Cornice triggered avalanche in Middle Basin

My partner and I were traveling along the ridgeline separating Beehive and Middle Basin. 60 meters before the prayer flags on the ridge, we were stomping on the cornices. We heard a very loud whumphf and the cornice directly below me fell. This and our stomping triggered shooting cracks along the ridge and remotely triggered a cornice 30 meters ahead of us. This cornice fall triggered a hard slab avalanche that was about 15 meters wide and ran at least 100 hundred meters, but we could not see the terminus in the trees. The crown was 1F wind slab failing on facets 35 cm deep. It immediately stepped down to basal facets in spots with total crown depth of 75 cm.  

We dug a pit several hundred meters further down the ridgeline in a more representative area. See attached for snowpilot and picture of large chained depth hoar at the ground.