Latitude, Longitude, and Spatial Distribution

Comprehensive vocabulary flashcards covering Earth's dimensions, the coordinate system, map projections, scales, and spatial distribution concepts.

Geoidal bulge

The phenomenon at the equator that causes the Earth to be a spheroidal shape rather than a perfect sphere.

Equatorial diameter

The distance across the Earth at the equator, measuring $7926\,\text{miles}$ ($12,756\,\text{kilometers}$).

Polar diameter

The distance between the Earth's poles, measuring $7900\,\text{miles}$ ($12,714\,\text{km}$).

Parallels of Latitude

Lines that run East-West, are parallel to each other, and are measured North or South from the Equator ($0^\circ$) to the poles ($90^\circ$).

Meridians of Longitude

Non-parallel lines that run North-South and are measured East or West from the Prime Meridian ($0^\circ$) to the International Date Line ($180^\circ$).

Prime Meridian

The arbitrary starting line for longitude ($0^\circ$) that runs through Greenwich, England.

Tropic of Cancer

A major line of latitude located at $23.5^\circ\,\text{N}$.

Tropic of Capricorn

A major line of latitude located at $23.5^\circ\,\text{S}$.

Arctic Circle

A major line of latitude located at $66.5^\circ\,\text{N}$.

Antartic Circle

A major line of latitude located at $66.5^\circ\,\text{S}$.

Time Zone

A geographic region representing $15^\circ$ of longitude, derived from the calculation $360^\circ/24\,\text{hr}$.

Greenwich Mean Time (GMT)

The local time in London, England (Greenwich) used as a reference point for time zones.

Map Projections

The orderly arrangement of parallels of latitude and meridians of longitude used to transfer the 3D globe onto a flat 2D surface.

Mercator

One of the most frequently used map projections, especially for large wall maps.

Scale

The ratio of the distance on a map to the actual distance on the ground.

Representative fraction

A way to show map scale as a ratio, such as $1:24,000$, meaning $1\,\text{inch}$ on the map equals $24,000\,\text{inches}$ on the ground.

Graphic scale

Also known as a linear or bar scale; a line marked at intervals to show the ground distance represented by the scale.

Large-scale map

A map (e.g., $1:24,000$) that shows a relatively small area of the Earth’s surface in high detail.

Small-scale map

A map (e.g., $1:1,000,000$) that shows a relatively large area of the Earth’s surface with less detail.

Thematic Maps

Common geography maps used to show the distribution of phenomena, relationships between places, or the diffusion of goods and ideas.

Spatial Distribution

The arrangement on the landscape of a feature being studied.

Density

The frequency with which a feature or phenomenon occurs within a given area.

Concentration

The arrangement or spread of a feature over a unit of area, describing whether units are clustered together or spread apart.

Pattern

The geometric arrangement of a feature across the landscape, such as in lines, squares, or a grid.

Mental map

The cognitive image or image in your mind of a particular area, place, or route.

Environmental perception

The process of shaping an image of a place based on memories (sights, sounds, smells) or prior knowledge from descriptions and media.