CHAPTER 12: EARTHS HISTORY AND INTERIOR

Question 1

How old is earth?

Answer 1

4.6 billion years

Question 2

How old is the universe?

Answer 2

13.8 billion years

Question 3

What is the anthropocene?

Answer 3

age of human transformation of earths physical systems

Question 4

When did the anthropocene start?

Answer 4

1800’s, industrial revolution

Question 5

Why did CO2 levels in the atmosphere rise?

Answer 5

Burnt coal and petroleum for energy

Question 6

Why are sea levels rising and becoming more acidic?

Answer 6

Increase in CO2

Question 7

How much has the sea level risen in the last century?

Answer 7

20cms

Question 8

How much of earths freshwater run off is used by people?

Answer 8

1/2

Question 9

How much of mammal biomass is made up of people and domesticated animals?

Answer 9

90%, only 0.1% 10000 years ago

Question 10

What is a light year?

Answer 10

How long it takes to move at a speed of 300km per second

Question 11

Edmun Hummel proposed which theory?

Answer 11

Expanding Universe Theory

Question 12

Galaxies, stars and planets are all formed from?

Answer 12

Dust and gas

Question 13

Solar System formed how many years ago and from what?

Answer 13

4.5-5 billion years by a nebula

Question 14

How many planets revolve around the sun?

Answer 14

8

Question 15

What orbits to the planets move around the sun in?

Answer 15

Elliptical orbits

Question 16

How many planets is earth away from the sun?

Answer 16

3

Question 17

What was earths atmosphere formed from?

Answer 17

Gases emitted by volcanoes

Question 18

How did oceans form?

Answer 18

Water vapour and volcanic emissions condensed out of atmosphere

Question 19

Example of a photosynthetic organism

Answer 19

Cyanobacteria

Question 20

What are stromatolites?

Answer 20

Colonies of cyanobacteria, earliest form of life in fossil records

Question 21

What is the Great Oxidation Event?

Answer 21

oxygen concentration increased, 2.4 billion years, ozonosphere formed

Question 22

What makes life possible on earth?

Answer 22

Ozonosphere blocking UV Rays

Question 23

Dinosaurs existed how many years ago?

Answer 23

240 million years

Question 24

modern humans existed how many years ago?

Answer 24

200, 000 years ago

Question 25

What are Eons?

Answer 25

largest division of time scales

Question 26

What eon are we currently living in?

Answer 26

Phamnezobnic eon

Question 27

What era are we living in?

Answer 27

Cenozoic era

Question 28

What period are we living in?

Answer 28

Quaternary period

Question 29

Which Eon accounts for 85% of geologic time?

Answer 29

Precambrian Eeon

Question 30

Oldest rocks found on earth are how old?

Answer 30

4 million years old

Question 31

What Epoch are we currently living in?

Answer 31

Holocene or anthropocene

Question 32

What is the idea of uniformitarianism

Answer 32

present is the key to the past, processes that have shaped landscapes of the past are the same and will shape the future

Question 33

Principle of Superposition

Answer 33

oldest rock layer at bottom

Question 34

Hutton's Unconformities is located at

Answer 34

Siccar Point

Question 35

define unconformity

Answer 35

an ancient land surface representing a time gap in the normal geological sequence

Question 36

2 Ways scientists date materials

Answer 36

1. Relative Age | 2. Absolute Age

Question 37

What is relative age?

Answer 37

compare age of one object or event with another without specifying how old either is, the order of eevnts

Question 38

What is absolute age?

Answer 38

specifies age in years!

Question 39

2 techniques used to determine absolute age

Answer 39

Dendrochronology | Radiometric Dating

Question 40

What is dendrochronology

Answer 40

tree ring analysis

Question 41

What is radiometric dating?

Answer 41

assigning ages to material based on radioactive half-life of unstable elements in those materials

Question 42

Which energy is sustainable and renewable?

Answer 42

Geothermal energy

Question 43

What are xenoliths?

Answer 43

rocks elevated to earths surface via magma

Question 44

Most of what we know about earths interior comes from analysis of...

Answer 44

seismic waves

Question 45

What is a seismic wave?

Answer 45

energy released by earthquakes that travel through the earths interior

Question 46

What is an earthquake?

Answer 46

sudden shaking of the ground caused by movements of earths crust

Question 47

What are surface waves?

Answer 47

Travel along/near surface Cauuses damage R & L waves

Question 48

What are body waves?

Answer 48

Pass through earth | P and S waves

Question 49

2 types of earthquake waves

Answer 49

Surface and Body Waves

Question 50

Which earthquake wave can travel through the core?

Answer 50

P-Waves

Question 51

what is the geothermal gradient?

Answer 51

earths interior increasing with depth

Question 52

how hot is earths core?

Answer 52

6000C

Question 53

4 FACTORS THAT MAKE EARTH HOT INTERIOR

Answer 53

Friction Asteroid bombardment Tidal Forces Radioactivity

Question 54

3 Principle lawyers of earths interior

Answer 54

CORE MANTEL LITHOSPHERE

Question 55

What is the radius of the earth?

Answer 55

6371km

Question 56

Earths inner core is solid or liquid?

Answer 56

SOLID

Question 57

Which elements are found in earths inner core

Answer 57

Iron and Nickel

Question 58

What keeps the inner core solid?

Answer 58

compressional forces

Question 59

Circulating liquid metal which generates earths magnetic field is located in the...

Answer 59

outer core

Question 60

What is a dynamo?

Answer 60

a device converting the energy of motion to that of an electric current

Question 61

What is the magnetosphere?

Answer 61

Protects earth from solar wind

Question 62

How many km does magnetic north move each year?

Answer 62

55km

Question 63

Temperature of earths mantle

Answer 63

4000-900C

Question 64

Which portion of the mantle is solid rock, but slowly deforms and flows in great circular convection loops

Answer 64

Lower Mantle

Question 65

Which portion of the mantle is in solid state, but nearer melting and weak and easily deformed?

Answer 65

Asthenosphere

Question 66

Which portion of the mantle is rigid and brittle

Answer 66

Lithospheric Manleys

Question 67

Layers of the mantle from bottom to top

Answer 67

Lower Mantle, asthenosphere, lithospheric mantle

Question 68

What 2 portions layers are apart of the upper mantle?

Answer 68

Lithosphere and Asthenosphere

Question 69

2 types of earth crusts

Answer 69

Continental crust | Oceanic crust

Question 70

Which crust is composed of mainly granite (forms from magma)

Answer 70

Continental crust

Question 71

Which crust forms from basalt (forms from lava)

Answer 71

Oceanic crust

Question 72

What is the Moho?

Answer 72

Boundary that separates the crust from the lithosphere mantle

Question 73

Moho is deepest under which crust?

Answer 73

Continental crust, 70km

Question 74

Moho is shallowest under which crust?

Answer 74

Oceanic crust, 7km

Question 75

The lithosphere is broken into how many major plates?

Answer 75

14

Question 76

What is diastrophism

Answer 76

plates buckle into mountains, bend and warp into hills and break causing earthquakes

Question 77

What moves the plates?

Answer 77

Convection

Question 78

Which plate is the largest?

Answer 78

Pacific Plate

Question 79

Which plate are we on?

Answer 79

North American Plate