Blasting powder

Heavy snows keep resorts' avalanche crews hopping

By Brian Metzler , Special to the Rocky

Published February 25, 2008 at 5:12 p.m.

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Photo by Vail Resorts / Special to the Rocky/2008

Breckenridge ski patrollers blast on the Lake Chutes in the Peak 8 area to control avalanches at the resort.

Photo by Chris Schneider / The Rocky

Slab avalanche

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Every morning an alarm clock goes off in Summit County around 3:45 a.m. with you and your ski buddies in mind.

While most skiers are still sound asleep, Will Barrett, Tim Haag or Mark Beardsley will arrive at the Peak 8 Patrol Headquarters at Breckenridge Ski Area and begin checking overnight snow totals, wind activity, humidity and other weather criteria, including avalanche forecasts from the Colorado Avalanche Information Center.

It's the continuation of an elaborate process that ultimately determines whether some of the resort's steepest and most sought-after terrain will be open later in the day.

Because Breckenridge has a large amount of above-tree-line terrain and several high-angle bowls and is situated in a very windy part of the Ten Mile Range, it's among the most active Colorado resorts when it comes to using explosives for avalanche control.

And this winter, which has brought large snow totals, lower-than-usual temperatures and heavy overnight winds, the resort's avalanche blasting crew - and those at other resorts - is as busy as ever.

Like the snowflakes that fall on the mountain, no two days are alike in the avalanche-control business. A dusting of new snow and heavy winds can create much greater avalanche susceptibility than a foot of powder can in still conditions, says Bob Tierney, snow- safety coordinator for the Breckenridge ski patrol.

Slopes from 20 to 60 degrees can be susceptible on any particular day, depending on current and previous snow and weather conditions, Tierney says. And that's why the process for the morning control work begins the previous afternoon with weather forecasts.

"It's a challenge to try to beat the elements and open terrain that sometimes Mother Nature would be holding back from," Tierney says.

After collecting weather data, the early-morning "weatherman" makes an initial report for the ski patrol and snow-safety centers around the mountain. When Tierney arrives at 6:30, he uses that information to formulate a plan for the ski patrol to mitigate potentially dangerous snow conditions. That plan might call for as many as 20 patrollers on four to seven control groups to head out with an assortment of avalanche explosives stored at a well-fortified midmountain bunker below Peak 7.

The explosives come in two forms: a 2- to 5-pound charge that's hand- thrown or dropped into place via a long nylon cord and detonated by a two- minute fuse, and a 1-kilogram projectile-rocket charge fired from an Avalauncher, a compressed-gas cannon with a 1,500-vertical-foot range.

The method of delivery depends on the accessibility of the "sweet spots," the places on a particular slope that the ski patrol knows from years of experience will effectively bring down most or all of a dangerous slab.

The crews head to the top of the mountain at 8:30 a.m., about an hour before the upper lifts are open to the public, and ideally they're able to complete the work between 9:30 and 11 a.m. But Tierney's initial plan often changes once patrollers take a visual assessment of the slopes and determine actual snow conditions from snow-pit tests.

If it's a big day, like it was on Feb. 12, avalanche-control crews might detonate 40 or more charges to mitigate wind-loaded slabs that developed the previous night. And if bad visibility impairs avalanche-control work from being done or it appears that bad visibility might remain for most of the day, Tierney might decide that the safest thing to do is to keep an area closed and focus on other terrain.

From there, a flurry of radio communication begins, control plans are adjusted and bombing begins. But it's not akin to lighting sky rockets and firecrackers on the Fourth of July; the job of an avalanche blaster takes some special skills and plenty of training.

Each avalanche blaster must undergo three years of on-the-job training, take written exams and submit to background checks by the FBI and the CBI in order to be licensed through the Colorado Department of Labor and Employment Division of Oil and Public Safety.

The effectiveness of the ski patrol's early morning-control work can have a big effect on whether Breckenridge can open its double-black-diamond terrain, such as the runs off Peak 7, Imperial Bowl and the Lake Chutes. On the blustery, low-visibility days when avalanche-control crews don't think it's safe to open some of the resort's most extreme terrain, the ski patrol has to answer to dissatisfied locals and constantly be on the lookout for rope-duckers insistent on skiing fresh powder at their own risk.

Contrary to popular belief, the resort doesn't hold fresh powder so it can extend the effects of a storm, says assistant ski patrol director Joe Holland.

"If it's socked in, if it's an ugly day and there are white-out conditions, there's usually not much questioning about, 'Hey, how come you're not opening that?' " Holland says. "But if it's a clear day and they can see it and it looks skiable to them, there's hardly any stopping them. So we need to take care of it and get it open."

Ducking under ropes to ski closed terrain is strictly prohibited under the Colorado Skier Safety Act. At the very least, the ski patrol will take away a skier or snowboarder's lift ticket or pass. But if the culprit has entered severe avalanche terrain, the patrol will turn the offender over to the Summit County sheriff's office. The maximum penalty can be a $1,000 fine and up to six months in jail.

"If it's a serious avalanche violation, they're setting themselves up for great risk and the possibility of a big rescue scenario, and we get very serious about that," Holland says.

Because of the safety precautions and the amount of control work done at Colorado ski resorts, inbounds avalanches are rare, but they do happen. Three years ago, a 53-year-old Boulder man was buried and killed by a medium-size wet-slab avalanche on the west side of the Pallavicini Run at Arapahoe Basin. Before that, the last time a skier was killed by an avalanche in open terrain at a Colorado ski area was in 1975.

This winter's big snowfalls have already led to inbounds slides at California's Mammoth Mountain and The Canyons in Park City, Utah. And with many resorts such as Breckenridge and Arapahoe Basin continuing to push their boundaries to offer more backcountry- style terrain, the need for effective avalanche control has only increased.

"Knock on wood, we've been extremely lucky to avoid that kind of situation," Tierney says.

Types of avalanches

There are generally three types of avalanches, each caused by different snow conditions.

* Slab avalanches: The most common type of avalanches, caused either by newly deposited snow sitting on harder layers of snow or by a hardened layer of snow caused by heavy wind loading. Soft slabs tend to occur below a trigger point (such as a skier's tracks), while hard slabs occur at a weak point in a large area, often well above a trigger point. Hard slabs generally are harder to trigger but are often the most deadly because of the magnitude of the slide they can produce.

* Loose-snow avalanches: Also known as "point releases," typically start from a single point and fan outward as they descend. Also known as sluffs, these types of avalanches are common but generally less dangerous, partially because most sluffs fracture beneath a trigger point (i.e., a skier's tracks). However, a large sluff can carry a skier down a slope or over a cliff and is capable of burying a vehicle or a house.

* Wet-snow avalanches: Caused by a decline in the strength of snowpack in a particular area, often when rain or prolonged melting snow increases the weight and density of snowpack. The slides generally are slow, but the density of the snow carried makes these kinds of slides extremely destructive and hard to escape. Once a wet- snow avalanche stops, the snow sets like concrete.

Resources

The Colorado Avalanche Information Center (http://avalanche. state.co.us/) is the ultimate resource for avalanche conditions in the state, as well as safety concerns and general information. The site is updated on a daily basis.

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