The closure of the Straits of Gibraltar caused the Mediterranean Sea to dry up, creating a deep, inhospitable desert. When the straits reopened, the sea catastrophically refilled in a dramatic flood event.
# Metadata
Title: Messinian Salinity Crisis Movietime: 11:19 Geographical Time: 5.96–5.33 Ma
Around 5.96 million years ago, tectonic uplift and falling sea levels closed off the Straits of Gibraltar. This event cut the Mediterranean Sea off from the Atlantic Ocean, leading to extreme evaporation and the complete desiccation of the basin. The Mediterranean became a vast salt desert, with surface temperatures exceeding 50°C and atmospheric pressure twice that of sea level.
Salt deposits over 1.5 km thick accumulated on the seafloor. Life in the region was devastated by hypersalinity and heat, and large portions of the basin sank far below global sea level.
Then, around 5.33 million years ago, the straits reopened — possibly due to tectonic subsidence or rising sea levels. The Atlantic Ocean rushed back into the basin in what is now called the **Zanclean Flood**. Estimates suggest that the basin may have refilled in just a few months to two years, with water pouring in at rates thousands of times greater than any modern river.