Alaska volcano

Max Kaufman / Alaska Volcano Observatory/University of Alaska Fairbanks Geophysical Institute

Most volcanoes rumble before they erupt, but Washington and Alaska researchers say a big recent eruption was preceded not by a rumble, but a scream.

Alaska’s Mount Redoubt blew its top several times in 2009. Leading up to many of the explosions were a series of little earthquakes—not uncommon for an active volcano. But these quakes began to accelerate, one after another, like a drumbeat building to a climax.

ANCHORAGE, Alaska — The alert level for a remote Alaska volcano has been raised after an apparent ash-producing explosion Tuesday afternoon.

There's a new lava dome forming on top of Alaska's Cleveland Volcano, and the Alaska Volcano Observatory bumped up its aviation warning level to orange. That means the volcano is "exhibiting heightened or escalating unrest with increased potential of eruption".