Chapter 4: Earth Systems and Resources

Plate tectonic theory

It states that Earth’s lithosphere is divided into a small number of plates that float on and travel independently over the mantle, with much of Earth’s seismic activity occurring at the boundaries of these plates.

Pangaea

In 1915, Alfred Wegener proposed that all present-day continents originally formed one landmass he called _.

Alfred Wegener

In 1915, proposed that all present-day continents originally formed one landmass he called Pangaea.

Seafloor Spreading Theory

geologic process in which tectonic plates —large slabs of Earth's lithosphere —split apart from each other.

lithosphere

The is the solid, outer part of the Earth and is broken into huge sections called plates, which are slowly moving.

plates

The lithosphere is the solid, outer part of the Earth and is broken into huge sections called , which are slowly moving.

Subduction zones

These are areas on Earth where two tectonic plates meet and move toward each other, with one sliding underneath the other and moving down into the mantle.

Convergent Boundaries

These occur where two plates slide toward each other.

Cascade Mountain Range

Example of Convergent Boundaries

Divergent Boundaries

These occur when two plates slide apart from each other.

Divergent Boundaries

It can create massive fault zones in the oceanic ridge system and areas of frequent oceanic earthquakes.

Mid-Atlantic Ridge and the East Pacific Rise

Example of Oceanic Divergent Boundary

East African Great Rift Valley

Example of Continental Divergent Boundary

island arc

When two oceanic plates converge, they create an _ — a curved chain of volcanic islands rising from the deep seafloor and near a continent.

undersea trench

A deep _ is located in front of such arcs where the descending plate dips downward.

Transform boundaries

These occur where plates slide past each other in opposite directions.

The san Andreas fault

Example of Transform boundaries

Soils

These are a thin layer on top of most of Earth’s land surface.

Surface Litter

Leaves and partially decomposed organic debris.

Topsoil

Organic matter, living organisms, and inorganic materials; it is very thick in grass lands.

Zone of leaching

Dissolved and suspended materials move downward.

Subsoil

Tends to be yellowish in color due to the accumulation of iron, aluminum, humic compounds, and clay leached from A and E horizons.

Weathered Parent Material

Partially broken-down inorganic materials.

Climate

Measured by precipitation and temperature, which results in partial weathering of the parent material, which forms the substrate for soil.

Living organisms

Include the nitrogen-fixing bacteria Rhizobium, fungi, insects, worms, snails, etc., that help to decompose litter and recycle nutrients.

Parent material

Refers to the rock and minerals from which the soil derives. The nature of the parent rock, which can be either native to the area or transported to the area by wind, water, or glacier, has a direct effect on the ultimate soil profile.

Topography

Refers to the physical characteristics of the location

Soil erosion

It is the movement of weathered rock and/or soil components from one place to another caused by flowing water, wind, and human activity.

Landslides

These occur when masses of rock, earth, or debris move down a slope.

Mudslides

It is also known as debris flows or mudflows, are a common type of fast-moving landslide that tends to flow in channels.

Igneous Rocks

These are formed by cooling and classified by their silica content.

Intrusive igneous rocks

Solidify deep underground, cool slowly, and have a large-grained texture.

Extrusive igneous rocks

Solidify on or near the surface, cool quickly, and have a fine-grained smooth texture.

Metamorphic Rocks

These are formed by intense heat and pressure, high quartz content.

Sedimentary

These are formed by the piling and cementing of various materials over time in low-lying areas.

Gravel

• Coarse particles.
• Consists of rock fragments.

Sand

• Sedimentary material coarser than silt.
• Water flows through too quickly for most crops.
• Good for crops and plants requiring low amounts of water.

Loam

• About equal mixtures of clay, sand, silt, and humus. Rich in nutrients.
• Holds water but does not become waterlogged. Particle size can vary.

Silt

• Sedimentary material consisting of very fine particles between the sizes of sand and clay.
  • Easily transported by water.

Clay

• Very fine particles.
• Compacts easily.
• Forms large, dense clumps when wet.

Humus

It is the dark organic material that forms in soil when plant and animal matter decays.

Aeration

Refers to how well a soil is able to absorb oxygen, water, and nutrients.

Degree of Soil Compaction

It is measured by dry unit weight and depends on the water content and compaction effort.

Nutrient-Holding Capacity

The ability of soil to absorb and retain nutrients so they will be available to the roots of plants.

Permeability

The measure of the capacity of the soil to allow water and oxygen to pass through it.

pH

It is the measure of how acidic or basic soil is.

Pore Size

Describes the space between soil particles.

Size of soil and particles

It determines the amount of moisture, nutrients, and oxygen that the soil can hold along with the capacity for water to infiltrate.

Water holding capacity

It is controlled primarily by the soil texture and the soil organic matter content.

Soil texture

A reflection of the particle size distribution of soil.

Water holding capacity formula

Soil Food Web

It is the community of organisms living all or part of their lives in the soil, and it describes a complex living system in the soil and how it interacts with the environments, plants, and animals.

Great Oxidation Event (GOE)

• 2.5 billion years ago killed almost all life on Earth.
  • It was a time period when the Earth’s atmosphere and the shallow ocean experienced a rise in oxygen.

Nitrogen (N2)

• Fundamental nutrient for living organisms.
• Found in all organisms, primarily in amino acids and nucleic acids.
• Makes up about 3% of the human body by weight.
• Deposits on Earth through nitrogen fixation and reactions involving lightning and subsequent precipitation.

Oxygen (O2)

• By mass, the third most abundant element in the universe, after hydrogen and helium.
• The most abundant element by mass in Earth’s crust, making up almost half of the crust’s mass as silicates.

Water Vapor (H2O)

• Largest amounts are found near the equator, over oceans, and in tropical regions.
• Polar areas and deserts lack significant amounts of _.

Carbon Dioxide (CO2)

• Produced during cellular respiration, the combustion of fossil fuels, and the decay of organic matter.
• Required for photosynthesis
• Major greenhouse gas contributing to global warming

Troposphere

The lowest portion of Earth’s atmosphere, 0–6 miles (0–10 km) above Earth’s surface.

Stratosphere

It is located 6–30 miles (10–50 km) above Earth’s surface.

Stratosphere

Ozone (O3) absorbs high-energy ultraviolet radiation from the sun and is broken down into atomic oxygen (O) and diatomic oxygen.

Weather

It is caused by the movement or transfer of heat energy, which results from the unequal heating of Earth’s surface by the sun.

Weather

It describes whatever is currently happening outdoors, whereas climate describes weather patterns in a place over a period of years.

Climate

The average weather conditions prevailing in an area in general or over a long period.

Climate

The statistical description in terms of the mean and variability of relevant quantities over a period ranging from months to thousands or millions of years.

Convection

It is the primary way energy is transferred from hotter to colder regions in Earth’s atmosphere and is the primary determinant of weather patterns.

Air Mass

A large body of air that has similar temperature and moisture content.

Albedo

An expression of the ability of surfaces to reflect sunlight.

Altitude

The distance above sea level.

Carbon Cycle

The process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere.

Distance to Oceans

Oceans are thermally more stable than landmasses; the specific heat of water is five times greater than that of air.

Front

Fronts: When two different air masses meet, the boundary between them forms a .

Cold Front

The leading edge of an advancing mass of cold air and is associated with thunderhead clouds, high surface winds, and thunderstorms.

Warm Front

The boundary between an advancing warm air mass and the cooler one it is replacing.

Stationary Front

A pair of air masses, neither of which is strong enough to replace the other, that tend to remain in essentially the same area for extended periods of time.

Greenhouse Effect

Without this effect, Earth would be cold and inhospitable.

heat energy

Climate is influenced by how is exchanged between air over the oceans and the air over land.

Latitude

The measurement of the distance of a location on Earth from the equator.

Moisture Content of Air

It is a primary determinant of plant growth and distribution and is a major determinant of biome type.

Pollution

Greenhouse gases are emitted from both natural sources and anthropogenic sources.

temperature cycles

Daily are primarily influenced by Earth’s rotation on its axis.

Sulfur-rich volcanic eruptions

It can eject material into the stratosphere, potentially causing tropospheric cooling and stratospheric warming.

Volcanic aerosols

These exist in the atmosphere for an average of one to three years.

They’re injected into the stratosphere can also provide surfaces for ozone-destroying reactions.

Land Breeze

It occurs during relatively calm, clear nights when the land cools down faster than the sea, resulting in the air above the land becoming denser than the air over the sea.

Sea Breeze

It occurs during relatively calm, sunny days, the land warms up faster than the sea, causing the air above it to become less dense.

High-pressure weather systems

They have higher pressure at their center than around them, so winds blow away from them.

Trade Winds

These are the prevailing pattern of easterly surface winds found in the tropics near Earth’s equator, within the troposphere or lower portion of Earth’s atmosphere.

Wind Speed

It is determined by pressure differences between air masses.

Wind Direction

It is based on the direction from which wind originated.

Easterly

Wind coming from the east.

Westerly

Wind coming from the west.

Coriolis Effect

A phenomenon wherein earth’s rotation on its axis causes winds to not travel straight, which causes prevailing winds in the Northern Hemisphere to spiral clockwise out from high-pressure areas and spiral counterclockwise toward low-pressure areas.

Hadley Air Circulation

• Air heated near the equator rises and spreads out north and south.
• After cooling in the upper atmosphere, the air sinks back to Earth’s surface within the subtropical climate zone.

Ferrel Air Circulation Cells

• Develop between 30° and 60° north and south latitudes.
• The descending winds of the Hadley cells diverge as moist tropical air moves toward the poles in winds known as the westerlies.

Polar cells

These cells originate as icy-cold, dry, dense air that descends from the troposphere to the ground.

Polar Vortex

A low-pressure zone embedded in a large mass of very cold air that lies atop both poles.

Hurricanes

Term used in the Atlantic and Northeast Pacific.

Cyclones

Term used in South Pacific and Indian Ocean.

Typhoons

Term used in Northwest Pacific.

Hurricanes

• _ begin over warm oceans in areas where the trade winds converge.
• A subtropical high-pressure zone creates hot daytime temperatures with low humidity that allow for large amounts of evaporation, with the Coriolis effect initiating the cyclonic flow.

eye

In the center of the hurricane is the _, an area of descending air and low pressure.