While there is only one global ocean, the vast body of water that covers 71% of Earth is geographically divided into distinct regions. The United States recognizes five named ocean basins: Arctic, Atlantic, Indian, Pacific, and Southern.
The ocean and large inland lakes play an integral role in many of the Earth's systems, including climate and weather. More than 50% of all species on Earth are found under the ocean and the ocean helps sustain human life above the water by providing 20% of the animal protein and 5% of the total protein in the human diet. In the United States alone, there are over 95,000 miles of shoreline. More than half of the U.S. population lives within 50 miles of the coast in the narrow area of land known as the "coastal zone."
On April 20, 2010, an explosion on the Deepwater Horizon/BP MC252 drilling platform in the Gulf of Mexico killed 11 workers and caused the rig to sink. As a result, oil began leaking into the Gulf creating one of the largest spills in American history. During the next 87 days an estimated 4 million barrels (168 million gallons) were released from the reservoir, of which 3.19 million (134 million gallons) were released into the Gulf of Mexico.
In the 200-plus years since the industrial revolution began, the concentration of carbon dioxide (CO2) in the atmosphere has increased due to humans burning fossil fuels (such as car emissions) and changing the way land is used (such as deforestation). During this time, the pH of surface ocean waters has fallen by 0.1 pH units. The pH scale, like the Richter scale, is logarithmic, so this change represents approximately a 30 percent increase in acidity.
Ocean water is on the move, affecting your climate, your local ecosystem, and the seafood that you eat. Ocean currents, abiotic features of the environment, are continuous and directed movements of ocean water. These currents are on the ocean’s surface and in its depths, flowing both locally and globally.
Want to climb the tallest mountain on Earth? First you will need to climb into a deep ocean submersible and dive almost 4 miles under the surface of the Pacific Ocean to the sea floor.
Where does this pollution come from? Where does it go? Some of the debris ends up on our beaches, washed in with the waves and tides, some sinks, some is eaten by marine animals that mistake it for food, and some accumulates in ocean gyres. Other forms of pollution that impact the health of the ocean come from a single, known sources, such as oil spills, or from accumulation of many dispersed sources, such as fertilizer from our yards.
Knowledge of the times, heights, and the flow of tides is of importance in a wide range of situations such as navigation through coastal waterways; construction of bridges, docks, breakwaters, and deep-water channels; and for fishing, boating, surfing, and water sports.
Tsunamis are just long waves — really long waves. But what is a wave? Sound waves, radio waves, even “the wave” in a stadium all have something in common with the waves that move across oceans. It takes an external force to start a wave, like dropping a rock into a pond or waves blowing across the sea. In the case of tsunamis, the forces involved are large — and their effects can be correspondingly massive.
