How Deep Are the Oceans?

Answer:

The smallest of the oceans — the Arctic Ocean — is also the shallowest, with an average depth of about 5,000 feet. But like the others, it is crossed by mountain ranges separating deep basins, one of which is 17,880 feet deep.

The next larger, the Indian Ocean, averages about 13,000 feet but at its deepest, in the Java Trench, reaches down 25,344 feet. The Atlantic is only slightly deeper, averaging 14,000 feet; it has a maximum depth of 28,374 feet in the Puerto Rico Trench, a great chasm just north of the West Indies.

The largest ocean, the Pacific, like the Atlantic, has an average depth of 14,000 feet. But its vast expanse conceals the deepest known scar in the earth’s crust. The Mariana Trench, a deep gash near Guam, at one point plunges to a depth of 36,198 feet. Its bottom is nearly seven miles beneath the surface of the sea ? more than a mile deeper than Mount Everest’s height above sea level.