The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.
On 7 October 2024, a significant landslide occurred at Porto da Terra Preta, in Manacapuru, Brazil. Information about this failure remains somewhat unclear, but some reports suggest that the loss of life might have been substantial. At this stage one fatality has been confirmed, sadly that of a child.
The journalist David de la Paz has tweeted a short aerial video of the site:-
There are also some news reports about the event, both in Portuguese and in English.
The site of this landslide appears to be [-3.2950, -60.6374]. This is a Google Earth image of the location, collected in February 2024:-
This image does not give any obvious indications as to why a landslide might have occurred. However, many of the local reports suggest that construction work was under way at the site. But, significantly, the Solimões River is at a historically low level currently, and the banks of the rivers in the Amazon region suffer a phenomenon known locally as “terras caídas” (fallen lands), which describes river bank landslides. There is a literature on this type of failure – a good starting point is Bandeira et al. (2018). These failures can occur in periods when the river level is falling, and under such circumstances are generally caused by toe erosion.
I am reminded also of the riverbank failures that occurred on the Murray River in Australia during the severe drought of 2010.
A search operation is ongoing at Porto da Terra Preta – it is to be hoped that those on the site managed to escape. But this event illustrates the risks of landslides along rivers, and highlights that failures are not always due to rainy conditions.
Reference
Bandeira, I.C.N., Adamy, A., Andretta, E.R. et al. Terras caídas: Fluvial erosion or distinct phenomenon in the Amazon?. Environmental Earth Sciences. 77, 222. https://doi.org/10.1007/s12665-018-7405-7
Text © 2023. The authors. CC BY-NC-ND 3.0
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