© David LynchMap of the San Andreas Fault (Red Line)
Researchers believe Colorado River damming projects that followed the creation of the Salton Sea could be one reason why Southern California is overdue for a major earthquake.
In a new study led by the Scripps Institution of Oceanography, scientists found that the floodwaters that periodically flowed through faults helped trigger earthquakes in the area, including several large ones along the mighty San Andreas.
The modern Salton Sea came to life nearly a century ago when record floodwaters from the Colorado River overwhelmed barriers, and during the course of two years created the massive body of water in a desert sink. Dams and other irrigation barriers were eventually built to stop the flow of water into the sea and end the periodic flooding that had long plagued the area.
But scientists wonder whether the creation of the Salton Sea tweaked the seismic dynamics of the area, which is crisscrossed by numerous fault lines that feed into the San Andreas.
The study's lead author, Daniel Brothers, a marine geophysicist for the U.S. Geological Survey, said that in the past the weight of the flowing floodwaters bent the Earth's crust, causing some sections of the faults to bow and others to bulge. In addition, floodwaters percolated into voids in the rock, exerting an outward pressure on the faults. All this helped trigger quakes, he said.