Seismology , a word that comes from the Greek language, is the science that studies earthquakes . An earthquake, meanwhile, is a sudden and sudden movement of the ground which is produced by the action of forces within the globe.
Seismology is considered part of the geophysics (the discipline which analyzes the physical issues of our planet). The object of study of seismology, therefore, are the seismic waves that cause earthquakes.
Seismology tries to determine the origins of the earthquakes and the mode of wave propagation. Among its objectives is prevention to mitigate the destructive effects of earthquakes.
It is common for an earthquake to occur within the limits of lithospheric plates (also calls tectonic plates ). When at least two of these plates they interact, tension builds up in their limits and then displacements occur. To study these issues, experts appeal to seismometers or seismographs .
These dispositives allow to evaluate the tremors that cause the displacements of the tectonic plates. Seismographs, thanks to their sensors, manage to record seismic waves and can study propagation. The registration made by these machines is called seismogram .
From the knowledge of seismology and the operation of seismographs, earthquakes began to qualify according to their magnitude . The Richter scale (considered according to Energy released) and the Mercalli scale (which studies the damage caused) are the popular ones.
In many countries of the world there are centers, agencies and institutions focused on seismology, fundamentally dependent on the government, that what they do is register all the information related to the earthquakes, analyze it, store it and, of course, find out if they will soon take place More movements of that kind.
In Spain, for example, there is the International Seismic Network and the Seismic Information Service, under the National Geographic Institute. Through the web spaces of the aforementioned service, it is possible to know what are the earthquakes that have taken place in the last year, to the existing statistics through the seismic stations that it has or what is known as a seismic-resistant norm.
In addition there is the National Seismiological Service in Mexico, in Cuba there is the National Seismological Research Center and in Colombia there is the National Seismological Network.
Throughout history there have been numerous figures who have dedicated themselves to analyze and study in depth the different earthquakes. This would be the case, for example, of the Frenchman Nicolas Lemery (1645-1715), of the American John Mitchell (1711-1768) or of the English seismologist Richard Dixon Oldham (1858-1936), who made great contributions regarding the study and the types of waves.
However, we must not ignore the role played in this discipline by the British Harold Jeffreys (1891 - 1989), who conducted a study of seismic waves that allowed us to discover that the Earth's core is liquid, and the Danish Inge Lehmann (1888 - 1993), which qualified the theory of the previous exposing the mixture of solid and liquid state in said nucleus.