Advertisement Upgrade to remove ads


a way of representing the properties of an object or system

coordinate system

the system for determining the coordinates of a point


the angular distance north or south of the equator


the parallel on Earth midway between the geographic north and south poles with a latitude of zero


the angular distance east or west of the prime meridian


any semi circle on earth surface connecting the north and south geographic poles

prime meridian

the meridian of zero longitude


any region of space or the environment that has some measurable value of a given quantity at every point


the varying values of a field represented on maps to connect points of equal field values

contour lines

isolines that connect points of equal elevation


the rate of change from place to place within the fields (slope)

gradient formula

change in amount of field value/ change in horizontal distance

topographic map (contour map)

a commonly used model of the elevation fields of the surface of earth


the vertical distance of height above or below sea level


the side view of an areas landscape

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording