noun
Tokyo near-field earthquake; major earthquake directly under the Tokyo metropolitan area
Refers to a hypothetical large earthquake with an epicenter directly beneath the Tokyo area, expected to cause severe damage. Also used historically for the 1855 Ansei Edo earthquake and the 1894 Meiji Tokyo earthquake.
首都直下地震の被害想定が発表された。
Damage estimates for a Tokyo near-field earthquake were released.
首都直下地震に備えて防災訓練が行われた。
A disaster drill was held in preparation for a major earthquake directly under Tokyo.
Refers to a massive plate-boundary earthquake along the Nankai Trough, affecting a wide area of western and central Japan, whereas 首都直下地震 is a local, shallow earthquake directly under Tokyo.
Compound of 首都 (capital), 直下 (directly below), and 地震 (earthquake). The term became widely used in Japanese disaster preparedness discourse from the late 20th century onward.