There are areas in Spain where the seismic hazard is high and strong earthquakes can occur. Fortunately, its frequency is lower than in the western Mediterranean region. Then we solve the unknown.
Two strong earthquakes devastated Turkey in the south and Syria in the north, one of the greatest disasters of the century, It has aroused interest in seismicity in Europe and the Mediterranean region. Many people wonder if the area they live in could experience such a devastating earthquake.
In this article we will analyze regions of Spain with more hazards and greater seismic risk, and we will see some of the most powerful events in the country’s history.
Spain at the collision point of two plates
The Iberian Peninsula is located in a contact zone between the Eurasian and African tectonic plates.. This collision zone stretching from the Atlantic (south of Portugal) and over the Mediterranean to Italy, Greece and Turkey, It is responsible for the seismicity registered in the south of Spain and Portugal.
Then there are other factors that complicate the picture, with microplates and active faults hundreds of kilometers from this collision zone: Seismicity in other parts of the peninsula, for example in the Pyrenees and Galicia.
The peninsula has a lower frequency of strong earthquakes compared to Turkey, Greece or Italy.
Because it is in the western Mediterranean the collision between tectonic plates is less rapid and intense than in the eastern Mediterranean, major seismic events occur less frequently.
It seems reflected On the seismic hazard maps of EuropeAs can be seen in the image below, intense red and purple (more dangerous) colored areas are concentrated in the southeastern part of the continent.
The low probability of a strong earthquake in Spain does not mean that there is no danger.. It should also be noted that strong earthquakes with an epicenter at sea can cause tsunamis, historically this has already happened, for example in 1522 and 1755.
seismic hazard It tells us the probability of severe earthquakes occurring in an area in the future.
seismic risk It is probabilistic, although it also takes into account exposures and vulnerabilities of buildings, people, infrastructures.
Seismicity in the Canary Islands is linked to volcanoes.
This Canary Islands they are not located along a collision point between plates. This Spanish archipelago is of volcanic origin and seismicity is associated with such activities.. In fact, a large number of seismic events occurred during the eruption of Cumbre Vieja in the fall of 2021, although none caused damage due to their medium or low magnitudes. There have not been historically strong destructive earthquakes in the Canary Islands.
The last notable earthquake occurred on May 1, 1989 in Tenerife.It measures 5.3 degrees. There was no damage, although much alarm was raised in the population.
How do you examine the risk of a major earthquake?
Geologists often use it to determine whether strong earthquakes will occur in an area. two types of knowledge: study of earthquake-producing faults and historical research To know the effects of past seismic events.
There are many in Europe historical documents telling us the events of the last two thousand years (and more), valuable information about seismic hazard.
Through the analysis of ancient texts, researchers managed to fill archives of European earthquakes This helps us know the frequency and location of seismic events.
Examining the historical documents of the last thousands of years has allowed us to fill in the seismic hazard map of Europe and shows us that the regions with the most frequent catastrophic events, with tens of thousands of deaths, are Turkey, Italy, Greece. .
Although catastrophic earthquakes are less frequent in Spain, low frequencies can be a ‘problem’ because the population forgets these events and there may be a false sense of security.
Knowing our seismic past helps us prepare for the future, to prevent damage from new events and to protect ourselves, for example by using earthquake resistant buildings and by preparing the public to take action in the event of an earthquake or tsunami.
The most dangerous areas
As can be seen, Spain and Portugal have been shaken by more severe earthquakes in the last centuries. The most affected areas are the southeast of the Peninsula (especially the Granada-Málaga and Murcia-Alicante regions) and the Pyrenees and Galicia regions..
coastal areas Southwest Spain and southern Portugal suffer strong earthquakes in the Atlantic Ocean in the Cabo San Vicente area that could cause tsunamis. A recent study also warned of the possibility of tsunamis caused by powerful earthquakes in the Alboran Sea.
Despite this seismic history, The Iberian Peninsula has been more protected from disasters than regions such as Italy and Turkey.It is the place where hundreds of thousands of people lost their lives due to severe and frequent earthquakes in the last centuries.
This website of the National Geographic Institute lists the most relevant earthquakes that have ever occurred in Spain: https://www.ign.es/web/terremotos-importantes
Reference article: https://www.tiempo.com/noticias/ciencia/riesgo-espana-sufrir-terremoto-como-el-de-turquia-y-siria.html
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