Scientists have figured out how the Red Sea was formed
The Red Sea, now one of the most important bodies of water on the planet, completely disappeared from the map about 6.2 million years ago.
This is reported in a new study published in the journal Communications Earth & Environment.
According to the scientists' conclusions, the ancient reservoir turned into a salt desert, but then was rapidly flooded by the waters of the Indian Ocean through the modern Bab el-Mandeb Strait. This catastrophic flood changed the face of the region and launched a new phase in the geological history of the Red Sea.
"We found that around 6.2 million years ago, the Red Sea dried up completely and then was refilled with seawater for less than 100,000 years - a blink of an eye by geological standards," said lead study author Dr Tihana Pensa of KAUST.
The Red Sea was originally connected to the Mediterranean Sea through a shallow passage in the north. However, this connection broke down and the isolated body of water began to evaporate. In the south, near the Hanish Islands, a volcanic ridge separated the sea from the Indian Ocean.
When climate and geodynamics changed, there was a dramatic rise in water levels. Seawater from the Indian Ocean burst through the southern barrier with tremendous force and filled the dried-up basin. The flow cut an underwater canyon 320 kilometres long - it can still be seen on the seabed. It was this flow that restored marine conditions and repopulated the region with marine life.
The formation of the Red Sea began about 30 million years ago when the Arabian Plate separated from the African Plate. It was first a system of lakes in a rift valley, then a shallow bay. 23 million years ago, the sea was first flooded by water from the Mediterranean Sea, giving rise to extensive coral reefs.
Over the next million years, however, there was intense evaporation and a drop in water levels, leading to extreme salinity and the death of marine life. Between 15 and 6 million years ago, the sea gradually dried up and its bottom was covered with gypsum and salt.
"This study highlights the importance of the Red Sea as a natural laboratory for studying the interactions between climate, tectonics and marine ecosystems," said co-author Professor Abdulkader Al-Afifi.