California's fearsome 'Big One' earthquake looks increasingly like it might actually be two, scientists have warned. Researchers uncovered the strongest evidence yet that a tremor along the infamous ...

A megaquake in the Pacific Northwest could trigger a large earthquake along California's San Andreas Fault, creating an unprecedented catastrophe up and down the Pacific Coast, a new study has found.

One of the most dangerous faults in the United States, the Cascadia Subduction Zone, may be able to trigger an earthquake on the San Andreas Fault, a new study says. But some scientists want more ...