku earthquake and for 17 out of 95 wells following the Gorkha earthquake; however, only 6 wells have permeability variations after both earthquakes.
Presenting Author: Yuchuan Ma
Student Presenter: No
Authors
Yuchuan Ma Presenting Author Corresponding Author mayuchuan@seis.ac.cn China Earthquake Networks Center |
Qiong Huang hfqiong@seis.ac.cn China Earthquake Networks Center |
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Groundwater Level Changes in the Chinese Mainland Following the 2011 Tohoku Japan Earthquake and the 2015 Gorkha Nepal Earthquake
Category
New Insights Into the Preparatory Phase of Earthquakes From Tectonic, Field and Lab Experiments