Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
Garrison, Tom S. Oceanography: An Invitation to Marine Science. Thompson Brooks/Cole, 2005: 4. "The average depth of the ocean is about 3,796 meters (12,451 feet), the volume of seawater 1.37 billion cubic kilometers" 1.37
billion km3
"The World Ocean." The Columbia Encyclopedia. CD-ROM. 2007, 6th Ed. New York: Columbia University Press. "The World ocean has an area of about 361 million sq km (139,400,000 sq mi), an average depth of about 3,730 m (12,230) ft, and a total volume of about 1,347,000,000 cu km (322,280,000 cu mi)." 1.347
billion km3
Viau, Elizabeth Anne. World Builders: Water on Earth. California State University Los Angeles. 2003. [see table 1] 1.310302
billion km3
Gleick, P.H. Earth's water distribution. Water Science for Schools. U.S. Geological Survey. 28 August 2006. [see table 2] 1.338
billion km3
"Ocean Volume and Depth." Van Nostrand's Scientific Encyclopedia 10th ed. 2008. "The volume of the oceans and their seas is nearly 1.5 × 109 [sic] cubic kilometers" 1.5
billion km3

You've heard it all before: 70 percent of the earth is covered in water! But what does that really mean? These waters that are spoken of have a breakdown into five different categories: Oceans, rivers, lakes, groundwater, and ice. As an essential part of our daily diet, water is vital for the survival of our ecosystem. The world's oceans comprise 97.3% of the total water on earth and consists of 5 oceans: Atlantic, Pacific, Indian, Arctic, and Southern. The current range for the volume of the world's ocean is from 1.3 to 1.5 billion cubic kilometers and it will still get larger and larger as time passes.

There are two origins of water: comets (extraterrestrial bombardment) and out gassing (condensation of steam from early volcanism). These processes are continuing today. It is estimated that the volume of the earth's ocean increases by 1 cubic meter every year.

Table 1: Where the Fresh Water Is
  Volume in Thousands
of Cubic Kilometers
Percentage of
Total Water on Earth
Remarks
Oceans 1,310,302 97.3 This is salty sea water. 
Ice 29,492 2.2 Much of this ice is in the Antarctic
Groundwater 6,733 0.5 Underground aquifers, deep wells
Lakes 242 0.02 Provide drinking water, irrigation water, fish and recreation
Soil Moisture 74 0.005 This is being used by our crops, trees, and surface vegetation
Water Vapor in the Atmosphere 14 0.001  Clouds, fog, and dew
Rivers 1.3 0.0001 Provide water for drinking, irrigation, and recreation
Adapted from: Environment Canada
Table 2: One estimate of global water distribution:
Water source Water volume,
in cubic miles
Water volume,
in cubic kilometers
Percent of
fresh water
Percent of
total water
Oceans, Seas, & Bays 321,000,000 1,338,000,000 -- 96.5
Ice caps, Glaciers, & Permanent Snow 5,773,000 24,064,000 68.7 1.74
Groundwater 5,614,000 23,400,000 -- 1.7
Fresh 2,526,000 10,530,000 30.1 0.76
Saline 3,088,000 12,870,000 -- 0.94
Soil Moisture 3,959 16,500 0.05 0.001
Ground Ice & Permafrost 71,970 300,000 0.86 0.022
Lakes 42,320 176,400 -- 0.013
Fresh 21,830 91,000 0.26 0.007
Saline 20,490 85,400 -- 0.006
Atmosphere 3,095 12,900 0.04 0.001
Swamp Water 2,752 11,470 0.03 0.0008
Rivers 509 2,120 0.006 0.0002
Biological Water 269 1,120 0.003 0.0001
Total 332,500,000 1,386,000,000 100
Source: Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York, vol. 2, pp. 817–823.

Ketsia Erra -- 2008