Imagine the scene 4,800 years ago when a rock avalanche nearly 2 km long buried much of the Zion Valley in a matter of 90 seconds, creating a dam on the Virgin River that flooded essentially the entire floor of the canyon that millions of visitors enjoy every year. The researchers that analyzed this event are in the Geohazards group of the University of Utah led by Dr. Jeff Moore. Dr. Moore happens to be an old classmate of mine from the geological engineering program at the University of Arizona. I didn’t dig up the publication where this Zion Canyon research was written before it went viral, but there are some great figures posted on his website and I’m sure you can click around and find the citation if you are interested. [Source: YouTube via Geoengineer.org. Image: YouTube]
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Three Gorges landslide threat forces villagers to flee
Nearly 100 villagers living upstream from the Three Gorges dam have been forced to leave their homes under threat of a landslide, which officials fear was disturbed during the filling of the dam’s reservoir last year, Xinhua News Agency reported last week. Read on for more info. (Photo by enkai)
NY Landslide Halts Highway Construction
A report has been released by the NYSDOT on the Scoby Hill Landslide which has impacted a 4.2-mi improvement project of Route 219. The report, dated May 20, 2008 was headed to an FHWA peer review panel.
The Feds were call in to help because of the unusual nature of the landslide. The slip surface is very deep, approximately 30-m (100-ft) below the surface and below all of the design phase investigations. And the remolded shear strength of the silty clay forming the slip surface was only 12-14 degrees.
Read on for more details of the slide. (Photo by NYSDOT)
North Carolina Landslide Hazards
Geology.com pointed out a very nice PDF version of a Power Point presentation by the North Carolina Geologic Survey on their landslide hazard mapping efforts in western North Carolina. The presentation was dated August 1 of last year. The NCGS also has their landslide mapping products available for download, and those so inclined can download the GIS data sets as well. (Photo by NCGS)