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Paleomagnetism & Plate Tectonics Theory - Physical Geography -
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In this lesson after explaining the phenomenon of Paleomagnetism, Bhanwar explains theory of Plate Tectonics and types of tectonic plates.

Bhanwar Singh
Ex- National Defence Academy (115 Course) Cleared Civil Services Examination, 2012

Unacademy user
Very good and helpful class
You are explaining all the stuff in a very lucid manner. Your lessons are really valuable. One suggestion from my side if possible please come up with a crash course on GEOGRAPHY OF INDIA also. Thank you.
sir please be slow while explaining the portions , u r getting fast and just passing information..i hope u understand and get my comments.
One correction: in slide 4 line 2, it should be "...towards the SOUTH magnetic pole", as it approximately corresponds to the Geographic North Pole.
Great course in a nutshell. Thank you sir.
thanku sir this course is awesome
  1. CRASH COURSE-WORLD GEOGRAPHY Presented by - Bhanwar Singh Sirohi


  3. ABOUT ME BA. (Hons) in Law from Awadh University I Defence Academy (115 Course) Cleared Civil Services Examination, 2012 Hobbies - Writing Poetry Course Fee Contribute Follow me on Unacademy at:

  4. PALEOMAGNETISM Earth has a magnetic field due to which compass needle always points towards North magnetic pole When the magnetic minerals in the surface cools down, they take an orientation parallel to any external magnetic field present at the time of cooling, for e.g. Magnetite Studies show that magnetic pole had apparently moved through time This indicates that either the Earth has had more than one magnetic pole at various times in the past or that different continents have moved relative to each other over time The second one seems possible deduction

  5. Normal magnetic Normal magnetioc polarity Reversed magnetic polarity b e Lithosphere Magma

  6. Magnetic North Pole Magnetic South Pole Magnetic North Pole 63 S 80 N 64 S 79 N 2000 199 1990 1985 1980 78 N 65 S Magnetic South Pole 1975 1970 1965 1985 77 N 1980 66 S 97 1970 1965 1955 76 N 1960 67 'S 195 75 N 1950 1950 68 S 94 74 N 1945 73 N 112 W 96 W 137*E 140 E 143 E 146 E 108 W 104 W 100 w

  7. PLATE TECTONICS Lithosphere is made up of big and smaller sections which are called plates These plates include not only the Earth's upper crust but also part of mantle and have average thickness of 100 km They float on upper mantle which is in plastic state called "Astheno sphere These plates when move in various directions in processes which is collectively known as Plate Tectonics Plate tectonics is often explained by the useful analogy of a conveyor belt in constant motion There are majorly three different type of plate boundaries-Divergent, Convergent and Transform

  8. TECTONIC PLATES Major plates of the world are North American plate South American plate Pacific Ocean plate Antarctic plate African plate European plate Indo-Australian plate There are various minor plates which includes, Caribbean plate, Cocas plate, Nazca plate, Juan de Fuca plate, Philippine plate, etc.

  9. Eurasian Plate Eurasian Plate North Americ n Plate CASCADE -RANGE - San Andreas Fautt Aleutian Trench Ring of Fire" Mid Ridge Arabian Plate Hawalian "Hot Spot Cocos Plate East Pacific Nazca Plate Sout American Plate Java Trench Rise- African Plate Indo-Australian Plate Pacific Plate Antarctic Plate

  10. DIVERGENT BOUNDARIES These are present where new crust is generated as the plates move in opposite direction to each other Occur where due to mantle convection currents plates are moving apart New crust is created due to oozing out of magma from the mantle and hence also called Constructive Plate Margins Block smokers or deep sea vents are example of kind of volcanic activity associated with Divergent Boundaries For example-Mid Atlantic Ridge and Great Rift Valley of Africa