The Ocean...

1. The Last Frontier on Earth... The Ocean... Academic

2. Warm up… • Please read and complete the “Introduction: Ocean System” article and respond to the questions. • This is part of your NOTES for the conference material.

3. The study of everything about Earth's oceans and seas • Physical properties • Chemical properties • Origin • Geology • Life living things that reside there What is Oceanography?

4. Geographical Features: Bodies of Water. 100% Educational Videos. 2000. unitedstreaming. 2 March 2006 <http://www.unitedstreaming.com/>

5. An ocean is… • Large body of saltwater • Closely linked with atmosphere • An important factor in climate

6. A sea is… • A large body of water • Sometimes a part or area of the ocean • Usually surrounded by land

8. 71% of Earth’s surface is covered by water *Northern hemisphere is 61% ocean *Southern hemisphere is 80% ocean Pacific Atlantic Indian Arctic Southern

9. Ocean Area (sq. miles) Average Depth (ft) Deepest depth (ft) Pacific 64,186,000 15,215 Mariana Trench, 36,200 ft deep Atlantic 33,420,000 12,881 Puerto Rico Trench, 28,231 ft deep Indian 28,350,000 13,002 Java Trench, 25,344 ft deep Southern 7,848,300 13,100 - 16,400 Southern end of the South Sandwich Trench, 23,736 ft deep Arctic 5,106,000 3,953 Eurasia Basin, 17,881 ft deep

10. Maybe graph the ocean volumes for a warm up/exit ticket?

11. Ocean Formation Work with a partner to come up with a theory for how the oceans formed on Earth. Describe your hypothesis.

12. Was your theory correct? • Watch to review!

13. How did the oceans form? The "degassing" of the Earth... • As Earth cooled, volcanic gases were released • Around 4 billion years ago, Earth cooled enough so that water vapor condensed and fell as rain • Rain collected in • lowest places on Earth • Oceans formed

14. Then…Collisions of planetesimals and cometesimals • Small dust particles were left over from the formation of the solar system • These Contained water vapor • They collided with Earth during the early formation stages, releasing water

15. Oceans throughout history... • Oceans probably began as 1 large ocean; • Panthalassa • Plate tectonics separated continents • and created multiple oceans Photo from: http://www.orionsarm.com/worlds/Panthalassa.html

16. Oceans Today... • Rocks weathered and eroded by runoff • Rivers carry dissolved minerals to the ocean • Water evaporates and leaves solids behind • If the ocean's total salt content were dried, it would cover the continents to a depth of 5 ft. Photo from: http://ga.water.usgs.gov/edu/runoff.html

17. Video courtesy of: Our Wondrous Oceans: Oceans, The Cradle of Life. United Learning. 1995. unitedstreaming. 2 March 2006 <http://www.unitedstreaming.com/>

18. What is the function of the oceans? • Absorb and release energy • Regulate daytime and nighttime temperatures • Regulate temperature in different locations Example: the British Isles are warmed by the Gulf Stream current

19. Review – How did the oceans form?How is water added to the oceans? Discuss – What is the difference between something that is active vs. passive?

20. Ocean Floor Features:Using the terms at your desk and the textbook, try to match the geologic feature with the picture on the screen.Put them in number order.

21. Ocean Floor Features 1. 11. 2. 8. Rift Valley 9. 10. 3. 7. 4. 5. 6. 13. 12.

22. Ocean Features

23. QUESTION: Look at Map below; explain the difference you see between the Atlantic Coast and the Pacific Coast of the U.S. .

24. Now… On the back of your Ocean Features page, draw a diagram of an active margin and a diagram of a passive margin. Label all the parts and give examples of each.

25. Active Margins • Found mainly around the Pacific Ocean • Convergent plate boundaries • Thinner continental shelf • Continental slope drops abruptly into a deep-ocean trench • Some subduction zones have little or no accumulation of sediments

26. Active Continental Margin • Found on coastlines where plates are colliding (Convergent Boundaries)

27. Active Margins Continental shelf Continental slope Abyssal plain Trench Oceanic Crust Continental Crust

28. Deep Ocean Trenches • Deepest parts of ocean • Near Active Margins (subduction zones) • Mostly in the Pacific • Long, narrow features • Associated with volcanic activity • Volcanic islands arcs • Continental volcanic arcs

29. Passive Margins • Found along most coastal areas that surround the Atlantic Ocean • Not associated with plate boundaries • Experience little volcanism • Few earthquakes

30. Passive Continental Margins • Found along coastlines where there are no plates colliding (no plate boundary)

31. Passive Margin Continent Continental shelf Continental slope Continental rise Continental Crust Abyssal plain (piled up sediment) Oceanic Crust

34. The last frontier???? • We know very little about the ocean Science has started studying the ocean more in the last several decades

35. 4. Locate minerals 1. Determine fish habitats 5. Study and assess the global environment 6. Speed and safety for global shipping and communications Why? 7. Ship and sub navigation; accuracy for subs, airplanes and intercontinental missiles 2. Understand the seafloor and the factors that affect it 3. Solve the mystery of Earth’s formation

36. How? • "Drain the Ocean"

37. SONAR- Sound NAvigation And Ranging • Sound is transmitted and echoes off the ocean floor http://dosits.org/science/ssea/1a.htm

38. 2. Satellite Altimetry:satellites use radar to measure the distance to the sea surface color patterns show different depths http://www.ngdc.noaa.gov/mgg/bathymetry/predicted/explore.HTML

39. http://sealevel.jpl.nasa.gov/technology/technology.html

40. What does the shape of the sea surface tell us about the sea floor? • Earth’s gravity field piles up water over top of sea floor features • The ocean surface mimics the shape of the seafloor • The surface rises up 1 meter for every rise of 1000 meters on the floor

41. The Atlantic Ocean Profile

42. Now you try… • Map the contour of the Atlantic Ocean • Answer the questions

43. Ocean Water Characteristics • Water flows from land into the oceans and bring minerals • At the same time, water is evaporating and leaving the minerals behind

44. Salinity • The amount of dissolved solids in a given amount of liquid is called salinity • Measured in ppt (parts per thousand) • For example: 1000 grams of ocean water can be evaporated and leave 35 grams of solids behind

45. Effects of Climate & Movement • Some parts of the ocean are saltier than others • Coastal waters in places with hotter, drier climates typically have higher salinity.

46. Climate and Movement Affect Salinity • Heat increases evaporation rate • Evaporation = Salinity

47. Climate and Movement Affect Salinity • Some parts of the ocean move less than other parts • Slower moving areas of water develop higher salinity Movement Salinity

48. Temperature Zones • The temperature of ocean water decreases as depth increases • This change is NOT gradual • Water in the ocean can be divided into three layers by temperature • Water at the surface is much warmer than the average water temperature

49. Temperature Zones in the Ocean • Surface Zone- • Warm top layer of ocean water • 300 meters below sea level • Sunlight heats the top 100 meters • Surface currents mix heated water with cooler water below

50. Temperature Zones in the Ocean • Thermocline- • Second layer of ocean water • 300-700 meters below sea level • Temperature drops with increased depth faster than in the other two zones