The Great Blue Hole, Belize

One of it kind, the Geat Blue Hole is a large underwater sinkhole off the coast of Belize. In this sea it appears as a pupil above the turquoise water. the hole is circular in shape measuring around 984 ft across and 410 ft deep. It is a result of the natural activity during the glacial period when the sea levels were very low. As the acean began to rise againdue to melting of ice, the roof flodded and collapsed consequently filling it with the sea water.

This is a popular site for scuba divers and ocean researchers who are attracted by no of species of fishes and various types of reef sharks like Caribbean Reef Shark and the Black Tip Shark.

Investigations by this expedition confirmed the hole's origin as typical karst. Stalactites were retrieved from submerged caves, confirming their previous formation above sea level. Some of these stalactites were also off-vertical by 10°-13° in a consistent orientation, thus indicating that there had also been some past geological shift and tilting of the underlying plateau, followed by a long period in the current plane.