A new study says that Spain and Portugal are moving very slowly because the Iberian Peninsula is rotating clockwise. The movement is caused by pressure from the African tectonic plate, which is slowly moving north towards the Eurasian plate near Gibraltar.
The movement is very small, around 5 millimetres a year, but scientists can now measure it using satellites and earthquake data. Researchers studied decades of earthquakes and compared them with GNSS satellite measurements, which can detect tiny changes in the ground.
The study found that the strongest movement and pressure are around southern and western Iberia, especially near Gibraltar, the Gulf of Cadiz, the Betic mountains and the Alboran Sea. These areas are close to the boundary between the African and Eurasian plates, where the Earth’s crust is being squeezed, stretched and pushed sideways.
Some parts of the region absorb the pressure, while other areas may transfer it inland. This helps explain why earthquakes can happen in places that may look calm on the surface. The study also shows that some faults may still be active, even if they are not easy to see.
Scientists say this information is important because it can help improve earthquake-risk maps. Cities such as Lisbon, Seville and other nearby areas could benefit from better knowledge of which faults are active and where stronger shaking is more likely.
The researchers also say more data is needed. More satellite stations, especially offshore and in North Africa, would help give a clearer picture of how the plates are moving.
Although the movement is tiny each year, over thousands or millions of years it can shape coastlines, mountains and fault lines. The study shows that the Iberian Peninsula is not completely still, but part of a slow and continuing geological process.
