Monday, Jan 21, 2013
Occasional small local earthquakes have been recorded recently. [more]
Makushin volcanoMakushin volcano is an ice-covered 1800-m-high stratovolcano on northern Unalaska Island west of the town of Dutch Harbor. The volcano contains a 2.5-km-wide caldera. Its broad, domical shape contrasts with the usual steep-sided profile of most other volcanoes in the Aleutians.
Background:Much of the volcano was formed during the Pleistocene, but the caldera (which formed about 8000 years ago), Sugarloaf cone on the ENE flank, and a cluster of about a dozen explosion pits and cinder cones at Point Kadin on the WNW flank, are of Holocene age. A broad band of NE-SW-trending satellitic vents cuts across the volcano. The composite Pakushin cone, with multiple summit craters, lies 8 km to the SW of Makushin. Frequent explosive eruptions have occurred during the past 4000 years, sometimes accompanied by pyroclastic flows and surges. Geothermal areas are found in the summit caldera of Makushin and on the SE and eastern flanks of the volcano. They represent the largest and most investigated high-temperature geothermal resources in Alaska. Small-to-moderate explosive eruptions have been recorded at Makushin since 1786.
Smithsonian / GVP volcano information