Download Earth`s Interior and Plate Tectonics

EARTH’S INTERIOR AND
PLATE TECTONICS
Chapter 19, Section 1
Planet Earth
OBJECTIVES
Identify Earth’s different geologic layers
 Describe the movement of Earth’s lithosphere using
the theory of Plate Tectonics
 Identify the three types of plate boundaries and the
principle structures that form at each of these
boundaries
 Explain how the presence of magnetic bands on the
ocean floor supports the theory of plate tectonics

KEY TERMS
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Crust
Mantle
Core
Lithosphere
Plate tectonics
Asthenosphere
Magma
Subduction
fault
THE EARTH’S INTERIOR
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Remember the model of
the egg
The shell
– The white
– The yolk
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Different types of crust
Oceanic
– Continental, (land)
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The mantle is a liquid
Magma below
– Lava at the surface
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THE EARTH’S TEMPERATURE
The deeper you move through the crust, the
warmer it gets, (-100 degree F in the coldest spot
on Earth), up to 347 degrees F
 The mantle is 2280 degree F
 The Core is 10800 degrees F due in
part to radiation
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PLATE TECTONICS
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Alfred Wegener pieced
together, (just a little joke),
evidence for the movement of
the lithosphere over the liquid
mantle.
The coast-line of the continents
look like puzzle pieces
– Fossil evidence suggests
similar animals/plants on both
continents across the oceans
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Structures on the ocean floor
give evidence of a mechanism
for movement or “continental
drift” (magnetic rock bands)
HOW DO THE PLATES MOVE? HEAT RISING!
THE PLATE BOUNDARIES
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Divergent – the crust separates because the
tectonic plates are pulling away from each other
exposing new lava that cools to rock
Convergent – plates are being pushed together so
the boundaries collide, (earthquakes)
– Forming mountains, sub-duction zones &
volcanoes
Transform Fault, (earthquake zones)
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Can happen anywhere the forces are strong enough
to break rock, (faults)
SUMMARY
The layers of the Earth are the crust, mantle, and core
 Earth’s outer layer, (lithosphere), is broken into several
pieces called plates
 The plates ride on top of the soft, liquid mantle,
(asthenosphere), beneath the plates
 Plates spread apart at divergent boundaries, collide at
convergent boundaries, and slide past each other at
transform fault boundaries
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SUMMARY
The entire landscape of our planet has been
shaped and re-shaped by these processes
 The alignment of iron and other magnetic
minerals in oceanic crust near divergent
boundaries supports the theory of plate tectonics.
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DEFINITIONS
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Crust is the outermost and thinnest layer of
Earth
Mantle is the layer of (liquid) rock between the
crust and the core
Core the center of a planetary body
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The core of the Earth is semi-solid to liquid
Lithosphere is the thin outer shell of the Earth
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Consisting of the crust and rigid upper mantle
DEFINITIONS
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Plate tectonics is the theory that the Earths lithosphere is
made of large moving plates
Asthenosphere is the part of the mantle that is moving due
to convection currents in the mantle
Magma molten, melted rock within the Earth
Subduction is a process where one tectonic plate goes
beneath another tectonic plate into the mantle
A Fault is a crack in the Earth created by stress and
fracture of the rock, (may be anywhere)