Mount Spurr Volcano, about 80 miles west of Anchorage across the Cook Inlet, has grown restless in recent months. Scientists at the Alaska Volcano Observatory (AVO) first noticed the unrest in early July when hundreds of small earthquakes occurred 3 to 4 miles beneath Spurr's summit. Aerial reconnaissance in mid-July and early August documented recent small flows of mud and rock and a recently formed “ice cauldron” in the summit ice cap. The ice cauldron is a collapse feature possibly caused by an increase in heat coming from deep beneath the summit. Using sensitive instruments, scientists flying around the volcano...