1. Maps
Pg. 21

2. Overview of Earth Science
Formation of Earth- nebular hypothesis; formed from a rotating cloud made of H and He
4 major spheres-
Hydrosphere: all water on Earth
Atmosphere- gasses surrounding Earth
Geosphere- Rocks, minerals, the interior
Biosphere- all life on Earth

3. Determining location
Use two measurements to measure location: latitude and longitude
Measured in degrees
Latitude is position north or south of the equator (lines run horizontally)
0-90 degrees N & S
Longitude is position east or west of the prime meridian (lines run vertically)
0 and 180 degrees W & E

4. Global Grid Equator marks 0o latitude
Divide northern and southern hemispheres
Prime meridian marks 0o longitude
Divides eastern and western hemispheres
Runs through Greenwich, England
Can mark absolute location of something
Latitude then longitude (32o N, 81o W)

6. Globes
Accurate way to map Earth in the way it truly is, just scaled down
Problem: not specific enough to be useful for everyday

7. The Mercator Projection
Gerardus Mercator created the map to help sailors navigate around Earth
Lines of longitude are parallel
Sizes and distances distorted, but directions accurate

8. Robinson Projection map
Show most distances, sizes, and shapes accurately.
Distortions around the edges
Shows whole globe as a flat map

9. Conic Projection Maps
Made by wrapping a cone of paper around a certain latitude
Almost no distortion along line of latitude, but much away
Used to make road and weather maps

10. Gnomonic Projections
Place a piece of paper on a globe so it touches one point
Points and lines are then projected on the paper
Shows with accuracy the shortest distance between two points

11. Topographic maps Represents Earth’s 3D surface in 2D
Shows elevation using contour lines
Also show water, roads, buildings, political boundaries, etc.
Very useful

13. Contour lines
Every position along a single line represents the same elevation
Every 5th line is bold and has the elevation labeled called index contour
Contour interval tells you difference between adjacent lines
Form a V when crossing a stream
Apex of the V points up stream

16. Steepness Can be determined by examining closeness of lines
Closer the lines, steeper the slope
Contour lines that form a circle represent a hill
A depression is represented by circles with hash marks that point to the center
Lines never intersect unless there is a vertical cliff

18. Scale Need to represent large areas Scale them down
Use ratios to represent scale (1:24,000)
Bar scales are represented on maps so you ca measure distance

19. Geologic Maps Shows the type and age of exposed rocks
Each rock formation is assigned a color and sometimes a pattern