27 April 2012

Before and after – the Hattian landslide in Pakistan

Posted by Dave Petley

I was looking at Google Earth imagery of the area affected by the 2005 Kashmir earthquake this week, and in particular focused in on the Hattian landslide.  This was by far the largest landslide triggered by the earthquake in 2005.  There is a detailed description of the landslide in a paper that we wrote for Engineering Geology, which can be downloaded here.  This image, collected in September last year, shows the landslide scar and the deposit.  Note that the main landslide lake breached in early 2010 – evidence of the higher water levels for ZalZal lake is clear upstream if the blockage:

An interesting comparison is the image from before the earthquake, in this case collected in 2002.  Note that Google Earth retains the labels indicating the location of the two lakes, which in this case is quite useful for orientation:

The area that the landslide affected is clearly identifiable in this image, and the condition of the topography appears quite deformed.  In particular, the streams are deeply incised in comparison with the adjacent areas.  Of course this then asks the question as to whether this site could have been identified as a potential landslide before the earthquake from visual inspection alone.  In fact I suspect that this would have been difficult, but I am interested hear the opinions of others.

Dunning et al paper on Hattian landslide