Estimates say it killed 830,000 people.Humans have documented earthquakes for nearly 4,000 years. Of those recorded, the deadliest occurred in China. On January 23, 1556, a powerful quake rocked the province of Shaanxi and the neighboring province of Shanxi, killing an estimated 830,000 people.Historical records often refer to the 1556 Shaanxi earthquake as the Jiajing Great Earthquake because it occurred during Emperor Jiajing’s reign in the Ming dynasty. The approximate death toll comes from local annals that also tracked 26 earthquakes in the region. In those records, the earthquake is starkly different from others: they describe leveled mountains, floods, fires...