Lecture 2: The Planet Earth

Question 1

Differentiate heliocentrism from geocentrism

Answer 1

Heliocentrism - Copernican Model

Geocentrism - Ptolemaic Model

Question 2

Explain the Big Bang

Answer 2

“singularity” – explosion of space-time; extremely hot and dense state which expanded rapidly and then slowly (dark matter) while cooling

Question 3

What were the pieces of evidence for the Big Bang?

Answer 3

1. Hubble’s Law (red shift) – 1929; star moves away
2. Cosmic Microwave Background Radiation – remnant/heat
3. Abundance of H, He

Question 4

What were the limitations of the big bang?

Answer 4

1. Only explains the universe
2. What was present before Big Bang?
3. How will it end? Will it ever end?

Question 5

Explain how the solar system forms

Answer 5

spins (contraction)

• conversion of Gravitational Energy to Thermal Energy
• cooling
• Temperature coalesce forming extraterrestrial bodies

Question 6

Differentiate terrestrial planets and jovian planets in terms of:
*composition

Answer 6

Rocky composition
Gaseous liquid form composition
(denser materials go through the center of mass)

Question 7

Differentiate terrestrial planets and jovian planets in terms of:
*elements

Answer 7

Si, Fe, O (Silicate rocks and metals)
Light elements (H, He, Ar, C, O, Ni)

Question 8

shape of earth

Answer 8

Oblate Spheroid

Question 9

Describe Oblate Spheroid

Answer 9

*flattened at poles; bulging at the equator

Question 10

Earth’s Axial Tilt

Answer 10

21.5 to 24.5 degrees

Question 11

Obliquity

Answer 11

23.4 degrees

Question 12

Orbital Speed

Answer 12

30 km/s

Question 13

Nebula planetesimals protoplanets

Answer 13

accretion, differentiation

Question 14

• accretion * differentiaion *

Answer 14

Nebula, planetesimals, protoplanets

Question 15

*: the process of growth or increase, typically by the gradual accumulation of additional layers of material

Answer 15

Accretion

Question 16

Accretion: the process of * or increase, typically by the gradual * of additional * of material

Answer 16

growth, accumulation, layers

Question 17

*: random chunks of primordial matter were transformed into a body whose interior is divided into concentric layers that differ from one another both physically and chemically.

Answer 17

Differentiation

Question 18

Differentiation: random * were transformed into a * whose interior is divided into * that * from one another both physically and chemically.

Answer 18

chunks of primordial matter, body, concentric layers, differ

Question 19

In Stage 1 of the formation of earth:

Answer 19

Fe, O, Si, Mg

*no continents, oceans, atmospheres

Question 20

*Temperature of the planet reached and surpassed the melting point of iron; denser elements sink to center and lighter elements float to top.

Answer 20

Iron Catastrophe

Question 21

Chemically distinct layers

• Core:
• Mantle:
• Crust:

Answer 21

Fe, Ni
O, Si, Fe, Mg
O, Si

Question 22

exposures on the surface of the Earth; large scale sequence of rocks

Answer 22

Ophiolites

Question 23

foreign rock (rock from mantle)

Answer 23

Xenoliths

Question 24

CO Age

Answer 24

4 Ga

160 Ma

Question 25

CO Thickness

Answer 25

35-40 km, 7-10 km

Question 26

CO Composition

Answer 26

Granitic (Si, O)

Basaltic (Mg, Fe)

Question 27

CO Density

Answer 27

2.7 g/cc, 3.0 g/cc

Question 28

• is the thickest layer

how thick?

Answer 28

Mantle

~2,900 km

Question 29

Mantle is rich in the mineral

Answer 29

perovskite

Question 30

uppermost mantle rock type:

Answer 30

peridotite

Question 31

Core is ____ alloy

Answer 31

Fe-Ni

Question 32

Crust * Mantle * Outer Core * Inner core

{Discontinuity}

Answer 32

Crust
Mantle
Outer Core

Question 33

Layers of Earth according to Physical Properties:

Answer 33

Lithosphere,

Question 34

Lithosphere is composed of:

It is ______

Answer 34

Crust + uppermost mantle

• solid but brittle
• ~100 km

Question 35

contrary to lithosphere, asthenosphere is …

Answer 35

solid but plastic or mobile

Question 36

*weak layer resulting from temperature/pressure conditions

Answer 36

asthenosphere

Question 37

*solid, rocky layer

Answer 37

mesosphere

Question 38

• 2,900 – 5,100 km in depth

* molten

Answer 38

outer core

Question 39

• 5,100 – 6,370 km in depth

* solid

Answer 39

inner core

Question 40

Differentiation of Earth’s Interior:
P-waves:
S-waves:

Answer 40

parehong solid and liquid

solid lang