It has not erupted since 1859, only an instant in terms of geological time. An earthquake swarm was measured near Cosigüina in 2002, indicating that tectonic forces are still active in the region although the volcano is somewhat isolated from the line of more recently active Central American volcanoes to the northwest and southeast. The only indicators of hydrothermal activity at the volcano are intermittently observed gas bubbles in Laguna Cosigüina and a hot spring along the eastern flank of the volcano. The fairly uniform vegetation cover on the volcano's sides also attests to a general lack of gas emissions or hot spots on the 872-meter-high cone.