Here are a few animations I made based on historical aerial imagery. There are four animations that run the years 1989, 2003, 2005, 2006, 2007, 2009, 2011, and 2013. I used the historic imagery available from google earth. There could be better imagery out there, but this took me 15 minutes to put together.
Here is an over view of the region from the Seattle Times:
Here are my animations (click on a map to watch the video on a new window or click on the link under a map to download the video):
- Overview:
Here is a link if you want to save it to your computer. - Oblique looking from the southeast:
Here is a link if you want to save it to your computer. - Oblique looking from the south:
Here is a link if you want to save it to your computer. - Oblique looking from the south zoomed in to observe the toe of the slide:
One may observe a large slide deposit sediment at the base of the slope of the right bank (away from you) prior to the 2006 image. This entire toe continues to exist through the 2013 image. There is also a fan deposited on top of this slide toe on the left (the west) of these images. The fan becomes apparent in 2007 and obvious in 2009. The sediment source for this fan is the eroding material from the landslide upslope. The fan becomes vegetated in 2011 and 2013. The river does not appear to be eroding at the toe of this slide area, unless it did so during this seasons flood season.
Here is a link if you want to save it to your computer. - Here is a map showing the landslide history of the region. The youngest slides are labeled A, the youngest slides are labeled D. USGS put together this paper that describes their interpretation.
Here is an article on the AGU landslide blog about the slide.
Here are some photos taken on March 24 during an aerial survey conducted by the Washington State Department of Transportation, Washington State Department of Natural Resources, U.S. Geological Survey, and King County Sheriff’s Office. Photo Credit: King County Sheriff’s Office – Air Support Unit. I got these from the USGS.
- Here is the seismograph recorded at site JCW by the University of Washington Pacific Northwest Seismic Network, operated in cooperation with the USGS.
- Here is the yt link for the embedded video below.
Video