Following the great 1906 san francisco earthquake, henry feilding reid. The theory of elastic rebound, most still accept the theory as valid. The elastic rebound theory was first stated in volume i, part i. Reid, who anal ysed geodetic surveys between 1851 and 1906 along the san andreas fault, as a comprehensive description of the earthquake mechanism and deformation in time along an active fault proved to be an effective addition to the free. The elastic rebound theory of earthquake sources allows rough prediction of the occurrence of large shallow earthquakes. In his hitchcock lectures at the university of california in 1911. Previously it was thought that ruptures of the surface were the result of strong ground shaking.
A elastic rebound theory b slip on a fault with a uniform stress drop c seismic moment d energy release during an earthquake ii elastic rebound theory h. Harry fielding reid, born may 18, 1859, baltimore, maryland, u. As the earths crust deforms, the rocks which span the opposing sides of a fault are subjected to shear stress. However, elastic rebound and quasiperiodic recurrence are not the same. Reids theory naturally enough great efforts were made to explain the causes of earthquakes h. In geology, the elastic rebound theory was the first theory to satisfactorily explain earthquakes. Reids 1910 paper discussed a number of basic ideas, including the theory that earthquakes result from elastic strain accumulation and the speculation that their times might be. The observation that some faults fail with quasiperiodic behavior is fundamental for earthquake prediction and hazard mitigation. From an examination of the displacement of the ground surface which accompanied the 1906 earthquake, henry fielding reid, professor of geology at johns hopkins university, concluded that the earthquake must have involved an. This theory is known as the elastic rebound theory.
Some insights into the strain patterns in the loading phase can be gained by examining the pattern of strain in the unloading or ear. The role of the elastic rebound theory in design and. When reid 1910 proposed his elastic rebound theory of. The textbook explains this theory very briefly on p. An elastic rebound model for normal fault earthquakes wiley. According to the elastic rebound theory reid, 1910, the seismic cycle consists of two phases. Reid gave, for example, a crude forecast of the next great earthquake near san francisco. Seismic wave radiation three main types of seismic waves. Geological survey calls the theory the basis for our modern understanding of earthquakes. Modern measurements using gps largely support reids theory as the basis of seismic movement, though actual. The elastic energy released is transported by seismic waves that travel throughout the earth. This snapping back into position, upon the release of strain, is the elastic rebound of reids theory the elastic rebound theory is an explanation for how energy is spread during earthquakes.
That information allows families to plan and protect themselves in the unlikely event that such an earthquake would occur. Reids elastic rebound theory how earthquake vibrations are generated when the slippage does occur, energy is released. Earthquake resistant design of structures earthquake resistant design of structures pankaj agarwal manish shrikhande. Geological survey, who also served on the lawson commission. Elastic rebound theory in plate tectonics was introduced in 1906 by h. These observations provided the basis for the landmark theory of elastic rebound, introduced by professor h. 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. Elastic rebound theory the elastic rebound theory of shallow tectonic earthquakes proposed by h. The first is the interseismic stage, during which elastic strain accumulates slowly with time due to. Under this view, earthquakes are assumed to possess both a characteristic energy and time scale scholz, 2002.
Reid of johns hopkins university, who served on lawsons commission. Why we need a new paradigm of earthquake occurrence. Elastic rebound theory and san andreas fault earthquakes this short video excerpt is from a usgsbay area earthquake alliance produced television program shock waves. According to the elastic rebound theory reids, 2 the seismic cycle consists of two phases. Rupture probabilities drop on a fault after experiencing a large rupture and build back up with time as tectonic stresses reaccumulate the basis of all previous wgcep models. However, he also points out that this assumes a complete stress drop, that is, release of all accumulated strain, by the 1906. Harry fielding reid examined the displacement of the ground surface around. From fragmentary ground dis placement data, reid proposed the elastic rebound theory to account for strike slip displacements at the time of. The theory also predicted, of course, that the place would be along tectonic earthquakes. The following animation shows a birds eye view of a country road that cuts through an orchard. If a stretched rubber band is broken or cut, elastic energy stored in the rubber band during the stretching will suddenly be released.
Elastic reboundtheory elasticrebound theelasticreboundtheoryisanexplanationforhow energyisspreadduringearthquakes. Reids elastic rebound theory is the theory2 that explains the vast majority of earthquakes. In geology, the elasticrebound theory is an explanation for how energy is released during an. The model presented here therefore represents our best estimate of the elasticrebound component of the system, under the assumption such behavior exists and can be meaningfully isolated from other time dependencies. Reids theory extended earlier insights into the earthquake process by g. Using reids elastic rebound theory, it becomes possible to look at what could be the worstcase scenario for a region. Elastic rebound theory of earthquakes, now generally recog nized as an important advance in the science of geology.
The degree to which reids theory was innovative is indicated by the fact that only a generation. Reid, 1911, which is based on geological intuition, predates the formulation of plate tectonics. For example, all previous working groups on california. Like all theories in any branch of physics, theories of the seismic source should be. This view of the origin of earthquakes is supported by the nature of seismic signals which emanate from many earthquakes, and is. Reid, university of california publications, bulletin of the department of geology, 6, 19, 1911 h. Since the formulation of reids elastic rebound theory 100 years ago laboratory mechanical models combining frictional and elastic elements have joined the forefront of the research on the. From an examination of the displacement of the ground surface which accompanied the 1906 earthquake, henry fielding reid. Earthquake precursors in the light of peroxy defects. Reids elastic rebound theory combined with our knowledge of plate tectonics suggests that we might someday be able to predict earthquakes.
At the instant of rupture, c, energy is released in the form of earthquake waves that radiate out in all directions. Historic developments in the evolution of earthquake. 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. But i would like you to gain a deeper more thorough understanding of the theory. Reids elastic rebound theory not only allowed to explain the phenomenology of earthquakes, it also provided huge hopes in the possibility of predicting the large, devastating events that were threatening california and many other places worldwide.
The elastic rebound theory of reid 1910 was formulated on the basis of crustal deformation observations and hence is quite explicit in prescribing the pattern of. Reids 1 elastic rebound theory indicates that an under standing of the pattern and magnitude of strain in the loading phase of the earthquake cycle is important for evaluating the seismic risk in an area. The elastic rebound theory is an explanation for how energy is. Assuming that the dislocation front propagates in one direction along the long.
According to this theory an earthquake is the result of strain release caused by sudden shearing motion along a fault. A more traditional explanation, based on reids elastic rebound theory, argues that an accelerating sequence of seismic energy release could be a consequence of increasing stress in a fault system whose stress moment release is dominated by large events. From an examination of the displacement of the ground surface which accompanied the 1906 earthquake, 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. Origins, legacy, and perspectives by ari benmenahem abstract the history of seismology has been traced since man first reacted lit erarily to the phenomena of earthquakes and volcanoes, some 4000 yr ago. Reids idea was that these distant forces cause a gradual build up of stress in the earth over tens or hundreds or thousands of years, slowly distorting the earth underneath our feet. Longterm timedependent probabilities for the third. Slowly they deform, until their internal rigidity is exceeded. The gradual accumulation and release of stress and strain is called the elastic rebound theory of earthquakes. When the in geology, the elastic rebound theory was the first theory to satisfactorily explain earthquakes. How a big disaster helped us better understand how the earth works.
Since fault planes are not usually very smooth, great amounts of energy can be stored if the rock is strong enough as movement is restricted due to interlock along the fault. In geology, the elasticrebound theory is an explanation for how energy is released during an earthquake as the earths crust deforms, the rocks which span the opposing sides of a fault are subjected to shear stress. In geology, the elastic rebound theory was the first theory to satisfactorily explain. Elasticreboundtheory elasticrebound theelasticreboundtheoryisanexplanationforhow energyisspreadduringearthquakes. Reids elastic rebound theory usgs earthquake hazards. In geology, the elasticrebound theory is an explanation for how energy is released during an earthquake. The field also includes studies of earthquake environmental effects such as tsunamis as well as diverse.
The theory also predicted, of course, that the place would be along. Reid see box below to explain how energy is released during earthquakes. Harry fielding reid american seismologist britannica. In reids original development of elastic rebound theory, he forecast that the next earthquake should be expected when the surface has been strained through an angle of 12000 reid, 1910. The rocky masses which form the two sides of the fault then snap back into a new position.
Previously it was thought that ruptures of the surface were the elastic rebound theory. Ground displacement and strain evoiution near a fault based,o,n reids elastic rebound theory. 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. The elasticrebound theory of earthquakes bulletin of.
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