Transcript weathering and erosion

Weathering
 The process by which
rocks are broken into
smaller pieces.
 It can be mechanical or
chemical
Erosion
 The word "erosion"
comes from an old word
meaning "eat away.”
 You see erosion
happening where the
forces of nature move
soil and rock.
 These agents of erosion
are water, wind, ice and
gravity.
 A physical process involving no change in chemical
composition.
 The rock is simply broken down into small fragments
by various methods.
 Freezing water expands in cracks and wedges
the rock apart.
 The grinding and wearing away of rock.
 Wind, water, and gravity can lead to abrasion.
 Caused by water, weak acids, and air.
 Acids are created by volcanic activity and pollution.
 Acids can be created by water reacting with limestone.
 The combination of
oxygen in the
atmosphere with a
mineral to produce
an oxide - high iron
content rocks are
particularly
vulnerable.
 If a particle is loosened, chemically or mechanically,
but stays put, it is “weathering”. Once the particle
starts moving, it is “erosion”.
 Wind and water (waves, streams and rivers, and
glaciers) are causes of erosion.
 The pounding of waves against the shoreline can
create sea stacks, sea arches, and sea caves.
 Wind combined with loose rock and sand can grind
the surfaces of rock.
 Glaciers are large masses of snow, ice, and rock debris
that accumulate in great quantities and begin to flow
outwards and downwards under the pressure of their
own weight.
 As glaciers flow, it erodes the surface by abrasion.
 Sediment is transported by the glacier and
deposited where the ice melts.
 Abrasion occurs
when debris-rich ice
slides over bedrock
abrading it like sand
paper on a block of
wood.
 U-shaped valleys, cirques, and hanging valleys are
some of the landforms created by glaciers.