Chapter 9

Question 1

Core

Answer 1

highest density; nickel and iron

Question 2

Mantle

Answer 2

moderate density; silicon, oxygen, etc.

Question 3

Crust

Answer 3

lowest density; granite, basalt, etc.

Question 4

How to use seismic waves to study the Earths Interior?

Answer 4

Vibrations that travel through
Earth’s interior tell us what Earth is
like on the inside.

Question 5

Differentiation

Answer 5

Gravity pulls high-density material to center.
Lower-density material rises to surface.
Material ends up separated by density.

Question 6

Lithosphere

Answer 6

A planet’s outer layer of cool, rigid rock
is called the lithosphere.
It “floats” on the warmer, softer rock
that lies beneath

Question 7

Heating of Planetary Interiors

Answer 7

Accretion and differentiation when planets were young
Radioactive decay is most important heat source today

Question 8

Cooling of Planetary Interiors

Answer 8

Convection
Conduction
Radiation

Question 9

Convection

Answer 9

transports heat as hot material rises and cool material falls

Question 10

Conduction

Answer 10

transfers heat from hot material to cool
material

Question 11

Radiation

Answer 11

sends energy into space

Question 12

What is the role of size?

Answer 12

Smaller worlds cool off faster and harden earlier.
The Moon and Mercury are now geologically “dead.”

Question 13

Surface Area to Volume

Answer 13

Heat content depends on volume.
Loss of heat through radiation depends on surface area.
Time to cool depends on surface area divided by volume

Question 14

What is the Source of Magnetic Fields?

Answer 14

Motions of charged particles are what create magnetic fields

Question 15

3 Req’s for a Magnetic Field?

Answer 15

• Molten, electrically conducting interior
• Convection
• Moderately rapid rotation

Question 16

Impact Cratering

Answer 16

Impacts by asteroids/comets
Craters are about 10 times wider than the object that made
them.

Question 17

Volcanism

Answer 17

Eruption of molten rock onto surface

Question 18

Tectonics

Answer 18

Disruption of a planets surface by internal stresses

Question 19

Erosion

Answer 19

Surface changes made by wind, water, or ice

Question 20

What are the 3 kinds of craters?

Answer 20

• Standard
• Impact into Icy Grounds
• Eroded Crater

Question 21

Outgasing

Answer 21

Volcanism also releases gases from Earth’s interior into the atmosphere

Question 22

Tectonics

Answer 22

Convection of the mantle creates stresses in the crust called tectonic forces.
Compression of crust creates mountain ranges.
Valley can form where crust is pulled apart

Question 23

When does most of cratering happen?

Answer 23

The first billion years

Question 24

Planets with slower rotation have___ ___ ___

Answer 24

• less weather
• less erosion
• weak magnetic field

Question 25

Planets with faster rotation have ___ ___ ____

Answer 25

- more weather - more erosion - stronger magnetic field

Question 26

Tectonic Features

Answer 26

Wrinkles arise from cooling and the contraction of a lava flood

Question 27

Geologically "Dead"

Answer 27

means that geological processes have virtually stopped

Question 28

Erosion Crater

Answer 28

Details of some craters suggest they were once filled with water