EARTHQUAKE HAZARD (DISASTER READINESS AND RISK REDUCTION).pptx

This pptx I made is for the subject DRRR

1. TAKE A LOOK!

2. What did you see? An aftermath of the 7.8 magnitude earthquake that struck Türkiye and Syria on February 06, 2023 at 4:17 AM. As of 5 March 2023, more than 52,700 deaths were confirmed: more than 45,900 in T ü rkiye , and more than 6,700 in Syria. It is the deadliest earthquake in T ü rkiye since the 526 Antioch earthquake and the deadliest in Syria since the 1822 Aleppo earthquake. Hence, a natural hazard transformed into a disaster.

3. LESSON 6 GEOLOGICAL HAZARD: EARTHQUAKE

4. Earthquake? Under what field of Science? SEISMOLOGY – a field of Science that deals with the study of earthquake or seismic activities. SEISMOLOGIST – a scientist who specialized (expert) in the study of earthquake.

5. In the Philippines, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) is the service institute of the Department of Science and Technology (DOST) that is mandated to monitor and study disasters that may be caused by earthquakes, volcanic eruptions, and other geotectonic phenomena.

6. EARTHQUAKE? What is it? EARTHQUAKE is the sudden or rapid shaking of the ground due to the release of potential energy stored in rocks.

7. EARTHQUAKE? How it is formed? When there is a movement in the tectonic plates (convergent, divergent, subduct, strike-slip), the potential energy stored in rocks are released vertically or horizontally, thus, generating seismic waves.

8. How seismic waves are generated? Earthquakes send out seismic waves as both body and surface waves. Body waves can travel through the Earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water.

9. P waves (compressional waves) propagate through the Earth with a speed of about 15,000 miles per hour and are the first waves to cause vibration of a building . S waves (shear waves) arrive next and cause a structure to vibrate from side to side. They are the most damaging waves , because buildings are more easily damaged from horizontal motion than from vertical motion.

10. W hereas,  Rayleigh waves  and  Love waves , which arrive last, mainly cause low-frequency vibrations. Some earthquake waves move only along the surface of the earth. Love waves shake the surface side-to-side. Rayleigh waves move the surface of the earth around in a circle, forward and down then back and up. This is the same as the motion in an ocean wave.

11. Love wave , named after British mathematician  A. E. H. Love (Augustus Edward Hough Love) , who worked out the mathematical model for this wave type in 1911. Love waves produce entirely horizontal motion. Rayleigh wave , named for  John William Strutt , known as Lord Rayleigh , who mathematically predicted the existence of this kind of wave in 1885.

12. Point of Reference of Earthquake FOCUS (HYPOCENTER) – the origin of seismic waves located deep down the crust. EPICENTER – the location in the surface directly above the focus.

13. Recording of Seismic Waves: What to use? Seismograph (Seismometer) – the instrument used in recording seismic waves. Seismogram – the record of ground shaking that was captured by the seismograph.

14. HOW EARTHQUAKE IS DESCRIBED? Magnitude – is the amount of energy released at the focus or origin of the earthquake. Magnitude is measured using Richter Scale. Charles F. Richter , American physicist and seismologist who developed the  Richter scale  for measuring  earthquake  magnitude.

15. HOW EARTHQUAKE IS DESCRIBED? Intensity – refers to the severity or extremity of its effects on the surface of the Earth. Intensity is described using Mercalli Scale. Giuseppe Mercalli (1850-1914) originally developed the scale, with ten levels. In 1902, Adolfo Cancani extended the scale to include twelve levels. August Heinrich Sieberg completely rewrote the scale. For this reason, the scale is sometimes named  Mercalli- Cancani - Sieberg scale, or MCS scale. Harry O. Wood and Frank Neumann translated it into English, and published it as  Mercalli–Wood–Neumann (MWN) scale.

16. MODIFIED MERCALLI INTENSITY SCALE (MMI) It was developed in 1931 by the American seismologists Harry Wood and Frank Neumann . This scale, composed of increasing levels of intensity that range from imperceptible shaking to catastrophic destruction, is designated by Roman numerals. It does not have a mathematical basis; instead it is an arbitrary ranking based on observed effects.

17. VARIOUS POTENTIAL EARTHQUAKE HAZARDS AND THEIR EFFECTS

18. 1. GROUND SHAKING - is a term used to describe the vibration of the ground during an  earthquake . Ground shaking is caused by  body waves and  surface waves . As a generalization , the severity of ground shaking increases as  magnitude increases and decreases as distance from the causative  fault increases. Effects: Damage or collapse of structure; may consequently cause hazards such as liquefaction and landslide.

19. Hyatt Terraces Hotel  in  Baguio City  collapsed during the  16 July 1990  Luzon Earthquake.

20. 2. GROUND RUPTURE - d eformation on the ground that marks the intersection of the fault with the earth’s surface. Effects:  fissuring, displacement of the ground due to movement of the fault

21. A continuous fault scarp of the North Bohol Fault in Brgy . Anonang , Inabanga , Bohol.

22. 3. LIQUEFACTION – a p henomenon wherein sediments, especially near bodies of water, behave like liquid similar to a quicksand.  Effects:  sinking and/ or tilting of structure above it; sand boil; fissuring

23. Gasoline tank pops out in Dagupan City due to 'liquefaction’.

24. 4. EARTHQUAKE-INDUCED LANDSLIDE – d own slope movement of rocks, solid and other debris commonly triggered by strong shaking. Effects:  erosion; burial and blockage of roads and rivers

25. Earthquake-induced Landslide

26. 5. EARTHQUAKE-INDUCED GROUND SUBSIDENCE (SETTLING) – is the lowering of the ground surface often occurs during an earthquake. Common causes include  consolidation or failure of the ground under a foundation, densification of sand and gravel layers due to the ground shaking and liquefaction. EFFECTS: sinkholes, inundation of land, aggravates flooding, changes topographic gradients, ruptures the land surface.

27. Ground Subsidence

28. Ground Subsidence 6. TSUNAMI - s eries of waves caused commonly by an earthquake under the sea. Effects:  flooding; coastal erosion; drowning of people and damage to properties

29. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011

30. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011

31. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 7. Fire - often associated with broken electrical and gas lines, is one of the common side effects of earthquakes. Gas is set free as gas lines are broken and a spark will start bringing "inferno". To complicate things water lines are broken and so there is no water to extinguish the fire. The San Francisco earthquake of 1906 caused 90% of damage by fire. EFFECTS: destruction of properties and loss of lives

32. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011

33. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 Earthquake Monitoring System At present, PHIVOLCS operates 108 (as of December 2020) seismic monitoring stations all over the Philippines. These stations are equipped with seismometers that detect and record earthquakes. Data is sent to the PHIVOLCS Data Receiving Center (DRC) to determine earthquake parameters such as magnitude, depth of focus and epicenter. Together with reported felt intensities in the area (if any), earthquake information is released once these data are determined.

34. Ground Subsidence As of today, there are no ways and means to predict earthquakes, specifically the date and time of its occurrence, its location and magnitude. The best way people can do is to increase their disaster preparedness and awareness on earthquakes and its hazards. As a student, how can you help your community to be prepared for an earthquake?

35. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 1. It is a field of Science that deals with the study of earthquake or seismic activities.

36. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 2. It is the service institute of the Department of Science and Technology (DOST) that is mandated to monitor and study disasters that may be caused by earthquakes, volcanic eruptions, and other geotectonic phenomena.

37. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 3 & 4. Two (2) Types of Body Waves

38. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 5. It is the origin of seismic waves located deep down the crust.

39. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 6. It is the record of ground shaking that was captured by the seismograph.

40. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 7. It is the amount of energy released at the focus or origin of the earthquake.

41. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 8. It refers to the severity or extremity of its effects on the surface of the Earth.

42. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 9 & 10. Two (2) Types of Surface Waves

43. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 11-17. Various Potential Earthquake Hazards

44. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 11-17. Various Potential Earthquake Hazards

45. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 18. Magnitude:_______ ; Intensity: Richter Scale

46. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 19. PHIVOLCS stands for:

47. Ground Subsidence Japan (Sendai and Tohoku) Tsunami on March 11, 2011 20. How many seismic monitoring stations installed all over the Philippines?