Sicily (the large island next to the ‘toe’ of Italy) still forms part of a divide between the Mediterranean’s darker basins, shaded in deeper blue. GEBCO / National Oceanographic Centre, UK, CC BY-NC-SA
The Conversation has an article about the mother of all floods... the flooding of the Mediterranean about 5 million years ago. The Atlantic Ocean seeped it's way through Strait of Gibraltar, which was blocked by the movement of tectonic plates. This caused the Mediterranean Sea to dry up and led to the formation of large salt deposits - kilometers thick in some places.
The Med was, at the time, a largely dry and salty basin, but so much water poured in that it filled up in just a couple of years – maybe even just a few months. At its peak, the flood discharged about 1,000 times the water of the modern-day Amazon river.
At least, that’s the thesis one of us put forward in a 2009 study of an underwater canyon excavated along the Strait of Gibraltar, which he presumed to have been carved out by this massive flood. If correct, (and some scientists do dispute the theory), the so-called Zanclean megaflood would be the largest single flood recorded on Earth.
But extraordinary claims like this require extraordinarily solid evidence. Our latest research investigates sedimentary rock from the Zanclean era that seems to record how the water surged through a gap between modern-day Sicily and mainland Africa to refill the eastern half of the Mediterranean.
