Jose Flores was driving with his family to see “Toy Story 5” on Wednesday in Caracas, Venezuela, when a loud earthquake alert went off on his wife’s Google Android phone. Six seconds later, he felt the earth starting to shake. Venezuela does not have a national early warning system of its own, but people with Android phones received alerts from Google’s Earthquake Alerts system, which can pull data from more than two billion phones equipped with built-in accelerometers. The same sensor that detects rotation on the screen can also sense vibrations from seismic waves. Three seconds after the quake started underground Seismic waves reached the surface and were picked up by phones. Phones detecting seismic activity Google said the system, which is available in nearly 100 countries, sent warnings that reached 11.4 million people on Wednesday, giving users seconds or up to two minutes notice before back-to-back powerful earthquakes struck. Several countries, including Japan, Mexico, Canada and the United States, have government-operated early warning systems. These largely rely on widespread regional networks of underground sensors …