That's called an "aquifer" if it's naturally-occurring. But a "cistern" is a man-made with a waterproof lining. If it's a really big cistern, it's a "covered reservoir".
Aquifers.
An aquifer
"subsurface water"
That is called an aquifer.
Geothermal energy can be stored in batteries, like all other electrical energy. There is no reason why geothermal energy has to be stored, as it can be produced round the clock, unlike wind and solar.A:The energy is stored in the form of dry steam which is water vapor with out water droplets, wet steam which is a mixture of water vapor and water droplets, and hot water trapped in fractured or porous rock.
Caverns can be under water and underground.
caverns
groundwater
A body of water stored in an underground space is an aquifer.
A body of water stored in an underground space is an aquifer.
A body of water stored in an underground space is an aquifer.
Aquifers.
An aquifer
An aquifer
water seeps through the ground and dissolves the limestone bedrock.
Yes. It will depend on the type of rock. For a porous rock,such as sandstone or shale, the water can be within the rocks. For non-porous rocks it will be stored between the rocks.
Gravity causes water to flow downwards. In porous ground the water will seep into the soil. If the water hits a non-porous layer (clay, for instance) the water will spread horizontally.