An earthquake can be defined as vibrations produced in the earth's crust. Tectonic plates have friction between them which builds up as it tries to push away and suddenly ruptures and then rebounds. The vibrations can range from barely noticeable to a disastrous, and destructive act of nature. Six kinds of shock waves are generated in the process. Two are classified as body waves, that is, they travel through the inside of the earth and the other four are surface …show more content…
Prince Boris Golitzyn. His device used a magnetic pendulum suspended between the poles of an electromagnet, created the modern era of earthquake research.
There are three general classes of earthquakes that are now recognized: tectonic, volcanic, and artificially produced. The tectonic kind is by far the most devastating, and these earthquakes create many difficulties for scientists trying to develop ways to predict them. The main cause of tectonic earthquakes is stress set up by movements of the dozen major and minor plates that make up the earth's crust. Most tectonic quakes occur at the boundaries of these plates, in zones where one plate slides past another, such as at the San Andreas Fault in California, North America's most quake-prone area, or where one plate slides beneath the other plate, subduction. Subduction-zone earthquakes count for nearly half of the world's destructive seismic events and 75 percent of the earth's seismic energy. They are concentrated along the "Ring of Fire", a narrow band about
38,600 km long, that meet with the border of the Pacific Ocean. The points at which rupture