Unit 8 Lesson 3 How Do Movements of the Crust Change Earth? Copyright © Houghton Mifflin Harcourt Publishing Company.

Download Report

Transcript Unit 8 Lesson 3 How Do Movements of the Crust Change Earth? Copyright © Houghton Mifflin Harcourt Publishing Company.

Unit 8 Lesson 3

How Do Movements of the Crust Change Earth?

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Objectives:



Describe what is below Earth’s surface.



Explain how the movement of Earth’s crust can change Earth’s surface.

Vocabulary:



Crust

      

Mantle Core Plate tectonics Earthquake Epicenter Fault Volcano

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

•

Inside the Earth

Earth is a sphere made up of very different layers.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Inside the Earth

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Inside the Earth

• Earth’s

crust

outer layer made of many minerals. is a rocky • The crust is thinnest under oceans and thickest under mountains. It makes up only about one percent of Earth’s mass.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Inside the Earth

• Right below Earth’s crust is the

mantle

Earth’s mass. , which is the thickest layer, making up about two-thirds of • The mantle contains some liquid rock but is mostly solid. High heat and pressure in the mantle cause it to flow like warm plastic. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Inside the Earth

• At the center of Earth is a

core

made of molten metal. The inner core is solid iron and nickel. The outer core is molten, liquid metal.

• The metal core makes up about one-third of Earth’s mass and is extremely hot.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Inside the Earth

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

• • •

Plate Tectonics

Many pieces of Earth’s crust, called plates, fit together like a jigsaw puzzle. The plates rest on Earth’s mantle and are always moving.

The theory that Earth’s crust is divided into moving plates is called

plate tectonics

. Plates are made from continental crust, oceanic crust, or a combination of both.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Tectonics

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Tectonics

• • Certain land features form where plates collide . Other features form where plates separate .

Mountain ranges, island chains, and enormous valleys are possible signs of a plate boundary.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Boundaries

• Different types of plate motion produce boundaries that shape different landforms. 1.

• Plates moving toward each other: Continental plates moving toward each other push up mountains.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Boundaries

• Oceanic plates moving toward each other can cause deep-ocean trenches and volcanic islands to form. • Oceanic plates colliding with continental plates causes mountains and volcanoes to form along the boundary between the plates.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Boundaries

• 2.

When two plates pull apart, new crust forms a rift, or separation, on both sides of the boundary, becoming two separate landmasses.

For example, the Great Rift Valley formed where the Arabian plate is splitting the African plate into two new, separate plates.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Boundaries

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Boundaries

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Plate Boundaries

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Earthquakes

fault

is a break in Earth’s crust where rock on one side can move in relation to rock on the other side.

• As plates move, pressure increases along a fault, causing the rock on one side to snap free and slide past the rock on the other side.

• This release of energy and shaking of the ground is called an

earthquake

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Earthquakes

• The point inside Earth where an earthquake begins is called the focus. • The point on Earth’s surface directly above the focus is called the

epicenter

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Earthquakes

• Scientists use seismographs to detect tremors and predict if an earthquake is likely to occur.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Earthquakes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Measuring Earthquakes

• An earthquake’s magnitude is the amount of energy it releases. • • 1.

The Richter scale measures the magnitude of earthquakes on a scale from 1 to 10. The Richter scale uses the size of waves on a seismograph to determine an earthquake’s strength.

An earthquake measuring 6.0 or higher on the Richter scale can cause heavy damage in populated areas.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Measuring Earthquakes

Scientists have also developed the moment magnitude scale to more accurately measure the magnitudes of larger earthquakes.

• This scale, which also assigns numbers between 1 and 10, uses a mathematical formula to calculate the total energy an earthquake releases.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Measuring Earthquakes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Earthquakes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Measuring Earthquakes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

•

Volcanoes

The liquid rock below Earth’s crust is called magma. • A

volcano

is an opening in the crust that allows magma to reach Earth’s surface. •

Lava

is the molten rock that erupts from the volcano along with ash and hot gases.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Volcanoes

Shield volcanoes are formed from non-explosive lava where broad sheets of lava steadily build up.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Volcanoes

Cinder cone volcanoes are formed from explosive eruptions where lava explodes into the air and quickly hardens.

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Volcanoes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Volcanoes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Volcanoes

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Volcano – crust – mantle – outer core – inner core

Unit 8

Lesson 3 How Do Movements of the Crust Change Earth?

Unit 8 Lesson 3 How Do Movements of the Crust Change Earth? Copyright © Houghton Mifflin Harcourt Publishing Company.

Transcript Unit 8 Lesson 3 How Do Movements of the Crust Change Earth? Copyright © Houghton Mifflin Harcourt Publishing Company.

Unit 8 Lesson 3

How Do Movements of the Crust Change Earth?

Objectives:

Describe what is below Earth’s surface.

Explain how the movement of Earth’s crust can change Earth’s surface.

Vocabulary:

Crust

Mantle Core Plate tectonics Earthquake Epicenter Fault Volcano

Inside the Earth

Inside the Earth

Inside the Earth

Inside the Earth

Inside the Earth

Inside the Earth

Plate Tectonics

Plate Tectonics

Plate Tectonics

Plate Boundaries

Plate Boundaries

Plate Boundaries

Plate Boundaries

Plate Boundaries

Plate Boundaries

Earthquakes

Earthquakes

Earthquakes

Earthquakes

Measuring Earthquakes

Measuring Earthquakes

Measuring Earthquakes

Earthquakes

Measuring Earthquakes

Volcanoes

Volcanoes

Volcanoes

Volcanoes

Volcanoes

Volcanoes

Volcano – crust – mantle – outer core – inner core

Focus – fault – plate tectonics – plates – epicenter earthquake

Directory