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150
Ptolemy
Ptolemy introduces latitude and longitude to the world map; he was the first to place a grid system on a map and use the same grid system for the entire planet. His collection of place names and their coordinates reveals the geographic knowledge of the Roman empire in the second century. -
325
Pytheas
About 325 BC, Pytheas proved that the earth was round, and extended beyond the oceans as known -
Jan 5, 1350
Prince Henry the Navigator
Prince Henry the Navigator of Portugal recognized the oceans’ importance to trade and commerce and he established a center of learning for the marine sciences. You could think of it as the first oceanographic institution. Mariners came to the center in Sagres, Portugal, to learn about the oceans and currents and how to make maps. -
Jan 5, 1519
Ferdinand Magellan
Magellan's expedition of 1519–1522 became the first expedition to sail from the Atlantic Ocean into the Pacific Ocean (then named "peaceful sea" by Magellan; -
Benjamin Franklin "river in the ocean"
Besides being a famous statesman and diplomat, Benjamin Franklin was a well-known American scientist. He contributed to oceanography in the mid- to late 1700s by making and compiling good observations of ocean currents off the US East Coast. -
James Cook
Over 10 years Cook led three world-encircling expeditions and mapped many countries, including Australia, New Zealand and the Hawaiian Islands. He was an expert seaman, navigator and scientist who made keen observations wherever he went. -
Darwin/ Galapagos
Darwin was also fortunate that the Beagle took him to the Galapagos Islands, where he observed various animals and birds that had evolved in an isolated environment. His observations led him to his famous theory of natural selection -
Matthew Maury
Maury realized the books contained a gold mine of information. By compiling records from many ships, he saw patterns. He made charts of ocean currents and winds that helped captains plot the best sea lanes for their voyages. He added more details to these charts by asking merchant captains to make more observations and send them to him. He also asked sailors to put messages in bottles. -
Challenger Expedition
Modern oceanography began with the Challenger Expedition between 1872 and 1876. It was the first expedition organized specifically to gather data on a wide range of ocean features, including ocean temperatures seawater chemistry, currents, marine life, and the geology of the seafloor. -
Mapping currents
In the late 1800s and early 1900s, Prince Albert of Monaco used a similar method to figure out what happened to the Gulf Stream as it approached Europe. By compiling the notes he received from people who found washed ashore bottles, he determined that the Gulf Stream splits in the northeastern Atlantic. One branch heads toward Ireland and Great Britain, while another part of the Gulf Stream heads south past Spain and Africa, and then back west. -
Sonar
Sonar was used in the 1900's. Sonar allows scientists to use sound waves to measure the distance from the ocean surface to the seafloor -
Charles Wegener
In 1915, Wegener proposed his continental drift theory. He said that the continents floated atop the mantle-a heavier, denser layer of rocks deep within the earth. Wegener predicted that heat rising within the hot mantle created currents of partially melted rocks that could move the continents around the earth’s surface. -
Bathysphere
Basically a mini submarine. William Beebe descends to a depth of 3027 feet off Bermuda in a tethered bathysphere to observe deep ocean life. Beebe invented and tested the bathysphere with his friend Otis Barton. -
Ocean Drilling
In 1968, an international group of oceanographic institutions and the U.S. National Science Foundation created a program of ocean drilling. Its initial goal was to test Tuzo Wilson's hypothesis of plate tectonics. -
Eratosthenes
Eratosthenes made a surprisingly accurate measurement of the circumference of the Earth. Details were given in his treatise ,on the measurement of the Earth, which is now lost.Eratosthenes compared the noon shadow at midsummer between Syene and Alexandria. He assumed that the sun was so far away that its rays were essentially parallel, and then with a knowledge of the distance between Syene and Alexandria, he gave the length of the circumference of the Earth as 250,000.
