Download Layers of Earth`s Interior Continental Drift/Seafloor

Plate Tectonics Study Guide
● Layers of Earth’s Interior
Compositional Layers
Physical Layers
Crust​ - outermost layer,
made of ​oceanic crust
(thin, very dense) &
continental crust​ (thick,
less dense)
Lithosphere -​ crust & uppermost part of the upper
mantle
Mantle ​- thickest layer,
liquid magma, convection
currents flow
Upper Mantle​ - rigid
Core ​- made of nickel &
iron
Outer Core​ - thick, liquid, magma
Asthenosphere -​ lower part of the upper mantle,
flowing/squishy properties
Lower Mantle​ - semi rigid
Inner Core​ - solid nickel & iron
● Continental Drift/Seafloor Spreading
○ Scientists used clue to prove that Pangea once existed (all continents as
one land mass)
■ Clues: shapes of continents, plant/animal fossils on different
continents, similar landforms such as deserts, rock types
○ Continental drift is the result of the seafloor spreading at divergent
boundaries
● Theory of Plate Tectonics
○ Pieces of the crust move around on the soft mantle
○ The rigid plates of the lithosphere move around on the
asthenosphere.
● 3 Types of Plate Boundaries
○ Divergent Boundary
■ Plates pulled apart by tension forces
■ Effects: underwater mountain ridges, earthquakes, seafloor
spreading
○ Convergent Boundary
■ Plates are pushed together by compression forces
■ Effects: subduction zone, volcanoes, mountains, trenches,
earthquakes
○ Transform Boundary - *San Andreas Fault
■ Shear forces cause plates to grind/slide past each other
■ Effects: shallow earthquakes
○ Earthquakes, along with volcanoes, mountains, ridges, and trenches occur
at the boundary between two plates.
Plate Tectonics Study Guide
● Convection Currents within the Earth’s Interior
○ Convection is the flow of heat through the flow of a material. The material
inside the Earth is magma
○ Less dense, hot magma is forced upward toward the crust at divergent
boundaries
○ Colder, more dense crust is pulled down into the crust at convergent
boundaries, at subduction zones
● Clip art that you should be able to understand and answer questions about:
Plate Tectonics Study Guide
Plate Tectonics Study Guide
Answers: #24 (1)
#25 (2)
Plate Tectonics Study Guide
Answer (1)