Percentage of Saline Water on Earth's Surface

Saline water refers to water that contains a significant amount of dissolved salts, such as sodium chloride (table salt). It is commonly found in oceans, seas, and saltwater lakes. The percentage of saline water on Earth's surface is a crucial aspect to understand, as it has implications for freshwater availability and various ecological processes.

Explanation:

- The correct answer to this question is option 'A', which states that 97.3% of the Earth's surface water is saline.
- This percentage refers to the total volume of water on Earth's surface that is composed of saline water.
- It is important to note that the remaining percentage, approximately 2.7%, represents freshwater, which is vital for various purposes, including drinking, agriculture, and sustaining terrestrial and aquatic ecosystems.
- The high percentage of saline water is primarily due to the vastness of the world's oceans, which cover about 71% of the Earth's surface.
- Oceans contain a significant amount of dissolved salts, making them saline. The salt content is primarily a result of the continuous erosion and weathering of rocks on land, which releases minerals into rivers that eventually flow into the oceans.
- In addition to oceans, saline water is also found in seas, saltwater lakes, and salt pans.
- The remaining freshwater is primarily found in glaciers, ice caps, and underground aquifers. Only a small fraction of freshwater is easily accessible in the form of lakes, rivers, and streams.
- It is important to conserve and manage freshwater resources effectively, as they are limited and essential for various human activities and the functioning of ecosystems.
- Desalination, the process of removing salts and minerals from saline water, is one method to obtain freshwater from the oceans. However, desalination is energy-intensive and relatively expensive, limiting its widespread use.
- Therefore, understanding the distribution and availability of saline and freshwater resources is crucial for sustainable water management and ensuring the well-being of both human and natural systems.

In conclusion, 97.3% of the Earth's surface water is saline, while approximately 2.7% is freshwater. This highlights the importance of conserving and effectively managing freshwater resources, as they are limited and vital for various purposes.