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ATLAS• Orient Longman• Study publication – India
and world• Oxford publication
• Goh Cheng Leong• Physical Geography – by
Savinder singh• India: comprehensive
geography by D.R. Khullar
Book list
Study material
All PowerPoint Slides available at
Mrunal.org/Download
Physical
Geomorphology
Climatology
OceanographySchemes of the Geography Lectures
• Geo= earth and Graphy = study, which means study of earth
• Geography can be divided into two parts:• Physical geography and Human geography
Meaning and span of Geography
Physical• Landforms• Atmosphere• Hydrosphere• Biosphere
Human• Habitation• Population• Agriculture• Industries-
resources
Two Parts of Geography
FUNDAMENTALS OF GEOGRAPHY
1. Latitudes2. Longitudes3. Seasons on Earth4. Time-zones
latitudes• Latitudes
=angular distance of a place from the equator
• All latitudes are concentric circles
• They are called parallels as well
Latitudes• Largest latitude –
equator• Tropics – heat surplus• Temperate, polar
regions – heat deficit• Responsible for
pressure system and planetary wind system
Spherical Earth1.Tropical
Zones2.Temperate
Zones
1. Skip 2. Attempt 3. Mark n
Review
Q. Who among the following was first to state that Earth was spherical?A. AristotleB. CopernicusC.PtolemyD.Strabo
UPSC Prelims 2001
Correct Answer is A
Reason for seasons: Tilted Earth
Summer and Winter Solstice
Prelims
2013
Q. Variations in length of daytime and night-time from season to season are due to a) Earth’s rotation on its axisb) Earth’s revolution around
the sun in an elliptical manner
c) Latitudinal position of the place
d) Revolution of earth on a tilted axis
UPSC
Question
Prelims
2013
Variations in length of daytime and night-time from season to season are due to a) Earth’s rotation on its axisb) Earth’s revolution around
the sun in an elliptical manner
c) Latitudinal position of the place
d) Revolution of earth on a tilted axis
UPSC
Question
Daylight Saving in Temperate regions
Longitudes
• Angular distance of a place from prime meridian
• Also called meridians• 0 degree = Greenwich in
UK• 180 degree =
International date line
International Date Line
• Earth rotates 360 °s in 24 hours
• 360/24 = 15°• 15° longitude • = 1 hour
31st Dec MorningRussia
30th Dec Morning
Alaska
International Date Line
Moving
West1 DAY Lost
Moving East1 DAY Gain
1) Every country selects its standard meridian. 2) Angular distance between standard meridian of a nation to Greenwich meridian time (GMT)
Standard time
• IST – 82.5 E Meridian• IST - 5.5 hours ahead
of GMT, so GMT+5.5
Indian Standard Time
British launched Chaibagaan time (1 hr ahead of IST) 150 years ago in Assam
After independence – rejected
2007 DST study – rejected – admin challenges
Jan 2014 CM of Assam – declare to apply Chaibagaan time
Chaibagaan time zone
IST
Russian Time Zones
If 12 noon at GMT what is the time at 75 °E?• Difference = 75 °• 15 ° => 1 hour• 75 ° => 5 hours• East (means add) 12
+5 = 5 pm
Timezones
Question
If 12 noon at GMT what is the time at 30 °W?• Difference = 30 °• 15 ° => 1 hour• 30 ° => 2 hours• East (means minus)
12 - 2 = 10 am
Timezones
Question
Prelims 1999
Q. If it is 10.00 am IST, then what would be the local time at Shillong on 92 deg E Longitude?a) 9.38 amb) 10.38 amc) 10.22 amd) 9.22 am
Ans. B)
UPSC
Exercise
Prelims 2006
Q. Through which one of the following groups of countries does equator pass?a) Brazil, Zambia and
Malaysiab) Columbia, Kenya and
Indonesiac) Brazil, Sudan and
Malaysiad) Venezuela, Ethiopia
and Indonesia
UPSC
Exercise
Prelims 2008
Q. Which of the following cities is nearest to the equator ? a) Colombob) Jakartac) Manilad) Singapore
UPSC
Exercise
Prelims
2008
Q. Which one of the following straits is nearest to the International Date Line? a) Malacca Straitb) Bering straitc) Strait of Floridad) Strait of Gibraltar
UPSC
Exercise
Malacca strait
Strait of Florida
Strait of Gibraltar
Prelims 2009
Q. Consider the following countries: 1. Australia2. Namibia3. Brazil4. ChileThrough which of the above does the Tropic of Capricorn pass?
UPSC
Exercise
Prelims 2009
a) 1 onlyb) 2,3 and 4c) 1,2 and 3d) 1,2,3,4
UPSC
Exercise
1. Longitude2. Latitude3. Reason for
Seasons on Earth
4. Time zones
Self StudyNCERT Class6: Chapter 2- Longitudes, Latitudes and time-zones
Map: Greenwich line passes through which famous cities and countries of the world?
Map: IST line passes through which famous cities and states of India?
NCERT
GEOMORPHOLOGY
Origin of the EarthNebula TheoryTheory of Laplace
Overview
Geomorphology
Gaseous cloud of H, He – radiation –cooling- Contracting • Separation of
outer ring – 9 parts => 9 planets
Origin of earth – Nebular theory of Laplace
• Heavier elements near the core and lighter at the surface
• Layered structure of earth’s interior
Nebular Theory of Laplace
1. Density study:2. Temperature study3. Structural study - Direct evidences- Indirect evidences
Interior of the Earth
Geomorphology
• Outer layer (continents)– SIAL
• Mantle and oceanic crust – SIMA
• Core – Ni +Fe
Edward Suess
• Seismic waves = mechanical waves = require medium for propagation
• Their behaviour changes with changes of medium
• 2 imp waves: primary P and secondary S waves• S waves can travel into only S and G medium• P can travel in all 3 mediums• But speed is highest in S>L>G
Seismic wave studies
S-wave Propagation
P-waves propagation
Observations• Asthenosphere –semi-
molten• Beyond
Asthenosphere- mantle rocks are dense • Outer core –liquid • The inner core is solid
Self StudyClass11 Chapter3: Interior of Earth NCERT
Earth as a whole• Iron (Fe) - highest• Oxygen (O2)• Silicon (Si)• Magnesium (Mg)• Sulphur (S)• Nickel (Ni)• Calcium (Ca)• Aluminum (Al) - lowest
• Oxygen (O2) - highest• Silicon (Si)• Aluminum (Al)• Iron (Fe)• Calcium (Ca)• Magnesium (Mg)• Sodium (Na)• Potassium (K) - lowest
Earth’s crust
Composition of the interior of the earth
Igneous rocksMetamorphous rocksSedimentary rocks
Rocks in the
crust
Geomorpho
Rock cycle
formed due to solidification of magma (I) or lava (E)
They don’t have strata or layers
Because entire lava is solidified
They are crystallineThey don’t have fossils
IgneousRocks
Rock Types
formed due to lithification of soil
erosion of rocks => deposition of granules => compaction => lithification
Always stratifiedThey may have fossils
Sedimentary rocks
Rock Types
• both igneous and sedimentary rocks changed under heat or pressure or both
• No fossil• No stratification
Metamorphosed rocks
gneissGranite
MarbleLimestone
quartziteSandstone
slate/ schistClay/mudsto
ne
Examples of metamorphosed rocks
Consider the following statements made about sedimentary rocks:1. Sedimentary rocks are formed
at earth’s surface by hydrological system
2. Formation of sedimentary rocks involves the weathering of pre-existing rocks
3. Sedimentary rocks contains fossils
4. Sedimentary rocks occur in layers
UPSC
Question
Prelims
2001
Prelims 2001
Q. Quartzite is metamorphosed from:a) Limestoneb) Obsidianc) Sandstoned) shale
UPSC
Question
Interior of the earth Different layers – structure and composition
Rocks Properties of rocks
Geological time scale of Earthyears Eon Era Importa
nce4.6 -3.5 billion
Pre-Cambrian
Proterozoic
No Life
3.5 -2.5 billion
Archean 1st life form
2.5 to 545 million
Hadean 1st fish eveloved
Years Eon Era Period Epoch Importance
545 ml – 245 ml
Phanerozoic
Paleozoic Carboniferous
Coal
245 ml-65 ml
Mesozoic
Triassic, Jurassic, Cretaceous
Reptiles => Dinosaurs => extinct
65 ml – present
Cenozoic tertiary Oiligocene,Pliocene
Birds and mammals
65000 years
quaternary
Holocene
Human
Geological time scale of the Earth
Rodinia in Pre-Cambrian
Rodinia break up - Palaeozoic
Mesozoic merger - Pangaea
200 ml years ago – break up of Pangaea
165 ml – break up of Gondwana
Movement of India
Continental drift Sea-floor spreading Plate tectonic theory
3 Theories
Alfred Wegener
• 1st to propound movement of continents
• His Continental Drift Theory
• His 4 main observations
1st ObservationMatching Coastlineszig-saw fit
2nd ObservationSimilarity of Age of the rocks
3th ObservationFossil evidences
4th observationPalaeo-climatic evidencesGlacial evidenced in Tropical lands
• Super continent - Pangaea• Ocean – Panthalasa• Continent – SIAL rocks• Ocean – SIMA rocks• Mid- Mesozoic Pangaea broke up and drifted
apart
Continental Drift Theory
• Driving force?• Gravitational pull of sun and moon• Idea of SIAL and SIMA
Limitation of Continental Drift theory
Limitation of Continental Drift theory
Mains
2013
What do you understand by theory of continental drift? Discuss the prominent evidences in its support. (5)
UPSC
Question
Prelims
2014
Q. Which of the following phenomena might have influenced the evolution of organisms?1. Continental drift2. Glacial cycles
Ans. Both
UPSC
Question
Arthur Holmes
• Arthur Holmes:• Convection current
theory• Convection cells – force
behind drifting of continents
Continental drift Sea-floor spreading Plate tectonic theory
3 Theories
Sea-floor mapping• During 1940s and
1950s• Diversity of ocean-
floor• Submarine hills –
guoyts – MOR –Trench
Questions:1) Ocean crust not older than mid-Mesozoic 2) Age increase away from MOR3) Sea-mounts deformed at trenches
Ocean floor mapping
• 1960s Harry Hass and Dietz answered question regarding ocean mapping using convection theory
• revealed mystery of mid-oceanic ridge and trenches
Sea floor spreading Theory
Mid- Oceanic Ridge
Mid –Oceanic ridge
• Rising limb of current breaks the Ocean crust• Basaltic eruption• Accumulation of lava – ridge => MOR• New Oceanic crust• Divergent limb – expansion of ocean crust
MOR
Trenches
• At trench Ocean floor destroyed – melted in mantle
• Oceanic crust heavier than continental crust
• Ocean floor act like conveyor belt
• Ocean floor – cyclic process – 300 ml yrs
MOR - Trench
Mariana trench
Prelims 2006
Q. In which one of the following oceans the Diamantina Trench is located?a) Pacific Oceanb) Atlantic Oceanc) Indian Oceand) Arctic Ocean
Ans. C)
UPSC
Question
Diamantine trench
Palaeo-magentism• Magnetism of rocks
along MOR • Magnetometer -
Magnetic parallel stripes– normal and reverse magnetic profile
• 1st Carlsberg ridge – Indian ocean
• Vine and mattheus • Molten lava get polarity
geomagnetic field of that period -Solidify
• Ocean floor – magnetic tape
Palaeo-magentism
conclusion1) Periodic reversal of magnetic field of the earth2) Rate of sea-floor spreading decided by age + distance between two equal magnetic stripes• Atlantic – 1.0 cm/ year• Indian – 1.5 cm/year• Pacific – 6.0 cm/year
Palaeo-magnetism
Prelims 2011
Q. Between India and East Asia, the navigation time and distance can be greatly reduced by which of the following?a) Deepening Malacca
strait between Indonesia and Malaysia
b) Opening a new canal across Kra Isthmus between gulf of Siam and Andaman sea
UPSC
Question
Continental drift Sea-floor spreading Plate tectonic theory
3 Theories