The waters were isolated more than 1,500 years at the bottom of the Pacific Ocean

Scientists found that a dark area in the northern Pacific Ocean with seawater does not move vertically for centuries.

Casimir de Lavergne, an oceanographer at the University of New South Wales, Australia, and colleagues discovered that the area below the North Pacific region meets about 2km of the Indian Ocean with a "dark zone" , where the sea is like there was no vertical movement for centuries, according to Science Alert. The results of the study are published in the November 8 issue of the journal Nature.

"The oldest dating method of carbon-14 radioisotopes shows that the North Pacific is 1,500 years old. So far, we have tried very hard to understand why. it is located around 2 km deep , " de Lavergne said.

The dark zone at a depth of 2km is sandwiched between the flow near the ocean floor generated by geothermal energy and the flow closely to the surface due to the wind.(Photo: Casimir de Lavergne).

The team conducted water motion analysis called deep-sea reversal circulation (abyssal overturning circulation) caused by the seabed shape . It prevents heavy seawater, located deep, circulating to the surface.

"On the north side of the 32th parallel south, the depth distribution of the seabed causes a large proportion of water in the south to flow north under a depth of about 4 km, then the water flows back to the south. the depth is greater than 2.5 km, "the team explained.

This means that in the northern Pacific region, there is an isolated water area of ​​about 6,000km from west to east and 2,000km from north to south. Deep water flows into a loop and almost never has a chance to reach the surface.

"We developed a theory to explain all of our observations. It simply depends on the shape of the seabed," said Ryan Holmes, a member of the research team at the System Science Center. ARC system, said.

Since the water is stuck almost never reaching the surface, seawater has much lower oxygen concentrations than higher water levels."This is not a strongly developed life area, but does not mean it is a dead zone , " de Lavergne said.