Description: From Neal and others (1995): "Pilot reports of an exceptionally large steam plume above Iliamna Volcano reached an AVO staff member at home on the night of April 12. The next day, at least one phone call from the local media indicated that word had spread about possible eruptive activity at Iliamna; AVO staff were able to examine seismic data and determine that the volcano was quiet. AVO also responded by including a comment in the weekly update about common sightings of benign (non-eruptive) steam plumes at Iliamna.
"At 0939 Universal Time (UT) (1:39 am Alaska Daylight Time [ADT]) on June 30, a large avalanche from the upper east flanks of Iliamna Volcano produced a strong seismic signal as far away as station SLK at Skilak Lake on the Kenai Peninsula 150 km (93 mi) northeast of the volcano. Small shocks were recorded on Iliamna station INE (1585 m [5200 ft] on the northeast flank) as early as 0900 UT (1:00 am ADT); the main event at 0939 UT (1:39 am ADT) saturated the INE record for about 5 minutes. AVO staff examined the strong seismicity the next morning and quickly determined that it was not related to volcanic activity. This information
was conveyed to Lake Clark National Park. AVO staff subsequently made observations on opportunistic fly-bys and spoke with pilots in the area.
"The avalanche deposit was viewed and photographed on July 1 [see fig. 4 in original text]. The headwall is at about 2,200 m (7,220 ft) on the steep east face of the volcano and the avalanche itself extends 5-7 km (3-4.3 mi) to an elevation of approximately 525-600 m (1720-1970 ft)."