How the Arctic Ocean became saline
The Arctic Ocean was once a gigantic freshwater lake. Only after the land bridge between Greenland and Scotland had submerged far enough did vast quantities of salt water pour in from the Atlantic. With the help of a climate model, researchers from the Alfred Wegener Institute have demonstrated how this process took place, allowing us for the first time to understand more accurately how Atlantic circulation, as we know it today came about. The results of the study have now been published in the journal Nature Communications.
Every year, ca. 3,300 cubic kilometres of fresh water flows into the Arctic Ocean. This is equivalent to ten percent of the total volume of water that all the world’s rivers transport to the oceans per year. In the warm and humid climate of the Eocene (ca. 56 to 34 million years ago), the inflow of freshwater was probably even greater. However, in contrast to today, during that geological period there was no exchange of water with other oceans. The influx of saline Atlantic and Pacific water, which today finds its way into the Arctic Ocean from the Pacific via the Bering Strait and from the North Atlantic via the Greenland-Scotland Ridge, wasn’t possible — the region that is today completely submerged was above the sea at that time.
Only once the land bridge between Greenland and Scotland disappeared did the first ocean passages emerge, connecting the Arctic with the North Atlantic and making water exchange possible. Using a climate model, researchers from the…
