Alaska Volcano Observatory (AVO)
ALASKA VOLCANOES UPDATE
February 13, 1997, 12:30 pm AST (2130 UTC)
A small eruption began this morning at Okmok volcano on Umnak Island, in the eastern Aleutian Islands, about 75 miles west-southwest of Dutch Harbor. AVO received a report from observers at the former Fort Glenn military base at the east end of the island at 10:46 am AST that an ash plume began rising from a cone inside the caldera at about 10 am AST. The dark plume rose to about 5,000 feet ASL (average sea level), was carried to the southwest by prevailing winds and was described as dissipating somewhat at the time of the call. Satellite images from 5 am and 10:30 am AST show a hot spot in the vicinity of a cone along the south rim of the caldera. AVO does not have seismic monitoring equipment on the island and therefore at this time is not instituting a color code designation.
Okmok volcano is a 6-mile-wide caldera that occupies most of the eastern end of Umnak Island that has had several eruptions in historic time. Historic eruptions typically consist of ash emissions occasionally to over 30,000 feet but generally to much lower altitudes; lava flows crossed the caldera floor in 1945 and 1958. The last eruption occurred November 1986 through February 1988 and was characterized by intermittent ash emission.
The nearest settlements are Nikolski, population about 35, about 45 miles west of the volcano, and a small number of people at the abandoned Fort Glenn military base 10 miles east of. the volcano.
AVO is closely monitoring the situation and will issue further updates as more information becomes available.