Download - Unit 4: Agents of Erosion
UNIT 4: AGENTS OF EROSION
UNIT BIG IDEA/ESSENTIAL QUESTIONS Water and wind are active agents of erosion
that constantly reshapes the earth’s surface. Essential Questions
How does porosity, permeability, aquitards, and aquifers influence groundwater?
What conditions would create karst topography? What importance does deltas have? How can glaciation erode, alter, and reshape the
earth’s surface?
ES Standards: 3.1, 3.4, 3.5
KEY VOCABULARY Alluvial fan Delta Drainage basin Infiltration Karst topography Meander Natural levee Oxbow lake Permeability Porosity
Alpine glacier Arete Cirque Deflation Drumlin Moraine (lateral,
medial) Till Zone of accumulation Zone of wastage
RECAPWeathering-process that breaks
downs materials (chemical and/or mechanically) at the earth’s surface.
Erosion- removes weathered material by wind and water.
Deposition- deposits eroded material in a new location making new features
QUESTION OF THE DAY
What is the hydrological cycle?
WATER Infiltration depends on
Intensity/duration of rainfallPrior wetted condition of soilSoil textureSlope of the landNature of vegetative cover
What is a Drainage Basin? River Systems
3 parts: zone of erosion, zone of sediment transport, zone of sediment deposition
STREAMFLOW Laminar or Turbulent
Which type of flow is responsible for whitewater rapids?
Stream Velocity is based uponGradientShape, size, and roughness of
channelDischarge
Width x depth x velocity
TRANSPORTATION OF ERODED MATERIAL Dissolved load, Suspended Load, Bed Load
Competence determines the maximum size of particles that can be carried
Capacity is based upon a streams discharge
Stream ChannelsBedrockAlluvial
Meanders, Oxbow Lakes, Cut banks and Point bars
Stream Valleys
DEPOSITIONAL FEATURES Floodplains Delta Levees Alluvial Fans
QUESTION OF THE DAYWhat are some ways to control flooding?
GROUNDWATERRate of movement and amount
depends onPorosityPermeabilityAquitardsAquifers
GLACIATION Two types Glacial Movement
Zone of accumulation Zone of wastage
Erosion by plucking and abrasion
GLACIAL FEATURES VIA EROSION Glacial Trough Hanging Valleys Cirques Aretes Horns Fjords
DEPOSITIONAL FEATURES Till vs. Stratified Drift Glacial Erratics Moranines Outwash Plains Drumlins Eskers Kames Kettle Lakes
CAUSES OF GLACIATION Plate Tectonics Changes in Earth’s Orbit Changes in output energy from Sun Albedo and Atmosphere composition
WIND EROSION AND DEPOSITION Deflations and Abrasion Loess Sand Dunes