Page 142 - Super Earth Encyclopedia

MARINE
UNDERWATER WORLD’S LARGEST

WONDER SINKHOLE

GREAT BLUE HOLE

At the heart of Lighthouse Reef in the Caribbean
lies a deep, dark, perfectly circular hole in the seabed.
It was formed during the last ice age when the sea
level was much lower and the surrounding limestone
was dry land. Rainwater seeping into the rock created
a limestone cave, and at some point, the roof collapsed
to form a circular sinkhole. When the sea level rose
at the end of the ice age, seawater flooded in to
create the Great Blue Hole.

AT A GLANCE
• LOCATION Western Caribbean,

60 miles (80 km) east of central Belize
• FORMATION Flooded limestone
sinkhole
• AGE Formed more than 15,000

years ago
• STATUS Part of the Belize Barrier Reef
Reserve System, a World Heritage Site

1,000 STATS AND FACTS

FEET SINKHOLE CAVE EXPLORATION
(300 M) The cave contains The sinkhole was
stalactites and first explored in
stalagmites— 1972 by French
WIDTH typical limestone marine researcher
cave features. Jacques Cousteau.
The Great Blue Hole TEMPERATURE temperature is about
WATER WORLD scuba-diving sites. °C 10 20 75 30 100 40
The warmest water
is one of the world’s
most renowned
85°F (29°C).
DEPTH
50
°F
410

FEET
(125 M)
140

US_140_141_Great_Blue_Hole.indd 140 01/03/17 12:26 pm