Earth's Interior

Question 1

What is it like inside the earth?

Answer 1

• Dense
• Hot
• Solid or liquid (depending)
• Outer core is a liquid
• Inner core is a solid
• See ESRT (pg.10)

Question 2

How do we know about the earth’s interior?

Answer 2

• From earthquake data
• From meteorites
• P-waves can travel through everything, S-waves can travel through solids only

Question 3

What does the speed of seismic waves depend on?

Answer 3

The density of the material

• More dense, faster waves
• The MOHO was discovered this way

Question 4

Why is there a shadow zone?

Answer 4

• Earth’s outer core is a liquid and seismic waves cannot travel through this zone
• P-waves are refracted and S-waves cannot travel through liquids
• 102 to 143 degrees away from epicenter

Question 5

Ring of fire:

Answer 5

• Earthquakes and volcanoes aren’t distributed randomly
• They can occur in specific regions, usually along a zone where plate boundaries meet
• It is the zone along the Pacific Ocean that rings it, where earthquakes and volcanoes are most common/active

Question 6

Seismic Hazards:

Answer 6

• Tsunamis

- Liquifaction

Question 7

Tsunamis:

Answer 7

• A giant wave generated by a slip in the earth’s surface and thus an earthquake
• Building collapses, fires, water main breaks and gas main breaks result

Question 8

Liquifaction:

Answer 8

• Occurs when ground saturated with water actually flows like a liquid with intense shaking
• Occurs with loose sediment

Question 9

Volcanic Hazards:

Answer 9

• Lava (ash is deadly)
• Mudflows or lahars (deadly)
• Toxic gases
• Pyroclastic bombs (explosions are deadly)
• Cause acid rain
• Landslides (even though violent, lead to fertile soil)