 Since 1772, only small phreatic eruptions were recorded before an explosive eruption that began in November 2002.More recently, the volcano has been quite active.On August 13, 2011 the volcano's early warning status was lifted from Level II, "Vigilant" () to Level III, "Alert" () following the swarm of long-period events, the increase of volcano tectonic earthquake rate, and an extremely high percentage (100%) of measured carbon dioxide gas in the ground at the summit crater.