Some new research on the Newmark Displacement Method for earthquake-induced landslides indicates that the method may be on the unconservative side. The Landslide Blog provides a short summary of the paper by Li et al. (2018) that was recently published in the journal Landslides. Their research was based on physical models on a shake table, comparing the results of the model experiments with a Newmark analysis. The paper should be worth a read for geotechnical engineers practicing in seismically active areas. It sounds like some additional study is needed to confirm these results and if they are true, propose different ways of analyzing earthquake-induced landslides.
The regular news media as well as the geo-blogosphere are all abuzz about Monday’s 7.9 magnitude earthquake in central China. Official death toll is at 12,000 right now and that’s in Sichuan Province alone. My guess is that number will swell substantially in the coming days. If you haven’t seen photos and video yet, they are absolutely gut-wrenching. My heart and prayers go out to the victims of this disaster. (Photo by Liu Hai, AP)
Several geo-bloggers have posts about the earthquake. Harold Asmis of Ontario-GeoFish describes the earthquake as a "big valley-thrust earthquake" or what he calls the "Fist of God". Dave’s Landslide Blog has started compiling reports of landslides related to the earthquake in this landslide prone region of China. And here is the USGS info on the earthquake.
Four engines pulling a freight train derailed July 9 and landed in the Mississippi River after hitting a landslide or major rockfall. The accident happened near Guttenburg in northeastern Iowa. Two workers on the train were injured, one was rescued by boat. The engines are now leaking diesel fuel and transmission oil into the river, but crews are on scene to attempt to contain the contamination which has apparently spread 5 miles downstream. Two ethanol tankers derailed as well but do not appear to be leaking. Several rail cars carrying grain have spilled also. There are 75 cars still on the track. Via Reuters and The Gazette (Cedar Rapids, IA). (Photo credit: Orlan Love/The Gazette)
The Utah Geologic Survey has released a "Landslide Susceptibility Map of Utah". They apparently relied quite heavily on GIS based thresholding of existing slope angles but only after they had statistically analyzed failure angles for particular geologic units. So it sounds like they throw the known landslides, the geologic map of Utah and a DEM into the GIS a blend it all up. Perhaps a slight oversimplification!