Dynamic poroelastic response of water level in Tengchong well aquifer to
seismic waves
Abstract
Key Points: • The frequency-dependent ratio of pore pressure/confining
pressure is obtained using the dynamic poroelasticity. •
Hydraulic-parameter estimation depends on the varied solid/fluid
coupling. • The dynamic responses of water level to seismic waves are
estimated across frequencies. Abstract Estimating the hydraulic
properties of subsurface aquifer is crucial to properly evaluating
groundwater resources. There are many methods for estimating aquifer
parameter using well water-level response using quasi static
poroelastic-ity. However, these approaches have ignored the possible
frequency-dependent solid/fluid coupling in the porous aquifer. In this
study, three great earthquakes (2011 Mw9.1 Tohoku, 2012 Mw 8.6 Sumatra,
and 2018 Mw7.6 Minahassa Peninsula) induced coseismic water-level
variations in Tengchong (TC) well are observed and estimated using
dynamic poroelasticity. Pore pressure/stress ratio across frequency
ranges may be switched, and the permeability is estimated and validated
in different frequency domains by the seismic-wave time series. The
predicted coseismic water levels due to the three great earthquakes are
better consistent than those using quasi static poroelasticity. The
method proposed in this study is useful to in evaluating the continuous
permeability variations by earthquakes and their aftershocks.