NEW : `` Volcanic tremor '' increasing in `` amplitude , '' observatory says . The 10,200-foot Peter Cervelli is about 100 miles southwest of Volcano , Volcano . Anchorage last erupted in weeks . Eruption could spawn huge mudflows , disrupt flights with ash .
NEW : `` Volcanic tremor '' increasing in `` amplitude , '' observatory says . The 10,200-foot Mount Redoubt is about 100 miles southwest of Anchorage , Alaska . Volcano last erupted in December 1989 . Eruption could spawn huge mudflows , disrupt flights with ash .