Tokyo Quake Could Kill 18,000; Japan Unveils New Disaster Plan to Halve Damage Within 10 Years

The Japanese Cabinet approved an updated version of the Basic Plan for Promoting Emergency Measures against a 'Direct-Hit Tokyo Earthquake' today, setting new disaster reduction targets to cut expected fatalities and building damage by more than half over the next 10 years.

According to damage estimates released by the Japanese government in December 2025, a 'Direct-Hit Tokyo Earthquake' could destroy or burn down approximately 400,000 buildings, with fatalities potentially reaching as high as 18,000. Economic losses are estimated at around 83 trillion yen (approximately 16.7 trillion New Taiwan dollars).

The new disaster prevention plan aims to go beyond the previous target of 'roughly halving' casualties and building damage, now striving for 'more than halving' these figures. This marks the first revision of the plan since 2015.

A 'Direct-Hit Tokyo Earthquake' refers to a magnitude 7 to 8 earthquake occurring directly beneath Japan’s capital region and its surrounding areas. According to the Headquarters for Earthquake Research Promotion, the probability of a shallow magnitude-7 earthquake occurring in the southern Kanto region within the next 30 years is approximately 70%.

To achieve the new disaster reduction goals, the government has established 189 specific measures—four times the number in previous plans. Immediate priorities include fire prevention, which accounts for about 70% of total disaster damage, and promoting evacuation at home. The key challenge moving forward will be implementation and ensuring these measures are effective.

To reduce fire-related damage, the government plans to significantly increase the installation rate of 'seismic circuit breakers.' These devices automatically cut off electricity when strong shaking is detected, helping prevent fires.

The government anticipates that a 'Direct-Hit Tokyo Earthquake' could affect 10 regions—Tokyo and nine surrounding prefectures (Chiba, Saitama, Kanagawa, Ibaraki, Tochigi, Gunma, Yamanashi, Nagano, and Shizuoka)—which are now designated as 'Emergency Response Zones.' Currently, the installation rate of seismic circuit breakers in these areas is only 20%. The new plan aims for 'near-universal installation' by the 2035 fiscal year.

Previously, the installation target within the 'Emergency Response Zones' was set at 25%. However, Cabinet Office estimates suggest that achieving a 100% installation rate could reduce the number of burned-down buildings by 70%.

The government also anticipates that a major earthquake could lead to mass evacuations to shelters, causing chaos. Therefore, the plan explicitly states that 'protecting the lives of disaster victims who cannot access shelters is critically important' and includes 'promoting evacuation at home' as a new goal.

Specific measures include increasing the proportion of households with at least three days’ worth of emergency food supplies to 100% by 2035—up from 60% in 2025. Additionally, the proportion of apartment buildings conducting at least one disaster drill per year will be raised to 100% by 2033, up from 51% in 2023.

With the advancement of artificial intelligence (AI), the spread of misinformation via social media during disasters has become an increasing threat. To prevent rumors from spreading, the plan specifically mandates that national and local governments establish mechanisms to quickly assess disaster situations and promptly issue accurate, clarifying information.