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Geomorphology by TOC \o "1-2" \h \z \u Interior Of The Earth PAGEREF _Toc482963934 \h 8Why know about earth’s interior PAGEREF _Toc482963935 \h 8Sources of information about the interior PAGEREF _Toc482963936 \h 8Some sources explained in detail PAGEREF _Toc482963937 \h 10Seismic waves PAGEREF _Toc482963938 \h 10What causes earthquakes? PAGEREF _Toc482963939 \h 11Earthquake Waves PAGEREF _Toc482963940 \h 11Behavior of Earthquake Waves PAGEREF _Toc482963941 \h 11Propagation of Earthquake Waves PAGEREF _Toc482963942 \h 13Emergence of Shadow Zone PAGEREF _Toc482963943 \h 14Earth’s Layers PAGEREF _Toc482963944 \h 16Earth’s Layers based on chemical properties PAGEREF _Toc482963945 \h 16Earth’s Chemical Composition PAGEREF _Toc482963946 \h 19Composition of Earth’s Crust PAGEREF _Toc482963947 \h 19Earth Movements PAGEREF _Toc482963948 \h 19Geomorphic processes PAGEREF _Toc482963949 \h 20Endogenetic Movements PAGEREF _Toc482963950 \h 20Diastrophism PAGEREF _Toc482963951 \h 21Sudden Movements PAGEREF _Toc482963952 \h 23Earth Movements - Exogenetic Forces PAGEREF _Toc482963953 \h 24Denudation PAGEREF _Toc482963954 \h 24Weathering PAGEREF _Toc482963955 \h 24Continental Drift Theory - Tectonics PAGEREF _Toc482963956 \h 29Introduction PAGEREF _Toc482963957 \h 29Plate Tectonics PAGEREF _Toc482963958 \h 29Important theories PAGEREF _Toc482963959 \h 31Continental Drift Theory (Alfred Wegener, 1922) PAGEREF _Toc482963960 \h 31Force for Continental Drift PAGEREF _Toc482963961 \h 32Evidence in support of Continental Drift PAGEREF _Toc482963962 \h 33Drawbacks of Continental Drift Theory PAGEREF _Toc482963963 \h 36Convectional Current Theory - Tectonics PAGEREF _Toc482963964 \h 36Mapping of the Ocean Floor PAGEREF _Toc482963965 \h 36Distribution of Earthquakes and Volcanoes PAGEREF _Toc482963966 \h 36Convectional Current Theory PAGEREF _Toc482963967 \h 37Paleomagnetism PAGEREF _Toc482963968 \h 38Paleomagnetism: Strong evidence of See Floor Spreading and Plate Tectonics PAGEREF _Toc482963969 \h 38Concept of Sea Floor Spreading PAGEREF _Toc482963970 \h 39Evidences PAGEREF _Toc482963971 \h 40Plate Tectonics PAGEREF _Toc482963972 \h 41Theory PAGEREF _Toc482963973 \h 41Major tectonic plates PAGEREF _Toc482963974 \h 41Minor tectonic plates PAGEREF _Toc482963975 \h 42Force for the Plate Movement PAGEREF _Toc482963976 \h 44Plate Tectonics - Interaction of Plates PAGEREF _Toc482963977 \h 45Divergence forming Divergent Edge or the Constructive Edge PAGEREF _Toc482963978 \h 45Convergence forming Convergent Edge or Destructive Edge PAGEREF _Toc482963979 \h 46Transcurrent Edge or Conservative Edge or Transform Fault PAGEREF _Toc482963980 \h 46Evidence in Support of Plate Tectonics PAGEREF _Toc482963981 \h 47Significance of Plate Tectonics PAGEREF _Toc482963982 \h 47Movement Of The Indian Plate PAGEREF _Toc482963983 \h 48Comparison: Continental Drift – See Floor Spreading – Plate Tectonics PAGEREF _Toc482963984 \h 49Ocean - Ocean Convergence or The Island - Arc Convergence PAGEREF _Toc482963985 \h 52Formation of Philippine Island Arc System PAGEREF _Toc482963986 \h 54Formation of Indonesian Archipelago PAGEREF _Toc482963987 \h 54Formation of Caribbean Islands PAGEREF _Toc482963988 \h 55Formation of Japanese Island Arc PAGEREF _Toc482963989 \h 55Explain the formation of thousands of islands in Indonesian and Philippines archipelagos PAGEREF _Toc482963990 \h 56In spite of extensive volcanism, there is no island formation along the divergent boundary (mid oceanic ridge) PAGEREF _Toc482963991 \h 57Continent - Ocean Convergence Or The Cordilleran Convergence PAGEREF _Toc482963992 \h 58Formation of the Andes - Continent - Ocean Convergence PAGEREF _Toc482963993 \h 59Formation of the Rockies - Continent - Ocean Convergence PAGEREF _Toc482963994 \h 60Wadati - Benioff zone: Earthquakes along Convergent boundary PAGEREF _Toc482963995 \h 60Continent - Continent Convergence or The Himalayan Convergence PAGEREF _Toc482963996 \h 62Volcanism and Earthquakes in Continent - Continent Convergence PAGEREF _Toc482963997 \h 62Formation of Himalayans and Tibet PAGEREF _Toc482963998 \h 64Indo-Australian Plate PAGEREF _Toc482963999 \h 64Explain the formation of Himalayas PAGEREF _Toc482964000 \h 64Evidences for the rising Himalayas PAGEREF _Toc482964001 \h 67Formation of Alps, Urals, Appalachians and the Atlas mountains PAGEREF _Toc482964002 \h 68Continent – Arc Convergence or New Guinea Convergence PAGEREF _Toc482964003 \h 69Orogeny PAGEREF _Toc482964004 \h 69Types of Mountains - Classification of Mountains PAGEREF _Toc482964005 \h 69‘Fault’ in Geology PAGEREF _Toc482964006 \h 72‘Fold’ in geology PAGEREF _Toc482964007 \h 72Fold Mountains PAGEREF _Toc482964008 \h 73Block Mountains PAGEREF _Toc482964009 \h 76Compression and Tension PAGEREF _Toc482964010 \h 76Volcanic mountains PAGEREF _Toc482964011 \h 77Residual mountains PAGEREF _Toc482964012 \h 77Significance of mountains PAGEREF _Toc482964013 \h 77Interaction of Plates PAGEREF _Toc482964014 \h 78Divergent boundary PAGEREF _Toc482964015 \h 78Evolution – Formation of Rift Lakes, Seas and Oceans PAGEREF _Toc482964016 \h 79Rift valley lakes PAGEREF _Toc482964017 \h 81East African Rift Valley PAGEREF _Toc482964018 \h 82Volcanism and seismicity along East African Rift Valley PAGEREF _Toc482964019 \h 83Great Rift Valley PAGEREF _Toc482964020 \h 84Transcurrent boundary or transform edge PAGEREF _Toc482964021 \h 84Important mountain ranges PAGEREF _Toc482964022 \h 85Andes PAGEREF _Toc482964023 \h 85Rocky Mountains PAGEREF _Toc482964024 \h 86Great Dividing Range PAGEREF _Toc482964025 \h 86Transantarctic Mountains PAGEREF _Toc482964026 \h 87Ural Mountains PAGEREF _Toc482964027 \h 87Atlas Mountains PAGEREF _Toc482964028 \h 88Appalachian Mountains PAGEREF _Toc482964029 \h 88Himalayas PAGEREF _Toc482964030 \h 88Alps PAGEREF _Toc482964031 \h 90Mountain ranges By height PAGEREF _Toc482964032 \h 91Why are world's highest mountains are at the equator? PAGEREF _Toc482964033 \h 91Highest mountain peaks of the world PAGEREF _Toc482964034 \h 92Volcanism PAGEREF _Toc482964035 \h 92Fissure Vent PAGEREF _Toc482964036 \h 93Causes of Volcanism PAGEREF _Toc482964037 \h 93Lava types in Volcanism PAGEREF _Toc482964038 \h 93Destructive Effects of Volcanoes PAGEREF _Toc482964039 \h 95Positive Effects of Volcanoes PAGEREF _Toc482964040 \h 95Geysers and Hot Springs PAGEREF _Toc482964041 \h 96Distribution of Volcanoes across the World PAGEREF _Toc482964042 \h 97The Distribution of Earthquakes PAGEREF _Toc482964043 \h 99Volcanos in India PAGEREF _Toc482964044 \h 100Extinct, Dormant and Active volcanoes PAGEREF _Toc482964045 \h 100Some significant Volcanic Eruptions PAGEREF _Toc482964046 \h 101Volcanic Landforms PAGEREF _Toc482964047 \h 102Extrusive Volcanic Landforms PAGEREF _Toc482964048 \h 102Intrusive Volcanic Landforms PAGEREF _Toc482964049 \h 104Volcanism Types – Exhalative, Effusive, Explosive and Subaqueous Volcanism PAGEREF _Toc482964050 \h 106Exhalative (vapor or fumes) PAGEREF _Toc482964051 \h 106Effusive (Lava outpouring) PAGEREF _Toc482964052 \h 107Explosive (Violent ejection of solid material) PAGEREF _Toc482964053 \h 107Volcanism – Acid Rain, Ozone Destruction PAGEREF _Toc482964054 \h 108Subaqueous Volcanism PAGEREF _Toc482964055 \h 109Eruptive Volcanism Types PAGEREF _Toc482964056 \h 109Hotspot Volcanism PAGEREF _Toc482964057 \h 111Hot spot PAGEREF _Toc482964058 \h 111Mantle plumes PAGEREF _Toc482964059 \h 111Hotspot volcano chain PAGEREF _Toc482964060 \h 112Hotspot volcanic landforms PAGEREF _Toc482964061 \h 112Reunion Hotspot Volcanism PAGEREF _Toc482964062 \h 112Distribution of Hotspot Volcanism PAGEREF _Toc482964063 \h 113Earthquakes PAGEREF _Toc482964064 \h 114Terms associated with earthquakes PAGEREF _Toc482964065 \h 114Causes of Earthquakes PAGEREF _Toc482964066 \h 115Seismic Waves or Earthquake Waves PAGEREF _Toc482964067 \h 116Types of Seismic Waves PAGEREF _Toc482964068 \h 116Earthquakes based on the depth of Focus PAGEREF _Toc482964069 \h 118Distribution of Earthquakes PAGEREF _Toc482964070 \h 119Effects of Earthquakes PAGEREF _Toc482964071 \h 119Tsunami PAGEREF _Toc482964072 \h 120What causes Tsunami? PAGEREF _Toc482964073 \h 120Mechanism in Earthquake induced Tsunami’s PAGEREF _Toc482964074 \h 121Propagation of tsunami waves PAGEREF _Toc482964075 \h 121Properties of Tsunami Waves PAGEREF _Toc482964076 \h 122Waves PAGEREF _Toc482964077 \h 123Normal waves vs Tsunami waves PAGEREF _Toc482964078 \h 125Tsunami waves are not noticed by ships far out at sea PAGEREF _Toc482964079 \h 1252004 Indian Ocean Tsunami PAGEREF _Toc482964080 \h 126Plate tectonics PAGEREF _Toc482964081 \h 126Tsunami waves PAGEREF _Toc482964082 \h 126Occurrence PAGEREF _Toc482964083 \h 128Shifts in Geography PAGEREF _Toc482964084 \h 128Warning Systems PAGEREF _Toc482964085 \h 128India’s preparedness PAGEREF _Toc482964086 \h 129Rocks – Different kinds of rocks PAGEREF _Toc482964087 \h 129Igneous Rocks PAGEREF _Toc482964088 \h 130Sedimentary Rocks PAGEREF _Toc482964089 \h 132Metamorphic Rocks PAGEREF _Toc482964090 \h 134Rock cycle PAGEREF _Toc482964091 \h 136Some Rock-Forming Minerals PAGEREF _Toc482964092 \h 137Landforms and Cycle of Erosion PAGEREF _Toc482964093 \h 138Fluvial Landforms and Cycle of Erosion PAGEREF _Toc482964094 \h 138Fluvial Erosional Landforms PAGEREF _Toc482964095 \h 138Various Aspects of Fluvial Erosive Action PAGEREF _Toc482964096 \h 138River Valley Formation PAGEREF _Toc482964097 \h 138River course PAGEREF _Toc482964098 \h 140Drainage Patterns PAGEREF _Toc482964099 \h 143Fluvial Depositional Landforms PAGEREF _Toc482964100 \h 144Alluvial Fans and Cones PAGEREF _Toc482964101 \h 144Natural Levees PAGEREF _Toc482964102 \h 145Delta PAGEREF _Toc482964103 \h 145Karst Landforms and Cycle of Erosion PAGEREF _Toc482964104 \h 148Cavern PAGEREF _Toc482964105 \h 148Arch/Natural Bridge PAGEREF _Toc482964106 \h 148Sink Hole/Swallow Hole PAGEREF _Toc482964107 \h 149Karst Window PAGEREF _Toc482964108 \h 149Sinking Creeks/Bogas PAGEREF _Toc482964109 \h 149Stalactite and Stalagmite PAGEREF _Toc482964110 \h 149Marine Landforms and Cycle of Erosion PAGEREF _Toc482964111 \h 149Marine Erosional Landforms PAGEREF _Toc482964112 \h 150Chasms PAGEREF _Toc482964113 \h 150Wave-Cut Platform PAGEREF _Toc482964114 \h 150Sea Cliff PAGEREF _Toc482964115 \h 150Sea Caves PAGEREF _Toc482964116 \h 150Sea Arches PAGEREF _Toc482964117 \h 151Stacks/Skarries/Chimney Rock PAGEREF _Toc482964118 \h 151Hanging Valleys PAGEREF _Toc482964119 \h 151Blow Holes or Spouting Horns PAGEREF _Toc482964120 \h 152Plane of Marine Erosion/Peneplain PAGEREF _Toc482964121 \h 152Marine Depositional Landforms PAGEREF _Toc482964122 \h 152Beach PAGEREF _Toc482964123 \h 152Bar PAGEREF _Toc482964124 \h 152Barrier PAGEREF _Toc482964125 \h 152Spit and Hook PAGEREF _Toc482964126 \h 152Tombolos PAGEREF _Toc482964127 \h 152Coastlines PAGEREF _Toc482964128 \h 153Coastlines of Emergence PAGEREF _Toc482964129 \h 153Coastlines of Submergence PAGEREF _Toc482964130 \h 154Neutral Coastlines PAGEREF _Toc482964131 \h 155Compound Coastlines PAGEREF _Toc482964132 \h 156Fault Coastlines PAGEREF _Toc482964133 \h 156Glacial Landforms and Cycle of Erosion PAGEREF _Toc482964134 \h 156Glacial Erosional Landforms PAGEREF _Toc482964135 \h 156Cirque/Corrie PAGEREF _Toc482964136 \h 157Glacial Trough PAGEREF _Toc482964137 \h 157Hanging Valley PAGEREF _Toc482964138 \h 157Arete PAGEREF _Toc482964139 \h 157Horn PAGEREF _Toc482964140 \h 157D-Fjord PAGEREF _Toc482964141 \h 157Glacial Depositional Landforms PAGEREF _Toc482964142 \h 158Outwash Plain PAGEREF _Toc482964143 \h 158Esker PAGEREF _Toc482964144 \h 158Kame Terraces PAGEREF _Toc482964145 \h 158Drumlin PAGEREF _Toc482964146 \h 158Kettle Holes PAGEREF _Toc482964147 \h 159Moraine PAGEREF _Toc482964148 \h 159Glacial Cycle of Erosion PAGEREF _Toc482964149 \h 159Arid Landforms and Cycle of Erosion PAGEREF _Toc482964150 \h 159Erosional Arid Landforms PAGEREF _Toc482964151 \h 159Water Eroded Arid Landforms PAGEREF _Toc482964152 \h 159Wind Eroded Arid Landforms PAGEREF _Toc482964153 \h 161Arid Depositional Landforms PAGEREF _Toc482964154 \h 163Ripple Marks PAGEREF _Toc482964155 \h 163Sand dunes PAGEREF _Toc482964156 \h 163Loess PAGEREF _Toc482964157 \h 165Lakes PAGEREF _Toc482964158 \h 166Classification of Lakes PAGEREF _Toc482964159 \h 167Lakes Formed by Earth Movement PAGEREF _Toc482964160 \h 168Lakes Formed by Glaciation PAGEREF _Toc482964161 \h 169Lakes Formed by Volcanic Activity PAGEREF _Toc482964162 \h 169Lakes Formed by Erosion PAGEREF _Toc482964163 \h 169Lakes Formed by Deposition PAGEREF _Toc482964164 \h 170Lakes and Man PAGEREF _Toc482964165 \h 170No lake is permanent over geologic time PAGEREF _Toc482964166 \h 172Important Lakes on Earth PAGEREF _Toc482964167 \h 172Lake Baikal [Deepest] PAGEREF _Toc482964168 \h 172Lake Tanganyika [Longest] PAGEREF _Toc482964169 \h 173World’s Highest and Lowest Lakes PAGEREF _Toc482964170 \h 173The largest lakes (surface area) by continent PAGEREF _Toc482964171 \h 173Great Lakes PAGEREF _Toc482964172 \h 173Dead Sea PAGEREF _Toc482964173 \h 174Aral Sea PAGEREF _Toc482964174 \h 175African Great Lakes PAGEREF _Toc482964175 \h 175Largest Lakes by Surface Area PAGEREF _Toc482964176 \h 175Largest Lakes by Volume PAGEREF _Toc482964177 \h 176Deepest Lakes in the World PAGEREF _Toc482964178 \h 176Plateau PAGEREF _Toc482964179 \h 176Model question on Plateaus PAGEREF _Toc482964180 \h 176Plateau Formation PAGEREF _Toc482964181 \h 177Thermal expansion PAGEREF _Toc482964182 \h 177Crustal shortening PAGEREF _Toc482964183 \h 178Volcanic Flood Basalts - Traps PAGEREF _Toc482964184 \h 178Others PAGEREF _Toc482964185 \h 178Plateau Types PAGEREF _Toc482964186 \h 179Dissected plateau PAGEREF _Toc482964187 \h 179Volcanic plateau PAGEREF _Toc482964188 \h 179Others PAGEREF _Toc482964189 \h 179Major plateaus of the World PAGEREF _Toc482964190 \h 179Tibetan Plateau PAGEREF _Toc482964191 \h 179Columbia – Snake Plateau PAGEREF _Toc482964192 \h 180Colorado Plateau PAGEREF _Toc482964193 \h 180Deccan Plateau PAGEREF _Toc482964194 \h 180Kimberley Plateau PAGEREF _Toc482964195 \h 181Katanga Plateau PAGEREF _Toc482964196 \h 181Mascarene Plateau PAGEREF _Toc482964197 \h 181Laurentian Plateau PAGEREF _Toc482964198 \h 182Mexican Plateau PAGEREF _Toc482964199 \h 182Patagonian Plateau PAGEREF _Toc482964200 \h 182Altiplano Plateau or Bolivian Plateau PAGEREF _Toc482964201 \h 182Massif Central PAGEREF _Toc482964202 \h 182Anatolian Plateau PAGEREF _Toc482964203 \h 182Others PAGEREF _Toc482964204 \h 182Interior Of The EarthThe configuration of the surface of the earth is largely a product of the processes operating in the interior of the earth. Exogenic as well as endogenic processes are constantly shaping the landscape. Why know about earth’s interiorUnderstanding of the earth's interior is essential to understand the nature of changes that take place over and below the earth's surface.To understand geophysical phenomenon like volcanism, earthquakes etc..To understand the internal structure of various solar system objectsTo understand the evolution and present composition of atmosphereFuture deep-sea mineral exploration etc.Sources of information about the interiorDirect SourcesDeep earth mining and drilling reveals the nature of rocks deep down the surface. [Mponeng gold mine and TauTona gold mine in South Africa are deepest mines reaching to a depth of 3.9 km. And the deepest drilling is about 12 km deep]Volcanic eruption forms another source of obtaining direct information. Mponeng mineSouth AfricaDeepest mineGold mineDeapth: 2.4 miles (3.9 km)Indirect SourcesDepth: With depth, pressure and density increases and hence temperature. This is mainly due to gravitation. Meteors: Meteors and Earth are solar system objects that are born from the same nebular cloud. Thus they are likely to have a similar internal structure.Gravitation: The gravitation force (g) is not the same at different latitudes on the surface. It is greater near the poles and less at the equator. This is because of the distance from the center at the equator being greater than that at the poles. The gravity values also differ according to the mass of material. The uneven distribution of mass of material within the earth influences this value. Such a difference is called gravity anomaly. Gravity anomalies give us information about the distribution of mass of the material in the crust of the earth.Magnetic field: The geodynamo effect helps scientists understand what's happening inside the Earth's core. Shifts in the magnetic field also provide clues to the inaccessible iron core. But their source remains a mystery.Not important for exam. But if you are a science enthusiast and if you want to know more…What causes the magnetic field of earth?Our planet’s magnetic field is believed to be generated deep down in the Earth’s core.Nobody has ever taken the mythical journey to the centre of the Earth, but by studying the way shockwaves from earthquakes travel through the planet, physicists have been able to work out its likely structure.Right at the heart of the Earth is a solid inner core, two thirds of the size of the Moon and composed primarily of iron. At a hellish 5,700°C, this iron is as hot as the Sun’s surface, but the crushing pressure caused by gravity prevents it from becoming liquid.Surrounding this is the outer core, a 2,000 km thick layer of iron, nickel, and small quantities of other metals. Lower pressure than the inner core means the metal here is fluid.Differences in temperature, pressure and composition within the outer core cause convection currents in the molten metal as cool, dense matter sinks whilst warm, less dense matter rises. The Coriolis force, resulting from the Earth’s spin, also causes swirling whirlpools.This flow of liquid iron generates electric currents, which in turn produce magnetic fields. Charged metals passing through these fields go on to create electric currents of their own, and so the cycle continues. This self-sustaining loop is known as the geodynamo.The spiraling caused by the Coriolis force means that separate magnetic fields created are roughly aligned in the same direction, their combined effect adding up to produce one vast magnetic field engulfing the planet.The shadow zone of 'S' waves extends almost halfway around the globe from the earthquake's focus. The shadow zone for ‘S’ waves is an area that corresponds to an angle between 1030 and 1800 This observation led to the discovery of liquid outer core. Since S waves cannot travel through liquid, they do not pass through the liquid outer core. Surface Waves (L waves)Also called as long period waves. They are low frequency, long wavelength, and transverse vibration.Generally affect the surface of the Earth only and die out at smaller depth. Develop in the immediate neighborhood of the epicenter. They cause displacement of rocks, and hence, the collapse of structures occurs.These waves are responsible for most the destructive force of earthquake. Recoded last on the seismograph.Propagation of Earthquake WavesDifferent types of earthquake waves travel in different manners. As they move or propagate, they cause vibration in the body of the rocks through which they pass. Distribution of Earthquakes and VolcanoesThis movement of the plates allowed the magma to rise up and harden into new rock. As the new rock was formed near the ridge, older rock, which formed millions of years ago when the magnetic field was reversed, got pushed farther away, resulting in this magnetic striping.Rising magma assumes the polarity of Earth’s geomagnetic field before it solidifies into oceanic crust. At spreading centres, this crust is separated into parallel bands of rock by successive waves of emergent magma. 3606800732790008519905929When Earth’s geomagnetic field undergoes a reversal, the change in polarity is recorded in the magma, which contributes to the alternating pattern of magnetic striping on the seafloor.Concept of Sea Floor SpreadingThe idea that the seafloor itself moves (and carries the continents with it) as it expands from a central axis was proposed by Harry Hess.According to this theory, the intense heat generated by radioactive substances in the mantle (100-2900 km below the earth surface) seeks a path to escape, and gives rise to the formation of convention currents in the mantle. Wherever rising limbs of these currents meet, oceanic ridges are formed on the sea floor and wherever the failing limbs meet, trenches are formed. Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere. Basaltic magma rises up the fractures and cools on the ocean floor to form new sea floor. Older rocks will be found farther away from the spreading zone while younger rocks will be found nearer to the spreading zone.Evidences The Hawaiian volcanoes are the most famous examples. These volcanoes are mostly made up of basalt, a type of lava that is very fluid when erupted. These volcanoes are not steep. They become explosive if somehow water gets into the vent; otherwise, they are less explosive. 44151559525Example: Mauna Loa (Hawaii).Fissure Type Flood Basalt Landforms [Lava Plateaus]Sometimes, a very thin magma escapes through cracks and fissures in the earth's surface and flows after intervals for a long time, spreading over a vast area, finally producing a layered, undulating (wave like), flat surface. Example: Deccan traps (peninsular India), Snake Basin, U.S.A, Icelandic Shield, Canadian Shield etc..485584511189Caldera LakeAfter the eruption of magma has ceased, the crater frequently turns into a lake at a later time. This lake is called a 'caldera'. Examples: Lonar in Maharashtra and Krakatao in Indonesia.Cinder cone 40745765425900A cinder cone is a steep conical hill of loose pyroclastic fragments, such as either volcanic clinkers, cinders, volcanic ash, or scoria that has been built around a volcanic vent.Tsunami Tsunami is a Japanese word for “Harbour wave”. They are also known as seismic sea waves.They are very long-wavelength water waves in oceans or seas. They are commonly referred to as tidal waves because of long wavelengths, although the attractions of the Moon and Sun play no role in their formation. They sometimes come ashore to great heights – tens of metres above mean tide level – and may be extremely destructive.What causes Tsunami?A tsunami can be caused by any disturbance that displaces a large water mass from its equilibrium position.River course YouthYoung rivers (A) close to their source tend to be fast-flowing, high-energy environments with rapid headward erosion, despite the hardness of the rock over which they may flow. Steep-sided "V-shaped' valleys, waterfalls, and rapids are characteristic features. 289785296MaturityMature rivers (B) are lower-energy systems. Erosion takes place on the outside of bends, creating looping meanders in the soft alluvium of the river plain. Deposition occurs on the inside of bends and on the river bed. Old AgeAt a river's mouth (C), sediment is deposited as the velocity of the river slows. As the river becomes shallower more deposition occurs, forming islands and braiding the main channel into multiple, narrower channels. As the sediment is laid down, the actual mouth of the river moves away from the source into the sea or lake, forming a delta.Head ward erosion == Erosion?at the origin of a stream channel, which causes the origin to move back away from the direction of the stream flow, and so causes the stream channel to lengthen.Climatology and Climatic Regions by TOC \o "1-2" \h \z \u Latitudes and Longitudes PAGEREF _Toc482963907 \h 3Latitude PAGEREF _Toc482963908 \h 3Longitude PAGEREF _Toc482963909 \h 5Motions of the earth: Rotation and Revolution PAGEREF _Toc482963910 \h 11Rotation of Earth PAGEREF _Toc482963911 \h 11Revolution PAGEREF _Toc482963912 \h 13Atmosphere PAGEREF _Toc482963913 \h 15Role of Earth’s Atmosphere PAGEREF _Toc482963914 \h 16Composition of Atmosphere PAGEREF _Toc482963915 \h 17Major Greenhouse Gases PAGEREF _Toc482963916 \h 19Structure of Atmosphere PAGEREF _Toc482963917 \h 20Temperature Distribution on Earth PAGEREF _Toc482963918 \h 22Insolation PAGEREF _Toc482963919 \h 22Ways of Transfer of Heat Energy PAGEREF _Toc482963920 \h 23Factors Affecting Temperature Distribution PAGEREF _Toc482963921 \h 23Latitudinal Heat Balance PAGEREF _Toc482963922 \h 26Heat Budget PAGEREF _Toc482963923 \h 27The Mean Annual Temperature Distribution PAGEREF _Toc482963924 \h 27Seasonal Temperature Distribution PAGEREF _Toc482963925 \h 29Lapse Rate PAGEREF _Toc482963926 \h 34Why does temperature fall with elevation PAGEREF _Toc482963927 \h 34Adiabatic Lapse rate PAGEREF _Toc482963928 \h 35Wet and Dry Adiabatic Lapse rate PAGEREF _Toc482963929 \h 37Weather conditions at different?adiabatic lapse rates PAGEREF _Toc482963930 \h 38Latent Heat of Condensation PAGEREF _Toc482963931 \h 40Latent Heat PAGEREF _Toc482963932 \h 40Vertical Distribution of Temperature PAGEREF _Toc482963933 \h 41Temperature Anomaly PAGEREF _Toc482963934 \h 41Temperature Inversion PAGEREF _Toc482963935 \h 41Types of Temperature Inversion PAGEREF _Toc482963936 \h 42Economic Implications of Temperature Inversion PAGEREF _Toc482963937 \h 45Pressure Systems PAGEREF _Toc482963938 \h 45Equatorial Low Pressure Belt or ‘Doldrums’ PAGEREF _Toc482963939 \h 48Sub-Tropical High Pressure Belt or Horse Latitudes PAGEREF _Toc482963940 \h 49Sub-Polar Low Pressure Belt PAGEREF _Toc482963941 \h 52Polar High Pressure Belt PAGEREF _Toc482963942 \h 53Pressure belts in July PAGEREF _Toc482963943 \h 53Pressure belts in January PAGEREF _Toc482963944 \h 54Factors Controlling Pressure Systems PAGEREF _Toc482963945 \h 55Factors affecting Wind Movement PAGEREF _Toc482963946 \h 56Pressure Gradient Force and Wind Movement PAGEREF _Toc482963947 \h 56Coriolis Force and Wind Movement PAGEREF _Toc482963948 \h 56Why are there no tropical cyclones at the equator? PAGEREF _Toc482963949 \h 57Frictional Force and Wind Movement PAGEREF _Toc482963950 \h 58Centripetal Acceleration PAGEREF _Toc482963951 \h 58Pressure and Wind: Geostrophic Wind PAGEREF _Toc482963952 \h 58More about Coriolis effect PAGEREF _Toc482963953 \h 59General Circulation of the Atmosphere PAGEREF _Toc482963954 \h 60Hadley Cell PAGEREF _Toc482963955 \h 61Ferrel Cell PAGEREF _Toc482963956 \h 61Polar Cell PAGEREF _Toc482963957 \h 61Walker Cell PAGEREF _Toc482963958 \h 63Classification of Winds PAGEREF _Toc482963959 \h 64Primary or Prevailing Winds PAGEREF _Toc482963960 \h 64Secondary or Periodic Winds PAGEREF _Toc482963961 \h 66Tertiary or Local Winds PAGEREF _Toc482963962 \h 68Water Cycle - Hydrological Cycle PAGEREF _Toc482963963 \h 70Water Vapour in Atmosphere PAGEREF _Toc482963964 \h 71Humidity PAGEREF _Toc482963965 \h 71Evaporation PAGEREF _Toc482963966 \h 74Condensation PAGEREF _Toc482963967 \h 74Processes of Cooling for Producing Condensation PAGEREF _Toc482963968 \h 75Forms of Condensation PAGEREF _Toc482963969 \h 76Smog PAGEREF _Toc482963970 \h 81Primary and secondary pollutants PAGEREF _Toc482963971 \h 81Sulfurous smog PAGEREF _Toc482963972 \h 81Photochemical smog PAGEREF _Toc482963973 \h 81Haze PAGEREF _Toc482963974 \h 82Effects of Smog PAGEREF _Toc482963975 \h 82Precipitation PAGEREF _Toc482963976 \h 84Types of Rainfall PAGEREF _Toc482963977 \h 85World Distribution of Rainfall PAGEREF _Toc482963978 \h 87Thunderstorm PAGEREF _Toc482963979 \h 89How does a thunderstorm form? PAGEREF _Toc482963980 \h 90Motion of a thunderstorm PAGEREF _Toc482963981 \h 91Downbursts PAGEREF _Toc482963982 \h 92Types of Thunderstorms PAGEREF _Toc482963983 \h 92Lightning and thunder PAGEREF _Toc482963984 \h 94Lightening from cloud to Earth PAGEREF _Toc482963985 \h 95Lightning deaths PAGEREF _Toc482963986 \h 95Prediction and precautions PAGEREF _Toc482963987 \h 96The world’s most electric place PAGEREF _Toc482963988 \h 96Deadly Strikes PAGEREF _Toc482963989 \h 96Features of Lightning PAGEREF _Toc482963990 \h 97Thunder PAGEREF _Toc482963991 \h 97Tornado PAGEREF _Toc482963992 \h 97Distribution of tornadoes PAGEREF _Toc482963993 \h 98Waterspout PAGEREF _Toc482963994 \h 99Damage caused by thunderstorms and tornadoes PAGEREF _Toc482963995 \h 99Latitudes and Longitudes41531511025600Latitudes and Longitudes are imaginary lines used to determine the location of a place on earth.The shape of the earth is ‘Geoid’. And the location of a place on the earth can be mentioned in terms of latitudes and longitudes.Example: The location of New Delhi is 28° N, 77° E. LatitudeLatitude is the angular distance of a point on the earth’s surface, measured in degrees from the center of the earth. As the earth is slightly flattened at the poles, the linear distance of a degree of latitude at the pole is a little longer than that at the equator. For example at the equator (0°) it is 68.704 miles, at 45° it is 69.054 miles and at the poles it is 69.407 miles. The average is taken as 69 miles (111km). 1 mile = 1.607 km.Important parallels of latitudesBesides the equator (0°), the north pole (90°N) and the south pole (90° S), there are four important parallels of latitudes–Tropic of Cancer (23?° N) in the northern hemisphere. Tropic of Capricorn (23?° S) in the southern hemisphere. Arctic circle at 66?° north of the equator. Antarctic circle at 66?° south of the equator.Latitudinal Heat zones of the earthEquatorial Low Pressure Belt or ‘Doldrums’ Lies between 10°N and 10°S latitudes.Width may vary between 5°N and 5°S and 20°N and 20°S. This belt happens to be the zone of convergence of trade winds from two hemispheres from sub-tropical high pressure belts. This belt is also called the Doldrums, because of the extremely calm air movements.The position of the belt varies with the apparent movement of the Sun.FormationAs this region lies along the equator, it receives highest amount of insolation. Due to intense heating, air gets warmed up and rises over the equatorial region (convection). Whenever there is vertically upward movement of air, the region at the surface will be at low pressure. Thus the belt along the equator is called equatorial low pressure belt. Question mains 2013: Major hot deserts in northern hemisphere are located between 20-30 degree north and on the western side of the continents. Why?Sub-Polar Low Pressure Belt Located between 45°N and S latitudes and the Arctic and the Antarctic circles (66.5° N and S latitudes). Owning to low temperatures in these latitudes the sub polar low pressure belts are not very well pronounced year long.On long-term mean climatic maps, the sub polar low-pressure belts of the northern hemisphere are grouped into two centers of atmospheric activity: the Iceland low and the Aleutian depression (Aleutian low). Such belts in the southern hemisphere surround the periphery of Antarctica and are not as well differentiated. Forms of Condensation The forms of condensation can be classified on the basis of temperature at which the dew point is reached. Condensation can take place when the dew point islower than the freezing point, higher than the freezing point. White frost, snow and some clouds (cirrus clouds) are produced when the temperature is lower than the freezing point.Dew, fog and clouds result even when the temperature is higher than the freezing point. Forms of condensation may also be classified on the basis of their location, i.e. at or near the earth’s surface and in free air. Dew, white frost, fog and mist come in the first category, whereas clouds are in the second category.Dew 4226752548257When the moisture is deposited in the form of water droplets on cooler surfaces of solid objects (rather than nuclei in air above the surface) such as stones, grass blades and plant leaves, it is known as dew. The ideal conditions for its formation are clear sky, calm air, high relative humidity, and cold and long nights. For the formation of dew, it is necessary that the dew point is above the freezing point.White Frost 4610411314829Frost forms on cold surfaces when condensation takes place below freezing point (0° C), i.e. the dew point is at or below the freezing point. The excess moisture is deposited in the form of minute ice crystals instead of water droplets. The ideal conditions for the formation of white frost are the same as those for the formation of dew, except that the air temperature must be at or below the freezing point.Fog When the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, condensation takes place within itself on fine dust particles. So, the fog is a cloud with its base at or very near to the ground. Because of the fog and mist, the visibility becomes poor to zero. In urban and industrial centers smoke provides plenty of nuclei which help the formation of fog and mist. Such a condition when fog is mixed with smoke, is described as smog (will be discussed in detail in next post). [Related Question Asked in Mains 2015: Mumbai, Delhi and Kolkata are the three mega cities of the country but the air pollution is much more serious problem in Delhi as compared to the other two. Why is this so?] Climatology and Climatic Regions by TOC \o "1-2" \h \z \u Jet streams PAGEREF _Toc482963995 \h 5Geostrophic Wind PAGEREF _Toc482963996 \h 5Jet streams PAGEREF _Toc482963997 \h 6Permanent jet?streams PAGEREF _Toc482963998 \h 11Temporary jet streams PAGEREF _Toc482963999 \h 11Influence of Jet?Streams?on Weather PAGEREF _Toc482964000 \h 12Jet Streams and Weather in Temperate Regions PAGEREF _Toc482964001 \h 13Jet Streams and Aviation PAGEREF _Toc482964002 \h 14Air Masses PAGEREF _Toc482964003 \h 14Source regions PAGEREF _Toc482964004 \h 15Conditions for the formation of Air masses PAGEREF _Toc482964005 \h 15Air masses based on Source Regions PAGEREF _Toc482964006 \h 15Cold Air Mass PAGEREF _Toc482964007 \h 16Warm Air Mass PAGEREF _Toc482964008 \h 16Influence of Air Masses on World Weather PAGEREF _Toc482964009 \h 16Classification of Air Masses PAGEREF _Toc482964010 \h 17Fronts PAGEREF _Toc482964011 \h 18Front Formation PAGEREF _Toc482964012 \h 18General Characteristics of Fronts PAGEREF _Toc482964013 \h 19Classification of Fronts PAGEREF _Toc482964014 \h 20Stationary Front PAGEREF _Toc482964015 \h 20Cold Front PAGEREF _Toc482964016 \h 21Warm Front PAGEREF _Toc482964017 \h 23Occluded Front PAGEREF _Toc482964018 \h 24Tropical Cyclones PAGEREF _Toc482964019 \h 25Conditions Favourable for Tropical Cyclone Formation PAGEREF _Toc482964020 \h 26Origin and Development of Tropical Cyclones PAGEREF _Toc482964021 \h 29Structure of a tropical cyclone PAGEREF _Toc482964022 \h 32Vertical Structure of a Tropical Cyclone PAGEREF _Toc482964023 \h 35Categories of Tropical Cyclones PAGEREF _Toc482964024 \h 35Favorite Breeding Grounds for Tropical Cyclones PAGEREF _Toc482964025 \h 36Regional names for Tropical Cyclones PAGEREF _Toc482964026 \h 36Characteristics of Tropical Cyclones PAGEREF _Toc482964027 \h 37Warning of Tropical Cyclones PAGEREF _Toc482964028 \h 37What is a Storm Surge? PAGEREF _Toc482964029 \h 38What is storm tide? PAGEREF _Toc482964030 \h 39What are the disaster potential of Storm Surge? PAGEREF _Toc482964031 \h 39Why do 'tropical cyclones' winds rotate counter-clockwise (clockwise) in the Northern (Southern) Hemisphere? PAGEREF _Toc482964032 \h 39Why there are fewer cyclones over the Arabian Sea as compared to the Bay of Bengal? PAGEREF _Toc482964033 \h 40Why there are very few Tropical Cyclones during southwest monsoon season? PAGEREF _Toc482964034 \h 40What are the causes of disaster during cyclone? PAGEREF _Toc482964035 \h 40Mains 2013: Naming of Cyclones PAGEREF _Toc482964036 \h 41Polar or Arctic Cyclones PAGEREF _Toc482964037 \h 43Maximum Sustained Wind PAGEREF _Toc482964038 \h 43Low Pressure, Depression and Cyclone PAGEREF _Toc482964039 \h 43Central Dense Overcast (CDO) PAGEREF _Toc482964040 \h 43Annual frequency of Cyclones over the Indian Seas PAGEREF _Toc482964041 \h 44States Vulnerable to Cyclones PAGEREF _Toc482964042 \h 44Which sector of the cyclone experiences strongest winds? PAGEREF _Toc482964043 \h 45What is the normal movement of a Tropical Cyclone? PAGEREF _Toc482964044 \h 45What is the role of upper tropospheric westerly trough ? PAGEREF _Toc482964045 \h 46What is 4-stage warning system for Tropical Cyclones? PAGEREF _Toc482964046 \h 46Modifying cyclones? PAGEREF _Toc482964047 \h 47How are Tropical Cyclones monitored by IMD? PAGEREF _Toc482964048 \h 47Temperate Cyclones or Extra Tropical Cyclones or Mid-Latitude Cyclones or Frontal Cyclones PAGEREF _Toc482964049 \h 47Origin and Development of Temperate Cyclones PAGEREF _Toc482964050 \h 47Seasonal Occurrence of Temperate Cyclones PAGEREF _Toc482964051 \h 49Distribution of Temperate Cyclones PAGEREF _Toc482964052 \h 50Characteristics of Temperate Cyclones PAGEREF _Toc482964053 \h 50Tropical Cyclones and Temperate Cyclones Comparison PAGEREF _Toc482964054 \h 52Polar Vortex PAGEREF _Toc482964055 \h 54Polar Vortex Cold Wave PAGEREF _Toc482964056 \h 55How it slips PAGEREF _Toc482964057 \h 55Ozone Hole [Ozone Depletion at South Pole] PAGEREF _Toc482964058 \h 57Halogen atoms like chlorine destroy ozone PAGEREF _Toc482964059 \h 57Polar Stratospheric Clouds (PSCs) PAGEREF _Toc482964060 \h 58El Nino PAGEREF _Toc482964061 \h 60Normal Conditions PAGEREF _Toc482964062 \h 60Walker circulation (Occurs during Normal Years) PAGEREF _Toc482964063 \h 61During El Nino year PAGEREF _Toc482964064 \h 62Effects of El Nino PAGEREF _Toc482964065 \h 64How El Nino impacts monsoon rainfall in India PAGEREF _Toc482964066 \h 65El Nino Southern Oscillation [ENSO] PAGEREF _Toc482964067 \h 65Southern Oscillation Index and Indian Monsoons PAGEREF _Toc482964068 \h 66Indian Ocean Dipole effect (Not every El Nino year is same in India) PAGEREF _Toc482964069 \h 67Impact on IOD on Cyclonogeneis in Northern Indian Ocean PAGEREF _Toc482964070 \h 69El Ni?o Modoki PAGEREF _Toc482964071 \h 69El Ni?o Modoki Impacts PAGEREF _Toc482964072 \h 70La Nina PAGEREF _Toc482964073 \h 70Effects of La Nina PAGEREF _Toc482964074 \h 71Koeppen’s scheme Of Classification Of Climate PAGEREF _Toc482964075 \h 72Tropical Wet Climate (Af) PAGEREF _Toc482964076 \h 75Distribution PAGEREF _Toc482964077 \h 76Equatorial Climate PAGEREF _Toc482964078 \h 76Equatorial Vegetation PAGEREF _Toc482964079 \h 77Life and Economy PAGEREF _Toc482964080 \h 78Factors Affecting the Development of Equatorial Regions PAGEREF _Toc482964081 \h 80Mineral resources PAGEREF _Toc482964082 \h 81Tropical Monsoon Climate PAGEREF _Toc482964083 \h 84Distribution of Tropical Monsoon Climate PAGEREF _Toc482964084 \h 84Climate PAGEREF _Toc482964085 \h 85Seasons PAGEREF _Toc482964086 \h 86Tropical Marine Climate PAGEREF _Toc482964087 \h 87Tropical Monsoon Forests PAGEREF _Toc482964088 \h 87Population and Economy in Monsoon Climate PAGEREF _Toc482964089 \h 88Agricultural Development in the Monsoon Lands PAGEREF _Toc482964090 \h 88Lumbering PAGEREF _Toc482964091 \h 89Shifting Cultivation PAGEREF _Toc482964092 \h 90Savanna Climate or Tropical Wet and Dry Climate or Sudan Climate PAGEREF _Toc482964093 \h 91Distribution of Savanna Climate PAGEREF _Toc482964094 \h 91Savanna Climate PAGEREF _Toc482964095 \h 92Natural Vegetation of Savanna Climate PAGEREF _Toc482964096 \h 93Animal Life of the Savanna PAGEREF _Toc482964097 \h 94Life and Economy in the Savanna PAGEREF _Toc482964098 \h 94B: Desert Climate PAGEREF _Toc482964099 \h 96Hot Desert Climate PAGEREF _Toc482964100 \h 96Mid-Latitude Desert Climate PAGEREF _Toc482964101 \h 97Desert Climate PAGEREF _Toc482964102 \h 97Desert Vegetation PAGEREF _Toc482964103 \h 99Life in the Deserts PAGEREF _Toc482964104 \h 99Steppe Climate or Temperate Continental Climate or Temperate Grassland Climate PAGEREF _Toc482964105 \h 101Distribution PAGEREF _Toc482964106 \h 101Climate PAGEREF _Toc482964107 \h 102Natural Vegetation of Steppe Climate PAGEREF _Toc482964108 \h 103Economic Development of Steppes PAGEREF _Toc482964109 \h 104Maps: Savanna Grasslands and Steppe Grasslands PAGEREF _Toc482964110 \h 106Mediterranean Climate or Warm Temperate Western Margin Climate or Warm Temperate West Coast Climate PAGEREF _Toc482964111 \h 107Distribution PAGEREF _Toc482964112 \h 108Mediterranean Climate PAGEREF _Toc482964113 \h 108Climate Graphs PAGEREF _Toc482964114 \h 109Local winds of the Mediterranean Climate PAGEREF _Toc482964115 \h 109Natural Vegetation in the Mediterranean Climate PAGEREF _Toc482964116 \h 110Agriculture in the Mediterranean Climate PAGEREF _Toc482964117 \h 111Economy PAGEREF _Toc482964118 \h 112Warm Temperate Eastern Margin Climate PAGEREF _Toc482964119 \h 113China Type PAGEREF _Toc482964120 \h 113Gulf Type PAGEREF _Toc482964121 \h 113Natal Type PAGEREF _Toc482964122 \h 113Climate PAGEREF _Toc482964123 \h 114Variations of Warm Temperate Eastern Margin Climate PAGEREF _Toc482964124 \h 115Climate Graphs PAGEREF _Toc482964125 \h 115The China type PAGEREF _Toc482964126 \h 116The Gulf type PAGEREF _Toc482964127 \h 116The Natal type PAGEREF _Toc482964128 \h 116Natural Vegetation PAGEREF _Toc482964129 \h 117Economic Development PAGEREF _Toc482964130 \h 117Farming in monsoon China PAGEREF _Toc482964131 \h 117Agriculture in the Gulf states PAGEREF _Toc482964132 \h 118Crop in Southern Hemisphere PAGEREF _Toc482964133 \h 119British Type Climate PAGEREF _Toc482964134 \h 120Distribution of British Type Climate PAGEREF _Toc482964135 \h 120Climate PAGEREF _Toc482964136 \h 121The seasons PAGEREF _Toc482964137 \h 122Climate Graph British Type Climate PAGEREF _Toc482964138 \h 122Natural Vegetation in British Type Climate PAGEREF _Toc482964139 \h 122Economy in British Type Climate PAGEREF _Toc482964140 \h 123Taiga Climate or Boreal Climate PAGEREF _Toc482964141 \h 126Distribution PAGEREF _Toc482964142 \h 127Absent in Southern Hemisphere PAGEREF _Toc482964143 \h 127Taiga Climate PAGEREF _Toc482964144 \h 127Climate Graph of Taiga Climate PAGEREF _Toc482964145 \h 128Natural Vegetation of Taiga Climate PAGEREF _Toc482964146 \h 129Characteristics of Coniferous forests PAGEREF _Toc482964147 \h 130Economic Development of Taiga Region PAGEREF _Toc482964148 \h 130Laurentian Climate or Cool Temperate Eastern Marine Climate PAGEREF _Toc482964149 \h 132Distribution of Laurentian Climate PAGEREF _Toc482964150 \h 132North American region PAGEREF _Toc482964151 \h 133Asiatic region PAGEREF _Toc482964152 \h 133Absent in Southern Hemisphere PAGEREF _Toc482964153 \h 133Laurentian Climate PAGEREF _Toc482964154 \h 133The North American region PAGEREF _Toc482964155 \h 134The Asiatic region PAGEREF _Toc482964156 \h 134Japan PAGEREF _Toc482964157 \h 135Climate Graph for Laurentian Climate PAGEREF _Toc482964158 \h 135Natural Vegetation - Laurentian Climate PAGEREF _Toc482964159 \h 136Lumbering PAGEREF _Toc482964160 \h 136Economic Development – Laurentian Climate PAGEREF _Toc482964161 \h 136Fishing off Newfoundland PAGEREF _Toc482964162 \h 137Fishing off Japan PAGEREF _Toc482964163 \h 137Why is fishing the dominant occupation of Japan? PAGEREF _Toc482964164 \h 138Tundra Climate or Polar Climate or Arctic Climate PAGEREF _Toc482964165 \h 139Distribution PAGEREF _Toc482964166 \h 139Tundra Climate PAGEREF _Toc482964167 \h 140Natural Vegetation - Tundra Climate PAGEREF _Toc482964168 \h 140Recent Development of the Arctic Region PAGEREF _Toc482964169 \h 141Jet streams Geostrophic WindThe velocity and direction of the wind are the net result of the wind generating forces. The winds in the upper atmosphere, 2 - 3 km above the surface, are free from frictional effect of the surface and are controlled by the pressure gradient and the Coriolis force. An air parcel initially at rest will move from high pressure to low pressure because of the Pressure Gradient Force (PGF). 3820962275938However, as that air parcel begins to move, it is deflected by the Coriolis force to the right in the northern hemisphere (to the left in the southern hemisphere). As the wind gains speed, the deflection increases until the Coriolis force equals the pressure gradient force (2 – 3 km above the ground, friction is low and winds travel at greater speeds). At this point, the wind will be blowing parallel to the isobars (perpendicular to Pressure Gradient Force). When this happens, the wind is referred to as geostrophic wind.Why winds don’t flow from tropical high pressure (in upper troposphere) to polar low (in upper troposphere) directly as shown in figure below?4150588440900Because these winds are geostrophic, i.e., they flow at great speeds due to low friction and are subjected to greater Coriolis force. So they deflect greatly giving rise to three distinct cells called Hadley cell, Ferrel Cell and Polar cell. Instead of one big cell (as shown in fig) we have three small cells that combinedly produces the same effect.Cold Front Such a front is formed when a cold air mass replaces a warm air mass by advancing into it or that the warm air mass retreats and cold air mass advances (cold air mass is the clear winner). In such a situation, the transition zone between the two is a cold front. Cold front moves up to twice as quickly as warm fronts.Frontolysis begin when the warm air mass is completely uplifted by the cold air mass.Weather along a cold frontThe weather along such a front depends on a narrow band of cloudiness and precipitation. Severe storms can occur. During the summer months thunderstorms are common in warm sector.In some regions like USA tornadoes occur in warm sector. El Ni?o ModokiEl Ni?o Modoki is a coupled ocean-atmosphere phenomenon in the tropical Pacific. It is different from another coupled phenomenon in the tropical Pacific namely, El Ni?o. Conventional El Ni?o is characterized by strong anomalous warming in the eastern equatorial Pacific. Whereas, El Ni?o Modoki is associated with strong anomalous warming in the central tropical Pacific and cooling in the eastern and western tropical Pacific (see figure below). Koeppen’s scheme Of Classification Of Climate The most widely used classification of climate is the empirical climate classification scheme developed by V. Koeppen. [empirical: verifiable by observation or experience rather than theory or pure logic][when dropped, stone falls to the ground – logic. Drop a stone to confirm that it falls to the ground – empirical] Koeppen identified a close relationship between the distribution of vegetation and climate. He selected certain values of temperature and precipitation and related them to the distribution of vegetation and used these values for classifying the climates. Koeppen recognized five major climatic groups, four of them are based on temperature and one on precipitation. The capital letters : A, C, D and E delineate humid climates and B dry climates. The climatic groups are subdivided into types, designated by small letters, based on seasonality of precipitation and temperature characteristics. The seasons of dryness are indicated by the small letters : f, m, w and s, where f corresponds to no dry season, m - monsoon climate, w - winter dry season and s - summer dry season. The small letters a, b, c and d refer to the degree of severity of temperature. The B - Dry Climates are subdivided using the capital letters S for steppe or semi-arid and W for deserts. Oceanography by TOC \o "1-2" \h \z \u Oceanography by PAGEREF _Toc482964069 \h 1Ocean Relief PAGEREF _Toc482964070 \h 3Major Ocean Relief Features PAGEREF _Toc482964071 \h 4Minor Ocean Relief Features PAGEREF _Toc482964072 \h 4Marginal Seas PAGEREF _Toc482964073 \h 12Marginal seas of the world PAGEREF _Toc482964074 \h 12Human Impact on marginal seas PAGEREF _Toc482964075 \h 13Phytoplankton Bloom (Algal Bloom) in Marginal Seas PAGEREF _Toc482964076 \h 14Biomass Production and Primary Productivity PAGEREF _Toc482964077 \h 14Water Circulation in Marginal Seas PAGEREF _Toc482964078 \h 15Bays, gulfs, and Straits PAGEREF _Toc482964079 \h 16Bays PAGEREF _Toc482964080 \h 16Gulfs PAGEREF _Toc482964081 \h 16Straits PAGEREF _Toc482964082 \h 17Isthmus PAGEREF _Toc482964083 \h 17The Pacific Ocean PAGEREF _Toc482964084 \h 18North and Central Pacific PAGEREF _Toc482964085 \h 18West and South-West Pacific PAGEREF _Toc482964086 \h 18South-East Pacific PAGEREF _Toc482964087 \h 18The Atlantic Ocean PAGEREF _Toc482964088 \h 19Continental Shelf PAGEREF _Toc482964089 \h 19Mid-Atlantic Ridge PAGEREF _Toc482964090 \h 21Seamounts and guyots PAGEREF _Toc482964091 \h 21Trenches PAGEREF _Toc482964092 \h 21The Indian Ocean PAGEREF _Toc482964093 \h 21Submarine ridges PAGEREF _Toc482964094 \h 21Islands PAGEREF _Toc482964095 \h 23Continental Shelf PAGEREF _Toc482964096 \h 23Trenches PAGEREF _Toc482964097 \h 23Straits PAGEREF _Toc482964098 \h 23Marginal seas PAGEREF _Toc482964099 \h 23Ocean currents PAGEREF _Toc482964100 \h 24Ocean Movements PAGEREF _Toc482964101 \h 24Ocean currents PAGEREF _Toc482964102 \h 24Primary Forces Responsible For Ocean Currents PAGEREF _Toc482964103 \h 25Secondary Forces Responsible For Ocean Currents PAGEREF _Toc482964104 \h 26Types of Ocean Currents PAGEREF _Toc482964105 \h 26General Characteristics of Ocean Currents PAGEREF _Toc482964106 \h 27Effects of Ocean Currents PAGEREF _Toc482964107 \h 28Desert Formation and Ocean Currents PAGEREF _Toc482964108 \h 29Temperature Distribution of Oceans PAGEREF _Toc482964109 \h 31Source of Heat in Oceans PAGEREF _Toc482964110 \h 31Factors Affecting Temperature Distribution of Oceans PAGEREF _Toc482964111 \h 32Vertical Temperature Distribution of Oceans PAGEREF _Toc482964112 \h 33General behavior PAGEREF _Toc482964113 \h 36Horizontal Temperature Distribution of Oceans PAGEREF _Toc482964114 \h 37Range of Ocean Temperature PAGEREF _Toc482964115 \h 37Pacific Ocean Currents PAGEREF _Toc482964116 \h 38Equatorial Pacific Ocean Currents PAGEREF _Toc482964117 \h 38Counter equatorial current PAGEREF _Toc482964118 \h 39Kuroshio current PAGEREF _Toc482964119 \h 40Oyashio Current and Okhotsk current PAGEREF _Toc482964120 \h 40North-Pacific current PAGEREF _Toc482964121 \h 41Alaska and Californian current PAGEREF _Toc482964122 \h 41East Australian current PAGEREF _Toc482964123 \h 41Peru current or Humboldt Current PAGEREF _Toc482964124 \h 41Phytoplankton and Fishing PAGEREF _Toc482964125 \h 41Atlantic Ocean Currents PAGEREF _Toc482964126 \h 44Equatorial Atlantic Ocean Currents PAGEREF _Toc482964127 \h 44Antilles current PAGEREF _Toc482964128 \h 45Gulf Stream and North Atlantic Drift PAGEREF _Toc482964129 \h 45Norwegian current PAGEREF _Toc482964130 \h 45Sargasso Sea PAGEREF _Toc482964131 \h 46Grand Banks-Richest Fishing Grounds on Earth PAGEREF _Toc482964132 \h 46Brazil current PAGEREF _Toc482964133 \h 47Benguela current PAGEREF _Toc482964134 \h 47Indian Ocean Currents PAGEREF _Toc482964135 \h 48Indian Ocean Currents and Monsoons PAGEREF _Toc482964136 \h 48Southern Indian Ocean Currents - Agulhas current, Mozambique current, West Australian current PAGEREF _Toc482964137 \h 50Ocean Salinity PAGEREF _Toc482964138 \h 51Role of Ocean Salinity PAGEREF _Toc482964139 \h 51Factors Affecting Ocean Salinity PAGEREF _Toc482964140 \h 51Horizontal distribution of salinity PAGEREF _Toc482964141 \h 52Vertical Distribution of Salinity PAGEREF _Toc482964142 \h 54Tides PAGEREF _Toc482964143 \h 55Tidal Bulge - Why there are two tidal bulges? - Why is there a tidal bulge on the other side? PAGEREF _Toc482964144 \h 55Factors Controlling the Nature and Magnitude of Tides PAGEREF _Toc482964145 \h 57Types of Tides PAGEREF _Toc482964146 \h 57Tides based on Frequency PAGEREF _Toc482964147 \h 57Tides based on the Sun, Moon and the Earth Positions PAGEREF _Toc482964148 \h 58Magnitude of tides based on Perigee and apogee of moon PAGEREF _Toc482964149 \h 60Magnitude of tides based on Perigee and Apogee of earth PAGEREF _Toc482964150 \h 60Ebb and Flood PAGEREF _Toc482964151 \h 60Importance of Tides PAGEREF _Toc482964152 \h 61Characteristics of Tides PAGEREF _Toc482964153 \h 62Tidal bore PAGEREF _Toc482964154 \h 62Coral Reefs PAGEREF _Toc482964155 \h 64Coral Reef Relief Features PAGEREF _Toc482964156 \h 65Development Of Major Coral Reef Types PAGEREF _Toc482964157 \h 69Ideal Conditions for Coral Growth PAGEREF _Toc482964158 \h 70Coral Bleaching or Coral Reef Bleaching PAGEREF _Toc482964159 \h 72Ecological Causes of Coral Bleaching PAGEREF _Toc482964160 \h 73Spatial and temporal range of coral reef bleaching PAGEREF _Toc482964161 \h 74Resources from the Ocean PAGEREF _Toc482964162 \h 75Ocean Deposits PAGEREF _Toc482964163 \h 75Mineral Resources PAGEREF _Toc482964164 \h 76Energy Resources PAGEREF _Toc482964165 \h 78Fresh Water PAGEREF _Toc482964166 \h 78Biotic Resources PAGEREF _Toc482964167 \h 78Jurisdiction over the Seas PAGEREF _Toc482964168 \h 80United Nations International Conferences on the Law of the Sea PAGEREF _Toc482964169 \h 80Law of the Sea and Marine Pollution PAGEREF _Toc482964170 \h 82Sea Level Change PAGEREF _Toc482964171 \h 84The major categories of change in sea level PAGEREF _Toc482964172 \h 85Importance of understanding Sea Level Changes PAGEREF _Toc482964173 \h 85Evidence in Support of Sea Level Change PAGEREF _Toc482964174 \h 85Mechanisms of the Change in Sea Level PAGEREF _Toc482964175 \h 87Short-Term Changes in Global Sea Level PAGEREF _Toc482964176 \h 89Long-Term Sea Level Changes PAGEREF _Toc482964177 \h 90Impact of Sea Level Fall PAGEREF _Toc482964178 \h 91Impact of Possible Rise in Sea Level PAGEREF _Toc482964179 \h 91Ocean Relief Ocean relief is largely due to tectonic, volcanic, erosional and depositional processes and their interactions. Ocean relief features are divided into major and minor relief features.Major Ocean Relief Features 4237990314974Four major divisions in the ocean relief are:the continental shelf, the continental slope, the continental rise, the Deep Sea Plain or the abyssal plain. Minor Ocean Relief FeaturesRidges, Hills, Seamounts, Guyots, Trenches, Canyons, Sleeps, Fracture zones, Island arcs, Atolls, Coral reefs, Submerged volcanoes and Sea-scarps.Continental Shelf Continental Shelf is the gently sloping seaward extension of continental plate. These extended margins of each continent are occupied by relatively shallow seas and gulfs. Continental Shelf of all oceans together cover 7.5% of the total area of the oceans.Gradient of continental is of 1° or even less. The shelf typically ends at a very steep slope, called the shelf break. The continental shelves are covered with variable thicknesses of sediments brought down by rivers, glaciers etc.. Massive sedimentary deposits received over a long time by the continental shelves, become the source of fossil fuels [Petroleum]. Examples: Continental Shelf of South-East Asia, Great Banks around Newfoundland, Submerged region between Australia and New Guinea.The shelf is formed mainly due to submergence of a part of a continent relative rise in sea level Sedimentary deposits brought down by riversThere are various types of shelves based on different sediments of terrestrial origin —glaciated shelf (Surrounding Greenland), coral reef shelf (Queensland, Australia), shelf of a large river (Around Nile Delta), shelf with dendritic valleys (At the Mouth of Hudson River) shelf along young mountain ranges (Shelves between Hawaiian Islands). WidthThe average width of continental shelves is between 70 – 80 km. The shelves are almost absent or very narrow along some of the margins like the coasts of Chile, the west coast of Sumatra, etc. [Ocean – Continent Convergence and Ocean – Ocean Convergence]. It is up to 120 km wide along the eastern coast of USA. On the contrary, the Siberian shelf in the Arctic Ocean, the largest in the world, stretches to 1,500 km in width. TidesThe periodical rise and fall of the sea level, once or twice a day, mainly due to the attraction of the sun and the moon, is called a tide. Movement of water caused by meteorological effects (winds and atmospheric pressure changes) are called surges (storm surge during cyclones). The study of tides is very complex, spatially and temporally, as it has great variations in frequency, magnitude and height. The moon’s gravitational pull to a great extent and to a lesser extent the sun’s gravitational pull, are the major causes for the occurrence of tides. Another factor is centrifugal force which acts opposite to gravitational pull of earth. Tides occur due to a balance between all these forces. Tidal Bulge - Why there are two tidal bulges? - Why is there a tidal bulge on the other side?Together, the gravitational pull and the centrifugal force are responsible for creating the two major tidal bulges on the earth. On the side of the earth facing the moon, a tidal bulge occurs while on the opposite side though the gravitational attraction of the moon is less as it is farther away, the centrifugal force causes tidal bulge on the other side. The ‘tide-generating’ force is the difference between these two forces; i.e. the gravitational attraction of the moon and the centrifugal force. On the surface of the earth, nearest the moon, pull or the attractive force of the moon is greater than the centrifugal force, and so there is a net force causing a bulge towards the moon. Indian Geography by TOC \o "1-2" \h \z \u India As A Geographical Unit PAGEREF _Toc482964583 \h 5Rock System Based on Geological History Of India PAGEREF _Toc482964619 \h 11Archaean Rock System (Pre-Cambrian Rocks) PAGEREF _Toc482964620 \h 14Dravidian Rock System (Palaeozoic) PAGEREF _Toc482964621 \h 15Aryan Rock System PAGEREF _Toc482964622 \h 15Major Physical Divisions of India PAGEREF _Toc482964623 \h 17Peninsular Plateau PAGEREF _Toc482964624 \h 18Himalayas PAGEREF _Toc482964625 \h 18Indo-Gangetic Plain PAGEREF _Toc482964626 \h 18Coastal Plains PAGEREF _Toc482964627 \h 18Indian Islands PAGEREF _Toc482964628 \h 19Himalayan Ranges PAGEREF _Toc482964629 \h 19Shiwalik Range PAGEREF _Toc482964630 \h 19Middle or the Lesser Himalaya PAGEREF _Toc482964631 \h 21The Great Himalaya PAGEREF _Toc482964632 \h 23The Trans Himalayas PAGEREF _Toc482964633 \h 24Purvanchal or Eastern Hills PAGEREF _Toc482964634 \h 25Syntaxial Bends of the Himalayas PAGEREF _Toc482964635 \h 27Himalayas – Regional Divisions PAGEREF _Toc482964636 \h 27Important Valleys in Himalayas PAGEREF _Toc482964637 \h 30Snow in Himalayas - Snowline PAGEREF _Toc482964638 \h 31Significance of the Himalayas PAGEREF _Toc482964639 \h 33Mineral Resources in Himalayas PAGEREF _Toc482964640 \h 35Major Passes in India and Indian Sub-continent PAGEREF _Toc482964641 \h 35Main Passes of the Himalayas PAGEREF _Toc482964642 \h 38Formation of Indo – Gangetic – Brahmaputra Plain PAGEREF _Toc482964643 \h 42Formation of Indo – Gangetic – Brahmaputra trough PAGEREF _Toc482964644 \h 43Depositional Activity PAGEREF _Toc482964645 \h 44New rivers and more alluvium PAGEREF _Toc482964646 \h 44Features of Indo – Gangetic – Brahmaputra Plain PAGEREF _Toc482964647 \h 45Geomorphological features of Indo – Gangetic – Brahmaputra Plain PAGEREF _Toc482964648 \h 45Regional Divisions of the Great Plains PAGEREF _Toc482964649 \h 47Significance of the Plain PAGEREF _Toc482964650 \h 50Peninsular Plateau PAGEREF _Toc482964651 \h 50Features of the Peninsular Plateau PAGEREF _Toc482964652 \h 51Minor Plateaus in the Peninsular Plateau PAGEREF _Toc482964653 \h 52Hill Ranges of the Peninsular Plateau PAGEREF _Toc482964654 \h 56Aravali Range PAGEREF _Toc482964655 \h 56Vindhyan Range PAGEREF _Toc482964656 \h 57Satpura Range PAGEREF _Toc482964657 \h 57Western Ghats (or The Sahyadris) PAGEREF _Toc482964658 \h 59Eastern Ghats PAGEREF _Toc482964659 \h 60Significance of the Peninsular Plateau PAGEREF _Toc482964660 \h 61Coastline of India – Indian Coastline PAGEREF _Toc482964661 \h 61East Coast of India PAGEREF _Toc482964662 \h 62West Coast of India PAGEREF _Toc482964663 \h 63Coastlines PAGEREF _Toc482964664 \h 63Western Coastal Plains of India PAGEREF _Toc482964665 \h 64Eastern Coastal Plains of India PAGEREF _Toc482964666 \h 65Significance of the Coastal Plains PAGEREF _Toc482964667 \h 66Indian Islands PAGEREF _Toc482964668 \h 67Andaman and Nicobar islands PAGEREF _Toc482964669 \h 68Lakshadweep Islands PAGEREF _Toc482964670 \h 69New Moore Island PAGEREF _Toc482964671 \h 71Drainage patterns PAGEREF _Toc482964672 \h 72Discordant drainage patterns PAGEREF _Toc482964673 \h 74Antecedent Drainage or Inconsequent Drainage PAGEREF _Toc482964674 \h 74Superimposed or Epigenetic (Discordant) or Superinduced Drainage PAGEREF _Toc482964675 \h 74Concordant Drainage Patterns PAGEREF _Toc482964676 \h 75Consequent Rivers PAGEREF _Toc482964677 \h 76Subsequent Rivers PAGEREF _Toc482964678 \h 76Dendritic or Pinnate Drainage Pattern PAGEREF _Toc482964679 \h 76Trellis Drainage Pattern PAGEREF _Toc482964680 \h 76Angular Drainage Pattern PAGEREF _Toc482964681 \h 77Rectangular Drainage Pattern PAGEREF _Toc482964682 \h 77Radial Drainage Pattern PAGEREF _Toc482964683 \h 77Annular Drainage Pattern PAGEREF _Toc482964684 \h 77Parallel Drainage Pattern PAGEREF _Toc482964685 \h 78Centripetal Drainage Pattern PAGEREF _Toc482964686 \h 78Deranged Drainage Pattern PAGEREF _Toc482964687 \h 78Barbed Drainage Pattern PAGEREF _Toc482964688 \h 78Contribution of Water by Various Rivers PAGEREF _Toc482964689 \h 79Classification of Drainage Systems of India PAGEREF _Toc482964690 \h 79Major River System or Drainage Systems in India PAGEREF _Toc482964691 \h 82Indus River System PAGEREF _Toc482964692 \h 85Indus River PAGEREF _Toc482964693 \h 86Major Tributaries of Indus River PAGEREF _Toc482964694 \h 88Ganga River System PAGEREF _Toc482964695 \h 89Ganga River PAGEREF _Toc482964696 \h 92Ganga – Brahmaputra Delta PAGEREF _Toc482964697 \h 93Right Bank Tributaries of The Ganga PAGEREF _Toc482964698 \h 93Left Bank Tributaries of The Ganga River PAGEREF _Toc482964699 \h 96Brahmaputra River System PAGEREF _Toc482964700 \h 98Peninsular River System or Peninsular Drainage PAGEREF _Toc482964701 \h 100Evolution of the Peninsular Drainage PAGEREF _Toc482964702 \h 100Peninsular River Systems PAGEREF _Toc482964703 \h 101Himalayan River System vs. Peninsular River System PAGEREF _Toc482964704 \h 101East Flowing Peninsular Rivers PAGEREF _Toc482964705 \h 103Mahanadi River PAGEREF _Toc482964706 \h 103Godavari River PAGEREF _Toc482964707 \h 105Krishna River PAGEREF _Toc482964708 \h 107Cauvery River PAGEREF _Toc482964709 \h 109Pennar River PAGEREF _Toc482964710 \h 112Subarnarekha PAGEREF _Toc482964711 \h 113Brahamani River PAGEREF _Toc482964712 \h 116Sarada River PAGEREF _Toc482964713 \h 116Ponnaiyar River PAGEREF _Toc482964714 \h 116Vaigai River PAGEREF _Toc482964715 \h 116West Flowing Rivers of The Peninsular India PAGEREF _Toc482964716 \h 116Estuary PAGEREF _Toc482964717 \h 117Narmada River PAGEREF _Toc482964718 \h 118Tapti River PAGEREF _Toc482964719 \h 119Sabarmati River PAGEREF _Toc482964720 \h 120Mahi River PAGEREF _Toc482964721 \h 123Luni River PAGEREF _Toc482964722 \h 123West flowing Rivers of the Sahyadris (Western Ghats) PAGEREF _Toc482964723 \h 127Ghaggar River – Inland Drainage PAGEREF _Toc482964724 \h 127Usability of Rivers PAGEREF _Toc482964725 \h 128Indian Monsoons PAGEREF _Toc482964726 \h 128Mechanism of Indian Monsoons PAGEREF _Toc482964727 \h 130Indian Monsoons – Classical Theory: Sir Edmund Halley’s Theory PAGEREF _Toc482964728 \h 130Indian Monsoons – Modern theory: Air Mass Theory PAGEREF _Toc482964729 \h 131Indian Monsoon Mechanism – Jet Stream Theory PAGEREF _Toc482964730 \h 133Indian Monsoon Mechanism – Role of Sub-Tropical Jet Stream (STJ) PAGEREF _Toc482964731 \h 135Indian Monsoons – Role of Tropical Easterly Jet (TEJ) [African Easterly Jet] PAGEREF _Toc482964732 \h 137Indian Monsoons – Role of Tibet PAGEREF _Toc482964733 \h 139Indian Monsoons – Role of Somali Jet PAGEREF _Toc482964734 \h 141Indian Monsoons – Role of Indian Ocean Dipole PAGEREF _Toc482964735 \h 142How Jet Streams affect the Monsoons in the Indian Sub-Continent? PAGEREF _Toc482964736 \h 143Projects to understand monsoons PAGEREF _Toc482964737 \h 151Western Disturbances PAGEREF _Toc482964738 \h 152Cloudburst in Jammu and Kashmir, Himachal Pradesh, Uttarakhand PAGEREF _Toc482964739 \h 154Indian Climate PAGEREF _Toc482964740 \h 156Features of Indian Climate PAGEREF _Toc482964741 \h 156Factors Influencing Indian Climate PAGEREF _Toc482964742 \h 157Indian Climate – Seasons PAGEREF _Toc482964743 \h 161Summer Season in India PAGEREF _Toc482964744 \h 165Rainy Season – South West Monsoon Season PAGEREF _Toc482964745 \h 170North East Monsoon Season – Retreating Monsoon Season PAGEREF _Toc482964746 \h 178Annual Rainfall [South West Monsoons + Retreating Monsoons] PAGEREF _Toc482964747 \h 180Climatic Regions of India PAGEREF _Toc482964748 \h 182Natural Vegetation of India PAGEREF _Toc482964749 \h 188Classification Of Natural Vegetation of India PAGEREF _Toc482964750 \h 188Moist Tropical Forests PAGEREF _Toc482964751 \h 190Dry Tropical Forests PAGEREF _Toc482964752 \h 194Montane Sub-Tropical Forests PAGEREF _Toc482964753 \h 196Montane Temperate Forests PAGEREF _Toc482964754 \h 197Alpine Forests PAGEREF _Toc482964755 \h 199Soil PAGEREF _Toc482964756 \h 199Soil Types – Sandy-Clayey-Loamy PAGEREF _Toc482964757 \h 200Soil Profile – Soil Horizon PAGEREF _Toc482964758 \h 200Parent Material PAGEREF _Toc482964759 \h 202Relief PAGEREF _Toc482964760 \h 204Climate PAGEREF _Toc482964761 \h 204Natural Vegetation PAGEREF _Toc482964762 \h 205Major Soil Groups of India PAGEREF _Toc482964763 \h 205Alluvial Soils PAGEREF _Toc482964764 \h 206Black Soils PAGEREF _Toc482964765 \h 208Red Soils PAGEREF _Toc482964766 \h 210Laterite – Lateritic Soils PAGEREF _Toc482964767 \h 211Forest – Mountain Soils PAGEREF _Toc482964768 \h 212Arid – Desert Soils PAGEREF _Toc482964769 \h 212Saline – Alkaline Soils PAGEREF _Toc482964770 \h 213Peaty – Marshy Soils PAGEREF _Toc482964771 \h 214Characteristics of Indian Soils PAGEREF _Toc482964772 \h 215Problems Of Indian Soils PAGEREF _Toc482964773 \h 215Soil Degradation PAGEREF _Toc482964774 \h 215Soil Erosion PAGEREF _Toc482964775 \h 216Deforestation PAGEREF _Toc482964776 \h 219Overgrazing PAGEREF _Toc482964777 \h 220Faulty Methods of Agriculture PAGEREF _Toc482964778 \h 221Soil Salinity and Soil Alkalinity PAGEREF _Toc482964779 \h 221Desertification PAGEREF _Toc482964780 \h 223Waterlogging PAGEREF _Toc482964781 \h 223Soil Conservation PAGEREF _Toc482964782 \h 224Crop Rotation PAGEREF _Toc482964783 \h 224Strip Cropping PAGEREF _Toc482964784 \h 224Use of Early Maturing Varieties PAGEREF _Toc482964785 \h 225Contour Ploughing PAGEREF _Toc482964786 \h 225Checking Shifting Cultivation PAGEREF _Toc482964787 \h 225Ploughing the Land in Right Direction PAGEREF _Toc482964788 \h 225Mulching PAGEREF _Toc482964789 \h 225Contour barriers PAGEREF _Toc482964790 \h 226Rock dam PAGEREF _Toc482964791 \h 226Terrace farming PAGEREF _Toc482964792 \h 226Contour Bunding PAGEREF _Toc482964793 \h 226Intercropping PAGEREF _Toc482964794 \h 226Contour ploughing PAGEREF _Toc482964795 \h 226Shelter belts or Windbreaks PAGEREF _Toc482964796 \h 227Sand fences PAGEREF _Toc482964797 \h 227Afforestation PAGEREF _Toc482964798 \h 227Checking Overgrazing PAGEREF _Toc482964799 \h 227Dams PAGEREF _Toc482964800 \h 227Indian Monsoons – Modern theory: Air Mass TheoryAccording to this theory, the monsoon is simply a modification of the planetary winds of the tropics. The theory is based on the migration of ITCZ based on seasons.South West Monsoon Season – June to mid-September. South West Monsoon Season is also known as hot-wet season. Sudden onset is the important feature of South West Monsoons.With the onset of monsoons, temperature falls drastically and humidity levels rise.Temperature during South West Monsoon SeasonSudden onset of South West Monsoons leads to significant fall in temperature [3° to 6°C].The temperature remains less uniform throughout the rainy season. The temperature rises in September with the cease of south-west monsoons.There is rise in temperature whenever there is break in the monsoons. The diurnal range of temperature is small due to clouds and rains. The highest temperatures are experienced at places west of the Aravali [38° to 40°C]. This is due to lack of clouds and hot continental air masses. Other parts of Northwest India also have temperatures above 30°C. The temperatures are quite low over the Western Ghats due to heavy rainfall. The coastal areas of Tamil Nadu and adjoining parts of Andhra Pradesh have temperatures above 30°C as they receive little rainfall during this season.Pressure and Winds During South West Monsoon SeasonLow pressure conditions prevail over northwest India due to high temperature. ITCZ (monsoon trough) lies along the Ganga plain. There are frequent changes in its location depending upon the weather conditions. The atmospheric pressure increases steadily southwards. Over the peninsular region, due to pressure gradient between north and south, winds blow in a southwest to northeast direction from Arabian sea and Bay of Bengal. Their direction undergoes a change in Indo-Gangetic plain where they move from east to west.Rainfall During South West Monsoon SeasonThree fourths of the total annual rainfall is received during this season. The average rainfall over the plains of India in this season is about 87 per cent. Normal date of the arrival of the monsoon is 20th May in Andaman and Nicobar Islands. The advance of the monsoon is much faster in the Bay of Bengal than in the Arabian Sea. The normal date of onset of the southwest monsoon over Kerala i.e. the first place of entry in the mainland of India is 1st June. The monsoons advance quickly accompanied with a lot of thunder, lightning and heavy downpour. This sudden onset of rain is termed as monsoon burst. Sometimes monsoons are delayed or they come much earlier than normal. Normally the onset occurs between 29th May and 7th June. The earliest onset was on 11th May in 1918 and 1955, while the most delayed onset was on 18th June in 1972. South West Monsoon – Arabian Sea branch and Bay of Bengal branchMonsoon winds beyond south Kerala progress in the form of two branches viz. the Arabian Sea branch and the Bay of Bengal branch. The Arabian Sea branch gradually advances northwards. It reaches Mumbai by 10th June. The Bay of Bengal branch spreads rather rapidly over most of Assam. The normal date of its arrival at Kolkata is 7th June. On reaching the foothills of the Himalayas the Bay branch is deflected westward by the Himalayan barrier and it advances up the Gangetic plain. The two branches merge with each other mostly around Delhi to form a single current. Both the branches reach Delhi more or less at the same time. The combined current gradually extends to west Uttar Pradesh, Haryana, Punjab, Rajasthan and finally to Himachal Pradesh and Kashmir. By the end of June the monsoon is usually established over most parts of the country. Major Soil Groups of IndiaGeologically, Indian soils can broadly be divided into soils of peninsular India and soils of extra-peninsular India.The soils of Peninsular India are formed by the decomposition of rocks in situ, i.e. directly from the underlying rocks. Soils of Peninsular India are transported and re-deposited to a limited extent and are known as sedentary soils. The soils of the Extra-Peninsula are formed due to the depositional work of rivers and wind. They are very deep. They are often referred to as transported or azonal soils.Major groups:Alluvial soils, Black soils, Red soils, Laterite and Lateritic soils, Forest and Mountain soils, Arid and Desert soils, Saline and Alkaline soils and Peaty and Marshy soils. Alluvial Soils Economic Geography by TOC \o "1-2" \h \z \u Iron Ore PAGEREF _Toc482964597 \h 4Commonly found impurities in Iron Ore PAGEREF _Toc482964598 \h 4What exactly happens in a blast furnace? PAGEREF _Toc482964599 \h 5Beneficiation = Improve Concentration of Iron PAGEREF _Toc482964600 \h 6Why coke and not coal in smelting? PAGEREF _Toc482964601 \h 6Role of limestone = Remove Sulphur PAGEREF _Toc482964602 \h 6Reduction = Remove Oxygen PAGEREF _Toc482964603 \h 7Pig Iron PAGEREF _Toc482964604 \h 7Cast iron PAGEREF _Toc482964605 \h 7Steel PAGEREF _Toc482964606 \h 7Stainless steel PAGEREF _Toc482964607 \h 7Wrought iron PAGEREF _Toc482964608 \h 8Types of Iron Ore PAGEREF _Toc482964609 \h 8Factors that determine the location of Iron and steel industry PAGEREF _Toc482964610 \h 9Iron Ore Distribution Across the World PAGEREF _Toc482964611 \h 9Iron Ore in China – Manchuria, Sinkiang, Si-kiang, Shandog Peninsula PAGEREF _Toc482964612 \h 9Iron Ore in Europe – Ruhr, South Whales, Krivoy Rog, Bilbao, Lorraine PAGEREF _Toc482964613 \h 9Iron ore in Africa – Transvaal, Liberia PAGEREF _Toc482964614 \h 10Iron ore in Russia, Kazakhstan – Ural region, Magnitogorsk PAGEREF _Toc482964615 \h 11Iron Ore in North America – Great Lakes [Mesabi Region], Labrador PAGEREF _Toc482964616 \h 11Iron Ore in South America – Carajas, Itabira, Minas Geriais PAGEREF _Toc482964617 \h 11Iron Ore in Australia – Pilbara Region, Koolyanobbing, Iron Duke, Iron Knob PAGEREF _Toc482964618 \h 12Iron Ore Distribution in India PAGEREF _Toc482964619 \h 12Iron Ore in Orissa PAGEREF _Toc482964620 \h 13Iron Ore in Chhattisgarh PAGEREF _Toc482964621 \h 14Iron Ore in Jharkhand PAGEREF _Toc482964622 \h 14Iron Ore in Karnataka PAGEREF _Toc482964623 \h 14Iron ore in other states PAGEREF _Toc482964624 \h 14Coal PAGEREF _Toc482964625 \h 15Formation of Coal PAGEREF _Toc482964626 \h 15Types of Coal – Peat, Lignite, Bituminous & Anthracite Coal PAGEREF _Toc482964627 \h 17Distribution of Coal in India PAGEREF _Toc482964628 \h 19Gondwana Coal PAGEREF _Toc482964629 \h 19Tertiary Coal PAGEREF _Toc482964630 \h 25Tertiary Coal – Lignite PAGEREF _Toc482964631 \h 26Tertiary Coal – Peat PAGEREF _Toc482964632 \h 27Problems of Coal Mining in India PAGEREF _Toc482964633 \h 27Coking Coal vs. Non-Coking Coal PAGEREF _Toc482964634 \h 28Coal Reserves in India by State PAGEREF _Toc482964635 \h 28Coal Production in India by State PAGEREF _Toc482964636 \h 29India’s Coal Imports and Exports PAGEREF _Toc482964637 \h 29Major Coalfields in India PAGEREF _Toc482964638 \h 30Distribution of Coal across the World PAGEREF _Toc482964639 \h 31Global Coal Reserves PAGEREF _Toc482964640 \h 32Top Producers and Consumers of Coal in the World PAGEREF _Toc482964641 \h 32Distribution of Coal in USA PAGEREF _Toc482964642 \h 33Distribution of Coal in China PAGEREF _Toc482964643 \h 34Petroleum and Mineral Oil PAGEREF _Toc482964644 \h 35Constituents of Petroleum and Mineral Oil PAGEREF _Toc482964645 \h 35Formation of Petroleum and Mineral Oil PAGEREF _Toc482964646 \h 35Distribution of Petroleum and Mineral Oil in India PAGEREF _Toc482964647 \h 37On-shore Oil Production In India PAGEREF _Toc482964648 \h 38Off-Shore Production in India PAGEREF _Toc482964649 \h 39Petroleum Refining PAGEREF _Toc482964650 \h 40Share of Oil in Power Generation PAGEREF _Toc482964651 \h 43India’s Oil Imports PAGEREF _Toc482964652 \h 44Petroleum and Mineral Oil - World distribution PAGEREF _Toc482964653 \h 44Natural gas PAGEREF _Toc482964654 \h 50Natural Gas Formation PAGEREF _Toc482964655 \h 51Uses of Natural Gas PAGEREF _Toc482964656 \h 51Importance of Natural Gas to India PAGEREF _Toc482964657 \h 52World Distribution of Natural Gas PAGEREF _Toc482964658 \h 52OPEC – Organization of Petroleum Exporting Countries PAGEREF _Toc482964659 \h 54Distribution of Natural Gas in India PAGEREF _Toc482964660 \h 54Petroleum and Gas Value Chain PAGEREF _Toc482964661 \h 55Unconventional Gas Reservoirs PAGEREF _Toc482964662 \h 58Coalbed Methane PAGEREF _Toc482964663 \h 59Shale Gas – Shale Gas Formation PAGEREF _Toc482964664 \h 60Bauxite PAGEREF _Toc482964665 \h 66Bauxite Distribution in India PAGEREF _Toc482964666 \h 66Bauxite Distribution – World PAGEREF _Toc482964667 \h 68Lead and Zinc PAGEREF _Toc482964668 \h 70Lead PAGEREF _Toc482964669 \h 70Zinc PAGEREF _Toc482964670 \h 70Distribution of Lead and Zinc ores - India and World PAGEREF _Toc482964671 \h 70Tungsten PAGEREF _Toc482964672 \h 71Distribution of Wolfram PAGEREF _Toc482964673 \h 71Pyrites PAGEREF _Toc482964674 \h 71Gold Reserves in India PAGEREF _Toc482964675 \h 72Karnataka PAGEREF _Toc482964676 \h 72Andhra Pradesh PAGEREF _Toc482964677 \h 73Jharkhand PAGEREF _Toc482964678 \h 73Kerala PAGEREF _Toc482964679 \h 73Gold Distribution Across the World PAGEREF _Toc482964680 \h 74Countries with highest gold deposits PAGEREF _Toc482964681 \h 75Major Gold Producing Countries PAGEREF _Toc482964682 \h 75Silver Distribution – India & World PAGEREF _Toc482964683 \h 75Manganese PAGEREF _Toc482964684 \h 76Manganese Ore Distribution in India PAGEREF _Toc482964685 \h 76State wise reserves of Manganese PAGEREF _Toc482964686 \h 77World Manganese Ore Distribution PAGEREF _Toc482964687 \h 79Chromite PAGEREF _Toc482964688 \h 80Chromite Ore Distribution In India PAGEREF _Toc482964689 \h 80Chromite Ore Distribution Across the World PAGEREF _Toc482964690 \h 81Copper PAGEREF _Toc482964691 \h 82Copper Reserves in India PAGEREF _Toc482964692 \h 83Major Copper Reserves Across the World PAGEREF _Toc482964693 \h 84Nickel PAGEREF _Toc482964694 \h 85Graphite PAGEREF _Toc482964695 \h 86Applications of Graphite PAGEREF _Toc482964696 \h 87Major Producers of Graphite – India & World PAGEREF _Toc482964697 \h 87Diamonds PAGEREF _Toc482964698 \h 88Diamonds in India PAGEREF _Toc482964699 \h 88Diamonds Across the World PAGEREF _Toc482964700 \h 89Differences Between Graphite and Diamond PAGEREF _Toc482964701 \h 91Non-Metallic Minerals PAGEREF _Toc482964702 \h 91Mica PAGEREF _Toc482964703 \h 91Limestone PAGEREF _Toc482964704 \h 93Dolomite PAGEREF _Toc482964705 \h 94Asbestos PAGEREF _Toc482964706 \h 95Magnesite PAGEREF _Toc482964707 \h 96Kyanite PAGEREF _Toc482964708 \h 96Sillimanite PAGEREF _Toc482964709 \h 97Gypsum PAGEREF _Toc482964710 \h 97Salt PAGEREF _Toc482964711 \h 98Conservation of Mineral Resources PAGEREF _Toc482964712 \h 98Nuclear fission PAGEREF _Toc482964713 \h 98How Nuclear Fission Releases Energy? PAGEREF _Toc482964714 \h 100Common Fissile Material PAGEREF _Toc482964715 \h 100Uranium Enrichment PAGEREF _Toc482964716 \h 100Nuclear Reactor PAGEREF _Toc482964717 \h 101Types of Nuclear Reactors PAGEREF _Toc482964718 \h 103Thermal Reactors and Fast Neutron Reactors [Breeder Reactors] PAGEREF _Toc482964719 \h 104Reactors based on Coolant and Moderator PAGEREF _Toc482964720 \h 104Light-water reactor (LWR) PAGEREF _Toc482964721 \h 104Pressurized Heavy-Water Reactor (PHWR) PAGEREF _Toc482964722 \h 107Atomic Minerals PAGEREF _Toc482964723 \h 109Uranium PAGEREF _Toc482964724 \h 109Thorium PAGEREF _Toc482964725 \h 113India's Three-Stage Nuclear Power Programme PAGEREF _Toc482964726 \h 116Stage I – Pressurized Heavy Water Reactor [PHWR] PAGEREF _Toc482964727 \h 117Stage II – Fast Breeder Reactor PAGEREF _Toc482964728 \h 118Stage III – Thorium Based Reactors PAGEREF _Toc482964729 \h 118Prototype Fast Breeder Reactor at Kalpakkam PAGEREF _Toc482964730 \h 119What Hinders Deployment of Thorium-Fuelled Reactors In India? PAGEREF _Toc482964731 \h 119Present State of India's Three-Stage Nuclear Power Programme PAGEREF _Toc482964732 \h 120Solution to India’s Fissile Shortage Problem – Procuring Fissile Material Plutonium PAGEREF _Toc482964733 \h 120Iron Ore The below data is important for Prelims [Will be helpful to answer some logic based questions in mains]To understand about the factors that influence the location of Iron and Steel Industry, we have to understand about iron ore smelting.Smelting is a process of converting ore to metal by removing impurities. Commonly found impurities in Iron OreSiliconFound in small quantities. Slightly raises the Strength and Hardness of Steel.Acts as a de-oxidizing Agent ==> small quantities is good. [Oxides decrease the strength of Iron]SulphurA VERY harmful element. Forms Iron Sulphide which is a very brittle substance. Iron Ore Distribution Across the WorldIron Ore in China – Manchuria, Sinkiang, Si-kiang, Shandog PeninsulaIron Ore in Europe – Ruhr, South Whales, Krivoy Rog, Bilbao, Lorraine Iron ore in Africa – Transvaal, LiberiaCoal formed millions of years ago when the earth was covered with huge swampy [marshy] forests where plants - giant ferns and mosses - grew. As the plants grew, some died and fell into the swamp waters. New plants grew up to take their places and when these died still more grew. In time, there was thick layer of dead plants rotting in the swamp. The surface of the earth changed and water and dirt washed in, stopping the decaying process. More plants grew up, but they too died and fell, forming separate layers. After millions of years many layers had formed, one on top of the other. The weight of the top layers and the water and dirt packed down the lower layers of plant matter. Heat and pressure produced chemical and physical changes in the plant layers which forced out oxygen and left rich carbon deposits. In time, material that had been plants became coal.Coals are classified into three main ranks, or types: lignite, bituminous coal, and anthracite. These classifications are based on the amount of carbon, oxygen, and hydrogen present in the coal. Coals other constituents include hydrogen, oxygen, nitrogen, ash, and sulfur. Some of the undesirable chemical constituents include chlorine and sodium. In the process of transformation (coalification), peat is altered to lignite, lignite is altered to sub-bituminous, sub-bituminous coal is altered to bituminous coal, and bituminous coal is altered to anthracite.Types of Coal – Peat, Lignite, Bituminous & Anthracite CoalPeat42840218315First stage of transformation.Contains less than 40 to 55 per cent carbon == more impurities.Contains sufficient volatile matter and lot of moisture [more smoke and more pollution].Left to itself, it burns like wood, gives less heat, emits more smoke and leaves a lot of ash.Lignite403644310795Brown coal.Lower grade coal.40 to 55 per cent carbon.Intermediate stage.Dark to black brown.Moisture content is high (over 35 per cent). It undergoes SPONTANEOUS COMBUSTION [Bad. Creates fire accidents in mines]Bituminous CoalSoft coal; most widely available and used coal.Derives its name after a liquid called bitumen. 40 to 80 per cent carbon.Moisture and volatile content (15 to 40 per cent)Dense, compact, and is usually of black colour.Does not have traces of original vegetable material. Calorific value is very high due to high proportion of carbon and low moisture. Used in production of coke and gas.Anthracite CoalBest quality; hard coal. 80 to 95 per cent carbon.Very little volatile matter.Negligibly small proportion of moisture.Semi-metallic lustre.Ignites slowly == less loss of heat == highly efficient.Unconventional Gas ReservoirsUranium EnrichmentNatural uranium is only 0.7% U-235, the fissionable isotope. The other 99.3% is U-238 which is not fissionable. The uranium is usually enriched to 2.5-3.5% U-235 for use in light water reactors.Centrifugal separators and laser enrichment procedures are used in uranium enrichment.The enriched uranium fuel used in fission reactors cannot be used to make a bomb.It takes enrichment to over 90% to obtain the fast chain reaction necessary for weapons applications. Enrichment to 15-30% is typical for breeder reactors.Nuclear ReactorA nuclear reactor is a system that contains and controls sustained nuclear chain reactions. Pic from: [Enriched uranium-235 or Plutonium-239] is placed into the reactor vessel along with a small neutron source. The neutrons start a chain reaction where each atom that splits releases more neutrons that cause other atoms to split. Each time an atom splits, it releases large amounts of energy in the form of heat. The heat is carried out of the reactor by coolant, which is most commonly just plain water. The coolant heats up and goes off to a turbine to spin a generator or drive shaft.The coolant is the material that passes through the core, transferring the heat from the fuel to a turbine. It could be water, heavy-water, liquid sodium, helium, or something else.The turbine transfers the heat from the coolant to electricity, just like in a fossil-fuel plant.The containment is the structure made of steel-reinforced concrete that separates the reactor from the environment. Chernobyl did not have a strong containment structure.Nuclear Reactor CoolantA nuclear reactor coolant — usually water or molten salt — is circulated past the reactor core to absorb the heat that it generates. The heat is carried away from the reactor and is then used to generate steam. Neutron ModeratorA neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction.When a large fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission. The heavy nucleus splits into two or more lighter nuclei, (the fission products), releasing kinetic energy, gamma radiation, and free neutrons. A portion of these neutrons may later be absorbed by other fissile atoms and trigger further fission events, which release more neutrons, and so on. This is known as a nuclear chain reaction.To control such a nuclear chain reaction, neutron poisons and neutron moderators can change the portion of neutrons that will go on to cause more fissionCommonly-used moderators include regular (light) water (in 74.8% of the world's reactors), solid graphite (20% of reactors), heavy water (5% of reactors) and beryllium.Control Rods or Reactivity controlThe power output of the reactor is adjusted by controlling how many neutrons are able to create more fissions.Control rods that are made of a neutron poison are used to absorb neutrons. Moderators slow down neutronsControl Rods absorb neutronsModerators are like acceleratorsControl Rods are like brakesAbsorbing more neutrons in a control rod means that there are fewer neutrons available to cause fission. ................
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