Tuesday, January 03, 2006
Augustine volcano's active behavior is still monitored in Alaska
Historically, Augustine Volcano is the most active volcano in the Cook Inlet region. And now AVO scientists have stepped up observation of the giant due to the return of elevated activity.
During December, several small steam explosions and venting sulfur dioxide has been recorded at Augustine Volcano, located in the lower Cook Inlet. But earthquakes there are a real sign of trouble. They are at levels not seen since the last eruption in 1986.
“The rates of earthquake activity is what's really got our attention. We're seeing as many as 30, 40, 50 earthquakes a day. We're averaging several hundred earthquakes a week at Augustine,” said Dr. John Power, AVO geophysicist.
Thermal imaging of the summit area using FLIR, or a Forward Looking Infrared Radiometer, confirmed the presence of new, high-temperature fumeroles, or steam vents high on the volcano.
“This is the new fumerole that's developed on the south side. This is the hottest temperature we've been able to measure at this point. This new area here has begun to fume rather vigorously. And then, we have this older fumerole, the Northeast Moat fumerole we call it, which has been inactive for years, but has recently begun to also steam quite vigorously,” said Power.
All these observations suggest that new magma may be present beneath Augustine. Based on past eruptions, there would be a sharp increase in earthquake activity prior to a significant eruption. At this time, seismicity levels are still well below that observed just before the '86 eruption.
AVO scientists will continue to closely monitor the active volcano. Overflights and field visits will continue as long as weather and daylight allow.