Chemical weathering involves chemical reactions that break down rock, often changing its color, while mechanical weathering is the physical breakdown of rock into smaller pieces through processes like freezing, heating, and abrasion. Weathering breaks rocks down over time, and erosion transports the broken pieces away. This can create unconformities, or gaps in the geologic record, when layers of older rock are removed and newer layers are deposited on top of the eroded surface. Unconformities show missing periods in Earth's history and change scientists' understanding of its past.
1. 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).
2. Today’s LEQ: How do chemical and mechanical weathering create unconformities in the earth? By the end of today, you should be able to… Compare and contrast chemical and mechanical weathering 2. Explain how chemical and mechanical weathering can create unconformities in the earth
4. 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
5. Draw this in your notes: Evidence for climate change: Ice Cores Tree Rings
6. Ice Cores: samples of ice that tell about the AIR in Earth’s atmosphere over time Example:
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8. Ice Cores: samples of ice that tell about the AIR in Earth’s atmosphere over time Example: Carbon Dioxide in atmosphere
9. 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
11. High CO2 = Warmer Temps Greenhouse Effect: certain gases, such as CO2, in Earth’s atmosphere trap energy from the sun and warm up Earth
12. 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?
19. Why does the Earth get colder after big volcanic eruptions? 24 Dust, ash glass, and rock are released into the air during a volcanic eruption. http://www.youtube.com/watch?v=fmsxmbVYMHo&NR=1
21. 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
22. 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!
23. Tree Rings: tell the amount of rain and precipitation over time. Example: 1 Ring = 1 year THICK = MORE RAIN THIN = LESS RAIN
24. 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
47. How Unconformities are formed… http://www.classzone.com/books/earth_science/terc/content/visualizations/es2902/es2902page01.cfm?chapter_no=visualization
48. FRAYER DIAGRAM: UNCONFORMITY DEFINITION: PICTURE: A missing piece in the rock record UNCONFORMITY EFFECTS: CAUSES: -WEATHERING (breaks rocks down) -EROSION (carries rocks away!) Incomplete information about the past!
49. HOT Q’s! 1. How does weathering contribute to unconformities? 2. How do unconformities change scientists’ understanding of Earth’s history?
50. SUMMARIZER What is the difference between chemical and mechanical weathering? How does weathering create gaps in our knowledge about earth’s history? How is an unconformity created?
