Changes in Permeability Caused by Two Consecutive Earthquakes—Insights From the Responses of a Well‐Aquifer System to Seismic Waves

Abstract

Earthquake‐induced aquifer permeability changes have been observed both in the laboratory and the field. However, the effects of multiple earthquakes on aquifer systems have rarely been differentiated. In this study, we analyze the piezometric response to earthquake pairs that occurred on the same day. The results show that events with higher seismic energy may result in a rise in piezometric level, and the seismic waves enhanced the permeability of the aquifer by different magnitudes. Stress/strain history from consecutive earthquakes may be retained, and permeability increased much more following the second earthquake than the first one. The method proposed in this study is useful in evaluating the permeability enhancement induced by consecutive earthquakes. The stress/strain memory of aquifers also has important implications for understanding aftershocks.

Frequency Dependence of In Situ Transmissivity Estimation of Well‐Aquifer Systems From Periodic Loadings

“…Since the actual transmissivity of the Jingle (estimated from pumping test) is higher than the upper limit of the tidal response model, the value obtained from the tidal response is significantly lower than the value obtained from coseismic response. Similar results were found in well X10; the transmissivity estimated from the coseismic response and pumping test (Sun, Xiang, & Shi, 2019) was 2 orders of magnitude higher than the value from the tidal response (Sun et al, 2018). Based on the understanding of frequency saturation, if the actual transmissivity is close to or lower than the upper limit, the value estimated from coseismic and tidal response should be similar.…”

“…Wang et al (2018) also attempted to determine the vertical leakage and transmissivity using the earth tide response of the well water level given by the leakage model of a semiconfined aquifer. The above methods have been widely applied in studies of coseismic water level response (Elkhoury et al, 2011; Shi et al, 2015; Sun et al, 2015), assessment of strain sensitivity of the well‐aquifer system (Sun, Xiang, Shi, Hu, et al, 2019; Yan et al, 2016, the earthquake‐induced variation of shallow crust permeability (Liao et al, 2015; Shi et al, 2018; Sun, Xiang, & Shi, 2019; Wang et al, 2016), and inversion of the aquifer permeability parameters (Elkhoury et al, 2006; Shi & Wang, 2016; Shi et al, 2019).…”

Earthquakes and extreme rainfall induce long term permeability enhancement of volcanic island hydrogeological systems

“…The permeability increase highlighted over the last twelve years is corroborated over geological ages thanks to the statistical analysis of existing pumping tests data in comparable aquifers of the island. Since we highlight over twelve years that permeability globally increase over the period, but that some earthquakes can also decrease permeability, it follows that permeability decrease should be transient because of: i) the tropical climate with hurricane and extreme rainfall regularly flushing particles and thus unclogging fractures, ii) the possible effect of successive earthquakes (as in 2018), considering that stress/strain from consecutive earthquakes may generate a stronger permeability increase following the second earthquake 54 , and iii) on a long-term scale, earthquakes increasing permeability may be more numerous than earthquakes decreasing permeability, with possible azimuthal 27 and compression/extension effects dependences.…”

Response to Tides, Barometric Pressure and Seismic Waves

“…where θ o = −0.92k(u 3 ) o and (u 3 ) o is the amplitude of the vertical displacement of the Rayleigh waves. Sun et al (2018Sun et al ( , 2019 interpreted the water-level oscillations in response to seismic waves to estimate the aquifer parameters based on Cooper's model (1965) which shows that the amplitude ratio and the phase shift of water-level oscillations response to Rayleigh waves have the following expressions for the amplitude ratio and the phase shift of the response…”

“…It has been known for a long time that groundwater responds to seismic waves (e.g., Byerly and Blanchard 1935). Some recent efforts have made use of this response to estimate aquifer properties (Barbour et al 2019;Shih 2009;Sun et al 2019Sun et al , 2020, based on a model developed by Cooper et al (1965). Such efforts may provide useful understanding on the dependence of aquifer properties on the frequency of the forcing mechanisms.…”