1. 1. Seismic Waves Prepared By: Mark Luwen Borigas Grade 10 - Generosity
2. 2. `Seismic Waves These are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and recorded on seismographs.
3. 3. `Types Seismic Waves Body waves - arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves. Surface waves(L-Waves) - are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost entirely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.
4. 4. ` Body Waves Primary Waves Secondary Waves push and pull side to side
5. 5. `Primary Waves Primary wavesare compression waves. They push and pull the rocks of the earth's surface. They can move through solid rock and fluids like water or the liquid core layers of the earth And first to 'arrive' at a seismic station.
6. 6. ` Primary waves push and pull on the rocks through which they are traveling. This creates a back and forth movement on the Earth's surface. This is just like sound waves pushing and pulling the air. Have you ever heard a big clap of thunder and heard the windows rattle at the same time? The windows rattle because the sound waves were pushing and pulling on the window glass much like P-waves push and pull on rock. Primary Waves
7. 7. `Secondary Waves Secondary waves travel slower than primary waves. Also called shear waves "or Transverse Waves. They create a side to side motion in the rocks through which they are traveling.
8. 8. `Secondary Waves Unlike the other earthquake waves, S-waves cannot travel through water or the liquid rock of the Earth's core layer. They can Travel through solid only-waves will rock buildings side- to-side.
9. 9. `Remember... Primary WavesSecondary Waves Also Called as Compression Waves. They Push and Pull the rock in the earths surface Also Called as Shear/Transverse Waves. They Push and Pull the rock in the earths surface
10. 10. ` Surface Waves(L-Waves) Moves along the surface of the earths surface. They move up and down. Love WavesRaleigh Waves
11. 11. `Surface Waves(L-Waves) Land waves move along the surface of the earth and cause it to move up and down like something bobbing on the surface of the ocean.
12. 12. `Surface Waves(L-Waves) Land waves only move along the surface of the earth. Their speeds vary depending on the material, rock or soil, forming the surface. These waves cause the surface to move up and down. These are the waves that cause The to buildings and other structures during an earthquake.
13. 13. ` Named after A.E.H. Love, a British mathematician who worked out the mathematical model for this kind of wave in 1911. Love Waves Love waves travel with a lower velocity than P or S waves, but faster than Rayleigh waves. These waves travels in lithosphere only.
14. 14. ` These waves are a type of surface acoustic wave that travel on solids Rayleigh Waves Named for John William Strutt, Lord Rayleigh, who mathematically predicted the existence of this kind of wave in 1885. Rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.
15. 15. ` Seismic Waves
16. 16. `Remember... Love Waves travels through lithosphere only. Has Low Velocity but faster than Rayleigh waves. Rayleigh Waves travel on solids and Rolls along the ground
17. 17. `Questions: 1. Other term for primary waves and secondary waves 2. Differentiate the P and s waves 3.Love waves are named after a mathematician. What is the name of the mathematician ? 4.How about rayleigh waves. What is the name of the mathematician ? The end
18. 18. ` Seismic Waves Body Waves P Waves S Waves Surface Waves Love Waves Rayleigh Waves Remember...