The Great Flooding of the Black Sea

This story starts with a tale of global warming. In times of antiquity—specifically during the last ice age—the Black Sea was actually the Black Lake.

It wasn’t connected to the ocean, and it was comprised of fresh water. However, during the Holocene period at the end of the last ice age, the glaciers began to melt and retreat, leading to a rise in sea levels.

These rising sea levels led to the Mediterranean Sea and the Black Lake becoming connected. Salt water rushed in, forming the landscape we are familiar with today.

The Black Sea is now fed from two different sources of water: freshwater rivers (such as the Danube, Dnieper, Rioni, and others) and saltwater inflows from the ocean. The result was a fairly unique set of circumstances.

The river water flowing in is warmer and less salty, while the flow from the Mediterranean is colder and saltier. This had led to two different layers of water in the Black Sea. On the surface is a warmer and lower salt layer, while underneath is a saltier, colder layer that is lower in oxygen. And that’s when things get really interesting.

Science and unintended discoveries


The rise of the oceans at the end of the last ice age, and the flooding of the Black Sea, is an event of great interest to archeologists. Recently the Black Sea Maritime Archaeology Project started exploring the Black Sea using remote operated vehicles (ROVs) to map the floor of the Black Sea as part of a study of prehistoric and historic environment and human activity in this region.

The Black Sea before and after the Glacial Age. Image: Woods Hole Oceanographic Institution

This is interesting from both the perspective of archeological history, as well as human history. Some theories hold that this flooding could be the source of flood myths in the area, including the flood in the story of Noah’s Ark.

Today: where the Black Sea meets the Bosphorus. Istanbul’s 3rd bridge near Rumelifeneri.

The Black Sea hypothesis theory suggests that the flooding process was spectacular and dramatic; water flowing into the Black Sea was the equivalent of 200 times the flow of Niagara Falls! However, other theories disagree, stating that the rise in sea level was much less dramatic.

The Bosphorus today connects the Aegean Sea with the Black Sea. Image: Google Earth

The research teams from MAP discovered quite a bit of data when they were mapping the sea floor, but they also found something they were not looking for–specifically, they found dozens of incredibly well-preserved shipwrecks from a period spanning about a thousand years.

In sea water, ropes and wood typically corrode quite quickly. This means that wrecks from the era of the wooden ship typically do not last long enough in a quality worthy of exploration.

However, it turns out that the relatively low-oxygen, and distinctly high salt environment at the bottom of the Black Sea was absolutely spectacular for preserving shipwrecks. The decay of wood, rope and other similar material was dramatically slowed.

The Black Sea and international trade

In historic times, water was generally the most efficient way to transport large quantities of bulk goods. It still is in many ways. Human beings have lived along the shores of the Black Sea for over a thousand years, and for as long as human beings have been sailing ships, we have lost some of those ships to storms and other catastrophes. Some of these ships date back to the Byzantine and Ottoman empires.

Image: Rodrigo Pacheco-Ruiz, Black Sea MAP.

Some of the wrecks that research teams have found were previously known, but many were not. The nature of the discovery of the multiple sunken ships was best described by the principle investigator of the project, Professor Jon Adams.

The wrecks are a complete bonus, but a fascinating discovery, found during the course of our extensive geophysical surveys.”

– Prof. Jon Adams

Some of the wrecks are in such good condition that the chisel markings on the wood can still be discerned on camera. Rope, rigging on the ship, small elements of ship construction, and even decorative carvings on the ships are surprisingly well preserved.

Medieval ship from the depths of the Black Sea
Medieval ship from the depths of the Black Sea (1100m). Photogrammetric model made of 4500 photos. Image: Rodrigo Pacheco-Ruiz, Black Sea MAP.

These wrecks provide an incredible window into a period of nautical history. Wooden shipwrecks are normally not found with this level of detail, and some of these wrecks are of ships we have never seen outside of historical drawings, artwork, and written records.

Image: Rodrigo Pacheco-Ruiz, Black Sea MAP.

As much as we believe we know everything there is to know about our world, the Black Sea Maritime Archaeology Project has helped remind us that there are still a number of amazing things out there for us to find. The world is an incredible place; history is being rewritten and filled in with more detail every year as we discover, learn, and interpret more.