Tangshan earthquake
A magnitude 7.6 earthquake struck Tangshan, China, on July 28, 1976, devastating the city and killing hundreds of thousands of people.
Tangshan fault: A concealed active fault beneath the Tangshan region that ruptured during the 1976 earthquake. Its rupture generated the earthquake beneath the densely populated city.
Tangshan: An industrial city in Hebei province, northern China, near the epicenter of the 1976 earthquake. The earthquake devastated the city and its surrounding communities.
North China Plain: A broad, densely populated lowland in eastern China, formed by sediments from major rivers. Tangshan lies on its northeastern margin, where regional tectonics produce earthquakes.
1976 Tangshan earthquake foreshock: A magnitude 7.1 earthquake that struck near Tangshan about 15 hours before the mainshock on July 28, 1976. The foreshock caused major damage before the larger mainshock struck.
Seismic wave: A vibration that carries energy through Earth or along its surface after an earthquake or other disturbance. Waves from the shallow rupture drove the destructive ground motion.
Earthquake casualty estimation: The assessment of deaths and injuries caused by an earthquake, often complicated by incomplete records. Official and later estimates differ, while the death toll remains extraordinarily high.
Tectonic plate: A large, rigid section of Earth’s lithosphere that moves relative to neighboring sections. Regional plate motions create stress that can reactivate faults beneath northern China.
1976 Tangshan earthquake aftershock sequence: The series of earthquakes that followed the Tangshan mainshock, including a destructive magnitude 7.2 event near Luanxian. Aftershocks prolonged danger and added damage across the region.
Peak ground acceleration: The greatest acceleration of ground motion recorded at a site during an earthquake. Strong acceleration helps explain why structures failed so abruptly.
Disaster response: The organized actions taken to protect people and meet urgent needs during and after a disaster. Rescue and relief operations confronted widespread destruction and disrupted communications.