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Sunday, April 03, 2016

South Bowl Ground Ripper

The south bowl avalanche as seen zoomed in from the road

This winter has been weird with the sharp snowline and lots of precipitation.  The steep slopes up high have a lot of snow on them.  Whereas the usual dry powder just sloughs off of them, this year the wet stuff has been sticking.  Then during our rain events these steep slopes have been catastrophically releasing as huge avalanches - right to the ground underneath.  The snowpack gets super heavy with all the water and it just can't hold onto the steep slopes and so releases all the way down to the ground.

This has been happening all winter.  A big one occurred back in January in the bowl behind the antenna field.  And in the last few weeks there have been more in that bowl and everywhere else it seems.  Just look up into the mountains and you'll see the brown stains where the avalanches have slid.  Where they haven't slid you can see huge cracks at the tops of the slopes.  These are called 'glide' cracks and represent the snow pack trying to slide and cracking.  Once the ground on the slope under the snowpack gets 'greased' with water it acts like a lubricant and the avalanche releases.  This happens with glaciers too - once there is unfrozen water on the bottom they speed up.

Anyway for the last couple of weeks there have been huge glide cracks on the face of Pyramid above the south bowl (click here to see them behind me and Stuey).  They looked like gaping knife wounds.  Then last Tuesday when I climbed up Pyramid in the fog I was surprised to see black on the face where ordinarily I see white.  I suspected an avalanche but it was too foggy and misty to tell for sure.  On Friday as I drove up to the pass it was finally clear enough that I could see the avalanche debris.  It was a big one.

Yesterday Lisa and I climbed up to check it out.  WOW!  An avalanche beacon wouldn't help you if you got caught in one of those - you'd be killed instantly not buried.

There is so much dirt and ripped sod that I am worried about increased erosion on the slopes above these bowls.  And what are the bowls going to look like?  Will the wild flowers all be covered with mud?  Patrick

First view of the fracture face as you look over into the south bowl

2 avalanches actually released during last Monday's rain

It looks like no more skiing this year in the south bowl gut

That was one big ground ripper!

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