Oceanography

Because the ocean covers over 70 percent of the planet and contains 99 percent of the living space on Earth, its composition (e.g., its physical, chemical, and biological makeup) has a significant impact on all life. This is true whether that life is in or out of the water. Oceanography is the study of that composition, the role the ocean plays in Earth’s ecosystems, and the ways in which the ocean impacts life on Earth (and vice versa). Oceanography covers a wide range of topics, including marine ecosystems, plate tectonics, ocean circulation, seabed geology, and the chemical and physical properties of the ocean. It is a vitally important field of study as climate change and pollution are threatening the ocean, rising sea levels are eroding coastlines and entire species of marine life are at risk of extinction.

The Four Branches of Oceanography

Oceanography is typically divided into the following four sub-disciplines: chemical oceanography, physical oceanography, geological oceanography, and biological oceanography (each of which has its own dedicated snapshot page elsewhere on the Ocean Connect website). These sub-disciplines are interrelated and closely aligned to other ocean-related fields such as ocean engineering, atmospheric science, and marine microbiology.

Chemical Oceanography

Chemical oceanography is considered a niche area within the broader field of oceanography. It is said that chemical oceanographers work at the “boundaries between chemistry and biology, geology and physics” and “apply their efforts to a broad spectrum of interdisciplinary challenges.” [1]  That is because the chemistry of the ocean is closely tied to ocean circulation and climate (physical oceanography), the plants and animals that live in the ocean (biological oceanography), and the exchange of material with the atmosphere, cryosphere, continents, and mantle (geological oceanography).[2] Chemical oceanographers are essentially oceanographers, but rather than studying the physics, biology, or geology of the oceans as a broad subject; they examine the chemical composition of this particular environment.

Physical Oceanography

Physical oceanography involves studying the properties (such as temperature and density) and movement (such as waves, currents, and tides) of ocean water.[3] It also involves studying the interaction between the ocean and the Earth’s atmosphere, how the ocean stores and releases heat, and coastal dynamics.[4] Stated another way, physical oceanographers study the interaction between the ocean and its boundaries — land, seafloor, and atmosphere — and the relationship between the sea, weather, and climate.[5]  Physical oceanography is divided into descriptive and dynamical physical oceanography. Descriptive physical oceanography “approaches the ocean through both observations and complex numerical model output used to describe the fluid motions as quantitatively as possible.”[6] Dynamical physical oceanography “seeks to understand the processes that govern the fluid motions in the ocean mainly through theoretical studies and process-based numerical model experiments.”[7]

Geological Oceanography

Geological oceanography is the study of the structure, creation, evolution, and history of the ocean floor. Geological oceanography is one of the broadest fields in the Earth Sciences and contains many subdisciplines, including geophysics and plate tectonics, petrology and sedimentation processes, and micropaleontology and stratigraphy.[8]  Geological oceanographers combine their knowledge of physical oceanography and marine chemistry to piece together information about how the Earth was formed and how the movement of plates and continents causes earthquakes and volcanoes.[9] The results of this work help us understand the processes that created the ocean basins and the interactions between the ocean and the seafloor.[10] By examining the distribution of fossils embedded in the seafloor, geological oceanographers also try to understand past changes in the Earth’s climate and the causes for those changes.[11]  And in studying the past, the belief is that the information collected can then be used to predict and ultimately help lessen the impacts of future climate change.

Biological Oceanography

Biological oceanography is the study of the ocean through the lens of marine life, its distribution, abundance, environmental interaction, and predation.[12] A biological oceanographer pays particular attention to the effects of chemical, physical or geographic properties of the ocean and how these affect the distribution and abundance of marine organisms in the sea. Biological oceanography has many similarities to marine biology. However, while marine biologists study the plants, animals, and protists in the ocean, biological oceanographers study marine organisms and their biological processes within the context of their natural environment.[13]

…

Citations

1. Chemical Oceanography, MIT-WHOI Joint Program.
2. Chemical Oceanography, School of Oceanography, University of Washington.
3. Oceanography, Texas A&M University.
4. Physical Ocean, NASA Science, Share the Science.
5. A Sea Grant Guide to Ocean Opportunities.
6. Descriptive Physical Oceanography: An Introduction, Talley, Lynne D. (2011).
7. Descriptive Physical Oceanography: An Introduction, Talley, Lynne D. (2011).
8. Oceanography, Geological, Water Encyclopedia.
9. OceanOpportunities, Woods Hole Oceanographic Institute.
10. What does an oceanographer do? National Ocean Service, NOAA.
11. OceanOpportunities, Woods Hole Oceanographic Institute.
12. Oceanography and Marine Biology (Are They Same or Different), Earth Eclipse.
13. Oceanography, Marine Careers, NH Sea Grant.