An atlas contains maps of countries, oceans, continents, and other geographic features. It uses a grid system of latitudes and longitudes to precisely locate places on Earth. The five oceans and seven continents are labeled on a world map. Key latitudes and the International Date Line help identify locations and determine time zones around the globe.

1. ENVIRONMENTS THROUGH
MAPS (PART 1)

2. What is an Atlas?
• An atlas is a book of maps and usually
contains
small-scale maps of countries in the world
• The world map is a common map found in an
atlas which shows the locations of oceans
and

3. • The bodies of water of the Earth are divided
into 5 oceans:
• the Atlantic, Pacific, Indian, Arctic and
Southern Oceans
• The rest of the Earth’s surface is made up of
large masses of land called continents (7 in
total):
• Asia, Australia, Europe, North America,
South America, Africa and Antarctica
Textbook
last page

4. Oceans and ARCTIC
continents OCEAN
66.5° 66.5°
NORTH ASIA
AMERICA EUROPE
23.5° ATLANTIC 23.5°
OCEAN
AFRICA
PACIFIC
OCEAN
INDIAN
OCEAN
SOUTH
AMERICA
AUSTRALIA
23.5° 23.5°
SOUTHERN
66.5° OCEAN
66.5°
ANTARCTICA

5. Locating Places and Features in an Atlas:
Latitudes
• Latitudes are
imaginary
horizontal lines
running in an
east-west
direction round
the Earth
• The Equator
is longest line
of latitude
which divides
the Earth into 2
equal halves

6. Locating Places and Features in an Atlas:
Latitudes
• The upper half from
the Equator to the
North Pole is called
the Northern
Hemisphere
• The lower half from
the Equator to the
South Pole is called
the Southern
Hemisphere

7. Locating Places and Features in an Atlas:
Latitudes
• Latitudes are measured in degrees from the
Equator
• They increase in value as we move from the
Equator to the North and South Poles
• The important latitudes are:
o
(a) Equator (0 )
o
(b) Tropic of Cancer (23.5 N)
o
(c) Tropic of Capricorn (23.5 S)
o
(d) Arctic Circle (66.5 N)
o
(e) Antarctic Circle (66.5 S)
o
(f) North Pole (90 N) Text pg 31
o
(g) South Pole (90 S)

8. Locating Places and Features in an Atlas:
Longitudes
• Longitudes
are imaginary
lines that run
in a north-
south
direction from
the North Pole
to the South
Pole on the
Earth’s
surface

9. Locating Places and Features in an Atlas:
Longitudes
• Longitudes are measured in degrees east or
o
west from the 0 longitude which is called the
Prime Meridian or the Greenwich Meridian
• Longitudes west of the Greenwich Meridian
o
are measured from 0 at the Greenwich
o
Meridian to 180 W
• Longitudes east of the Greenwich Meridian
o
are measured from 0 at the Greenwich
o
Meridian to 180 E
• Both 180 W and 180 E lie on the same
o o
longitude

10. Locating Places and Features in an Atlas: Using Latitudes and
Longitudes to locate Places
• Latitudes and longitudes cross each other to
form a network of lines or a grid
• This grid makes it possible to state the
exact location of any place on the Earth’s
surface
• To describe the location of a place on a
map, we state the latitude first, followed by
the longitude
• eg Singapore (position 1.18 oN 103.50 oE)
o o
: 1.18 north of the Equator and 103.50
east of the Greenwich Meridian

11. Locating Places and Features in an Atlas:
The International Date Line (IDL)
• The International Date Line (IDL) is the 180 o
longitude that lies directly opposite the
Greenwich Meridian
• our date moves back by one day when we
travel east across the IDL
• however our date moves forward by one day
when we travel west across the IDL
• IDL is not a straight
line and bends at
certain places to
allow these land
areas to have the
same calendar date

12. Time Zone Variations
• Places on different parts of the Earth
experience day and night at different times
due to the rotation of the Earth
• The world is divided into 24 standard time
zones:
• each time zone represents 15 longitude, or
o
the distance the Earth rotates in 1 hour
• the Greenwich Mean
o
Time (GMT) at 0
longitude, is the base
time zone

13. Time Zone Variations
• The nearest
time zone west
of Greenwich
experiences 1
hour earlier
than Greenwich
while the
nearest time
zone east of
Greenwich
experiences 1
hour later