A 6.9-magnitude earthquake followed by a 7.1-magnitude tremor struck southern Japan on Thursday, the U.S. Geological Survey said, and the local weather agency warned of tsunamis that could hit coastal areas.
Tsunamis of up to one metre are expected to hit or have already hit some coastal areas on Kyushu and Shikoku islands, broadcaster NHK reported.
“Tsunamis will occur again. Please do not enter the sea or approach the coast until the warning is lifted,” the Japan Meteorological Agency said Friday.
There were no immediate reports of damage.
The USGS said the first quake struck at 4:42 p.m. at a depth of 33 kilometers, about 29 kilometers southeast of Miyazaki in Kyushu.
The second occurred less than a minute later, at a depth of 26 meters and 20 kilometers northeast of Miyazaki.
The Japanese government has set up a special task force in response to the earthquakes, according to a statement.
Located on four major tectonic plates along the western edge of the Pacific “Ring of Fire,” Japan is one of the most tectonically active countries in the world.
The archipelago, home to around 125 million people, experiences around 1,500 tremors each year and is responsible for around 18% of the world's earthquakes.
On New Year's Day, at least 260 people died after a major earthquake struck the peninsula, including 30 “earthquake-related” deaths in addition to those who died directly in the disaster.
Japan has strict building regulations designed to ensure buildings can withstand strong earthquakes and periodically holds emergency drills to prepare for a major tremor.
But the country is haunted by memories of a massive 9.0-magnitude undersea earthquake off northeastern Japan in March 2011, which triggered a tsunami that left around 18,500 people dead or missing.
