noun
Nankai megathrust earthquake
Refers to a hypothetical massive earthquake expected to occur along the Nankai Trough off Japan's Pacific coast. Used in disaster preparedness and scientific contexts.
南海トラフ巨大地震に備えて、防災訓練が行われた。
Disaster drills were conducted in preparation for the Nankai megathrust earthquake.
Compound of 南海 (Nankai, 'South Sea'), トラフ (trough, from English), and 巨大地震 (huge earthquake). The term specifically denotes the anticipated great earthquake in the Nankai Trough region.