GEOL 2503 Introduction to Oceanography
Dr. David M. Bush
Department of Geosciences
University of West Georgia
GEOL 2503 Introduction to Oceanography
Dr. David M. Bush
Department of Geosciences
University of West Georgia
POWERPOINT SLIDE SHOW NOTES
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Topic 1: The History of Oceanography
Humans surely have been interacting with the oceans throughout history, but hard
evidence so far only goes back several thousand years.
Middens are essentially garbage dumps. Piles of oyster and clam shells, fish bones,
broken pottery, arrow heads, etc. We can learn a lot about historical cultures from the
stuff they leave behind.
Long before exploration began in the Atlantic basin, Polynesians had sailed throughout
the South Pacific.
The ancient Greeks set the stage for much of our understanding of early oceanography.
Ancient Greek map of the known world.
Pytheas saw a relationship between the moon and tides.
Eratosthenes calculated the circumference of Earth, but Ptolemy thought it was smaller
and Ptolemy was a more important figure.
Vikings made it to North America long before Columbus. Good navigators using cloud
patterns, birds, smells.
Map of Viking routes.
Viking ship.
Little Ice Age. Period of cooling in otherwise warming trend.
Chinese invented the compass. Improved navigation.
European Great Age of Discovery. England, Spain, Portugal dominated.
Prince Henry the Navigator
Christopher Columbus
Columbus’ ships, Nina, Pinta, Santa Maria
Amerigo Vespucci
Balboa
Map of Balboa route across Central America.
Ponce de Leon
Map Ponce de Leon routes
Magellan
Francis Drake
Drakes’ ship, Golden Hinde
Map, Magellan and Drake voyages
Henry Hudson
Hudson’s ship, Half Moon
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Map, Hudson voyages
Captain Cook
Map, Cook’s voyages
Cook’s ship, Resolution
Ben Franklin and Captain Timothy Folger drew first map of the Gulf Stream, and of
circular currents around the North Atlantic.
Satellite image of sea-surface temperature. You can see the warm water of Gulf Stream
carrying heat from the tropics to the North Atlantic.
Invention of sextant allowed accurate measurement of latitude
An example of how a sextant works. Simply, you measure how many degrees above the
horizon a known star or planet is. The easiest way to visualize this is to find the north
star (Polaris). If you are at the north pole, Polaris would be 90° above the horizon. Thus,
your latitude is 90° north. If you are at 45° north latitude, say around Portland, Oregon.
Measuring with your sextant you will see that Polaris is 45° above the horizon.
At the equator, you will spot Polaris right at the horizon. That is, 0° above the horizon.
The equator is 0° latitude.
Nautilus was a very early submarine, designed by Robert Fulton who built the first
steam-powered ship. Fulton was commissioned by Napoleon to build a submarine.
Charles Darwin is best known for his work with natural biologic evolution. However, in
oceanography, Darwin developed an understanding of how atolls form.
Charles Darwin
Track of the famous Beagle, the ship made famous by Darwin.
Formation of an atoll.
Perhaps the most significant, but relatively unknown, oceanographic expedition is the
United States South Seas Exploring Expedition of 1838-1842, better known as the U. S.
Ex. Ex.
The U. S. Ex. Ex. Is also referred to as the Wilkes Expedition.
The Wilkes expedition was comprised of seven ships, each with a different specialty and
function.
Track of the U. S. Ex. Ex.
U. S. Ex. Ex. Flagship: USS Vincennes
Vincennes in Disappointment Bay, Antarctica
It is likely that Wilkes, not Cook, proved the existence of Antarctica
James Dana was a geologist on the Wilkes Expedition
Reports of the expedition were written by the various experts
Many drawings were made, samples taken.
Matthew Maury helped quantify and map ocean currents, waves, temperatures, etc. His
data was obtained from ships’ logs.
Commander Matthew Fontaine Maury, USN (1806-1873)
Beginning of Maury’s important book, The Physical Geography of the Sea published in
1855
An ocean depth profile made by Maury
An ocean depth chart made by Maury
Same, colorized
Temperatures by Maury
The Challenger Expedition. Commonly referred to as the first true oceanographic
research expedition. The Wilkes expedition predates this, but Wilkes was not highly
regarded and is largely forgotten.
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HMS Challenger
Various Challenger sketches.
Wyville Thomson, scientific director of the expedition.
Track of the Challenger expedition.
Nares and Thomson
Fridtjof Nansen
Voyage of Nansen’s Fram
USS Albatross
HMS Titanic played a role in oceanography
HMS Titanic
HMS Titanic has been much studied
Location of wreck of HMS Titanic
North Atlantic Ice Patrol founded as a result of Titanic’s sinking
Precision depth profiling. Much easier to map depth of sea floor. Speed of sound in
water is about 1,500 meters per second (m/s).
An old precision depth recorder (PDR) profile. Now the data is recorded and analyzed
digitally.
PDR trace from off the Bahamas.
Bathyscaphe Trieste made the deepest dive ever.
The deepest spot in the ocean is the Challenger Deep in the Mariana Trench. It is
deeper than Mount Everest is high.
Trieste and service boats
Trieste being deployed for a dive. The researchers are in the small sphere at the
bottom.
Plan of Trieste
Trieste photos and diagrams source
International Geophysical Year (IGY)
Modern oceanography
Perhaps the most well-known research submersible is Alvin. It is still in operation.
Inside Alvin.
An ROV (remotely operated vehicle).
Drill ship to study sea floor and rocks beneath the oceans.
Some Ocean Drilling Program drill sites.
Satellites are crucial to modern oceanography.
One of the most famous ocean research facilities, Woods Hole Oceanographic
Institution, Woods Hole, Massachusetts.
Another famous facility is Scripps Institute of Oceanography, in La Jolla, California.
Harbor Branch Oceanographic Institute, Fort Pierce, Florida.