Chapter 1: The Earth in Context

Question 1

What are volatile materials?

Answer 1

hydrogen, helium, methane, ammonia, water, and carbon dioxide

• remain in a gaseous state closer to the sun
• beyond the ‘frost line’ some volatiles can freeze into ice

Question 2

What are refractory materials?

Answer 2

Solid soot sized particles of dust

• melt only at high temperatures
• planets closest to the sun are largely made up of refractory materials

Question 3

What are planetesimals?

Answer 3

Large grainy blocks of rock in space whose diameter exceeded about 1km.

• Because of their mass, planetesimals exert enough gravitational attraction to pull in other objects that are nearby
• Eventually forms a protoplanet

Question 4

Differentiation

Answer 4

When the heat in a planetesimal rises high enough to cause internal melting, dense metal (mostly iron) separated out and sank to the center of the planet body, whereas relatively lighter rocky materials remained in a shell surrounding the center.
Aka: How planets developed internal layering early in their history. (pg. 26)

Question 5

Magnetosphere

Answer 5

The region inside Earth’s magnetic shield

Question 6

Groundwater

Answer 6

Water filling tiny holes and cracks underground, down to a depth of several kilometers.

Question 7

Hydrosphere

Answer 7

Oceans, surface water on land, and groundwater (pg. 32)

Question 8

Geosphere

Answer 8

The solid earth from the surface to the center (pg. 33)

Question 9

Topography

Answer 9

the variation in land surface elevation

Question 10

Bathymetry

Answer 10

variations in the depth of the seafloor

Question 11

Continental shelves

Answer 11

regions where water depths are generally less than 200m

Question 12

internal energy

Answer 12

heat (thermal energy) stored or produced inside the Earth. (pg. 35)

Question 13

external energy

Answer 13

reaches the Earth from outside of it (pg. 35)

- comes in the form of radiation from the sun

Question 14

Chemical Layering (egg example)

Answer 14

• Core: iron rich (most dense)
• Mantle: peridotite
• Crust: basaltic or granitic (least dense)
  (pg. 36)

Question 15

Earthquake

Answer 15

When the Earth breaks along a fault; the sudden movement that generates vibrations, and the ground shaking that results when these vibrations reach the Earth’s surface.

Question 16

Seismic waves

Answer 16

Earthquake waves

Question 17

oceanic crust

Answer 17

thinner & more dense than continental crust

• younger
• the top layer is made up of sediment containing clay and tiny shells, basalt, and gabbro (deepest)
• ~7-10km thick
  (pg. 38)

Question 18

continental crust

Answer 18

Thicker and less dense than oceanic crust

• older
• ~25-70km thick
• Granitic felsic

Question 19

the mantle

Answer 19

• Mostly s o l i d
• largest part of the earth in terms of volume
• made up entirely of ultramafic (dark and dense) rock called peridotite
• two layers, upper and lower mantle

Question 20

transition zone

Answer 20

the part of the mantle where seismic-wave velocities increase in a series of steps due to abrupt changes in the character of minerals making up mantle rock.

Question 21

the core

Answer 21

• made up of iron alloy (iron mixed with nickel and lesser amount of oxygen, silicon, and sulfur)
• outer core: liquid because the temperature in the outer core is so high that even the great pressures squeezing the region cannot keep the atoms locked into a solid framework, generates the Earth magnetic field
• inner core: solid

Question 22

rigid materials

Answer 22

can bend or break but cannot flow easily

Question 23

plastic materials

Answer 23

relatively soft and can flow without breaking

Question 24

lithosphere

Answer 24

rigid outer layer of the Earth, made up of the crust plus the uppermost part of the upper mantle (lithospheric mantle)
NOTE: lithosphere and crust are NOT the same thing! The crust is the top layer of the lithosphere.

Question 25

asthenosphere

Answer 25

• Below the lithosphere, the portion of the mantle that behaves like soft plastic and can flow.

Question 26

Types of waves which reveal the materials/density of the earths interior?

Answer 26

s-waves, p-waves, and surface waves

Question 27

P - Waves

Answer 27

• Horizontal particle motion
• Go through whole interior of the earth (solids and liquids)
• First seismic waves that move the seismometer

Question 28

S - Waves

Answer 28

Does not travel through liquid

Question 29

Surface Waves

Answer 29

most damaging to the earths surface

Question 30

mechanical layering

Answer 30

Determined by physical properties of the layers; based on temperature mainly
○ Solid inner core
○ Liquid outer core
○ Mesosphere (solid)
○ Asthenosphere: Plastic (weak and deformable)
○ Lithosphere (Solid)