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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Judge Rules City of San Diego Not Responsible for Mt. Soledad Landslide in 2007
The Mt. Soledad Landslide in a La Jolla California neighborhood destroyed 3 houses and damaged others and it also shut down Mt. Soledad Road for an entire year after it occurred in October of 2007. Residents blamed the city of San Diego, and 65 homeowners filed suit, claiming that leaking pipes caused the landslide and the City should cover damages.
Last week, a superior court judge ruled in favor of the City of San Diego. So far I have not seen anything indicating if the residents plan to appeal the ruling.
One interesting note regarding the trial, the City released an 8-minute cell phone video taken by a geotechnical engineer or drilling contractor employed by the City that showed the road cracking and buckling just prior to failure. The homeowners used the video to try to make their own case. Click through for a portion of the video and a link to the full one.
Utah Considers Stricter Rules for Development in Landslide Prone Areas
The Utah Governer’s Geologic Hazards Working Group, which includes no one from the private sector, is considering some model legislation that can be adopted by cities and counties to make it more difficult for developers to build in landslide prone areas. Also, among other things, the group may recommend that Utah adopt stricter grading requirements based on the experiences of California. Read on for more info.