Scientists and vulcanologists seem to be in agreement that the eruption of Alaska’s Mount Redoubt is imminent. The question is not if there will be an eruption but when it will happen and how strong it will be. Redoubt has a long history of documented eruptions. The most recent occurred in 1989-90 and was characterized by large explosions that produced ash clouds reaching altitudes of 40,000 feet that disrupted air traffic operations in and out of Anchorage.

Possible scenarios for this new event range from no eruption at all to a complete collapse of the mountain flank, but according to the Alaska Volcano Observatory, the most likely scenario is an eruption similar to the 1989-90 event that could persist for weeks or months. The AVO warns that the hazards associated with this type of eruption could include ash clouds reaching 40,000 feet or higher; ash fall; mudflows that could travel east down the Drift River, possibly reaching the Cook Inlet; and pyroclastic flows (fast-moving clouds of hot ash and gas) that could travel swiftly down the mountain flanks, affecting areas within about nine miles of the volcano.

Judge for yourself. First, take a look at the photos of the 1989-90 eruption:

Geologist uses a theodolite to measure the dimensions of the lava dome at Redoubt Volcano. From the same installation, scientists also utilized a laser-ranging device to measure distances to reflectors. Repeated measurements of these distances allow for detection of ground deformation that may be related to volcanic activity. Photograph by R.G. McGimsey, June 04, 1990.

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