Scientists Find Drastic Shift In Atlantic Ocean Currents
However, that pattern appears to have been repeated only occasionally in recent decades.
"Now the southern current has taken over, it's really a drastic change," Schubert told AFP, pointing to the evidence of the shift towards warmer water in the northwest Atlantic.
Research was based on nitrogen isotope signatures in 700-year-old coral reefs on the ocean floor, which feed on sinking organic particles.
While water pushed by the Gulfstream is salty and rich in nutrients, the colder Arctic waters carried by the Labrador Current contains fewer nutrients.
Changes could be dated back because of the natural growth rings that are found in corals.
"The researchers suspect there is a direct connection between the changes in oceanic currents in the North Atlantic and global warming caused by human activities," said EAWAG in a statement.
The scientists published their study recently in the Proceedings of the National Academy of Sciences.