GRADE8-SCIENCE-EARTH-AND-SPACE-MELC 12.pptx
- 1. DELA PAZ NATIONAL HIGH SCHOOL
- 3. DELA PAZ NATIONAL HIGH SCHOOL
- 4. DELA PAZ NATIONAL HIGH SCHOOL MELC 12 Explain how earthquake waves provide information about the interior of the earth (S8ES-IIb-17)
- 5. DELA PAZ NATIONAL HIGH SCHOOL At the end of this lesson, you should be able to: Identify correctly the layers of the earth; Distinguish the different types of seismic waves and how they move the Earth; Describe the two types of body waves; Locate the P-wave and S-wave using diagram; and
- 8. Crust: The crust is the outermost layer of the planet, the cooled and hardened part of the Earth that ranges in depth from approximately 5-70 km (~3-44 miles). This layer makes up only 1% of the entire volume of the Earth, though it makes up the entire surface (the continents and the ocean floor).
- 9. Crust: The thinner parts are the oceanic crust, which underlies the ocean basins at a depth of 5-10 km (~3- 6 miles), while the thicker crust is the continental crust. Whereas the oceanic crust is composed of dense material such as iron magnesium silicate igneous rocks (like basalt), the continental crust is less dense and composed of sodium potassium
- 10. Upper Mantle: It makes up about 84% of Earth's volume, is predominantly solid, but behaves as a very viscous fluid in geological time. The upper mantle, which starts at the "Mohorovicic Discontinuity" (aka. the "Moho" – the base of the crust) extends from a depth of 7 to 35 km (4.3 to 21.7 mi) downwards to a depth of 410 km (250 mi). The uppermost mantle and the overlying crust form the lithosphere, which is relatively rigid at the top but becomes noticeably more plastic beneath.
- 11. Lower Mantle: The lower mantle lies between 660-2,891 km (410-1,796 miles) in depth. Temperatures in this region of the planet can reach over 4,000 °C (7,230 °F) at the boundary with the core, vastly exceeding the melting points of mantle rocks.
- 12. Outer Core: The outer core, which has been confirmed to be liquid (based on seismic investigations), is 2300 km thick, extending to a radius of ~3,400 km. In this region, the density is estimated to be much higher than the mantle or crust, ranging between 9,900 and 12,200 kg/m3. The outer core is believed to be composed of 80% iron, along with nickel and some other lighter elements.
- 13. Inner Core: Like the outer core, the inner core is composed primarily of iron and nickel and has a radius of ~1,220 km. Density in the core ranges between 12,600- 13,000 kg/m3, which suggests that there must also be a great deal of heavy elements there as well – such as gold, platinum, palladium, silver and tungsten.
- 14. Inner Core: Because the inner core is not rigidly connected to the Earth's solid mantle, the possibility that it rotates slightly faster or slower than the rest of Earth has long been considered. By observing changes in seismic waves as they passed through the core over the course of many decades, scientists estimate that the inner core rotates at a rate of one degree faster than the surface.
- 16. Seismic waves are the vibrations generated by the earthquake, explosion, or similar energetic source and propagated within the Earth or along its surface.
- 17. DELA PAZ NATIONAL HIGH SCHOOL Seismograph is an instrument used to record the motion of the ground during an earthquake.
- 18. DELA PAZ NATIONAL HIGH SCHOOL SEISMIC WAVES
- 22. Types of Seismic Waves 1. Body Waves can travel through the interior of the Earth. DELA PAZ NATIONAL HIGH SCHOOL 2. Surface Waves can travel in surface of the Earth a.) P waves or Primary wave b.) S waves or Secondary wave a.) Rayleigh waves b.) Love waves
- 23. Types of Seismic Waves DELA PAZ NATIONAL HIGH SCHOOL ⮚ P waves are faster and can travel through both solid and liquid ⮚ S waves are slower and cant travel through liquid ⮚ They can travel depends on the properties of the materials through which they travel. https://thumbs.dreamstime.com/b/types-seismic-waves-as-earth-movement-earthquake-outline-collection-set-educational-labeled-rayleigh-love-body-surface-228245141.jpg
- 24. DELA PAZ NATIONAL HIGH SCHOOL How seismic waves can give information about the internal structure of the Earth? https://pubs.usgs.gov/gip/dynamic/graphics/FigS1-1.gif
- 25. DELA PAZ NATIONAL HIGH SCHOOL Seismic waves travel more quickly through denser materials and therefore generally travel more quickly with depth. In hot areas seismic waves slow down.
- 26. DELA PAZ NATIONAL HIGH SCHOOL Seismic waves move more slowly through a liquid than a solid. Molten areas within the Earth slow down P waves and stop S waves because their shearing motion cannot be transmitted through a liquid. Partially molten areas may slow down the P waves and weaken S waves.
- 27. Inside The Earth DELA PAZ NATIONAL HIGH SCHOOL https://akm-img-a-in.tosshub.com/indiatoday/images/story/201602/seismic-waves-650_042715041742.jpg The shaking starts from the focus and then spreads out. As seismic waves travel through the body of the Earth, they behave in different ways, depending on what they encounter along the way.
- 28. Inside The Earth DELA PAZ NATIONAL HIGH SCHOOL https://akm-img-a-in.tosshub.com/indiatoday/images/story/201602/seismic-waves-650_042715041742.jpg As seismic waves travel deeper into the crust, they speed up. That means that at depth the rocks are denser. In the upper part of the mantle, the waves slow down. That means the rocks there are partially molten.
- 29. Inside The Earth DELA PAZ NATIONAL HIGH SCHOOL As the waves reach the core, S-wave disappears. That means the outer core is liquid. At certain depths, the waves reflected and refracted (bent). It means the Earth must be layered. https://www.bgs.ac.uk/wp-content/uploads/2020/04/Hypothetical_PWaves_BGS.jpg
- 35. Activity 1: Did You Know it? Learning Intention: To describe the two types of body waves. Directions: Write check mark ( ) on the √ appropriate column which describes the characteristics of P- wave and S- wave.
- 36. Activity 1: Did You Know it?
- 37. Activity 2: Let’s Locate! Learning Intention: To locate the P-wave and S-wave. You will locate the P-Wave and S-Wave. You will write your answer in your notebook.
- 38. Activity 2: Let’s Locate! S-WAVE P & S-WAVE P-WAVE S-WAVE P-WAVE P-WAVE
- 39. Now that you know Antipolo City is one of the possible places can be affected if the West valley fault move, how will you participate in decision-making on how to build structures such as houses, building, church, restaurant and other structures?
- 40. As a student, how will you disseminate information about earthquake preparedness in your community?
- 41. ---QUIZ TIME-- Directions: Read each item carefully. Choose the letter of the correct answer. 1. The order of earthquake waves arrived at seismic stations. a. P- waves, then S- waves, then surface waves b. S- waves, then P- waves, then surface waves c. S- waves, then surface waves, then P- waves d. Surface waves, then P- waves, then S- waves
- 42. ---QUIZ TIME-- 2. These waves can travel through the inner core a. P waves only c. S waves only b. P and S waves d. Neither P and S waves
- 43. ---QUIZ TIME-- 3. These waves can travel through solid rock a. P waves only c. S waves only b. P and S waves d. Neither P and S waves
- 44. ---QUIZ TIME-- 4. P and S waves travel through the earth, and so are called a. surface waves c. body waves b. tsunami d. earth waves
- 45. ---QUIZ TIME-- 5. Choose the correct statement regarding P and S seismic waves. a. P waves travel through solids, whereas S wave do not. b. P and S travel through liquid, but P waves do not travel through solids. c. S waves travel through solids, but P waves travel through liquid. d. P and S waves travel through solids, but S waves do not travel through liquid
Editor's Notes
- #6: The earth’s interior has four layers that has shown in the picture, that are physically and chemically different from one another. We most familiar with the crust, the solid rock layer that makes up the outermost shell of the earth. The outer core differs from the rest of the earth’s interior because it is the only liquid layer. It composed of iron and nickel, resulting in a very thick liquid that flows chaotically. At the very center of the earth is the 1220 km-thick inner core, which is the densest layer and is composed of solid iron with some amount of nickel.
- #18: There are three basic types of seismic waves.
- #19: P waves and S waves are sometimes collectively called body waves.
- #20: P waves, also known as primary waves or pressure waves, travel at the greatest velocity through the earth because of their speed, they are the first waves to be recorded by a seismograph during an earthquake.
- #21: S waves, also known as secondary waves shear waves or shaking waves, are transverse waves that travel slower than P wave.
- #24: Studies of the different types of seismic waves can tell us much about the nature of the Earth's structure. For example, seismologists can use the direction and the difference in the arrival times between P-waves and S-waves to determine the distance to the source of an earthquake.
- #25: READ FIRST: Seismic velocities depend on the material properties such as composition, mineral phase and packing structure, temperature, and pressure of the media through which seismic waves pass.
- #28: When an earthquake occurs, seismic energy radiates form the focus as seismic waves.
- #29: Earthquake waves give us a picture of the Earth’s interior, the way an “ultrasound” provides an image of a baby inside the womb. This is why scientists know a bit about the interior of our home planet, even if no one has gone deep into the Earth yet.
- #30: That means the rocks there are partly melted as the waves enter the core 1 variety of seismic waves. S waves disappears. That suggests that the outer core is liquid. At particular depths, the waves are reflected and refracted. That means the earth must exist layered.
- #32: When few waves hit a liquid or partially liquid layer, they bend. When few waves reach the solid layer, they bend again after numerous earthquakes. Seismologists were able to use the pattern of P waves reaching the surface. To see into the Earth.
- #33: as seismic waves move through the body of the Earth. They perform in diverse forms depending on whatever they encounter along the way.
- #34: Now that you know the characteristics of P-waves and S-waves, let’s check your understanding by doing the Activity 4.
- #36: Now that you are familiar with the characteristics of P-Waves and S-Waves, on the next activity you will locate the P-Waves and S-Waves using the diagram of the earth.
- #38: Processing Questions: What are your clues in locating the P-Waves and S-Waves? How P-Waves and S-Waves describe the interior of the earth?
- #40: To check what you’ve learn from the lesson , let’s have a QUIZ.