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L3 EARTH'S INTERNAL HEAT.pptx
- 1. Earth and Life Science QuarterI – Week 3: Lesson 3: Earth’s Internal Heat Supplementary Learning Materials (SleM) Writer: LEARNI J. ESCOTE Content Editor: SANDRA CARETATIVO Language Editor: PRINCESS A. CAYETANO Format Editor: VIRNA E. GARCIA SQAT Chairman: NOEL S. FAVILA, Principal
- 2. Learning Objectives Describe wherethe Earth’s internal heat comes from. (S11/12ES-Ib-14) Day 1: Describe the effect of the accretion of dust and gas particles on the internal heat of the earth. Day 2: Describe the effect of radioactive decays and frictional heating on the internal heat of the earth Describe how magma is formed (magmatism) (S11/12ES-Ic-15) Day 3: Explain the three processes that melt the asthenosphere to form magma. Day 4: Describe the conditions of magma formation
- 5. Layers of theEarth
- 7. The Earth ismade up of 3 main layers: Crust Mantle Core
- 8. Think of thelayers of the Earth like the layers of a cake.
- 9. Use the Layersof the Earth Foldable to take notes
- 10.
- 11. The Earth’s crustis like the skin of an apple.
- 12. • Thinnest layerof the Earth • Made up of large amounts of silicon and aluminum • Composed of plates on which the continents and oceans rest. These “ride” over molten mantle. • Crust is part of the lithosphere. • To types of Crust: Oceanic and Continental Ocean Land Crust
- 13. Continental vs. OceanicCrust Category Continental Oceanic Rock Type Granite Basalt Thickness 5 – 70km (Thicker) 3 – 8 km (Thinner) State Solid Solid Crust Age 4 billion years old or Older 180 million years old or Younger Density Less Dense More Dense Element Composition Oxygen, Sodium, Silicon, Aluminum, Potassium Iron, Magnesium, Calcium
- 14. TheLithosphere The crust andthe upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere.
- 15. The lithosphere (crustand upper mantle) is divided into separate plates which move very slowly in response to the “convecting” part of the mantle.
- 16. The Lithospheric Plates •Thecrust of the Earth is broken into many pieces called plates. The plates "float" on the soft, semi-rigid asthenosphere.
- 17.
- 18. The Mantle The Mantleis the largest layer of the Earth at 2900 km thick. The middle mantle is composed of very hot dense rock that flows like asphalt under a heavy weight. The movement of the middle mantle (asthenosphere) is the reason that the crustal plates of the Earth move.
- 19. The Asthenosphere The asthenosphere isthe semi-rigid part of the middle mantle that flows like hot asphalt under a heavy weight.
- 21. Convection Currents The middlemantle "flows" because of convection currents. Convection currents are caused by the very hot material at the deepest part of the mantle rising being less dense, then cooling becoming more dense and sinking again --repeating this cycle over and over.
- 22. • Solid butcapable of flow (like fudge) Semi-Solid/Semi Liquid • Thickest layer of the Earth 2900km (1800 miles) • Element Composition: Magnesium, Silicon, Oxygen, and Iron • The hot magma rises then cools and sinks. • These convection currents cause changes in the Earth’s surface. • Conveyor belt for the tectonic plates. Upper Mantle Convection Currents Middle Mantle Lower Mantle Mantle
- 23.
- 24. Outer Core • Composition: Molten(liquid) metal that is about 4,700°C (8,500°F) • Thickness: 2,266 km (1,400) miles • State of Matter: Composed of the melted metals nickel and iron (liquid) • Located about 1,800 miles beneath the crust.
- 25. • Solid spheremade mostly of iron and has Nickel • It is believed to be as hot as 6,650°C (12,000°F) • Heat in the core generated by the radioactive decay of uranium and other elements • It is solid because of the pressure from the outer core, mantle, and crust compressing it. • Thickness: 1271 km (800 miles) Inner Core
- 27. What do thesetwo images tell us about the layers of the Earth?
- 28. Temperature increases as depthincreases
- 29. Look at theinformation in the graph and table below. What’s the relationship between depth and density/pressure?
- 30. Density and Pressure increaseas depth increases
- 31. Add this statementto the arrow going down on your foldable. Temperature, Density and Pressure increases as depth increases
- 32. Which layer ofthe Earth has the greatest temperature, pressure, and density? Core
- 33. • How farhave scientists drilled into the earth? •7.6 miles – Only 0.2% of the distance to the earth’s core
- 34. How do weknow so much about what’s under Earth’s surface? • Through INDIRECT EVIDENCE, mostly from seismic waves caused by earthquakes (more on this later this semester...) • Sometimes indirect evidence is the only option for scientists to develop a theory • Lets give it a try...
- 35. Practice Quiz Question •Can you label the following layers?
- 36.
- 37. Which of thefollowing statements regarding what we know about Earth’s interior is most accurate? A) We have been able to drill into the earth’s core B) Much about what we know about Earth’s mantle and core comes from caves and mines C) We know only about what is on the very surface of the earth, in what is known as the crust D) Energy waves allow us to see precisely what is deep inside the Earth, like a “tricorder” or scanner from Star Trek
- 38. Earth’s Interior What weknow about Earth’s interior comes from indirect avenues of investigation. Earth’s diameter is approximately 12,756 km (~ 7,500 miles). -the deepest hole we have ever drilled into the Earth is only 9.6 km (~5 mi). so how do we know what it’s like? Seismic waves! - natural and man-made
- 39.
- 40. Earthquakes seismic (energy) wavestravel through the earth some energy bounces off harder layers called reflection some energy travels through but gets bent, changing the direction the wave is traveling called refraction some energy is absorbed as it encounters materials called attenuation Allow us to model what waves show up at given locations, and when they arrive at given locations.
- 41. Shallow high frequencyseismic waves allow us to see reflectors and refractors at depth
- 42. Wave paths are influencedby density, temperature, and the angles at which they strike boundaries as they travel through and around the Earth
- 43. Factors affect seismicwaves distance: farther = more attenuation density: higher = faster temperature: colder = faster liquid vs solid - solid = faster; p-waves and s-waves - liquid = slower; no s-waves angle of incidence- controls how much is reflected and how much is absorbed vertical arrangement of layers - controls the resultant direction of travel
- 44. P-wave and S-waveshadow zones - caused by transmissive and refractive properties of the waves interacting with rock and liquid
- 45. Zones of materialwith distinctive characteristics make up each layer in the Earth Greatly simplified it looks like concentric spheres
- 46. Crust- the rigidouter shell of the Earth, composed of solid rock; very thin- averages only 20 km thick (the crust is part of the Lithosphere) two kinds of crust Oceanic- most abundant; consists of rocks formed from mafic magma; very dense; very thin- 10 km thick Continental- underlies continents; consists of rock formed from felsic and intermediate magma; less dense than oceanic crust; thick-30 to 85 km thick
- 47. Uppermost mantle- Aesthenosphere Continentalcrust Oceanic crust Mohorovicic Discontinuity “The Moho” Model of Lithosphere and Aesthenosphere showing thickness of Oceanic vs Continental crust
- 48. Isopach contour lines= lines of equal thickness of the crust
- 49. The boundary zonebetween the crust and the mantle is called the Mohorovicic Discontinuity or the “Moho” - a zone of low velocity transmission of seismic waves Mantle- the semi-solid (jello-like) material underlying the crust. Extends down to about 3000 km depth The uppermost part of the mantle is called the Aesthenosphere. mostly molten material
- 50. The mantle isheated closer to the core Heated mantle material rises upward very slowly millions of years to move upward As it near the earth’s surface, the mantle material liquefies (due to pressure and temp relationships) It also begins to cool, and slowly starts to sink back into the core This creates a Convection current
- 51.
- 52. Heated rising material Cooledsinking material 3D models of mantle convection currents
- 53. 3D maps ofthe earth’s convection currents based on seismic wave analysis- complicated looking!
- 54. Earth’s core Divided intoan inner and outer zone Outer zone is liquid- doesn’t transmit s-waves Probably composed of Nickel (Ni) and Iron (Fe), some heavier radioactive elements, along with some other elements (S or N- Sulfur or Nitrogen) Inner core is solid- based on speed of P-wave travel composed of same materials as outer core Important for generating Earth’s magnetic field
- 55. Earth’s magnetic fieldis created by the rotation of the outer fluid core around the solid inner core This creates an electrical current Generates an electromagnetic Field. Similar to a bar magnet with a positive and negative end
- 56. Earth’s magnetic fieldinteracts with solar particles, forcing them to the north or south pole, creating the Aurora Borealis
- 57. Earth’s magnetic fieldplays a vital role in the development of Plate tectonics theory Identification of a process that allows for Sea Floor Spreading.
- 58. Big Ideas •The Earthis divided into 3 Main Layers • Crust • Mantle • Core •Main Rock type of the 2 types of Crust • Oceanic – Basalt • Continental – Granite •Oceanic Crust is denser than Continental Crust
- 59. Big Ideas Continued •The lithosphere is divided into tectonic plates. • The Mantle has the convection currents which causes the plates to move. • The Asthenosphere flows semi-liquid on which the plates move • Temperature, pressure, and density increases as depth increases. This is a direct relationship.
- 60.
- 61. •Thermal energy transferis heat moving from a warmer object to a cooler object.
- 62. How is HeatTransferred? There are THREE ways heat can move. – Conduction – Convection – Radiation
- 63. CONDUCTION •Heat is transferredfrom one particle of matter to another in an object. • Conduction = CONTACT
- 64. Have you ever… Toucheda metal spoon sitting in a pan of boiling water only to be surprised by HOW hot it is? What conducts heat better, metal or nonmetal? Why?
- 65. EXAMPLE OF CONDUCTION •A piece of cheese melts as heat is transferred from the meat to the cheese (Contact)
- 66. CONVECTION • Convection isthe movement that transfers heat within fluids • Fluids = anything that flows • Heat is transferred by currents within the fluid or gas
- 67. Examples of Convection: •Haveyou ever noticed that the air on the second floor of your house is warmer than the first floor? Or that water in a pool is cooler at the deep end?
- 68. Examples of Convection Convectioncurrents cause the cooler breezes you experience by a large body of water. These currents also cause the movement of magma within the earth.
- 69. RADIATION • Radiation isthe transfer of energy by waves • What type of waves? • ELECTROMAGNETIC • Radiation does NOT require matter to transfer thermal energy
- 70. Radiation May ComeFrom Other Sources Have you ever sat too close to a campfire? You’re enjoying the warmth ….. only to notice that your skin is really warm?
- 71. Examples of RADIATION 1.Fire 2. Heat Lamps 3. Sun
- 72. As a groupcome up with two ideas/inventions where conduction, convection or radiation can be used to make society better. Does not have to be real, but must be realistic! Be able to explain how this type of heat transfer works and makes society better.
- 73.
- 74. The way to getstarted is to quit talking and begin doing. 2/1/20XX Walt Disney
- 75.