11 May 2010

Possible flowslide (not a sinkhole) in St Jude, Canada

Posted by Dave Petley

The Canadian media is reporting the case of a “sinkhole” that developed in St Jude, 77 km to the north of Montreal, last night.  The sinkhole included a family house, with four people inside.  At the moment these occupants are reported to be missing. 

The Montreal Gazette has a photo gallery of the site.  One of the photos is this one:

Based upon this image this does not look like a sinkhole but instead to be a quick clay slide, probably in Leda Clay.  Such slides are not uncommon in this area.  I have covered a previous example in Norway on this blog.  The famous Rissa quick clay landslide in Norway is available as a video here if you want an idea of the extreme end of this type of failure.Quick clay slides often occur on very low angled slopes, and can be triggered through ground disturbance which causes the clay to restructure, allowing it to flow.

At the moment I am unsure of the exact location of this event, but St Jude is at 45.77 N, 72.99 W.

Hat-tip to Peter Weisinger for highlighting this one.