首都 しゅと直下 ちょっか地震 じしんだったら
shutochokkajishindattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 首都直下地震

1. If/when there was a direct hit earthquake under the capital:; If/when a direct-hit earthquake occurred under the capital:

Tara Conditional