Icon - Water Science School Quiz

A huge amount of water exists in the ground below your feet, and people all over the world make great use of it. But it is only found in usable quantities in certain places underground — aquifers. Read on to understand the concepts of aquifers and how water exists in the ground.

There is an immense amount of water in aquifers below the earth's surface. In fact, there is a over a thousand times more water in the ground than is in all the world's rivers and lakes. Here we introduce you to the basics about groundwater.

Yes, water below your feet is moving all the time, but not like rivers flowing below ground. It's more like water in a sponge. Gravity and pressure move water downward and sideways underground through spaces between rocks. Eventually it emerges back to the land surface, into rivers, and into the oceans to keep the water cycle going.

As a non-existent proverb states: " Humans don't live by surface water alone. " For thousands of years, people have also relied on groundwater to serve their every need. Groundwater is invaluable for many uses, from irrigation to drinking-water supply. But, you can't see groundwater, so how do water scientists know where it is in order to be able to drill wells and pump it out for use?

It is a frightening thought to imagine the ground below your feet or house suddenly collapsing and forming a big hole in the ground. Sinkholes rarely happen, but when they strike, tragedy can occur. Sinkholes happen when the ground below the land surface cannot support the land surface. They happen for many reasons; read on to educate yourself about sinkholes.

Artesian water is really not different from other groundwater, except for the fact that it flows to the land surface because pressure in the rocks underground force it to the surface. But, having water flow to the surface naturally is a handy way to tap groundwater resources.

Dissolved oxygen (DO) is a measure of how much oxygen is dissolved in the water - the amount of oxygen available to living aquatic organisms. The amount of dissolved oxygen in a stream or lake can tell us a lot about its water quality.

Plants and trees couldn't thrive without capillary action. Capillary action helps bring water up into the roots. With the help of adhesion and cohesion, water can work its way all the way up to the branches and leaves. Read on to learn more about how this movement of water takes place.

In practical terms, density is the weight of a substance for a specific volume. The density of water is roughly 1 gram per milliliter but, this changes with temperature or if there are substances dissolved in it. Ice is less dense than liquid water which is why your ice cubes float in your glass. As you might expect, water density is an important water measurement.