How were the oceans formed?
Oceans were made during the Earth’s formative years. In the beginning, the Earth was extremely hot and gases escaped from it. Steam which was also released, covered the planet with thick clouds. As the Earth cooled gradually, rain fell from these clouds, collecting water in low-lying places on the Earth’s surface. The water got deeper and formed oceans as more rain fell.
Scientists believe that planets and the sun were formed from large clouds of dust and gas. Parts of this cloud started spinning collecting dust and gas which stuck together. These collections of dust and gas also attracted other matter. Over time, these collections of dust, gas and other matter grew into the Earth, the other planets and the sun.
As the Earth spun, it got smaller. The heavier materials went to the center and the lighter ones rose to the surface. The Earth was so hot initially that the surface rocks were molten. Gases, including steam, bubbled out of this liquid rock. More gases and steam were forced out of the Earth with lava from volcanoes. The steam formed huge clouds.
When rain fell from these clouds, at first, the Earth’s immense heat turned this rain back into steam but then as the Earth slowly cooled and its crust formed, the rainwater settled on the Earth’s surface.
It is unknown how much rain the Earth received back them, but it is certain that it was enough to fill up vast oceans.
What is the ocean floor made of?
The ocean floor consists of long chains of mountains which form mid-ocean ridges that rise to the heights of 3 kilometers above the sea bed. There are trenches too that are even taller than the Mount Everest. The ocean floor is also home to several volcanoes.
When oceanic plates move apart, they form mid ocean ridges. When the plates move into each other, they form trenches. As plates move against each other, they cause terrible earthquakes.
How deep can we go in the oceans?
The deeper you dive into the ocean, the more the water pressure. Underwater vessels need to be extremely strong to withstand such pressure. Some of the strongest vessels can dive up to about 20,000 feet.
In the ocean depths, water pressure is very high. Underwater vessels have to be extremely strong to withstand such pressure. Some of the strongest can dive to depths of about 20,000 feet.
Things to do –
- Try doing this experiment. Ask your parents to boil some water. Once the water reaches boiling point open the lid. You will see that steam rushes out of the vessel. Now carefully place the cover of the vessel above the steaming water, you will find that the steam collects on the cover of the vessel. What happens thereafter?
- Take a bucket of water and try and sink a plastic toy in it. You will see than no matter how hard you try to push it down, the toy always keeps coming up. Why does this happen?
- Research for images of underwater ridges, trenches and volcanoes.
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