Transcript Life on an Ocean Planet

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►The History of Oceanography – Why Study It?
►Ancient Uses and Explorations (5000 B.C. - 800 A.D.)
►The Middle Ages (800 A.D. - 1400)
►European Voyages of Discovery (1400 - 1700)
Chapter Topic Menu
►The Birth of Marine Science (1700 – 1900)
►Twentieth-Century Marine Science
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Why Study It?
 1. The history of oceanography is connected to the world’s
overall history.
 2. Oceanography’s past helps us understand why and how
people apply marine sciences today.
 3. It is interesting.
 The history of oceanography can be divided
into four stages:
Chapter 2 Pages 2-2 & 2-3
The History of Oceanography – Why Study It?
 Three very good reasons to learn the history
of oceanography:
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1. Ancient Uses and Explorations (5000 B.C. - 800 A.D.)
2. The Middle Ages (800 - 1400)
3. European Voyages of Discovery (1400 - 1700)
4. The Birth and Growth of Modern
Marine Science (1700 - present)
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Prehistory and the Rise of Seafaring
 1. To obtain food.
 2. To discover new lands.
 3. As a means of trade.
 The earliest recorded sea voyage appears
to be 3200 B.C. under the auspices of
Egyptian Pharaoh Snefru.
Ancient Phoenician
Explorations and Discoveries
Chapter 2 Pages 2-4 to 2-6
Ancient Uses and Explorations (5000 B.C. – 800 A.D.)
 Three primary reasons for early civilization
to interact with the ocean:
 The Phoenicians contributed to ocean
exploration by establishing the first trade
routes throughout the Mediterranean, even
as far north as Great Britain.
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 The significance of Polynesian seafaring
is that it is the earliest known regular,
long-distance, open-ocean sailing
beyond sight of land.
 Spreading eastward from Fiji,
Tonga, and Samoa, Polynesians
settled islands in an area of about
26 million square kilometers
(10 million square miles).
Chapter 2 Pages 2-7 & 2-8
Ancient Uses and Explorations (5000 B.C. – 800 A.D.)
Ancient Polynesian Explorations
and Discoveries
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
The Greeks used references on shore to navigate. This is
called piloting.
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As seafaring advanced they learned to use the sun,
constellations, the North Star and sea conditions to navigate
in the open ocean.
The Greeks knew the Earth was a sphere, not flat.
Pytheas (314 B.C.) noted that he could predict tides in
the Atlantic based on the phases of the moon.
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Chapter 2 Pages 2-8 & 2-9
Ancient Uses and Explorations (5000 B.C. – 800 A.D.)
Ancient Greek Explorations
and Discoveries
He could determine how far North or South one was from the
North Star by measuring the angle between the horizon and
the North Star. This was a significant improvement
in navigation.
Eratosthenes (264-194 B.C.) is credited with two
contributions:
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1. He calculated the Earth’s circumference.
2. He invented the first latitude/longitude system.
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Chapter 2 Pages 2-9 & 2-10
Ancient Uses and Explorations (5000 B.C. – 800 A.D.)
The Greeks Excelled at Mapmaking
 In 127 B.C., Hipparchus improved Eratosthenes’ maps
by inventing the regular grid system.
 In 450 B.C., Herodotus published a detailed history of
Greece’s struggles with the Persian Empire. This work
was significant because it was one of the earliest published
maps of the world the Greeks knew.
 In 63 B.C.-24 A.D., Strabo published a 17-book work
called Geographic that contained a map expanding
knowledge/accuracy about the world.
 In c. 100-168 A.D., Ptolemy developed the first known
map to show a portion of the Earth as a sphere on
flat paper.
 It showed latitude/longitude by dividing the grid into
degrees, minutes, and seconds of the arc.
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 The purpose of the latitude and longitude mapping system
is to identify specific locations on the Earth’s surface.
 Latitude Lines
 Also called parallels
 Run east-west
 0º parallel is also called the equator
 Longitude Lines
 Also called meridians
 Run north-south
 Prime Meridian is located on the longitude of
the Royal Naval Observatory in Greenwich, England.
Chapter 2 Pages 2-12 & 2-13
Ancient Uses and Explorations (5000 B.C. – 800 A.D.)
Latitude/Longitude System
 Further Accuracy
 Degrees are subdivided into 60 minutes, minutes are
subdivided into 60 seconds.
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The European Middle Ages
 Also known as the Dark Ages because during this time further advancements in
the knowledge of geography and science were suppressed in Europe.
 Little ocean exploration by Europeans was made, only trade continued.
 The Vikings were the only people with significant exploration taking place in
Europe during the Dark Ages:
Chapter 2 Pages 2-16 & 2-17
The Middle Ages (800 A.D. – 1400)
Viking Explorations and Discoveries
 They established trade routes throughout Britain, Ireland, Southern Europe, North
Africa, and Central Asia.
 In the 9th century there was a global warming that freed the North Atlantic of ice
allowing the Vikings to explore westward discovering Iceland, Greenland, and North
America.
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Chinese Explorations and Discoveries
 The Chinese were very active explorers during the Middle Ages and were
responsible for many important contributions.
 By the mid 1400s in China shipbuilding
was well established.
 Chinese ships from that period had
central rudders and watertight
compartments – these are part of
today’s modern ships.
Chapter 2 Pages 2-18
The Middle Ages (800 A.D. – 1400)
 Probably the most important of their discoveries was the magnetic compass dating
about 1000 A.D. and in widespread use about 1125.
 Europe’s first reference to the compass was in 1190 in a poem, but was not widely
used until the 1400s.
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The End of the Middle Ages and
a Route Around Africa
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The period of 1400-1700 is called the Renaissance. A new interest in long ocean
expeditions and travel in the 15th century was motivated by economics, politics and
religion.
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Three explorers tried to establish a
route to the East around Africa:
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Chapter 2 Pages 2-19 & 2-20
European Voyages (1400-1700)
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The first of these was Prince Henry
the Navigator of Portugal in the early
1400s. He went down the west coast
of Africa, but did not find a route
around the Cape of Good Hope.
The second was Bartholomeu Dias who
completed a voyage around the Cape of
Good Hope in 1487, but did not make
it all the way to India.
The third was Vasco da Gamma. In 1497
he led the first expedition around the
Cape of Good Hope all the way to India.
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Exploration of the New World
 Christopher Columbus took the first of his four voyages to find a
route to Asia in 1492. He believed he’d found Asia when he landed on a
Caribbean island.
 In the early 1500s, Vasco Nuñez de Balboa led an expedition that crossed the
Isthmus of Panama and discovered the Pacific Ocean. Balboa was the first
European to sail in the Pacific.
Chapter 2 Pages 2-20 & 2-21
European Voyages (1400-1700)
 Between 1454-1512, Amerigo Vespucci voyaged to South America. He
explored much of the east coast, the mouth of the Amazon River, and is credited
as the first European to recognize that South America was a new continent.
The Americas are named in honor of Vespucci.
 News that the Pacific lay beyond the Americas renewed the hope that one could sail
around the world west-to-east.
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Exploration of the New World (continued)
 In 1519, Portuguese explorer Ferdinand Magellan led the first expedition to
circumnavigate the world. He had five ships and about 260 men.
Magellan died in the Philippines in a fight with islanders.
One ship and 18 men completed the journey in 1522. Three year journey !!
 The second successful circumnavigation of the world was made in
1577 by Francis Drake.
Chapter 2 Pages 2-21 & 2-22
European Voyages (1400-1700)
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 He left England for the New World with
the purpose of raiding Spanish
ships and settlements for treasure.
 Drake returned to England
in 1580 where he was knighted
for his exploits as well as for
bringing back treasure and
spices worth a fortune.
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Cook’s Expeditions
 His reports changed the western view of the world.
 He discovered Australia, New Zealand,
many islands in the South Pacific, the
Hawaiian Islands, the West Coast of the
US and Canada, the Bering Strait and
the Antarctic Circle.
Chapter 2 Pages 2-23 to 2-26
The Birth of Marine Science (1700-1900)
 The voyages of Captain James Cook receive credit as
the first sea expeditions devoted to methodical,
scientific oceanography.
 A major contribution to Cook’s voyages
was the invention of the chronometer.
 In 1735, John Harrison invented a clock
that runs accurately at sea. This made it
possible to determine longitude accurately.
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The United States Exploring Expedition
 Under command of Lt. Charles Wilkes, it was one of the first
significant scientific expeditions launched by the US.
 The most outstanding achievement of the US Exploring
Expedition was proving the existence of Antarctica.
The Father of Physical Oceanography
Matthew Maury
Chapter 2 Pages 2-27 & 2-28
The Birth of Marine Science (1700-1900)
 The objective was to explore the southern Atlantic and Pacific
Oceans, to collect specimens, and to map, illustrate and
provide text to document their discoveries.
 Between 1842-1855, Matthew Maury published many
detailed works on sea navigation. He earned global
acclaim for his work and his data was adopted worldwide.
 In 1855, he published The Physical Geography of the Sea,
which is now considered the first textbook on modern
oceanography and he is remembered today as the
father of physical oceanography.
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Darwin and the H.M.S. Beagle
 But, coral reefs extend deeper than
coral grows. Darwin observed the
massive reefs must form when the
sea floor slowly sinks and coral
grows upward from its base to
remain in shallow water.
Chapter 2 Pages 2-28 & 2-29
The Birth of Marine Science (1700-1900)
 The Beagle began it’s five-year voyage with Charles Darwin as the ship’s
naturalist in 1831. The H.M.S. Beagle ultimately circled the Earth.
 Darwin noted that coral grows in relatively shallow, warm, upper depths.
 Darwin is renowned for his
theories on natural selection
and the evolution of species.
 In 1859, he published The Origin of Species.
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The Challenger Expedition
 The Challenger expedition (1872-1876), is known and recognized as the first
devoted entirely to marine science.
 Among its accomplishments and discoveries, the expedition:
Chapter 2 Pages 2-30 & 2-31
The Birth of Marine Science (1700-1900)
 The two men responsible for the mission were Scottish professor Sir Charles Wyville
Thomson and British naturalist Sir John Murray.
 Took the first soundings deeper than 4,000 meters (13,123 feet) –
8,200 meters (26,900 feet) in the Marianas Trench.
 Captured biological samples in midwater and
along the bottom with a towed device.
 Discovered marine organisms in the deepest
parts of the ocean, contrary to popular belief
at the time.
 Sampled and illustrated plankton in various
habitats and depths not previously studied.
 Cataloged and identified 715 new genera and
4,717 new species.
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The Oceanography Explosion
 The Industrial Revolution spearheaded the growth and expansion of marine
sciences. This included:
Better ships made of iron with steam engines.
Improvements in the design and building of research equipment.
The advent of the submarine.
Global conflict helping to accelerate
research in science and technology.
Three Expeditions
 The German Meteor Expedition (1925)
Chapter 2 Pages 2-33 & 2-34
Twentieth-Century Marine Science
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 Crossed the Atlantic 14 times in two years.
 Data collected established patterns for ocean
water circulation, nutrient dispersal, and
plankton growth.
 Primary accomplishment was mapping the Atlantic seafloor with
echo-sounding technology.
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Three Expeditions (continued)
 The United States Atlantis Expedition – 1931
 The first ship specifically designed and built for ocean studies.
 Atlantis added to the work of the Meteor as well as confirmed the existence of the
Mid-Atlantic Ridge and mapped it.
Chapter 2 Page 2-35
Twentieth-Century Marine Science
 The H.M.S. Challenger II Expedition – 1951
 Mission to measure the depths of the Atlantic,
Pacific, and Indian oceans.
 Used eco-sounding technology for mapping.
 Challenger II’s most noted discovery was
finding the deepest known part
of the ocean. At 10,838 meters (35,558 feet) deep,
this is still the deepest known place in the world.
 This spot, located in the Marianas Trench, was
named Challenger Deep in honor of the
first Challenger expedition.
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Submersibles and Self-Contained Diving
 Instead of grabbing samples blindly, a scientist could
pick specific ones.
 Scientists could take delicate samples without damaging
them and living organisms without killing them.
 Scientists can directly observe the geology, life, and
other phenomena without taking any samples.
Submersibles
 Three types of submersibles used for underwater research:
Chapter 2 Pages 2-36 & 2-37
Twentieth-Century Marine Science
 How the oceans were studied was changed forever by the submersibles and
self-contained diving.
 Bathysphere - operated only vertically.
 Bathyscaphe - operated much like a blimp air ship by releasing ballast and had a
small electric motor to give it limited horizontal mobility.
 Deep-diving submersibles - state of the art today, far less fragile than bathyscaphes,
easier to launch and use in rough seas. This makes them suitable for more varied
types of research. Some even have robotic arms.
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Self-Contained Diving
 In 1840, Augustus Siebe introduced the first practical dive
equipment; hard-hat diving that supplied air from the surface
through a hose.
 In 1878, Englishman Henry Fleuss introduced the first workable
self-contained underwater breathing apparatus, called scuba today.
 In 1943, Jacques Cousteau introduced the first practical scuba.
Chapter 2 Pages 2-38 to 2-42
Twentieth-Century Marine Science
 Used mainly for underwater construction, salvage, and ship
maintenance. Limited because it is heavy and requires a
support team and vessel.
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ROVs, AUVs, Electronic Navigation, and Satellites
 Technology such as electronics and space travel have provided
four important contributions to oceanography:
 A ROV is a small, unmanned submarine with propellers, video camera,
and an umbilical to the surface.
 ROVs are an economical way to match the capability of a submersible
and the dexterity of a scuba diver.
 2. Autonomous Underwater Vehicles (AUVs)
Chapter 2 Pages 2-43 to 2-45
Twentieth-Century Marine Science
 1. Remotely Operated Vehicles (ROVs) became common in the
late 1970s.
 AUVs are untethered robotic devices propelled through the water by
self-contained power systems.
 Piloted by an onboard computer, AUVs are launched from the surface
and are maneuvered in three dimensions.
 AUVs sample the ocean along precise preprogrammed underwater paths.
 3. The first electronic navigation came into use in the late 1960s.
 LORAN (LOng RAnge Navigation), later called Loran-C, used land based
radio transmitters along the coasts. However, accuracy varied with distance
from the transmitters. The farther from a transmitter the less accurate
is the position.
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ROVs, AUVs, Electronic Navigation, and Satellites (continued)
 Satellites orbit the Earth and assist oceanographers
with global observations of the oceans.
 Satellites assist oceanographers in understanding the
influence and effect of the oceans on the global
climate systems.
 Information gathered from satellites helps to validate
computer models that numerically simulate climatic events.
 5. In the 1990s, GPS (Global Positioning System) replaced the Loran.
 GPS is based on signals from orbiting satellites and works everywhere
on Earth, all the time, in all weather and is more accurate – to within
1-2 meters (3-6 feet).
 Electronic navigation has been very important for oceanographers:
Chapter 2 Page 2-45
Twentieth-Century Marine Science
 4. Satellites – sea surface observations.
 Scientists know where they are when they take samples or conduct research.
 They can provide this information to other scientists who need to conduct research
in the same location.
 Makes navigation significantly more accurate and easy.
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ROVs, AUVs, Electronic Navigation, and Satellites
(continued)
 How GPS works.
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 Three types of sea surface observations made by satellites to benefit
oceanographers:
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Chapter 2 Page 2-46
Twentieth-Century Marine Science
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GPS uses triangulation to accurately determine a position
on Earth. Satellite 1 transmits its location and time. This
process is repeated for 2 and 3. Where the three signals
meet at the GPS is its location expressed in specific coordinates.
Satellite 4’s signal is required to obtain the elevation of the
GPS unit. In the 1990s, GPS replaced Loran.
GPS is based on signals from orbiting satellites and works
everywhere on Earth, all the time, in all weather and is accurate
– to within 1-2 meters (3-6 feet).
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1. Provide long-time continuous measurements of variables such as sea-surface height, shape,
temperature, and color over the entire planet.
2. Can detect algae blooms and river plumbs, monitor pollution, and assist oceanographers in
understanding the influence and effect of the oceans on the global climate system.
3. Can look at very large areas of the world in a very short period of time.
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