Almost a year ago, a team of divers explored the blue hole located off the Australian coastline. Although many photos have been taken of this natural phenomenon, a researcher has recently taken the first video capturing the interior of the hole for the first time!
The video was created by the Australian marine biologist Johnny Gaskell. He participated in the Australian Geographic Nature Photographer of the Year 2018 competition and won an award in the “endangered species” category with his shot of the Chelonia mydas turtle. (See below)
The researcher launched his expedition at the end of 2017. The aim was to explore the blue hole 30 metres deep and located off the Australian Great Barrier Reef, 200 km from Daydream island (North-eastern coast of Australia). It takes at least 12 hours to arrive at the hole by boat! Not long ago a edited video was published by the National Geographic.
Johnny Gaskell describes this type of blue whole as a “time capsule.” Sediments accumulate there over thousands of years, which attracts an abundance of marine life (turtles, fish etc). Gaskell explains that inside the hole there is practically no current. As a result of there being no current and the absence of waves, the coral reef can develop in very peculiar shapes.
Blue holes, with their striking deep blue depths in comparison to the shallower turquoise waters, were formed during the last glaciation period. This is when ocean levels were 100 metres lower than they are today. The phenomenon originates with chemical alterations of limestone as a result of acidic rainwater from vegetation. The rainwater filtered into the ground, creating large underground cavities. The ceilings of these caves then collapsed before the sea covered them up.
Here is the superb shot taken by Johnny Gaskell that won him a prize at the Australian Geographic Nature Photographer of the Year 2018 :