One of the mysterious features of the world’s waters are ‘blue holes’ – huge underwater sink holes that can span the length of skyscrapers.
Believed to have formed during the last ice age, the blue holes are seen as ‘ecological hot spots’ with an abundance of plant and animal life.
Now, scientists have revealed that they have found the world’s second largest blue hole, located in Chetumal Bay off the coast of Mexico.
Known as Tam Ja’, which means ‘deep water’ in Mayan, it reaches a total depth of 900.2 feet (274.4 m) – the same length as Williams Tower in Houston.
But it doesn’t measure up to the world’s deepest blue hole off the coast of China, which goes down 987 feet (300.89 meters).
A bird’s eye shot of the entrance to Tam Ja (left) – the world’s second-deepest blue hole – as well as an underwater view of the hole’s mouth (right).
Tam Ja’ is located in Chetumal Bay on the southeast coast of Mexico’s Yucatan Peninsula
A sampling and survey of the blue hole was conducted in September 2021, but only now have researchers revealed its existence in a new study.
The team, based at the research center Colegio de la Frontera Sur (ECOSUR) in Mexico, says, ‘The data collected revealed a maximum recorded depth of 274.4 meters below sea level (mbsl).
The ‘Tam Ja’ Blue Hole (TJBH) is the second deepest known blue hole in the world.
‘The origin and geological evolution of the TJBH deserves further investigation.’
According to the National Oceanic and Atmospheric Administration, blue holes are similar to sink holes on land, except they are filled with water, so ocean-going ships can pass over them.
They are diverse biological communities filled with marine life, including corals, sponges, molluscs, sea turtles, sharks and more.
However, little is known about them due to their lack of accessibility and ‘unknown distribution and abundance’.
The Blue Hole is popular with daredevil deep sea divers, although attempts to traverse its depths have proven fatal.
According to the Mexican team of researchers, knowledge provided by local fishermen encouraged them to investigate this particular location.
Photos of the Tam Ja’ Blue Hole located in Chetumal Bay on the southeast coast of Mexico’s Yucatan Peninsula
Tam Ja’ reaches a total depth of 900.2 feet (274.4 m) – about the same length as the Williams Tower in Houston, Texas.
This was despite the fact that there is no reference to the Blue Hole at Chetumal Bay in the current scientific literature.
The team used echo-sounding – the use of reflected sound pulses – to determine how far down it reached, as well as scuba diving to probe the depths above it.
Tam Ja has an ‘almost circular shape’ on its surface with sides sloping more than 80 degrees, forming a ‘massive conical structure’, the researchers say.
The walls of the Blue Hole are covered with a fine-grained layer and coated by brown algal biofilms—slippery communities of algae that bond together to survive.
Researchers point out that Tam Ja’ is close to the coasts of Mexico and Belize and its discovery could increase local and foreign visitors.
‘Currently, the local population is not aware of the existence of TJBH,’ they conclude in their paper, Published in Journal Frontiers in Marine Science.
‘[We] Encourage the scientific community to explore, monitor and expand TJBH’s research to adequately settle for responsible social appropriation in the near future.’
The world’s deepest blue hole, discovered in 2016, is located in the South China Sea and is named Dragon Hole or Longdong.
At 987 feet or 300.89 meters, Longdong is only 30 feet shorter than The Shard skyscraper in London.
Prior to its discovery, the world’s deepest blue hole was believed to be Dean’s Blue Hole in the Bahamas, which is 663 feet (202 m) deep.
Meanwhile, the Great Blue Hole off the coast of Belize in Central America – described by French explorer Jacques Cousteau as one of the world’s top scuba diving sites – is 407 feet (120 m) deep.
Pictured, the Great Blue Hole in Belize, Central America, is described as one of the top scuba diving sites in the world.
Unfortunately, the Blue Hole has historically been used to dump waste in the Bahamas, causing contamination.
A team of researchers, including Virgin billionaire Sir Richard Branson, led an expedition down the Great Blue Hole in 2018.
Branson himself saw plastic bottles at the bottom of the hole, as well as a shell ‘graveyard’ made by thousands of shellfish falling into the chasm.
Gaping Maw is also filled with hydrogen sulfide—a foul-smelling, colorless gas that is toxic, flammable, and highly corrosive—and its deepest depths are completely devoid of oxygen.
Jacques Cousteau and the Great Blue Hole
The Great Blue Hole was made famous by French ocean explorer Jacques Cousteau, who named it one of the top five scuba diving sites in the world.
He brought his famous research vessel, Calypso, to probe the sinkhole’s depth in 1972.
The expedition found some submerged stalactites in the hole, and was able to conclude that the Blue Hole formed before sea levels rose.
The Great Blue Hole was made famous by French ocean explorer Jacques Cousteau (left), who named it one of the top five scuba diving sites in the world. He brought his famous research vessel, Calypso, to probe the sinkhole’s depth in 1972.
Investigations by this expedition confirmed the origin of the hole as a typical karst limestone formation, which formed before sea level rose in at least four stages, 21 m (69 ft), 49 m (161 ft), and 91 m. (299) leaves the edge at a depth of feet).
Stalactites were recovered from submerged caves, confirming their former formation above sea level.
Some of these stalactites were also consistently off-vertical in orientation by 5˚, indicating that some geological shift and tilting of the underlying plateau had occurred in the past, followed by a long period in the present plane.
The tilt suggests that this was land movement rather than just sea level rise.
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