If those poor souls who still live in California don’t have enough to worry about, how about The Big One?
Geologists are watching a spike in vibrations along a section of the San Andreas Fault where a 7.8 earthquake occurred in 1857.
“...Researchers at the University of California, Berkeley, monitored seismic activity on the fault’s central section between July 2001 and February 2009 and recorded more than 2,000 tremors. The tremors lasted mere minutes to nearly half an hour.
Unlike earthquakes, tremors occur deeper below the surface and the shaking lasts longer.
During the study period, two strong earthquakes hit—a magnitude-6.5 in 2003 and a magnitude-6.0 a year later. Scientists noticed the frequency of the tremors doubled after the 2003 quake and jumped six-fold after 2004.
Tremor episodes persist today. Though the frequency of tremors have declined since 2004, scientists are still concerned because they are still at a level that is twice as high as before the 2003 quake….”