An earthquake of “relatively low” magnitude occurred in Celorico da Beira and was felt with maximum intensity in Covilhã. It is most likely associated with a “village failure”. North Madeira also vibrated.
An earthquake magnitude 4,1 occurred at a depth of 20 kilometers this morning in Celorico da Beira and was felt in several municipalities in the districts of Guarda, Aveiro, Castelo Branco, Vila Real e Viseuaccording to the Portuguese Institute of the Sea and Atmosphere (IPMA).
Shortly before, this Friday, an earthquake of the same magnitude was recorded by the Spanish meteorological services north of the island of Madeira, at 7:24 pm. The seismic activity occurred at a depth of 30 kilometers.
In a statement, the IPMA said that the earthquake with a magnitude of 4.1 on the Richter scale occurred at 00:38 and had its epicenter approximately four kilometers west-southwest of Celorico da Beira, district of Guarda.
“This earthquake, according to the information available so far, did not cause personal or material damage and was felt with maximum intensity IV/V (modified Mercalli scale) in the municipality of Covilhã (Castelo Branco)”, highlighted IPMA.
According to the same source, it was felt with less intensity in the municipalities of Aveiro, Santa Maria da Feira, Mealhada, Ovar, Vale de Cambra (Aveiro), Sertã (Castelo Branco), Guarda (Guarda), Alijó (Vila Real), Cinfães, Nelas and Viseu (Viseu)”.
“Interesting”
“There is a set of interesting factors” in yesterday’s phenomenon, says geologist and professor at the Faculty of Sciences of the University of Lisbon, Filipe Rosas, to RTP Notícias and CNN.
The earthquake that occurred in mainland Portugal is considered slight, of “relatively low” magnitude. It is most likely associated with a “vilariça failure”a “zone of sudden rupture and very important energy release with a Northeast-Southwest orientation that passes close to the epicenter”, explains the geologist.
“There was a historic earthquake on the same fault in 1858”, but the fault did not form in the usual context. “It is a zone of weakness inherited from a tectonic history prior to the one that governs us today and is resumed in this context of collision between the Eurasian and African plates”.
“If the situation so warrants, new communications will be issued,” added IPMA.
Filipe Rosas also warns that people must be more informed and prepared to know how to act before, during and after an event like these.
“Outside the house, people are woken up”
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 respective description”.
With an intensity IV, considered moderate, “suspended objects swing, the vibration is similar to that caused by the passing of heavy vehicles or the sensation of a heavy ball hitting the walls, parked cars sway, windows, doors and crockery shake, glass and crockery rattle or clank and at the upper part of this level the walls and wooden structures creak”, according to IPMA.
With an intensity V, considered strong, the shock is “felt outside the home, the direction of movement can be assessed, people are woken up, liquids oscillate and some leak, small objects in unstable balance move or are knocked over”.
