Sea Water sinks through the crust and is filtered Cold seawater sinks down through the crust. O2 and K are removed from the seawater. Ca, SO4, and Mg are removed from the fluid. Na, Ca, and K from the crust enter the fluid. Highest temperatures (350- 400 oC), Cu, Zn, Fe, and H2S from the crust dissolve in the fluids. Hot & acidic fluids with dissolved metals rise up through crust. The hydrothermal fluids mix with cold, O2-rich seawater. Metals and sulfur combine to form metal-sulfide minerals: MnO2, FeO(OH), … Basically cold seawater is converted to a very hot fluid rich in dissolved metals. Promotes robust chemistry initial phase of life?
www.pmel.noaa.gov/vents Robust and complex chemistr y
Black & White smokers 2. As the water heats up, it reacts with the rocks in the ocean crust All oxygen is removed.; It becomes acidic. It picks up dissolved metals, including iron, copper and zinc. It picks up hydrogen sulfide. 3.The hot rising 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 up in the fluids combine with sulfur to form black minerals called metal sulfides. These tiny mineral particles give the hydrothermal fluid the appearance of smoke. Many factors trigger this reaction. One factor is the cold temperature of the seawater. A second equally important factor is the presence of oxygen in the seawater. Without oxygen, the minerals would never form.
Hydrothermal Vent Distribution Pink, western Pacific; green, northeast Pacific; blue, East Pacific Rise; yellow, Azores; red, Mid-Atlantic Ridge; orange, Indian Ocean
Hydrothermal energy source H 2 S + O 2 SO 4 + + H + + ATP Chemosynthetic (sulfur oxidizing) Chemosynthetic (sulfur oxidizing) Thermophilic Bacteria (up to 120 o C) Thermophilic Bacteria (up to 120 o C) Hot, anoxic, sulfide rich water mixes with Cold oxygenated water Hot, anoxic, sulfide rich water mixes with Cold oxygenated water Hydrothermal Vents as origin of Life? Hydrothermal Vents as origin of Life?
Bacteria from 120 o C http://mollie.berkeley.edu/~volkman/
Vent biological communities BACTERIA (Bacteria and Archea) BACTERIA (Bacteria and Archea) 400 morphological invertebrate species 400 morphological invertebrate species New species every 2 weeks during 25 years!New species every 2 weeks during 25 years! Evolutionary Origin Evolutionary Origin Derived from surrounding Deep SeaDerived from surrounding Deep Sea Derived from Shallow Water speciesDerived from Shallow Water species Many evolutionary radiations at species levelMany evolutionary radiations at species level Many vent taxa originated at other organically enriched environments (cold seeps and whale bones)Many vent taxa originated at other organically enriched environments (cold seeps and whale bones) Vents as stable refugia from Global extinctions Vents as stable refugia from Global extinctions
Cold Seeps CH 4 + O 2 CO 2 + H 2 0 +ATP CH 4 CH3 - + H + +ATP H 2 S + O 2 SO 4 + + H + + ATP Hydrocarbon reservoirs Hydrocarbon reservoirs “methane bubbling” “methane bubbling” Continental shelves and Trenches Continental shelves and Trenches 200 invertebrate species 200 invertebrate species ATP is used as an energy carrier for cells; natural synthesis
Invertebrate food sources Food chain based on sulfur-oxidizing bacteria Symbiosis with Bacteria Symbiosis with Bacteria tube worms tube worms Vent Mussels and vent clams Vent Mussels and vent clams Ingestion of Bacteria Ingestion of Bacteria Grazers (gastropod limpets and snails) Grazers (gastropod limpets and snails) Filter Feeders (vent shrimp, polychaete worms, amphipods, anemones) Filter Feeders (vent shrimp, polychaete worms, amphipods, anemones) Predators Predators Ventfish, octopus Ventfish, octopus Scavengers Scavengers Crabs Crabs
Sea floor Spreading opens new vent areas over geological time www.pmel.noaa.gov/vents/PlumeStudies
Chemical Reactions Depends on ambient temperature
Geol 104/BioES 154 Hydrothermal Vent Communites � 25 years of exploration have revealed: � A new phylum � At least 20 new families � Over 90 new genera � Over 300 new species � Over 250 new strains of free-living bacteria � Biomass � Up to 30 kg/m 2 � 1000 x greater than typical biomass observed on deep-sea floor
Geol 104/BioES 154 Hydrothermal Vent Macrofauna: Environmental Constraints on Life Cycles and Reproduction � Suitable vent environments for these organisms are rare. � Individual vents have short life-spans. � Volcanic eruptions and earthquakes pose further hazards. � These conditions favor rapid growth rates, continuous reproduction, and high fecundity.