A geothermal pool is called a reservoir.
aquifer
Aquifer
Thermal comes to mind. Geothermal is another.
Billiards.
pool, lagoon
Pond, pool.
Geothermal energy is heat from the Earth.
A kitty. A fund. A pot.
Weak
It is used for heating houses and sometimes the hot water that comes from the ground (geothermal water) is used as a freshwater pool and also for cooking.
earth heat
With the growing 'green economy', geothermal energy is a viable option for power.