For 90% of human existence, sea levels have been lower than the present by as much as 130 m. The current sea level was only established about 6,000 years ago. As humans mainly lived close to the water, a large majority of humanity's development took place on areas that are now submerged.
However, it is only within the past decade that there has been a clear recognition of how important the missing data is on the submerged shelf. Growing numbers of prehistoric underwater archaeological sites stretching over whole landscapes, ranging in age from over 300,000 years to 6,000 years ago, have been discovered, often with spectacular conditions of preservation of organic materials such as wood and fibres.
Such discoveries have for instance been made in parts of the Baltic Sea, the North Sea and the Black Sea. See the Splashcos project.
Some of the world's best-preserved prehistoric landscapes have survived at the bottom of the North Sea. Dating mainly from approx. 50,000-60,000 years ago, they contain traces of prehistoric and Neanderthalian hunting grounds and camp sites. It is estimated that hundreds or even thousands of square miles of post-Ice Age prehistoric landscapes may have survived in this way.
9,000 years ago, Denmark, Sweden and England were one continent and the Baltic Sea a lake. When the ice cap melted, due to the end of the Ice Age, the sea level rose and the many human settlements were submerged.
A submerged coastline 17 meters below the waters of the Black Sea provides evidence of a flooding 7,500 years ago, an event which is supposed to be a possible source for the story of Noah’s Ark. Scientists suppose that the Black Sea extended when melting glaciers raised the sea level of the Mediterranean, until a natural dam on the Bosporus broke. Proof of the prior smaller extension is provided by the remains of submerged Mesolithic settlements found off the coast of Turkey and the discovery of an ancient log boat at another site.