Earth Sciences 11 - Sample Test - Unit 4 and 5

From Nebular Dust to the Blue Planet: Accretion of the Earth and Formation of the Moon

1. Early hypothese that addressed the issue of how the Solar System formed include:

a. Condensation

b. Encounter

c. Nebular Turbulence

d. All of the Above

2. The idea that the Sun and planets cooled from a hot nebula, a cloud of dust and gas in the interstellar medium, with the spin of the nebula being important.

a. Condensation

b. Encounter

c. Nebular Turbulence

d. All of the Above

3. A hybrid of nebular condensation ideas, modified to recognize the great heterogeneity and turbulence in a condensing spinning nebula. This is key to explaining why the planets have the angular momentum of the system

a. Condensation

b. Encounter

c. Nebular Turbulence

d. All of the Above

4. The idea that the star formed first, and then close passage of another star gravitationally 'ripped' some of the material out, which cooled in place to make the planets.

a. Condensation

b. Encounter

c. Nebular Turbulence

d. All of the Above

5. True or False. The Planets are all in the Plane of the Ecliptic, and orbit the Sun (and for the most part rotate) in the same direction as the Sun' rotation.

6. True or False. The Planets have a regular spacing, with each planet having an orbital radius half that of the Planet next nearest to the Sun. This is Bode's Law (Rn+1 = 2Rn)

7. Which of the following statements is correct with respect to a nebula?

a. The balance of heat and light leads to a flattened disk.

b. The balance of gravity and rotation leads to a flattened disk.

c. The balance of cooling and expansion leads to a flattened disk.

d. The balance of gravity and light leads to a flattened disk.

8. As the hot gas in the nebula cools, materials begin to freeze out of the gas, assuming solid state at temperatures that vary depending on the particular compound. This is called

a. the Condensation Sequence

b. the Evaporation Sequence

c. the Precipatation Sequence

d. the Contemplation Sequence

9. As the Nebula cooled to 1400 C it began to freeze out

a. volatile material

b. liquid material

c. gaseous material

d. refractory material.

10. True or False. Hot, close-in terrestrial planets formed from volatile materials, with the more refractory materials still being in a gas state and not being incorporated into the growing planet.

11. Which accretion model builds entire planets out of direct aggregation from the condensed mist of granules.

a. The zero step

b. The one step

c. The two step

d. The three step

12. Which accretion model builds planets by first accumulating as 'planetisimals', small masses, which then collide to form the larger planets.

a. The zero step

b. The one step

c. The two step

d. The three step

13. Which accretion model is favored for several reasons

a. The zero step

b. The one step

c. The two step

d. The three step

14. The two step accretion model is favored for several reasons, except:

the very low inert gas content of the Earth relative to the expected abundance from that of a. the nebula (i.e. the solar abundance)

b. models of planetisimal trajectories

c. lack of neutrinos showing the correct wavelength in the visible spectrum

d. the very tightly constrained ages of the meteorites

15. The accretion of the Earth took place about

a. 4.55 billion years ago.

b. 5.44 billion years ago

c. 4.55 million years ago

d. 5.44 million years ago

16. The age of the earth is based on

a. the dating of lead isotopes in meteorites

b. inferences from the lead/Uranium history of materials on the Earth

c. all of the above

d. none of the above

17. As the nebula cooled, the refractory materials accreted into a single core, and later, less refractory materials added on, in layers, to give an iron rich core overlain by silicates. a. Heterogeneous Accretion

b. Homogeneous Accretion

18. The above process may have occurred on the scale of planetisimals, but these then accreted into a larger body, such that the initial distribution of materials was fairly uniform through the planet.

a. Heterogeneous Accretion

b. Homogeneous Accretion

19. During the formation of the Earth there are two means of increasing the temperature sufficiently to allow the iron to drain toward a growing core.

a. Radioactive heating and Impact heating

b. Solar radiation and Neutrino bombardment

c. Comet impacts and greenhouse gases

d. None of the above

20. One of these rare, large planetisimals about the size of Mars impacted the Earth just after the core formed. This sprayed much of the initial Earth's rocky mantle into space with a huge collision, converting the rocky material into liquid and even gas. While some material fell back to Earth and some escaped to space, a significant amount re-condensed and cooled, finally accreting to form

a. the Atmosphere

b. Mercury

c. the Moon.

d. Haley's Comet

21. Observations of the Moon's bulk composition show

a. low iron content

b. its rotation to be clockwise

c. its diameter to be 4000 km

d. velocity to be 1500 km/h

22. The tilt of the Earth's axis with respect to the plane of the eccliptic yields

a. our solid core

b. our day and night

c. our moon

d. our seasons

23. How do we know the age of the Moon?

a. using spectroscopy

b. using meteorology

c. using the doppler effect

d. None of the Above

24. True or False. The simulations of this collision indicate that the Moon was initially much further from the Earth, and is slowly approaching.

25. Why does the evidence of intense meteorite bombardment persist on the Moon?

a. without atmosphere it continues to be bombarded.

b. because there are no healing processes such as occur on the Earth.

c. until recently, the evidense was protected by a layer of ice.

d. none of the above

26. Which of the following was essential for life to evolve on the planet?

a. accumulation of liquid iron at the core of the Earth

b. accumulation of molten lava at the surface of the Earth

c. accumulation of gaseous water at the surface of the Earth

d. accumulation of liquid water at the surface of the Earth

27. The mass of the Earth the is sufficiently large to have enough gravity to retain large gaseous molecules, such as

a. N

b. H

c. He

d. None of the above

28. a massive planet such as Jupiter is burdened by huge amounts of small gaseous molecules, held to the planet by its massive gravity, such as

a. N

b. H

c. He

d. Two of the above

29. True or False. One of the most remarkable conditions of the Earth is that its surface temperatures span the relatively narrow range of the liquidus and gaseous of water.

30. True or False. Water is one of the few materials that contracts upon freezing (ice floats), which has played a key role in allowing organisms to survive under frozen streams.

31. Was Venus ever cold enough to allow liquid water?

a. Yes

b. No

c. This is debated.

d. None of the above

32. Was Mars ever warm enough to allow free water?

a. Yes

b. No

c. This is debated.

d. None of the above

33. True or False. Earth is at a favorable distance from the Sun in that the amount of solar radiation which heats the atmosphere daily does not drive huge damaging storms continually.

34. True or False. The radiation received by the Earth is relatively mild, yet enough to provide good visible light and modest UV that produces mild rates of chromosomal mutation to facilitate evolution.

35. Study of biological processes through time, evolution, extinction.

a. Geochemistry

b. Geophysics

c. Geology

d. Paleontology

36. Study chemical processes, melting, rock formation, erosion, cosmochemistry

a. Geochemistry

b. Geophysics

c. Geology

d. Paleontology

37. Study of rocks and surface processes using analytic tools and field observations.

a. Geochemistry

b. Geophysics

c. Geology

d. Paleontology

38. Study physical processes of the solid Earth, liquid core, atmosphere and oceans. Convection, heat transport, magnetic field generation, gravity.

a. Geochemistry

b. Geophysics

c. Geology

d. Paleontology

39. The Earth is best described as a chemically differentiated, radially stratified planet. The original soup of atoms of the solar nebula from which the planet accreted have been processed through

a. gravitational processes

b. chemical processes

c. melting processes

d. all of the above

40. True or False. The Earth has a thin 6-70 km mantle layer of very light rocky materials that overlies a thick 2840 km layer of crustal materials that are mainly Mg, Si, O rocky silicates.

41. True or False. The core is itself stratified, in that there is an inner core which is liquid iron, and the inner core is slowly shrinking as the core cools

42. True or False. Key to melting differentiation is that in a melt the light material rises and the heavy sinks very efficiently, which allowed the crustal materials to separate as well as the iron in the core.

43. True or False. The bulk composition of the Earth is thought to be very similar to that of primitive meteorites that fall to Earth.

The shallow Earth is of most concern in this class, both, for

44. This is where the dynamic systems affect Humans as catastrophic processes.

a. the upper mantle and the surface

b. the lower mantle and the outer core

c. the upper mantle and the inner core

d, the lower mantle and the surface

45. The upper 100 km of the shallow Earth comprise

a. The Lithosphere.

b. The plates of Plate Tectonics

c. a region of heat transport by thermal conduction

d. All of the above

46. True or False. Beneath the lithosphere, the temperature increases and the next 100-200 km are more ductile, comprising the asthenosphere.

47. On the Earth's surface there are localized regions of very high mountains on continents and localized regions of very deep trenches in oceans. To sustain even these small regions requires

a. ongoing dynamic processes

b. ongoing static processes

c. past dynamic processes

d. past static processes

48. True or False. Rocks are very solid for short-time scale loads, but do behave fluidly given steady application of forces over long periods of time.

49. This is the primary mechanism by which the planet is cooling off.

a. plasma regeneration

b. solid state convection

c. ionic conduction

d. proton donation

50. When hot rock rises to the surface, as crust pulls apart, this hot rock cools to form new crust, releasing the heat energy to the surface to radiate into space. This is

a. plasma regeneration

b. ionic conduction

c. solid state convection

d. proton donation

51. How is the creation of new sea floor balanced on a planet with constant surface area?

a. oceanic crust and lithosphere age, cool and sink back into the interior.

b. wind erosion removes most of the new mass

c. water erosion removes most of the new mass

d. solar radiation reduces the new mass

52. The cycling of oceanic crust/lithosphere occurs on a time scale much shorter than the age of the Earth, and therefore

a. To find older rocks, we look to the continents

b. 70% of the planet surface is very young.

c. Both of the Above

d. None of the Above

53. True or False. All old fossils, all reconstructions of past motions of the continents, and all inferences about mountain building events more than 200 million years old are based on continental rock records.

54. We can tell the latitude at which rocks formed

a. by various means of radioactive decay

b. by the magnetic record preserved in the rocks.

c. by there scrapings

d. All of the Above

55. True or False. The magnetic field is constant, not changing with time, and is not known to undergo reversals of polarity.

56. True or False. The origin of the magnetic pole is convection of the solid iron outer core.