Eyal Shalev
Earthquake Hydrogeology
The mechanical interplay between pore pressure and stress is responsible for many geophysical processes before, during, and after an earthquake.
Pore pressure oscillations are shown to correlate with seismic waves and earth tides (Shalev et al., 2016a,b). The undrained short-term response of water levels includes water level oscillations and sustained level change is followed by the drained response of water levels that could take months (Lutzky et al., 2019). Prior to the earthquake, changes in groundwater pumping may trigger earthquakes (Wetzler et al., 2019). In these studies we use high precision sensors that record the water pressure in a high sampling rate in monitoring boreholes around Israel. The data is then processed with seismic data and modeled using poroelasticity and damage rheology.
See online water level data:
Sea Water Intrusions
The interrelation between the sea and coastal aquifers is of critical importance to the large human populations living in coastal areas. The interrelation involves the submarine ground water discharge of relatively fresh water to the sea and the intrusion of sea water into the aquifer, which impairs the quality of ground water. Many factors that affect the intrusion and the submarine discharge include: aquifer properties, pumping, tides, and storms. This research involves field study (Shalev et al., 2009; Levanon et al., 2013; Levanon et al., 2017), laboratory experiments (Oz et al., 2010; Oz et al., 2014; Oz et al., 2015; Levanon et al., 2019), and numerical simulations (Shalev et al., 2007; Yechieli et al., 2009; Yechieli et al., 2010; Kafri et al., 2013; Amir et al., 2013; Kafri et al., 2018; Paldor et al., 2019; Stein et al., 2019).
Poroelastic Damage Rheology Modelling
Rock deformation becomes non-linear at large strain. Damage rheology captures important features of different deformation regimes of brittle and ductile rock deformation and account for temporal evolution of rock properties (Shalev and Lyakhovsky, 2018). In addition, pore fluids add complexity to this already non-linear process (Shalev and Lyakhosky, 2013a). The formulation of the poroelastic damage model in a state of the art numerical method allows modelling complex processes such as: hydrofracturing, deformation bands, sinkhole formation, hysteresis, brittle-ductile failure (Shalev et al, 2013b; Gajst et al., 2018; Shalev and Lyakhovsky, 2012; Baer et al., 2018; Lyakhovsky et al., 2015)
