Fjords are underwater U-shaped glacial valleys and are found around the world. Learn about fjords from this fact-filled article about fjords.

Learn about the bifurcation of rivers, the separation of rivers into distributary streams.

An overview of water desalination, the process of changing sea water into fresh water.

Water is becoming more and more a scarce and valuable resource as population and consumption rise. Learn more about water as a scarce resource.

Fog: Read this article to learn about fog. Learn about how fog forms, the different types of fog, and where some of the foggiest places in the world are.

Geography of the Earth's Seas: Refer to this article to learn about the Earth's largest seas. Learn the names of the seas, area, average depth and what oceans they are within from Geography at About.com.

A history and definition of the idiom The Seven Seas. Find out what the ancient and modern Seven Seas consist of, from the About.com Geography Site.

An overview of coral reefs - their growth and development along with the bleaching and destruction of coral reefs through global warming and sea rise.

An overview of water and water resources. Learn all about water as a natural resource in the world.

Oceanography is the study of the world's oceans; learn the essentials of oceanography from this easy-to-understand overview from the Geography GuideSite at About.com.

A thorough and complete overview all about dams and their uses and the reservoirs that store water behind dams, from the About.com Geography GuideSite.

A comprehensive overview of icebergs from their formation from ice sheets to their movement in the world oceans to their tracking and monitoring to their melting.

A comprehensive overview of aquifers and information about the Ogallala Aquifer in the United States, from Geography at About.com.

An overview of dew point, which represents the temperature at which the air is completely saturated with water vapor. This overview of dew point is from your About.com Guide to Geography.

An overview of evapotranspiration, which is a combination of evaporation and transpiration. Learn about the climate concept of evapotranspiration and potential evapotranspiration from your About.com Geography site.

A comprehensive overview of glaciers. Includes the types of glaciers, how glaciers carve the land, and the importance of glaciers. From Colin Stief of Geography at About.com.

Discover the fascinating intertidal zone, where land, ocean, and air meet.

Find out the similarities (and differences) between different types of water bodies, from your About.com Guide to Geography.

Learn about ocean currents and how they circulate water in the oceans around the planet, from the About.com geography site.

An overview of ocean waves, which are caused by the friction of wind over open ocean water. Learn all about ocean waves from this geography article on About.com.

Discover the fascinating truth behind oxbow lakes, billabongs, and bayous.

An overview of pluvial lakes, which were formed when the earth's climate was much wetter than today's climate. An article about pluvial lakes from About.com's Geography site.

Average annual precipitation is a vital piece of climatic data - one that is recorded through a variety of methods. Precipitation (which is most commonly rainfall but also includes snow, hail, sleet, and other forms of water falling to the ground) is measured in units over a given time period.

Floods are the most common natural disaster. Learn more about floods, the definition of a 100-year-flood, and how to prepare.

Rivers provide us with food, energy, recreation, transportation routes, and of course water for irrigation and for drinking. Learn all about rivers from the About.com Guide to Geography.

The classification of streams or rivers was developed to measure the size of the waterways of the world. Learn about stream order from this overview on the About.com Geography Site.

The Gulf Stream is a strong, fast moving, warm ocean current that originates in the Gulf of Mexico and flows into the Atlantic Ocean. Learn all about the Gulf Stream from this article from the expert Geography at About.com site.

A summary of how water gets from ocean to land to river and back again, through the hydrologic cycle from your About.com Guide to Geography.

An easy-to-understand overview of how the sun and moon create tides that affect the earth's oceans; includes graphics.

An overview of watersheds, the relationship of watersheds to rivers and streams, and information about watershed management from the About.com expert Geography Site.

An overview and information all about wetlands. Learn about wetlands from this informative article from the About.com expert geography site.

Learn about the formation of river deltas, the different types of deltas and why they are important for our planet and for humans.