Forum ridge N slope lower

Failure at 20cm after 5 hard hits between two soft slabs on what looked like a very thin surface hoar layer. Interestingly,the failure was not on the 45 cm ice crust layer. Only one test was done, on low angle terrain ~10°, NE aspect, in thin trees. Significant whumpfing observed under skier weight on low angle and convex roll terrain. We suspected the whumpfing was from the 40cm ice layer, but our test didn't fail at this layer.