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Posts Tagged ‘avalanche’

One of my goals for 2010 was to complete an AIARE Level 2 Avalanche Course. Alpine World Ascents offered a course that fit my schedule so I found myself in Boulder spending a Thursday with 4 backcountry skiers and our instructor, Tim Brown, reviewing a few concepts from our Level 1 courses and laying the theoretical ground work for the next 3 days.

On Friday morning we meet in Empire for a morning of additional classroom work, then headed up to Loveland Pass for our first field session. We started the day with a short tour to a 5-day old avalanche on the Pass Lake slide path.

We spent some time digging in the avalanche debris to produce a few holes in which to hide beacons for a rescue scenario.

While digging, I took time to have a close look at the depth hoar crystals that persist at the bottom of Colorado’s usual snowpack.

After discussing our beacon rescues and a few quirks with some beacons, we toured to a small pond around 11,560 feet to dig our first snow pit with the objective of gathering a baseline profile.

This work was finished by headlamp, but Tim knew the way out to the road. Unfortunately, the snow in the trees had thinned considerably in the couple days since he’d last exited this way. With lots of exposed rocks and downed timber, I decided to remove my skis and boot it out the last bit to the road. There we caught a hitch back to our cars and called it a day.

Saturday again began with a classroom session before we went into the field. Once we moved up to the pass, we practiced taking a full set of weather data (air and snow surface temperatures, elevation, wind speed, sky cover, precipitation rates, etc).

Then it was time to “tour” back to our pond for a more practice making snow pit observations. The others may have been touring, but I’d switched to snowshoes for this short travel day as my skiing skills left a lot to be desired and my snowshoe boots were warmer than my ski boots for standing in a snow pit all afternoon.

Along the way to the pond site we practiced some travel techniques to reduce exposure, such as spreading out through possible avalanche terrain.

I wallowed down a steep slope in my shoes while the others got a couple turns just above our pit site.

After making a full set of observations and doing a few instability tests on columns of snow, we returned to the road and home to await the final day.

Once again we started with a classroom session, including making a tour plan for the day. Given the driving time to and from the pass, we shortened our route up to just do an out-and-back into the No Name basin to dig some pits in a new aspect. Once we arrived at the trailhead, Caleb practiced giving our trailhead talk (going over plans and procedures for the day).

We boot packed our way to a saddle leading into the eastern portion of No Name basin and then spent some time discussing the best way into the drainage.

I was back on skis today, given the distance we’d be touring. Skiing isn’t one of my strengths, and the variable snowpack (half wind slab, half cohesion-less grains) sent me on a skis-over-head tumble. Eventually we all arrived at our intended study-site on the ridge leading to the Hippie Trees.

We worked together to gather weather observations, dig the pit, identify the layers and do a few instability tests. The last included digging out a Rutchblock for Caleb to jump on.

It was nearing dark by the time we wrapped up and began skinning up to the ridge crest. Full darkness caught us there and we slipped down our previous track keeping our skins on before boot packing the last bit to the road.

Back in Empire we wrapped up the course with a better understanding of just how complex the snowpack can be, but in possession of a few more tools to practice and continue our learning.

Complete photo album

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Clinton Peak

In Pete’s quest to climb the 100 highest peaks of Colorado he only had 6 summits in the San Juans and Clinton Peak. Winds looked relatively low up high so we decided to tackle Clinton Peak and get Pete that much closer to his goal. After spending a night in Breckenridge we headed south over Hoosier Pass and hit the parking area to find windy conditions. After gearing up in our cars we headed out to start the hike up a 4wd road.

We had a good look at the ice climbing at Lincoln Falls as we left the parking area and both had a moment’s regret that we weren’t taking advantage of the conditions. Maybe in January we’ll hit the ice here again. As we worked past an old mine the sun began to light up Mount Lincoln’s cliffs.

I’d thought about bringing skis for the long road hike in, but I’m glad I didn’t. Parts of the road were wind blown dry and others were mini-staking rinks of ice. Snowshoes worked best for these conditions.

The sun disappeared behind Mount Lincoln as we continued west up the valley. When it was time to branch off towards Wheeler Lake it was nice to hit the sun again.

Just above the lake the terrain presented some problems in route finding. Avalanche conditions were rated “considerable” on these aspects with a shallow snow cover highly granulated then covered with wind slabs from a week prior. We’d already hit some collapsing layers in the low-angled terrain as we hit the valley. Now I needed to find a reasonable way to pass the somewhat steeper terrain just above the lake.

Pete and I linked a few 20-25 degree slopes with exposed rock areas that I deemed safe. We had to cross one snow slope that I checked at 25 degrees before venturing across.

I crossed without incident and waited at some more exposed rocks. Pete followed and then I hit a small bowl. After taking a few steps forward I heard a large “whoopf” as the windslap I stood on collapsed. I looked up at the slightly steeper slopes above and my eyes were draw to the even steeper slopes above the terrain we’d just crossed. A crack appeared and I watched a mass of snow break away and begin to slide across the path we’d just crossed.

The slopes above us showed a few compression cracks, but didn’t release. They were lower-angled than the terrain above what we’d just crossed.

I was extremely thankful I’d stopped at the exposed rocks while Pete crossed the slope. The avalanche didn’t run over the whole possible slope and wasn’t very powerful, but could have definitely partially buried a person and broken a limb. I believe if I’d kept to some rocks just to my right the avalanche would never have been triggered. Pete questioned if we should continue, and we discussed the conditions and the possibility that we’d turn back.

We decided to press on and stick to very wind swept aspects or angles below 30 degrees. Pete was moving a little slowly since he’d run 21 miles the day before. Our original plan was to head up unranked Traver Peak then follow the ridge to McNamee and finally Clinton. However, with our reduced speed we decided to follow some windblown and rock-exposed slopes directly up Clinton in the interest of time.

We moved from rocky section to rocky section over lower angle slopes and watched as we gained elevation against the nearby 13’ers and 14’ers.

The wind picked up as we reached the ridge crest, but the views of the 10 Mile range to the north provided some motivation.

The wind was well above the forecasted 10 mph speed as we contoured around a false summit just east of the true summit.

A windy and undulating ridge led us on to the real summit.

It was windy enough that we didn’t even try to dig out the summit register, but just took a single photo and started back.

We discussed a few descent options, but the extremely windblown south face of the mountain led us in that direction. We negotiated bare rocks for a couple hundred feet and descended out of the worst of the wind. Eventually, the bare slopes turned back into snow and we had to pick the most gentle descent route and watch for additional avalanche terrain. Slope meter in hand I picked my way down 30 degrees slopes to safer angles.

Once back in the valley we enjoyed descending without snowshoes and worked our way back to our upward track. After a food and drink break in sight of “our” avalanche, we crossed the debris slope.

A few of the broken slab blocks were quite large in size.

As we descended below the avalanche track we kept looking back at the closest we’d been to a running avalanche track. Pete thought about acquiring the skills and gear to deal with type of terrain and I thought about the level 2 course I was planning to take next month.

It was a relief to be out of the steep terrain and we returned to our tracks on the road for the long hike out.

After 8 hours we returned to the cars and split up with different plans for Sunday.

Complete photo album

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The next day on North Star Mountain I took the following photo of our avalanche. I’ve added our approximate route track and other notes to the photo to help explain the incident.

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Markus Beck, the owner and head guide of Alpine World Ascents gave an avalanche clinic on Wednesday night at Neptune Mountaineering in Boulder.

Markus started with the basics of avalanches: types (loose vs slab), features of slabs (weak layer, crown, bed surface, etc) and the factors of terrain, snowpack, weather and triggers. He said the most important factors to leave the presentation remembering were incline (most slab avalanches release on slopes between 35 and 40 degrees) and aspect (wind-loaded slopes are much more dangerous). Throughout the introduction, Markus also passed on some information about the human factors (heuristics) that so often cause us to make bad decisions.

The second half of the presentation dealt with common myths of avalanches and the sometimes “grain of truth” within each myth. Examples of the myths Markus discussed were “Avalanches only happen during storms”, “Waiting 2-3 days after storms is safe”, “If there are tracks then the slope is safe”, and “I’ve never seen this slope slide, so it’s safe.”

A moderate-sized but very engaged crowd showed up for the presentation and asked a lot of questions, especially about safety gear such as beacons and Avalungs. Several audience members also related avalanche stories of their own.

Upcoming shows, including future avalanche clinics presented by Markus can be seen at Neptune’s Schedule. Markus is on the schedule to present a clinic once a month with the following avalanche topics: terrain selection, risk management and a review of accidents.

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French Gulch Road

Helen and I were disappointed to see that the French Gulch Road had been plowed past the trailhead so we found ourselves shouldering our skis and hiking.

Before long we had views of Mount Guyot and the north face which was our skiing goal for the day. Last week I’d spotted the northwest ridge of Mount Guyot from Bald Mountain and thought it looked like an avalanche safe route. A little internet research showed that the north face was moderately angled and should be a nice ski.

We initially hiked past the turn off that accessed the north side of the mountain and by the time we doubled back Helen was willing to admit that she wasn’t feeling well. She’d suffered all through last month with a flu-like sickness and since Thursday night she’d started to feel a resurgence. Deciding to make the best of a low-energy day we practiced searching for avalanche beacons. I took off my beacon and buried it in the snow out of Helen’s sight. Helen then turned her beacon to search mode and tracked it down, probed for it then dug it out.

Then we switched and I searched for her beacon. I decided my old probe was too flimsy for real rescue use and determined to buy a new one. We both ran through a second search and bettered our search times.

Feeling we at least accomplished something useful, we packed up our skis and headed back to town.

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