22 November 2015

Vasquez Canyon: a new landslide in Santa Clarita, California

Posted by dr-dave

Vasquez Canyon landslide

A significant landslide has developed in the last few days in Vasquez Canyon, in Santa Clarita in California.  The landslide, which appears to be progressive and has no obvious recent trigger, has caused extensive buckling of the road, which has been closed over a three kilometre stretch.  This image, from the Santa Clarita Valley Signal, provides quite a good general view of the situation beyond the road:

Vasquez Canyon

The landslide, from the Santa Clarita Valley Signal

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The landslide has caused impressive damage to the highway:

Vasquez Canyon

Vasquez Canyon road from KTLA5

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interestingly, the media are suggesting that this buckling has occurred because the road is moving upwards.  Whilst this might sound a little odd, this excellent drone footage suggests that this might the case:

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This is a still from the drone footage of the landslides, showing the damage to the highway:

Vasquez Canyon Road via Youtube

Vasquez Canyon Road via Youtube

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This is Google Earth imagery of this section of the road, dated April 2015 – i.e. seven months ago:

Vasquez Canyon

Vasquez Canyon Road via Google Earth

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There are clearly some signs of instability in this image, and note the other landslides in the image.  The section of road that has failed is in a box cut, so it would appear that unloading of the slope may be a key factor in the landslide. And interestingly, this imagery from two years ago (May 2013) suggests significant movement at that time as well:

Vasquez Canyon

Vasquez Canyon road in 2013 from Google Earth

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And finally, this is Google Street View imagery of the road, taken in 2011:

Vasquez Canyon road

Vasquez Canyon road via Google street view

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The extensive deformation in the road was clear even then – indeed the road shows longitudinal cracks along this entire section.  Thus, although this landslide looks very sudden, it has been developing over a prolonged period.