Mount Redoubt
Written by John Carl Villanueva
Mount Redoubt is one of the active volcanoes in the highly volcanic Aleutian Range in Alaska. Redoubt's most recent eruption was in March of 2009. Eruptions also occurred in 1881, 1902, 1922, 1966, and 1989.
The volcano reaches up to an elevation of 3,108 m, making it the third tallest in the Aleutian Range. It trails Mount Torbert, which towers above the rest at 3,478 m, and Mount Spurr, which is a close second to Torbert at 3,374 m.
Described as having a steep-sided cone with a 10-km diameter at the base, this stratovolcano has a volume of approximately 30-35 cubic kilometers. It stands some 166 km from Anchorage, a city with nearly 280,000 residents. The first ascent on its slopes was carried out in 1959 by fellows going by the surnames Deehr, Gardey, Kennel, and Wescott.
Known as Ujakushatsch to locals, which means "fortified place", this volcano is made up of pyroclastic flow deposits as well as lava flows. Its current main vent is located on the north side of the crater by the head of the Drift glacier.
Recent eruptions of Mount Redoubt produced volcanic rocks such as andecite, basalt, and dacite.
The Mount Redoubt eruption of 1989 caused the damage of a KLM aircraft (Flight 867), which happened to fly overhead when the volcano spewed forth volcanic ash. The cloud of volcanic ash enveloped the aircraft and caused all four engines to fail.
Luckily, Captain Karl van der Elst and his crew managed to restart the engines after descending for more than 14,000 feet. The plane eventually landed safely but sustained damage costing about US$80 million. Still, the most important thing was that everyone on board survived the ordeal.
That eruption lasted for at least six months. Since the summit of Mount Redoubt is capped with snow, the melted snow evolved into lahars which eventually flowed down the northern part of the volcano.
The most recent eruption of Mount Redoubt is said to have released ash clouds up to as high as 20,000 m. Observers also note that the volcano grew a lava dome in the summit crater, a phenomena predicted to last for months.
The largest concern over a Mount Redoubt eruption is the oil production facility in Cook Inlet. Even when spared from destruction, the temporary shutdown of the facility during the recent eruption costs about US$1.5 million per month in taxes.
We have some related articles here in Universe Today. Here are the links:
Here are the links of two more articles from Alaska Volcano Observatory (AVO):
Here are two episodes at Astronomy Cast that you might want to check out as well:
Filed under: Astronomy
Tags: alaskan volcano, Flight 867, lahar, mount redoubt
