Black Smokers
Introduction
Black smokers (hydrothermal vents) were discovered by scientists aboard the
Alvin in 1977. They were looking for vents in the ocean floor where hot lava
flowed out and mixed with seawater on the ocean floors where tectonic plates
were separating. Scientists aboard the Alvin were stunned to find an entire
ecosystem living off bacteria around hydrothermal vents.
Discovering the Rose Garden
The oceanographers in the
submersible found huge tube worms, giant clams and other animals living around
chimney-like structures with black smoke-like material flowing out of the top
of the structures. They named the area around the vents the Rose Garden and the
vents were nicknamed black smokers.
Black smokers surrounded by ecosystem
not dependent on the sun, NOAA
Hydrothermal vents
Scientists had speculated that hydrothermal vents might lie along the spreading
ridges where tectonic plates were separating. This speculation began after
Harry Hess proposed a theory that new seafloors were being created at mid-ocean
ridges and were being destroyed in subduction zones. Magnetism in the rocks
that are located on either side of the spreading ridge proved the hypothesis.
Sulfur-bearing minerals
around the vents
These vents are created by hot water seeping down into cracks on the ocean
floor where plates are separating. The ocean water is superheated up to 350°C
(662°F) by the hot lava. The superheated water dissolves minerals in the basalt
on a mid-ocean ridge volcano creating high concentrations of sulfur-bearing
minerals called sulfides.
How the vents are formed
The superheated water is immediately cooled when it reaches the cold ocean
waters. The minerals crystallize in the cold water and fall around the vent
forming chimneys made of the crystallized minerals, hence their name black
smokers.
Life without sunlight
Scientists had long believed that nothing could live at the great pressures
found on the ocean floors and that all life on our planet required sunlight to
thrive. Both of these theories were proved incorrect in 1977 when the first
hydrothermal vents were discovered.
Bacteria are the basis of
the food chain
Giant tube worms, long necked barnacles, giant clams all lived in communities
around the smokers. Since their discovery it has been found that a unique type
of bacteria is able to metabolize large amounts sulfur that is found in the
superheated water that flows out of the vents. The bacteria are the basis of
the food chain because no sunlight reaches these areas that are often over a
mile deep.
Newly discovered black
smokers
Since the discovery of the vents scientists have found many more of these
hydrothermal fields that range in size from 4 square meters (43 square feet) to
the size of a tennis court. The fields are typically about 10 meters in
diameter. Today scientists are studying three areas around the globe looking
for hydrothermal fields.
Juan de Fuca Ridge,
Galapagos Rift, and East Pacific Rise
Three areas being studied by scientists today are the ridge on the Juan de Fuca
Plate that lies off the Oregon and Washington coast, Galapagos Rift along the
eastern Pacific Ocean basin, and the Southern East Pacific Rise in the Southern
Pacific Ocean. Only a small portion of the ocean floor has been studied and it
is expected that many more black smokers will be found in future years.
Rich deposits of minerals
Many of the richest deposits of minerals found on are planet were created
around hydrothermal vents. Copper ores mined on the island of Cyprus in the
Mediterranean Sea were once the site of hydrothermal vents before they were
uplifted to form the island of Cyprus. Today research is being conducted to see
if active vents can also be mined for their rich mineral deposits. At the
present time the fields are too small and too far below sea level to make
mining the minerals profitable.
More information about the oceans
The Oceans on our planet cover approximately 70% of the Earth. The water that covers our planet is essential to life on our planet. From space the Earth looks like a blue ball partly covered with white wispy clouds.
The Great Barrier Reef off the coast of Australia are one of the seven great wonders of the natural world. Find out more about this World Heritage Site.
The Mid Atlantic Ridge is a divergent plate boundary where continental plates are moving apart down the middle of the Atlantic Ocean.
Viperfish are one of the fiercest predators living in the deep ocean. Find out how they attract their prey with a “fishing lure” and impale their prey with fang-like teeth.
Oceanic Zones are specific areas of the ocean. Most ocean life lives in one specific zone. Marine biologists have discovered some animals, whales, can dive to great depths to hunt for food.
The 2004 Indian Ocean Tsunami lifted the seabed and moved it sideways along a 1,600 km (1000 mile) crack in the Earth’s surface. The Indian Plate slipped beneath the Burma Plate during the earthquake.
Rift Valleys are not caused by erosion but are created by tectonic activity. These valleys form when oceanic plates are moving in different directions forming a divergent boundary.
Marine Sponges are sessile animals that look like plants. Some sponges have been found living on the ocean floors that are over 8,800 meters (5.5 miles) deep.
Caribbean Spiny Lobsters are found in tropical and sub-tropical waters. They are also known as Florida spiny lobsters and are famous for their migration each year into deeper waters.
Rogue Waves for centuries were believed to be tall tales sailors told during shore leave. They said waves rose out of the sea as a vertical wall of water that crashed into a ship without warning.
Ghost Crabs live on beaches in tropical and sub-tropical regions. They are found along beaches from Rhode Island south to Brazil. They only need to wet their gills to live on land.
Black Smokers (hydrothermal vents) were discovered by scientists aboard the Alvin in 1977. An entire ecosystem lives around the chimneys with bacteria the base of the food chain.
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