Wednesday, November 26, 2014

Crevasses

Our field work this year will take us out onto glaciers. Even though we study soil, we’ll have to cross glaciers and ice to get to the locations we want to sample.

One of the dangers associated with walking on ice is that we could fall into a crevasse. Crevasses are cracks that form in large chunks of ice (like glaciers and ice sheets). They can be narrow or wide. Sometimes you can hop across it, but sometimes they can be too wide to get across. They can be shallow (ankle or knee depth) or very deep (100 feet deep or more).

Crevasses aren’t always visible from the surface, because they can be covered with a thin ceiling of ice and snow on top, making it difficult to spot. However, that “ice bridge” covering the ceiling of a crevasse may not be strong enough to hold the weight of a human, particularly one wearing heavy clothing and a backpack full of gear and samples!

People have died from falling into deep crevasses. Typically, we try our absolute best to avoid going into them! However, they have secured one crevasse and we are allowed to visit it. We use a lot of safety gear to make sure we don’t fall further into the crevasse, should it become unstable. It’s absolutely amazing inside!
 It’s like being in a cave made of ice, with icicles instead of stalactites. The only light is what can filter through the snow above our heads, so everything is very blue.

The picture below shows the tiny hole we had to squeeze through in order to get access to the expansive cave. You can see how easy it might be to not realize that a vast, deep cave is down there. You could easily step on it and fall into it! It was fun going into a crevasse under my own control with the necessary safety gear, but we certainly don’t want to surprise ourselves by falling into one while we’re out sampling.

To avoid these dangers in the field, we follow very strict safety protocols. Yesterday, we were trained on how to properly keep our team safe. We will walk roped together, carrying all of the appropriate gear that will be necessary to save someone from a crevasse should the worst happen. We had to practice all of these techniques during our training. Here’s Uffe practicing the method for raising yourself out of a crevasse if you fall in. (Of course, he’s doing it completely unharmed in a warm, dry building, which is very different from how it would feel if this were a real situation!)

We are still waiting for the sea ice to blow out so that we can start sampling. Bad weather is predicted to roll in, so it might be next week before we can go.