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Hydrosphere General Knowledge

▬ There is an expansion of the hydrosphere over 3/4 of the entire earth (about 71%). The total amount of water present on Earth is in the oceans, which is saline. Only 2.5% of the amount of water is clean water or sweet water.

▬ Ocean water has two important properties – temperature and salinity.

▬ The large part of the hydrosphere which has no definite boundary – is called ocean. The largest ocean is the Pacific Ocean.

▬ Sea: The large part of the hydrosphere, which is surrounded by water on three sides and mixed with the ocean on one side, is called the sea.

▬ Gulf: The area of water that forms after entering the terrestrial part of the sea is called a bay.

▬ Bay: It is surrounded by two sides of the site, a group of islands on one side and the estuary on the other side joins the sea.

▬ Normally the temperature of ocean water is between 5 ° C to 33 ° C.

▬ Due to the difference in size, the annual temperature in the Atlantic Ocean is higher than in the Pacific Ocean.

▬ Northern Hemisphere has higher temperature than South Hemisphere.

▬ Salinity is expressed in per thousand, the average salinity of seawater is about 35 per thousand.

▬ The line drawn by joining places of equal salinity is called Isohaline.

▬ The highest salinity is found between 20 ° – 40 ° north latitude and 10 ° – 30 ° south latitudes.

▬ Turkey’s Van Lake has the highest salinity (330 %%).

▬ Gai Aut-flat heading sea mountains are called Gai Aat.

▬ Mariana trough is the deepest trough in the Pacific Ocean near the island of Guam. Its depth is about 11 km (11033 m). It is also called Challenger trough.

Some important troughs



Depth (m)





Pacific Ocean




Pacific Ocean




Pacific Ocean


Puerto Rico


Atlantic Ocean (P Islands)




Southern Atlantic Ocean




East Indian Ocean (Java Island)

▬ Shoal: The part of submerged uplift where the depth of water is shallow, it is called shola, it is not made of coral.

▬ Great Barrier Reef: It is the largest coral reef in the world near Queensland, Australia. It is in the Pacific Ocean.

▬ Pacific Ocean: It covers 1/3 of the surface with its enclosed sea. Its area is 16,57,23,23,740 square kilometers. Its shape is triangular and the area is more than the area of the entire site. Its top is on the Bering Strait and the base is on the Antakatika continent. Its length at the equator is more than 16000 km. It has continents of Asia and Australia in its west, North and South America in the east and Antarctica in the south. The coral reefs are the main feature of the Pacific Ocean. In total there are more than 2000 islands in this vast ocean. Most of the coastal ocean is in the western part of the Pacific Ocean. Among them, the Bering Sea, Aakhotsk Sea, Japan Sea, Yellow Sea and East China Sea are important. The Gulf of California is famous only on the east side. The average depth of its basin is 7,300 meters.

▬ Atlantic Ocean: It is the sixth part of the whole world. Its area is 8,29,63,800 sq km, which is about half of the Pacific Ocean. Its shape resembles the S-shape of English. It has both America in the west and Europe and Africa in the east, Antarctica in the south. Greenland in the north, Hudson’s Bay, the Valtic Sea is located on the North Sea Magnut. The most important feature of this ocean is the Mid-Atlantic Ridge. It is approximately 14,000 km long and 4,000 tall, from Iceland in the north to Bouvet Island in the south. Even though it is a submerged cuttack, many of its peaks have become small islands above the water. Pico Deep of Azores and the Cape Verde Island are prime examples. The steepest peak is that of the group of islands called St. Paul near the geocentric line. Bermuda coral islands and Ascension, Dryista di Kanha, St. Helena, Gua and Bowett Deep volcanic islands in the Atlantic Ocean. The ocean widens near latitude 55 ° north. Where it is called as Telegraphic Pattar. Romanche Deep near the equator divides it into two parts. The northern part is named Dolphin Range and the southern part is Challangar Cuttack. Along the shores of the Atlantic Ocean, the Bay of Bayfin, Hudson Bay, North Sea, Baltic Sea, Gulf of Mexico, Mediterranean Sea and Caribbean Sea are important seas.

▬ Indian Ocean: Asia continent to its north, Antarctica continent to south, Australia continent to east and Africa continent to west. It is a semi-ocean. Its total area is 7,34,25,500 sq km. It is joined by the Pacific Ocean on one side and the Atlantic Ocean on the other. The Tropic of Cancer is the northern boundary of this ocean. It has examples of Lakshadweep and Maldive coral islands near the southwest coast of India. The islands of Mauritius and Reunion are islands originating from the volcanic process. The largest island in this ocean is Madagascar. East of Madagascar is the island of Mauritius. There are only two onshore seas in this ocean. They are the Red Sea and the Persian Gulf. The Arabian Sea and the Bay of Bengal are also counted in the seas, but these are only the northern expanse of the Indian Ocean. The island of Diagogarsia lies in this ocean.