Locating an earthquake

The hypocentre is the point, deep in the Earth, where the breakage that provoked the earthquake occurred. The epicentre is the equivalent point on the Earth’s surface. Normally the area of the epicentre is the one in which the most severe damages are recorded, while the intensity of an earthquake decreases as one goes further away. By studying the time it takes the waves to reach particular stations placed at different distances from the epicentre ,it is possible to determine the position of the hypocentre precisely, and also to identify the mechanism of movement that produced the earthquake. The seisms of a greater intensity naturally produce waves that can be felt very far away, at times they cross the entire planet and bounce several times along the various internal “layers” of the Earth. At times, on the occasion of the more powerful earthquakes, the Earth continues to oscillate for a number of days and the effects are so significant that some of the terrestrial parameters may be changed, as for example the inclination of the axis, as apparently occurred with the event of the 26th December. However, these are events that do not bear any consequences on life on the planet, and if the events are measured by the instruments, they are not felt by most living beings.
The information collected during earthquakes of great intensity, have enabled the study and understanding of how the Earth is made inside, determining its structure in concentric “shells”, based on the type of waves and the speed at which these propagate in different materials. Disastrous and catastrophic events on the other hand can, at times, offer precious insights in the study of the behaviour of our planet, and enable us to build forecasting models for the future. For this reason, rescue teams work to bring aid to the affected populations alongside teams of seismologists and geophysicists who are always, silently, at work to better understand the behaviour of our restless planet.

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