This last MLK Weekend, a group of us took a three-day avalanche safety course up at Hatcher Pass that was run by Alaska Avalanche School. We took their Level I Backcountry Avalanche Hazard Evaluation & Rescue Techniques Workshop. The class was taught at the old Independence Mine at Hatcher Pass. The mine is now a state park and the manager's house is a museum. Most of the class stayed in the main house. My friends and I rented a cabin down at the lodge. We had to make a 30 minute hike up the road in the morning and another hike back down in the evening. But it was nice to have our own space to spread out in.The course ran from 8am until 7pm. It began with 2 hours of class time. Then, after it got light, we left to head out and learn in the field. Once it was dark we'd return to the mine for another two hours of class. These were seriously full days.
We drove out to Hatcher Pass on Friday night. Once we got there we checked into our cabin, moved our stuff in and headed to bed pretty quickly. We knew the morning would come early.
Saturday we had to be up at the mine by 8am to register, so we headed out from our cabin at 7:15. It was cold, but clear. My friends were on their backcountry skis and skinned up. I was on snowshoes. MK and I were in the back of the group and it was still quite dark. Also, we had on full packs with our gear and food. We lucked out and caught a ride on a snowmachine driven by Lloyd, the caretaker of the mine. (No, this is not an episode of Scooby Doo.) Once we were up, we registered and found places in the main room.
The class was about 20 people. Most were about our age with a few outliers. Introductions were made and the course launched right in. The first lectures were an introduction to avalanche safety and the first day focused on rescue procedures.
While we learned rescues first, the instructors made it very clear that rescue was the least important skill. Rescue skills are important, but the best course is to avoid the avalanche entirely. That's why the rest of the course focused on reading the snowpack and plotting safe travel routes.
After the first set of lectures we split the class up into three groups. I was in a group of 7 with MK, Justin, Meg, Jill, Eli and Scott. We were named the "Depth Hoars", which is the term for faceted snow flakes that exist at the deep part of the snow pack (as opposed to Surface Hoar - which forms on the surface). For a more thorough explanation, click here. The intern, John, was also placed with our group. Nancy was our instructor for the first day.Our group headed just a bit south of the mine to a safe slope on which we could practice our rescue skills. First, we concentrated on using our avalanche tansponders. Groups of two headed out of each others' range and took turns hiding one transponder under the snow while the other had to find it. Quite a bit of fun.
Next we started working on finding multiple transponders. It can take a bit of time to get the knack for reading multiple locations. But we got there eventually. After working with transponders, we started learning to use our avalanche probes.
The probes are fiberglass and about 3 meters long. You poke down through the snow to see if you hit anything. I guess if you are buried under a thousand pounds of snow, you don't mind getting poked by a sharp stick if it means you might get dug out.Then it was time for the real fun. We split up into two teams. One team went off behind a building and the other set up an avalanche scenario. I was in the team that would work the scenario first with MK, Jill and Scott. When it was time to come back, Meg was running towards us screaming that her friends had been buried in an avalanche. She was hysterical in both senses of the word. Top acting honors to her. We quickly (sort of) got the info from her and did a quick beacon sweep. We had the first two people (buried packs) out of the snow under 15 minutes. The last person took us a lot longer. They weren't wearing a transponder and so we had to suss out their location from a lone glove on the surface and the knowledge that they were somewhere between our two other found people during the avalanche. Eventually we found "them" buried in some bushes at the base of the avalanche.
Now it was our turn. We put a few twists on our scenario (such as having me be a half buried screaming person at the top demanding immediate attention). The other team did a fine job and had all the people found pretty quickly.
We finished off the field section with a brief tutorial on digging. Then it was back to the mine for the evening lectures. The highlight of the evening was a demonstration by "Dr. Science" on how avalanches work. Blaine (aka Dr. Science) set up a board with three types of surface areas (rocky, grass and smoot) with fake trees at the top and little cars at the bottom. Then layers of flour, sugar, potato flakes were laid down to represent different layers of different types of snow. The board was tilted up and the different layers avalanched at different angles. See the videos at the bottom of the post!After the day was finished we headed back down to the lodge where about 10 of our friends had come up for the day. We played cards, ate a wonderful potluck dinner and sat in the sauna. It's a rough life in Alaska.
The next day was the opposite, weather-wise, of our first. It was snowing and storming. The wind gave us a push up the trail to the mine, and it was howling around us. The second day focused on predicting avalanches by looking at snow conditions, weather and other factors. This was the most interesting day.
Our field sessions were led by Joe. He led us, again, down the southeast side of the valley and we looked for good places to sample snow conditions. While walking, we talked about slope angles and which areas we should avoid. The wind was really blowing hard and snow was flying in our faces. While working our way around a small valley, a cornice let go and a slab avalanche set off along the entire north face of the slope we were looking at. We couldn't appreciate how far it went because of the conditions, but we later walked all the way around it and found the toe of the debris.
The majority of the day was spent analyzing the snow in a pit that we dug. First we dug out an exposed vertical face so that we could look at the layers from the top of the snow to the ground. We plotted the different layers, looked at what they were made up (rounds or facets) and analyzed their hardness. Then we dug a rutschblock (article here or here). To perform a rutschblock test, you dig out a 2 meter wide by 1.5 meter deep block to isolate a column of snow. Then a skier slowly steps out onto the block and you grade the block based on how quickly the block slides. There is a video of our block sliding below.After our tests we headed back. It was time to get out of the wind. As we sat through the evening's lectures, the wind picked up and buckets of snow began to come down. We knew we were going to have to make our way back down to our cabin through the snow. We set out at 7 and could just barely make out the lights of the cabins below. Luckily we were able to find our way by following a snow machine track and reflective poles on the road. We were happy to make it down. Ryan had decided to stay behind to have dinner with the class and ended up having to spend the night at the mine when the storm worsened. The rest of us cozied up in the cabin. We all packed for our early morning departure and then enjoyed a bit of talk and a beer.
The next morning we emptied the cabin and loaded the gear into the trucks. The morning was cloudy, but the wind had died down. The third day of the course focused on safe travel practices. Our group was led by Blaine. Blaine was a blast. We headed southeast of the mine and our first plan was to get on a ridge and make our way to the top of microdot (a minor peak).
The day's conditions were perfect for avalanches. We had a layer of wind scoured snow (wind slab) from Sunday covered with about 6 inches of fresh powder from the night's storms.We tried to find a safe slope to get onto the ridge. We picked a slope that looked like it was below 25 degrees. Blaine said the best procedure was to pick the least valuable member of the group and then send them up the slope to break a trail. I was sent up. It was quite a bit of work to break the trail. The fresh powder came up to my thighs. I had to kick my way up through the snow and then pack it down on each step. I zigzagged my way up the slope moving around rocks. As I walked, I heard several good-sized whumphs, which is the noise you hear when a weaker layer of snow below you collapses. It's a sign of snow instability and avalanche danger.
After a particularly loud whumph, the group started yelling about an avalanche around the bend. Apparently the entire ridge north of where we were had let loose and slid because of the stress of me (all 160 or so pounds with gear) walking up the low angle slope. I could see where several avalanches had run out onto the flat below the ridge. We scrapped our microdot plan and decided to get a better look at the slopes that had avalanched.
We walked back around to the toe of the slope and figured out the slope angle (36 degrees) and looked at the layer on which the snow had slid. We then worked our way up to the crown of the avalanche. The path of a recently slid avalanche is actually quite safe because anything that would have slid would have already done so when the thousands of pounds of snow let loose.It took us about an hour to figure out the snow and Blaine again took us through a series of shear tests. The view was gorgeous. From our spot on the side of the ridge we could see other slides around the valley and even saw a huge pile of powder fly up on the air from a huge slide on the opposite side of the mine.
Then we descended and walked along the line of the ridge keeping a safe angle away from the ridge (less then a 20 degree angle from the top of the ridge). In all, about a half a mile of ridge had slid. Amazing. We discussed safe travel procedures and then headed back for the final class session.
After the final talks we helped clean up the mine and headed back down the hill. We jumped in the cars and headed back to Anchorage. It was a great weekend, but we were all exhausted.
PICTURES:
http://picasaweb.google.com/jack.r.mckenna/AvalancheSafetyCourseAtHatcherPass
VIDEOS:
A Rutschblock Test - Meg stepping out onto our rutschblock and it collapsing.
Dr. Science explains an avalanche part 1 - Blaine uses a piece of board, sugar, potato flakes, and flour to demonstrate avalanches.
Dr. Science explains an avalanche part 2
Jackalanche - a video showing the area where I set off an avalanche
