Volcanic activity at Mount Redoubt – about 180 kilometres southwest of Anchorage, Alaska – since 22 March has seen eruptions sending plumes of steam and ash up to 50,000 feet skyward forcing some air cargo flights destined for technical stops at Ted Stevens Anchorage InternationalAirport to be diverted elsewhere.

The last time Mount Redoubt erupted, in December 1989, the mountain shot ash more than 12,000 metres high and caught a KLM Royal Dutch Airlines flight in its plume, shutting down all four of the plane’s engines.

The plane plummeted 4,000 metres before pilots were able to restart the engines and make an emergency landing in Anchorage.

The airport was closed for a full 24 hours following a 28 March eruption that covered the runways with ash fall. The Federal Aviation Administration has imposed flight restrictions within a 16-km range of the volcano.

Hundreds of flights have been rerouted to Fairbanks (580 kilometres northeast of Anchorage), Seattle and Vancouver to eliminate the possibility of damaging engines and the aircraft. Seattle’s SeaTac Airport reported that it received 180 cargo freighters diverted from Anchorage between March 23 and 30.