A new assessment from a Japanese government expert panel anticipates that a worst-case magnitude 7.3 earthquake directly striking the Tokyo metropolitan area could cause approximately 18,000 fatalities and result in staggering economic losses estimated at ¥83 trillion, or roughly HK$4.2 trillion. The forthcoming projections, the first update since 2013, show a notable reduction in anticipated casualties and financial damage, reflecting progress in regional seismic mitigation efforts but underscoring the enduring vulnerability of the capital region.
New Projections Detail Impact and Progress
The updated forecast, which models a high-impact “capital-region direct-hit” earthquake with an epicenter beneath greater Tokyo, indicates significant improvements compared to the 2013 estimates. The projected death toll has decreased by 5,000, and the expected economic fallout is reduced by ¥12 trillion. These positive shifts are largely attributed to extensive seismic retrofitting of older infrastructure and the implementation of enhanced fire-prevention measures across the densely populated urban area, according to reports by Kyodo News.
Despite this progress, the potential devastation remains immense. A magnitude 7 event in the densely populated area is estimated to destroy or severely damage approximately 400,000 buildings through collapse and fire. Furthermore, the disaster could render about 8.4 million people homeless or unable to immediately return to their residences.
Key Findings from the Draft Assessment:
- Fatalities: 18,000 deaths (worst-case scenario), reduced from the previous estimate.
- Economic Impact: ¥83 trillion in losses, a reduction of ¥12 trillion from 2013.
- Infrastructure Damage: Approximately 400,000 buildings destroyed or burned.
- Displaced Population: About 8.4 million people unable to return home.
A significant new element in this assessment is the estimation of disaster-related deaths—casualties not caused by the immediate shaking but by deteriorating health during prolonged evacuation or disruption of medical services. Drawing on lessons learned from past earthquakes, the panel places the range for these indirect fatalities between 16,000 and 41,000, highlighting the challenge of managing long-term disruption.
Target Missed, Strategy Revision Planned
In 2015, the government established the Basic Plan for Promoting Countermeasures, setting an ambitious goal to halve earthquake fatalities within a decade. While the new figures show improvement, this target has not yet been achieved. This shortfall necessitates a strategic revision, with the government planning to introduce further measures to accelerate preparation and close the gap between current preparedness and desired mitigation levels.
Additionally, the expert panel warned about the operational continuity of government functions. A major quake could severely constrain the ability of central government ministries and key agencies to resume normal operations efficiently, posing a severe crisis management challenge beyond the immediate humanitarian response.
The expert panel is scheduled to finalize this comprehensive assessment later this month. While a government official cautioned that the figures are still subject to review and potential adjustments, the release of the updated projections serves as a critical call to action. It confirms the nation’s proactive investments in resilience are bearing fruit, yet it powerfully reaffirms that continuous, accelerated investment in urban planning, infrastructure hardening, and public readiness remains vital for the survival and rapid recovery of the world’s largest metropolitan area.