Nankai Trough Megaquake: Updated Estimates Reveal Lower Death Toll but Increased Tsunami Risk
The Nankai Trough megaquake death toll estimate dropped to 298,000, with a larger tsunami-impacted area by 30%. Predictions indicated 26,000 to 52,000 indirect deaths and economic damage at ¥292 trillion. The probability of a magnitude 8 or 9 quake is now about 80% within 30 years, necessitating strengthened disaster preparedness and updated government plans.
The estimated death toll from a potential megaquake in the Nankai Trough has been adjusted down to approximately 298,000. This figure is a reduction from earlier predictions that estimated 323,000 fatalities. Simultaneously, projections indicate that the tsunami-affected area will be 30% larger than previously thought, resulting in added risks for those in coastal regions.
The report also forecasts that between 26,000 and 52,000 individuals may die indirectly due to disaster-related issues. Economic impacts have been calculated, estimating damages will reach ¥292 trillion, significantly higher than prior estimates mainly due to rising costs.
A potent earthquake, with a possible magnitude of 8 or 9, is anticipated along the Nankai Trough, extending from Shizuoka to Miyazaki Prefectures. The Earthquake Research Committee recently increased the likelihood of such an event occurring within the next 30 years to around 80%. This follows the historical context of significant earthquakes in the region, including 7.9 and 8.0-magnitude quakes in 1944 and 1946, respectively.
The Central Disaster Management Council has refined its estimates over the years to incorporate advanced topographical data, improving the understanding of current resilience and evacuation infrastructure. The updated report indicates that a tsunami exceeding three meters could inundate 115,150 hectares of coastal land.
Key factors influencing the estimated 298,000 death toll include the timing of the tsunami, which could strike late at night, potentially preventing timely evacuations. The model anticipates that 20% could evacuate immediately, leading to significant casualties, particularly in densely populated areas like the Tokai region.
Evacuation efforts could involve approximately 12.3 million people, with around 950,000 suffering injuries and about 2.35 million homes at risk of destruction due to the quake and tsunami effects. The reassessed economic damage reflects ¥225 trillion for assets and ¥67 trillion impacting economic activity.
Notably, the report also highlights the potential for a coseismic slip, in which separate 8.0-magnitude quakes might occur with a time delay. This could lead to additional casualties, with estimates suggesting up to 176,000 fatalities in such scenarios. Concerns about Japan’s aging and declining population may exacerbate the disaster’s effects, urging comprehensive preparation strategies from all sectors.
Following this report, the government plans to update the 2014 Basic Plan regarding disaster mitigation targets to enhance readiness and countermeasures.
Additionally, monitoring efforts for the Nankai Trough will continue, yet no unusual seismic activities have been detected so far. Authorities emphasize the importance of reexamining disaster preparedness to mitigate potential future impacts.
The revised estimates regarding the Nankai Trough megaquake underscore the urgency for improved disaster preparedness measures. While the death toll estimates have been lowered, the expansion of the tsunami-affected area points to increased risks for vulnerable populations. The projected economic impacts further highlight the need for comprehensive strategies to enhance community resilience against significant seismic events.
Original Source: japannews.yomiuri.co.jp
