EARTHQUAKE AND TSUNAMI in disaster readinesspptx

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1. DISASTER RISK EXPOSURE HAZARD VULNERABILITY

2. 1. Identify the hazard shown in the picture above. Why is it considered a hazard? 2. Identify the disaster shown in the picture above. Why is it considered a disaster? 3. Identify the vulnerability shown in the picture above. Why is it considered a vulnerability? 4. Based on your answer in the previous question, what is vulnerability? The hazard in the image is the boulder on top of the hill. It is considered a hazard because it has the potential to cause damage to exposed elements such as people, infrastructures, etc. The disaster in the image is the fallen boulder. It is considered a disaster because it has caused damage to the person below the hill. The vulnerability in the image is location or the distance of the person to the hill. The close distance of the person to the path of the boulder makes him susceptible when it falls down the hill. Vulnerability is the susceptibility of a person, community, asset or system to the impacts of hazards.

3. DISASTER HAZARD CAPACITY VULNERABILITY RESILIENCE MITIGATION ADAPTATION PREVENTION EXPOSURE

4. Disaster risk is the result of the interaction between a hazard and the characteristics that make people and places vulnerable and exposed.

5. What can you think of when you hear the word EARTHQUAKE? Shaking, Damages Collapse of building Injuries Deaths

6. DEFINITION OF EARTHQUAKE An earthquake is a feeble shaking to violent trembling of the ground produced by the sudden displacement of rocks or rock materials below the earth’s surface. It is the result of a sudden release of energy in the earth’s crust that creates seismic waves.

7. If you throw a stone in a pond of still water, series of waves are produced on the surface of water. These waves spread out in all directions from the point where the stone strikes the water. Similarly, any sudden disturbances in the earth’s crust may produce vibration which travel in all direction from the point of disturbance.

8. TYPES OF EARTHQUAKE Tectonic Earthquakes are those generated by the sudden displacement along faults in the solid and rigid layer of the earth.

9. TYPES OF EARTHQUAKE Volcanic Earthquakes are earthquakes induced by rising lava or magma beneath active volcanoes.

10. About 80% of all earthquakes occur in the Circum-Pacific Belt. Most of these result from convergent margin activity. About 15% occur in the Mediterranean-Asiatic Belt. Remaining 5% occur in the interior of plates and on spreading ridge centers.

11. TERMINOLOGIES ASSOCIATED TO EARTHQUAKE SEISMOLOGY The study of earthquake and the waves they create. SEISMOLOGISTS - Scientists who study and measure earthquakes to learn more about them and to use them for geological discovery.

12. TERMINOLOGIES ASSOCIATED TO EARTHQUAKE SEISMOGRAPH An instrument used to record earthquake using waves. The larger the wave the stronger the earthquake. SEISMOGRAM - A graph output by a seismograph.

13. HOW ENERGY IS RELEASED DURING EARTHQUAKE ELASTIC REBOUND THEORY Rocks bend until the strength of the rock is exceeded. Rupture occurs and the rocks quickly rebound to an undeformed shape. Energy is released in waves that radiate outward from the fault.

14. SEISMIC WAVES A seismic wave is an elastic wave generated by an impulse such as an earthquake or an explosion. Seismic waves may travel either along or near the earth's surface or through the earth's interior. It has 2 types : A. Body Waves B. Surface Waves

15. 2 TYPES OF BODY WAVES PRIMARY WAVE (P-WAVE) They are the fastest wave since they are the first type of wave to arrive at seismic recording stations. They travel through solids, liquids, and even gases. It cause the ground to compress and expand, that is, to move back and forth, in the direction of travel. Material movement is in the same direction as wave movement.

16. 2 TYPES OF BODY WAVES SECONDARY WAVE (S-WAVE) S waves are called secondary waves because they always arrive after P waves at seismic recording stations. It can travel only through solid materials. These are the shake waves that move the ground up and down or from side to side. 

17. 2 TYPES OF SURFACE WAVES LOVE WAVES Travel slightly faster than Rayleigh Waves. Named after the British seismologist who first predicted their existence. (Augustus Edward Hough Love) These are the shake waves that move the ground up and down or from side to side.  

18. 2 TYPES OF SURFACE WAVES RAYLEIGH WAVES Travel slower that love waves. Named after the British physicist who first mathematically demonstrated their existence. (Lord Rayleigh) A Rayleigh wave is a seismic surface wave causing the ground to shake in an elliptical motion.

19. CLASSIFICATION OF EARTHQUAKE Earthquakes are usually classified on the following bases: Cause of Origin Tectonic Earthquake Non-Tectonic Earthquake (Volcanic, Explosive, Collapse) Depth of Focus Intensity and Magnitude of Earthquake

20. DEPTH OF FOCUS SURFACE EARTHQUAKE The depth of the focus is less than 10 kilometers. SHALLOW EARTHQUAKES The depth of the focus is between 10 to 50 kilometers. INTERMEDIATE-FOCUS EARTHQUAKE The earthquake originated at a depth of 50 to 300 kilometers. DEEP-FOCUS EARTHQUAKE The depth of the focus is more than 300 kilometers.

21. INTENSITY (Rossi- Forel Scale) an arbitrary numerical scale of intensity of seismic disturbances ranging from one for a barely perceptible tremor to 10 for an earthquake of the highest intensity.

22. INTENSITY (Mercalli Scale) describe the effects of an earthquake, at a given place, on natural features, on industrial installations and on human beings

23. MAGNITUDE (Richter Scale) It is the quantitative measure of an earthquake’s magnitude (size), devised in 1935 by American seismologists Charles F. Richter and  Beno Gutenberg.

24. TYPES OF DAMAGE CAUSED BY EARTHQUAKES PHYSICAL DAMAGE Landslides Tsunamis Fires Mudslides Liquefaction STRUCTURAL DAMAGE Buildings Collapse Roadways Collapse EMOTIONAL DAMAGE Death

25. A tsunami is a Japanese word meaning “harbor waves”. A tsunami is commonly generated by disturbances associated with earthquakes occurring below or near the ocean floor. It occurs when the earthquake is shallow-seated and strong enough to displace parts of the seabed and disturb the mass of water over it. In addition, underwater volcanic eruptions and landslides can also generate a tsunami.

26. Sometimes, tsunamis are erroneously called “tidal waves”. Remember that tsunamis are generated by earthquakes and tsunami waves are generated because of movement of fault under the sea. Tsunamis have nothing to do with high tide and low tide which is caused by the gravitational pull between the earth and moon. The increase in wave heights associated or during typhoons (when there are strong winds) or tropical cyclones are called “storm surges”.

27. CAUSES OF TSUNAMI Volcanic Eruptions, Ice Falls, Heavy Rainfall, Seismic Activities, Submarine Landslides, Cosmic Impacts, Mass Movements Above or Below Water

28. EARTHQUAKE-GENERATED TSUNAMI An earthquake can generate tsunami if the quake: occurs just below a body of water is of moderate of high magnitude displaces a large enough volume of water

29. All of our country’s coastlines are vulnerable to tsunamis, and in fact, history shows that we’re already affected by several destructive tsunamis, like the Moro Gulf Earthquake and Tsunami last 1976 that killed more than 4,000 people. The last destructive one was in Mindoro in 1994, when a Magnitude 7.1 earthquake struck, killing 78 people .

30. KINDS OF TSUNAMI PRONE TO TRENCH-RELATED LOCAL AND DISTANT TSUNAMI These are areas that are exposed to possible tsunami coming from trenches located near the area (ex. Philippine Trench) or those across the ocean, such as from large earthquakes originating in South America (ex. 1960 Valvidia Tsunami). PRONE TO TRENCH-RELATED LOCAL TSUNAMI These are areas exposed from tsunami originating from a local trench (ex. Manila Trench). You can see here that even if Palawan doesn’t have any local active faults, its coastlines are still exposed to tsunami from neighboring trenches. PRONE TO OFFSHORE FAULT AND SUBMARINE LANDSLIDE-RELATED LOCAL TSUNAMI These are areas that are not directly exposed to major trenches, but can still experience tsunami from offshore faults or underwater landslides in the vicinity.

31. SIGNS OF AN IMPENDING TSUNAMI Feel an earthquake. If the ground shakes under your feet in a coastal region, a tsunami may have been caused by a strong undersea earthquake. However, you may not feel an earthquake if the event is far away. See ocean water disappear from the beach, bay or river Before a tsunami arrives, water may recede from the shoreline before returning as a fast-moving wall of water. If you notice the water is disappearing, tell your family and friends and prepare to move inland or to higher ground. Hear an unusual roaring sound If you hear a loud roar approaching (a bit like a passenger jet or a train), tell your family and friends. It could be a tsunami approaching.

32. ACTIVITIES 1.4 AND 1.5