1906 San Francisco earthquake
At 05:12 Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated moment magnitude of 7.9 and a maximum Mercalli intensity of XI (Extreme). High-intensity shaking was felt from Eureka on the North Coast to the Salinas Valley, an agricultural region to the south of the San Francisco Bay Area. Devastating fires soon broke out in San Francisco and lasted for several days. More than 3,000 people died, and over 80% of the city was destroyed. The event is remembered as the deadliest earthquake in the history of the United States. The death toll remains the greatest loss of life from a natural disaster in California's history and high on the lists of American disasters.
Ruins in the vicinity of Post and Grant Avenue
Damaged houses on Howard Street
Seismographs on the U.S. east coast recorded the earthquake some 19 minutes later; some early death estimates exceeded 500.
Arnold Genthe's photograph, looking toward the fire on Sacramento Street
An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.
Global plate tectonic movement
Aerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles
Collapsed Gran Hotel building in the San Salvador metropolis, after the shallow 1986 San Salvador earthquake
The 2023 Turkey–Syria earthquakes ruptured along segments of the East Anatolian Fault at supershear speeds; more than 50,000 people died in both countries.