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Water. How much of the Earth’s surface is covered by water?. Three-fourths of the Earth’s surface is covered by water. Drinkable water. How much of Earth’s water is drinkable?.
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Water How much of the Earth’s surface is covered by water? Three-fourths of the Earth’s surface is covered by water.
Drinkable water How much of Earth’s water is drinkable? Most of the water on Earth, 97% to be exact, is salt water found in the oceans. Only about 3% is fresh for drinking and irrigation.
Water How old is the water you drank at this morning? The water in your glass may have fallen from the sky as rain just last week, but the water itself has been around pretty much as long as the earth has!
Water Properties A water molecule consists of one atom of oxygen bound to two atoms of hydrogen.
States of Matter (phases) Water can be found as a solid, liquid or gas. Water's state is determined mostly by temperature.
Molecules Small pieces of water are called molecules. Molecules are always moving.
Solid, liquid, gas Liquid: The molecules are further apart and are not arranged in any special order. They are free to move in any direction, but are confined by their container. Gas: The molecules are further apart and have little interaction with one another. Solid: The molecules are relatively close to one another, and the motion of each molecule is restricted by its interaction with other molecules.
Density at Freezing 39° 32°
Freezing/Melting • Freezing turns a liquid into a solid. • Melting turns a solid into a liquid.
Condensation and Evaporation • Condensation is a gas changing into a liquid. • Liquids evaporate into gases.
Sublimation and Frost • Sublimation is a solid changing into a gas. • A gas becomes solid through deposition.
Water Cycle (Hydrologic Cycle) Water is constantly being cycled between the atmosphere, the ocean and land. This cycling is a very important process that helps sustain life on Earth. Each part of the cycle drives the other parts. Condensation Precipitation Evaporation Infiltration
Evaporation Evaporation is the process where a liquid changes from its liquid state to a gaseous state.
Approximately 80% of all evaporation is from the oceans, with the remaining 20% coming from inland water and vegetation. Only about 10 percent of the water evaporated from the oceans is transported over land and falls as precipitation. Once evaporated, a water molecule spends about 10 days in the air.
Humidity Most of the time, you can't see it, but the air contains a lot of water. The amount of water in the air is called humidity. The atmosphere is the super-highway of the water cycle.
Wind speed: the higher the wind speed, the more evaporation.Temperature: the higher the temperature, the more evaporation.Humidity: the lower the humidity, the more evaporation.
Transpiration Transpiration is the loss of water from the leaves by evaporation; this helps keeps water moving round the plant by sucking water up from the roots. 10% of total evaporation
Condensation Condensation is the opposite of evaporation. Condensation occurs when a gas is changed into a liquid.
Cloud Formation In the United States, there are 40 trillion gallons of water above your head on an average day.
Cloud Formation When the air cools, water vapor condenses into tiny water droplets, which form clouds.
Condensation Nuclei The particles around which water vapor condenses are called condensation nuclei. Some condensation nuclei are smoke, dust, or salt crystals from the ocean.
Three Main Ingredients • Moisture • Cooling air • Condensation Nuclei
What stops a cloud from falling? 1 mile in diameter and 300 feet thick
Stratus and Cumulus The word stratus comes from the Latin word that means "to spread out." Stratus clouds are horizontal, layered clouds that stretch out across the sky like a blanket. The word cumulus comes from the Latin word for a heap or a pile. Cumulus clouds are puffy in appearance. They look like large cotton balls.
Cirrus and Nimbus The word cirrus comes from the Latin word for a tuft or curl of hair. Cirrus clouds are very wispy and feathery looking. Nimbus means rain cloud.
Precipitation When the temperature and atmospheric pressure are right, the small droplets of water in clouds form larger droplets and precipitation occurs.
Runoff and Infiltration • Once the precipitation hits the ground: • It may become run-off • It may be soaked into the ground (infiltration)
Infiltration Infiltration is an important process where rain water soaks into the ground. Water that infiltrates the ground becomes groundwater making up an aquifer.
Infiltration As the water infiltrates through the soil and rock layers, many of the impurities in the water are filtered out. This filtering process helps clean the water.
Vegetation 2 1 3 4 5
Aquifer Aquifer is the term given to a rock unit that will yield water in usable quantities to wells or springs. Aquifers must be both • Porous • Permeable
Twin Falls Idaho Falls Craters of the Moon Less than 50 50-100 100-200 200-300 More than 300
Surface Runoff If precipitation occurs faster than it can get into the ground, it becomes runoff. Runoff remains on the surface and flows into streams, rivers, and eventually lakes or the ocean.
