Text for video below: "Every spring the sun shines on the side of the stack of layers at the North Pole of Mars known as the north polar layered deposits. The warmth destabilizes the ice and blocks break loose. When they reach the bottom of the more than 500 meter tall cliff face, the blocks kick up a cloud of dust."
At 2:13 in the video you can see the linear trails from ice sliding down. We were right that it is ice from cornices sliding down. We were years ahead of NASA. :-)
It would be nice to show that ice is accumulating as a cornice, but if this is still going on every spring after millions of years, ice must be accumulating near the top of the cliff, which is almost the definition of a cornice.
