Geo Exam Review - Unit 2 PDF

Unit 2: Interactions in the Physical Environment Plate tectonics is the theory that Earth’s outer shell is made up of individual plates that move. This event can cause earthquakes, volcanos, mountains, and the formation and destruction of the crust. There are three types of plate movement. Divergen...

Unit 2: Interactions in the Physical Environment Plate tectonics is the theory that Earth’s outer shell is made up of individual plates that move. This event can cause earthquakes, volcanos, mountains, and the formation and destruction of the crust. There are three types of plate movement. Divergent boundaries occur when two plates move away from each other. This event happens more commonly along a mid-oceanic ridge. A mid oceanic ridge is a feature created by the spreading of the sea floor where two plates are diverging. The best known example runs through the Atlantic ocean from north to south. Convergent boundaries happen when two plates move towards each other. There are two types of convergence. 1.​ Continental plate meets oceanic plate: The heavier oceanic plate slides underneath a continental plate. This process of one plate sliding under the other is called subduction, where the crust that moves into the earth’s interior is melted and “recycled”, balancing the new crust forming at a divergent plate boundary. 2.​ Continental plate meets continental plate: When two continental plates run into each other, massive layers of rock are folded, broken, and forced upwards by the pressure of the collision. This process has created some of the world’s most important mountain ranges, such as The Himalayas (including Mount Everest). 3.​ Transform: This occurs when two plates move in opposite directions, and plates are neither larger nor smaller. In some occasions, these plates can lock up for many years until a massive release of energy occurs, resulting in earthquakes. —---------------------------------------------------------------------------------------------------------------------------- Rock cycle - There are three forms of rocks: Igneous, Sedimentary, and Metamorphic rocks. Igneous rocks form when magma or lava cools. Most cooling happens out of sight, either at the bottom of the ocean or inside earth’s crust. Sedimentary rocks are created after millions of years of compaction and cementation of loose sediments. The type of sedimentary rock depends on the sediment. Metamorphic rocks are changed versions of igneous, sedimentary, and other metamorphosis. This change occurs when the rocks are exposed to great amounts of heat and pressure. —---------------------------------------------------------------------------------------------------------------------------- Glaciation - Glaciation is the process of ice advancing and covering large areas of land. Although it’s not as powerful of a force as plate tectonics, it’s still important to the formation of the Canadian landforms that we see. The two impacts of glaciation are erosion and deposition. Erosional effects include the removal of materials and changes to drainage patterns. Depositional effects have two types:  1.​ Deposition by meltwater: Fast-moving meltwater can move heavy particles like gravels and rocks. 2.​ Deposition by ice: Two common features formed by ice are till plains, which are small hills and valleys, and moraines, which are deposits of till that form at the edges of a glacier. —---------------------------------------------------------------------------------------------------------------------------- Landform regions of Canada - Canada’s landform regions are divided into three types: Canadian shield: An immense area of ancient, worn down mountains. It is the geologic foundation of Canada, and by far the oldest and largest landform region. -​ It is of Precambian age. -​ It covers more than half of Canada, most of Greenland, and two small areas of the United States. -​ Aboriginal people are the majority of the population on much of the shield. -​ It is one of the most important sources of metallic minerals and diamonds. -​ Most of the shield is not good for farming due to the rock and poor soil. -​ It has a large supply of fresh water -​ Most of its rivers flow into Hudson Bay. -​ Rivers in the south part of the Shield are used to generate hydroelectric power. Lowlands: This area surrounds the Canadian Shield. The three lowlands are: 1.​ Interior Plains: -​ One of the two most important agricultural areas in Canada (along with the GL-SL), accounting for about 75% of the country’s total farm production. -​ The sedimentary rocks beneath the IP are very important to the production of oil and natural gas. -​ This region is the world leader in the production of potash 2.​ Great Lakes St. Lawrence Lowlands: -​ One of the two most important agricultural areas in Canada (along with the IP), accounting for about 75% of the country’s total farm production. -​ Almost 60% of Canadians live in the GL-SL, even though the area makes up only 2% of the country. 3.​ Hudson Bay Arctic Lowlands: -​ Aboriginal people are the majority of the population Highlands: This area surrounds the lowlands. The complex geology of its regions results in valuable mineral resources found in some locations. The three highlands are: 1.​ Western Cordillera 2.​ Innuitian Mountains -​ Canada’s most remote region and has no full time population 3.​ Appalachian Mountains -​ Much older, hence shorter than the IM and WC. -​ Not all of the AM has high elevation. —---------------------------------------------------------------------------------------------------------------------------- Climate factors - The LOWERN factors include: Latitude: The farther you are from the equator, the less direct sunlight you receive. Ocean currents: Ocean currents moving away from the equator are relatively warmer than the surrounding water, while currents moving towards the equator are cooler. Winds/air masses: Air masses forming over an ocean contain moist air, while one forming far from the ocean has very dry air. Elevation: At a higher elevation, air rises and pressure decreases. As a result, the air expands and cools. Relief: Relief in geography means the shape of the surface of land. It is an important factor in determining the amount of precipitation the area gets. Places on the windward side (side facing the wind) of a height land gets more rain and snow than places on the leeward side. Near water: Places that are closer to an ocean have a maritime climate, with mild temperatures. Places that are far from oceans have a continental climate, with extreme temperatures. —---------------------------------------------------------------------------------------------------------------------------- Soil - Soil profile is the three different layers that exist in the soil beneath the surface of the ground. Leaching is when too much water is constantly moving downwards through soil. This process removes nutrients important for plant growth, such as mineral compounds of nitrogen, phosphorus, potassium, etc. When leaching occurs, the soil loses fertility and tends to be a greyish colour. Wet-climate soils are soils that develop where leaching is the dominant soil-forming process. Dry-climate soils are soils that develop where calcification is dominant in the soil-forming process. In these drier areas, moisture moves upwards, bringing valuable plant nutrients with it. The rich and dark topsoil layer stands out. However, if the climate is too dry, the soil will be infertile. Tundra soils cover most of Canada, and are found in areas with extremely cold climates. They tend to be rich in old plant material that can’t decompose because it’s too cold. Permafrost is an unusual soil condition that commonly exists in Tundra soils.In the far north of Canada, only the top meter or so of the soil thaws in the summer, which is called an active layer. The lower layer that remains frozen is the permafrost, preventing water from draining away and resulting in waterlogged and swampy areas. Feedback loops are cycles in which the output of a process becomes an input back into the process. —---------------------------------------------------------------------------------------------------------------------------- Vegetation processes - The two types of trees in Canada: Coniferous (also called evergreen, needle-leaved, softwood): -​ They have a pointy and needle like leaf shape -​ Can survive in areas with poor quality soils -​ Their sticky sap stops needles from freezing in cold winters -​ Waxy needles and thick bark preserve moisture during dry conditions -​ Needles and flexible branches shed snow, preventing damage to the tree Examples: white spruce, black spruce, balsam fir, red pine, white pine Deciduous (also called broadleaf, hardwood): -​ Round and broad leaf shape -​ Having no leaves in the winter lessens the snow load on the branches -​ They are dormant in winter, but sap flows strongly as spring warms -​ Most deciduous species need at least five months with average temperatures above 10oC Examples: sugar maple, beech, hickory, poplar, red oak Vegetation regions: Tundra: -​ Arctic climate -​ Incredibly harsh conditions for plant growth -​ Only very small trees grow here -​ Small shrubs, flowering plants, mosses, and lichens grow close to the surface where they soak up as much heat as possible in the very short growing season Boreal and Taiga forest: -​ One of the largest forest regions in the world -​ The growing season gets longer the farther south we go, while the precipitation levels are generally higher. The result is more lush forests and a wider range of species farther south in the boreal forest. -​ Winters are long and cold -​ Summers are warm and short -​ Soil conditions are not very good, with thin and acidic soils and poor fertility caused by large amounts of leaching -​ Hardy species of deciduous trees such as white birch and poplar are common in the southern part of the boreal forest. Farther north, only the hardiest coniferous trees like black spruce and balsam fir can survive. Grassland: -​ Too dry for significant tree growth -​ Some trees such as trembling aspen, willow, and spruce grow in the wetter areas of the grasslands -​ Natural grasses grow taller in the wetter areas than in the drier areas. These areas are called the tall-grass prairie and the short-grass prairie -​ A transition zone exists between the tall-grass and the adjoining boreal forest called parkland Mixed forest: -​ Transition zone between the boreal and the deciduous forests  -​ Farther north is mainly boreal while farther south is mainly deciduous -​ Winters are cool and summers are warm -​ Soils are also transitional Deciduous forest: -​ Hot summers and mild winters allows a wide range of species to exist -​ Almost the entire forest region has been cleared for farming and urban growth -​ Soils are fertile. West coast forest: -​ Some trees are more than 50 metres tall. They are able to grow so large due to the mild temperatures and abundant precipitation -​ Part of the diverse Cordilleran region -​ Receives so much precipitation that it is called a temperate rainforest -​ Large coniferous species —---------------------------------------------------------------------------------------------------------------------------- Climate change - Mitigation is the act of reducing how harmful something is. When referred to in climate change, it is also referred to as decarbonization. Adaptation is the process of changing to suit different conditions. Greenhouse effect is the process by which heat from the Earth’s surface is absorbed by gases in the atmosphere and re-radiated back to Earth. Greenhouse gasses are a group of natural and man-made gases released into the atmosphere that contribute to the greenhouse effect. Humans have been changing the composition of the atmosphere by burning fossil fuels such as coal, oil and natural gas. When these are burned, carbon dioxide is produced and builds up in the atmosphere, increasing the greenhouse effect. Other man-made sources of greenhouse gasses include methane (produced from livestock) and nitrous oxide (produced from nitrogen based fertilizers). These greenhouse gases trap even more heat energy and raise the temperature of Earth. This process is called global warming. Carbon dioxide (CO2): ​ Human sources: -​ Burning fossil fuels and industrial emissions -​ Deforestation ​ Natural sources: -​ Volcanic eruptions -​ Decay of organic material -​ Forest and grass fires Methane (CH4): ​ Human sources: -​ Livestock farming -​ Landfill sites -​ Coal mining ​ Natural sources: -​ Wetlands  -​ Melting permafrost Nitrous oxide (N2O): ​ Human sources: -​ Burning fossil fuels and wood -​ Nitrogen based fertilizers ​ Natural sources: -​ Nitrogen released by soils and water Hydrofluorocarbons: ​ Human sources: -​ Foam insulation -​ Coolants in refrigerators and air conditioners Perfluorocarbons: ​ Human sources: -​ Coolants in refrigerators and air conditioners -​ Aluminum production Over the last 60 years the average annual temperature in Canada has warmed by 1.5oC. Regions showing the strongest warming are in the far north. Effects of climate change: Aspects: ​ Changes in temperature ​ Changes in precipitation ​ Changes in weather patterns Physical effects: ​ Loss of forests ​ More forest fires ​ More pests and diseases ​ Changes in habitat and animal species ​ Changes in soil and water quality ​ Inability for species to adapt to new climate fast enough to facilitate migration Economic & social effects: ​ Reduced timber supply ​ Changes in employment ​ Increased risk of property loss due to fire ​ Changes in market for timber products ​ Reduces revenue