Japan Vows to Cut Nankai Megaquake Death Toll by 80%

Basic Disaster Prevention Plan Revised for the First Time in 11 Years

The Japanese government on July 1 reiterated its targets for reducing damage related to the anticipated Nankai Trough megaquake.

A two-story house in a residential area of Kanazawa, Ishikawa Prefecture, central Honshu, Japan, toppled backward during the earthquake that occurred in January 2024. Photo by Yonhap News

In its newly revised "Basic Plan for Promoting Disaster Prevention Measures" regarding the Nankai megaquake?the first major revision in 11 years?the government announced that, based on simulation estimates, it aims to reduce the projected number of fatalities by 80% and damage to buildings by 50% within the next 10 years.

In March, Japan projected that a maximum of 298,000 people could die and 2.35 million buildings could collapse or be destroyed by fire in the event of a Nankai megaquake. The government has now set concrete reduction targets for these estimates.

Previously, in 2014, Japan also released both the projected numbers of fatalities and building damage, as well as reduction targets, in the event of a Nankai megaquake. Under the worst-case scenario, the projections were 332,000 fatalities and 2.504 million homes damaged or destroyed.

In the "Basic Plan for Promoting Disaster Prevention Measures" formulated at that time, the government also set targets to reduce projected fatalities by 80% and building damage by 50%.

Under the new plan established on this day, the Japanese government has designated 723 basic municipalities?where strong shaking or tsunamis over 3 meters high are expected?as "disaster prevention promotion areas," and has set specific targets for 205 priority measures.

The priority measures include expanding the number of earthquake-resistant homes, strengthening the seismic resilience of disaster base hospitals, and improving coastal levees. Among these, the government aims to increase the levee improvement rate from 42% in 2023 to 50% by 2030.

The Nankai Trough is a geological feature that stretches from offshore Shizuoka Prefecture, west of the Tokyo metropolitan area, to the southern coast of Shikoku and the eastern coast of Kyushu. A trough refers to a deep trench on the ocean floor. Large earthquakes are known to occur in this region at intervals of 100 to 150 years.

The Japanese government has continued research and disaster prevention activities in preparation for a magnitude 8 to 9 earthquake occurring along the Nankai Trough.