11 November 2020

The Queja landslide: Planet Labs imagery

Posted by Dave Petley

The Queja landslide: Planet Labs imagery

The search for the victims of the Queja landslide appears now to be ceasing, with the site of the disaster being declared a “camposanto”, or a resting place for the dead, and the location will be declared as being uninhabitable.  Whilst understandable, one should not underestimate the impact on the remaining population, whose future will now be very perilous.  AP has a nice syndicated article about the vulnerability of Guatemalan communities to future events.  This will not be the last catastrophic landslide in Guatemala.

Meanwhile, the skies have finally cleared, meaning that optical satellite imagery has become available for the site.  Planet Labs captured a good image of the location using their 3 m resolution PlanetScope instrument yesterday:-

Queja landslide

The Queja landslide in Guatemala. Planet Labs PlanetScope image captured on 10 November 2020. Copyright Planet Labs, used with permission.

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Note the scale bar , which gives an idea of the size of this landslide.  On first inspection this image supports my sense that there are in effect two landslide sources here, both of which had an element of rotation before transitioning to a more flow style of movement.  The larger to the two sources (source 1), to the north and west has generated a flow that has spread laterally, inundating a larger area.  The other source (source 2) has spread rather less, but has had a longer runout. It is this part of the landslide that appears to have caused the greatest damage.  As I noted in my first post on this failure, there is a stand of trees between the two sources.

I suspect some interesting work could be done on the timing of the two failures as there is some evidence of material from source 1 in the west side of the flow that is mostly from source 2.

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Quickslide 1: a deadly landslide at a resort in Malaysia

Two people were killed in a hot springs resort landslide in Tambun, Malaysia.  The failure was triggered by heavy rainfall.

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Quickslide 2: The tenth anniversary of the Pike River Mine accident

Next Thursday (19th November) will be the tenth anniversary of the Pike River Mine disaster in New Zealand.  Otago Daily Times has a good article about events on that tragic day.  Attempts to re-enter the mine continue, but it is not possible to recover the victims.

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Acknowledgement

Planet Team (2020). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/