Paragraph on “Fiords and Atolls” complete paragraph for Class 9, Class 10, Class 11 and Class 12

Fiords and Atolls

After the ice age glaciers flowed down from the mountains, as they moved they cut the mountains to form deep IF or ‘V’ shaped valleys. As the glaciers disappeared these valleys were filled with sea water to form Fiords. Fiords are mostly found along the mountainous coastline and they are shallow closer to the coast but deeper between the mountains. Most of the worlds Fiords are found in the northern most parts of Europe, Greenland etc. Some of the fiords are more than 300 kms long and 3 to 4 km wide and have depths ranging upto 1200 metres in the valleys. A coral reef forming a complete or a broken circle around a lagoon is called an Atoll. Atolls are formed from coral reef which may have existed around an island made up of a volcano. Over a period of time, as the level of the sea changed, the coral reef continued to grow while the volcano sank below sea level. Sinking of the volcano formed a lagoon while the growing coral reef encircled it to form an atoll. Atolls are not common all over the world because coral reefs need specific temperature and climatic conditions to thrive. This is the reason why most of them are found in the Indian ocean and the Pacific ocean.