Earthquakes

An accessible overview explains earthquakes as sudden releases of strain in the crust driven by plate tectonics and describes how faults and fault motion produce seismic waves. It categorizes plate boundaries—spreading, transform, and subduction—and contrasts shallow and deep earthquake behavior while noting that some events occur within plate interiors. The text surveys historical seismic events to illustrate impacts and geographic patterns. It also summarizes mechanisms of ground shaking, methods of measurement and hazard assessment, and approaches in engineering and preparedness to reduce damage and casualties.