Even though the volcano is in an uninhabited area, an eruption could still cause a big mess. According to CNN, some 90 percent of air freight from Asia to Europe and North America passes over Alaska, along with hundreds of commercial flights.
Officials say that intermittent and sudden explosions could happen at any time, generating ash clouds up to 20,000 feet above sea level.The Alaska Volcano Observatory (AVO) has elevated the Aviation Color Code from Yellow to Orange, indicating that Cleveland Volcano is exhibiting “heightened or escalating unrest with increased potential of eruption.” Orange is the second highest warning level in the AVO’s four-color alert system.
The observatory says that as of Monday, the lava dome was approximately 130 feet in diameter.
The volcano erupted twice recently, on Christmas and again on December 29, sending an ash plume 15,000 feet high.
But that was just a rumble compared to the eruption in 2001, which saw ash clouds as high as 39,000 feet.
Over the past year, the Cleveland Volcano in the Aleutians has been a up and down. This new alert status for the volcano has bounced back and forth from Yellow/Advisory to Orange/Watch multiple times due to the growth of a dome of lava in the summit crater area.This dome has the potential to “plug” the conduit, causing the pressure behind the dome to rise until an explosive eruption occurs. This is exactly what happened on December 25 and 29 of 2011 when Cleveland had one of its first major explosive eruptions in years and the dome that grew in the crater over much of 2011 was destroyed.
Things quieted down at Cleveland after that explosion, but new satellite imagery has shown that a new dome is already growing inside the summit crater – and now it is already 40 meters in diameters. This new dome growth has prompted the Alaska Volcano Observatory to raise the alert status for Cleveland back to Orange/Watch from Yellow/Advisory because if the volcano decides to have another explosive eruption, the hundreds of flights that come over the Aleutians will need to be alerted and/or rerouted to avoid the volcano ash.The Cleveland Volcano in Alaska’s Aleutian Islands may be on the verge of another eruption, and it is an especially difficult volcano to monitor as satellite imagery and first hand observations from people on the ground or in aircraft are really the only ways AVO has to keep track of what is going on due to the fact that there are no seismometers near the volcano and visibility in the Aleutians is difficult, however there is a webcam pointed towards it, but again, visibility is an issue.