CalTech ran the first real demonstration of its earthquake early-warning system at in Pasadena Wednesday.
"You can get notice that an earthquake has occurred and is about to shake your location before you actually feel the shaking," said Doug Given, U.S. Geological Survey.
The early-warning system sounds an audible alert, shows a countdown timer and estimates the intensity of an earthquake.
Seismologists say that once the technology advances, they should be able to faster determine a quake's magnitude and send that information out to the public before the strongest shaking waves reach your location.
"In the case of the first event last night, here in Pasadena we got about 9 seconds' warning before the strongest shaking was felt here. In the case of the second quake it was a little bit less, about 4 seconds' warning," said Given.
A few seconds may not sound like much, but the farther away you are from the epicenter, seismologists say, the more advanced warning you'll get.
So at a time when every second counts, why isn't the early-warning technology publicly available in California?
"It's also rather fragile at this point because it's built on the older technologies and with the very limited funding that the USGS currently has," said Given.