Colchuck avalanche

Is there any history of glacial outburst flooding/internal water pooling on the Colchuck?

^ I was wondering that, too.

This event was after/during a rain saturation period, right? Full-pack wet-slab-on-rock release somewhere high up?

Considering the rapid changes we've seen (especially after last year), there may be no history of GLOFs, but that type of action may very well have played a part here. Interested to hear what people find upon investigation of the site.

GLOFs: en.wikipedia.org/wiki/Glacial_lake_outburst_flood

Mikes mole rock theory has been debunked! We went up there today(tr to follow) and "discovered the cause" there was a huge land slide on the Colchuck side that was the mechanism for the start of the release.  It really was just amazing, I wanted to torture Mike and his theory! HA!

He is require to submit a new "stamped" drawing to explained the new discovery.

The large amounts of water migrating downhill within the snow at this time of year is a big factor when something loads the slope like a big rockfall. Very persistent layers within the snow left over from winter can provide a base for this water to track along.

Mikes mole rock theory has been debunked!

I was way off. Here is we found:

The trigger was a huge rock fall from the shoulder of Colchuck.

colchuck col is at the left on the skyline. The green line is what I believe to be the event boundary. It's possible that the gap in the skyline did not exist before this event. I wonder if someone has a photo for comparison?








All the snow slid off the glacier on the steep pitch near the top. The bed surface is glacier ice. On the left side in this photo, the snow depth at the skyline was just more than a ski pole, and near the bottom of the slope the sidewall was just over 300cm deep. There was a weak layer between 155cm and 195cm from the surface where my probe met very little resistance. I don't think the weak layer played any part in this event. The snow depth tapered on the right, at one point to zero where glacier ice is exposed at the surface (right of center in the photo)


The debris pile was truly impressive. It filled a large portion of the flat above the terminal moraine. 15 feet (estimated) deep at the lowest edge.


I re-watched the videos. The woman from the lake mentioned hearing something and then a few minutes later seeing the avalanche. Her video shows white snow. The climbers videos both show white snow, especially the debris flow into the moraine basin which was snow chunks with an occasional large rock. What Jamie and I found in the debris pile was a mix of rock and snow with sand over the top.