OK
So now we've established that defrosting CO2 icepack and dust can form an avalanche, and that the chutes and linear chennels on the margins of the North Pole are essentially driven by these avalanches.
In a little while, someone will make the stunning deduction that maybe the gullies and channels in mid-lattitudes are caused by similar flows, under slightly different climatic conditions.
Now, where have I seen this ideabefore?