On 23 December 1738 the province of Qinghai was struck by an earthquake with an estimated magnitude of 7.6 Mw.

[1] It ruptured the westernmost part of the Xianshuihe fault system, the Dangjiang segment.

The plateau is divided into several blocks bounded by large WNW-ESE trending left lateral strike-slip fault zones.

The estimated slip rate on the Dangjiang segment is about 6–7 mm per year.

The lack of seismic activity on this fault since 1738 means that sufficient slip has occurred to generate an earthquake of Mw  7.3.