Chapter 1 Introduction to Planet Earth

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Chapter 1Introduction to Planet Earth

• Essentials of Oceanography
• 7th Edition

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Geography of the oceans

• Earths oceans
• Cover 70.8 of Earths surface
• Are interconnected (world ocean)
• Have huge size and volume (as a reservoir,
  contain 97 of Earths water)

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The four principal oceans

• Pacific
• Atlantic
• Indian
• Arctic
• Plus
• Southern or Antarctic Ocean

Figure 1-2
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Comparing oceans to the continents
Figure 1-3
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Comparing depth of the oceans to elevation on land
Figure 1-4
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Early exploration of the oceans

• Pacific navigators peopled many remote islands

Figure 1-6
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Early exploration of the oceans

• Advancements of European navigators
• Phoenicians explored the Mediterranean Sea and
  beyond
• Pytheas developed method to determine latitude
• Eratosthenes calculated circumference of Earth
• Ptolemy produced map that shows known land
  surrounded by largely unexplored oceans

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Early exploration of the oceans

• The Vikings explored the North Atlantic and
  established many colonies

Figure 1-7
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Early exploration of the oceans

• During the Age of Discovery, Columbus and
  Magellan make journeys of exploration

Figure 1-8
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Early exploration of the oceans

• Voyaging for science began with English navigator
  and explorer Captain James Cook
• Mapped many unknown islands
• Determined outline of the Pacific Ocean
• Sampled ocean properties
• Modified shipboard diet to eliminate scurvy
• Used John Harrisons chronometer to determine
  longitude

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The scientific method
Figure 1-10
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Origin of the Solar System and Earth

• Cloud of gas and space dust (nebula) began to
  contract about 4.6 billion years ago

The Nebular Hypothesis
Figure 1-12
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Origin of the Solar System and Earth

• Protoplanets were created from the nebula
• Protoearth was initially homogenous
• Larger in size than todays Earth
• Had lots of volcanic activity
• No continents or oceans
• No life

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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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Density stratification creates a layered Earth
Figure 1-13
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Origin of the oceans

• As a result of density stratification, water for
  the oceans is outgassed from inside Earth

Figure 1-14
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Origin of the atmosphere

• Density stratification caused Earths early
  atmosphere (water vapor and carbon dioxide) to be
  outgassed from inside Earth
• The initial atmosphere was rich in hydrogen and
  helium
• Earths present atmosphere is rich in nitrogen
  and oxygen

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Photosynthesis releases oxygen to the atmosphere
Figure 1-16
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Origin of life on Earth

• Stanley Millers experiment simulating conditions
  of an early Earth showed that life probably began
  in the oceans

Figure 1-15
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Major events in Earths development
Figure 1F
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End of Chapter 1

• Essentials of Oceanography
• 7th Edition