Oceans For Dummies. Joseph Kraynak

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Chapter 1

      Brushing Up on Ocean Fundamentals

      IN THIS CHAPTER

       Getting a big-picture view of the ocean and related bodies of water

       Wrapping your brain around the water cycle

       Sampling the vast diversity of ocean life

       Building a mutually beneficial relationship with the ocean

      Before you dive into any large or complex topic, you’re wise to step back and look at the big picture. A general understanding provides a framework on which to hang the details. In this chapter, we provide that framework, establishing a context for understanding the many facets of the ocean and how they all fit together.

      We start by introducing you to the ocean and breaking it down into its five “oceans.” Then, we get into a few topics in the realm of physical oceanography — the water cycle, the shapes of the ocean basins, meteorology, and other properties and processes that explain what makes the ocean tick from a physical standpoint. We then introduce you to the various groups of life-forms that populate the ocean — plants, animals, and beings that fit in neither (or both) categories. Finally, we wrap things up with a discussion of the ocean’s current state and the human-ocean relationship — the benefits we gain from the ocean and our responsibilities as environmental stewards in protecting and preserving it.

      Get ready for a wild ride. In this chapter, we cover a lot of ground, not to mention all that water!

Taking a Nickel Tour of the Ocean(s)

      The ocean is big. How big? Well, it covers about 360 million square kilometers (140 million square miles), which is just a smidgen more than 70 percent of Earth’s surface. Volume-wise it contains approximately 1.3 billion cubic kilometers (321 million cubic miles) of water — that translates to about 352 quintillion gallons, which accounts for about 97 percent of Earth’s water. In terms of living space, the ocean comprises about 99 percent of the biosphere — all land, water, and atmosphere where life on Earth exists.

      Because it’s so big, people have developed all sorts of ways to slice and dice it to better understand and describe the different areas that make it up.

      Dividing the ocean into oceans … or not

Earth has only one ocean, which is why we will refer to it as the ocean (singular) throughout this book. Geographically, it’s divided into four or five oceans, depending on who’s doing the dividing. Prior to the year 2000, text books recognized four oceans: the Atlantic, Pacific, Indian, and Arctic. Sometime around the year 2000, the International Hydrographic Organization designated a fifth ocean the Southern Ocean — a band that wraps around the world from the coast of Antarctica to 60 degrees south latitude (see Figure 1-1). Here’s a brief description of each of the five oceans, in order of size, because, well, size matters.