ALASKA VOLCANO OBSERVATORY INFORMATION STATEMENT
U.S. Geological Survey
Friday, February 16, 2024, 11:44 AM AKST (Friday, February 16, 2024, 20:44 UTC)
Due to severe winter weather conditions, AVO is unable to receive quality data from earthquake and other monitoring stations at Mount Spurr volcano 120 km (75 miles) west of Anchorage. Data are insufficient to establish the state of the volcano. As a result, the Aviation Color Code and Volcano Alert Level are changed to UNASSIGNED/UNASSIGNED.
Summary
Heavy snowpack is preventing data from seismic stations at Mount Spurr volcano from reaching AVO in Anchorage.
As a result, AVO can no longer track volcanic activity in real-time to provide early warning of eruptive activity.
AVO plans to visit to a key repeater to assess damage and implement repairs during the next suitable weather window.
Cause of network failure
The high-altitude environment at Cook Inlet volcanoes often degrades network performance through the winter, but this season’s significant snowfall is having an outsized impact. Heavy snow and ice loads on antennas have blocked most data transmission from Mount Spurr monitoring stations back to Anchorage. Attempts to reroute and reduce data transmission by prioritizing critical sites provided temporary relief, but continued signal degradation has now impacted these remaining data streams as well. Current data are extremely limited and are insufficient to monitor volcanic signals from Mount Spurr.
Prognosis
AVO is planning to visit a key repeater on Mount Susitna to assess damage and implement repairs during the next suitable weather window, but the scope of damage is unclear and network restoration may not be possible until the summer field season. As days lengthen and snowmelt occurs, data transmission could improve sooner.
Activity and monitoring at Mount Spurr
This move to UNASSIGNED does not reflect a change in activity at the volcano, but rather a change in AVO’s ability to track volcano activity at Mount Spurr. Though AVO’s monitoring is temporarily compromised, the most probable eruption scenario for Mount Spurr involves several months of intensifying earthquake activity before erupting, and prior to network failure, Mount Spurr was not showing any signs of unrest.
However, with current monitoring network health, AVO is unable to provide timely eruption forecasts or quickly confirm or dismiss reports of activity. As with other un-instrumented volcanoes, AVO will use satellite data, regional seismic, infrasound and lightning networks, and reports from pilots and ground observers to detect signs of unrest or eruptive activity. These monitoring data may detect ongoing eruptive activity, but AVO will be limited in its ability to identify precursory signals and provide early warning of impending eruptions.
Mount Spurr volcano is an ice- and snow-covered stratovolcano located on the west side of Cook Inlet approximately 120 km (75 mi) west of Anchorage. The only known historical eruptions occurred in 1953 and 1992 from the Crater Peak flank vent located 3.5 km (2 mi) south of the summit of Mount Spurr. These eruptions were brief, explosive, and produced columns of ash that rose up to 20 km (65,000 ft) above sea level and deposited several mm of ash in south-central Alaska, including approximately 6 mm of ash on Anchorage in 1953. The last known eruption from the summit of Mount Spurr was more than 5,000 years ago. Primary hazards during future eruptions include far-traveled ash clouds, ash fall, pyroclastic flows, and lahars or mudflows that could inundate drainages all sides of the volcano, but primarily on the south and east flanks.
Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497
Ronni Grapenthin, Acting Coordinating Scientist, UAFGI, rgrapenthin@alaska.edu (907) 378-5460
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.