Mine Water Discharge and Flooding: A Cause of Severe Earthquakes

Abstract

Severe earthquakes can be triggered by dewatering and flooding of mines, as these activities alter the loading of the Earth’s crust and tectonic stresses in its interior. Worldwide, more than 200 studies have noted sites where human-induced stresses could have reactivated preexisting faults, triggering earthquakes with seismic moment magnitudes of up to M = 7 on the Richter scale. This can only occur where faults are already under high tectonic stresses that have built up over many years. Stable continental regions are seismically less active than unstable regions (e.g. California, Japan, and Turkey). Consequently, faults in stable continental regions can be more earthquake-trigger sensitive, since accumulated stresses have not reached failure conditions. This paper provides an overview of officially recognized mining-triggered earthquakes with magnitudes M ≥ 5.0. The article illuminates that these earthquakes can cause serious socio-economic losses with negative implications for the long-term sustainable development of countries abundant in natural resources and of mining regions, in particular. Historic data suggest that regional geological conditions (e.g. structural geology and tectonic in-situ stress states) are more important in forecasting the potential of earthquake triggering than the scale of the mining activities. Overall, such forecasts should be made to estimate and mitigate potential socio-economic earthquake risks associated with geoengineering operations of extractive industries such as mining.