1 | P a g e ACADEMY OF CIVIL SERVICES #1 Rated Online Coaching for APSC Naliapool, Dibrugarh- Assam Indian Geography For Admission Visit: www.acsassam.com To Join our Coaching contact us on Mob: 9085268769 (English and Assamese)/ 8800512202 (English Only) Email: [email protected] Copyright © Academy of Civil Services All rights are reserved. No part of this document may be reproduced or copied without prior permission of Academy of Civil Services, Dibrugarh (Assam) Copyright © Academy of Civil Services www.acsassam.com 2 | P a g e Fundamentals of Physical Geography Solar System ➢ Sun • Hottest layer of the Sun is Core with a temperature of 15 million Degree Celsius • In the radiative zone, energy generated by nuclear fusion in the core moves outward as electromagnetic radiation • Temperature in this region is below 2 million Degree Celsius • In the convection zone energy is transported by convection • Temperature in this zone is 5800 degree Celsius • Photosphere is the layer where light (Photos) is formed • It is the visible layer of the sun • Temperature of this sphere is 5500 degree Celsius • Chromosphere: The chromosphere's rosy red colour is only apparent during eclipses • Temperature is 27800 Degree Celsius Copyright © Academy of Civil Services www.acsassam.com 3 | P a g e • Corona of the Sun is a circle of plasma that surrounds the sun • It is fully visible during the eclipses • Its temperature is about 2 million Degree Celsius Planets ➢ Mercury • Inner most planet • It has the fastest revolution • Second slowest rotation • Once in 3 to 30 years, Venus and mercury comes exactly between Sun and Earth • Temperature of mercury is the second highest after Venus: 427 Degree Celsius ➢ Venus • It has highest temperature: 462 Degree Celsius • It has a plateau like structure named as Ishtar Terra Copyright © Academy of Civil Services www.acsassam.com 4 | P a g e • Prominent mountain in the atmosphere of Venus is Maxwell Montes • It has the slowest rotation among all planets • Rotation: 243 days • Revolution: 224 days • The only planet whose rotation takes more time than revolution • Size is approximately equal to that of earth and hence known as the Earth’s twin ➢ Mars • It has ice-caps on the poles • Olympus mons is the highest mountain in Mars • Deepest valley is Valles Marineris • It is known as red planet • Prominent satellites are Phobos (inner most/Closer to Mars) and Deimos (Outer) • Both were discovered by Asaph Hall in 1877 ➢ Jupiter • Most massive planet in solar system • 318 times as massive as earth • About 1000 earths are needed to fill up Jupiter • Fastest rotation in 9 hours and 56 minutes • One revolution takes 12 years • It has largest number of satellites (67) • 4 satellites are discovered by Galelio and known as Galelian Satellites • They are: Io (Volcanically active), Europa, Ganymede (Biggest Satellite of Jupiter), and Callisto • Jupiter has one ring (Saturn has seven rings) ➢ Saturn • Second most massive after Jupiter • Second largest number of confirmed satellites (62) • Second fastest rotation after Jupiter (10 hours and 30 minutes) • It has 7 rings around it Copyright © Academy of Civil Services www.acsassam.com 5 | P a g e • One revolution is 29 and half years ➢ Uranus • 3rd largest number of satellites (27) • Revolution takes 84 years • One rotation takes 17 hours and 14 minutes ➢ Neptune • Longest revolution: 165 years • It has 14 Satellites • Satellite Triton is the coldest satellite in the whole solar system Copyright © Academy of Civil Services www.acsassam.com 6 | P a g e • Permanent atmosphere of Neptune is called as Great Dark Spot ➢ Kuiper Belt Objects are rocky icy objects beyond solar system ➢ Pluto is a prominent Kuiper Belt object ➢ Asteroid belt is made up of rocky mass between Mars and Jupiter Some Points on Earth ➢ Equinox is the moment in which the plane of Earth's equator passes through the centre of the Sun, which occurs twice each year, around 20 March and 23 September. ➢ On these days, all parts of earth will have equal day and night ➢ The Solstice occurs twice each year (around June 21 and December 22) as the Sun reaches its most northerly or southerly excursion relative to the celestial equator on the celestial sphere ➢ One these days, there will be maximum inequality between day and night Latitudes and Longitudes of Earth • Latitudes are the lines parallel to equator • Angle varies at 0 at equator to 90 at poles • Equator passes through 13 countries • They are Ecuador, Colombia, Brazil, Sao Tome & Principe, Gabon, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Somalia, Maldives, Indonesia and Kiribati • Based on latitude, earth can be further divided into following sub-divisions 1. Tropical Region (Between Tropic of Cancer (23 ½ North ) and Tropic of Capricorn 23 ½ South) Vertical movement of Sun is limited to this region 2. Sub-tropical Region: It is between 23 ½ latitude and 60 Degree latitude in both hemispheres Sun light reaches here, but does not come vertically 3. Sub- Polar Region: Between 60 and 90 degrees on both regions 4. Polar Region at 90 degree on both hemispheres Copyright © Academy of Civil Services www.acsassam.com 7 | P a g e Longitudes • Longitudes are vertical lines which meet at poles • Time of a region is fixed based on it • 0 Degree passes through Greenwich and it is considered as international standard time • Difference in one point on longitude makes a difference of 4 minutes in the time • Moving east, time will be ahead • Moving West, time will be behind • France has 12 time zones • United States and Russia have 11 time zones • India has only one-time zone Internal Structure of Earth Crust • It is from 5kms to 40Kms (Total length of crust is 35Kms) • Crust has 2 parts: Upper Crust is dominated by SIAL (Silicon and Aluminum) Lower Crust is dominated by SIMA (Silicon and Magnesium) Conrad discontinuity is the border between upper and lower crust Copyright © Academy of Civil Services www.acsassam.com 8 | P a g e • Mohorovicic discontinuity is the border between crust and mantle Mantle • The distance from the surface is 2900kms • The border between Mantle and outer core is called Guttenberg discontinuity Core • Outer core is molten metal (Nickel and iron) • Inner core is solid metal (Nickel and Iron) • Lehman discontinuity is the border of these two parts Copyright © Academy of Civil Services www.acsassam.com 9 | P a g e Oceans • 97% of total water is in ocean • 3type of movement of the water of Oceans • 1 waves 2) tides 3) Currents Waves • caused by pushing action of wind on ocean coast Tides • Sea water rises and falls twice a day at regular interval • It’s called tides • cause: Attraction of moon and some extend that of sun • Highest Elevation -Hight tide • Lowest Depression -Low tide • It's of great use in navigation trade and finishing • Increase of water near the cost at the time of high tide helps the ships to enter and leave the harbour safety • Eg; Kandla in Gujrat Ocean Current • Def: Constant flow of water on the surface of the ocean as a stream in definite direction • speed: 20-10/km hr. • 2types • 1. Warm current • 2. Cold current • warm current moving from equatorial region to pole • cold: - from poles to equator Copyright © Academy of Civil Services www.acsassam.com 10 | P a g e Effects of ocean currents • They have considerable influence on climate and Agriculture of the coastal region • Warm currents make the place warmers and cold current makes the place colder • Wind blowing over warm currents absorbs moisture and brings heavy rainfall over cost • E. USA Ireland and Britain receive such rainfall • Opposite with cold currents Hence hot deserts are found near the places passed by the cold currents eg: Atacama deserts in South America • Planktons are largely found where warms cold currents meet • Hence, they support fish in large numbers • Meeting of WC and CC produces very thick fog • it's dangerous for ships because visibility is reduced. • A ship sailing down the current will move faster • ships prefer to go with current to save time and fuel • Warm Currents helps to melt icebergs which is an advantage to navigation Largest oceans in the order 1. Pacific Ocean 2. Atlantic Ocean 3. Indian Ocean 4. Arctic Ocean • Mariana trench is the deepest trench. It is in the Pacific Ocean • Pacific Ocean is surrounded by Asia and Australia on one side and South and North Americas on the other side • Atlantic Ocean is surrounded by North and South America on one side and Europe and Africa on the other side • It is busiest ocean from the point of view of commerce • Indian ocean has Africa on its west, Asia on its north and Australia on its east • Arctic is the northward extension of Atlantic • Bering Strait is the connection between Arctic and Pacific ➢ Copyright © Academy of Civil Services www.acsassam.com 11 | P a g e Types of Rocks • Igneous Rocks ✓ Formed from hot molten lava or magma ✓ 2/3 of earth’s crust is made up of it ✓ Examples are Granite and Basalt rocks ✓ Another name is Primary/ Basic rocks • Sedimentary Rocks ✓ Formed by sediments ✓ It is soft and break easily ✓ It is most of the rocks found on earth’s surface ✓ Egs: Conglomerate, Sandstone, Limestone, Shale and Coal • Metamorphic Rocks ✓ Formed by chemical and structural changes in existing rocks ✓ Metamorphic means change of form ✓ Eg: Gneiss is change in form of Granitic Rocks ✓ Slate is change in form for Shale ✓ Marble is a change in form for limestone ✓ Diamond is a change in form for Coal Copyright © Academy of Civil Services www.acsassam.com 12 | P a g e Atmosphere Gases of Atmosphere ▪ Nitergon: 78% ▪ Oxygen: 20% ▪ Argon: 1% ▪ CO2: .03% Copyright © Academy of Civil Services www.acsassam.com 13 | P a g e Layers of Atmosphere ▪ Troposphere.