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76 terms

Chapter 3: Earth's Independent Systems

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Abiotic
Pertaining to factors or things that are separate and independent from living things; nonliving
Acid
Any compound that releases hydrogen ions when dissolved in water. Also, a water solution that contains a surplus of hydrogen ions
Air mass
Enormous bodies of air that move as a unit
A layer
A soil horizon below the O layer. Formed of weathered rock, with some organic material; often referred to as topsoil
Alkaline
A basic substance; chemically, a substance that absorbs hydrogen ions or releases hydroxyl ions; in reference to natural water, a measure of the base content of the water
Aquifer
An underground layer of porous rock, sand, or other material that allows the movement of water between layers of nonporous rock or clay. Frequently tapped for wells
Arable
Land that's fit to be cultivated
Asthenosphere
The part of the mantle that lies just below the lithosphere
Atmosphere
The gaseous mass or envelope surrounding a celestial body, especially the one surrounding the Earth, which is retained by the celestial body's gravitational field
Barrier island
A long, relatively narrow island running parallel to the mainland, built up by the action of waves and currents and serving to protect the coast from erosion by surf and tidal surges
Biological weathering
Any weathering that's caused by the activities of living organisms
Biotic
Living or derived from living things
B layer
A soil horizon that receives the minerals and organic materials that are leached out of the A horizon
Chemical weathering
The result of chemical interaction with the bedrock that is typical of the action of both water and atmospheric gases
C layer
A soil horizon made up of larger pieces of rock that have not undergone much weathering
Clay
The finest soil, made up of particles that are less than 0.002 mm in diameter
Conduction
The transmission or conveying of something through a medium or passage, especially the transmission of electric charge or heat through a conducting medium without perceptible motion of the medium itself
Convection
The vertical movement of a mass of matter due to heating and cooling; this can happen in both the atmosphere and Earth's mantle
Convection currents
Air currents caused by the vertical movement of air due to atmospheric heating and cooling
Convergent boundary
A plate boundary where two plates are moving toward each other
Coral reef
An erosion-resistant marine ridge or mound consisting chiefly of compacted coral together with algal material and biochemically deposited magnesium and calcium carbonates
Coriolis effect
The observed effect of the Coriolis force, especially the deflection of an object moving above the Earth, rightward in the Northern Hemisphere, and leftward in the Southern Hemisphere
Crop rotation
The practice of alternating the crops grown on a piece of land - for example, corn one year, legumes for two years, and then back to corn
Delta
A usually triangular alluvial deposit at the mouth of a river
Divergent boundary
A plate boundary at which plates are moving away from each other. This causes an upwelling of magma from the mantle to cool and form new crust
Doldrums
A region of the ocean near the equator, characterized by calms, light winds, or squalls
Drip irrigation
A method of supplying irrigation
Earthquake
The result of vibrations (often due to plate movements) deep in the Earth that release energy. They often occur as two plates slide past one another at a transform boundary
El Niño
A climate variation that takes place in tropical Pacific about every three to seven years, for a duration of about one year
Erosion
The process of soil particles being carried away by wind or water. Erosion moves the smaller particles first and hence degrades the soil to a coarser, sandier, stonier texture
Estuary
The part of the wide lower course of a river where its current is met by the tides
Fault
The place where two plates abut each other
Greenhouse effect
The phenomenon whereby the Earth's atmosphere traps solar radiation, caused by the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that allow incoming sunlight to pass through, but absorb heat radiated back from the Earth's surface
Green Revolution
The development and introduction of new varieties of (mainly) wheat and rice that has increased yields per acre dramatically in countries since the 1960s
Hadley cell
A system of vertical and horizontal air circulation predominating in tropical and subtropical regions and creating major weather patterns
Headwaters
The water from which a river rises; a source
Horizon
A layer of soil
Humus
The dark, crumbly, nutrient-rich material that results from the decomposition of organic material
Hurricane
A severe tropical cyclone originating in the equatorial regions of the Atlantic Ocean or Caribbean Sea or eastern regions of the Pacific Ocean, traveling north, northwest, or northeast from its point of origin, and usually involving heavy rains
Inner core
The molten core of the Earth
Insolation
The rate of delivery of solar radiation per unit of horizontal surface
Jet stream
A high-speed, meandering wind current, generally moving from a westerly direction at speeds often exceeding 400 km (250 miles) per hour at altitudes of 15 to 25 km (10 to 15 miles)
Land degradation
When soil becomes water-logged and then dries out, and salt forms a layer on its surface
La Niña
A cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns
Lithosphere
The outer part of the Earth, consisting of the crust and upper mantle, approximately 100 km (62 miles) thick
Loamy
Soil composed of a mixture of sand, clay, silt, and other organic matter
Mantle
The layer of the Earth between the crust and the core
Monoculture
The cultivation of a single crop on a farm or in a region or country; a single, homogeneous culture without diversity or dissension
Monsoon
A wind system that influences large climactic regions and reverses direction seasonally
O layer
The uppermost horizon of soil. It is primarily made up of organic material, including waste from organisms, the bodies of decomposing organisms, and live organisms
Physical (mechanical) weathering
Any process that breaks rock down into smaller pieces without changing the chemistry of the rock; typically wind and water
Plate boundaries
The edges of tectonic plates
Prior appropriation
When water rights are given to those who have historically used the water in a certain area
Rain shadow
The low-rainfall region that exists in the leeward (downwind) side of a mountain range. The rain shadow is the result of the mountain range's causing precipitation on the windward side
Red tide
A bloom of dinoflagellates that causes reddish discoloration of coastal ocean waters. Certain dinoflagellates of the genus Gonyamlax produce toxins that kill fish and contaminate shellfish
R horizon
The bedrock, which lies below all of the other layers of soil
Riparian right
The right, as to fishing or to the use of a riverbed, of one who owns riparian land (the land adjacent to a river or stream)
Salinization
The process in which soil becomes saltier and saltier until, finally, the salt prevents the growth of plants. Salinization is caused by irrigation because salts brought in with the water remain in the soil as water evaporates
Sand
The coarsest soil, with particles 0.05-2.0 mm in diameter
Silt
Soil with particles 0.002-0.05 mm in diameter
Southern Oscillation
The atmospheric pressure conditions corresponding to the periodic warming of El Niño and cooling of La Niña
Subduction zone
In tectonic plates, the site at which an oceanic plate is sliding under a continental plate
Thermocline
A layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt
Thermosphere
The outermost shell of the atmosphere, between the mesosphere and outer space, where temperatures increase steadily with altitude
Topsoil
The A layer of soil; the layer of soil most important for plant growth
Trade winds
The more or less constant winds blowing in horizontal directions over the Earth's surface, as part of Hadley cells
Transform boundary
Also known as transform faults, boundaries at which plates are moving past each other, sideways
Tropical storm
A cyclonic storm having winds ranging from approximately 48 to 121 km (30 to 75 miles) per hour
Upwelling
A process in which cold, often nutrient-rich, waters from the ocean depths rise to the surface
Volcanoes
An opening in the Earth's crust through which molten lava, ash, and gases are ejected
Watershed
The region draining into river system or other body of water
Water-scarce
Countries that have a renewable annual water supply of less than 1,000 m³ per person
Water-stressed
Countries that have a renewable annual water supply of about 1,000-2,000 m³ per person
Weather
The day-to-day variations in temperature, air pressure, wind, humidity, and precipitation mediated by the atmosphere in a given region
Weathering
The gradual breakdown of rock into smaller and smaller particles, caused by natural chemical, physical, and biological factors
Wetlands
A lowland area, such as a marsh or swamp, that is saturated with moisture, especially when regarded as the natural habitat of wildlife