Geographic Tools
GPH 111
Tools to cover…
 Latitude and Longitude
 Projections
 Map Scale
 Conversions
Columbus and America
Latitude…
and Longitude…
International Dateline
15 of longitude
equals 1 hour of
time…
How do you state Latitude and
Longitude?
Paradise Valley Community
College
33° 39’ 08” N, 112° 00’ 37”
W
Degrees Minutes Seconds
33.6522, -112.0102
Decimal
Let’s practice…
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Find These Locations:
New York, NY
Flagstaff, AZ
Seattle, WA
Paris, France
Bangkok, Thailand
Sydney, Australia
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32.72, -117.18
25.92, -80.24
38.90, -77.04
33° 59’ N, 116° 25’ E
30° 2’ N, 31° 21’ E
33° 55’ S, 18° 22’ E
Projections…
How
projections
work…
Equal Area (equivalence) and True
Shape (conformal) Projections
Projection Differences…
This baby does both… kinda…
Great Circle Routes and Rhumb
Lines
Great Circle Route:
The shortest distance
between any two points on
Earth.
Rhumb Line:
Lines of constant
direction and facilitate
plotting directions
between two points.
What is Map Scale?
Verbal Scale
What is the scale of this map?
If we know the distance from San Francisco to Washington DC
is roughly 2,850 miles, how do we determine this map’s scale?
What can we do with map scale?
How far is it from San Diego to New York?
How far is it from Miami to Seattle?
What is the distance between the southern bottom of Lake
Michigan to the southern tip of Texas?
Converting between Representative
Fraction and Written Scales…
Some Practice (English):
1:100,000 to in. = miles _______
1:50,000 to in. = miles _______
1 in. = 10 miles to RF _______
1 in. = 5,000 ft to RF _______
Is 1:15,000 large or small _______
Important Numbers (English):
5,280 ft in mile
63,360 inches in a mile
12 inches in a foot
English to Metric Conversions…
First, some Metric practice:
1:100,000 to cm = km ________
1 cm = 10 km to RF _________
Important Metric Numbers:
1 km = 100 meters; 100 cm = 1 meter
1 km = 10,000 cm
Important Numbers:
1 in = 2.54 cm; 1 foot = 0.305 meters
1 cm = 0.394 inches; 1 mile = 1.61 km
1 meter = 3.28 feet; 1 km = 0.621 miles
Practice:
5 feet = ____ meters; 150 cm = ____ in; 8 miles = ____ km
4 meters = ____ feet ; 80 in = ____ cm; 12 km = ____ miles
Things to know…
Latitude and Longitude
What is the significance of the equator, prime meridian, and
international dateline
How to state Latitude and Longitude (DMS, and Decimal)
What is a map projection and why are they used
Advantages with Equal Area versus True Shape projections
The importance of great circle routes and rhumb lines
What is map scale?
How to measure the scale of a map and convert between
representative fractions and verbal scales
How to convert basic English and Metric length units
Help: Chapter EG