Shaanxi earthquake

On January 23, 1556, during the reign of the Jiajing Emperor of the Ming dynasty, a powerful earthquake struck the valley of the Wei River in Shaanxi province, in northwest China, near the cities of Huaxian, Weinan and Xi'an. Modern estimates put its magnitude at around 8. Ming records say that about 830,000 people died, making it the deadliest earthquake ever recorded, and that destruction reached counties across several provinces. Aftershocks reportedly continued for months.¹²

Two features of the region made the toll so high. The Wei valley sits on an active fault zone where the crust is pulling apart, and it was among the most densely settled farmland in Ming China. Much of the population lived on the loess plateau, thick deposits of soft windblown silt, where many families dug yaodong, cave dwellings cut into cliff faces. The shaking collapsed these caves and the cliffs above them, burying people in their sleep. Landslides and ground fissures opened across the countryside, and famine and disease followed in the ruined villages.²¹

The disaster is known through official reports and the writings of survivors, and seismologists still use these records to study the fault history of the Wei valley. China has since suffered other catastrophic quakes in loess country, including Haiyuan in 1920, and in 1976 at Tangshan. The 1556 toll is a record-based figure, not a census, and scholars treat it as an order of magnitude.¹³