A scientific team from the University of Southern Denmark has found that large amounts of carbon accumulate in sea trenches in the abyssal depths of the oceans.

The researchers published 3 studies in 3 different scientific journals, and indicated in their studies that trenches play an important role in storing organic matter in the deep sea, and in the balance of carbon dioxide in the atmosphere.

Explore the trenches of the seas

Deep sea trenches are among the least explored places on Earth due to the difficulty of accessing them.

They are coarse black and the pressure is very high, so collecting samples and making reliable measurements of the processes that regulate the circulation of organic matter at depth is difficult.

But in the past few years, researchers from the University of Southern Denmark have made a number of expeditions to deep-sea trench areas, known as the Hadal zone, which are trench areas located at depths between 6 to 11 kilometers below sea level.

The researchers used, in their exploration trips to the area of ​​the trenches, advanced underwater "robots" that they had previously created. The bottom of the trench in the depths of the sea is a veritable hotspot for the deposition of microbial life forms that transform matter.

Deep sea trenches are among the least explored places on Earth due to the difficulty of accessing them (Shutterstock)

Carbon buildup in trenches

According to the University of Southern Denmark press release, the researchers found that organic carbon - which is difficult to decompose, including so-called black carbon - accumulates in large quantities at the bottom of the trenches.

black carbon consists of particles formed during the burning of fossil fuels, wood and forests;

This leads to the release of carbon dioxide, and therefore the presence of black carbon is an indication of the extent of fossil combustion, as the particles themselves can also contribute to warming, as wind and weather transport them to ice-covered regions - such as the polar regions - so they settle on ice, which increases heat absorption. ;

Hence the solubility.

"Now we see that large amounts of black carbon end up at the bottom of deep-sea trenches," said the head of the scientific team of the study, Roni N. Glod, head of the Danish Research Center specializing in the study of deep trenches.

On the other hand, the university statement says that the researchers obtained samples from a depth of more than 6 kilometers, analyzed them, and found that in one year between 500 thousand to one million and 500 thousand tons of black carbon are stored in the depths of the sea.

Sea trenches play an important role in storing organic matter in the deep sea (Shutterstock)

Flexible carbon types

The university's statement adds that "not only are there disproportionately large amounts of black carbon deposited in the depths, the same is happening for other flexible carbon species that are difficult to decompose, as analyzes have shown that every square meter in the central parts of the deep-sea trench buries 70 times as much water." Carbon is more elastic than the deep sea in general."

"Although the explored area makes up only a very small part of the sea floor, disproportionately more carbon is stored than the deep sea in general," says Glodd. "So despite the fact that deep trenches have a relatively high turnover of microbes, these The region studied is part of the global carbon cycle and reflects the rate at which carbon dioxide is accumulating in the atmosphere.

The sea is a garbage dump

The university's statement says there is a possibility that the black carbon is from burning fossil fuels in Denmark's neighboring countries sending the black carbon into the sea with the wind.

This hypothesis is consistent with the fact that the black carbon content is higher in trenches near industrialized countries, while trenches near less industrialized countries such as New Guinea have lower content.

Black carbon content is higher in trenches near industrialized countries (Getty Images)

According to Ronnie N. Glod, deep-sea trenches act as sedimentation zones for organic matter, as the process is facilitated by frequent earthquakes, as these earthquakes carry large amounts of materials to the deepest parts of the trenches and bury them in oxygen-free sediments, which leads to their accumulation over centuries. and thousands of years, so one might ask whether deep-sea trenches are suitable for storing carbon.

Gloud says, "Man has always used the sea and the depths of the sea as a waste area under the pretext that it is out of sight and out of mind, but today we know that this is not true. The ocean is rich in life, and what it contains of biological and chemical materials, and the vitality of the processes in it is important to the function of the globe; this also applies." on the trenches of the seas.

He adds, "We know today that those trenches that were studied have a rich and diverse life, which is very dynamic and diverse, and these materials from the ground and surface find their way into the interior, including, unfortunately, plastic and other pollutants that reach the depths of the oceans, which was shown by the sediment samples that were obtained." from the study area, which contains high levels of mercury.