8. Great Blue Hole, Belize.
|
Great Blue Hole |
|
|
The Great Blue Hole is one of the Seven Natural Wonders of North America. The
Great
Blue Hole is a large submarine sinkhole
off the coast of Belize. It lies near the center
of Lighthouse Reef, a small atoll 70 kilometers from the mainland and Belize
City. The hole is circular in shape, over 300 meters across and 124 meters
deep. It was formed during several episodes of quaternary glaciations when sea
levels were much lower. The analysis of stalactites found in Great Blue
Hole shows that formation took place 153,000, 66,000, 60,000, and 15,000 years
ago.
Blue holes are roughly circular, steep-walled depressions, and so named
for the dramatic contrast between the dark blue, deep waters of their
depths and the lighter blue of the shallows around them. Their water
circulation is poor, and they are commonly anoxic below a certain depth; this environment is unfavorable for most sea life, but nonetheless can support large numbers of bacteria.
The deep blue color is caused by the high transparency of water and bright white carbonate sand.
Blue light is the most enduring part of the spectrum; where other parts
of the spectrum are red, yellow, and finally green are absorbed during
their path through water, blue light manages to reach the white sand and
return back upon reflection.
A blue hole is
a cave (inland) or underwater sinkhole.
They are also called vertical caves. The Great Blue Hole and surrounding reef are commonly home to the
Caribbean Reef Shark, the Blacktip Shark, nurse sharks, giant groupers,
and abundant other aquatic life. Although not routinely seen, the
sinkhole and surrounding reef have also been home to the bull shark and
the hammerhead shark.
|
Skydiving at the Great Blue Hole |
|
Great Blue Hole |
This is a popular spot amongst recreational scuba divers, who are lured
by the opportunity to dive in crystal-clear water and meet several
species of fish, including giant groupers, nurse shark and several types of reef sharks such as the Caribbean reef shark and the Blacktip shark. Other species of sharks, like the bull shark and hammer,
have been reported there, but are not regular sightings.
|
Snorkeling at the Great Blue Hole |
Usually, there are some activities that the tourist can joint which include one dive
in the Blue Hole and two further dives in nearby reefs. Recently diving
has also been offered from the island Long Caye in the Lighthouse Reef
only a couple of miles away from the Great Blue Hole.