The California Geologic Survey has published a new map of landslide susceptibility for the entire state of California. It addresses only deep-seated landslides, not shallow slides such as debris flows. The criteria used for developing the map included slope angle, geology, rock shear strength and history of landslides in a given area. You can download the map for free from the California Geologic Survey.
Since I last posted about this landslide, ADOT has added several videos to their YouTube channel. It’s clear that this highway is going to be closed for the long term. ADOT and their on-call geotechnical consultant tasked with this project, Kleinfelder, are currently drilling boreholes to attempt to characterize the failure surface and determine what the geometry of the failure surface is. They are installing at least 10 inclinometers to try to determine the location of the slip plane or planes at depth and they have two extensometers to measure if any additional movement occurs. They are also performing LIDAR surveys as well. Check out the videos below.
Initial ADOT Video Describing the Failure
Click through for the videos!