A. Ocean Exploration

1. A. Ocean Exploration

3. 1. Vocabulary • Fathom: Six feet down in depth. 1 fathom = 6 feet • Nautical mile: 6,076 feet across the ocean surface.

4. Oceanography: The scientific study of the ocean using chemistry, biology, physics, geology and other sciences

5. 2. Matthew Maury US Naval officer who was the father of modern oceanography.

6. 3. H.M.S. Challenger • 1872- The first large-scale ocean research project • Onboard lab to measure ocean depths, take water samples record temperatures and study currents.

7. Note the name of the chief Scientist in your notes

9. 4. World War II • Big advances in oceanography • Submarines • Surface ships- More accurate ocean charts • Sonar • Magnetic recorders

10. Bathysphere:a strong steeldiving sphere/Deep sea Diving suits

11. sonar

12. 5. Modern Ocean Research • Research vessels • Deep-sea corers- JOIDES Resolution • Alvin: Mini-sub that has explored deep-sea trenches, vents and the Titanic • Argo: Robotic sled that has lights and cameras • Buoys: collect data

14. Alvin

15. Sediment Sampling • Core sampling is used to look at seafloor sediments • Cores can remain intact and easy to study layers • Dredging- scooping up sediment to study

16. Core Samples

17. SONAR-Echo sounding • Depth recorder sends out sound waves that travel to the ocean floor and return • The time is recorded and used to find distance • Intensity of reflected beam can determine sea floor composition and shape of objects. • D= S x t

19. Satellite Observations • Echo sounding is a very slow method of mapping ocean floor • Satellites provide a better range and speed to mapping. • Satellites look for variations in surface elevations to make maps

20. B. Salinity of Ocean Water (pgs. 76-78) Salinity-measure of the amount of dissolved salt contained in water

21. B. Salinity of Ocean water • Average 35 parts salt dissolved per thousand parts water(35/1000) NaCl, MgCl and MgS most common salts • Salt sources could be from wave action, volcanic action or erosion of glaciers and rivers • About 85 elements found in the ocean • The amount of salt present determines density (high salinity-more dense)

22. 5. Variations in Salinity • Location • How much fresh water is present (low where there is a lot) • Rate of evaporation/ freezing-faster is higher salinity

23. C. Gases in Ocean Water • The same gases found in air are dissolved in ocean water • Nitrogen, oxygen, carbon dioxide • Ocean animals take in oxygen and give off carbon dioxide • Plants use carbon dioxide and release oxygen THIS YOU SHOULD ALREADY KNOW

24. D. Ocean Temperatures • Surface (top)- Warmest layer and varies with location and season. Less dense • Thermocline (middle)- Area of rapid temperature change with depth. Warm and cold do not mix well here • Deep Water (bottom)- Coldest layer. Denser water. Polar water found in all water in all latitudes except for Mediterranean Sea. ***The polar regions of the world do not have these zones

25. E. Ocean Features (text 80-82) If we look at the ocean, we see miles and miles of water. However, if we were to look under the water, we would see many features that are similar to those found on land. There are two major areas of the ocean.

26. 1. ContinentalMargin-where the underwater edge of the continent meets the ocean floor • Shoreline-where land and ocean meet • Continental Shelf- Shallow depth. Flat . Many resources found here (oil & gas) • Continental slope- Water depth increases. Land drops. Boundary between oceanic and continental crust • Continental rise- Accumulation of sediment at the bottom of Continental slope.

28. d. Submarine Canyons • Large underwater valleys that have resulted from mudslides from the continent. • Some line up with rivers and some do not • Turbidity currents are also responsible for making the canyons.

29. Submarine canyons

30. Continental Margins • Active (earthquakes, volcanoes): West coast of U.S. • Passive: East Coast of the U.S.

32. 2. Deep Ocean Basin • Abyssal Plains: Flat areas of ocean floor; Larger in the Atlantic and Indian Ocean. The Pacific ocean has many deep cracks that trap sediments like mud, sand and ooze (remains of organisms) • Ocean trench-long, narrow, steep-sided clefts or troughs (volcanic and earthquake activity) • Mariana trench is deepest in world

33. c. Mid-Ocean Ridges-greatundersea mountain ranges. Vents or underwater geysers found near these d. Seamount- cone shaped mountain peaks. Lot in Pacific where volcanoes hot spots are **Guyots- Seamounts with tops sliced off by wave action and sinking of ocean crust. e. Volcanic Mountains-underwater volcanoes tall enough to reach the surface of the water

34. Mid-Ocean Ridge and fracture zones

35. Seamounts

37. Reefs • Occur in tropical waters near the continental shelf • Coral reefs • Masses/ridges of limestone rocks • Contain the shells of animals • 3 types • Fringe reefs (Y)-touchthe shore of volcanic islands (letter C-already sinking) • Barrierreefs(Z)-separated from shore by a lagoon. Island (F) is eroding and sinking • Atoll (X)-surrounds a sunken island (X above)and forms a • A lagoon (A, E) is water surrounded or trapped by reefs