1. THE EARTHS INTERIOR Introduction 2. In Module 1, you have learned about the different processes and landforms along plate boundaries that slowly shaped the Earths surface. In Module 2, you will learn the connection between these processes with the internal structure and mechanisms of our planet. 3. What to expect: This module will help you visualize and understand the composition and structure of the Earths interior. 4. It provides you scientific knowledge that will help you describe the different layers of the Earth as well as understand their characteristics. 5. You will also learn concepts that explain the physical changes that it underwent in the past. This module also consists of activities that will help you develop your critical thinking skills to have a deeper understanding about the planet where you live. 6. Key Questions: 1. How do the structure and composition of the Earth cause geologic activities and physical changes? 2. What are the possible causes of the lithospheric plate movements? 3. What proves the movement of the tectonic plates? 7. Studying the Earths Interior Scientists tried to explore and study the interior of the Earth. Yet, until today, there are no mechanical probes or actual explorations done to totally discover the deepest region of the Earth. 8. How did they know? The Earth is made up of three layers: the crust, the mantle, and the core. The study of these layers is mostly done in the Earths crust since mechanical probes are impossible due to the tremendous heat and very high pressure underneath the Earths surface. 9. Reading Resources and Instructional Activities Read the given resources and answer Act. 1. 10. Activity 1A: Amazing Waves! Objectives: Define seismic waves scientifically. Differentiate the different types of seismic waves. Recognize the importance of seismic waves in the study of the Earths interior. 11. Procedure: (1whole) Construct your own organizer that shows necessary information and summarizes the concept about seismic waves. Answer Q1 and Q2. 12. Seismic Waves Seismic waves from earthquakes are used to analyze the composition and internal structure of the Earth. What are seismic waves? 13. Seismic waves Earthquake is a vibration of the Earth produced by the rapid release of energy. This energy radiates in all directions from the focus in the form of waves called seismic waves. 14. Earthquake: Seismic Wave Wave Direction Fault Epicenter Focus 15. Types of Seismic Wave Surface waves Body Waves 16. Surface Waves can only travel through the surface of the Earth arrive after the main P and S waves 2 Types of Surface Waves Love Waves Rayleigh Waves 17. Love Wave named after A.E.H. Love, a British mathematician who worked out the mathematical model for this kind of wave in 1911. faster than Rayleigh wave it moves the ground in a side-to-side horizontal motion, like that of a snakes causing the ground to twist cause the most damage to structures during an earthquake. 18. Love Wave 19. Rayleigh Wave named after John William Strutt, Lord Rayleigh, who mathematically predicted the existence of this kind of wave in 1885 wave rolls along the ground just like a wave rolls across a lake or an ocean up and down or side-to-side similar to the direction of the waves movement shaking felt from an earthquake 20. Rayleigh Wave 21. Body waves can travel through the Earths inner layers they are used by scientists to study the Earths interior higher frequency than the surface waves 22. Body waves 2 types P-Waves (Primary waves) S-waves (Secondary waves) 23. P-waves (Primary) is a pulse energy that travels quickly through the Earth and through liquids travels faster than the S- wave it reaches a detector first 24. P-waves (Primary) compressional waves, travel by particles vibrating parallel to the direction the wave travel move backward and forward as they are compressed and expanded they travel through solids, liquids and gases 25. S-waves (Secondary/Shear) pulse energy that travels slower than a P-wave through Earth and solids Move as shear or transverse waves, and force the ground to sway from side to side, in rolling motion that shakes the ground back and forth perpendicular to the direction of the waves 26. S-waves (Secondary/Shear) cannot travel through any liquid medium led seismologists to conclude that the outer core is liquid 27. Seismic Waves movement 28. Cross section of the Earth as seismic waves travel through it 29. Propagation of Seismic Waves Through Earths Interior Longitudinal waves travel through both solids and liquids. Transverse waves travel through solids only. 30. Remember: P-waves are detected on the other side of the Earth opposite the focus. A shadow zone from 103 to 142 exists from P-waves Since P-waves are detected until 103, disappear from 103 to 142, then reappear again, something inside the Earth must be bending the P-waves 31. Remember: existence of a shadow zone, according to German seismologist Beno Gutenberg (u t n bk), could only be explained if the Earth contained a core composed of a material different from that of the mantle causing the bending of the P-waves To honor him, mantlecore boundary is called Gutenberg discontinuity 32. Remember: From the epicenter, S-waves are detected until 103, from that point, S- waves are no longer detected S-waves do not travel all throughout the Earths body knowing the properties and characteristics of S-waves (that it cannot travel through liquids), and with the idea that P-waves are bent to some degree, this portion must be made of liquid, thus the outer core 33. Remember: 1936, the innermost layer of the Earth was predicted by Inge Lehmann, a Danish seismologist discovered a new region of seismic reflection within the core Earth has a core within a core 34. Remember: the outer part of the core is liquid based from the production of an S wave shadow and the inner part must be solid with a different density than the rest of the surrounding material size of the inner core was accurately calculated through nuclear underground tests conducted in Nevada. echoes from seismic waves provided accurate data in determining its size 35. Bring the ff. (by grp) 15g cornstarch 2 small cups Medicine dropper Stirring rod or spoon 36. Act. 1B. Simulating Plasticity Procedure: Put 15 g cornstarch into one of the beakers. Put 10 ml water into the other beaker. Add one drop full of water to the cornstarch. Stir the mixture. How does the mixture react like; solid, liquid or gas? 37. Continue to add water to the mixture, one drop full at a time. Stir the mixture after each addition. Stop adding water when the mixture becomes difficult to stir. Pour the mixture into your hand. Roll the mixture into a ball and press it. 38. Answer the ff. questions How does the mixture behave like? How is the mixture of cornstarch and water similar to the earths mantle? How is it different from the earths mantle? How does the plasticity of the earths mantle influence the movement of the lithospheric plates? 39. Bring the ff: (by grp) hardboiled egg/s bread knife used paper/newspaper to work on 40. Activity 1C: Hard Boiled Earth PROCEDURE: 1. Prepare the materials. (hardboiled egg, bread knife, used paper to work on) 2. Place used paper or newspaper on your working area. Cut the egg into halves using a knife or a cutter. 41. Procedure: Using qualitative observation, describe the parts of the egg from the outermost to the innermost by completing the table. Write your answer on a piece of paper/ short bond paper. PARTS OF THE EGG DECSRIPTION EQUIVALENT TO THE EARTHS LAYER DESCRIPTION 42. Procedure: 4. Draw the appearance of the cut hard-boiled egg. 5. Answer the ff. A. How many layers does a hard-boiled egg have? B. Which is the largest part? The thinnest? C. Compare the parts of the egg to the model of the earth. D. Aside from the hard-boiled egg, what other things can you compare to the earths interior layers? 43. OUR HOME PLANET, EARTH Our Earth is about average among the planets in the Solar System, in many respects: largest and most massive of the four terrestrial planets, but smaller and less massive than the four giant, or Jovian, planets third in distance from the Sun among the four terrestrial planets has a moderately dense atmosphere; 90 times less dense than that of Venus but 100 times denser than that of Mars 44. OUR HOME PLANET, EARTH Earth is also unique in many respects: the only planet with liquid water on its surface. the only one having a significant (21%) proportion of molecular oxygen to our best current knowledge, the only planet in the solar system having living organisms the only terrestrial planet having a moderately strong magnetic field the only terrestrial planet having a large satellite 45. OUR HOME PLANET, EARTH 46. The Solid Earth geology -the study of the structure, history, and activity of the solid Earth, including its interactions with the atmosphere, hydrosphere, cryosphere, and biosphere solid Earth contains four major zones: the core (which is divided into inner and outer zones), the (upper and lower) mantle, the asthenosphere, and the lithosphere 47. The Solid Earth the outer zones is not uniform and fixed over the surface of the Earth, but shows much variability with position and time. The field of plate tectonics deals with this spatial and temporal variability. Geological phenomena such as earthquakes, volcanoes, and continental drift are accounted for by plate tectonics. 48. The Composition of the Earths Interior 49. Seismic Waves: Interior Part 50. HW 4: Describe the unique characteristics of each interior layer of the earth. (10pts) Bring: (by group) Coloring materials Pencil Marker 51. Activity 2: Our Dynamic Earth Objectives: Describe the properties of the layers of the Earth. Tell the composition of the layers of the Earth. 52. Did you know? The deepest mine in the world, the gold mine in South Africa, reaches a depth of 3.8km. But... You would have to travel more than 1,600 times that distance-over 6000km-to reach the earths center. 53. The Composition of the Earths Interior 54. DENSITY AND TEMPERATURE VARIATION IN DEPTH 55. The Crust 56. The Crust thinnest and the outermost layer of the Earth that extends from the surface to about 32 kilometers below Continental Oceanic 57. Stanley, 1989, p. 14 Continental Stanley, 1989, p. 14 Continental Root Moho Oceanic Lithosphere Asthenosphere 58. Continental mainly made up of silicon, oxygen, aluminum, calcium, sodium, and potassium mostly 35-40 kilometers found under land masses made of less dense rocks such as granite 59. Oceanic oceanic crust is around 7-10 kilometers thick which its average thickness is 8 kilometers. found under the ocean floor made of dense rocks such as basalt heavier than the continental crust. 60. The Crust: Continental GRANITE -crystalline igneous rock composed primarily of quartz and feldspar. forms from slowly cooling magma that is subjected to extreme pressures deep beneath the earth's. 61. The Crust: Oceanic BASALT -volcanic rock forms from lava flows along mid-ocean ridges and also in igneous intrusions such as dikes and sills. Columnar jointing, pictured here at Devil's Tower, Wyoming, occurs when molten basalt cracks as it cools, producing separate, polygonal fractures on the surface of the rock. 62. Elements in the Crust 63. Moho Discontinuity While studying the speed of earthquake waves, Croatian geophysicist Andrija Mohorovii discovers a boundary between Earth's crust and mantle, which becomes known as the Mohorovii, or Moho, Discontinuity. 64. The Mantle Beneath the crust is the mantle extends to about 2900 kilometers from the Earths surface about 80% of the Earths total volume about 68% of its total mass mainly made up of silicate rocks and contrary to common belief, is solid, since both S-waves and P-waves pass through it 65. The Mantle mostly made of the elements silicon, oxygen, iron and magnesium lower part of the mantle consists of more iron than the upper part lower mantle is denser than the upper portion temperature and the pressure increase with depth high temperature and pressure in the mantle allows the solid rock to flow slowly 66. Remember: The ability of the asthenosphere to flow slowly is termed as plasticity. crust and the uppermost part of the mantle form a relatively cool, outermost rigid shell called lithosphere (Gk.lithos means stone) and is about 50 to 100 kilometers thick 67. Remember: Beneath the lithosphere lies the soft, weak layer known as the asthenosphere (Gk. asthenes means weak) made of hot molten material, about 300 800o C upper 150 kilometers has a temperature enough to facilitate a small amount of melting, and make it capable to flow facilitates the movement of the lithospheric plates lithosphere, with the continents on top of it, is being carried by the flowing asthenosphere. 68. Layers 69. The Core 2000-5000o C core is subdivided into two layers: the inner the outer core. 70. Outer Core 2900 kilometers below the Earths surface 2250 kilometers thick made up of iron and nickel temperature reaches up to 2000oC at this very high temperature, iron and nickel melt 71. Outer Core Aside from seismic data analysis, the Earths magnetic field strengthens the idea that the Earths outer core is molten/liquid mainly made up of iron and nickel moving around the solid inner core, creating Earths magnetism 72. The Inner Core made up of solid iron and nickel and has a radius of 1300 kilometers about 5000oC extreme temperature could have molten the iron and nickel but it is believed to have solidified as a result of pressure freezing, which is common to liquids subjected under tremendous pressure 73. The Inner Core Aside from the fact that the Earth has a magnetic field and that it must be iron or other materials which are magnetic in nature, the inner core must have a density that is about 14 times that of water. Average crustal rocks with densities 2.8 times that of water could not have the density calculated for the core. So iron, which is three times denser than crustal rocks, meets the required density. 74. Clues that the inner core and the outer core are made up of iron Iron and nickel are both dense and magnetic. overall density of the earth is much higher than the density of the rocks in the crust suggests that the inside must be made up of something denser than rocks 75. Clues that the inner core and the outer core are made up of iron Meteorite analysis have revealed that the most common type is chondrite. Chondrite contains iron, silicon, magnesium and oxygen; some contains nickel. The whole earth and the meteorite roughly have the same density, thus the Earths mantle rock and a meteorite minus its iron, have the same density. 76. HW5 Write a short story that describes the most exciting part of your own imaginary journey to Earths center. Bring the ff. (by group) scissors old magazines brown envelope