Akutan contains a 2 km-wide caldera formed during a major explosive eruption about 1600 years ago.Recent eruptive activity has originated from a large cinder cone on the NE part of the caldera.It has been the source of frequent explosive eruptions with occasional lava effusion that blankets the caldera floor.A lava flow in 1978 traveled through a narrow breach in the north caldera rim to within 2 km of the coast.The volcano erupted most recently in 1992, but there is still fumarolic activity at the base of Lava Point and there are hot springs North-East of the caldera.