Mysterious Tracks of the Great Blue Hole have a Simple Explanation

The Great Blue Hole in Belize holds a fascinating set of tracks in its depths.

This giant marine sinkhole was formed during numerous occurrences of ‘Quaternary Glaciation’ and is located near the center of Lighthouse Reef, a small atoll which is about 70 kilometers away from the mainland of Belize. The analysis of stalactites revealed that the formation of this massive hole was completed in four different phases. The first one of them occurred at around 153,000 years ago while the last one was finished some 15,000 years ago. That’s the reason why we find ledges at different depths in this hole.

The Great Blue Hole is circular in shape, with an approximate diameter of 318 meters. It earned the status of a World Heritage Site of UNESCO in 1996. Prior to that, Jacques Cousteau declared it one of the top 5 scuba diving destinations in the world (in 1971). This expedition is often given the credit of popularizing the Great Blue Hole as it confirmed the origin of the hole. Some of the stalactites were off-vertical by 5^o which indicated the geological tilting of the underlying plateau in the past. Despite this basic information, humanity doesn’t know much about this beautiful place.

Bottom of the Great Blue Hole

In an attempt to know more about this legend of the deep, a team of researchers dived right to the very bottom of the Great Blue Hole in December 2018. They used a custom-equipped submarine for this journey and found something really amazing in the depth of this hole. However, there was nothing mysterious about the discovery which was quite surprising for most. What explorers found there was a set of tracks at a depth of about 125 meters. Quite a lot of people suggested the existence of deep-sea monsters in this hole but the actual discovery is less mysterious and more heartbreaking.

Researchers mentioned that they did find signs of life in the deep sea but that was not flourishing life. The discovered set of tracks was actually created by struggling living things who tried to survive in the anoxic (without Oxygen) water of the world’s largest sinkhole. Erika Bergman, the Chief Submarine Pilot on the expedition, explained that it is quite common for conches to fall inside the blue hole. These unfortunate creatures are unable to escape the steep walls of the hole which ultimately suffocates them to death. She used the term “Conch Graveyards” to describe the Great Blue Hole and said,

“We can see each conch with little tracks back up the hill trying to escape, then a slide mark where it slid back down after presumably being asphyxiated in the anoxic environment. So much sand billows down the steep rim of the hole at this location that fallen conch must be getting covered up quickly, so the sheer number of visible shells is a pretty good indicator that the conch population is healthy – it’s slightly morbid but describes something positive.”    

Limestone Caves

The Great Blue Hole is a complex system of limestone caves that stood on dry land before it drowned 14,000 years ago. In an attempt to figure out some useful information about this unexplored natural wonder, Bergman was accompanied by Richard Branson and the grandson of Jacques Cousteau, Fabien Cousteau. Branson was shocked to imagine the rate at which seas must have risen to drown such a huge hole. He referred to the vastness of this hole by saying,

“At 300 feet down you could see the change in the rock where it used to be land and turned into sea. It was one of the starkest reminders of the danger of climate change I’ve ever seen.”

He mentioned that they dove right into a dark fog of Hydrogen Sulphide as they continued to go deep into the Great Blue Hole. The transition was so quick that it felt like a light switch has been turned off. The researchers were sure that they won’t find any living creatures beyond that point. Sadly, things turned out differently as they found remains of conches, crabs and other creatures in the hole.

Real Monsters

Branson also talked about Maya mystery and clarified that they found no monsters in the Great Blue Hole. Instead, they found the terrifying consequences of humanity (climate change and plastic) in the depth of the sea. He commented on that in the following words:

“Well, the real monsters facing the ocean are climate change – and plastic. Sadly, we saw plastic bottles at the bottom of the hole, which is a real scourge of the ocean. Hopefully, by this trip taking place, we have raised even more awareness of the need to protect the ocean and tackle climate change now – before it is too late.”