Unit 2: Interactions in the Physical Environment Flashcards
4 layers of the earth
Inner core, outer core, mantle, crust
Convection currents
Occurs in the mantle, the force moving the plates.
Divergent plate boundary
When 2 plates move apart. Commonly occurs along a mid-oceanic ridge. When this happens, both plates get larger. New areas of the crust are constantly being created this way. Most volcanoes occur along divergent plate boundaries.
Convergent plate boundary: continental meets oceanic
The heavier oceanic plate slides underneath the continental plate (subduction). Existing crust is recycled by subduction, which balances the new crust forming at divergent plate boundaries.
Convergent plate boundary: continental meets continental
2 continental plates run into each other, massive layers of rock are folded, broken, and forced upward by the immense pressures of the collision.
Transform plate boundary
Plates move in roughly parallel, but opposite directions. Plates are made neither larger nor smaller.
Precambrian era
- 4600 to 570
- Precambrian shields formed
- First multi-celled organisms
- First single-celled organisms
Paleozoic era
- 570 to 245
- Periods when large parts of North America are covered by shallow seas
- Appalachians formed
- Age of amphibians and fish
- First insects
- Large swamps (coal formed from this vegetation)
- First plants and animals appear on land
Mesozoic era
- 245 to 66
- Formation of Rocky Mountains begins
- Innuitian Mountains formed
- Shallow seas in the interior of North America at various times
- Age of reptiles
- First flowering plants
- First birds and mammals
Cenozoic era
- 66 to present day
- Ice sheets cover much of North America
- Continents take on their present shape
- Formation of Rocky Mountains completed
- Human beings develop
- Age of mammals
- Modern forms of live evolve
Igneous rock
Forms when magma/lava cools. Intrusive rocks cool underground and contain large crystals, while extrusive rocks cool above ground and contain tiny crystals.
Sedimentary rock
Created after millions of years of compaction and cementation of loose sediments. Sometimes contains deposits of fossil fuels.
Metamorphic rock
Transformed versions of igneous, sedimentary, or other metamorphic rocks. Occurs when rocks are exposed to great amounts of heat and pressure. Metamorphic versions of sedimentary rock are harder than the original.
Compaction
Occurs as loose sediments become tightly packed from drying or the weight of more layers on top.
Cementation
Sediments become cemented together by minerals deposited in between.
Erosional processes
Weathering, erosion, deposition
Weathering
The breaking down of rocks
Erosion
The moving of broken-up pieces of rock
Deposition
The building up of eroded materials in a new location
Forces involved in the erosional processes
Water, wind, glaciers, gravity
Glaciation
The process of ice advancing and covering large areas of land
Impact of glaciation
- Erosion: removal of materials, changes to drainage patterns
- Deposition: by ice (till plains, moraines), by meltwater (by moving water, by still water)
2 factors responsible for the appearance of all landforms in Canada
- The underlying geology
- The impact of glaciation
Number of landform regions in Canada
7
Largest landform region
Canadian Shield
Landform region we live in
Great Lakes- St. Lawrence Lowlands
The Canadian Shield
- Contains some of the world’s oldest rocks (3.96 billion years old)
- Mostly igneous and metamorphic rock, which contain minerals such as lead, gold, nickel, copper, and zinc
- Called the “storehouse of Canada’s metallic minerals”
- ill-suited for farming due to its thin soils, but ideal for recreation, and the plentiful flow of water makes the region an excellent source of water-generated energy
The Lowlands
- Interior Plains
- Great Lakes- St. Lawrence Lowlands
- Hudson Bay- Arctic Lowlands
interior Plains
- Part of the Great Plains of North America
- Were often covered by shalow inland seas
- Reefs formed close to the surface of these seas during the Paleozoic era, and contain a lot of oil, gas, and potash
- Differential erosion resulted in 3 different levels of elevation, each separated by an escarpment
- Glacial deposits left a rounded landscape
- Soil is deep and fertile
- Known as “Canada’s Breadbasket”
Potash
A mineral used as a fertilizer
Great Lakes- St. Lawrence Lowlands
- Consists of 2 parts separated by a thin piece of the Canadian Shield
- Bedrock formed from sedimentary rock during Paleozoic era
- Many escarpments (Niagara Escarpment)
- Glaciers created a rolling landscape in the Great Lakes area
- Most southerly region, well suited to agriculture because of its excellent soils and warm climate
- Flat land makes it ideal for transportation and cities
Hudson Bay- Arctic Lowlands
- Very flat, covered by swampy forest
- Layer of sedimentary rock on top of ancient rock of the Shield
- In Canada’s far north, gently rolling landscape
- Contains lignite, oil, and gas deposits
Highlands
- Appalachians
- Innuitians
- Western Cordillera
Appalachian Mountains
- Oldest highland region, formed about 300 million years ago
- Layers of sedimentary rock rich in deposits of non-metallic minerals such as coal
- Millions of years of erosion reduced its jagged peaks to rolling mountains and hills
Innuitian Mountains
- Found in Canada’s far north
- Mostly sedimentary rock, although there’s igneous and metamorphic as well
- Younger than Appalachians, so erosion hasn’t had a chance to reduce them to rounded hills
- Cold and barren
Western Cordillera
- On the west coast
- Young, high and rugged
3 major divisions:
1. Coast mountains
2. Interior plateaus
3. Eastern mountains
3 things to remember in order to understand Canada’s climate
- Very large country, means widey varying climates
- Northern parts have different climates than southern parts
- Coastal areas have different climates than inland areas
6 factors that determine climate
Latitude Ocean currents Wind, air masses, jet streams Elevation Relief Nearness to water
Climate factor: latitude
Increase in latitude away from equator = colder
Climate factor: ocean currents
Ocean currents moving away from equator: warmer
Ocean currents moving towards equator: colder
Climate factor: winds and air masses
Air masses that form over water = moist
Air masses that form in north = cold
Climate factor: elevation
Temperature decreases as elevation increases
Air pressure decreases as elevation increases
Climate factor: relief
Windward side = more precipitation
Leeward side = less precipitation (rain shadow)
Climate factor: nearness to water
Maritime = mild winters, cooler summers, more precipitation Continental = extreme temperatures because land heats/cools faster than water, less precipitation
What aspect of climate change makes it difficult for us to adapt?
The speed with which it’s occuring
5 major greenhouse gases
- Carbon dioxide
- Methane
- Nitrous oxide
- Hydrofluorocarbons
- Perfluorocarbons
Why is Canada among the highest emitters of greenhouse gases per capita?
- Large size of country
- Resource-based economy
- Energy demand due to climate
- Amount of exports
Aspects of climate change
- Changes in temperature
- Changes in precipitation
- Changes in weather patterns
Physical effects of climate change on forests
- 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 fast enough to facilitate migration
Economic and social effects of climate change on forests
- Reduced timber supply
- Changes in employment
- Increased risk of property loss due to fire
- Changes in market for timber products
- Reduced revenue
Environmental effects of climate change on Atlantic Canada
More storms, increased storm intensity, rising sea levels, storm surges, coastal erosion, flooding
Social and economic effects of climate change on Atlantic Canada
- Negative impact on fishing and tourism industries
- Coastal communities most vulnerable
Environmental effects of climate change on Central Canada
- Increased temperature
- Heat waves, smog
Social and economic effects of climate change on Central Canada
- Increased health risk due to heat waves and smog
- Changes support spread of vector-borne diseases such as Lyme disease and West Nile Virus
Environmental effects of climate change on Prairies
- Increased temperature
- Heat waves, smog
Social and economic effects of climate change on Prairies
- Agriculture affected by precipitation changes, extreme weather events, and increasingly frequent pests and diseases
Environmental effects of climate change on Western Canada
- Forest fires, storm surges, coastal erosion, landslides, hail storms, blizzards, droughts, floods
- Northern migration of mountain pine beetle
- Rising sea levels, higher freshwater temperatures, changes in river flows
Social and economic effects of climate change on Western Canada
- Forestry, tourism, and fishing industries affected
Environmental effects of climate change on Canada’s North
- Sea ice, glaciers, and ice caps melting and affecting northern waters, forests, plants, and animals
Social and economic effects of climate change on Canada’s North
- Communities forced to adapt to changes
Number of vegetation regions in Canada
7
Tundra
- Small trees/bushes
- Harsh climate, short growing season
- Low precipitation
- Permanently frozen ground
- Small humus layer
Boreal and Taiga forests
- Largest vegetation region
- Coniferous trees
- Long winters, short summers
- Higher precipitation further south
- Acidic soil
Mixed forest
- Deciduous
- Cool winters and warm summers
- Abundant rain
- Fertile soil
Deciduous forest
- Deciduous
- Long and hot summers, mild winters
- Abundant precipitation
- Fertile soil
- More humus than mixed forest
Grasslands
- Long and cold winters, warm summers
- Limited rainfall
- High evaporation
- Rich soils
- Sod mat absorbs and stores moisture
- Calcified brown soils
Cordillera Vegetation
- Coniferous trees
- Moderate summers and winters
- 500 to 1000 mm precipitation depending on location
- Wide variety of mountain soils
West Coast Forest
- Tall coniferous trees
- Mild climate
- Temperate rain forest
- Heavy rainfall
- A lot of plant material to make humus but high rainfall leaches minerals deep into the soil
Soil
Surface layer of earth, composed of minerals and organic materials, air, and water
Parent material
Rock from which soil is derived
Humus
Dark upper layer of soil made up of partially decayed plant material
Soil profile
Different layers in the soil and rock layer below the soil, each with different physical, biological, and chemical characteristics
Topsoil
Surface layer of soil
4 components that make up true soil
Bacteria and organic materials
Air
Moisture
Minerals
Bacteria and organic materials
Bacteria breaks down organic material
Air
Plants need air around roots. high humus levels, worms, insects, and small animals allow for/create air pockets
Moisture
Dissolves nutrients and is taken up by plants through roots
Minerals
Becomes part of the soil through weathering. Many are nutrients that plants need for growth.
How long has it taken to form topsoil in Canada?
6000-12,000 years, since the end of the last ice age
Why does topsoil differ in thickness in different parts of Canada
Amount of organic material being deposited
Leaching of soil
In areas where there is a lot of precipitation, there’s a continua downward movement of water through the soil. As water moves down, it dissolves the chemical nutrients in the soil and carries them away.
Calcification of soil
Occurs in dry areas, is an upward movement. As water in the topsoil evaporates, water from below is drawn up to replace it (capillary action). As the water evaporates, it leaves behind the minerals that were dissolved in it.
Alfred Wegener
Came up with the theory of continental drift
Which ice sheet covered our region during the last period of glaciation?
Laurentide
The Canadian climate region that receives the most precipitation
The Pacific
Vegetation region with the richest soil in Canada and some of the most productive grain-growing land in the world
Mixed forest
Largest vegetation region in Canada
Boreal and Taiga forest
Describe the erosional process by making specific reference to all 3 stages
Weathering: breaking down of rocks into sediments (when waves crash into rocks on the shore)
Erosion: the moving of sediments (when a river carries sand particles away in its current)
Deposition: the building up of sediments (when a current deposits the sand particles at the mouth of a river)
Explain 2 ways climate change will impact a specific region of Canada
Arctic region: temperature will increase, which will accelerate the melting of the glaciers. This could bring benefits to people living there, since they wouldn’t need to use as many natural resources to warm themselves. Melting of glaciers could also make marine navigation easier, therefore allowing more resources to be brought to the people. However, there will also be adverse effects. Melting of glaciers could result in flooding, and many animals and natural habitats could e endangered as they are unable to adapt in time.
