Unit 2: Plate Tectonics Test Review What is the name of the SUPERCONTINENT that was once one land mass? Pangaea Wegener’s THEORY that best explains the movement of continents over millions of years is called ___. Continental Drift Untold tragedies of Continental Drift. . Name the 3 types of heat transfer. Here are some hints… Types of Heat Transfer: What is the boundary called where 2 plates pull away from each other or divide? What is this type of stress called? Divergent Boundary Stress of Tension New ocean floor is added at ___ boundaries, where the sea floor spreads apart. Divergent What is the boundary called where 2 plates crash or crunch into each other? Convergent Boundary The stress that presses rock at convergent boundaries is ____. A. tension B. compression C. shearing Compression When 2 continental plates crunch together very slowly, what may form? A mountain range When 2 plates converge in the ocean, what can form? An island arc The Aleutian Islands The Caribbean Islands What are 2 geologic features that may occur at divergent boundaries? Rift Valley on continents: Seafloor Spreading creates new ocean floor: Basalt is the dark, fine textured igneous rock making up the oceanic crust. True or False? Shearing is the stress that stretches rock thin at divergent boundaries. FALSE! Tension stretches rock thin at divergent boundaries. True or False? Shearing stresses rock so much that it breaks at strike slip faults. TRUE! What geologic event could occur at this famous transform boundary? Famous Fault in California! Earthquakes! Most earthquakes occur at strike-slip faults, where rock is pushed in opposite directions Geologists learn about the interior of Earth by studying __, which move through Earth when earthquakes occur. A.Land formations B. Seismic waves C. Weather patterns Seismic Waves Which area in the picture is labeled to show where the earthquake is the strongest & most damaging? The epicenter After the rock is under stress it breaks. Where does the rock break? A crack/break in the crust is called a FAULT  The FOCUS What are the 3 types of seismic waves that move through Earth when an earthquake occurs? Surface Waves What process is shown below? Remember: Pay attention to the direction of the arrows! Subduction: Where a dense plate dives under a less dense plate is a subduction zone. Rock can be “recycled” as it melts back into magma. Volcanoes may form & erupt here. What causes the mantle rock to flow very slowly? Convection Currents Cycles of slowly flowing melted rock are created as heat is transferred in the mantle. When the earthquake happened near Japan, it was reported as a 9.0 on the Richter Scale. What does this number tell us about the earthquake? a. b. c. d. How much it repairs will cost The time of day the quake occurred The size/magnitude of the quake How long he quake lasted c. The size/magnitude of the quake The Indian Ocean earthquake off the coast of Sumatra had damage reports from people in particular locations. These reports were given as ROMAN NUMERALS with descriptions. What do we call this scale that is used to report damage? a. Richter Scale b. Mercalli Scale c. Geiger Scale b. Mercalli Scale (Remember our ‘Locating the Epicenter’ Radio Activity…) True or False? Volcanoes may form at transform boundaries. False • Volcanoes may form when plates converge or diverge. A weak spot in Earth’s crust where magma comes to the surface is called a ___. VOLCANO Magma forms in the mantle. Label the pictures below. (Hint: They are areas of Geothermal Activity that show past or present volcanic activity) A. B. A. Geyser B. Hot Spring When a volcanic mountain collapses, what do we call the huge hole left behind? A caldera The Hawaiian Islands are forming over ___. a. a divergent boundary b. a hot spot in the Pacific Ocean c. a convergent boundary b. A hot spot in the Pacific Ocean Name the types of volcanic eruptions described below: A. Thick & sticky magma, high viscosity B. Magma gently flows, low viscosity Types of eruptions A. Explosive B. Quiet Which volcano is described below? 1. A wide gently sloping mountain 2. A tall cone-shaped mountain with explosive eruptions 3. A cone-shaped mountain that erupts ash, cinders & bombs 1. Shield Volcano (Vanilla Wafer) 2. Composite Volcano (Hershey's Kiss) 3. Cinder Cone Volcano (Chocolate Chip) What is this area around the Pacific Ocean where there is a major belt of volcanoes? The Ring of Fire What do we call huge waves that are created by an underwater earthquake? TSUNAMI Tsunami in Japan Can you describe what happens with convection currents in Earth’s mantle? Look at this diagram. I have some questions for you… Looking @ the arrows… • • • • • • Which type of boundary is at letter X? What is happening at letter X? What would form at letter X? Which type of boundary is at letter Z? What is happening at letter Z? What could form at letter C?