The scale of the movement can be seen in these two Planet Labs<\/a> images of the site, taken five days apart:-<\/p>\n Satellite images of the Old Fort Landslide, showing the movement over five days. The image on the left was collected on 19 June 2020 whilst the one on the right was collected on 24 June 2020. Copyright Planet Labs<\/a>, used with permission<\/p><\/div>\n .<\/p>\n Note in particular the displacement of the road, which can just be made out in the second image.\u00a0 The toe of the landslide has also displaced, and there are signs of significant amounts of deformation towards the crown of the landslide.<\/p>\n In the gallery of image<\/a>s the most interesting one may be this image of the crown area of the landslide:-<\/p>\n Image of the crown area of the Old Fort landslide. Image from BC Transport and Infrastructure.<\/p><\/div>\n .<\/p>\n There is much to note in this fascinating image.\u00a0 The main slide extends into the distance – the now destroyed road can just be seen.\u00a0 In the foreground the rotational component of the system is clear. On the lower left of the image there is a rear scarp, several metres high.\u00a0 Below this (in the centre right of the image) there is a large block that has displaced and rotated.\u00a0 This block is starting to break up – note the large tension crack running across it, and the rent on the right hand side of the block.\u00a0 Finally, note the very clear lateral shear just to the left of centre of the image, beside the hillock.<\/p>\n Given the weather, I would expect movement of this slide to reduce in the coming days.\u00a0 However, the system is primed to reactivate in future heavy rainfall events, with similar impacts.\u00a0 Stabilisation of such a large, complex landslide is unlikely to be economic.<\/p>\n This landslide reminds me of the Tessina landslide in northern Italy<\/a>.\u00a0 Back in the mists of time I wrote a paper (Petley et al.<\/em> 2005<\/a>) that examined the ways in which the style of movement of these landslides change as the blocks that feed the system transition from rotational movement to flow.<\/p>\n .<\/p>\n The summer monsoon is rapidly developing across Asia.\u00a0 In Nepal, warnings have been issued for heavy rainfall today<\/a> amid reports of ongoing landslide induced disruption<\/a>.\u00a0 In China, heavy rainfall warnings have been issued across a wide area<\/a>.<\/p>\n .<\/p>\n![\"Old](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/06\/20_06-Old-Fort-5.jpg\")
![\"Old](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/06\/20_06-Old-Fort-6.jpg\")
On reflection 1: The building Asian monsoon<\/h4>\n
On reflection 2: Heavy rainfall causes debris flows in Ukraine<\/h4>\n