Printer friendly versionAVO/USGS Volcanic Activity Notice
Current Volcano Alert Level: ADVISORY
Previous Volcano Alert Level: WATCH
Current Aviation Color Code: YELLOW
Previous Aviation Color Code: ORANGE
Friday, October 12, 2018, 11:45 AM AKDT
Alaska Volcano Observatory
N 51 deg 55 min E 179 deg 35 min
2625 ft (800 m)
Volcanic Activity Summary: Recent satellite observations and a lack of seismic tremor over the past week indicate eruptive activity at Semisopochnoi has paused. Thus we are lowering the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY. Although seismic tremor is currently absent at Semisopochnoi, discrete earthquake activity remains above background levels.
Pauses in eruptive activity lasting for weeks to months are known to occur during volcanic eruptions. A return to eruptive activity remains a possibility at Semisopochnoi that could occur with little or no warning. AVO will continue to monitor the volcano closely.
[Volcanic cloud height] Unknown
[Other volcanic cloud information] Unknown
Semisopochnoi is monitored with an on-island seismic network, and remotely by satellite and lightning sensors. An infrasound array on Adak Island could detect explosive emissions from Semisopochnoi with a 13 minute delay if atmospheric conditions permit.
Michelle Coombs, Scientist-in-Charge, USGS
firstname.lastname@example.org (907) 786-7497
David Fee, Coordinating Scientist, UAFGI
email@example.com (907) 322-4085
A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at
The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.