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Earth’s ocean is a source of wonder, delight, sustenance, economic benefit, and awe in the face of its overwhelming mystery and power. It dominates the natural world in ways that scientists are only now beginning to understand. And although we call our home planet Earth, it would be more accurate to name it Ocean, since 71% of the globe is covered with water, and beneath the waves churn forces that make our world unique in the solar system:

  • Along mid-ocean ridges, lava flows from Earth’s interior, forming new oceanic crust and driving the formation and movement of continents via the crucial process of plate tectonics.
  • The ocean’s tremendous mass and thermal inertia serve as a climate control thermostat, moderating temperatures and making the planet habitable.
  • Life began in the ocean and was exclusively marine for billions of years; we owe our oxygen-rich atmosphere to the photosynthetic activity of oceanic organisms.

But for all its importance, the ocean hides its secrets, and it is only with the advent of new sounding and sampling techniques, satellite sensors, and deep sea submersibles that its riddles are being solved, shedding light on a domain that is breathtaking in its complexity and beauty.

Oceanography: Exploring Earth’s Final Wilderness takes you on a scientific expedition to fathom the ocean’s mysteries in 36 intensively illustrated half-hour lectures delivered by ocean scientist and Professor Harold J. Tobin of the University of Wisconsin–Madison, a researcher who has visited and mapped landscapes on the seabed that no human eyes had ever seen before.

Oceanography encompasses a wide range of fields, from biology and ecology, to geology, meteorology, chemistry, physics, and ocean engineering. No background in science is needed to follow these lectures, which provide a thorough appreciation for the ocean as a system that is arguably more intricate and fascinating than the continents, not least because it is a world that is fully three-dimensional, from the tidal zone to the deepest point on the ocean floor.

Piecing Together the Puzzle of the Ocean

Professor Tobin compares the exciting discoveries in oceanography in the past half-century to the exploration of a previously unknown planet. Scientists have been amazed again and again at what they’ve learned about the world beneath the waves. In these compelling lectures, you relive those discoveries, assembling the many pieces of the puzzle to gain a comprehensive picture of how the ocean works and how it affects the atmosphere, continents, and the web of life.

Among the discoveries you learn about are these:

  • New crust: Geologists once assumed that the ocean was a catch basin for sediments accumulating almost since Earth began. Instead, the seafloor is in a continual process of renewal and has the youngest rocks on the planet, far younger than rocks on land or even the water in the ocean itself.
  • Alien-like organisms: Biologists long believed that life could not exist at great depths. But not only does it exist, it flourishes in the utter darkness, cold, and high pressure of the deep sea in fantastic forms fit for a science fiction movie.
  • Living off Earth: Until recently, all life on Earth could be traced to photosynthetic processes drawing energy from the sun. But that was before the discovery of deep sea thermal vents, where organisms thrive on the primordial energy of the planet.
  • Rogue waves: Accounts of 100-foot-high “rogue” waves in the open ocean were long dismissed as physically impossible sailors’ yarns. However, satellite and other measurements show that they occur and account for many ships that go missing.

Above all, you will learn to see the ocean as a single entity of striking complexity. Despite the names we have assigned to different regions of the ocean—Atlantic, Pacific, Indian, Arctic—they are all one continuous body of water, dominating the planet with features such as mid-ocean ridges that encircle the globe like the seams on a baseball.

A Story of Pure Exploration

The ocean is a huge subject, and you begin Oceanography by taking stock of the vast scope of the discipline. “This story is one of pure exploration,” says Professor Tobin, and he approaches it by breaking the field down into its most important themes. First, he reviews the history of ocean exploration, before moving on to the topography of the seabed and how it is mapped. Diving deeper, he covers

  • the variety of habitats for ocean organisms;
  • the role of plate tectonics in creating and destroying the seafloor;
  • the origins of the ocean and life;
  • the sediments on the seabed and the conditions that produce oil and gas;
  • the reason that the sea is salty and why it isn’t getting saltier.

Then he spends a lecture on water itself, investigating the special properties that make it indispensible to life. He continues with

  • the origins of waves and tides;
  • the diversity of marine life, from the ocean air to the deepest ocean trench;
  • the forces that shape coastlines;
  • the nature of bottom life, from tide pools to the deep sea;
  • and the links between weather, climate, and the ocean environment.
  • Professor Tobin closes the course with a glimpse into the future of the ocean and humanity’s role in defining that destiny.

    The Ocean in Your Life

    Whether you live far from the coast or right on the water, the ocean touches on countless aspects of your life, from the climate to the oxygen-producing activity of ocean organisms to the many products that come to you by sea. The ocean’s relevance also shows up in news stories about overfishing, ocean dumping, and other environmental issues, as well as in accounts of disasters such as the following, which Oceanography covers in detail:

    • Japanese tsunami: The devastating tsunami that engulfed coastal Japan in 2011 was set in motion by a gigantic undersea earthquake along a subduction zone, where the ocean floor is plunging beneath the rocks of the continent.
    • Gulf of Mexico oil spill: The Deepwater Horizon blowout in 2010 caused the largest uncontrolled release of oil and natural gas into the ocean ever recorded. You look at the expected—and unexpected—repercussions on marine life.
    • Hurricane Katrina: Unusually warm water in the Gulf of Mexico in the summer of 2005 turned an average hurricane into a category 5 monster. You investigate the ocean conditions that spawn hurricanes and the surprising power of their storm surges.
    • El Niño: Every few years the global climate enters a period of more extreme weather, when the Pacific trade winds slacken and the sea surface temperatures rise off the coast of Peru. You investigate the resulting cascade of effects, known as El Niño.

    Enrich Your Understanding of the Ocean World

    Oceanography is one of the most exciting areas in science, combining the thrill of exploring an otherworldly realm with the insights it gives into how the Earth works in all of its domains. Having spent nearly a year-and-a-half of his life cumulatively at sea on research expeditions, Professor Tobin is not only an expert on the subject but an eyewitness to the many wonders he describes.

    After taking this course, says Professor Tobin, you will gain “an appreciation for the complexity and richness of the ocean environment”—a world of organisms that have evolved to live in every conceivable niche in the sea, of ceaseless volcanic activity that is hidden beneath miles of water, of tides and currents that girdle the globe, and of other fascinating phenomena that make the ocean the most dynamic part of the planet.

    Next time you go to the beach, spend time on a sailboat, take a cruise, or even read a book or watch a movie or nature program about the sea, you will think of the expanse of blue water in a new way, with an enriched understanding of the ocean world.

    Visit Oceanography: Exploring Earth’s Final Wilderness (The Great Courses) to read more...


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