Presentation on theme: "The Water Cycle. Water is… The only common substance that exists as a solid, a liquid, and a gas. Present everywhere on Earth. In a continuous state."— Presentation transcript:
Water is… The only common substance that exists as a solid, a liquid, and a gas. Present everywhere on Earth. In a continuous state of change and movement.
The Water Cycle Definition: the combination of all of the different movements of water Also known as the hydrologic cycle A flow of matter (water) and energy Called a “closed” system –A material [water] moves from place to place but nothing is gained nor lost.
Major Processes of the Water Cycle Evaporation and Precipitation There is more evaporation than precipitation over the surface of the Earth’s oceans. There is more precipitation than evaporation over the surface of the Earth’s continents.
Evaporation Definition: the change of state of matter from a liquid to a gas. Heat is absorbed. Example: boiling water to steam
Oceans Cover about 75% of the Earth Ocean water is constantly evaporating into the atmosphere (becomes water vapor) When water vapor cools: –Forms clouds at higher altitudes –Forms fog if close to the ground
Precipitation Definition: water that falls to the surface from the atmosphere as rain, snow, hail, or sleet
After the precipitation Water can take different routes: –Evaporate –Ground Water –Soil Moisture –Surface runoff
Evaporation Back into the atmosphere The higher the temperature, the faster evaporation occurs.
Ground Water Water soaks into the ground until it reaches a zone where all of the pores are filled with water. Example: underground streams, aquifers
Soil Moisture Water that remains in the surface layer of soil the roots of plants absorb this water. –Travels up through the stems and branches of the plant into the leaves and is released into the atmosphere as vapor in a process called transpiration.
Surface Runoff Water that flows downhill into streams and rivers Eventually empties into the ocean
What makes the ocean salty? Water flows from the surface of the continents into the oceans This water carries sediment particles and dissolved minerals into the ocean. When ocean water evaporates, it leaves the sediments behind. Over time, the ocean becomes more and more salty.
Reservoir vs. Flux Reservoir – a place in the Earth system that holds water. –Ex. Oceans, Atmosphere, Clouds, etc Flux – the movement of water from one reservoir to another.
Energy is required to make water flow from one reservoir to another. On average, the total amount of water in all reservoirs combined is nearly the same. The amount of water stored in any one reservoir varies over time.