Why Study It?

1
Why Study It?

• Three very good reasons to learn the historyof
  oceanography
• 1.
• 2.
• 3.

2

• The history of oceanography can be dividedinto
  four stages
• 1.
• 2.
• 3.
• 4.

3
Prehistory and the Rise of Seafaring

• Three primary reasons for early civilization to
  interact with the ocean
• 1.
• 2.
• 3.
• The earliest recorded sea voyage appears to be
  3200 B.C. under the auspices of Egyptian Pharaoh
  Snefru.

4
Ancient Polynesian Explorations and Discoveries

• 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,
  Polynesianssettled islands in an area of about
  26 million square kilometers (10 million square
  miles).

5
Ancient Phoenician Explorations and Discoveries
6
Ancient Greek Explorations and Discoveries

• The Greeks used references on shore to navigate.
  This is called piloting.
• 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.
• 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
• 1. He calculated the Earths circumference.
• 2. He invented the first latitude/longitude
  system.

7
The Greeks Excelled at Mapmaking

• In 127 B.C., Hipparchus improved Eratosthenes
  mapsby inventing the regular grid system.
• In 450 B.C., Herodotus published a detailed
  history ofGreeces struggles with the Persian
  Empire. This workwas significant because it was
  one of the earliest publishedmaps of the world
  the Greeks knew.
• In 63 B.C.-24 A.D., Strabo published a 17-book
  workcalled Geographic that contained a map
  expandingknowledge/accuracy about the world.
• In c. 100-168 A.D., Ptolemy developed the first
  knownmap to show a portion of the Earth as a
  sphere onflat paper.
• It showed latitude/longitude by dividing the grid
  intodegrees, minutes, and seconds of the arc.

8
Latitude/Longitude System

• The purpose of the latitude and longitude mapping
  systemis to identify specific locations on the
  Earths surface.
• Latitude Lines
• Longitude Lines
• Further Accuracy