SCM 330 Ocean Discovery through Technology

1. SCM 330 Ocean Discovery through Technology Area F GE

2. Ocean Discovery Goal: Provide a background of the history of Ocean Discovery and the Technological Advances that got us to where we are today.

3. Prehistoric Oceanography • Paleolithic humans developed barbed spears and harpoons • Neolithic humans used bone • fishhooks and nets • Copper fishhooks appeared • around 5000 BC • Hunter-gatherers along the • seashore and shallow • Waters • Sailing Vessels in Egypt as • far back as 4000 BC • Phoenicians trading across • the Mediterranean Sea as • early as 1500 BC

4. Ocean Discovery • The ocean was a barrier and a pathway in the spread of humanity. Technology and knowledge required for voyaging led to scientific understanding. • The convention of latitude and longitude. Shape of the earth and commonly used map projections. • Two approaches: mathematic (e.g. Greeks) and observational (e.g. Polynesians). • Key problems: determination of bearing & latitude, charting.

5. Three Major Stages Ocean Discovery • Exploration, Boundaries Needed Navigation Skills 2) Scientific, Describe Once Observations were made, formulated questions… 3) Modern Oceanography Development of a discipline and tools for discovery

6. Ancient Period • Greeks thought Thalassa (Mediterranean Sea) was surrounded by land, which in turn was surrounded by a great encircling river called Oceanus. • Eratosthenes (Egyptian, 200 BC) made first known calculation of Earth’s circumference: 40,000 km (24,840 mi), which is close to the actual circumference of 40,032 km (24,860 mi). • Strabo (Roman, 25 BC) observed volcanic activity and concluded that land periodically sank and rose, causing the ocean to cover land and then recede again. Herodotus 450 BC

7. Greek and Roman Science • The first World Map • Created by Ptolemy (c. 150 AD) • Included Europe, Asia and Africa • Used latitude and longitude lines for reference • Error in assumption of circumference • Used 29,000 km instead of 40,000 km Greek Trading Ship ca. 500 BC

8. Migration in Oceania Ancestors of Polynesians spread from southeast Asia to New Guinea and Philippines about 20,000 years ago Mid-Pacific Islands have been colonized for about 2,500 years Fiji, Tonga - 1140 BC Marquesas - 30 BC Easter - 400 AD Hawaii - 500 AD Two schools of thought about migration paths: (1) from the west (Asia) or (2) from the east (South America)

9. Ship design/fabrication limited by lack of metal. • Population growth on islands necessitated dispersion. • Superb navigation based on acute observation. Navigated using only knowledge of wind, current and weather patterns.

10. Middle Ages After Ptolemy, intellectual and scientific thought declined for about 1000 years (the Dark Ages) Cosmas, 6th century

11. Vikings came from Scandinavian countries where wood and iron was plentiful. • Their ship building technology and seafaring skills were much more advanced than in the rest of Europe. • The ships lacked a central rudder and could only sail with the wind.

12. Warming trend in 9th century allowed Vikings to sail west • Vikings explored North Atlantic near end of first millennium • Purpose was to conquer new lands • Failed to establish cultural dominance.

13. Chinese Contributions • Chinese navigators became more skilled and vessels became larger and more seaworthy, allowing long, distant voyages. The Chinese Explorer Zheng He made a series of expeditions 1403-1433. • Innovations include multiple compartments and a central rudder. Also developed the magnetic compass, later used by European explorers • Controversially, he might even have reached N. America (see G. Menzies). • The end of this effort seems to have been a deliberate political decision.

14. European Exploration • Age of discovery – started 1487 • Spain and Portugal lead exploration • Diaz – reached the Cape of Good Hope (Africa) – 1488 • DeGama – around Africa – 1498 • Columbus – tried to get western route to the East – 1492 • Magellan – 1st circumnavigation of the world • England • Cabot – traveled to North America – 1497 • England became the most active voyagers after this period of exploration

15. Cartography • Henry the navigator established an institute for exploration and cartography • By the 1650, cartography had become a true science—capable of prediction. Waldseemullermap (1507)

16. Ferdinand Magellan (ca. 1480-1522) Started with flotilla of 5 ships HMS Victoria was the only ship to return to Spain Only 18 of the original crew of 260 survived the voyage

17. Robert Boyle (1627-1691) Studied relation of: water temperature, salt content (salinity) and pressure to the water depth Father of Chemical Oceanography

18. Sir Isaac Newton (1642-1727) First to correctly explain tidal forces

19. Longitude was a major problem of the 1700’s • Although the shape of the world was reasonably well known, mariners could not calculate their longitude. • The British government offered a huge prize (£20,000) for a solution in 1714. • The prize was claimed in 1760 by John Harrison, who invented the modern timepiece.

20. Definition of Latitude & Longitude • Take any point on the globe and imagine a line from there to the center of the earth. By definition, this point lies on a meridian. • There are two angles that can be measured with respect to this line. • Longitude is the east or west separation from an arbitrary origin (0°) • Latitude is the north or south separation along the meridian compared to the equator.

21. Latitude vs. Sun’s Altitude Angle To see how latitude is related to the Sun’s altitude angle, consider the simplest case where the Sun is directly above the equator. This occurs only on the dates of the Spring and Fall Equinox. Latitude = (90 – Sun’s Altitude)

23. Using a Sextant to Find Latitude Sometime about plus or minus 30 minutes of 12 o’clock noon in your time zone, the sun will reach its highest point in the sky and will be directly south of you. This time is called local apparent noon or the meridian crossing. It is when the sun crosses your local meridian of longitude. a =Sun’s Altitude (angle)

24. Using Time to Find Longitude 360 degrees in 24 hours = 15 degrees/hour Longitude = 15 x (Greenwich Noon – Local Apparent Noon)

25. Constructed between 1730 and 1735, H1 is essentially a portable version of Harrison's precision wooden clocks. It is spring-driven and only runs for one day (the wooden clocks run for eight days). The moving parts are controlled and counterbalanced by springs so that, unlike a pendulum clock, H1 is independent of the direction of gravity.

26. Larger and heavier than H1, H2 is of fundamentally the same design as H1. Harrison began work on H2 in 1737 but in 1740 realized its design was wrong. The bar balances did not always counter the motion of a ship, a deficiency that could be corrected if the balances were circular. Harrison requested more money to work on a third timekeeper...

27. H3 incorporated two inventions of Harrison's; a bimetallic strip, to compensate the balance spring for the effects of changes in temperature, and the caged roller bearing, the ultimate version of his anti-friction devices.

28. H4 is completely different from the other three timekeepers. Just 13 cm in diameter and weighing 1.45 kg, it looks like a very large pocket watch. Harrison's son William set sail for the West Indies, with H4, aboard the ship Deptford on 18 November 1761. They arrived in Jamaica on 19 January 1762, where the watch was found to be only 5.1 seconds slow! It was a remarkable achievement but it would be some time before the Board of Longitude was sufficiently satisfied to award Harrison the prize.

29. James Cook (1768 – 1779) – three large scale naval voyages First,aboard HMS Endeavour - Charted New Zealand & Eastern Australia. Second,HMS Adventure & Resolution - Circumnavigated globe at 60o S lat., ‘proving’ there was no “Southern Continent.” Third, Discovered many Pacific Islands (including the Hawaiian). First to sail both north and south polar seas.

30. English Admiralty wanted to discover Antarctica, other lands to claim • Mapping, soundings for water depth, winds, currents, temperature • He was part of a 200+ year effort to chart the ocean for trade and military voyaging. Cook killed in Hawaii 1779 Hawaiians thought he was God Lono, but figured out he wasn’t

31. Franklin’s chart of the Gulf Stream (1777) was the first true map of a current. (1706-1790)

32. Charles Darwin (1809-1882) • Student at Cambridge - wanted to become a minister • Unpaid naturalist and “dinner companion” on board HMS Beagle for 4.5 yr – 1831-1836 • Sampled organisms from the land and sea • Observations of corals • His theory of atoll formation (1842) is still accepted • Published On the Origin of a Species 20 years later (1859)

33. Polar Region Explorers: Sir James Ross (1800-1862) (Antarctic) and his Uncle, Sir John Ross (Arctic) Samples of Bottom Dwelling Life

34. Fridjof Nansen wanted to test his ideas about the direction of ice drift in the Arctic Ocean by freezing a vessel into the ice pack and drifting with it to reach the North Pole • Also famous for inventing the Nansen bottle/sled • Fram (to push forward) was specially-built for the trip • 38 m (123 ft) wooden ship with planks 1.2 m (4 ft) thick w/ smoothly-rounded hull Fram Nansen Fram’s drift across Arctic ice pack (1893-1895)

35. Matthew Fontaine Maury (1806-1873) • First Oceanographer • Purpose was to get better charts for navigation • 1st wind and current charts of N. Atlantic • Wrote 1st ocean textbook – “Physical Geography of the Sea”

36. Edward Forbes (1815 - 1859) Maintained the ocean was lifeless at depths greater than 550m (1750 ft).

37. Beginning of Modern Ocean Science • Controversy in oceanography • Edward Forbes believed that marine life did not exist at deep water depths • Progressive decrease in abundance with depth • Sir John Ross and Sir John James Clark Ross collected animals from the ocean floor at 1800 m water depth and thought Forbes wrong Debate resulted in public interest of large scale voyages for scientific study HMS Challenger expedition

38. Challenger Expedition 1872 - 1876 • Charles Wyville Thomson directed the cruise • A primary goal of the cruise was to resolve the controversy over life in the abyss of the oceans • Royal Society of London sponsored the voyage and wanted measures of: • The chemical composition of seawater • The distribution of life forms at all depths • Coastal and ocean currents • The sedimentary deposits blanketing the seafloor • Accomplishments: • More than 360 deep--sea soundings (Marianas Trench, 8185 m) • Hundreds of deep-sea dredgings (bottom samples) • Trawls and water temperature profiles • Nearly 5000 new species discovered • First comprehensive survey of ocean salinity and depths • Found sea-life as deep as 9 kilometers (5.6 mi) • Findings published in 50 volumes

40. Institutions established to advance oceanography Museé Oceanographique Monaco (~1900) Scripps Institution of Oceanography University of California San Diego (1903) Woods Hole Oceanographic Institution Massachusetts Institute of Technology (1930)

41. Voyage of the German Meteor (1925-27) • Studied the South Atlantic Ocean • Led by George Wüst • Model for four-layer circulation of Atlantic Ocean • Used acoustic depth sounders for detailed maps

42. Early Bathysphere designed by (Charles) William Beebe, 1934

43. Effect of World Wars on Oceanography • Battles at sea required information on transmission of sound, bathymetry, waves, currents. • Underwater Sound – Hydrophone (1914) • Sonar developed (1934) • Echosounders further developed – used to increase efficiency of bathymetry collection • Need to know Salinity and Temperature • Submarines developed the need to recover • them. • Weather Forecasts and effects on ocean • Tides

44. Trieste, deepest diving submersible

45. 1963 - USS TRESHER sunk 1968 - USS SCORPION sunk The Navy realized that the DSRVs would only be useful if the damaged submarine does not sink and will not be destroyed by the pressure of the water. But 77% of the ocean are too deep and so the Navy decided to purchase only two DSRVs.1970 the first of the two DSRVs was launched

46. Advances in technology • Human submergence to deep water • Deep diving • William Beebe descends to 923m in 1934 • Trieste - descended to bottom of Mariana Trench (1960) • DSRV Alvin currently used

47. R/V FLIP R/V Knorr Drilling Vessel JOIDES Resolution (ODP-IODP)

48. Modern Oceanography • In the 20th century, study of the oceans has been driven by: • Technical Needs: military • Navigation: study winds and currents to improve safety • Economic: fisheries, oil, and minerals • Academic: • Fundamental interests in how the ocean works • Models of ocean circulation • Global budgets • Anthropogenic Effects

49. Modern Oceanography Gov’t interest in oceanography developed from its importance during WWII. Development of Agencies 1940-1970. • Office of Naval Research (ONR) • National Oceanographic and Atmospheric Adminsitration (NOAA) • National Science Foundation Ocean Sciences program • Offshore Drilling Program (formerly DSDP, now IODP)

50. Multidisciplinary Programs • As the questions oceanographers ask become more complex and the scope of the answers become ever broader, single institutions or individuals can no longer provide enough resources to find solutions. Likewise, problems often involve many disciplines, e.g. chemistry, physical science, & biology. • Examples include: • GLOBEC (Global Ocean Ecosystems Dynamics) • JGOFS (Joint Global Ocean Flux Study) • RIDGE (Ridge Interdisciplinary Global Experiment) • Future programs include Ocean Observation Program, Office of Ocean Exploration.