Top vent in the Redoubt summit crater. Picture Date: March 21, 2009–Image Creator: Read, Cyrus; Image courtesy of AVO/USGS.

Alaska’s Mount Redoubt Volcano is grumbling again, seven weeks after renewed activity there put the seismic hot spot back on the radar and into the headlines.

Back in February, scientists said the boiling mountain would blow its top within days or weeks after a vapor plume slipped out of the summit’s crater.

And true to form, Redoubt is making music once again. From late Sunday night until nearly sunrise Monday, the volcano erupted five times, sending ash clouds soaring 60,000 feet into the atmosphere. Ash fall was subsequently reported in Skwentna, Talkeetna, Wasilla, and Trapper Creek.

Redoubt, located on the Kenai Peninsula, 106 miles southwest of Anchorage, is one of 130 volcanoes in the “Land of the Midnight Sun.”

Scientists from the Alaska Volcano Observatory (AVO) are monitoring events round-the-clock at Redoubt, which has been assessed by the U.S. Geological Survey (USGS) as one of the nation’s highest-threat volcanoes.

Redoubt’s last eruption stretched from late 1989 into 1990. The series of eruptions were the second most costly in the history of the United States, and had significant impact on the aviation and oil industries, as well as the people of the Kenai Peninsula.

The AVO says the current alert is a Code Red. That means eruption is believed imminent with significant emission of volcanic ash into the atmosphere. Seismic unrest continues at Redoubt in the form of elevated volcanic tremor.

Last night’s explosive eruptions caused melting of the Drift glacier and greatly increased discharge down the Drift River. The eruptions were preceded by approximately 60 hours of elevated seismicity in the form of discrete earthquakes under the volcano.

Location of Redoubt volcano, in relationship to surrounding towns, roads, and other volcanoes. Picture Date: September 26, 2008 Image Creator: Schaefer, Janet, Image Creator:Image courtesy of the AVO/ADGGS.

Further explosive activity could occur with little or no warning, and could occur intermittently for weeks or months.

Since 1700, at least 41 volcanoes in Alaska have erupted, some of them as many as 25 times, according to an Ash Alert brochure linked from the Alaska Division of Home Security and Emergency Management.

Ashfall is one of the greatest dangers associated with volcanic eruptions. According to the USGS website, volcanic ash consists of tiny jagged pieces of rock and glass. Ash is hard, abrasive, mildly corrosive, conducts electricity when wet, and does not dissolve in water. Ash is spread over broad areas by wind. During an ashfall, daylight can change to complete darkness. Accompanied by rain and lightning, the gritty ash can also lead to power outages, prevent communications, and disorient people.

The AVO website states that on the Kenai Peninsula, during the 1989-90 eruptions, schools were closed and some individuals experienced respiratory problems. Drifting ash clouds disrupted air traffic as far away as Texas. Ash also interrupted commercial air traffic into and out of Anchorage, and mudflows from the volcano threatened an oil storage facility near Cook Inlet.