HYDROTHERMAL VENTS
IMPORTANT FACTS HYDROTHERMAL VENTS OCCUR WHERE HIGH TEMPERATURE WATER IS COMING INTO THE OCEANS. First discovered in 1977 by Bob Ballard.
HOW THEY WORK * COLD OVERLYING SEAWATER PENETRATES DOWN THROUGH CRACKS * ENCOUNTERS HOT MAGMA AND BECOMES HEATED * RISES THROUGH CHIMNEY-LIKE STRUCTURES.
BECAUSE OF CHEMICALS DISSOLVED IN THE HOT WATER, THE AREAS HAVE LOTS OF MARINE LIFE ASSOCIATED WITH THE VENTS. This astonishing assemblage of benthic (bottom-dwelling) organisms is like an oasis in the deep sea.
WHERE ARE THEY FOUND? FOUND ANYWHERE THERE IS HOT MAGMA, BUT MOSTLY AROUND MID-OCEAN RIDGES AND SEAMOUNTS (LIKE THE NEW HAWAIIAN SEAMOUNT NAMED LOIHI). (LOW-EE-HEE) First one found by Alvin near the Galapagos Spreading Center in the Pacific Ocean. Most 1000 s of meters below surface.
HYDROTHERMAL FLUIDS Hydrothermal fluids are usually very hot (around 380 C or 716 F yet the water doesn t boil because of the pressure) The hot water chemically reacts with the hot rock (calcium sulfate & magnesium are removed from the water and Fe, Cu, Zn, and Mn are added).
BLACK SMOKERS VS. WHITE SMOKERS * Sulfides, Cu, Zn, and Fe make up most of the black smoke of a black smoker. * White smokers, on the other hand, are cooler and have more calcium, barium, and silicon.
1.Cold seawater (2 C) seeps down through cracks into the ocean floor. 1. Cold seawater (2 C) seeps down through cracks into the ocean floor.
2. The seawater seeps in the ocean crust. Energy radiating up from molten rock deep beneath the ocean floor raises the water's temperature to around 350-400 C. As the water heats up, it reacts with the rocks in the ocean crust. These chemical reactions change the water in the following way: -All oxygen is removed. -It becomes acidic. -It picks up dissolved metals, including iron, copper and zinc. -It picks up hydrogen sulfide.
3. Hot liquids are less dense and therefore more buoyant than cold liquids. So the hot hydrothermal fluids rise up through the ocean crust just as a hot-air balloon rises into the air. The fluids carry the dissolved metals and hydrogen sulfide with them.
4. The hydrothermal fluids exit the chimney and mix with the cold seawater. The metals carried in the fluids combine with sulfur to form black minerals called metal sulfides, and give the hydrothermal fluid the appearance of smoke. Many factors trigger this reaction. -cold temperature -presence of oxygen in the seawater (minerals need it to form).
Hydrogen sulfide exits the vent and is used as an energy source. Instead of photosynthesis, organisms use chemosynthesis. BACTERIA OXIDIZE THE HYDROGEN SULFIDE, AND ARE OFTEN EATEN BY OTHER ORGANISMS FOR ENERGY. THIS TYPE OF SYMBIOSIS (LIVING TOGETHER) IS THE BASE OF THE VENT AREA FOOD CHAIN.
OVER 400 SPECIES ARE FOUND AT THE VENTS Tube worms Vent shrimp Limpets Mussels Serpulid worms
Vent Bacteria Vent Zooplankton Vent Shrimp Riftia Worm - Tubeworm Vent Amphipod Symbiotic Bacteria gills of clams Vent Clam Vent Mussel Dandelion Siphonophore Pompeii Worm Vent Octopus Galatheid Crab Zoarcid Fish Tube Dwellling Anemone Vent Ratfish Blind Crab
GODZILLA Geologists are intrigued by how rapidly vent chimneys grow up to 9 meters (30 ft) in 18 months. A SCIENTIST AT THE UNIVERSITY OF WASHINGTON HAS BEEN MONITORING THE GROWTH OF GODZILLA, A VENT CHIMNEY IN THE PACIFIC OCEAN OFF THE COAST OF OREGON. IT REACHED THE HEIGHT OF A 15- STORY BUILDING BEFORE IT TOPPLED. IT IS NOW ACTIVELY REBUILDING.
WHY??? There are many other reasons why scientists want to learn more about hydrothermal vents. These underwater geysers are believed to play an important role in the ocean s temperature, chemistry, and circulation patterns. Scientists also are fascinated by the unusual life that inhabits vent sites. THE CREATURES WHO LIVE IN DARKNESS, FROM BACTERIA TO TUBEWORMS, MAY LIGHT THE WAY TO THE DEVELOPMENT OF NEW DRUGS, INDUSTRIAL PROCESSES, AND OTHER PRODUCTS USEFUL TO US ALL.
WORM TUBE THE TUBE IS MADE OUT OF A HARD SUBSTANCE CALLED CHITIN, THE SAME MATERIAL FOUND IN THE OUTER SKELETONS OF CRABS AND SHRIMP. The tubes protect the worms from predators and the toxic chemicals from the vents. They also serve as an outer skeleton, supporting the worm. A worm can never leave its tube.
PLUME THE PLUME IS BRIGHT RED BECAUSE IT IS FILLED WITH BLOOD. THE PLUME FILTERS OXYGEN, HYDROGEN SULFIDE, AND CARBON DIOXIDE FROM THE SEAWATER. THE BLOOD THEN TRANSPORTS THESE COMPOUNDS TO THE BACTERIA IN THE CAVITY. Like human blood, tube worm blood contains hemoglobin, a protein that carries oxygen. It is the hemoglobin that turns the blood red.
MUSCLE THE MUSCLE HOLDS THE WORM IN THE TUBE. CAVITY THE CAVITY, OR TROPHOSOME, IS PACKED WITH BACTERIA. THE BACTERIA MANUFACTURE SUGARS THROUGH CHEMOSYNTHESIS. THE TUBE WORM ABSORBS SOME OF THESE SUGARS AND USES THEM AS FOOD.
MORE FOR #4 IN WHITE SMOKERS, THE HYDROTHERMAL FLUIDS MIX WITH SEAWATER UNDER THE SEAFLOOR. OTHER TYPES OF COMPOUNDS, INCLUDING SILICA, REMAIN IN THE FLUID. When the fluid exits the chimney, the silica precipitates out. Another chemical reaction creates a white mineral called anhydrite. Both of these minerals turn the fluids that exit the chimney white.