1920 Haiyuan earthquake
A magnitude 7.8 earthquake that struck Gansu, China, on December 16, 1920, causing widespread destruction and landslides.
Haiyuan Fault: A major left-lateral strike-slip fault in north-central China, part of the boundary between the Tibetan Plateau and the Ordos Block. The earthquake ruptured this fault system, producing extensive horizontal displacement.
1920 Haiyuan earthquake landslides: Mass slope failures triggered by the 1920 Haiyuan earthquake across loess-covered terrain in northwestern China. These landslides buried villages and were among the disaster’s deadliest effects.
Gansu: A province in northwestern China, bordering the Tibetan Plateau and the Loess Plateau. The earthquake struck this province, which then included areas now in Ningxia.
1923 Great Kantō earthquake: A magnitude 7.9 earthquake that devastated Tokyo and Yokohama, Japan, on September 1, 1923. Both were catastrophic early twentieth-century earthquakes, but their urban and rural impacts differed sharply.
Loess: A fine-grained, wind-deposited sediment that can form thick, porous deposits and steep slopes. Earthquake shaking destabilized loess slopes, triggering destructive landslides.
Lijunbu landslide: A catastrophic loess landslide near Lijunbu, China, triggered by the 1920 Haiyuan earthquake. It exemplifies how earthquake shaking could collapse entire loess slopes.
Ningxia: An autonomous region in northwestern China, located along the upper Yellow River. The hardest-hit area lies largely within present-day Ningxia, though historical accounts call it Gansu.
1976 Tangshan earthquake: A magnitude 7.6 earthquake that struck Tangshan, China, on July 28, 1976, killing many thousands. It offers a later Chinese comparison in a densely settled industrial city rather than loess uplands.
Seismic landslide: A landslide triggered by earthquake shaking, often involving slope collapse or liquefaction. Thousands of slope failures amplified destruction beyond direct shaking.
Earthquake death toll: The number of people killed directly or indirectly by an earthquake and its associated hazards. Published estimates for the Haiyuan disaster vary, reflecting incomplete records and later reassessments.