Unalaska, AK – Redoubt may not be in the Aleutians, but the ash from this week's eruptions is still causing cancelled flights between Unalaska and Anchorage. No flights arrived or left Monday though they should be on track for Tuesday. It is unclear how long the Cook Inlet volcano will affect air travel in the region. Alaska Volcano Observatory scientist Tom Murray said they can only predict the volcano's behavior based on past eruptions.

"The past is always the key to the future. We might expect the volcano to behave that way again, however it does have a way of writing a new history, if you will," he told a press conference in Anchorage and via teleconference. "The volcano could behave very differently, it could shut down at this point, go into a longer eruption, it's really something where we're going to have to wait and see."

Signals seem to suggest that it might be similar to the 1989-90 eruption, when it had spurts of 2-3 days of ash plumes with breaks of up to a few weeks. Scientists are also comparing Redoubt to other similar volcanoes to try to chart what it might do. Murray said the most significant impact of the eruption will be on air travel.

"Aircraft and ash really don't mix. It's the principle hazard that you see in Alaska. You can imagine flying an airplane into a sand blaster. That's what happens when you fly an airplane into an ash cloud. Presently airplanes are doing all they can to stay out of the ash."

PenAir's Chief Operating Officer Scott Bloomquist says the volcano is directly between Anchorage and the Aleutians and its ash will occasionally interrupt travel. Monday's cloudy weather near the volcano made it hard to see and avoid the ash so PenAir cancelled all flights. Tuesday's conditions were different.

"So we've been able to take off today, get up, and actually see the volcanic activity and fly around it," he said Tuesday morning.

Bloomquist said they will schedule extra flights to accommodate passengers from canceled flights. PenAir will only fly during daylight hours and in clear weather if there might be volcanic ash in the area. He encourages all passengers to check with the airport to see if flights are going. If the volcanic activity decreases, then the flights will not be affected.