Intermediate-field hydrogeological response induced by L’Aquila earthquake: the Acque Albule hydrothermal system (Central Italy)

Using groundwater level data recorded in six piezometers in the Acque Albule Basin (Tivoli travertine quarry area) and in the Cornicolani Mts (Pozzo del Merro shaft), the intermediate-field hydrological response to the 6th April 2009 L’Aquila earthquake (Mw 6.3) has been studied. The hydrogeological setting of the Tivoli area is characterized by two superimposed aquifers, the deep one is in carbonate rocks, the shallow one is in travertine rocks. Has been observed that in five piezometers located in the travertine quarry area the groundwater level contemporary decreased exactly at the time of the L’Aquila earthquake occurrence, while there is a slight increase of level in the Pozzo del Merro karst lake located in the carbonate aquifer. A conceptual model to explain those variations has been proposed, assuming that the variations in groundwater level are given by variation of permeability in the aquifers caused by the dynamic stress change, at the seismic waves passage.