Hydrothermal circulation refers to the movement of water through the Earth's crust, particularly in areas near mid-ocean ridges and volcanic systems. This process involves seawater seeping into the ocean floor, where it is heated by underlying magma. The heated water then rises back to the surface, carrying dissolved minerals and nutrients. This circulation plays a crucial role in regulating ocean chemistry and supporting unique ecosystems, such as those found around hydrothermal vents. These vents release mineral-rich water, creating habitats for various organisms that thrive in extreme conditions, demonstrating the interconnectedness of geological and biological processes.