Granada is a province where numerous earthquakes take place frequently. Although they are not very high and dangerous earthquakes, they are very recurrent. All this means that scientists have to study more about this part of the Iberian Peninsula and the possible consequences of so many earthquakes. many people wonder why are there so many earthquakes in Granada.
For this reason, we are going to dedicate this article to telling you in depth why there are so many earthquakes in Granada and what consequences they have.
Why are there so many earthquakes in Granada?
It is normal for the Earth to tremble slightly and repeatedly in the Granada Basin, one of the areas with the highest seismic risk on the peninsula. The surface earthquakes felt in Granada towns such as Atarfe, Santa Fe or Vegas del Genil they are due to a series of earthquakes that began in early December and were reactivated in January.
Ana Crespo Blanc, professor of geodynamics at the University of Granada and expert in earthquakes, explained that the magnitude of the earthquake is related to the length of the fault, which in Granada it is only 20 or 25 kilometers, so it is unlikely that there will be more strong earthquake damage such as those that could occur in San Francisco (USA).
The cause of the current seismic activity is the conflict between the African and Iberian tectonic plates. “We are at a plate boundary that is moving 5 millimeters a year, and this deformation can cause earthquakes to be repeated,” said Crespo.
What is a seismic swarm
This slow movement of plates can trigger earthquakes of different magnitudes, known as seismic swarms, in nearby areas.
Manuel Regueiro, dean of the College of Geologists, pointed out: "The relaxation of tension that occurs in faults, which are cracks in the rock, when a person moves creates a chain, and they all move and cause each fault." According to the researchers, the depth of the last earthquake was almost zero, and its intensity increased the state of social alertness because, on the surface, citizens perceived it better.
If the epicenter is deeper, even stronger, the wave will weaken and will be less felt on the surface. Remember from IGN that the 2010 earthquake was greater than the current magnitude (6,2 on the Richter scale) but, because it went deeper, it was less intense.
As a result, up to 40 earthquakes were recorded this morning in Granada and were felt in up to 6 Andalusian provinces, 30 of which occurred in three hours. The strongest magnitudes were 4,3 and 4,2, with an epicenter in Santa Fe. The impact of the aftershocks shocked the people of Granada, who despite being accustomed to seismic movements, left them on edge last night.
Earthquakes on short faults
"The earthquake here is on a relatively short fault line," he explained, adding that the feel also depends on the location of the house. In rocky areas the phenomenon is less pronounced, and in the Vega area, where Santa Fe or Atarfe are, is amplified because the subsoil is not as solid.
Its depth also affects the impact of earthquakes. The 3,1 degree temperature recorded around noon on Tuesday occurred just 5km away: "The neighbors felt that it was normal and that it was more in that area."
Jesús Galindo, professor of geodynamics at the University of Granada, has requested more funding to be able to collect the data necessary to predict this type of event. "We had the tools, but we needed financing," he recalled, as tension broke out over a dozen kilometers of faults in Granada, causing this type of movement in other nearby areas.
In this way, he predicts that "there will be other similar series in the future, as in the past." The rapprochement of Eurasia and Africa makes the region of the Betik Mountains, covered by the sea 10 million years ago, the rest is raised higher so that the terrain stands out more. “There are many small and medium faults in the Vega region, which are places where energy is concentrated. They are capable of producing earthquakes of magnitude plus or minus 5».
In any case, “Today's buildings are much better than before.. They are structures that resist. The trim or cladding of the façade is going to come off.”
Junta de Andalucía prepared to face earthquakes
Elías Bendodo, Minister of the Presidency, Public Administrations and the Interior, reported this Wednesday that the commission is carrying out a "continuous monitoring" of the seismic swarms that affect Granada and its metropolitan area, in case it becomes necessary the start-up phase of its contingency plan for seismic risk is currently in the pre-emergency phase, because according to expert data, the series of earthquakes could extend over time.
During a visit to the 112 Emergency Coordination Center in the province of Granada, Bondodo also visited the Andalusian Institute of Geophysics and Prevention of Seismic Catastrophes and witnessed first-hand the series of interventions associated with the earthquake that occurred in the Granada region of Vega.
Bondodo said he understood the "general fear and uncertainty" of Granadans at times like the present, and added that "Andalusia is prepared to face these contingencies because we have emergency services at the forefront of the country, it is possible to guarantee security and intervene using specific protocols at all times.”
Why are there so many earthquakes in Granada frequently
The deformation zone extends southeast to the Alberan Sea, where a major earthquake occurred in 2016, leaving more than 20 people injured in Melilla. Next, continue to Al Houcemas in Morocco, which also experienced a catastrophic earthquake in 2004.
Some of the most important earthquakes recorded in the Iberian Peninsula occurred near Granada. Such was the case of Arenas del Rey in 1884, which killed more than 800 people and destroyed thousands of buildings; Albolote, in 1956, with 11 deaths, or Dúrcal, one of the most powerful records ever recorded in our country, whose magnitude was 7.8, but it did not cause much damage since it occurred at a depth of 650 kilometers.
Before these earthquakes, in 1431, a 6,7-magnitude earthquake shook Granada, then a Muslim kingdom, and caused extensive damage to the Alhambra. Tuesday's 4,5-magnitude quake was the most significant in the past 40 years, and you'd have to go back to 1964 to find another 4,7 on the Richter scale.
I hope that with this information you can learn more about why there are so many earthquakes in Granada.