Richter seismological scale

The Richter magnitude measurement scale is the most common measurement standard for measuring the intensity of earthquakes. It was invented in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device for comparing the size of earthquakes. The Richter seismological scale is used to rate the magnitude of an earthquake, which is the amount of energy released during an earthquake. The Richter scale does not measure earthquake damage which depends on a variety of factors including the population at the epicenter, terrain, depth, etc. It is a quantitative measureof the magnitude or size of an earthquake. The magnitude of the earthquake is determined using the logarithm of the amplitude or height of the largest seismic wave calibrated to scale by a seismograph. Although modern scientific practice has replaced the original Richter scale with other, more accurate scales, the Richter scale is still erroneously mentioned in news reports on earthquake severity as the general name for the logarithmic scale on which earthquake severity is measured. earthquakes.

Origin of the Richter seismological scale

The Richter scale was developed during the 1930s . Realized the magnitude of an earthquake could become as knowing the time lag between the onset of the P waves and S waves and the amplitude of both.

Who developed the Richter scale

The Richter scale was developed by the American-born seismologist Charles Richter in 1985 and was developed with the aim of evaluating and making comparisons in the intensity of earthquakes as it measures the energy of the earthquake in the hypocenter and is based on a scale of different intensities.

How to measure an earthquake

The earthquake is measured based on the P and S waves of motion on the Richter scale . The P waves are responsible for making the instrument vibrate depending on the displacement of the wave. S waves are those that are responsible for making the medium vibrate in a perpendicular direction depending on the displacement. Earthquakes are measured by means of a mathematical formula that varies by a factor of 10. The scale has 9 degrees and there are, in addition to the Richter seismological scale, different scales that are used to measure earthquakes, such as, for example, the scale of wave magnitude internal, the scale of magnitude of length, of superficial and local magnitude .

Richter seismological scale formula

The scale formula is measured by means of a logarithmic scale , this is a measurement that replaces the value of a variable with its logarithm in a given base:  log _base value . In the logarithmic scale, the OX axis and the Olog _base Y axis are used .  The Richter scale is based on a logarithmic decimal scale.This means that they have a base 10. This means that each increase in the scale implies that its value is increased by 10. This being the case, for example, in an earthquake of magnitude 6, a wave amplitude 10 would be obtained. times greater than one of 5. The formula is currently used with values ​​from 2.0 to 6.9. The representation of the energy that is released by an earthquake uses a different formula, also logarithmic, and that is associated with an increase of approximately 32 times the energy that has been released during the earthquake.

Magnitude scale

The scale is reflected by means of a table showing the amount of energy that is released . Depending on the magnitude, this will be the expected damage during the movement. It is important to mention that the damages also depend on the distance from the epicenter , the depth of the earthquake, the focus of the epicenter and the geographical conditions of the area where the earthquake occurs.

• Less than 2 : it is considered a micro earthquake and they are not perceived by the population.
• From 2 to 2.9 : it is also considered a smaller earthquake and cannot be perceived by people either.
• From 3 to 3.9: these  are minor earthquakes that can sometimes be perceived but do not cause any type of damage.
• From 4 to 4.9 : these are considered light earthquakes and the movement of objects and some noises can occur. They are earthquakes that can be felt but that cause practically no type of damage.
• From 5 to 5.9 : these earthquakes are of slight intensity. They can cause some damage to buildings that have been poorly constructed or that present some type of damage.
• From 6 to 6.9 : these earthquakes are considered strong movements and can even destroy populated areas, affecting a diameter of approximately 160 kilometers.
• From 7 to 7.9 : these are major earthquakes and can cause extensive and serious damage in and around the areas where they originate. There may be destruction of buildings and deaths.
• From 8 to 8.9 : they are catastrophic earthquakes that cause devastation in the areas they affect.
• 9 to 9.9 : there are no records of earthquakes that have reached this magnitude, but it is considered that they would be capable of eliminating entire villages .
• 10 or more: it  is considered a legendary or apocalyptic earthquake . There are no records of earthquakes of this magnitude.

Importance of the Richter seismological scale

The Richter scale is important because it allows us to know and measure the impact that earthquakes can have on the planet. In addition, through it, scientists obtain information on the movement of tectonic plates that are in constant motion and that are responsible for producing earth movements.