But it wasn't until after the Los Angeles quake of 1971, which resulted in surface ruptures, that California passed the Alquist-Priolo Act, which mandated that all known faults be put on a map at a scale of 1: 24,000.
但直到一九七一年洛杉磯地震造成地表破裂，一九七二年加州才通過地震斷層調查法案，比較有系統的將斷層統一畫在二萬四千分之一的活斷層地質圖上。