Great Sitkin volcano news & activity updates:
Great Sitkin volcano (Alaska): alert level lowered back to green
Friday Jan 19, 2018 07:01 AM | DOOR: T
The recent unrest at the volcano, likely caused by a small intrusion of magma, has ended and the alert level was lowered to Green, the Alaska Volcano Observatory (AVO) reported earlier.
"Earthquake activity at Great Sitkin Volcano has declined over the past two months to near background levels. No significant activity has been observed in satellite data during this time period and no steam plumes have been reported. AVO is thus lowering the Aviation Color Code
and Alert Level to GREEN/NORMAL.
The number of earthquakes located at Great Sitkin increased as early as late July 2016, and the elevated seismicity continued throughout most of 2017.
The unrest was likely the result of a magma intrusion beneath the volcano. The decline over the past two months in the number of earthquakes suggests the intrusion has stalled and the volcano is returning to a period of background seismicity.
Future intrusions at Great Sitkin should also lead to an increase in
earthquakes prior to any eruptive activity." (AVO)
Tuesday, Nov 28, 2017
Recent observations of a robust steam plume and a period of gradually increasing seismicity over several months at Great Sitkin prompted AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory on 22 November. ... [meer...]
Friday, Nov 24, 2017
An increase in seismic activity and degassing prompted the Alaska Volcano Observatory (AVO) to raise the alert level of the volcano to yellow today: ... [meer...]