From land to sea, countless landscapes are strange
People can't help but be fascinated, awe- and love
Nature has shown mankind its magic
Today I will talk about one of its masterpieces
Known as the Eye of the Ocean, the Blue Cave
The Blue Cave can be divided into two kinds: the Blue Cave on Land and the Blue Cave in the Ocean, which is a rare geological formation with steep walls and straight walls, open to the sky, and appears dark blue due to the influence of depth and refraction.
The Ocean Blue Cave is a unique unit of ocean landforms that is a nearly circular underwater deep hole in a shallow reef disk.
Due to the large water depth, the water body appears dark blue, and it looks like a big blue eye from the sky, mysterious and beautiful. It has been praised by scientists as "the last legacy of the earth to keep the secrets of the universe for mankind".
Most of the blue holes are concentrated in the islands, peninsulas and their nearby seas, and the famous blue holes are the Great Blue Cave in Belize, Honduras, the Blue Cave in Dahab, Egypt, and the Blue Cave in Capri, Italy.
Blue Hole, Belize
China's "Yongle Dragon Cave" in Sansha, South China Sea, is the deepest known ocean blue cave in the world, with a depth of 300.89 meters.
Located in the reef plate of Jinqing Island and Shiyu Island in Yongle Atoll, Xisha Islands, Sansha City, China, the "Sansha Yongle Blue Hole" (Sansha Yongle BlueHole), the address coordinates are 16 °31 ′30 "N, 111 ° 46 ′ 05"E, and the depth is 300.89 meters.
Yongle Dragon Cave has been confirmed to be the deepest known ocean blue cave in the world, and it can be flooded even if the Eiffel Tower is thrown into it.
From August 2015 to June 2016, the Xisha Trail Research Institute used sonar side sweeping equipment, electronic counting plumb, deep-sea current meter, deep-sea water quality analyzer, underwater robot, underwater photography and video equipment and other equipment and equipment;
Using the method of combining scientific equipment detection and artificial diving observation and measurement, the depth and basic form of the blue cave were successfully explored.
After exploration, the Blue Cave of Xisha Yongle is basically a vertical cave, the diameter of the blue cave is 130 meters, the diameter of the bottom of the cave is about 36 meters, and the connection between the blue cave and the outer sea has not been observed, and there is no obvious flow of water in the cave.
Through visual inspection, more than 20 species of fish and other marine life similar to the surrounding sea were found in the upper layer of the cave.
There are two more common causes of blue caves, one is the cause of limestone caves, and the other is the cause of coral reef growth structure.
Similar to karst landforms, in carbonate areas, groundwater temperature and pressure are higher than surface water, contain CO2 and organic acids, and have great solubility and strong dissolution effect on carbonate minerals, forming karst landforms.
Later, the sea level rose, flooding these caves, forming blue caves. This type of blue cave still preserves the remains of stalagmites, stone stalactites, and the wreckage of the collapsed roof of the cave.
Most of the current marine blue holes, such as the Blue Hole in Belize and the Blue Hole in Saipan, belong to this type of cause.
The reef growth structure is represented by the Hauteman-Abroshols Reef Blue Cave on australia's southwestern outer shelf.
Since the Holocene, 10,000 years ago, corals have grown rapidly around the island, and a little bit of coral skeleton has accumulated to form a carbonate wall around the island, and later the middle island has been weathered and eroded, and a deep blue cave has been formed in the middle of the coral reef.
The blue caves that have gone through vicissitudes and tens of thousands of years of tempering have high scientific research value for human beings, and some blue holes have almost anaerobic bottoms, perfectly collecting biological bones and fossils;
Some are almost enclosed, isolated from the rest of the world, and are home to strange creatures.