The Salt Lake Tribune published an article recently on some trenching activity by the Utah Geologic Survey and the USGS to better date past movements on this active fault.
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]
October 17 was the 18th anniversary of the 6.9 magnitude Loma Prieta earthquake that struck the Bay area. But a recent story by the Bay Area’s local ABC affiliate, ABC7, chose to focus on another earthquake, a 1868 earthquake of about the same magnitude that occurred on the Hayward Fault. According to the USGS, the Hayward Fault has a return period of about 140-years and "It’s the most heavily urbanized fault in the U.S. and it’s just waiting to go off…" Next year will be the 140-th anniversary of the last earthquake on the Hayward Fault. At some point it has the potential to be a very bad earthquake there. More after the break. (Photo by sanbeiji)