UNIT 5 VOCABULARY

Catastrophic Event A violent, usually destructive natural

occurrence.

*Drought A prolonged period of abnormally low

precipitation; a shortage of water resulting from this.

*Earthquake the result of a sudden release of energy

in the Earth’s crust.

*Tsunami is a series of water waves caused by the

displacement of a large volume of a body of water, usually an ocean.

*Flood an overflow of an expanse of water that

submerges land.

*Hurricanes A storm with a violent wind, in particular

a tropical cyclone in the Caribbean.

*Tornado a violent, dangerous, rotating column of

air that is in contact with both the surface of the earth and a cumulonimbus cloud.

*Volcano an opening, or rupture, in a planet's

surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface.

*Wildfire A large, destructive fire that spreads

quickly.

Ecoregion is an ecologically and geographically

defined area that is smaller than an ecozone and larger than an ecosystem.

Weathering the breaking down of rocks, soils and

minerals as well as artificial materials through contact with the Earth’s atmosphere and waters.

Mechanical Chemical

Erosion is the process by which materials are

removed from a region of the Earth's surface.

Deposition is the geological process by which

material is added to a landform or land mass.

Watershed The region draining into a river, river

system, or other body of water.

Aquifer A layer of rock or soil able to hold or

transmit much water.

Ground Water is water that is found underground in the

cracks and spaces in soil, sand and rock.

Porosity the ratio of the volume of openings

(voids) to the total volume of material. Porosity represents the storage capacity

of the geologic material.

Permeability is a measure of the ability of a porous

material (often, a rock or unconsolidated material) to allow fluids to pass through it.

Pollution the introduction of contaminants into a

natural environment that causes instability, disorder, harm or discomfort to the ecosystem.

Percolation Percolation is the movement of water

through the soil, and it's layers, by gravity and capillary forces.

Infiltration the process by which water on the

ground surface enters the soil