The eruption of Mount Spurr remains likely, and Alaskans have a lot of questions.
Last month, we published answers to a list of frequently asked questions about the Southcentral Alaska volcano. When we asked for questions we missed, you sent us dozens of them.
Here are some answers.
SCIENCE
Why hasn’t Mount Spurr erupted from its summit rather than its Crater Peak vent, and how strong would a summit eruption be?
Geological data shows that Spurr’s summit hasn’t erupted for at least 5,000 years, while Crater Peak has erupted twice in the last 70 years — in 1953 and 1992 — according to Matt Haney, head scientist at the Alaska Volcano Observatory. Although magma is closer to the surface beneath the summit, Haney said, Crater Peak is more porous because of its prior eruptions.
“The pathways beneath Crater Peak are going to require much less force to open up and initiate a new eruption (than) beneath the summit,” Haney said. “If it hasn't erupted for 5,000 years, the amount of force to break it open, the rock is just going to be — it’s going to require much, much greater force.”
Do scientists have any estimates of how a Spurr eruption would compare to Mount St. Helens’ 1980 eruption in Washington, or Mount Redoubt’s previous eruptions in Alaska?
Mount St. Helens’ devastating 1980 eruption, which killed 47 people, was much more powerful than any of Spurr’s eruptions in recent history, Haney said. Although Spurr’s summit sits inside a caldera formed by a massive eruption about 10,000 years ago, he called a blast of that magnitude “an extremely rare event” and said it remains the least likely scenario based on its current activity.
“(If Spurr were to) move towards a larger explosive eruption, the geophysical data, like our deformation data and even the earthquake data, would indicate that ahead of time,” Haney said.
Mount Redoubt’s 2009 eruption was roughly comparable to Spurr’s 1953 and 1992 eruptions, which scientists say is a much more likely outcome.
“There are some differences between the eruptions,” Haney said. “But they sent ash clouds to a similar altitude into the atmosphere and they were explosive, ash-producing eruptions.”
Is earthquake activity 1,200 miles away in the Adak area connected or related in any way to Spurr’s activity?
Many Alaska volcanoes are fueled by plate tectonics, according to Haney, as the Pacific plate of Earth’s crust slides beneath its North American plate in a process called subduction. But, he said, volcanic activity is based on conditions at individual sites rather than wide-ranging single incidents.
“Those earthquakes out by Adak are just occurring because of the very specific conditions out there,” he said. “They don't have anything to do with the specific conditions at Mount Spurr right now.”
How long did it take ashfall to arrive in Anchorage after Spurr’s August 1992 eruption, and how long did it actively fall from the atmosphere?
Historical records show that in 1992, ash reached Anchorage slightly over three hours after Spurr’s eruption, with active ashfall continuing for another three to four hours.
Those times can be greatly affected by wind speeds, however, as Spurr’s previous eruption showed.
“In 1953, the winds were slower that day that it exploded,” Haney said. “And in that case, it took six to seven hours to travel to Anchorage.”
The volcano observatory has posted an ash plume forecast for Spurr, with projections of where ash would travel should it erupt under current weather conditions.
Will the ash or eruption have a smell?
“That’s a good question,” Haney said.
Volcanic eruptions are often accompanied by strong sulfuric odors, but any Spurr sulfur should dissipate before it can reach Anchorage, nearly 80 miles to the east.
Although ash can irritate one’s nose or throat, Haney said, “it doesn't have a distinct scent.”
How far could ash from Spurr travel?
Haney said Spurr erupted three times during 1992, in June, August and September. While the August eruption blanketed much of Anchorage with volcanic ash, a smaller amount of ash from that eruption reached Juneau. A similar quantity from the September eruption reached Interior Alaska, traveling more than 500 miles east to Carmacks in Canada’s Yukon territory.
“It was detectable, but it would not be anything like closer to the volcanic (eruption) like in Anchorage,” he said.
ANIMALS
What do wild animals do during an eruption? Are there do’s and don’ts for aiding wildlife?
It’s not totally clear what wild animals in Alaska do when a volcano erupts.
“We haven't studied what wild animals do to a great extent during an eruption,” said Chris Krenz, the Alaska Department of Fish and Game’s wildlife science coordinator. He noted that the department largely focuses on land mammals, as most birds are typically overseen by federal agencies.
The department won’t be actively seeking distressed animals, but people can report them to their local Fish and Game office. Krenz urged people to avoid helping animals on their own.
“The public should not try and take action themselves, as many of the wild animals can be dangerous, especially if they're in distress,” he said. “So please report any concerns to Fish and Game staff.”
When after a Spurr eruption is it safe to let pets outside? If the ash is still on the ground but not actively falling, does that put my dog at risk?
It depends, said State Veterinarian Sarah Coburn. In dry conditions, ashfall can be kicked back up by strong winds, so you might need to keep pets indoors for longer.
Once they do go outside, owners should try to keep their pets out of the ashfall as much as possible.
“Making sure dogs aren't sticking their face into a pile of ash and rubbing their face in it or their paws,” she said. “Checking them before they come back in, brushing them off, checking eyes, checking feet, that kind of thing.”
Another issue is cleaning and protecting any food or water sources for pets or livestock, especially those left outdoors.
“Making sure that their feed and hay stores are covered ahead of time,” Coburn said. “And then as things go on, if it does kick back up after the fact or if there's wind, checking and making sure that the feed is protected or covered, or at least not contaminated when you go to feed it.”
Outdoor water bowls should be washed out and refilled after any ashfall, she said.
Do I need to protect my dog from ashfall in other ways, like cotton balls in ears or goggles?
Coburn said most veterinarians she’s spoken with who were present for previous Spurr eruptions said their effects on pets were “pretty minimal.”
Although some dogs have already been acclimatized by their owners to wearing goggles, she warned against any need to block their ears or make significant changes to their daily lives.
“I've kind of been recommending that people try and keep the routines, as much as they can, the same for their pets,” she said. “And not to make any drastic changes for them that may be uncomfortable or cause other problems, that they're going to be scratching at their face because they have goggles on that they're not used to. That's going to be counterproductive.”
EFFECTS
Will the Emergency Broadcast System be utilized so that we will know Spurr is erupting?
Probably not, said Jeremy Zidek, a spokesman for the state Division of Homeland Security and Emergency Management.
“We don't anticipate that this is going to be a disaster event, that it has any life-threatening consequences to people,” Zidek said.
Zidek said people can receive alerts about Spurr activity from various agencies, including the Alaska Volcano Observatory via the U.S. Geological Survey, the National Weather Service and the Federal Emergency Management Agency. You can also sign up for emergency updates from Anchorage by texting ANCHORAGE to 67283 or signing up online.
If you are away from home when Spurr erupts, should you shelter in place or leave immediately?
Zidek said the small amount of ashfall anticipated from a Spurr eruption would not require people to shelter in place. People should avoid driving through active ashfall areas. But it you must get somewhere, he said, you should be safe if you drive cautiously and take steps to protect your vehicle.
“Anticipated ashfall will be an inconvenience if people take simple protective measures, not a major life, health, or safety concern,” he said.
Can the ash lead to issues with electricity or water?
Officials with electric utilities in the region say they don’t anticipate any major power outages, according to Zidek.
“The amount of ash that we're anticipating, between an eighth of an inch and a quarter of an inch based on previous Spurr eruptions, really wouldn't have too bad of an impact on our electrical system,” Zidek said. “And if it did, it may just be some localized blackouts.”
Water utilities have expressed similar confidence, Zidek said.
One issue that did emerge during Spurr’s 1992 eruption: people using a lot of water to clear ashfall.
“The recommended way to clean ash is with water, so that greater demand put a stress on the water system,” he said. “So as we move into a cleanup period, if there's an eruption, we'd ask people to be mindful about the amount of water that they're using — use what they need to do the cleanup, but maybe be mindful of that.”
Will Anchorage and Eagle River’s drinking water be safe to drink out of the tap after Spurr erupts?
Yes, said Sandy Baker, a spokeswoman for the Anchorage Water and Wastewater Utility.
“We don’t anticipate a Mount Spurr eruption affecting our ability to provide clean, safe drinking water,” she said.
In a statement, Baker said that both ashfall and the arrival of spring can make water from AWWU’s Eklutna Lake reservoir cloudier, increasing its turbidity.
“AWWU is experienced and prepared to adjust production levels and maintain operations during increased turbidity, whether due to seasonal changes or ashfall from Mount Spurr,” Baker said.
Baker also noted that only Anchorage Fire Department personnel, as well as people with valid use permits, are allowed to use local fire hydrants.
Should ashfall on solar panels be treated in a similar way to windshields?
Yes.
It’s recommended that people rinse off their windshields with water rather than using windshield wipers, to prevent the ash from scratching the glass. Zidek said that advice should be adaptable for most solar panels.
“I would say that the recommendation for a solar panel would be similar — that you would want to use water to wash off the panels, and prevent the abrasive ash from marring the surface of the panels,” he said.
How do we cover our gas fireplace and furnace exhausts so ash doesn’t get into the pipes?
The best way to protect heating systems from ashfall, Zidek said, is by maintaining their air filters. He advised against blocking systems’ intakes, which could shut them down entirely.
“The combustion in your furnace or heating system does need that air,” he said. “So our recommendation is that you would clean and/or change those air filters often, and make sure that they're not being clogged with ash and the filters are operating properly.”
SCHOOLS
If ash falls in Southcentral Alaska, how long would school be canceled?
Anchorage School District officials have been preparing extensively for an eruption of Spurr. Should one happen, they say school staff would shut all doors and windows, and officials would then decide next steps.
“One of the big things is making the determination of whether schools will remain open, whether they will close, and if they are closing, how we get those students home safely back to their families,” said Jared Woody, senior director of the district’s Office of Emergency Management.
The district says if classes are not in session and ashfall is imminent, the district will close schools and schools will remain closed “until conditions are safe for students and staff to return.” If school is in session and ashfall is imminent, staff will aim to send children home early before conditions worsen.
“If conditions deteriorate rapidly, ASD may implement shelter-in-place procedures until it is safe for dismissal,” the district says.
Jim Anderson, ASD’s chief operating officer, said the district will work with parents who opt to keep their kids home in response to ashfall.
“Parents always have the ability to make a choice for their kids’ safety,” he said. “I have already reached out to the Commissioner of Education, and her office will work with us if we have some questions that go (to) remote learning. I suspect that it wouldn't be a large number if that were to occur, but we'll work with each individual family and understand that they have choices to make.”
Will children be stranded at school if ashfall happens during a school day?
According to Anderson, if students can’t be bused home before ash begins falling on Anchorage, elementary students will be taken to nearby middle and high schools where supplies are staged in 40-foot Conex container boxes. Parents will be asked to pick kids up from those schools.
The district also says bus routes may be altered to avoid hazardous areas. Buses are currently undergoing air filter inspections to prevent engine damage.
The Matanuska-Susitna Borough School District and the Kenai Peninsula Borough School District have outlined similar plans for their students in the event of a Spurr eruption.
TRAVEL
Would a Spurr eruption cancel a cruise to Alaska?
Lanie Downs, a Alaska-based spokeswoman for Cruise Lines International Association, said in a statement that its member companies “prioritize safety in all of their operations and closely monitor any situation that may impact the guest experience.”
“Cruise lines also have the unique ability to adjust routes and itineraries if needed in the best interest of passengers and crew,” Downs said. “Cruise lines have an exceptional safety record thanks to ongoing intensive training, vigilance, and response plans. This applies both onboard the ships and throughout shoreside land operations and tours.”
What would Alaska Airlines do if Spurr erupted?
Alaska Airlines spokesman Tim Thompson said in a statement that operations teams at both the airline and subsidiary Horizon Air “are closely monitoring the volcanic activity of Mount Spurr.”
“If an eruption occurs, we will immediately assess the movement of the ash cloud,” Thompson said. “Among other concerns, abrasive volcanic ash can significantly damage aircraft and their engines. We’ll work closely with our airport partners to divert planes to other locations if necessary and possibly cancel flights until conditions are deemed safe.”
The airline will work with affected passengers “to safely get them to their destinations,” Thompson said.
