ANATOMY OF AN EARTHQUAKE.pptx

Anatomy of an earthquake

1. ANATOMY OF AN EARTHQUAKE

2. THE THREE BASIC TYPES OF FAULTS

3. THE TWO TYPES OF SEISMIC WAVES 1) BODY WAVES

4. THE TWO TYPES OF SEISMIC WAVES 2) SURFACE WAVES

5. EARTHQUAKE MAGNITUDE & INTENSITY

6. EARTHQUAKE MAGNITUDE & INTENSITY Magnitude is the measure of the energy released by the earthquake, measured by an instrument called seismometer (the instrument used to detect seismic waves). Intensity refers to the effects and damage caused by an earthquake. It is determined by actual observation or on-site inspection of the affected areas, including interviews with people.

7. PHILVOLCS EARTHQUAKE INTENSITY SCALE

8. PHILVOLCS EARTHQUAKE INTENSITY SCALE (MODIFIED MERCALLI SCALE)

9. PHILVOLCS EARTHQUAKE INTENSITY SCALE Perceptible to people under favorable circumstances. Delicately balanced objects are disturbed slightly. Still water in containers oscillate slowly.

10. PHILVOLCS EARTHQUAKE INTENSITY SCALE Felt by few individuals at rest indoors. Hanging objects swing slightly. Still water in containers oscillate noticeably.

11. PHILVOLCS EARTHQUAKE INTENSITY SCALE Felt by many people indoors, especially in upper floors of the buildings. Dizziness and nausea are experienced by some people. Hanging objects swing moderately.

12. PHILVOLCS EARTHQUAKE INTENSITY SCALE Felt generally by people indoors and by some people outdoors. Light sleepers are awakened. Vibration is felt like the passing of a heavy truck. A rumbling sound may sometimes be heard.

13. PHILVOLCS EARTHQUAKE INTENSITY SCALE Generally felt by most people indoors and outdoors. Many sleeping people are awakened. Strong shaking and rocking felt throughout the building. Hanging objects swing violently. Standing vehicles rock noticeably.

14. PHILVOLCS EARTHQUAKE INTENSITY SCALE Some people lose their balance. Motorists feel like they are driving with flat tires. Heavy objects or furniture move or may be shifted. Very old or poorly-built houses and man-made structures are slightly damaged, though well-built structures are not affected.

15. PHILVOLCS EARTHQUAKE INTENSITY SCALE People find it difficult to stand in upper floors. Heavy objects and furniture overturn or topple. Some well-built structures are slightly damaged. Some cracks may appear on dikes, fish ponds, road surfaces or concrete hollow block walls. Trees are shaken strongly.

16. PHILVOLCS EARTHQUAKE INTENSITY SCALE People find it difficult to stand even outdoors. Many well-built buildings are considerably damaged. Concrete dikes and foundations of bridges are destroyed by ground settling or toppling. Railway tracks are bent or broken. Fissures and fault rupture may be observed.

17. PHILVOLCS EARTHQUAKE INTENSITY SCALE People are forcibly thrown to ground. Most buildings are totally damaged. Bridges and elevated concrete structures are toppled or destroyed.

18. PHILVOLCS EARTHQUAKE INTENSITY SCALE Practically all man-made structures are destroyed. Massive landslides and liquefaction, subsidence and uplifting of landforms and many ground fissures are observed.