Transcript Slide 1

Latitude and Longitude
Latitude lines run east/west but they measure north or south
of the equator (0°) splitting the earth into the Northern
Hemisphere and Southern Hemisphere.
Latitude
North Pole
90
Lines of
latitude are
numbered
from 0° at the
equator to
90° N.L. at the
North Pole.
80
70
60
[
50
40
30
20
10
]
10
20
30
40
50
60
70
80
90
South Pole
Lines of
latitude are
numbered
from 0° at
the equator
to 90° S.L. at
the South
Pole.
Latitude
The North Pole
is at 90° N
The equator is
at 0° latitude.
It is neither
north nor
south. It is at
the center
between
north and
south.
40° N is the 40°
line of latitude
north of the
equator.
The South Pole
is at 90° S
40° S is the 40° line
of latitude south
of the equator.
Longitude
Lines of longitude begin
at the Prime Meridian.
60° W is the
60° line of
longitude west
of the Prime
W
Meridian.
60° E is the
60° line of
longitude
east of the
E Prime
Meridian.
The Prime Meridian is located at 0°. It is neither
east or west
180°
East Longitude
West Longitude
North Pole
Longitude
N
W
PRIME MERIDIAN
E
S
Lines of longitude are numbered east from the
Prime Meridian to the 180° line and west from the
Prime Meridian to the 180° line.
Prime Meridian
The Prime Meridian (0°) and the 180° line split the earth
into the Western Hemisphere and Eastern Hemisphere.
Prime Meridian
Western
Hemisphere
Eastern
Hemisphere
Places located east of the Prime Meridian have an east longitude
(E) address. Places located west of the Prime Meridian have a
west longitude (W) address.
INTERNATIONAL DATE LINE
180°
• SEPARATES 2 CALENDAR DAYS.
America to Asia – gain a day
Asia to America – lose a day
By combining latitude and longitude, any
location can be pinpointed
A location’s coordinates
(____° N or S, ____ ° E or W)
Application
N
W
E
S
North America is in the Northern Hemisphere because it is north
of the Equator. North America is in the Western Hemisphere
because it is west of the Prime Meridian.
LONGITUDE AND TIME
• The world rotates (spins) 360° in 24 hours.
360° / 24 hours = 15° per hour
• The world has 24 time zones, each l5° apart.
THERE IS A 1 HOUR TIME DIFFERENCE
FOR EVERY 15° OF LONGITUDE
Greenwich, England is the logical starting
point for time zones
• The world rotates west to east
(counterclockwise), time zones to the east are
ahead of the those time zones to the west
ANOTHER CHEESY SAYING
• EAST INCREASE
Time is forward to all places to the east
• WEST LESS
Time is backward to all places to the west
East Increase – West Less
(1 hr per l5°)
If it 9 p.m. at Position D, what time is it at position C? Position
B?
If it is 1 p.m. at Position X, at which location is the time 5 p.m.
Earth rotates west to east
Solar time is based on the position of
the sun
NIGHT IS FALLING ON EARTH
Look at the East Coast of the United
States. The lights are already lit.
California the sun is still visible.
This pictures shows
AMERICAN CITIES at
night.
Saguenay
Thunder Bay
Toronto
Sept-Iles
St.John
Ottawa
It’s still daylight
in California
Québec
Montréal
Detroit
Those light are Boston, New
York, Philadelphia and
Washington.
Dallas
Puerto Rico
Houston
Mexico
City
Miami
Havana
Port-au-Prince
NIGHT IS FALLING ON EARTH.
Look at Paris and Barcelona, the lights are
already lit, meanwhile in London, Lisbon and
Madrid the sun is still visible.
Looking south, we can see the islands in the
middle of the ocean.
We have a perfect view of the British Islands,
Iceland and Canada.
Iceland
England
Atlantic
France
Ocean
Spain
Italy
AFRICA
Mapping the World
• There are many types of maps that have been
created over time to help geographers and
people know where things in the world are.
Globes
• The best way to represent the earth is a globe.
• It is the same shape as the earth so it gives a
better picture. The only difference is the
reduced scale.
Globe - Advantages
• A globe is a true representation of 4 important
properties:
a)
b)
c)
d)
Size
Shape
Distance
Direction
Globe - Disadvantage
• Globes are small and can only give a general
representation and details are lost.
• You cannot see the entire globe at once.
• Globes are not easily portable.
Maps
• Maps are flat representations of a sphere. It is
impossible to draw a map perfectly as a result.
• This is called distortion and appears on all
paper maps. No matter what projection is
used, something will always be wrong with at
least one of the four important properties that
globes represent accurately.
• Generally, size and shape are the most
important and to represent them correctly,
cartographers need to choose which is more
important.
• A map that represents size correctly is called
an equal area projection or equivalent map
projection.
• A map that represents the shape of areas
correctly is called a conformal map
projection.
Equal Area Projection
• One that shows the relative size of places
correctly in all areas of the map.
• An equal area map will have disfigured
shapes.
Conformal Map Projection
• One that retains the proper shape of surface
features, but, the size of landforms are
distorted.
• All conformal projections have meridians and
parallels crossing each other at right angles.
• The farther away from the equator that a
landform is, the larger it appears on this type
of map.
Mercator Projection
• The most popular and one of the oldest
projections.
• Created by Gerardus Mercator in 1569.
• The mercator projection solved the problem
of flattening the globe into a paper map and
keep lines of latitude and longitude accurate.
• The Mercator map is conformal, meaning that
shapes are accurate, with parallels and meridians
meeting at right angles.
• The size of the landforms are wrong. Antarctica
and Greenland are much bigger than they really
are.
• The biggest problem with the Mercator
projection is that is gives an incorrect picture as
to relative sizes of land masses.
Goode Homolosine Projective
• Created in 1923 by J. Paul Goode.
• It is an equal area projection.
• This means the sizes are correct, but the
shapes are distorted.
Winkel-Tripel Projection
• Created in 1921 by Oswald Winkel.
• It is neither equal area or conformal. Instead
it tries to combine the best of both types of
projections.