Japanese officials on Thursday ended the state of “megaquake advisory” announced last week for the archipelago nation’s southern two-thirds following a 7.1 magnitude event that seismologists warned could have portended a large megathrust quake was imminent, Reuters reports.
The first ever advisory had prompted local governments to review evacuation plans as an event on the scale of the 9.1 magnitude 2011 Tōhoku quake could have sent a raging tsunami into cities including Tokyo, Yokohama, and Osaka, killing tens or even hundreds of thousands. Officials with railway lines along the Pacific coast had ordered trains slowed down during the advisory.
It’s not clear why the advisory had a six-day period it or what information the government had used to determine that the immediate threat of a megathrust quake along the coast had subsided.