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CHAPTER 2 : CANADA’S PHYSICAL LANDSCAPE Canada’s geography (landscapes and climate) has a profound effect on Canada’s identity. Canada has some of the oldest rock in the world (about 4 billion years old) The Earth is formed in layers. The innermost layer of the Earth’s interior is called the core. This is a solid layer of rock The middle layer of the earth, the Mantle, is not solid but a hot, dense, slow moving liquid called magma. A German scientist named Alfred Wegener developed a theory called Continental Drift. This theory states that the earth’s crust is not continuous but made of several plates that are slowly moving. Wegener believed that the earth’s continents were once joined together in 1 supercontinent called pangaea. The movement of the continents on the earth’s plates is called Continental Drift. Canada is moving further away from Europe at a rate of 2-4 cm every year. A Subduction Zone occurs when 1 plate on the earth;’s crust slides beneath another plate . This is the case on the Pacific coast. This is why the west coast of Canada is prone to earthquakes. Landforms are the natural features of the land’s surface. Landscape refers to an area’s landforms together with its cover of vegetation, water, ice, rock and the activities of life forms. The topography or features of the land’s surface is described by several factors : 1. Elevation = height of land above sea level 2. Relief = difference in elevation between points on the earth’s surface 3. Gradient = the steepness of the slopes 4. Geology = the types of rocks and their histories 5. General Appearance = a description of the landforms Landforms are built or created in several ways. Sometimes, convection currents in the earth’s mantle causes magma to break through the earth’s crust in the form of lava and volcanic ash. Sometimes, magma causes earth’s plates to separate or collide. This causes the crust to move upwards creating block mountains or downwards to create trenches or rift valleys Block Mountain Rift Valley - Iceland Lava is magma that flows onto the earth’s surface Magma is molten rock within the earth. Fault is a break in the rocks on the earth’s crust along which movement can take place Fault Lines Lava Magma Landforms are by 4 forces : 1. Mountain building 2. Weathering = wearing down or exposure to atmosphere 3. Erosion = wearing down 4. Deposition = rocks are deposited elsewhere to form new landscapes Plateaus are relatively flat areas that occur between mountains. It is formed as a result of movements of the earth’s crust. Plains are lands formed under a lake or a sea. It was exposed as the water receded. Canada was almost completely covered by ice 18000 years ago. A shield is the base of an ancient mountain. The Canadian Shield was formed during the Precambrian Era. Canada is so large that Geographers break it into regions. A Region is an area that shares common features which makes it different than other areas. Landform Regions are classified according to : 1. Age of rock 2. Type of rock 3. Relief 4. Gradient 5. Process that shaped the area Canada has 8 major landform regions : 1. 2. 3. 4. 5. 6. 7. Canadian Shield Appalachian Mountains Western Cordillera Innuitian Mountains Arctic Lowlands Interior Plains Great Lakes-St. Lawrence Lowlands 8. Hudson Bay Lowlands The Canadian Shield has the oldest rock in Canada (4 billion years old). It acts as the foundation of Canada’s other landform regions. Much of the Shield has thin acidic soils called podzols. This soil is not good for farming. However, in areas where glacial lakes have left deposits (Great Lake area), the soil is good for farming. The Appalachian Mts were probably formed about 375 million years ago when the Eurasian and North American plates collided during the formation of Pangaea. Appalachians have been worn down over time to rolling hills and broad valleys. A typical height for mountains in this chain is 1000m. The Western Cordillera is a series of parallel mountain ranges including the Coast Mts, Columbia Mts, and the Rocky Mts. Average height of mountains in this chain is 3000m and they are separated by extensive plateaus Western Cordillera includes British Columbia, Yukon and Alberta. The Innuitian Mts are located in the far north. They rise over 2000m with steep sides. It is too cold for tree growth. The Arctic Lowlands, located to the south of the Innuitians, is a region of tundra with a cold dry climate and poorly drained soil The Interior Plains is located between the Canadian Shield and the Western Cordillera. It was created when inland seas receded. In Canada, the Interior Plains covers most of Alberta, Saskatchewan, Manitoba and the Northwest Territories In some parts of the Plains, the deep, moist soil called black earth or chernozen is ideal for growing wheat The Great Lakes-St. Lawrence Lowlands was formed about 10,000 years ago when the Champlain Sea, an ancient arm of the Atlantic Ocean, retreated. This retreat left deposits of sands and clays in a nearly level area. This created a very fertile soil called brown earth. The Hudson Bay Lowlands is within the southern area of the Canadian Shield. It’s mainly flat but poorly drained. Its soil is a mix of tundra and podzols creating wetlands. Profile Maps Rules for drawing profile maps : 1. Copy the elevations on the map to the lines below (lowest on bottom) 2. Using the line (AB) drawn across the map, place a dot at each point that the AB line touches the contour lines. 3. Using a straight-edge, place on each dot and place a new dot on the lines below on the appropriate contour line (see dotted lines on map). NOTE : YOU DO NOT DRAW THE DOTTED LINES! 4. Connect the dots below to show the horizontal image. ( solid black line on map) Homework : Complete the 3 profile map below (see handout) for homework Determining Geographic Significance is based on several factors : 1. Magnitude : How important is the influence? 2. Scope : How many people will be affected? 3. Duration : How long will it last? Assign activity chart on page 32. Climate and Weather The science of weather is called meteorology Climate is how we describe the patterns of weather conditions over a long period of time. Ex. Last winter was very wet and cold. The elements of climate include : Global Factors Regional Factors 1. 2. 3. 4. 1. Altitude 2. Bodies of Water 3. Mountain Barriers Latitude Air Masses & Winds Ocean Currents Clouds & Precipitation Global Factors Affecting Climate : 1. Latitude = because the earth is round, places closer to the Equator gets increased sunlight and therefore warmer climates. Places closer to the Poles have cooler climates. 2.Air Masses takes on the temperature and humidity characteristics of the area in which it originates. Moves as a result of changing air pressure systems. 3. Ocean Currents Air passing over an ocean current is influenced by the characteristics of that current. Ex. the Gulf Stream brings warm moist air to the Maritimes whereas the Labrador current brings a cold moist air mass and climate to the same region. 4. Clouds & Precipitation : these occur when water vapour in the air cools below the dew point. 3 types of precipitation : A. Orographic B. Convectional C. Frontal Watch video clips “Weather and Climate Part 2, 3 and 4 in Staff Shared Folder - Orographic = precipitation air cools as it rises over higher ground Warm, dry air Air cools and condenses as it rises Hot, moist air Hot dry air Convectional = air rises when warmed from below Frontal = when warm air and cold air meet, the warm, moist air rises Regional Factors Affecting Climate : 1. Altitude = the higher you are from sea level, the thinner the air is and the colder the temperature gets. (Every 100 m = -1.0˚C) 2. Proximity to Water : Land and the air above it heats up quickly & cools quickly whereas the water is much slower. Thus, areas near the water stays cooler in the summer but warmer in the winter than areas inland. 3. Mountain Barriers : west-facing windward sides of mountains tend to be wetter than the east-facing leeward sides of mountains. A climate region is an area that experiences similar weather conditions within its boundaries throughout the year. A German climatologist named Wladimir Koppen divided the world’s climates into 5 zones. Canada has 4 of these zones. These zones are : A. Tropical = not in Canada B. Dry climates = more evaporation than precipitation C. Warm, Moist climate = humid summers, mild winters D. Cool, Moist climates = 70% of Canada cool summers and precipitation most of year E. Polar Climates = North has 2 very cold and dry climates A Microclimate is a smaller climate area within a bigger area where the average conditions are different from the rest End of chapter 2