Late in February, we received word from the Pacific Northwest Seismic Network and the University of Washington that there had been a noticable surface seismic event (not an earthquake) that appeared to be near the top of the Nisqually Cleaver. You may recall that in the summer of 2012, a large portion of the Nisqually Cleaver gave way at about 12,000 feet and tumbled down to about 8000 feet on the Nisqually Glacier. This wasn't as big, but nevertheless the PNSN and the UW gave us a heads up and asked if anyone had seen anything.
Reports and pictures started to come in.
I hiked up to Camp Muir on Friday, February 28th and was able to snap these quick, low-res images.
You can see the brownish stain on the surface of the glacier below the Nisqually Cleaver. This is exactly where the large rock avalanche occured in 2012.
However, what was more noticeable was a snow avalanche that occured from the 11,500 foot level on the Nisqually Icefall and travelled all the way down to the terminus of the Nisqually Glacier. I have seen avalanche debris on the Nisqually down to about 6500 feet before, but never down to the terminus!
Here are some pictures.
6800 feet to 6200 on the Nisqually Glacier. The avalanche debris was powdery and dry up above, but became loose and wet down below.
6400 feet to 5600 on the Nisqually Glacier.
6100 feet over the terminus. The avalanche lobe nearest the foreground ended up spilling over the eastern terminus of the Nisqually at this point and travelling all the way down the lower western terminus below the Nunatak.
This was one of the longest, but not largest, avalanches I've ever seen on Mt. Rainier!
Check out the Google Earth map of the two avalanches.