Society & Culture & Entertainment Hobbies & Science

What Are the World's Four Main Water Sources?

    Surface Water

    • Ninety-seven percent of the world's surface water is in the oceans, which covers 71 percent of the surface area of the globe. Fresh water in lakes and rivers accounts for another 1 percent. Ocean water is 220 times saltier than fresh water. According to the U.S. Geological Survey (USGS), evaporating 1 cubic foot of ocean water yields 2.2 pounds of salt, whereas a similar sample from a freshwater lake will yield only one-hundredth of a pound. The salt in the oceans is a combination of mineral salts and decayed biological matter that have accumulated for as much as 500 million years.

    Ground Water

    • Water that falls to the ground as rain, sleet and snow soaks down to become stored in sand and gravel below the surface as aquifers and underground rivers. Seeping water gradually fills the porous material below the surface, gradually raising the saturation level toward the surface. The uppermost limit of this area of saturation is known as the water table. People make wells to extract water from the ground by boring below the water table and pumping the ground water to the surface. The Earth's natural filtration keeps groundwater clean and useable.

    Water Vapor

    • The amount of water vapor in the air varies from trace amounts to about 4 percent, depending on the aridity and temperature of the region. There tends to be less in colder areas with little surface water and the most in moist tropical regions. When the concentration exceeds 4 percent, the vapor condenses and falls to the earth as rain or snow. While being essential for the repletion of surface and groundwater supplies, atmospheric water vapor is also the most abundant greenhouse gas. It traps energy to raise Earth's surface temperature while giving the atmosphere its characteristic blue color.

    Ice

    • Both of Earth's poles are covered with ice, and some of that ice may have existed for as much as 8 million years. Antarctica has the majority of the world's ice, almost 90 percent, while the Greenland ice cap accounts for another 10 percent. Melting from the northern polar ice cap feeds fresh water into the oceans and into rivers that in turn feed freshwater lake systems like the Great Lakes. Glaciers cover 10 percent of all the Earth's land mass and account for the remaining small percentage of the world's ice. If all of Earth's ice were to melt at once, the USGS estimates that the sea level would rise by 230 feet.

SHARE
RELATED POSTS on "Society & Culture & Entertainment"
How to Calculate the Expansion of the Volume of a Liquid
How to Calculate the Expansion of the Volume of a Liquid
How to Polish the Air Bubbles Out of the Finish
How to Polish the Air Bubbles Out of the Finish
Pine Trees That Are Used to Make Corrugated Cardboard
Pine Trees That Are Used to Make Corrugated Cardboard
Easy Ways to Get TF2 Items
Easy Ways to Get TF2 Items
How to Survey an Ellipse
How to Survey an Ellipse
Who Is Jasper Johns?
Who Is Jasper Johns?
What Are the Dangers of Furniture Made With Pine Beetle-Kill Wood?
What Are the Dangers of Furniture Made With Pine Beetle-Kill Wood?
Energy Sources of Fuel
Energy Sources of Fuel
Forging & Smelting Techniques
Forging & Smelting Techniques
How to Make a Human DNA Model Using Clay
How to Make a Human DNA Model Using Clay
Recycled Newspaper Projects
Recycled Newspaper Projects
Instructions for an Aoyue INT 2702
Instructions for an Aoyue INT 2702
Making Clay Pots on a Wheel
Making Clay Pots on a Wheel
Ways to Reduce Heat Conductivity in Metal
Ways to Reduce Heat Conductivity in Metal
How to Convert a Metric Wrench to a Standard Wrench
How to Convert a Metric Wrench to a Standard Wrench
How to Make a Table Organizer
How to Make a Table Organizer
What Does Frequency Mean in Science?
What Does Frequency Mean in Science?
How to Glue Plastic to Aluminum
How to Glue Plastic to Aluminum
Planetary Gear Train Analysis
Planetary Gear Train Analysis
How to Make a Fish Kite
How to Make a Fish Kite
How to Cover a Model Plane With MonoKote
How to Cover a Model Plane With MonoKote
How to Make a 3D Button
How to Make a 3D Button
How Does UV Light Affect the Ocean?
How Does UV Light Affect the Ocean?

Leave Your Reply

*