Earthquakes and Earthquakes and VolcanoesVolcanoes

C12-17 and C20-25C12-17 and C20-25

v.martinezv.martinez

1. Earthquake1. Earthquake

An earthquake is a vibration, or shaking of An earthquake is a vibration, or shaking of Earth’s crust.Earth’s crust.

2. Fault2. Fault

A fault is a break in the crust along which the A fault is a break in the crust along which the rocks move.rocks move.

3. Focus3. Focus

The focus is the point underground where the The focus is the point underground where the movement first took place.movement first took place.

4. Epicenter4. Epicenter

The epicenter is the point on the surface that is The epicenter is the point on the surface that is right above the focus.right above the focus.

5. Seismograph5. Seismograph

A seismograph is an instrument that records A seismograph is an instrument that records earthquake waves.earthquake waves.

7. Why do earthquakes occur?7. Why do earthquakes occur?

There is a build up and sudden release of There is a build up and sudden release of energy in rocks.energy in rocks.

8. Where do most earthquakes 8. Where do most earthquakes occur?occur?

Most earthquakes occur along faults.Most earthquakes occur along faults.

8. The San Andreas Fault8. The San Andreas Fault

The San Andreas Fault is in California. The San Andreas Fault is in California. Dozens of major earthquakes occur here.Dozens of major earthquakes occur here.

9. Volcano9. Volcano

A volcano is a mountain that forms when red-A volcano is a mountain that forms when red-hot melted rock flows through a crack onto the hot melted rock flows through a crack onto the earth’s surface. earth’s surface.

10. Magma10. Magma

Magma is melted rock inside the earth.Magma is melted rock inside the earth.

11. Lava 11. Lava

Lava is melted rock that reaches the earth’s Lava is melted rock that reaches the earth’s surface.surface.

12. Vent12. Vent

The magma flows onto the surface through a The magma flows onto the surface through a rock opening called a vent to form volcanic rock opening called a vent to form volcanic mountains. mountains.

13. Magma Chamber13. Magma Chamber

A magma chamber is an underground pool that A magma chamber is an underground pool that holds hot magma. holds hot magma.

15. What are the three ways 15. What are the three ways volcanoes form?volcanoes form?

1. When two plates collide1. When two plates collide

2. When two plates separate 2. When two plates separate

3. When plates move over hot spots in the 3. When plates move over hot spots in the mantlemantle

Plates collidingPlates colliding

Plates separatingPlates separating

Plates moving over hot spots in the Plates moving over hot spots in the mantlemantle