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)
On March 21, 2008 a landslide caused the closure of Arizona State Route 87 between Payson and Phoenix near mile post 224. So far there are no official estimates as to the size, but based on aerial photos, it appears to be at least 50,000 sq-ft in plan. The offset at the head scarps was approximately 2-meters (6.6-ft) according to AZGS Geologists on site. It appears to have been a rotational slide as the toe of the landslide heaved the southbound roadway up by as much as 1-meter (3.3 ft). There was an existing soil-nail retaining wall on the slope that was destroyed by the slide as well. Lateral deformations can be seen in photos of the median barrier and the roadway striping. The deformations extended into the northbound lanes as well. More photos and links after the break. (Photo by ADOT)
A massive landslide has destroyed at least a quarter-mile of State Route 410 in Washington State, about 10 miles from Naches in Yakima County. It has also damaged about 12 structures including residential homes and quarry buildings and diverted the Naches River. The media has been referring to it as the Naches Slide, but the personnel from the Washington Department of Natural Resources, Division of Geology and Earth Resources who have began investigating the slide as well as WSDOT are calling it the Nile Landslide. (Photo by WAStateDNR-DoGaER)
Click through for photos and videos. For more info on the slide, check out the Sliding Thought Blog, an unofficial blog by Isabelle Sarikhan of the WAStateDNR – Division of Geology and Earth Resources “aka” the Washington Geologic Survey. She’s been actively investigating the slide along with some colleagues.