Japan Placed On High Alert Of Earthquake

 Experts have warned Japan to stay vigilant for the next big one after a 7.8-magnitude earthquake struck off the coast of the country, injuring a dozen people.

The United States Geological Survey (USGS) reported that buildings swayed for about a minute in Tokyo on Saturday night as the quake struck at a remote spot in the Pacific Ocean 542 miles (874 km) south of the capital.

The USGS and the Pacific Tsunami Warning Centre both however said that despite its power, there was no risk of a tsunami as the epicentre was 676km below the Earth’s surface.

Twelve people were reportedly injured, including a 56-year-old man who broke his ribs, but no one was killed, according to a Tokyo fire department official and local media.

Four hundred people were trapped on the observation decks of Tokyo Tower as its elevators stopped for more than an hour.

Runways at Haneda Airport in the capital were closed for about 30 minutes, with trains also temporarily halted, while a football match in the city was briefly suspended, reports said.

There were however no reported problems at any of the region’s mothballed nuclear power plants.

A separate 6.2-magnitude quake struck on Sunday morning off the Izu Islands south of Tokyo, the USGS said, but there were no reports of damage or injuries.

Recall that a massive undersea quake in March 2011 sent a tsunami barreling into Japan’s north-east coast, killing thousands of people and sending three reactors into meltdown at the Fukushima nuclear plant.

The nuclear disaster, the world’s worst since Chernobyl, displaced tens of thousands of people and rendered tracts of land uninhabitable, possibly for decades.

Saturday’s quake was the second sizeable tremor that Tokyo has experienced in a week, after a much less powerful – but far shallower – earthquake close to the capital on Monday.

Some experts warn recent quakes and volcano eruptions may be signs that areas near the country are entering an active phase of crustal changes.