AP Environmental Science: Earth Systems and Resources

Core

Innermost zone of the Earth, consisting of a solid inner core and a liquid outer core.

Mantle

Thickest layer of the Earth, composed of molten rock that circulates in convection currents.

Asthenosphere

Upper layer of the mantle, semi-molten, allowing tectonic plates to slide.

Lithosphere

Cool, rigid outer layer of the Earth, including the crust and the upper mantle.

Crust

Brittle outer shell of the Earth.

Oceanic Crust

Thinner, denser part of the crust made of basalt.

Continental Crust

Thicker, less dense part of the crust made of granite.

Plate Tectonic Theory

Theory stating the lithosphere is divided into plates that float on the asthenosphere.

Convergent Boundaries

Boundaries where two plates collide; results can vary by crust density.

Subduction

Process where the denser oceanic plate sinks beneath the lighter continental plate.

Oceanic-Oceanic Subduction

When one older, denser oceanic plate subducts under another.

Continental-Continental Collision

Collision where neither plate subducts, resulting in upward push.

Divergent Boundaries

Boundaries where two plates move apart, leading to the creation of new crust.

Mid-Ocean Ridges

Underwater mountain ranges created at divergent boundaries.

Rift Valleys

Valleys created by diverging continental plates.

Transform Boundaries

Boundaries where plates slide past each other laterally.

Hot Spot

Location where a stationary plume of hot magma rises, forming volcanoes.

Pedogenesis

The process of soil formation by weathering and other factors.

Physical Weathering

Breakdown of rocks without chemical change.

Chemical Weathering

Breakdown of rocks through chemical reactions.

Biological Weathering

Weathering caused by living organisms.

O Horizon

The organic layer of soil rich in decomposed material.

A Horizon

Topsoil layer that is nutrient-rich and supports plant roots.

B Horizon

Subsoil layer where minerals accumulate from above layers.

Soil Erosion

Displacement of the upper layer of soil, often accelerated by human activity.

Loam

Ideal agricultural soil composed of roughly 40% sand, 40% silt, and 20% clay.

Porosity

Volume of open spaces in soil.

Permeability

Rate at which water flows through soil.

pH

Measure of soil acidity or alkalinity.

Cation Exchange Capacity (CEC)

Soil's ability to hold positively charged nutrient ions.

Troposphere

Layer of the atmosphere where weather occurs and the most dense.

Stratosphere

Layer containing the ozone layer, where temperature increases with altitude.

Mesosphere

Layer where meteors burn up, temperature decreases with altitude.

Thermosphere

Layer with significantly high temperatures, where auroras occur.

Coriolis Effect

Apparent deflection of moving objects due to Earth's rotation.

Hadley Cell

Convection cell creating rainforests at the equator and deserts at 30° latitude.

Trade Winds

Winds blowing from East to West between the equator and 30° latitude.

Watershed

Land area that drains water into a common body of water.

Tributaries

Smaller streams that feed into a main river.

El Niño

Phase of ENSO characterized by warming of ocean waters that affects global weather.

La Niña

Cool phase of ENSO with stronger trade winds causing cooler ocean conditions.

Insolation

Amount of solar radiation reaching a given area.

Rain Shadow Effect

Phenomenon where one side of a mountain receives high precipitation while the other side remains dry.