Development / Introduction to Planet Earth

Question 1

Planets grow from

Answer 1

dust: meteorite –> asteroid –> planet
crust and mantle = oil and water

Question 2

Differentiation

Answer 2

seperation of core, mantle, crust

Question 3

Earth’s Magnetic field

Answer 3

• deflects solar wind
• protects Earth from sun
• protects Earth from UV
• protects ozone layer

Question 4

Earth’s Geodynamo

Answer 4

• rapid motion of liquid iron outer core
• enhanced by planet’s rotation

Question 5

Trace in Rock record of magnetic field

Answer 5

• remnant magnetic material (3.5 GA)

Question 6

Solidification of Earth’s Core

Answer 6

• dipoles gradually decay –> geodynamo begins to collapse –> core begins to solidify –> formation of modern magnetic field

Question 7

Plate tectonics

Answer 7

Unique to Earth

Question 8

Sustaining Earth’s habitability

Answer 8

• weather cycle
• CHNOPS

Question 9

Earth’s Atmosphere before life

Answer 9

• volcanic gases
• high CO2 and H2 concentrations
• no oxygen
• methane rich haze

Question 10

Late Permian Extinction

Answer 10

• most severe biotic crisis in history of Earth
• extinction of over 95% of species on Earth
• due to warming of planet/oceans - volcanism / oxygen depletion in ocean s

Question 11

Evolution of life throughout mass extinctions

Answer 11

• evolved in response to changes in climate, atmosphere, oceans, etc.

Question 12

Major Biological Transitions

Answer 12

(1) origin of life/prokaryotes
(2) Photosynthesis/great oxidations/paleoproterozoic glaciations
(3) Eukaryotic differentiation/neuroproterzoic glaciations/secondary oxidation/cambrian explosion
(4) humans evolved/anthropocene