earthspn.gif (56266 bytes) What are

Hydrothermal Vents?                                   

 


Many scientists think that life on Earth started in one of two places -- on the sea surface exposed to lightning and sunlight, or at the bottom of the ocean in hydrothermal vents.

In the late 1970's, scientists on a routine study of the ocean floor in the Pacific made a discovery. On the East Pacific Rise not far from the Galapagos Islands, nearly 8000 feet below the surface, was a strange alien landscape littered with what looked like chimneys expelling clouds of black smoke. Surrounding these chimneys was a unique type of ecosystem that had never been seen before. Until this day, science had always assumed that all life on Earth obtained its energy from the sun. The plants convert sunlight into energy through a process called photosynthesis. The plants, in turn, provide food for countless species of animals in a complex web of life. But here was proof for the first time that life could be sustained by the earth itself.

 

Science had discovered deep-sea hydrothermal vents. These vents occur in geologically active regions of the ocean floor. Within these regions, seawater seeps down deep into the earth's crust through cracks and fissures in the ocean floor. The intense heat of magma below the surface then heats this water. As the water is heated to a boil, it expands and rises back to the surface. On it’s way back up through the cracks through which it fell, the hot water dissolves minerals and other chemicals from the rock. When it reaches the ocean floor, the water is a dark, chemical soup. Some of the minerals precipitate out of the seawater and harden on the rim of the vent. Over time, the rim of the vent is built up into a tall, chimney-like structure. The dark color of the water spewing forth from these vents has earned them the name, "black smokers". The temperature of the water coming out of these vents exceeds 360º. The real surprise was the discovery that a myriad of life forms actually live and thrive around these vents, totally cut off from the world of sunlight.