How do i find out how many years it will take?   the san andreas fault is a dextral (right-lateral) strike-slip fault that runs between los angeles and san francisco. this means that los angeles is slowly approaching san francisco. assuming the average slip rate of 2.1 cm/year remains constant, in about how many years will los angeles be directly west of san francisco? los angeles is presently 519 km from san francisco. (hint: 1 cm = 0.00001 km.)