1. Mapping

2. Standards
Use appropriate technologies to collect, analyze and communicate scientific data
Convey results of investigations using diagrams, charts and other data displays

3. Latitude and Longitude
Lines that form a reference grid to locate places on Earth’s surface
Earth’s axis of rotation provides reference points for defining directions
These reference points are the geographic north and south poles
Halfway between the north and south poles is the equator – a line that divides the Earth into northern and southern hemispheres

4. Latitude Latitude lines run east and west parallel to the equator
Also known as parallels
The equator is the reference line of latitude, so it equals 0 latitude

5. Latitude Since Earth is a sphere, the circumference of Earth is 360
Latitude lines are measured from 0 at the equator to 90 at the pole, and are specified as being north or south
Each degree of latitude is equal to 111 km on Earth’s surface

6. Latitude
Degrees of latitude are further broken down into smaller units called minutes and seconds
Minutes – there are 60 minutes in 1 degree, so each minute = 1.85 km
The symbol for minutes is ’
Seconds – there are 60 seconds in each minute
The symbol for seconds is ”

8. Longitude Longitude lines run north and south and meet at the poles.
They are also known as meridians
The prime meridian, which passes through Greenwich, England, was selected to be 0
The meridian halfway around the world from the prime meridian is 180
All locations east of the prime meridian have longitudes between 0 and 180 E
All locations west of the prime meridian have longitudes between 0 and 180 W

9. Longitude Can also be further divided into minutes and seconds
For meridians, the distance of a degree depends on location
At the equator, a degree is ~111 km
Since all meridians meet at the poles, the distance measured by a degree of longitude decreases when moving from the equator to the poles
Ex: at a latitude of 60 N, 1 degree of longitude equals ~55 km

11. Great Circles A circle that divides the globe into equal halves
Any circle formed by two meridians of longitude that are directly opposite each other is a great circle
The equator is the only line of latitude that is a great circle
Great circles are often used for navigation
They are the shortest distance between two points on a sphere

12. Magnetic Declination
The earth has geographic poles and geomagnetic poles, which are different from each other
A compass points to the geomagnetic north pole
The angle between the direction of the geographic north pole and geomagnetic north pole is called the magnetic declination
It is measured in degrees east or west of the geographic north pole

13. Magnetic Declination
Magnetic declination varies according to where you are on Earth
A compass can be set with the declination for a specific area so that it points to geographic north

14. Reading a Map
To read a map, you must be able to find directions, calculate distances and understand the symbols

15. Map Directions
The cardinal directions (N, S, E & W) are marked by a compass rose, or by a north arrow

16. Map Directions
Direction is determined in relation to parallels and meridians
Parallels (latitude) and meridians (longitude) are labeled in degrees, minutes and seconds

17. Map Symbols Features on a map are represented by symbols
These symbols are explained on the map legend

18. Map Scales In order to be accurate, a map must be drawn to scale
Map scale indicates the relationship between distance on the map and actual distance
Three types:
Graphic scale
Fractional scale
Verbal scale

19. Graphic Scale A printed line with markings similar to those on a ruler
The line represents a certain distance, such as a mile or kilometer, and may be broken down into smaller segments

20. Fractional Scale Expresses distance as a ratio
Ex: a scale of 1:25,000 indicates that 1 unit of distance on the map represents 25,000 of the same unit on Earth
The larger the ratio of the map, the less detail is shown

21. Verbal Scale Expresses scale in sentence form
Ex: 1 cm on the map is equal to 1 km on earth

22. Types of Maps There are many different types of maps
Examples of maps used in geology include, but are not limited to:
Geologic maps
Topographic maps

23. Geologic Maps
Show the rocks and geologic features that are exposed at the surface

24. Topographic Maps Show the topography of a given area
Topography – the elevation, change in elevation and shape of a region
Elevation is the distance above, or below, sea level

25. Contour Lines Elevation is represented by contour lines
They connect points of equal elevation
The shape of the contour lines reflects the shape of the land
Contour lines never cross (if they did, the point where they crossed would have two elevations)

27. Contour Interval & Index Contours
Contour interval - the difference in elevation between one contour line and the next
Index contours - every fifth contour line on a map is made darker and marked with the elevation
This makes the map less cluttered and easier to read
Exact elevations, such as a mountain peak, are marked by an x and labeled with the elevation

29. Landforms on Topographic Maps
The shape and spacing of contour lines show the shapes of the landforms represented on the map
Widely spaced contour lines indicate a gradual change in elevation
Closely spaced contour lines indicate terrain that is steep, such as a mountain slope
Depressions, such as volcanic craters, are marked by hachures –short, perpendicular lines inside a closed contour loop
V shaped contours indicate a valley, and they always point upstream.