MECCA, CA – JULY 3: A valley filled with the swirled shapes of earth layers that were deformed by the collision of the Pacific and North American tectonic plates along the southern San Andreas Fault north of the Salton Sea is seen on July 3 near Mecca, California. Scientists have discovered that human-created changes effecting the Salton Sea appear to be the reason why California’s massive “Big One” earthquake is more than 100 years overdue and building up for the greatest disaster ever to hit Los Angeles and Southern California. Researchers found that strands of the San Andreas Fault under the 45-mile long rift lake have have generated at least five 7.0 or larger quakes about every 180 years. This ended in the early 20th century when authorities stopped massive amounts of Colorado River water from periodically flooding the into this sub-sea level desert basin. Such floods used to regularly trigger major quakes and relieve building seismic pressure but the last big earthquake on the southern San Andreas was about 325 years ago. Dangerous new fault branches that could trigger a 7.8 quake have recently been discovered under the Salton Sea. (Photo by David McNew/Getty Images)
