8 August 2010
Images of the Meager Creek landslide in Canada
Posted by Dave Petley
The Meager Creek landslide in British Columbia, Canada on Friday was a very large and very energetic event. The latest estimates suggest that it had a volume of about 40 million cubic metres, making it one of the largest slides in Canada in recent decades. Indeed, the Vancouver Sun quotes Rick Guthrie in stating that the slide travelled at 30 metres per second over a distance of 10 km.
Some good images of this event are now available, despite the smoke-filled air (the smoke is from local forest fires). Worth a look is the Global Winnipeg gallery of the slide here, from which these images are derived:
This image shows the location at which the slide entered the main valley and then spread. Note the way that the trees on the far valley wall have been stripped off by the flow. This is called super-elevation and is an indication of the speed of the flow. To generate this degree of super-elevation the flow must have been moving very quickly.
This is a view from the opposite side of the valley looking up the main flow. Note the small lake forming upstream of the blockage. This problem has now apparently been resolved.
This image shows the flow path of the slide down the valley. Again, note the stripping of vegetation up the valley walls, suggesting a very considerable flow depth.
This is the upper reaches of the main slide, giving a great perspective on the magnitude of the flow.
The very best images of the slide are available on the Flickr page of DBSteers, a member of the Search and Rescue team that flew over the slide. The images are explicitly copyrighted, so I will not reproduce them here, but I strongly recommend that you take a look. The page is here:
Take a look – you won’t regret it!
You are right, those photos from the SAR team are spectacular.
Excellent work Do you have any info/data such as wash heights on opposite side of bay on the knight inlet slide at Glacier bay late 1990'sI have before and after photosalpenglowpro.wordpress.com
Great site, Dr. Jeff Masters linked you , glad he did.Any thoughts on the triggering mechanism for this one ?
I'm just a layman, but from what I've gleaned from reading and talking to those involved:The Meager Complex is Canada's most active volcano, last erupting about 2600 years ago. It is very unstable and landslides are common.Geo-techs have been warning of this, as the glaciers that cap the complex, and hold it together, have been melting fast, retreating and leaving unstable rock supporting the glaciers. It appears the melt saturated the ground below the glacier to the point the entire mountain top, and glacier, broke away and went for a ten km ride.I'm told there's water coming out of the base of the mountain still.
There's an excellent paper on the 1998 slide: http://www.bgcengineering.ca/files/publications/MJ_bovis_jakob_meager_2000.pdf
Great site, timely and well illustrated.I will follow this closely
There is a good question that the local geomorphologists/engineers can answer.The photos all show weathered pumice as well as the freshly exposed pumice. How much of the glacier retreat in the past 100 yrs and in particular in the past ten years has led to oversteepened slopes where the ice has receded.Is this a contributing factor among the many other risks that are present?Comments?
Check out the seismic activity in Pemberton Valley and you will see more.
dbsteers has a bunch of new pics up. If you visited his Flickr when it was originally posted, it's worth going back…
And a pretty dramamtic first hand account from someone who was on the scene:http://www.piquenewsmagazine.com/pique/index.php?cat=C_Frontpage&content;=Meager%20slide
Nice pictures!Surely there can be a good hike!
One more article, not much new, but some interesting points about past activity in the area…http://thetyee.ca/News/2010/08/12/MeagerLandslide/