RIDGECREST, Calif.—Shaken residents are cleaning up from two of the biggest earthquakes to rattle California in decades as scientists warn that both should serve as a wake-up call to be ready when the long-dreaded “Big One” strikes.
California is spending more than $16 million to install thousands of quake-detecting sensors statewide that officials say will give utilities and trains precious seconds to shut down before the shaking starts.