Download App

Geography Write short note

Ocean Resources · Maharashtra Board STD 11 Commerce / Arts (MSBSHSE - English Medium). 6 questions.

Questions

Write short note

Take a timed test

6 questions · self-marked practice — reveal the answer and mark yourself.

Question 14 Marks
Deposition and Continental Slope
Answer
  1. After the extent of continental shelf is over, there is a sharp drop in the ocean floor.
  2. The gradient of slope in this region can be between 2° to 5°. This is called continental slope.
  3. The depth of this slope extends from 200 m up to 4000 m from sea level.
  4. Due to its steepness, the continental slope stretches over a limited area.
  5. The deposition of sediments is also limited in this part.
  6. The continental slopes are generally considered as boundaries of continents. Methane hydrate, a compound of water and methane, is present on the continental slopes.
  7. On the slope, we find many traces of submarine landslide activity, ocean canyons and huge avalanche fans. For example, Congo Canyon is a submarine canyon found near Africa.
View full question & answer→
Question 24 Marks
Abundance of minerals in oceans
Answer
  1. The continental shelves contain the world’s largest reservoirs of natural oil and gas.
  2. The other deposits like diamonds, chromite, ilmenite, magnetite, platinum, gold and phosphorite are also found.
  3. Sand, gravel aggregates and industrial silica sand are the most important of hard minerals now extracted in the near offshore zone.
  4. The abyssal plains are often littered with nodules of manganese containing varying amounts of iron, nickel, cobalt, and copper.
  5. The most common resources obtained from oceans are sodium chloride i.e. common salt.
  6. A large number of metallic and non-metallic minerals are found on the ocean floor, e.g., potassium occurs in large quantities.
  7. Gypsum forms during evaporation of sea water. The gypsum deposits are mined and converted into Plaster of Paris and used for construction.
  8. The most important minerals extracted from the sea floor are mineral oil and natural gas.
View full question & answer→
Question 34 Marks
Oceanic tourism
Answer
  1. Ocean tourism is developed along the coastal areas of seas and oceans.
  2. Ocean tourism comes in many forms like cruises, scuba-diving, fishing, beach tourism, etc. Such activities are increasingly becoming popular.
  3. Generally, water sports activities such as scuba diving, surfing, water skiing, etc., are developed along the coastline. For example, sport activities along the coast of Goa.
  4. There is beautiful scenery along the coastline due greenery of trees along the coast, huge waterbody of sea or ocean, clean air and coolness due to nearness to water, therefore many resorts, hotels, marina, etc., are developed and coastal areas have become popular for tourism.
View full question & answer→
Question 44 Marks
EEZ
Answer
  1. Generally, a state’s exclusive economic zone is an area beyond and adjacent to the territorial sea, extending seaward to a distance of no more than 370 km out from its coastal baseline.
  2. The exception to this rule occurs when exclusive economic zones would overlap; that is, state coastal baselines are less than 740 km apart. When an overlap occurs, it is up to the states to delineate the actual maritime boundary.
  3. The exclusive economic zone stretches much further into sea than the territorial water, which ends at 22 km from the coastal baseline if following the rules set out in the UN Convention on the Law of the Sea). Thus, the exclusive economic zones include the contiguous zone.
  4. States also have rights to the seabed of what is called the continental shelf up to 650 km from the coastal baseline, beyond the exclusive economic zones, but such areas are not part of their exclusive economic zones.
  5. The legal definition of the continental shelf does not directly correspond to the geological meaning of the term, as it also includes the continental rise and slope, and the entire seabed within the exclusive economic zone.
  6. The idea of allotting nations with EEZs is to give them more control of maritime affairs outside territorial limits, gained acceptance in the late 20th Century.
View full question & answer→
Question 54 Marks
Desalination
Answer
  1. Sea water contains lot of salt, so it is not useful for drinking or irrigation purpose. Therefore, it is necessary to convert the sea water into fresh water.
  2. Desalination is the process of removal of salt from sea water and converting sea water into fresh water.
  3. Desalination is done by heating water or freezing water or by electrical processes.
  4. The desalination process is very expensive, therefore it is used where there is acute shortage of water.
  5. The Minjur Desalination Plant is the largest in India, located at Kattupalli village, a northern suburb of Chennai on the coast of the Bay of Bengal that supplies water to the city of Chennai.
  6. These desalination plants are more used in developing countries since the cost for processing is high. Desalination plants are located in Saudi Arabia, Oman, Cyprus, Algeria, Spain and UAE.
  7. Desalination plants have adverse effect on the coastal environment. Small sea organisms like plankton and baby fish may be killed. Their food chain is disturbed.
  8. It is still used in some countries to get fresh water.
View full question & answer→
Question 64 Marks
Causes of climate change
Answer
The portion of the continents that are submerged under water and borders the coastal areas is known as a continental shelf.

They are broad, shallow and gently-sloping plains covered by water.

The continental shelf does not extend into the ocean uniformly. Near some coasts, it is narrow while in some parts it may extend for hundreds of kilometres. For example, they are almost absent or very narrow along the coasts of Chile, Sumatra etc., while the Siberian coast near the Arctic Ocean is around 1500 km in width.

Generally, its depth from the sea level is about 180 m to 200 m.

As the sunlight reaches this part of the ocean bed, it is rich in plankton. These millions of microscopic organisms found in sea water are an important food for fish. Millions of fishes thrive here. The shelf has some of the richest fishing grounds in the world, such as the Grand Banks and Georges Bank in North America.

The continental shelves contain the world’s largest reservoirs of natural oil and gas. For example, the Mumbai High in Arabian sea. Besides oil and gas, minerals are also found here.

Diamonds, chromite, ilmenite, magnetite, platinum, gold and phosphorite deposits are common. Sand, gravel aggregates and industrial silica sand are the most important of hard minerals now extracted in the near offshore zone.
View full question & answer→
Generate Paper FreeAll Ocean Resources topics