The California Geologic Survey has published a new map of landslide susceptibility for the entire state of California. It addresses only deep-seated landslides, not shallow slides such as debris flows. The criteria used for developing the map included slope angle, geology, rock shear strength and history of landslides in a given area. You can download the map for free from the California Geologic Survey.
From the USGS Newsroom:
USGS scientist Ken Hudnut fills us in on how science created the theoretical magnitude 7.8 earthquake behind the Great Southern California ShakeOut—the largest earthquake preparedness drill in U.S. history, coming Nov. 13—and what such an earthquake would do to downtown Los Angeles.
Seems like they did it right wiith this study. They had multiple teams independenlty come up with the ground shaking model, then had different structural engineers who are experts in seismic design of large buildings review the tall buildings in the L.A. area for the design earthquake. They say that buildings would likely come down in the 7.8 magnitude event. Click through to watch the video interview from the USGS.
Released: 4/14/2008 12:02:15 PM
California has more than a 99% chance of having a magnitude 6.7 or larger earthquake within the next 30 years, according scientists using a new model to determine the probability of big quakes.
The likelihood of a major quake of magnitude 7.5 or greater in the next 30 years is 46%-and such a quake is most likely to occur in the southern half of the state.
[Editor] At Left: Figure 1. The colors on this California map represent the UCERF probabilities of having a nearby earthquake rupture (within 3 or 4 miles) of magnitude 6.7 or larger in the next 30 years. As shown in the table, the chance of having such an event somewhere in California exceeds 99%. The 30-year probability of an even more powerful quake of magnitude 7.5 or larger is about 46%. [/Editor]