AP Environmental Science Unit 4

• Watershed


  An ecosystem where all water runoff drains into a single body of water
• Troposphere


  The lowest layer of Earth's atmosphere

  
• Stratosphere


  The second-lowest layer of Earth's atmosphere.
• Albedo


  Ability of a surface to reflect light

  
• adiabatic cooling


  the cooling effect of reduced pressure on air as it rises higher in the atmosphere and expands

  
• adiabatic heating


  the heating effect of increased pressure on air as it sinks toward the surface of Earth and decreases in volume

  
• latent heat release


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

  
• Atmospheric convection current


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

  
• Hadley Cell


  a system of vertical and horizontal air circulation predominating in tropical and subtropical regions and creating major weather patterns.

  
• Intertropical Convergence Zone (ITCZ)


  The latitude that receives the most intense sunlight, which causes the ascending branches of the two Hadley cells to converge

  
• Polar Cell


  Cells of air circulation occurring between 60 degrees north and south and each pole.
• Ferrel Cell


  A convection current in the atmosphere that lies between Hadley cells and polar cells

  
• Coriolis effect


  The effect of Earth's rotation on the direction of winds and currents.

  
• 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

  
• Gyre


  a circular motion of water in each of the major ocean basins

  
• Upwelling


  The movement of deep, cold, and nutrient-rich water to the surface

  
• thermohaline circulation


  an oceanic circulation pattern that drives the mixing of surface water and deep water

  
• El Nino-Southern Oscillation (ENSO)


  The periodic changes in winds and ocean currents, causing cooler and wetter conditions in the southeastern United States and unusually dry weather in southern Africa and Southeast Asia.

  
• core

  The central part of the earth below the mantle

  
• Mantle


  The layer of hot, solid material between Earth's crust and core.

  
• Magma


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

  
• Asthenosphere


  The soft layer of the mantle on which the lithosphere floats.

  
• Lithosphere


  A rigid layer made up of the uppermost part of the mantle and the crust.

  
• Crust


  The thin and solid outermost layer of the Earth above the mantle

  
• hot spot


  An area where magma from deep within the mantle melts through the crust above it

  
• plate tectonics


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

  
• tectonic cycle


  the sum of the processes that build up and break down the lithosphere

  
• Subduction


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

  
• volcano


  A vent or fissure in the Earth's surface through which magma and gases are expelled

  
• divergent plate boundary


  an area beneath the ocean where tectonic plates move away from each other

  
• seafloor spreading


  The process that creates new sea floor as plates move away from each other at the mid-ocean ridges

  
• convergent plate boundary


  A tectonic plate boundary where two plates collide, come together, or crash into each other.

  
• transform plate boundary


  Boundary between two plates that are sliding past each other.

  
• fault


  A break in the earth's crust

  
• seismic activity


  the frequency and intensity of earthquakes experienced over time

  
• fault zone


  a large expanse of rock where a fault has occurred

  
• earthquake


  The shaking that results from the movement of rock beneath Earth's surface.

  
• Epicenter


  the point on the Earth's surface directly above the focus of an earthquake

  
• Richer scale


  a scale that rates an earthquakes magnitude based on the size of its seismic wave

  
• Tsunami


  A giant wave usually caused by an earthquake beneath the ocean floor.