Unit 4 Flashcards
Upwelling
The upward movement of ocean water toward the surface as a result of diverging currents.
Rock cycle
The geologic cycle governing the constant formation, alteration, and destruction of rock material that results from tectonics, weathering, and erosion, among other processes.
Collision zone
An area where two continental plates are pushed together and the colliding forces push up the crust to form a mountain range.
C horizon
The least-weathered soil horizon, which always occurs beneath the B horizon and is similar to the parent material.
B horizon
Commonly known as subsoil, a soil horizon is composed primarily of mineral material with very little organic matter.
Lithosphere
The outermost layer of Earth, including the solid upper mantle and crust.
Acid precipitation (Acid rain)
Precipitation high in sulfuric acid and nitric acid.
Ozone
A pale blue gas composed of molecules made up of three oxygen atoms (O3).
Aqueducts
Pipes and canals that move water from where it is abundant to areas where it is scarce.
Island arc
A chain of islands formed by volcanoes as a result of two tectonic plates coming together and experiencing subduction.
Mesosphere
The layer of the atmosphere above the stratosphere, extending roughly 50 to 85 km (31–53 miles) above the surface of Earth.
Base saturation
The proportion of soil bases to soil acids, expressed as a percentage.
Ferrell cell
A convection current in the atmosphere that lies between Hadley cells and polar cells.
Water holding capacity
The amount of water a soil can hold against the draining force of gravity.
Coriolis effect
The deflection of an object’s path due to the rotation of Earth.
La Niña
Following an El Niño event, trade winds in the South Pacific reverse strongly, causing regions that were hot and dry to become cooler and wetter.
Troposphere
A layer of the atmosphere closest to the surface of Earth, extending up to approximately 16 km (10 miles).
Core
The innermost zone of Earth’s interior, composed mostly of iron and nickel. It includes a liquid outer layer and a solid inner layer.
Intertropical convergence zone (ITCZ)
The latitude that receives the most intense sunlight, which causes the ascending branches of the two Hadley cells to converge.
O horizon
The organic horizon at the surface of many soils, composed of organic detritus in various stages of decomposition.
Magma
Molten rock.
Porosity
The size of the air spaces between particles.
Chemical weathering
The breakdown of rocks and minerals by chemical reactions, the dissolving of chemical elements from rocks, or both these processes.
Thermohaline circulation
An oceanic circulation pattern that drives the mixing of surface water and deep water.
Volcano
A vent in the surface of Earth that emits ash, gases, or molten lava.
Humus
The most fully decomposed organic matter in the lowest section of the O horizon.