Hydrothermal circulation is a geothermal process where hot water or steam circulates through the Earth's crust. The process brings minerals and nutrients up to the surface, feeding unique ecosystems in the form of hydrothermal vents, geysers, and hot springs. Other synonyms for hydrothermal circulation include geothermal convection, thermal convection, thermal circulation, and hydrothermal convection. These processes occur throughout the world and are important for the development of alternative energy sources. The circulation of hot fluids within the Earth's crust also plays a crucial role in mineral formation, geologic activity, and ecological niches. Hydrothermal circulation supports unique life forms that thrive in the extreme conditions of high temperatures and pressures.