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The Theory of Plate Tectonics. S6E5. Students will investigate the scientific view of how the earth’s surface is formed. Earth’s crust, mantle , and core including temperature, density, and composition
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S6E5. Students will investigate the scientific view of how the earth’s surface is formed. Earth’s crust, mantle, and core including temperature, density, and composition • a. Compare and contrast the crust, mantle, and core including temperature, density, and composition. • d. Describe processes that change rocks and the surface of the earth. • e. Recognize that lithospheric plates constantly move and cause major geological events on the earth’s surface. • f. Explain the effects of physical processes (plate tectonics, erosion, deposition, volcanic eruption, gravity) on geological features including oceans (composition, currents, and tides).
YES!!!!!!!!! • Very, Very, Very, Very slowly • About 2 cm per year Is the earth changing today?
A well tested concept that explains a wide range of observations What is a scientific theory?
The lithosphere (upper most part of the mantel under the crust) has cracks in it. • The separate sections are called plates. Plates
Oceanic plates • Heavy • Water soaked • Under the ocean • Continental plates • Lighter than oceanic plates • Not water soaked • Under the continents What kinds of plates are there?
The theory of plate tectonics states that the pieces of the lithosphere are in a slow, constant motion driven by convection currents in the mantle. How do the plates move?
The theory of plate tectonics explains the: • 1) formation, • 2) movement, • 3) and subduction of the Earth’s plates.
When one plate moves under another plate (subduction), gravity pulls one edge down and the rest of the plate follows.
Collide, • Pull apart, • Or grind past each other. How do plates move?
Volcanoes • mountains ranges • deep ocean trenches are formed. What happens when the plates move?
A plate boundary What is the edge of the plate called?
NO! it is not a character defect – • BUT it is • A break in the Earth's crust where the rocks have slipped past each other What is a fault?
Divergent boundary • Convergent boundary • Transform boundary What do you call the different boundaries?
A mid-ocean ridge is formed in the ocean • A rift valley is formed on land • The Great Rift Valley in Africa What happens when the plates move apart?
Where the plates move APART What is a divergent boundary?
A collision occurs! • The heavier plate sinks and the lighter plate ends up on top What happens when the plates move come together?
Where the plates move TOWARD each other or TOGETHER What is a convergent boundary?
If both are oceanic plates – • The heavier plate sinks • If both plates are continental plates • Mountain ranges are formed • If one plate is a continental plate and one plate is an oceanic plate • Subduction occurs and the oceanic plate sinks under the continental plate What happens when the plates move come together?
When two plates slide past each other in different directions What is a transform boundary?
Earthquakes occur What happens when the plates move past each other?
The surface of the Earth as changed • Weather patterns have changed • Ocean currents have changed • Climates have changed What happens when plates move over time?
What areas of North America have the highest and lowest risks of earthquakes? AlaskaCaliforniaMemphis, Tennessee
