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HYDROTHERMAL VENTS. According to some scientists, life on Earth was said to have originated in the deep oceans. The Discovery - 1977.
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HYDROTHERMAL VENTS
According to some scientists, life on Earth was said to have originated in the deep oceans
The Discovery - 1977 • An expedition from Woods Hole Oceanographic Institution using ALVIN, discovered communities of animals living around deep hydrothermal vents off the Galapagos Islands • Named – The Rose Gardens • Depths of 8000 – 8500 feet
What We Know Today • Hydrothermal vent activity is known to occur at seafloor-spreading centers worldwide. • These communities are found between 9° and 21°N latitude along the East Pacific Rise, N. Fiji Basin, Mid-Atlantic Ridge, and Gorda and Juan de Fuca Ridges in the NE. Pacific
Environmental Conditions of the Deep Sea Vents • High water temperatures (68 -752°F) • High Pressure • High Concentrations of Sulfides • Lack of Oxygen • Acidic pH Levels • Absence of light • Located 100-1000 meters below surface
What are Hydrothermal Vents? • Geysers of heated water from beneath the ocean surface • Generally found at the mid-ocean ridges or spreading plates • Seawater seeps down through cracks in the ridges to depths of 1.25 to 2mi • About halfway through the thickness of the oceanic crust
More on Vents... • The water is super-heated to 400-450°C (750-840°F) • This superheated water then re-ascends to the center of the mid ocean ridge and emerges as a fast jet about 350°C. • As it mixes with cold ocean water (34-36°C), hydrogen sulfide precipitates instantly often coloring the jet black.
Types of Vent Structures • Black Smokers • White Smokers • Warm Water Vents
Black Smokers • Hottest of all vents (+350°C) • Emits high concentration of sulfide • Hydrogen Sulfide is usually toxic to life, but the specialized communities around the black smokers could not survive without it • Forms the largest chimneys
White Smokers • Cooler temperature of water released (300°c vs. 350°C) • Lower sulfide concentration • Barium, calcium and silicone released forming white precipitate
Warm Water Vents • Low ion content as compared with black and white smokers • Cool water temperatures (20-40°C) • Above Ground – Yellowstone Old Faithful
Biological Communities • “An oasis in the deep” containing an astonishing assemblage of benthic organisms • More than 400 different species identified in vent communities
Suspension Feeders Deep Sea Anemone
Chemosynthetic bioluminescent bacteria
Key Players in a Hydrothermal Vent Community
Fastest Growing Marine Invertebrate BIG Tube Worms