Alaska Volcano Eruption at Great Sitkin Island Sparks Red Warning

A volcanic eruption from the Alaskan volcano of Great Sitkin has launched ash high into the air and further explosions are possible, according to the authorities.

The Alaska Volcano Observatory (AVO) has issued a red aviation alert for Great Sitkin, meaning "significant emission" of volcanic ash into the atmosphere is likely. The eruption does not appear to have sparked any evacuation warnings.

The observatory issued a notice for aircraft at around 6 a.m. UTC Wednesday morning in which it warned an "explosive eruption" occurred about an hour prior, sending up a cloud of volcanic ash. The eruption is thought to have lasted between one and two minutes.

Initial reports suggested the cloud from the eruption was 15,000ft high. Since that explosion the cloud has detached from the volcano and is moving eastward.

AVO has warned additional explosions are possible. The Aviation Color Code warning remains red, and the Volcano Alert Level remains at "Warning."

It is unclear at the time of writing how the eruption may affect or has affected flights over the region. Newsweek has contacted the United States Geological Survey (USGS) for comment.

Volcanic ash is known to have damaging effects on aircraft because it can erode crucial components such as turbine blades in the engine and scratch landing lights and windscreens.

It can also block fuel nozzles and air filters, set off fire alarms in the cabin, interfere with radio communication systems, and block sensors that let the pilots know how fast the aircraft is going.

The continuous monitoring of airspace helps airline companies avoid volcanic ash clouds.

Great Sitkin is a volcano that occupies most of the northern half of Great Sitkin Island, which is part of the Aleutian Islands chain. The volcano is oval-shaped, eight by 11 kilometers at its base, and 5,709ft tall.

It is about 26 miles east of the community of Adak, and around 1,167 miles away from Anchorage, Alaska's most populous city, which is to the north east.

The last time Great Sitkin erupted was in 1974, marking at least the third time it had done so during the 20th century.

That eruption caused a cloud of ash that is thought to have probably risen to an altitude of more than 25,000ft above sea level. It also produced a lava dome in the center of the volcano's crater.

To monitor the volcano, AVO uses a combination of satellite, seismic, and sound data.

Great Sitkin
The crater of Great Sitkin smoulders in this photo taken in around 1955. The volcano is thought to have erupted at least three time during the 20th century, according to the Alaska Volcano Observatory. Ted Bank Jr/Three Lions / Hulton Archive / Getty