[MCR] Snow Spider Mt Coast Range

We skied on the N face of Snow Spider yesterday. We saw evidence of 3 separate Na size 1.5-2 on South aspects near 2000m. They appeared to be radiation triggered with the recent snowfall of 25 cm failing on the Suncrust. Although small the propagation was very broad and they ran far, one went close to full path.

 

A Test Profile in a sheltered Treeline location on the North side at 2000m revealed well preserved Jan 04 Surface Hoar crystals up to 10mm in size down 60cm from the surface, and producing sudden planar shears in the low end of moderate Compression Test range.

 

Another profile at 2150m in an alpine bowl showed decomposing Surface Hoar crystal 3-5mm in size and producing sudden planar shears in the upper end of moderate range when we did Compression tests. We witnessed no cracking and had no ski test results. However this layer is definitely a concern in specific locations and could become reactive with increased load.

 

Additionally there was much whumping in the valley bottom on the newest Surface Hoar layer which I observed earlier in the week under Mt Joffre as large as 20mm and as high as 1600m. Play safe with additional snow accumulation.

Tim Pochay

MG

 

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