Alaska's Cleveland volcano has been continuously erupting since Saturday morning and ash plumes from the landmass have prompted concern that air travel from North America to Asia could be affected as the Alaska Volcano Observatory (AVO) raised aviation warnings to Orange.
The continuous, low-level eruptions at Mt. Cleveland started with a series of explosions Saturday and emitted gas, steam and ash, but initially caused no resulting flight restrictions.
"Sudden explosions of blocks and ash are possible with little or no warning," the AVO reported. "Ash clouds, if produced, could exceed 20,000 feet above sea level."
The activity began with an explosion at 5 a.m. Saturday, followed by two others at 9:17 and 11:44 a.m.
The nearly symmetrical stratovolcano towards the western edge of the Aleutian island chain is 5,675 feet (1,730m) high. It is considered one of the most active volcanoes in the region, having erupted at least 22 times in the last 230 years.
According to the AVO, if a "large ash-producing event" occurs, monitoring networks should alert officials. However, because the volcano is monitored by distant seismic and infrasound instruments and satellite data, instead of locally, a delay of several hours is possible.
The most up-to-date information from the AVO can be found here.