What Are Aquifers?

• A. Underground Locations Where Groundwater Is Stored
• B. Rivers
• C. Atmospheric Moisture
• D. Caverns

Answer: (A)

An aquifer is an underground layer of permeable rock or sediment that stores and can transmit groundwater. Water from rain and other sources infiltrates downward, filling the interconnected pore spaces and cracks. The saturated zone below the surface, separated from the air by the water table, holds this groundwater, which can move slowly through the material so wells or springs can access it. Aquifers can be unconfined, with the water table open to the surface above, or confined between impermeable layers that pressurize the water. This underground storage of groundwater is different from rivers (surface flow), atmospheric moisture (water in the air), or caverns (hollow spaces), even though caves can intersect aquifers.