What is the percent of fresh water and salt water?
To determine the percentages of fresh water and salt water on Earth, we can look at the total volume of water and divide it into the two categories.
1. Find the total volume of water on Earth:
- The total amount of water on Earth is estimated to be around 1,386 million cubic kilometers (Mm3) or 1.386 × 10^9 km^3.
2. Determine the amount of fresh water:
- Freshwater includes water found in lakes, rivers, underground sources like aquifers, ice caps, and glaciers. It is only about 2.5% of the total global volume of water.
- So, multiply the total volume by the percentage of freshwater: 1.386 × 10^9 km^3 × 0.025 = 34.65 million cubic kilometers (Mm3) or 3.465 × 10^7 km^3.
3. Calculate the amount of salt water:
- Saltwater refers to water found in oceans and seas. It makes up the remaining portion after subtracting the freshwater volume from the total water volume.
- Subtract the amount of freshwater from the total volume: 1.386 × 10^9 km^3 - 3.465 × 10^7 km^3 = 1.352 × 10^9 km^3.
4. Convert volumes to percentages:
- To find the percentages, divide each volume by the total volume and multiply by 100.
- Percent freshwater: (3.465 × 10^7 km^3 / 1.386 × 10^9 km^3) × 100 ≈ 2.5%
- Percent saltwater: (1.352 × 10^9 km^3 / 1.386 × 10^9 km^3) × 100 ≈ 97.5%
Therefore, approximately 2.5% of the Earth's water is freshwater, while about 97.5% is saltwater.