Atmosphere
The gaseous envelope of air surrounding Earth, made up of a mixture of about 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases and water vapor; one of the four spheres of the Earth system
Biosphere
All living organisms in the Earth system and their environments; one of the four spheres of the Earth system
Carbon Cycle
The biogeochemical circulation of carbon through the Earth system
Closed System
A system in which energy can enter or leave, but matter cannot
Cycle
The physical or chemical processing of Earth materials that repeats over time, for example, the water cycle, carbon cycle, and rock cycle
Earth System Science
The study of Earth materials and processes subdivided into a group of four interconnected spheres of activity: atmosphere, geosphere, hydrosphere, and biosphere
Energy Cycle
The movement of energy into and out of the Earth system
Evapotranspiration
The rapid cycling of water vapor into the atmosphere by evaporation from Earth's surface or transpiration from plant leaves
Geosphere
The rocks, mountains, lithospheric plates, and other physical features of Earth, except for water; one of the four spheres of the Earth system
Geothermal Energy
Heat energy that originates from within Earth and drives the movement of Earth's tectonic plates
Hydrosphere
All water in the Earth system-- gaseous (water vapor), solid (snow and ice), and liquid (rain and water); one of the four spheres of the Earth system
Model
a simplified representation of an object, process, or phenomenon, used as the basis for further study or investigation
Open System
A system in which there is a free exchange of both energy and matter between the system and its surroundings
Solar Energy
Energy emitted by the sun
System
A naturally occurring group of objects or phenomena that share matter and energy, for example, the four spheres of the Earth system
Tidal Energy
Energy created by the gravitational pull of the sun and moon on Earth's oceans
Water Cycle
The continuous circulation of water through the hydrosphere as solid, liquid, or gas