Chelungpu Fault

It is a major 90-km structure with a shallow eastward pointing tilt (30°) and primarily slips within and parallel to the bedding of the Pliocene Chinshui shale.

The 1999 Jiji earthquake happened along the Chelungpu fault line in western part of the island of Taiwan.

[7][8][9]The fault was reportedly discovered by Dr. Wen-shan Chen, Professor of Geology at National Taiwan University, in November 2002.

[11] The Chelungpu Fault has unique characteristics that make it an ideal research site, easy to drill and measure.

The purpose of the project was to obtain physical samples of the fault, in particular where large displacements occurred during the 921 earthquake.

Most notably, the project led to an empirical breakthrough in seismology, measuring the thickness of an earthquake slip zone for the first time.