Volcanic Mudflow from Mt. Redoubt

The recent eruptions of Mount Redoubt in Alaska have resulted in a series of large lahars, or volcanic mudflows, streaming down the Drift River valley and into Cook Inlet. Lahars are a dramatic, little-known, and often deadly consequence of volcanic eruptions, and they can be particularly powerful when — as in the case of Redoubt — an erupting volcano melts ice and snow that streams into nearby valleys. The photograph below, taken April 4 by NASA’s Earth Observing-1 satellite, shows the ash-filled lahar carving wide channels into the snowy banks of the Drift River and nearly engulfing the Drift River Oil Terminal. Had the lahars been more powerful, they might have caused a major spill of 6.2 million gallons of crude oil stored at the terminal in late March. A tanker removed 3.7 million gallons of oil from the terminal on April 6, reducing the risk of a spill. The most deadly lahar in recorded history occurred during the eruption of Nevada del Ruiz volcano in Colombia in 1985. The eruption melted large amounts of ice and snow, producing a 16-foot wall of mud and debris that buried the city of Armero, killing 23,000 people.