Earthquake and Different Seismic Waves ppt

Earthquake

1. Good morning, students! SCIENCE 10 MR. BOHARI A. SARO

2. Attendance Check!

3. How are you doing today?

4. EARTHQUAKE Science 10

5. LESSON OBJECTIVES After the lesson, the students are expected to: a. identify the three seismic waves, b. characterize the seismic waves in terms of their speed, c. explain the triangulation method in determining the earthquake epicenter, and d. locate the epicenter of an earthquake using the triangulation method

6. PRE-TEST

7. What is an earthquake? I. The shaking and trembling of the Earth’s crust. II. A man-made calamity. I III. Can be measured through a thermometer. IV. Systematic waves that are created due to the sudden release of energy in the Earth crust’s. A. I and II B. I and IV C. II only D. II and III

8. 2. Why is Philippines prone to experience earthquakes? A. It is within the Pacific Ring of Fire. B. The Pacific Ocean causes daily shaking of the archipelago. C. It has plenty of stored energy in the crust part. D. The Philippines is in tropical area

9. 3. They are the scientists who study earthquakes. A. Seigmographists B. Seismologists C. Seismologihists D. Seismogists

10. 4. Which of the seismic waves travels the fastest? A. Instant Wave B. Primary Wave C. Secondary Wave D. Surface Wave

11. 5. Seismic waves start at the . A. epicenter B. focus C. seismic distance D. seismic gap

12. LET’S LOOK BACK

13. WHAT DO YOU KNOW ABOUT EARTHQUAKE ?

14. EARTHQUAKE also known as quake, tremor or temblor a phenomenon where there is a sudden release of extreme energy from the earth crust resulting in shaking and displacement of the ground along with the creation of seismic waves

15. ACTIVITY 1. Watch a video about the different types of Body waves, be guided with the following questions: What are the two types of Body waves? What are the characteristics of Primary wave? What are the characteristics of Secondary wave?

16. SEISMOLOGY Seismology is the study of earthquakes and seismic waves that move through and around the earth. A seismologist is a scientist who studies earthquakes and seismic waves.

17. can be defined as, “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 is recorded on seismograph . SEISMIC WAVES

18. SEISMOGRAPH AND SEISMOGRAM Seismograph possesses the capacity to record the phenomena. A record produced by a seismograph on a display screen or paper printout is called a seismogram.

19. Body Waves propagate within a body of rock. The faster of these body waves is called Primary wave (P-wave) , or longitudinal wave or compressional wave, and the slower one is called Secondary wave (S-wave) or shear wave. TYPES OF SEISMIC WAVES

20. 2. Surface wave its motion is restricted to near the ground surface s uch waves correspond to ripples of water that travel across a lake can be divided into two types; Love waves and Rayliegh waves TYPES OF SEISMIC WAVES

21. P wave or primary wave fastest kind of seismic wave the first to 'arrive' at a seismic station also known as compressional wave or longitudinal can move through solid rock and fluids it pushes and pulls the rock people can only feel the bump and rattle of these waves. BODY WAVE: PRIMARY WAVE

22. S wave or secondary wave slower than a P wave can only move through solid rock, not through any liquid medium Transverse wave (travels perpendicular to the wave movement) move rock particles up and down BODY WAVE: SECONDARY WAVE

23. named after A.E.H. Love, a British mathematician it's the fastest surface wave moves the ground from side-to-side produce entirely horizontal motion SURFACE WAVE: LOVE WAVE

24. John William Strutt, Lord Rayleigh, in 1885. rolls along the ground 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 wave SURFACE WAVE: RAYLEIGH WAVE

25. Seismic waves travel fast, on the order of kilometers per second (km/s). depends on several factors; most important is the composition of the rock Temperature tends to lower the speed Pressure tends to increase the speed. Velocity generally increases with depth Seismic Wave Speed

26. Earthq uake Classif ication Scales

27. The magnitude of an earthquake is a measure of how destructive it is. Basically the magnitude corresponds to how much energy is released. The Richter Scale is used to express earthquake magnitude on the basis of the height (amplitude) of the largest line (seismic wave, P or S) on a seismogram. MAGNITUDE

28. The Mercalli scale it measures the intensity of how people and structures are affected by the seismic event. In essence, Mercalli scale it measures the intensity It is much more subjective and uses numbers ranging from 1 (no damage) to 12 (total destruction). INTENSITY

29. THE E PIC ENTER

30. The epicenter is the point on the earth's surface vertically above the hypocenter (or focus) , point in the crust where a seismic rupture begins. EPICENTER

31. The Triangulation Method Scientists use triangulation to find the epicenter of an earthquake. When seismic data is collected from at least three different locations , it can be used to determine the epicenter by where it intersects LOCATING THE EPICENTER

32. To locate the epicenter of an earthquake, scientists must have seismograms from at least three seismic stations. The procedure for locating an epicenter has three steps: Scientists find the difference between the arrival times of the primary and the secondary waves at each of the three stations. PROCEDURE

33. 2. The time difference is used to determine the distance of the epicenter from each station. The greater the difference in time, the farther away the epicenter is. 3. A circle is drawn around each station, with a radius corresponding to the epicenter’s distance from that station. The point where the three circles meet is the epicenter. PROCEDURE

34. REMEMBER...

35. There are three types of seismic waves, namely: P, S, and L waves. ● P waves are the fastest among seismic waves thus, take the shortest time to travel from the origin while L waves need the longest time to travel. ● In a seismogram, the P waves are recorded first, followed by the S waves, and lastly, the L waves.

36. L waves are the most destructive since they are felt on the surface difference in the arrival time of P and S waves are used to locate the earthquake epicenter. ● Data from three seismic stations are needed to locate the earthquake epicenter using the triangulation method.

37. SOURCES https://www.dnr.sc.gov/geology/pdfs/Earthquakes.pdf https://nidm.gov.in/easindia2014/err/pdf/earthquake/seismic_wav.pdf http://www.classzone.com/vpg_ebooks/sci_sc_8/accessibility/sci_sc_8/page_233.pdf