Topographic maps use contour lines to represent elevation (height above sea level). Each contour line connects points of equal elevation. The closer the contour lines are together, the steeper the slope. A contour interval is the vertical distance between adjacent contour lines. What does a steep slope look like on a topographic map?

Map scale is the ratio between a distance on the map and the corresponding distance on the ground. A representative fraction (e.g., 1:24,000) means that 1 unit on the map equals 24,000 units on the ground. A large-scale map shows a small area in great detail (e.g., 1:10,000). A small-scale map shows a large area with less detail (e.g., 1:1,000,000). Which type of map would you use to show a city neighborhood?

Map projections are methods of representing the curved surface of the Earth on a flat map. All projections introduce some distortion (area, shape, distance, or direction). The Mercator projection preserves direction (good for navigation) but greatly distorts area at high latitudes (Greenland appears larger than Africa). The Robinson projection balances distortions. Which projection is commonly used for world maps in classrooms?

The Universal Transverse Mercator (UTM) system divides the Earth into 60 zones, each 6° of longitude wide. It uses meters as units. The Military Grid Reference System (MGRS) is based on UTM. UTM coordinates are given as easting (distance east within the zone) and northing (distance north from the Equator). What system is used by GPS devices (WGS84)?

Thematic maps show spatial patterns of specific data (population density, climate, elections). A choropleth map uses shading or colors to represent data. An isoline map uses lines to connect points of equal value (e.g., contour lines on a topographic map). A weather map showing temperature with lines connecting points of equal temperature uses what type of map?

To orient a map, you align the map's north with the actual north (magnetic north or true north). A compass points to magnetic north, which differs from true north by magnetic declination. The difference between true north and magnetic north is called magnetic declination. Declination varies by location and changes over time. What is magnetic declination?

GPS (Global Positioning System) uses satellites to determine precise location on Earth. GIS (Geographic Information Systems) is software used to analyze and visualize spatial data. How many satellites are in the GPS constellation?

A bearing is the direction from one point to another, measured in degrees clockwise from north. True north is 0° (or 360°). East is 90°, south is 180°, west is 270°. What is the bearing of east?

Triangulation is a method of determining your position by measuring the bearing to two or more known landmarks and using geometry to calculate your location. This technique was used in surveying before GPS. How many landmarks are needed for triangulation?

Terrain association is the skill of matching features on a map to features on the ground (hills, valleys, ridges, streams, roads). It is essential for land navigation without GPS. A "saddle" (or col) is the low point between two hills. A "ridge" is an elongated high point. A "valley" is a low area between hills with water flow. What is a ridge on a topographic map?