oceanography upsc vision ias

Due to the greater expanse of the Pacific and the absence of an obstructing land mass the volume of water is very much greater than that of the Atlantic equatorial current. (C) 3. It also establishes requirements for reception facilities for wastes from exhaust gas cleaning systems, incinerators, fuel oil quality, for off-shore platforms and drilling rigs and for the establishment of SOx Emission Control Ain reas (SECAs). They are also divided on the basis of velocity, dimension and direction into Drifts, Currents and Streams. Water moves ahead from one place to another through ocean currents. Select the correct answer using the code given below. Brazilian Basin is confined between the Equator and 30°S latitude an East coast of Brazil in the west and Para Rise in the east. As of January 2015. Toxic metals can also be introduced into marine food webs. The Indian Ocean is the third largest ocean by area and it is bounded by Asia in the north and east, Africa in the west, Australia in the south-east and Antarctica in the south. Arabian Basin: It is located in almost circular shape between Laccadives-Chagos ridge and Socotra- Chagos ridge with the depth of 3,600 – 5,500 m. Somalia Basin: It is bordered by Socotra- Chagos in the northwest, Central ridge in the east, Seychelles-Mauritius ridge in the southwest and African coast in the west. The width of continental shelves largely depends on the nature of reliefs of the coastal land. Fuel minerals (petroleum, natural gas), iii. The width of continental shelves has been largely controlled by the reliefs of the coastal lands. Central Zone: represents mid-oceanic ridges with numerous islands. Steep waves are fairly young ones and are probably formed by local wind. The ocean has the largest number of islands (>2000). There is a lagoon in the middle of a coral ring. are main sources of generation of electricity. Warm currents raise the temperature of the affected areas, whereas Cold currents lower down the temperature. Important theories on origin of tides include Equilibrium theory by Issac Newton, Dynamical theory by Laplace, Progressive wave theory by William Whewell, Canal theory by G.B. The mountain ranges can have peaks as high as 2,500 m and some even reach above the ocean’s surface. Shallow lagoon reefs are minor reef features which are annular in shape and are found in epicontinental seas like Indonesian Sea, South China Sea, etc. This has proven controversial for shipping and ferry operators across Europe. When the sun, the earth and the moon are in the same line (full moon and new moon) their gravitational forces work together and high tides are formed. Alternatively marine biological resources can also be divided into the following 3 categories. Since ships can only enter and leave port on the tide, most of the World’s. Vision IAS Prelims 2021 Test 19 With Solution PDF Download Now you have made up your mind to become IAS officer and looking for the books and study materials to achieve your goal.Well, you are on the right page. fishing, mining etc.) This causes a very slight gradient and water tends to flow down the slope. Currently, widening of the ocean (4 cm/year) is observed through seafloor spreading. 2. The biotic and abiotic resources found in the oceanic water and bottoms are called marine resources, which include marine water, inherent energy in the oceanic water (e.g. This unique phenomenon is seen at, (a) Bhavnagar (b) Bheemunipatnam (c) Chanidpur(d) Nagapattinam, 1. Currents and waves also determine the shape of the coral reefs. Coral reefs are formed due to formation of one shell upon another shell along submarine platforms at suitable depth. It is beyond doubt that if the present rate of growth of world population continues, the demand for world supply of food would also increase proportionately in future, which cannot be met with land sources alone. Wind causes waves to travel in the ocean and the energy is released on shorelines. JAPAN TSUNAMI: In 2011, undersea earthquake of magnitude of 8.9 with epicentre 130 km off the coast of Sendai city. Islands are formed from the emergence of central ridge or its branches above the sea level. The survival of some animals that have phytoplankton larvae will be adversely affected, 4. The maximum temperature of the oceans is always at their surface, because it directly receives the insolation and the heat is transmitted to the lower sections of the oceans through conduction mechanism. A mid-oceanic ridge is composed of two chains of mountains separated by a large depression. Since beginning man used to hunt whales to get different materials from whales for various purposes e.g. The concerned coastal state has the exclusive right of the survey, exploitation, conservation and management of mineral resources of ocean deposits, ocean floor (crust), marine water energy, water and marine organisms within this Exclusive Economic Zone (EEZ). For example, EI Nino current destroys planktons off the peruvian coasts and causes several diseases resulting into mass deaths of fishes. ), ii. The Hydrosphere is divided into Oceans, Inland Seas, Small enclosed seas, Bays, etc. Pelagic fishes and demersal fishes. It is noted that the role of temperature in controlling water density is more pronounced in low latitudes, whereas the importance of temperature in controlling sea water decreases poleward. The temperature decreases from the ocean surface with increasing depth and it is not uniform. More saline water freezes slower than lesser saline water. On the planet earth, most of the freshwater exists as ice caps and glaciers. The solar rays very effectively penetrate upto 20 m depth and do not go beyond 200 m depth. The zone of steep slope extending from the Continental shelf to the deep sea plains is called, At the edge of the Continental Shelf, there is an abrupt change of gradient, forming the. The reef is partially submerged. Salinity decreases with maximum runoff during rainy season and increases in the season of minimum runoff. Ocean currents transport planktons from one area to the other area. Apart from the clockwise circulation of the currents, there are also currents that enter the North Atlantic from the Arctic regions. Pico island of Azores (8,200 m). Salinity and density of sea water are positively correlated i.e. The Study Portal has also published its Ebooks/ PDF on various aspects & dimensions of World, India and Rajasthan. Plant resources (phytoplanktons, sea grass etc. on the basis of their size and location. Once in the food webs, these pesticides can cause mutations, as well as diseases, which can be harmful to humans as well as the entire food web. Coral reefs protected by a barrier (found in Sakau Island, southern Florida). Moderate bleaching: resulting into 20-50% coral mortality but with quick recovery. High Sea extends beyond the seaward limit of the exclusive economic zone and includes the vast oceanic areas. Barrier reefs are the largest, most extensive, highest and widest reefs of all types of coral reefs. The ocean salinity also affects the marine organisms and plant community. The monsoon drifts (currents) move east to west along the coast during north-east monsoon in winter seasons and these flow in north-eastern direction under the influence of south west monsoon in summer season. (D) 5. A few species of whales, like large baleen whales, have been so massively killed that they are on the verge of extinction. Density of pure water is 1.00 g/cm3 and density of water with 35% salinity is 1.028 g/cm3. This community grows so quickly that within a short span of time they cover very large area of sea surface. On an average, the northern and the southern hemisphere records average salinity of 34% and 35% respectively. Areas of high atmospheric pressure are characterised by low volume of water and vice versa. As the tidal bores move upstream, their effects continue to decrease. The estimated oil reserve is 200,000,000 tonnes. Gulf Stream warm current raise the temperature near the eastern coasts of North America, Labrador cold current lowers down the temperature of north-east coast of North America. Coral reefs are generally long but narrow in width. The origin of tides in the oceans is primarily concerned with the gravitational forces of the sun and the moon. According to an estimate one cubic kilometer of seawater contains 41.25 million tonnes of solid materials in dissolved form. Thus, there is transfer of nutrients from the upper surface downward. It begins where the bottom of the continental shelf sharply drops off into a steep slope. Due to high temperature in equatorial region, the water density decreases because of greater expansion of water particles whereas the density of sea water becomes comparatively greater in polar areas. Plankton Community includes the groups of buoyant and floating marine plants and animals which live in the photic (euphotic zone or eupelagic zone) upto the depth of 200m from sea level. Aadhar Government Scheme news Services Study Kisan Credit Card Scheme (kcc ), now the scope of this scheme has not been limited to farming only. Salinity is directly positively related to seawater density. Usually, the average annual range of temperature of ocean water is -12° C but there is a lot of regional variation which is due to regional variation in insolation, nature of seas, prevailing winds, location of seas, etc. Narrow and low-lying coastal river with gentle channel gradient. Find below the IAS Geography syllabus: UPSC Syllabus Geography Optional Paper I: UPSC Syllabus Geography Optional Paper II: Geography optional should be prepared thoroughly if one has chosen it for the UPSC Mains by studying the previous yearsâ papers and also going through relevant books on Geography for UPSC. Generally, the mean annual temperature of the surface ocean water decreases from 21° C in equatorial areas to around 12.7° C in 45° N and S latitudes and drops almost to freezing point at the poles. According to an estimate 4 grams of gold can obtain from every one million tonnes of seawater and it is also estimated that the total reserve of gold dissolved in seawater is. The contribution of fishes in the world annual income from marine resources of all categories stands second (next to trade and transport). Sovereign rights over their continental shelves up to a depth of 200 metres or to a distance where the depth of waters admitted of resource exploitation were claimed by the marine nations that signed the Convention on the Continental Shelf drawn up by the UN’s International Law Commission in 1958. The size of the oceans and seas also affects annual range of temperature (bigger the size, lower the annual range and vice versa). 1. Ocean mining sites are usually around large areas of. Waves travel because wind pushes the water body in its course while gravity pulls the crests of the waves downward. Magnesium Sulphate 4.7 Lowest temperatures of the oceans – New Scotland region, Highest temperatures of the oceans – Western Pacific Ocean region. Mining for Copper, Gold. What would happen if phytoplankton of an ocean is completely destroyed for some reason? North Atlantic Drift is deflected towards the right when it crosses over the Wyville Thompson ridge. ), biotic life of marine water (plants and animals), marine deposits and abiotic elements (minerals, fossil fuels etc. On the other hand, cold currents discourage rainfall. On the basis of sources and location minerals of sea deposits are divided into two categories viz. Annual range of temperature is higher in the enclosed seas than in the open seas. Hence, it records only 35% salinity. Fishing areas (fisheries) are divided in two categories on the basis of temperature of sea water e.g. Obstructed by the tip of southern Chile, the current turns northwards along the western coast of South America as the cold Humboldt or Peruvian Current. Plant planktons, called as phytoplanktons produce food through the process of photosynthesis with the help of sunlight, water and atmospheric carbon dioxide and thus they are primary producer green plants and are also called as autotrophs. The oceans in the northern hemisphere record relatively higher average temperature than in the southern hemisphere. It is mentioned that the proportion of various elements remains constant in sea water everywhere, though the salinity vary from place to place. Which of the statements given above is/are correct? Evaporation, precipitation, influx of river water, prevailing winds, ocean currents and sea waves are significant controlling factors. Salinity is low at the surface at the Equator, due to high rainfall and transfer of water through equatorial currents (but salinity is observed below the surface). Sodium Chloride 77.8 the temperature of sea surface is lower than the temperature below the surface waters. Its deep blue waters are easily distinguishable from the yellow, muddy waters carried hundreds of miles out to sea by the Amazon further north. The variation in salinity is both horizontal and vertical. The temperature of sea water also affects the climate of coastal lands and plants and animals therein. The prominent basins are Mexico basin and Caribbean basin. It may be mentioned that there is to and fro vertical movement of marine animals (i.e. The four major oceans of â¦ Continue reading "Oceanography" The organisms of this community are characterized by large species diversity. UNCLOS came into force in 1994, a year after Guyana became the 60th nation to sign the treaty. Oceanography for UPSC IAS Exam: Find here the Oceanography UPSC Notes, Study Material and related questions. 6. These regions have increased salinity and water density. Ocean currents help in maintaining the temperature balance of ocean water as the warm currents transport warm waters of the tropical zones to the colder areas of the temperature and polar zones and cold currents bring cold waters of high latitudes to the areas of low latitudes. Currents of Indian Ocean show seasonal changes in their flow directions due to monsoons. The ocean was formed due to drifting of North and South America to the west due to plate tectonics. Current modifying factors (direction and shape of coastlines, bottom reliefs of the ocean basins, seasonal variations and rotation of the earth). When the depth of water is less than half of the wavelength of the wave, then the wave breaks. La Nina is suspected to have caused recent floods in Australia. There is seasonal change in the directions of currents in some areas in response to seasonal change in weather conditions. Thus flood currents move coastward and ebb currents move away from the coasts. Amended Regulations 12 concerns control and record keeping of Ozone Depleting Substances. Test Series. There is need for effective laws related to the exploitation of deep sea resources, strategic and military uses of seas, scientific researches and international cooperation to make marine resources useful for world human community. (i)those marine animals which live in waters as well as on lands such as seals, and (ii) the second category of swimming marine mammals includes those animals which spend their entire life in sea water such as whales. i. Most of the waves are caused by the wind driving against water. Vision IAS Governance Notes 2020 PDF â Click here Other Vision IAS Notes PDF â Click here. Subterranean Water Body: The World’s largest underground ocean, i.e. (b) Rivers drain out large amounts of fresh water into the sea. The South Equatorial Current, driven by the South – East Trade winds, flows southwards along the coast of Queensland as the East Australian Current, bringing warm equatorial waters into temperate waters. Peru Basin is located to the west of Peru coast between 5° S and 24° S latitudes extends upto 110° W longitude. 1. Atolls are found in Antilles Sea, Red Sea, China Sea, Australian Sea and Indonesian Sea. E.g. Many countries have already started commercial production of petroleum and natural gas. The rivers bring salt from land to the oceans. On an average, the temperature of surface water of the ocean is. Marine pharmacologists are presently busy in researches to use marine organisms (plants and animals) for vitamins and medicines to cure different diseases. This rise and fall of seawater due to gravitational forces of the sun and the moon are called Tides. Fishes of numerous species are most important members of this community. A minimum tidal range of 5m is a prerequisite condition for electricity generation. The winds blowing from the land towards the oceans and seas. The ‘S’ shape of the ocean indicates the fact that landmasses (continents) on its either side were once a contiguous part. Islands formed of volcanic materials & Coral reefs – Hawaii island, Fizi, Ellice, Coral Islands. 1. From the standpoint of production, three offshore oil fields of India are most significant e.g. When the sun and the moon are in one side of the earth is called conjunction (Solar eclipse). The daily range of temperature is usually 0.3° C in the lower altitudes and 0.2° to 0.3° C. The diurnal range depends on the conditions of sky, Stability or instability of air and stratification of sea water. Its warm waters are carried polewards as the North Pacific Drift, keeping the ports of the Alaskan coast ice-free in winter. (B) 8. In the North Atlantic Ocean, the Cayenne Current is joined and reinforced by the North Equatorial Current and heads north – westwards as a large mass of equatorial water into the Caribbean Sea. Aliabet offshore oilfields are located 45km away from Bhavnagar in the Gulf of Khambat. 13. Evaporation is controlled by salinity of the oceans. 3. The height of such spring tides is 20% more than normal tides. Oceanic salinity affects the density of ocean water (salinity increases the density) and density variation causes ocean currents. There is a wide range of variation in the spatial distribution of salinity within the oceans and the seas. The current system of the South Pacific is the same as that of the South Atlantic. (i) vertical displacement method, (ii) salter device, and (iii) dam atoll method. etc., is another source of marine pollution. Construction materials (gravels, sands etc.). Different metallic and non – metailic minerals of the seas are found in two forms e.g. Less fishery production, adversely affects population of coastal regions, Disturbance in marine food chain and productivity. Mid-Atlantic ridge. Zooplanktons are of the three types. E.g. High Tide Water: The rise of seawater and its movement towards the coast is called tide and resultant high water level is known as High Tide Water (HTW) Low Tide Water: The fall of seawater and its movement towards the sea is called ebb and the resultant low water level is called Low Tide Water (LTW) Tidal Range: The difference between high tide water and low tide water is called Tidal Range. 80% of marine pollution comes from land. IAS Prelims CSAT 4-October 2020 Video Explanations Part 4- Q 61 to 80, IAS Prelims CSAT 4-October 2020 Video Explanations Part 2- Q 41 to 60, IAS Prelims CSAT 4-October 2020 Video Explanations Part 2- Q 21 to 40, IAS Prelims CSAT 4-October 2020 Video Explanations Part 1- Q 1 to 20, 1. The swimmer marine mammals of nekton community are divided into two groups e.g. There are regional variations in salinity due to upwelling of water, ocean currents, in flux of water or high evaporation. This was partly superseded by the 1982, United Nations Convention on the Law of the Sea which created the 200 nautical mile-exclusive economic zone and extended continental shelf rights for states with physical continental shelves that extend beyond that distance. (D) 10. The average salinity in the oceans and the seas is 35%, but is spatially and temporarily varies in different oceans, seas and lakes. Changes in marine biological environment due to overfishing. Similarly, the western coast of North Africa is washed by the cold currents while warm currents are experienced along the eastern coast of southern USA at the same latitude. the Great Britain, Norway, Sweden, Denmark, Netherlands etc.) (i) mixed with sea water in solution form, and (ii) mixed with ocean bottom deposits. Land and air pollution have proven to be harmful to marine life and its habitats. In the Atlantic Ocean, the North and South Equatorial Current origins near the equator. The largest waves are found in the open oceans. iv. The sea water level becomes relatively higher in the areas of low evaporation and high rainfall. This may lead to reduction in world production of fishes in future. In some areas, high temperature is recorded at greater depths. The average salinity varies 33% – 37% in different oceans and seas. Many marginal seas are located on the continental shelves in the North Atlantic, but absent in the South Atlantic. Winds also help in redistribution of salt in the oceans and the seas (winds drive away saline water to lesser saline areas). Attempts are being made at world level for haulting massive killing of whales and a few international regulations have been formulated for their conservation. The temperatures of the coastal countries (e.g. Ships can pollute waterways and oceans in many ways. Dust from the Sahara moving around the southern periphery of the subtropical ridge moves into the Caribbean and Florida during the warm season as the ridge builds and moves northward through the subtropical Atlantic. Similarly, the currents from equator towards the South Pole and currents from South Pole to the equator are deflected towards their left. There is movement of ocean water below the water surface from polar areas to warmer equatorial areas to balance the loss of water in equatorial areas. The submarine ridges usually deflect the course of currents. Very high proportion of oceanic salinity is injurious for the growth of coral polyps because such waters contain little amount of calcium carbonates, whereas lime is important food for coral polyps. iii. Proper arrangement of canning and refrigeration for storage of fishes. Salinity decreases with increasing depth. As of 2015, 152 states, representing 99.2 per cent of the world’s shipping tonnage, are state parties to the convention. In these examinations, many questions are coming from PubAd.So, therefore, Vision IAS Mains 2020 Test 5 With Solutions is a important subject in all these examinations. Since the Pacific Ocean is girdled by the ring of earthquakes and volcanoes, tsunamis are more common in the Pacific Ocean with a minimum frequency of 2 tsunamis per year. The current hugs the coast of America as far as Cape Hatteras (latitude 35°N), where it is deflected eastwards under the combined. It may be mentioned that the depth zone of oceans between 300 m – 1000 m is characterised by varying trends of vertical distribution of temperature, density and salinity of sea water. The currents in the oceans are originated due to combined effects including internal and external factors. Slow and steady waves originate from faraway places, possibly from another hemisphere. Ocean tides, sea waves and thermal variation between upper warm surface of sea and lower cold water mass etc. Diurnal Thermoclines form in shallow water depth usually less than 10-15 m. The polar seas have only one layer of cold water mass from the ocean surface to the deep ocean floor. Such tide, which is lower in height than the normal tide is called neap tide (generally 20% lower than normal tides).