Tsunamis are short term events, but impacts on human infrastructure and environment can be severe and enduring. Especially coastal freshwater resources, most often the source of public and private water supplies, are vulnerable to the imprint of saltwater that comes along with the tsunami flooding event. Secondary impacts on the groundwater system involve the potential displacement or disturbance of the freshwater-saltwater interface or balance below the shore due to the incoming force and increased hydraulic pressure of the waves.
Below the surface, earthquakes open fractures that can release and shift gases and fluids, discharging groundwater from aquifers and altering streamflow on the surface. Additionally earthquakes can temporarily expose groundwater to pollution and change its composition.