Unit 4- Earth Systems and Resources

Albedo

Ability of a surface to reflect light. Higher for snow, lower for dark soil or pavement.

Asthenosphere

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

Atmosphere

A thin layer of gases surrounding Earth; mainly nitrogen and oxygen.

Clay

The finest size of soil particles.

Climate

The average weather conditions in an area over a long period of time (at least 30 years).

Convection

The transfer of thermal energy by the circulation or movement of a liquid or gas, with warmer air/fluid rising.

Convergent boundary

A tectonic plate boundary where two plates move towards each other.

Coriolis effect

The effect of Earth's rotation on the direction of winds and currents, causing them to turn left in the southern hemisphere and right in the northern hemisphere.

Crust

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

Divergent boundary

A tectonic plate boundary where two plates move away from each other.

Earthquake

Sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust.

El Niño

A periodic change of climate conditions that occurs in the equatorial Pacific, when trade winds weaken causing less upwelling.

Elevation

The height above sea level; altitude.

ENSO

The El Niño Southern Oscillation, the combined effects of El Niño and La Niña climate conditions.

Equator

Imaginary line drawn around the earth equally distant from both poles, dividing the earth into northern and southern hemispheres and constituting the parallel of latitude 0°.

Equinox

The two days of the year on which neither hemisphere is tilted toward or away from the sun; once in March and once in September.

Erosion

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

Exosphere

The outer layer of the atmosphere extending into outer space that is the thinnest layer with molecules far apart.

Fault

A crack in the earth's crust where earthquakes occur.

Hot spots

Places in the middle of tectonic plates where molten material from the mantle reaches the surface.

Infrared radiation

Electromagnetic waves with wavelengths that are longer than visible light but shorter than microwaves.

Insolation

Incoming solar radiation from the sun.

La Niña

A periodic change of climate conditions that occurs in the equatorial Pacific, with stronger tradewinds and increased upwelling.

Latitude

Distance north or south of the equator.

Leaching

Process in which various chemicals in upper layers of soil are dissolved and carried to lower layers.

Lithosphere

The rigid outer layer of the earth that floats on the asthenosphere.

Loam

Soil with an equal mixture of sand, silt, and clay that is ideal for agriculture.

Mantle

The hot, mostly solid, layer of the Earth between the core and crust.

Mesosphere

The middle and coldest layer of the atmosphere between the stratosphere and thermosphere OR the solid middle layer of the earth between the asthenosphere and outer core.

Organic material

Carbon-based substances that were once part of living things.

Parent material

The base geological material in a particular location from which the inorganic parts of soil are derived.

Permeability

The ability of a rock or sediment to let fluids flow through its open spaces.

pH

A scale from 0-14 that is a measure of the hydrogen ion concentration in a substance, with lower values being acidic and higher values being alkaline or basic.

Plate boundary

The region where two tectonic plates meet.

Plate tectonics

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

Porosity

A measure of how much of a rock is open space, which allows it to hold water.

Precipitation

Any form of water that falls from clouds and reaches Earth's surface; including rain, snow, and hail.

Prevailing winds

The predominant direction of the movement of air in a particular place or season.

Rain shadow effect

Low precipitation on the leeward side of a mountain when prevailing winds flow up and over a high mountain or range of high mountains.

Sand

The coarsest size of soil particles.

Seafloor spreading

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

Silt

The intermediate size of soil particles.

Soil

A mixture of inorganic rock fragments, organic material, living organisms, water, and gases that can support the growth of plants.

Soil horizons

Horizontal layers of soil with differing characteristics such as color and texture.

Soil profile

A vertical section of soil that shows all of the horizons that make up the soil in a particular place.

Soil texture

Relative amounts of the different types and sizes of mineral particles in a sample of soil.

Solstice

The two days of the year on which the sun is farthest north or south of the equator leading to the longest day in one hemisphere and the shortest in the other; occurs in June and December.

Stratification

The process in which sedimentary rocks are arranged in layers of deposited minerals.

Stratosphere

The second-lowest layer of Earth's atmosphere; where the ozone layer is found.

Tectonic plates

Sections of the Earth's lithosphere that move due to convection currents in the asthenosphere below.

Thermosphere

The region of the atmosphere above the mesosphere and below the exosphere, where temperature increases as altitude increases.

Transform boundary

A tectonic plate boundary where two plates move past each other in opposite directions.

Troposphere

The lowest layer of Earth's atmosphere; most dense layer of air; where weather occurs.

Turnover

Seasonal changes in warm and cool water layers that occurs in freshwater lakes.

Upwelling

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

Volcano

A fissure in the earth's crust that allows magma as well as gases to reach the surface.

Watershed

The land area where water runs off into a body of water.

Weather

The conditions of Earth's atmosphere at a particular time and place.

Weathering

The breaking down by wind, water, or chemical means, of rocks on the Earth's surface.

Wind

The movement of air from an area of high pressure to one of low pressure.