E ARTH ’ S I NTERIOR AND P LATE T ECTONICS Chapter 19, Section 1 Planet Earth.

EARTH’S INTERIOR AND PLATE TECTONICSChapter 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

• Crust• Mantle • Core• Lithosphere• Plate tectonics• Asthenosphere• Magma• Subduction• fault

THE EARTH’S INTERIOR

• Remember the model of the egg– The shell– The white– The yolk

• Different types of crust– Oceanic– Continental, (land)

• The mantle is a liquid– Magma below– Lava at the surface

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

PLATE TECTONICS• 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

• 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

• 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)

– 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

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.

DEFINITIONS

• 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• The core of the Earth is semi-solid to liquid

• Lithosphere is the thin outer shell of the Earth• Consisting of the crust and rigid upper mantle

DEFINITIONS• 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)