EARTHQUAKE.pptx
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EARTHQUAKE.pptx
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Earthquake hazardsEarthquake Hazards Overview Earthquake hazards include any physical phenomenon associated with an earthquake that may produce adverse effects on human activities. While they are often used as synonyms, it is useful to distinguish between "hazards" and "risk". Hazards are the natural phenomena that might impact a region, regardless of whether there is anyone around to experience them or not. Risk refers to what we stand to lose when the hazard occurs; it is what we have built that's threatened. Risk can usually be measured in dollars or fatalities. Hazard is generally measured in more physical units: energy, shaking strength, depth of water inundation, etc. Primary earthquake hazards are: ground shaking landslides liquefaction surface rupture Secondary earthquake hazards are those that are caused by the primary hazards, and may often be more catastrophic: tsunami seiche flooding fire Secondary hazards are caused as a consequence of that ground shaking, such as ground settlement, lateral ground displacement, liquefaction, landslides and rock falls, tsunamis, floods, fires and falling debris. Earthquake Hazards · Ground shaking: Ground shaking is both a hazard created by earthquakes and the trigger for other hazards such as liquefaction and landslides Deformation 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 An earthquake (also known as 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 intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word tremor is also used for non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides. In its most general sense, the word earthquake is used to describe any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter. The shaking of the earth is a common phenomenon that has been experienced
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EARTHQUAKE.pptx
- EARTHQUAKE HAZARDS
- OBJECTIVES 1. Identify various potential earthquake hazards; 2. Apply precautionary and safety measures before, during and after an earthquake; 3. Prepare a Family Emergency Plan; 4. Appreciate the importance of earthquake preparedness;
- What is an EARTHQUAKE? An earthquake (also known as a quake, tremor or temblor) is the perceptible shaking of the surface of the Earth resulting from the sudden release of energy in Earth crust that creates seismic waves. (US Geological Science -USGS)
- Potential Earthquake Hazards Geologists explain that an earthquake is a type of hazard that depends on the strength of seismic activity , along with such factors as local topographic and built features, subsurface geology and groundwater. A large earthquake will always be followed by a sequence of aftershocks that normally aggravates its effect on human and material element like buildings and infrastructure.
- Where do they usually happen? What are the origins of earthquakes? How do we measure earthquakes? What are the potential earthquake hazards? Give a brief explanation of each. Other salient information. • Earthquake and Its Hazards AVP.mp4 - https://www.youtube.com/watch?v=Py9k7dacoKo
- Potential Earthquake Hazards
- 1. Ground or Surface Rupture Surface rupture is an offset of the ground surface when fault rupture extends to the Earth's surface. Any structure built across the fault is at risk of being torn apart as the two sides of the fault slip past each other. Effects: fissuring and displacement of the ground
- Ground or Surface Rupture
- 2. Ground Shaking or Ground Motion The earth shakes with the passage of earthquake waves which radiate energy that had been “stored” in stressed rocks and were released when a fault broke and the rocks slipped to relieve the pent-up stress. Effects: damage or collapse of structure and may consequently cause hazards such liquefaction and landslide
- Ground Shaking or Ground Motion
- Ground Subsidence and Lateral Spreading • Subsidence, or lowering of the ground surface, often occurs during earthquakes. It can occur as ground shaking causes loose sediments to “settle” and to lose their load bearing strength or to slump down sloping ground . • Lateral spreading occurs where sloping ground starts to move downhill, causing cracks to open up , that are often seen along hill crests and river banks.
- Ground Subsidence and Lateral Spreading
- 3. Liquefaction A phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading. It normally occurs in saturated soils , that is soils in which the space between individual particles is completely filled with water. Effects: sinking and/or tilting of structure above it, and fissures.
- Liquefaction
- Liquefaction
- Earthquake-induced Landslides
- 4. Earthquake-induced Landslides Landslides frequently triggered by strong ground motions. They are important secondary earthquake hazard. The term landslides includes a wide range of ground movement, such as rock falls, deep failure of slopes, and shallow debris flows. Effects: erosion, burial and blockage of roads and rivers
- Tsunami
- 5. Tsunami also known a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including denotations of underwater nuclear devices), landslides, glacier cavings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. Effects: flooding, coastal erosion, drowning of people and damage to properties
- NATURAL SIGNS OF AN IMPENDING TSUNAMI 1. ANIMAL BEHAVIOR
- 2. DRAWBACK an observable natural sign of an impending tsunami that is noteworthy. drawback can serve as brief warning.
- • Drawback will occur as the shoreline recedes dramatically , exposing normally submerged areas. Drawback can exceed hundreds of meters , and people unaware of the danger sometimes remain near the shore to satisfy their curiosity or to collect fish from the exposed seabed.
- 3. Feel an earthquake 4. Hear an unusual roaring sound.
- GROUP ACTIVITY 1.Group and Share: Form a group and share what you will do Before, During and After an Earthquake. (15 minutes) • Groups 1 and 6 – Before • Groups 2 and 5 – During • Groups 3 and 4 – After 2.Share your output to the class. (3-5 minutes per group)
- RUBRICS (PRESENTATION) Criteria Indicators 4 3 2 1 Content Students discussed the topic very well, with explanation and elaboration. Students are at ease with the topic but failed to elaborate. Students have difficulty explaining the topic/content. Students have not grasped the topic given to them. Organization Student presents information in logical, interesting sequence which the audience can follow. Student presents information in logical sequence which audience can follow. Audience has difficulty following the presentation because the presenter jumps around different ideas. Audience cannot understand the presentation because there is no proper sequence of information. Cooperation All members of the group participated in the activity. More than half of the members of the group participated in the activity. Less than half of members of the group participated in the activity. Only one member of the group performed the activity. Timeliness Students finished on the allotted time. Students finished the task a minute after the allotted time. Students finished the task several minutes after the allotted time. Students were not able to finish the task.
- GROUP PRESENTATION
- What to before an EARTHQUAKE? 1. Engage yourself in training activities that promote safety and disaster preparedness. 2. Participate in government-initiated earthquake drills and evacuation drills. 3. Some private companies provide training on emergency response skills. Participate. This is part of your preparation. 4. Share your acquired knowledge and skills to your family and friends.
- What to do during an EARTHQUAKE? 1. If you're inside a room building, duck under a sturdy desk or table, and hold on to it or protect your head with your hands or arms. 2. Stay away from glass window, shelves, cabinets and other heavy object. 3. Beware of falling objects. Be alert and keep your eyes open.
- 4. Those who are outside should move to an open area, and follow the safety measure (PHILVOCS) • Stay away from trees, powerlines, posts, and concrete structure. • Move away from steep slopes which may be affected by landslide. • If near the shore and feeling an earthquake, specially a strong one, quickly move to a higher ground in anticipation of possible tsunamis.
- 5. Those who are in a moving vehicle should stop and get out. Do not attempt to cross bridges, overpasses or flyovers which may have been damaged.
- What to do after an EARTHQUAKE? 1. Take the fastest and safest way out of the building. 2. Do not use elevator. 3. Do not enter damaged building. 4. Most of all don't panic.
- 1. What are the different earthquake hazards? What is the importance of knowing these hazards? 2. Why is it necessary and helpful to know and apply the precautionary measures before, during and after an earthquake?
- PREPARE A FAMILY EMERGENCY PREPAREDNESS PLAN Each student will prepare a Family Emergency Preparedness Plan. This should include, but not be limited to, hazard identification and safety assessment, communication details, emergency contact numbers, things to prepare/survival kits, roles and responsibilities of family members, evacuation/relocation sites, and measures to do before, during and after an earthquake. Discuss the plan with your family members. Let your parent/guardian sign the document/plan.
- RUBRICS Criteria Performance Indicator 5 4 3 Content (60%) Describes the framework of a comprehensive FEMP and identifies measures to implement to great extent. Somewhat describes the framework of a comprehensive FEMP and identifies specific measures to implement. Insufficiently describes the framework of a FEMP and identifies specific measures to implement. Organization (20%) Information is presented in a logical and easy to read manner with minimal errors. Information is presented in a logical and easy to read manner with 4-7 errors. Information is presented in an illogical and easy to read manner 8 or more errors. Mechanics and Visual Appeal (10%) Overall design is pleasing. Free from grammatical errors. Words are legible and pertinent to topic. Overall design is pleasing. Some grammatical errors are seen. More than five grammatical errors are seen. Words used are not pertinent to the topic. Timeliness of Submission (10%) Submitted on or before the deadline. Submitted a day after the deadline. Submitted days after the deadline.