29 October 2008
Highway 97 latest update
Posted by Dave Petley
The latest update on the Highway 97 landslide in Canada (see here and here) is as follows:
- The slope is still moving. Between 19:00 on Monday and 14:00 on Tuesday the mass moved about 15 millimetres (i.e. about 0.8 mm per hour). This is quite high for a large mass. The rate of movement is described as being constant;
- The mobile volume is now estimated to be 200,000 cubic metres;
- The road remains closed (unsurprisingly!);
- There are provisional plans to remove material from the top of the unstable slope and to move it to the toe. The aim here is to reduce the mass that is driving the movement and to increase the mass that is supporting it.
I am sure in the background there is an enormous amount of work going on. Analysis of the pattern of movement in time and space, especially by looking at vectors of movement and accelerations and decelerations will give a pretty good idea of what is happening in the slope. This gives a potential for providing a short term warning of an impending collapse, but does not really tell us how likely this is in the medium term.
Dave Petley is the Vice-Chancellor of the University of Hull in the United Kingdom. His blog provides commentary and analysis of landslide events occurring worldwide, including the landslides themselves, latest research, and conferences and meetings.
let her rip !! It’s going to happen anyway so its better to get it over and help it out with a few more than a 100 sticks of the good stuff.Ken DaviesKelowna B.C. Resident
Highway 97 remains closed- but Ministry of Transportation and Highways has now instigated a water taxi service around the problem area and also has upgraded an existing Forest Service road (FSR 201) between Kelowna and Pentiction. Trouble is, the FSR is not paved, and is suitable only for cars and light trucks. Frustratingly, the Ministry has not yet published a map showing the alternate routes and ferry terminals.It is certainly commendable that the Ministry has been so pro-active in dealing with this issue, and also that they are allowing the contractor involved to post pictures and commentary about the problem.
There now is a map showing alternate routes- go to http://www.th.gov.bc.ca/OkanaganValley/advisory/index.html