The North China Plain appears flat, stable, and geologically uninteresting. It is none of these things. Beneath the sediments deposited by the Yellow River lies a web of fault systems capable of generating catastrophic earthquakes. The North China Craton, one of the oldest pieces of continental crust on Earth, is cut by a continental rift system and bounded by major faults including the Tanlu Fault, which has produced magnitude 8.0 or greater earthquakes in recorded history. The 1668 Shandong earthquake and the 1679 Sanhe-Pinggu earthquake were predecessors. The same tectonic system would later produce the 1975 Haicheng and 1976 Tangshan earthquakes. Heze sits above the Liaokao Fault Zone, a structure predominantly buried beneath the sediments of the south-central plain.

The precursor events were extraordinary. Before the mainshocks arrived, heavy rains and fierce winds battered the region. The air became so hot and humid that residents suffered heat injuries and livestock died. Walls of homes overheated and burned. Most striking were the changes to the water table: wells fluctuated wildly, with water rising and overflowing, changing color, bubbling, and foaming. These hydrological disturbances are consistent with the buildup of tectonic stress in the shallow crust, as fault movement compresses and releases groundwater in underground aquifers. The people of Heze had no seismological framework to interpret what they saw. They simply knew that something terrible was coming.

The destruction was devastating. Thirty percent of all residential homes in Heze were destroyed. Sections of the city walls and battlements collapsed. The Guanyin Temple fell. Ground fissures, some up to a meter wide, erupted water and extended as far as 30 kilometers from the epicenter. In one account, a farmer fell into a fissure and was washed away by the rushing water that filled it. In Dongming County, 20 percent of homes were lost. At Xuzhou in Jiangsu province, over 50 homes collapsed, killing more than 20 people. Damage extended across 40 counties in five provinces: Shandong, Henan, Anhui, Jiangsu, and Hebei. The shaking was felt as far as Beijing, Zhenjiang, and Luoyang.

The timing could not have been worse. Japan had invaded China on July 7, 1937, just weeks before the first earthquake struck. The Second Sino-Japanese War consumed the Chinese government's attention and resources, and rescue operations in the earthquake zone were, by all accounts, ineffective. The survivors were left largely to their own devices in a landscape where homes had become rubble, wells had been poisoned by geological contamination, and more than 6,000 livestock lay dead. The Heze earthquakes became a footnote in a year dominated by military catastrophe, overshadowed by the fall of Shanghai and the Nanjing Massacre later that same year. But for the people who lived through the shaking, the war was still distant. The earthquake was underfoot.