ANCHORAGE, Alaska, March 23 (UPI) -- Mount Redoubt, a volcano in southern Alaska, spewed anew Monday, the fifth eruption since it rumbled back to life, the U.S. Geological Survey said.
The eruptions that began Sunday night were obscured by darkness and snow, CNN reported.
The volcano's activity, which is expected to continue for weeks or months, caused some interference with air travel, officials said.
The alert level went to red, the highest level, when the eruptions began, the Alaska Volcano Observatory Web page said. A red alert means eruption is imminent with the likelihood of significant emission of volcanic ash into the atmosphere, or eruption is under way or suspected with significant emission of volcanic ash into the atmosphere.
"We would expect Redoubt to have some level of explosive activity for the next weeks or months," USGS geophysicist John Power said during a news conference.
The last time Mount Redoubt was active was 1989, when eruptions lasted for five months, Power said.
The USGS estimated the height of the eruption cloud at 50,000 feet, warning that mudflows were possible on the Drift and Crescent rivers and ash likely would fall downwind from the volcano.
The eruptions also affected air travel, Powers said.
"I understand a number of commercial flights have been canceled coming in and out of Anchorage International Airport," Power said. "We could see disruptions to air travel to south-central Alaska and Alaska as a whole for a period of weeks to months."