In the next 30 years, a catastrophic mega-earthquake could strike Earth. Who is at risk?

Geologists do not possess a crystal ball to predict future earthquakes, but Japanese seismologists, based on their observations, believe that the likelihood of a strong earthquake is gradually increasing. Just last year, scientists estimated the figures to be 10% lower, and today the probability of a catastrophic earthquake has reached 80%, as reported by IFLScience.

According to the Japanese Earthquake Research Committee, the chance of a major catastrophic earthquake occurring in the Nankai Trough within the next 30 years is currently 80%. Similar events have occurred in this region before, and it has been 79 years since the last earthquake. Now, scientists claim that the likelihood of such an event is growing literally every year.

The Nankai Trough stretches 900 kilometers along the southern part of Japan's largest island, Honshu. Researchers point out that this subduction zone is located where the Philippine Sea Plate is being pushed under the Eurasian Plate, making it a hotspot for seismic activity.

Scientists note that the Nankai Trough is infamous for its megathrust earthquakes — powerful seismic events that occur when one tectonic plate descends beneath another, releasing an incredible amount of energy. Previous studies have already indicated that if the Nankai Trough experiences a significant shock at some point, it is likely to be devastating.

The Japanese government takes this threat seriously, and as a result, Nankai's explosive earthquakes are considered a top priority in Japan's disaster response strategy. Local authorities are also developing plans to prepare for a potential eruption.

Researchers highlight that one of the earthquakes in Nankai has gained particularly grim notoriety. The disaster occurred in 1946: an earthquake with a magnitude of 8.1 claimed the lives of 1,362 people, destroyed or damaged more than 36,000 homes, and over 2,100 structures were swept away by a 6-meter high tsunami.

Unfortunately, predicting earthquakes is quite challenging; however, scientists are employing the latest technologies to calculate the probability of seismic shocks occurring in a certain area within a specific timeframe.

Researchers also predict that a megathrust earthquake in Nankai could be catastrophic and may cause more extensive damage than the Great East Japan Earthquake of 2011, with casualties potentially exceeding 320,000 people. Nevertheless, scientists once again emphasized that their forecasts are by no means definitive.

According to Professor Eishioka Seiichi of the Urban Safety Research Center, statistically, earthquakes in this region are likely to occur every 90-150 years. At least, this is indicated by observational data. It should be noted that reliable earthquake predictions must accurately extrapolate three factors:

• the location of occurrence;
• the timing of occurrence;
• the magnitude of the earthquake.

Among these three factors, predicting the timing of an earthquake is particularly difficult.