ANCHORAGE - Redoubt volcano's exterior appears to be unchanged, despite a swarm of earthquakes at the peak earlier this week, scientists with the Alaska Volcano Observatory say.
The scientists inspected Redoubt's lava dome from an airplane on Thursday, and found it looked the same as it did before the earthquakes, which died down by midweek.
"That's what we were hoping to see," Tom Murray, chief scientist at the observatory, told the Anchorage Daily News.
Nevertheless, observatory scientists are advising continued caution and kept the volcano's aviation alert level at yellow on Saturday, meaning there are signs of elevated activity above the known background level. They will continue daily monitoring of the volcano 160 miles southwest of Anchorage until they determine it's safe to bring the alert level down to code green - inactive status.
"We're watching it closely now. It can still go either way," Murray said.
Following eruptions that began last spring, Redoubt's fresh lava dome grew to nearly 68 million cubic feet. Until the earthquakes that began last Sunday, the volcano had been mostly quiet since the summer.
Observations this week showed some high temperature areas on the surface of the dome, which was expected, but scientists also noticed that gas emissions were higher than they were in November.
It's possible that new magma has been added to the volcano or the magma has shifted, observatory scientists said Friday.
It's unlikely Redoubt will erupt without additional earthquakes and other significant disruptions, they said.
The 2009 eruptions created ash plumes, disrupted air traffic, produced mudflows that threatened a Cook Inlet oil terminal and caused Chevron to shut in some of its Cook Inlet oil production wells.
Until last year, Redoubt's most recent eruptions were in 1902, 1966-1968 and 1989-1990.