Roughly 75 percent of the Earth’s surface is covered by water, mainly in the oceans, which explains why the Earth is frequently called a “water planet”.  Ninety-seven percent of all the Earth’s water is in the oceans.  Two-thirds of the 3 percent that is not in the oceans is in the form of ice in glaciers and ice caps. Of the remaining one percent, most of that is below your feet, in the form of sub-surface “ground water”.

The distribution of land versus ocean around the Earth is uneven. Much more of the Southern Hemisphere is covered by oceans than is the Northern Hemisphere. The major oceans are the Atlantic, Pacific, and the Indian. The Pacific Ocean covers a surface area of 64 million square miles, the Atlantic covers 32 million square miles, and the Indian covers 28 million square miles. Two other smaller oceans are found close to the polar areas. The Arctic Ocean covers a surface area of 5 million square miles, while the Southern Ocean (so designated in 2000) covers the non-land area close to Antarctica, extending poleward from 60 degrees south latitude.

Much of the Earth’s population lives at or near the coasts of the oceans. Over half of the population lives within 125 miles of an ocean coast, and eight of the ten largest cities on Earth are on an ocean coast. These include Tokyo, Mumbai, New York City, Shanghai, Lagos, Los Angeles, Calcutta and Buenos Aires. However, the Earth’s oceans impact weather and climate over huge areas far removed from their coasts.