EAPS 105 Exam 2 Study Guide PDF

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EAPS 105, The Planets Exam 2 Study Guide From the lecture slides you should know the following: Unit 4: Heating and Cooling 1. Consequence of a planet or moon being hot inside. 2. The state (solid/liquid) of each layer in the Earth. 3. How Earth’s internal temperature compares to that of the surface of the Sun. 4. What happens to atoms when they heat up. 5. How accretion leads to heat. 6. How core formation leads to heat. 7. What is meant by primordial heating. 8. The primary source of Jupiter’s moon Io’s internal heat. 9. Why Lord Kelvin’s calculation the age of the Earth did not work. 10. How radioactive decay produces heat. 11. What contributes to the current internal temperature of the Earth. 12. Why smaller planets cool faster than larger ones. 13. Why Pluto is still hot inside. 14. The mediums by which conduction, convection, and radiative heat transfer move heat. 15. How conduction transfers heat. 16. How convection transfers heat. 17. The difference between radioactive decay and radiative heat transfer. 18. How each layer within the Earth transfers heat. 19. What lithosphere is. 20. What asthenosphere is. 21. Why drives plate tectonic. 22. What a mid-ocean ridge is. 23. What a subduction zone is. 24. What a transform fault is. 25. Where strike slip faults are found besides Earth. 26. The tell-tale signs of plate tectonics. Mid-ocean ridges, and subduction zones 27. Which other terrestrial planets currently exhibit plate tectonics. None, they have tectonics, but no plate tectonics 28. Why there are thrust faults on Mercury and The Moon. The surface is contracting as its interior continues to cool, causing thrust faults 29. Why there are thrust faults on Pluto. Pluto has thrust faults due to the cooling of a subsurface ocean. (water expands when it freezes into ice.) 29. Why Venus does not experience plate tectonics. Venus is so hot that its lithosphere may flow slowly rather than break into plates Venus is so dry that its lithosphere may be too strong to break 30. What happened to Venus’ surface about 500 million years ago. Catastrophically resurfaced by volcanism. The entire surface is the same age 31. How to increase the strength of an induced magnetic field. Coil the wire and make it surround a metal (like iron) 32. What is required to generate a planetary dynamo.

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Electrical conducting liquid layer that is convecting Convection in this conducting layer is organized into coils by planetary spin These coils spiral around more conducting material, thus greatly increasing field strength 33. Where Earth’s magnetic north pole is really located. In the south 34. What protects us from the solar wind. Magnetic Field protects from stream of deadly charged particles 35. What causes auroras. Solar wind deflection by magnetic field, which excites the nitrogen and oxygen in our atmosphere 36. What a magnetosphere is. Region where a planet’s magnetic field is the predominant…… 37. Why the Sun has a strong magnetic field. Abundance of freely moving electrons 38. Why Venus does not have a magnetic field. Venus spins slowly, so convection does not organize into spirals 39. Why Jupiter has a magnetic field. Free flowing electrons and a huge metallic hydrogen core 40. Why Neptune has a magnetic field. Water and ammonia conduct electricity when mixed. Much bigger than Earth’s 41. What if we lost our magnetic field Compasses would go crazy Auroras would be visible every night, everywhere More charged particles would reach us – widespread outages and broken satellites Migratory animals could have difficulties -

Mercury spins slowly and thus has a weak magnetic field

Unit 5: Volcanism 41. The difference between magma and lava. 42. Which type of volcanism is observed on the other terrestrial planets 43. How much of the Earth’s mantle is actually melted rock. 44. The 3 ways to get hot rocks to melt. 1. F 2. Decrease Pressure 3. Add water to the minerology (hydration induced melting 45. What causes hot rocks to melt at subduction zones. Water pushed out from the subducting plate lowers the melting temperature of the hot mantle above, causing it to melt 45. What the Ring of Fire refers to. Pacific rim that is surrounded by subduction zones 46. Why there are fewer active volcanoes in the U.S. southwest compared to the northwest. No active subduction zones in southwest 46. What causes hot rocks to melt at hotspots. Core heats out the base of the mantle, causing a hot, buoyant plume of mantle to rise 47. Why hotspots on Earth lead to hotspot tracks. When a tectonic plate moves over the hotspot, volcanoes initiate over the hotspot then go extinct as the volcano moves away from it, and a new volcano develops 48. What an effusive volcanic eruption is. 2

If magma can flow 49. Why pressure in magma builds as it rises toward the surface. The dissolved gasses expand to form gas bubbles, which take up more volume than dissolved gas 50. What volcanic ash is. Broken, ejected shards of those gas bubbles (volcanic glass) 51. What viscosity is a measure of. Ease with which a fluid flows Low viscosity – flows easy (effusive) High viscosity – sticky (Explosive) 52. The kinds of volcanoes low viscosity magma lava leads to. Lead to broad, shallow sloped……….. 53. The tallest mountain on Earth as measured form its base to its peak. 54. How a stratovolcano forms. 55. How a cinder cone forms. 56. The combination of magma viscosity and gas content is most likely to lead to explosive eruptions. High pressure + High Gas content = explosive 57. The factors that control how much gas pressure builds below the surface. Amount of magma Amount of dissolved gas Viscosity of magma 58. The least and most powerful types of volcanic eruptions. Least – Hawaiian eruptions Strombolian Vulcanian Most – Plinian eruption 59. Where giant flood basalts originate from. 60. Which planets are covered by flood basalts. 61. Which flood basalts on the Moon are primarily only found in large impact basins. 62. Why Olympus Mons is so big. It is not steep at all! Weak gravity allows high topography No plate tectonics on mars tp move a volcano off a hotspot Weaker erosional processes on mars, allow for taller topography 63. Why Venus volcanoes are so flat. Venus has a much denser atmosphere 64. The kind of volcanoes found on Mercury. Viscosity of lava on Mercury is so LOW that the lava seeps out of fissures instead of through valcanoes 65. How a caldera forms. A caldera is a massive volcanic crater that is formed when the surface collapses into an emptying magma chamber 66. The lava fountains have been observed on Io. The light from lava saturated the camera 67. The components of an eruption column. Gas thrust – pressure that throws material out

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moreeeeeeee 68. How gravity influences an eruption column. Less gravity = higher column 69. What cryovolcanism is. Eruption of water vapor and icey particles erupting (nitrogen, ammonia, or methane) 70. Where cryovolcanoes are found on Earth. They do not exist on Earth 71. How one can most easily sample the subsurface ocean of Enceladus. The space craft cassini sampled from a plume Unit 6: Impact Cratering 72. How planet mass and radius influence a planet’s escape velocity. The greater the radius of the planet, the lower the velocity needed to escape its gravity (because mass is more distributed) The greater the mass of the planet, the higher the velocity needed to escape its gravity 73. What the minimum impact velocity of an asteroid or comet depends on. The escape velocity (11km/s for earth) due to gravity pulling it 74. The typical range of speeds of asteroid and comet impacts. 75. Why impact speeds into the Earth and Moon are similar. Objects hitting the moon get an assist from Earth’s gravity 76. Why comets impact faster than asteroids. Comets spend more time being accelerated toward the inner solar system by the sun’s gravity 77. Why impacts into Mercury are faster than the other terrestrial planets. It is so close to the sun, that objects are given a big gravitational assist 78. The size of impact craters compared impactor size. 10-30times larger than the impactors 79. Why most craters on the Moon are round. Because impacts act as explosions 80. The order of impact processes. Contact and Compression – initial stage of first contact; begins compression Excavation Stage – rocks are thrown out (ejecta) Modification stage – Transient crater collapses, fills crater with breccia (broken rock) and impact melt 81. What a transient crater is. The maximum crater size that occurs at the end of the excavation stage. Rocks are not strong enough to support the steep topography for long, so it begins to collapse When it collapses, the crater is fairly shallow 82. The geometry of simple craters. Nice bowl shape with breccia Distinct rim 83. The geometry of complex craters. Flat floor, filled with breccia and some melts Central uplift 4

Can also have a peak ring or multiple rings 84. The relative size of different crater morphologies. 85. How far an ejecta blanket generally extends. Around 1 crater diameter (twice the size of the crater) Each particle has a ballistic (Parabolic) trajectory 86. Why ejecta blankets on Mars look fluidy. Because Mars has a thick permafrost layer (subsurface ice) 87. What crater rays are. Brighter lines of ejecta that extend very far from the impact site 88. What space weathering is. Changes the color of the surface, enabling any disturbance of the surface to show up distinctly 89. Why young craters appear brighter than older craters. They reveal fresher surface material, overtime, sand and such can blow around and remove the shown color 90. Why there are few recognized impact craters on the Earth compared to the Moon. About 170 recognized impact craters The moon has no significant erosional processes 91. Why the Kentland Crater does not look like an impact crater. The top 300m of the crater was removed by glaciation 10,000 years ago 92. What causes shatter cones to form. Shatter cones are formed from the passage of a high-pressure shock wave 93. The evidence that a large impact killed off the dinosaurs. There is a thin boundary of iridium, soot, and shocked quartz 94. How the Chicxulub Crater was found. Revealed by mapping the gravity signature and dated of cores drilled through the sediments 95. That mass extinctions have likely been caused by asteroid impacts. Woodleigh Crater, Manicouagan, Morokweng Crater, Chicxulub 96. How often a ~10-km-diameter asteroid hits the Earth. Once about every 100million 97. How many Near Earth Asteroids ≥1 km in diameter are currently being tracked. 98. The best strategy to avoid an extinction level size asteroid from hitting the Earth. Deflect it! If we detect it early enough 99. The potential strategies for changing the orbit of an asteroid or comet on a collision course with Earth.  Kinetic impact: Crash into it  Spacecraft Propulsion- create a thrust to alter trajectory  Solar heat – works only for comets, and would vaporize material  Nukes – detonate to alter trajectory (don’t leave big chunks)  Solar sail – use solar pressure to shift trajectory

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