Glossary
Contemporary Maps
Modern maps that are highly accurate, data-driven, and created using advanced technology like satellite imagery and GPS, focusing on precise measurements and data representation.
Example:
A Google Maps satellite view of a city is a contemporary map, offering precise details and real-time data for navigation.
Early Maps
Maps created in earlier historical periods, often characterized by symbolic representation, artistic interpretation, and less emphasis on precise measurements or accurate scale.
Example:
Ancient Babylonian clay tablets depicting local areas are examples of early maps, prioritizing local knowledge and cultural understanding over global accuracy.
Equal-Area Projection
A type of map projection that preserves the true relative sizes of landmasses, ensuring that areas on the map are proportional to their actual areas on Earth.
Example:
When studying global deforestation rates, an equal-area projection would be preferred to accurately compare the extent of forest loss across different continents.
Equator
The imaginary line of 0° latitude that circles the Earth midway between the North and South Poles, dividing the Earth into the Northern and Southern Hemispheres.
Example:
Countries located near the Equator, like Ecuador and Kenya, typically experience consistent warm temperatures and high humidity year-round.
Geographic Grid
A system of imaginary lines (latitude and longitude) that crisscross the Earth's surface, used to determine the absolute location of any point.
Example:
Using the geographic grid, a ship's captain can pinpoint their exact location at sea by knowing their latitude and longitude coordinates.
Graphic Scale
A type of map scale represented by a bar line on the map, divided into segments that show the actual distances on the ground.
Example:
When you see a ruler-like bar at the bottom of a map, allowing you to measure distances directly with a physical ruler, that's a graphic scale.
Grid Patterns
A regular, geometric arrangement of objects or features, often seen in urban planning (like street layouts) or agricultural fields, characterized by intersecting perpendicular lines.
Example:
Many cities in the United States, such as New York City, feature grid patterns in their street layouts, making navigation straightforward and organized.
International Date Line
An imaginary line of longitude, roughly following 180°, that marks the boundary where each new calendar day begins, causing a change in date when crossed.
Example:
When flying from Tokyo to Los Angeles, crossing the International Date Line means you gain a day, arriving on the same calendar day you departed.
Large-scale maps
Maps that show a small geographic area with a high level of detail, meaning the ratio between map distance and ground distance is relatively large.
Example:
A detailed street map of a college campus is a large-scale map, allowing students to find specific buildings and pathways easily.
Latitude
Imaginary horizontal lines (parallels) that run east to west around the Earth, measuring distance north or south of the Equator.
Example:
The Tropic of Cancer is a specific line of latitude located at approximately 23.5° North, marking the northernmost point where the sun's rays can be directly overhead.
Longitude
Imaginary vertical lines (meridians) that run from the North Pole to the South Pole, measuring distance east or west of the Prime Meridian.
Example:
The International Date Line is a line of longitude that roughly follows 180 degrees, where the calendar day officially changes.
Map Distortion
The inevitable inaccuracies in shape, distance, relative size, or direction that occur when transforming the curved, three-dimensional surface of the Earth onto a flat, two-dimensional map.
Example:
The stretching of Canada and Russia on a Mercator map is a clear example of map distortion in terms of relative size.
Map Projections
Methods used to represent the three-dimensional surface of the Earth onto a two-dimensional flat map, which always introduces some form of distortion.
Example:
Cartographers choose different map projections depending on the purpose of the map, such as preserving area for population density maps or direction for navigation.
Map Scale
The relationship between a distance on a map and the corresponding distance on the ground, indicating how much the real world has been reduced to fit on the map.
Example:
Understanding the map scale is crucial when planning a road trip, as it tells you how many actual miles each inch on your paper map represents.
Mercator Projection
A cylindrical map projection known for preserving angles and directions, making it useful for navigation, but it significantly distorts the size of landmasses, especially near the poles.
Example:
On a Mercator Projection, Greenland appears much larger than South America, even though South America is actually many times bigger.
Peters Projection
An equal-area map projection that accurately shows the relative sizes of landmasses, but distorts their shapes and distances.
Example:
The Peters Projection is often favored by organizations focusing on global equity because it visually corrects the size biases seen in other projections, making Africa and South America appear in their true relative sizes.
Prime Meridian
The imaginary line of 0° longitude that passes through Greenwich, England, serving as the reference point for measuring distances east and west around the globe.
Example:
All time zones are calculated based on their distance from the Prime Meridian, with locations to its east having later times and locations to its west having earlier times.
Ratio Scale
A type of map scale expressed as a fraction or ratio (e.g., 1:25,000), where one unit on the map represents a specified number of the same units on the ground.
Example:
A map with a ratio scale of 1:10,000 means that 1 centimeter on the map corresponds to 10,000 centimeters (or 100 meters) in the real world.
Robinson Projection
A compromise map projection that attempts to balance distortions of shape, size, distance, and direction, commonly used for general-purpose world maps.
Example:
Many textbooks and atlases use the Robinson Projection for world maps because it offers a visually appealing and less extreme representation compared to Mercator or Peters.
Small-scale maps
Maps that show a large geographic area with less detail, meaning the ratio between map distance and ground distance is relatively small.
Example:
A world political map showing all countries is a small-scale map, useful for understanding global distributions but not for navigating individual cities.
Written Scale
A type of map scale that uses words to describe the relationship between map distance and ground distance.
Example:
A map stating "1 inch equals 1 mile" uses a written scale, making it straightforward to understand distances for many users.