Observations of this volcano and neighbouring Lastarria indicate that they are part of an actively deforming system , named by Pritchard and Simons ( 2002 ) the Lazufre system with an axis length of . The modelled centre of deformation is closer to Azufre than Lastarria . Sometimes Cerro Bayo Gorbea is also associated to this complex . This inflation started in the late 1990s and is probably due to the accumulation of volcanic fluids ( hydrothermal or magmatic ) beneath the volcanic system . The precise date when the uplift started is unclear , because satellite observation of the area is scarce . The start of the uplift may be related to an earthquake in Chile in 1998 , but this is questionable . Aftershocks of the 1995 Antofagasta earthquake may be responsible instead . Between 1998 and 2000 the long axis of deformation amounted to , with a later increase to . In 2008 the area had already reached a diameter of and surface area of . In 2015 deformation was observed over a surface of , at depths and with speeds of until 2010 . This uncertainty is largely because estimates trade off between depth , pressure and shape of the deformation . Research in 2016 indicated that the uplift dome has a diameter of . Since 2005 uplift speeds of have been observed with InSAR and a magma flux rate of has been inferred . Other research has indicated an inflation rate of , comparable with other plutons in the area . One estimate in 2009 indicated a depth . Another estimate in 2016 indicated a chamber depth of
1995 Antofagasta earthquake
1995 Antofagasta earthquake
Cordón del Azufre