Major 7.5-magnitude quake hits off Japan, tsunami warning issued

Tokyo: A magnitude 7.5 earthquake struck off the northeastern coast of Japan on Monday, prompting authorities to tell residents to stay away from coastal areas where tsunami waves of up to three metres were expected.

The tremor had an epicentre in the Pacific Ocean and was 10 kilometres deep, according to the Japan Meteorological Agency. The biggest waves were forecast to hit Iwate and Aomori prefectures at the top of Japan’s main Honshu island, and the northern island of Hokkaido, authorities said.

In the hour following the earthquake, which struck at 4.52pm (5.52pm AEST), tsunami waves as high as 80 centimetres had been detected. Warnings remained in place for possible larger waves at the top of Japan’s main island Honshu and the northern Hokkaido region.

There were no immediate reports of casualties or major damage, government spokesperson Minoru Kihara told a news conference as night fell in the capital Tokyo.

Several port towns, including Otsuchi and Kamaishi – both hit hard by a massive earthquake and tsunami in 2011 – earlier issued evacuation orders for thousands of residents, according to public broadcaster NHK. Bullet train services were halted and some motorways were closed following the tremors.

Prime Minister Sanae Takaichi, who said the government had set up an emergency taskforce, urged citizens in the affected areas to evacuate to safety.

Ships sailed out of Hachinohe port in Hokkaido in anticipation of the waves, footage aired on NHK showed, as a “Tsunami! Evacuate!” alert flashed across the screen.

Big aftershocks may occur in the following days and weeks, an official from Japan’s Meteorological Agency (JMA) said at a separate televised press conference.

A three-metre tsunami could cause damage to low-lying areas, flooding buildings, and anybody exposed would be caught in its currents, according to JMA.

The quake measured an “upper five” on Japan’s seismic intensity scale – strong enough to make it difficult for people to move around. In many cases, unreinforced concrete-block walls collapse.

Japan is one of the world’s most earthquake-prone countries. A tremor occurs in the island nation at least every five minutes. Located in the “Ring of Fire” of volcanoes and oceanic trenches partly encircling the Pacific Basin, Japan accounts for about 20 per cent of the world’s earthquakes of magnitude 6.0 or more.

There are no nuclear power plants in operation in the affected areas and Hokkaido Electric Power Co and Tohoku Electric Power Co said there were no abnormalities reported at their idled facilities there.

Reuters