An Aleutians Island volcano that has sent up major ash eruptions in the past is heating up near its summit.
Scientists at the Alaska Volcano Observatory say satellite data obtained a week ago indicates a lava dome is growing on Cleveland Volcano.
The volcano is on an uninhabited island 940 miles southwest of Anchorage.
The nearest community is Nikolski 45 miles away.
The observatory says the dome is about 328 feet in diameter. It had not changed as of Saturday.
The dome led the observatory to change the volcano’s alert level to “orange,” indicating heightened or escalating unrest. Development of a lava dome indicates sudden explosions of ash could be produced with little warning.
Ash clouds above 20,000 feet are a threat to major aircraft on trans-Pacific flights.