Vocabulary # 16 - Earth's Watter Supply

Desalination: getting fresh water from seawater.

     












Water cycle: the continous movement of water between Earth's surface and the air, changing form liquid to gas to liquid.



Groundwater: water that seeps into the ground into spaces between bits of rcok and soil.



Water table: teh top of the water-filled spaces in the ground.



Aquifer: an underground layer of rock or soil filled with water.



Spring: a place where ground-water seeps out of the ground.

   

Well: a hole dug below the water table that water seeps into.



Reservoir: a storage area for freshwater supplies.

Vocabulary # 15 - Earth's Atmosphere

Renewable resource: a resource that can be replaced in a short period of time.

  

Ozone layer: a layer of ozone gas in the atmosphere that screens out much of the Sun's UV rays.

  

Fossil fuel: a fuel formed from the decay of ancient forms of life.

 

Smog: a mixture of smoke and fog.





Acid rain: moisture that falls to Earth after being mixed with wastes from burned fossil fuels.

Vocabulary # 14 - Earth's Rocks and Soil

Rock: a naturally formed solid in the crust, made up of one or more minerals.



Igneous rock: a rock formed when melted rock material cools and hardens.

    

Sedimentary rock: a rock made of bits of matter joined together.

   

Fossil: any remains of imprint of living things of the past.

    

Metamorphic rock: a rock formed under heat and pressure from another kind of rock.

    

Humus: decayed plant or animal material in sil.

     

Pollution: adding any hrmful substances to Earth's land, water, or air.

     

Rock cycle: rocks changing from one form into another in a never-ending series of processes.

Vocabulary # 13 - Minerals of Earth's Crust

Mineral: a solid material of Earth's crust with a definite composition.

  

Luster: the way light bounces off a mineral's surface.

     
Streak: the color of the powder left when a mineral is rubbed against a hard, rough surface.

  

Hardness: how well a mineral resists scratching.





Cleavage: the tendency of a mineral to break along flat surfaces.



Ore: a mineral containing a useful substance.

 

Gem: a mineral valued for being rare and beautiful.

    
 
Nonrenewable resource: a resource that cannot be replaced within a short period of time or at all.

 

Vocabulary # 12 - Earth's Changing Crust

Fault: a crack in the crust , whose sides show evidence of motion.

    

Geologist: a scientist who studies Earth.

 

Magma: hot, molten rock deep below Earth's surface.

  

Lava: magma that reaches Earth's surface.

  

Weathering: the breaking down of rocks into smaller pieces.



Erosion: the picking up and carrying away of pieces of rock.

     

Deposition: the dropping off of bits of eroded rock.



Meteorite: a chunk of rock from spce that strikes a surface (such as Earth or the Moon)