Snowcraft 2 or Crevasse Rescue School
Today Andrei, Brian, Dan, Joe and Lora went to Snowcraft 2 or Crevasse Rescue School. This class is required because we will be traveling in areas that may contain crevasses. A crevasse is a crack in a glacier or ice sheet caused by the ice motion. They often form on slope breaks where the glacier accelerates, causing strain within the ice, resulting in a crack. Crevasses can be covered or bridged by snow. These snow bridges are helpful when they are thick as they allow for a relatively safe travel route over the crevasse. However, snow bridges are dangerous when thin and weak, masking the void beneath. At crevasse rescue school you practice skills for walking safely on the ice as well as emergency skills if someone were to accidentally fall into a crevasse
On the US ITASE traverse, we are very careful to avoid crevassed areas. Routes are planed well away from known crevassed areas. We also use ground penetrating radar to detect unexpected crevasses as we are driving (We will discuss more about this radar in a future log). Although there is minimal risk of falling into a crevasse, we must still practice rescue techniques and the practice is quite fun.
Crevasse Rescue School takes place at the base of the Silver City Ice Fall on the Ross Ice Shelf. A big trench has been dug in the ice shelf to simulate a large crevasse. We drove a Hagglunds vehicle to the crevasse simulator. A Hagglund is a specially-designed articulated snow tractor built in Sweden; it is a tough little vehicle (although a bit slow). The crevasse simulator has very steep sides and ramps at both ends. We used the end ramps to practice foot placement and safe walking on snowy/icy slopes. Once we got our feet under us, we were given ice axes and taught the self–belay and self–arrest techniques. These techniques are needed in case our feet slip out from under us on a steep slope. It was fun to slide in the snow and see if we could stop ourselves with the ice axe.
The next part of crevasse training was learning safe glacier travel techniques. This involves putting on harnesses and roping ourselves together, if one person falls into a crevasse the others on the rope can catch them before they fall too far. We learned how to put on harnesses properly and then how to tie the knots that anchor us to the rope. We learned the Figure–8 and Prusik knots. If you would like to know more about the knots we learned, check out Animated Knots by Grog and click on the "Climbing" link.
We practiced walking around while roped together; this requires good teamwork and communication skills. One person on the rope team would then simulate a crevasse fall and the others would attempt a rescue. We learned how to construct snow anchors that will easily hold the weight of a person on a rope. By the end of the day we were all a little cold but had thoroughly enjoyed ourselves nonetheless