Investigating the World Stage 4 Geography
Our World

• Recognise continents using different map projections.
• Use latitude to describe the global pattern of climate including the
spatial and seasonal change in insolation
• Use longitude to explain world time zones.
•Describe global patterns of physical and human features.
Map Projections

 Cartographers are people who make maps.
 They have different perspectives on how a world map can be
drawn and have invented different ways of showing the curved
surface of an almost spherical lump of rock—our planet—on a
flat piece of paper.
 These different ways of drawing the world are called map
projections.
 The Earth is a spherical shape, but it bulges at the middle due
to the quick rotation around its axis—once every 24 hours it
completes a revolution. It is flattened at the Poles and is a rough
irregular shape. This makes drawing maps of the world
difficult.
Map Projections

Map projections attempt to show correctly:
the shape of continents and oceans
the area or size of continents and oceans
the distance between two points
 direction.
How Are Map
Projections Made?

 Map projections are made by shining a light through
part of a transparent globe so that the lines of
latitude and longitude and the outlines of continents
and oceans make a chart on the screen behind it.
 On the drawn map, areas near the centre will be
about the right shape, but areas near the Poles will
be distorted.
Diagram showing how to
make a map projection

Types of map
projections

 The main types are constructed in the following ways.
 Cylindrical—By projecting the surface of the globe onto a
cylinder that just touches the outside edges of the globe
 Conical—By projecting the surface of the globe onto a cone
that just touches the outside edges
 Azimuthal—By projecting the surface of the globe onto a
flat surface that just touches the outside edges. Rectangular
maps are prone to area and distance stretching, while round
ones distort the shape.
 Interrupted projections - cut the world map along less
important features—like oceans—to show size and shape
correctly.
Diagram Of Different
Types Of Map Projections

Cylindrical

Diagram of Cylindrical

Conical

Diagram of Conic

Azimuthal

Diagram of azimuthal

Interrupted

Diagram of interrupted

Latitude

 Latitude measures how far north or south of the Equator
a location is.
 The Equator is an imaginary line that runs around the
middle of the Earth, separating it into two halves or
hemispheres
 Latitude and longitude are angles and therefore are
measured in degrees (°). The measurement of latitude is
between 0 degrees at the Equator and 90 degrees either
north (N) or south (S).
 The latitude of the South Pole is 90°S and the North Pole
is 90°N.
 Lines of latitude are called parallels because they never
meet each other. They run from east to west on a map.
Latitude Affects Climate

 Climate is the usual condition of the atmosphere near the
Earth’s surface—the long-term weather of a place.
Incoming solar radiation (insolation) is the energy that
reaches the Earth from the Sun and it determines our
climate.
 Insolation is greatest at the Equator because the Sun is
directly overhead and the rays hit the Earth’s surface at a
direct angle.
 Places at the Equator are generally hotter than places near
the Poles. At the higher latitudes the rays come in at an
angle and the same energy is spread over a larger area.
Diagram Of Zones Of
Latitude

Other Influences On
Climate

 Height above sea level—High elevations or altitudes
experience colder conditions.
 Ocean currents—Warm ocean currents bring wet
conditions, while cold currents bring dry conditions.
 Being close to the ocean—The ocean heats and cools
more slowly than land, causing temperatures to be milder
near the sea.
 Prevailing or usual wind patterns—Winds that come
over water may bring rain, but winds over land may
bring dry conditions.
 Aspect—North-facing slopes in the Southern Hemisphere
will be warmer than south-facing slopes.
The Seasons

 The amount of insolation is also affected by the
Earth’s orbit around the Sun.
 The Earth revolves around the Sun once a year and
spins on its axis at a tilt of 23 1⁄2 degrees. As the
Earth rotates on its axis and orbits around the Sun
different parts of the world receive more or less
energy.
 This creates the seasons— spring, summer, autumn
and winter.
The Seasons

 At the Equator there is very little difference between
the seasons. The further away from the Equator you
are, the greater the difference between the seasons.
 Twice a year at the Equator there are equal hours of
day and night. At the South Pole there are 24 hours
of darkness for six months in winter, and 24 hours of
daylight in summer.
Diagram Of How Seasons
Are Caused

Longitude

 Lines of longitude run in a north–south direction, or
longways, down a map.
 They are not parallel to each other so all the lines meet at
the North and South Poles.
 They are called meridians of longitude.
 Longitude measures the distance east or west of the Prime
Meridian or 0 degrees.
 The Prime Meridian is an imaginary line at 0 degrees that
runs from the North Pole to the South Pole passing
through Greenwich, a suburb of London. It is also
referred to as the Greenwich Meridian. This line separates
the Eastern Hemisphere from the Western Hemisphere.
Longitude Affects Time

 Day and night occur because the Earth is spinning on an
axis.
 It takes 24 hours for the Earth to complete one rotation. It
makes sense that the Earth is divided into 24 time zones,
one for each hour of the day. Some time zones zigzag so
that people living in a region can have the same time.
 Time changes as you move east or west. Each degree of
longitude represents a difference in time of four minutes.
 Each time zone of one hour is approximately equal to 15
degrees longitude. If it is 12 noon where you are, 15
degrees to the west it will be 11 a.m. and 15 degrees to the
east it will be 1 p.m.
How Does Time Work ?

 At the Prime Meridian, Greenwich Mean Time
(GMT) is set by the most accurate clock in the world.
 All other places in the world set their time according
to this clock
World Time Zones

Skills Question – Use The World Time Zone
Chart To Answer The Following Question

a)
b)
c)
d)
e)
f)
What time is it in Sydney when it is 11 a.m. Monday in London?
What is the time in London when it is 3 p.m. Tuesday in Sydney?
What is the time difference between Sydney and Los Angeles?
Jenny is in Sydney and wants to telephone her sister Anne in Los
Angeles at 6 p.m. on Sunday Los Angeles time. What time should
she call from Sydney?
Anne wasn’t home when Jenny rang so she left a message. Anne
didn’t return Jenny’s call until 8 a.m. Monday, Los Angeles time.
At what time did Jenny receive the call in Sydney?
Dave is flying from Sydney to Los Angeles. The flight leaves
Sydney at 2 p.m. on Tuesday and takes 14 hours. What is the day
and time when the plane arrives in Los Angeles?
Physical Maps

- Show Natural
Features Of The
World Including
Continents,
Islands, Rivers,
Mountains And
Elevation, Lakes,
Deserts, Oceans,
Seas And
Sometimes Ocean
Currents
Political Maps

– The countries are
coloured so that they
can be distinguished
from one another.
The continents are
not labelled, as the
map would become
cluttered.