About six million years ago, the Strait of Gibraltar closed – the Mediterranean dried up. How much water was left over is controversial. The discovery of a river system provides new clues.
Scientist spotted the tracks of a huge river system under the eastern Mediterranean. In a report in the journal “Geology “, the researchers published data that suggest river sedimentation in the seabed off the coast of Cyprus, Syria, Lebanon and Israel. Houston-based Chevron Energy Technology Company team could provide clues as to what happened when the Mediterranean turned into a salt desert about six million years ago.
The Mediterranean dried up as the Strait of Gibraltar, the strait between present-day Spain and Morocco, closed. Thus, the Mediterranean was cut off from the Atlantic, the water evaporated – and the Mediterranean slowly dried up. The event during this period is called the “Messinian salinity crisis”. Until now, it was not clear how much water was left at that time. Due to plate shifts, the narrowness opened more than 600,000 years later.
The researchers around Andrew Madof assume that in the time of the “Messinian salinity crisis” much water must be evaporated – because only so can explain the formation of the river system. “Maybe 75 to 80 percent of the basin had dried up, but there was probably a lake into which the river system flowed,” Madof told the magazine “Eos . “
Using two-dimensional and three-dimensional seismic data, Madof and his colleagues were able to record the subsurface of the eastern Mediterranean and map the accumulation of sedimentary deposits – they called them Nahr Menashe. From these measurements, they could conclude that the river was flowing from today’s Turkey and Syria and flowed into a lake in the dry Mediterranean.