The Desiccation and Catastrophic Refilling of the Mediterranean: 50 Years of Facts, Hypotheses, and Myths Around the Messinian Salinity Crisis

Abstract

According to some authors, the Messinian salinity crisis was ended by a giant waterfall or megaflood 5.33 million years ago, when the Atlantic Ocean reconnected in a catastrophic way with the desiccated Mediterranean, creating the Strait of Gibraltar. An erosional surface deeply cutting upper Miocene or older rocks and sealed by lower Pliocene sediments is the geological feature that inspired this fascinating hypothesis. The hypothesis, which recalls several ancient myths, is well established in the scientific community and often considered to be a fact. However, several studies are suggesting that the Atlantic–Mediterranean connection through the Strait of Gibraltar was probably active before and during the entire Messinian salinity crisis. This allows us to consider the possibility that long-lived, more gradual physical processes were responsible for the evolution of the strait, opening the idea of a nondesiccated Mediterranean Sea.