Revision Notes: Geography for All competitive Exams of 2025

Revision Notes: Geography for all competitive exams of 2025. These important one liner are compiled with reference to NTPC(RRB) syllabus of Geography. Comprehensive notes will be added later.

GEOGRAPHY- SET 1

• Geomorphology studies the Earth’s structure, the rocks that make up the earth, relief features and their evolution.
• Hydrology is the study of the movement, distribution and quality of water throughout the earth.
• Oceanography is the study of ocean currents, waves and tides.
• Climatology is the study of climatic features such as temperature, precipitation and humidity.
• Biogeography deals with the distribution of flora and fauna in different parts of the world.
• Carbon dating is the most important method for estimating the age of fossils found in the rocks of the earth’s crust.
• The age of the earth is estimated to be about 4.6 billion years.
• Alfred Lothar Wegener became famous for his theory of continental drift.
• The Earth’s Crust is the outer layer, varying between 5 to 50 km in depth.
• The outermost layer of the crust is composed of lighter silicates termed as sial (Silica + Aluminium).
• Moho or Mohorovicic discontinuity separates crust from mantle.
• The Mantle is a layer between crust and the core.
• The Core is the central region of the earth.
• The inner core is composed of NiFe (Ni for Nickel Fe for Iron).
• Earth is the third planet of the solar system and ranks fifth in size.
• The shape of the earth is an oblate spheroid or a geoid.
• Geographic Information Systems (GIS) uses computers for storing and processing information about the Earth’s surface and land use.
• The most abundant element in atmosphere is Nitrogen (78%).
• The most abundant element in the universe is hydrogen.
• A rock can be defined as an aggregate of minerals.
• Lithification is the process of rock formation, consolidation of mineral particles.
• Albedo is the ratio between the total amount of light reflected from an object and the total amount of light falling on an object.
• Earth has an albedo of 0.34 (34%).
• Earth moves around the sun in an elliptical orbit.
• The bulging of the central part (equatorial region) is due to centrifugal force.
• The Earth’s axis is inclined and makes an angle 66½° with the orbital plane.
• 71% of the total surface area of earth is water and 29% is land.
• The movement of earth can be mainly divided into two as, rotation and revolution.
• Rotation is the spinning of earth on its own axis.
• When two continental plates collide, mountain ranges are created.
• Summer Solstice (on or around June 21) is when the sun shines directly over the tropic of cancer.
• Winter Solstice (on or around December 22) is when the South pole tilts towards the sun and the North pole away from it.
• Longest day (shortest night) in the northern hemisphere is June 21.
• Shortest day (longest night) in the northern hemisphere is December 21.
• A meridian is an imaginary line extending from the north pole to the south pole at right angles to the equator.
• Prime Meridian is the 0° meridian which passes through Greenwich,a place near London.
• Longitudes are equi-distant lines drawn east and west of the Greenwich meridian.
• One hour is equal to 15° of longitude.
• Local time varies from Greenwich time at the rate of four minutes / degree of longitude.
• Standard time is the uniform time fixed by each country.
• Standard time in India is the local time of a place near Allahabad at 82 ½°E longitude.
• Greenwich Mean Time is the standard time of U.K..
• The International Date Line is situated at 180° meridian from Greenwich.
• When the date line is crossed from the east to the west, the date must be advanced by one day.
• When the date line is crossed from the west to the east, the date must be set back by one day.
• The International Date Line runs down the mid Pacific Ocean.
• Sidereal day is the time between two observed passages of a star over the same meridian of longitude.
• Solar day is the time between two successive transits of the sun over the same meridian.
• Magma is the molten rock material in the earth’s interior; upon reaching the surface, it is called Lava.
• Crater is a funnel shaped depression having a circular plan.
• An extinct volcano shows no sign of life, e.g: Mt. Kilimanjaro.
• The Pacific belt is known as the Ring of fire because of the largest number of active volcanoes.
• Batholiths are a large mass of magma which often forms the root of a mountain and is made up of granite.
• The point of origin of an earthquake in the interior of the earth is called the seismic focus.
• Seismology is the study of earthquakes and their impact.
• Intensity is the measure of the local effect of an earthquake, expressed in Points.
• Magnitude is a measure of the strength of the earthquake at its source (focus), assessed in Richter scale.
• An earthquake is measured by its Magnitude and Intensity.
• The Richter Scale has no upper limit.
• The Moment Magnitude Scale has been devised for more precise study of great earthquakes.
• Earthquakes with magnitude of about 2.0 or less are usually called microearthquakes.
• A tsunami is a long-wave length, long-period sea wave produced by the sudden or abrupt movement of large volumes of water.
• Most destructive tsunamis are caused by earthquakes of magnitude 7.5 or more.
• Rocks are solid materials that makes up the earth’s crust.
• Rocks may be classified into igneous, sedimentary and metamorphic.
• Igneous rocks are formed by the solidification of molten magma from the interior of the earth.
• About 95% of the earth’s crust is made up of igneous rocks.
• Igneous rocks generally do not occur in layers.
• Sedimentary rocks are formed from the sediments deposited on the ocean beds.
• Sedimentary rocks comprise only about 5% of the earth’s crust, but covers about 75% of the total land surface.
• Fossils are commonly found in sedimentary rocks.
• Sedimentary rocks are also called stratified rocks.
• Shale is the most abundant of all sedimentary rocks.
• Sandstone is a common sedimentary rock which is formed mainly of quartz particles.
• Coal and Peat represents the accumulation of vegetation which originated in swamps.
• ‘Black Twins’ is the name given to iron and coal.
• ‘Black lead’ is graphite.
• Anthracite is the most superior type of coal.
• There are three major landforms – mountains, plateaus and plains.
• Volcanic mountains are formed by the accumulation of volcanic material.
• Continental plateaus rise abruptly from the lowlands or from the sea.
• Lava plateaus are formed when lava spreads out to cover the pre-existing land surface.
• Peneplains are formed by the wearing down of land due to weathering and erosion.
• The Vindhyas separates Southern India from Northern India.
• Satpuras lies in between Narmada and Tapti.
• The southernmost tip of Western Ghats is called Cardamom Hills.
• Sahyadri and Nilgiri are parts of the Western Ghats.
• Western Ghats and Eastern Ghats meet at Nilgiri Hills.
• Earth’s rotation is the rotation of the solid Earth around its own axis, towards the east.
• The most celebrated test of Earth’s rotation is the Foucault pendulum first built by physicist Léon Foucault in 1851.
• Ionosphere is that part of the thermosphere which is an electrically charged layer characterised by the ionisation of atoms.
• The effect of rotation of earth on the direction of winds is called the Coriolis effect.
• Trade winds blow towards the equator between 5° and 30° north and south latitude.
• Trade winds are also called tropical easterlies.
• The word ‘monsoon’ is derived from the Arabic word ‘mausin’ meaning seasonal winds.
• Polar winds blow from the high pressure area around the poles towards the temperate regions.
• The Mistral is the most famous local cold wind that blows from Alps over France towards the Mediterranean sea.
• Loos are very hot and dry local winds that blows from the west in the plains of Northern India and Pakistan in the months of May and June.
• Land breeze is defined as the process by which cold winds blows from the land to sea during night.
• Wind Wane is Instrument for knowing the direction of wind.
• Anemometer measures the velocity of the wind.
• Beaufort wind scale is an internationally accepted wind scale which consists of a series of number to indicate different wind strengths.
• Cirrus clouds form delicate patches and give a fibrous and feathery appearance.
• Cumulous clouds have a flat base and have the appearance of rising domes, often described as having cauliflower structure.
• Stratus clouds are sheets of layer that covers much or all of the sky.
• Precipitation is the formation of water particles or ice within the cloud that falls towards the earth’s surface.
• Hails are ice-pellets that develops in and fall from cumulo nimbus clouds.
• Equator is the biggest circle drawn on the globe.
• The regions between 5° north and 5° south of the equator is called the Equatorial region.
• Polar Climate is also known as the tundra.
• Fog is made up of droplets of water suspended in the lower layers of atmosphere.
• Smog also called smoke fog, is a form of fog that occurs in areas where the air contains a large amount of smoke.
• Mist is the term given for a reduction of visibility between 1 -.
• Greenhouse gases such as Carbon dioxide, methane, nitrous oxide, CFC’s and others thicken the blanket of greenhouse gases over the earth’s atmosphere.
• Deforestation accelerates global warming by reducing the absorption of carbon dioxide in the atmosphere.
• There are five major oceans: Pacific, Atlantic, Indian, Arctic and the Antarctic or Southern Ocean.
• The Pacific Ocean is the largest ocean in the world. It covers one-third of the earth.
• The Atlantic Ocean is the busiest ocean route in the world.
• The Indian Ocean is the third largest ocean in the world and the only ocean named after a country, India.
• The greatest depth in the Indian Ocean is the Java Trench (7,725 m).
• High seas are the open seas or oceans outside any territorial waters of countries, also known as International waters.
• Within the Exclusive Economic Zone (EEZ) the coastal state has the right to exploit all economic resources.
• An estuary is the single v-shaped mouth of a river when it merges into the sea.
• Shoal is a shallow region in a sea, river or lake.
• Hydrosphere is The mass of water that covers about 71% of the earth’s surface.
• Oceans contains more than 97% of the total water on the earth.
• Arctic ocean is the smallest ocean in the world.
• The two most abundant elements in sea water are chlorine and sodium.
• Peninsula is a piece of land almost surrounded by water.
• Southern India is a peninsula.
• The sea with the highest degree of salinity is the Dead Sea.
• No fish live in this sea.
• The Panama Canal links the Pacific Ocean with the Atlantic Ocean.
• The Abyssal Plain is the deepest and most extensive part of the ocean floor.
• Jog or Gersoppa Falls on Sharavati in Karnataka is the highest waterfall in India.
• A glacier is a moving mass of ice.
• June 17 : World day to combat desertification.
• The Takla Makan is the largest desert in China.
• Gobi (Mongolia) is the coldest desert in the world.
• Largest Desert in India is Thar Desert.
• Camel is known as the ship of the desert.
• Atacama Desert in Northern Chile is the driest place on Earth.
• Kalahari Desert lies in Southern Africa.
• Denakit Depression, Ethiopia, is listed as the Hottest Place (34.4°C).
• Dji Buti is listed as the Hottest inhabited place.
• Greenland is the largest island in the world.
• Archipelago is a group of islands.
• Greenland is the example of Continental Island.
• Savannah is a region which lies on both sides of the equator roughly between 5 degrees and the tropics.
• Deciduous forests are forests with trees which shed their leaves seasonally.
• Mawsynram India (1141 cm) is the rainiest place in the world (Note: Source also states 1187 cm in).
• India is the seventh largest country in the world.
• The northern most point of the country is known as Indira Col.
• The southernmost point in Indian territory is the Indira Point.
• India is entirely contained on the Indian Plate.
• The Himalayas is one of the youngest mountain systems in the world.
• ‘the Himalayas’ meaning ‘the abode of snow‘.
• The Siachen Galcier is considered the largest glacier outside the polar areas.
• The Peninsular Plateau is also called the The Deccan Plateau.
• Aravallis is the oldest mountain range in India.
• Sahyadri hills is a part of the Western Ghats.
• Nilgiris is also a part of Western Ghats and is known as the Blue Mountains.
• Annaimudi is the highest peak in the peninsular region.
• The most important waterfall formed by the Narmada is the Dhuandhar Falls near Jabalpur, also called the Marble Falls.