1 In recent years, the U.S. has seen a number of winter storms that have caused surprisâ¦. 2  The Periodic Table of Elements Life is sustained by a number of chemical elements. 3  They are responsible for the birth of planets and the evolution of cells to complex organisms.
Water distribution on Earth - Distribution of saline and fresh water. 1  The total volume of water on Earth is estimated at 1.386 billion kmÂ³ (333 million cubic miles), with 97.5% being salt water and 2.5% being fresh water. 2  The total volume of water in rivers is estimated at 2,120 kmÂ³ (510 cubic miles), or 2% of the surface fresh water on Earth.
About 71% of the Earth's surface is covered with water, most of which is found in the oceans. In fact, 97% of Earth's water, nearly all of it, is in the Earth's oceans. This means that just 3% of Earth's water is fresh water, water with low concentrations of salts (Figure 13.2). Most freshwater is found as ice in the vast glaciers of Greenland and the immense ice sheets of Antarctica.