The document discusses plate tectonics and how it explains biogeographic patterns and geological phenomena. It describes how Philip Sclater observed that the flora and fauna differed between the eastern and western Indonesian islands over a distance of just 15 km (Wallace Line). Alfred Wegener later proposed continental drift to explain similarities between separated landmasses. The theory of plate tectonics was developed, explaining how convection currents in the mantle cause rigid tectonic plates to move and interact at boundaries.

1. Plate Tectonics The Rage of the Earth

2. Why do some parts of the world erupt & the rest do not?

3. Why do earthquakes strike at some places and do not at other?

4. Why do Tsunamis strike at some coasts and do not at others?

5. Colonial History

6. Pope Alexander VI

7. In 1493 Pope Alexander VI divided the world in two parts - Eastern part to Portuguese and - Western part to Spaniards for looting and plunder, in the name of Christianity.

8. Dark Green = Spain’s Half Light Green = Portugal’s Half

9. Indonesia

10. Thus Indonesia fell to Portugal. But Dutch replaced Portugal.

11. Colonial Indonesia under the Dutch rule

12. Modern Indonesia

13. Indonesia - Natural Beauty

16. Philip Sclater & the Distinct Fauna Western Islands - Eastern Islands

17. Eastern Indonesia Western Indonesia

18. Like this

19. Western Islands have…

20. Woodpecker

21. Barbet

22. Trogon

23. Shrike

24. Minivet

25. Drongo

26. Woodpecker Drongo Barbet Minivet Shrike Trogon

27. But these birds were not present at the Eastern Islands. In the Eastern Islands there were…

28. Bird of Paradise

29. Bird of Paradise

30. Cockatoo

31. Emu

32. Cassowary

33. Cockatoo Bird of Paradise Cassowary Emu

34. Animals were also different

35. Western Islands had…

36. Lemur

37. Tiger

38. Wolf

39. Mongoose

40. Otter

41. Tapir

42. Rhinoceros

43. Porcupine

44. Polecat

45. Scaly Anteater

46. Polecat Wolf Anteater Porcupine Rhinoceros Tapir Lemur Tiger Mongoose Otter

47. And these were not present at the Eastern Islands. But there were some animals on the Eastern Islands…

48. Kangaroo

49. Wombat

50. Opossum

51. Platypus

52. Kangaroo Wombat Opossum Platypus

53. … which were not present at the Western ones

54. In making an eastward journey - the traveler will leave one world & entered another one, utterly different.

55. The Eastern Islands had flora and fauna more akin to that of Australia

56. Eastern Islands, Indonesia

57. Australia

58. Australia on the world Map

59. … while Western Islands had that akin to India

60. Western Islands, Indonesia

61. India

62. India on the world Map

63. I st Break Animals & birds of the Western Islands of Indonesia were different from those of the Eastern ones

64. Alfred Russel Wallace

66. Charles Darwin

67. Natural Evolution – “… species mutate and grow into another species by the process of Natural Selection and Imperfect species are eliminated & Perfect ones carry on.”

69. … species evolve differently when they are separated geographically for great distance & time. So if two landmasses are diverse in their flora & fauna then it means that they are two separate blocks.

70. Eastern Islands & Western Islands - two different landmasses . But they are so near to each other. Then how is it possible?

71. The difference in the Indonesian islands come in just 15 kilometers. If we cross from Bali in the West to Lombok in the East, then we get to see the difference, as if a very thin boundary is running between them

72. The position of Bali & Lombok

73. The difference comes in just 15 miles

74. West East What invisible boundary is dividing these two 15 miles apart islands?

75. He postulated Wallace Line

76. Wallace’s Division of World Flora & Fauna

78. II nd Break Now we have learnt that the difference between the two landmasses is just 15 miles wide And this is due to the Evolution. Wallace postulated that there was a large landmass in the past which then broke up into several smaller landmasses.

79. Then came Alfred Wagner

80. World Map

81. He stated that South America fits into Africa

82. Earlier observed by Francis Bacon and others Because of Biblical belief in the immovability of land, people didn’t believe them

83. These two continents had indeed been together in the past. Pangaea Laurasia & Gondwanaland

84. He gave us terms like Continental Displacement or Continental Drift

85. He supported his theory by the fossil evidence Wegener stated that these two continents had indeed been together in the past

86. He proposed that in the past there was one single continent called Pangaea

88. … which then broke into Laurasia and Gondwanaland and then into other smaller islands and continents

89. Gondwanaland drifting Apart

90. … which then broke into Laurasia and Gondwanaland and then into other smaller islands and continents

92. Plate Tectonics

93. Continental Moves

95. IIIrd Break This theory said that continents and landmasses float and drift, break apart and converge. Where they break away, cracks, rifts, trenches remain Where they collide, ranges of folded mountains appear.

99. First time a rock solid explanation for continental drift had been given, which defeated the Church.

100. Discovery on the North Western US Coast of sea-floor spreading.

101. How South America & Africa got apart?

102. Sea-floor Spreading

104. Map of Oceanic Ridges

105. How the sea floor spreads?

106. It seemed that there is a hotspot at a particular point in the earth’s mantle, a deep and stationary hot spot.

108. Convection Current

109. Structure of the Earth

110. It was proposed that Earth has convection currents like there would be in water

111. Where land is created ridges are formed… Where plates collide trenches are formed…

114. The Early Earth & Tectonic Plates

120. Divergent Boundary

121. Convergent Boundary

122. Side-long Boundary

124. Types of Convergent Boundaries

125. Convergent Boundary

126. Convergent Boundary

128. Ocean Floor Spreading

129. Transform Fault – Only one type

130. San Andreas Fault

131. San Andreas Fault – Transform Fault

134. Tsunami… The Fatal Wave The Mechanism of Tsunami

136. Drawing of tectonic plate boundary before earthquake

137. Overriding plate bulges under strain, causing tectonic uplift

138. Plate slips, causing subsidence and releasing energy into water

139. The energy released produces tsunami waves

140. Tsunamis have a small amplitude (wave height) offshore, and a very long wavelength (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a slight swell usually about 300 millimetres (12 in) above the normal sea surface. They grow in height when they reach shallower water, in a wave shoaling process

141. Wave Shoaling

143. Japan

144. Thank You