A History of Marine Science

Transcription

1 Oceanography, An Invitation to Marine Science 9e Tom Garrison 2 A History of Marine Science

2 What is Marine Science? Marine science is a broad field that covers the link between oceanography and marine biology. Marine scientists study everything from the physics of ocean currents to the communication behavior in marine mammals. (bkgd)comstock Images/PictureQuest

3 What is Marine Science? Marine biologists study the organisms that inhabit the sea including all water that has some degree of salinity, like the estuaries at river mouths. Oceanographers mainly study the physical (non-living) aspects of the ocean, including tides, currents, waves, and the chemical make-up of seawater. (bkgd)comstock Images/PictureQuest

4 Why Study Marine Science? 1. Since life is believed to have arisen in the sea, studying marine life can provide clues about early life on Earth. 2. Many products come from the sea including food resources, medicines derived from marine species, and other items for human use. 3. Marine organisms produce oxygen used by all kinds of organisms, including humans. (bkgd)comstock Images/PictureQuest

5 Why Study Marine Science? 4. The marine environment provides recreation and supports tourism worldwide. 5. The oceans help regulate climate. Water is slow to change in temperature, which keeps coastal land masses more stable year-round. (bkgd)comstock Images/PictureQuest

6 Evidence suggests that humans have been using the sea since early times. Clam shells, which are approximately 165,000 years old, have been discovered in a cave previously inhabited by humans in South Africa. Shell harpoons and fishhooks that are estimated to be 110,000 years old also have been found. History of Marine Science

7 Key Concepts The ocean did not prevent the spread of humanity Any coastal cultures skilled at raft building or small boat navigation had economic and nutritional advantages over less skilled competitors

8 Ancient Uses and Explorations Prehistory and the Rise of Seafaring When was the first sea voyage in a ship? No one knows although several cultures have similar stories of a worldwide flood and a large boat full of animals, the existence of the Ark (4000 B.C.) is widely debated. Therefore, the earliest recorded sea voyage seems to have taken place around 3200 B.C. by the Egyptians.

9 Ancient Phoenician Explorations and Discoveries Early peoples traveled the ocean for economic reasons. Phoenicia was an ancient civilization centered in the north of ancient Canaan. Phoenician civilization was an enterprising maritime trading culture that spread across the Mediterranean during the first millennium BC, between the period of 1200 BC to 900 BC.

10 Ancient Phoenician Explorations and Discoveries The ancient Phoenicians were among the most important early Western seafarers. Traveled great distances for their day. Established the first trade routes throughout the Mediterranean and as far north as Great Britain. They steered at night by observing the constellations and the north star (Polaris, 430 l.y.a.) in the ancient world, the north star was called the Phoenician Star. This is one of the earliest references to using the North Star for navigation.

11 Ancient Polynesian Explorations and Discoveries Polynesian seafaring is the earliest known regular, long distance, open ocean seafaring beyond sight of land. It s estimated that it took more than 1000 years for the area to be fully settled. But had been so for hundreds of years when the first Europeans arrived.

12 Ancient Greek Explorations and Discoveries Ancient Greeks first used mathematical principles and sophisticated maps for seafaring. By applying their advancements in early science and mathematics, this culture contributed to understanding the oceans in many ways. Although western civilization would lose the knowledge during the Middle Ages, the Greeks knew that the world was a sphere and not flat.

13 Ancient Greek Explorations and Discoveries The Greek Pytheas noted that he could predict the tides in the Atlantic based on the phases of the moon. About 150 years later, Eratosthenes ( B.C.) calculated the Earth s circumference and invented the first latitude/longitude system a system of imaginary lines on the Earth, used for navigation and mapping. Hipparchus invented a better system the one used today later.

14 Erastosthenes s method for calculating circumference of Earth Used simple geometric reasoning based on the assumptions that Earth is spherical and that the sun is very far away. Using this method, he was able to calculate the circumference to within about 8% of its true value. This knowledge was available more than 1,700 years before Columbus began his voyages.

15 The Latitude/Longitude System One of the Greeks primary contributions to oceanography and seafaring is the latitude/longitude system. Latitude lines run east-west and longitude lines run northsouth. Because they run around the sphere of the Earth, they are numbered in degrees. For further accuracy, degrees are numbered into 60 minutes and minutes into 60 seconds like time.

16 Prime Meridian and Equator Longitude lines begin at one pole and end at the other. Sometimes called meridians, the 0⁰ meridian runs through the Royal Naval Observatory in Greenwich, England. This is called the Prime Meridian. Directly on the other side of the world is the 180⁰ meridian. North Pole Latitude 60 N 30 N North Pole Prime meridien North Pole 60 N 30 N Equator 0 30 S 60 W Longitude 0 60 W 30 W 0 30 E 0 30 S South Pole South Pole South Pole

17 Where We Are: Latitude and Longitude

18 2.1 Understanding the Ocean Began with Voyaging for Trade and Exploration Early peoples traveled the ocean for economic reasons The first cartographers (chart makers) came from the Mediterranean Systematic study of the ocean began at the Library of Alexandria

19 Ancient Greek Explorations and Discoveries Evolution of ancient maps of the known world

20 The European Middle Ages The period of about 500 A.D. to 1500 in Europe is called the Middle Ages (Also known as the dark ages because Europe entered an age of intellectual darkness.) Middle Ages map of the know world based on descriptions in the bible. Except for the Viking Voyages, there was little ocean exploration by Europeans during this period.

21 Viking Explorations and Discoveries The Viking period stretches from about 790 A.D. to During this period Vikings raided nearby land, explored, and established trade routes throughout Britain, Ireland, Southern Europe, Northern Africa, and Asia. This was the only significant exploration taking place in Europe during this period. Viking raiders discovered North America

22 Chinese Explorations and Discoveries Although science and exploration lay idle in Europe during the Middle Ages, that wasn t the case in China. The first global exploratory expeditions were undertaken by Chinese admiral Zheng He beginning in 1405 Skilled navigators with important contributions in that era, the Chinese were responsible for inventing the magnetic compass. Shipbuilding: central rudders and watertight compartments.

23 The Age of European Discovery Prince Henry the Navigator of Portugal Established a center for marine science and navigation Christopher Columbus Discovered the New World Ferdinand Magellan Circumnavigated the globe Portugal ROCKED!

24 Exploration of the New World In 1492, Portuguese Christopher Columbus set out on the first of his four famous voyages. As others..the purpose was to find a route to Asia and the East Indies. Because he was using Ptolemy s estimation of the Earth s size (which was too small) He thought he d reach Asia when he landed on a Caribbean Island. NEVER actually landed in America

25 Ferdinand Magellan, a Portuguese Explorer In service to Spain, Magellan s expedition was first to circumnavigate the world. Magellan himself did not survive the voyage; only 18 out of 260 sailors managed to return after 3 years of dangerous travel.

26 Magellan s and Drake s around the world voyage of discovery

27 The Birth of Marine Science ( ) As Britain began to compete with France and Spain for Global conquest, they realized that the more they knew about the seas and the world, the better. The Royal Navy launched voyages with the objectives of exploration, mapping, and projecting British presence around the world. The crew often included scientists and naturalists.

28 Cook s Expeditions The Voyages of Captain James Cook and his crew, which included naturalists, sailed around the world beginning in first expeditions devoted to scientific oceanography. A major contribution to Cook s voyages was the invention of the chronometer clock or watch that wasn t affected by the waves and motion of the sea. One of his missions was to map the path of Venus between Earth and the Sun to calculate the distance between the Earth and the Sun. Although he never found Antarctica, they were the first Europeans to view the Antarctic ice fields, and land on Hawai i, Tahiti, and many other Pacific islands and that was his downfall. He was considered an oceanographer, anthropologist and naturalist. His crew did extensive mapping and brought back many specimens.

29 Cook s Expeditions

30 Darwin and the HMS Beagle Charles Darwin-Sailed on the HMS Beagle from as a naturalist While the primary goal of the expedition was to map coastlines, Darwin observed, collected, and wrote detailed written descriptions of the organisms he observed. His observations led him to formulate his principle of natural selection and evolution. In addition to his work in the Galapagos and the rest of his five year voyage, Darwin also contributed to modern day marine science. Darwin hypothesized that the massive coral reefs they saw could only result when the seafloor slowly sinks, accepted by most scientist today.

31 United States Exploring Expedition One of the most important scientific expeditions launched by the US was the US Exploring Expedition also referred to as the Wilkes Expedition after its commander, Charles Wilkes. Lt. Charles Wilkes Commanded a United States exploratory expedition from that laid the foundation for government spending of scientific research. They collected numerous biological specimens. In addition to surveying many parts of North and South America, they found the elusive southern continent Antarctica.

32 United States Exploring Expedition Around the same time, US Naval officer Mathew Maury who was among the first to envision a worldwide pattern for surface winds and currents produced instructions for making long distance sailing more efficient by working with the prevailing currents and winds. Also, his systems for recording oceanographic data from vessels was adopted worldwide.

33 History of Marine Science Edward Forbes Extensively studied the seafloor around the British Isles, Aegean Sea, and other locations in 1840s and 1850s He discovered that species on the seafloor vary greatly depending on depth, a fundamental principle of marine biology. (bkgd)comstock Images/PictureQuest

34 The Challenger Expedition 1872 Prompted by Charles Wyville Thomson, led by Captain George Nares Recognized as the only expedition to date that was solely devoted to marine science. First major exploration devoted to the study of marine life Challenger s contributions to oceanography and marine science were great. From over 4,700 new species species previously undescribed to new habitats not previously thought to hold life. The crew published 50 volumes of information from the data collected over the next 19 years.

35 Challenger Expedition (bkgd)comstock Images/PictureQuest

36 The Challenger Expedition

37 The Oceanography Explosion Too many to list, the great increase in the exploration of oceanography and marine science in general stemmed in large part from the industrial revolution with the evolution of scientific and technological advancements. Three expeditions stand out though

38 German Meteor Expedition, Atlantis, and HMS Challenger II One of the first modern research cruises, the Meteor s main accomplishment was the mapping of the Atlantic seafloor with echo-sounding technology. In 1931, the US launched the Atlantis. The significance of the Atlantis is that she was the first ship specifically designed and built for ocean studies. In 1951, the HMS Challenger II began a two year voyage to measure the depths of the ocean. Its greatest discovery was the deepest known point on Earth located at the Mariana Trench discovered by the 1 st Challenger. The deepest spot was named Challenger deep after the 1 st vessel.

39 Advances in Technologies

40 Voyaging Combined with Science to Advance Ocean Studies Captain James Cook first marine scientist First scientific sea voyage HMS Endeavour

41 Advances in Accurate Mapping An accurate determination of longitude was key to oceanic exploration and mapping Astrolabe-uses Phoenician (North) Star Early European explorers used the stars

42 Advances in Accurate Mapping Need an accurate chronometer (clock) for use in day time Invented by John Harrison (1759) Crucial to the accurate determination of longitude (or east-west direction from a given meridian on the globe. Latitude could be easily established by measuring the height of the sun (or stars above the horizon) with the aid of a good sextant. HMS Beagle Marine chronometer

43 The First Scientific Expeditions Were Undertaken by Governments Matthew Maury discovered worldwide patterns of wind and ocean currents Built on the work of Benjamin Franklin The Challenger expedition Inspired by Charles Darwin s Beagle voyage First oceanography

44 The Challenger Expedition HMS Challenger s track from December 1872 to May The Challenger Expedition remains the longest continuous oceanographic survey on record.

45 Ocean Studies Have Military Applications Sea power military capacity on the ocean Greeks defeat the Persian fleet (480 BCE) Brittish Admiral Horatio Nelson defeats France in 1805 Alfred Thayer Mahan American Naval officer-the Influence of Sea Power Upon History, Rise and fall of Nation States, influenced many countries

46 Contemporary Oceanography Makes Use of Modern Technology Polar exploration Fridtjof Nansen allowed his ship to be trapped in Arctic ice and drift for four years 1958 first submarine sailed beneath the North Pole New ships for new tasks Meteor expedition used modern optical and electronic equipment Echo sounder

47 Echo Sounders Echo sounders sense the contour of the seafloor by beaming sound waves to the bottom and measuring the time required for the sound waves to bounce back to the ship. If the round-trip travel time and wave velocity are known, distance to the bottom can be calculated

48 Beam of sound waves travels to bottom and is reflected back to ship Depth = V ( T 2 ) Stepped Art Figure 2-28

49 Contemporary Oceanography Makes Use of Modern Technology Oceanographic institutions oversee complex research projects First founded in Monaco in 1906 In United States: Woods Hole Oceanographic Institution Scripps Institution of Oceanography NOAA National Oceanic and Atmospheric Administration

50 Robot Devices-Remotely operated vehicles As a hybrid ROV, Nereus can act autonomously or under guidance from human operators aboard ship or ashore. HROV Nereus in launch position. The deepestdiving vehicle now in use, Nereus can reach depths of 11,000 meters (36,000 feet).

51 Satellites for Exploration Seastat st oceanographic satellite 1992 TOPEX/Poseiden 835 miles above earth GPS-Positions within 1 cm Jason-I 2001 global climate