history of ocean exploration - duncanville isd...middle ages –500 to 1500 ad suppression of...
TRANSCRIPT
HISTORY OF OCEAN EXPLORATION
Into the Wide Blue Yonder
3 MAIN REASONS FOR SEAFARING
Food
Trade
Discovery of
new land
ANCIENT SEAFARING
Biblically – Noah’s Ark and similar stories of floods: Not really out to Sea
1st Recorded – 3200 BCE Egyptian reed boats to Phoenicia for Trade
1st Exploration – 2750 BCE Egyptians to southern tip of Arabian Peninsula
Phoenicians – established trade routes in Mediterranean and as far north as Great Britain. All routes within sight of land.
ANCIENT SEAFARING CONT.
Polynesians
2000 – 500 BCE
Traveled thousands of miles across Pacific Ocean
Settled most habitable islands of the Pacific
including Hawaii
Used basic maps made
from sticks, shells,
ropes, knots & rocks.
TOOLS OF ANCIENT SEAFARING
Reference points on land
Use sun, constellations, stars
Cloud patterns that develop
near islands and coastlines
Shore birds
ANCIENT GREEK MATHEMATICIANS
Developed knowledge lost during middle ages
Knew Earth was round not flat.
Calculated Circumference of the Earth
Developed sophisticated maps with latitude
and longitude
Ptolemy developed coordinate system still used
today.
PTOLEMY
Astronomer,
mathematician,
geographer circa 87 – 150
AD
First map of a spherical
earth projected on to a
FLAT map
Introduced latitude and
longitude
LATITUDE
Easy to figure out while at sea,
even long ago
Not so much…
LONGITUDE
Latitude:
Measures the angular distance north or south of
the equator expressed in degrees
Longitude:
Measures the angular distance east or west
expressed in degrees.
Equator – Great Circle1/2way between North and South Poles
0⁰ latitudeCircles are different sizes
Circles Never intersect & run
parallel to each other90⁰ N
90⁰ S
0⁰
Prime Meridian – Great Circle
Passes through Greenwich England
0⁰ longitude
Circles are equal sizes
Each intersect at Poles
West East
TRAVELING AT SEALatitude
sextant - used to
calculate the
degree of
difference
between observer
and equator
(incredible
accuracy)
LongitudeLongitude
is the
degree of
difference
between
an
observer
and the
prime
meridian –
How do
you do
that?????
CHRONOMETERS
You needed a clock to determine longitude
1 hour from the prime meridian = 15°
1° = 30 nautical miles
Not so simple really –
Degree lengths along meridian aren’t
constant (earth is not a perfect sphere:
69 miles/degree at equator
17 miles/degree at 80° N
0 at the poles
IMAGINE 1714
Clocks?
nope
England offers 20,000 pounds
John Harrison
1726 – the first semi-accurate “regulators”
1759 – “H4” is completed (it’s a clock)
Weighs 3 lbs
5” diameter
A FEW FACTS
Earth’s diameter at equator – 24,902 miles
Earth’s diameter at poles – 24,818 miles
Distance on Earth’s surface for 1⁰ of latitude
OR longitude ~ 70 miles
END OF PART I
MIDDLE AGES – 500 TO 1500 AD
Suppression of science and geography caused loss of knowledge
Vikings – 790 to 1100 AD Explored from central Asia west to New Foundland, Canada and throughout Europe to North Africa
Chinese – developed magnetic compass; two technological innovations of ships: central rudders and watertight compartments
EUROPEAN VOYAGES OF DISCOVERY
1400 – 1700 AD
3 motives
Economics
Politics
Religion
Asia to the East
Prince Henry – Western Africa
Bartholomeu Dias – Cape of Good Hope (1487)
Vasco de Gama – Through Cape to India (1497)
EUROPEAN VOYAGES OF DISCOVERY
1400 – 1700 AD
Asia to the West
Christopher Columbus (1492) - Landed on Caribbean Islands
Vespucci – First to recognize South America as new continent (1499-1504)
Vasco Nunez de Balboa – 1st European
to sail in Pacific; Crossed over Panama
Peninsula (1513)
Ferdinand Magellan
Circumnavigated globe
Left: 5 ships, 200 men (some say 270)
Returned: 1 ship, 18 men, no Magellan
AGE OF EXPLORATION (1700 – 1900)
James Cook- 1st major expedition launched with Science and Exploration as only goal
Chronometer
Developed by John Harrison
Clock not affected by motion of sea
Determined longitude accurately
Discovered New Zealand and Australia
3rd Voyage discovered Hawaii
AGE OF EXPLORATION (1700 – 1900)
Charles Wilkes
Early U.S. expedition
Proved existence of Antartica
Matthew Maury
Father of Physical Oceanography
Knowledge of prevailing winds and surface currents
Produced 1st modern oceanography textbook
AGE OF EXPLORATION (1700 – 1900)
Charles Darwin
Gathered scientific data aboard HMS Beagle
Later wrote The Origin of Species describing evolution through natural selection
Challenger Expedition (1872 – 1876)
1st expedition devoted specifically to marine science
Discovered Mid-Atlantic Ridge and Marianas Trench
Most new species ever discovered on one expedition until deep-sea vents in 1970s
MODERN OCEANOGRAPHY
Mapping sea floor using echo-sounding
Meteor, Atlantis, and Challenger II
DEVELOPMENT OF SUBMERSIBLES AND
SELF-CONTAINED DIVING
Bathyscaphe Trieste – 1st and only manned
submersible to bottom of Challenger Deep
Research Submersibles allow for direct
observations of abyssal plain and limited
specimen collecting
Jacques Cousteau and Emile Gagnon develop
SCUBA that allows direct manipulation during
underwater research (limited depth)
ROV, AUV, ELECTRONIC NAVIGATION, AND
SATELLITES
Remotely Operated Vehicles –Tethered/unmanned
Autonomous Underwater Vehicles – Untethered/Computer controlled
LORAN and GPS – Allow for accurate coordinate measurements
Satellites – track large scale weather and ocean phenomena
SOMEONE ASKED: HOW MANY GALLONS OF
WATER ARE IN THE OCEAN?
1 cubic kilometer of water =1 trillion liters of water
Therefore - ~ 1,300,000,000,000,000,000,000 liters of water (1.3 sextillion liters)
Gallons? 3.78541178 liters = 1 gallon
=343,423,668,428,484,681,262 gallons
= 343 quintillion gallons
or --- 343 billion BILLION gallons.
That's a lot of water.
The Oceans have around 1.3 billion cubic kilometers of water
SO… You tell me.
You may not ask Siri, Cortana, or Google…
http://www.youtube.com/watch?v=I_KKMC7fju
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http://www.youtube.com/watch?v=6Z7REEnw
KOQ&feature=related
http://www.youtube.com/watch?v=OvE22AUl-
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