Seismic risk or earthquake risk is the potential impact on the built environment and on people's well-being due to future earthquakes. Seismic risk has been defined, for most management purposes, as the potential economic, social and environmental consequences of hazardous events that may occur in a specified period of time. A building located in a region of high seismic hazard is at lower risk if it is built to sound seismic engineering principles. On the other hand, a building located in a region with a history of minor seismicity, in a brick building located on fill subject to liquefaction can be as high or higher risk.
Lead Rubber Bearing being tested at the UCSD Caltrans-SRMD facility
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.