# The Process of an Earthquake

Topics: Earthquake, Plate tectonics, Earth Pages: 4 (1497 words) Published: April 17, 2013
Have you ever wondered what has to happen to make the Earth quake? British engineer John Michell did. He was one of the first fathers of seismology and was also the first to correctly state what the cause of earthquakes was. In 1960, Michell noted that “earthquakes and the waves of energy that they make are caused by shifting masses of rock, miles below the surface” in a scientific memoir (USGS, 32). In order for you to completely understand the process of an earthquake you must first understand the process of how an earthquake is measured. An earthquake may not be able to be predicted at the moment but the intensity and magnitude of the earthquake can be measured and categorized. This is done using the Richter magnitude scale. The Richter magnitude scale was developed as a mathematical instrument to compare the size of earthquakes in 1935 by Charles Francis Richter. He was able to recognize that the seismic waves radiated by all earthquakes can provide good estimates of their magnitude (Richter). A seismograph is what is used to measure the amount of energy that an earthquake releases as well as the magnitude of the earthquake. It is a logarithmic scale, which means that the numbers on the scale measures factors of 10, so each whole number unit represents a tenfold increase in amplitude. The energy that is measure is about 32 times greater than the next smaller whole number. Using this scale, a magnitude 5 earthquake would result in ten times the level of ground shaking as magnitude 4 earthquakes. Think of it in relation to the energy that is released by explosives. A magnitude 1 seismic wave releases as much energy as blowing up 1 ounce of TNT, which is the equivalent of slamming a large rock onto a table. A magnitude 8 earthquake releases as much energy as detonating 1 million tons of TNT (Richter). An earthquake measuring more than 6.0 can cause detrimental damage (see fig.1). The biggest quake in the world since 1900 scored a 9.5 on the...