Skip to main content

Geology of Kasatochi volcano, Aleutian Islands, Alaska


Publication Date
Start Date
End Date
File Modification Date
2017-08-08 12:08:00


Nye, C.J., Scott, W.E., Neill, O.K., Waythomas, C.F., Cameron, C.E., and Calvert, A.T., 2017, Geology of Kasatochi volcano, Aleutian Islands, Alaska: Alaska Division of Geological & Geophysical Surveys,


Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The 2008 eruption enlarged [...]


Attached Files

Click on title to download individual files attached to this item.


Kasatochi volcano is located at the intersection of the flat, shallow Aleutian platform and the Bering slope rise, an area of high biologic productivity. As a result, the island hosts a large sea lion colony and nesting sites for hundreds of thousands of seabirds. A large eruption in 2008 blanketed the island in pyroclastic deposits, covering nesting sites and almost all existing vegetation. A multidisciplinary effort to document recovery of the ecosystem was initiated, and this study of the geology of the island was undertaken as part of that effort. This study is the first to document the geology of the entire island, and presents a snapshot of the island early in its response to the 2008 eruption.

Additional Information


Type Scheme Key

Item Actions

View Item as ...

Save Item as ...

View Item...