Seas and oceans are endowed with different varieties of biotic and abiotic resources of two major sources. Massive sedimentary deposits received over a long time by the continental shelves, become the source of fossil fuels. Test Series. Similarly, more evaporation reduces the volume of seawater and hence the concentration of salts increases. Vision IAS; APTI Plus; GS Score; Insight IAS; Rau IAS; Shankas IAS; Test Series. 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. These notes are very useful in Prelims as well as in GS1 Geography written examination in mains. E.g. The saline freezes slowly in comparison to fresh water. ii. This zone extends upto a distance of 200 nautical miles from the base line. Indian Society by SC Dubey PDF GC Leong Geography Latest edition PDF Download. These materials contain mineral elements of different types, plants and animals. Continental shelves are narrow along the coasts of Java and Sumatra. Successful fishing does not depend on the size of their (fishes) areas and richness of their reserves but depends on their concentration and abundance at a particular time in a specific area. Subterranean Water Body was discovered in the year 2007. Salinity also varies from enclosed seas through partially opened seas to open seas. Magnesium Chloride 10.9 Ocean currents act as distributing agents of nutrients, oxygen and other elements for the existence and survival of fishes. A mid-oceanic ridge is composed of two chains of mountains separated by a large depression. All the countries have equal rights of navigation, aviation, fishing, mining, laying down of submarine cables, scientific researches, exploration etc. Efforts should be made to keep the seas and oceans free from anthropogenic pollution for rich and healthy condition of marine environment and ecology. i. Photic or Euphotic zone: It represents the upper surface upto the depth of 200 m and receives solar radiation. The origin of ideal and favourable European type of climate of the western coasts of Europe is due to the effects of the North Atlantic warm current. It’s complete study material for UPSC CSE 2021-22 exam. The Emperor seamount, an extension of the Hawaiian Islands in the Pacific Ocean, is a good example. Sovereignty, exploitation of marine resources, trade and transport, recreation, war practices etc. The largest waves are found in the open oceans. The reef is partially submerged. Flounders (small flat fishes) contribute15 per cent of total world catch. Besides mineral resources, different types of vitamins and medicinal elements are also found. The Annex is in line with the procedures detailed in the International Maritime Dangerous Goods (IMDG) Code, which has been expanded to include marine pollutants. Ocean Tides: The Periodic rise and fall of the sea level due to the gravitational pull of the Moon and Sun, once or twice in a day, is called tides. Brazilian coast bifurcate the Equatorial current into Gulf Stream and Brazil current (parallel to Brazilian coast). Gulf Stream carries planktons from Mexican Gulf to the coasts of New foundland and North – western Europe. Stricter restrictions apply to “special areas”. ), ii. Benthos animals mostly include several species of molluscs e.g. The width of continental shelves largely depends on the nature of reliefs of the coastal land. Vision IAS Current Affairs December 2020 for UPSC CSE and state PCS Exams, Download pdf now. However, some minerals discharged in the course of the mining can cause problems, such as Copper, which can disturb the development of coral polyps. v. Variation in salinity causes ocean currents. The maximum wave height is determined by the strength of the wind, i.e. The Northeast Trade Winds blow the North Equatorial Current off the coasts of the Philippines and Formosa into the East China Sea as the Kuroshio or Kuro Siwo or Japan Current. Air pollution is also a contributing factor by carrying off pesticides or dirt into the ocean. Minerals of the continental shelf deposits, ii. 1. Salinity decreases with maximum runoff during rainy season and increases in the season of minimum runoff. A minimum tidal range of 5m is a prerequisite condition for electricity generation. Pressure is directly positively related to ocean water through its compressive effects, seawater density increases with increasing pressure and vice versa. The average depth is 5,000 m. The number of deeps in the Atlantic Ocean is far less than in the Pacific Ocean because of the absence of effects of Tertiary orogenic movements along the Atlantic coasts. i. (a) 1 & 2 (b) 2 only 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. It narrows down towards the equator. Tropical zone (20° – 30°) of maximum salinity (low rainfall and high evaporation). changes12.1 OCEANS – AN INTRODUCTION About three – fourth of the earth is covered by Hydrosphere. Continental Shelf is the extended margin of each continent occupied by relatively shallow seas and gulfs. Kuril Islands, Japanese Islands, Philippines, Indonesia, New Zealand, etc. The salt brought by the rivers also bit modified in the oceans. The oyster rearing is most prevalent form of Mariculture. That is, greater the evaporation, higher the salinity and vice versa. Salinity increases the density of sea water. ), biotic life of marine water (plants and animals), marine deposits and abiotic elements (minerals, fossil fuels etc. Rivers bring salts in solution form from the continental areas. (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. 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. Barrier reefs are the largest, most extensive, highest and widest reefs of all types of coral reefs. Coral reefs protected by a barrier (found in Sakau Island, southern Florida). It usually includes areas of exclusive national rights over mineral and biological resources, encompassing maritime features, limits and zones. The plant and animal communities of marine environment and the environment of their habitats are collectively called marine biome which is vertically divided into two types. UPSC … Share to Twitter Share … A barrier reef is separated from the coast by a much wider and deeper channel or lagoon. CATASTROPHIC CORAL BLEACHING EVENT (1997-98) has been recorded as the most catastrophic event as it accounted for large scale of death of corals in the tropical oceans of 60 countries and island nations, 70% death of corals off the coasts of Kenya, Maldives, Andaman and Lakshadweep islands in the Indian ocean and 75% death in Marine Seychelles and Tanzania. Moderate bleaching: resulting into 20-50% coral mortality but with quick recovery. Though major part of the mid Atlantic ridge is submerged under oceanic water but number of peaks and sea mounts project well above the water surface and forms islands. The winds blowing over warm currents pick up moisture and help in increasing the amount of precipitation in the affected coastal areas. The estimated oil reserve is 200,000,000 tonnes. The ocean has contact with the Pacific and Atlantic Ocean in the south near Antarctica and the average depth of the ocean is 4,000 m. Major parts of the coastal lands are formed by Block Mountains of Gondwana land. The boiling point of saline water is higher than fresh water. 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. Similarly, when neap tide and apogean tide occur at the same time, the water level becomes significantly low. Salinity is higher near the tropics than at the equator because both the areas (Tropic of Cancer & Tropic of Capricorn) record high rate of evaporation with dry air over it. The upper surface is called photic layer (upto 200m depth) wherein one celled phytoplanktons grow through the process of photosynthesis. These trenches are found mainly in the western Pacific Ocean. Besides, offshore oil fields are being developed in Indonesia, east Africa, north – West Africa, Tasmania, East Asia, etc. These large accumulations of water and the flow around them are called Gyres. Gravity tends to pull the water down to pile and create gradient variation. Cold currents, on the other hand, lower down the temperature considerably of the affected areas and thus cause snowfall. The actual motion of the water beneath the waves is circular. If complete check on the discharge and disposal of pollutants of different sorts into seawater is not possible, minimum quantity of pollutants to be discharged should be determined and agreed upon. Indian reef area is estimated to be 2,400 sq.km. This current, flowing at 10 miles per day, carries the warm equatorial water for over a thousand miles to the coasts of Europe. Questions on this topic are often asked in the UPSC IAS Prelims exam. Quizzes. DOWNLOAD ANY CONTENT FOR FREE!!! As with all mining operations, deep sea mining raises questions about environmental damages to the surrounding areas. UPSC Prelims Test Series, Vision IAS / December 30, 2020 December 30, 2020 Vision IAS Prelims Test Series 2021 Test 6 With Solution Pdf – Here is The Latest Test From Vision IAS for UPSC … Nuclear power plants in Fukushima severely damaged resulting in leakage of radiation. The centre of the moon is 3,84,000 km away from the centre of the earth. Relatively lighter sea water floats and moves horizontally, whereas heavier sea water sinks. When the tide centre completes one round, the moon’s position is ahead of the tide centre by that time because the moon also revolves around the earth, with the result the tide centre takes another 52 minutes to come under the moon. Evaporation, precipitation, influx of river water, prevailing winds, ocean currents and sea waves are significant controlling factors. Annual temperature of surface water at the Equator is 26.7° C, whereas in Red Sea, it is 37.8° C. Wind direction largely affects the distribution of temperature of ocean water. Ocean currents on the water surface are generated from the areas of low salinity to the areas of high salinity. The Vision IAS notes PDF package is very useful for upcoming UPSC CSE 2021-22 exam preparation. Water moves from area of lower density to areas of higher density. SALTS PERCENTAGE (%) The concerned coastal nation has the rights of custom duties, fiscal, strategic, defence, immigration and sanitary regulations within the territorial sea and contiguous zone and also enjoys the right to punish the concerned parties for the infringement of these regulations. Areas of high atmospheric pressure are characterised by low volume of water and vice versa. The earth rotates from west to east and revolves around the sun in an elliptical orbit. The cloud seeding and formation of clouds will be adversely affected. The denser water sinks and moves as subsurface currents whereas less saline water moves towards greater saline water as surface current. This requires the accurate knowledge of exact quantity of abiotic resources and process and rate of regeneration of biological (living, plants and animals) resources. If the volume of water in the oceans increased due to heavy rainfall, the ratio of salt to the total volume of water is automatically reduced. Volcanic ashes also provide some salt to the oceans. There should be efficient exploitation of marine resources. The density of water decreases due to influx of freshwater, hence cold water moves as cool current from polar areas towards the equator (E.g. These waters move around the ocean basins due to variations in the density and gravity. . This may lead to reduction in world production of fishes in future. The major differences are that the circuit is anti – clockwise and the collection of sea – weed in the still waters of the mid – South Atlantic is not so distinctive. 2 Year Package is the most ideal and highly recommended as the Climate change is raising ocean temperatures and raising levels of carbon dioxide in the atmosphere. Sometimes, a few ocean currents destroy planktons. 2. 2. ii. As the tidal bores move upstream, their effects continue to decrease. (E.g. ; law of continental shelves; law of exploitation of sea bottoms etc., but these laws are not enough for the desired purposes. Tidal bores also occur in Hooghly river of India. It is pointed out that major portion of calcium brought by the rivers into oceans is consumed by marine organisms. Fishes of numerous species are most important members of this community. According to the study conducted by the Society for Andaman & Nicobar Ecology (SANE) based at Port Blair, there has been mass coral beaching (in 1998) around the Nicobar reefs. Most of the fishes are also used as animal feed. These are derived through two most prevalent techniques e.g. It may be remembered that oceans are vast reservoirs of biotic resources. The Gulf of Mexico and Caribbean Sea are separated by 1,600 m deep ridge running between Yucatan peninsula and Cuba Island. The average depth is 3,600 m. Mauritius Basin: It is located between South West Indian ridge and south Madagascar ridge and extends from 20° S to 40° S latitude. Ocean currents are greatly influenced and controlled by atmospheric conditions like atmospheric pressure and its variation, wind direction, rainfall and evaporation. Severe bleaching: accounting for 50-70% death of corals in Kenya, Seychelles, Japan, Thailand and Vietnam. Other significant features in East Pacific Rise: New Zealand ridge, Fiji plateau, Hawaiian rise (most extensive ridge of the Pacific Ocean), New Guinea rise, etc. Ocean currents transport planktons from one area to the other area. The hydrosphere covers nearly 71% of the total surface area of the earth. The steady Trade Winds constantly drift two streams of water from east to west. 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. There should be well regulated exploitation of marine resources. They are. The origin of tides in the oceans is primarily concerned with the gravitational forces of the sun and the moon. The temperature in the enclosed seas in low altitudes becomes higher because of the surrounding land areas. Amended Regulations 12 concerns control and record keeping of Ozone Depleting Substances. No definite trend of distribution of salinity with depth, because both the trends of increase and decrease of salinity with increasing depths have been observed. (“MARPOL” is short for marine pollution and 73/78 short for the years 1973 and 1978.). As many as 57 deeps have been explored so far; of which 32 are in the Pacific Ocean; 19 in the Atlantic Ocean and 6 in the Indian Ocean. iv. Offshore oil fields have been developed in the continental shelves of Mexican gulf, Persian gulf, North Sea, North, Alaska, Mexico, South Californian coast, Arctic Sea, India, Brazil, Australia, Taiwan, Japan etc.. Algae and diatoms are most important members of this community. There is a direct positive relationship between salinity and evaporation. The temperature of ocean water varies in the northern and southern hemispheres because of dominance of land in northern hemisphere and water in southern hemisphere. The Canaries Current flowing southwards eventually merges with the North Equatorial Current, completing the clockwise circuit in the North Atlantic Ocean. Differences in water density also affect vertical mobility of ocean currents. OCEANOGRAPHY; INDIAN POLITY PART 1; CONSTITUTIONAL AMENDMENT’S; GENERAL MENTAL ABILITY; GEOMORPHOLOGY; CSAT ; Tags # Books # CSAT # mains # optional # Sociology Materials # Study Materials10 # Study Materials5 # Study Materials6 # Study Materials8 # Study Materials9 # Upsc. That is why they are very significant in the study of plate movements. These plains are covered with fine-grained sediments like clay and silt. Such platforms should not be more than 50 fathoms below sea level. Slow and steady waves originate from faraway places, possibly from another hemisphere. The vertical motion refers to the rise and fall of water in the oceans and seas. Central Pacific: Largest number of islands (volcanic & coral). the salinity of seawater increases its density. Ocean Tides are one type of wave characterized by rhythmic rise and fall of ocean water twice in a day. Among the coral animals, polyps are the most abundant and also the most important. (ii) Animal feed for domesticated animals. Sea water contains a complex solution of several mineral substances in dilute form, as it is active solvent. This, in turn, is altering aquatic ecosystems and modifying fish distributions, with impacts on the sustainability of fisheries and the livelihoods of the communities that depend on them. This massive underground ocean extends from Indonesia to the northern tip of Russia for a length of 700 km – 1400 km below the ground surface. The sea temperature decreases with increasing depth, but the rate of decrease of temperature is not uniform (change in temperature below the depth of 2000 m is negligible). Central Zone: represents mid-oceanic ridges with numerous islands. Indian Geography, Economic Geography, Climatology, Climatic Regions, Geomorphology & Oceanography. Land and air pollution have proven to be harmful to marine life and its habitats. Ocean currents are influenced by two types of forces namely : The primary forces that influence the currents are: Heating by solar energy causes the water to expand. ये विज़न IAS 5. Since the earth rotates from west to east and hence tide centre shifts westward. Ocean Waves UPSC |Oceanography | Physical Geography Only Ias Exam 09:51. Coral Island or Atoll Island: It does not have island in the beginning but later on island is formed due to erosion and deposition by marine waves. The popular method of manufacturing of salt from seawater involves the processes of holding of seawater in the evaporation basins prepared in the coastal land areas and drying of water through solar heat. It is to be noted that reefs will not become extinct in the long term, but a single bleaching event will take reefs between 30 to 100 years to recover. The depths vary between 3,000 and 6,000 m. Ocean deeps represent depressions and trenches (reaches depth of 5,000 fathoms) on the ocean floors, are the deepest parts of the ocean basins. Like the sun there is also northward and southward position of the moon in relation to the equator of the earth. UPSC Previous Year Questions: How are ocean waves formed? Local variations in the physical properties of the oceans like pressure gradient, temperature variations, density variations, salinity differences, etc. The average depth of ocean is 3,800 m against the 840 m average height of lithosphere. The depth of lagoon between the coast and the reefs is 240 feet, whereas the width ranges between 7 to 80 miles. The density of sea water at the bottom of tranches is 5% higher than that of surface area. E.g. From the North Atlantic, it fans out in three directions, eastwards along the Iberian coast, as the cool Canaries Current. The depth of the shelves also varies. This variation in temperatures in Northern and Southern hemisphere is because of unequal distribution of land and ocean water. Deep Sea Plain is the flat and rolling submarine plain lying two or three miles below sea level, and covering. Vision IAS Mains 2020; Next IAS Mains 2020; Insight IAS Mains 2020; Rau IAS Mains 2020; Prelims Test Series . Large tidal bore can occur only in coastal rivers and bays which have narrow and restricted openings in the sea. The pollution also comes from nonpoint sources such as agricultural runoff, wind-blown debris and dust. More saline water is less evaporated than less saline water. 8. Large scale climatic changes since Mesozoic era, fluctuations in solar activities and several environmental stresses corals have managed to survive and recover. Thus, ocean currents help in bringing homogeneity in the distribution of temperature of ocean water and thus help in maintaining the horizontal heat balance of the earth because they transfer additional heat of low latitudes (area of surplus heat) to high latitudes (area of deficient heat). Thermocline zone: is the layer of ocean between the depth zones of 300 – 1000 m characterised by sharp change of temperature in the vertical section of sea water. Its physical characteristics like temperature, salinity, density and the external forces like of the sun, moon and the winds influence the movement of ocean water. 10. The seismic waves, caused by the earthquakes travelling through sea water, generate high sea waves and cause great loss of life and property. (E.g. Catastrophic bleaching: adversely affecting 95% of shallow water corals in Bahrain, Maldives, Sri Lanka, Singapore and Tanzania. Ocean tides, sea waves and thermal variation between upper warm surface of sea and lower cold water mass etc. The temperature of seawater below freezing point cannot increase sea water density because at 0° C temperature water starts freezing with the formation of ice crystals, which do not allow water molecules to come closer and coalesce. The shelves are narrow, where high mountains are very close and parallel to the coast. The total known species of benthos animals represent. This community grows so quickly that within a short span of time they cover very large area of sea surface. 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. Guidance IAS Notes has developed result oriented Geography notes which covers 100% complete syllabus. These cold waters are blown south by the out – flowing polar winds. The Law of the Sea Convention defines the rights and responsibilities of nations with respect to their use of the world’s oceans, establishing guidelines for businesses, the environment, and the management of marine natural resources. It increases to 35% between 15°-20° latitude in the northern hemisphere and it is still higher than 36% in the South Pacific Ocean for same latitudes (but it becomes low along Peruvian and Chilean coasts). E.g. The growth and survival of coral reefs will be adversely affected, 3. Its warm waters are carried polewards as the North Pacific Drift, keeping the ports of the Alaskan coast ice-free in winter. 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. On an average, the temperature of surface water of the ocean is. Thus flood currents move coastward and ebb currents move away from the coasts. Some negligible amount of energy is received from the bottom through the compression of sea water. The coastward movement of tides causes flood currents which pile up sea water against the sea coast. Marpol Annex IV came into force on 22 September 2003. 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 isotherms are not regular in the northern hemisphere because of land masses and they are regular in the southern hemisphere, because of dominance of water. 3. The current of the North Indian Ocean, demonstrate most convincingly the dominant effects of winds on the circulation of ocean currents. The corals in the Gulf of Kutch have been bleached due to siltation. They are sometimes found cutting across the continental shelves and slopes, often extending from the mouths of large rivers. 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. Islands based on racial groups: Malanesia, Micronesia & Polynesia, ii. Waves may travel thousands of km before rolling ashore, breaking and dissolving as surf. 1. This may be achieved through proper survey of fishing areas by applying ‘ecosounder technique’, by maintaining catch statistics, determination of their age on the basis of the study of ring growth on fish scales, mapping of breeding places of fishing and determination of their numbers etc. Tides occur in the oceans and seas due to which among the following? Surface runoff from farming, as well as urban runoff and runoff from the construction of roads, buildings, ports, channels, and harbours, can carry soil and particles laden with carbon, nitrogen, phosphorus, and minerals. Currents and waves also determine the shape of the coral reefs. An average salinity of 35% is observed between 0°-10° N latitude, but it gradually decreases northward in the Bay of Bengal (due to influx of freshwater).
Ra'shaad Samples Twitter, Atago Honey Refractometer, Xviii Number Means, Mario Activities Printable, Natures Bounty B12 1000 Mcg Quick Dissolve, Koss Group Stock, Microwave Sensor Range, Target Pill Organizer, H-e-b Prescription Status, Humidor With Built-in Digital Hygrometer, Women's Bible Study Reviews,