Text Box:      Text Box: 12-18-06, Castle Rock and Other Avalanches              Toby Weed           

            

 

 

 

 

Someone has an exciting avalanche survival story from last weekend, but I haven't heard it yet.  I came across this large Hard Slab avalanche in Castle Rock, just south of Naomi Peak, which appears to have been triggered over the weekend by some apparently very lucky snowmobilers.

 

The crown of the avalanche on a north facing slope at around 9400' is several hundred feet wide, essentially encompassing the entire cirque.

 

The avalanche failed on a thin weak layer made up of sugary or faceted snow.  The crown was 2 to 4' deep

 

Looking up the east flank of the avalanche.

 

A few partially covered snowmobile tracks at east side of the crown tell a scary story.

 

This shot shows the far east flank of the the avalanche, where it appears to have been triggered.  Partially buried snowmobile tracks are visible in the upper left.

 

 

 

 

Other Avalanches

Here's another Hard Slab on a northeast facing slope at 9800', just north of Naomi Peak.

 

This broad avalanche on a northeast facing slope is in way Upper White Pine Canyon.

 

You can see a couple broad natural avalanches from a distance on northeast facing slopes in Wood Camp Hollow

 

Text Box: A couple extended column tests showed instant propagation across the face and a compression failure of 13 taps on a deeper faceted layer. Snow from November. Text Box: The slab failed in the easy moderate range on a layer made up of frost crystals called surface hoar and small sugary facets. Snow that was on the surface in early December Text Box: □ Text Box: □ Text Box:   Text Box: →

I dug a test pit on a north facing test slope at around 8500'.  Because of the presence of a slab on top of weak sugary snow, I was spooked just getting out on the short 35 degree pitch.