Fellow geo-blogger David Petley of Durham University posted today about the 105th anniversary of the Frank Landslide in Canada. The slide had an estimated volume of 30 million cubic meters and took all of about 100 seconds to travel down the mountain and engulf a portion of a nearby coal mining town. 76 people were killed, and a number of bodies were never recovered because of the massive amount of material. Since 2003, they have installed real-time monitoring equipment to warn if the mountain fails again, which seems likely based on an interesting video (requires Windows Media Player). It shows some of the massive tension cracks at the top of the limestone mountain. (Photo by Natural Resources Canada by way of Dave’s Landslide Blog)
The Chilliwack Times reports that the City of Chilliwack will pay 80% of the assessed home value for up to 42 homes in an Eastern Hillside subdivision that are located on a slow moving landslide. The issue was first noticed in 2001 and several homes have had significant damage, but most are currently undamaged. The City denies any responsibility, but it’s legal counsel recommended a settlement. (Photo by Paul J. Henderson, Chilliwack Times)
Normally the geotechnical engineer for the subdivision would be held accountable. But apparently the slip surface is located 30-m below grade, much deeper than borings for a typical investigation for a subdivision. I wonder if there were any geologists consulted? Click through for a Google map view of the area and you can do your own armchair photogeology quarterbacking! Your heart does go out to the people losing their homes, they had no idea. But it could be worse, they could be in La Jolla and be getting squat.