How maps work

Question 1

map?

Answer 1

is a visual representation of an area– a representative depiction highlighting relationships between “elements” of that space.

Question 2

topographic maps

Answer 2

characterized by large-scale detail and quantitative representation of relief, usually using contour lines.

Question 3

geologic maps

Answer 3

show the locations, kinds and orientations of rock units, as well as structural features (faults and folds).

Question 4

map projection

Answer 4

is the conversion of a three-dimensional sphere into a two-dimensional map.

Question 5

Orthographic

Answer 5

a perspective map projection (hemisphere), where shapes and areas are distorted toward edge.

Question 6

Mercator

Answer 6

a cylindrical map projection, which increasing distorts size and shape toward poles.

Question 7

Polyconic

Answer 7

a conical map projection having distances between meridians along every parallel equal to those distances on a globe.

Question 8

Sinusoidal

Answer 8

a pseudocylindrical equal-area map projection that presents accurate area and distance at every parallel and at the central meridian; distortion increases at the outer meridians and at high latitudes..

Question 9

Maps of Earth’s surface must contain certain basic elements. 3 things

Answer 9

1. Location – a way to show precisely where the area is located.
2. Scale and Distance – a way to measure the distance between features.
3. Direction – an accurate portrayal of directions between features.

It is also important to know elevation and steepness of slope.

Question 10

Maps published by the U. S. Geological Survey (USGS) use different grid systems. (2 and what are they?)

Answer 10

1. Latitude and Longitude – based on location north or south of the Equator and east or west of the Prime Meridian.
2. Universal Transverse Mercator (UTM) – divides Earth into 1,200 segments,each containing 6o of longitude and 8o of latitude.

Question 11

Different ways to describe map scale. (2 ways)

Answer 11

1. Proportional scale – Tells exactly how much the ground has been scaled down to make the map, such as 1:24,000 (refers to all units of measure).
2. Graphical (Bar) Scale – Can be shown graphically using a bar scale to express the same relationship as the verbal scale.

Question 12

topographic map shows what 8 things

Answer 12

topographic map shows location, distance and direction very accurately, as well as shapes of landforms, elevations and steepness of slopes using contour lines.

Question 13

A contour line is a line that

Answer 13

connects points of equal elevation on topographic maps.

Question 14

The contour interval is the

Answer 14

difference in elevation represented by each contour line on a topographic map.

Question 15

Geologic maps illustrate the following information. 5 things

Answer 15

1. The land surface.
2. Records geologic information (location, description and age relationships of rock units).
3. The occurrence of faults and folds.
4. The location of economic mineral deposits.
5. Sometime the location of fossils.