Combining Electrical Sounding and Tomography to Explain Artesian Aquifer Spring in Andesitic Volcanic Setting

Summary A multidisciplinary study combines geophysical measurements (electrical soundings and electrical resistivity tomographies) and hydrogeological surveys (springwater electrical conductivity, spring discharge). It allows to describe the geological structure of artesian aquifer spring context in the slopes of an andesitic stratovolcano on Java Island, Indonesia. A typical interpreted geophysical vertical section shows a resistive substratum (the artesian aquifer) underlying a conductive layer (impervious lahar deposits). The hydrogeophysical results show that the artesian aquifer extends below the entire surficial watershed, and is everywhere sealed by an impermeable, clayed confining roof.