| A | B |
|---|
| hydrosphere | an Earth system that includes all the water on the planet |
| atmosphere | the layer of gases that surrounds Earth |
| surface water | water found on Earth's surface in places like oceans, lakes, rivers and reservoirs |
| reservoir | a protected artificial or natural lake that is used to store water |
| glacier | a huge mass of ice that forms on land when snow and ice accumulate faster than they melt |
| groundwater | water that collects under ground |
| water table | the upper level of water underground; below the water table, all spaces are filled with groundwater |
| water cycle | a set of processes energized by the Sun that keep water moving from place to place on Earth; also called the hydrologic cycle |
| evaporation | the process by which a substance in its liquid phase gains energy and enters the gaseous phase; a phase of the water cycle |
| water vapor | water in gas form |
| transpiration | the process by which plants lose water through tiny pores on their leaves; a phase of the water cycle |
| condensation | the process by which a substanve in its gaseous phase loses energy and enters its liquid phase; a phase of the water cycle |
| precipitation | condensed water vapor in the atmosphere falling back to Earth in the form of rain, hail, sleet, or snow; a phase of the water cycle |
| surface runoff | water that flows over land until it reaches lakes, rivers, and oceans |
| percolation | the process of liquid moving through a porous substance |
| aquifer | a underground area of sediment and rocks that is filled with groundwater |
| watershed | an area of land that catches all percipitation and surface runoff and collects it in a body of water such as a river |
