Hydrothermal Vent - Black Smokers and White Smokers

Black Smokers and White Smokers

Some hydrothermal vents form roughly cylindrical chimney structures. These form from minerals that are dissolved in the vent fluid. When the super-heated water contacts the near-freezing sea water, the minerals precipitate out to form particles which add to the height of the stacks. Some of these chimney structures can reach heights of 60 m. An example of such a towering vent was "Godzilla", a structure in the Pacific Ocean near Oregon that rose to 40 m before it fell over.

A black smoker or sea vent is a type of hydrothermal vent found on the seabed, typically in the abyssal and hadal zones. They appear as black chimney-like structures that emit a cloud of black material. The black smokers typically emit particles with high levels of sulfur-bearing minerals, or sulfides. Black smokers are formed in fields hundreds of meters wide when superheated water from below Earth's crust comes through the ocean floor. This water is rich in dissolved minerals from the crust, most notably sulfides. When it comes in contact with cold ocean water, many minerals precipitate, forming a black chimney-like structure around each vent. The metal sulfides that are deposited can become massive sulfide ore deposits in time.

Black smokers were first discovered in 1977 on the East Pacific Rise by scientists from Scripps Institution of Oceanography. They were observed using a deep submergence vehicle called ALVIN belonging to the Woods Hole Oceanographic Institution. Now black smokers are known to exist in the Atlantic and Pacific Oceans, at an average depth of 2100 metres. The most northerly black smokers are a cluster of five named Loki's Castle, discovered in 2008 by scientists from the University of Bergen at 73 degrees north, on the Mid-Atlantic Ridge between Greenland and Norway. These black smokers are of interest as they are in a more stable area of the Earth's crust, where tectonic forces are less and consequently fields of hydrothermal vents are less common. The world's deepest black smokers are located in the Cayman Trough, 5,000 m (3.1 miles) below the ocean's surface.

White smokers are vents that emit lighter-hued minerals, such as those containing barium, calcium, and silicon. These vents also tend to have lower temperature plumes. These alkaline hydrothermal vents also continuously generate acetyl thioesters, providing both the starting point for more complex organic molecules and the energy needed to produce them, Microscopic structures in such alkaline vents "show interconnected compartments that provide an ideal hatchery for the origin of life".

In addition, hydrothermal vents are not the only source allowing life to develop completely independent of the sun. Deep sea vessels made an even more extraordinary find in 1990. On the barren seabed of the Gulf of Mexico, an underwater lake composed of a much denser salt solution was discovered, with what appeared to be a sandy beach. However, this beach was composed of hundreds of thousands of mussels; once again, an ecosystem based on energy other than that of the sun. See Cold Seep.