activating strategy
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Activating Strategy. Study Jams Video Breaker and Whoosh JUST WRITE THE NOTES IN WHITE PRINT The other is information to make you more intelligent about erosion…and know some cool facts to share with others!!. Erosion. - PowerPoint PPT PresentationTRANSCRIPT
Activating Strategy
Study Jams VideoBreaker and Whoosh
JUST WRITE THE NOTES IN WHITE PRINTThe other is information to make you
more intelligent about erosion…and know some cool facts to share with others!!
Erosion
• Process by which soil and sediment are transported from one location to another
Erosion by Gravity
p. 359-361
Open the flapTop half: Notes
• Gravity is the force that moves rock and other materials downhill.
• Mass movement can be fast or S L O W .
Examples
• Landslides• Mudflows• Slump• Creep
Landslide
LaConchita Sycamore Canyon
Las Colinas (view from the top)
Las Colinas (large view)
Mudflows
Mount St. Helens
Slump
Creep
Bottom Half:Picture
•Now illustrate erosion by gravity
•One giant scene with the examples of erosion by gravity
What if…
What if you could buy a mountain home near a river or on the waterfront?
Things you should know before buying a waterfront property
What do you think???Pros: • good view,• use of beach• boat docking
Cons: • could have
restrictions on use of the beach with protected plants and animals
• flooding• high insurance costs
Things you should know before buying a mountain home…
• Pros: • High property value
because of the beauty of the land
• mineral rights (you might find minerals on the mountain and can make profit from them
• Cons: • Ice and snow can cause
problems trying to get around
• small creeks can flood and cause erosion
• might not have access to electricity, internet, sewage systems, etc.
Erosion by Waterp. 308-314
Top Half:Notes
• Moving water is the major agent of erosion that has shaped the Earth’s land surface
Bottom Half:Picture
•Now illustrate erosion by water
•One giant scene with the examples of erosion by water
Website for more information
http://www.geolsoc.org.uk/gsl/education/resources/rockcycle/page3462.html
These two photos were taken from the same place 63 years apart. How are they alike? How are they different?
1941 2004
Ag Upsala Glacier, South America
Grinnell Glacier, Montana
• 1935 • 2005
South Cascade Glacier, Washington
Erosion by Ice
• A glacier is a huge mass of ice and snow that moves over land. It erodes and deposits large amounts of rock material.
• p. 352-356
How glaciers form
• Over time, the weight of the snow packs the snow and forms a giant mass of ice.
• Gravity causes them to flow slowly like a “river of ice”
Glacier ice is the largest reservoir of fresh water on the planet, storing an estimated 75
percent of the world’s supply
A glacier can range in length from the equivalent of a football field to more than 100 miles.
The Antarctic ice sheet is actually a glacier. If it were to melt, sea levels
would rise 210 feet
Though it sits on the equator, Mount Kilimanjaro is glaciated
• A single glacier ice crystal can grow to be as large as a baseball
Mountain valleys are typically “V” shaped before being taken oven by a glacier; during glaciation,
the valley widens and deepens and becomes “U” shaped.
Alaska is estimated to have more than 100,000 glaciers. Most remain unnamed.
Erosion by Wind
• Wind carries and deposits sediment.
• Deserts, coastlines, and areas with little plant coverage are the most affected by wind erosion.
leewardleeward
windward
Piles of sand deposited by wind - Leeward side has a steeper slope
Sand Dunes
What do you see in the picture that is helping to slow down erosion?
….at the beach
• How did humans slow down erosion in this picture?
….in the desert
Barchan dunes of the Namib Desert
Crescent shaped dunes formed from a unidirectional (one-direction) wind.
Ripple marks are miniature dunes within a dune formed by crosswinds (not more than 2 inches tall). They appear to be traveling in a different direction than the large dune.
Hueco Bolson Desert – Texas
The Dust Bowl of the 1930s
Rock formations in the Wadi Desert in Egypt
Rock Arches --formed when wind and water weather (erode) softer material first. Arches National Canyon, Utah
Ventifact—formed when wind carries fine particles that work like a sand blaster (i.e. sand, silt, clay, and ice particles)
Mt. Falconer - Canada
Deflation--formed in arid environments when wind carries finer, more lightweight particles such as sand away; large particles are left behind and protect from further erosion
Desert pavement
Yellowish, fine grained silt and clay sized particles formed by glaciers millions of years ago; carried and deposited by wind
Loess Deposits - Banks, Pennsylvania
Base of a rock is weathered and eroded more quickly due to abrasion (sand blasting)
Wind could only pick up sand grains a couple of feet.
Pedestal rockAfrica
What caused the rock to look like this??
Although moving water is the major agent of erosion that has shaped the Earth’s land surface; Human activity causes 10 times more erosion of the continental surface of the Earth than all natural processes combined.
Erosion by Human Activity
Why is this critical?• Earth's surface involves a balanced process,
where new soil forms at about the same rate as it erodes.
****If humans are stripping soil at that rate, nature won't be able to keep up***• Almost all the land that is capable of producing
crops is being used by the rapidly growing population.
Renewable resource – is a natural resource which can replenish with the
passage of timeExamples water (hydroelectricity)
solar energybiofuel (contains energy from living organisms)
Non-renewable resource --used faster than it is made by the earth
Examples natural gas, fossil fuels, metal ores (in human timeframe)
Help!!!
What do we do now?
Terracing
Banaue rice terraces, Philippines
Soil Conservation--protection, preservation, restoration
Crop Rotation
Check each pageName on the back with class period
Notes—definition of each type of erosion
Illustrations• Quality drawings (I’m not an art teacher, but try your
best to clearly illustrate!)• May need labels• Color!!
DUE TUESDAY 10/29