Earthquake: A Tragedy to life and property
- 1. SOCIAL SCIENCE PROJECT By: VANSHIKA SINGH Session (2021-2022)
- 2. EARTHQUAKE A Tragedy To Life and Property
- 3. INDEX o Introduction o What is an earthquake? o Terms related to earthquake o Causes o Effects of earthquake o Protection against earthquakes o Deadliest earthquakes o bibliography
- 4. INTRODUCTION Earthquake constitutes one of the worst natural hazards which often turn into disaster causing widespread destruction and loss to human life. The effects of earthquake vary upon the magnitude and intensity. Earthquakes occur every now and then all around the world, except in some places where earthquakes occur rarely. The devastation of cities and towns is one of the effects of earthquake.
- 5. WHAT IS AN EARTHQUAKE? An Earthquake (a.k.a. quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to propel objects and people into the air, and wreak destruction across entire cities. The seismicity, or seismic activity, of an area is the frequency, type, and size of earthquakes experienced over a period of time.
- 6. The other destructive natural phenomena like cyclones and lightning can be predicted in advance to some extent. This is not so in the case of earthquakes. Earthquake is a destructive natural phenomena which can not be predicted in advance. Nobody can tell when and where an earthquake will occur. This unpridictable nature of earthquakes makes them even more dangerous.
- 7. TERMS RELATED TO EARTHQUAKE FOCUS: The point within the earth where an earthquake rupture starts. EPICENTER: The point on the Earth's surface that is directly above the focus, the point where earthquake or undergriund explosion originates.
- 8. AFTERSHOCKS: Smaller earthquakes that occur after the main earthquake in the same place as the mainshock. Aftershocks are linked to the size of the mainshock and if this is large can continue for many weeks, months or years. FAULT: A crack in the Earth's crust along which the rocks slide. Faults are found at the edges of the plates where the crust is moving in different directions. FAULT PLANE: The planar (flat) surface along which two blocks of the earth's crust suddenly slip past one another during an earthquake.
- 9. MAGNITUDE: A number that categorizes the amount of energy released during an earthquake. MAINSHOCK: The largest, main earthquake. SEISMICITY : The intensity, frequency, and distribution of earthquakes in a specific area. SEISMOGRAPH: A very sensitive instrument that can detect, measure and record ground vibrations and their intensities during an earthquake.
- 10. CAUSES The plates of earth's crust are made of huge rocks having rough edges. Due to their highly rough edges, movement of two crust plates relative t one another is not smooth. When the two huge plates of earth's crust slide past one another, they rub against one another ferociously and the rocks on the edges get entangled. This builds up the pressure between the two plates of crust. When sufficient pressure has been built up between the two crushed plates, the entangled rocks of the two crust plates break open suddenly with a big jolt. This sudden release of tremendous amount of energy produces shock waves which makes the earth shake. When the two plates of the earths crust moving in opposite directions collide with each other, then the ends of these crust plates buckle and fold forming new mountains and causing earthquakes.
- 11. A separate type of earthquake is associated with volcanic activity and is called a volcanic earthquake. Yet it is likely that even in such cases the disturbance is the result of a sudden slip of rock masses adjacent to the volcano and the consequent release of elastic strain energy.
- 12. STRENGTH OF EARTHQUAKE The intensity and strength of an earthquake is measured on Richter scale, the scale invented by Charles Richter in 1935. An earthquake of magnitude 1.5 on Richter scale is the smallest earthquake that can be felt by us. An earthquake of magnitude 4.5 causes some damage but not much damage. The earthquakes having magnitudes higher than 7 on Richter scale are really destructive earthquakes causing great loss of life and property.
- 13. o The Ring of Fire (a.k.a. the Pacific Ring of Fire, the Rim of Fire or the Circum-Pacific belt) is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquake occur. o About 76% of the Earth's seismic energy is released as earthquakes in the Ring of Fire. o About 90% of the Earth's earthquakes and about 81% of the world's largest earthquakes occur along the Ring of Fire
- 14. EFFECTS OF EARTHQUAKE GROUND SHAKING o Ground shaking is the most familiar effect of earthquakes. It is a result of the passage of seismic waves through the ground, and ranges from quite gentle in small earthquakes to incredibly violent in large earthquakes. o Buildings can be damaged or destroyed, people and animals have trouble standing up or moving around, and objects can be tossed around due to strong ground shaking in earthquakes.
- 15. Ground Rupture o Ground rupture is another important effect of earthquakes which occurs when the earthquake movement along a fault actually breaks the Earth's surface o Landslides o Landslides are caused by earthquakes both by direct rupture and by sustained shaking of unstable slopes. They can easily destroy buildings in their path, or block roads and railroad lines, or take hilltop homes with them as they tumble. They even can dam rivers on occasion, like in the 17 August 1959 Hebgen Lake earthquake (magnitude 7.1) in Montana.
- 16. Tsunami o Tsunamis are a series of water waves caused when the seafloor moves vertically in an earthquake and which can travel vast distances in a short period of time. Tsunami speeds in the deep ocean have been measured at more than 700 km/hr, comparable to some jet planes, and when tsunamis reach shallow water near the coast, they can reach heights of more than 27 meters
- 17. Fires o Fires are a major source of damage after earthquakes. Ground rupture and liquefaction can easily rupture natural gas mains and water mains, both contributing to the ignition of fires and hindering the efforts to control them. o In the 1923 Kanto earthquake in Japan nearly 100,000 people died over 70,000 of them due to fires which swept the area after the earthquake. Other Effects of earthquakes include: o Loss of life and property o Damage to infrastructure o Damage to transport system o Economic activities like agriculture, trade etc are severely affected.
- 18. PROTECTION AGAINST EARTHQUAKES Earthquakes are highly destructive and cannot be predicted. So it is necessary that we take precautions. o All the houses and other buildings in seismic zones should be designed and constructed in such a way that they can withstand major earthquake tremors.
- 19. o All buildings should have fire-fighting Equipements in working. o Objects such as heavy mirrors, photo frames, water heaters, glass wares, glass bottles etc should be mounted securely on the walls at such places in the house that they do not fall on people during an earthquake. IF WE ARE AT HOME WHEN AN EARTHQUAKE OCCURS, THEN... o We should take shelter under a sturdy table or a kitchen counter and stay there till the shaking stops. We should cover our heads with our hands. o We should stay away from glass windows that may shatter dues to tremors. o We should stay away from tall and heavy objects, so that if they topple, they may not fall on us.
- 20. oDo not re-enter badly damaged buildings. Turn off the water, gas and electricity. oKeep calm. Don’t panick. Turn on the transistor radio and listen to the instructions carefully. oKeep away from electric poles, beaches and low banks of rivers. oIf you are aware of people buried in the debris, tell the rescue team. Do not rush and try to worsen the situation. oDo not drink water from open containors. IF YOU ARE OUTDOORS WHEN AN EARTHQUAKE OCCURS... o If we are in a car (or a bus) we shoul not come out of it. The car should be driven slowly to a clear and safe place away from buildings or trees.
- 21. SOME DEADLIEST EARTHQUAKES... This Photo by Unknown author is licensed under CC BY-SA. The April 2015 Nepal earthquake killed nearly 9,000 people and injured nearly 22,000. It occurred at 11:56 Nepal Standard Time on 25 April 2015, with a magnitude of 7.8M or 8.1M.
- 22. . On October 30 2020, the western province of İzmir, Turkey was hit by a 6.6-7.0 earthquake that damaged Izmir city. The earthquake was followed by a tsunami which damaged coastal areas and towns of the province. It was followed by over 1,400 aftershocks with 43 of them being over a magnitude of 4.0 .
- 23. This Photo by Unknown author is licensed under CC BY-NC. A magnitude 9.0 earthquake struck in the Pacific Ocean off the northeast coast of the Tōhoku region of Japan’s Honshu island on March 11, 2011. It Triggered a massive tsunami that flooded more than 200 square miles of coastal land. Waves were estimated to be as high as 38 meters, the height of a 12-story building.
- 24. DID YOU KNOW?
- 25. BIBLIOGRAPHY... https://topex.ucsd.edu/es10/es10.1997/lectures/lecture20/secs.with.pics/node 10.html#:~:text=The%20primary%20effects%20of%20earthquakes,important %20secondary%20effect%20of%20earthquakes. https://www.britannica.com/science/earthquake-geology/Surface-phenomena WIKIPEDIA- EARTHQUAKES, RICHTER SCALE https://www.sms-tsunami-warning.com/pages/earthquake- glossary#.YJkP5rUzZPZ
- 26. THANK YOU!