AP Environmental Science Unit 4: Earth Systems and Resources

Magma

A molten mixture of rock-forming substances, gases, and water from the mantle.

Intertropical Convergence Zone

An area of Earth that receives the most intense sunlight; where the ascending branches of the two Hadley cells converge.

Watershed

An area or ridge of land that separates waters flowing to different rivers, basins, or seas.

Thermohaline Circulation

A part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.

Rain Shadow

A region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side.

Permeability

The ability of a rock or sediment to let fluids pass through its open spaces, or pores.

Floodplain

The area subject to flooding during a given number of years according to historical trends.

Gyre

A large-scale pattern of water circulation that moves clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

Rainshadow Effect

A location of little rain on the leeward side of a mountain range due to descending air.

Richter Scale

A scale that rates an earthquake's magnitude based on the size of its seismic waves.

Rock Cycle

A series of processes on the surface and inside Earth that slowly changes rocks from one kind to another.

Hot Spot

A small area or region with a relatively hot temperature in comparison to its surroundings.

Transform Fault

A strike-slip fault occurring at the boundary between two plates of the earth's crust.

Earthquake

A sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.

Adiabatic heating and cooling

As air rises in the atmosphere its pressure decreases and the air expands. Conversely, as air sinks, the pressure increases and the air decreases in volume.

Plate Boundaries

At plate boundaries, Earth's crust is broken (fault) and rocks slip past each other in one of 3 types of plate boundaries.

Coriolis Effect

Causes moving air and water to turn left in the southern hemisphere and turn right in the northern hemisphere due to Earth's hemisphere.

Acid Precipitation

Conversion of sulfur oxides and nitrogen oxides to acids that return to Earth as rain, snow, or fog.

Soil Degradation

Damage to soil - for example, as a result of deforestation or the removal of topsoil from bare land by water and wind erosion.

ENSO (El Niño/ Southern Oscillation, La Niña)

El Niño refers to the large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific. The Southern Oscillation refers to changes in sea level air pressure patterns in the Southern Pacific Ocean between Tahiti and Darwin, Australia. During El Niño conditions, the average air pressure is higher in Darwin than in Tahiti. La Niña refers to a period of where the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3 to 5°C (5.4 to 9°F). Persisting for at least five months, La Niña has extensive effects on the weather across the globe, particularly in North America, even affecting the Atlantic and Pacific hurricane seasons.

Insolation

Exposure to the sun's rays.

Troposphere

First layer of the atmosphere; extends to 10 miles above Earth's surface, site of weather, organisms, contains most atmospheric water vapor (temperature decreases with increasing altitude, pressure decreases).

Atmospheric Convection Current

Global patterns of air movement that are initiated by the unequal heating of Earth.

Watershed Divide

Higher elevation (ridge) separating two watersheds.

Igneous, Sedimentary, Metamorphic

Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. Sedimentary rocks are types of rock that are formed by the accumulation or deposition of small particles and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Metamorphic rock consists of pre-existing rock mass in which new minerals or textures are formed at higher temperatures and greater pressures than those present on the Earth's surface.

Parent Material

Material from which a soil is formed, determines composition and properties of the soil.

Water Holding Capacity/Retention

Measure of how much water a particular amount of soil can hold.

Tilt

Move or cause to move into a sloping position.

Saltwater Intrusion

Movement of salt water into freshwater aquifers in coastal and inland areas as groundwater is withdrawn faster than it is recharged by precipitation.

Convection Cells: Hadley, Polar, Ferrell

The Hadley cells and polar cells are direct cells, driven by convection and the subsidence of cold, dense air. The Ferrell cells are indirect cells, driven by the direct cells to the north and south of them. Together, the Hadley, Ferrell, and polar cells comprise the three-cell model.

Horizons: O/A/E/B/C

O -(humus or organic) Mostly organic matter such as decomposing leaves. The O horizon is thin in some soils, thick in others, and not present at all in others. A -(topsoil) Mostly minerals from parent material with organic matter incorporated. A good material for plants and other organisms to live. E - (eluviated) - Leached of clay, minerals, and organic matter, leaving a concentration of sand and silt particles of quartz or other resistant materials - missing in some soils but often found in older soils and forest soils. B - (subsoil) Rich in minerals that leached (moved down) from the A or E horizons and accumulated here. C - (parent material) The deposit at Earth's surface from which the soil developed.

Soil Texture Triangle

One of the tools that soil scientists use to visualize and understand the meaning of soil texture names.

Physical and Chemical Weather

Physical and chemical weathering degrade rocks in different ways. While physical weathering breaks down a rock's physical structure, chemical weathering alters a rock's chemical composition. Physical weathering works with mechanical forces, such as friction and impact, while chemical weathering takes place at the molecular level with the exchange of ions and cations.

Epicenter

Point on Earth's surface directly above an earthquake's focus.

Stratosphere

Second layer of the atmosphere; extends from 10 to 30 miles up; location of ozone layer; absorbs 95% of Ultraviolet radiation; temperature increases with altitude increase.

Core, Mantle, Crust

The Earth's core is the part of Earth in the middle of our planet. It has a solid inner core and a liquid outer core. The mantle is the mostly-solid bulk of Earth's interior. The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust. The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up a whopping 84% of Earth's total volume. The mantle is the mostly-solid bulk of Earth's interior. The Earth's crust is a thin shell on the outside of the Earth, accounting for less than 1% of Earth's volume. It is the top component of lithosphere: a division of Earth's layers that includes the crust and the upper part of the mantle. The lithosphere is broken into tectonic plates that move, allowing heat to escape from the interior of the Earth into space.

Divergent and Convergent

The convergent boundaries are where tectonic plates come together. This results in the formation of mountains and subduction zones. The opposite of this is the divergent boundary. The divergent boundaries are where tectonic plates move apart from each other.

Seafloor Spreading

The formation of new ocean crust as a result of magma pushing upward and outward from Earth's mantle to the surface.

Seismic Activity

The frequency and intensity of earthquakes experienced over time.

Saturation Point

The maximum amount of water vapor that can be in the air at a given temperature.

Exosphere

The outer layer of the thermosphere, extending outward into space.

Porosity

The percentage of the total volume of a rock or sediment that consists of open spaces.

Subduction

The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.

Erosion

The process by which wind, water, ice, or gravity transports soil and sediment from one location to another.

Albedo

The proportion of the incident light or radiation that is reflected by a surface, typically that of a planet or moon.

Latent Heat Release

The release of energy when water vapor in the atmosphere condenses into liquid water.

Lithosphere

The solid, outer layer of the earth that consists of the crust and the rigid upper part of the mantle.

Weather

The state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain, etc.

Mesosphere

The strong, lower part of the mantle between the asthenosphere and the outer core.

Plate Tectonics

The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle.

Cation Exchange Capacity (CEC)

The total amount of exchangeable cations that can be held by the soil, expressed in terms of milliequivalents per 100 grams of soil at neutrality (pH 7.0) or at some other stated pH value. The term, as applied to soils, is synonymous with base-exchange capacity but is more precise in meaning.

Asthenosphere

The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

Thermosphere

The uppermost layer of the atmosphere, in which temperature increases as altitude increases.

Upwelling

The upward movement of ocean water toward the surface as a result of diverging currents.

Climate

The weather conditions prevailing in an area in general or over a long period.