Introduction--Lecture Notes

What is Oceanography? Oceans are nebulous storehouses of dynamic and complex interactions between physical and chemical properties of water and atmosphere, geography of the coastal regions and seafloor, geology of the ocean crust and sediments, and the flora and fauna. Therefore, Oceanography is an amalgamation of Physics, Chemistry, Geography, Geology, Botany, and Biology. Add in the "history" aspect and you have a bit of Paleontology to boot!

To appreciate the diversity of Oceanography, one needs to look at the historical development of the science (add in History, Economics, Sociology, etc., etc.). The developmental pattern is a reflection of humanity's needs for sustainability, exploitation, warfare, and general interest in the mysterious realm. Of primary importance was furthering navigation on the seas; later came advances in monitering and dissection the oceans.

Two fundamental theories have directed the recent study of the oceans: Plate Tectonics and Oceanic Ecology. Plate Tectonics is an all-encompassing theory that explains the development, configuration, and evolution of the ocean basins. The theory is founded on the premise that convective forces within the Earth cause the outer, hardened layer to break into various plates of differing densities and then these forces mover the plates around in a complex dance.

The processes as outlined in Plate Tectonic theory can be recognized in the pattern and layering of sediments along the coastlines and on the sea floor. Oceanic sedimentation is also influenced by complex physical, chemical, and biological pathways.

The fundamental physico-chemical process acting in the oceans is related to the strong forces tied up in the water molecule. Add to this the effects of various dissolved salts and organic matter and it is easy to see why the oceans are such a complex stage for chemical processes.

Since the oceans cover 3/4 of the Earth's surface, they play a fundamental role in driving the atmosphere (e.g., El Niño). Meteorology is the study of weather which is the term we apply to the Earth's way of dealing with budgeting heat and moisture. Many of these budgetary fluxes are also influenced by the rotation of the planet.

The rotation of the planet also is the culprit in directing ocean circulation. Circulation, or currents, are initiated by a combination of winds, density differences in water masses, and ocean basin geography and sea bottom topography.

Most of us interact with the physical energy of the ocean water movement through waves. Waves are also driven by the wind (with the important exception of tidal-, density-, and tectonic-driven waves). Although beautiful in their simplicity, the fundamental properties of waves are very complex and their shape and pattern is dictated by water depth, wind speed, coastline configuration, and a host of other factors.

As we delve deeper into Oceanography (pun intended), we realize that the various aspects become more complicated. Living in Humboldt County, we have an inate appreciation for the diversity of coastlines and how the geology-both rock type and structure-and oceans/rivers sculpt the landscape. Add to this the effects of human intervention and a complex picture develops indeed!

Perhaps the most intriguing aspect of the oceans is the complex web of life that it harbors. Right now, biological oceanography is undergoing a fundamental revamping of the science that parallels the upheaval caused by plate tectonic theory (another pun intended). We used to think of "food chains", but we now realize that the nutrient pathways in the ocean are as complex as any other aspect of the oceans with many feedback loops. The bulk of the life exists as primary producers in the upper waters of the broad oceans. Larger organisms, from sedentary corals to awe-inspiring whales feed on these organisms and various lesser consumers along the way.

The communities of organisms are found in a variety of environments from the estuaries near river mouths, to reefs, to open oceans, and even upon chimneys of boiling water in the great ocean depths. Even more astounding are the complex communities found within and upon a sand grain as it settles through the water column.

Of all the organisms that rely upon the oceans, we tend to be most concerned with ourselves. Many food and materials in our daily lives come from the oceans. Yet, our activities as individuals and cultures threaten the very oceans we depend upon. How can we both utilize the resources of the oceans and also protect it while navigating (yet another intended pun!!) the tempest of conflicting economic, legal, sociological, and environmental forces?

As a final note, I must admit that to yours truly, the most interesting aspect of oceanography deals with looking at how the oceans, and all that they contain, have evolved over time. On one level, we look at broad patterns that span time scales of tens to hundreds to thousands of millions of years. These patterns are largely dictated by plate tectonics and evolution. On another level, "paleoceanographers" investigate changes that have occurred on the thousands to hundreds of thousands years scales. In contrast, these patterns are typically governed by localized and global environmental fluctuations.