Sensitivity of hydraulic properties to dynamic strain within a fault damage zone

Seismic Waves Could Decrease the Permeability of the Shallow Crust

“…Both static and dynamic stresses are likely to cause permeability changes (Brodsky et al, 2003;Elkhoury et al, 2006;Liao et al, 2015;Manga et al, 2012;Manga & Brodsky, 2006;Rojstaczer et al, 1995;Xue et al, 2013;Yan et al, 2016). Since the static strain caused by an earthquake is too small The permeability k is related to the transmissivity (T) by k = Tμ/ρgd, where μ is the fluid dynamic viscosity, ρ is the density of the fluid, g is the acceleration due to gravity, and d is the thickness of the open interval of the well.…”

“…Dozens of wells constructed as components of a nationwide network of groundwater monitoring wells in China are located on or near the Tan-Lu fault; these wells were designed to monitor possible changes in the water level that could serve as earthquake precursors. These sensors can record measurements ranging from 0 to 10 m with a resolution of 1 mm (Yan et al, 2016). The water level in the Junan well is recorded by LN-3A digital instruments with a sampling interval of 1 min, while the water level in the Dingyuan well is observed by SW40-1 instruments with a sampling interval of 1 hr.…”

“…Earthquakeinduced enhancements in permeability have been widely observed in both the field and the laboratory (Brodsky et al, 2003;Elkhoury et al, 2006;Faoro et al, 2012;Ingebritsen, 1998;Manga & Brodsky, 2006;. In addition, some studies have indicated that earthquakes could decrease permeability (Shi et al, , 2018Yan et al, 2016). In addition, some studies have indicated that earthquakes could decrease permeability (Shi et al, , 2018Yan et al, 2016).…”

Fault Zone Permeability Decrease Following Large Earthquakes in a Hydrothermal System

“…Many previous studies document that fault zone properties will change under the static and dynamic stresses produced by earthquakes (Kinoshita et al, ; Kitagawa et al, ; Shi et al, ; Xue, ), which will cause changes in subsurface transport (Wang et al, ). Such changes can be captured and observed through monitoring the variation in physical and chemical parameters in groundwater wells and springs (Manga & Rowland, ; Yan et al, ). Thus, monitoring the hydrological changes in fault zones provides a way to obtain the spatial and temporal changes of fault zone properties in response to earthquakes and other tectonic activities.…”

Heterogeneous Permeability Changes along a Fault Zone Caused by the Xingwen M5.7 Earthquake in SW China

“…It is well known that earthquakes can result in changes to the well water level or spring flow (Rojstaczer et al, ; Skelton et al, ; Manga & Wang, ; Shi & Wang, ), with these changes reflecting interactions between tectonic activities and hydrological systems (Manga et al, ; Shi, Wang, et al, ; Wang & Barbour, ). Studies have shown that static or dynamic stresses generated during earthquake genesis and occurrence can cause permeability changes to fault zones (Kinoshita et al, ; Kitagawa et al, ; Shi et al, ), which in turn cause changes in groundwater flow conditions (Wang et al, ), thus making it possible to effectively obtain permeability changes of fault zones by monitoring changes in the well water level or the spring flow in faults (Manga & Rowland, ; Yan et al, ).…”