Chapter 2
History of Ocean
Exploration
Key Ideas
 Earliest direct evidence for voyaging was from the Mediterranean.
There may well have been intentional or unintentional ocean travel
previous to that time.
 The origins of marine science lie in voyaging – traveling on the
ocean for a purpose, which varied form one culture and time to
another. Technological advances made during voyaging and later
marine exploration led to the rise of scientific oceanography.
 Earth’s shape and circumference were accurately estimated around
230 B.C. at the Library of Alexandria, Egypt. The use of latitude
and longitude for positioning and navigation also began there.
 Polynesian adventurers were the first to perfect methods of
sustained, long-distance, open-ocean travel. Possibly as early as
900 BCE, but surely by 300 AD
 The first systematic voyages of oceanic exploration were
undertaken by the Chinese in the fifteenth century.
Key Ideas Continued…
 Christopher Columbus did not discover North America, and he did not sail
around the world.
 Captain James Cook, Royal Navy, was perhaps the first ocean
observer careful enough to be considered a marine scientist.
 The Challenger expedition was the first purely scientific voyage of
oceanic exploration.
 Polar Studies greatly advanced marine science at the beginning of the
twentieth century.
 Nearly all research is conducted not by individuals but by teams of
specialists working in large, nationally funded oceanographic or
military institutions.
 Satellites are increasingly important tools of oceanographic
research.
Understanding the Ocean Began with
Voyaging for Trade and Exploration

Our word ocean is derived from oceanus, a Latin root of the word okeanos originally
named by the early Greek seafarers. Thought to be an immense river.

Voyaging on water was important to many early civilizations. The Egyptians, Cretans,
and Phoenicians were all skilled sailors.

Cartographers, or chart makers, recorded information about locations and
landmarks and currents. Today, charts are detailed graphic representations of
water and water-related information.

The Library at Alexandria, in Egypt, was founded in the third century B.C. This
library stored information on every area of human endeavor. .
http://en.wikipedia.org/wiki/Library_of_Alexandria

Eratosthenes of Cyrene was the second librarian at Alexandria. He was the first to
calculate the circumference of Earth. He also invented a system of longitude and
latitude.

The principles of celestial navigation were invented at the Library at Alexandria.
Eratosthenes Accurately Calculated the Size
and Shape of Earth
A diagram showing Eratosthenes’s technique for calculating the
circumference of Earth.
As described in the text, he 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 discover the circumference of
Earth to within about 8% of its true value.
Latitude and Longitude
Diagrams showing the calculation of lines of latitude and longitude.
Latitude is calculated by
measuring the angle
between the north Star,
Polaris and the horizon.
Longitude is more
difficult to measure.
John Harrison’s clock.
He won ₤20,000 in 1728 for solving this technologic problem. Earlier clocks
used pendulums. How does knowing an accurate calculation of the time help
you figure out where you are? The Earth rotates 360° every 24 hours. Hint:
What time is it in New York City? How far (in °) is it to NYC?
A third century B.C. chart showing the system of
latitude and longitude developed by Eratosthenes.
Oceania Seafarers Colonized
Distant Islands
(Right) The Polynesian triangle.
Ancestors of the Polynesians spread
from Southeast Asia or Indonesia to
New Guinea and the Philippines by
about 20,000 years ago. The midPacific islands have been colonized
for about 2,500 years, but the
explosive dispersion that led to the
settlement of Hawaii occurred about
A.D. 450-600.
The Polynesian colonization's are an
example of knowledge of oceans and
marine science used to colonize a vast
number of islands.
Polynesian Navigation
http://www.imachination.net/next100/brainstorm/polynesia.html
The Vikings
The Chinese Undertook Organized
Voyages of Discovery
Chinese navigators set out in the early 1400s to explore the Indian Ocean,
Indonesia, Africa and the Atlantic. Their ships were laden with gifts
designed to show China’s wealth and degree of civilization! The Chinese
invented:
 The central rudder
 Water-tight compartments
 Sails on multiple masts
 marine compass
The Age of Discovery
Europeans explored the world by sea during
the Renaissance.
 Henry the Navigator – Explorers under his patronage
compiled detailed charts and explored the west coast of
Africa.
 Christopher Columbus – Although he never saw the
mainland of North America, his stories inspired other
explorers to follow.
 Ferdinand Magellan – Although Magellan died en
route, the small surviving portion of his crew
circumnavigated the globe.
European Age of Discovery
Voyaging Combined with Science to
Advance Ocean Studies
James Cook, a commander in the British Royal Navy, is credited
with leading voyages that greatly contributed to scientific
oceanography. Some of the accomplishments of James Cook and his
scientists include:
– Verification of calculations of planetary orbits
– Charting of New Zealand and the Great Barrier Reef, Tonga
and Easter Islands
– Initiation of friendly relations with many native populations
– Sampling marine life, land plants and animals
– Recording data concerning the ocean floor and geological
formations
Cook’s 3 Voyages
Benjamin Franklin and the
Gulf Stream
Voyaging Combined with Science
• The United States Exploring Expedition
launched in 1838 was a naval and scientific
expedition.
• The HMS Beagle, on which Charles Darwin served
as a naturalist, voyaged to South America and
some Pacific Islands.
“In the light of the fate of Stokes and the suicide of his own uncle,
FitzRoy was concerned about the lonely position of a captain at that
time. His attempts to get a friend to accompany him fell through, and
he asked his friend and superior, Captain Francis Beaufort, to seek a
gentleman passenger who would act as a companion as well as
having opportunities as a naturalist. This led to Charles Darwin joining
the voyage.”
http://en.wikipedia.org/wiki/HMS_Beagle
The British Challenger expedition of 1872-1876
was the first oceanic expedition dedicated to
scientific research.
Advances in oceanic exploration in
the twentieth century?
– Polar Exploration – explorers reached both the North and
South poles in the twentieth century. Scandinavians very
important in early oceanography and meteorlogy.
– The Meteor Expedition – the first expedition to use modern
optical and electronic equipment for oceanographic
investigation
– The Atlantis – investigations by scientists on this research
vessel confirmed the presence of the Mid-Atlantic Ridge.
– The Trieste – a blimp-like bathyscape which descended into
the Challenger Deep area of the Mariana Trench
– Glomar Challenger – ocean floor samples (mud and rock)
obtained by scientists on this drilling ship provided confirming
evidence for seafloor spreading and plate tectonics.
New Ships for New Tasks
Ocean drilling
(sediment and rock),
water sampling
(Temperature, Salinity,
chemistry, etc), Echo
sounders, side scan
radar, submersibles,
Remotely Operated
Vehicles (ROVs) and
now satellites in space
(TOPEX, SeaWifs etc)
Oceanographic Institutions Arose to
Oversee Complex Research Projects
Three of the most prominent oceanographic institutions
in the United States:
– Woods Hole Oceanographic Institution
– Scripps Institution of Oceanography
– Lamont-Doherty Earth Observatory of Columbia University