DO NOW HW DUE FRIDAY! 1. What is the formula for density? 2. What is the density of an object with a mass of 6 g and a volume of 2 ml? 3. If solution A is floating on top of solution B, which one is more dense? How did you know? 4. List the layers of the earth from least dense to most dense. 5. What do you think the lithosphere is?
The Shifting Earth Pangaea and Convection Currents
See how smart you are! Inquiry activity l Your group has 7 puzzle pieces do the best you can to put them together. l Use your lab sheet and the map of the world to guide you! 1. What made you put the puzzle pieces the way that you did? Were there any clues that helped you put the pieces a certain way? 2. Do you think that this puzzle is real or could be real? Why or why not? A member of each group will present their puzzle and their team s answer to the questions!
Extension: l Read the article and answer the three questions in your notebook DO NOT write on the article!
Alfred Wegener and Continental Drift Theory l Who was he? l A scientist who studied the movement of the Earth s continents. l What was his famous hypothesis? l CONTINENTAL DRIFT a theory that all of the continents were once a single landmass before they broke apart and started drifting away from each other.
Continental Drift
What is Pangaea? l A word that means all lands l It is the name for the SUPERCONTINENT that existed a long time ago
WHAT WAS WAGNER s EVIDENCE? l Wagner s proposal was different, and many people did not believe him at first l What evidence did he have? (For each video, take down important vocabulary words in your notebook) l Video 1: Wagner and Continental Drift l Video 2: Putting together pieces of a puzzle
Evidence for Pangaea l http://www.explor elearning.com/in dex.cfm?method =cresource.dsp View&ResourceI D=633 l Username: woodlandms l pw: science FOSSILS GLACIERS
What evidence supports continental drift? 1. South America and Africa fit together like a jigsaw puzzle
What evidence supports continental drift? 2. Fossil evidence : - Mesosaurus fossils were found in both Africa and South America. - This is odd because Mesosaurus was a dinosaur that lived in fresh water (the ocean is sea water). - Mesosaurus couldn t have swum across the salty Atlantic ocean!
What evidence supports continental drift? 2. Fossil evidence, continued - The mesosaurus must have lived when all the continents were still together (Pangaea). - Mesosaurus became extinct, fossils formed in this land area, and then Pangaea broke apart.
What evidence supports continental drift?
What evidence supports continental drift? 3. Mountain ranges and glaciers: - Some mountain ranges on different continents seem to line up.
What evidence supports continental drift? l Big Idea: Climate what evidence that we have seen would be linked to climate (weather, temperatures)?
Review 1. Who was Alfred Wegener and what was his important hypothesis? 2. Why are Africa and South America such important pieces of evidence for Pangaea? 3. What are some other pieces of evidence that suggest that Pangaea once existed?
Exit Ticket
DO NOW 1. Who was Alfred Wagner and what was his important hypothesis? 2. What is Pangaea? 3. List three pieces of evidence to support the theory of Pangaea. 4. Explain how each piece of evidence supports continental drift and Pangaea.
Convection Currents
Plate Tectonics The Lithosphere l Lithosphere is the crust & the very top part of the upper mantle (solid). l The lithosphere is broken up into pieces called plates
Plate Tectonics - Asthenosphere Asthenosphere the plasticlike part of the mantle right underneath the l The plates of the lithosphere lithosphere. shift and move around on top of the plastic-like asthenosphere l Like a surf board on top of the ocean, the lithosphere surfs on the asthenosphere
Lab Demo: Why do these plates move? l What do you think the clear bin represents? l What do you think the food dye represents l What do you think will happen when I put a cup of hot water underneath the food dye. (hypothesis) l What actually happened? l What do you think the cup of hot water represents? l Relate this to magma in the mantle (asthenosphere and how it moves the plates (lithosphere)
Why do the plates move? l Plates move because of convection currents l Convection currents are the circular movement of heat through the asthenosphere Hot material moves through the mantle in circles!
PK&S: Things are heating up! (cont d) l Convection currents begin when the magma is heated by the outer core and lower mantle. When the magma is heated, it floats because it is less dense. l The magma is cooled by the lithosphere and then sinks because it is more dense. The cycle continues once the magma sinks.
PK&S: Things are heating up! (cont d) l Convection currents in the asthenosphere move slowly because it is made of a sappy or molten or melted rock (magma). l Remember, Earth is a giant magnet because of currents in the asthenosphere. Those currents are called convection currents.
Catalyst HW due Wed 10/28 1. What is the lithosphere? What is the asthenosphere? 2. Explain the relationship between the lithosphere and the asthenosphere. 3. What are convection currents? 4. Explain how convection currents work in the mantle of the Earth to move the plates. (hint: talk about density & temperature)
How do Convection Currents Work? l The hottest material rises from the bottom, cools and then sinks back down. l WHY? Density is the key! l Heat makes things less dense and they rise l Cooling makes things more dense and they sink l PRACTICE! Draw out a convection current! HOT COLD
The effect Plate Tectonics! -The plates of the earth begin to shift and move around -Convection currents in action: -https://www.youtu be.com/watch?v=p0 dwf_3pyh4
Review 1. Draw a convection current! Label the following: hot, cold, more dense, less dense. 2. How do convection currents cause the plates to move?
Exit Ticket
Book Work l Read pgs. 246-248 in small textbook l Define the following words: pangaea, continental drift, and plate tectonics l Answer questions 1-6 on pg. 248