A catastrophic earthquake and subsequent tsunami could result in nearly 298,000 deaths and economic losses of up to $2 trillion in Japan, according to a new government estimate. This updated projection, reported by AFP, revises a 2014 estimate that had predicted even higher casualties.
Nankai Trough: A Looming Threat
The anticipated megaquake is expected to occur along the Nankai Trough, an 800-kilometer-long undersea trench stretching from Shizuoka, west of Tokyo, to the southern tip of Kyushu. This region is known for its high seismic activity as the Philippine Sea tectonic plate gradually moves beneath the continental plate supporting Japan. Over centuries, energy builds up until it is violently released through powerful earthquakes.
According to Japan’s Cabinet Office disaster management group, the revised fatality projections include:
- 215,000 deaths from tsunamis
- 73,000 deaths due to collapsed buildings
- 9,000 deaths from fires
While these figures are alarming, they are slightly lower than the 2014 estimate of 323,000 potential fatalities.
Japan’s Megaquake History and Rising Probability
Japan has a long history of devastating earthquakes, with megaquakes occurring in the Nankai Trough every 100 to 200 years. The most recent such event took place in 1946. A government panel in January 2025 warned that the probability of another megaquake within the next 30 years has increased to 75-82%.
Being one of the most seismically active nations, Japan experiences around 1,500 tremors annually. While most are mild, the extent of damage depends on the quake’s location and depth. Japan has strict building regulations designed to withstand strong tremors, but massive earthquakes still pose a significant threat.
Past Disasters and Their Impact
Japan has suffered multiple devastating earthquakes in recent history, including:
- March 2011: A magnitude 9.0 earthquake triggered a tsunami that killed 18,500 people and caused the Fukushima nuclear disaster, the worst since Chernobyl. The estimated cost was $112 billion, excluding long-term nuclear decommissioning expenses.
- January 1, 2024: A major earthquake on Japan’s Noto Peninsula killed 260 people and caused severe destruction during New Year celebrations.
- August 2023: The Japan Meteorological Agency (JMA) issued its first-ever megaquake advisory after a magnitude 7.1 earthquake in southern Japan. The warning led to widespread panic, with shortages of rice and essential supplies.
Preparedness Measures and Future Risks
With the likelihood of a megaquake rising, Japan continues to strengthen its disaster preparedness. Strict building codes, early warning systems, and public awareness campaigns play a crucial role in minimizing casualties. However, experts warn that no system can fully eliminate the risk posed by a potential magnitude 8+ earthquake.
As Japan braces for the possibility of another large-scale disaster, authorities urge citizens to stay prepared, invest in emergency kits, and remain vigilant about seismic warnings.
