Oceanography - Study of the World's Oceans

An ocean
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Oceanography is a discipline within the field of Earth sciences (like geography) that is focused entirely on the ocean. Since the oceans are vast and there are many different things to study within them, the topics within oceanography vary but include such things as marine organisms and their ecosystems, ocean currents, waves, seafloor geology (plate tectonics included), the chemicals making up seawater and other physical characteristics within the world's oceans.

In addition to these broad topic areas, oceanography includes topics from a number of other disciplines like geography, biology, chemistry, geology, meteorology, and physics.

History of Oceanography

Some of the earliest oceanic explorations were an attempt to map the world's oceans to make navigation easier. However, this was mainly limited to areas that were regularly fished and well-known. This changed in the 1700s though when explorers like Captain James Cook extended their explorations into previously unexplored regions. During Cook's voyages from 1768 to 1779 for example, he circumnavigated areas such as New Zealand, mapped coastlines, explored the Great Barrier Reef and even studied portions of the Southern Ocean.

During the late 18th and into the early 19th centuries, some of the first oceanographic textbooks were written by James Rennell, an English geographer and historian, about ocean currents Charles Darwin also contributed to the development of oceanography in the late 1800s when he published a paper on coral reefs and the formation of atolls after his second voyage on the HMS Beagle.

The first official textbook covering the various topics within oceanography was later written in 1855 when Matthew Fontaine Murray, an American oceanographer, meteorologist, and cartographer, wrote Physical Geography of the Sea.

Shortly thereafter, oceanographic studies exploded when the British, American and other European governments sponsored expeditions and scientific studies of the world's oceans. These expeditions brought back information on ocean biology, physical formations, and meteorology.

In addition to such expeditions, many oceanographic institutes were formed in the late 1880s. For example, the Scripps Institution of Oceanography was formed in 1892. 1902, the International Council for the Exploration of the Sea was formed; creating the first international organization of oceanography and in the mid-1900s, other research institutions focused on oceanography were formed.

Recent oceanographic studies have involved the use of modern technology to gain a more in-depth understanding of the world's oceans. Since the 1970s for example, oceanography has emphasized the use of computers to predict ocean conditions. Today, studies focus mainly on environmental changes, climate phenomena like El Niño and seafloor mapping.

Topics in Oceanography

Chemical oceanography studies the different chemical elements present in seawater and how they interact with the Earth's atmosphere. For example, nearly every element in the periodic table is found in the ocean. This is important because the world's oceans serve as a reservoir for elements like carbon, nitrogen, and phosphorus- each of which can impact the Earth's atmosphere.

Ocean/atmosphere interactions is another topic area in oceanography that studies the links between climate changes, global warming and concerns for the biosphere as a result. Mainly, the atmosphere and oceans are linked because of evaporation and precipitation. In addition, weather patterns like wind drive ocean currents and move around different species and pollution.

Finally, geological oceanography studies the geology of the seafloor (such as ridges and trenches) and plate tectonics, while physical oceanography studies the ocean's physical characteristics which include the temperature-salinity structure, mixing levels, waves, tides, and currents.

Importance of Oceanography

In addition, oceanography is significant to geography because the fields have overlapped in terms of navigation, mapping and the physical and biological study of Earth's environment- in this case, the oceans.

For more on oceanography, visit the Ocean Science Series website, from the National Academy of Sciences.