When the clans came around the mountain they expected to find the cave bears, but a wall of ice stopped them. It was 23,000 years ago on the treeless fields of southern Europe. The hunters turned in defeat. It was the height of Eurasian Ice Sheet Complex (EISC). The path to the north was blocked.

By the time EISC was fully formed, it covered Europe from Sicily to Franz Joseph Land and from Ireland to Moscow. It extracted so much water from the ocean that sea levels dropped 20 m everywhere in the world. The ice shield spanned 4500 km and was the result of three independent ice caps that merged to form the third largest ice sheet of the last Ice Age.

Then it began to melt.

Scientist from Norway, Sweden, and the US compiled enormous data on the fall of the EISC from to its zenith during the year of the cave bear to its demise by 13,000 years ago. In a just-released report in Quaternary Science Reviews, Henry Patton and his colleagues describe the melting of the EISC and the massive changes it wrought that altered the shape of a continent. 

That time, the ice took 8000 years to melt. The ice that covered Ireland, parts of England and Scotland melted quickly from the surface on down. But in the Barents Sea, massive glacier calving occurred that outstripped any we are familiar with today in Greenland or the Antarctic.

How fast did it melt? For 2000 years, 200-700 cubic miles of ice deglaciated each year. Just one cubic mile of ice is 750 billion tons of water.

Within a 500-year period, the EISC melted so dramatically that seas around the world rose 8 feet everywhere.

Melting caused the development of the Fleuve Manche, an enormous delta from what is now the Vistula to the Thames--perhaps twice the size and flow of the Amazon River delta.

About 10,000 years ago, the massive amounts of water caused an erosion of land so massive that the English Channel was formed. Human and animal populations were split and isolated, and entire ecosystems vanished.

The shape of Europe is a direct result of the deglaciation of EISC. When new clans of hunters finally travel north, when the walls of ice no longer blocked their way, the cave bears were extinct and face of the land had changed forever.