The plate boundary between Africa and the Iberian Peninsula could cause large tsunamis

Due to the lack of data, the studies available until now underestimated the seismic and tsunami risk of these large faults.

A new study carried out by an international team led by the Institute of Marine Sciences (ICM) of Barcelona, ​​attached to the Higher Council for Scientific Research (CSIC) in Spain, and the ICREA (Catalan Institution for Research and Advanced Studies), also in Barcelona has revealed the exact location of the boundary between the European and African tectonic plates, located in the Alboran Sea region. Likewise, the work evaluates its potential capacity to produce large earthquakes that, in turn, could trigger devastating tsunamis on the coast.

The study, recently published in the academic journal Nature Communications, defines for the first time the complex geometry of this system of active faults and tells how they have been moving during the last 5 million years. Finally, the work shows that the system has absorbed almost all the deformation of the colliding plates in this region.

“The quality of our data has made it possible to study, for the first time, the deep structure of these faults, and thereby quantify the deformation they accumulate. The results show that it is one of the most important fault systems in the region and that it has been absorbing most of the deformation caused by the collision of the Eurasian and African plates”, explains Laura Gómez de la Peña, a researcher at the ICM and lead author of the study.

Although the geological structure of the subsoil of the Alboran Sea has been extensively studied since the 1970s, until now the data was not precise enough to understand the tectonics of the area. However, the quality of the data and the modern methodologies used to carry out the work have made it possible to characterize in detail a system of active faults that extends over 300 kilometers in length and is now considered the most important, in terms of accumulation of deformation, of the Iberian Peninsula.

“To prepare the study, we used the latest data acquisition techniques on board the Spanish oceanographic vessel Sarmiento de Gamboa, and the processing was specifically designed to be able to observe the structures described now for the first time,” details the ICM researcher and ICREA professor. César R. Ranero, who has also participated in the study.

The fault system that joins the European and African plates extends over 300 kilometers. (Image: ICM / CSIC)

Until now, it was unknown whether the Alboran Sea harbored large active faults, as well as the exact location of the tectonic boundary where the European and African plates collide. This knowledge is essential to reassess the seismic and tsunami risk to which the coastal areas of the western Mediterranean are exposed.

In fact, in another study carried out by the same group of experts in collaboration with GEOMAR (Germany) and INGV (Italy), the authors delve into the tsunamigenic potential of this plate boundary and suggest that it could be greater than expected. it was believed Most of the previous studies on seismic and tsunami risk did not correctly consider these large faults due to lack of data, so the risk had been underestimated.

“These studies are a first assessment of the seismic and tsunami potential of these large faults that until now we were practically unaware of and that must be thoroughly evaluated in future studies,” concludes Gómez de la Peña. (Source: BWI)