At Caltech, engineers announced they had about 10 seconds warning before they felt shaking.Ten seconds may not seem like a lot of time, but it is enough to stop trains and traffic and to warn people to take cover.For those inside, it will give them a few seconds to consider a safe response and to take adequate cover.Instead of crouching under the first desk or chair they find, they may have more time to seek shelter under a sturdier table.
The system works by detecting shaking and by triangulating the origin of the event.
Quakes can also be frightening because everything moves, even things people would never expect to move, such as sturdy furniture. Seconds after the quake begins, shaking can intensify, which can shock people.
It is hoped the system will be functional by 2019 and will begin to protect schools and public infrastructure at that time.
This can be dangerous because as the shaking intensifies, roofing material, glass, and facades can fall, striking people just as they exit the structure.
An early warning might give some lucky people a chance to get to safety before shaking starts.