CHAPT THE WoRLD OCEAN t has been called the new frontier The great body of water embracing Earth's continents is also known as the world ocean Its major subdivisions are the Pacific the Atlantic the Indian and the Arctic oceans Some people divide the world ocean into the North Pacific South Pacific North Atlantic South Atlantic Indian Arctic and Antarctic a total of seven The term seven seas however originated with medieval ARCTIC OCEAN NORTH AMERICA RIDGE A S NORTH AMERIC EUROPE KARAiLaurTAN TRENCH ATLANT TRENCH PACIFIC OCEAN 3 MID PACIFIC MTs AFRICA ATLANTIC OCEAN BASIN SOUTH MERICA BASN ANGOLA 2 BASIN MANHK PLATEAU EB MID AUSTRALIA TEST RIDGE SOUTHWEST PACIFIC ARGENTINE INDIAN RIDGE INDIAN OCEAN ATLANTIC INDIAN RIDGE KERGUELEN ENDERBY PLATE AT E PACIFIC ANT ARCTIC RIDGE 1994 Encyclopaedia Britannica Inc ANT ARCTICA 2500 km Cylindrical Equal Distance Projection Major features of the ocean basins IO
THE WORLD OCEAN Arabic geographers who knew only the waters of Europe and Asia Around the borders of the oceans lie par tially enclosed seas and gulfs such as the Mediterranean Caribbean Baltic Black Red and North seas the Gulf of Mexico and the Persian Gulf The landlocked Caspian Sea was part of a great ocean in an earlier geologic era Gulfs are generally described as extensions of oceans or seas The Gulf of Mexico is larger than most seas Straits are narrow passage ways connecting two large bodies of water such as the Strait of Gibraltar between the Atlantic Ocean the Mediterranean Sea and Oceans seas gulfs and straits cover about 71 percent of Earth's surface No other known planet is as watery as Earth The Atlantic Pacific Indian and Arctic Oceans cover 129 428 700 square miles 335 218 800 square kilometers The Pacific Ocean is the largest It occupies almost one third of Earth's total area The oceans are not evenly distributed over Earth s surface About 43 percent of their total area lies in the Northern Hemisphere and 57 percent in the Southern Hemisphere The word ocean is derived from Oceanus in Greek mythology one of the Titans He was a son of Uranus the sky and Gaea Earth II
INVESTIGATING EARTH's OCEANS the first rulers of the world Oceanus per Sonified the river that the Greeks believed encircled the flat Earth The oceans influenced the formation of Earth's land surface as it is known today Deadliest A Roman mosaic from 3rd century AD depicts the god Oceanus DEA G Dagli Orti Getty Images 12
THE WORLD OCEAN During several periods of Earth s history large parts of North America were covered by the ocean Most of the limestone sandstone and shale on land was deposited as sediment on the bottom of ancient shallow seas Chalk such as that found in England and the U S states of Texas and Kansas was formed on seabeds from the shells of sea creatures The oceans also affect climate Water has a high capacity for storing heat It warms more slowly than land and it also cools more slowly Thus the coasts of the continents have cooler summers and warmer winters than the inland areas One example of this moderating effect is the Gulf Stream a warm current in the North Atlantic flowing from Gulf of Mexico north east along United States coast to Massachusetts and then eastward toward Europe The oceans are also the birthplace of storms that affect cli mate throughout the world OCEANOGRAPHIC RESEARCH The scientific study of all aspects of the oceans is called oceanography The major branches of this study are concerned with the physical nature of the oceans their chemical and mineral constituents the great variety of living things that inhabit 13
