The Shadow
Blue holes have been discovered around the world, some fresh water and some salt water, holding more questions for divers than answers.
Since tides and currents that keep the bodies of water in motion are controlled by factors such as the moon’s gravitational pull on the Earth, the oceans are often unpredictable in that unexplained gigantic rogue waves and deadly whirlpools can form without warnings.
Because the gravitational pull is stronger on one side of Earth nearest the moon than it is on the far side of Earth from the moon, an unequal pull impacts oceans by affecting their tides.
As for blue holes, water-filled sink holes that usually lead to underground cave systems that may be filled with fresh water or salt water have been explored by many divers who have found human remains, artifacts and much debris that create more questions than answers.
With underwater sand constantly pouring into a blue hole in the Atlantic Ocean, divers who have only limited time to explore due to the danger of diving at extreme depths question what has been covered up by the sand that has been filling up the blue hole for decades.
One diver discovered a mangled sailboat at the bottom of one saltwater sinkhole.
The Great Blue Hole near Belize is nearly 1,000 feet wide and several hundred feet deep. It has been a favorite diving area for years, but it took a submarine to reach its bottom in 2019.
At the depth of 290 feet, it was discovered that toxic hydrogen sulfide gas formed as a byproduct of bacteria and rotting plant debris is trapped in the area called a halocline. The depth is over 400 feet in places, but no marine life was found in the halocline part of The Great Blue Hole while the area above the 290 depth was teaming with marine life.
The submarine’s crew credited with exploring the bottom of the Great Blue Hole found the remains of two of three missing divers.
Dean’s Blue Hole in the Bahamas is 663 feet deep, the second deepest blue hole that has been discovered, second only to the Dragon Hole, 987.2 feet deep, discovered in the South China Sea.
Also, the Dragon Hole is known as the Yongle Blue Hole, and it is named for the emperor of the third Minge dynasty.
One of the strangest and unexplained phenomena that scientists have discovered concerning holes in the ocean floor are not blue holes, however.
Rather the symmetrical holes 1.7 miles beneath the surface appear to be manmade and are spaced the same distance apart, each extending one mile in depth beneath the Atlantic Ocean’s seabed.
Whether it be strange, unexplained holes in the seabed or sinkholes on land or in the ocean, more questions for scientists to find answers remain: What causes such holes? What lies at the bottom of the holes? What has been covered at the bottom of the holes, waiting to be discovered? Do the ocean’s blue holes create whirlpools at times that destroy ships in the waters of the Bermuda Triangle?
Just as sinkholes, especially in Florida, suddenly form and swallow entire structures, sinkholes have been forming in other parts of the world for years.
The causes of sinkholes have been attributed to underground mining or limestone that dissolves, forming an underground cave that weakens the ground above it till it gives way.
On Feb. 12, 2014 in Bowling Green, Ky., the National Corvette Museum fell victim to a sinkhole that took eight classic Corvettes some 20’ deep. The sinkhole was 30’ to 40’ in width, and it has taken nearly a decade to remove the Corvettes and restore them.
The cause of the museum’s floor giving way was that limestone had been worn away by groundwater beneath the building, weakening the earth till the weight of the building caused the floor to collapse.
In May, the largest sinkhole in the world was discovered in China, the Xiaoxhai Tiankeng Sinkhole that is 660 feet deep. A team of spelunkers made the discovery, and to the world’s surprise, the explorers found a primitive forest growing at the bottom.
