Japan's government and experts have issued a warning about the increasing likelihood of a mega-earthquake striking the nation within the next 30 years. According to the Japanese government's earthquake investigation panel, the probability of a megaquake happening has risen to over 80 percent, with estimates of 82% for an 8.0 or 9.0 magnitude earthquake. This marks an increase from previous estimates, which placed the probability between 70% and 80%. The panel's findings, reported by The Independent, emphasize the urgency for preparedness in the face of the imminent threat.
The most probable location for such an earthquake is along the Nankai Trough, an underwater fault line that runs parallel to Japan's eastern coastline for 800 kilometers from Shizuoka to Kyushu Island. This area is where the oceanic tectonic plate of the Philippine Sea is slowly sliding beneath the continental plate on which Japan is located, making it a hotspot for seismic activity. The Nankai Trough has a history of producing megathrust earthquakes and is being closely monitored due to the risk it poses.
A megaquake, defined as an earthquake with a magnitude of 8 or greater, brings the potential for destructive power, including gigantic tsunamis that could kill hundreds of thousands and cause billions in damages. Experts state a mega-earthquake occurring in the Nankai Trough region could lead to destruction, with projections estimating approximately 2.1 million destroyed buildings and more than 230,000 deaths, in addition to missing people.
Historic patterns indicate that megaquakes in the Nankai Trough have occurred every 100 to 200 years over the past 1,400 years, with the most recent megaquake recorded in 1946. on December 26, 1707, all segments of the Nankai Trough ruptured simultaneously, causing an earthquake that remains Japan's second-most powerful on record. This event, known as the Hoei Earthquake, not only devastated regions along the coast but also triggered the last eruption of Mount Fuji.
"It has been 79 years since the last earthquake, and the likelihood of another earthquake occurring is increasing each year at a rate of about one percent," said a secretariat official from the Japan Earthquake Research Committee. This gradual increase underscores the escalating risk Japan faces and the importance of vigilance.
"This probability is a number indicating that it would be no surprise if an earthquake were to happen at any time," said Naoshi Hirata, head of the expert panel, as reported by The Independent. The potential consequences of such a disaster are profound.
Japan is located in one of the most tectonically active areas of the world, making it a land where seismic hazard is very high. The country suffers about 1,500 earthquakes every year, averaging four earthquakes daily. "About 10 percent of the world's earthquakes of magnitude 6 or higher occur in or around Japan, so the risk is much higher than in places like Europe or the eastern United States, where earthquakes are rare," explained Shoichi Yoshioka, a professor at Kobe University in Japan, according to The Independent.
The movement of tectonic plates is at the heart of this seismic activity. The Philippine Sea plate is slowly slipping beneath the continental plate that Japan sits on. As these plates get stuck while moving, they store a large amount of energy, and when they break free from their stuck position, this energy is suddenly released, which could result in a megaquake.
However, not all experts are convinced by the predictions of a Nankai Trough megaquake. Robert Geller, a seismologist and professor emeritus at the University of Tokyo, criticizes the idea of issuing regular warnings about a Nankai Trough quake. He argued that earthquakes don't follow predictable cycles and can occur unpredictably, as reported by The Independent. This view contrasts with the traditional scientific belief in the "stick-slip" process, where stress builds up along faults and is eventually released in earthquakes.
According to government estimates published in 2012, small islands along the Japanese coast are at risk of being submerged by tsunami waves more than 30 meters high, as reported by Der Standard.
This article was written in collaboration with generative AI company Alchemiq