News Beat
Japan braces for once-a-century Megathrust quake on scale of 1940s double-disaster that left 2,500 dead in 33ft tsunamis
ALARM bells are sounding across Japan over a terrifying once-a-century megathrust that could kill thousands and cause colossal tsunami waves.
A massive 7.5 earthquake ripped into the country’s north-eastern flank on Monday, tearing apart highways and injuring at least 34 people.
Soon after, Japan’s Meteorological Agency issued it’s first evenr megaquake warning, renewing fears of the so-called “big one”.
These giant quakes usually come every hundred years or so and often strike in pairs.
The last two did just that in 1944 and 1946, killing over 2500 people and prompting gigantic waves to swamp the southern Honshu coast.
Back in September, Japan’s earthquake investigation panel said there was a 60 to 90 per cent chance of a monster quake ripping through the Nankai Trough in the next 30 years.
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This vast fault runs along the Pacific coast and has produced some of the country’s deadliest quakes.
In April, authorities warned that a megaquake could unleash a tsunami more than 20m (66ft) high, smashing parts of Tokyo and surrounding prefectures.
They predicted around 300,000 deaths with trillions of dollars in damage.
After Monday’s tremor, people were warned to stay alert, however no evacuation orders were issued.
A follow-up 5.7 magnitude quake struck off the east coast of Honshu at a shallow depth of only 19 miles, adding to the barrage of seismic activity.
Japan is one of the world’s most earthquake-prone countries, with a tremor occurring at least every five minutes.
The islands are located in the “Ring of Fire” of volcanoes and oceanic trenches partly encircling the Pacific Basin.
Japan gets around 1,500 tremors a year and accounts for about 20 percent of the world’s earthquakes of magnitude 6.0 or greater.
Most cause little harm, but the 2011 9.0 magnitude quake sent a deadly tsunami into the north east coast, killing nearly 20,000 people.
It was the most powerful earthquake ever recorded in Japan and triggered waves that reached heights of 133ft in Miyako, Iwate Prefecture.
The massive tremors also triggered the Fukushima nuclear accident, the only incident along with Chernobyl to be rated seven on the International Nuclear Event Scale.
The fallout from the accident is expected to carry on until at least 2051.
Now experts fear that a big rupture in the more crowded south could be even worse in the absolute worst case scenario.
The Nankai Trough has a history of destruction.
A 1707 rupture along its entire 600 kilometre length unleashed the second biggest quake ever recorded in Japan and was followed by an eruption of Mount Fuji.
Geologists Kyle Bradley and Judith A Hubbard have called this long expected event “the original definition of the ‘Big One’”.
They wrote that “the history of great earthquakes at Nankai is convincingly scary” so as to be concerning.
Japan introduced its warning system after 2011 to try to avoid another tragedy and used it for the first time in August 2024.
The JMA tried to calm fears, saying: “The likelihood of a new major earthquake is higher than normal, but this is not an indication that a major earthquake will definitely occur”.
