April 7, 2011
TOKYO — A strong aftershock rattled Japan and officials issued a tsunami warning Thursday night nearly a month after a devastating earthquake and tsunami flattened the northeastern coast.
The warning was lifted 90 minutes later, but not before announcers on Japan's public broadcaster NHK told coastal residents to run to higher ground and away from the shore.
The Japan meteorological agency had issued a tsunami warning for a wave of up to 6 feet after the quake. The warning was issued for a coastal area already torn apart by last month's tsunami, which is believed to have killed some 25,000 people and has sparked an ongoing crisis at a nuclear power plant.
The U.S. Geological Survey initially recorded Thursday's quake at 7.4 in magnitude, but later downgraded it to 7.1.
The latest quake knocked power out at several nuclear power plants, a spokeswoman for Japan’s Nuclear and Industrial Safety Agency told msnbc.com, forcing the plants to operate on emergency power. None of the damage to nuclear sites posed any danger at the moment, she said.