An earthquake with an estimated magnitude of 6.3 hit off Kyushu on Friday, injuring a man and disrupting some local transportation networks, authorities said.
The 8:48 a.m. quake occurred at a depth of about 20 kilometers under the seabed off Miyazaki Prefecture. It measured a lower 5 on the Japanese seismic intensity scale to 7 in the city of Miyazaki and Miyakonojo, also in the prefecture, while minor jolts were felt in wider areas of western Japan, the Meteorological Agency said.
In neighboring Oita Prefecture, a 79-year-old man who was trimming trees when the quake struck was taken to a hospital after falling from a stepladder. His condition is not life-threatening, local authorities said.
The agency warned that another strong quake measuring up to lower 5 could strike the region within a week, but dismissed concerns that Friday’s seismic activity could immediately trigger a mega-quake along the Nankai Trough, which extends southwest from central Japan along the Pacific coast.
The government says there is a 70 to 80 percent chance of a magnitude 8 or 9 Nankai Trough quake — capable of generating a devastating tsunami resulting in an estimated death toll of up to 300,000 people — occurring within 30 years.
Friday’s quake briefly suspended shinkansen services on Kyushu, causing delays of up to around 15 minutes, according to the operator. A speed limit of 50 kph was set on some expressways.
No problems were reported on runways at airports in Miyazaki, Kumamoto and Kagoshima prefectures after safety checks, airlines said.
Kyushu Electric Power Co. said no abnormalities were detected at its Sendai nuclear power plant in Kagoshima Prefecture, where two reactors are in operation.
In the city of Miyazaki many elevators at commercial and residential buildings were halted by the quake, according to maintenance companies.
A water pipe burst in the city, while some 150 households in Ebino, Miyazaki Prefecture, were temporarily left without power.
The central government set up a liaison unit at the crisis management center of the Prime Minister’s Office in Tokyo to gather information about the temblor.