Mapping our world - study guide

Cartography

The science of map making.

Latitude

Helps find positions north or south, with the Equator as the reference point.

Longitude

Helps find positions east and west, also known as meridians.

Equator

Circles Earth, separating it into Northern and Southern Hemispheres, with 0 degrees latitude.

Prime Meridian

The reference point for longitude, 0 degrees longitude.

International Date Line

The 180 degrees meridian used to determine time zone changes.

Mercator Projection

Map projection that maintains correct shapes of continents but distorts areas, useful for navigation.

Conic Projection

Projects lines from a globe onto a cone, useful for road maps and weather maps.

Gnomonic Projection

Projects lines from a globe onto paper, useful for plotting long-distance trips by air and sea.

Topographic Maps

Detailed maps showing changes in elevation using lines, symbols, and colors.

Contour Lines

Lines that connect points of equal elevation showing distance above or below sea level.

Contour Interval

The difference in elevation between two side-by-side contour lines.

Map Legend

Explanation of symbols used on a map.

Map Scales

Ratios between distances on a map and actual distances on Earth.

Remote Sensing

The process of collecting data about Earth from above its surface using electromagnetic radiation.

GPS

Global Positioning System, a radio-navigation system of at least 24 satellites to determine location.

SONAR

Use of sound waves to detect and measure underwater objects, determining distance to the ocean floor.