סמינר בגיאופיזיקה: Earthquake swarms triggered by groundwater extraction near the Dead Sea Fault
Dr. Nadav Wetzler, Geological Survey of Israel
In 2013 and 2018, earthquake swarms with a maximum magnitude of 4.5 occurred within 5 km of the northern section of the Dead Sea Transform Fault. Here we show that aquifer pressure data, InSAR surface deformation time series and seismic monitoring suggest that groundwater withdraw triggered these earthquakes. Continuous groundwater extraction from several wells located ~10 km west of the swarms has accelerated since 2010 and resulted in a total decrease of ~50 m of the groundwater level at the time of the 2018 earthquake swarm. The withdrawal also corresponds to surface subsidence of ~10 mm/yr based on repeat InSAR measurements. The temporal correlation, extensive subsidence, anomalous swarm characteristics and normal faulting orientation all connect the groundwater withdrawal to the earthquakes. Poroelastic modeling demonstrates that pumping-induced pore pressure decrease west of the earthquake fault could have caused significant dilatational stresses that led to normal faulting events outside the aquifer.
מארגני הסמינר: פרופ' משה רשף וד"ר אלון זיו