Preparing for a fall: How ready is the peninsula to deal with a major eruption?

Posted: Friday, December 30, 2005

 

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  Researchers with the Alaska Volcano Observatory work out of their Anchorage office. With facilities there and in Fairbanks, they monitor the activity of the state's active volcanos. Clarion file photo

Researchers from the Alaska Volcano Observatory, at center left, are dwarfed by the remains of a large ash flow in the shadow of Mount Redoubt during a trip to check monitoring equipment several years ago.

File photo by M. Scott Moon

Ninety-four years ago in what is now Katmai National Park and Preserve, Novarupta Volcano exploded launching an estimated 21 cubic miles of material into the atmosphere over a three-day period, and burying the surrounding landscape with an ash flow 100 to 700 feet deep.

Four hours after it began, according to historical data from the U.S. Geological Survey, ash began falling on Kodiak, eventually accumulating to a foot or more.

Breathing was difficult due to ash and sulfur dioxide gas, drinking water turned bad, streams choked, aquatic life died and salmon ceased to spawn. Many land animals and millions of birds fell victim. Avalanches bulldozed some buildings. Lightening ignited others. Roofs collapsed. Radio communications were cut off and ships could not dock.

Kodiak eventually recovered, but a few villages closer to the volcano were abandoned.

In 1912, Southcentral Alaska’s population was a lot smaller; infrastructure was more a dream than reality; commerce was meager by today’s standards. Such an event today would have a far greater and likely longer-lasting economic impact.

To be sure, the Cook Inlet region has seen volcanic activity since 1912, including eruptions in recent decades at Mount Augustine, Mount Spurr and Mount Redoubt. But they paled in comparison to the three-day Novarupta event, the largest volcanic eruption of the 20th century.

Scientists with the U.S. Geological Survey say the chance of another cataclysmic event on Novarupta’s scale occurring in any given year is small, but over time a virtual certainty. Ten peaks in southern Alaska are considered capable of such destruction, and ash surveys show at least seven deposits of comparable size dumped within 500 miles of Anchorage in the last 4,000 years.

The picturesque peaks lining the peninsula’s western horizon are dangerous, and two — Augustine and Spurr — are showing signs they are stirring to life. How prepared are municipal authorities in the central peninsula and the population in general to deal with the havoc of a 1912-type event should such an ash fall occur here?

The latest version of the Kenai Peninsula Borough’s All Hazard Mitigation Plan, finished in June, covers a variety of possible disasters, including storms, earthquakes, wildfire, floods, tsunamis and volcanoes. Other than adopting hazard descriptions from the state’s plan drafted in August 2004, defining a few relevant terms, outlining some history and providing a few maps of likely ash trajectories, the borough’s plan offers little practical advice or agency-specific direction for managing the economic and social havoc of a significant ash fall.

Generally, the volcano sections of the Kenai, Soldotna, Seward, Homer and Kachemak City emergency plans aren’t any more informative.

The borough’s plan is derived from the state’s plan and appears to place heavy reliance on the Alaska Volcano Observatory emergency alert protocol. The observatory color-codes volcanic activity (green, yellow, orange, and red) depending on circumstances. Augustine and Spurr are currently rated yellow, meaning eruptions are considered possible “in the next few weeks” and could occur with little or no warning.

The borough would use the Internet and fax outlets to notify authorities, the media, the aviation industry and the public in the event of an eruption. The borough’s Office of Emergency Management Web site offers downloadable pamphlets with helpful suggestions for supplies residents should have on hand in their homes and cars. The bottom line, however, is that Alaskans are expected to be self-reliant in the initial stages of a major eruption and ash fall.

“A lot will depend on personal preparedness,” said Scott Walden, the newly appointed Emergency Management Coordinator for the Kenai Peninsula Borough.

 

Researchers with the Alaska Volcano Observatory work out of their Anchorage office. With facilities there and in Fairbanks, they monitor the activity of the state's active volcanos.

Clarion file photo

In an ash fall, Walden said, there would be particular concern for young children and older persons with respiratory ailments. Beyond that, the major issues will be ensuring a supply of water, the structural integrity of buildings, opening transportation routes and delivering energy — in short, the infrastructure of modern living.

“In a heavy ash fall, you’d get darkness at noon. Brownouts would likely occur. Water meters could short out. There would be clogged drains. Machinery in general would get messed up,” he said.

An inch of ash can weigh 5 to 10 pounds per square foot dry, and 10 to 15 pounds per square foot wet, according to U.S.G.S. data. “It would be important to get roofs cleared off quickly,” Walden said.

Ash, especially wet ash, is slippery, making driving difficult. Ash from Redoubt’s last eruption contributed to car accidents on the peninsula. The Alaska Division of Emergency Services’ Web site, which also has downloadable pamphlets, recommends having an evacuation plan. But how realistic is it to expect evacuation would be possible?

Since 2002, the volcano observatory has maintained seismic monitoring networks on at least 23 of Alaska’s 41 active peaks, recording data 24 hours per day. Thus, AVO scientists would get the earliest warnings of a pending or actual eruption. Presumably, they would know when a really large event had occurred and be able to give residents of the peninsula several hours’ notice before an ash cloud would be overhead. Depending where one is, that might provide the time to leave the peninsula. Then again, perhaps not.

In theory, at least, leaving would be possible. For instance, authorities could turn the Sterling Highway into a one-way road.

“To a certain degree, whether to evacuate would amount to a personal decision,” Walden said. “Unfortunately, with wind patterns around Cook Inlet, it may not serve a good purpose to evacuate to Anchorage or to the Mat-Su Valley.”

“It’s often better to encourage people to shelter in place,” Walden said.

Staying indoors would be safer than moving about in an ash fall and information available from local and state authorities can help residents seal their homes against incoming ash. But some travel would be necessary and unavoidable, such as delivering emergency services and maintaining vital energy systems.

“The major utilities all have contingency plans to protect the power grid and gas lines,” Walden said. “But it is a good thing that many Alaskans think a generator is just another yard tool.”

Emergency communication networks across the peninsula have built-in redundancy, so aside from occasional disruptions, information should reach most residents in a timely manner, Walden said. But in the early stages of a major eruption — perhaps for a period of several days — residents would be expected to show the kind of self-reliance Alaskans often are known for.



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