AP Environmental Science Unit 4: Earth Systems & Resources Vocabulary

Practice vocabulary flashcards for AP Environmental Science Unit 4: Earth Systems & Resources, covering plate tectonics, atmospheric and oceanic patterns, soil composition, and weathering.

Tectonic plate

A large, moving piece of Earth’s outer rocky layer.

Lithosphere

Earth’s rigid outer layer, including the crust and uppermost mantle.

Plate tectonics theory

The idea that Earth’s outer plates move slowly over time.

Divergent boundary

Where two tectonic plates move apart.

Convergent boundary

Where two tectonic plates move toward each other.

Transform boundary

Where two tectonic plates slide past each other.

Subduction zone

An area where one tectonic plate sinks beneath another.

Hot spot

An unusually hot area beneath a plate that can form volcanoes.

Solar radiation

Energy from the Sun that reaches Earth.

Climate

The usual weather patterns in an area over many years.

Latitude

How far north or south a place is from the equator.

Elevation

Height above sea level.

Convection cell

A cycle of rising warm material and sinking cool material.

Hadley cell

A large wind circulation pattern between the equator and subtropics.

Coriolis effect

The apparent curving of moving air and water due to Earth’s rotation.

Coriolis force

The apparent force used to describe this curving motion.

Windward

The side of a mountain facing incoming wind.

Leeward

The side of a mountain sheltered from incoming wind.

Rain shadow

A dry area on the leeward side of a mountain.

NPK (nitrogen, phosphorus, potassium)

Three major nutrients plants need to grow.

pH

A scale showing how acidic or basic something is.

Cation-exchange capacity (CEC)

How well soil holds positively charged nutrient ions.

Weathering

The breaking of rock into smaller pieces or new materials.

Soil texture

The amounts of sand, silt, and clay in soil.

Soil horizons

Different layers of soil.

O horizon

Top layer made mostly of leaves and other organic material.

A horizon

Topsoil with minerals, nutrients, and organic matter.

B horizon

Subsoil where clay and minerals often collect.

C horizon

Partly weathered rock beneath the soil.

Soil porosity

How much empty space is between soil particles.

Soil permeability

How easily water moves through soil.

Soil infiltration

Water soaking into the soil from the surface.

Soil runoff

Water flowing over land instead of soaking into soil.

El Niño–Southern Oscillation (ENSO)

A recurring pattern of changing Pacific Ocean temperatures and winds.

El Niño

The warmer-than-usual phase of ENSO in the central and eastern tropical Pacific.

La Niña

The cooler-than-usual phase of ENSO in the central and eastern tropical Pacific.

Thermocline

A layer of water where temperature changes quickly with depth.

Upwelling

Deep, cold, nutrient-rich water rising toward the ocean surface.

Solstice

One of the two days with the most or least daylight in a hemisphere.

Longitude

How far east or west a place is from the prime meridian.

Tropic of Cancer

Latitude $23.5^{\circ}$ north.

Tropic of Capricorn

Latitude $23.5^{\circ}$ south.

Trade winds

Steady tropical winds that generally blow toward the equator from the east.

Westerlies

Winds that generally blow from west to east in middle latitudes.

Prevailing winds

The winds that most often blow in an area.

Earthquakes

Shaking caused by a sudden release of energy in Earth’s crust.

Volcanoes

Places where molten rock, gases, or ash escape Earth’s surface.

Mean sea level

Average ocean surface height used to measure elevation.

Physical weathering

Breaking rock into smaller pieces without changing its chemistry.

Chemical weathering

Changing rock minerals through chemical reactions.

Biological weathering

Weathering caused by living things.

Deposition

Dropping or settling of sediment in a new place.

Humus

Dark, decomposed organic material in soil.

Soil nutrients

Elements plants need from soil to grow.

E horizon

A pale soil layer where minerals are washed out.

Zone of accumulation

Soil layer where materials washed down from above collect.

Loam

Soil with a useful mixture of sand, silt, and clay.