A team of Andalusian scientists has reconstructed what the Gibraltar Arc was like 9 million years ago, during the Messinian Salinity Crisis, when the Mediterranean dried up. The study, published in the journal Nature Communications, reveals that the Gibraltar Arc was a narrow and deep strait, with a maximum width of 20 kilometers and a depth of more than 1,000 meters.

The Messinian Salinity Crisis was a geological event that occurred between 5.96 and 5.33 million years ago, when the Mediterranean Sea was isolated from the Atlantic Ocean and its water evaporated, leaving behind a vast salt desert. This event had a profound impact on the climate and environment of the region, and it is thought to have been a major factor in the evolution of the human species.

The Gibraltar Arc is a tectonic structure located between the Iberian Peninsula and North Africa. It is formed by the collision of the African and Eurasian plates, and it is the site of the present-day Strait of Gibraltar. The new study provides important insights into the geological history of the Gibraltar Arc and its role in the Messinian Salinity Crisis.

The scientists used a variety of techniques to reconstruct the Gibraltar Arc, including seismic reflection profiling, gravity data, and geological samples. They found that the strait was formed by the tectonic activity of the African and Eurasian plates, and that it was initially a narrow and shallow channel. However, as the Mediterranean Sea dried up, the strait deepened and widened, reaching its maximum dimensions during the Messinian Salinity Crisis.

The study also provides new insights into the climate and environment of the Gibraltar Arc during the Messinian Salinity Crisis. The scientists found that the strait was a major source of dust and sand, which was transported by the winds across the Mediterranean basin. This dust and sand contributed to the formation of the evaporite deposits that are found in the region, and it also had a significant impact on the climate of the region.

The new study provides important insights into the geological history and environmental impact of the Messinian Salinity Crisis. It also sheds light on the evolution of the Gibraltar Arc, and its role in the development of the Mediterranean Sea.