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Download QUESTION 1 What are the 4 layers of Earth called? Describe each
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QUESTION 1 What are the 4 layers of Earth called? Describe each layer. What is it made of, and why is this important? ANSWER TO QUESTION 17 Seismic waves can be : P, S, L. P = primary. These waves move side to side, and travel quickly through rock material. They’re the “early warning” waves, and aren’t very damaging to the surface materials. S = secondary/shear waves. These waves lift up at right angles to the surface. They arrive more slowly, and are more destructive. L = love waves. These are the slowest, and they’re rolling waves. They also disrupt and cause damage to Earth’s surface. QUESTION 2 Find the following (write down their locations) -3 ocean-continental convergent plate boundaries (world map) -2 divergent plate boundaries (world map) -3 transform faults (BC map) ANSWER TO QUESTION 1 Crust (outer layer) – solid, brittle, made of rocks. Thinner under the ocean, thicker on continents. Broken into plates that move. Mantle (2nd layer) – viscous (plasticky/fluid), made of magma (melted rock). Heat causes convection currents, which move the plates. Outer core – liquid, melted metals (iron/nickel) Inner core – solid metal (iron/nickel). At the core’s temperature, this should be liquid… but there’s too much pressure, so the particles cram together. QUESTION 3 Add plate boundary icons to this map in the appropriate places. Use: ANSWER TO QUESTION 2 Ocean-continent: - Pacific plate into North American (BC) - Nazca plate into South American - Pacific plate into Eurasian (Japan) Divergent: - Mid-Atlantic ridge (Atlantic Ocean) - East Pacific Rise (Pacific Ocean) - African Rift Valley (East Africa) Transform: - Queen Charlotte - Juan De Fuca - San Andreas - QUESTION 4: What evidence do we have that plates are moving? ANSWER TO QUESTION 3 QUESTION 5: Which of the following locations would create the most new crust? Explain! ANSWER TO QUESTION 4: -Fossils of non-swimming creatures match up across oceans. This suggests the ocean didn’t used to separate these 2 continents. -Puzzle-piece fit of continents -Types of rocks match up in bands across continents -Evidence of glaciers shows some land used to be closer to the poles, and also connected -Magnetic patterns in rocks on the ocean floor suggest the sea floor is spreading. -an ocean trench -a mid-ocean ridge -a continental volcano -a transform fault QUESTION 6: What is the difference between these 3 terms: Ridge, Rift, Trench ANSWER TO QUESTION 5: The mid-ocean ridge produces new rock as the plates pull away from the centre and expose new magma. Volcanoes also can produce new crust, but piled on top of existing crust… Convergence zones (trenches) destroy crust. QUESTION 7: Why do tectonic plates move? ANSWER TO QUESTION 6: -Ridges and Rifts are part of the valleys created as the Earth’s crust pulls apart at a divergent plate boundary. A ridge is the raised edge. The rift is the gap. -Trenches are valleys created at convergent plate boundaries. As a dense ocean plate subducts under another plate, it creates a valley at the point where the 2 plates are being pulled into the Earth. QUESTION 8: What are the 2 main differences between oceanic and continental crust, and why does it matter? ANSWER TO QUESTION 7: Heat from the Earth’s core (from radioactive decay and leftover from Earth’s formation) warms magma in the mantle. This magma becomes less dense, and rises. Cooler magma sinks to take its place, creating convection currents. Plates on top of the rising magma zones are pushed apart: QUESTION 9: Name and label 3 features you would find at this plate boundary: ANSWER TO QUESTION 8: Continental crust is thicker than oceanic crust (it is thick enough to poke up above the water level, creating land!) Oceanic crust is denser than continental crust. When they collide, the denser plate will be dragged down (subducted). This means that ocean plates dive under continental ones, and not the other way around. QUESTION 10: What is causing these volcanoes? Explain the process, and give the term. ANSWER TO QUESTION 9: QUESTION 11: At which kind of plate boundary do we find the largest volcanoes? Explain why. ANSWER TO QUESTION 10: The islands are caused by a hot spot. This is a location of superheated magma that rises, and pushes through the ocean crust. As the crustal plate moves over the hot spot, several islands form. QUESTION 12: How can you tell which volcano in a string of hotspot volcanoes is the oldest? Ex: ANSWER TO QUESTION 11: Big volcanoes are found at convergent plate boundaries where subduction is taking place. The volcanoes break through the plate that’s “on top” as subducted rock get heated below the surface. There is lots of heat and pressure, which makes the eruptions more powerful. QUESTION 13: ANSWER TO QUESTION 12: The islands on the top left are oldest. Big reason: if the plate is moving as shown, it must have passed over the hot spot, made an island, and kept moving. The first island to form is the one at the head of the chain. (Interesting detail: the oldest island has been eroded and is smaller) Put the plate boundaries in order, from MOST POWERFUL earthquakes to WEAKEST earthquakes. Explain QUESTION 14: Which location, X or Y, has the youngest crust? ANSWER TO QUESTION 13: Convergent boundaries build up huge amounts of pressure & friction under the Earth. These cause LARGE, DEEP earthquakes. Transform faults build up pressure, but release it regularly as the plates slip past each other. Earthquakes here are moderate, and frequent. Divergent boundaries have the smallest earthquakes. Plates are not being forced together. QUESTION 15: Where is the Ring of Fire? What is the it? ANSWER TO QUESTION 14: X’s crust is youngest. New crust forms at the ridge, as magma comes to the surface. This new rock is pulled away from the centre ridge. Y is further away, so was laid down longer ago. QUESTION 16: ANSWER TO QUESTION 15: The Ring of Fire is the rim of the Pacific Ocean. It includes the west coast of North & South America, Japan, Indonesia, etc. Explain the difference between the FOCUS and the EPICENTRE of an earthquake. It is a series of subduction zones, and has high earthquake and volcano activity. QUESTION 17: Describe the 3 types of Earthquake (seismic)waves ANSWER TO QUESTION 16: The FOCUS is the place where the earthquake started, usually deeper in the Earth (X in the diagram). The EPICENTRE is the spot on Earth’s surface, directly above the focus. It is the first place on the surface to feel the earthquake waves.