Jul 03, 2018 earthquakes earthquake measurements slides and pdf files 1. Which of the following is an aspect of the elastic rebound theory. Oblique view of a highly generalized animation of a subduction zone where an oceanic plate is subducting beneath a continental plate. Reids elastic rebound theory rocks store elastic energy until they cannot store it any longer, then snap like a rubberband. Earthquake summary posters for significant earthquakes. In geology, the elastic rebound theory is an explanation for how energy is released during an earthquake.
Earthquakes can be so small they go completely unnoticed, or so large that it can take years for a region to recover. The stored elastic energy has to go somewhere because it has been suddenly released. Earthquakes earthquake measurements slides and pdf files 1. Introduction earthquake sequences elastic rebound theory rate. At some point the stresses become so great that the. Slow accumulation and rapid release of elastic energy. Feb 22, 2014 1 the veolcity of s waves decreases as the waves enter the asthenosphere what does this suggest about the asthenosphere compared to the overlying lithosphere.
What makes an elastic rebound possible during an earthquake. In elastic rebound theory, what must occur to produce an. Earthquakes earthquake measurements slides and pdf files. Similarly, the crust of the earth can gradually store elastic stress that is released suddenly during an earthquake. However, based on studies done in the tonga islands, earthquakes occur within the weak, ductile asthenosphere. Basically elastic rebound is the primary reason earthquakes even happen. Previously it was thought that ruptures of the surface were the result of strong ground shaking rather than the converse suggested by this theory. Earthquakes affect almost every part of the earth and like rain they can be either mild or catastrophic. Elastic rebound theory jerky motions on faults produce eqs three fs of earthquakes.
According to the theory, a tectonic earthquake occurs when strains in rock masses have accumulated to a point where the. However some of the characteristics of earthquakes can be explained by using a simple elastic rebound theory. Elastic rebound theory is directly related to earthquakes. Elastic rebound theory this theory was discovered by making measurements at a number of points across a fault. Reid gave, for example, a crude forecast of the next great earthquake near san francisco. Over time stresses in the earth build up often caused by the slow movements of. Illuminates the causes of earthquakes by elastic rebound theory and earthquake location as focus and epicenter. List the key observations that revealed earth to possess a. A range of mechanisms has been proposed for earthquakes, including elastic rebound hypothesis reid.
Energy built up when plates try to get past each other is released when plates break free. Over time stresses in the earth build up often caused by the slow movements of tectonic plates. Explain the elastic rebound theory, which provides an explanation for the origin of earthquakes. Defining an earthquake defining an earthquake an earthquake is a natural occurrence, like rain. After the devastating 1906 san francisco, california earthquake, a fault trace was discovered that could be followed along the ground in a more or less straight line for 270 miles. The elastic rebound theory predicts that earthquakes can be generated only in the lithosphere.
Observation and interpretation of precursory phenomena. How do earth scientists explain this contradiction. The elastic rebound theory of earthquake sources allows rough prediction of the occurrence of large shallow earthquakes. Jan 12, 2014 elastic rebound theory elastic rebound theory over the course of time, one can observe that the two sides of an active fault are in slow but continuous movement relative to one another. According to elastic rebound theory, the blocks of rock on opposite side of a fault are forced in opposite directions by stress. Elastic rebound theory of earthquakes in the past, earthquakes were believed to occur because the ground would shake in a very strong manner. The goal of this lesson is for students to learn the concepts of elastic rebound and friction and how these apply to earthquakes and faults.
In elastic rebound theory, what must occur to produce an earthquake. Fixed recurrence and slip models better predict earthquake. Duponts plasticslip theory rocks store bending energy until they cannot store it any longer, then snap like a rubber ball. Most earthquakes are the result of the sudden elastic rebound of previously stored energy. As the earths crust deforms, the rocks which span the. On incorrectness in elastic rebound theory for cause of. In geology, the elastic rebound theory was the first theory to satisfactorily explain earthquakes.
The elastic rebound theory is an explanation for how energy is spread during earthquakes. On the other hand, the plate tectonic theory gives the reasons why and how the elastic stress can be built up in crustal fault rocks for cause of earthquakes associated with the elastic rebound theory 5. On earths surface, any straight line like a road or a fence a crossing a fault would be gradually deformed or bent b as rocks on one side of the fault move relative to those on the other side. The elasticrebound theory of earthquakes bulletin of. Elastic rebound theory eventually, the strain along the fault exceeds the limit of the rocks at that point to store any additional strain. Elastic rebound and friction lab lesson plan by deborah kane and dave van dusen.
This activity was developed for use in a high school grades 912 earth science class. Elastic rebound theory rocks at the edges of tectonic plates are subject to tremendous forces resulting in intense deformation. In geology, the elasticrebound theory is an explanation for how energy is released during an earthquake. The fault then rupturesthat is, it suddenly moves a comparatively large distance in a comparatively short amount of time. Tectonics are explained by the socalled elastic rebound theory, formulated by the american geologist harry fielding reid after the san andreas fault ruptured in 1906, generating the great san francisco earthquake. D all of the above elastic rebound theory suggests. Which one of the following best characterizes tsunamis a they cause the land to ivy tech community college of indiana scin 100 spring 2014 chapter 10 earth science. Passing right down the middle of the orchard, and across the road, is a fault zone. Earthquake vibrations are measured with seismometers. Jan 21, 2016 elastic rebound theory is one of the central ideas to the mechanics of earthquakes and was originally proposed by reid 1910 following the 1906 san francisco earthquake on the san andreas fault. Type of faults dip slip faults strike slip faults figure 6. It is a way for the stored energy to be released through a sudden action. The theory involves the slow build up of elastic strain due to largescale stresses in the crust on either side of a locked fault i. Elastic strain buildup and brittle rupture stage b figure 7.
The material for the next two lectures is based on chapter 8. Earthquakes 7 tectonic settings of earthquakes intraplate bowling green most often associated with failed rift zones and reactivation of ancient faults. A theory of tectonics in which the outer part of the earth lithosphere is comprised of rigid plates that interact collide, translate, rift apart, subduct. According to the elastic rebound hypothesis, most earthquakes are produced by the rapid release of energy stored in rock that has been subjected to great forces. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. A better understanding of these processes provides an improved ability to anticipate and communicate the unique aspects of earthquake hazards.
The mechanisms and processes involved when earthquakes occur are extremely complex. The gradual accumulation and release of stress and strain is called the elastic rebound theory of earthquakes. The sudden release of energy should cause the youth to stumble and possibly tumble. Elastic rebound theory more grades 912 science on the learning videos channel duration.
Reid, university of california publications, bulletin of the department of geology, 6, 19, 1911. It can be done in small groups or as a classroom demonstration, with students recording data. D all of the above elastic rebound theory suggests that. Earthquakes are caused by plate interactions along tectonic plate. Dows recovery theory rocks recover violently when a mass collides with them.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. The collection of material points at the fault over which slip occurs usually constitutes an oblong threedimensional volume, with its long dimension often running into tens of kilometers in case of significant earthquakes. The force per unit area acting on a rock is called stress. This activity helps learners see the elastic properties of rocks by actually bending marble. Elastic rebound theory involves the sudden release of progressively stored strain in rocks, causing movement along a fault. Earthquakes occurring along subduction zones cause tsunamis. According to the elastic rebound hypothesis most earthquakes. Causes of earthquakes earthquake hazard and emergency management 27 c. This is the principle that reid proposes through his elastic rebound theory of earthquakes. His theory of how earthquakes occur as a result of fracture of rocks along a fault is called elastic rebound theory.
Slowly they deform, until their internal rigidity is exceeded. Video lecture by ross stein of the usgs exerpt from the video, shock waves. Pdf physical mechanism of major earthquakes by earthquake cases. Elastic rebound theory is one of the central ideas to the mechanics of earthquakes and was originally proposed by reid 1910 following the 1906 san francisco earthquake on the san andreas fault. Ask students if this feels more like how an earthquake would happen. This gradual accumulation and release of stress and strain is now referred to as the elastic rebound theory of earthquakes. Dependent friction spatial heterogeneity stress corrosion slider. Life after death experience nde with steve gardipee, vietnam war story one of the best ndes duration. The material for the next two lectures is based on chapter. The theory also predicted, of course, that the place would be along tectonic earthquakes. What happens when the narcissist knows youve figured them out duration. Ancient cultural explanations of earthquakes were often. Types of earthquakes and faults most earthquakes in the world occur along the.
Nov 17, 20 the elastic rebound theory predicts that earthquakes can be generated only in the lithosphere. Stickslip sliding alternating time periods of noslip and suddenslip. How is the elastic rebound theory related to earthquakes. Photos, videos, and podcasts selected lists of earthquake damage, faults, and effects photos, videos, and podcasts. How rocks respond to stress is a fundamental concept, critical to forming explanatory models in the geosciences e.
Shallow foci but can have high magnitude due to high strength of continental basement rocks. This simulates the build up and stress release of an earthquake, known as elastic rebound theory. Whereas learners are likely to have lots of experience with rocks, few will have directly experienced them behaving elastically. Energy released at an earthquakes focus radiates outward as body waves, which are of two kinds. Previously it was thought that ruptures of the surface were the result of strong ground shaking. Causes of earthquakes earthquake hazard and emergency management 22 nature of the causative geological processes is of particular relevance. Due to the motion of the earths tectonic plates, the ground beneath our feet is always moving, just too slow and g. None of the above are aspects of the elastic rebound. However, based on studies in the tonga islands, earthquakes occur within the weak, ductile asthenosphere. Presently, no models of normal fault earthquake cycles exist, and in. This lab exercise teaches students about elastic rebound and friction and how these concepts related to earthquakes. Describe the characteristics of seismic waves and explain the difference between primary waves, secondary waves, and surface waves. The material for the next two lectures is based on chapter 8 pgs 2516 press and siever 1994.
Plate movement concentrates energy in crust when the stored energy exceeds the strength of the crust, the crust ruptures the rupture generally occurs along faults because this is the weakest point the sudden return of elastically deformed rock to its original shape. The masses of rock undergo elastic strain, slowly flexing and moving in opposite directions. Elastic rebound theory this explains how energy is released during earthquakes. Learning earthquake tip 1 earthquake design and construction. In 1906, henry fielding reid, professor of geology at johns hopkins university, concluded that the earthquake must have involved an elastic rebound of previously stored elastic stress. Plate movement concentrates energy in crust when the stored energy exceeds the strength of the crust, the crust ruptures the rupture generally occurs along faults because this is the weakest point. Earthquakes and earths interior summary abrupt movements of faults that release elastically stored energy cause earthquakes elastic rebound.
This scenario can happen repeatedly on a 100500 year cycle. As the earths crust deforms, the rocks which span the opposing sides of a fault are subjected to shear stress. Reids elastic rebound theory usgs earthquake hazards. Rocks at the edges of tectonic plates are subject to tremendous forces resulting in intense deformation. The following animation shows a birds eye view of a country road that cuts through an orchard. Over the course of geological time, earthquakes, floods, and other natural events have helped to shape the surface of our planet. The three types of directional stress experienced by rocks are compressional, tensional, and shear stress fig. The term refers to how the earth is built of plates, and the theory. Elastic rebound elastic rebound theory explanation to how earthquakes occur. When the strength of the rock is exceeded, it suddenly breaks, releasing some of its stored energy as seismic waves. Fault zones are often located near major population centers.
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