The document provides an overview of planet Earth and its oceans. It discusses four main topics: 1) the formation of Earth and its atmosphere/oceans from a nebula approximately 4.6 billion years ago, 2) Earth's internal structure of layered shells by density, 3) early life emerging in oceans over 3.5 billion years ago, and 4) scientific dating methods used to determine Earth's age and origin of life.

1. Introduction to Planet “Earth”
Dewi Embong Bulan
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2. Oceanography
 Geological Oceanography
 Chemical Oceanography
 Physical Oceanography
 Biological Oceanography
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3. Overview
 70.8% Earth covered by ocean
 Interconnected global or world ocean
 Oceans contain 97.2% of surface water
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Fig. 1.3ab

4. The four principal oceans
Pacific
Atlantic
Indian
Arctic
Plus:
Southern or
Antarctic Ocean
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5. Comparison of elevation and depth
 Average depth 3729 m (12,234 ft)
 Average elevation 840 m (2756 ft)
 Deepest ocean Mariana Trench 11,022 m (36,161 ft)
 Highest continental mountain Mt. Everest 8850 m (29,935 ft)
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6. Fig. 1.3cd
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7. Exe. 01-01
 Name principle oceans on the earth.
 Do you think if “earth” is misnamed for
our planet? Why?
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8. Scientific method
Observations
Hypotheses
Testing and modification of hypotheses
Theory
Probably true versus absolutely true
Science is continually developing
because of new observations
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9. Scientific method
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Fig. 1.9

10. Density
Density is defined as:
Mass of unit divided by Volume of
unit
 = m / V
Example:
A rock has a mass of 5000 Kg
Its volume is 2 m3
 = m / V
 = 5000 Kg / 2 m3
 = 2500 Kg/m3
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11. Density stratification
 Protoearth experiences density stratification
 Density = how heavy something is for its size
 Density stratification causes high density material to sink while
low density material rises
 High density material = rock material and metals
 Low density material = gases
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12. Origin of the Solar System and Earth
Cloud of
gas and
space dust
(nebula)
began to
contract
about 4.6
billion years
ago
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The Nebular Hypothesis

13. Origin of the Solar System and Earth
 Protoplanets were created from the nebula
 Protoearth was initially homogenous:
 Larger in size than today’s Earth
 Had lots of volcanic activity
 No continents or oceans
 No life
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14. Origin of Earth’s atmosphere
Partial melting resulted in outgassing
about 4 billion years ago
Similar to gases emitted from volcanoes
Mainly water vapor
Carbon dioxide, hydrogen
Other gases such as methane and
ammonia
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15. Origin of Earth’s oceans
Water vapor released by outgassing
Condensed as rain
Accumulated in ocean basins
About 4 billion years ago
Ice Comets were also important to
adding water to the Earth system
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16. Fig. 1.17
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17. Ocean salinity
Rain dissolves rocks
Dissolved compounds (ions)
accumulate in ocean basins
Ocean salinity based on balance
between input and output of ions
Ocean salinity nearly constant
over past 4 billion years
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18. Exe. 01-02
 Please describe how our solar system, the atmosphere and ocean were
formed on the earth?
 What is density stratification?
 Why is sea water salty?
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19. Earth’s internal structure
Highest density material at center
(core)
Lowest density material at surface
(crust)
Earth layered
Chemical composition
Physical properties
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20. Chemical composition
Crust
Low-density, mainly silicate
minerals
Mantle
Mainly Fe and Mg silicate minerals
Core
High-density, mainly Fe and Ni
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21. Layered
Earth
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Fig. 1.14

22. Physical properties
Lithosphere
Asthenosphere
Mesosphere
Outer core
Inner core
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23. Physical properties
Lithosphere
Cool, rigid, brittle
Surface to about 100 km (62 miles)
Asthenosphere
Warm, plastic, able to flow
From 100 km to 700 km (430 miles)
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24. Fig. 1.15
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25. Lithosphere
Oceanic crust
Underlies ocean basins
Igneous rock basalt
Average thickness 8 km (5 miles)
Relatively high density
3.0 g/cm3
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26. Lithosphere- Crust and Uppermost
mantle fused together.
Continental crust
Underlies continents
Igneous rock granite
Average thickness 35 km (22 miles)
Lower density
2.7 g/cm3
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27. Asthenosphere
Upper mantle
Plastic—deforms by
flowing
High viscosity—flows
slowly
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28. Exe. 01-03
 In terms of chemical property, how many layers does the
earth have? List them.
 In terms of physical property, how many layers does the
earth have? List them.
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29. Life in oceans
Earliest life forms fossilized
bacteria in rocks about 3.5 billion
years old
Marine rocks
Life originated in oceans?
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30. Stanley Miller’s experiment
 Organic molecules formed by ultraviolet light, electrical spark (lightning),
and mixture of water, carbon dioxide, hydrogen, methane, and ammonia
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31. Fig. 1.18a
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32. Age of Earth
Radiometric age dating
Spontaneous change/decay
Half-life
Earth is about 4.6 billion years old
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33. Geologic time
scale
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Fig. 1.H

34. Exe. 01-04
 How old is the earth? When did life start on the earth? How
do we know these?
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35. Summary
 General Information: earth, oceans
 Scientific Methods
 Origin of Earth, Ocean, Atmosphere
 Internal Structure of Earth
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