01/12/2016. Introduction. Planet Earth. Plate Tectonics. Social Studies

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1 Introduction Social Studies Chapter 2 Canada s Physical Landscape Canada s geography its landforms and climate - has a great impact on Canadians sense of identity. Planet Earth The earth is divided into layers: Core: the center Made of 2 layers: a hot solid inner layer and a liquid outer core Mantle: the middle layer of the earth; made up of magma (melted rock). When Magma erupts from the Earth through an opening or crack it is called lava. Crust: the solid outer layer of the earth Continental Drift: Movement of the Earth s continents on the Earth s plates Plate Tectonics Plate Tectonics: Concept of convection currents and plate movement. The theory that plates move together to cause earthquakes, and form volcanoes and mountains. 1

2 The Theory of Continental Drift and Plate Tectonics First suggested by the German geologist and meteorologist Alfred Wegener in The theory states that the Earth's crust is divided into plates that move slowly due to convection currents in the mantle. Wegener hypothesized that there was a gigantic supercontinent 200 million years ago, which he named Pangaea, meaning "All-earth". Evidence to support Wegener s theory: The fit of the land masses Presence of similar fossils in rocks separated by an ocean Matching rocks on the either side of the Atlantic Ocean Canada s Crust Located on the northern part of the North American Plate 2

3 Moving 2-4cm a year to the west, separating from the Eurasian plate creating a separation on the sea floor called the Mid- Atlantic Ridge The Pacific Coast is located on the western edge of the North American Plate. The Pacific Plate moves in a north-easterly direction. This creates a subduction zone an area of the earth s crust where one plate slides beneath another. This creates volcanoes and cause earthquakes to occur. Earthquakes in Canada British Columbia experiences approximately onefifth of Canada s thousand or so earthquakes. Earthquakes occur along faults: the area where two plates meet Convection Currents Movement of liquid caused by heat (ex. water bubbling as it boils) The heat of the Earth s interior creates convection currents in the mantle Convection currents move the tectonic plates forming different landforms Landforms 3

4 What are Landforms? Landforms are the topography, or 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. Clarence Gagnon. In the Baie St. Paul Valley, Charlevoix Baffin Island - Lawren Harris (Group of Seven) 1931 There are urban and rural landscapes. Landscapes directly affect people s lives, influencing what they eat, how they earn a living, and many other factors of daily life. Topography can be described using the following terms: Elevation height of land above sea level. Relief difference in elevation between two points on the earth s surface Gradient refers to the steepness of slopes Geology the types of rocks and the history of those rocks General appearance the description of landforms How are Landforms Built? The earth s surface is built of material that comes from beneath the crust, or it is formed by the movement of the Earth s crust itself. How Are Landforms Shaped? Canada s topography is the result of four forces: Mountain Building (building up force) Weathering the breakdown of rock (wearing down force) Erosion wearing down due to running water, wind, waves and glaciers (wearing down force) Deposition depositing of eroded rock to make new landforms 4

5 Volcanic Mountains Formed when magma moves towards the surface. It pushes up the crust but then cools and hardens as it nears the surface. Fold Mountains formed when two plates collide and one moves upward. Mont Saint-Hilaire, an intrusive mountain in Quebec Herbert Lake in Banff National Park, Alberta, Canada. Block Mountain and Rift Valley When the land between two parallel faults is pushed up, a landform called a block mountain is formed. The process can also result in a block of land being pushed down, forming a rift valley. Plateau a large highland area of fairly level land separated from surrounding land by steep slopes. Some plateaus lie between mountain ranges. Others are higher than surrounding land. Plain flat land under a lake or sea that is exposed when the water recedes 5

6 Canada s Landform Regions Canada is so large that geographers divide it into regions to make it easier to study. A region is an area that is defined on the basis of the presence or absence of certain characteristics. Landform Regions Geographers classify landform regions based on a combination of characteristics: Age of rock Type of rock Relief Gradient Process that has shaped the area Canada s Landform Regions Canada is made up of three distinct landform regions: Canadian Shield Highlands Lowlands Within these landforms there are smaller sub-regions which have different characteristics Canada s Landform Regions Canadian Shield Highlands: Appalachian Mountains Western Cordillera Innuitian Mountains Lowlands: Interior Plains Great Lakes-St. Lawrence Lowlands Hudson Bay Lowlands Arctic Lowlands Canadian Shield 6

7 Canadian Shield The geological core of the country, from which all the other areas were created 4 billion years old in some areas Used to be a huge mountain range Over time was worn down by erosion, and now is nearly flat with rounded hills of rock Canadian Shield Made of different minerals and metals which were formed in the igneous and metamorphic rocks of the Shield Due to these mineral deposits, many towns and cities have been built on top of it (ie. Sudbury ON, Thompson MN.) The Shield is not well suited for farming, as the soil is thin on top of the rock, from glacial erosion. As well, water does not drain well as the Shield is rock, and impervious to water. Appalachian Mountains These mountains are the oldest highland region in Canada, formed about 300 million years ago. Appalachian Mountains Tectonic folding forced the layers of rock upwards as the North American plate collided with the plates of Europe and Africa during the formation of Pangaea. Appalachian Mountains Millions of years of erosion has worn the peaks of the Appalachians down into rolling hills and mountains. During the last ice age, the weight of the glaciers on the region forced the plate downwards, and allowed the flooding of the lower areas by the ocean. As a result, the coastline of the area is dotted with deep inlets. 7

8 The Innuitian Mountains These mountains were formed in the Mesozoic era, by the northward movement of the North American plate. The Innuitian Mountains Since these mountains are younger than the Appalachians, they have not been worn down as dramatically. Due to their location and climate, the mountains are barren as trees cannot survive on them. Mineral deposits in this region have been found, but are not commercially feasible, due to the remoteness of their location. The Western Cordillera This region, on the Western coastline of Canada, is made up of tall, rugged mountains. These features tell us that the mountains here are still geologically young. The Western Cordillera The interaction of the Pacific and North American plate led to the uplifting of the region into several mountain ranges. The large cities in this region (Victoria, Vancouver, etc.) are built in the flatter coastal area. Tourist towns, such as Banff and Jasper, offer tourists a view of the beauty of the mountains. Glaciers still exist in the northern and elevated areas of the region. 8

9 A Common Misconception of the Cordillera Region There are three distinct and different mountain ranges in this region: The Eastern Mountains (Rocky & Columbia Mountains) The Interior Plateaus (Okanagan Valley, etc) The Coast Mountains The Western Cordillera is therefore not only the Rocky Mountains, but several other ranges. The Lowlands There are three lowland regions in Canada, surrounding the Shield: The Interior Plains The Great Lakes-St. Lawrence Lowlands The Hudson Bay-Arctic Lowlands The bedrock of these regions was formed by the eroded material of the shield being deposited by the seas which covered parts of Canada. These sediments were gradually compressed over time into rock. Interior Plains This region stretches from the 49th parallel (the U.S.-Canada border) up to the Arctic Ocean (about 2700 km) Interior Plains At the southern point, the plains stretch 1300 km east to west, but are only about 275 km wide in the Northern regions. The soil that has developed in this region is fertile and deep, and has allowed the growth of many crops in the Prairie region (Canada s breadbasket ) The region was also shaped by glaciation, and lakes such as Lake Winnipeg were formed as a result of glacial forces. Great Lakes-St. Lawrence Lowlands South of the Canadian Shield, this region is made up of two different parts, which are intersected at one point (near Kingston) by the Shield. 9

10 Great Lakes-St. Lawrence Lowlands South of this point, the Great Lakes lowlands are found. The region is relatively flat and made up of sedimentary rocks left by glaciers. The Great Lakes were themselves gouged out of the landscape by glacial movement. The St. Lawrence lowlands were formed as a result of tectonics, in a process called faulting. Two plates moving apart left a valley in between, which became flooded with water. The St. Lawrence River is a result of this process. The warm climate and good soil of the Great Lakes-St. Lawrence region allow agriculture to prosper. In addition, these factors have allowed the growth of large cities, which are well situated for trade on the major waterways. About 50% of Canada s population live in this region, and 70% of the countries manufacturing takes place here. Hudson Bay & Arctic Lowlands The Northern regions of Canada are also relatively flat and formed from glacial debris and sediment. The harsher climate of this region makes it difficult for agriculture, as the ground remains frozen in many areas, year round. The Hudson Bay lowlands are located near the southwestern shore of Hudson Bay and James Bay. The Arctic lowlands refer to the islands scattered across Canada s far north. Climate 10

11 Classwork: Read p. 33 to 40 Define: Meteorology Climate Dewpoint Front Jetstream Microclimate Climograph Questions: 1. What are the 4 types of air masses? 2. What are the 3 types of precipitation? 3. What are the 7 factors that affect climate? Weather atmospheric conditions on any given day Climate patterns of weather conditions over the long term. Meteorology the science of studying weather Climate is a major factor of Canada s geography that affects all Canadians and their sense of identity. W. Kurelek Factors that influence climate: Global factors that influence climate Latitude Air masses Winds Ocean currents Clouds Precipitation Regional factors that affect climate Altitude Bodies of water Mountain barriers Latitude Global Factors that influence Climate As distance from the Equator increases, it gets colder due to less direct sunlight. 11

12 At low latitudes the sun s rays strike the earth at a direct angle, are more intense and heat a small area, it is warmer. At high latitudes, because of the curve of the earth, radiation strikes the earth at an indirect angle, is spread over a larger area, is less intense, and it is colder. Air Masses and Wind Air mass A huge body of air with the same temperature and moisture conditions throughout. Wind air moving from one place to another. Types of Air Masses Classifying by moisture levels: Types of Air Masses Classifying by temperature: Maritime Air forms over water and is moist Continental Air forms over land and is dry Tropical Air warm, originate near the equator Arctic Air cold (Polar Air cool), originate in the north/poles Types of Air Masses These can create different types of air masses. For example: Maritime Tropical (mt) air is warm and moist. Ocean Currents The movement of large quantities of ocean water, can be warm or cold, making the surrounding area the same. 12

13 Precipitation Front: The leading edge of an air mass Warm front the leading edge of a warm air mass. Cold front the leading edge of a cold air mass. North Pacific Current brings warm water/air to coast of British Columbia. Labrador Current brings cold water/air to Newfoundland & Labrador. Gulf Stream brings warm water/air to Atlantic Canada. Dewpoint The temperature where condensation occurs Types of Precipitation There are 3 types of precipitation: 1. Frontal 2. Convectional 3. Relief or Orographic Frontal Precipitation When two air masses meet, the warmer one will rise over the colder one. As it rises, the air will cool and condense, causing it to rain. Convectional Precipitation Occurs as a result of vertical movement within an air mass. Occurs over flat land on a hot summer day. The land will heat up quickly, the air will rise, cool, and precipitation will result Relief or Orographic Precipitation Occurs when moist air moves over a mountain barrier When moist air comes in off the ocean and it has to rise over a mountain it will cool, condense and rain will occur The opposite (leyward) side of the mountain is very dry (rain shadow) 13

14 Altitude/Elevation: Regional Factors that affect Climate Temperature decreases as elevation increases. As you go higher above sea level, the temperature decreases due to the thinning of the air Mountain Barriers Orographic effect (Rain shadow) Winds with moisture cool as they move up the mountain and dry out windward side Weather patterns weaken or are even stopped as they move across the mountains leeward side Proximity to Water Water heats up and cools down more slowly than land. Bodies of water have a moderating effect on temperature. Places close to large bodies of water will have less extreme temperatures. In summer the ocean is cooler than the land, winds from the ocean cools the land. In winter the water keeps the heat longer, and winds from the ocean warm the land. Places inland will have more extreme temperatures. In summer the land is warm, meaning warm temperatures. In winter the land is cold, resulting in colder temperatures. No ocean winds are nearby to moderate the temperature. Maritime Climate located close to the ocean has moderate temperatures has cooler summers and warmer winters receives more precipitation Continental Climate located away from the ocean has extreme temperatures has warmer summers and colder winters receives less precipitation 14

15 Climate Zones in Canada Climate Zones in Canada A climate zone is an area that experiences similar weather conditions within its boundaries throughout a year. Developed in the early 1920 s by Wladimir Köppen, a German botanist and climatologist. Köppen divided the world s climate into five types based on total annual temperatures and their precipitation, and their distribution throughout the year. The Köppen system recognizes five major climatic types; each type is designated by a capital letter. Climate Zone A Tropical Moist Climates: all months have average temperatures above 18 Celsius. not found in Canada Climate Zone B Dry Climates: with deficient precipitation - evaporation and transpiration exceeds precipitation during most of the year. Can be cool or warm Climate Zone C Warm, moist climates Mild winters and warm, humid summers Parts of coastal British Columbia 15

16 Climate Zone D Cool, moist climates Most of Canada Wide range of average temperatures Climate Zone E Polar Climates: Extremely cold winters and cool summers Very Dry Climographs mm J F M A M J J A S O N D C 16