What are hydrothermal vents?

What are hydrothermal vents?

• A. Nuclear reactors
• B. Coral reefs
• C. Underwater openings in Earth's crust that emit heated water, supporting unique ecosystems
• D. Freshwater springs

Answer: (C)

Hydrothermal vents are underwater openings in Earth's crust along the seafloor where seawater seeps in, is heated by magma, and bursts out as hot, mineral-rich fluid. This heated fluid creates a chemical energy source for a unique ecosystem that relies on chemosynthesis rather than sunlight. Nuclear reactors are man-made power sources, not natural features of the ocean floor. Coral reefs are built by living corals and depend on sunlight for their energy through photosynthesis. Freshwater springs involve water from underground that is not heated by magma and do not form deep-sea vent systems.