Chapter 1 Introduction to Planet “Earth”

1. Chapter 1Introduction to Planet “Earth” Essentials of Oceanography 7th Edition

2. Geography of the oceans Earth’s oceans: • Cover 70.8% of Earth’s surface • Are interconnected (“world ocean”) • Have huge size and volume (as a reservoir, contain 97% of Earth’s water)

3. The four principal oceans • Pacific • Atlantic • Indian • Arctic Plus: • Southern or Antarctic Ocean Figure 1-2

4. Comparing oceans to the continents Figure 1-3

5. Comparing depth of the oceans to elevation on land Figure 1-4

6. Early exploration of the oceans • Pacific navigators peopled many remote islands Figure 1-6

7. 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

8. Early exploration of the oceans • The Vikings explored the North Atlantic and established many colonies Figure 1-7

9. Early exploration of the oceans • During the Age of Discovery, Columbus and Magellan make journeys of exploration Figure 1-8

10. 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 Harrison’s chronometer to determine longitude

11. The scientific method Figure 1-10

12. 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

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

14. 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

15. Density stratification creates a layered Earth Figure 1-13

16. Origin of the oceans • As a result of density stratification, water for the oceans is outgassed from inside Earth Figure 1-14

17. Origin of the atmosphere • Density stratification caused Earth’s early atmosphere (water vapor and carbon dioxide) to be outgassed from inside Earth • The initial atmosphere was rich in hydrogen and helium • Earth’s present atmosphere is rich in nitrogen and oxygen

18. Photosynthesis releases oxygen to the atmosphere Figure 1-16

19. Origin of life on Earth • Stanley Miller’s experiment simulating conditions of an early Earth showed that life probably began in the oceans Figure 1-15

20. Major events in Earth’s development Figure 1F

21. End of Chapter 1 Essentials of Oceanography 7th Edition