5.3 earthquake off Ventura County coast triggers early warning system at Caltech

PASADENA, Calif. (KABC) -- A magnitude 5.3 earthquake on Thursday afternoon triggered an early warning system that is being developed at Caltech.

The alert was activated by sensors about 10 seconds before the quake, which struck near the Channel Islands off the coast of Ventura.

Scientists at Caltech lauded the performance of the U.S. Geological Survey warning system, which did not notify the public because it is still under development.

The temblor originated about 7 miles below the ocean floor, some 20 miles from Santa Cruz Island.

Dr. Susan Hough heard the early warning while she was at her desk at Caltech in Pasadena.

"And then, within a few seconds, I felt the shaking in my seat, essentially," she said. "And then my desk lamp kind of vibrated. So it was the first successful demonstration that I've seen, of the early warning system, personally."