Presentation on theme: "Plate Tectonic Makeup Bellwork. Bellwork 1.Alfred Wegener could not explain what caused the continents to move. It is now believed that _____ currents."— Presentation transcript:
Plate Tectonic Makeup Bellwork
Bellwork 1.Alfred Wegener could not explain what caused the continents to move. It is now believed that _____ currents inside Earth cause plates to move. 2.Bands or stripes of basaltic rock on the seafloor showing alternating magnetic orientation indicate Earth's magnetic field has _____ in the past. 3.While studying the ocean floor, scientists found _____ of magnetism. 4.As you get farther from a mid-ocean ridge, sea floor rocks become _____. Answer Bank convection Mid-ocean ridges older stripes reversed
Answer Bank older Ocean ridges Continental Fossils seafloor Bellwork 1)(see figure above) As you get farther from a mid- ocean ridge, sea floor rocks become ______. 2)Alfred Wegner noticed that the _____, rocks, and mountains matched up across continents 3)Mid-_____ _______ are a continuous chain of volcanoes that extends through many of the earth’s oceans where new crust of the Earth is created. 4)The two theories that lead up to plate tectonics are ______ drift and ______ spreading.
Bellwork 1. Earth’s magnetic field protects us from the ____ ______ 2. When magma cools at mid-ocean ridges, a mineral called magnetite ______ itself with the earth’s magnetic field. 3. Harry Hess noticed ______ on the seafloor. 4. Each magnetic ________on the seafloor showed a _______in the earth’s magnetic field. 5. These magnetic stripes were strong evidence for seafloor ________ and plate tectonics. Answer Bank Reversal Reversed spreading Stripe(2) younger Solar wind aligns
Bellwork 1)East Africa and Mid-ocean ridges are two examples of a _______ plate boundary. 2)A _______ zone is the area where the plate sinks back into earth melting as it descends. 3)The two types of crust are ________ and _______ crust. 4)An island arc like Japan formed by a collision of ocean crust colliding with _____ crust at a convergent plate boundary. 5)The Himalayan Mountains formed from the collision of continental crust colliding with _________ crust. 6) Draw & Label: Convergent Boundary Divergent Boundary Subduction Zone Answer Bank Subduction Continental (use twice) Ocean (use twice) Divergent Rift Valley
Bellwork 1)A _______ is located at location A where plates collide and ocean plate subducts. 2) New rock or plate is created at ______ boundaries and plate is destroyed at _________ boundaries. 3) At location B, ocean plate is _____ as it subducts and sinks 4) The subduction of oceanic plate beneath continental plate produces ____ _____ Answer Bank Volcanic mountains Trench convergent Divergent Melting