Avalanche Observations Report March 7, 2012
Tues March 6 we were at Harvey Pass- 60cm of recent storm snow on the bed sfc from the remote we had on Feb 29 which ran on the Feb 9 surface hoar. We did some compression tests in a different slope and got moderate results on the same layer, now buried 125 cm at 2000m. So, can this layer still be triggered by a skier, sledder, cornice fall?
Well, meanwhile at Inverted Ridge, a sledder triggered a 100m wide x 200m long slab on the same layer down 4′ (1.2m) and was fully buried for close to 30 minutes. His buddies dug him up. This slide on a slope below treeline which propagated above, beside and below the sled – the crown was on a convex feature.
Then, today, we had a search and rescue call from Matheson. Some sledders got stuck and needed help getting out – there were a couple of 1m slabs out above the road they were on and one of them ran ~ 120 vert m to the cut block below. No involvements or injuries BUT make no mistake, the Feb SH layer is alive and well and can be triggered by humans, either directly or remotely. With warm weather continuing, yikes, don’t trust anything over 25 degrees.
LAst week we triggered an 85 cm slab on a N aspect W of the saddle (skiers left) at Harvey – walking to a large tree on the flat ridgetop the slab propagated from shallow snow in the tree well out into the top of the slope (40 deg ) and then 60m wide and 200m long – a serious sz 2. This location is only a few hundred metres from a slope below the cliffs to the E where a sledder was buried with only his head and one hand exposed one week ago. The buried SH is touchy if you hit the wrong spot – we need to give slopes greater than 25 degrees a wide berth. Here are the images:
Gord Ohm
Avalanche Technician
South Rockies
250-423-8984
