Karst topography is characteristic of sandstone regions. Hot springs have been tapped to produce geothermal energy. Most water runs off and does not become groundwater. Streams that lose water to the aquifers beneath them are influent streams. The boundary between the zone of saturation and the zone of aeration is the capillary fringe.
Salt water is less dense than freshwater.
An aquifer is a body of rock that can yield economically significant quantities of water. The rate of groundwater flow is directly proportional to the vertical distance separating two points and inversely proportional to the vertical drop in head between these points. The potentiometric surface is another name for the water table. The dustbowl resulted from severe drought and poor farming practices. The Ogallala aquifer underlies the high plains of Minnesota.