The Richter scale is a graduation of the magnitude of earthquakes, deduced in 1935 by the geophysicist Charles Richter and later developed by him and Reno Gutemberg. The scale was originally defined as the logarithm of the amplitude of motion of a standard seismograph located 100 km from the epicenter of an earthquake. It is also known as the local magnitude scale, and it is the scale most used by seismologists.
This scale is used to evaluate the damage caused by earthquakes, and it measures the amount of energy released from an earthquake in its center or focus, the scale range goes from 1 to 10 degrees, and the intensity grows exponentially by a number to the next.
Since the Richter scale is logarithmic, each unit of magnitude indicates a 10-fold increase in the amplitude of the wave. But the increase in energy corresponding to each unit is estimated by seismologists as approx. 30 times; a magnitude 2 earthquake is 30 times more powerful than a magnitude 1; a magnitude 3 earthquake is 30 times more powerful than a magnitude 2 earthquake, and therefore 900 times more powerful than a magnitude 1 earthquake, and so on.
When the earth begins to shake, the seismograph immediately records the generated seismic waves and represents them in the form of seismograms, which allow the mediation of the magnitude or amount of energy released under Richter parameters.
The range of magnitudes of earthquakes is very wide, from the faintest vibration (2 degrees) that only the instrument detects, and is not perceived by humans, to the intense movements that knock down entire buildings. An event with a magnitude of 7 or more is generally considered significant. The largest earthquake that has been measured to date was the one that occurred in the city of Valdivia (Chile) in 1960, reaching a magnitude of 9.5.
Below are examples of the effects that may occur in some cases, depending on the energy of each grade:
- 3.5 degrees. Weak earthquake that is only felt in the upper floors.
- 4.5 degrees. Windows, furniture and parked cars shake.
- 5.5 degrees. Some trees fall and some damage occurs.
- 6.5 degrees. Damage to some structures and collapse of walls.
- 7.5 degrees. Destruction of many buildings and subsidence of poles.
- More than 8.1 degrees. Total destruction of a city and lifting of the earth's crust.
The Richter scale is open, this means that although an earthquake with a magnitude greater than 9.6 has not been recorded up to now, it is possible that there is one that exceeds 10.
