RAMMS

Do you know this case?
It was a large landslide on Aoraki - Mount Cook National Park in New Zealand, ocurred 21st January 2013, detached from west face of Mount Dixon.

Reports about how it was seen from Plateau Hut under way after rockslide, and the climbers evacuation.

It was a rock avalanche with snow and ice entrainment along the track, and changing the movement mechanism from granular fluidized mass at high velocity, to a slow slide on the plateau with clear creep behavior.
It is a complex granular flow that I suggest to be calculated with RAMMS as a back-analysis.

Some videos to take an idea:
Landslide seen from Plateau Hut:


Helicopter fligth:


Report with interviews:


Another point of view of the avalanche


Dave Petley in his AGU-blog made a preliminary interpretation.
I added some comments to this.

I think that is more or less the opposite of a debrisflow formation:
- For debrisflow, normally first is the flowing water (liquid hydraulics) and, exceeding a discharge treshold, the erosion becomes suddenly very relevant, what means the entrainment of solid particles to perform a bi-phase flow (rocks in water).
- In this case, first is the debris part, and due the entrainement it appears the matrix part of the bi-phase flow (rocks in snow), or perhaps a multi-phase granular flow.

In summary, the mixture of rock-ice-snow-water-air is explaining the rehological properties of the flow in this final part of the track.

What do you think about?
Nice case to be modeled with RAMMS?

Dear Marc

Thanks a lot for the nice movies. We heard about this event. I hope we will find time to do some investigations on that case soon.