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Professor Rosenheim EENS/EBIO 223

Intoductory Oceanography

Introductory Oceanography (EENS/EBIO 223)

Prof. Rosenheim Blessey 210 862-3196

[email protected]

Textbook:

Introductory Oceanography, 10th Edition. Thurman and Trujillo

Book Use: Required readings, test questions – you will do better with the book!

History of Oceanography

Chapter 1



Science of Oceanography

• Physical Oceanography• Chemical Oceanography• Biological Oceanography• Marine Geology and Geological

Oceanography (Paleoceanography)

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What is Oceanography?

• Study of our oceans– The basins that are the oceans– The water in those basins– The life in that water– Interactions between the water and the

atmosphere– The remnants of life collecting on the bottom

of the basins



How We View the Oceans

• Resource – time immemorial

• Travel and commerce – 2000 B.C. to present

• Integral part of our environment – 20th

century - present



The Beginnings

• Commerce & Exploration• Navigational Needs

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Early Navigation

• Pacific Islanders



PolynesiansUsed astute observations to construct charts and inhabit dispersed Pacific Islands from Asia



Age of Exploration

• Early Exploration– Pheonicians 2000-450 B.C.– Greeks

• Pytheas – measured latitude and sailed to Iceland• Eratosthenes – Spherical Earth of r = 6366km

– Today, r = 6370km

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Pheonicians

• Mediterranean explorers and traders



Middle Ages, Dark Ages

• Much was forgotten during the Middle Ages – religious suppression of science



Vikings• Vikings

– 9th Century A.D. – Vikings explore Eastern Europe

– 900 A.D. – Discovered Greenland, Iceland, and N. America (did not colonize the latter)

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Age of Exploration

• Renaissance and beyond– Chinese – diplomatic missions as far as Africa– Spanish – Re-discovery of N. America,

Magellan’s circumnavigation of the world– British – growing marine power by the end of

the 16th century



Notable Explorers

• Prince Henry the Navigator – Explored outside of Europe

• Bartholomeu Diaz – sailed to tip of Africa• Vasco de Gama – sailed around Africa• Columbus – sailed west to find the “East”• John Cabot – landed on N. America• Vasco Nunez de Balboa – crossed

Panama and saw Pacific



Magellan’s Circumnavigation5 ships and 288 sailors to 1 ship and 18 sailors,

1519-1521

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Navigation for Further Exploration

• Polynesians– Navigated small distances using known wave

patterns and wind direction• Latitude

– Measured by early navigators using sun and stars



Navigation for Further Exploration

• Longitude– Related to time – time couldn’t be kept on

board a ship!– John Harrison invented a sea-going clock in

1735, perfected in 1761.



Modern Oceanography

• Ben Franklin – 1700’s– Published map of Gulf Stream based on

fishermen’s and merchants’ experiences

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Birth of Marine Science

• Inquisitive Exploration – Captain James Cook – 1768-1779– depth soundings, SST, Antarctica

• Bottom Samples– Ross and Forbes

• Bottom samples in the tropics were similar to surface samples in the polar regions



Voyage of the HMS Beagle 1831-1836

• Crew member Charles Darwin– (not much of an old salt)– specialization of peculiar species (Galapagos)– coral reef life history and geology



Matthew Fontaine Maury – the “Father of Oceanography”

• Depot of Naval Charts• International Meteorological Conference

1853• Physical Geography of the Sea 1855• Ocean currents documented• Hypothesized open seas near North Pole.

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Voyage of the HMS Challenger 1872-1876 (C. Wyville Thompson)

• Physics, chemistry and biology of world’s seafloors – ignited by the Ross-Forbes debate

• Bottom temperature records, dredge samples, bottom trawls– 4717 new species discovered– Record depth of Mariana Trench measured



Polar Oceanography

• George Washington DeLong and the USS Jeanette – stuck in polar ice north of Alaska

• Fridtjof Nansen and the Fram– Inspired by distance that some parts of the

Jeanette had traveled in pack ice– Designed the Fram to withstand ice and set

“sail” stuck in ice



The Fram Voyage, 1893-1895

• Findings– 3000 m deep– Warm subsurface

water (1.5oC)– Nansen bottle– Ekman’s principles

of wind driven drift

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Voyage of the Meteor, 1925-1927

• Set sail in 1925 for 25 months• 310 sampling stations in the South Atlantic• Topography currents and chemistry



Echo Sounder

• Used aboard the Meteor– Use sound waves to measure depth– More accurate than long rope from a drifting

ship– Meteor mapped much more of seafloor

• Found long mountain range in center of the Atlantic – Mid-Atlantic Ridge



Bathymetric Charts

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Ocean Sampling

• Alexander Agassiz – Brought oceanography recognition as a

science• Active and opinionated, but sometimes wrong

– Used dredge to collect bottom organisms• One haul produced more specimens than the

entire Challenger Voyage!• Skimmed rather than plowed



Oceanography and the Navy

• Warfare necessitated increased maritime knowledge– Anti-submarine capabilities

• Sonar • Sea floor topography

– Waves and Currents– ONR – Office of Naval Research



Post WWII

• Institutionalization of oceanography– Federal Sea Grant– Scripps– RSMAS– WHOI

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Current

• Collaboration is international– IODP – Integrated Ocean Drilling Program– ICDP – International Continental Drilling

Program



Current

• Observations are ever more encompassing– Satellite Oceanography



Satellite Oceanography

• Electromagnetic radiation does not penetrate the oceans deeply– “Skin temperatures” – top mm of ocean water

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Physical Oceanography

• Study of movements of water and interactions between different masses of water– Waves– Currents– Tides– Interaction with atmosphere



Chemical Oceanography

• Chemistry of seawater– The water molecule and its peculiarities– Constituents dissolved in seawater– Chemical tracers of ocean movement



Biological Oceanography

• Study of sea life– Plankton– Whales and dolphins

• Which is more important?

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Geologic Oceanography

• Paleoceanography– Past ocean conditions and circulation

• Marine Geology– Geology under the sea

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