Hydrological response to multiple large distant earthquakes in the Mile well, China

Abstract

Groundwater level changes of up to 0.716 m and temperature changes of up to 0.0708°C have been observed in the Mile well, Yunnan Province, China, in response to earthquakes with a seismic energy density exceeding 1 × 10 À3 JÁm À3 from 2004 to 2012. Sustained water level changes, however, only occurred in earthquakes with a surface wave magnitude M s ≥ 8.0. Groundwater temperature and permeability changes also only occurred following such large earthquakes. This indicates that larger earthquakes (with M s ≥ 8.0) are more effective at triggering hydrologic responses than smaller earthquakes. The amplitudes of changes in groundwater level and groundwater temperature were positively correlated, indicating that temperature changes are possibly caused by advection-diffusion and mixing following groundwater inflows into the well. We used a tidal response as a proxy to investigate aquifer properties, showing that the changes in groundwater level and temperature correlate well with phase shift and tidal factor. Based on the aquifer parameters calculated from the tidal response using the M 2 wave, we found that amplitudes of inferred changes in transmissivity and storage coefficient have a positive relationship with the groundwater level and temperature changes. The scale of transmissivity change was much larger than that of the storage coefficient. We interpret the co-seismic changes in groundwater level and temperature in the Mile well to be due to changes of permeability in the aquifer due to unclogging of fractures induced by seismic waves.

Fault Zone Permeability Decrease Following Large Earthquakes in a Hydrothermal System

“…The mechanisms proposed to explain earthquake‐related hydrological responses are associated with earthquake‐induced changes in aquifer parameters, especially for coseismic hydrological responses beyond the near field (Mohr et al, ; Shi et al, ; Yan et al, ). Most documented permeability changes in the field show permeability enhancement of different magnitudes (Elkhoury et al, ; Lai et al, ; Liao et al, ; Rojstaczer et al, ; Shi & Wang, ; Wang et al, ). Thus, hydrogeologists, geophysicists, and oil reservoir engineers tend to take permeability enhancement as an important factor in many engineering applications such as evaluating the risk of earthquakes affecting subsurface waste repositories (Carrigan et al, ), the safety of the water supply (Mohr et al, ), increasing oil well production (Beresnev & Johnson, ), triggering seismicity (Hill & Prejean, ), and geothermal exploitation (Elkhoury et al, ).…”

Aquifers switched from confined to semiconfined by earthquakes

“…Changes in groundwater level [ Shi et al ., ; Wang and Chia , ], stream flow [ Manga et al ., ; Mohr et al ., ], water temperature [ Wang et al ., ], and chemical composition [ Claesson et al ., ; Skelton et al ., ] are the most widely documented hydrological responses to earthquakes. Various mechanisms have been proposed to explain these phenomena: (1) groundwater level changes are always associated with changes in aquifer parameters (permeability or storativity) through unclogging/clogging of temporary barriers [ Brodsky et al ., ], elastic deformation [ Jang et al ., ; Wang and Chia , ], or rupture of the aquifer [ Wang et al ., ; Ward , ]; (2) stream flow changes following earthquakes are associated with permeability enhancement [ Rojstaczer et al ., ; Wang and Manga , ; Wang et al ., ] or coseismic consolidation/liquefaction of sediments [ Manga et al ., ; Montgomery et al ., ]; (3) water temperature changes are attributed to earthquake‐induced permeability changes and the resultant mixing of different water [ Mogi et al ., ; Shi and Wang , ]; and (4) changes in chemical composition have been attributed to the rupturing of hydrological barriers between chemically distinct aquifers, permitting rapid mixture [ Claesson et al ., ; Skelton et al ., ].…”

Seismological and Hydrogeological Controls on New Zealand-Wide Groundwater Level Changes Induced by the 2016 Mw7.8 Kaikōura Earthquake

“…A notable exception are the geoengineered schist landslides in Cromwell Gorge [34], which have fracture permeability and water tables that have been displaced from their natural condition by drainage tunnels. In contrast to these examples from New Zealand, many international studies of earthquake hydrology provide datasets on aquifers in well-consolidated and crystalline rocks (e.g., [35][36][37]).…”