Unit 4 Forces that Change the Earth Flashcards
Catastrophic Event
Extreme weather events such as floods, hurricanes, and tornadoes; classified by the extent and intensity of their impact on the ecosystem
Ecosystem
A community of organisms and their nonliving environment
Flood
A rising of body of water that submerges normally dry land
Hurricane
A tropical cyclone with wind speeds categorized from 74 to 249 MPH
Tornado
A violently rotating column of air extending from a thunderstorm to the ground with wind speeds categorized from 40 to 318 MPH
Ecoregion
A relatively large area that is characterized by distinctive plant and animal communities, climate, and ecological features
Weathering
The mechanical or chemical processes that break down into smaller pieces
Sediments
Earth material that is broken down by processes of weathering, can be eroded and deposited by the agents of water, wind, ice, and gravity
Erosion
The process by which water, ice, wind, and gravity remove and transport sediments from one place to another
Deposition
The process by which gravity, water, wind, and ice deposit weathered and relocated sediments
Topography
A description of land surface area with reference to elevation variations
Watershed
An area of land where the surface water and groundwater drains into a particular body of water, separated from each other by drainage divides
Drainage Divide
A geographical barrier, such as a ridge, hill, or mountain, separating one watershed land area from another
Surface Water
Water from precipitation that drains into a gully that flows into a stream, which in turn flows into a river, lake, reservoir, estuary, wetland, or the ocean
Groundwater
Water that collects in cracks and pores in underground soil and rock layers
Water Table
The top of the saturation zone, below which water fills all open spaces between the rock
Zone of Aeration
The upper portion of soil and rock that can be temporarily filled with water as the water enters the ground but then moves deeper
Saturation Zone
Below the water table where all spaces not filled with solid material fill with water
Aquifer
A layer of permeable rock that allows water to flow through
Permeable Rock
Allows water movement to flow through the material, the opposite of impermeable
Subsidence
Sunken land surface due to underlying compression of earth material as a result of the removal of ground water
Point-Source Water Pollution
A single identifiable and localized source of water pollution such as wastewater discharge into a stream
Non-Point Source Water pollution
Pollutants introduced into surface or ground water that are without a specific location source, such as water flowing over a lawn that has been fertilized and into a drain
