Always write coordinates Lat./Long.
Latitude:
- Lines circling East to West, but measuring
North to South
- Ex. Equator = 0o
N. Pole = 90oN
S. Pole = 90oS
Tropic of Cancer = 23.5o N
Tropic of Capricorn = 23.5oS
Diagram:
Longitude:
- Lines circling North to South, but
measuring East to West
- Converge at the pole (come together)
- Ex.
Prime Meridian = 0o
International Date Line = 180o
- 0o to 180o including N. America “W”
designation
- 180o to 0o including Asia “E” designation
Diagram:
Hemispheres:
 4 (northern, southern, western, eastern)
Time Zones:
Determined by Earth’s Rotation
15o/hr gives you time zones
Overhead
Use of Polaris to determine Latitude:
Northern Hemisphere only
Angle that Polaris is from the horizon = observer’s
latitude
Ex: 42o angle of Polaris from the Horizon = 42oN
Latitude
Zenith:
An object that is directly overhead of an observer
Ex: Polaris when standing on the North Pole
Map Projections:
 The smaller the area mapped the more
accurate the map is.
 Ideal map: Accurate shapes, location, distance
 3 Types of Maps
1. Mercator – map of the entire world minus
the Polar Regions.
Good – Shows true directions
Bad – High latitude areas are bigger
than they actually are
Ex: Greenland is shown as big as N. America;
however, N. America is 12 times the size of
Greenland.
2. Gnomonic – Appearance of laying a piece
of paper over the Earth’s surface.
Good – correctly shows the shortest
distance between points
Bad – Directions and distances are
distorted
3. Polyconic – small areas, most accurate
(shape and size), used for topographic
maps
Fields:
- A region of space where there is a measurable
quantity of a given property at every point.
- Field quantity(s)
 Pressure
 Humidity
 Temperature
 Magnetic
 Wind
 Velocity
Types of Fields:
Scalar fields:
- Magnitude only
 Ex. Temperature, humidity,
pressure, elevation
Vector fields:
- Magnitude and direction
 Ex. Velocity, wind
Isolines:
- Connect points of equal field values
Isosurface:
- A surface which passes through all points of
the same value
Isotherms:
- Lines of equal temperature
Isobars:
- Lines of equal pressure
Contour lines:
- Lines connecting points of equal elevation
Gradient:
- Rate at which a field quantity changes as
you go from one point to another in a field
- Formula in reference tables
Profile:
- Side view of the Earth or landscape
- Obtained from a topographic map
Contour Map Symbols:
Contour Interval
- Located at the bottom of the map
- Change in elevation from 1 line to another.
- If it is not located at the bottom of the map it
can be determined
Indicator Line – (Reference)
- Actually states the elevation of that contour
line
- Darker in color
Contour line –
- Light colored line
- Does not show the elevation
Scale
- Must be given somewhere on the map
- Cannot be determined like the contour interval
Steepness of Hills:
- Determined by contour lines
- Lines that are close together – steep hillside
- Lines that are far apart – gentle hillside
Flow of Rivers, Streams, or Creeks:
- Determined by contour lines or elevation
- Streams, etc will not flow from low to high
elevation, but from high to low elevation
- Contour lines will form a “V” when they
cross a stream, etc.
- The “V” points upstream, therefore the
stream flows the opposite direction of the
“V”
Bench Mark
- (BM, X) is a point of exact elevation
Hachured Lines
- Used to show a hole or a depression
- The hachured line is the same elevation as the
lowest adjacent regular contour line
Mean Sea Level
- Average sea level
- ½ way between high and low tides
- All elevations are measured from
- 0’ elevation
Contour Map Profile Explanation/Demonstration:
- Steps:
1. Use a ruler to draw the baseline on the
topographic map.
2. Draw parallel horizontal lines on your blank
paper as long as your baseline.
3. Label the elevations of these horizontal
lines at the appropriate contour interval; one
line for each contour interval crossed by the
baseline.
4. Place the edge of your paper along the
baseline and label your start and finish
points. Drop vertical lines from the
baseline everywhere it crosses a contour
line down to your horizontal contours.
Make sure to go to the appropriate contour
interval.
5. Connect your points to show a vertical cross
section along your baseline.
You cannot determine the exact elevation between two
contour lines!!