Read: What if a ‘big one’ strikes during the pandemic?
Detecting and tracking unstable slopes can give local governments time to install warning systems, so scientists are working to identify unstable land; they’re focusing on monitoring landslides near communities in southeast and south-central Alaska.
In mid-October, Gabriel Wolken—the manager of the Climate and Cryosphere Hazards Program for the Alaska Division of Geological and Geophysical Surveys—took a helicopter to Barry Arm. From the air, he conducted a lidar survey, using a laser scanner to measure the topography of the slide area in fine detail, calculating how the landslide has moved and changed since June. The data are still being processed. However, there are new rockfalls in the area every time he visits, indicating the area’s instability. “The rock itself isn’t very competent,” Wolken says. “It’s basically falling apart.”
Whittier residents are aware of the risk, says Peter Denmark, who runs a commercial kayaking business in the community. When tsunami-warning sirens blare in Whittier, residents know to move swiftly away from the coast and head to higher ground. The state encourages coastal residents to keep a “go bag” filled with emergency supplies and to plan evacuation routes.
“With the people around town, there’s a laissez-faire attitude about it,” Denmark says. Alaskans have “thick skins” when it comes to disasters, he adds. “If it’s not tsunamis, earthquakes, volcanoes, forest fires—it’s one thing or another.” Still, Denmark says, he’s taking precautions; he avoids the Barry Arm area on kayaking tours.
Kelly Bender and her husband, Mike, rely on summer tourism in Prince William Sound. From their waterfront office, she charters water taxis, fishing boats, kayaking, and sightseeing tours. Bender says that before news of the potential landslide broke, their fleet went into Barry Arm daily. With its scenic location—close to glaciers and a popular beach—the state estimates that during peak tourism season, up to 500 people could be in the area at any given time. Bender has changed tour routes, canceled water-taxi trips, and even canceled a planned wedding. “The danger part of it—people are feeling like, ‘We know what to do in a tsunami,’” Bender says. “It’s the business part of it that we’re all really, you know, hanging by a thread.”
While it’s still possible to avert or mitigate many of the worst impacts of climate change, there really isn’t an option to eliminate landslide-generated tsunamis. The state uses howitzer cannons to trigger controlled avalanches in railway and highway corridors, but there’s no easy way to gently coax a colossal landmass off the side of a mountain and into the ocean. “It’s pretty much science fiction,” Higman says.
Smaller landslides might be able to be stabilized from the bottom up. But large landslides, like the one in Barry Arm? “Forget about it,” Liljedahl says. Increasing preparedness, installing a robust monitoring system on and near landslides, and creating an effective localized-alert system are the best ways to protect communities, she says.
Some locals—like Denmark, the kayak outfitter—might prefer a quicker approach. “My idea was to just blast it down and duck,” he says. “But nobody thought that was a good idea.”
This post appears courtesy of High Country News.