Ocean's Depth and Volume Revealed

The Earth's oceans are among the most mysterious places on the planet, but scientists now have at least figured out how deep the oceans are and just how much water they hold. A group of scientists used satellite measurements to get new estimates of these values, which turned out to be 0.3 billion cubic miles (1.332 billion cubic kilometers) for the volume of the oceans and 12,080.7 feet (3,682.2 meters) for the average ocean depth. Both of these numbers are less than many previous estimates of the ocean's volume and depth.

"A lot of water values are taken for granted," said Matthew Charette, an associate scientist at the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Mass., who led the new audit of the oceans. "If you want to know the water volume on the planet, you Google it and you get five different numbers, most of them 30- or 40-year-old values."
Crude measurements of volume

The depth estimate of 2.3 miles is about 69 to 167 feet (21 to 51 meters) less than previous estimates. (Some areas of the ocean, such as the Mariana Trench (at nearly 7 miles or 11 km deep) are of course much deeper than the average, while other areas, such as the Mid-Atlantic Ridge are shallower.)

The researchers report that the world's total ocean volume is less than the most recent estimates by a volume equivalent to about five times the Gulf of Mexico, or 500 times the Great Lakes. While that might seem a lot at first glance, it is only about 0.3 percent lower than the estimates of 30 years ago.