Report on Korovin (United States) — May 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 5 (May 1986)
Managing Editor: Lindsay McClelland.
Korovin (United States) Steam emission follows magnitude 7.7 earthquake
Please cite this report as:
Global Volcanism Program, 1986. Report on Korovin (United States). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 11:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198605-311161.
52.381°N, 174.166°W; summit elev. 1518 m
All times are local (unless otherwise noted)
[On 6 May], James Dickson noted a 500-m vertical steam plume over the SE part of the summit [of Korovin]. On 23 May at about 1730, Aleutian Air pilot Thomas Madsen noted a 600-m steam plume containing traces of ash rising above the rim of a 240-m-deep crater in the SE part of the summit area. A shallow magnitude 7.7 earthquake centered roughly 100 km [SSW] of Korovin at [51.52°N, 174.78°W] occurred 7 May [at 2247 GMT].
John Reeder and Kirk Swanson climbed [Korovin] in July 1983, observing only minor steaming from deep within the crater, rising to only 60 m above its floor.
Geologic Background. Korovin, the most frequently active volcano of the large volcanic complex at the NE tip of Atka Island, contains a 1533-m-high double summit with two craters located along a NW-SE line. The NW summit has a small crater, but the 1-km-wide crater of the SE cone has an unusual, open cylindrical vent of widely variable depth that sometimes contains a crater lake or a high magma column. A fresh-looking cinder cone lies on the flank of partially dissected Konia volcano, located on the SE flank. The volcano is dominantly basaltic in composition, although some late-stage dacitic lava flows are present on both Korovin and Konia.
Information Contacts: J. Reeder, ADGGS; T. Miller and M.E. Yount, USGS Branch of Alaskan Geology, Anchorage.