My first college dictionary, Webster's 20th Century Dictionary of the English Language (1979), defines oceanography as "the branch of geography dealing with the oceans." Is this course a geography class? I don't think so! Let's check somewhere else.
Here's an entry from WWWebster Dictionary:
Main Entry: ocean·og·ra·phy
Etymology: International Scientific Vocabulary
: a science that deals with the oceans and includes the delimitation of their extent and depth, the physics and chemistry of their waters, marine biology, and the exploitation of their resources
- ocean·og·ra·pher /-f&r/ noun
- ocean·o·graph·ic /-n&-'gra-fik/ also ocean·o·graph·i·cal /-fi-k&l/ adjective
- ocean·o·graph·i·cal·ly /-fi-k(&-)lE/ adverb
They describe oceanography as "a science that deals with the oceans and includes the delimitation of their extent and depth, the physics and chemistry of their waters, marine biology, and the exploitation of their resources."
Now we're getting somewhere. The simplest definition of oceanography, the one you probably know, is "the study of the oceans." That's what it says in my illustrated Oxford Dictionary (1998). What does it say in your dictionary?
Garrison (3rd Edition) defines oceanography as "the science of the ocean." Some textbooks characterize oceanography as "a broad field in which many sciences are focused on the common goal of understanding the oceans." My favorite definition is "an interdisciplinary science aimed at understanding the relationships between physical, geological, chemical and biological processes in the sea." (It's my favorite because I made it up. I'm allowed to do that because I am a world famous card-carrying oceanographer. My American Express card was taken away, however...)
All these definitions notwithstanding, how can such a seemingly simple word be so complicated?
Consider this early attempt to define oceanography, as reported by the International Council for the Study of the Sea in 1902:
"...it was seen from the beginning that the study of the physical conditions, of the chemical nature of the ocean waters, of the currents, etc., was of the greatest importance for the investigation of the problems connected with life, that on the other hand, the study of the floating organisms had particular worth for the solution of the hydrographic problems, and consequently that a sharp line should never be drawn between these two main divisions..."
And this report in 1908, upon publication of the first edition of the Internationale Revue der gesamten Hydrobiologie und Hydrographie
"Above all, the editors recognize the necessity of a synthesis of our biological and hydrographic-geological knowledge of the waters. These two spheres of investigation are inseparable..."
Thus, oceanography integrates, synthesizes, and blends many types of knowledge. It is a "problem" that has been recognized for quite some time, and one with which we continue to grapple to this very day. In truth, there is probably not one single field of science that doesn't touch oceanography in some fashion.
Perhaps a better definition for oceanography would be "the science of all sciences as they relate to the ocean and its influences." Figuring that people in a galaxy far, far away could make out the blue color of the Earth, I would even venture to say that "alienology", the study of aliens, has some connection with oceanography!
As with many sciences, oceanography has its roots as a practical discipline. Early man needed oceanographic information to navigate, fish, trade, live, and survive on the sea. Sea travel was one of the principal means by which man traversed great distances and founded new civilizations. Thus, oceanography has great importance to the social and economic development of man, a role it continues to play to this day.
All of this is just another way of saying that oceanography is a hard field to define. It is a science that encompasses a whole bunch of subdisciplines. For this reason, oceanography is often referred to as an interdisciplinary science (i.e. composed of many disciplines). Thus, to study oceanography, one must be familiar with many different fields of science, a sort of "jack of all trades."
No less perplexing is the task of defining the ocean itself! Is the ocean defined by the seawater? Is it the basins that hold the seawater? Is the ocean an ecosystem, consisting of all the physical and biological forces that exist within it? Does this topic make your head swim?
Again, Webster's defines the ocean as "the great body of salt water that covers more than two thirds of the surface of the earth." It's the water! But if I take a bottle of seawater home with me, is it still the ocean?
Hmmm, Webster's also allows that geographic provinces across the globe are called oceans, such as the Atlantic Ocean, the Pacific Ocean, and the Indian Ocean. Yet there really aren't any boundaries separating the water in these oceans. Your book (and other ocean textbooks) commonly refer to the three great ocean basins (the Atlantic, the Pacific, and the Indian). Thus, it would appear that an "ocean" could be defined as the seawater contained within a major ocean basin.
Using this definition (if we can call it that), we can divide the world ocean (uh-oh) into three oceans: the Atlantic, the Pacific, and the Indian. However, the influence of mythology on oceanography has led to a popular tendency to name seven oceans (not to be confused with the seven seas), which include the Arctic, the North Atlantic, the South Atlantic, the North Pacific, the South Pacific, the Indian, and the Antarctic. In actuality, there is no such thing as separate oceans. All of the waters of the planet constitute one vast global ocean called the world ocean.
That settled, let's complicate things even further. What is the difference between an ocean and a sea? Nothing, most of the time, except...from a geographic point of view (does anyone detect a geographical conspiracy here?), a sea is considerably smaller than an ocean or (here's the part I like) a sea can be part of an ocean. Consider the seven seas dating back to ancient times and known to the Mohammedans before the 15th century: the Mediterranean Sea, the Red Sea, the East African Sea, the West African Sea, the China Sea, the Persian Gulf, and the Indian Ocean (hey, that's not a sea!). Hardly an around-the-world cruise! Add to that the Sargasso Sea which lies smack dab in the middle of the Atlantic Ocean and what have you got? A lot of unbounded water!
Confused? Consider the list of seas (54 in all) compiled by the International Hydrographic Bureau. They include seven seas within the Mediterranean Sea alone: the Adriatic, the Aegean, the Balearic, the Ligurian, the Tyrrhenian, the Ionian, and the Mediterranean proper. Thus, one could sail seven seas and never venture into an ocean!
My point in telling you all this is to help you realize that definitions, by their very nature, can only provide a general sense of a subject. There is always an exception and there is always more than one way to use a word. Stretch your mind. Go beyond the mere words. Think about the concepts presented here and the ones I will present over the next 17 weeks. Science is not a study in memorization. It is an approach to understanding the world about us; it is a process. The sooner you get comfortable with this idea, the easier this course will become.
With that in mind, I would like to introduce another abstract idea. I propose that the ocean is a living, organic, self-sustaining being. It is a self-sufficient biological system interacting with the physical environment as a whole to maintain a steady-state, self-regulating, system that balances the flow of energy from the atmosphere and the movement of materials from the lithosphere.
In other words, the ocean, the world ocean, is a global biosphere. It receives energy from the actions of the sun, winds, and tides, and distributes that energy around the globe. In addition, the ocean transforms chemical matter from the ocean basins and continents, and cycles that matter through living organisms and sediments. You might think of the ocean as a giant switchboard operator, orchestrating the movement of energy and matter across, within, and beyond the globe.
We will return to this concept of a living, breathing ocean when we talk about James Lovelock's controversial Gaia hypothesis. In the meantime, you should begin thinking about the relationships between the organisms of the sea and their environment. The interaction of physical, geological, chemical and biological processes within the sea is one of my favorite themes. Tune your mind to it!
Finally, one last little quick definition: My dictionary defines an oceanographer as "one who studies the ocean." Well, you just finished studying something about the ocean. That makes you an oceanographer from this moment forward. Congratulations! You've read a few pages and already you've launched a new career. Tell it to the world!
Carnegie Mellon University School of Computer Science On-Line