an imaginary line that runs through Earth’s center from the North Pole to the South Pole

a complete trip of Earth around the sun.

the layer of gasses surrounding Earth

one of two days of the year when the sun reaches its northernmost or southernmost point. 

one of two days each year when the sun is directly overhead at the equator. 

 the water that falls on the ground as rain, snow, sleet, hail, or mist. 

an area that receives reduced rainfall because it is on the side of a mountain facing away from the ocean. 

a large, unbroken mass of land.

 one of the 16 pieces of Earth’s crust.

a place where two tectonic plates grind against each other.

an event in which the ground shakes or trembles, brought about by the collision of tectonic plates.

a long, narrow band of volcanoes surrounding the Pacific Ocean.

a giant ocean wave caused by volcanic eruptions or movement of the earth under the ocean floor.

 the process by which Earth’s surface is worn away by natural forces.

the process by which weathering bits of rock are moved elsewhere by water, wind, or ice.

a large body of ice that moves slowly across the land

a flat area that rises above the surrounding land

 a large expanse of land that can be flat or have a gentle roll

a narrow strip of land that connects two larger land areas.

 a long, narrow, steep-sided cut on the ocean floor

a process that makes salt water safe to drink.

the water contained inside Earth’s crust.

 an area where sand, silt, clay, or gravel is dropped at the mouth of a river

the process in which water is used and reused on Earth, including precipitation, collection, evaporation, and condensation.

the change of liquid water to water vapor.

 the result of water vapor changing to a liquid or a solid state.