In Córdoba there was a beach: the Mediterranean had a strait south of the province

There was a time when Córdoba literally had a sea. In fact, there were areas of the province that remained submerged and were part of a second strait, located north of the Gibraltar Strait. This occurred between eight and five million years ago, as indicated by the findings of Expedition 401 of the International Ocean Discovery Program.

The expedition, made up of a group of 27 scientists from more than fifteen countries, including three from Spain, analyzed the exchange of water between the Mediterranean Sea and the Atlantic Ocean. Under the name Investigating Miocene Mediterranean-Atlantic Gateway Exchange, between December 2023 and February of the following year, this group of experts boarded a vessel that traversed the entire area. During the journey, they used cutting-edge technology to collect sediments with the aim of revealing the environmental and oceanic changes that the territory underwent throughout its history and its impact on global climate.

The surveys were conducted off the coast of the Algarve (Portugal), in the area of Cádiz, in the Alboran Sea, near Marbella (Málaga), and in the Guadalquivir Basin, west of Seville, in addition to a fifth in the southern Rif basin, north of Morocco.

Among the main conclusions of the analysis, it is determined that, in addition to the Gibraltar Strait, there existed a second channel in Andalusia, the so-called Betic Strait. This has been determined, among other things, thanks to the discovery of marine sediments on both sides of the strait.

This second corridor extended from Murcia to the province of Cádiz, passing through a channel similar to the Subbética across Jaén, Seville, and Córdoba, and was formed in the Miocene (eight million years ago). Between the two corridors, there was a series of archipelagos covering points of the provinces of Cádiz, Málaga, Granada, and Almería. Additionally, points currently occupied by cities such as Cádiz, Huelva, or Rabat, the capital of Morocco, were submerged.

As can be seen in the report's map, territories that today occupy Montilla or Lucena would be underwater. Meanwhile, the capital would be a few kilometers from the beach.

, indicates the analysis in its conclusions. Among the causes is a >, the report continues. Moreover, the disappearance of the strait triggered the salinity of the Mediterranean and altered the climate, leading to global cooling>>, the text continues. It would not be until the Early Pliocene (5 million years ago) that the connection disappeared definitively.

The Betic corridor, the document indicates, played a crucial role in the exchange of water between the Mediterranean and the Atlantic>>. In fact, its closure resulted in the isolation of the sea, which saw a drastic reduction in water due to increasing evaporation. The study estimates that the Mediterranean dropped up to 1,500 meters compared to its current level. This led to a higher concentration of salt, exceeding levels found in the Dead Sea today. This period is known as the Messinian Salinity Crisis and has left a thick layer of up to two kilometers of this compound, buried under hundreds of meters of sediments, especially in the areas of the Balearic Islands and Algeria.

The disappeared strait also helped regulate the climate in the area, which enjoyed more stable and temperate temperatures, thanks to the greater exchange of water between the Mediterranean and the Atlantic. Global ocean currents were also altered. Finally, the study mentions that this geological process affected biodiversity, as it led to the extinction of marine fauna due to salinity.