Earthquakes How do they occur? Nehal Murti
Earthquakes are very devastating as they destroy buildings and the lives of thousands of people.
Tectonic Earthquakes An earthquake is the sudden release of energy in the earths crust. This causes seismic waves (tremors). Earthquakes are also caused by volcanic activity under the earths surface. Tectonic earthquakes occur where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. In the case of transform or convergent type plate boundaries, which form the largest fault surfaces on earth, they will move past each other smoothly only if there are no irregularities along the boundary that increase the frictional resistance. Most boundaries do have such asperities and this leads to a form of stick-slip behaviour. Earthquakes are measure on the seismograph(seismometer). The magnitude of an earthquake is determined by the Richter scale.