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3˚C
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60˚C
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Vent Chemistry
350-400˚C
Click on the numbers to find out more about hydrothermal vent chemistry.
Do Vents Affect the Entire Ocean?The world’s oceans contain many chemicals other than water and salt. Where do these chemicals come from? Rivers carry some of the chemicals into the ocean. Hydrothermal vents supply others. When seawater seeps down into the ocean crust and is heated by the magma, it undergoes lots of chemical reactions.
When the fluid rises up through the seafloor, it carries many new chemicals with it, such as copper and zinc. These chemical reactions also remove chemicals from the seawater, such as oxygen and magnesium. Here is a look at some of the many chemical reactions that take place.
150˚C
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Cold seawater sinks down through cracks in the crust.
Oxygen and potassium are removed from the seawater.
Calcium, sulfate, and magnesium are removed from the fluid. Sodium, calcium, and potassium from the surrounding crust enter the fluid.
The fluids have reached their highest temperatures. Copper, zinc, iron, hydrogen sulfide, and hydrogen dissolve in the fluids.
Degassing magma may add carbon dioxide and other trace gases.EndFragment
Hot fluids carrying dissolved metals rise up through crust.
The hydrothermal fluids mix with cold, oxygen-rich seawater. Metals and sulfur combine to form black metal-sulfide minerals.
The hot fluids mix with cold seawater below the surface, producing warm fluids that are rich in dissolved chemicals. Microbes thrive here by using chemosynthesis.