Why are vent sites so different? That’s a big question scientists have been trying to answer.

Some vent fields have black smokers. Others have “white smokers,” which belch slightly cooler, but still superheated fluids without dark mineral particles. At still other vent sites like the Galápagos, warm (but not superhot) vent fluids seep out of seafloor cracks (but not in chimneys).

How do massive mineral-rich deposits form at vent sites like TAG on the Mid-Atlantic Ridge, but not at others? Why did white, silica-rich deposits form at “Cauliflower Gardens” near Galápagos vents, but not at TAG?

Why does the chemical composition of vent fluids vary from place to place? What causes vent sites to turn on and to turn off? Each vent sites is unique because each is a result of a unique combination of interacting forces. In different places on the seafloor, the movement of Earth’s tectonic plates creates different seafloor topography, different sorts of cracks in the seafloor, and different amounts of volcanic activity. All these factors combine to create differences in vents—and perhaps differences in the communities that live around them.