Which ocean is the smallest?

With a total area of about 14 million square kilometers (5.4 million square miles), the Arctic Ocean is roughly 1.5 times the size of the United States. In addition to being the smallest, the Arctic Ocean is also the most inaccessible and least studied of all the Earth’s major ocean basins. The deepest parts of the Arctic Ocean (5,441 meters; 17,850 feet), known as the Canada Basin, are particularly isolated and unexplored because of year-round ice cover.

Exploration of the Arctic Ocean has become increasingly urgent because the Arctic environment is changing at a dramatic rate. Scientific communities now generally agree that the Arctic is in need of additional measurements and observations to accurately monitor and predict future changes. Arctic sea ice cover extent has decreased by about three percent per decade over the last 25 years and observations from submarines indicate a loss in ice thickness in all parts of the Arctic. Climate models predict that Arctic summer sea ice cover might be lost by 2100, which would turn the Arctic Ocean into an ice-free ocean for several months per year.

Obviously, one visible result of changes in the Arctic is the rapid loss of glaciers and sea ice. Less visible are the impacts on living organisms that depend upon glaciers and sea ice for their habitat. Loss of these habitats can also have direct effects on human communities. The Bering and Chukchi Seas and associated marine life are thought to be particularly sensitive to global climate change because these seas are places where steep temperature, salinity, and nutrient gradients in the ocean meet equally steep temperature gradients in the atmosphere.