History of Oceanography

Voyaging – First Travelers Voyaging – traveling on the ocean for a specific purpose First direct evidence of voyaging comes from records of trade in the Mediterranean Sea. First regular ocean traders were the Cretans or Phoenicians. (1200 b.c.) Phoenicians were skilled sailors who carried their wares as far as Britain and the west coast of Africa on simple ships.

Why Did Early People Travel the Ocean? Economic reasons Benefits of mobility Greater access to food supplies Nutritional advantage Those that wanted to learn about the ocean benefited

Cartography Early mariners began to record info to make voyages easier and safer. – Labeled rocks, landmarks, direction of currents, and traveling time between locations The first cartographers (chart makers) were Mediterranean traders who made routine journeys from producing areas to markets. Today’s charts depict water and water- related information (depth, currents, etc) – Maps show land and land related information

Early People Greeks – Began to explore outside the Mediterranean into the Atlantic around b.c. – Noticed a current running from north to south beyond Gibraltar. – Thought only rivers had currents so they decided that this huge mass of water was part of an immense flowing river and named it okeanos. – First to realize that the Earth is spherical ( BC)

The Strait of Gibraltar

Early People Chinese – Began to engineer an extensive system of inland waterways, some of which connected with the Pacific Ocean. – More convenient long-distance transport of goods Polynesians – Polynesians had been moving easily among islands off the coast of SE Asia and Indonesia since 3000 b.c. and were beginning to settle the mid-Pacific islands.

Early People None of the civilizations had come into contact with each other, but they all developed their own methods of charting and navigation. Many early travelers actually used the stars and the sun to tell direction. Curiosity and commerce encouraged risky voyaging which was made possible by: – Knowledge of shape and size of Earth – More advanced ships – Better charts – Better understanding of the ocean

Library of Alexandria (Egypt) Progress in applied marine science began here. Founded in the 3 rd century b.c. by Alexander the Great. Greatest accumulation of ancient writings Written knowledge of all kinds were housed there. – Characteristics of nations, trade, natural wonders, artistic achievements, tourist sights, investment opportunities, etc.

Library of Alexandria When any ship entered the harbor, all written documents were removed and copied (by law). – The copies were returned to the owner and the originals were kept by the library. – Caravans were also searched. Manuscripts describing the Mediterranean coast were of great interest. Traders quickly realized the competitive benefits of this information. – Why?

Library of Alexandria

Ancient Library of Alexandria

Library of Alexandria In 415 A.D., the library was burned down by a mob led by Julius Caesar All contents were lost – more than 700,000 scrolls burned Academic loss was incalculable – All writings were lost – Researchers and scientists moved to new locations Trade suffered – no nautical charts or info Very little advancement in sciences and math for the next 1,000 years

Present-day Library of Alexandria Opened in 2002

Eratosthenes of Cyrene 2 nd librarian at Alexandria ( b.c.) Greek astronomer, philosopher, poet First to calculate the circumference of the Earth – His calculation was within 8% Latitude and longitude lines were drawn through well known locations

Latitude and Longitude Hipparchus invented our current lat/long system – Divided Earth into 360˚ Latitude – horizontal lines that measure north and south of the Equator – 0˚ latitude = Equator Longitude – vertical lines that measure east and west of the Prime Meridian – 0˚ = Prime Meridian (drawn through Greenwich, London, England)

Latitude vs Longitude

The Polynesians One of four cultures that inhabited 10,000 islands scattered across nearly 26 million sq. km of the Pacific Ocean In order to travel to these remote islands, a profound knowledge of the sea was required. Slowly spread from island to island As the easily accessible islands became overpopulated, groups of people ventured off to find new lands.

The Polynesians Many times, ships set sail not knowing where they were going. All they knew is that they needed to find new land to live on. – Many ships were lost at sea – Many people died a.d. - nearly all inhabitable islands were colonized in the Polynesian Triangle – Easter Island and Hawaii were found during this time – considered to be the last two places on Earth to be populated

The Polynesian Triangle

Why take these risky voyages? Religious warfare – People were banished from home island had to find new place to inhabit Had great new technology – Dual-hulled sailing ships that could carry 100 – New navigation techniques – New ways of storing food, water, and seeds

The Vikings Dark Ages were periodically punctuated by the raids of Vikings – Swept down the coast of Europe robbing and looting towns on the coast Had strong, fast and stable ships 62 ships participated – spectacular display of technology, sea power, seamanship, and navigation As the Europeans became stronger, the Vikings ventured west Greenland (996 a.d.) and Iceland (850 a.d.) were discovered by ships blown off course

The Vikings

The Chinese During the Dark Ages, the Chinese became more skilled and their ships stronger – Admiral Zheng He (“jung huh” commanded the greatest fleet – 317 ships and 27,500 men – Largest ship: 9 masts, 134 m (440 ft) – 7 missions to explore Indian Ocean, Indonesia, and around the tip of Africa into Atlantic – Purpose: display the wealth and power of the young Ming dynasty and to show kindness to people of distant places

The Chinese In order to partake in such excursions, the Chinese invented: – Compass (4 th century) – Central rudder – Watertight compartments – Sophisticated sails on multiple masts

The Chinese Ships

European Age of Discovery Prince Henry the Navigator felt that ocean exploration held the key to great wealth and successful trade. – He established a center for the study of marine science and navigation Christopher Columbus “discovered” the New World by accident – Native Americans has been living there for about 11,000 years – Norwegian Vikings had already made about 2 dozen journeys 500 years before – Why did he get the credit? His souvenirs, stories, inaccurate charts, promises of wealth – He actually thought it was India or Japan (due to his lack of knowledge in Earth’s size - thought it was ½ its size)

Capt. James Cook First marine scientist – Commander of HMS Endeavor – Goals: Search for a southern continent Found and charted New Zealand, mapped the Great Barrier Reef, marked position of small islands – Commander of Resolution and Adventure – Charted Tonga and Easter Island – Discovered New Caledonia in the Pacific and South Georgia in the Atlantic – 1 st to circumnavigate the world at high latitudes – 71° south - but never sighted Antarctica

Capt. James Cook 1776 – Captain of Resolution and Discovery – “Discovered” the Hawaiian Islands – Hawaiians were already there – Charted west coast of N. America – 1779 – had an elaborate farewell dinner in Hawaii but angered the Hawaiians and Cook, along with many others, were killed. In his travels, he collected samples of marine life, land plants and animals, the ocean floor, and geological formations Logged, charted, and recorded everything – His charts were very accurate and his conclusions were not exaggerated Cook recorded and successfully interpreted events in natural history, anthropology, and oceanography.

Longitudinal Accuracy Stars and clocks (pendulum) were originally used to determine longitude while at sea – Became inaccurate after long periods at sea – Many died due to getting lost In 1714, British government offered prize money £20,000 pounds (equivalent to $12 million dollars) to anyone who could invent a way to determine longitude within ½˚ after 30 days at sea

John Harrison Developed the 1 st chronometer (clock w/ spring instead of pendulum) – Tested at sea in 1736 – wasn’t accurate enough but was given some prize money to continue work – Given £500 as encouragement to keep trying Over the next 25 yrs he built 3 more chronometers Number Four was his best and was finished in 1760 – Used to travel from England to Jamaica – Calculated longitude within 1.4 miles Chronometer allowed for better records for samples collected at sea

Chronometer Number 1 Number 4

Matthew Maury Studied a large number of logs and charts from past voyages Put all of this information into one First to sense and chart worldwide patterns of surface winds and ocean currents – Importance: Made traveling overseas quicker and easier – ships traveled with winds and currents instead of against them Discovered the Mid-Atlantic Ridge

Challenger Expedition First sailing expedition devoted entirely to marine science – covered 79,300 miles Steam winch on board allowed collection of samples from deep sea (up to 26,800 ft) – Sediments were kept for further study – Manganese nodules found led to deep-sea mining 4717 species were discovered Also took salinity, temperature, and water density measurements and kept water samples for further study

Steam-powered Winch

Polar Exploration – Fridtjof Nansen aboard the Fram – Fram was specially designed to be trapped in the Arctic ice – Fram drifted with the ice pack for 4 years – Traveled over 1000 miles – Traveled further north than anyone else ever had – Found that no Arctic continent exists

Other Expeditions – Meteor – 1 st to use echo sounding – Revealed an extremely rugged ocean floor 1931 – Atlantis – Confirmed Maury’s findings of the Mid-Atlantic Ridge and discovered its extent – New Challenger ( Challenger II ) – Precise depth measurements in the Atlantic, Pacific and Indian Ocean and the Mediterranean Sea – Discovered the Mariana Trench – named the deepest part the “Challenger Deep” 1968 – Glomar Challenger – Capable of drilling into the ocean bottom beneath 20,000 ft of water and collecting sediment samples – Confirmed seafloor spreading and plate tectonics