weathering and erosion 2015 - lcps.org
TRANSCRIPT
3/5/2015
1
Do you know the answers?
What large landform in the western United States
was formed by the movement of water over millions
of years?
Why do the pyramids in
Egypt look like this?
The Grand Canyon was formed by the
Colorado River
Weathering due to sand
and acid rain
Agenda 03 – 04 MAR 15
1.Quiz Review (I have – Who has?)
2.Vocabulary Quiz
3.Weathering and Erosion Notes
4.Weathering Lab
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WEATHERING AND EROSION
Human!
The Natural Bridge
was a sacred site of
the Native American
Monacan Tribe tribe
here in Virginia.
215 feet
tall!
90 feet
across!
Click the pic to watch a video!
Weathering
The breaking down of rocks, soils, and minerals in
the Earth’s crust into smaller pieces
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Weathering
Chemical
Weathering
Physical (Mechanical) Weathering
Physical Weathering
Process by which rocks are broken down into
smaller pieces by external conditions without
changing their chemical composition
Types:
Frost breaking rock (2 kinds!)
Plant roots
Friction and repeated impact
Burrowing of animals
Temperature changes
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Frost Wedging
Water seeps into cracks in the rock and freezes. Freezing water expands, pushing apart the rocks. Repeated cycles will eventually split the rock!
Frost Heaving An upward swelling of soil due to water freezing beneath the surface. This can even make buildings shift upward!
Click the pic to watch a video!
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Plant Roots
(Root Wedging)
Plant roots extend into fractures and begin to grow which causes the fracture to expand. Continued growth and expansion can break the rock!
Friction and
Repeated Impact
Rocks continually scrape or bump into other rocks, breaking smaller pieces off. These smaller pieces continue to bump and scrape against other rocks, eventually wearing away completely.
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Burrowing of Animals
Temperature
Changes
Heating causes rocks to expand. Cooling causes rocks to contract (shrink). When this happens unevenly, rocks can break. Heating can be caused by sunlight or fires!
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Chemical Weathering
The process that breaks down rock through
chemical changes.
Types:
Dissolving by water
Oxygen (Oxidation)
Carbon dioxide
Living organisms (urine) or dead decomposing
Acid rain
Water Water weathers rock by dissolving it.
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Oxygen Oxygen combines with other elements to form new substances. For example, oxygen combines with iron in the presence of water. The product of this oxidation reaction is rust.
Carbon
Dioxide
Carbon dioxide (CO2) dissolves in rain water, forming carbonic acid. Carbonic acid can easily dissolve limestone and marble, causing significant weathering.
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Living & Dead
Organisms
Lichens that grow on rocks produce weak acids that chemically weather rock. Decaying organisms can also produce acids (from bacteria) that are capable of weathering rock.
Acid Rain Compounds from burning coal, oil, and gas react chemically with water forming strong acids. Acid rain causes very rapid chemical weathering.
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Karst Topography
A type of landscape in rainy regions that causes
disappearing streams, caves, and sinkholes
Created by chemical weathering of limestone
Example of Karst: Disappearing Streams
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Example of Karst: Caves
Example of Karst: Sinkholes
Click the pic to watch a video!
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Erosion Movement of rocks and soil
by water, wind, or ice.
Water Erosion
Rivers, streams, and runoff
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Mass Movements
Landslides, mudslides, slump, creep, and debris flow
Click the pic to watch a video! Click the pic to watch a video!
Ice Erosion
Glaciers
Click the pic to watch a video!
Click the pic to watch a video!
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Wind Erosion
Click the pic to watch a video!
1. FOLLOW all directions
2. Work with YOUR group
3. Write down your very BEST answer
4. CLEAN UP your lab station
5. Turn in to the “IN BOX”
6. Becomes homework if not done!
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Websites and Videos from the Presentation
1. http://studyjams.scholastic.com/studyjams/jams/science/rocks-minerals-
landforms/weathering-and-erosion.htm
(Study Jams – Weathering and Erosion)
2. https://www.youtube.com/watch?v=9jzycX380PA
(Foundation Frost Heaving)
3. http://pbskids.org/dragonflytv/show/sinkholes.html
(Sinkholes)
4. http://video.nationalgeographic.com/video/101-videos/landslides
(Landslides 101)
5. https://www.youtube.com/watch?v=_yCnQuILmsM
(Amazing Flash Flood/Debris Flow Southern Utah)
6. https://www.youtube.com/watch?v=njTjfJcAsBg
(Underneath a Glacier Time Lapse)
7. www.discovery.com/tv-shows/frozen-planet/videos/time-lapse-glacier-movement/
(Time Lapse Glacier Movement)
8. http://pbskids.org/dragonflytv/show/sand_dunes.html
(Sand Dunes by Victoria and Alejandra)
9. https://ees.as.uky.edu/sites/default/files/elearning/module07swf.swf
(Weathering and Climate Animation)
Extra material!