August 26, 2016 12:00 pm
A terrifying earthquake with a magnitude of 6.2 has struck central Italy during the early hours of Wednesday 24th August. The earthquake, a result of the Tyrrhenian basin (the area between Sicily and Sardinia) expanding, and pushing Eurasia towards Africa faster than the Eurasian and African plates can compress, had its epicentre in Rieti, but could be felt as far as Rome.
This is not the first time this region of Italy had been struck by a high intensity quake. In April 2009 a magnitude 6.3 earthquake left at least 295 dead and 55 000 homeless, while in January 1915 the largest quake recorded in the area, of magnitude 6.7, killed approximately 32 000 people.
But what does this magnitude number mean? The magnitude is a rating given to earthquakes, which is calculated from measurements taken using seismographs. There are three commonly used units of measurement for an earthquake – the surface wave magnitude, based on surface waves, the moment magnitude scale, based on the seismic moment, and the Richter magnitude scale, which measures the energy of an earthquake.
The above magnitudes are assigned according to the Richter scale, a base-10 logarithmic scale, which defines magnitude as the logarithm of the ratio of the amplitude of the seismic waves to a minor amplitude. In other words, a seismometer measures the number of waves produced in a given time and calculates the energy released.
According to the Richter scale, magnitude 6.0-6.9 quakes are considered strong and can cause moderate damage to even earthquake-resistant structures.
Written by Iweta Kalinowska
Communication Trainee at TermCoord
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