Wednesday, April 12, 2017

Slide Causing Highway 530 Closure

The landslide that caused the closure of the State Highway as well as evacuations of a few homes is labeled in the LiDAR imagery below at the Montague Slide (my name as it is located just west of a creek by that same name).

I had initially presumed that the Skaglund Hill slide had moved as it has caused road problems in the past. The Montague slide is not a new slide. LaHusen and others (2015) estimated that the Montague slide was less than 500 years old based on surface roughness from LiDAR combined with carbon dates from several locations on nearby slides. The recent sliding on part of the Montague slide area will add some new roughness.

The slide itself has not impacted the highway; the highway is below the slide area. The concern is that the slide may become very active and slide down onto the valley floor and the highway. Hence, some monitoring of slide movement before any further decisions regarding the highway. 

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