Volcano Type: Stratovolcano
Volcano Status: Historical
Last Known Eruption: 1995
Summit Elevation: 1307 m 4,288 feet
Latitude: 51.923°N 51°55’22″N
Longitude: 177.168°W 177°10’4″W
Symmetrical Kanaga stratovolcano is situated within the Kanaton caldera at the northern tip of Kanaga Island. The rim of Kanaton caldera forms a 760-m-high arcuate ridge south and east of Kanaga; a lake occupies part of the SE caldera floor. The volume of subaerial dacitic tuff is smaller than would typically be associated with caldera collapse, and deposits of a massive submarine debris avalanche associated with edifice collapse extend nearly 30 km to the NNW. Several fresh lava flows from historical or late prehistorical time descend the flanks of Kanaga, in some cases to the sea. Historical eruptions, most of which are poorly documented, have been recorded since 1763. Kanaga is also noted petrologically for ultramafic inclusions within an outcrop of alkaline basalt SW of the volcano. Fumarolic activity occurs in a circular, 200-m-wide, 60-m-deep summit crater and produces vapor plumes sometimes seen on clear days from Adak, 50 km to the east.
Kanaga is near the middle of the Aleutian Islands chain in the North Pacific ocean, in the Andreanof Islands. It’s a young stratocone in the middle of the ruins of an earlier volcano named Kanaton. Like most young and active volcanoes, it has a well-formed cone shape, and like all the Aleutian volcanoes it is the product of arc volcanism.
Kanaga Island is part of the Alaska Maritime National Wildlife Refuge. The volcano summit contains a small, circular crater 200 meters in diameter and 50-70 meters deep. Fumaroles are located in the crater and around the crater rim. Glacial ice is not present on the volcano or on other parts of Kanaga Island, but in winter there is substantial amounts of snow.
Originally posted 2010-08-21 05:01:04.
