3 September 2021

Landslides from the 14 August 2021 earthquake in Haiti

Posted by Dave Petley

Landslides from the 14 August 2021 earthquake in Haiti

On 14 August 2021 a M=7.2 earthquake struck Haiti to the west of the capital Port-au-Prince.  Whilst this event affected an area that is less densely populated than was the case for the 2010 event, it still killed over 2,000 people.

The earthquake affected an area that is mountainous at a time of year in which rainfall is common, so landslides were inevitable.  In a post soon after the earthquake, NASA highlighted that substantial numbers of landslides had indeed happened.

The image below shows the landscape around Pic Macaya National Park, which was close to the fault that ruptured to trigger the earthquake in Haiti.  The landscape is densely vegetated and mountainous:-

The area around Pic Macaya National Park that was affected by the 14 August 2021 earthquake in Haiti.

The area around Pic Macaya National Park that was affected by the 14 August 2021 earthquake in Haiti. Image copyright Planet Labs, used with permission, dated 10 August 2021, four days before the earthquake..

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Some landslides are visible, particularly in the central south of the area and to the east.  However, the image below shows the same area after the earthquake:

The area around Pic Macaya National Park that was affected by the 14 August 2021 earthquake in Haiti.

The area around Pic Macaya National Park that was affected by the 14 August 2021 earthquake in Haiti. Image copyright Planet Labs, used with permission, dated 29 August 2021, about two weeks after the earthquake.

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The image shows a very dramatic increase in the number of landslides, particularly in the catchments in the centre of the image.  The satellite image below provides more detail of some of these landslides:-

Detail of landslides in Pic Macaya National Park after the 14 August 2021 earthquake in Haiti.

Detail of landslides in Pic Macaya National Park after the 14 August 2021 earthquake in Haiti. Image copyright Planet Labs, used with permission, dated 29 August 2021, about two weeks after the earthquake.

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There are hundreds, possibly thousands, of landslides in the images, with densities approaching those seen in areas of the Wenchuan earthquake in China, although over a smaller area.  Most of the images appear to be shallow disrupted slides, as is usually the case in such events.

The area was affected by a large rainstorm two days after the earthquake, when Tropical Depression Grace crossed Haiti on 16 August 2021.  It is likely that the landslides in the images is a consequence of the combination of the earthquake and mobilisation of slope materials and landslide debris in the storm.

It is not clear how many people were killed by landslides in the 2021 Haiti earthquake, but the numbers are likely to have been substantial.

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Reference and acknowledgement

Planet Team (2021). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/