The Largest Flood in Earth’s History Exploded in the Atlantic 5 Million Years Ago, Refilled the Entire Mediterranean

The Mediterranean Sea, today a glimmering cradle of civilizations, was once a huge, parched desert. Salt flats shimmered where dolphins now swim. This was not the doing of human hands or even ice age glaciers. No, nature itself played god, draining a sea and then, just a few million years later, unleashing a flood so huge, it carved canyons, moved mountains, and remolded Earth forever. Scientists have only recently begun to piece together the gravity of this deadly event, one that may be the largest flood in Earth’s history, stated The Conversation.

Approximately 5.3 million years ago, something stunning happened—water from the Atlantic Ocean burst through the present-day Strait of Gibraltar like a juggernaut. The dry Mediterranean basin, a desert left behind by the Messinian Salinity Crisis, was about to be drowned quickly.

Geologist Giovanni Barreca, co-author of the study, believes that the level of this flooding was way bigger than human imagination. There was a wall of water, hundreds of meters deep, pacing at speeds up to 115 km/h (71 mph), remolding entire landscapes in its path, via The Conversation. This deadly refill known as the Zanclean mega flood did not just trickle in. It bolted through a kilometre-high slope from the Atlantic, gouging a trench so deep that it challenged modern skyscrapers.

Moreover, at its peak, the flood delivered water at a rate nearly 1,000 times that of the Amazon River, enough to fill the entire Mediterranean in just a few years or maybe even months. It was like pouring the contents of an ocean through a fire hose. The Mediterranean was not always this way. Geological records show that tectonic shifts separated it from the Atlantic around six million years ago, triggering the Messinian Salinity Crisis. Most of the sea evaporated, leaving behind a layer of salt several miles thick. Fossil proof suggests shallow, hypersaline lakes dotted the basin. Then, what happened, readers must wonder? The Zanclean flood brought the ocean crashing back—first through Gibraltar, then over the Sicily Sill, a ridge connecting Africa and Italy, stated The Independent.

New research has confirmed that this second installment of water into the eastern Mediterranean was no gentle tide. Instead, it was another mega flood. Barreca and his team deeply researched the low hills of southern Sicily and found landforms strikingly similar to those etched by glacial floods in Washington State. Streamlined hills, deep erosional troughs, and bizarre hilltops pointed to only one angle that this was not the work of wind or time; it was a flood of forces that cannot be comprehended by the human brain.

Intriguingly, computer models back up this claim. This was just a fraction of what had already spilled through Gibraltar. Less than 11% of marine life survived the disaster. The Mediterranean today may be a bliss, but hidden beneath its depths lies proof of one of Earth’s most notorious rebirths — a time when the sea returned with a vengeance.