upgrade
upgrade
🌏AP Environmental Science Unit 4 Vocabulary

80 essential vocabulary terms and definitions for Unit 4 – Earth Systems & Resources

Study Unit 4
Practice Vocabulary
🌏Unit 4 – Earth Systems & Resources
Topics

🌏Unit 4 – Earth Systems & Resources

4.1 Tectonic Plates

TermDefinition
convergent plate boundariesPlate boundaries where two tectonic plates move toward each other, resulting in compression and the formation of mountains, island arcs, earthquakes, and volcanoes.
divergent plate boundariesPlate boundaries where two tectonic plates move away from each other, resulting in seafloor spreading, rift valleys, volcanoes, and earthquakes.
earthquakesSudden releases of energy in the Earth's crust that occur when stress overcomes a locked fault, commonly found at all types of plate boundaries.
faultsFractures in the Earth's crust where rocks have shifted relative to each other, commonly associated with plate boundaries and earthquakes.
hot spotsStationary areas of intense heat in the Earth's mantle that can produce volcanoes as tectonic plates move over them.
island arcsCurved chains of volcanic islands formed at convergent plate boundaries where oceanic plates collide.
locked faultA fault where stress has accumulated but the rocks are held in place, releasing energy suddenly when the stress overcomes the friction.
mountainsHigh elevation landforms that can block or redirect precipitation and affect local weather and climate patterns.
plate boundariesThe edges where tectonic plates meet, classified as convergent, divergent, or transform based on the direction of plate movement.
rift valleysDeep valleys formed at divergent plate boundaries where the crust is pulled apart and subsides.
seafloor spreadingThe process by which new oceanic crust is created at divergent plate boundaries as plates move apart.
stressThe force applied to rocks at plate boundaries that can accumulate and eventually cause earthquakes when it overcomes friction.
transform plate boundariesPlate boundaries where two tectonic plates slide horizontally past each other, resulting in earthquakes.
volcanoesOpenings in the Earth's crust where magma, gases, and ash are expelled, commonly formed at convergent and divergent plate boundaries.

4.2 Soil Formation and Erosion

TermDefinition
parent materialThe original rock or mineral material that is weathered to form soil.
soil erosionThe wearing away and loss of topsoil, often caused by water or wind, particularly accelerated when vegetation is removed.
soil filtrationThe process by which soil filters and cleans water that moves through it.
soil horizonsDistinct layers within soil that differ in composition, color, and organic material content.
weatheringThe process by which parent material is broken down into smaller particles through physical, chemical, or biological processes.

4.3 Soil Composition and Properties

TermDefinition
biological properties of soilCharacteristics of soil related to living organisms and organic matter, such as microbial activity and decomposition.
chemical properties of soilCharacteristics of soil related to its chemical composition, such as pH, nutrient content, and ion exchange capacity.
clayThe smallest soil particles (less than 0.002 mm), which significantly affect soil water retention and plasticity.
particle sizeThe diameter or dimensions of individual soil particles, which affects soil properties like porosity and permeability.
permeabilityThe ability of soil to allow water and air to move through it, influenced by particle size and pore connectivity.
physical properties of soilCharacteristics of soil related to its structure and composition, such as texture, porosity, and water holding capacity.
porosityThe proportion of void spaces (pores) in soil relative to the total soil volume, affecting water and air movement.
sandThe largest soil particles (0.05-2 mm) that increase soil porosity and permeability.
siltMedium-sized soil particles (0.002-0.05 mm) that contribute to soil structure and water retention.
soil fertilityThe capacity of soil to provide essential nutrients and favorable conditions for plant growth and productivity.
soil horizonA distinct layer of soil with specific physical and chemical properties that differ from layers above and below it.
soil texture triangleA diagram used to classify and identify soil types based on the relative percentages of clay, silt, and sand particles.
soil typesDifferent categories of soil distinguished by their physical and chemical properties, such as clay, silt, and sand composition.
water holding capacityThe total amount of water that soil can retain and hold against gravitational forces.

4.4 Earth's Atmosphere

TermDefinition
atmosphereThe layer of gases surrounding Earth that is composed of major gases in varying proportions and is organized into distinct layers based on temperature.
exosphereThe outermost layer of Earth's atmosphere where gas molecules are sparse and gradually transition to outer space.
mesosphereThe layer of the atmosphere above the stratosphere where temperature decreases with altitude and meteors burn up.
stratosphereThe layer of the atmosphere above the troposphere where temperature increases with altitude and the ozone layer is located.
temperature gradientsThe changes in temperature with altitude that define and distinguish the different layers of the atmosphere.
thermosphereThe layer of the atmosphere above the mesosphere where temperature increases with altitude due to absorption of solar radiation.
troposphereThe lowest layer of Earth's atmosphere where temperature generally decreases with altitude and where most weather occurs.

4.5 Global Wind Patterns

TermDefinition
atmospheric circulationThe large-scale movement of air in the atmosphere driven by differences in solar heating and the Coriolis effect.
Coriolis effectThe apparent deflection of moving objects (including air) due to Earth's rotation, which influences the direction of wind patterns.
density differencesVariations in air density caused by unequal heating, which drive the movement of air masses in the atmosphere.
global wind patternsLarge-scale, predictable wind systems that result from solar heating and the Coriolis effect.
solar radiationEnergy from the sun that reaches Earth's surface and atmosphere, with the most intense radiation occurring at the equator.

4.6 Watersheds

TermDefinition
soilThe layer of weathered rock and organic material on Earth's surface that supports plant growth and varies among biomes.
vegetation typesThe different kinds of plants and plant communities present in a watershed, which influence water infiltration and runoff.
watershedA geographic area of land where all water drains to a common outlet, characterized by specific physical and biological features.
watershed areaThe total surface area of land contained within a watershed that contributes water to a common outlet.
watershed dividesThe boundaries or ridgelines that separate one watershed from adjacent watersheds, determining the direction of water flow.
watershed slopeThe gradient or steepness of the land within a watershed, which affects water flow rate and erosion patterns.

4.7 Solar Radiation and Earth's Seasons

TermDefinition
angle of the sun's raysThe angle at which solar radiation strikes Earth's surface, which determines the intensity of the radiation received.
daylight hoursThe length of time during which the sun is above the horizon at a particular location, which varies seasonally due to Earth's axial tilt.
Earth's axis of rotationThe imaginary line around which Earth rotates, whose tilt causes seasonal variations in solar radiation and daylight hours.
equatorThe latitude line at 0 degrees that receives the highest solar radiation per unit area on Earth.
insolationIncoming solar radiation received by Earth, which varies with season and latitude.
intensity of solar radiationThe amount of solar energy received per unit area, which varies based on latitude and the angle of the sun's rays.
latitudeThe angular distance north or south of the equator, which affects the intensity of solar radiation received at a location.
polesThe northernmost and southernmost points on Earth where solar radiation intensity is lowest.
seasonA period of the year characterized by particular weather patterns and varying amounts of solar radiation received at a location.
solar radiationEnergy from the sun that reaches Earth's surface and atmosphere, with the most intense radiation occurring at the equator.
tilt of Earth's axisThe 23.5-degree angle of Earth's rotational axis relative to its orbital plane, which causes seasons and variations in daylight hours.

4.8 Earth's Geography and Climate

TermDefinition
climateLong-term patterns of atmospheric conditions, including average temperature and precipitation, over decades or centuries at a specific location.
elevationThe height of a location above sea level, which affects temperature, precipitation, and climate patterns.
geographic factorsPhysical features of Earth's surface, such as mountains and ocean temperature, that affect weather and climate patterns.
geographyThe physical features and characteristics of Earth's surface, including landforms, water bodies, and their spatial distribution.
geologic factorsPhysical characteristics of Earth's crust and interior, such as rock composition and volcanic activity, that influence weather and climate.
mountainsHigh elevation landforms that can block or redirect precipitation and affect local weather and climate patterns.
ocean temperatureThe thermal conditions of ocean water that influence atmospheric temperature, precipitation, and weather patterns.
precipitationWater falling from clouds to Earth's surface in the form of rain, snow, sleet, or hail.
rain shadowA region of land that receives less precipitation because a higher elevation area blocks moisture-bearing winds from reaching it.
sun's energySolar radiation that drives weather and climate systems on Earth.
weatherShort-term atmospheric conditions including temperature, precipitation, wind, and humidity at a specific location.

4.9 El Niño and La Niña

TermDefinition
El NiñoA climate phenomenon characterized by warmer than normal ocean surface temperatures in the Pacific Ocean that causes global changes to rainfall, wind, and ocean circulation patterns.
El Niño-Southern OscillationThe coupled ocean-atmosphere system in the tropical Pacific that includes both El Niño and La Niña events and their effects on global climate patterns.
La NiñaA climate phenomenon characterized by cooler than normal ocean surface temperatures in the Pacific Ocean that causes global changes to rainfall, wind, and ocean circulation patterns.
ocean circulation patternsThe movement and flow of ocean currents and water masses, which can be altered during El Niño and La Niña events.
ocean surface temperaturesThe temperature of water at the ocean's surface, which changes during El Niño and La Niña events and influences global climate patterns.
rainfall patternsThe distribution and amount of precipitation across regions, which can be altered globally during El Niño and La Niña events.
wind patternsThe direction and strength of winds across regions, which can be changed globally during El Niño and La Niña events.