Evidence of elevated volcanic activity indicate eruption of Alaska's Mount Spurr volcano could happen within weeks or months, federal officials say.

Researchers predict the most likely outcome of the unrest at Mt. Spurr is “one or more explosive events” that could last as long as a few hours and produce ash clouds carried for hundreds of miles.

The most probable scenario is an eruption similar to those in 1953 and 1992, each lasting hours and producing clouds of ash that circulated for hundreds of miles around Southcentral Alaska.