Nankai Trench Japanese authorities warn population of mega-quake

Tobias Benz

9.8.2024

The endangered area near the Nankai Trench marked in yellow.
The endangered area near the Nankai Trench marked in yellow.
Image: NHK

Following a magnitude 7.1 earthquake in southwestern Japan, the Tokyo Meteorological Agency has for the first time warned of a higher risk of a mega-quake on the island nation's Pacific coast.

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  • Japan is one of the most earthquake-prone countries in the world. Now the earth is shaking again in the southwest. According to experts, the risk of a mega-quake has now increased.
  • According to the Japanese government, there is a 70 to 80 percent probability of a magnitude 8 to 9 quake in the next 30 years.
  • According to estimates, over 300,000 people could lose their lives.

A panel of experts declared that the probability of a major earthquake along the so-called Nankai fault has increased "many times over". People have been urged to prepare for all eventualities. This is a deep-sea trench that extends off the coast of the Asian economic powerhouse for around 900 kilometers from Shizuoka Prefecture on the main island of Honshu - where the capital Tokyo is located - to Kyushu.

According to estimates by the Japanese government, there is a 70 to 80 percent probability that an earthquake of magnitude 8 to 9 will occur along the Nankai Trench within the next 30 years. According to estimates, up to 323,000 people could lose their lives.

The classification of an increased risk by the meteorological authority followed a tremor off Kyushu in the southwest, one of Japan's four main islands. According to Japanese media, several people were injured and there were also reports of damage to buildings and roads. However, there were no irregularities at nuclear power plants in the region, according to reports.

Horror scenario: mega-quake near Tokyo

The earth has repeatedly shaken in the Nankai Trench area, most recently in 1946. Today, a mega-quake and subsequent tsunami would cause devastating damage in the island kingdom. In the worst-case scenario, Tokyo and other major cities with millions of inhabitants would also be affected.

Following the triple disaster in March 2011, when a magnitude 9 quake triggered a massive tsunami in north-eastern Japan, killing around 20,000 people and causing a nuclear disaster in Fukushima, Japan's seismologists are therefore paying particular attention to the Nankai Trench. It is feared that the consequences of a mega-quake in this zone would be considerably worse than in 2011.

Thursday's quake occurred at a depth of around 30 kilometers off the coast of Miyazaki Prefecture. The operation of high-speed trains was temporarily interrupted. The shaking and the classification of an increased risk for the Nankai Trench show Japan's population once again what dangers lie in wait for them.

Thursday's quake had a magnitude of 7.1.
Thursday's quake had a magnitude of 7.1.
Image: NHK

Strong earthquakes can strike at any time. No one can predict exactly where and when they will occur. Many fear that a major earthquake will hit Tokyo at some point.

However, there was no panic among the population this time either. What is sometimes misunderstood in the West as equanimity is in fact the composure and perseverance with which the Japanese face forces of nature such as the one on Thursday. The realization that one can ultimately only resign oneself to living on a powder keg has led to exceptional endurance in times of crisis among the islanders. The island kingdom of Japan is one of the countries most threatened by earthquakes in the world.


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