Shifts of the head of Zhengguo canal dug in Qin dynasty and recent activity of the fault on north margin of the Weihe downfaulted basin

Vertical differential movement rates of the fault on north margin of the Weihe downfaulted basin in recent 2000 years are analyzed by using the data of shifts of the head of Zhengguo canal, dug in Qin dynasty and the data of burial depths of historical relics and the data of levelling. The results show that in Ming dynasty this fault experienced the highest differential up-and-down movement, about 6.6 mm/a, while the rate became lower since Qing dynasty, about 2.6 mm/a. The high rate activity coincided with the period of high seismic activity in the Weihe downfaulted basin in the 15 – 16th centuries. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 195–200, 1992. This project is sponsored by the Chinese Joint Seismological Science Foundation.