TOKYO Last month's massive earthquake that devastated Japan's northeast shifted the seabed near the epicenter by 24 meters (79 ft), the coast guard said.
The 9.0 magnitude quake was one of the biggest ever recorded.
The movement is four times larger than any previous land shift recorded in Japan.
The largest quake in Japan's recorded history also elevated the seabed off the coast of Miyagi prefecture by 3 meters, the coast guard said on Wednesday.
The quake and subsequent 10-meter tsunami left nearly 28,000 dead or missing in the northeast and triggered the world's worst nuclear disaster in 25 years at a power plant in Fukushima, 240 km (150 miles) north of Tokyo.
(Reporting by Yoko Nishikawa, editing by Jonathan Thatcher)