Japan has the most advanced earthquake early-warning system in the world, reports Lucy Birmingham for Time. 'It took just seconds for a seismometer located on land, closest to the epicenter, to detect enough signals to determine an alert was necessary. The alert was automatically issued at 2:46:48 via locations such as factories, schools, TV networks, radio stations and mobile phones.'
Explore further
Hazards
Earthquake
Country and region
Japan