Introducing Earth

The southern San Andreas has a smaller, neighboring fault to its west

Earthquake risk may go up or down

Sediment layers

NEWFANGLED FAULT   Scripps geologist Neal Driscoll taking measurements of  sediment layers along the eastern edge of the Salton Sea.

Scripps Institution of Oceanography, UC San Diego

By Thomas Sumner

- More than 2 years ago

Meet the San Andreas Fault’s newfound neighbor. Mapping deformations deep underground along the shoreline of a Southern California lake called the Salton Sea, seismologists discovered a fault that runs parallel to San Andreas’ southern end.