Hi Sarah! Can you help me with chapter 'Water and its Circulation'
Sure, Lily! Come in!
Yes, these words are a little difficult. Could you explain these?
Let's start with the new terms:1. hydrological cycle2. Saline water3. waves4. currents5. crest6. trough
Let's start with the water cycle or the hydrological cycle. Water from seas and oceans evaporates in to the sky where it condenses to form water droplets. These water droplets grow in size and and eventually fall as rain. This water goes back into the oceans and the cycle continues
Yes! Now I understood this concept. So the hydrological cycle is a continuous process including evaporation, condensation and precipitation
And isn't salinity the amount of salts present in the oceans.
Now let us talk about fresh and saline water. Fresh water contains very little dissolved salts, whereas saline water contains a large amount of dissolved salts. Around 97% of all water on earth is saline. However, only 3% of fresh water is available on Earth, out of which only 1% is accessible by humans.
Yes. You are absolutely right! And also there are many factors that affect salinity
Let's talk about oceans. Oceans are of domestic, economic and climatic importance to us. The temperature of ocean water is not the same everywhere. They are warmer near the equator and become cooler towards the poles. Oceans show two types of movements - waves and currents.
I think I can tell about waves. Waves are the up and down movement of water particles caused by wind. The upper part of a wave is called the crest while the lower part is called a trough. Huge tidal waves, called tsunami, can cause massive destruction.
Yes! You are absolutely right! You are learning very well!
Lastly, we have ocean currents. These are streams of ocean water continuously flowing in definite directions. They are narrow and swift and can travel at speeds from 3 to 10 km. They move clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere. They are of two types - warm currents and cold currents. The affect the climate and human activities on the coasts. Hope you understood whatever I taught.
Yes, I understood! Thank You! You helped me a lot!