Mysterious tremors detected on San Andreas Fault

hu Jul 9, 2:01 pm ET

LOS ANGELES – Scientists have detected a spike in underground rumblings on a section of California's San Andreas Fault that produced a magnitude-7.8 earthquake in 1857.

What these mysterious vibrations say about future earthquakes is far from certain. But some think the deep tremors suggest underground stress may be building up faster than expected and may indicate an increased risk of a major temblor.

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.

The team also recorded unusually strong rumblings days before the 2004 temblor

shiiit god must be pissed off at cali

Could it be doom?

I hate California

California is so bad that even the ground is trying to get away from it

Well written! Thanks for the chuckle.

I work a few miles from the fault on occasion -- if it goes and I'm there I'll try and give a report if I can

we are overdue.

love peace and joy

rb

p.s. for Americans wishing to see this well, it may be the end of us -- Cali is a huge part of the USA and without us the whole place goes -- especially in the precarious position we're already in economically.