World’s deepest underwater sinkhole discovered in South China Sea

Researchers in China have declared a blue hole off the Paracel Islands in the South China Sea to be the world’s deepest.

Sansha Ship Course Research Institute for Coral Protection researchers used an underwater robot and depth transducer to determine the depth of the underwater sinkhole hole, named “Dragon Hole.” Its depth? About 300 metres.

READ MORE: Massive sinkhole forms in Oregon town

Traditionally known as Longdong, locals call the phenomenon the “eye” of the South China Sea.

In areas beyond the reach of the divers, the robot was able to measure the temperature, salinity and dissolved oxygen level of the water.

Though the robot found more than 20 fish species and other marine organisms present in the first 100 metres, no oxygen was detected further than that, meaning life below is unlikely.

The 202-meter-deep Dean’s Blue Hole on Long Island in the Bahamas was considered the world’s deepest known blue hole prior to the new findings.

Visualization by Graphiq

A blue hole is a circular sinkhole, with the name reflecting the colour contrast between the dark blue inside the hole compared with the light blue water surrounding it.

The Paracel Islands are claimed all or in part by China, Vietnam and several other Asian countries.

Visualization by Graphiq


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