Event Name : Spurr 2012/6
|Start:||June 25, 2012 ||Observed|
|Fumarolic or hydrothermal activity: ||
|Glacier outburst flood: ||
|Seismicity with no confirmed eruption: ||
|Eruption Type:||Not an eruption.|
From Herrick and others (2014): "In January , the number of located earthquakes beneath Mount Spurr increased over background. By January 30, the rate of small events was 1-3 events per hour, increasing to 2-4 events per hour on January 31. Seismicity remained slightly elevated into early February (up to 2-6 events per hour) but abated by February 12. AVO seismologists attributed the swarm to deformation within glaciers covering the edifice triggered by unseasonably warm weather. Several deep, low frequency events also occurred in February and March, but this was not considered a significant departure from background.
"On May 15, a pilot familiar with the volcano reported sulfur odors, likely hydrogen sulfide, during an overflight of the Mount Spurr area. He noted typical fumarolic activity on the summit cone, describing white plumes rising vertically in calm wind conditions. Some yellow-tinged (sulfur) snow was visible, but otherwise, the pilot reported no significant changes in the summit region. Snow continued to slowly infill the southern portion of the 2004 summit melt cauldron (Coombs and others, 2006) compared to previous views. An airborne gas measurement flight to Mount Spurr on June 22 took advantage of clear conditions to photograph the summit area. White vapor plumes rose from the long-lived fumarolic vents within the summit crater. Sulfur-dioxide (SO2) flux was low, but flying conditions were difficult and the aircraft may have been unable to travel completely below the plume (C. Werner, USGS, written commun., 2012).
"On June 25, a glacial outburst flood was recorded on seismograph station CKN located downstream of the Kidazgeni Glacier that flows from the Mount Spurr summit icefield and around the eastern flank of Crater Peak. Based on the duration of seismicity, the event lasted at least 45 minutes. Later observations indicated that water had escaped from beneath the Kidazgeni Glacier, flowing downstream and into the Chakachatna River that drains into Cook Inlet. By June 27, seismicity related to the outburst flood at ended. The seismic record of this event was similar to that observed during another Kidazgeni outburst flood in 1993 (Nye and others, 1995).
"On October 17, a pilot contacted AVO to report visible vapor emissions from the summit area of Mount Spurr. After AVO staff reviewed avialable satellite images, the local web camera, and seismic data, it was determined that no significant change had occurred. Slightly elevated surface temperatures were detected at Mount Spurr in satellite images on October 18 and 23, however, they were not considered significant departures from background."