Transcript Geographic Fundamentals

Social Studies
Geographic Fundamentals Review
Geographic Basics
Continents
 There are seven continents –
North America, South America,
Europe, Asia, Africa, Australia
and Antarctica.
 Geographers describe
continents as large continuous
bodies of land.
 Greenland is sometimes
described as an island
continent but it is not a true
continent
 The Caucasus Mountains are
the general boundary between
Europe and Asia.
Hemispheres
 The term hemisphere means
half a sphere.
 The earth is divided into a
northern hemisphere and a
southern hemisphere.
 These two hemispheres are
divided by the equator.
 There is also an eastern
hemisphere and a western
hemisphere.
 The prime meridian or
Greenwich meridian divides the
eastern and western
hemispheres.
Cardinal Directions
 The four cardinal or main
directions are north,
east, south and west.
 There are also four
intermediate directions
which are points halfway
between each pair of
cardinal directions.
 The intermediate
directions are NE, SE,
SW and NW.
Map Basics
To be useful a map
should have
A Title
A Legend
Scale
Maps use many
symbols to illustrate
the various features
depicted.
A Map Legend
Map Projections
Map Projections
 The earth is round or
three dimensional but
maps are flat or two
dimensional.
 To transfer any portion of
the earth’s spherical
surface to a flat map a
map projection must be
used.
 There are many different
types of map projections.
Map Projections II
 A projection may be
“equidistant” and preserve
the accuracy of distances or
directions from any point.
 “Conformal” projections
preserve directions at any
point on the surface of the
earth.
 “Equal area” projections
preserve the size of any
area on the globe.
 There are projections which
do not do any of these
things.
Map Projection
Of Canada
Map Projections III
 The type of projection
used will depend on
several factors including
the purpose of the map.
 The Mercator projection
is one of the most
famous projections.
 It has long been popular
because it produces a
rectangular map but it
tends to distort areas of
the globe located at high
latitudes.
Map Projection of the World
using a Cylinder
Map Scale
Map Scale
Map scales allow geographers to relate
the distance on a map to actual distance
on the surface of the earth.
For example if 3 cm on a map represents
1 km on the ground then the scale would
be
Line Scale
This type of scale appears as ruler or bar on the
map.
In the example each interval or space along the
ruler stands for 10 km on the earth’s surface.
A piece of paper can be used to mark the
distance between two places on a map and then
applied to the line scale for measurement.
Representative Fraction
Representative Fraction or RF scale is expressed
as a ratio.
RF scale is very useful because it applies easily
to any units of linear measurement so it can be
used for yards, meters or feet.
An RF of 1:25,000 means that one unit of
measure on the map is equal to 25,000 of that
same unit of measure on the ground.
Using metric units an RF of 1:2,000 means that
one cm on the map represents 20 meters on the
ground.
Detail and Scale
 Small scale maps do not
show very much detail.
 Large scale maps are
very detailed.
 An RF of 1:40,000,000
would be a small scale
map and not detailed.
 Whereas an RF of 1:
2,000 would be a large
scale map and very
detailed.
Latitude and Longitude
Earth Grid
 An earth grid is a series
of lines on the surface of
the globe which are used
to locate places and
objects.
 A simple grid uses
horizontal and vertical
parallel lines which can
be numbered or lettered.
 The grid position of the
object is 6E.
Military Grid Reference
System
 This rectangular grid
appears on topographic
maps.
 The numbers identify
horizontal and vertical
lines.
 To locate the circle the
line to the west (91) is
used first, followed by
the line to the south (94).
 The reference square for
the circle is 9194.
Military Grid Reference
System II
 A more precise reference
for the circle can be
obtained by dividing the
reference square into 100
smaller squares.
 The circle is 5/10 of the
way between lines 91
and 92 and 6/10 of the
way between lines 94
and 95.
 The exact location of the
circle is 91(5) and 94(6)
or 915946.
Latitude and Longitude
 Latitude and longitude form a
slightly more complex earth
grid which has specific
application on the spherical
surface of the globe.
 The earth rotates around an
imaginary axis which if
extended become the north
and south poles.
 An imaginary line drawn on
the earth’s surface connecting
all points that are exactly
halfway between the poles is
called the equator.
Latitude
 It is from the equator
that all lines of latitude
are measured 90 degrees
north and south to each
pole.
 The equator is a great
circle because it divides
the earth into two equal
parts.
 The shortest distance
between any two
locations on the earth’s
surface is a great circle.
Latitude II
A line connecting
points of equal
latitude is called a
parallel of latitude.
This line is parallel
to the equator and
to all other lines of
latitude.
Longitude
 Lines of longitude are drawn through
the north and south poles to intersect
with lines of latitude.
 The Greenwich meridian or prime
meridian is the line of longitude from
which all other lines are measured –
east and west – around the globe.
 Lines of longitude are measured from
0 degrees at the prime meridian to
180 degrees at another line called the
International Date Line.
 Meridians of longitude are not parallel
to each other because they converge
at the poles.
Latitude and Longitude
With this grid system any point on the
earth’s surface can be accurately located
in degrees, minutes and seconds.
Each degree contains sixty minutes and
each minute sixty seconds.
The latitude and longitude of Vancouver,
British Columbia is 49 13N 123 06W.
Time
Time Zones
 Time zones are organized so that
most places in the world have the
sun at its highest point in the sky
at noon.
 The earth rotates 15 degrees of
longitude each hour which allows
the world to be divided into 24
time zones (15 X 24 = 360).
 All time zones are measured from
the prime or Greenwich meridian.
 At the Greenwich meridian the
time is described as GMT or
Greenwich Mean Time.
Time Zones II
Greenwich Mean Time is sometimes described
as Universal Time and useful for airlines and
other organizations wishing to use only one
standard time.
The International Date line is located on the
opposite side of the globe from the Greenwich
meridian.
Not all time zones follow exactly the 15 degree
divisions around the world.
Political and administrative considerations often
result in modifications to this system.
Time Zones II
In Canada we have several standard time zones.
In British Columbia we use Pacific Standard
Time which is 8 hours ahead of GMT.
When it is noon in Vancouver it is already 8 PM
on the Greenwich meridian.
Our time zone is called zone + 8 so we must
subtract 8 hours from GMT to determine our
time.
Daylight-Saving Time
 Daylight-saving time is used
to make a small adjustment
to daylight hours in the
summer to conform to the
time when people are awake.
 Usually the clock is advanced
one hour on the first Sunday
in April and set back one
hour on the last Sunday in
October.
 The phrase “spring forward,
fall back” helps us to
remember which way to set
our clocks.
Topographic Maps
Topographic Maps
Topographic maps provide the geographer with
images of data related to the surface of the
earth.
A topographic map provides a three dimensional
picture of a portion of the earth’s surface on a
flat map.
In addition a topographic map shows all of the
human alterations to the natural environment
such as roads, railways and cities.
Contour Lines
 Topographic maps are
standard maps used
for most navigation on
the earth’s surface.
 On these maps
contour lines are
continuous lines
marking all points of
the same elevation
 All points on a contour
line are at the same
height above sea level.
Contour Lines II
 Contour lines which are
close together represent
a steep slope.
 Widely spaced lines
indicate a gradual slope.
 Contour lines form a V
pattern crossing a stream
and the V always points
upstream.
 A U shaped contour line
points downhill.
Contour Lines III
A profile across a
topographic map may
obtained by drawing
a line between two
points; X and Y.
The profile can then
be drawn as
illustrated in the
diagram.
Contour Lines IV
 This topographic map
shows a small area of
Poland.
 Note the contour lines
which are found along
the river in the centre of
the map.
 Because the lines are
close together they show
a valley with fairly steep
sides.
Graph Skills
Circle Graphs
 Circle graphs are used to
show the relationship
between a whole thing
and its various parts.
 These graphs are
sometimes referred as
pie charts or graphs
 This graph shows the
percentage of the
population speaking
English, French and other
languages in a small
community.
Languages Spoken
Bar Graphs
Bar graphs use
columns to show a
relationship between
two or more ideas.
They allow visual
comparison of the
parts of something
with the whole.
SCHOOL GROWTH
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Line Graphs
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The lines on a line
graph show how
things grow in
number or size.
The can also allow us
to project the trend of
growth by extending
the line in the general
direction of its
movement.
Average Test Marks
Climate
What is climate?
 Weather is what happens
on a daily basis.
 It may rain, snow or be
sunny and clear.
 Climate is the average of
weather conditions over
an extended period of
time.
 Just like the weather
climate is highly variable.
Climate
 It is common to use July
and January as months in
which climate is
compared.
 The highest temperatures
in the northern
hemisphere are usually
reached in July.
 In January temperatures
are generally at their
lowest.
Temperature Maps
 The lines on the map in
the diagram are called
isotherms because they
connect places with the
same average
temperature.
 The spaces between each
isotherm are zones which
are coloured to allow a
clearer view of the area
of similar temperature.
Average July Temperatures
Climate Graphs
 Climate graphs show the
average annual
temperature and
precipitation figures for
any selected place.
 The line graph is used to
show the temperature for
each month from January
on the left to December
on the right.
 The bar graph shows the
precipitation for each
month.
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Climate Controls - Latitude
 Temperature is affected
by latitude.
 The farther north or
south of the equator the
colder it will generally be.
 This is because the sun’s
rays cover a larger area
in the higher latitudes.
 In the lower latitudes
near the equator the
sun’s rays are more direct
and cover a smaller area.
Climate Controls – Ocean
Currents
 Three ocean currents affect
Canada.
 The warm Alaska Current sweeps
across the North Pacific onto the
coast of British Columbia.
 The cold Labrador Current comes
out of the Arctic and extends down
the coast of Atlantic Canada.
 Finally, there is the warm Gulf
Stream which originates in the
Caribbean Sea and flows north to
moderate the Labrador Current.
 Each of these ocean currents has
an important role to play in
regulating weather conditions on
the coasts of Canada.
Climatic Controls – Air
Masses
 Air masses tend to have the
same average temperature
and level of moisture.
 These factors are
determined by where the
air originated.
 Arctic air masses tend to be
cold and dry whereas
Pacific air masses are warm
and moist.
 Air masses take with them
these climatic conditions
and in turn influence the
areas into which they move.
Climatic Controls Elevation
 Air cools by one degree
Celsius for every 100
meters of elevation.
 This is because it
expands as it rises and,
as a result, loses heat.
 A relative humidity of
100% reduces the rate of
cooling as water vapour
condenses to form water.
Climatic Controls - Relief
 Relief is the variation in
elevation on the surface
of the earth.
 High mountains block the
movement of air masses.
 On the west coast of
Canada the Coastal
Mountains force warm
moist Pacific air to rise.
Climatic Controls – Relief
II
 On the windward slope
this becomes rain or
snow but on the leeward
slope the warm air
retains moisture and it is
dry.
 We call this the
“rainshadow” effect.
 Relief rain is called
orographic percipitation.
Climatic Controls –
Proximity of Water
 Large bodies of water
have the effect of
moderating land
temperatures keeping
temperatures cool in
summer and warmer in
winter.
 Regions which are close
to oceans or large lakes
will also tend to receive
more precipitation
because air masses will
absorb the moisture.
Climatic Controls –
Proximity of Water II
We call climates
which are removed
form the influence of
bodies of water
“continental.”
Regions close to large
bodies of water will
have “maritime
climates.”
Conclusion
Geography
Geography is a study
of basic skills which
can be applied to the
use of maps and
globes.
It is also a study of
the interaction of the
earth and the natural
forces which act upon
it.