20 May 2010

Surprising landslides from the Amazonas earthquake in Peru

Posted by Dave Petley

On Tuesday evening at 11:45 pm Peru suffered a Mw=6.0 earthquake 125 km (80 miles) NNW of Moyobamba in Amazonas.  This is the USGS location on a Google Earth image:

The USGS record suggests that this earthquake was very deep – 132 km – which means that such an event would not normally be associated with landslides.  However, the local paper La Republica is reporting that a large section of a road between Bagua and Tarapoto was severely damaged.  They have several images that appear to show very serious damage.  Some of that damage may well be due to liquefaction, but this image undoubtedly shows very large-scale landslides:

The Google Earth image below shows the location of the two towns and the earthquake epicentre.  I am unsure where on the road between the two this landslide event occurred:

This image is also intriguing.  I can think of several different explanations for how this came about.  I wonder what the true story is:

  That such large landslides and other damage should occur in an earthquake of this magnitude and so deep is very surprising.  I wonder what is going on here.