As the statewide avalanche and artillery program manager for the Alaska Department of Transportation and Public Facilities, Glassett's job is to prevent snow from sliding to the valley bottom and blocking the highway. In the past, one of the only ways to collect this kind of information was through direct observation, which for Glassett often required driving in poor road conditions midstorm.
Now, a new series of sensors — paid for by a federal grant program to help DOT modernize avalanche monitoring and mitigation systems in Alaska — casts information straight to Glassett's iPhone. While infrasound has been used for decades to detect earthquakes and volcanic eruptions, crews are now training it on what avalanches sound like.
"Every year, we have individuals driving into avalanche debris or getting hit by avalanches on the highway," Glassett said. "This technology can keep those people out of that hazard zone."
This technology, along with blasting and Doppler radar monitoring techniques, are part of the department's new Avalanche Mitigation Alert Detection project. The ongoing project is making it easier to monitor rapidly changing winter storm conditions, and creates less dangerous ways to trigger controlled avalanches — options not involving artillery or manned helicopters dropping explosives.
Transportation officials hope the technology boosts safety for drivers and winter maintenance crews, and reduces travel disruptions created when snow buries a highway. During a closure, it's common for there to be no alternative routes for drivers to reach their destination.
The project is supported by a $1.1 million federal grant intended to pilot technologies that are "proven, but not yet widely adopted" in the transportation field, said Stan Caldwell, director of the federal SMART Grants Program. He called the Alaska Department of Transportation "pioneers" in avalanche mitigation, and said it's a case study that could eventually be scaled up to inform programs in other states.
"How can we use technology to improve safety?" Caldwell asked. "That's what they're demonstrating here, and we want to make sure everyone in the Lower 48 learns from that."
According to Glassett, DOT uses infrasound at two locations statewide: along the Seward Highway near Bird Point, and Juneau's Thane Road, which extends southeast from the city's downtown along Gastineau Channel.
Midday Tuesday, Glassett was alerted to infrasonic activity on the slopes above Thane Road. Moments later, a colleague in Juneau shared a video of an avalanche that had come down, kicking up a cloud of snow as it tumbled. Thane Road had been preventively closed prior to the event and remained closed Wednesday morning.
Glassett said infrasonic monitoring, in conjunction with weather information, will help the transportation department determine when a road should close.
NEW TOOLS ON HAND
As the Seward Highway winds south from Anchorage into the mountains, it passes under 200 avalanche paths, Glassett said. Sometimes avalanche debris makes it to the pavement and covers the road and adjacent Alaska Railroad, electric utilities and natural gas lines. Between October and March 24, DOT logged 49 "road hits," and several thousand hours of avalanche-related road closures around the state, he said.
The transportation department's snow avalanche program is designed to trigger and detect numerous small avalanches to prevent snow from burying the highway. Crews monitor conditions daily and, in some cases, use blasting equipment to preventively release pockets of snow to avoid build-up after a significant storm.
In the past, DOT's standard choice for avalanche mitigation has been howitzer cannons, an operation that requires intensive manpower, longer road closures and temporary flight restrictions in the area, Glassett said. But the support and maintenance assistance from the U.S. Army that DOT relies on for this method is waning, Glassett said.
This past winter, the state transportation department had options that do not require artillery fire from a cannon designed in the 1920s. Using mobile equipment called a "Boom Whoosh," DOT staff can create avalanches using a mixture of propane and oxygen. It sounds like gunfire, but uses an air blast to force avalanches to release from a slope. It's launched from a 10-foot-long tube that can be hitched to a trailer.
Although not included in the grant program, Alaska's transportation department also became the first in the country to use drones to remotely trigger avalanches in harder-to-reach places after receiving approval from the Federal Aviation Administration last year. Drones are helping DOT replace the use of helicopter flights, during which crews drop explosives from a moving aircraft, an inherently risky task, Glassett said.
Drones are also a cheaper tool to have on hand. Helicopters can cost thousands of dollars to operate and fuel, while drones require a battery charge, Glassett said. Drones can also take advantage of shorter weather windows that would typically keep a helicopter on standby.
With the drone, operators can send explosives up to a "very specific and accurate location very quickly" and trigger a controlled avalanche, said Dan Justa of Drone Amplified, the Nebraska -based company partnered with the DOT.
The department can quickly reopen roads after the mission.
"You can do some precise mitigation from pretty far away without going to the site physically yourself," Justa said.
DETECTING MORE AVALANCHES
The new technology also benefits Chugach National Forest Avalanche Center forecasters, who share phone calls and text messages almost daily with DOT and other groups that depend on forecast data. This winter, it's helped forecasters register changing conditions more quickly before they venture into the field on skis or snowmachines to "get a look at things," said lead avalanche specialist and forecaster Andrew Schauer.
"Tim and his program are detecting more avalanches that would often go unnoticed," Schauer said.
After the state transportation department finishes testing the new equipment, Glassett said he hopes to do a full rollout in "high risk" areas across the state, including Thompson Pass, Atigun Pass and the Klondike Highway. He has plans to integrate alerts into the Alaska 511 transit platform, install active warning lights on the side of the highway and eventually automate avalanche closure gates.
"We are still using our ability to forecast avalanches, which we're really good at, but we can make mistakes," he said. "This technology is not eliminating that human element, but this thing can look through clouds, storms (and) blizzards, and it's still going to work."
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