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Chapter 9: Plate Tectonics
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continental drift Wegener's hypothesis that all continents were once connected in a single large landmass that broke apart and drifted slowly to their current positions.
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Pangaea the large "supercontinent” that is believed to have connected all of the continents on earth about 225 million years ago
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Evidence for Continental Drift Hypothesis
The continental puzzle – continents fit together like a puzzle Matching fossils – fossil evidence for continental drift includes several fossil organisms found on different continents. Rock type and structures – rock evidence for continental drift exists in the form of several mountain belts that end at one coastline, only to reappear on a landmass across the ocean. Ancient climates – ancient climate evidence supported continental drift
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plate tectonics the theory that the earth's outer shell is composed of a number of large plates, or slabs of rock, whose constant movement explains earthquakes and volcanic activity.
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Plate tectonics : chapter 9.3 & 9.4
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tectonic plate a large section of Earth's lithosphere that moves around on the asthenosphere.
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Convection currents Convection currents occur when a gas or a liquid is heated from the bottom. Warm gasses & liquids are less dense than cold. The warm substance rises and the cold sinks. This process is responsible for air, ocean, & mantel currents. Pair share: what lab did we do that demonstrated convection currents?
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Convection currents Convection currents occur when a gas or a liquid is heated from the bottom. Warm gasses & liquids are less dense than cold. The warm substance rises and the cold sinks. This process is responsible for air, ocean, & mantel currents. Pair share: what lab did we do that demonstrated convection currents?
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Convection currents Convection currents occur when a gas or a liquid is heated from the bottom. Warm gasses & liquids are less dense than cold. The warm substance rises and the cold sinks. This process is responsible for air, ocean, & mantel currents. Pair share: what lab did we do that demonstrated convection currents?
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Types of Plate Boundaries
The three main types of boundaries are convergent, divergent, and transform fault boundaries.
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Divergent Boundaries in divergent boundaries plates move apart
Most divergent boundaries are located along the crests of oceanic ridges.
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seafloor spreading The process by which plate tectonics produces new oceanic lithosphere at ocean ridges
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Convergent Boundaries
Convergent Boundaries – two tectonic plates move TOGETHER
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Convergent Boundaries
Oceanic – Continental When a continental plate converges with an oceanic plate, the more dense oceanic plates subducts under the continental plate Continental volcanic arc / volcanic activity is caused by the subduction of the oceanic crust melting below when it sinks into the asthenosphere.
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Convergent Boundaries
Oceanic – Continental plate boundary
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Convergent Boundaries
Continental- Continental the collision of the two continental plates form complex mountains. ex: Himalayan Mountains
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Convergent Boundaries: Continental-Continental
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subduction zone A destructive plate margin where oceanic crust is being pushed down into the mantle beneath a second plate
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subduction zone A destructive plate margin where oceanic crust is being pushed down into the mantle beneath a second plate
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trench A surface feature in the seafloor produced by the descending plate during subduction
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Transform Boundaries At a transform plate boundary, plates grind past each other without destroying the lithosphere. Ex: San Andreas Fault
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Transform Boundaries At a transform plate boundary, plates grind past each other without destroying the lithosphere. Ex: San Andreas Fault
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Earth Science – Chapter 9.2
9.2 Plate tectonics
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Earth Science – Chapter 9.2
9.2 Plate tectonics
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Earth’s Major Plates
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Types of Plate Boundaries Quiz
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Types of Plate Boundaries Quiz
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volcanic island arc A chain of volcanic islands generally located a few hundred miles from a trench where subduction of one oceanic slab beneath another is occurring
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