Question 1: How are blue holes formed in the ocean? What's in it? Author: Ran Jing

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I've been paying attention to this problem recently. The topic is about the blue hole between Jinqing Island in Yongle Atoll in Sansha City and Shiyu Island Reef Plate. Its geographical coordinates are 16 3 1' 30 "in north latitude and11/46' 05" in east longitude. It has been proved to be the deepest blue hole in the world, with a depth of 3000.

The word "Blue Hole" comes from the literal translation of the English word "blue hole", which refers to a water-filled cave system developed on carbonate platforms, coasts and islands. It is exposed on the earth's surface and consists of seawater, fresh water and water mixed with their chemical components. It has a great depth below the surface and can enter along it.

Blue holes can be divided into ocean blue holes and inland blue holes. The former leads directly to the marine environment, usually with tidal water; The latter is exposed on the land surface, including seawater, fresh water and mixed water affected by tides. Mostly distributed in tropical and subtropical marine or coastal environments, it is a rare geological landscape. The largest blue hole in the world is Belizean blue hole, and the deepest ocean blue hole was originally Deanes blue hole in Bahamas, but the discovery of Yongle Dragon Cave replaced its position as the deepest ocean blue hole in the world.

From the formation process, there are three different types of geological processes that can form blue holes.

The first one is that when the sea level drops during the ice age, the surface water dissolves on the limestone (including reef limestone) islands exposed from the water surface to form karst shafts, and when the sea level rises during the interglacial period, the shafts are filled with water to form blue holes. Most of the blue holes we see in the ocean now belong to this type.

The second type occurs on the land at a distance from the ocean, that is, in the carbonate platform, there is no surface water system, but a cave system is formed by groundwater flowing to the ocean. Later, the cave developed back to the source, and the top of some cave sections collapsed to form a series of deep water-filled collapse buckets or natural wells. The blue hole group on Mexico Yucatan Peninsula is a typical example of this kind of blue hole.

Third, on the coastal edge, due to geological actions such as geological tectonic movement, deep cracks are generated on the surface, and after the cracks are filled with water, they eventually develop into blue holes.

Sansha Track Research Institute has made a preliminary scientific exploration of Yongle Longdong by using underwater robots, sonar instruments, current meters and automatic water quality analyzers. The measured maximum depth of Yongle Longdong is 300.89 meters, and the diameter from the transition edge of the entrance to the reef flat is 130 meters. According to the underwater robot's repeated exploration and sonar scanning, the profile of Yongle Longdong is generally vertical, with obvious turning and inclination to the north at the depth of160m.

According to the core analysis obtained from the cave wall of Yongle Long Cave, the lithology of the cave wall is mainly a reef composed of marine debris such as coral. In Yongle Longdong Cave, it was not found that the water in the cave was connected with the open sea or the lake, but it was found that there were different water layers, and the water body was basically static. From the depth of 105 meters to the bottom of the cave, there is a seawater anaerobic environment with a depth of nearly 200 meters where dissolved oxygen tends to zero.

At present, the detection of Yongle Longdong is still very preliminary. I wonder if there are any ancient primitive creatures in this extreme environment. Besides the known branch cave of Yongle Longdong, are there any side caves? The entrance of the branch hole has been covered by coral reefs that have grown for a long geological time and cannot be found.

Question 2: What are the famous blue sea caves in the world? Blue hole refers to a huge "deep hole" where the seabed suddenly sinks, which is a rare natural geographical phenomenon on the earth. Seen from the sea, the blue hole appears dark blue, which is different from the surrounding waters, and forms a huge deep hole on the seabed, which is praised by scientists as "the last legacy of the earth to keep the secrets of the universe for mankind".

The blue hole in Yongle Atoll of Xisha Islands was confirmed by experts' field investigation. It has been proved to be the deepest ocean blue hole known in the world. It is located in the reefs of Jinqing Island and Shiyu Island in Yongle Atoll of Xisha Islands in Sansha City. The blue hole has a diameter of130m, a bottom diameter of about 36m and a depth of 300.89m.. It was named "Yongle Longdong".

Previously, the depth rankings of the world's four major ocean blue caves were: Deanes Blue Cave (202m) in Long Island of Bahamas, Hadabu Blue Cave (130m) in Egypt, Belize Blue Cave (123m) in Honduras and Gozo Blue Cave (60m) in Malta. At present, the newly discovered Yongle Blue Cave in Xisha has greatly set a new record for the world's ocean blue caves and become the deepest blue cave in the world.

Deanes Blue Cave, Long Island, Bahamas

Deanes Blue Cave is an underwater maze located in a bay in Clarence, Long Island, Bahamas, with a length of1500km. It contains tunnels and caves formed during the ice age and is one of the most dangerous new areas in the world.

Blue Cave in Hadab, Egypt

Hadabu Blue Cave is located in the Red Sea. There is an arched passage near Hadabu Blue Cave. Many experienced divers ventured there to prove their superb skills. Due to many unfortunate events, the Blue Cave of the Red Sea is even called the "Tomb of Divers" by the outside world.

The big blue cave in Belize, Honduras

The Great Blue Cave in Belize is located on the edge of the submarine plateau in Grand Bahama Shoal, 60 miles from Belize City. It is a world-famous diving resort and is rated as one of the top ten diving treasures in the world.

The Great Blue Cave in Belize City is almost round in shape, surrounded by two coral reefs, with a diameter of over 305 meters and a depth of 123 meters.

Because the water is too deep, the whole cave presents a dark blue tone, which is completely different from the surrounding water and highlights the uniqueness of the blue cave.

Gozo Blue Cave, Malta

Gozo Blue Cave is located in the southwest of malta island. Its shape is similar to that of Elephant Trunk Mountain in Guilin, and it was gradually formed by the impact and erosion of waves for thousands of years. In 2004, the Hollywood blockbuster Troy Horses was filmed in the Blue Hole. Together with Malta's "blue window" and "blue lagoon", it is called Malta's "three blues".

Saipan blue cave

Located in the northeast corner of Saipan, Saipan Blue Cave is the most famous and difficult place to dive in Saipan. Here, divers can often be seen practicing launching here.

Blue caves in Capri, Italy

The blue cave in Capri Island is called one of the seven wonders of the world. The hole of the blue hole is under the cliff. The hole is so small that you can only go in by boat.

Due to the special structure of the cave, on the one hand, sunlight can enter the cave from the inside, on the other hand, it can be reflected from the bottom of the cave, so the seawater in the cave is crystal blue and mysterious, and even the rocks in the cave turn blue, so it is called "blue hole".

Question 3: How are the blue holes in the ocean formed? What water is in it?

Question 4: Blue hole in the ocean The blue hole in the ocean is a huge "deep hole" where the seabed suddenly sinks. Its name comes from the fact that this "deep hole" at the bottom of the sea is dark, and there is a mysterious dark blue tone when looking at the surrounding waters from the sea. The blue hole is hundreds of feet deep. When the diver dived into the blue hole to investigate, he found that there was a serious lack of oxygen, which may be due to the lack of water circulation to support marine life. However, the ocean blue hole has great scientific research value. Scientists found many ancient fossil remains at the bottom of the blue hole in the ocean. Blue Cave in Xisha Islands, China Overlooking the mysterious Longdong in Xisha Islands from space, there is a mysterious place-Longdong. According to Zhao Baoxun, a veteran of naval surveying and mapping who once worked in Xisha, after our army recovered the Yongle Islands in Xisha on 1974, the superior asked for military surveying and mapping. In the process of surveying and mapping, the fishermen who helped them tell them a mysterious "dragon cave": there is an bottomless abyss on the reef plate on the northeast side of Jinqing Island, which the fishermen call "dragon cave". This cave is unfathomable, and it is said that there are huge animals in it ... fishermen dare not go near this place, nor dare they go near it. After listening to this, the surveying and mapping troops were very curious and felt obliged to find out. So the next day, I persuaded the fishermen to come to this place by boat. I saw a dark blue sea with a radius of 200 meters in the green shallow sea of reef plate, which was very scary. Everyone restrained their nervousness and rowed to the mouth of the cave to prepare for sounding. The soldiers hoisted the sounding hammer with a rope and put down the water. As a result, the 200-meter rope was not finished ... At this time, the wind blew and the sampan shook violently, so they had to come back quickly. I was busy with other tasks and never measured the hole again. The secret of Longdong has never been solved, and I don't even know the depth. The veteran is sorry. According to the clues provided by veterans, I used Google Earth to find Jinqing Island in Xisha, and then looked northeast. I found a "blue hole" (measured on the map) on the reef plate 7 kilometers away from Jinqing Island, which is smaller than the veteran said. The diameter measured on the map is about 100 m, which is very smooth. This is what fishermen call the "Dragon Cave". Xisha has always been a military restricted area, so we can't visit it on the spot. We can only browse the wonders of the "Dragon Cave" from space. If one day, Xisha is open to Chinese people, it will be a "holy land" for diving exploration. What is the structure of Longdong? How deep is it? Are there any sea monsters? These secrets are bound to be uncovered.

Question 5: What is a blue hole? The blue hole in the ocean is a huge "deep hole" where the seabed suddenly sinks. Its name comes from comparing the surrounding waters from the sea surface.

This "deep hole" on the seabed is dark and has a mysterious dark blue tone. The blue hole is hundreds of feet deep. When the diver dived into the blue hole to investigate, he found that there was a serious lack of oxygen, which may be due to the lack of water circulation to support marine life. However, the ocean blue hole has great scientific research value. Scientists found many ancient fossil remains at the bottom of the blue hole in the ocean.

Question 6: What does the "blue hole" of the science and education channel mean? All I know is that it has something to do with water! Adoption is only for certain people, that is, Dahab Blue Hole.

The Blue Cave in Belize is located in the lighthouse reef on the edge of the submarine plateau in Grand Bahama Shoal. The perfect circular hole is surrounded by two coral reefs. This is a famous diving resort.

On some quiet near-ocean surfaces, a dark blue round water suddenly appears, which looks like the pupil of the sea from high altitude and is deep, mysterious and strange from an inexplicable depth. This phenomenon is called blue hole. There are many blue holes of different sizes and shapes in the oceans around the world, the most famous of which is the blue hole located 60 miles east of Belize City, the capital of Belize in Central America.

The shape of the blue hole in Belize City is almost perfect, with a diameter of over 1000 feet (305 meters) and a depth of 400 feet (123 meters). Latitude and longitude: 17.438+05438+0,-87.50089.09886 During the Ice Age, this cave was once the entrance to a dry cave system. After the glaciers melted and the sea level rose, the caves were flooded and became a sacred place for many brave divers. Today, the Blue Cave is famous for its sponges, barracuda, corals, angelfish and a group of sharks that often patrol the cave.

Question 7: Which country is the largest blue hole in the ocean in the world? On July 24th, after on-site investigation by experts, Sansha officially named the ocean blue cave in Yongle Atoll of Xisha Islands as "Sansha Yongle Blue Cave" on the afternoon of 24th, and was confirmed as the deepest known ocean blue cave in the world, with a depth of 300.89 meters.

Question 8: How deep is the blue hole in China? On July 24th, 20 16, after on-the-spot investigation by experts, Sansha officially named the ocean blue cave in Yongle Atoll of Xisha Islands as "Sansha Yongle Blue Cave" on the afternoon of 24th, and was confirmed as the deepest ocean blue cave in the world, with a depth of 300.89 meters.

Question 9: What caused the blue hole in the ocean? Ocean blue holes are huge "deep holes" that suddenly sink on the seabed. Their name comes from their dark blue hue relative to the surrounding waters. It is reported that this blue hole is hundreds of meters deep. When divers dive into the blue hole of the ocean to investigate, they find that there is a serious lack of oxygen, which may be caused by the lack of water circulation, so it is difficult to support the existence of marine life. However, the ocean blue hole has great scientific research value. At present, scientists have found many ancient fossil remains in the depths of the blue hole in the ocean.