In this investigation you will make an estimate of the amount of Earth’s water in its oceans. Then you will make a model to see how close you came to the right answer.


What you need:


What you do:

1. Make a model of all of Earth’s water:

2. Make an estimate:

See all that blue between the continents? That’s all ocean except for the water frozen around the North Pole and in the Antarctic ice sheets.

3. Make a model of Earth’s ocean water:

Not much fresh water is there? There are 56 ml of fresh water left in your Earth Fresh bottle. Less than 3% of all of the water on Earth is fresh water.


Ocean water, fresh water, what’s the difference? Fresh water in the kind of water you could drink. Ocean water is salty. You can’t drink very much ocean water without getting sick. More that 97% of Earth’s water is ocean water.


How much salt would be in your ocean water? Ocean water on average has about 3 grams  of salt in every 100ml of ocean water. If you were to turn you’re the water in your Ocean bottle into ocean water, you would have to add almost 60 grams of salt to it.


What else do you want to know about ocean water? Some questions you might want to explore are:


Do some research and see you if you can find out the answers to those questions and questions you have.