Explore the world's deepest green hole in the South China Sea

The new exploration of a mysterious green hole in the South China Sea has shown that it is the deepest green hole in the world. According to Xinhua, Longdong or Dragon's pit is 300.89 m deep and deeper than the blue hole Dean in the Bahamas - once held the previous record (Dean's blue hole is about 202 m deep). Ancient legends say that the Dragon hole was mentioned in the " Journey to the West " Ming Dynasty novel - a supernatural monkey given a wand by a dragon who ruled the kingdom deep under the sea.

Scientists in this field are still testing and confirming this, but Dr. Pete van Hengstum, a marine geologist at Texas A&M University, said: if measured in size, the Dragon hole deeper than the blue hole Dean. He conducted research in green holes and water funnels that flow through the Caribbean.

Water wonders

Dr Van Hengstum said: "Blue holes are funnels filled with water to create carbonate rocks like limestone." For a long time, the carbonate rock mass dissolved below the ground and created caves or holes.

" Finally, the dissolution process causes the cave to approach closer to the surface of the Earth and if the ceiling of the cave falls, it will form a blue hole or a water funnel ." Some green holes, like the Dragon hole, create a marine environment and other holes are inland.

Some mysteries are why blue holes are formed in this place and what factors affect their development. Lisa Park Boush, a geography scientist at the University of Connecticut, is a researcher of the sediments found in green holes, saying that the general chemical reaction between salt water and fresh water can produce weak and corrosive acids. limestone as well as other types of carbonates. As a result, sea level rise and fall can affect the time and place of green hole formation.

Boush also replied to Live Science: " There is a research team that learns about bacterial activity ." In some cases, bacteria can help dissolve the bedrock and build green holes. In addition to bacteria, other creatures also consider these beautiful natural wide holes to be their home.

Life in the green hole

Geography scientist Boush said: " It's great to directly see life in green holes ," and call the habitat in green holes a " mystery ".

According to Xinhua, scientists together with the Sansha Ship Research Institute on coral protection in China have used underwater robots and depth sensors to discover the mysterious world of the Dragon Hole. - is a special point in Yongle, a coral reef near Xisha islands in the East Sea. They found more than 20 marine creatures living on the top of the pit. On July 22, the researchers replied that: Under a depth of about 100 m, the seawater in the blue hole is nearly oxygen-free, so there is very little life.

She also notes that deep diving in the blue holes is extremely dangerous and that is " One of the reasons why it is so dangerous is because of the oxygen limit and even there is a lot of it. sulfuric water . "

Dr Van Hengstum said: " Well trained divers can participate in that visit ." In other cases, researchers park their boats right on the green hole and drop the device to measure depth, temperature, oxidation and other factors. Both Boush and van Hengstum studied the sediments at the bottom of the green holes. These sediments contain information about the past environment, climate change and sometimes fossils.

Van Hengstum also said that the Dragon hole in the South China Sea was formed in the same environment as the green holes in the Bahamas. More recently, many green holes are flooded by sea water in the Bahamas like water-digging funnels during the glacier period when the sea level is lower. But after the last ice age flooded, continental glaciers melted and sea levels around the world increased.

Boush said: "The Bahamas is on a large flat carbonate with places up to 610 m. Some of these carbonates are haunted by organisms such as corals - excreting calcium carbonate as a protective structure. But calcium Carbonates are also present in lime algae (algae with hard calcium carbonate skin layer) and even in fish feces ".

" Fish eat coral reefs, " Boush said. " For example: The grouper chews. When you dive with the compressed air, you will hear a 'click, click, click, click, click' and that's the sound of grouper eating coral. Yes, that's all even what happens is repeated. "