Spain is not an earthquake-free country, but it is not in a geological zone comparable to Venezuela either. The devastation of the double seismic blow recorded in the South American country makes us wonder whether Spain could suffer an earthquake of similar magnitude and which territories are most exposed to a large ground movement.
The experts' answer is clear: Spain has relevant seismic activity, especially in the peninsular southeast, the Alboran Sea, the Gulf of Cadiz, the Pyrenees, and the Canary Islands, but the probability of an earthquake of magnitude greater than 8 near a large Spanish city is low. Not impossible, but much less likely than in regions located on more active plate boundaries.
Spain does have seismic risk, but not like Venezuela
The main difference lies in geology. Venezuela is in a contact zone between large tectonic plates, with faults capable of accumulating a lot of energy and releasing it in large magnitude earthquakes.
Spain, on the other hand, is affected by the interaction between the African and Eurasian plates, but this deformation is slower, more diffuse, and distributed in different zones. That is why the country registers earthquakes, some destructive, but it is not part of the regions of the planet with the highest frequency of large earthquakes.
The National Geographic Institute maintains seismicity and hazard maps that show that Spanish seismic activity is concentrated in specific areas, especially in the south and southeast of the Peninsula, in the vicinity of the Alboran Sea, in the Gulf of Cadiz, in the Pyrenees, and in the Canary Islands.
The most sensitive areas of Spain
The peninsular southeast is the most sensitive area of Spain to suffer destructive earthquakes. The area of Granada, Almería, Málaga, Murcia, and the Vega Baja del Segura, in Alicante, concentrates part of the greatest seismic hazard in the country.
The explanation lies in the contact between the African plate, the Iberian microplate, and the Alboran block. This tectonic context generates active faults in the Betic mountain ranges and in the vicinity of the Alboran Sea.
In this area, relevant historical earthquakes have occurred, as well as recent episodes, such as that of Lorca in 2011. Although that earthquake had a moderate magnitude, 5.1, it caused serious damage due to its shallow depth, its proximity to the city, and the vulnerability of some buildings.
Alboran Sea and eastern Andalusian coast
The Alboran Sea is another of the key points of seismic risk in Spain. It particularly affects the coast of Malaga, Granada, and Almeria.
Active tectonic structures linked to the convergence between Africa and Eurasia converge in this area. Earthquakes can occur under the sea and be felt strongly on the coast, especially if they are shallow and close.
Not all marine earthquakes imply a tsunami, but the risk associated with Alboran is not limited solely to ground shaking: it also requires monitoring possible secondary effects in coastal areas.
Gulf of Cadiz and Cape St. Vincent: the zone of great historical earthquakes
The Gulf of Cadiz and the surroundings of Cape St. Vincent are the most important area when talking about earthquakes of great magnitude that can affect Spain.
Some of the largest historical earthquakes related to the Iberian Peninsula are located there. The best known is the Lisbon earthquake of 1755, estimated at magnitude 8.5, which caused a tsunami and also caused casualties in Spain. Another notable precedent is the earthquake of 1969 southwest of Cape St. Vincent, magnitude 7.8.
The difference compared to the peninsular southeast is that many of these large events have a marine epicenter relatively far from the main Spanish cities. This does not eliminate the risk, but it changes the type of impact: it can be felt in wide areas and generate coastal risk, although it does not necessarily cause the same level of urban destruction as a shallow earthquake under a city.
Pyrenees: Navarre, Huesca, Lleida, and Girona
The Pyrenees are also a seismically active area. The risk is explained by the ancient collision between the Iberian plate and the Eurasian plate, which left geological structures capable of generating earthquakes.
Pyrenean activity particularly affects Navarre, Aragon, Catalonia, and southern France. It is not the Spanish area with the highest urban risk, but it does present historical seismicity and the capacity to produce damaging earthquakes.
Canary Islands: seismic risk linked to volcanism
The Canary Islands have a different reality. Their seismicity is not primarily explained by the direct collision between large plates as occurs in other regions of the world, but by their volcanic origin.
The archipelago registers earthquakes associated with volcanic activity and the movement of magma at depth. This means that the Canary Islands have permanent seismic monitoring, especially on volcanically active islands such as Tenerife, La Palma, or El Hierro.
Even so, an earthquake like the one in Venezuela is not the most likely scenario in the Canary Islands. The danger there is more linked to volcanic crises, seismic swarms, and ground deformations than to large faults capable of generating earthquakes of magnitude 7 or 8.
Galicia and the Iberian Northwest
Galicia and the Iberian Northwest also register earthquakes, although with generally lower risk than the southeast, the Alboran Sea, the Gulf of Cadiz, or the Pyrenees.
There are faults and intraplate activity, meaning earthquakes that occur far from major plate boundaries. They can be perceptible and cause alarm, but they do not constitute the main seismic risk zone in the country.
Can Spain suffer an earthquake like the one in Venezuela?
As we have seen, Spain can suffer significant earthquakes, but a scenario similar to Venezuela's is unlikely in most of the territory. The key is to distinguish between magnitude, location, and damage. A high-magnitude earthquake does not cause the same effects if it occurs far from the coast, at great depth, or under the sea, as it does if it occurs at shallow depth and near a city.
That is why an earthquake of magnitude 5 or 6 can be very destructive if it occurs under a vulnerable urban center, while an earthquake of magnitude 7 or 8 in the sea can be felt over a huge area but cause more limited damage on land, unless it generates a tsunami.
Map of seismic risk in Spain
If Spanish zones are ordered by seismic sensitivity, the map looks like this:
- Southeastern Iberian Peninsula: Granada, Almería, Málaga, Murcia, and Alicante.
- Alboran Sea and eastern Andalusian coast.
- Gulf of Cadiz and Cape St. Vincent.
- Pyrenees: Navarra, Huesca, Lleida, and Girona.
- Canary Islands, due to their volcanic seismicity.
- Galicia and the Iberian Northwest, with minor but existing activity.
Although the danger exists, it should not translate into generalized alarm. The key lies in prevention, monitoring by the IGN, emergency planning, and compliance with seismic-resistant regulations in the most exposed areas.