The Oceans

2. The Oceans

3. The Earth is the only Planet in the Universe (that we know of) with liquid water on its surface!!!!!

4. The Oceans (quick facts) • 71% of the earth is covered by water • most is salty (about 97%) • Average depth – 14,000 feet (nearly 3 miles deep) • divided up into 4 sections • What are the 4 sections?

5. 4 Major Ocean Basins • Pacific Ocean – covers 30% of the planet Avg Depth – 13,740 ft Mariana Trench – 36,200 ft • Atlantic Ocean – 2nd largest, ½ the size of Pacific Avg Depth – 12,254 ft Puerto Rico Trench – 28,374

6. 4 Major Ocean Basins • Indian Ocean – 3rd largest Avg Depth – 12,740 ft Java Trench – 25,344 ft • Arctic Ocean – smallest and often ice covered Avg Depth - 3,047 ft Eurasian Basin – 17,881 ft

7. How did the oceans form? • 4 billion years ago • water vapor from volcanoes on Earth and comets from space • condensed, fell as rain, filling the ocean basins

8. Oceanography • Oceanography – the scientific study of the oceans. • Ocean depth • Currents • Temperature • Water density • Salinity (saltiness) • Waves • Life Forms

9. How did we figure out how deep the oceans are? • Bathymetry – using tools to determine ocean floor topography (changes in elevation) • 3 ways: • 1) Lead Line Survey • 2) Sonar • 3) Satellites

10. Bathymetry (underwater topography) • 1st measured using a lead weight and rope

11. Bathymetry (underwater topography) • Sonar – sound waves sent through the water until they reach the sea floor. The time it takes for the noise to return and be detected relates to the distance • D = ½ t*v • D= depth • T = time • V = 1.500 m/s

12. Bathymetry (underwater topography) • Satellites – (Seasat and Geosat) send signals that are bounced off the ocean surface and slight differences in water height are measured. Based on small differences in the pull of gravity, images are created that reflect the underwater features of an area.

13. Bathymetry Graphing using sonar data • Calculate the depth of the oceans • Graph the data on the other side of the paper • Use a partner to try to figure out what color to use for the ocean floor features – Use the textbook as a resource

14. Oceans are divided into 2 parts • Continental Margin – near the continents • Ocean Basin – deep ocean areas

15. Continental Margin • Continental Shelf – part of the continents that are under shallow water. Basically flat areas that extend outward from a few up to an average of 300km

16. Continental Margin • Continental Slope – begins at edge of shelf. Very steep area where water depth increases rapidly and change to oceanic crust occurs. May contain submarine canyons (huge cut into the slope from the motions of rivers

17. Continental Margin • Continental Rise – gently sloping region between the slope and oceanic basin. Composed of deposits of sediments that originated from the motions of rivers

18. Oceanic Basin • Abyssal Plain – beginning at the end of the continental rise, flattest area on Earth, found at or about 4,500 m in depth and made of spread out sediments

19. Oceanic Basin • Abyssal Hills - raised areas extending outward from the mid-ocean ridges. Can be totally covered by sediments in many places

20. Oceanic Basin • Mid-Ocean Ridge – underwater mountain range that forms at divergent plate boundaries and runs a total of 80,000km over the entire earth

21. Ocean Basin • Seamounts – cone shaped volcanic mountains rising from the sea floor from hot spots or diverging plates. If rise to water’s surface an island is formed. Often these islands have their tops eroded by waves. Guyots – underwater seamounts with their tops cut off (plateau)

22. Ocean Basin • Trenches – deepest spots in the ocean. From wherever two plates converge and subduct

23. Ocean Water • WHAT IS SALT WATER? • 96.5% H2O and 3.5% dissolved minerals (75 different elements) • sodium chloride • magnesium chloride • calcium sulfate • Some rare metals such as gold and uranium

24. Ocean Water • WHERE DID THE SALT COME FROM? • 1) Each year the world’s rivers carry about 400 billion kg of solids into the ocean. • Most of the solids are salts that came from dissolved minerals on land

25. WHERE DID THE SALT COME FROM? • 2)Water also evaporates from the oceans , leaving salts behind to accumulate

26. WHERE DID THE SALT COME FROM? • Underwater volcanoes also add salts to the water

27. Ocean Water • The amount of dissolved salts has not changed over time due to the natural processes that remove salts from the water • For example: • Deposition of sediment • Plant and animal processes

28. SALINITY • FACTORS THAT AFFECT SALINITY • Salinity levels vary around the world • Equator = high evaporation = higher salinity • Poles = low evaporation = lower salinity • Rivers = added freshwater = lower salinity • Currents and depth impact salinity as well!

29. SALINITY • The measurement of the amount of salt dissolved in salt water • 1000 g of ocean water • 965 grams H2O • 35 grams of salt

31. Ocean Currents • 2 types of ocean currents: • 1) Surface Currents • 2) Deep Water Currents

32. Surface Currents ColdCurrents move away from the Poles Warm Currents move away from the Equator

33. Surface Currents • Water moves because of surface winds!!!!!!! • Shaped by the spinning of the Earth and the locations of the continents • Hot water at the equator moves toward the poles (western side of the ocean basins) • Cold water at the poles moves toward the equator (eastern side of the ocean basins)

34. Deep Water Currents • Caused by differences in density!!!!!!!!!!!!!!! • Cold Water at the poles sinks (more dense) to the bottom of the ocean, Hot water (less dense) at the equator moves across the surface –causing a slow movement of water • Polar water is the densest – extremely cold and salty due to freshwater ice forming

35. GLOBAL “CONVEYOR BELT”

36. GLOBAL “CONVEYOR BELT” • The 2 currents work together to completely circulate the waters of the ocean • Surface waters move from the equator to the poles, sinks and returns to the equator where it is eventually warmed again • Slow – takes 1,000 years to complete • Important for life on Earth as it recycles and redistributes heat, nutrients, and oxygen.

37. Surface Currents

39. ECOSYSTEMS: 3/10

40. 1.1 WHAT IS ECOLOGY? • Ecology is the study of how organisms interact with one another and with their physical environment

41. 1.1 What is ecology? • Structure of life--- • Atoms • Macromolecules • Genes • Chromosomes • Nucleus • Cell • Organism (species) Smallest Largest

42. 1.1 What is ecology? • Macromolecules – large and complex organic compounds • 4 major macromolecules: • 1) Complex Carbohydrates (glucose) • 2) Proteins (amino acids) • 3) Nucleic Acids (nucleotides) • 4) Lipids (fats and oils)

43. 1.1 What is ecology? • Genes – sequences of nucleotides that contain the genetic information for making specific proteins • Chromosome – single DNA molecule together with a number of proteins which contains thousands of genes

44. 1.1 What is ecology? • Cells are the basic units of life!!!!!!! • Cell Theory = all living things are composed of cells • Cells – smallest, most fundamental structural and functional units in life

45. 1.1 What is ecology? • Species – similar organisms that generally resemble one another in their appearance, behavior, chemistry, and genetic make up… and can produce fertile offspring • We have identified 1.8 million species – mostly insects • May be somewhere between 4 and 100 million species (10 -14 million best guess)

46. 1.1 What is ecology? • ECOLOGISTS STUDY CONNECTIONS IN NATURE! Levels of Organization in Ecology: • Biosphere • Ecosystem • Community • Population • Organism -------------------- • Cell • Nucleus • Chromosomes • Genes • Macromolecule • Atom Largest smallest

47. Organism-

48. Population • Population - # of a particular species in a particular place

49. Community • Community – all the populations of all the species living in a particular area

50. Ecosystem • Ecosystem – all the living and non-living things in a particular area