APES 4.1-4.5

Convergent Boundary

Occurs when plates crash towards each other, forming mountains, island arcs, earthquakes, and volcanoes.

Divergent Boundary

When plates move away from each other, resulting in new oceans, drift valleys, seafloor spreading, rift valleys, volcanoes, and earthquakes.

Transform Boundaries

Boundaries that can result in earthquakes due to the sliding past of tectonic plates.

Core

The innermost zone of the planet made of iron and nickel.

Mantle

The layer above the core, containing magma that slowly circulates due to convection.

Asthenosphere

The uppermost portion of the mantle, containing molten rock.

Crust

The outermost layer of the planet.

Lithosphere

The brittle outermost layer of the planet that includes oceanic and continental crusts.

Hotspots

Places where molten material from the mantle reaches the lithosphere.

O Horizon

The organic layer of soil composed of leaves, needles, twigs, and animal bodies.

A Horizon

The topsoil layer containing organic material mixed with minerals.

B Horizon

The subsoil layer composed primarily of mineral material with very little organic matter.

C Horizon

The parent material layer, the least weathered horizon, often saturated with groundwater.

E Horizon

A heavily leached layer that may form between the A and B layers.

Weathering

The process when rocks are exposed to air, water, chemicals, or biological agents that degrade the rock.

Physical Weathering

The mechanical breakdown of rocks and minerals.

Chemical Weathering

The breakdown of rocks and minerals through chemical reactions that produce a new substance.

Erosion

The physical removal of rock fragments from a landscape or ecosystem.

Deposition

The accumulation of eroded material such as sediment, rock fragments, or soil.

Parent Material

The rock material from which soil is derived.

Soil Salinization

The gradual accumulation of salt in the soil, often occurring in arid and semi-arid areas.

Desertification

The degradation of formerly fertile land into nonproductive desert.

Weather

The short-term atmospheric conditions in a local area.

Climate

The average weather that occurs in a given region over a long period.

Adiabatic Heating and Cooling

The process where rising air cools and expands while descending air warms and compresses.

Latent Heat Release

The energy released when water vapor condenses into liquid water.

Hadley Cells

Convection currents that cycle between the equator and 30 degrees north and south.

Intertropical Convergence Zone (ITCZ)

The area that receives the most intense sunlight where the ascending branches of Hadley cells converge.

Coriolis Effect

The deflection of an object's path due to Earth's rotation.

Watersheds

The land area that supplies water to a river system.

Gyres

Large-scale patterns of water circulation in the ocean.

Upwelling

The upward movement of water that brings nutrients from the ocean floor.

Thermohaline Circulation

Ocean circulation that drives the mixing of surface water and deep water.

El Niño

A phenomenon where trade winds weaken, causing warm water to move eastward toward South America, suppressing upwelling.

La Niña

The cooling of surface ocean waters along the tropical west coast of South America.