18 January 2017

The Mount Sulzer avalanches: the amazing video

Posted by Dave Petley

The Mount Sulzer avalanches: the amazing video

Yesterday I posted details of the four Mount Sulzer avalanches in Wrangell-St. Elias National Park and Preserve in Alaska. Information about these landslides was provided by Mike Loso – he can be contacted at the following email address:- michael_loso@nps.gov . I noted that he had kindly sent to me a video of the fourth of these events, shot from the air by Luke Wassink, a National Park Service Ranger.  Luke and Mike have given permission for me to make this video available via Youtube, so I have uploaded it this morning.  The video, which is remarkable, should be accessible here, and I have embedded it below:

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I very much appreciate the help and support of Michael and Luke in making this available.  The video is remarkable, not least because of the incredible power of the flow.  But note that this event was tiny compared with the two largest events.  Compare the deposit in this image with the trim lines left by the earlier flows in the image below, taken from the video:

Mount Sulzer avalanches

Still from the video of one of the Mount Sulzer avalanches, by Luke Wassink. Mote the trimlines that show how large the earlier events must have been

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The materials involved in these Mount Sulzer avalanches is a complex mix of ice and debris. This image, taken by Mike Loso, shows the aftermath of the August 2016 event:-

Mount Sulzer avalanches

The aftermath of the August 2016 Mount Sulzer avalanche showing the complex mix of materials. Image by Mike Loso.

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This type of landslide is poorly studied because of the difficulties in obtaining good data.  The video is a remarkable addition to the portfolio of information about these slides. It will now be very interesting to see if further Mount Sulzer avalanches occur in the coming summer.

Acknowledgements

Once again I would like to thanks Mike Loso and Luke Wassink of Wrangell-St. Elias National Park and Preserve in Alaska for making this material available.