Alaska volcano back on eruption watch

Researchers have raised the alert status at Mount Redoubt, a volcano in southern Alaska, after another increase in seismic activity. "Shallow earthquake activity under the volcano has been as high as 26 events per 10-minute period," officials at the Alaska Volcano Observatory said Sunday in a statement announcing that the alert level was raised to "watch" status. http://www.cnn.com/2009/TECH/science/03/22/alaska.volcano/