How to Dig a Snow Pit
Fancy yourself a backcountry legend? The Sultan of the Skin Track? The Poobah of Powder? Maybe, but all your carefully edited headcam videos and skin-ripping glamour shots will be consigned to the junkyard of broken dreams if you end up as the latest avalanche statistic.
Staying safe’s the raddest thing you’ll do this winter—learn how to properly dig a pit and analyze the snowpack, and you’re way more likely to make it home still able to brag about what you just sent. To get your snow safety career started, we caught up with the Utah Avalanche Center’s Bruce Tremper for a quick rundown on the basics of digging a snow pit and conducting stability tests (seriously, these are the BASICS. Take an accredited avy course, too).
In snowpack analysis, as in real estate and tattoos, location is everything. For accurate information, dig your pit on a slope with the same aspect and steepness as what you plan on skiing. Also, don’t wait until you’re halfway up your line to dig—the point is to have an idea of a slope’s stability before you’ve committed yourself. Pick a smaller slope with more manageable consequences (it’s OK to choose something slightly lower-angle, too, for safety’s sake), and you’ll be more comfortable taking the time to do the job right.
Found a good spot? Your first step is to do some probing, either with your pole or—wait for it—probe, to get a feel for any weak layers that might be hiding under your feet (most guides and backcountry vets frequently perform quick probe tests as they’re moving). You’ll feel a weak layer if your probe seems to drop away into nothing; look for it when you’re digging. Keep the walls smooth and vertical, and don’t be afraid of getting in there with your hands—feel for strong and weak layers, look at crystals, get friendly with it.
Once you’re tight with your pit, the relationship’s reached the point where you can really start getting to know each other. Perform a Compression Test by cutting out three sides of a shovel-sized column (so it’s isolated), place the shovel blade on top, and give it ten firm taps from the wrist. If it’s solid, keep tapping from the elbow, and if the column still hasn’t failed after ten of those, give it ten more all the way from the shoulder, watching for collapse the whole way.
Next, isolate a column 90cm across and 30cm deep for what’s called an Extended Column Test, which’ll show you whether the snowpack’s likely to collapse and if it has the energy to propagate into a full-scale avalanche. The Place your shovel on a corner of the column, just like you did in the first test, and start the tapping process from the top. If the weak layer fails and the column slides, a fracture is able to propagate and potentially release a larger slide. Keep an eye on the quality of the shear, too—a slumpy fracture doesn’t possess as much energy, while an aggressive, clean shear means the slab is poorly bonded to the weak layer, and more likely to produce an avalanche.