20 May 2011
It has been very noticeable in the last few weeks that western and central areas of the US and Canada are suffering a high incidence of landslides, mostly causing significant disruption to the road network and some property damage. The cause seems to be a combination of heavy rainfall and rapid melt of an unsually large snowpack. One notable example has occurred in the Snake River Canyon, near to Jackson in Wyoming, where a rather interesting landslide has been moving over the last few days. This is an area of known landslide hazard – indeed it is even highlighted in the USGS paper on landslides in the USA, and there are several reports about landslide issues in this area. Trib.com has the following rather nice picture of the landslide:
I think that this makes the location of the landslide here:
And a Google Earth perspective image of the site before the failure:
As is clear from the images, this landslide, which is a classic earthflow, is completely blocking the road. Interestingly, it is still moving at a rate of about 50 cm per hour. As a result, the Wyoming DoT have captured and released this terrific time-lapse video of the landslide motion:
In terms of the motion of the landslide, this is quite wonderful. Note that the displacement rate is quite constant with time but that there are two distinct flows in operation. The Benny Hill style moment is hilarious (did he really try to touch his toes?) and quite inspired. It deserves to go viral!
The Wyoming DOT have suspended clearance operations until the movement ceases (a good call in my view as continued work whilst this is so wet and unstable will only destabilise more material upslope, and endanger those involved). Once clearance operation start they are expected to last about five days.
Can anyone in the area provide any addition information about, or images of, the landslide?