Earthquakes occur when the tectonic plates that make up the earth’s crust interact with one another. Some earthquakes are caused by the plates moving passed one another and others are caused by one plate sliding under the other. The size of an earthquake depends on the amount of force that has built up at the point of contact. Sometimes the plates moving causes only a slight tremor, whereas in other instances the movement can cause cataclysmic destruction. So how are earthquakes measured? Read this article to find out.
How are Earthquakes Measured?
Earthquakes are measured using a specialized piece of scientific equipment called a seismometer. A seismometer measures the movements in the earth surface. Seismometers are combined with recording equipment to create seismographs. Seismographs record seismic waves that are produced by shifts in the tectonic plates. From a seismograph scientist can calculate the magnitude of an earthquake. A seismograph produces wavy lines that represent the size of the seismic waves that have passed under them. A number of these are used to calculate the magnitude of an earthquake.
As with most natural disasters, scientists have developed a system to measure and chart the magnitude of an earthquake. This is used to compare earthquakes with one another and as a way to inform the public. Earthquakes are measured using the Moment magnitude scale. This scale was invented in the 1970′s to replace the Richter Scale. The Richter Scale was invented in the 1930’s by a seismologist named Dr Charles Richter. The Richter scale used the largest seismic wave to be measured within 100 kilometers of the epicenter of an earthquake. The Moment magnitude scale is now used for all major earthquakes. The Modified Mercalli intensity scale is used to measure the intensity of the earthquake on the earth’s surface.