A long road to quake alerts for LA
LOS ANGELES - Earthquake early warning systems have been part of life in metropolises like Tokyo, Taipei and Mexico City for years.
But bringing the technology to California, crisscrossed by numerous faults, proved to be a complex and timely undertaking.
The faults that produce Japan and Mexico's largest earthquakes are quite distant from their biggest cities, but the longest faults in California are much closer to urban centers like Los Angeles and San Francisco. That required the installation of more sensors and sophisticated software to detect shaking and send alerts.
The further a quake's epicenter is from cities, the more warning residents there can receive - perhaps a minute for a temblor that begins more than 100 miles away. But quakes centered much closer could leave time for only a few seconds of warning, requiring the technology to render almost instantaneous
