Radar images show ground movements two years before slide

Radar images show ground movements two years before slide

June 16, 2017
Head of Communication

An enormous landslide buried part of California’s Highway 1 along the Pacific coastline on May 20. Norut has processed radar images from the Sentinel-1 satellite that show the ground was moving in the two years before the landslide. 

On 20 May, over a million tonnes of dirt and rock buried part of California’s Highway 1 along the Pacific coastline in the state’s Big Sur region. Referred to as the Mud Creek Landslide, it did not cause any injuries as the highway had been closed off. Local authorities believe it will take a year until the highway can reopen. In addition to cutting off the route, the landslide has caused major changes to the shoreline.

In the aftermath of the landslide, Norut Senior Research Scientist Tom Rune Lauknes has processed radar images from the area taken over the previous two-year period. The image series from the European Space Agency (ESA) satellites show clear ground movements in the area during the period.

“Regular images from Sentinel-1 in the period before the collapse of the mountainside provide us with a unique opportunity to study movement in the early stages of a landslide. We can use this landslide as an example so we can better understand the processes leading up to the collapse. This will help us to be better equipped to measure changes and implement precautionary measures,” says Lauknes.

He adds that the study of the Mud Creek Landslide is extremely relevant to national landslide mapping and monitoring in Norway.

Lauknes has used interferometry (InSAR) to process the radar images. This technique can detect and monitor movements over wide areas with high sensitivity. The analysis of the images can detect movements as small as a few millimetres.

See Josef Aschbacher, ESA Director of Earth Observation, presenting the image analyses from Norut: 
Google Talk: The Big Picture from Space (starts at 19:15) 

Get the whole picture here:

Landslide on the radar (ESA)

More: 

Slope movements seen from new satellite