Scientists see holes in Alaska volcano glacier

Water has also been seen streaming down the glacier, indicating heat from magma is reaching higher elevations of the mountain, and adding to concerns that an eruption is near. Scientists with the Alaska Volcano Observatory flew close to Drift Glacier and spotted vigorous steam emitted from a hole on the mountain.

The last eruption happened in 1990. If the volcano erupts, it could shoot an ash cloud 50,000 feet into the jet stream. The ash could shroud several cities, including Anchorage, which is about 100 miles northeast of Mount Redoubt.

Particulate released during an eruption has jagged edges and can injure skin, eyes and breathing passages. It can also hamper engines.

A warning from scientists about the increase in earthquake activity under the volcano and imminent eruption has residents buying dust masks and car air filters.