Lecture 6: Solar System / Earth

Question 1

Earth

Answer 1

• Strong magnetic field
• Differentiated interior
• Active Surface

Question 2

Planetary Interiors

Answer 2

• Seismic Waves, Magnetic Fields, Surface Features, and Gravitational Deviations are the best way to determine the inside of a planet

Question 3

Earthquake Waves

Answer 3

• P waves are primary or pressure waves and are the fastest seismic waves
• S waves are secondary or shear waves
• Surface waves are slower than S and P waves

Question 4

Earth Seismic Waves

Answer 4

• Waves refract depending on different things
• Temperature and density increase with depth
• heat generate dis proportional to planet’s mass
• Heat escapes through planet’s surface

Question 5

Heating vs. Cooling of Planets

Answer 5

• Heating mechanisms are proportional to mass, volume or radius cubed
• Cooling mechanisms are proportional to surface area or radius squared
• Larger bodies cool more slowly

Question 6

Planetary magnetic fields

Answer 6

• A rotating metallic core will act as a dynamo and produce a magnetic field
• Earth’s magnetic field comes form charged particles in its outer liquid core
• Solar wind distorts shape of magnetosphere
• Aurora’s are caused by solar winds with magnetic field (northern lights)

Question 7

Planetary Surfaces: Earth

Answer 7

• The surface of a planet can give clues to what’s happening inside the planet
• Continental drift causes constant changes to surface (mountains)
• Erosion of surface, meteorite impacts
• North America result of subduction, collisions, volcanism, erosion, and sedimentary deposits

Question 8

Techtonic Plates

Answer 8

• Can compress or stretch the crust
• Can slide along each other and pull apart, causing earthquakes and rift valleys

Question 9

Volcanism

Answer 9

• An upwelling of molten rock (magma) from deep within the planet to the surface
• Can cover up old surface features and make new ones, as well as produce additional gas
• Caused by Techtonic plates and thermal plumes

Question 10

Impact Cratering

Answer 10

• Features depend on speed, angle, impactor, and surface material, and are different from volcanic craters
• Small craters bowl shaped
• Large craters have central peak and concentric rings, multiring basins

Question 11

Erosion

Answer 11

• Atmosphere and Surface Water act to level the surface
• Acts on all scale
• Chemical Reactions

Question 12

Planetary Atmospheres: Earth

Answer 12

• CO2 has increased in the last 50 years likely due to global warming
• Surface Temperature is a combination of solar heating, infrared radiation trapped by cloud layer, and hot interior
• Climate depends on heating and rotation
• Atmosphere blocks some light, transmits others

Question 13

Atmospheric Mass Change

Answer 13

• Greenhouse effect heats surface
• Atmospheres gain mass due to outgassing, evaporation, and impacts
• Atmospheres lose mass by thermal escape, solar winds, impacts, condensation, and chemical reactions

Question 14

Atmospheric Heating

Answer 14

• Warm air rises near the equator and cools as it gets to the poles
• Circulation cell in each hemisphere
• Rotation affects atmospheric circulation
• Coriolis Effect causes circulation cells to divide into three cells per hemisphere