Hey, back to transcripts! I’m pleased that this one was next in the sequence, because it actually ties in nicely with a post I’ve been wanting to do about engineering with ice and snow.
“The wind came back today. It started out calm enough, and we almost went out to make measurements. But when we called the forecasters at McMurdo, they told us that the wind was due to pick up soon, and would get to thirty knots–gusting to fifty–sometime tomorrow.
On hearing this, Mel pointed out that we were going to need to prepare the camp for the onslaught of wind and drifting snow. This meant building another snow wall.
A snow wall is both made of snow and designed to control snow. It’s simply a low structure made of snow blocks that serves to slow down the wind and make it drop its snow upwind of camp, instead of on top of us. The wind carries truly impressive amounts of drifting snow across the landscape, and it dumps it every time it gets slowed down by passing over irregularities, such as our tents. We already have two snow walls, but in the six weeks the camp has been here, the space behind them has already entirely filled with drifted snow.
Most of the snow around here is extraordinarily hard-packed, and our resident snow scientists are astonished by its strength-to-weight ration. In many places, you need a chainsaw to really make much of a dent in it in any sort of efficient way. So, Mel got out the chainsaw, and cut enough blocks to make our walls.
We had them assembled in fairly short order, so we got a little creative. Mel built an arch, I built a turret, and Martin and Ruschle spent most of the afternoon digging a snow pit and being astonished at it.
Martin says the snow here consists mostly of depth hoar, a sort of re-crystallized snow that’s ordinarily [that is, in more temperate regions] light and crumbly, but here is very hard—“like cement”, he says. Ordinary snow shovels would break on the first try. We use sturdy metal gardening shovels (the labels say they’re “contractor grade”) and they still have trouble. The depth hoar snow is also full of little crystalline cups and ??, quite delicate-looking for all its strength.
So, we have a new snow wall, and hopefully we’re well prepared for the coming storm. I’ll let you know how it goes. Cheers!”