Unit 2: Interactions in the Physical Environment

Flashcards covering Unit 2: Interactions in the Physical Environment, including population patterns, geological theories, plate tectonics, climate factors, and traditional ecological knowledge.

Population Density

A way of describing how crowded a place is by measuring the number of people living in an area divided by the size of the area.

Population Density Formula

$$Population\,density = \frac{Number\,of\,people\,living\,in\,an\,area}{Size\,of\,area\,in\,km^2}$$

80%

The percentage of Canadians who live in cities and towns.

Census Metropolitan Area (CMA)

An urban area in Canada with a population over $100,000$ that is centred around a city and extends beyond its borders.

Dispersed Population

A population spread evenly across the land, which is common in agricultural areas.

Concentrated Population

A population focused in patches with specific resource industries such as mines or paper mills.

Lower cost of living / More nature

Advantages associated with living in areas with lower population density.

Rural Settlement Patterns (Factors)

Influenced by the nature of resources, transportation methods, and the role of government.

Linear Population

A population settled along a line, such as a coastline, river, or highway.

Theory of Continental Drift

Suggested that about $300$ million years ago, all of Earth's landmasses collided to form one supercontinent before slowly drifting apart.

Pangaea

The supercontinent that incorporated almost all of Earth's landmass approximately $240$ to $300$ million years ago; means "all land."

Alfred Wegener

The German scientist who proposed the Theory of Continental Drift in $1915$.

Wegener’s Jigsaw Fit

Evidence for continental drift based on the matching coastlines of South America and Africa.

Wegener’s Fossil Evidence

The discovery of identical plant and animal fossils on widely separated continents.

Wegener’s Mountain Evidence

Similarities in age and structure of mountains on both sides of the Atlantic Ocean, formed roughly $300$ million years ago.

Appalachian Mountains

A mountain range in the U.S.A. and Canada that matches the age and structure of the Caledonian Mountains in Europe.

Caledonian Mountains

Mountains in the northern British Isles and Europe that parallel the structure of the Appalachians.

Wegener’s Ice Sheet Evidence

Ice sheets covered parts of southern Africa, India, Australia, and South America $250$ million years ago, suggesting they were once near the South Pole.

Continental Drift Limitation

Wegener could not explain what force was powerful enough to move the continents.

1960s

The decade when technology finally existed to develop Wegener’s theory further into plate tectonics.

Theory of Plate Tectonics

States that Earth's outer shell is divided into several large, rigid plates that glide over a weaker, semi-molten layer.

Lithosphere

The rigid outer layer of Earth consisting of the crust and the uppermost mantle.

Asthenosphere

The part of the mantle under the lithosphere that flows like soft rock and allows plates to float on it.

J. Wilson

The scientist credited with creating the Theory of Plate Tectonics.

Tectonic Plates

Massive, irregularly shaped slabs of solid rock that fit together like a cracked shell of a hard-boiled egg.

North American Plate

One of Earth’s major tectonic plates on which Canada is located.

Juan de Fuca Plate

A major tectonic plate located off the west coast of North America.

Pacific Plate

A major tectonic plate covering much of the Pacific Ocean basin.

South American Plate

A major tectonic plate covering South America and part of the Atlantic seabed.

African Plate

A major tectonic plate including the continent of Africa and surrounding oceanic crust.

Eurasian Plate

A major tectonic plate that includes most of the continent of Eurasia.

Indian Plate

A major tectonic plate that includes the Indian subcontinent.

Australian Plate

A major tectonic plate that includes the continent of Australia.

Antarctic Plate

A major tectonic plate that includes the continent of Antarctica.

Canadian Mountain Chains

Grew on the east and west coasts as a result of plates colliding.

Fossil Fuels in Canada

Oil, gas, and coal formed when Canada's landmass was located in a warmer, tropical climate.

Divergent Plate Movement

Occurs when two plates move apart, most commonly along a mid-ocean ridge.

Mid-Ocean Ridge Spacing

New areas of Earth's crust are constantly created along $70,000\,km$ of these ridges globally.

Rift Valleys

Landforms created when divergent plate movement happens on land.

Convergent Plate Movement

Occurs when two plates move toward each other.

Plate Density (Oceanic vs. Continental)

Rocks that make up deep ocean plates are denser than those that make up continental plates.

Subduction

The process in which a denser oceanic plate slides underneath a lighter continental plate.

Subduction Tension Release

Energy release that can result in a massive earthquake of magnitude $8.0$ to $9.0+$.

Continental-Continental Convergent

Collision where massive layers of rock are folded, broken, and forced upward to create mountain ranges.

Himalayas / Mount Everest

World-important mountain ranges created by the collision of two continental plates.

Transform Plate Boundary

Also known as a conservative boundary where plates move in roughly parallel but opposite directions.

Transform Earthquake Magnitude

Enormous releases of energy at transform boundaries typically resulting in damaging earthquakes between $5.5$ and $7.5$.

Mid-Atlantic Ridge / Iceland

Example locations of divergent plate boundaries.

Andes / Mariana Trench

Example locations of convergent plate boundaries (Oceanic + Continental).

San Andreas Fault

A famous example of a transform plate boundary.

Convection Currents

The circular movement of hot and cool material in the asthenosphere that drives the movement of tectonic plates.

Continental Crust

Thicker, less dense crust that forms the continents.

Oceanic Crust

Thinner, denser crust that forms ocean floors, primarily composed of basalt.

Latitude

A geographic coordinate measuring the distance north or south of the equator in degrees.

Equator

The line of latitude located at $0^\circ$ that receives the most direct sunlight.

North Pole / South Pole

The highest latitudes located at $90^\circ N$ and $90^\circ S$, respectively.

Sun’s Rays at the Equator

Hit the Earth directly, concentrating energy in a smaller area and making temperatures warmer.

Sun’s Rays at Higher Latitudes

Hit the Earth at a steeper angle, spreading energy over a larger area and making temperatures cooler.

Seasonal Temperature Variation

Higher latitude locations usually experience larger temperature differences between summer and winter.

Ocean Currents

Large, fast-moving streams of water that move warm or cold water from one place to another.

Ocean Current Direction Rule

Currents moving away from the Equator carry warm water; currents moving toward the Equator carry cold water.

North Pacific Current

A warm current that moves toward Canada's west coast, keeping British Columbia's temperatures relatively mild.

Labrador Current

A cold current that carries Arctic water southward along the east coast of Canada.

Fog Formation (Currents)

Occurs when warm, moist air meets colder water and cools quickly, such as where the Gulf Stream meets the Labrador Current.

Gulf Stream

A warm ocean current that meets the cold Labrador Current near Newfoundland.

Relative Temperature

Ocean currents are classified as warm or cold based on their temperature compared to the surrounding water.

Prince Rupert, BC vs. Cartwright, NL

Two locations at $54^\circ N$ with different average temperatures ($7.5^\circ C$ vs $0^\circ C$) due to warm and cold ocean currents.

Air Mass

A large body of air that has similar temperature and moisture characteristics based on where it forms.

Moist Air Mass

An air mass that forms over oceans.

Dry Air Mass

An air mass that forms over land.

Wind

The movement of air from high-pressure areas to low-pressure areas.

High-Pressure System Weather

Usually brings clear skies and calm weather.

Low-Pressure System Weather

Usually brings clouds and precipitation.

Thunderstorms

A weather event that can occur when warm, moist air rises into colder air.

Global Wind Belts (Westerlies)

Major winds that blow from west to east across much of North America/Canada.

Elevation (Altitude)

The height of a geographical location above a fixed reference point, usually sea level.

Elevation-Temperature Relationship

Temperature decreases as elevation increases.

Elevation-Pressure Relationship

Air pressure decreases as elevation increases because there is less air above pushing down.

Dry Rate of Cooling

The temperature of rising air decreases by about $1.0^\circ C$ for every $100\,m$ of elevation before condensation.

Moist Rate of Cooling

The temperature of rising air decreases by about $0.6^\circ C$ for every $100\,m$ after condensation begins.

Relief

Refers to the shape and elevation of the land surface, including mountains, valleys, and highlands.

Windward Side

The side of a mountain that faces the wind and usually receives more precipitation.

Leeward Side

The side of a mountain that faces away from the wind; the air becomes warmer and drier.

Rain Shadow

The dry area on the leeward side of a mountain caused by the loss of moisture on the windward side.

Maritime Climate

A climate near the ocean with moderate temperatures, small temperature ranges ($< 25^\circ C$), and high annual precipitation ($> 1000\,mm$).

Continental Climate

A climate far from water with large temperature ranges ($> 25^\circ C$) and low annual precipitation ($< 1000\,mm$).

Modified Continental Climate

A climate near the Great Lakes that is far from the ocean but influenced by large lakes, showing more precipitation and slightly moderate temperatures.

Climate

Long-term data with respect to temperature and precipitation over years, decades, or longer.

Weather

Short-term data or day-to-day overview of temperature and precipitation.

Average Annual Temperature Calculation

Add together the 12 average monthly temperatures and divide by 12.

Temperature Range Calculation

Subtract the lowest monthly temperature from the highest monthly temperature.

Total Annual Precipitation Calculation

Add up all the monthly precipitation totals.

Snowfall Equivalent Calculation

For months at or below $0^\circ C$, multiply the monthly precipitation by 10.

Length of Growing Season

The total number of days in months with an average temperature of $5^\circ C$ or more.

Winter Months (Climate Calculation)

October, November, December, January, February, March.

Summer Months (Climate Calculation)

April, May, June, July, August, September.

Wet-Climate Soil

Soils that develop where leaching is the dominant process, often appearing grey-ish and lacking fertility.

Leaching

The process where water constantly moves downward through the soil, removing plant nutrients and reducing fertility.

Dry-Climate Soil

Soils developed where calcification is dominant, often resulting in a thick layer of fertile topsoil.

Calcification

The process where moisture moves up from the subsoil, bringing plant nutrients to the topsoil horizon.