Report on Korovin (United States) — March 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 3 (March 1987)
Managing Editor: Lindsay McClelland.
Korovin (United States) Ash eruption from Korovin summit and two nearby vents
Please cite this report as:
Global Volcanism Program, 1987. Report on Korovin (United States). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 12:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198703-311161.
52.381°N, 174.166°W; summit elev. 1518 m
All times are local (unless otherwise noted)
On 18 March at 1954 a NOAA 10 satellite image showed three distinct plumes, each 95 km long, drifting ENE. The estimated vent locations were: 52.38°N, 174.15°W (Korovin's summit); 52.31°N, 174.24°W; and 52.29°N, 174.21°W (5.5 km WSW and 6.5 km SW of Mt. Kliuchef, a cone on Korovin's S flank). More accurate locations will be determined by USGS Anchorage. Just before midnight on the same day US Navy pilot Jeffrey Sullivan observed a southward-drifting ash plume rising to at least 3,000 m altitude, lit by an orange "flame" from Korovin. Smaller orange flickering "flames" from two other vents at lower elevation were visible. Two of the vents were ~2 km apart and the third vent was ~10 km NE of the other two vents.
Earlier in the day (at 1300) Julie Dirks and other Atka residents noticed sulfur smells (~18 km from the volcano). Although the weather was clear Dirks did not notice any "unusual" eruptive activity. On 19 March a SIGMET notice was issued to warn pilots of volcanic ash 185 km on either side of a line from 52°N, 175°W to 54°N, 172°W. The warning remained in effect until 0930. Pilots reported that the ash cloud reached 3,600 m.
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; M. Matson, NOAA/NESDIS; T. Miller, USGS, Anchorage.