Unit Two – Geographical Influences on
Identity
Canada’s
physical geography, its landforms and climate have a profound influence on
Canadians’ sense of identity. The poem
“Unity” by Michael O. Nowlan captures an amazing sense of what it means to be
Canadian.
Building Landforms
Planet Earth
The earth is made up of many different rocks of various
ages. Canada
has some rocks as old as four billion years, some of the oldest on record. Scientists believe that the earth formed in
layers. The denser materials settled in
the earth’s center, while lighter materials, including gases formed the outer
layers and the atmosphere.
The core, the earth’s center has two layers: a solid inner
core which is very hot due to pressure, and a liquid outer core. The earth’s crust is the surface layer and it
is solid. The mantle or middle layer is
made up of a type of melted rock known as magma. Magma is a hot, dense and slow moving fluid.
Movement of the Crust
A German scientist named Alfred Wegener developed the theory
of continental drift. This theory
proposed that the earth’s crust is not continuous. Instead it is divided into a number of plates
that move due to currents in the earth’s mantle. Pangaea, the name given to the
Supercontinent is made up of all the earth’s continents. Over 100 million years ago, Pangaea began to
split apart. The continents are still moving today.
Evidence for Wegener’s theory includes:
- The
fit of continental land masses
- The
presence of similar fossils in rocks now separated by oceans
- Matching
magnetic bands in the rocks on
either side of the mid-Atlantic Ridge
- The
fact that fossils of sea animals have been found high in the rocks of the Himalayas
Canada’s Crust
Canada
is located on the northern part of the North American Plate. This plate moves westward at 2cm to 4cm each
year. Canada’s
Pacific Coast
is the western edge of the North American Plate. The Pacific Plate moves in a northeasterly
direction. This creates a subduction
zone – an area of the earth’s crust where one plate slides beneath
another. This creates volcanoes and
potential earthquakes. Thus, each year British
Columbia experiences approximately 1/5 (200) OF Canada’s
thousand or so earthquakes. Plate
movement also means the distance between Atlantic Canada and Europe
increases each year.
What are Landforms?
Landforms are the topography or the natural features of the
land’s surface. A landscape is an area’s
landforms together with its cover of vegetation, water, ice and rock. Landscape also includes the activities of humans
and other animals. Cities are often
referred to as urban landscapes, while agricultural areas are called rural
landscapes. Landscapes can also have an
effect on people’s lives, influencing what they eat, how they earn a living,
who they do business with and many other factors of daily life.
Topography may be described using the following terms:
- Elevation
– used to describe the height of a landform, from sea level
- Relief
– the difference in elevation between points on the earth’s surface
- Gradient
– refers to the steepness of slopes
- Geology
– types and history of rock
How are Landforms
Shaped?
Canada’s
topography is the result of four forces:
- Mountain
building
- Weathering
- Erosion
- Deposition
See figure 2.8 on page 25 of your textbook.
Canada’s Landform Regions
Canada
is so large that geographers divide it into regions to make it easier to
study. Geographers classify landform
regions based on a combination of characteristics:
·
Age of rock
·
Type of rock
·
Relief
·
Gradient
·
Process that has shaped the area
Geographers agree on the following eight regions in Canada:
·
Canadian Shield
·
Appalachian Mountains
·
Western Cordillera
·
Innuitian
Mountains
·
Arctic Lowlands
·
Interior Plains
·
Great Lakes – St. Lawrence Lowlands
·
Hudson Bay Lowlands
See figure 2.11 on page 27 of your textbook.
Climate and Weather
Weather is another major factor of Canada’s
geography. Weather affects all
Canadians and their sense of identity.
Meteorology, the science of weather was one of the first sciences to
develop. Climate is how we describe the
patters of weather conditions over the long term.
What are the Elements
of Climate?
The temperature or climate of any giver room can be
controlled by adjusting the thermostat, or opening a window. The earth also has controls that act upon the
elements to produce different types of weather and climate. There are two main sources which influence
weather; global and regional location.
Global Factors
- Latitude
– the further away one is from the equator, the less intense is the solar
radiation (sunshine). For example,
solar radiation is the most intense along the equator, and it lessens as
you move towards the North or South Poles.
- Air
masses and Winds- if a volume of air remains in a place long enough it
will take on some of the characteristics of that place. There are four traditional air masses
all having different characteristics.
They are:
i.
Maritime Tropical – warm water makes the air warm and
moist
ii.
Maritime Polar – cold water makes the air cold and
moist
iii.
Continental Arctic – cold land
makes the air cold and moist
iv.
Continental Tropical – desert makes the air hot and dry
Storms are the result when two or more air masses clash.
- Ocean
Currents – move immense amounts of heat and cold around the world. Air passes over an ocean current is
influenced by the temperature of that current.
Regional Factors
- Altitude
– air temperature drops as altitude increases and air pressure decreases
(the higher you go, the colder it gets).
- Bodies
of Water – water heats up more slowly than land but retains its heat for a
longer period of time. Thus bodies
of water such as lakes and oceans influence climate.
- Mountain
Barriers – as the name implies mountain ranges block weather patterns,
usually creating high amounts of precipitation, both snow and rain.
Climate Regions of Canada
There are five climate types generally accepted world wide:
- Tropical
Climates- Canada
does not have any tropical zones
- Dry
Climate – when the rate of evaporation exceeds the amount of
precipitation. Canada’s
dry climate zone has an annual temperature of less than 18*C
- Warm,
Moist Climate – warm humid summers and mild winters
- Cool,
Moist Climate – this is the climate of over 70% of Canada
- Polar
Climates – Canada’s
north, very cold and dry, covers about 25% of our country.