DORSEYLAND (NOT DISNEYLAND)

November 26, 2006, Google Earth

Underwater Wonders of the World

Take a deep breath, we’re going under. Here are the Seven Underwater Wonders of the World.

W ~ O ~ W

The Belize Barrier Reef in Central America is the longest barrier reef in the Western Hemisphere and the second longest in the world after Australia’s Great Barrier Reef.

Deep-sea Vents, or “black smokers”, pictured at the top of the post, are a type of hydrothermal vent found on the ocean floor. Generally hundreds of metres wide, they’re formed when superheated water from below the Earth’s crust comes through the ocean floor.

They are rich in dissolved minerals from the crust, most notably sulfides, which crystallise to create a chimney-like structure around the vent. When the superheated water in the vent comes in contact with the frigid ocean water, many minerals are precipitated, creating the distinctive black colour.

Black smokers were first discovered in 1977 around the Galapagos Islands by the National Oceanic and Atmospheric Administration’s submersible vehicle Alvin. Today they’re known to exist in the Atlantic and Pacific, at an average depth of 2,100 metres.

The temperature of the water they vent can reach 400 degrees C, but does not boil due to the high pressure at that depth. The water is also extremely acidic, often having a pH value close to that of vinegar.

The Galápagos Islands are an archipelago of some 13 volcanic islands and associated islets and rocks in the Pacific Ocean off Ecuador.

The oldest of the islands are about four million years old and the youngest are still in the process of being formed.

They are famed for their vast number of endemic species and the studies conducted by Charles Darwin that led to his theory of natural selection. The equator crosses the northern part of the largest island, Isabela.

Also among the Seven Natural Wonders of the World, Australia’s Great Barrier Reef is the planet’s largest coral reef, stretching 2,000 kilometres.

The first European to see it was Captain James Cook, who ran aground on it on June 11, 1770. Due to its vast biodiversity, warm clear waters and its accessibility from the floating guest facilities called “live-aboards”, the reef is popular with scuba divers.

The reef is sometimes referred to as the single largest living animal in the world, but in reality is many colonies of corals.

Lake Baikal is in southern Siberia, Russia, and at 636 kilometres long and 80 wide is the largest freshwater lake in Asia. It’s also the deepest lake in the world at 1,637 metres, and at 25 million to 30 million years of age is one of the world’s most ancient lakes.

US and Russian studies of sediment cores in the 1990s provided a detailed record of climatic variation over the past 250,000 years.

If all the sediment were scoured from the lake, it would be nine kilometres deep.

The Northern Red Sea, part of the gulf, or basin, of the Indian Ocean, to which it connects in the south through the Bab el Mandeb sound and the Gulf of Aden.

In the north are the Sinai Peninsula, the Gulf of Aqaba and the Gulf of Suez.
The sea is 1,900 kilometres long and at its widest 300. The sea floor has a maximum depth of 2,500 metres, but it also has extensive shallow shelves, noted for their marine life and corals.

Palau is a group of about 200 volcanic islands and islets in the Caroline Islands of the western Pacific Ocean.

When the Carolines became part of the Federated States of Micronesia in 1978, Palau chose to form a republic in free association with the United States, which became effective in 1994.