Presentation on theme: "Explore p. 650 - 662. 4. At a rate of 2 cm/second how long did it take your plate to move across your work table? About 75 seconds, or 1 minute 15."— Presentation transcript:
4. At a rate of 2 cm/second how long did it take your plate to move across your work table? About 75 seconds, or 1 minute 15 seconds 6. Let’s scale up the velocity from 2cm/second to see how far the plate moves in a year. 7. Using the rate above (km/yr) how long would it take your plate to move to different states? cm/seccm/mincm/yrm/yrkm/yr ,115,200631,000631
8. Tectonic plates move at a rate of 3cm/year. How long would it take a tectonic plate to move across your work table? If the table is 150cm long, it would take 50 years. 150cm x 1year/3cm = 50 years S&T #1a: Continents move about 3cm/yr. What step from #6 has units that are easiest to compare with the velocity of continents? Why? S&T #1b: Is the paper plate’s or continent’s velocity faster? How much faster? The paper plate is about 21,000,000 times faster 63,115, 200 cm/yr / 3 cm/yr = 21,038,400
Learning Target: I can distinguish between uplift and erosion processes in mountain belts. Skills: I can analyze coral terraces and graph elevation changes I can calculate uplift rates from this graph I can compare uplift, erosion, and erosion half-life
Read Introduction p. 654 Some vocabulary: Glacial period – periods where the overall global climate is cold. Glacials are characterized by low sea levels and the widespread extent of ice sheets. Interglacial period – periods where the overall global climate is warm. Interglacials are characterized by high sea level and a limited extent of ice sheets. Radiometric dating - is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
kya means thousands of years ago mya means millions of years ago
Work with your partner to complete P&P #1-10. p (2 days to complete) Make sure you answer all questions in your science notebook. Graphs should be done on graph paper and taped into your science notebook! Must get through step 6 today HW: Read “Weather to Erode” p. 659 and take notes! Don’t forget a summary at the end!
If you are planning to take the retest for the dimensional analysis quiz, the review worksheet is due today. You must schedule a time to take the quiz either before school, after school, or during lunch on Monday.
First, you used the diagrams of the coral terraces in Papua New Guinea and Barbados to create a data table (elevation vs. age of coral). You measured the distance (in mm or cm) from sea level to the top of the coral terrace on the sketch. You used the scale as a conversion factor to calculate the elevation in meters. (New Guinea: 200m/15mm) (Barbados: 50m/11mm)
Then you graphed elevation vs. age. What did the slope correspond to? What can you say about the uplift rates of the two locations?
(Step 6) Then you began with an uplift rate of 2.5 mm per year (m/yr), and converted it first to meters per thousand years (m/kyr), then to kilometers per million years (km/Myr). What did you find?
(Step 8) You used the uplift rate of 2.5 mm per year (m/yr) to calculate how much uplift would occur in a mountain chain over 1 Million years. (It was helpful to refer back to your table from step 6). You repeated this to calculate uplift over 10 Myr. You compared your calculations to the actual elevation of Mt. Everest (8,850m) over 30 Myr. Why are they different?
(Step 9) You applied the concept of erosion half-life to see how a mountain chain that is not being uplifted changes over time. How did the mountain profile change?
You should be able to use a geologic diagram to determine elevation vs. age graph elevation vs. age calculate an uplift rate from your graph Convert uplift rates from mm/yr to m/kyr to km/Myr Calculate how much uplift occurs in a given amount of time, given an uplift rate Explain why the calculated uplift may be different than the actual elevation of a mountain Predict the elevation of peaks and valleys given an erosion half-life (before and after) Compare erosion half-lives and discuss why they are different for different areas Discuss how erosion and uplift affect mountains