Mappin’ Out Earth

How to, kinds of and info on – maps!

A compass rose with cardinal directions and intermediate (intercardinal) directions provides orientation.

Determining Location

Latitude and longitude are lines on the globe that are used to determine location.• Latitude is distance north or south of the

equator, measured in degrees, lines run east to west, and are a.k.a. parallels.

• Longitude is distance east or west of the prime meridian, measured in degrees, lines run north to south and are a.k.a. meridians.

Where it all begins…

Initial parallel = equator

Initial meridian = prime meridian (Greenwich, England)

No matter what kind of map is made, some portion of the surface will always look either too small, too big, or out of place.

Mapmakers have, however, found ways to limit the distortion of shape, size(area), distance and direction.

Maps and Mapping

Type of Projections

Transformation from lat/long to a flat surface

A conic projection = a cone is wrapped around the globe

A cylindrical projection = a cylinder is wrapped around the globe-have a lot of distortion in the polar regions (that is, the size of the polar regions is greatly exaggerated on these maps).

A planar projection = details of the globe are projected onto a plane (a flat surface) yielding a rectangular-shaped map. Planar maps have a lot of distortion towards the edges.

http://geology.isu.edu/geostac/Field_Exercise/topomaps/images/projections.jpg

Scale Types Fractional scale: - is a fixed ratio between linear measurements on the map and corresponding distances on the ground. It is sometimes called the representative fraction or R.F.

Example: R.F. 1:62,500

Graphical scale: - is simply a line or bar drawn on the map and divided into units that represent ground distances.

Example:

Verbal scale: - is a convenient way of stating the relationship of map distance to ground distance.

Example: 1 inch equals 1 mile

Topographic Maps Topographic maps represent Earth’s

surface in three dimensions; they show elevation, distance directions, and slope angles.• Contour lines are lines on a topographic map that indicate

an elevation.

• Contour interval is the distance in elevation between adjacent contour lines.

Features of Topographic Maps

TOPOGRAPHY (RELIEF): - printed in brown - contour lines shows hills, mountains, plains, etc.

WATER FEATURES: - printed in blue- includes oceans, lakes, ponds, rivers, canals,

etc.

CULTURE: - printed in black- human-made works such as roads, railroads, buildings, land boundaries, etc.

Mapping technology:

Today we have more accurate maps than ever, made possible by remote sensing.

This technique uses satellites and computers.

The data can be verified through a technique known as ground truthing.

Green River Topographi

c Map Activity

Green River Topographic Map Activity

1. What is the contour interval?

Green River Topographic Map Activity

1. What is the contour interval?

20

Green River Topographic Map Activity

2. What do the contour lines do when they cross Green River?

Green River Topographic Map Activity

2. What do the contour lines do when they cross Green River?

They point upstream and show that the river flows out of the “V”

Green River Topographic Map Activity

3. Which mountain has an old volcanic crater at it’s top?

Green River Topographic Map Activity

3. Which mountain has an old volcanic crater at it’s top?

Fire Mountain: it is shown by Depression Contours.

Green River Topographic Map Activity

4. What is the elevation of point A?

Green River Topographic Map Activity

4. What is the elevation of point A?

150

Green River Topographic Map Activity

5. Which side of Fire Mountain is the steepest? (North or South)

Green River Topographic Map Activity

5. Which side of Fire Mountain is the steepest? (North or South)

The South side because the contour lines are closer together.

Green River Topographic Map Activity

6. What is the elevation of point B?

Green River Topographic Map Activity

6. What is the elevation of point B?

110

Green River Topographic Map Activity

7. If you walk from point D to point E would you be going uphill or downhill?

Green River Topographic Map Activity

7. If you walk from point D to point E would you be going uphill or downhill?

Uphill

Green River Topographic Map Activity

8. When the stream first begins, what direction is it flowing?

Green River Topographic Map Activity

8. When the stream first begins, what direction is it flowing?

Southeast

Green River Topographic Map Activity

9. What is the difference in elevation between points A and C?

Green River Topographic Map Activity

9. What is the difference in elevation between points A and C?

40

Green River Topographic Map Activity

11. Select the most accurate profile that runs from A to A` from the choices.

Green River Topographic Map Activity

11. Select the most accurate profile that runs from A to A` from the choices.

Green River Topographic Map Activity

10. What is elevation of the highest contour line on this map?

Green River Topographic Map Activity

10. What is elevation of the highest contour line on this map?

260