Japan issued a tsunami warning yesterday after a 6.8-magnitude earthquake struck off its eastern coast, but officials later said the waves generated posed little danger and lifted the warning. There were no reports of injuries or damage from the quake.
The earthquake struck at 3:11pm about 200km off the coast of Chiba prefecture, the Meteorological Agency said.
It was centered 10km below the ocean floor. The shaking was weak and hardly felt in Tokyo or nearby areas.
The agency issued warnings for tsunami, or waves caused by seismic activity, as high as 50cm near the Izu Island chain on the Pacific Ocean. The agency lifted all warnings at 4:55pm.
Waves ranging in height from 10cm to 30cm were recorded at the Izu islands, the agency announced about an hour after the quake.
Officials on nearby islands took immediate precautions.
Yoshinori Takahashi, chief of the disaster prevention department on the island of Izu Oshima, said that there were no reports of tsunami hitting any of the islands' shores.
"We have not seen any changes on the water around the island," Takahashi said about 20 minutes after the tsunami was expected to hit.
"We have issued a tsunami warning on our public speaker system set up throughout the island to warn residents not to approach the coast," he said.
On Kozu Island, town spokesman Akiyoshi Shimizu said officials have gone down to ports to check any changes but found no major damage. The town office warned residents to immediately evacuate to safer areas on higher altitude.
Stuart Weinstein, a geophysicist at the Pacific Tsunami Warning Center in Honolulu, said the quake failed to generate a Pacific-wide tsunami.
US experts measured the quake at a magnitude of 6.4, below the threshold for the center issuing any kind of advisory, he added.
The tsunami that killed more than 160,000 people in South Asia and Africa was generated by a 9.0 earthquake near Indonesia under the Indian Ocean. The region does not have a tsunami alert system. Yesterday's quake occurred under the Pacific Ocean near Japan, a region that possesses a tsunami alert system.