(by Stu Woo, WSJ.com) – A volcano in Alaska erupted five times on Sunday night and Monday morning, forcing flight cancellations and delays in Anchorage as it spewed ash 60,000 feet high.

Scientists at the Alaska Volcano Observatory say Mount Redoubt’s eruptions pose more of an inconvenience than a threat to residents, because they are taking place relatively far from populated areas. The closest city, Kenai, is 45 miles east, while Anchorage, Alaska’s most-populous city, is 100 miles northeast. 

Steam rises from the summit crater of Alaska's Mount Redoubt, shown Saturday, before it erupted five times Sunday night and early Monday morning.Steam rises from the summit crater of Alaska’s Mount Redoubt, shown Saturday, before it erupted five times Sunday night and early Monday morning. The nine-mile-high ash plume led the Federal Aviation Administration to implement a 40-mile-wide no-fly zone around the volcano.

“Everybody’s prepared,” said Ronnie Sackett, a maintenance worker at the Moose Is Loose bakery in Soldotna, a small town on the Kenai Peninsula. “Once it starts rumbling, they get on their horse and do their thing.”

The eruptions have disrupted operations at Ted Stevens Anchorage International Airport, where many flights were canceled Monday. The Federal Aviation Administration has implemented a 40-mile-wide no-fly zone around the volcano, said operations manager Mark Brys.

Mr. Brys said about 1,500 flights depart from, arrive at or fly over the city daily, but far fewer were expected to do so Monday amid the eruptions. The few planes that did land at the airport reported no problems. Flights from the U.S. to Asia might have to alter their routes slightly, Mr. Brys said, because Mount Redoubt sits on a major international flight route.
The Alaskan Volcano Mount Redoubt has shown signs of pending approaching eruption for about two months now, and has finally erupted. Video courtesy of Reuters.

Scientists warn that the smoke, made of pulverized lava, could harm those with respiratory problems. A coating of ash about the thickness of a dime is expected to fall in mostly unpopulated areas north of the volcano, prompting officials to urge residents to limit outdoor exposure.

Experts expect Mount Redoubt to erupt again in coming days or weeks. A similar Alaskan volcano, Augustine, erupted at least a dozen times over several months in 2006, but caused few problems because of its remote location.

Scientists had been expecting Mount Redoubt to explode for months. In the late fall and early winter, the volcano began spouting steam and triggering earthquakes. The temblors began again Friday night, and the first eruption occurred about 10:38 p.m. Sunday. The fifth and most recent occurred at 4:31 a.m. Monday.

Mount Redoubt has gone through at least three periods of eruptions since 1900, most recently in 1989, when a KLM Boeing 747 flew into the plume of smoke and lost engine power. The pilot was able to restart the engines and land the plane safely.

If Mount Redoubt continues to erupt, delays in airport traffic could affect many Alaskans, Mr. Brys said. “That’s how we get a lot of groceries,” he said.

Write to Stu Woo at Stu.Woo@wsj.com.

Copyright 2009 Dow Jones & Company, Inc.  All Rights Reserved.  Reprinted here for educational purposes only.  Visit the website at wsj.com.  

Questions

1. The first paragraph of a news article generally answers the questions who, what, where and when. Answer those questions for this article.

2. Why do the eruptions of Mount Redoubt pose more of an inconvenience than a threat to residents?

3. How have the volcano’s eruptions affected air travel?

4. How many periods of eruptions has Mount Redoubt gone through in the past 110 years?

5. If eruptions continue to occur, what effect will it have on many Alaskans?

Background

ALASKA’S VOLCANOES (from the Alaska Volcano Observatory website at avo.alaska.edu/volcanoes/about.php)

  • Alaska contains over 130 volcanoes and volcanic fields. … Of these volcanoes, … more than 50 have been active within historical time (since about 1760, for Alaska).
  • The volcanoes in Alaska make up well over three-quarters of U.S. volcanoes that have erupted in the last two hundred years.
  • Alaska’s volcanoes are potentially hazardous to passenger and freight aircraft as jet engines sometimes fail after ingesting volcanic ash. On December 15, 1989, a Boeing 747 flying 150 miles northeast of Anchorage encountered an ash cloud erupted from Redoubt Volcano and lost power in all four jet engines. The plane, with 231 passengers aboard, lost more than 9,800 feet of elevation before the flight crew was able to restart the engines. After landing, it was determined the airplane had suffered about $80 million in damage.
  • Estimates, based on information provided by the Federal Aviation Administration, are that more than 80,000 large aircraft per year, and 30,000 people per day, are in the skies over and potentially downwind of Aleutian volcanoes, mostly on the heavily traveled great-circle routes between Europe, North America, and Asia. Volcanic eruptions from Cook Inlet volcanoes (Spurr, Redoubt, Iliamna, and Augustine) can have severe impacts, as these volcanoes are nearest to Anchorage, Alaska’s largest population center.
  • The series of 1989-1990 eruptions from Mt. Redoubt 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. On the Kenai Peninsula, during periods of continuous ash fallout, schools were closed and some individuals experienced respiratory problems. At the Drift River oil terminal, lahars and lahar run-out flows threatened the facility and partially inundated the terminal on January 2, 1990 (Waythomas and others, 1998). The Redoubt eruption also damaged five commercial jetliners, and caused several days worth of airport closures and airline cancellations in Anchorage and on the Kenai Peninsula (Casadevall, 1994). Drifting ash clouds disrupted air traffic as far away as Texas. More information about the Redoubt 1989-1990 eruptions, including impact to people and infrastructure, is available here.

Resources

Go to wsj.com for video of the volcano before it erupted.

For updated news on Mount Redoubt, go to a local Alaska news channel at ktuu.com/Global/story.asp?S=10051900.

For a regional map of Alaska volcanoes, go to avo.alaska.edu/volcanoes. and for images, go to avo.alaska.edu/volcanoes/volcimage.php?volcname=Redoubt.

Get Free Answers

Daily “Answers” emails are provided for Daily News Articles, Tuesday’s World Events and Friday’s News Quiz.