An earthquake with a magnitude of 2.1 on the Richter scale was felt today in the municipality of Évora, without causing any personal or material damage, the Portuguese Sea and Atmosphere Institute (IPMA) said.
The earthquake, “according to the information available so far, caused no personal or material damage and was felt with a maximum intensity of II/III (modified Mercalli scale) in the municipality of Évora,” the IPMA said in a statement.
According to the same organization, the earthquake, whose epicentre was located around 12 kilometers south-southwest of Évora, was recorded at 14:52 at the mainland’s seismic network stations.
The IPMA also pointed out that locating the epicenter of an earthquake is a complex process that depends on the data set, algorithms and seismic wave propagation models, meaning that different agencies can produce slightly different results.
“Different agencies can produce slightly different results. Likewise, preliminary determinations are usually corrected later by integrating more information,” he added.
According to the Richter scale, earthquakes are classified according to their magnitude as micro (less than 2.0), very small (2.0-2.9), small (3.0-3.9), slight (4.0-4.9), moderate (5.0-5.9), strong (6.0-6.9), large (7.0-7.9), important (8.0-8.9), exceptional (9.0-9.9) and extreme (when greater than 10).
The Modified Mercalli scale measures “degrees of intensity and their description”.
With an intensity of III, considered to be weak, the tremor was felt inside the house and hanging objects rattled, with a “vibration similar to that caused by the passage of heavy vehicles”, according to the IPMA website.
When there is an IV intensity, considered moderate, parked cars sway, windows, doors and crockery shake and “glass and crockery rattle or clink”, and walls or wooden structures may creak.