[2] The Alaska Volcano Observatory also uses simply "Redoubt"; it lists the same alternate names in addition to: Goryalaya, Redoute Mtn., and Redutskaya, Sopka.

[13] Similarly, in 2003, a blowing cloud of snow was mistaken by an employee of the ConocoPhillips Building in Anchorage for an ash plume.

[15] There was apparently an eruption described as "to the eastward, Redoubt Volcano, 11,060 feet (3,370 m) high, is constantly smoking, with periods of exaggerated activity.

A great eruption took place in 1881, when a party of native hunters half-way up its slopes were overwhelmed by a lava-flow and only two escaped."

A local newspaper stated, "Word has just been received that Redoubt, one of the volcanoes at Cook's Inlet had an eruption on January 18, and the country for 150 miles (240 km) around was covered with ashes and lava.

Newspapers seemed to suggest that the ash had traveled for more than 150 miles (240 km), reaching the opposite side of the Cook Inlet.

The lahars entered a nearby river, worrying officials that they might destroy an oil storage facility located along it.

[20] Since lahars were produced repeatedly, scientists realized that they could use these to analyze a trial period for a newly developed device proposed to measure the movement of rocks against each other.

On January 30, 2009, scientists from the Alaska Volcano Observatory (AVO) warned that an eruption was imminent, sending experienced[clarification needed] Alaskans shopping for protection against a dusty shower of volcanic ash that could descend on south-central Alaska.

[citation needed] By January 31, volcanic earthquakes increased to several per hour,[23] and a large hole in the glacier on the side of the mountain was spotted.

[24] Scientists began to monitor seismic data from the mountain twenty-four hours a day in an effort to warn people in nearby communities.

[25] A fly over conducted by the AVO detected "significant steaming from a new melt depression at the mouth of the summit crater near the vent area of the 1989-90 eruption.

[3] AVO recorded numerous volcanic eruptions and/or explosions at Redoubt volcano during this period of activity.