Chapter 3 – Agents of Erosion and Deposition

Chapter 3 – Agents of Erosion and
- Erosion is breakdown and movement of
materials, while Deposition is where these
materials are dropped
- Waves (section 1)
 Size depends on how hard the wind is
blowing and for how long
 Wave breaks when it can no longer
support itself (too tall)
 Longshore current = movement of H2O
parallel to the shore, can create
landforms in open H2O
 Erosion can produce a variety of features
- Wind (section 2)
 Landscapes most commonly impacted
are deserts and coastlines
 Saltation = movement of sand-sized
 Deflation = lifting and removal of fine
 Abrasion = grinding and wearing down
of rock surfaces by other rock or sand
 Dunes = mounds of wind-deposited
sand, common in deserts and along
 Loess = thick deposits of windblown,
fine-grained sediment, far away from
- Ice (section 3)
 Major contributor = Glaciers
 2 kinds of glaciers
1) Alpine – mountainous areas
2) Continental – large ones that can
cover entire continents
- largest kind is a cont. ice sheet
 Antarctica  91% of all glacial ice
 Glaciers can move downhill when
thickness and slope are right
- move by 2 ways: ice @ bottom
melts & solid ice crystals sliding
over each other
 Landforms carved by glaciers are
different based on the kind of glacier
 Glaciers pick up rock material and move
it away, creating striations in the process
 Glacial drift  all the material picked
up is deposited when they melt
1) Stratified drift – H2O sorts and
deposits it
2) Till – directly by the ice as it
melts (unsorted = all sizes)
- Gravity’s effect (section 4)
 Angle of Repose = steepest angle at
which loose material will NOT slide
 Mass Movement = movement of any
material downslope
 Two kind M.M.  1) Rapid 2) Slow
 Rapid examples
1) Rock fall
2) Landslide
3) Mudflow
4) Lahars
 Slow  Creep