Japan faces a tsunami alarm after 7.4-magnitude quake

A 7.4-magnitude earthquake struck northern Japan on Monday, Japan’s Meteorological Agency (JMA) notified it with issuing a tsunami warning for waves up to three metres (10 feet).

The quake, which hit at 4:53 pm (local time) in Pacific waters off northern Iwate prefecture, was strong enough to shake large buildings as far as Tokyo, being hundreds of kilometres away.

Around 40 minutes later, an 80-centimetre tsunami wave hit a port at Kuji in Iwate, according to the JMA.

“Evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building,” it stated, warning that damage due to tsunami waves was expected.

“Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted,” it warned.

Footage from national broadcaster NHK did not show any immediate visible damage around several ports in Iwate. JMA official warned in a televised press briefing that more quakes could strike the area.

The prime minister’s office said that it had set up a crisis management team.

“For those of you who live in areas for which the warnings have been issued, please evacuate to higher, safer places such as higher ground,” Prime Minister Sanae Takaichi told reporters, adding that the government was trying to confirm whether there were any casualties or property damage.

Japan is one of the world’s most seismically active countries, sitting on top of four major tectonic plates along the western edge of the Pacific ‘Ring of Fire’.

The archipelago, home to around 125 million people, typically experiences around 1,500 jolts every year and accounts for about 18 percent of the world’s earthquakes.

The vast majority are mild, although the damage they cause varies according to their location and the depth below the Earth’s surface at which they strike.

Japan is haunted by the memory of a massive 9.0-magnitude undersea quake in 2011, which triggered a tsunami that killed around 18,500 people and caused a devastating meltdown at the Fukushima nuclear plant.

In 2024, the JMA issued its first special advisory of a possible ‘megaquake’ along with the Nankai Trough.

This 800-kilometre undersea trench is where the Philippine Sea oceanic tectonic plate is subducting or slowly slipping underneath the continental plate that Japan sits atop. The government has said that a quake in the Nankai Trough and subsequent tsunami could kill as many as 298,000 people and cause up to $2 trillion in damage.