Earthquake activity has allowed the identification of a candidate magma reservoir beneath Pampa Sepina northeast of Sabancaya about away from the summit. Between 1992 and 1996 this area inflated at a depth of below sea level, indicating that the magma supply system of Sabancaya may not be centered directly below the volcano. Indeed, a phase of ground uplift at Hualca Hualca volcano and earthquake swarms in 1990 could indicate that the magma chamber of Sabancaya is actually under the neighbouring volcano.