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.