January 15th, 2013-
San Andreas stress rupture could shake entire state: For the first time, scientists and emergency planners are examining whether a super quake could affect both Northern and Southern California, rendering the entire state helpless in the aftermath of the “Big One.” Seismologists have warned Southern California that a major quake on the lower San Andreas Fault, the so-called Big One is inevitable. But that the population centers of both Southern and Northern California could be affected simultaneously by one quake on the San Andreas Fault has only recently been recognized as a possibility. The study by Professor Nadia Lapusta at the California Institute of Technology (Caltech) and Japanese collaborator Hiroyuki Noda focused on explaining the behavior of two devastating quakes in Asia: the 1999 magnitude 7.6 temblor in Taiwan, and the 2011 magnitude 9.0 quake off the eastern coast of Japan. In both cases, the quake spread across so-called “creeping“ fault segments long thought to be incapable of transmitting quakes, according to Caltech Staff Seismologist Kate Hutton, a Lapusta colleague. “The general idea until this paper was that they would stop a quake,” Hutton said. It was believed the slow, creeping movement prevents stress from building up and keeps such a segment stable, Hutton added. Lapusta and Noda developed a computer model to explain how under certain conditions “a rupture could just kind of barge right through,” Hutton said. “Now the question is how this would apply to California.” Such a creeping zone has been identified in a stretch of the San Andreas Fault in central California, just north of seismically active Parkfield. The Great San Francisco quake of 1906 occurred on the San Andreas north of the creeping zone. The 1857 Fort Tejon quake occurred to the south. No known quake has ever spanned across that creeping zone. Whether the model developed by Lapusta and Noda could apply there would depend on local geological variables not yet completely understood, Hutton said. –NBC LA
San Francisco- A special report released in the January issue of the San Francisco Public Press contains a list of nearly 3,000 potentially earthquake-unsafe buildings in the city estimated to be housing more than 58,000 people.
The list, which was initially compiled by the Department of Building Inspection but not released to the public, shows all of the city’s “soft-story” buildings, which are at a high risk of collapse during intense seismic activity due to their weak ground floors.
The buildings on this list have not necessarily been verified in-person by building inspectors as needing additional work in order to become earthquake safe. These are buildings that, at least superficially, resemble many of the ones that sustained the most damage in the 1989 Loma Prieta earthquake.
In 2011, San Francisco voters rejected a $46 million bond measure that would have gone towards funding soft-story retrofits on the city’s affordable housing and single-room occupancy units. There is reportedly a plan circulating around City Hall to get the most dangerous buildings retrofitted by 2017 and have the rest completed by 2020.
Public Press reports that the list was released against the advice of many city officials, who worried that putting this information out in the open would needlessly alarm the public. However, the non-profit investigative reporting media outlet came down on the side of the public’s need to know.
“A major quake, of course, can strike San Francisco at any time,” Edward Field, chairman of the U.S. Geological Survey’s Working Group on California Earthquake Probabilities, told the Bay Citizen. “There is roughly a 28 percent chance that an earthquake of at least magnitude 6.7 will hit the Bay Area within 10 years.”
A recent study conducted by researchers at CalTech and the Japan Agency for the Marine-Earth Science and Technology, found that zones in the San Andreas fault previously thought to be relatively stable actually have the potential to trigger a “mega-quake” that could shake California from Los Angeles to San Francisco. –Huffington Post
Along with the constant threat of earthquakes and tsunamis along the west coast of the US, there are also some who believe the sun will help trigger these events.
Here is a link to a web prediction that has the entire west coast on ‘red’ alert for a possibly large earthquake caused by a solar CME or flare in the next few days: