1) The
Pacific is the largest of these oceans, covering 63,784,077 sq miles
(165,200,000 km²). It fills the area between the western coastline of the
Americas, the eastern coastlines of Asia and Africa, and is capped to the North
and South by the Arctic and Antarctic regions. In part because of the numerous
tropical islands of East Asia, the Pacific boasts the longest total shoreline,
some 84,300 miles (135,663 km). It also holds the deepest point on the earth’s
sea floor, the Challenger Deep in the Marianas Trench, near the island of Guam.
At close to 11,000 meters below sea level, or almost 7 miles, this crevice was
first sounded in 1875 by the HMS Challenger. It would be thought that life
forms could not exist at that depth and extreme water pressure. But beginning
with radiolarians dredged by the Challenger, hundreds of different species have
been found in the Challenger Deep, including shrimp, flatworms, and
single-celled protests thought to be very similar to Earth’s earliest life
forms. The Pacific was named by Portuguese explorer Ferdinand Magellan, who set
sail from Spain in 1519 to find a westerly route to the Spice Islands around
the southernmost tip of South America. Rounding the Horn for the first time in
November 1520, Magellan passed through the Straits now named for him into a
vast sea so calm he described it as a “beautiful, peaceful ocean.”
2) The
next largest ocean is the Atlantic, with an area of 41,081,270 sq miles
(106,400,000 km²). It is bounded by the Americas to its west, and by the
western shores of Europe and Africa to its east. It includes the Mediterranean,
Caribbean and Baltic Seas, and the Gulf of Mexico. Like the Pacific Ocean, it
reaches to the Arctic and Antarctica. In European History, the Indian and
eastern Atlantic Oceans were the most completely charted of the world’s seas
until the 15th Century; indeed this area was considered the sum total of the
known world. With the escalation of the Spice Trade, desire for a Western route
to the East Indies led to the eventual navigation of the globe as we now know
it. The warm, stormy waters of the North Atlantic once supported great
populations of cod and sperm whale. Cod has been an important human food source
for hundreds of years, notably during the founding of America’s colonies, when
North American settlements relied heavily upon cod’s easily preserved
high-quality flesh. The sperm whale, at over 20 meters in length, is the
largest living toothed animal. It has huge stores of bodily oil, used to light
the lamps of Europe and North America, made this whale greatly sought-after in
the late 18th and early 19th Centuries, nearly leading to its extinction. While
high-quality whale oil continued to be used in many industries well into the
20th Century, the development of kerosene meant the end to large-scale sperm
whale hunting. Learn more about the Atlantic Ocean.
3) The
Indian Ocean covers a 28,400,130 sq mile (73,556,000 km²) area between the
eastern coast of Africa, the shores of the Middle East and India to its north,
and is separated from the Atlantic Ocean by Southeast Asia and
Australia/Oceania. Home to a great variety of humankind throughout history, the
Indian Ocean is also rich in exotic plant and animal species, and still
supplies the world with spices such as black pepper, nutmeg, and ginger. While
these spices are now used primarily to flavor the world’s cuisines, they were
used from earliest times to preserve foods, and were thought to have great
medicinal properties. Indeed, during the terrible plagues of the 13th through 17th
Centuries, Europeans were so convinced of their curative powers that their
countries fought repeated wars and gambled untold fortunes to gain control of
the Spice Islands, and the number of explorers and sailors willing to risk
their lives charting new maps to reach them is difficult to imagine.
4)
At 5,400,025 sq miles
(13,986,000 km²), the Arctic is the smallest and shallowest of the five Oceans,
and falls mostly within the Arctic Circle. It is surrounded by the Eurasian and
North American continents, and includes Hudson Bay and the North and Barents
Seas. For most of the year, these seas are a mass of ice often hundreds of feet
thick; even during the brief summer months ice can make the Arctic Ocean
impassable, and it wasn’t known until modern times that there is little solid
ground in the most northern reaches of the Earth. Nonetheless, its icy
landscape has been inhabited since ancient times by the hardy ancestors of the
Inuit of North America, the Sami of Scandinavia, and the Nenets of Russia. The
great explorers of the 16th-19th Centuries were determined to find passage from
the North Atlantic through to the rich shores of Asia in search of spices,
silks and opium. The majority of these explorations ended in failure and
disaster; but in the 19th and 20th Centuries accurate passage was finally
charted through the mostly frozen waters of the Arctic.
5) Until the mid-20th Century, the waters
surrounding Antarctica were generally considered to be extensions of the
adjoining oceans. But in 2000, members of the International Hydrographic
Organization almost unanimously agreed to identify these southernmost waters as
the Southern Ocean. Although its definite boundaries are yet to be determined,
below 60°S latitude is generally accepted, giving it an area of 7,848,299 sq miles
(20,327,000 km²), and making it the fourth largest of the Earth’s oceans.
Joining waters of the southern Pacific, Atlantic and Indian Oceans with a
persistent easterly current, the frigid Southern Ocean has a great influence on
the Earth’s weather patterns.
