Avalanche details emerge in online report | AspenTimes.com

Avalanche details emerge in online report

Editor’s note: The following is a report from the Colorado Avalanche Information Center posted online at 11 p.m. Monday.About 2:45 Sunday afternoon, a 32-year-old man was buried and killed in a sizable avalanche in the backcountry near Aspen Highlands. At the time of the avalanche the man was participating in a Level II avalanche-awareness class in Five Fingers Bowl. He was the only person caught. Details are few and what follows is preliminary and subject to change. We know the group had dug several snow pits across the top of the bowl as they traversed southward. Stability tests indicated moderate shears or what we might call “so-so conditions.” The tests and pits apparently did not reveal obvious instability or stability. The group – skiing one at a time – was working its way down a prominent rib and gully below the “Thumb” (a point at 12,495 feet). A skier would ski toward the gully or perhaps even in the gully and then traverse back to the rib to wait for the next skier. The victim – skiing third – skied into or toward the gully and fell and rolled. This triggered the avalanche that broke some distance above him and swept him down nearly the entire track. RescueWords likely cannot describe the horror the group experienced watching one of their own swallowed up in a churning torrent of snow. They descended quickly but cautiously; at one point they had to remove their skis to down-climb a rock band. It may have taken as long as 20-30 minutes to reach the debris, and a transceiver signal was quickly detected. It was only a matter of minutes before they had pinpointed the signal and started digging. They found their friend under 3-4 feet of snow, and started CPR for at least an hour without success.Minutes after the avalanche two members of Mountain Rescue Aspen were driving from Ashcroft back to Aspen when they noticed the fresh-looking avalanche. From the road and using binoculars they were able to see ski tracks, including one track ending at the fracture line. They could not see the skiers and drove a short distance down the road and looked again. This time they could see the skiers descending the debris. It was a short time later their rescue pagers sounded with the report of the accident. They quickly drove to the trailhead and started up to help. The body was evacuated by the group and by Mountain Rescue Aspen. The Pitkin County Coroner’s Office said the victim died from asphyxiation.The avalancheEarly reports classify the avalanche as a medium- to large-sized avalanche – large only because it ran so far – released about 3 feet deep by about 150 feet across. The slab fractured 200 feet above the helpless skier. The fracture line was just below 12,200 feet and the avalanche fell about 3,000 vertical feet, stopping below 9,200 feet, or just short of the last steep pitch above Conundrum Creek. The avalanche released from the steep northeast-facing side of the gully in cold, dry snow, but by the time the avalanche stopped it had plowed into wet snow low in the runout. The victim was found about 200 yards uphill of the toe or end of the debris. The weatherThe weather on Sunday was beautiful and spring-like; however, it was not a cause for the accident. Though snow near the valley floor was wet, the snow high in Five Fingers Bowl was cold and dry. Temperatures at the time of the accident were in the upper 20s and a light breeze blew from the west.Temperatures during February and for the first six days of March were very mild. The average daily temperatures stayed in the upper teens to upper 20s for nearly the entire month. Only on three days did the average daily temperature barely dip below 10, and those days were weeks earlier. As mild as temperatures were, February snowfall at both Aspen Highlands and Aspen Mountain was probably about normal with 40 and 46 inches reported. At higher elevations like the upper reaches of Highland Bowl and Five Fingers Bowl, even more snow fell. In the first few days of March, 2.4 and 4.6 inches of new snow were reported at Aspen Highlands and Aspen Mountain. The snowpackFew exact details are known. Most likely a persistent layer of faceted, sugar-like grains that likely formed during the dry and mild last two weeks of January were the culprit. This particular slope may have avalanched earlier this season, leaving behind a generally shallow snow cover where a strong temperature gradient weakened the snow cover. If the slope did not avalanche, near-surface facets formed during the dry end of January. In both situations, the weak snow was buried by February snows. The backcountry avalanche danger posted (by telephone hotlines) Sunday morning for the central mountains was “overall moderate near and above tree line, low below tree line.”As we learn more information about the snow cover, we will pass it along.


Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.



News


See more