World Geography

🔘

Winds of World Region wisepdf







Denudation  : The process of wearing away the earth causes a general lowering and levelling out of the surface. It has four phases.

• Weathering : Gradual disintegration of Rocks by atmospheric forces 

Chemical  - slow decompostion of rocks due to exposure to air and water

Mechanical - 

• Erosion : The active wearing away of Earth's surface by running forces like water, wind, ice, wave.
• Transportation  : Removal of eroded debris in new positions 
• Deposition : Dumping of Debris accumulated to form New rocks

Continental Shelf : 

• The continental rise is an underwater feature found between the continental slope and the abyssal plain.
• This feature can be found all around the world, and it represents the final stage in the boundary between continents and the deepest part of the ocean. 
• The environment in the continental rise is quite unique, and many oceanographers study it extensively in the hopes of learning more about the ocean and geologic history.
• Continental Shelf is the submerged edge of a continent which is a gently sloping plain that extends into the Ocean. 
• The typical gradient is less than 1°. The average width of continental shelves is about 80 km. 
• The largest shelf is the Siberian Shelf in the Arctic Ocean, which stretches to 1,500 kilometers in width. Because of the gentle slope, the continental shelf is influenced by the changes in the sea level.

The continental shelf is formed mainly due to

• Rise in sea level
• Submergence of a part of a continent
• Sedimentary deposits brought down by rivers

Tsunami 

• is a large ocean wave that is caused by sudden motion on the ocean floor. 
• This sudden motion could be 
• an earthquake, 
• a powerful volcanic eruption, 
• an underwater landslide. 
• The impact of a large meteorite could also cause a tsunami. 
• Tsunamis travel across the open ocean at great speeds and build into large deadly waves in the shallow water of a shoreline.

Earth Crust : Moho, or Mohorovičić discontinuity, boundary between Earth’s crust and its mantle. The Moho lies at a depth of about 22 mi (35 km) below continents and about 4.5 mi (7 km) beneath the oceanic crust. Modern instruments have determined that the velocity of seismic waves increases rapidly at this boundary. The Moho was named for Andrija Mohorovičić.
The depth of Mohorovicic discontinuity is higher under the continental crust than it is below oceanic crust.

FJORD is a long, deep, narrow body of water that reaches far inland. Fjords are often set in a U-shaped valley with steep walls of rock on either side. Fjords are found mainly in Norway, Chile, New Zealand, Canada, Greenland, and the USA of Alaska.

Fjords were created by glaciers. Glaciation carves deep valleys. This is why fjords can be thousands of meters deep. Fjords are usually deepest farther inland, where the glacial force was strongest.

Regolith : remains of rock

Granite is made of three main minerals Quartz feldspar and Mica

The mineral olivine is a magnesium iron silicate with the formula (Mg²⁺, Fe²⁺)₂SiO₄.

Note : Frictional heating is caused by denser core material sinking to the centre of the planet caused due to gravitation.

As material slides against each other, heat generated is retained deep within the earth and temperature remains high.

It is estimated that about 50% of the heat given off by the Earth is generated by the radioactive decay of elements such as uranium and thorium, and their decay products.

• What are neutron stars?

Neutron stars are the final stage in the curve of evolution of very massive stars – which are more than 20-30 times as massive as the sun. Initially, the stars glow and burn up their fuel. Due to internal pressure building up, they expand and since their mass is so high, they actually undergo a supernova explosion, throwing out the outer layers into space. 

The inner core collapses under its own gravity, shrinking to a small size, of a few tens of kilometres diameter. It stops short of becoming a black hole, as the mass is not sufficient to enable that. But this is a neutron star – its density is extremely high. As explained by Dibyendu Nandi of CESSI Kolkata explains, a spoonful of the material can weigh more than Mount Everest. Their magnetic fields are also huge in comparison to the Earth’s.

Neutron stars threw off energy and light during their merging – unlike black holes that do not allow light to escape from within their boundary, neutron stars can throw off matter and light – the merger also had a light signal. This was not in the visible spectrum but in the form of gamma radiation. 

Havre  world’s largest deep ocean volcanic eruption happened in New Zealand. It was recently confirmed by the researchers.

Cumulonimbus Cloud is a dense, towering vertical cloud associated with thunderstorms and atmospheric instability, forming from water vapour carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. 

Cumulonimbus can form alone, in clusters, or along cold front squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell( Rotating Thunderstorms). 

Bomb cyclone

a mid-latitude winter cyclone that intensifies rapidly, hammering the eastern coast of the US, bringing snow, ice, flooding, and strong winds. A bomb cyclone happens when atmospheric pressure in the middle of the storm drops at least 24 millibars over 24 hours, quickly increasing in intensity.  lower the pressure, the stronger the storm.

Cyclones :

• A system of low atmospheric pressure in which the barometric gradient is steep. 
• Cyclones represent circular fluid motion rotating in the same direction as the Earth. This means that the inward spiralling winds in a cyclone rotate anticlockwise in the Northern Hemisphere (code - NAC) and clockwise in Southern Hemisphere of the Earth. (code SC)
• Most large-scale cyclonic circulations are centred on areas of low atmospheric pressure. 
• The cyclones can be tropical cyclones or temperate cyclones (extra-tropical cyclones).
• Tropical cyclone is a system of low pressure occurring in tropical latitudes characterized by very strong winds. The formation of tropical storms are confined to oceans. The tropical cyclones are largely formed in summer and autumn. A tropical cyclone can be visualized as a giant vertical heat engine supported by mechanics driven by physical forces such as the rotation (Coriolis force) and gravity of the Earth. Inflow of warmth and moisture from the underlying ocean surface is critical for tropical cyclone strengthening. The rotation of the Earth causes the system to spin (Coriolis Effect) giving it a cyclonic characteristic and affecting the trajectory of the storm.
• Temperate cyclones are generally called depressions. They have low pressure at the centre and increasing pressure outwardly. They are of varying shapes such as circular, elliptical. The temperate cyclones are formed over land and sea alike.  Temperate Cyclones are formed in 35-65° North as well as South Latitudes. The temperate cyclones are formed in generally winter. Rainfall in these cyclones is low and continuous not as furious as in case of tropical cyclones.

Requirements for formation of Tropical Cyclone :

• Water temperatures of at least 26.5 °C down to a depth of at least 50 m, so that it may cause the overlying atmosphere to be unstable enough to sustain convection and thunderstorms.
• Rapid cooling with height, so that it may cause release of the heat of condensation that powers a tropical cyclone.
• High humidity
• Low amounts of wind shear as high shear is disruptive to the storm’s circulation.
• A distance from the Equator is necessary, which should be at least 555 km or 5° of latitude, so that it allows the Coriolis effect to deflect winds blowing towards the low pressure centre and creating a circulation. Because the Coriolis effect initiates and maintains tropical cyclone rotation, tropical cyclones rarely form or move within about 5° of the equator, where the Coriolis effect is weakest.
• A pre-existing system of disturbed weather
• To continue to drive its heat engine, a tropical cyclone must remain over warm water, which provides the needed atmospheric moisture to keep the positive feedback loop running. 
• When a tropical storm moves over waters significantly below 26.5 °C, it will lose its strength. This is because of losing its tropical characteristic of the warm core.

——> Cyclones or hurricanes do NOT develop within about 5° N and S of the equator because Coriolis force is very weak.

The conditions required for tropical cyclones are sea surface temperature more than 26 degree Celsius, sufficient Coriolis force, pressure gradient force and pre-existing vortex. Tropical cyclones do not form near the Equator (within 5 degrees latitude) because the Coriolis force is ZERO and air tends to flow straight into low pressure centres, so it feels up before the pressure can drop enough.

Hurricanes, cyclones and typhoons are all tropical storms. They are all the same thing but are given different names depending on where they appear. When they reach populated areas they usually bring very strong wind and rain which can cause a lot of damage.

Hurricanes — tropical storms that form over the North Atlantic Ocean and Northeast Pacific. 

Cyclones — formed over the South Pacific and Indian Ocean. 

Typhoons — formed over the Northwest Pacific Ocean.

Fujiwhara effect :

When two cyclones approach one another, their centres will begin orbiting cyclonically about a point between the two systems. The two vortices will be attracted to each other and eventually spiral into the centre point and merge. When the two vortices are of unequal size, the larger vortex will tend to dominate the interaction, and the smaller vortex will orbit around it. This phenomenon is called the Fujiwhara effect.

•  ‘ANTICYCLONE’ is opposite to a cyclone, in which winds move into a low-pressure area. 

• In an anticyclone, winds move out from a high-pressure area with wind direction clockwise in the northern hemisphere, anti-clockwise in the southern hemisphere. 
• An anti-cyclone -- also known as a high pressure area -- is a large atmospheric circulation system.
• The extents(strength, length, scope) are generally large and the effects are also pronounced. 
• Such a high pressure area is usually spread over a large area, created by descending warm air devoid of moisture. 
• The absence of moisture makes the dry air denser than an equal quantity of air with moisture. When it displaces the heavier nitrogen and oxygen, it causes an anti-cyclone.

Anticyclones form from air masses cooling more than their surroundings, which causes the air to contract slightly making the air denser. Since dense air weighs more, the weight of the atmosphere overlying a location increases, causing increased surface air pressure. 

• Winds are of moderate speed, and at the outer edges, cloudy and precipitation conditions exist. 
• Cloudy conditions and precipitation exists at the periphery of anticyclones. Otherwise, such a high pressure region generally shows fine and clear weather. 

——> Extratropical storms are a global, rather than a localized, phenomena with moisture usually carried in the upper atmosphere (unlike tropical storms where it is carried in the lower atmosphere). In the case of the subcontinent, moisture is sometimes shed as rain when the storm system encounters the Himalayas.
Jet streams are an important component of upper air circulation which is dominated by westerly flow. These jet streams blow south of Himalayas, all through the year except in summer affecting India’s climate and weather.
The western cyclonic disturbances experienced in the north and north-western parts of the country are brought in by this westerly flow which affects rainfall in Northern and north-western India.

Extratropical cyclones

• In mid-latitudes, much of our weather is associated with a particular kind of storm, the extratropical cyclone. 
• Extratropical cyclones derive their energy from horizontal temperature contrasts. 
• They typically form on a boundary between a warm and a cold air mass associated with an upper tropospheric jet stream .
• Their circulations affect the entire troposphere over a region 1000 km or more across. 
• Extratropical cyclones tend to develop with a particular lifecycle. 
• The low pressure centre moves roughly with the speed of the 500 mb wind above it. 
• An extratropical cyclone tends to focus the temperature contrasts into ‘frontal zones’ of particularly rapid horizontal temperature change.

• Extra-tropical cyclones are also known as mid-latitude storms or baroclinic storms.
• These cyclones move from west to east but tropical cyclones, move from east to west.

Jet streams 

• are a narrow belt of high altitude (above 12,000 m) westerly winds in the troposphere. 
• Their speed varies from about 110 km/h in summer to about 184 km/h in winter. 
• A number of separate jet streams have been identified.
• At most times in the Northern and Southern Hemispheres, there are two jet streams: 
• A subtropical jet stream centered at about 30 degrees latitude and a polar-front jet stream whose position varies with the boundary between polar and temperate air. 
• A reverse jet stream blows toward the west in tropical high altitudes during the Northern Hemispheres summer.
• It is associated with the heating of the Asian continent and may help bring summer monsoons to the Indian Ocean.

 

Winds can be broadly divided into three types. 

1. Permanent winds – The trade winds, westerlies and easterlies are the permanent winds. These blow constantly throughout the year in a particular direction. 
2. Seasonal winds – These winds change their direction in different seasons. For e.g. monsoons in India. 
3. Local winds – These blow only during a particular period of the day or year in a small area. For example, land and sea breeze; Loo in India.
   

Trade winds are confined the area near equator, whereas Westerlies and Easterlies blow even beyond the sub-tropics 

Water :

Tides : The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides. 

The water of the earth closer to the moon gets pulled under the influence of the moon’s gravitational force and causes high tide. 

• During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides. 
• But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and earth resulting in low tides. These tides are called neap tides. 

Inter-tidal zones are regions between the high tide and low tide area. They are biologically productive, but foggy weather is not experienced there 

Marine upwelling zones are rich in nutrients, as nutrient rich water is upwelled to come to the top. But, again foggy weather is not experienced 

——> Areas where warm and cold currents meet tend to have regular foggy conditions, as the overlying warm and cold air come in contact with each other. 

• They also tend to have high biological productivity, because plankton growth is encourage by the mixing of warm and cold currents. 
• Some of the world's most productive fishing grounds are located where warm and cold currents converge. 
• For example, where Labrador current (cold) and Gulf stream (warm) meet, a dense fog is there and it is one of the richest fishing grounds of the world.
  

Note : Productivity of fishery is high along the coast of Peru because Phytoplankton production is high there because wind driven upwelling brings nutrients from deeper water to the surface.

Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as “upwelling.”

Upwelling occurs in the open ocean and along coastlines. The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom.

Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity.  Therefore, good fishing grounds typically are found where upwelling is common. The anchovy population that is the basis of the Peru fishery, the world’s largest, is a phytoplankton feeding species, supported by an upwelling based ecosystem.

There are three types of mountains - 

Fold Mountains, Block Mountains and the Volcanic Mountains. The Himalayan Mountains and the Alps are young fold mountains with rugged relief and high conical peaks. 

Block Mountains are created when large areas are broken and displaced vertically. The uplifted blocks are termed as horsts and the lowered blocks are called graben. The Rhine valley and the Vosges mountain in Europe are examples of such mountain systems. 

Volcanic mountains are formed due to volcanic activity. Mt. Kilimanjaro in Africa and Mt.Fujiyama in Japan are examples of such mountains. 

In terms of forest cover, the state/UT that has 

1. The largest geographical area of forests is Madhya Pradesh. 
2. The largest percentage of geographical area as forest cover is Lakshadweep.
   

A layer of ozone envelops the Earth and keeps damaging ultraviolet, or UV, radiation from reaching living things on the planet’s surface. The ozone layer exists mainly in the stratosphere, a layer of the atmosphere that reaches from 10 to 50 kilometers (about 6 to 30 miles) above the Earth’s surface.

The ozone hole is a region of depleted layers of ozone above the Antarctic region, whose creation is linked to increased cases of skin cancer.

Ozone which protects us from UV rays is found here. Stratosphere is also stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler higher up and warmer farther down. 

At moderate latitudes the stratosphere is situated between about 10–13 km and 50 km altitude above the surface, while at the poles it starts at about 8 km altitude, and near the equator it may start at altitudes as high as 18 km. 

Why Ozone hole in Antarctica despite major anthropogenic activities in Mainlands :
Reactions that take place on polar stratospheric clouds (PSCs) play an important role in enhancing ozone depletion. PSCs form more readily in the extreme cold of the Arctic and Antarctic stratosphere. 

Methane gas comes outside through oceans from inter tectonic plates is responsible for hole.

\\ Tropical deciduous are the monsoon forests found in the large part of India, northern Australia and in Central America. These regions experience seasonal changes. Trees shed their leaves in the dry season to conserve water.
The hardwood trees found in these forests are sal, teak, neem and shisham. Hardwood trees are extremely useful for making furniture, transport and constructional materials. Tigers, lions, elephants, langoors and monkeys are the common animals of these regions.

Evergreen forests are mainly found in the areas recording over 150 cm of average annual rainfall where the temperature varies between 25°C to 27°C. North- East India, parts of Western Ghats, the Andaman and Nicobar, upper Assam, lower slopes of Eastern Himalayas, Orissa, along the foot-hills of Himalayas, Bhabhar and Tarai regions. 

Decidous can be further found in Bihar, Jharkhand, Odisha, Chattisgarh, AP, Kerala, Karnataka, MP, TN etc. 

A&M Islands, Mangroves, Decidous, Evergreen, all kinds of vegetation are found. 

Climate Classification and Climatic Regions of the World

A - Tropical Moist Climates :

• All months have average temperatures above 18° Celsius.
• Three minor climate types exist in the group, and their designation is based on seasonal distribution of rainfall. 
1. Af or tropical wet is a tropical climate where precipitation occurs all year long. Because of intense surface heating and high humidity, cumulus and cumulonimbus clouds form early in the afternoons almost every day. Daily highs are about 32° Celsius, while night time temperatures average 22° Celsius. 
2. Am is a tropical monsoon climate. Annual rainfall is equal to or greater than Af, but most of the precipitation falls in the 7 to 9 hottest months. During the dry season very little rainfall occurs. 
3. The tropical wet and dry or savanna (Aw) has an extended dry season during winter. Precipitation during the wet season is usually less than 1000 millimeters, and only during the summer season.

B - Dry Climates: 

• Deficient precipitation during most of the year
• Potential evaporation and transpiration exceed precipitation. 
• These climates extend from 20 - 35° North and South of the equator and in large continental regions of the mid-latitudes often surrounded by mountains. 
• Minor types of this climate include:
• BW - DRY ARID (desert) is a true desert climate. It covers 12% of the Earth's land surface and is dominated by xerophytic vegetation. 
• BS - DRY SEMIARID (steppe) Is a grassland climate that covers 14% of the Earth's land surface. It receives more precipitation than the BW either from the ITCZ or from mid-latitude cyclones. 

C - Moist Mid-latitude Climates with Mild Winters

• Warm and humid summers with mild winters. 
• Its extent is from 30 to 50° of latitude mainly on the eastern and western borders of most continents. 
• During the winter, the main weather feature is the mid-latitude cyclone. Convective thunderstorms dominate summer months. 
• Three minor types exist: 
1. Cfa - humid subtropical : hot muggy summers and frequent thunderstorms. Winters are mild and precipitation during this season comes from mid-latitude cyclones. e.g. southeastern USA
2. Cs - Mediterranean : receive rain primarily during winter season from the mid-latitude cyclone. Extreme summer aridity is caused by the sinking air of the subtropical highs and may exist for up to 5 months. Locations in North America are from Portland, Oregon to all of California.
3. Cfb - marine climates are found on the western coasts of continents. They have a humid climate with short dry summer. Heavy precipitation occurs during the mild winters because of the continuous presence of mid-latitude cyclones. 

D - Moist Mid-Latitude Climates with Cold Winters

• Moist continental mid-latitude climates have warm to cool summers and cold winters. 
• The location of these climates is pole ward of the C climates. 
• The average temperature of the warmest month is greater than 10° Celsius, while the coldest month is less than -3° Celsius. 
• Winters are severe with snowstorms, strong winds, and bitter cold from Continental Polar or Arctic air masses. 
• There are three minor types: 
1. Dw - dry winters; 
2. Ds - dry summers; 
3. Df - wet all seasons.

E - Polar Climates: with extremely cold winters and summers

• Polar climates have year-round cold temperatures with the warmest month less than 10° Celsius. 
• Polar climates are found on the northern coastal areas of North America, Europe, Asia, and on the landmasses of Greenland and Antarctica. 
• Two minor climate types exist. 
1. ET or polar Tundra is a climate where the soil is permanently frozen to depths of hundreds of meters, a condition known as permafrost. Vegetation is dominated by mosses, lichens, dwarf trees and scattered woody shrubs. 
2. EF or polar ice caps has a surface that is permanently covered with snow and ice.

British type Climate : 

• The mean annual temperatures are usually between 5 degree C in winters to 15 degree C in summers thus have a short annual temperature range.  
• They are the regions of frontal cyclonic activity [Temperate Cyclones]
• The cool temperate western margins are under the influence of the Westerlies all-round the year.
• Hence the climate of this maritime region as a whole may be described as equable with moderately warm summers & fairly mild winter.
• It is aka North West European Maritime Climate.
• Westerlies come all the year round and there is a tendency towards an autumn or winter maximum of rainfall. Light snow falls in winter. Ports are never frozen, but frosts do occur on cold nights. The seasons are very distinct 
• From Britain, the climatic belt stretches far inland into lowlands of N-W Europe, including such regions as northern & western France, Belgium, Netherland, Denmark, Western Norway & N-W Iberia.

• In northern America, the high Rockies prevent the on shore westerlies from penetrating far inland & British type of climate is confined mainly to coastlands of British Columbia (West coast of Canada).
• In the southern hemisphere, this type of climate is experienced in southern Chile, Tasmania (southern Australia) & Most parts of New Zealand, particularly in south island, surrounded by large expanses of water.

Siberian Type Climate :

• Cool temperate continental (Siberian) climate is only experienced in northern hemisphere, where the continents within the high latitudes have a broad east west spread.
• On its poleward side, it merges into Arctic tundra of Canada & Eurasia at around Arctic Circle;
• Southwards, the climate becomes less severe & fades into the temperate Steppe climate.
• Predominant vegetation of this Siberian or sub-arctic type of climate is evergreen coniferous forests that stretch in a great, continuous belt across North America, Europe & Asia.
• The greatest single band of the coniferous forest is Taiga (a Russian word for coniferous forest) in Siberia.
• In Europe, this climate & forests are mainly confined to Northern Europe, Sweden & Finland;
• However there are small amount of coniferous forests at high altitudes in Germany, Poland, Austria, Switzerland & other parts of the Europe.
• In North America, the sub-arctic belt stretches across from Alaska across Canada into Labrador & is found in the high Rocky Mountains further south.

The Siberian climate is conspicuously absent in the southern hemisphere because of the narrowness of the southern continents in the high latitudes. The strong oceanic influence reduces the severity of the winters & coniferous forests are found only on the mountainous uplands of southern Chile, New Zealand, Tasmania & South East Australia.

Coniferous Evergreen forests

• Four major groups of conifers viz. Fir, Pine, Spruces & Larch
• There is no annual replacement of new leaves as in deciduous trees.
• The same leaf remains on the tree for as long as 5 years.
• Soils of coniferous forests are poor, podzolized, excessively leached & very acidic.
• Evergreen leaves provide little leaf fall for humus formation & the rate of decomposition of the leathery needles in a region of such a low temperature is slow.

• Due to the warping, sagging, bending and fracturing of the earth’s crust, tectonic depressions occur. Such depressions give rise to lakes of immense sizes and depths. They include Lake Titicaca, occupying a huge depression in the inter mont plateau of the Andes, 12,500 feet above sea level the highest lake in the world; and the Caspian Sea, 143,550 square miles, the largest lake, almost 5 times larger than its nearest rival, Lake Superior. 
• Due to faulting, a rift valley is formed by the sinking of land between two parallel faults, deep, narrow and elongated in character. Water collects in these troughs and their floors are often below sea level.
  It includes such lakes as Lakes Tanganyika (4,700 feet deep, the world’s deepest lake), Malawi, Rudolf, Edward. Albert, as well as the Dead Sea 1,286 feet below mean sea level, the world’s lowest lake. The best known example is the East African Rift Valley which runs through Zambia, Malawi, Tanzania, Kenya and Ethiopia, and extends along the Red Sea to Israel and Jordan over a total distance of 3,000 miles. 

Lakes of World :

• Lake Titicaca, occupying a huge depression in the inter mont plateau of the Andes, 12,500 feet above sea level the highest lake in the world. It is centre of the Incan civilisation, and today straddles the boundary between Peru and Bolivia. It is Longest(in height) freshwater lake in world.
• Caspian Sea, 143,550 square miles, the largest lake(but SALTY), almost 5 times larger than its nearest rival, Lake Superior which is second largest lake. 
• Lake Baikal in Siberia is deepest lake in the world having deepest point is 1637 meters. It holds 20% of the world's fresh surface water and is the also world's largest freshwater lake by volume. (Deepest, Oldest, Largest by volume)
• Lake Tanganyika, an African Great Lake is second oldest freshwater lake in the world, second largest by volume, and the second deepest, in all cases after Lake Baikal in Siberia; it is also the world's longest freshwater lake
  
• Lake Superior, on United States/Canada border, is named freshwater lake with the greatest surface area at 31,700 square miles (82,103 square kilometers)
• Five Lakes of USA - HOMES ( Huron, Ontario, Michigan, Erie, Superior )

Coffee growing Belt :

seychelles 

Materials & Minerals :

• Cinnabar : bright scarlet to brick-red form of Mercury(II) Sulfide ( HgS ) 
• Calamine : Zinc
• Haematite , Magnetite : Iron Ore
• Siderite is a mineral composed of :  iron(II) carbonate (FeCO3).
• Bauxite : Aluminium
• Lignite : brown coal 
• 
  

Sphalerite ((Zn, Fe)S) :

• A mineral that is the chief ore of zinc. 
• It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. 
• When iron content is high it is an opaque black variety, marmatite. 
• It is usually found in association with galena, pyrite, and other sulfides along with calcite, dolomite, and fluorite. 
• Miners have also been known to refer to sphalerite as zinc blende, black-jack and ruby jack.

Kaolin or Kaolinite or china clay :  
soft white clay that is an essential ingredient in the manufacture of china and porcelain and is widely used in the making of paper, rubber, paint, and many other products. Kaolin is named after the hill in China (Kao-ling) from which it was mined for centuries.
It is tetrahedral sheet of silica linked through oxygen atoms to one octahedral sheet of alumina octahedra.

Corundum :

• is a crystalline form of aluminium oxide typically containing traces of iron, titanium, vanadium & chromium. It is a rock-forming mineral. It is also a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. 
• extremely hard crystallized alumina, used as an abrasive. Ruby and sapphire are varieties of corundum.
• use as an abrasive, owing to the extreme hardness and used for grinding optical glass and for polishing metals and has also been made into sandpapers and grinding wheels.

Talc : is a hydrated magnesium silicate that is commonly used in the manufacture of leather, rubber, paper, textiles, and ceramic tiles as well as iron and nickel. As often in combination with corn starch, is widely used as baby powder.

Gypsum : is a soft sulfate mineral composed of calcium sulfate dihydrate. It is widely mined and is used as fertilizer and as the main constituent in many forms of plaster, blackboard/sidewalk chalk and drywall.

Chiquicamata in Chili (South America) : for Copper 

There are four type of Coal : PLBA

• Peat :  
• Lignite : known as brown coal is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It is considered the lowest rank of coal due to its relatively low heat content. It has a carbon content around 60–70 percent. It is mined all around the world and is used almost exclusively as a fuel for steam-electric power generation, but is also mined for its germanium(Semiconductor) content in China.
• Bituminous : or black coal is a relatively soft coal containing a tarlike substance called bitumen or asphalt. It is of higher quality than lignite coal but of poorer quality than anthracite. 
• Anthracite : or hard coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal except for graphite and is the highest ranking of coal. Anthracite is the most metamorphosed type of coal. Anthracite accounts for about 1% of global coal reserves and China accounts for majority of anthracite coal.

Graphite : Referred to as plumbago, is a crystalline allotrope of carbon, a semimetal, a native element mineral, and a form of coal. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.

Graphene 

• an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice. 
• It is nearly transparent. & basic structural element of many other allotropes of carbon, such as graphite, charcoal, carbon nanotubes and fullerenes. 
• Its thin composition and high conductivity means it is used in applications ranging from miniaturised electronics to biomedical devices. 
• These properties also enable thinner wire connections; providing extensive benefits for computers, solar panels, batteries, sensors and other devices. 
• The one-atom-thick sheets of carbon conduct electrons better than silicon and have been made into fast, low-power transistors. 
• Now, for the first time, researchers have measured the intrinsic strength of graphene which is the strongest material ever tested. 
• Given its strength, electrical conductivity and elasticity, it can be used as an alternative to lithium-ion batteries since its discovery in 2004. 
• It can be used to develop smaller, slimmer batteries but with higher capacity. 
• The potential applications of graphene include water filtration and purification, renewable energy, sensors, personalised healthcare and medicine. 

Biome : 

• Collection of a similar type of ecosystems distributed all over the world. 
• All the tropical rainforests could be collectively referred as the biome of that ecosystem. 
• Primarily there are two main types of biomes known as aquatic and terrestrial; 
• Aquatic biomes are of two main types known as freshwater biomes and marine biomes. Climatology and geography have been defined for a particular biome, so that those conditions are similar in each ecosystem distributed on the earth of the particular biome. However, the composition of biological species in different ecosystems of the same biome could be different. Despite the differences in species, the ecological niches are the same in each ecosystem within one biome; thus, the type of species would be mostly similar.

Biosphere : 

• Collection of all the living beings of the earth
• All the ecosystems of the earth could be collectively referred to as the biosphere.
• The biosphere is composed of biomes; biome is a collection of similar ecosystems, and ecosystem is a collection of different species where they coexist with each other by sharing different ecological niches. 
• Each species is composed of different individuals. Therefore, the basic component of the biosphere is an individual of any species.
• It is the sum of all ecosystems and those are distributed in different regions depending on the climate and geography; hence, the biosphere is the Life Zone of the Earth.
• The species richness is always at its highest level in the biosphere while it is at a comparatively lower level in a biome.

Great Oxygenation Event or oxygen catastrophe which happened 2400 million years ago in the Proterozoic eon triggered an explosive growth in the diversity of minerals on Earth. Three types of Rocks are Sedimentary, Igneous and Metamorphic.

1. Sedimentary rocks 
• They are the most common rock types which are freely exposed on the earth’s surface. 
• They are formed from other rock materials since they are made up from the build up of weathered and eroded pre-existing rocks.
• Sedimentary rocks are produced from previous rocks that are relentlessly weathered or eroded and then deposited where they undergo compaction and cementation through a process known as lithification - changing of sediments into a rock. 
• The sediment is buried and then it is compacted as more and more material is deposited on top. In several thousand to Lakhs of years, the sediment becomes so dense that it becomes a rock.

2. Igneous rocks
• These rocks have crystallized from magma which is made up of various components of pre-existing rocks and has been subjected to melting either at subduction zones or within the Earth’s mantle.

3. Metamorphic rocks
• These rocks once existed as igneous or sedimentary rocks but have been subjected to varying degrees of pressure and heat within the Earth’s crust. 
• The processes involved changes the composition and fabric of the rock and their original nature is often hard to distinguish.
• Metamorphic rocks are typically found in areas of mountain building.

——> The above three classes of rocks are constantly being transformed (as below) from one to another in a continuous process through which the crustal minerals have been recycled during many millions of years of geologic time. 

Indian Ocean Dipole (IOD)

• known as the Indian Niño, is an irregular oscillation of sea-surface temperatures in which the western Indian Ocean becomes alternately warmer and then colder than the eastern part of the ocean.
• A 2009 study has demonstrated a significant correlation between the IOD and drought in the southern half of Australia, in particular the south-east.
• During the Positive IOD, the eastern equatorial Indian Ocean off Sumatra in Indonesia becomes colder than normal while the western tropical part of the Indian Ocean near the African coast becomes unusually warm. This is beneficial for the monsoon.
• During the Negative IOD the eastern equatorial Indian Ocean off Sumatra in Indonesia becomes abnormally warm while the western tropical part of the ocean near the African coast becomes relatively colder. This effect obstructs the progression of monsoon over India.

El-Nino :

La-Nina :


ITCZ :