10/4/11 B DayLEQ: How do chemical and mechanical weathering create unconformities in the earth?

1. What is one thing we can learn from ice rings? 2. What are two things that we can learn from ice cores?3. Is our climate getting warmer or colder? What do greenhouse gases have to do with it?!4. Copy and complete the following sentence:

Increased levels of carbon dioxide cause the global temperature to (increase/decrease).

Today’s LEQ: How do chemical and mechanical weathering create unconformities in the earth?

By the end of today, you should be able to…1. Compare and contrast chemical and

mechanical weathering

2. Explain how chemical and mechanical weathering can create unconformities in the earth

Track your Progress: Unit 1 Quiz B-1 = 95 -9 = 55 -17 = 15-2 = 90 -10 = 50 -18 = 10-3 = 85 -11 = 45 -19 = 5-4 = 80 -12 = 40-5 = 75 -13 = 35-6 = 70 -14 = 30-7 = 65 -15 = 25-8 = 60 -16 = 20

EOG Question From Last Year’s Test:

• A scientist has a hypothesis that a large volcanic eruption caused a change in global temperature. Which information gained from ice cores is most useful in supporting the scientist’s hypothesis?�–A. levels of dissolved oxygen –B. identities of trace metals –C. estimates of natural radioactivity –D. amounts of atmospheric dust

Draw this in your notes:Evidence for climate change:

Ice Cores Tree Rings

Ice Cores: samples of ice that tell about the AIR in Earth’s atmosphere over time

Example:

Ice Cores: samples of ice that tell about the AIR in Earth’s atmosphere over time

Example:

Carbon Dioxide in atmosphere

The Greenhouse Effect

• How does it feel when you get into a car after it’s been sitting in the hot summer sun all day? Why do you think it feels that way?

• The Greenhouse Effect works the same way!

• Greenhouse Brainpop

Let’s take a closer look…

High CO2 = Warmer Temps

• Greenhouse Effect: certain gases, such as CO2, in Earth’s atmosphere trap energy from the sun and warm up Earth

HOT Q: • You take an ice core from Antarctica and you

find significantly more carbon dioxide bubbles in the layers of ice that are closer to the top.

What can you infer about the climate?

1000 years of CO2 and Global Warming

Ice Cores: samples of ice that tell about the AIR in Earth’s atmosphere over time

Example:

Carbon Dioxide in atmosphere

Pollution

THE YEAR THAT CONGRESS PASSED THE CLEAN AIR ACT

Ice Cores: samples of ice that tell about the AIR in Earth’s atmosphere over time

Example:

Carbon Dioxide in atmosphere

Pollution

Volcanic Ash

HOT Q: The Earth gets COLDER after big volcanic eruptions!

WHY?

These things block the sun from reaching earth!

Why does the Earth get colder after big volcanic

eruptions? Dust, ash glass, and rock are released into the air during a volcanic eruption.

http://www.youtube.com/watch?v=fmsxmbVYMHo&NR=1

24

Clouds of ash can cover

entire continents!

EOG Question From Last Year’s Test:

• A scientist has a hypothesis that a large volcanic eruption caused a change in global temperature. Which information gained from ice cores is most useful in supporting the scientist’s hypothesis?�–A. levels of dissolved oxygen –B. identities of trace metals –C. estimates of natural radioactivity –D. amounts of atmospheric dust

Ice Cores and Climate Change!

Ice in Greenland and Antarctica can be deeper than the height of skyscrapers and up to 530,000 years old!

Tree Rings: tell the amount of rain and precipitation over time.

Example:1 Ring = 1 year

THICK = MORE RAIN

THIN = LESS RAIN

SUMMARIZER: How do rocks, fossils, and ice cores help us paint a picture of Earth’s history?

(3-5 sentences please!)

• Your answer MUST INCLUDE the following vocabulary:• TREE RINGS• ICE CORES• INDEX FOSSILS• LAW OF SUPERPOSITION

FOCUS VOCABULARY

27. Chemical Weathering28. Mechanical Weathering29. Erosion30. Unconformity

SMARTIE SCIENCE

Chemical Weathering

Mechanical Weathering

MECHANICAL WEATHERING:

• Physical changes to rock (rocks break into smaller pieces)

• Example:

Mountains get worn down to become pebbles!

EXAMPLE:ICE breaks

rocks apart!!

MECHANICAL WEATHERING:

• Physical changes to rock (rocks break into smaller pieces)

• Example: ice, salt, wind, and water break down rocks

CHEMICAL WEATHERING:

• Chemicals break down rock by chemically changing the rock

• Usually indicated by color change!

• Example:

COLOR CHANGE CAUSED BY ACID RAIN

CHEMICAL WEATHERING:

• Chemicals break down rock by chemically changing the rock

• Usually indicated by color change!

• Example: Acid Rain, rust

HOT Q: WHAT DO THEY HAVE IN COMMON?!

• Break or wear down

rock

Chemical or Mechanical?

Chemical or Mechanical?

Chemical or Mechanical?

Discovery Streaming Clip

• http://www.youtube.com/watch?v=lvKkPFoRiaw (breaker and woosh)

GALLERY WALK

Write Time! (In your notebook, write at least 3 complete sentences)

How was the activating strategy similar to chemical and mechanical weathering?Which step was CHEMICAL?Which step was MECHANICAL?

FRAYER DIAGRAM: UNCONFORMITY

UNCONFORMITY

DEFINITION:

CAUSES: EFFECTS:

PICTURE:

A missing piece in the rock record

PICTURE: (draw in Frayer diagram)UNCONFORMITY

How Unconformities are formed…

• http://www.classzone.com/books/earth_science/terc/content/visualizations/es2902/es2902page01.cfm?chapter_no=visualization

FRAYER DIAGRAM: UNCONFORMITY

UNCONFORMITY

DEFINITION:

CAUSES:

-WEATHERING (breaks rocks down)

-EROSION (carries rocks away!)

EFFECTS:

PICTURE:

A missing piece in the rock record

Incomplete information about the past!

HOT Q’s!

1. How does weathering contribute to unconformities?

2. How do unconformities change scientists’ understanding of Earth’s history?

SUMMARIZER

1. What is the difference between chemical and mechanical weathering?

2. How does weathering create gaps in our knowledge about earth’s history?

3. How is an unconformity created?