Details

Autor(en) / Beteiligte

• Scott, William E
• Nye, Christopher J
• Waythomas, Christopher F
• Neal, Christina A

Titel

August 2008 Eruption of Kasatochi Volcano, Aleutian Islands, Alaska—Resetting an Island Landscape

Ist Teil von

• Arctic, antarctic, and alpine research, 2010-08, Vol.42 (3), p.250-259

Ort / Verlag

UCB 450, University of Colorado, Boulder, Colorado 80309-0450, U.S.A: The Institute of Arctic and Alpine Research

Erscheinungsjahr

2010

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• Kasatochi Island, the subaerial portion of a small volcano in the western Aleutian volcanic arc, erupted on 7–8 August 2008. Pyroclastic flows and surges swept the island repeatedly and buried most of it and the near-shore zone in decimeters to tens of meters of deposits. Several key seabird rookeries in taluses were rendered useless. The eruption lasted for about 24 hours and included two initial explosive pulses and pauses over a 6-hr period that produced ash-poor eruption clouds, a 10-hr period of continuous ash-rich emissions initiated by an explosive pulse and punctuated by two others, and a final 8-hr period of waning ash emissions. The deposits of the eruption include a basal muddy tephra that probably reflects initial eruptions through the shallow crater lake, a sequence of pumiceous and lithic-rich pyroclastic deposits produced by flow, surge, and fall processes during a period of energetic explosive eruption, and a fine-grained upper mantle of pyroclastic-fall and -surge deposits that probably reflects the waning eruptive stage as lake and ground water again gained access to the erupting magma. An eruption with similar impact on the island's environment had not occurred for at least several centuries. Since the 2008 eruption, the volcano has remained quiet other than emission of volcanic gases. Erosion and deposition are rapidly altering slopes and beaches.