Although interconnected, the World Ocean is usually subdivided into five oceans: the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean. The word "ocean" is sometimes used interchangeably with "sea," although a sea generally refers to a part of the ocean that is partially enclosed by land. Given the great importance that oceans have on the planet, they are studied extensively. Oceanography, which is sometimes referred to as oceanology, is the study of all aspects of the ocean, and a person who studies the ocean is called an oceanographer. Oceanography covers a wide range of topics including ocean waves, currents, ecosystem, eddies, and geophysical dynamics.
Brief History of Oceanography
Aristotle and Strabo are considered the first to study the ocean, as they observed and recorded ocean tides in Ancient Greece. Initially, the ocean was primarily explored for cartography, and exploration was mostly limited to the surface of the ocean and the animals brought out of the water by fishermen. In 1513, Spanish explorer Juan Ponce de León discovered the Gulf Stream. However, Benjamin Franklin was the first to conduct a scientific study of the Gulf Stream and to give it a name. Additionally, Franklin was able to measure the water temperature and explain the cause of the stream. Eighteenth-century explorers such as French admiral Louis Bougainville and British navigator James Cook were the first to gather information on the Pacific Ocean. The first detailed scientific textbooks on oceanography were authored by British geographer James Rennell and primarily focused on current flows of the Atlantic and Indian Oceans.
Branches of Oceanography
The study of oceanography has five branches: biological, chemical, geological, physical, and paleoceanography. Each branch deals with a specific aspect of the ocean, although some branches are closely related.
Biological oceanography or marine biology is the study of plants, animals, and microbes in the ocean. The study aims to determine the number of marine organisms and how they develop, adapt, and interact with one another and the marine environment.
Chemical oceanography or marine chemistry is the study of the chemical composition of the ocean and how such chemicals interact with the atmosphere and seafloor. The study involves analysis of the components of seawater and the impact of chemical processes on marine organisms. A central topic in chemical oceanography is ocean acidification, which generally describes a decrease in the ocean’s pH levels resulting from the emission of anthropogenic carbon dioxide into the atmosphere.
Geological oceanography is the study of the ocean floor and the processes that lead to the formation of ocean features such as valleys, canyons, and mountains. Through sampling, geological oceanographers can examine the history of the ocean floor over millions of years, climate, and the oceanic circulation.
Physical oceanography is the study of physical attributes of the ocean including waves, currents, tides, coastal erosions, and the interaction of the ocean and atmosphere. The key topics studied by physical oceanographers include ocean heat content and ocean currents.
Paleoceanography deals with the history of the ocean in the geologic past with regards to factors such as chemistry, geology, biology, circulation, and sedimentation patterns. The study involves the use of environmental models to assess the roles of various oceanic processes in global climate.