Aim: What is Erosion?

Objective: Ability to differentiate the different type of weathering

Vocabulary: mechanical weathering, chemical weathering, carbonation, oxidation, hydrolysisCatalyst, sediment, glaciers

Interactions of the Spheres

Definition of Erosion

Process in which weathered pieces of the lithosphere are moved from on place to another

Occurs because of Weathering

Weathering

Is the decay of rocks, minerals, mountains, and other hard surfaces of the earth

The decay breaks larger particles into smaller ones

The decay can either be mechanical or chemical or both

Physical Weathering

GravityRunning Water Freeze-Thaw CycleWind Glacier

What happens when two rocks bang into each other?

Little chips of the rocks break off Sometimes large chips, sometimes small

ones. Multiply that by 1,000,000 years Will the original rocks be larger or smaller Mechanical Weathering

Freeze-Thaw Cycle

If you put a can of soda in the freezer what happens?

The same things happens in nature when water freezes

Over millions of years – changes the lithosphere breaking parts of it into millions of pieces

Freeze Thaw

Frost Wedging

Freeze Thaw CycleWhen the rock finally breaks up there, what causes it to fall ?

Man on the Mountain, NH

This Process Created:

What happens when water rushes down a mountain

Brings everything with itSoilRocksNow multiply that effect by 10,000,000 years

How dramatic can the effect be?

Most of the sand deposits on the east coast are the weathered remains of granite mountains from …

Appalachian Mountains

Running Water

The faster the water runs,

the larger the particles (sediment)

the water is able to move !

Running Water

Running WaterMoves things “down-stream”Created the Grand Canyon over 30,000,000

yearsLiterally washed mountains down valleysAnd sometimes into the oceansCreates new landforms

Running Water

Running Water Creates Deltas

Running Water Creates Deltas

Where did this whole landform come from?

Abrasion

Moving Water

Plant Acids

Glaciers

Extremely Vast Regions of Ice/SnowMillions of Years OldContinental (Greenland – Antarctica)Mountain (Alpine) Glaciers

Glaciers

Move rock and sediment in their pathWhen they retreat (melt), the carried

remains are left behindFormed Long Island – last Ice AgeSometimes they form hill, and lakesDrumlins and the Finger Lakes

Chemical Weathering

Chemical weathering is where the rock material is changed into another substance by reacting with a chemical.

1. Oxidation:

2. Hydrolysis:

Oxidation is another form of chemical weathering

Your bicycle if made of iron What happens to it in the rain Turns to rust Oxygen + Iron = Iron Oxide (rust) Water is a catalyst = speeds up the process

Weathering can also be chemical

Carbon dioxide (air) mixes with water (rain) to form carbonic acid

Carbonic acid can dissolve some sedimentary rocks – particularly limestone

Over millions of years this forms large caves and caverns. (Howe Caverns)

Often when water combines with limestone or marble an acid is formed

Howe Caverns

LimestoneCave

Hydrolysis is another form of chemical weathering

Water has a tendency to dissolve other substances

Water is called the universal solvent When water combines with another

substance is called hydrolysis

Rates of weathering will be influenced by surface area: More surface exposed, the faster the weathering will occur.

1. What type of steam carries more sediment?

a)Fast moving

b)Slow moving

c)No correlation

2. What type of steam cause more erosion?

a)Fast moving

b)Slow moving

c)No correlation

3. During a heavy rain, a stream probably moves

a)Faster

b)Slower

c)No correlation

4. During a heavy rain, there is probably _______ erosion

a)more

b)less

c)No correlation

5. During a hurricane, there is probably _______ erosion

a)more

b)less

c)No correlation

6. There is more gravitational erosion on a ______ slope.

a)Steep

b)gentle

c)No correlation

7. There is more erosion on a ______ flowing stream

a)Steep sloping

b)Gentle sloping

c)No correlation

8. Freeze-Thaw reactions

a)Create sediment

b)Reverse seditment

c)No correlation

9. How was Long Island created

1. Chemical Weathering

2. Erosion

3. Glaciers (glaciations)

10. Deltas are created from

1. Wave Action

2. Carried sediment from upstream

3. Glaciers