Term | Definition |
system | A group of objects that interact such as the four parts that make up Earth. |
atmosphere | The mixture of gases that surrounds and protects the Earth. |
hydrosphere | All water on Earth - in the atmosphere and in oceans, rivers, lakes and underground resvoirs. |
bioshpere | All living organisms on Earth: in the air, on the land and in the waters. |
geosphere | All features on Earth's surface - continents, islands and the seafloor and everything below the surface. |
relief map | A map that shows the differences in elevation in an area using contour lines, shading, or colors. |
map scale | The comparison of distance on a map with the actual distance on what the map represents. |
map legend | A chart that explains the meaning of each symbol used on a map. Also called a key. |
equator | An imaginary east-west line around the center of Earth that divides it into the Northern and Southern Hemispheres. |
latitude | The distance in degrees north or south from the equator. |
longitude | The distance in degrees east or west of the prime meridian. These lines are numbered from 0 to 180 degrees. |
prime meridian | An imaginary north-south line that divides the planet into the Eastern and Western Hemispheres. |
projection | A representation of Earth's curved surface on a flat map. |
topography | All natural and human-made surface features of a particualr area. |
contour line | The line on a topographic map that joins points of equal elevation. |
contour interval | On a topographic map, the difference in elevation from one contour line to the next. |
slope | A measure of how steep a landform is. |
relief | The difference in elevation between an area's high and low points. |
elevation | A measure of high something is above a reference point such as sea level. |