11 May 2020
Waterford, New York: a large, damaging landslide
An unexpected landslide at Waterford in New York state in the United States last week threatened a number of houses. There are many news reports about this event, which will have been devastating to those living in the vicinity. The best set of images that I have seen were collected by Jim Franco using a drone, and posted to Twitter:-
Unfortunately the rear scrap of the landslide continues to undergo retrogression, with up to 2 metres having been lost since the main failure, causing collapse of the decking. Local officials have noted, rightly, that stabilising the land is going to be a major challenge. The materials that form the landslide appear to me to be complex fluvioglacial deposits, which will be prone to erosion.
The image below provides a good sense of the whole of the failure:-
Note that whilst it might appear that the landslide is on the outside of the bend in the river, this is not the case. The water at the toe of the slope is a small lake. Given that the landslide was not triggered by rainfall, the cause of the failure is somewhat unclear.
The location of the landslide is 42.799, -73.680. The Google Earth image below was collected in June 2018. There is nothing that is immediately obvious here that appears to indicate that a failure was likely, although the dense vegetation makes interpretation very difficult:-
Rainfall across Africa continues to cause high levels of loss from floods and landslides. In Rwanda, dozens of people have been killed, including eight members of a single family in a landslide at Gakenke. In Kenya, landslides have affected a number of areas, whilst three people have been killed by a landslide in Uganda. In Ethiopia, 12 people were killed in yet another landslide.