Weathering and Erosion
By: Issa Lachica and Kenzie
Edens
Weathering
 Weathering is the breaking
down of rocks, soils and
minerals.
 There are two important
classification of weathering
process. Physical and
Chemical weathering.
 Physical weathering involves
breakdown of rocks and soils.
 Chemical weathering involves
the direct effect of atmospheric
or biological chemicals in the
breaking down of rocks,soils
and minerals.
Erosion
 Erosion is the process by
which soil and rock are
removed from the Earth’s
surface by natural processes
like wind or water flow, and
then transported and deposited
in other locations.
Pictures of different types of
weathering
 This is a picture of
cavernous
weathering.
This is a picture of
mechanical
weathering.
Pictures of weathering and Erosion
This is a picture of
what weathering
looks like.
This is what erosion
looks like.
Causes of weathering and Erosion
 The Sun’s heat causes surface
rocks to expand and fracture,
and moisture can evaporate.
Rain dissolves atmospheric
gases to form acids that add
with minerals in surface layers.
 Water can also freeze at night
or in winter, expanding cracks
and carrying away smaller
rocks and dust.
 Wind and water also carry
small particles that can impact
and erode rocks and carry
away loose soil.
Factors controlling the rate of
erosion
 Soil erosion is a very
complicated problem to solve,
because there are so many
factors include: soil type,
rainfall, crops, landscape and
farm management. There is an
equation to predict the soil loss
from fields using this five
factors.
USGS~ Difference Between
Erosion and Weathering
 Weathering involves two
processes that always work in
concert to decompose rocks.
Both processes occur in place.
No movement is involved in
weathering.
 Chemical weathering is a
chemical change in at least
some of the minerals within a
rock.
 Mechanical weathering is
physically breaking rocks into
fragments without changing
the chemical make up of the
minerals within it.
 As soon as a rock particle
moves, we call it erosion or
mass wasting. We call it
Erosion if the rock particle is
moved by some flowing agent
such as air, water, or ice.
 If you cut it short, a particle is
loosened, chemically or
mechanically, but stays put we
call it weathering once the
particle moving we call it
erosion.
Soil Erosion
 Soil is naturally removed
by the action of water or
wind. Erosion removes at
roughly the same rate soil
is formed. During times of
erosive rainfall,
windstorms, soil may be
detached, transported, or
deposited.
Study of the historic Hopi Buttes
Area
• Hopi buttes is a volcanic field
located in northeastern
Arizona. The Volcanic field
consists of about 300 maars
and diatremes in an area if 965
square miles.
• The maars are volcanic cones
that form from volcanic
explosions near the surface.
The diatremes are subsurface
pipes that fed maars and were
filled by volcanic material at
the time of an eruption.
Erosion in the Southwest
 Erosion is carving into the
southwest Washington
beaches. Erosion rates at
Cape shoal water have
averaged over 100 feet per
year for a century .New
erosion hotspots have
developed in the past few
decades. One erosion hot spot
is located at ocean shores,
north of the Grays Harbor
North Jetty.
Coastal erosion prevention
 One of the most visual
reminders of any major
hurricane, flood, or storm event
causes different changes in the
shape of beaches. A visitor o
the shore will see that the
coastline has retreatedsometimes literally overnightand large amounts of sand
disappeared. As shoreline is
lost the risk of damage to
coastal property increases.
 First we need to understand
and prepare. For us to
understand we need to focus
on the shores structure. The
most recognized shore
component, the beach, is a
dynamic system and changes
all the time.
 Sand comes and goes, and
sand moves. The concern for
uncontrolled erosion and
economic dynamics of the
coast is the sand dune.
Wind Erosion Prevention
 Wind erosion happens when
the soil is left unprotected from
the strong winds. The loss of
top soil lowers the quality of
the soil. This makes crops
more expensive because it’s
harder to grow good crops.
Country and city people should
both be concerned with wind
erosion.
Beach Erosion prevention study
 According to Stephen
Leatherman of the national
healthy beaches campaign,
beach erosion is defined by
the actual removal of sand
from a beach to deeper water
off shore or along shore into
inlets, tidal shoals bays.
 Such erosion can result from
any number of factors,
including the simple inundation
of the land by rising sand
levels resulting from melting of
the polar ice caps.
Geologic Hazards: Landslides
 Landslides commonly occur in
connection with other major
natural disasters such as
floods, wildfires, earthquakes,
and volcanoes.
 Landslides constitute a major
geological hazard because
they are wide spread.
Landslides are very dangerous
and can cause death.
Federal Emergency Management Agency
(FEMA) landslides and mudflows
 Landslides occur all over the
world caused by a variety of
factors including earthquakes,
storms, volcanic eruptions, fire
and by human modification of
land. Landslides can occur
quickly often with little notice
and the best way to prepare is
to stay informed about
changes in and around your
home that would signal that a
landslide is likely to occur.
 Landslide problems can be
caused by land
mismanagement particularly in
mountains, canyons, and
coastal regions. Land-use
zoning, professional
inspections and proper design
can minimize many landslides,
mudflow, and debris flow
problems
The Solution to solve Erosion and
Weathering
 These is some of the ways
people try to prevent erosion.
Some farmers put ditches
around the field to catch the
eroded soil. Soil erosions are
caused when deforestation is
plowed. The roots of trees
holds the soil firmly
underground to prevent soil
erosion. But when people start
to chop down trees erosion will
follow up. People can prevent
erosion by taking proper care
of the soil.
• These are some of the ways
people try to prevent
weathering. To prevent
weathering problems we need
to practice conservation along
with agriculture. Using farming
methods such as no-till crop
rotation, and planting or
conserving tree cover near
crop lands we can reduce the
effect of wind and rain erosion.
Bibliography
 http://www.educatoral.com/weathering_erosion_webques.html
 www.spindigo.com/doctorluke/.../2_10_soil_erosion_factors.htm
 http://volcano.oregonstate.edu/vwdocs/volc_images/north_america/c
oliseum_maar.html
 http://www.scientificamerican.com/article.cfm?id=what-causesbeach-erosion
 http://www.ready.gov/landslides-debris-flows
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