Human triggered slides into this old snow layering is becoming increasingly difficult. Still, as the observation in Argenta (north side of Kessler Peak) in BCC suggests, not impossible. If not for the slope angle and the terrain features, this slope would have avalanched. Argenta often harbors shallow, weaker snow and we - as avalanche forecasters - often seek out the outliers for testing. In 2010, Birkeland, Simenhois, and Heierli presented a great study, THE EFFECT OF CHANGING SLOPE ANGLE ON EXTENDED COLUMN TEST RESULTS: CAN WE DIG PITS IN SAFER LOCATIONS? In a nutshell, they found that we don't necessarily need to "hang it out there" and dig pits in steep terrain for it to be representative of the slope. Aspect and elevation are enough. This was great confirmation that we can assume less risk in order to gather the info we want. On a side note, I know of at least two people who - when performing tests in a snowpit - triggered and were caught and carried in an avalanche. They ended up being ok, but I am still wondering how to score those test results. (cartoon from Mike Clelland of the Allen and Mike's book series - check them out)