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