New research:
This new research finds that these RSL features are flows of granular material and thus, align with the long-standing hypothesis that the surface of Mars lacks flowing water.
They can tell by how the RSLs stop after the slope is not as steep that it is granular material sliding down the hill and not flowing water. So they have the "avalanche" part right even though they are not using that word yet.
They still don't understand the how and why of the avalanche. If the path has H2O in it then there is frozen H2O sliding down the hill. In order to get RSLs year after year somehow frozen H2O is carried to the tops of mountains. We think that the atmosphere is making frost or snow that is blown up one side and collects just past the peak where the peak blocks the wind. On Earth we call this collection of snow a "cornice". Then when things warm up it makes an avalanche. So other investigators have not yet settled on the "cornice" part of our answer.
However, it seems they are getting closer and closer and that in another two years it will be clear that "cornice avalanches on mars" is the right answer. Will keep updating this blog.
