Important Discovery of Carbon as Old as 8000 Years Found in Deepest Blue Hole by the Researchers

Do you know which is the world’s deepest blue hole? According to the journal JGR Biogeosciences, the Yongle Blue Hole (YBH), the world’s deepest blue hole, was recently discovered in the South China Sea and contained carbon dating back more than 8,000 years. Carbon dates back over 8,000 years.

These underwater caves, dubbed “blue holes,” are generated when carbonate rocks deteriorate as global sea levels rise or fall. They are not connected to the ocean and do not receive fresh rainwater, unlike other underwater caverns. They are frequently round in shape, have steep walls, and are open to the ground.

According to the journal JGR Biogeosciences, investigators observed low levels of dissolved organic carbon in YBH but high levels of dissolved inorganic carbon in the same location.

Due to the high carbon concentrations in deep marine holes like Yongle blue hole, they serve as a natural laboratory for studying carbon cycling and the mechanisms that control it in the marine ecosystem. YBH is 300 metres deeper than the previous record-holder, Dean’s Blue Hole in the Bahamas, which was 202 metres deep. Now you know which is the world’s deepest blue hole?

Which is the world’s deepest blue hole?

While the YBH’s geomorphology is typically contained, the oceanic exchange has an effect on the surface water. As is the case with the majority of blue holes, it is anoxic, meaning that it is depleted of dissolved oxygen at a certain depth. The vast majority of marine life cannot thrive in this anaerobic environment.

Numerous studies have been conducted on low oxygen levels in aquatic environments. According to the magazine, they are a serious environmental and ecological problem because they have been responsible for numerous catastrophic extinctions.

The biogeochemistry and chemistry of the ocean are harmed as it transitions from an aerobic to an anaerobic condition. When it comes to blue holes, the transition takes place within a few hundred metres of the surface, and there are significantly fewer variables at work.

What is a blue hole?

According to a linked article published in Nature, researchers studying the physical and biological principles underlying carbon cycling and unique ocean conditions will now have greater access to the blue hole ecosystem. As sea levels fluctuate globally due to human-caused climate change, new depositional environments known as “blue holes” occur with carbonate platforms. They are frequently described as an ecosystem with deep bio-geo chemical gradients and varied microbial populations because of their relatively constrained geomorphology and limited exchange of water. 

Numerous research has been conducted in recent decades to identify the vertical gradient in the biological properties of water columns. Despite this, little is known about the elemental cycles of these ecosystems, particularly the carbon cycle. The Yongle Blue Hole (YBH), a dragon hole in the South China Sea, has been coveted by ancient Chinese fishermen for several years because of its deep blue colour and near-limitless depth.

The YBH is an incomprehensibly deep, dark blue hole. In 2016, the Yongle Blue Hole was named the world’s deepest discovered blue hole, surpassing the previous record held by the Black Hole. Mr Liang Fu, head of the Sansha Tracks Ocean Coral Reefs Conservation Research Institute of China, estimates the YBH’s depth to be 300 metres, far greater than the previous record-holder, Dean’s Blue Hole in the Bahamas, which was 200 metres. Mr L Fu, an accomplished deep diver and underwater photographer, has dived in the YBH countless times. Now you know which is the world’s deepest blue hole?

Pilot scientific inquiry

Three months following the finding, he organised a pilot scientific inquiry, bringing together to conduct a pilot’s scientific investigation. This assessment included the testing of sampling equipment and an examination of the fundamental chemical and physical characteristics of the Yongle Blue Hole water column in order to formulate sampling strategies for future studies. In comparison to initial readings, dissolved organic and inorganic carbon were found to be much lower or higher than the surrounding water.

They were both astonished and delighted to discover that the concentrations of DOC and DCI were compared to those found in radiocarbons-aged deep seawater. In the subsequent sample, the collected water layer increased the sensitivity of radiocarbons and mixed carbons studies, which led us to focus on dissolved carbon. Now you know which is the world’s deepest blue hole?

Second scientific research

On March 1, 2017, following the conclusion of the South China Sea winter season, second scientific research was done. Chemical data were collected to have a better understanding of how dissolved carbon is transferred across the water-sediment system. Samples were collected using an ROV from a depth of fewer than 200 metres. Due to the fact that pH, DO, and H2S are all time-sensitive variables, a small laboratory was built on-site at the Yongle Blue Hole to perform the analysis. 

Now you know what a blue hole.

Conclusion

Finally, the discovery of thousands of years old deep dissolved carbon in the YBH shows that either these extraordinarily shallow waters have been isolated from the open ocean for a lengthy period of time or that another ageing process is in action. Despite this, we have no idea how long the water remained in the deep hole or how much carbonate dissolution from the hole’s walls contributed to the fluctuation in the DIC ages over time. The bottom waters of the YBH do not appear to contain any evidence of underground freshwater that could have introduced ancient dissolved carbon from the surrounding environment. Now you know which is the world’s deepest blue hole?