Saturday, December 26, 2009

Large Rock Avalanches on the Nisqually

OK, folks, there're some major rock avalanches happening on the Nisqually Glacier. Anyone venturing near the Nisqually or even traversing across it lower down to get across to the Fan should read this post. We're not talking about a bunch of rocks, but many thousands of tons of debris in a 50' wall of snow, ice, water, dust, and rock coming down the glacier that would outrun anything in its path.


Rangers, climbers, and guides at Camp Muir first were aware when these series of slides started on the 24th of June. Rangers reported feeling the earth shake and hearing a very loud rumble. Indeed, you can tell from extent of airborne dust in the picture above that it must have been loud. Shortly after the slide occurred, the geologists at the Cascades Volcano Observatory called us and asked us what was up. Below is the seismograph reading during the event.Here's a quote from one of the original emails between the NPS and USGS. - "FYI about 10 minutes ago the climbing rangers at Camp Muir saw what they all described as the biggest icefall they've ever seen come off the Nisqually. A guide party at 8,000 ft on the Wilson glacier reported that it had multiple fingers & traveled down to about 7,800 ft. They also described it as the biggest icefall they've ever seen anywhere.
The rangers at Muir described the debris as a mix of rock & ice and being about 50 feet thick but couldn't judge the acreage covered as it is hard to see the entire run-out zone from Muir.
" from Ranger Ben Guttridge.

After I heard about the slide, and saw it from my house in Packwood, I decided to hop in my airplane and take a ride towards the mountain to get some pictures as close as I could.


All in all, there have been three slides of this size in the last two days. Right now, we don't recommend crossing the Nisqually Glacier at all - although at this time, the park has not declared a "closure" of the area. If you are intent on doing the Kautz Glacier route, think about accessing the base of the route by Comet Falls trailhead. Click on this link for a Google Earth KMZ file of the approximate extent of the series of avalanches. Also, here is the screenshot of this file from Google Earth.


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